The design, implementation and application of a concept for object-oriented in finite element analysis of multi-field problems is presented in this paper. The basic idea of this concept is that the underlying governin...
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The design, implementation and application of a concept for object-oriented in finite element analysis of multi-field problems is presented in this paper. The basic idea of this concept is that the underlying governing equations of porous media mechanics can be classified into different types of partial differential equations (PDEs). In principle, similar types of PDEs for diverse physical problems differ only in material coefficients. Local element matrices and vectors arising from the finite element discretization of the PDEs are categorized into several types, regardless of which physical problem they belong to (i.e. fluid flow, mass and heat transport or deformation processes). Element (ELE) objects are introduced to carry out the local assembly of the algebraic equations. The object-orientation includes a strict encapsulation of geometrical (GEO), topological (MSH), process-related (FEM) data and methods of element objects. Geometric entities of an element such as nodes, edges, faces and neighbours are abstracted into corresponding geometric element objects (ELE-GEO). The relationships among these geometric entities form the topology of element meshes (ELE-MSH). Finite element objects (ELE-FEM) are presented for the local element calculations, in which each classification type of the matrices and vectors is computed by a unique function. These element functions are able to deal with different element types (lines, triangles, quadrilaterals, tetrahedra, prisms, hexahedra) by automatically choosing the related element interpolation functions. For each process of a multi-field problem, only a single instance of the finite element object is required. The element objects provide a flexible coding environment for multi-field problems with different element types. Here, the C++ implementations of the objects are given and described in detail. The efficiency of the new element objects is demonstrated by several test cases dealing with then no-hydro-mechanical (THM) cou
The Grid Services Base Library (GSBL) is a procedural application programming interface (API) that abstracts many of the high-level functions performed by Globus Grid services, thus dramatically lowering the barriers ...
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The Grid Services Base Library (GSBL) is a procedural application programming interface (API) that abstracts many of the high-level functions performed by Globus Grid services, thus dramatically lowering the barriers to writing Grid services. The library has been extensively tested and used for computational biology research in a Globus Toolkit-based Grid system, in which no fewer than twenty Grid services written with this API are deployed. (c) 2006 Elsevier B.V. All rights reserved.
Transforming programs to alter their semantics is of wide interest, for purposes as diverse as off-the-shelf component adaptation, optimizatiom. trace generation, and experimentation with new language features. The cu...
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Transforming programs to alter their semantics is of wide interest, for purposes as diverse as off-the-shelf component adaptation, optimizatiom. trace generation, and experimentation with new language features. The current wave of interest in advanced technologies for better separation of concerns, such as aspect-orientedprogramming, is a solid testimony of this fact. Strangely enough, almost all proposals are formulated in the context of Java, in which tool providers encounter severe restrictions due to the rigidity of the environment. This paper presents BYTESURGEON, a library to transform binary code in Smalltalk. BYTESURGEON takes full advantage of the flexibility of the Squeak environment to enable bytecode transformation at runtime, thereby allowing dynamic, on-the-fly modification of applications. BYTESURGEON operates on bytecode in order to cope with situations where the source code is not available, while providing appropriate high-level abstractions so that users do not need to program at the bytecode level. We illustrate the use of BYTESURGEON via the implementation of method wrappers and a simple MOP, and report on its efficiency. (c) 2005 Elsevier Ltd. All rights reserved.
The BQM-an acronym that stands for Bottom-up Query machine, the role played by our system in the framework of the KIWIS system [2]-system extends deductive database technology with knowledge structuring capabilities t...
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The BQM-an acronym that stands for Bottom-up Query machine, the role played by our system in the framework of the KIWIS system [2]-system extends deductive database technology with knowledge structuring capabilities to provide an advanced environment for the development of data and knowledge-based applications. The system relies on a knowledge representation language that combines the declarativeness of logic programming with the notions of object, inheritance with exceptions, and message passing. Exceptions are supported by allowing rules with negated heads. The use of exceptions inside the inheritance mechanism makes the language inherently nonmonotonic. The paper contains a comprehensive description of both the language and the implementation principles of the BQM system. It begins by providing a model-theoretic semantics of the language based on the notion of least model. A fixpoint semantics, providing a constructive definition of the least model, is given as well. Then, a number of implementation techniques for efficient query evaluation are described. Such techniques significantly extend ''traditional'' deductive database query evaluation strategies to deal with monotonic reasoning. A description of the architecture of the current prototype of the BQM system is also given.
A major challenge facing software libraries for scientific computing is the ability to provide adequate flexibility to meet sophisticated, diverse, and evolving application requirements. object-oriented design techniq...
