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 SysML enforces its equivalence of navigation and ownership by means of constraints that the block stereotype enforces on the existing UML metamodel. OMG Systems Modeling Language (SysML) 1.7 Association, Property::isNavigable(), Association::ownedEnd Block SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO The only form of an association end that SysML allows an association to own directly is an unnamed end used to carry an inverse multiplicity of a reference property. This unnamed end provides a metamodel element to record an inverse multiplicity ... OMG Systems Modeling Language (SysML) 1.7 Association, Property::isNavigable(), Association::ownedEnd Block SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO SysML excludes variations of associations in UML in which navigable ends can be owned directly by the association. In SysML, navigation is equivalent to a named property owned directly by a block. OMG Systems Modeling Language (SysML) 1.7 Association, Property::isNavigable(), Association::ownedEnd Block SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO The keyword «participant» before a property name indicates the property is stereotyped by ParticipantProperty. They are always the same as the corresponding association end type. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock, ParticipantProperty, ParticipantProperty::end SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO Participant properties can be the ends of connectors owned by an association block. The association block can be the type of multiple other connectors to reuse the same internal structure for all the connectors. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock, ParticipantProperty, ParticipantProperty::end SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO The value of a participant property on an instance (link) of the association block is the value or object at the end of the link corresponding to this end of the association. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock, ParticipantProperty, ParticipantProperty::end SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO To refer to linked objects and values of an instance of an association block, it is necessary for the modeler to specify which (participant) properties of the association block identify the instances being linked at which end of the association. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO Each instance of an association block can link together instances of the end classifiers of the association. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO The Block stereotype extends Class, so it can be applied to any specialization of Class, including Association Classes. These are informally called "association blocks." An association block can own properties and connectors, like any other block. OMG Systems Modeling Language (SysML) 1.7 AssociationClass AssociationBlock SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO SysMLv1.7: UMLCompartmentableShapes that have a modelElement stereotyped by Allocated or one of its specializations may have a compartment titled “allocatedElements” and a compartment titled “allocatedToElements.” OMG Systems Modeling Language (SysML) 1.7 Allocate, Allocate::/getAllocatedFrom(in ref), Allocate::/getAllocatedTo(in ref) SysMLv1.7
INFO An Activity shall have ... two ActivityParameterNodes for each inout Parameter. Unified Modeling Language 2.5.1 Activity, Behavior, Parameter, ActivityParameterNode, ActivityEdge, ParameterDirectionKind::in, ParameterDirectionKind::out, ParameterDirectionKind::inout, ParameterDirectionKind::return
INFO A multiplicity on the composing end of a composite aggregation must not have an upper bound greater than 1. inv: isComposite and association <> null implies opposite.upperBound() <= 1 Unified Modeling Language 2.5.1 multiplicity, MultiplicityElement::upperValue, MultiplicityElement::upperBound, Property, Property::aggregation, AggregationKind::composite, Property::isComposite
INFO A NestedConnectorEnd stereotype of a UML ConnectorEnd is automatically applied to any connector end that is nested more than one level deep within a containing context. OMG Systems Modeling Language (SysML) 1.7 Connector NestedConnectorEnd
INFO If there are two or more aggregations to the same aggregate, a conforming tool may as a purely presentational option show them as a tree by merging the aggregation ends into a single segment adorned by the solid or hollow aggregation diamond symbol. Unified Modeling Language 2.5.1 Association, Association::memberEnd
INFO Not all links need to be classified by an Association. Unified Modeling Language 2.5.1 link, Association Unified Modeling Language
INFO Those ownedAttributes of a StructuredClassifier that have isComposite = true (see 9.5.3) are called its parts. Hence parts constitute a subset of roles. Unified Modeling Language 2.5.1 StructuredClassifier::ownedAttribute, StructuredClassifier, Property::isComposite, AggregationKind::composite
INFO The frame shall designate a model element that is the default namespace for the model elements enclosed in the frame. A qualified name for the model element within the frame shall be provided if it is not contained within default namespace. OMG Systems Modeling Language (SysML) 1.7 Diagram, diagram frame, Namespace SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO The frame is a rectangle that is required for SysML diagrams. (Note: the frame is optional in UML). OMG Systems Modeling Language (SysML) 1.7 Diagram, diagram frame SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO [DEPRECATED] Atomic flow ports relay items that are classified by a single Block, ValueType, or Signal classifier. A nonatomic flow port relays items of several types as specified by a FlowSpecification. OMG Systems Modeling Language (SysML) 1.7 Port flow port, atomic flow port, nonatomic flow port, FlowSpecification SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO [DEPRECATED] We distinguish between atomic flow port and a nonatomic flow port. OMG Systems Modeling Language (SysML) 1.7 Port flow port, atomic flow port, nonatomic flow port SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO A Port of an EncapsulatedClassifier is shown as a small square symbol. The Port symbol may be placed either overlapping the boundary of the rectangle symbol denoting that EncapsulatedClassifier or it may be shown inside the rectangle symbol. Unified Modeling Language 2.5.1 Property, Property::aggregation, AggregationKind::composite, Port, EncapsulatedClassifier
