Capability (C079):— representing_properties_numerically Date: 2007/06/22 12:22:11
Revision: 1.46
CoverContentsIntro.Overview Info. modelTemplatesCapabilities.Ref. dataEXPRESS defsEXPRESSIssues

Capability EXPRESS information model

This section describes the EXPRESS information model for the capability.

From module : Property_assignment - using subset


TYPE property_assignment_select = EXTENSIBLE SELECT;
END_TYPE;

Property_representation

A Property_representation is an association between an Assigned_property and one of its Representations.


ENTITY Property_representation;
  description : OPTIONAL STRING;
  property : Assigned_property;
  rep : Representation;
  role : OPTIONAL STRING;
END_ENTITY;

description: the text that provides further information about the Property_representation. The value of this attribute need not be specified.

property: the assigned property.

rep: the Representation associated with the property.

role:

the string that specifies the role of the representation with respect to the property. The value of this attribute need not be specified.

EXAMPLE    'detailed representation', 'simplified representation' are examples of role.

From module : Foundation_representation - using subset

Numerical_representation_context

A Numerical_representation_context is a type of Representation_context in which units and uncertainties may be defined. These units and uncertainties apply to the instances of Representation_item that are used in that context.


ENTITY Numerical_representation_context
  SUBTYPE OF (Representation_context);
  units : OPTIONAL SET[1:?] OF Unit;
  accuracies : OPTIONAL SET[1:?] OF Uncertainty_with_unit;
END_ENTITY;

units:

the set of Units that apply for attribute values of instances of Representation_item used in that context. The value of this attribute need not be specified.

NOTE    The units of Numerical_representation_context is only intended to provide a default unit. Its use is not intended to prevent representation items being specified with the same or different units to the context.

accuracies: the uncertainty measures that apply on attribute values of instances of Representation_item used in that context. The value of this attribute need not be specified.

Representation

A Representation is a collection of one or more instances of Representation_item that are related in the specified Representation_context.


ENTITY Representation;
  id : OPTIONAL STRING;
  name : STRING;
  description : OPTIONAL STRING;
  context_of_items : Representation_context;
  items : SET[1:?] OF Representation_item;
END_ENTITY;

id: the identifier for the Representation. The value of this attribute need not be specified.

name:

the words by which the Representation is known.

EXAMPLE    The name of a Representation may be the name of a CAD model.

description: the text that provides further information about the Representation. The value of this attribute need not be specified.

context_of_items: the Representation_context that specifies the context of the Representation.

items: the set of Representation_item instances directly included in the Representation.

Representation_context

A Representation_context is a context in which instances of Representation_item are related.


ENTITY Representation_context;
  id : STRING;
  kind : STRING;
INVERSE
  representations_in_context : SET[1:?] OF Representation FOR context_of_items;
END_ENTITY;

id: the identifier for the Representation_context.

kind:

the text that describes the type of the context.

EXAMPLE 1   'numeric values' is an example of kind of Representation_context.

EXAMPLE 2   '2D space' or '3D space' are examples of kind which can be used for geometric representation contexts.

Representation_item

A Representation_item is an element of representation.

A Representation_item shall be in the set of items of one or more instances of Representation or it shall belong to one or more instances of Representation, being referred to, directly of indirectly, by items of these instances of Representation.

NOTE    this constraint is formally represented in the Express specification of the resource entity that corresponds to Representation_item in the MIM schema.

Only specializations of Representation_item can be instantiated.


ENTITY Representation_item
  ABSTRACT SUPERTYPE ;
  name : STRING;
END_ENTITY;

name:

the words by which the Representation_item is known.

EXAMPLE    The name of a geometric Representation_item may be its element tag in the originating CAD system.

Representation_relationship

A Representation_relationship is an association between two instances of Representation.


ENTITY Representation_relationship;
  relation_type : STRING;
  description : STRING;
  rep_1 : Representation;
  rep_2 : Representation;
END_ENTITY;

relation_type:

the string that specifies the type of the relationship.

Where applicable, the following values shall be used:

description: the text that provides further information about the relationship.

rep_1: one of the instances of Representation that is a part of the relationship.

rep_2: the other instance of Representation that is a part of the relationship. If one element of the relationship is the dependent upon the other, this attribute shall be the dependent one.

From module : Value_with_unit - using all


TYPE any_number_value = NUMBER;
END_TYPE;


TYPE any_string_value = STRING;
END_TYPE;


TYPE length_measure = REAL;
END_TYPE;


TYPE measure_value = EXTENSIBLE SELECT
   (any_number_value,
    any_string_value,
    length_measure,
    plane_angle_measure);
END_TYPE;


TYPE plane_angle_measure = REAL;
END_TYPE;

Amount_of_substance_unit

An Amount_of_substance_unit is a type of Unit in which the number of elementary entities of a substance as compared to the number of atoms in 0.012 kilograms of carbon-12 is expressed.

NOTE 1   This definition applies to the SI quantity 'mole'. When the mole is used, the elementary entities, whose quantity is expressed, must be specified . They may be atoms, molecules, ions, electrons or other particles or specified groups of such particles (see ISO 31-8).

NOTE 2   This unit corresponds to one of the seven fundamental quantities as specified in ISO 1000.


ENTITY Amount_of_substance_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Context_dependent_unit

A Context_dependent_unit is a type of Unit that is not related to the system of units defined in this part of ISO 10303.

EXAMPLE    The number of parts in an assembly is a physical quantity that may be measured in a unit called 'parts'. Such a unit cannot be related to an SI unit.


ENTITY Context_dependent_unit
  SUBTYPE OF (Unit);
WHERE
  WR1: EXISTS(SELF\Unit.name);
END_ENTITY;

Conversion_based_unit

A Conversion_based_unit is a type of Unit that that is based on another and related by a conversion factor.

