Snippets (text quotes and extracts from authoritative sources)

A Snippet is a short quote or extract (typically a phrase, a sentence, or at most a few sentences) from an authoritative source document such as a specification, technical manual, or design manual. Throughout this site, content is often related to supporting Snippets and each Snippet page links back to the content pages that reference it! The Snippet and Note concepts are very closely related and they support each other.

The Snippet concept is also at the heart of the Parsing Analysis recipe for UML® and SysML®

Kind Snippet quote/extract Source UML keywords SysML keywords Keywords
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). Wikipedia DRY, WET
INFO 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, ... Wikipedia DRY, WET
INFO 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. Wikipedia DRY, WET
INFO "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. Wikipedia DRY, WET
INFO 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. Semantics of a Foundational Subset for Executable UML Models 1.4 "InterruptibleRegion", InterruptibleActivityRegion Foundational UML, simulation
INFO 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. Semantics of a Foundational Subset for Executable UML Models 1.4 Enumeration, EnumerationLiteral
INFO 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. Unified Modeling Language 2.5.1 Enumeration, Generalization, EnumerationLiteral
INFO As a specialization of Classifier, Enumerations can participate in generalization relationships. Unified Modeling Language 2.5.1 Enumeration, Generalization, EnumerationLiteral
INFO If onPort is given, then the Port shall be an owned or inherited feature of the type of the target InputPin of the Action. Unified Modeling Language 2.5.1 InvocationAction::onPort, SendSignalAction, SendSignalAction::target
INFO fUML-1.4: 7.6.2.1: Reception: [1] fuml_reception_no_method: A reception must not have an associated method.self.method->isEmpty() Action Language for Foundational UML 1.1 Reception, Signal, receptions compartment
INFO 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. Semantics of a Foundational Subset for Executable UML Models 1.4 ExpansionRegion fUML, Foundational UML
INFO 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) Semantics of a Foundational Subset for Executable UML Models 1.4 Class, CreateObjectAction, CreateObjectAction::classifier fUML, Foundational UML
INFO Features that are not denoted as a DirectedFeature are implicitly provided features. As such they can be matched against a corresponding required feature. OMG Systems Modeling Language (SysML) 1.7beta1 DirectedFeature, FeatureDirectionKind::provided, FeatureDirectionKind::required, FeatureDirectionKind::providedrequired, FeatureDirectionKind
INFO 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 ... OMG Systems Modeling Language (SysML) 1.7beta1 DirectedFeature, FeatureDirectionKind::provided, FeatureDirectionKind::required, FeatureDirectionKind::providedrequired, FeatureDirectionKind
INFO 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). OMG Systems Modeling Language (SysML) 1.7beta1 DirectedFeature, FeatureDirectionKind::provided, FeatureDirectionKind::required, FeatureDirectionKind::providedrequired, FeatureDirectionKind
INFO 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. OMG Systems Modeling Language (SysML) 1.7beta1 Actor, UseCase::subject, UseCase
INFO Actors represent classifier roles that are external to the system that may correspond to users, systems, and or other environmental entities. OMG Systems Modeling Language (SysML) 1.7beta1 Actor, UseCase::subject, UseCase
INFO An Actor specifies a role played by a user or any other system that interacts with the subject. Unified Modeling Language 2.5.1 Actor, UseCase::subject, UseCase
INFO A Property may represent an attribute of a Classifier, a memberEnd of an Association, or in some cases both simultaneously. Unified Modeling Language 2.5.1 Property, Association, Association::memberEnd, Association::ownedEnd, Property::association, Property::owningAssociation
INFO CallBehaviorAction::behavior : Behavior [1..1] ... The Behavior being invoked. Unified Modeling Language 2.5.1 CallBehaviorAction, Behavior, CallBehaviorAction::behavior
INFO Flow Port and Flow Specification are deprecated in this version of SysML and are defined for backward compatibility. OMG Systems Modeling Language (SysML) 1.7beta1 DEPRECATED:FlowPort, DEPRECATED:FlowSpecification Systems Modeling Language, SysML, SysMLv1.6, SysMLv1.7
INFO 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. Wikipedia vapour, Psychrometrics, gas, critical temperature, pressure
INFO 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. Wikipedia vapour, Psychrometrics, gas
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, cooling
