INFO

WET: The opposing view to DRY is called WET, a backronym commonly taken to stand for write everything twice (alternatively write every time, we enjoy typing or waste everyone's time).

Source

When the DRY principle is applied successfully, a modification of any single element of a system does not require a change in other logically unrelated elements. Additionally, elements that are logically related all change predictably and uniformly, ...

Source

The DRY principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system". The principle has been formulated by Andy Hunt and Dave Thomas in their book The Pragmatic Programmer.

Source

"Don't repeat yourself" (DRY) is a principle of software development aimed at reducing repetition of information which is likely to change, replacing it with abstractions that are less likely to change, or using data normalization which avoids redundancy.

Source

InterruptibleRegion – Interruptible regions are excluded from fUML because they are considered to be more appropriate for “higher level” process modeling and outside the scope of fUML.

Source

Semantics of a Foundational Subset for Executable UML Models 1.4

8.6.2.4 EnumerationValue: An enumeration value is a value whose (single) type is an enumeration. Its literal must be an owned literal of its type.

Source

Semantics of a Foundational Subset for Executable UML Models 1.4

An Enumeration that specializes another may define new EnumerationLiterals that are not defined in the generalizing Enumeration; in such a case the set of applicable literals comprises inherited literals plus locally-defined ones.

Source

Unified Modeling Language 2.5.1

As a specialization of Classifier, Enumerations can participate in generalization relationships.

Source

Unified Modeling Language 2.5.1

If onPort is given, then the Port shall be an owned or inherited feature of the type of the target InputPin of the Action.

Source

Unified Modeling Language 2.5.1

fUML-1.4: 7.6.2.1: Reception: [1] fuml_reception_no_method: A reception must not have an associated method.self.method->isEmpty()

Source

Action Language for Foundational UML 1.1

fUML1.4: 7.11.2.6 ExpansionNode: [2] fuml_expansion_node_no_crossing_edges: Edges may not cross into or out of an expansion region.

Source

Semantics of a Foundational Subset for Executable UML Models 1.4

fUML1.4: 7.11.2.5: CreateObjectAction [1] fuml_create_object_action_is_class: The given classifier must be a class. self.classifier.oclIsKindOf(Class)

Source

Semantics of a Foundational Subset for Executable UML Models 1.4

Features that are not denoted as a DirectedFeature are implicitly provided features. As such they can be matched against a corresponding required feature.

Source

OMG Systems Modeling Language (SysML) 1.7beta1

A providedRequired feature specifies a symmetric dependency between two connected blocks whereby a block’s internal use of such a feature is delegated to the connected block with the corresponding feature and conversely that block’s internal use of ...

Source

OMG Systems Modeling Language (SysML) 1.7beta1

A DirectedFeature indicates whether the feature is supported by the owning block (provided) for other connected blocks to use, or is to be supported by a connected block for the owning block to use (required), or both (providedRequired).

Source

OMG Systems Modeling Language (SysML) 1.7beta1

The use case diagram describes the usage of a system (subject) by its actors (environment) to achieve a goal, that is realized by the subject providing a set of services to selected actors.

Source

OMG Systems Modeling Language (SysML) 1.7beta1

Actors represent classifier roles that are external to the system that may correspond to users, systems, and or other environmental entities.

Source

OMG Systems Modeling Language (SysML) 1.7beta1

An Actor specifies a role played by a user or any other system that interacts with the subject.

Source

Unified Modeling Language 2.5.1

A Property may represent an attribute of a Classifier, a memberEnd of an Association, or in some cases both simultaneously.

Source

Unified Modeling Language 2.5.1

CallBehaviorAction::behavior : Behavior [1..1] ... The Behavior being invoked.

Source

Unified Modeling Language 2.5.1

Flow Port and Flow Specification are deprecated in this version of SysML and are defined for backward compatibility.

Source

OMG Systems Modeling Language (SysML) 1.7beta1

Vapor refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance.

Source

In physics, a vapor or vapour is a substance in the gas phase at a temperature which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature of the vapor.

Source

On [a] psychrometric chart, this process is represented as [a] line sloping downward and to the left. This process is assumed to occur as simple cooling first and then condensation. While the moisture is condensing the air is assumed to remain saturated.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Mathematica: v13.2+: Division of one temperature by another will result in a numeric ratio given by the value of both temperatures in Kelvin.

Source

Wolfram Language (Mathematica) online help reference

Mathematica: v13.2+: Division by temperature units will produce a quantity equivalent to the temperature converted to Kelvin before division, with results canonically given in Kelvin.

Source

Wolfram Language (Mathematica) online help reference

Determine the total, sensible and latent cooling required cooling 20,000 cfm of air from a temperature of 90 F and a relative humidity of 60% to a temperature of 55 F and 100% relative humidity.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Hot humid day 90°F and 90% RH. Condition the air to 70°F at about 50% RH. Chill the air to condense out enough moisture to dehumidify it: goal is air with absolute humidity not exceeding 0.008 lbs of moisture per pound of air. Show processes.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

How much moisture is added to 20 lb of air going from 50°F, 50% RH to 80°F, 60% RH?

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Determine the amount of sensible heat needed to increase the temperature of air from 50°F and 50% RH to 90°F.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Ninety cubic-ft of lumber is dried at 140°F 'tdb' and 125.6°F 'twb'. The drying rate of the lumber is 5.68 lb of water per hour. If outside air is at 80.6°F 'tdb' and 80% relative humidity how much outside air is needed per min to carry away the moisture?

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Determine the cooling required to sensibly cool 20,000 cfm of air from a temperature of 90 F and a relative humidity of 60% to a temperature of 75 F.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Calculate the amount of sensible heat that must be added to 100lb of air at 85°F dry bulb and 75°F wet bulb to raise the temperature of air to 100°F dry bulb.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

The dry bulb reading is 85°F and the wet bulb is 60F. Using the chart determine the following values. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

The dry bulb reading is 70°F and the wet bulb is 54°F. Using the chart determine the following values. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

The dry bulb reading is 78°F and the wet bulb is 58°F. Using the chart determine the following values: Relative humidity; Dew Point; Absolute humidity; Specific volume; [Specific] enthalpy.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

An air-conditioned room at sea level has an indoor design temperature of 75°F and a relative humidity of 50%. Determine the humidity ratio, enthalpy, density, dew point, and thermodynamic wet bulb temperature of the indoor air at design condition.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

A sling psychrometer gives a dry-bulb temperature of 78°F and a wet-bulb temperature of 65°F. Determine other moist air properties from this information.

Source

CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'

Heat released by a system into its surroundings is by convention a negative quantity (Q < 0); when a system absorbs heat from its surroundings, it is positive (Q > 0).

Source

In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary

Source

Defined quantitatively, the heat involved in a process is the difference in internal energy between the final and initial states of a system, and subtracting the work done in the process. This is the formulation of the first law of thermodynamics.

Source

Heat is energy in transfer to or from a thermodynamic system, by a mechanism that involves the microscopic atomic modes of motion or the corresponding macroscopic properties.

Source

A thermodynamic system does not contain heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system.

Source

The Boltzmann constant is defined to be exactly 1.380649×10^(−23) J⋅K^(−1)

Source

As part of the 2019 redefinition of SI base units, the Boltzmann constant is one of the seven "defining constants" that have been given exact definitions. They are used in various combinations to define the seven SI base units.

Source

In 1982, the International Union of Pure and Applied Chemistry (IUPAC) recommended that for the purposes of specifying the physical properties of substances, standard pressure should be precisely 100 kPa (1 bar).

Source

In chemistry and in various industries, the reference pressure referred to in standard temperature and pressure (STP) was commonly 1 atm (101.325 kPa) but standards have since diverged;

Source

When calibrated to ITS-90, where one must interpolate between the defining points of gallium and indium, the boiling point of VSMOW water is about 10 mK less, about 99.974 °C.

Source

Precise measurements show that the boiling point of VSMOW water under one standard atmosphere of pressure is actually 373.1339 K (99.9839 °C) when adhering strictly to the two-point definition of thermodynamic temperature.

Source

A ValueSpecification is the specification of a (possibly empty) set of values. A ValueSpecification is a ParameterableElement that may be exposed as a formal TemplateParameter and provided as the actual parameter in the binding of a template.

Source

Unified Modeling Language 2.5.1

Property::defaultValue : ValueSpecification [0..1] Specifies a ValueSpecification that represents a value to be used when no argument is supplied for the Parameter.

Source

Unified Modeling Language 2.5.1

If a Property has a specified default, and the Property redefines another Property with a specified default, then the redefining Property’s default is used in place of the more general default from the redefined Property.

Source

Unified Modeling Language 2.5.1

The evaluated default then becomes the initial value (or values) of the Property.

Source

Unified Modeling Language 2.5.1

If there is a defaultValue specified for a Property, this default is evaluated when an instance of the Property is created in the absence of a specific setting for the Property or a constraint in the model that requires the Property to have a specific val

Source

Unified Modeling Language 2.5.1

CreateObjectAction::result : OutputPin [1..1]{subsets Action::output} The OutputPin on which the newly created object is placed.

Source

Unified Modeling Language 2.5.1

CreateObjectAction::classifier : Classifier [1..1] The Classifier to be instantiated.

Source

Unified Modeling Language 2.5.1

A CreateObjectAction is an Action that creates an instance of the specified Classifier.

Source

Unified Modeling Language 2.5.1

If the DecisionNode does not have a decisionInput, then the value contained in the object token on the decisionInputFlow is made available to the guards on each outgoing edge, regardless of whether the primary incoming flow is a ControlFlow or an ObjectFl

Source

Unified Modeling Language 2.5.1

If a DecisionNode has a decisionInputFlow, then a token must be offered on both the primary incoming edge and the decisionInputFlow before the token from the primary incoming edge is offered to the outgoing edges.

Source

Unified Modeling Language 2.5.1

AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter.

Source

Datasheet: Atmel ATmega640/V-1280/V-1281/V-2560/V-2561/V

UML 2.5.1: «Trace»: As model changes can occur in both directions, the directionality of the dependency can often be ignored. The mapping specifies the relationship between the two, but it is rarely computable and is usually informal.

Source

Unified Modeling Language 2.5.1

UML 2.5.1: «Trace»: Specifies a trace relationship between model elements or sets of model elements that represent the same concept in different models. Traces are mainly used for tracking requirements and changes across models.

Source

Unified Modeling Language 2.5.1

JTAG: The connector pins are: 1. TDI (Test Data In); 2. TDO (Test Data Out); 3. TCK (Test Clock); 4. TMS (Test Mode Select); 5. TRST (Test Reset) optional.

Source

JTAG (named after the Joint Test Action Group which codified it) is an industry standard for verifying designs and testing printed circuit boards after manufacture.

Source

Don't judge a book by its cover

Source

clothes maketh the man

Source

This means that: Not all words appearing between guillemets are necessarily keywords, and words appearing in guillemets do not necessarily represent stereotypes.

Source

Unified Modeling Language 2.5.1

In addition to identifying keywords, guillemets are also used to distinguish the usage of stereotypes.

Source

Unified Modeling Language 2.5.1

For some kinds of Classifiers, optionally in the right hand corner an icon denoting the kind of Classifier can be displayed.

Source

Unified Modeling Language 2.5.1

If a role is typed by a classifier other than Class, the name compartment of the part box symbol contains the appropriate keyword (e.g., «component») above the name.

Source

Unified Modeling Language 2.5.1

Stereotypes applied to behaviors may appear on the notation for CallBehaviorAction when invoking those behaviors, as shown in Figure 11-2.

Source

OMG Systems Modeling Language (SysML) 1.6

The stereotype applies to all parameters corresponding to the pins notated by the object node.

Source

OMG Systems Modeling Language (SysML) 1.6

Stereotypes applying to parameters can appear on object nodes in activity diagrams, as shown in Figure 11-7, when the object node notation is used as a shorthand for pins.

Source

OMG Systems Modeling Language (SysML) 1.6

As its name indicates, a triple is a set of three entities that codifies a statement about semantic data in the form of subject–predicate–object expressions (e.g., "Bob is 35", or "Bob knows John").

Source

A semantic triple, or RDF triple or simply triple, is the atomic data entity in the Resource Description Framework (RDF) data model.

Source

The start of the book begins with an eight-year-old orphan girl named Sophie lying in bed ...

Source

The giant then says that he will not eat her as he is the Big Friendly Giant, or BFG for short.

Source

The giant laughs and explains that most giants do eat human beings (which he pronounces as "human beans") ..

Source

When he sets Sophie down, she begins to plead for her life, believing that the giant will eat her.

Source

The BFG (short for The Big Friendly Giant) is a 1982 children's book written by British novelist Roald Dahl and illustrated by Quentin Blake.

Source

The modern English alphabet is a Latin alphabet consisting of 26 letters, each having an upper- and lower-case form.

Source

... an English-language pangram — a sentence that contains all of the letters of the English alphabet.

Source

"The quick brown fox jumps over the lazy dog" ...

Source

"The quick brown fox jumps over the lazy dog" is an English-language pangram — a sentence that contains all of the letters of the English alphabet.

Source

This is why we want to work with across variables that have not been overly differentiated.

Source

Modelica By Example

An essential point here is that differentiation is lossy. If we know position, we can easily express velocity. But if we only know velocity, we cannot compute position without knowing an additional integration constant.

Source

Modelica By Example

If we had chosen velocity (the derivative of position with respect to time), then we would have been in the awkward situation of trying to describe the behavior of a spring in terms of velocities, not positions.

Source

Modelica By Example

So, for example, we chose position for translational motion because position is used in describing the behavior of a spring (i.e., Hooke’s law).

Source

Modelica By Example

The second constraint is that the across variable should be the lowest order derivative to appear in any of our constitutive or empirical equations in the domain.

Source

Modelica By Example

The reason for this constraint is that the through variable will be used to formulate generalized conservation equations in our system. As such, it is essential that the through variables be conserved quantities.

Source

Modelica By Example

The first constraint is that the through variable should be the time derivative of some conserved quantity.

Source

Modelica By Example

You may have seen a similar table before with slightly different choices. For example, you will sometimes see velocity (in ) chosen as the across variable for translational motion. The choices above are guided by two constraints.

Source

Modelica By Example

The following table covers four different engineering domains. In each domain, we see the choice of through and across variables that we will be using along with the SI units for those quantities.

Source

Modelica By Example

In this section, we’ll discuss relatively simple engineering domains. These are ones where a connector deals with only one through and one across variable. Conceptually, this means that only one conserved quantity is involved with that connector.

Source

Modelica By Example

As we will see in many of the examples to come, there are many different types of relationships between the through and across variables (Ohm’s law being just one of many).

Source

Modelica By Example

These flows are usually the result of some difference in the across variables across a component model. For example, current flowing through a resistor is in response to a voltage difference across the two sides of the resistor.

Source

Modelica By Example

The second class of variables we will discuss are “through” variables (also called flow variables). Flow variables normally represent the flow of some conserved quantity like mass, momentum, energy, charge, etc.

Source

Modelica By Example

Typical examples of across variables, that we will be discussing shortly, are temperature, voltage and pressure. Differences in these quantities typically lead to dynamic behavior in the system.

Source

Modelica By Example

The first class of variables we will discuss are “across” variables (also called potential or effort variables). Differences in the values of across variables across a component are what trigger components to react.

Source

Modelica By Example

In order to understand one specific class of connector semantics, it is first necessary to understand a bit more about acausal formulations of physical systems. An acausal approach to physical modeling identifies two distinct classes of variables.

Source

Modelica By Example

In thermodynamics, heat is energy in transfer to or from a thermodynamic system, by mechanisms other than thermodynamic work or transfer of matter.

Source

Some signals in the example reflect physical quantities, but this is not physical interaction in the sense of physical substances with flow rates and potentials ...

Source

A.5 Humidifier: A.5.1 Introduction: This subannex gives a model of a room humidifier as an example of signal flows and state machines.

Source

In many English-speaking countries, however, the most common shape of a handwritten Arabic digit 1 is just a vertical stroke; that is, it lacks the upstroke added in many other cultures.

Source

In 1990, the International Committee for Weights and Measures stated that it was too early to choose a single symbol for the litre.

Source

In the UK and Ireland, as well as the rest of Europe, lowercase l is used with prefixes, though whole litres are often written in full (so, "750 ml" on a wine bottle, but often "1 litre" on a juice carton).

Source

In these countries, the symbol L is also used with prefixes, as in mL and μL, instead of the traditional ml and μl used in Europe.

Source

The United States National Institute of Standards and Technology now recommends the use of the uppercase letter L, a practice that is also widely followed in Canada and Australia.

Source

Therefore, the digit "1" may easily be confused with the letter "l". In some computer typefaces, the two characters are barely distinguishable. As a result, L (uppercase letter L) was adopted by the CIPM as an alternative symbol for litre in 1979.

Source

Originally, the only symbol for the litre was l (lowercase letter L), following the SI convention that only those unit symbols that abbreviate the name of a person start with a capital letter.

Source

The litre (British English spelling) or liter (American English spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm^3), 1000 cubic centimetres (cm^3) or 0.001 cubic metre (m^3).

Source

The enthalpy of vaporization of Water at 100 deg C = 2257 (J/g)

Source

The enthalpy of vaporization is often quoted for the normal boiling temperature of the substance.