NOTE    A Conversion_based_unit is often used to convert a unit in one system of units to a similar unit in another system.

EXAMPLE    An Imperial inch is 25.4 millimetres


ENTITY Conversion_based_unit
  SUBTYPE OF (Unit);
  conversion_factor : Value_with_unit;
WHERE
  WR1: EXISTS(SELF\Unit.name);
END_ENTITY;

conversion_factor: the Value_with_unit that defines the conversion.

Derived_unit

A Derived_unit is a type of Unit that is defined by an expression of other units.

EXAMPLE    Newtons per square metre is a derived unit.


ENTITY Derived_unit
  SUBTYPE OF (Unit);
  elements : SET[1:?] OF Derived_unit_element;
END_ENTITY;

elements:

a set of units and their exponents whose product defines the Derived_unit.

NOTE    Each element is one term in the Derived_unit.

Derived_unit_element

A Derived_unit_element is the association of an exponent with a Unit.


ENTITY Derived_unit_element;
  base_unit : Unit;
  exponent : REAL;
END_ENTITY;

base_unit: the unit of a term in the Derived_unit.

exponent: the real number for the Derived_unit.

Duration

A Duration is a type of Value_with_unit that defines the magnitude of a time interval.


ENTITY Duration
  SUBTYPE OF (Value_with_unit);
WHERE
  WR1: 'VALUE_WITH_UNIT_ARM.' + 'TIME_UNIT' IN TYPEOF(SELF\Value_with_unit.unit);
END_ENTITY;

Electric_current_unit

An Electric_current_unit is a type of Unit with which movement of electrically charged particles is expressed.


ENTITY Electric_current_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Length_unit

A Length_unit is a type of Unit in which distances are expressed.


ENTITY Length_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Luminous_intensity_unit

A Luminous_intensity_unit is a type of Unit in which the brightness of a body is expressed.


ENTITY Luminous_intensity_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Mass_unit

A Mass_unit is a type of Unit with which mass is expressed.


ENTITY Mass_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Plane_angle_unit

A Plane_angle_unit is a type of Unit by which a angles in planes are expressed.


ENTITY Plane_angle_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Ratio_unit

A Ratio_unit is a type of Unit that expresses the dimensionless ratio of two quantities of the same kind.


ENTITY Ratio_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Solid_angle_unit

A Solid_angle_unit is a type of Unit that is solid angle.


ENTITY Solid_angle_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Thermodynamic_temperature_unit

A Thermodynamic_temperature_unit is a type of Unit in which the degree of heat of a body is expressed.


ENTITY Thermodynamic_temperature_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Time_unit

A Time_unit is a type of Unit with which the duration of a period is expressed.


ENTITY Time_unit
  SUBTYPE OF (Unit);
END_ENTITY;

Uncertainty_with_unit

An Uncertainty_with_unit is a type of Value_with_unit that specifies the uncertainty that applies to a type of measure. An Uncertainty_with_unit applies to each Representation_item that uses the type of measure specified in the value_component of the Uncertainty_with_unit.


ENTITY Uncertainty_with_unit
  SUBTYPE OF (Value_with_unit);
  name : STRING;
  description : OPTIONAL STRING;
END_ENTITY;

name: the words by which the Uncertainty_with_unit is known.

description: the text that provides further information about the Uncertainty_with_unit. The value of this attribute need not be specified.

Unit

A Unit is a unit quantity.


ENTITY Unit
  SUPERTYPE OF (ONEOF (Amount_of_substance_unit,
                       Electric_current_unit,
                       Length_unit,
                       Luminous_intensity_unit,
                       Mass_unit,
                       Plane_angle_unit,
                       Ratio_unit,
                       Solid_angle_unit,
                       Thermodynamic_temperature_unit,
                       Time_unit));
  name : STRING;
  si_unit : BOOLEAN;
END_ENTITY;

name: the words by which the Unit is known.

si_unit: the boolean value that indicates whether the Unit is one of the units defined in the SI system.

Value_with_unit

A Value_with_unit is the specification of a physical quantity by its value and its unit.


ENTITY Value_with_unit;
  unit : Unit;
  value_component : measure_value;
END_ENTITY;

unit: the Unit with which the physical quantity is expressed.

value_component: the value of the quantity.

From module : Measure_representation - using subset

Measure_item

A Measure_item is a type of Representation_item that conveys the value of a quantity. Only specializations of this entity can be instantiated.


ENTITY Measure_item
  ABSTRACT SUPERTYPE
  SUBTYPE OF (Representation_item);
WHERE
  WR1: SIZEOF(USEDIN(SELF, 'FOUNDATION_REPRESENTATION_ARM.REPRESENTATION.ITEMS'))>0;
END_ENTITY;

Numerical_item_with_unit

A Numerical_item_with_unit is a type of Measure_item that is also a Value_with_unit. The quantity value is therefore provided with its own unit.

NOTE    A unit that is specified by Numerical_item_with_unit supersedes a unit associated with the Numerical_representation_context.


ENTITY Numerical_item_with_unit
  SUBTYPE OF (Measure_item, Value_with_unit);
END_ENTITY;

Property_value_representation

A Property_value_representation is a type of Representation that represents one or more quantity values.

NOTE    The present version of this application module does not enable to represent whether the values have been imposed or were derived or measured. It is expected that a future version will add this capability.


ENTITY Property_value_representation
  SUBTYPE OF (Representation);
  SELF\Representation.context_of_items : Numerical_representation_context;
END_ENTITY;

context_of_items: the Numerical_representation_context in which the value is represented.