INFO Mathematica: v13.2+: Division of one temperature by another will result in a numeric ratio given by the value of both temperatures in Kelvin. Wolfram Language (Mathematica) online help reference Wolfram, Wolfram Language, Mathematica, temperature, celsius, Fahrenheit, kelvin, Kelvins
INFO 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. Wolfram Language (Mathematica) online help reference Wolfram, Wolfram Language, Mathematica, temperature, celsius, Fahrenheit, kelvin, Kelvins
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, water, moisture
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, water, moisture
INFO How much moisture is added to 20 lb of air going from 50°F, 50% RH to 80°F, 60% RH? CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, water, moisture
INFO Determine the amount of sensible heat needed to increase the temperature of air from 50°F and 50% RH to 90°F. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, cooling
INFO 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? CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, cooling, humidification
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer, cooling
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, sensible heat, heat, energy, energy transfer
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, psychrometer, sling psychrometer
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, psychrometer, sling psychrometer
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, psychrometer, sling psychrometer
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, air conditioning, air conditioner, air
INFO 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. CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)' thermodynamics, Psychrometrics, humid air, temperature, dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, psychrometer, sling psychrometer
INFO 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). Wikipedia heat, thermodynamics, energy, energy transfer
INFO 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 Wikipedia heat, thermodynamics, energy, energy transfer
INFO 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. Wikipedia heat, thermodynamics, energy, energy transfer
INFO 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. Wikipedia heat, thermodynamics, energy, energy transfer
INFO 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. Wikipedia heat, thermodynamics, energy, energy transfer
INFO The Boltzmann constant is defined to be exactly 1.380649×10^(−23) J⋅K^(−1) Wikipedia Boltzmann constant, thermodynamics, physics
INFO 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. Wikipedia Boltzmann constant, thermodynamics, physics
INFO 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). Wikipedia standard atmosphere, standard temperature pressure, 1 bar
INFO 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; Wikipedia standard atmosphere, standard temperature pressure, 1 atm
INFO 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. Wikipedia thermodynamics, temperature, celsius, kelvin, Kelvins, water, boiling point
INFO 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. Wikipedia thermodynamics, temperature, celsius, kelvin, Kelvins, water, boiling point
INFO 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. Unified Modeling Language 2.5.1 Property, Property::defaultValue, ValueSpecification, ParameterableElement UML, Unified Modeling Language
INFO Property::defaultValue : ValueSpecification [0..1] Specifies a ValueSpecification that represents a value to be used when no argument is supplied for the Parameter. Unified Modeling Language 2.5.1 Property, Property::defaultValue, ValueSpecification UML, Unified Modeling Language
INFO 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. Unified Modeling Language 2.5.1 Property, Property::defaultValue UML, Unified Modeling Language
INFO The evaluated default then becomes the initial value (or values) of the Property. Unified Modeling Language 2.5.1 Property, Property::defaultValue UML, Unified Modeling Language
INFO 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 Unified Modeling Language 2.5.1 Property, Property::defaultValue UML, Unified Modeling Language
INFO CreateObjectAction::result : OutputPin [1..1]{subsets Action::output} The OutputPin on which the newly created object is placed. Unified Modeling Language 2.5.1 CreateObjectAction, CreateObjectAction::result UML, Unified Modeling Language
INFO CreateObjectAction::classifier : Classifier [1..1] The Classifier to be instantiated. Unified Modeling Language 2.5.1 CreateObjectAction, CreateObjectAction::classifier UML, Unified Modeling Language
INFO A CreateObjectAction is an Action that creates an instance of the specified Classifier. Unified Modeling Language 2.5.1 CreateObjectAction UML, Unified Modeling Language
INFO 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 Unified Modeling Language 2.5.1 DecisionNode, DecisionNode::decisionInput, DecisionNode::decisionInputFlow UML, Unified Modeling Language
