Datatypes

1994 ◽  
Author(s):  
Douglas Schenck ◽  
Peter Wilson
Keyword(s):  
Named Entities ◽  
Generic Type ◽  
Formal Parameter ◽  
Actual Parameter ◽  
Type Parameter ◽  
Local Variable ◽  
The Way

This chapter explains the EXPRESS pseudotypes and datatypes. You will also want to read about defined types and entity types, both of which are covered in Chapter 11. Datatypes represent domains of values. A domain is the set of possible values associated with an attribute, local variable or formal parameter. Datatype values can be operated upon as explained in Chapter 14. EXPRESS is fussy about the way datatypes are used. The datatypes are grouped this way: • Pseudo (Generic and Aggregate — see 10.1) • Simple (Integer, String, etc. — see 10.2) • Collection (Array, List, etc. — see 10.3) • Enumeration and Select (see 10.4 and 10.5). • Named (entities and defined types — Chapter 11) Then, the context in which a reference to a datatype is made will be • as the type of an attribute, • as the type of a local variable, • as the type of a formal parameter, or • as the underlying type of a defined type. At last, a summary of the datatypes that can be used in the different contexts is given in Table 10.1. Notice that pseudotypes can only be used as formal parameter types and, the enumeration and select types can only be used as the underlying types of defined types. Pseudotypes are used only as the types of the formal parameters of functions and procedures. They can be regarded as templates into which various specific types can be placed. See 11.5.1 for more about formal parameters. The domain of a generic pseudotype is every conceivable value. When a procedure or function that has a generic type parameter is invoked it will accept any kind of actual parameter. No questions asked! Functions or procedures that use formal parameters typed as generic must be prepared to deal with whatever actual stuff is tossed its way and any operations performed on them will depend on the specific type of the actual parameter. Generic parameters should never be used when a more specific type can be used instead. In any event, the mechanics involved in writing an algorithm that is capable of handling every possible input value are tricky. The message is: Don’t use generic parameters unless you simply have to.

scholarly journals Diagrammatic logic applied to a parameterisation process

2010 ◽  
Vol 20 (4) ◽  
pp. 639-654 ◽  
Author(s):  
CÉSAR DOMÍNGUEZ ◽  
DOMINIQUE DUVAL
Keyword(s):  
Category Theory ◽  
Formal Parameter ◽  
Actual Parameter ◽  
Definition Of ◽  
The Given ◽  
Parameter Passing

This paper provides an abstract definition of a class of logics, called diagrammatic logics, together with a definition of morphisms and 2-morphisms between them. The definition of the 2-category of diagrammatic logics relies on category theory, mainly on adjunction, categories of fractions and limit sketches. This framework is applied to the formalisation of a parameterisation process. This process, which consists of adding a formal parameter to some operations in a given specification, is presented as a morphism of logics. Then the parameter passing process for recovering a model of the given specification from a model of the parameterised specification and an actual parameter is shown to be a 2-morphism of logics.

scholarly journals Data Types as Functions

1978 ◽  
Vol 7 (89) ◽  
Author(s):  
Brian H. Mayoh
Keyword(s):  
Data Type ◽  
Extended Version ◽  
Data Types ◽  
Formal Parameter ◽  
Actual Parameter ◽  
Definition Of ◽  
Simple Definition

This paper introduces a new, simple definition of what a data type is. This definition gives one possible solution of the theoretical problems: when can an actual parameter of type T be substituted for a formal parameter of type T'? When can a type T' be implemented as another type T''? The preprint is an extended version of a paper presented at MFCS 78, Zakopane.

scholarly journals Involute profile globoidal gear honing

2019 ◽  
Vol 2019 (5) ◽  
pp. 19-23 ◽  
Author(s):  
Владимир Спирин ◽  
Vladimir Spirin ◽  
Владимир Макаров ◽  
Vladimir Makarov ◽  
Олег Халтурин ◽  
...  
Keyword(s):  
Design Parameters ◽  
Machining Conditions ◽  
Actual Parameter ◽  
Gear Honing ◽  
Definition Of

In the paper technological potentialities of globoidal gear honing are considered. With this purpose there are used complex measurements for involute gearings. A problem on a design definition of globoidal gear honing errors depending on machining conditions and parameters of a hone installation is solved. The results are presented as Talyrond traces of actual parameter deviations of the involute from theoretical ones (design parameters).

scholarly journals Temperature Prediction in 3013 Containers in K-Area Material Storage (KAMS) Facility Using Regression Methods

2008 ◽  
Author(s):  
Narendra K. Gupta
Keyword(s):  
Thermal Loading ◽  
Structural Integrity ◽  
Thermal Analyses ◽  
Design Parameters ◽  
Surveillance Program ◽  
Regression Methods ◽  
Actual Parameter ◽  
Long Term Storage ◽  
Bearing Materials ◽  
Parameter Values