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A major challenge facing software libraries for scientific computing is the ability to provide adequate flexibility to meet sophisticated, diverse, and evolving application requirements. object-oriented design techniques are valuable tools for capturing characteristics of complex applications in a software architecture. In this paper, we describe certain prominent object-oriented features of the SAMRAI software library that have proven to be useful in application development. SAMRAI is used in a variety of applications and has demonstrated a substantial amount of code and design re-use in those applications. This flexibility and extensibility is illustrated with three different application codes. We emphasize two important features of our design. First, we describe the composition of complex numerical algorithms from smaller components which are usable in different applications. Second, we discuss the extension of existing framework components to satisfy new application needs. Published in 2002 by John Wiley Sons, Ltd.
The vehicle routing and facility location Fields are well-developed areas in management science and operations research application. There is an increasing recognition that effective decision-making in these Fields re...
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The vehicle routing and facility location Fields are well-developed areas in management science and operations research application. There is an increasing recognition that effective decision-making in these Fields requires the adoption of optimization software that can be embedded into a decision support system. In this paper, we describe the implementation details of our software components for solving the vehicle routing and facility location problems.
This paper discusses the development of a set of object-oriented modular simulation tools for solving lumped and spatially distributed models generated from chemical process design and simulation problems. Developed i...
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This paper discusses the development of a set of object-oriented modular simulation tools for solving lumped and spatially distributed models generated from chemical process design and simulation problems. Developed in the context of simulating semiconductor manufacture equipment, this framework reduces the software development cycle time associated with designing process systems and it improves the overall efficiency of the simulator development process. Modularized simulator components can be solved and analyzed individually, as well as formed into modular systems that can be solved using sequential or simultaneous approaches. A tungsten chemical vapor deposition simulation application is presented to illustrate the capability of the proposed tools in facilitating an evolutionary simulation approach. (c) 2006 Elsevier Ltd. All rights reserved.
An increasingly popular approach to scientificomputing is to combine Pythonand compiled modules. Such an approach merges the high performance typically found in compiledroutines with the interface of a flexible, scala...
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An increasingly popular approach to scientificomputing is to combine Pythonand compiled modules. Such an approach merges the high performance typically found in compiledroutines with the interface of a flexible, scalable, and easy-to-learn interpreted *** using to hand-code extensions to Python binds the latter to a given compiled asset inC++, programmers who used C++'s more advanced features (until recentlylacked the automated supportavailable in Fortran and C. One tool for creating Python bindings to the Simplified Wrapper andInterface Generator. SWIG-an open-source application used by a large and ever-expandingcommunity-began as an effort to expose physics packages in a large parallel simulation code tointerpreted languages. SWIG preprocesses and C++ code and generates library bindings in severalinterpreted languages including Python, Pert, Tcl, and Java. Recent improvements to SWIG providegreater support for binding C++ code. SWIG now creates, for example, bindings for some of C++'s moreadvanced features such as templates and exceptions. This article explores how SWIG does this byexamining a series of small C++ code examples.
Interruptions to supply and sags of distribution system voltage are the main aspects causing customer complaints. There is a need for analysis of supply reliability and voltage sag to relate system performance with ne...
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Interruptions to supply and sags of distribution system voltage are the main aspects causing customer complaints. There is a need for analysis of supply reliability and voltage sag to relate system performance with network structure and equipment design parameters. This analysis can also give prediction of voltage dips, as well as relating traditional reliability and momentary outage measures to the properties of protection systems and to network impedances. Existing reliability analysis software, often requires substantial training, lacks automated facilities, and suffers from data availability. Thus it requires time-consuming manual intervention for the study of large networks. A user-friendly sag and reliability assessment tool (SRAT) has been developed based on existing impedance data, protection characteristics, and a model of failure probability. The new features included in SRAT are a) efficient reliability and sag assessments for a radial network with limited loops, b) reliability evaluation associated with realistic protection and restoration schemes, c) inclusion of momentary outages in the same model as permanent outage evaluation, d) evaluation of the sag transfer through meshed subtransmission network, and e) simplified probability distribution model determined from available faults records. Examples of the application of the tools to an Australian distribution network are used to illustrate the application of this model.
The location of corridors or fights-of-way across a landscape for the purpose of siting a facility such as a power transmission line has been the subject of much research. Many different computerized models have been ...
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The location of corridors or fights-of-way across a landscape for the purpose of siting a facility such as a power transmission line has been the subject of much research. Many different computerized models have been developed to address this design and layout problem. Any environmental review usually requires that alternative routes be considered. Thus, the value of a model can be measured not only in terms of determining a good solution but in supporting the search for good alternatives as well. Such problems have been posed as multiobjective programming models. This paper presents a novel user interface that is designed to help explore possible alternative corridors. This new interface allows for exploration in terms of both objective space and decision space and could be modified for other spatial decision-making problems as well.
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