Source

The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Source

The enthalpy of vaporization (symbol ∆Hvap), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy (enthalpy) that must be added to a liquid substance to transform a quantity of that substance into a gas.

Source

The volumetric heat capacity can also be expressed as the specific heat capacity (heat capacity per unit of mass, in J/K/kg) times the density of the substance (in kg/L, or g/mL).

Source

The SI unit of volumetric heat capacity is joule per kelvin per cubic meter, J/K/m3 or J/(K·m3).

Source

Informally, it is the amount of energy that must be added, in the form of heat, to one unit of volume of the material in order to cause an increase of one unit in its temperature.

Source

The volumetric heat capacity of a material is the heat capacity of a sample of the substance divided by the volume of the sample.

Source

Isobaric volumetric heat capacity C(P,v) J⋅cm−3⋅K−1 of liquid Water at 100 °C = 4.2160

Source

Isobaric volumetric heat capacity C(P,v) J⋅cm−3⋅K−1 of liquid Water at 25 °C = 4.1796

Source

The blocks used in these diagrams are introduced in Subannex A.5.4.

Source

The internal structure of VaporGenerationPlant uses blocks Heating and Evaporation, which have internal structures depicted in Figure 70 and Figure 71, respectively.

Source

The internal structure of Humidifier in Figure 68 uses a block VaporGenerationPlant, which has an internal structure shown in Figure 69.

Source

The internal structure of HumidifiedRoom depicted in Figure 66 uses a block RelativeHumidity, which has an internal structure depicted in Figure 67.

Source

The internal structure of the block HumidifierSystem shown in Figure 65 uses the blocks HumidifiedRoom and Humidifier. These two blocks have their own internal structures.

Source

A.5.3 Internal structure: Figure 65 through Figure 71 show the internal structure of the total humidifier system and its components through seven nested internal block diagrams.

Source

The humidifier uses information about the room’s humidity level to determine how much vapor to input to the room. The humidifier includes a water tank, a heater controller, and a vapor generation plant.

Source

A.5.2 System being modeled: The total humidifier system has two main components: the humidified room and the humidifier, see Figure 64.

Source

In nonideal fluid dynamics, the Hagen–Poiseuille equation ... is a physical law that gives the pressure drop in an incompressible and Newtonian fluid in laminar flow flowing through a long cylindrical pipe of constant cross section.

Source

Figure 62 and Figure 63 show the parametric diagrams of the tank and the pipe, respectively.

Source

Binding connectors link constraint parameters to simulation variables and constants, indicating their values must be the same.

Source

Component parametric diagrams show properties typed by constraint blocks (constraint properties), as well as component and port simulation variables and constants.

Source

Equations in constraint blocks are applied to components using binding connectors in component parametric diagrams.

Source

Also, the fluid flow in the tank, fluidFlow, is related to the change in the fluid height level fluidHeight over time and the cross-sectional surface area of the tank, surfaceArea.

Source

The tank constraints specify that the pressure in the tank, pressure depends on the height of the fluid level in the tank, fluidHeight, as well as properties of the fluid, fluidDensity.

Source

The sum of the fluid flow rates going through the two pipe openings is zero (the fluid is assumed to be incompressible).

Source

The magnitude of fluid flow rate through the pipe fluidFlow is the same as the magnitude of flow rates opening1FluidFlow and opening2FluidFlow going through the pipe’s openings, though the values differ in sign.

Source

The fluid flow rate through the pipe, fluidFlow, is proportional to the pressure difference by the constant resistance, which depends on the geometric properties of the pipe as well as fluidic properties.

Source

The pipe constraints specify that the pressure pressureDiff across it is equal to the difference of fluid pressures opening1Pressure and opening2Pressure at each end of the pipe.

Source

In this example, constraint blocks PipeConstraint and TankConstraint define parameters and equations for pipes and tanks, respectively, as shown in Figure 61.

Source

Equations define mathematical relationships between the values of numeric variables. Equations in SysML, are constraints in constraint blocks that use properties of the blocks (parameters) as variables.

Source

An alternative for specifying initial values of part properties in the ConnectedTanks is to specialize it and redefine the part properties with default values for various configurations ...

Source

SysML initial values specify property values for components used in internal block diagrams. Figure 59 shows initial values for fluid density, gravity, tank surface area, pipe radius, pipe length, and dynamic viscosity of the fluid ...

Source

Item flows on connectors indicate fluid passes through the ports and between the parts. The diagram connects a tank to each end of a pipe.

Source

Part properties, typed by blocks ... represent components in this system. They are connected to each other through ports, which represent openings in the tanks and pipe ...

Source

Figure 59 shows the internal structure of a ConnectedTanks block.

Source

Each type of component has its own behaviors, defined as constraints ...

Source

Tanks and pipes have openings for fluid to pass through, one for tanks and two for pipes. The openings are represented by ports of type VolumeFlowElement, from the physical interaction library ..

Source

Figure 60 shows block definitions for components of ConnectedTanks in Figure 59.

Source

A.4.1 Introduction: This subannex gives a model of a simple hydraulic system as an example of physical interaction (fluid flow). It does not include any signal flows

Source

A.4.2 System being modeled: The hydraulic system has three components: two fluid reservoir tanks and a pipe for connecting these tanks, see Figure 58.

Source

Figure 52 through Figure 57 show parametric diagrams for the source, amplifier, high-pass fil[t]er, low-pass filter, mixer, and sink, respectively.

Source

Binding connectors link constraint parameters to simulation variables and constants, indicating their values must be the same.

Source

Component parametric diagrams show properties typed by constraint blocks (constraint properties), as well as component and port simulation variables and constants.

Source

Equations in constraint blocks are applied to components using binding connectors in component parametric diagrams.

Source

The source constraint specifies a sine wave signal with the parameter amp as its amplitude. The sink constraint displays (scopes) the output signal from the signal processor.

Source

The mixer constraint specifies the relationship between its one output and the two inputs that come from the low-pass and high-pass filters. The constraint defines the output to be the average of the inputs.

Source

The amplifier changes the signal strength by a factor gain, the low-pass filter eliminates the high-frequency components of the incoming signal, and the high-pass filter eliminates the low-frequency components of the signal.

Source

The amplifier, low-pass fil[t]er, and high-pass filter constraints show the input-output relationship of these components as the signal passes through them.

Source

In this example, a constraint block BinarySignalComponentConstraint defines the parameters for one input (ip) and one output (op), common to amplifiers, low-pass filters, and high-pass filters, as shown in Figure 51.

Source

Equations define mathematical relationships between the values of numeric variables. Equations in SysML, are constraints in constraint blocks that use properties of the blocks (parameters) as variables.

Source

The xi and scope properties have the PhSVariable stereotype applied, specifying that their values might vary during simulation.

Source

The amp, alpha and g properties have the PhSConstant stereotype applied, specifying that their values are constant during each simulation run.

Source

The amplifier, filters (high-pass and low-pass), signal source, and signal sink have properties g, alpha and xi, amp, and scope, respectively.

Source

This value type has no unit, reflecting that the signals are not measurements of physical quantities and do not follow conservation laws.

Source

In this example, ports are typed by RealSignalOutElement and RealSignalInElement from the signal flow library ... which both have a flow property rSig typed by Real, from SysML, as shown in Figure 49.

Source

Signals flowing in and out of components are modeled by ports typed by interface blocks that have flow properties typed by numbers.

Source

Each kind of component has its own behaviors, defined as constraints ...

Source

Signal flow is the movement of numbers between system components. These numbers might reflect physical quantities or not. In this example, they do not ...

Source

Mixers have inputs u1 and u2, and an output y.

Source

In Figure 50, amplifiers, low-pass filters, and high-pass filters, each have an input and an output. Since they are similar in this sense, a generalized TwoPinSignalComponent component has an input u and an output y.

Source

The input for SignalSink is named u and is typed by RealSignalInElement, also from the library. The signal processor has an input and output, transforming the signal from the source and passing it to the sink.

Source

The output for SignalSource is named y and is typed by RealSignalOutElement, from the signal flow library ...

Source

Figure 49-Figure 50 show block definitions for components of TestBed and SignalProcessor in Figure 47 and Figure 48, respectively.

Source

Figure 47 shows an initial value for source amplitude amp, while Figure 48 shows initial values for amplifier signal gain g and filtering properties xi and alpha ...

Source

SysML initial values specify property values for components used in internal block diagrams.

Source

Figure 48 connects the signal processor input to an amplifier, the output of the amplifier to a high-pass filter in parallel with a low-pass filter, the outputs of the filters to a mixer, and the output of the mixer to the signal processor output.

Source

Figure 47 connects a signal source to a signal processor, which it connects to a signal sink that displays the output.

Source

Signals pass through ports in the direction shown by the arrows. Item flows on connectors indicate that the signals are real numbers.

Source

Part properties, typed by blocks ... represent the components of the system. They are connected through ports .. which represent signal outputs and inputs ...

Source

Figure 47 and Figure 48 show the internal structure of blocks TestBed and SignalProcessor, respectively

Source

A.3.2 System being modeled The signal processor and its testbed have a wave generator, an amplifier, high-pass and low-pass frequency filters, a mixer, and a signal sink, see Figure 46.

Source

The source constraint defines the voltage across it as a sine wave with the parameter amp as its amplitude.

Source

The source constraint defines the circuit’s electrical source. The ground constraint specifies that the voltage at the ground pin is zero.

Source

The constraints for the resistor, capacitor, and inductor specify the voltage/current relationship with resistance, capacitance, and inductance, respectively.

Source

The sum of the current going through the two pins adds up to zero (one is the negative of the other), because the components do not create, destroy, or store charge.

Source

The current i through the component is equal to the current going through the positive pin.

Source

These specify that the voltage v across the component is equal to the difference between the voltage at the positive and negative pins. The current i through the component is equal to the current going through the positive pin.

Source

In this example, a constraint block BinaryElectricalComponentConstraint defines parameters and constraints common to resistors, inductors, capacitors, and sources, as shown in Figure 40.

Source

Equations define mathematical relationships between the values of numeric variables. Equations in SysML, are constraints in constraint blocks that use properties of the blocks (parameters) as variables.

Source

A.2.2 System being modeled: The electrical circuit has six components: ground, electrical source, inductor, capacitor, and two resistors, see Figure 37.

Source

The block SpringMassSys has a SysML constraint property smsc typed by SMSConstraint. The constraint block has six parameters, each bound to a property reachable from the spring mass system:

Source

Figure 25 shows an example [USAGE OF A] constraint block for a signal flow application, using ports like those defined in Figure 22, Subclause 10.7.3, except in a system containing a spring attached to another object.

Source

Continuous variables have values that are close to their values at nearby times in the past and future. Discrete variables have values that are the same as their values at nearby times in either the past or future, or both.

Source

A PhSVariable has values that can vary over time in a continuous or discrete fashion.

Source

A PhSConstant has values that do not change during simulation runs. Values can change between simulation runs.

Source

11.5.2 Platform profile: This subclause defines stereotypes that Subclause 11.3 applies to the base classes and properties (including ports) of its blocks, to specify which library elements of Modelica and Simulink correspond to them.

Source

Component PhSConstants (SimulinkParameters and ModelicaParameters) for vectors and matrices have MultidimensionalElement applied, with dimension * and ,, respectively ...

Source

Component input ports for vectors are typed by specializations of RealVectorSignalInElement, while component output ports for vectors are typed by specializations of RealVectorSignalOutElement ...

Source

Component input ports for scalars are typed by RealSignalInElement, IntegerSignalInElement, or BooleanSignalInElement, while component output ports for scalars are typed by RealSignalOutElement, IntegerSignalOutElement, or BooleanSignalOutElement ...

Source

Simulation platform data specified in the Component Ports (Input and Output), PhSConstants, and platform Parameters columns are scalar, unless marked with a V (vector) or an M (matrix).

Source

RealInSignalElement has an in flow property rsig, while RealOutSignalElement has the same property with an out direction.

Source

Figure 22 shows an example signal flow application. The block Spring has two ports u and y, of type RealInSignalElement and RealOutSignalElement from the signal flow library ..., respectively.

Source

When the computer is in StandBy, y.sigsp [ERROR] is set to 8, and when the computer is On, y.sigsp [ERROR] is set to 3.

Source

The transition from On to StandBy has a ChangeEvent with an expression indicating that the transition is triggered when u.sigsp [ERROR] is equal to 0.

Source

The transition from StandBy to On has a ChangeEvent with an expression indicating that the transition is triggered when u.sigsp [ERROR] is equal to 1 (this is a signal as in signal flow simulation, not as in SysML).

Source

The transition from the initial pseudostate to StandBy has a relative TimeEvent with an expression indicating that the transition fires 5 seconds after the initial pseudostate is entered.

Source

The state machine has one initial pseudostate, and two states StandBy and On.

Source

Computer has ports u and y of type RealInSignalElement [ERROR:TYPO] and RealOutSignalElement [ERROR:TYPO] from the signal flow library (see Subclause 11.2.1), respectively.

Source

The following Modelica code corresponds to Figure 29.

Source

The following Modelica code corresponds to Figure 28. It has a type Force, which extends Real, and the unit symbol N assigned to it.

Source

Modelica data types can be subtyped to add a unit symbol. The interpretation of this symbol is not defined in Modelica.

Source

Figure 28 shows how a value type with units is defined in SysML, from the units library in Figure 20 [ERROR], Subclause 11.2.2 [ERROR]. It has a value type Force that specializes the Real value type and has newton as unit. The newton unit has a symbol N.

Source

SysML numeric value types can be linked to units, where units are modeled with the SysML Unit block. These units are linked to value types that are generalized by SysML’s numeric value types. Units and their symbols are from ISO 80000.

Source

Data types in SysML are called value types.

Source

It has a model B with a val component. The val component has a start value of 10. A class A is defined with a component b of type B. A component modification indicates that the start value of b.val is 20.0.

Source

The following Modelica code corresponds to Figure 15 [ERROR].

Source

SysML default and initial values correspond to start values of Modelica components. Start values are marked as fixed, requiring the values be set at the beginning of the simulation (otherwise, simulators only take the values as suggestions ...)

Source

f1 is replaced by p1.f, v1 is replaced by p1.lV, x is replaced by lengthchg, k is replaced by springcst, v is replaced by velocitydiff, f is replaced by forcethru, v2 is replaced by p2.v, and f2 is replaced by p2.f.

Source

The following Modelica code corresponds to Figure 26. It has five equations from the SysML constraint block. SysML parameter names are replaced in the Modelica equations according the bindings in Figure 14 [ERROR]:

Source

(and flow properties in SysML property paths leading to PhSVariables on conserved quantity kinds are omitted in Modelica, see Subclause 10.7.8).

Source

In a SysML block with constraint properties, the constraints correspond to the same equations in Modelica ... except the SysML parameters in those equations correspond in Modelica to the properties they are bound to in SysML

Source

SysML parameter names are replaced in the Modelica equations according to the bindings in Figure 13 [ERROR]: f is replaced by u, pos is replaced by y, x is replaced by position, k is replaced by springcst, v is replaced by velocity, m is replaced by mass.

Source

The following Modelica code corresponds to Figure 25. It has three equations from the constraint block.

Source

In a SysML block with constraint properties, the constraints correspond to the same equations in Modelica ... except the SysML parameters in those constraints correspond in Modelica to the properties they are bound to in SysML.

Source

Model [ERROR] contains a connect equation linking component p2 of s1 to component p1 of s2.

Source

The following Modelica code corresponds to Figure 24. It has a model Example with two components s1 and s2 of types SpringA and SpringB, respectively. The models SpringA and SpringB have two components p1 and p2 of type Flange, defined similarly to Spring

Source

SysML connectors correspond to Modelica connect equations, which link components typed by Modelica connectors. This depends on the correspondence between SysML port types and Modelica connectors ...

Source

The following Modelica code corresponds to Figure 21. It has a model A, with three properties v1, v2 and v3 of type Real, that are continuous, discrete, and parameter, respectively.

Source

SysML packages correspond to Modelica models defined as the root element of a file. The following Modelica code corresponds to Figure 17. It has a model P owning a model B ...

Source

The following Modelica code corresponds to Figure 20. It has a model A with component c1 indicated as replaceable, and a model B extending A with a component of the same name redeclaring it to alter the type ...

Source

The following Modelica code corresponds to Figure 19. It has a model A with a component c1 of type C, and a model B that extends A. As a result, B inherits the component c1 from A.

Source

The following Modelica example corresponds to the SysML block A in Figure 18. It has a Modelica model A corresponding to the SysML block A, with a component b1 typed by Modelica model B, corresponding to the SysML property b1 typed by block B.

Source

The flange of the mass and the flange of the ground replace the participant properties of the association block and are connected to the property f of type Friction in the same way as in the association block

Source

The connector and its property fa in Figure 2 is replaced by the content of the association block FrictionAssociation (the connector and its property and association block are removed).

Source

Connectors typed by association blocks, including their connector properties, are replaced by the internal structure of the association blocks. Figure 3 shows the content of Figure 2 after processing.

Source

The following Modelica code corresponds to Figure 23. It has a model Spring, with two components p1 and p2 of type Flange. Flange is a connector that has one flow component f, and one regular component lV.