3013 containers are designed in accordance with the DOE-STD-3013-2004. These containers are qualified to store plutonium (Pu) bearing materials such as PuO2 for 50 years. DOT shipping packages such as the 9975 are used to store the 3013 containers in the K-Area Material Storage (KAMS) facility at Savannah River Site (SRS). DOE-STD-3013-2004 requires that a comprehensive surveillance program be set up to ensure that the 3013 container design parameters are not violated during the long term storage. To ensure structural integrity of the 3013 containers, thermal analyses using finite element models were performed to predict the contents and component temperatures for different but well defined parameters such as storage ambient temperature, PuO2 density, fill heights, weights, and thermal loading. Interpolation is normally used to calculate temperatures if the actual parameter values are different from the analyzed values. A statistical analysis technique using regression methods is proposed to develop simple polynomial relations to predict temperatures for the actual parameter values found in the containers. The analysis shows that regression analysis is a powerful tool to develop simple relations to assess component temperatures.

Usage notes

1994 ◽  
Author(s):  
Douglas Schenck ◽  
Peter Wilson
Keyword(s):  
Formal Specification ◽  
Object Oriented ◽  
Data Type ◽  
Test Case ◽  
Test Cases ◽  
Formal Definition ◽  
Actual Parameter ◽  
Parameter Values ◽  
Individual Objects

Now we discuss some of the potential uses of the EXPRESS-I language. In Object-Oriented terms, an EXPRESS entity would be called a class, and an instance of a class is termed an object. One object may reference another object. EXPRESS, though, distinguishes between entities and types (i.e., the enumeration, select and the defined data type) as entities may be subtyped whereas types cannot be. EXPRESS-I treats entity instances as objects in the OO sense. It also allows types to be treated as objects in that they can be instantiated and referenced. Alternatively, type values may be embedded in entity instances. The simplest use of EXPRESS-I is as a paper exercise in displaying examples of EXPRESS declarations that are populated with data. The language allows the display of entity instances as referenceable objects. Types instances may also be displayed as referenceable objects, or they may appear as unreferenceable values within other objects' values. Examples in this book show both forms of type instantiation. Values of explicit entity attributes are required. The values of derived or inverse attributes need not be displayed, except as exemplars, because as noted, these are essentially calculable from the values of the explicit attributes. Examples of EXPRESS schemas can also be displayed, as well as individual objects. The EXPRESS-I model construct is provided to enable the display of multiple schemas. Typically, a model would be used when two or more EXPRESS schemas interact with each other. Note that EXPRESS itself does not support such a construct. Note: We do not discuss models in this book. The test case construct is provided to assist in the formal specification of test cases against the implementation of an EXPRESS schema. EXPRESS itself does not provide an equivalent construct. For a test case, a base set of EXPRESS-I objects must be defined which will be the objects (and their supporting data) to be tested. The values of these objects may be in the form of parameters, whose formal definition are given in an enclosing context. A series of test cases may then be defined on the context, by providing actual parameter values.

Research on the Designing and Checking Method for Electric Actuator Used on Supersonic Speed Target Cruise Missile

2014 ◽  
Vol 574 ◽  
pp. 633-638
Author(s):  
Dong Xu Zhang ◽  
Jiao Zhang ◽  
Yuan Xiang Liu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Characteristic ◽  
Control Strategy ◽  
Mathematic Model ◽  
Cruise Missile ◽  
Supersonic Speed ◽  
Electric Actuator ◽  
Actual Parameter

According to the control strategy of the supersonic speed target cruise missile and the demand of the actuator, the principle of choosing motor and the method of designing electric actuator were presented. The mathematic model of the electric actuator was built with the actual parameter and the checking method of the dynamic characteristic of the electric actuator was described. With the mathematic model and the actual electric actuator designed, the numerical simulation and the experiment on turret were made. The conclusion showed that the electric actuator designed with the designing and checking method described met the control demand of the target missile.

Calculating the Sensitivity of a Salmonid Population Model

1986 ◽  
Vol 43 (4) ◽  
pp. 863-868 ◽  
Author(s):  
Geoffrey T. Evans ◽  
J. Brian Dempson
Keyword(s):  
Life History ◽  
Simple Model ◽  
Computer Simulations ◽  
Population Model ◽  
Theoretical Calculations ◽  
Protection Measures ◽  
Habitat Protection ◽  
Actual Parameter ◽  
Management Actions ◽  
Parameter Values

We present a simple model of salmonid life history, and calculate the sensitivity of its outputs to its parameters. Theoretical calculations are preferred to computer simulations. There are some parameters for which the sign of the sensitivity is independent of the actual parameter values. In an uncertain world, management actions aimed at altering such parameters are safer than other actions. For example, habitat protection measures are more certain to have the desired effect than are changes in fishery regulations.

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