INFO 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. Unified Modeling Language 2.5.1 DecisionNode, DecisionNode::decisionInput, DecisionNode::decisionInputFlow UML, Unified Modeling Language
INFO 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. Datasheet: Atmel ATmega640/V-1280/V-1281/V-2560/V-2561/V electronics, Microchip, AVR microcontroller, Atmel, ATmega2560
INFO 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. Unified Modeling Language 2.5.1 Trace, «trace»
INFO 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. Unified Modeling Language 2.5.1 Trace, «trace»
INFO 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. Wikipedia JTAG, electronics, PCB, printed circuit board, micro-controller
INFO 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. Wikipedia JTAG, electronics, PCB, printed circuit board, micro-controller
INFO Don't judge a book by its cover Wikipedia proverb, Webel Parsing Analysis
INFO clothes maketh the man Wiktionary proverb, Webel Parsing Analysis
INFO This means that: Not all words appearing between guillemets are necessarily keywords, and words appearing in guillemets do not necessarily represent stereotypes. Unified Modeling Language 2.5.1 «keyword», Stereotype, guillemets UML, MagicDraw UML
INFO In addition to identifying keywords, guillemets are also used to distinguish the usage of stereotypes. Unified Modeling Language 2.5.1 «keyword», Stereotype, guillemets UML, MagicDraw UML
INFO For some kinds of Classifiers, optionally in the right hand corner an icon denoting the kind of Classifier can be displayed. Unified Modeling Language 2.5.1 role, Property, Class, Classifier, Stereotype, Stereotype:icon, icon secondary stereotype, UML, MagicDraw UML
INFO 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. Unified Modeling Language 2.5.1 role, Property, Class, Classifier, «keyword», Stereotype, Component, «component» secondary stereotype, UML, MagicDraw UML
INFO Stereotypes applied to behaviors may appear on the notation for CallBehaviorAction when invoking those behaviors, as shown in Figure 11-2. OMG Systems Modeling Language (SysML) 1.6 CallBehaviorAction, Behavior, Stereotype secondary stereotype, SysML, Systems Modeling Language, MagicDraw SysML, Cameo Systems Modeler
INFO The stereotype applies to all parameters corresponding to the pins notated by the object node. OMG Systems Modeling Language (SysML) 1.6 Stereotype, Parameter, Pin, ObjectNode, elided Pin notation secondary stereotype, SysML, Systems Modeling Language, MagicDraw SysML, Cameo Systems Modeler
INFO 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. OMG Systems Modeling Language (SysML) 1.6 Stereotype, «keyword», Parameter, ObjectNode, Pin, elided Pin notation SysML Activity Diagram secondary stereotype, SysML, Systems Modeling Language, MagicDraw SysML, Cameo Systems Modeler
INFO 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"). Wikipedia semantic triple, semantic web, RDF, OWL
INFO A semantic triple, or RDF triple or simply triple, is the atomic data entity in the Resource Description Framework (RDF) data model. Wikipedia semantic triple, semantic web, RDF, OWL
INFO The start of the book begins with an eight-year-old orphan girl named Sophie lying in bed ... Wikipedia Webel Parsing Analysis
INFO The giant then says that he will not eat her as he is the Big Friendly Giant, or BFG for short. Wikipedia Webel Parsing Analysis
INFO The giant laughs and explains that most giants do eat human beings (which he pronounces as "human beans") .. Wikipedia Webel Parsing Analysis
INFO When he sets Sophie down, she begins to plead for her life, believing that the giant will eat her. Wikipedia Webel Parsing Analysis
INFO 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. Wikipedia Webel Parsing Analysis
INFO The modern English alphabet is a Latin alphabet consisting of 26 letters, each having an upper- and lower-case form. Wikipedia pangram, Webel Parsing Analysis
INFO ... an English-language pangram — a sentence that contains all of the letters of the English alphabet. Wikipedia pangram, Webel Parsing Analysis
INFO "The quick brown fox jumps over the lazy dog" ... Wikipedia pangram, Webel Parsing Analysis
INFO "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. Wikipedia pangram, Webel Parsing Analysis
INFO This is why we want to work with across variables that have not been overly differentiated. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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). Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO The first constraint is that the through variable should be the time derivative of some conserved quantity. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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). Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection
INFO 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. Modelica By Example Modelica, acausal connection