Source

The following Modelica code corresponds to Figure 22. It has a model Spring, with two components u and y of type Real and of direction respectively in and out.

Source

By default, Modelica properties are continuous. PhSVariables with isContinuous=true correspond to continuous components, PhSVariables with isContinuous=false correspond to discrete components, and PhSConstants correspond to parameter variables.

Source

10.6.3 Modelica modeling: The variability of Modelica properties are of four kinds: continuous, discrete, parameter, and constant.

Source

SysPhS-1.1: This specification: Gives translations between SysML as extended above and two widely-used simulation languages and tools for physical interaction and signal flow simulation.

Source

SysPhS-1.1: This specification: Includes a platform-independent SysML library of simulation elements that can be reused in system models.

Source

SysPhS-1.1: This specification: Provides a human-usable textual syntax for mathematical expressions.

Source

SysPhS-1.1: This specification: Extends SysML with additional information needed to model physical interaction and signal flow simulation independently of simulation platforms.

Source

Today this process can occur in reverse, with the digital model developed first followed by the physical asset.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

Traditionally, industry has created digital twins by retrospectively mapping, scanning, surveying, digitising or developing a digital copy of a real world object.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

Sensors [DISPUTED] in office buildings for example, can adjust lights, blinds and temperature to balance optimal working environment with energy consumption, with the digital twin managing and adjusting in near real-time.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

The famous pipe. How people reproached me for it! And yet, could you stuff my pipe? No, it's just a representation, is it not? So if I had written on my picture "This is a pipe", I'd have been lying!

Source

Often depicting ordinary objects in an unusual context, his work is known for challenging observers' preconditioned perceptions of reality.

Source

René François Ghislain Magritte was a Belgian surrealist artist. He became well known for creating a number of witty and thought-provoking images.

Source

An actuator is a device that is responsible for moving or controlling a mechanism or system. It is controlled by a signal from a control system or manual control.

Source

A sensor is a transducer that receives and responds to a signal or stimulus from a physical system. It produces a signal, which represents information about the system

Source

In contrast to traditional digital models, digital twins can connect with the physical ‘twin’ they model, changing alongside the physical system via real-time sensors and actuators.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

They encompass potential or actual physical assets, processes, people, places, systems, devices and the natural environment.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

Digital twins are dynamic, data driven, multi-dimensional digital replicas of a physical entity.

Source

ANZLIC 2019 - Principles for Spatially Enabled Digital Twins of the Built and Natural Environment in Australia

Validation can be expressed by the query "Are you building the right thing?" and verification by "Are you building it right?"

Source

Completion events have dispatching priority. That is, they are dispatched ahead of any pending Event occurrences in the event pool.

Source

Unified Modeling Language 2.5.1

In case of simple States, a completion event is generated when the associated entry and doActivity Behaviors have completed executing. If no such Behaviors are defined, the completion event is generated upon entry into the State.

Source

Unified Modeling Language 2.5.1

The event that enables this trigger is called a completion event and it signifies that all Behaviors associated with the source State of the completion Transition have completed execution.

Source

Unified Modeling Language 2.5.1

14.2.3.8.3 Completion Transitions and completion events: A special kind of Transition is a completion Transition, which has an implicit trigger.

Source

Unified Modeling Language 2.5.1

Trigger::event : Event [1..1] The Event that detected by the Trigger.

Source

Unified Modeling Language 2.5.1

Trigger::port : Port [0..*] A optional Port of through which the given effect is detected.

Source

Unified Modeling Language 2.5.1

InvocationAction::argument : InputPin [0..*] The InputPins that provide the argument values passed in the invocation request.

Source

Unified Modeling Language 2.5.1

InvocationAction::onPort : Port [0..1] For CallOperationActions, SendSignalActions, and SendObjectActions, an optional Port of the target object through which the invocation request is sent.

Source

Unified Modeling Language 2.5.1

SendSignalAction::signal: The Signal whose instance is transmitted to the target.

Source

Unified Modeling Language 2.5.1

SendSignalAction::target: The InputPin that provides the target object to which the Signal instance is sent

Source

Unified Modeling Language 2.5.1

Instead of the client specifying which service it will use, the injector tells the client what service to use. The "injection" refers to the passing of a dependency (a service) into the object (a client) that would use it.

Source

In the typical "using" relationship the receiving object is called a client and the passed (that is, "injected") object is called a service. The code that passes the service to the client can be many kinds of things and is called the injector.

Source

In software engineering, dependency injection is a technique in which an object receives other objects that it depends on. These other objects are called dependencies.

Source

Trade studies are commonly used in the design of aerospace and automotive vehicles and the software selection process ... to find the configuration that best meets conflicting performance requirements.

Source

These viable solutions are judged by their satisfaction of a series of measures or cost functions. These measures describe the desirable characteristics of a solution. They may be conflicting or even mutually exclusive.

Source

A trade study or trade-off study, also known as a figure of merit analysis or a factor of merit analysis, is the activity of a multidisciplinary team to identify the most balanced technical solutions among a set of proposed viable solutions (FAA 2006).

Source

Top: The formation of a virtual image using a diverging lens. Bottom: The formation of a virtual image using a convex mirror. In both diagrams, f is the focal point, O is the object and I is the image, shown in grey ...

Source

Top: The formation of a real image using a convex lens. Bottom: The formation of a real image using a concave mirror. In both diagrams, f is the focal point, O is the object, and I is the image.

Source

In an imperfect lens L, all the rays do not pass through a focal point. The smallest circle that they pass through C is called the circle of least confusion.

Source

This is a major advantage for solar telescopes, where a field stop (Gregorian stop) can reduce the amount of heat reaching the secondary mirror and subsequent optical components.

Source

In the Gregorian design, the primary mirror creates a real image before the secondary mirror. This allows for a field stop to be placed at this location, so that the light from outside the field of view does not reach the secondary mirror.

Source

As the name implies, the "tube" of this design is actually composed of an upper 'cage assembly', which contains the secondary mirror, and focuser, held in place by several rigid poles over a ‘mirror box’ which contains the objective mirror.

Source

Collapsible "truss tube" Dobsonians appeared in the amateur telescope making community as early as 1982 and allow the optical tube assembly, the largest component, to be broken down.

Source

In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture"). It is also known as the focal ratio, f-ratio, or f-stop

Source

Light path in a Cassegrain telescope.

Source

Light path in a Newtonian telescope.

Source

The overall focal ratio of the complete telescope will be f/8 and the optical prescription is an aplanatic Gregorian telescope.

Source

Diagram of the lightpath through a Gregorian telescope.

Source

In a prime focus design no secondary optics are used, the image is accessed at the focal point of the primary mirror.

Source

The Gregorian telescope consists of two concave mirrors; the primary mirror (a concave paraboloid) collects the light and brings it to a focus before the secondary mirror (a concave ellipsoid) where it is reflected back through a hole in the centre ...

Source

A segmented mirror is an array of smaller mirrors designed to act as segments of a single large curved mirror. ... They are used as objectives for large reflecting telescopes.

Source

It is free of coma and spherical aberration at a nearly flat focal plane if the primary and secondary curvature are properly figured.

Source

The Ritchey–Chrétien telescope ... is a specialized Cassegrain reflector which has two hyperbolic mirrors (instead of a parabolic primary).

Source

The cassegrain telescope (sometimes called the "Classic Cassegrain") ... has a parabolic primary mirror, and a hyperbolic secondary mirror that reflects the light back down through a hole in the primary.

Source

A flat secondary mirror reflects the light to a focal plane at the side of the top of the telescope tube.

Source

The Newtonian telescope ... usually has a paraboloid primary mirror but at focal ratios of f/8 or longer a spherical primary mirror can be sufficient for high visual resolution.

Source

There are several large modern telescopes that use a Gregorian configuration such as the Vatican Advanced Technology Telescope, the Magellan telescopes, the Large Binocular Telescope, and the Giant Magellan Telescope.

Source

The Gregorian telescope ... employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. This produces an upright image

Source

Film or a digital sensor may be located here to record the image, or a secondary mirror may be added to modify the optical characteristics and/or redirect the light to film, digital sensors, or an eyepiece for visual observation.

Source

A curved primary mirror is the reflector telescope's basic optical element that creates an image at the focal plane [OF THE PRIMARY IF THERE IS NO SECONDARY]. The distance from the mirror to the focal plane is called the focal length.

Source

This image may be ... viewed through an eyepiece, which acts like a magnifying glass. The eye then sees an inverted magnified virtual image of the object.

Source

This image may be ... viewed through an eyepiece, which acts like a magnifying glass. The eye then sees a ... magnified virtual image of the object.

Source

Schematic of a Keplerian refracting telescope. The arrow at (4) is a (notional) representation of the original image; the arrow at (5) is the inverted image at the focal plane; the arrow at (6) is the virtual image that forms in the viewer's visual sphere

Source

rays that enter the system parallel to the optical axis are focused such that they pass through the rear focal point

Source

A principal focus or focal point is a special focus: For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused.

Source

If the medium surrounding the optical system has a refractive index of 1 (e.g., air or vacuum), then the distance from the principal planes to their corresponding focal points is just the focal length of the system.

Source

The front and rear (or back) focal planes are defined as the planes, perpendicular to the optic axis, which pass through the front and rear focal points.

Source

An object infinitely far from the optical system forms an image at the rear focal plane.

Source

Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics.

Source

In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge.

Source

A real image occurs where rays converge, whereas a virtual image occurs where rays only appear to diverge.

Source

In ray diagrams ... real rays of light are always represented by full, solid lines; perceived or extrapolated rays of light are represented by dashed lines.

Source

A real image ... is an image which is located in the plane of convergence for the light rays that originate from a given object.

Source

A converging lens (one that is thicker in the middle than at the edges) or a concave mirror is also capable of producing a virtual image if the object is within the focal length. Such an image will be magnified.

Source

A diverging lens (one that is thicker at the edges than the middle) or a convex mirror forms a virtual image. Such an image is reduced in size when compared to the original object.

Source

Because the rays never really converge, a virtual image cannot be projected onto a screen. In contrast, a real image can be projected on the screen as it is formed by rays that converge on a real location.

Source

In diagrams of optical systems, virtual rays are conventionally represented by dotted lines.

Source

a virtual image is found by tracing real rays that emerge from an optical device (lens, mirror, or some combination) backward to perceived or apparent origins of ray divergences.

Source

A real image is the collection of focus points actually made by converging rays, while a virtual image is the collection of focus points made by extensions of diverging rays.

Source

In optics, an image is defined as the collection of focus points of light rays coming from an object.

Source

The eyepiece is placed near the focal point of the objective to magnify this image. The amount of magnification depends on the focal length of the eyepiece.

Source

The objective lens or mirror collects light and brings it to focus creating an image.

Source

Objectives can be a single lens or mirror, or combinations of several optical elements.

Source

In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image.

Source

For example, in a telescope, the aperture stop is typically the edges of the objective lens or mirror (or of the mount that holds it). One then speaks of a telescope as having, for example, a 100-centimeter aperture.

Source

In some contexts, especially in photography and astronomy, aperture refers to the diameter of the aperture stop rather than the physical stop or the opening itself.

Source

A telescope's ability to resolve small detail is directly related to the diameter (or aperture) of its objective (the primary lens or mirror that collects and focuses the light), and its light gathering power is related to the area of the objective.

Source

There are telescope designs that do not present an inverted image such as the Galilean refractor and the Gregorian reflector. These are referred to as erecting telescopes.

Source

Most telescope designs produce an inverted image at the focal plane; these are referred to as inverting telescopes.

Source

This image may be recorded or viewed through an eyepiece, which acts like a magnifying glass. The eye then sees an inverted [DISPUTED] magnified virtual image of the object.

Source

The basic scheme is that the primary light-gathering element, the objective (the convex lens or concave mirror used to gather the incoming light), focuses that light from the distant object to a focal plane where it forms a real image.

Source

An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors.

Source

Under ideal laboratory conditions, people can see infrared up to at least 1050 nm; children and young adults may perceive ultraviolet wavelengths down to about 310–313 nm.

Source

Various sources define visible light as narrowly as 420–680 nm to as broadly as 380–800 nm.

Source

It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time interval of 1⁄299792458 second.

Source

The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its exact value is defined as 299792458 metres per second (approximately 300000 km/s, or 186000 mi/s)

Source

The value of c can ... be found by using the relation c = fλ.

Source

Near Infrared: 2.0 to 2.4: Wavelength (micrometres): K band: Most major optical telescopes and most dedicated infrared telescopes

Source

Many optical telescopes, such as those at Keck Observatory, operate effectively in the near infrared as well as at visible wavelengths.

Source

For this reason, the near infrared region of the spectrum is commonly incorporated as part of the "optical" spectrum, along with the near ultraviolet.

Source

Infrared radiation with wavelengths just longer than visible light, known as near-infrared, behaves in a very similar way to visible light, and can be detected using similar solid state devices ...

Source

Far infrared (FIR) is a region in the infrared spectrum of electromagnetic radiation. Far infrared is often defined as any radiation with a wavelength of 15 micrometers (μm) to 1 mm

Source

There are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light).

Source

Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency of approximately 30 PHz) to 400 nm (750 THz), shorter than that of visible light but longer than X-rays.

Source

Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz.

Source

The wavelength of infrared light ranges from 0.75 to 300 micrometers. Infrared falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.

Source

Infrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared (IR) radiation.

Source

Infrared and optical astronomy are often practiced using the same telescopes, as the same mirrors or lenses are usually effective over a wavelength range that includes both visible and infrared light.

Source

Optical radiation is part of the electromagnetic spectrum. It is subdivided into ultraviolet radiation (UV), the spectrum of light visible for man (VIS) and infrared radiation (IR). It ranges between wavelengths of 100 nm to 1 mm [DISPUTED]

Source

A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image.

Source

In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s.

Source

The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope.

Source

An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device.

Source

All refracting telescopes use the same principles. The combination of an objective lens and some type of eyepiece is used to gather more light than the human eye is able to collect on its own, focus it, and present the viewer with a brighter, clearer, ...

Source

They were used for both terrestrial applications and astronomy.

Source

The first known practical telescopes were refracting telescopes invented in the Netherlands at the beginning of the 17th century, by using glass lenses.

Source

The word telescope now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.

Source

A telescope is an optical instrument using lenses, curved mirrors [DISPUTED], or a combination of both to observe distant objects ...

Source

The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.

Source

Protons and neutrons are both nucleons, which may be bound together by the nuclear force to form atomic nuclei.

Source

A neutron contains two down quarks with charge −1⁄3 e and one up quark with charge +2⁄3 e.

Source

The finite size of the neutron and its magnetic moment both indicate that the neutron is a composite, rather than elementary, particle.

Source

The neutron is classified as a hadron, because it is a composite particle made of quarks. The neutron is also classified as a baryon, because it is composed of three valence quarks.

Source

The neutron has a magnetic moment, however, so the neutron is influenced by magnetic fields. The neutron's magnetic moment has a negative value, because its orientation is opposite to the neutron's spin.

Source

The neutron has no measurable electric charge. With its positive electric charge, the proton is directly influenced by electric fields, whereas the neutron is unaffected by electric fields.

Source

The neutron has a mean square radius of about 0.8×10−15 m, or 0.8 fm, and it is a spin-½ fermion.

Source

The free neutron has a mass of 939,565,413.3 eV/c2, or 1.674927471×10−27 kg, or 1.00866491588 u.

Source

Beta decay, in which neutrons decay to protons, or vice versa, is governed by the weak force, and it requires the emission or absorption of electrons and neutrinos, or their antiparticles.

Source

Neutrons or protons bound in a nucleus can be stable or unstable, however, depending on the nuclide.

Source

The free proton is stable.

Source

This radioactive decay, known as beta decay, is possible because the mass of the neutron is slightly greater than the proton.

Source

A free neutron is unstable, decaying to a proton, electron and antineutrino with a mean lifetime of just under 15 minutes (881.5±1.5 s).

Source

Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons.

Source

Protons and neutrons constitute the nuclei of atoms.

Source

The neutron is a subatomic particle, symbol n or n0, with no electric charge and a mass slightly greater than that of a proton.

Source

The remainder of a proton's mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together.

Source

The rest masses of quarks contribute only about 1% of a proton's mass.

Source

Protons are composite particles composed of three valence quarks: two up quarks of charge + 2/3e and one down quark of charge –1/3e.

Source

Although protons were originally considered fundamental or elementary particles, in the modern Standard Model of particle physics, protons are classified as hadrons, like neutrons, the other nucleon.

Source

The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol Z). Since each element has a unique number of protons, each element has its own unique atomic number.

Source

One or more protons are present in the nucleus of every atom; they are a necessary part of the nucleus.

Source

Protons and neutrons, each with masses of approximately one atomic mass unit, are collectively referred to as "nucleons" (particles present in atomic nuclei).

Source

A modern perspective has a proton composed of the valence quarks (up, up, down), the gluons, and transitory pairs of sea quarks.

Source

The two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons.

Source

A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron.

Source

The quarks that determine the quantum numbers of hadrons are called valence quarks; apart from these, any hadron may contain an indefinite number of virtual "sea" quarks, antiquarks, and gluons, which do not influence its quantum numbers.

