The role of stress analysis in design is limited by the batch processing of single design geometries when subjected to prescribed load cases. While this approach is reasonable for detailed design, it limits the engine...
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The role of stress analysis in design is limited by the batch processing of single design geometries when subjected to prescribed load cases. While this approach is reasonable for detailed design, it limits the engineer in early stage design, when rapid availability of stress information for different geometries is perhaps more important than geometric precision. This paper presents structural re-analysis in a boundary element context, providing information on a suitable object-oriented structure, and giving details on the operations required when processing various types of re-analysis. Computational performance improvements (over a full analysis) of 50-80% are found, depending on the degree of perturbation to a pre-existing boundary element method model. An illustration, in which multiple modifications are made to different parts of a design geometry, shows how stress reduction and weight reduction may be achieved as analysis results guide the design in the concept stage. (C) 2001 Elsevier Science Ltd. All rights reserved.
The emergence of exception handling (EH) mechanisms in modern programming languages made available a different way of communicating errors between procedures. For years, programmers trusted in correct documentation of...
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The emergence of exception handling (EH) mechanisms in modern programming languages made available a different way of communicating errors between procedures. For years, programmers trusted in correct documentation of error codes returned by procedures to correctly handle erroneous situations. Now, they have to focus on the documentation of exceptions for the same effect. But to what extent can exception documentation be trusted? Moreover, is there enough documentation for exceptions? And in what way do these questions relate to the discussion on checked against unchecked exceptions? For a given set of Microsoft .NET applications, code and documentation were thoroughly parsed and compared. This showed that exception documentation tends to be scarce. In particular, it showed that 90% of exceptions are undocumented. Furthermore, programmers were demonstrated to be keener to document exceptions they explicitly throw while typically leaving exceptions resulting from method calls undocumented. This conclusion lead to another question: how do programmers use the EH mechanisms available in modem programming languages? More than 16 different .NET applications were examined in order to provide an answer. The major conclusion of this work is that exceptions are not being correctly used as an error-handling mechanism. These results contribute to the assessment of the effectiveness of the unchecked exceptions approach.
System integrators considering software components depend on component Suppliers to adequately describe their components. A component description must be trustworthy and contain sufficient detail for integrators to un...
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System integrators considering software components depend on component Suppliers to adequately describe their components. A component description must be trustworthy and contain sufficient detail for integrators to understand its real abilities. The European Clear and Reliable Information for Integration project has developed a flexible, property-value approach that lets you similarly manage simple and complex properties.
The methodology for developing intelligent integrated computer-aided design and manufacturing systems based on object-oriented principles is discussed. The ways in which the application of these principles affects the...
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The methodology for developing intelligent integrated computer-aided design and manufacturing systems based on object-oriented principles is discussed. The ways in which the application of these principles affects the nature of these systems are reviewed. The implementation of an automated, intelligent, and flexible computer-integrated-manufacturing (CIM) system prototype using an object-oriented programming environment (Smalltalk-80, Version 4.0) is detailed. A CIM system includes CAD, a process planner, and an inspection planner. Each of these components is discussed individually
We all know that the web is a fantastic resource of information that can help us, but we also know that information is often hard to find. Website Wanderer is a column where we have invited an active researcher or dev...
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We all know that the web is a fantastic resource of information that can help us, but we also know that information is often hard to find. Website Wanderer is a column where we have invited an active researcher or developer in some area to share their knowledge of which websites are worth visiting. In this issue, we focus on patterns-encapsulations of knowledge that can be reused in some way when developing software.
The contributions of this paper are two-fold: first, we introduce a novel, axiomatically defined, object-oriented data model called the Demeter kernel model;and secondly, we present abstraction and optimisation algori...
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The contributions of this paper are two-fold: first, we introduce a novel, axiomatically defined, object-oriented data model called the Demeter kernel model;and secondly, we present abstraction and optimisation algorithms and their relationships for designing classes from objects in the kernel model. We analyse several computational problems underlying the class design process, which is divided into two phases;a learning phase and an optimisation phase. This study focuses on approximation algorithms for the optimisation phase and aims to lead to a better understanding and a partial automation of the object-oriented design process. The algorithms and the theory presented here have been implemented in the C + + Demeter System, a CASE tool for object-oriented design and programming.
We have presented in this work, a computer-aided-design software for flywheels using object-oriented programming approach of Visual Basic. The various configurations of flywheels (rimmed or solid) formed the basis for...
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We have presented in this work, a computer-aided-design software for flywheels using object-oriented programming approach of Visual Basic. The various configurations of flywheels (rimmed or solid) formed the basis for the development of the software. The software's graphical features were used to give a visual interpretation of the solutions. The software's effectiveness was tested on a number of numerical examples, some of which are outlined in this work. (c) 2005 Elsevier Ltd. All rights reserved.
The Telecommunications Information Networking Architecture (TINA) Consortium is an international collaboration aiming at defining and validating an open architecture for telecommunication services for the broadband, m...
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The Telecommunications Information Networking Architecture (TINA) Consortium is an international collaboration aiming at defining and validating an open architecture for telecommunication services for the broadband, multimedia, and information era. The architecture is based on distributed computing, object orientation, and other concepts and standards from the telecommunications and computing industries. This paper provides an introduction to TINA.
We look in detail at an individual-based simulation of the spread of barley yellow dwarf virus. The need for a very large number of individual plants and aphids along with multiple runs using different model parameter...
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We look in detail at an individual-based simulation of the spread of barley yellow dwarf virus. The need for a very large number of individual plants and aphids along with multiple runs using different model parameters mean that it is important to keep memory and processor requirements within reasonable bounds. We present implementations of the model in both imperative and object-oriented programming languages, particularly noting aspects relating to ease of implementation and runtime performance. Finally, we attempt to quantify the cost of some of the decisions made in terms of their memory and processor time requirements. (C) 2003 Elsevier B.V. All rights reserved.
Purpose - This paper develops C++ and Fortran-90 solvers to establish parallel solution procedures in a finite element or meshless analysis program using shared memory computers. The paper aims to discuss these issues...
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Purpose - This paper develops C++ and Fortran-90 solvers to establish parallel solution procedures in a finite element or meshless analysis program using shared memory computers. The paper aims to discuss these issues. Design/methodology/approach - The stiffness matrix can be symmetrical or unsymmetrical, and the solution schemes include sky-line Cholesky and parallel preconditioned conjugate gradient-like methods. Findings - By using the features of C++ or Fortran-90, the stiffness matrix and its auxiliary arrays can be encapsulated into a class or module as private arrays. This class or module will handle how to allocate, renumber, assemble, parallelize and solve these complicated arrays automatically. Practical implications - The source codes can be obtained online at http//***/similar to juju. The major advantage of the scheme is that it is simple and systematic, so an efficient parallel finite element or meshless program can be established easily. Originality/value - With the minimum requirement of computer memory, an object-oriented C++ class and a Fortran-90 module were established to allocate, renumber, assemble, parallel, and solve the global stiffness matrix, so that the programmer does not need to handle them directly.
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