INFO A Port is a Property of an EncapsulatedClassifier that specifies a distinct interaction point between that EncapsulatedClassifier and its environment or between the Behavior of the EncapsulatedClassifier and its internal roles. Ports are connected by ... Unified Modeling Language 2.5.1 Property, Property::aggregation, AggregationKind::composite, Port, EncapsulatedClassifier
INFO A part may be shown by graphical nesting of a box symbol Unified Modeling Language 2.5.1 Property, Property::aggregation, AggregationKind::composite, part object
INFO Composite aggregation is a strong form of aggregation that requires a part object be included in at most one composite object at a time. If a composite object is deleted, all of its part instances that are objects are deleted with it. Unified Modeling Language 2.5.1 Property, Property::aggregation, AggregationKind::composite, part object
INFO 16.3.2.1 AbstractRequirement: id : String [1] The unique id of the requirement. OMG Systems Modeling Language (SysML) 1.7
INFO (Datastore already has an overwrite semantics) OMG Systems Modeling Language (SysML) 1.7 DataStoreNode SysML, SysMLv1, Systems Modeling Language, Model-Based Systems Engineering
INFO An “X” on a single end of an association to indicate that an end is not navigable has similarly been dropped, as has the use of a small filled dot at the end of an association to indicate that the end is owned by the associated classifier. OMG Systems Modeling Language (SysML) 1.7 Association
INFO The use of navigation arrowheads on an association has been simplified by excluding the case of arrowheads on both ends, and requiring that such an association always be shown without arrowheads on either end. OMG Systems Modeling Language (SysML) 1.7 Association
INFO Notational and metamodel support for n-ary associations and qualified associations has been excluded from SysML. OMG Systems Modeling Language (SysML) 1.7 Association
INFO The supported variety of notations for associations and association annotations has been reduced to simplify the burden of teaching, learning, and interpreting SysML diagrams for the systems engineering user. OMG Systems Modeling Language (SysML) 1.7 Association
INFO The dot shows that the model includes a Property of the type represented by the Classifier touched by the dot. This Property is owned by the Classifier at the other end. Unified Modeling Language 2.5.1 Association, Classifier, Property::isNavigable(), Association::navigableOwnedEnd, Association::ownedEnd, Association::memberEnd, Element::owner, AggregationKind, Property::aggregation, ownership dot
INFO The dot is to be drawn integral to the graphic path of the line, at the point where it meets the Classifier, inserted between the end of the line and the side of the node representing the Classifier. Unified Modeling Language 2.5.1 Association, Classifier, Property::isNavigable(), Association::navigableOwnedEnd, Association::ownedEnd, Association::memberEnd, Element::owner, AggregationKind, Property::aggregation, ownership dot
INFO Ownership of Association ends by an associated Classifier may be indicated graphically by a small filled circle, which for brevity we will term a dot. Unified Modeling Language 2.5.1 Association, Classifier, Property::isNavigable(), Association::navigableOwnedEnd, Association::ownedEnd, Association::memberEnd, Element::owner, AggregationKind, Property::aggregation, ownership dot
INFO Aggregation type, navigability, and end ownership are separate concepts, each with their own explicit notation. Association ends owned by classes are always navigable, while those owned by associations may be navigable or not. Unified Modeling Language 2.5.1 Association, Classifier, Property::isNavigable(), Association::navigableOwnedEnd, Association::ownedEnd, Association::memberEnd, Element::owner, AggregationKind, Property::aggregation
INFO Navigability notation was often used in the past according to an informal convention, whereby non-navigable ends were assumed to be owned by the Association whereas navigable ends were assumed to be owned by the Classifier at the opposite end. DEPRECATED. Unified Modeling Language 2.5.1 Association, Classifier, Property::isNavigable(), Association::navigableOwnedEnd, Classifier, Association::ownedEnd, Association::memberEnd, Element::owner
INFO [OBSOLETE] SysMLv1.2: 8.3.1.1.10 Property-specific type Enclosing the type name of a property in square brackets specifies that the type is a local specialization of the referenced type, which may be overridden to specify additional values or ... OMG Systems Modeling Language (SysML) 1.2
INFO The notation for properties typed by a property-specific type shows the name of the most specific generalization of the property-specific type that is not a property-specific type (or nothing if there is no generalization) between parentheses after the .. OMG Systems Modeling Language (SysML) 1.7 PropertySpecificType
SEMANTIC If a StructuralFeature is marked with isReadOnly true, then it may not be updated once it has been assigned an initial value. Unified Modeling Language 2.5.1 StructuralFeature::isReadonly, StructuralFeature
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 SysMLv1.7: Flow Port and Flow Specification are deprecated in this version of SysML and are defined for backward compatibility. OMG Systems Modeling Language (SysML) 1.7 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»