Source

Hadrons contain, along with the valence quarks that contribute to their quantum numbers, virtual quark–antiquark pairs known as sea quarks.

Source

Elementary fermions are grouped into three generations, each comprising two leptons and two quarks.

Source

Elementary fermions are grouped into three generations, each comprising two leptons and two quarks. The first generation includes up and down quarks, the second strange and charm quarks, and the third bottom and top quarks.

Source

Antiparticles of quarks are called antiquarks, and are denoted by a bar over the symbol for the corresponding quark, such as ū for an up antiquark.

Source

The Standard Model is the theoretical framework describing all the currently known elementary particles. This model contains six flavors of quarks (q), named up (u), down (d), strange (s), charm (c), bottom (b), and top (t).

Source

For every quark flavor there is a corresponding type of antiparticle, known as an antiquark, that differs from the quark only in that some of its properties (such as the electric charge) have equal magnitude but opposite sign.

Source

Because of this, up and down quarks are generally stable and the most common in the universe, whereas strange, charm, bottom, and top quarks can only be produced in high energy collisions (such as those involving cosmic rays and in particle accelerators).

Source

The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state.

Source

Up and down quarks have the lowest masses of all quarks.

Source

There are six types, known as flavors, of quarks: up, down, strange, charm, bottom, and top.

Source

A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with spin of 1/2) that interacts only via the weak subatomic force and gravity.

Source

Quarks ... are the only known particles whose electric charges are not integer multiples of the elementary charge.

Source

Quarks ... are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as fundamental forces (electromagnetism, gravitation, strong interaction, and weak interaction).

Source

Quarks have various intrinsic properties, including electric charge, mass, color charge, and spin.

Source

Due to a phenomenon known as color confinement, quarks are never found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons, or in quark–gluon plasmas.

Source

Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei.

Source

A quark is a type of elementary particle and a fundamental constituent of matter.

Source

The resulting attraction between different quarks causes the formation of composite particles known as hadrons

Source

Unlike leptons, quarks possess color charge, which causes them to engage in the strong interaction.

Source

Both of these decays imply that color is no longer a property of the byproducts.

Source

Uncharged mesons may decay to photons.

Source

Charged mesons decay (sometimes through mediating particles) to form electrons and neutrinos.

Source

All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond.

Source

In particle physics, mesons are hadronic subatomic particles composed of one quark and one antiquark, bound together by strong interactions.

Source

Four closely related Δ baryons exist: Δ++ (constituent quarks: uuu), Δ+ (uud), Δ0 (udd), and Δ− (ddd), which respectively carry an electric charge of +2 e, +1 e, 0 e, and −1 e.

Source

The Δ baryons have ... a spin of 3⁄2 ...

Source

In particle physics, a hadron ... is a subatomic composite particle made of two or more quarks ...

Source

Exotic baryons containing five quarks (known as pentaquarks) have also been discovered and studied.

Source

Since baryons are made of three quarks [DISPUTED], their spin vectors can add to make a vector of length S = 3/2, which has four spin projections (Sz = +3/2, Sz = +1/2, Sz = −1/2, and Sz = −3/2), or a vector of length S = 1/2 with two spin projections ...

Source

If two quarks have unaligned spins, the spin vectors add up to make a vector of length S = 0 and has only one spin projection (Sz = 0), etc.

Source

Two quarks can have their spins aligned, in which case the two spin vectors add to make a vector of length S = 1 and three spin projections (Sz = +1, Sz = 0, and Sz = −1).

Source

Because spin projections vary in increments of 1 (that is 1 ħ), a single quark has a spin vector of length 1/2, and has two spin projections (Sz = +1/2 and Sz = −1/2).

Source

Quarks are fermionic particles of spin 1/2 (S = 1/2).

Source

Protons are spin-1/2 fermions and are composed of three valence quarks, making them baryons (a sub-type of hadrons).

Source

The neutron ... is a spin-½ fermion.

Source

The most familiar baryons are protons and neutrons, both of which contain three quarks, and for this reason these particles are sometimes described as triquarks.

Source

They are also classified as fermions, i.e., they have half-integer spin.

Source

Baryons belong to the hadron family of particles, which are the quark-based particles.

Source

In particle physics, a baryon is a type of composite subatomic particle which contains an odd number of valence quarks (at least 3).

Source

According to the spin-statistics theorem in any reasonable relativistic quantum field theory, particles with integer spin are bosons, while particles with half-integer spin are fermions.

Source

Some fermions are elementary particles, such as the electrons, and some are composite particles, such as the protons.

Source

Fermions differ from bosons, which obey Bose–Einstein statistics.

Source

Fermions include all quarks and leptons, as well as all composite particles made of an odd number of these, such as all baryons and many atoms and nuclei.

Source

In particle physics, a fermion is a particle that follows Fermi–Dirac statistics and generally has half odd integer spin 1/2, 3/2 etc. These particles obey the Pauli exclusion principle.

Source

The Pauli exclusion principle is the quantum mechanical principle which states that two or more identical fermions (particles with half-integer spin) cannot occupy the same quantum state within a quantum system simultaneously.

Source

sz is the spin projection quantum number along the z-axis.

Source

there are only two possible values for a spin-1/2 particle: sz = +1/2 and sz = -1/2. These correspond to quantum states in which the spin component is pointing in the +z or −z directions respectively, and are often referred to as "spin up" and "spin down"

Source

Furthermore, it means that a lepton can have only two possible spin states, namely up or down.

Source

Leptons are spin 1/2 particles. The spin-statistics theorem thus implies that they are fermions and thus that they are subject to the Pauli exclusion principle: No two leptons of the same species can be in the same state at the same time.

Source

The positron is symbolized by e+ because it has the same properties as the electron but with a positive rather than negative charge.

Source

As the symbol e is used for the elementary charge, the electron is commonly symbolized by e−, where the minus sign indicates the negative charge.

Source

Within the limits of experimental accuracy, the electron charge is identical to the charge of a proton, but with the opposite sign.

Source

Electrons have an electric charge of −1.602176634×10−19 coulombs, which is used as a standard unit of charge for subatomic particles, and is also called the elementary charge.

Source

The invariant mass of an electron is approximately 9.109×10−31 kilograms, or 5.489×10−4 atomic mass units. On the basis of Einstein's principle of mass–energy equivalence, this mass corresponds to a rest energy of 0.511 MeV.

Source

In theory, a particle and its anti-particle (for example, a proton and an antiproton) have the same mass, but opposite electric charge and other differences in quantum numbers. For example, a proton has positive charge while an antiproton has negative ...

Source

In modern physics, antimatter is defined as matter which is composed of the antiparticles (or "partners") of the corresponding particles of 'ordinary' matter.

Source

While the electron has a negative electric charge, the positron has a positive electric charge, and is produced naturally in certain types of radioactive decay. The opposite is also true: the antiparticle of the positron is the electron.

Source

For example, the antiparticle of the electron is the antielectron (which is often referred to as positron).

Source

In particle physics, every type of particle is associated with [an] antiparticle with the same mass but with opposite physical charges (such as electric charge).

Source

According to certain theories, neutrinos may be their own antiparticle. It is not currently known whether this is the case.

Source

For every lepton flavor, there is a corresponding type of antiparticle, known as an antilepton, that differs from the lepton only in that some of its properties have equal magnitude but opposite sign.

Source

electromagnetism ... is proportional to charge, and is thus zero for the electrically neutral neutrinos.

Source

Unlike quarks, however, leptons are not subject to the strong interaction, but they are subject to the other three fundamental interactions: gravitation, the weak interaction, and to electromagnetism ...

Source

Leptons have various intrinsic properties, including electric charge, spin, and mass.

Source

a helium atom in the ground state has spin 0 and behaves like a boson, even though the quarks and electrons which make it up are all fermions.

Source

In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.

Source

The system is unstable: the two particles annihilate each other to predominantly produce two or three gamma-rays, depending on the relative spin states.

Source

Thus electrons are stable and the most common charged lepton in the universe, whereas muons and taus can only be produced in high energy collisions (such as those involving cosmic rays and those carried out in particle accelerators).

Source

The heavier muons and taus will rapidly change into electrons and neutrinos through a process of particle decay: the transformation from a higher mass state to a lower mass state.

Source

Electrons have the least mass of all the charged leptons.

Source

and the third are the tauonic leptons, comprising the tau ( τ− ) and the tau neutrino ( ν τ)

Source

the second are the muonic leptons, comprising the muon ( μ− ) and the muon neutrino ( ν μ);

Source

The first-generation leptons, also called electronic leptons, comprise the electron ( e− ) and the electron neutrino ( ν e);

Source

There are six types of leptons, known as flavours, grouped in three generations.

Source

The best known of all leptons is the electron.

Source

Positronium (Ps) is a system consisting of an electron and its anti-particle, a positron, bound together into an exotic atom, specifically an onium.

Source

Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed.

Source

Two main classes of leptons exist, charged leptons (also known as the electron-like leptons), and neutral leptons (better known as neutrinos).

Source

In particle physics, a lepton is an elementary particle of half-integer spin (spin 1⁄2) that does not undergo strong interactions.

Source

«effbd» Specifies that the activity conforms to the constraints necessary for EFFBD.

Source

OMG Systems Modeling Language (SysML) 1.6

«nonStreaming» Used for activities that accept inputs only when they start, and provide outputs only when they finish. The activity has no streaming parameters.

Source

OMG Systems Modeling Language (SysML) 1.6

«streaming» Used for activities that can accept inputs or provide outputs after they start and before they finish. The activity has at least one streaming parameter.

Source

OMG Systems Modeling Language (SysML) 1.6

The stereotype does not override UML token offering semantics, just indicates what happens to the token when it is accepted. When the stereotype is not applied, the semantics is as in UML, specifically, tokens arriving at object nodes do not replace ...

Source

OMG Systems Modeling Language (SysML) 1.6

For object nodes that are the target of continuous flows, «overwrite» and «nobuffer» have the same effect.

Source

OMG Systems Modeling Language (SysML) 1.6

The number of tokens replaced is equal to the weight of the incoming edge, which defaults to 1.

Source

OMG Systems Modeling Language (SysML) 1.6

A null token removes all the tokens already there.

Source

OMG Systems Modeling Language (SysML) 1.6

Tokens arriving at a full object node with the Overwrite stereotype applied take up their positions in the ordering as normal, if any. The arriving tokens do not take the positions of the removed tokens.

Source

OMG Systems Modeling Language (SysML) 1.6

For upper bounds greater than one, the token removed is the one that has been in the object node the longest. For FIFO ordering, this is the token that is next to be selected, for LIFO it is the token that would be last to be selected.

Source

OMG Systems Modeling Language (SysML) 1.6

This is typically used on an input pin with an upper bound of 1 to ensure that stale data is overridden at an input pin.

Source

OMG Systems Modeling Language (SysML) 1.6

When the «overwrite» stereotype is applied to object nodes, a token arriving at a full object node removes one that is already there before being added (a full object node has as many tokens as allowed by its upper bound).

Source

OMG Systems Modeling Language (SysML) 1.6

NoBuffer::1_not_overwrite The «nobuffer» and «overwrite» stereotypes cannot be applied to the same element at the same time

Source

OMG Systems Modeling Language (SysML) 1.6

The stereotype does not override UML token offering semantics; it just indicates what happens to the token when it is accepted. When the stereotype is not applied, the semantics are as in UML, specifically, tokens arriving at an object node ...

Source

OMG Systems Modeling Language (SysML) 1.6

For object nodes that are the target of continuous flows, «nobuffer» and «overwrite» have the same effect.

Source

OMG Systems Modeling Language (SysML) 1.6

This is typically used with fast or continuously flowing data values, to prevent buffer overrun, or to model transient values, such as electrical signals.

Source

OMG Systems Modeling Language (SysML) 1.6

When the «nobuffer» stereotype is applied to object nodes, tokens arriving at the node are discarded if they are refused by outgoing edges, or refused by actions for object nodes that are input pins.

Source

OMG Systems Modeling Language (SysML) 1.6

Discrete rate is a special case of rate of flow ... where the increment of time between items is a non-zero. Examples include the production of assemblies in a factory and signals set at periodic time intervals.

Source

OMG Systems Modeling Language (SysML) 1.6

When the «probability» stereotype is applied to output parameter sets, it gives the probability the parameter set will be given values at runtime. These shall be between zero and one inclusive, and add up to one for output parameter sets of the same ...

Source

OMG Systems Modeling Language (SysML) 1.6

When the «probability» stereotype is applied to edges coming out of decision nodes and object nodes, it provides an expression for the probability that the edge will be traversed. These shall be between zero and one inclusive, and add up to one ...

Source

OMG Systems Modeling Language (SysML) 1.6

When the «optional» stereotype is applied to parameters, the lower multiplicity shall be equal to zero. This means the parameter is not required to have a value for the activity or any behavior to begin or end execution ...

Source

OMG Systems Modeling Language (SysML) 1.6

Once the test fails and the loop is completed, the tokens on the bodyOutput OutputPins from the last iteration are moved to the result OutputPins and offered on any edges outgoing from those OutputPins.

Source

Unified Modeling Language 2.5.1

After the completion of each execution of the bodyPart of the LoopNode, any remaining tokens on the loopVariable OutputPins are destroyed and tokens on the bodyOutput OutputPins are copied to the corresponding loopVariable OutputPins so that they are ...

Source

Unified Modeling Language 2.5.1

When the LoopNode begins executing, the tokens on the loopVariableInput InputPins are moved to the corresponding loopVariable OutputPins before the first iteration of the loop.

Source

Unified Modeling Language 2.5.1

If a LoopNode has loopVariable OutputPins, then it must also have matching sets of loopVariableInput InputPins, bodyOutput OutputPins (owned by Actions within the bodyPart), and result OutputPins.

Source

Unified Modeling Language 2.5.1

A LoopNode may also define a set of loopVariable OutputPins used to hold intermediate values during each loop iteration. These OutputPins may have outgoing ActivityEdges, in order to make the values they hold available within the test and bodyPart ...

Source

Unified Modeling Language 2.5.1

After each execution of the bodyPart, the test section is executed again, for the next iteration of the loop.

Source

Unified Modeling Language 2.5.1

The test section has an Action owning the decider OutputPin with type Boolean identified by the LoopNode. When the test section has completed execution, if the value on the decider OutputPin is true, then the bodyPart is executed. Otherwise ...

Source

Unified Modeling Language 2.5.1

Execution of the test section may precede or follow execution of the bodyPart, depending on whether isTestFirst is true or false, respectively. ... If the bodyPart is executed first (isTestFirst=false), it is always executed at least once ...

Source

Unified Modeling Language 2.5.1

The setupPart of a LoopNode is executed first. When the setupPart has completed execution, the iterative execution of the loop begins.

Source

Unified Modeling Language 2.5.1

Any ExecutableNode in the LoopNode must be included in the setupPart, test or bodyPart for the LoopNode.

Source

Unified Modeling Language 2.5.1

A LoopNode is a StructuredActivityNode that represents an iterative loop. A LoopNode consists of a setupPart, a test and a bodyPart, which identify subsets of the ExecutableNodes contained in the LoopNode.

Source

Unified Modeling Language 2.5.1

This means that an Activity model in which non-determinacy occurs may be subject to timing issues and race conditions. It is the responsibility of the modeler to avoid such conditions in the construction of the Activity model, if they are not desired.

Source

Unified Modeling Language 2.5.1

If a token is offered to multiple ActivityNodes at the same time, it shall be accepted by at most one of them, but exactly which one is not completely determined by the Activity flow semantics.

Source

Unified Modeling Language 2.5.1

However, the same token can only be accepted at one target at a time (unless it is copied, whereupon it is not the same token, see ForkNodes ... and ExecutableNodes ...).

Source

Unified Modeling Language 2.5.1

As an ActivityNode may be the source for multiple ActivityEdges, the same token can be offered to multiple targets.

Source

Unified Modeling Language 2.5.1

The ActivityEdges going out of ForkNodes continue to hold the tokens they accept until all pending offers have been accepted by their targets.

Source

Unified Modeling Language 2.5.1

a predefined guard “else” (represented as an Expression with “else” as its operator and no operands) may be used for at most one outgoing edge. This guard evaluates to true only if the token is not accepted by any other outgoing edge from the DecisionNode

Source

Unified Modeling Language 2.5.1

If the Action is an invocation of a Behavior with streaming Parameters ... the Action execution may consume additional data supplied to InputPins corresponding to streaming input Parameters ... Otherwise ... any additional data on InputPins has no effect

Source

Unified Modeling Language 2.5.1

For structured Actions (StructuredActivityNodes ... ), data can remain on InputPins during Action execution, otherwise they are immediately removed from the InputPins by the ActionExecution.

Source

Unified Modeling Language 2.5.1

The Action execution consumes input data on all InputPins on the Action up to the upper multiplicity for each InputPin.

Source

Unified Modeling Language 2.5.1

However, if the Action is an invocation of a Behavior with streaming Parameters ... then the Action execution may also post data to OutputPins corresponding to streaming output Parameters before completion of the execution ...

Source

Unified Modeling Language 2.5.1

When completed, an Action execution provides any output data on the OutputPins of the Action, and it terminates.

Source

Unified Modeling Language 2.5.1

An Action continues executing until it has completed. The detailed semantics of the execution of an Action and the definition of its completion depend on the particular kind of Action being executed.

Source

Unified Modeling Language 2.5.1

The time at which an Action executes and what inputs are accepted by each execution are determined by the kind of Action it is, characteristics of its InputPins, and the Behavior in which it is used.

Source

Unified Modeling Language 2.5.1

When an Action in an Activity completes execution, object tokens for output data placed on its OutputPins may be offered on any outgoing ObjectFlows from those Pins ... In addition, control tokens shall be offered on any outgoing ControlFlows ...

Source

Unified Modeling Language 2.5.1

A ValuePin provides a value by evaluating a ValueSpecification ... When the Action is enabled by other means, the ValueSpecifiation of the ValuePin is evaluated, and the result is provided as an input to the Action when it begins execution.

Source

Unified Modeling Language 2.5.1

When the Action is enabled by other means, values are computed as specified for the ValuePins and ActionInputPins owned by an Action, and the results are provided as inputs to the Action when it begins execution.

Source

Unified Modeling Language 2.5.1

ValuePins and ActionInputPins are InputPins, but are not used in the determination of whether an Action is enabled for execution. If an Action has no other way to start execution, simply having ValuePins or ActionInputPins for its inputs will not enable..

Source

Unified Modeling Language 2.5.1

An Action may not put more values into an output in a single execution than the [upper] multiplicity of that OutputPin.

Source

Unified Modeling Language 2.5.1

For each execution, an Action cannot terminate itself unless it can put at least as many values into its outputs as required by the multiplicity lower bounds on those OutputPins. Values that may remain on the OutputPins from previous executions are not...

Source

Unified Modeling Language 2.5.1

An OutputPin is a Pin that holds output values produced by an Action.

Source

Unified Modeling Language 2.5.1

Tokens consumed by an Action are immediately removed from its InputPins when the action begins an execution (except in some cases for StructuredActivityNodes, where tokens may remain on InputPins during the Action execution ...)

Source

Unified Modeling Language 2.5.1

The upper multiplicity determines the maximum number of values that can be consumed from an InputPin by a single execution of its Action.

Source

Unified Modeling Language 2.5.1

An Action cannot start execution if one of its InputPins has fewer values than the lower multiplicity of that InputPin.

Source

Unified Modeling Language 2.5.1

An InputPin is a Pin that holds input values to be consumed by its Action.

Source

Unified Modeling Language 2.5.1

Action::/output : OutputPin [0..*] ... The ordered set of OutputPins representing outputs from the Action.

Source

Unified Modeling Language 2.5.1

An Action may accept inputs and produce outputs, as specified by InputPins and OutputPins of the Action, respectively. Each Pin on an Action specifies the type and multiplicity for a specific input or output of that Action.

Source

Unified Modeling Language 2.5.1

Pins are used to specify the inputs and outputs for Actions.

Source

Unified Modeling Language 2.5.1

An ActivityFinalNode is a FinalNode that stops all flows in an Activity (or StructuredActivityNode, see sub clause 16.11). A token reaching an ActivityFinalNode owned by an Activity terminates the execution of that Activity.

Source

Unified Modeling Language 2.5.1

A FlowFinalNode is a FinalNode that terminates a flow. All tokens accepted by a FlowFinalNode are destroyed. This has no effect on other flows in the Activity.

Source

Unified Modeling Language 2.5.1

A FinalNode is a ControlNode at which a flow in an Activity stops. A FinalNode shall not have outgoing ActivityEdges. A FinalNode accepts all tokens offered to it on its incoming ActivityEdges. There are two kinds of FinalNode:

Source

Unified Modeling Language 2.5.1

An OpaqueAction is an Action whose specification may be given in a textual concrete syntax other than UML. An OpaqueAction may also be used as a temporary placeholder before some other kind of Action is chosen.

Source

Unified Modeling Language 2.5.1

A MergeNode is a control node that brings together multiple flows without synchronization.

Source

Unified Modeling Language 2.5.1

A JoinNode is a ControlNode that synchronizes multiple flows. A JoinNode shall have exactly one outgoing ActivityEdge but may have multiple incoming ActivityEdges.

Source

Unified Modeling Language 2.5.1

Tokens offered to a ForkNode are offered to all outgoing ActivityEdges of the node. If at least one of these offers is accepted, the offered tokens are removed from their original source and the acceptor receives a copy of the tokens.

Source

Unified Modeling Language 2.5.1

A ForkNode is a ControlNode that splits a flow into multiple concurrent flows. A ForkNode shall have exactly one incoming ActivityEdge, though it may have multiple outgoing ActivityEdges.

Source

Unified Modeling Language 2.5.1

When an ExecutableNode completes an execution, the control token representing that execution is removed from the ExecutableNode and control tokens are offered on all outgoing ControlFlows of the ExecutableNode. That is, there is an implicit fork ...

Source

Unified Modeling Language 2.5.1

In some cases, multiple concurrent executions of an ExecutableNode may be ongoing at one time (see the semantics of isLocallyReentrant=true for Actions ... ). In this case, the ExecutableNode holds one control token for each concurrent execution.

Source

Unified Modeling Language 2.5.1

While the ExecutableNode is executing, it is considered to hold a single control [token] indicating it is execution [executing].

Source

Unified Modeling Language 2.5.1

The effect of object tokens accepted from ControlFlows is not specified (see isControlType for ObjectNodes ...), but the semantics above applies if the effect is to execute the ExecutableNode.

Source

Unified Modeling Language 2.5.1

Before an ExecutableNode begins executing, it accepts all tokens offered on incoming ControlFlows. If multiple tokens are being offered on a ControlFlow, they are all consumed.

Source

Unified Modeling Language 2.5.1

An ExecutableNode shall not execute until all incoming ControlFlows (if any) are offering tokens. That is, there is an implicit join on the incoming Control Flows. Specific kinds of ExecutableNodes may have additional prerequisites ...

Source

Unified Modeling Language 2.5.1

An ExecutableNode may also consume and produce data, but it must do so through related ObjectNodes (Actions use Pins for this purpose ...

Source

Unified Modeling Language 2.5.1

An ExecutableNode is an ActivityNode that carries out a substantive behavioral step of the Activity that contains it.

Source

Unified Modeling Language 2.5.1

All concrete kinds of ExecutableNodes are Actions ...

Source

Unified Modeling Language 2.5.1

Generally, the ControlNodes and ObjectNodes in an Activity are largely there to control the sequencing and to manage the flow of data between the ExecutableNodes of the Activity.

Source

Unified Modeling Language 2.5.1

An ExecutableNode is a kind of ActivityNode that may be executed as a step in the overall desired behavior of the containing Activity.

Source

Unified Modeling Language 2.5.1

kind = internal ... This kind of Transition can only be defined if the source Vertex is a State.

Source

Unified Modeling Language 2.5.1

kind = internal is a special case of a local Transition that is a self-transition (i.e., with the same source and target States), such that the State is never exited (and, thus, not re-entered), which means that no exit or entry Behaviors are executed ...

Source

Unified Modeling Language 2.5.1

kind = local ... However, for local Transitions the target Vertex must be different from its source Vertex. A local Transition can only exist within a composite State.

Source

Unified Modeling Language 2.5.1

kind = local is the opposite of external, meaning that the Transition does not exit its containing State (and, hence, the exit Behavior of the containing State will not be executed). ...

Source

Unified Modeling Language 2.5.1

kind = external means that the Transition exits its source Vertex. If the Vertex is a State, then executing this Transition will result in the execution of any associated exit Behavior of that State.

Source

Unified Modeling Language 2.5.1

The semantics of a Transition depend on its relationship to its source Vertex. Three different possibilities are defined, depending on the value of the Transition’s kind attribute ...

Source

Unified Modeling Language 2.5.1

When multiple triggers are defined for a Transition, they are logically disjunctive, that is, if any of them are enabled, the Transition will be triggered.

Source

Unified Modeling Language 2.5.1

A Transition may own a set of Triggers, each of which specifies an Event whose occurrence, when dispatched, may trigger traversal of the Transition. A Transition trigger is said to be enabled if the dispatched Event occurrence matches its Event type.

Source

Unified Modeling Language 2.5.1

Transitions are executed as part of a more complex compound transition that takes a StateMachine execution from one stable state configuration to another.

Source

Unified Modeling Language 2.5.1

NOTE. The duration of a Transition traversal is undefined, allowing for different semantic interpretations, including both “zero” and non-“zero” time.

Source

Unified Modeling Language 2.5.1

It may have an associated effect Behavior, which is executed when the Transition is traversed (executed).

Source

Unified Modeling Language 2.5.1

A Transition is a single directed arc originating from a single source Vertex and terminating on a single target Vertex (the source and target may be the same Vertex), which specifies a valid fragment of a StateMachine Behavior.

Source

Unified Modeling Language 2.5.1

Otherwise, the appropriate history entry into the Region is executed (see above). If no default history Transition is defined, then standard default entry of the Region is performed ....

Source

Unified Modeling Language 2.5.1

This is a Transition that originates in the history Pseudostate and terminates on a specific Vertex (the default history state) of the Region containing the history Pseudostate. This Transition is only taken if execution leads to the history Pseudostate a

Source

Unified Modeling Language 2.5.1

In cases where a Transition terminates on a history Pseudostate when the State has not been entered before (i.e., no prior history) or it had reached its FinalState, there is an option to force a transition to a specific substate, using the default ...

Source

Unified Modeling Language 2.5.1

Shallow history (shallowHistory) represents a return to only the topmost substate of the most recent state configuration, which is entered using the default entry rule.

Source

Unified Modeling Language 2.5.1

The effect is the same as if the Transition terminating on the deepHistory Pseudostate had, instead, terminated on the innermost State of the preserved state configuration, including execution of all entry Behaviors encountered along the way.

Source

Unified Modeling Language 2.5.1

Deep history (deepHistory) represents the full state configuration of the most recent visit to the containing Region.

Source

Unified Modeling Language 2.5.1

Two types of history Pseudostates are provided.

Source

Unified Modeling Language 2.5.1

If there is no outgoing Transition inside the composite State, then the incoming Transition simply performs a default State entry.

Source

Unified Modeling Language 2.5.1

In effect, the latter is a continuation of the external incoming Transition, with the proviso that the execution of the entry Behavior of the composite State (if defined) occurs between the effect Behavior of the incoming Transition and the effect ...

Source

Unified Modeling Language 2.5.1

Entry points represent termination points (sources) for incoming Transitions and origination points (targets) for Transitions that terminate on some internal Vertex of the composite State.

Source

Unified Modeling Language 2.5.1

If the composite State has an exit Behavior defined, it is executed after any effect Behavior of the incoming inside Transition and before any effect Behavior of the outgoing external Transition.

Source

Unified Modeling Language 2.5.1

In a well-formed model, such a Transition should have a corresponding external Transition outgoing from the same exit point, representing a continuation of the terminating Transition.

Source

Unified Modeling Language 2.5.1

Exit points are the inverse of entry points. That is, Transitions originating from a Vertex within the composite State can terminate on the exit point.

Source

Unified Modeling Language 2.5.1

Regardless of how a State is entered, the StateMachine is deemed to be “in” that State even before any entry Behavior or effect Behavior (if defined) of that State start executing.

Source

Unified Modeling Language 2.5.1

If the Transition explicitly enters one or more Regions (in case of a fork), these Regions are entered explicitly and the others by default.

Source

Unified Modeling Language 2.5.1

If the Transition terminates on the edge of the composite State (i.e., without entering the State), then all the Regions are entered using the default entry rule above.

Source

Unified Modeling Language 2.5.1

If the composite State is also an orthogonal State with multiple Regions, each of its Regions is also entered, either by default or explicitly.

Source

Unified Modeling Language 2.5.1

Transition::trigger : Trigger [0..*] ... Specifies the Triggers that may fire the transition

Source

Unified Modeling Language 2.5.1

Transition::target : Vertex [1..1] ... Designates the target Vertex that is reached when the Transition is taken.

Source

Unified Modeling Language 2.5.1

Transition::source : Vertex [1..1] ... Designates the originating Vertex (State or Pseudostate) of the Transition.

Source

Unified Modeling Language 2.5.1

Transition::/redefinitionContext : Classifier [1..1] ... References the Classifier in which context this element may be redefined.

Source

Unified Modeling Language 2.5.1

Transition::redefinedTransition : Transition [0..1] ... The Transition that is redefined by this Transition.

Source

Unified Modeling Language 2.5.1

Transition::guard : Constraint [0..1] ... If the guard is true at that time, the Transition may be enabled, otherwise, it is disabled. Guards should be pure expressions without side effects. Guard expressions with side effects are ill formed.

Source

Unified Modeling Language 2.5.1

Transition::guard : Constraint [0..1] ... A guard is a Constraint that provides a fine-grained control over the firing of the Transition. The guard is evaluated when an Event occurrence is dispatched by the StateMachine. ...

Source

Unified Modeling Language 2.5.1

Transition::effect : Behavior [0..1] ... Specifies an optional behavior to be performed when the Transition fires.

Source

Unified Modeling Language 2.5.1

Transition::container : Region [1..1] ... Designates the Region that owns this Transition.

Source

Unified Modeling Language 2.5.1

Transition::kind : TransitionKind [1..1] = external Indicates the precise type of the Transition.

Source

Unified Modeling Language 2.5.1

A Transition represents an arc between exactly one source Vertex and exactly one Target vertex (the source and targets may be the same Vertex). It may form part of a compound transition, which takes the StateMachine from one steady State configuration...

Source

Unified Modeling Language 2.5.1

Regardless of how a State is exited, the StateMachine is deemed to have “left” that State only after the exit Behavior (if defined) of that State has completed execution.

Source

Unified Modeling Language 2.5.1

When exiting from an orthogonal State, each of its Regions is exited. After that, the exit Behavior of the State is executed.

Source

Unified Modeling Language 2.5.1

If the exit occurs through an exitPoint Pseudostate, then the exit Behavior of the State is executed after the effect Behavior of the Transition terminating on the exit point.

Source

Unified Modeling Language 2.5.1

When exiting from a composite State, exit commences with the innermost State in the active state configuration. This means that exit Behaviors are executed in sequence starting with the innermost active State.

Source

Unified Modeling Language 2.5.1

If the State has a doActivity Behavior that is still executing when the State is exited, that Behavior is aborted before the exit Behavior commences execution.

Source

Unified Modeling Language 2.5.1

When exiting a State, regardless of whether it is simple or composite, the final step involved in the exit, after all other Behaviors associated with the exit are completed, is the execution of the exit Behavior of that State.

Source

Unified Modeling Language 2.5.1

... if a doActivity Behavior is defined for the State, this Behavior commences execution immediately after the entry Behavior is executed. It executes concurrently with any subsequent Behaviors associated with entering the State, such as the entry ...

Source

Unified Modeling Language 2.5.1

... the entry Behavior of the State is executed (if defined) upon entry, but only after any effect Behavior associated with the incoming Transition is completed.

Source

Unified Modeling Language 2.5.1

A State may also have an associated doActivity Behavior. This Behavior commences execution when the State is entered (but only after the State entry Behavior has completed) and executes concurrently with any other Behaviors that may be associated ...

Source

Unified Modeling Language 2.5.1

In addition, a State may also have an associated exit Behavior, which, if defined, is executed whenever the State is exited.

Source

Unified Modeling Language 2.5.1

A State may have an associated entry Behavior. This Behavior, if defined, is executed whenever the State is entered through an external Transition.

Source

Unified Modeling Language 2.5.1

A State is said to be active if it is part of the active state configuration.

Source

Unified Modeling Language 2.5.1

StateMachine execution is represented by transitions from one active state configuration to another in response to Event occurrences that match the Triggers of the StateMachine.

Source

Unified Modeling Language 2.5.1

An executing StateMachine instance can only be in exactly one state configuration at a time, which is referred to as its active state configuration.

Source

Unified Modeling Language 2.5.1

For example, one valid state configuration for an execution of the StateMachine depicted in Figure 14.9 is: <CourseAttempt - Studying – (Studying::Lab2, Studying::TermProject, Studying::FinalTest)>.

Source

Unified Modeling Language 2.5.1

Similarly, we can talk about such a hierarchy of substates within a composite State. This complex hierarchy of States is referred to as a state configuration (of a State or a StateMachine).

Source

Unified Modeling Language 2.5.1

Consequently, a particular “state” of an executing StateMachine instance is represented by one or more hierarchies of States, starting with the topmost Regions of the StateMachine and down through the composition hierarchy to the simple, or leaf, States.

Source

Unified Modeling Language 2.5.1

In general, a StateMachine can have multiple Regions, each of which may contain States of its own, some of which may be composites with their own multiple Regions, etc.

Source

Unified Modeling Language 2.5.1

A SignalEvent represents the receipt of an asynchronous Signal instance.

Source

Unified Modeling Language 2.5.1

A CallEvent models the receipt by an object of a message invoking a call of an Operation.

Source

Unified Modeling Language 2.5.1

A trigger for an AnyReceiveEvent is triggered by the receipt of any message that is not explicitly handled by any related trigger.

Source

Unified Modeling Language 2.5.1

A TimeEvent is an Event that occurs at a specific point in time.

Source

Unified Modeling Language 2.5.1

A ChangeEvent models a change in the system configuration that makes a condition true.

Source

Unified Modeling Language 2.5.1

An Event is the specification of some occurrence that may potentially trigger effects by an object.

Source

Unified Modeling Language 2.5.1

A MessageEvent specifies the receipt by an object of either an Operation call or a Signal instance.

Source

Unified Modeling Language 2.5.1

A given BehavioredClassifier may implement more than one Interface and that an Interface may be implemented by a number of different BehavioredClassifiers.

Source

Unified Modeling Language 2.5.1

Required Interfaces specify services that a BehavioredClassifier needs in order to perform its function and fulfill its own obligations to its clients.

Source

Unified Modeling Language 2.5.1

Interfaces may also be used to specify required Interfaces, which are specified by a Usage dependency between the BehavioredClassifier and the corresponding Interfaces.

Source

Unified Modeling Language 2.5.1

The set of Interfaces realized by a BehavioredClassifier are its provided Interfaces, which represent the services and obligations that instances of that BehavioredClassifier offer to their clients.

Source

Unified Modeling Language 2.5.1

The receptions compartment contains ownedReceptions ...

Source

Unified Modeling Language 2.5.1

The operations compartment of a Class contains notation for its ownedOperations ...

Source

Unified Modeling Language 2.5.1

The parametric diagram is a new SysML diagram type that describes the constraints among the properties associated with blocks. This diagram is used to integrate behavior and structure models with engineering analysis models such as performance, ...

Source

OMG Systems Modeling Language (SysML) 1.6

The requirement diagram is a new SysML diagram type. A requirement diagram provides a modeling construct for text- based requirements, and the relationship between requirements and other model elements that satisfy or verify them.

Source

OMG Systems Modeling Language (SysML) 1.6

Tabular representations, such as the allocation table, are used in SysML but are not considered part of the diagram taxonomy.

Source

OMG Systems Modeling Language (SysML) 1.6

Activity diagrams have also been modified via the activity extensions.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, the block definition diagram and internal block diagram are similar to the UML class diagram and composite structure diagram respectively, but include extensions ...

Source

OMG Systems Modeling Language (SysML) 1.6

SysML reuses many of the major diagram types of UML. In some cases, the UML diagrams are strictly reused, such as use case, sequence, state machine, and package diagrams, whereas in other cases they are modified so that they are consistent with SysML ...

Source

OMG Systems Modeling Language (SysML) 1.6

In the case of the profile diagram, profile definitions can be captured on a package diagram and the parametric diagram.

Source

OMG Systems Modeling Language (SysML) 1.6

SysML does not use all of the UML diagram types such as the object diagram, communication diagram, interaction overview diagram, timing diagram, deployment diagram, and profile diagram.

Source

OMG Systems Modeling Language (SysML) 1.6

For example “velocity” can be specified as the product of “length” to the power one times “time” to the power minus one, and subsequently “speed” can be specified as “velocity” to the power one.

Source

OMG Systems Modeling Language (SysML) 1.6

A DerivedQuantityKind may also be used to define a synonym kind of quantity for another kind of quantity.

Source

OMG Systems Modeling Language (SysML) 1.6

A DerivedQuantityKind is a QuantityKind that represents a kind of quantity that is defined as a product of powers of one or more other kinds of quantity.

Source

OMG Systems Modeling Language (SysML) 1.6

For example the measurement unit “metre per second” for “velocity” is specified as the product of “metre” to the power one times “second” to the power minus one.

Source

OMG Systems Modeling Language (SysML) 1.6

A DerivedUnit is a Unit that represents a measurement unit that is defined as a product of powers of one or more other measurement units.

Source

OMG Systems Modeling Language (SysML) 1.6

Two such InstanceSpecifications represent the same "measurement unit" if and only if their definitionURIs have values and their values are equal.

Source

OMG Systems Modeling Language (SysML) 1.6

The definitionURI of an InstanceSpecification classified by a kind of Unit identifies the particular "measurement unit" [VIM3-1.9] that the InstanceSpecification represents.

Source

OMG Systems Modeling Language (SysML) 1.6

Modelers specialize Unit as done in SysMLs QUDV model library or in a similar manner in other model libraries.

Source

OMG Systems Modeling Language (SysML) 1.6

Unit, or a specialization of it, classifies an InstanceSpecification to define a particular "measurement unit" in the sense of a "real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared ...

Source

OMG Systems Modeling Language (SysML) 1.6

Unit is defined as a non-abstract SysML Block defined in the SysML UnitAndQuantityKind model library.

Source

OMG Systems Modeling Language (SysML) 1.6

A unit may also specify less stable or precise ways to express some value, such as a cost expressed in some currency, or a severity rating measured by a numerical scale.

Source

OMG Systems Modeling Language (SysML) 1.6

A unit often relies on precise and reproducible ways to measure the unit. For example, a unit of length such as meter may be specified as a multiple of a particular wavelength of light.

Source

OMG Systems Modeling Language (SysML) 1.6

A Unit is a quantity in terms of which the magnitudes of other quantities that have the same quantity kind can be stated.

Source

OMG Systems Modeling Language (SysML) 1.6

The only valid use of a QuantityKind instance is to be referenced by the quantityKind property of a ValueType or Unit.

Source

OMG Systems Modeling Language (SysML) 1.6

Two such InstanceSpecifications represent the same "kind-of-quantity" if and only if their definitionURIs have values and their values are equal.

Source

OMG Systems Modeling Language (SysML) 1.6

The definitionURI of an InstanceSpecification classified by a kind of QuantityKind identifies the particular "kind-of-quantity" [VIM3-1.2] that the InstanceSpecification represents.

Source

OMG Systems Modeling Language (SysML) 1.6

Modelers specialize QuantityKind as done in SysMLs QUDV model library or in a similar manner in other model libraries.

Source

OMG Systems Modeling Language (SysML) 1.6

... a SysML value property is understood to correspond to the VIM concept of "quantity" defined as a "property of a phenomenon, body or substance, where the property has a magnitude that can be expressed as a number and a reference" [VIM3-1.1].

Source

OMG Systems Modeling Language (SysML) 1.6

QuantityKind, or a specialization of it, classifies an InstanceSpecification to define a particular "kind-of-quantity" in the sense of an "aspect common to mutually comparable quantities" [VIM3-1.2], ...

Source

OMG Systems Modeling Language (SysML) 1.6

QuantityKind is defined as a non-abstract SysML Block defined in the SysML UnitAndQuantityKind model library.

Source

OMG Systems Modeling Language (SysML) 1.6

A QuantityKind is a kind of quantity that may be stated by means of defined units. For example, the quantity kind of length may be measured by units of meters, kilometers, or feet.

Source

OMG Systems Modeling Language (SysML) 1.6

Slot::value : ValueSpecification [0..*]{ordered, subsets Element::ownedElement} ... The value or values held by the Slot.

Source

Unified Modeling Language 2.5.1

Slot::owningInstance : InstanceSpecification [1..1] ... The InstanceSpecification that owns this Slot.

Source

Unified Modeling Language 2.5.1

Slot::definingFeature : StructuralFeature [1..1] ... The StructuralFeature that specifies the values that may be held by the Slot.

Source

Unified Modeling Language 2.5.1

A Slot designates that an entity modeled by an InstanceSpecification has a value or values for a specific StructuralFeature.

Source

OMG Systems Modeling Language (SysML) 1.6

InstanceSpecification::specification : ValueSpecification [0..1] ... A specification of how to compute, derive, or construct the instance.

Source

Unified Modeling Language 2.5.1

InstanceSpecification::slot : Slot [0..*] ... It is not necessary to model a Slot for every StructuralFeature, in which case the InstanceSpecification is a partial description.

Source

Unified Modeling Language 2.5.1

InstanceSpecification::slot : Slot [0..*] ... A Slot giving the value or values of a StructuralFeature of the instance. An InstanceSpecification can have one Slot per StructuralFeature of its Classifiers, including inherited features. ...

Source

Unified Modeling Language 2.5.1

InstanceSpecification::classifer : Classifier [0..*] ... The Classifier or Classifiers of the represented instance. If multiple Classifiers are specified, the instance is classified by all of them.

Source

Unified Modeling Language 2.5.1

An InstanceSpecification can act as a DeploymentTarget in a Deployment relationship, in the case that it represents an instance of a Node. It can also act as a DeployedArtifact, if it represents an instance of an Artifact.

Source

Unified Modeling Language 2.5.1

An InstanceSpecification is a model element that represents an instance in a modeled system.

Source

Unified Modeling Language 2.5.1

A Complex value type represents the mathematical concept of a complex number. A complex number consists of a real part defined by a real number, and an imaginary part defined by a real number multiplied by the square root of -1 ...

Source

OMG Systems Modeling Language (SysML) 1.6

A DataType may be parameterized, bound, and used as TemplateParameters.

Source

Unified Modeling Language 2.5.1

Instances of a structured DataType are considered to be equal if and only if the structure is the same and the values of the corresponding attributes are equal.

Source

Unified Modeling Language 2.5.1

If a DataType has attributes (i.e., Properties owned by it and in its namespace) it is called a structured DataType. Instances of a structured DataType contain attribute values matching its attributes.

Source

Unified Modeling Language 2.5.1

A DataType is a kind of Classifier. DataType differs from Class in that instances of a DataType are identified only by their value. All instances of a DataType with the same value are considered to be equal instances.

Source

Unified Modeling Language 2.5.1

Block::isEncapsulated : Boolean [0..1] ... If false, or if a value is not present, then connections can be established to elements of its internal structure via deep-nested connector ends.

Source

OMG Systems Modeling Language (SysML) 1.6

Block::isEncapsulated : Boolean [0..1] If true, then the block is treated as a black box; a part typed by this black box can only be connected via its ports or directly to its outer boundary.

Source

OMG Systems Modeling Language (SysML) 1.6

Delegation Connectors can be used to model the hierarchical decomposition of behavior, where services provided by an EncapsulatedClassifier may ultimately be realized by one that is nested multiple levels deep within it.

Source

Unified Modeling Language 2.5.1

A request that arrives at a Port that has a delegation Connector to one or more Properties or Ports on Properties will be passed on to those targets for handling.

Source

Unified Modeling Language 2.5.1

A delegation Connector is a Connector that links a Port to a role within the owning EncapsulatedClassifier. It represents the forwarding of requests (Operation invocations and Signals).

Source

Unified Modeling Language 2.5.1

Such a Port is called a behavior Port. If there is no Behavior defined for this EncapsulatedClassifier, any communication arriving at a behavior Port is lost.

Source

Unified Modeling Language 2.5.1

A Port has the ability, by setting the property isBehavior to true, to specify that any requests arriving at this Port are handled by the Behavior of the instance of the owning EncapsulatedClassifier, rather than being forwarded to any contained instances

Source

Unified Modeling Language 2.5.1

Connectors may be drawn that cross the boundaries of nested properties to connect to properties within them. The connector is owned by the most immediate block that owns both ends of the connector.

Source

OMG Systems Modeling Language (SysML) 1.6

In contrast to Associations, which specify links between any instance of the associated Classifiers, Connectors specify links between instances playing the connected parts only.

Source

Unified Modeling Language 2.5.1

A Connector specifies links that enables communication between two or more instances.

Source

Unified Modeling Language 2.5.1

A ConnectorEnd is an endpoint of a Connector, which attaches the Connector to a ConnectableElement.

Source

Unified Modeling Language 2.5.1

Each Connector may be attached to two or more ConnectableElements, each representing a set of instances that contribute to the instantiation of the containing StructuredClassifier.

Source

Unified Modeling Language 2.5.1

In contrast to Associations, which specify links between any suitably-typed instance of the associated Classifiers, Connectors specify links between instances playing the connected roles only.

Source

Unified Modeling Language 2.5.1

Each link may be realized by something as simple as a pointer or by something as complex as a network connection, and may represent the possibility of instances being able to communicate because their identities are known by virtue of being passed in ...

Source

Unified Modeling Language 2.5.1

A Connector specifies links ... between two or more instances playing owned or inherited roles within a StructuredClassifier.

Source

Unified Modeling Language 2.5.1

A Usage is a Dependency in which the client Element requires the supplier Element (or set of Elements) for its full implementation or operation.

Source

Unified Modeling Language 2.5.1

This means that the complete semantics of the client Element(s) are either semantically or structurally dependent on the definition of the supplier Element(s).

Source

Unified Modeling Language 2.5.1

A Dependency is a Relationship that signifies that a single model Element or a set of model Elements requires other model Elements for their specification or implementation.

Source

Unified Modeling Language 2.5.1

If a Property has a specified default, and the Property redefines another Property with a specified default, then the redefining Property’s default is used in place of the more general default from the redefined Property.

Source

Unified Modeling Language 2.5.1

A derived Property may redefine one which is not derived. An implementation shall ensure that the constraints implied by the derivation are maintained if the Property is updated.

Source

Unified Modeling Language 2.5.1

Property is indirectly a kind of RedefinableElement, so Properties may be redefined. The name and visibility of a Property are not required to match those of any Property it redefines.

Source

Unified Modeling Language 2.5.1

Four general categories of properties of blocks are recognized in SysML: parts, references, value properties, and constraint properties.

Source

OMG Systems Modeling Language (SysML) 1.6

Properties of any type may be shown in a "properties" compartment or in additional compartments with user-defined labels.

Source

OMG Systems Modeling Language (SysML) 1.6

Part, reference, value, and constraint properties may be shown in block definition compartments with the labels "parts," "references," "values," and "constraints" respectively.

Source

OMG Systems Modeling Language (SysML) 1.6

A property typed by a SysML ValueType is classified as a value property, and always has composite aggregation.

Source

OMG Systems Modeling Language (SysML) 1.6

A property typed by a SysML Block that has composite aggregation is classified as a part property, except for the special case of a constraint property ...

Source

OMG Systems Modeling Language (SysML) 1.6

A property typed by a Block that does not have composite aggregation is classified as a reference property.

Source

OMG Systems Modeling Language (SysML) 1.7beta1

Constraint properties are further defined in Clause 10. A port is another category of property, as further defined in Section 9.

Source

OMG Systems Modeling Language (SysML) 1.6

SysML establishes four basic classifications of properties belonging to a SysML Block or ValueType.

Source

OMG Systems Modeling Language (SysML) 1.6

Classifier::isAbstract : Boolean [1..1] If true, the Classifier can only be instantiated by instantiating one of its specializations. An abstract Classifier is intended to be used by other Classifiers e.g., as the target of Associations or Generalizations

Source

Unified Modeling Language 2.5.1

SysML blocks can be used throughout all phases of system specification and design, and can be applied to many different kinds of systems.

Source

OMG Systems Modeling Language (SysML) 1.6

Constraint Properties are a special class of property used to constrain other properties of blocks...

Source

OMG Systems Modeling Language (SysML) 1.6

Ports are a special class of property used to specify allowable types of interactions between blocks ...

Source

OMG Systems Modeling Language (SysML) 1.6

A block can include properties to specify its values, parts, and references to other blocks.

Source

OMG Systems Modeling Language (SysML) 1.6

The Internal Block Diagram in SysML captures the internal structure of a block in terms of properties and connectors between properties.

Source

OMG Systems Modeling Language (SysML) 1.6

It captures the definition of blocks in terms of properties and operations, and relationships such as a system hierarchy or a system classification tree

Source

OMG Systems Modeling Language (SysML) 1.6

The Block Definition Diagram in SysML defines features of blocks and relationships between blocks such as associations, generalizations, and dependencies.

Source

OMG Systems Modeling Language (SysML) 1.6

Parts in these systems may interact by many different means, such as software operations, discrete state transitions, flows of inputs and outputs, or continuous interactions.

Source

OMG Systems Modeling Language (SysML) 1.6

These include modeling either the logical or physical decomposition of a system, and the specification of software, hardware, or human elements.

Source

OMG Systems Modeling Language (SysML) 1.6

The specific kinds of components, the kinds of connections between them, and the way these elements combine to define the total system can all be selected according to the goals of a particular system model.

Source

OMG Systems Modeling Language (SysML) 1.6

Blocks provide a general-purpose capability to model systems as trees of modular components.

Source

OMG Systems Modeling Language (SysML) 1.6

Each block defines a collection of features to describe a system or other element of interest. These may include both structural and behavioral features, such as properties and operations, to represent the state of the system and behavior ...

Source

OMG Systems Modeling Language (SysML) 1.6

Blocks are modular units of system description.

Source

OMG Systems Modeling Language (SysML) 1.6

Although SysML indirectly imports the UML 2 PrimitiveTypes library ... due to the transitivity of package import, SysML provides a PrimitiveValueTypes model library that systems engineers can extend via SysML’s ValueType stereotype.

Source

OMG Systems Modeling Language (SysML) 1.6

Stakeholder::concernList : Comment [0..*]

Source

OMG Systems Modeling Language (SysML) 1.6

Stakeholder::/concern : String [0..*] (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

A Conform relationship is a generalization between a view and a viewpoint. The view conforms to the specified rules and conventions detailed in the viewpoint. When this is done, the view is said to conform to the viewpoint.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::stakeholder : Stakeholder [0..*] Set of stakeholders whose concerns are to be addressed by the viewpoint.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::purpose : String [1] The purpose addresses the stakeholder concerns.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::presentation : String [0..*] The specifications prescribed for formatting and styling the view.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::/method : Behavior [0..*] The behavior is derived from the method of the operation with the Create stereotype. (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::language : String [0..*] The languages used to express the models that represent content which is represented by the view. The language specification such as its metamodel, profile, or other language specification is referred to by its URI.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::concernList : Comment [0..*] The interests of the stakeholders addressed by this viewpoint.

Source

OMG Systems Modeling Language (SysML) 1.6

Viewpoint::/concern : String [0..*] The interest of the stakeholders displayed as the body of the comments from concernList. (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

For example, the security viewpoint may require the security requirements, security functional and physical architecture, and security test cases.

Source

OMG Systems Modeling Language (SysML) 1.6

A Viewpoint is a specification of the conventions and rules for constructing and using a view for the purpose of addressing a set of stakeholder concerns. They specify the elements expected to be represented in the view...

Source

OMG Systems Modeling Language (SysML) 1.6

Just like a Class, a Stereotype may have Properties, which have traditionally been referred to as Tag Definitions. When a Stereotype is applied to a model element, the values of the Properties have traditionally been referred to as tagged values.

Source

Unified Modeling Language 2.5.1

A Comment is shown as a rectangle with the upper right corner bent (this is also known as a “note symbol”). The rectangle contains the body of the Comment. The connection to each annotatedElement is shown by a separate dashed line.

Source

Unified Modeling Language 2.5.1

ElementGroup::/size : Integer [1] Number of members in the group. Derived. (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

ElementGroup::orderedMember : Element [0..*] Organize member according to an arbitrary order. Optional. (subsets: ElementGroup::member)

Source

OMG Systems Modeling Language (SysML) 1.6

ElementGroup::name : String [1] Name of the element group

Source

OMG Systems Modeling Language (SysML) 1.6

ElementGroup::/member : Element [0..*] Set specifying the members of the group. Derived from Comment::annotatedElement. (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

ElementGroup::/criterion : String [0..1] Specifies the rationale for being member of the group. Adding an element to the group asserts that the criterion applies to this element. Derived from Comment::body. (derived)

Source

OMG Systems Modeling Language (SysML) 1.6

Element groups can be members of other element groups, but this does not imply that members of the first are members of the second.

Source

OMG Systems Modeling Language (SysML) 1.6

The elements in a group are identified by the modeler, as opposed to being the result of a query, as in views.

Source

OMG Systems Modeling Language (SysML) 1.6

Element groups do not own their elements and thus an element can participate in an unlimited number of groups.

Source

OMG Systems Modeling Language (SysML) 1.6

Grouped elements are the annotated elements of the comment to which the stereotype is applied. This has several implications:

Source

OMG Systems Modeling Language (SysML) 1.6

ElementGroups appear in diagrams as comments, and properties of the stereotype appear in the notation for stereotype properties.

Source

OMG Systems Modeling Language (SysML) 1.6

Optionally, members of an element group can be ordered using its orderedMember property.

Source

OMG Systems Modeling Language (SysML) 1.6

The criterion for membership in an element group is specified by the body of the comment the stereotype is applied to. By grouping elements, the modeler asserts that the criterion of the group applies to the member.

Source

OMG Systems Modeling Language (SysML) 1.6

Element groups are named using the name property.

Source

OMG Systems Modeling Language (SysML) 1.6

The semantics of ElementGroup is modeler-defined. In particular, the body text is not restricted. It can describe the grouped elements as well as elements or values related to the grouped elements.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, it can group elements that are associated with a particular release of the model, have a certain risk level, or are associated with a legacy design.

Source

OMG Systems Modeling Language (SysML) 1.6

The ElementGroup stereotype provides a lightweight mechanism for grouping various and possibly heterogeneous model elements by extending the capability of comments to refer to multiple annotated elements.

Source

OMG Systems Modeling Language (SysML) 1.6

AllocateActivityPartition::2_not_uml_semantics ... Classifiers or Properties represented by an «AllocateActivityPartition» do not have any direct responsibility for invoking behavior depicted within the partition boundaries. ...

Source

OMG Systems Modeling Language (SysML) 1.6

AllocateActivityPartition::2_not_uml_semantics The «AllocateActivityPartition» shall maintain the constraints, but not the semantics, of the UML::ActivityPartition.

Source

OMG Systems Modeling Language (SysML) 1.6

A typical example is the allocation of activities to blocks (e.g., functions to components)

Source

OMG Systems Modeling Language (SysML) 1.6

... does not try to limit the use of the term “allocation,” but provides a basic capability to support allocation in the broadest sense. It does include some specific subclasses of allocation for allocating behavior, structure, and flows.

Source

OMG Systems Modeling Language (SysML) 1.6

The allocation relationship can provide an effective means for navigating the model by establishing cross relationships, and ensuring the various parts of the model are properly integrated.

Source

OMG Systems Modeling Language (SysML) 1.6

System modelers often associate various elements in a user model in abstract, preliminary, and sometimes tentative ways. Allocations can be used early in the design as a precursor to more detailed rigorous specifications and implementations.

Source

OMG Systems Modeling Language (SysML) 1.6

The concept of “allocation” requires flexibility suitable for abstract system specification, rather than a particular constrained method of system or software design.

Source

OMG Systems Modeling Language (SysML) 1.6

Allocation is the term used by systems engineers to denote the organized cross-association (mapping) of elements within the various structures or hierarchies of a user model.

Source

OMG Systems Modeling Language (SysML) 1.6

UseCases need not be owned by their subject.

Source

Unified Modeling Language 2.5.1

A UseCase may be owned either by a Package or by a Classifier. Although the owning Classifier typically represents a subject to which the owned UseCases apply, this is not necessarily the case ...

Source

Unified Modeling Language 2.5.1

Two UseCases specifying the same subject cannot be associated as each of them individually describes a complete usage of the subject.

Source

Unified Modeling Language 2.5.1

UseCases may have associated Actors, which describe how an instance of the Classifier realizing the UseCase and a user playing one of the roles of the Actor interact.

Source

Unified Modeling Language 2.5.1

It may also be described indirectly through a Collaboration that uses the UseCase and its Actors as the Classifiers that type its parts.

Source

Unified Modeling Language 2.5.1

The behaviors of a UseCase can be described by a set of Behaviors (through its ownedBehavior relationship), such as Interactions, Activities, and StateMachines, as well as by pre-conditions, post-conditions and natural language text where appropriate.

Source

Unified Modeling Language 2.5.1

Moreover, the UseCases may also state the requirements the specified subject poses on its environment by defining how the Actors should interact with the subject so that it will be able to perform its services.

Source

Unified Modeling Language 2.5.1

UseCases can be used both for specification of the (external) requirements on a subject and for the specification of the functionality offered by a subject.

Source

Unified Modeling Language 2.5.1

It is deemed complete if, after its execution, the subject will be in a state in which no further inputs or actions are expected and the UseCase can be initiated again, or in an error state.

Source

Unified Modeling Language 2.5.1

Each UseCase specifies a unit of useful functionality that the subject provides to its users (i.e., a specific way of interacting with the subject). This functionality must always be completed for the UseCase to complete.

Source

Unified Modeling Language 2.5.1

A subject of a UseCase could be a system or any other element that may have behavior, such as a Component or Class.

Source

Unified Modeling Language 2.5.1

A UseCase can include possible variations of its basic behavior, including exceptional behavior and error handling.

Source

Unified Modeling Language 2.5.1

UseCases define the offered Behaviors of the subject without reference to its internal structure. These Behaviors, involving interactions between the Actors and the subject, may result in changes to the state of the subject and communications with its...

Source

Unified Modeling Language 2.5.1

A UseCase is a kind of BehavioredClassifier that represents a declaration of a set of offered Behaviors. Each UseCase specifies some behavior that a subject can perform in collaboration with one or more Actors.

Source

Unified Modeling Language 2.5.1

A UseCase may apply to any number of subjects. When a UseCase applies to a subject, it specifies a set of behaviors performed by that subject, which yields an observable result that is of value for Actors or other stakeholders of the subject.

Source

Unified Modeling Language 2.5.1

AbstractRequirement::/master : AbstractRequirement [0..*] This is a derived property that lists the master requirement for this slave requirement. The master attribute is derived from the supplier of the Copy dependency ...

Source

OMG Systems Modeling Language (SysML) 1.6

The master/slave relationship is indicated by the use of the copy relationship.

Source

OMG Systems Modeling Language (SysML) 1.6

A slave requirement is a requirement whose text property is a read-only copy of the text property of a master requirement. The text property of the slave requirement is constrained to be the same as the text property of the related master requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

Since the concept of requirements reuse is very important in many applications, SysML introduces the concept of a slave requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

The use of namespace containment to specify requirements hierarchies precludes reusing requirements in different contexts since a given model element can only exist in one namespace.

Source

OMG Systems Modeling Language (SysML) 1.6

Context blocks are typically the owner of the first property in the path of properties, but can be specializations of the owner to limit the scope of the relationship.

Source

OMG Systems Modeling Language (SysML) 1.6

The DirectedRelationshipPropertyPath stereotype based on UML DirectedRelationship enables directed relationships to identify their sources and targets by a multi-level path of properties accessible from context blocks for the sources and targets.

Source

OMG Systems Modeling Language (SysML) 1.6

Trace::getTracedFrom (in ref : NamedElement) : AbstractRequirement [0..*] The query getTracedFrom() gives all the requirements that are clients ("from" end of the concrete syntax) of a «Trace» relationship whose supplier is the element in parameter ...

Source

OMG Systems Modeling Language (SysML) 1.6

AbstractRequirement::/tracedTo : NamedElement [0..*] Derived from all elements that are the client of a «trace» relationship for which this requirement is a supplier. (derived) [ERROR]

Source

OMG Systems Modeling Language (SysML) 1.6

Refine::getRefines (in ref : NamedElement) : AbstractRequirement [0..*] The query getRefines() gives all the requirements that are suppliers ("to"end of the concrete syntax) of a «Refine» relationships whose client is the element in parameter ...

Source

OMG Systems Modeling Language (SysML) 1.6

A Class has four mandatory compartments: attributes, operations, receptions ... and internal structure ... A Class may also have optional compartments as described for Classifiers in general

Source

Unified Modeling Language 2.5.1

A Class is shown using the Classifier symbol. As Class is the most widely used Classifier, no keyword is needed to indicate that the metaclass is Class.

Source

Unified Modeling Language 2.5.1

The Trace stereotype specializes UML4SysML Trace and DirectedRelationshipPropertyPath to enable traces to identify their sources and targets by a multi-level path of accessible properties from context blocks for the sources and targets.

Source

OMG Systems Modeling Language (SysML) 1.6

A Verify relationship is a dependency between a requirement and a test case or other model element that can determine whether a system fulfills the requirement. As with other dependencies, the arrow direction points from the (client) element to the (suppl

Source

OMG Systems Modeling Language (SysML) 1.6

Examples of additional non-normative stereotypes based on AbstractRequirement are included in E.8.

Source

OMG Systems Modeling Language (SysML) 1.6

The only normative stereotype based on AbstractRequirement is the Requirement stereotype, ...

Source

OMG Systems Modeling Language (SysML) 1.6

An AbstractRequirement establishes the attributes and relationships essential to any potential kind of requirement. Any intended requirement kind should subclass AbstractRequirement.

Source

OMG Systems Modeling Language (SysML) 1.6

An entire specification can be decomposed into children requirements, which can be further decomposed into their children to define the requirements hierarchy.

Source

OMG Systems Modeling Language (SysML) 1.6

A composite requirement may state that the system shall do A and B and C, which can be decomposed into the child requirements that the system shall do A, the system shall do B, and the system shall do C

Source

OMG Systems Modeling Language (SysML) 1.6

A composite requirement can contain subrequirements in terms of a requirements hierarchy, specified using the UML namespace containment mechanism. This relationship enables a complex requirement to be decomposed into its containing child requirements.

Source

OMG Systems Modeling Language (SysML) 1.6

These include relationships for defining a requirements hierarchy, deriving requirements, satisfying requirements, verifying requirements, and refining requirements.

Source

OMG Systems Modeling Language (SysML) 1.6

Several requirements relationships are specified that enable the modeler to relate requirements to other requirements as well as to other model elements.

Source

OMG Systems Modeling Language (SysML) 1.6

A standard requirement includes properties to specify its unique identifier and text requirement. Additional properties such as verification status, can be specified by the user.

Source

OMG Systems Modeling Language (SysML) 1.6

A requirement is defined as a stereotype of UML Class subject to a set of constraints.

Source

OMG Systems Modeling Language (SysML) 1.6

The requirements modeling constructs are intended to provide a bridge between traditional requirements management tools and the other SysML models.

Source

OMG Systems Modeling Language (SysML) 1.6

The requirements diagram described in this clause can depict the requirements in graphical, tabular, or tree structure format. A requirement can also appear on other diagrams to show its relationship to other modeling elements.

Source

OMG Systems Modeling Language (SysML) 1.6

SysML provides modeling constructs to represent text-based requirements and relate them to other modeling elements.

Source

OMG Systems Modeling Language (SysML) 1.6

A requirement specifies a capability or condition that must (or should) be satisfied. A requirement may specify a function that a system must perform or a performance condition a system must achieve.

Source

OMG Systems Modeling Language (SysML) 1.6

However, full ports can be linked to non-full ports by binding connectors, because this does not necessarily imply identity with other parts of the system.

Source

OMG Systems Modeling Language (SysML) 1.6

They cannot be behavioral ports, or [be] linked to internal parts by binding connectors, because these constructs imply identity with the owning block or internal parts.

Source

OMG Systems Modeling Language (SysML) 1.6

Full ports specify a separate element of the system from the owning block or its internal parts. They might have their own internal parts and behaviors to support interaction with the owning block, its internal parts, or external blocks.

Source

OMG Systems Modeling Language (SysML) 1.6

The rest of the connectors linked to a port are external.

Source

OMG Systems Modeling Language (SysML) 1.6

Internal connectors to ports are the ones inside the ports owner (specifically, they are the ones that do not have a UML partwithPort on the connector end linked to the port, assuming NestedConnectorEnd is not applied to that end, or if NestedConnectorEnd

Source

OMG Systems Modeling Language (SysML) 1.6

However, blocks can be defined with non-behavioral proxy ports that do not have internal connectors, with the expectation that these will be added in specialized blocks.

Source

OMG Systems Modeling Language (SysML) 1.6

This can be achieved in several ways. For instance by making it behavioral, by binding it to a fully specified internal part or by having all its properties individually bound to internal parts.

Source

OMG Systems Modeling Language (SysML) 1.6

A completely specified proxy port shall describe how any interaction through the port is handled or initiated.

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy ports do not specify their own behaviors or internal parts, and shall be typed by interface blocks. Their nested ports shall also be proxy ports.

Source

OMG Systems Modeling Language (SysML) 1.6

Internal connectors to proxy ports can be typed by association blocks, including when the connector is binding. Association

Source

OMG Systems Modeling Language (SysML) 1.6

This aggregate is not a separate element of the system, and only groups the internal parts for purposes of binding to the proxy port.

Source

OMG Systems Modeling Language (SysML) 1.6

When a proxy port is connected to multiple internal parts, the connectors have the same semantics as a single binding connector to an aggregate of those parts, supporting all their features, and treating flows and invocations from outside the aggregate...

Source

OMG Systems Modeling Language (SysML) 1.6

(the value of the proxy port and the connected internal part are the same; links of associations typing the connector are between all objects and themselves, and no others)

Source

OMG Systems Modeling Language (SysML) 1.6

When a proxy port is connected to a single internal part [or port or internal part], the connector shall be a binding connector, or have the same semantics as a binding connector ...

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy ports can be connected to internal parts or ports on internal parts, identifying features on those parts or ports that are available to external blocks.

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy ports identify features of the owning block or its internal parts that are available to external blocks through external connectors to the ports. They do not specify a separate element of the system from the owning block or internal parts.

Source

OMG Systems Modeling Language (SysML) 1.6

If the general ports had both behaviors and internal binding connectors, then both specializations would be invalid.

Source

OMG Systems Modeling Language (SysML) 1.6

Unstereotyped ports have the basic functionality of stereotyped ones, including flow properties and nested ports, so they can be used as long as the modeler is not concerned with the distinction between proxy and full, and the constraints they impose.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, if the port types on the general block in Figure 9-7 had behaviors defined, then the proxy specialization would be invalid. If the general ports had binding connectors to internal parts, then the full specialization would be invalid.

Source

OMG Systems Modeling Language (SysML) 1.6

Unstereotyped ports do not commit to whether they are proxy or full, and do not prevent or dictate future application of the stereotypes, except for ports that violate constraints of the stereotypes.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 9-7 happens to use unstereotyped ports on a general block distributed to users, and stereotyped ports on its specializations for implementation, but the modelers might have not used stereotypes at all, if they did not care whether the model met ...

Source

OMG Systems Modeling Language (SysML) 1.6

Modelers can apply stereotypes for proxy and full ports at any stage of model development, or not all if the stereotype constraints are not needed.

Source

OMG Systems Modeling Language (SysML) 1.6

The stereotypes of proxy and full ports might be elided in these cases to simplify diagrams.

Source

OMG Systems Modeling Language (SysML) 1.6

Using existing blocks with ports only requires knowing the port types, because they define the features available for linking or communication with those ports via connectors.

Source

OMG Systems Modeling Language (SysML) 1.6

Modelers have the option of applying stereotypes for proxy and full ports to indicate whether ports are specifying features of their owners and internal parts (proxy), or for themselves separately (full). This is a concern when defining ports, rather ...

Source

OMG Systems Modeling Language (SysML) 1.6

Modelers can choose between proxy or full ports at any time in the development lifecycle, or not at all, depending on their methodology.

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy and full ports support the capabilities of ports in general, but these capabilities are also available on ports that are not declared as proxy or full.

Source

OMG Systems Modeling Language (SysML) 1.6

In either case, users of a block are only concerned with the features of its ports, regardless of whether the features are surfaced by proxy ports, or handled by full ports directly.

Source

OMG Systems Modeling Language (SysML) 1.6

Ports that are not specified as proxy or full are simply called “ports.”

Source

OMG Systems Modeling Language (SysML) 1.6

Full ports cannot be behavioral in the UML sense of standing in for the owning object, because they handle features themselves, rather than exposing features of their owners, or internal parts of their owners.

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy ports are always typed by interface blocks, a specialized kind of block that has no behaviors or internal parts.

Source

OMG Systems Modeling Language (SysML) 1.6

Proxy ports define the boundary by specifying which features of the owning block or internal parts are visible through external connectors, while full ports define the boundary with their own features.

Source

OMG Systems Modeling Language (SysML) 1.6

Both are ways of defining the boundary of the owning block as features available through external connectors to ports.

Source

OMG Systems Modeling Language (SysML) 1.6

SysML identifies two [EDIT:ADDITIONAL] usage patterns for ports, one where ports act as proxies for their owning blocks or its internal parts (proxy ports), and another where ports specify separate elements of the system (full ports).

Source

OMG Systems Modeling Language (SysML) 1.6

All ports and nested ports (i.e., proxy, full, and ports with no stereotype applied), and their type definitions (e.g., interface blocks, blocks) can include compartments with textual and graphical representations to display their features ...

Source

OMG Systems Modeling Language (SysML) 1.6

Ports are specialized kinds of properties, and can be shown in same way as other properties. They can appear in block compartments in the same format as other properties of their owning blocks, or as the ends of associations, with the port appearing ...

Source

OMG Systems Modeling Language (SysML) 1.6

Ports that are not proxy or full can appear in block compartments labeled ports.

Source

OMG Systems Modeling Language (SysML) 1.6

Port rectangles can have port rectangles overlapping their boundaries, to notate a port type that has ports (nested ports).

Source

OMG Systems Modeling Language (SysML) 1.6

Nested ports that are not on proxy ports can appear anywhere on the boundary of the owning port rectangle that does not overlap the boundary of the rectangle the owning port overlaps.

Source

OMG Systems Modeling Language (SysML) 1.6

The item flow in each case specifies what “does” flow on the connector in the particular usage (e.g., gas, water) and the flow property specifies what can flow (e.g., fluid). This enables type matching between the item flows and between flow properties...

Source

OMG Systems Modeling Language (SysML) 1.6

For example, tanks might include a flow property that can accept fluid as an input. In a particular use of tanks, “gasoline” flows across a connector into a tank, and in another use of tanks, “water” flows across a connector into a tank.

Source

OMG Systems Modeling Language (SysML) 1.6

This important distinction enables blocks to be interconnected in different ways depending on its usage context.

Source

OMG Systems Modeling Language (SysML) 1.6

Whereas flow properties specify what “can” flow in or out of a block, item flows specify what “does” flow between blocks and/or parts in a particular usage context.

Source

OMG Systems Modeling Language (SysML) 1.6

Item flows specify the things that flow between blocks and/or parts and across associations or connectors.

Source

OMG Systems Modeling Language (SysML) 1.6

The itemProperty attribute has no values if the item flow is realized by an Association.

Source

OMG Systems Modeling Language (SysML) 1.6

ItemFlow::itemProperty : Property [0..1] An optional property that relates the flowing item to the instances of the connectors enclosing block. This property is applicable only for item flows realized by connectors. The itemProperty attribute has no ...

Source

OMG Systems Modeling Language (SysML) 1.6

The target flow property type shall be the same as, or a generalization of, a classifier of the item flow or the source flow property type, whichever is more specialized.

Source

OMG Systems Modeling Language (SysML) 1.6

Each classifier of conveyed items on an item flow shall be the same as, a specialization of, or a generalization of at least one flow property type on each end of the connected block usages (or their accessible nested block usages recursively, ...

Source

OMG Systems Modeling Language (SysML) 1.6

Item flows on connectors shall be compatible with flow properties of the blocks usages at each end of the connector, if any. The direction of the item flow shall be compatible with the direction of flow specified by the flow properties.

Source

OMG Systems Modeling Language (SysML) 1.6

Item properties are owned by the common (possibly indirect) owner of the source and target of the item flow, rather than by the source and target types, as flow properties are.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, a label of "liquid: Water" means Water items might flow and these items are the values of the property "liquid," i.e., the values of the "liquid" item property are the instances of Water flowing at any given time.

Source

OMG Systems Modeling Language (SysML) 1.6

In addition, if the item flow identifies an item property, then one can label the item flow with the item property.

Source

OMG Systems Modeling Language (SysML) 1.6

One can label an ItemFlow with the classifiers of the items that may be conveyed. For example: a label Water would imply that instances of Water might be transmitted over this ItemFlow.

Source

OMG Systems Modeling Language (SysML) 1.6

To signify that only water flows between the pump and the tank, we can specify an ItemFlow of type Water on the connector.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, a pump connected to a tank: the pump has an "out" flow property of type Liquid and the tank has an "in" FlowProperty of type Liquid.

Source

OMG Systems Modeling Language (SysML) 1.6

An ItemFlow describes the flow of items across a connector or an association. It may constrain the item exchange between blocks, block usages, or ports as specified by their flow properties.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, the ports supporting torque flows in the transmission example might have nested ports for physical links to the engine or the driveshaft.

Source

OMG Systems Modeling Language (SysML) 1.6

Ports nest other ports in the same way that blocks nest other blocks. The type of the port is a block (or one of its specializations) that also has ports.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, a block might provide particular services to other blocks as operations, or have a particular geometry accessible to other block, or it might require services and geometries of other blocks.

Source

OMG Systems Modeling Language (SysML) 1.6

Required and provided features are operations, receptions, and non-flow properties that a block supports for other blocks to use, or requires other blocks to support for its own use, or both.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, a block specifying a car’s automatic transmission could have a flow property for Torque as an input, and another flow property for Torque as an output.

Source

OMG Systems Modeling Language (SysML) 1.6

Provided behavioral features are invoked with the owning block as target, while required behavioral features are invoked with an external block as target (required).

Source

OMG Systems Modeling Language (SysML) 1.6

Provided non-flow properties are read and written on the owning block, while required non-flow properties are read or written on an external block

Source

OMG Systems Modeling Language (SysML) 1.6

Using non-flow properties means to read or write them, and using behavioral features means to invoke them.

Source

OMG Systems Modeling Language (SysML) 1.6

(the owning block for features on types of proxy ports is the type of the block usage the proxy port is standing in for, which might be an internal part).

Source

OMG Systems Modeling Language (SysML) 1.6

[SysML1.6: PREFER SysML1.7] A DirectedFeature indicates whether the feature is supported by the owning block (provided), or is to be supported by other blocks for the owning block to use (required), or both ...

Source

OMG Systems Modeling Language (SysML) 1.6

~InterfaceBlock::original : InterfaceBlock [1] The InterfaceBlock that this is a conjugation of.

Source

OMG Systems Modeling Language (SysML) 1.6

Conjugation is specified by a constraint giving the features of ~InterfaceBlocks according to those of their original InterfaceBlocks ... It is expected that tools conforming to this specification automatically create features of ~InterfaceBlocks.

Source

OMG Systems Modeling Language (SysML) 1.6

InterfaceBlock ... for example, in flow properties are conjugated as out flow properties and provided features are conjugated as required features.

Source

OMG Systems Modeling Language (SysML) 1.6

The ~InterfaceBlock stereotype (shall be pronounced: "conjugated interface block") is a specialization of InterfaceBlock that has the same features as its original InterfaceBlock except that its DirectedFeatures and FlowProperties are reversed (conjugated

Source

OMG Systems Modeling Language (SysML) 1.6

Then it is delivered to a factory, reclassified from a warehouse item to a factory resource (while still being a machine), and records the percentage of time it is operating.

Source

OMG Systems Modeling Language (SysML) 1.6

At first it is not an item or resource and is classified only as a machine. Before delivery to the factory, a new machine is stored in a warehouse, classified additionally as a warehouse item, and is assigned a storage location.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 8-23 shows the classification of a particular machine over time, identified by its serial number.

Source

OMG Systems Modeling Language (SysML) 1.6

The properties disappear once an item leaves a warehouse or a resource is no longer used in a factory, because they are declassified as WarehouseItems and FactoryResources at that time, respectively.

Source

OMG Systems Modeling Language (SysML) 1.6

The properties appear when an item arrives in a warehouse or a resource is used in a factory, because they are classified as WarehouseItems and FactoryResources at that time, respectively

Source

OMG Systems Modeling Language (SysML) 1.6

Items in warehouses are assigned a location, while resources in factories indicate own much they are being used as a percentage of time. Only objects that are items in warehouses or resources in factories have these location and utilization properties.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 8-22 shows property-specific types in a model of facilities that includes factories and warehouses. Items flow through facilities, while resources operate on items.

Source

OMG Systems Modeling Language (SysML) 1.6

The PropertySpecificType stereotype can be applied to classifiers that type exactly one property and that are owned by the owner of that property. Classifiers with this stereotype applied shall be generalized by at most one other classifier.

Source

OMG Systems Modeling Language (SysML) 1.6

The Verify relationship is shown on Figure 16-7 using callout notation anchored to the diagram frame, which indicates that the BurnishTest test case verifies the Burnish requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 17-1 [Figure 16-7] is a state machine diagram of the BurnishTest test case, which expresses the textual sequence and criteria of the Burnish requirement in state machine form.

Source

OMG Systems Modeling Language (SysML) 1.6

The Burnish requirement is shown as having a Verify relationship to the BurnishTest test case using callout notation on the diagram, indicating that the Burnish requirement is verified by the BurnishTest test case.

Source

OMG Systems Modeling Language (SysML) 1.6

The example in Figure 16-6 is taken from the automotive safety domain, and shows a Burnish requirement contained in the NHTSASafetyRequirements requirement. Note that the text of the Burnish requirement indicates a specific sequence of steps and transitio

Source

OMG Systems Modeling Language (SysML) 1.6

A test case is a method for verifying a requirement is satisfied.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 16-5 illustrates the use of the Copy dependency to allow a single requirement to be reused in several requirements hierarchies. The master tag provides a textual reference to the reused requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

A Copy dependency created between two requirements maintains a master/slave relationship between the two elements for the purpose of requirements re-use in different contexts

Source

OMG Systems Modeling Language (SysML) 1.6

A Copy relationship is a dependency between a supplier requirement and a client requirement that specifies that the text of the client requirement is a read-only copy of the text of the supplier requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

Satisfy::getSatisfies (in ref : NamedElement) : AbstractRequirement [0..*]

Source

OMG Systems Modeling Language (SysML) 1.6

As with other dependencies, the arrow direction points from the satisfying (client) model element to the (supplier) requirement that is satisfied.

Source

OMG Systems Modeling Language (SysML) 1.6

A Satisfy relationship is a dependency between a requirement and a model element that fulfills the requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

The diagram in Figure 16-3 shows derived requirements and refers to the design elements that satisfy them. The rationale is also shown as a basis for the design solution.

Source

OMG Systems Modeling Language (SysML) 1.6

As with other dependencies, the arrow direction points from the derived (client) requirement to the (supplier) requirement from which it is derived.

Source

OMG Systems Modeling Language (SysML) 1.6

For example, a system requirement may be derived from a business need, or lower-level requirements may be derived from a system requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

A DeriveReqt relationship is a dependency between two requirements in which a client requirement can be derived from the supplier requirement.

Source

OMG Systems Modeling Language (SysML) 1.6

The diagram in Figure 16-2 shows an example of a compound requirement decomposed into multiple subrequirements.

Source

OMG Systems Modeling Language (SysML) 1.6

The allocation table can also be shown using a sparse matrix style as in the following example shown in Figure 15-9.

Source

OMG Systems Modeling Language (SysML) 1.6

The table shown in Figure D.40 is provided as a specific example of how the «allocate» dependency may be depicted in tabular form, consistent with the automotive example above.

Source

OMG Systems Modeling Language (SysML) 1.6

The need also arises, when adding detail to a structural model, to allocate a connector (at a more abstract level) to a part (at a more concrete level).

Source

OMG Systems Modeling Language (SysML) 1.6

For example, if a particular user model includes an abstract logical structure, it may be important to show how these model elements are allocated to a more concrete physical structure.

Source

OMG Systems Modeling Language (SysML) 1.6

Systems engineers have frequent need to allocate structural model elements (e.g., blocks, parts, or connectors) to other structural elements.

Source

OMG Systems Modeling Language (SysML) 1.6

Allocation of ControlFlow is not shown as an example, but it is not prohibited in SysML.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 15-5 shows flow allocation of [an] ObjectFlow to a Connector, or alternatively to an ItemFlow.

Source

OMG Systems Modeling Language (SysML) 1.6

The allocation to Activity6 comes from a nested part, and uses the attributes of DirectedRelationshipPropertyPath to specify the path of properties to reach that part. The sourceContext of the allocation is Block4 and the sourcePropertyPath is (Part5).

Source

OMG Systems Modeling Language (SysML) 1.6

Note that the AllocateActivityPartition, if used in this manner, is unambiguously associated with behavior allocation.

Source

OMG Systems Modeling Language (SysML) 1.6

Specific behavior allocation of Actions to Parts are depicted in Figure 15-4.

Source

OMG Systems Modeling Language (SysML) 1.6

AllocateActivityPartition is used to depict an «allocate» relationship on an Activity diagram. The AllocateActivityPartition is a standard UML::ActivityPartition, with modified constraints...

Source

OMG Systems Modeling Language (SysML) 1.6

State machines in block definition diagrams can also appear with the same notation as submachine states.

Source

OMG Systems Modeling Language (SysML) 1.6

Properties with AdjunctProperty applied, where the principal of the AdjunctProperty is a parameter of the state machine, can be used as the end of the associations towards the parameter type.

Source

OMG Systems Modeling Language (SysML) 1.6

Properties with AdjunctProperty applied, where the principal of the AdjunctProperty is a submachine state, can be used as the end of the associations towards the sub state machine.

Source

OMG Systems Modeling Language (SysML) 1.6

State machines in block definition diagrams appear as regular blocks, except the «stateMachine» keyword may be used to indicate the Block stereotype is applied to a state machine, as shown in Figure 13-1.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure D.10 shows the sequence of communication that occurs inside the HybridSUV when the vehicle is started successfully.

Source

OMG Systems Modeling Language (SysML) 1.6

The “hybridSUV” lifeline represents another interaction which further elaborates what happens inside the “hybridSUV” when the vehicle is started.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure D.9 shows an interaction that includes events and messages communicated between the driver and vehicle during the starting of the vehicle.

Source

OMG Systems Modeling Language (SysML) 1.6

CombinedFragments are used to illustrate that steering can take place at the same time as controlling the speed and that controlling speed can be either idling, accelerating/cruising, or braking.

Source

OMG Systems Modeling Language (SysML) 1.6

To manage the complexity, a hierarchical sequence diagram is used which refers to other interactions that further elaborate the system behavior (“ref StartVehicleBlackBox”).

Source

OMG Systems Modeling Language (SysML) 1.6

Figure D.7 illustrates the overall system behavior for operating the vehicle in Sequence diagram format.

Source

OMG Systems Modeling Language (SysML) 1.6

In an instance of Operating Car, which is one execution of it, instances of Brake Pressure and Modulation Frequency are linked to the execution instance when they are in the object nodes of the activity.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 11-14 shows a block definition diagram with composition associations between the activity in Figure 11-10 and the types the object nodes in that activity, with AdjunctProperty applied to the object node type end.

Source

OMG Systems Modeling Language (SysML) 1.6

Like all composition, if an instance of Operating Car is destroyed, terminating the execution, the executions it owns are also terminated.

Source

OMG Systems Modeling Language (SysML) 1.6

Each instance of Operating Car is an execution of that behavior. It owns the executions of the behaviors it invokes synchronously, such as Driving.

Source

OMG Systems Modeling Language (SysML) 1.6

Figure 11-13 shows a block definition diagram with composition associations between the activities and AdjunctProperty applied to the part ends in Figures 11.10, 11.11, and 11.12, as an alternative way to show the activity decomposition of Figures ...

Source

OMG Systems Modeling Language (SysML) 1.6

The ed