At the conceptual design stage, automobile body is evaluated by simplified frame structure, consisting of thin-walled beams (TWBs). In the automobile practice, design engineers mostly rely on their experience and intu...
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At the conceptual design stage, automobile body is evaluated by simplified frame structure, consisting of thin-walled beams (TWBs). In the automobile practice, design engineers mostly rely on their experience and intuition when making decisions on cross-sectional shape of TWBs. So this paper presents a cross-sectional shape optimization method in order to achieve a high stiffness and lightweight TWB. Firstly, cross-sectional property formulations is summarized and reviewed. Secondly, we build up a shape optimization model to minimize the cross-sectional area and satisfy the stiffness and manufacturing demands. The objective and constraints are nonlinear polynomial functions of the point coordinates defining the cross-sectional shape. Genetic algorithm is introduced to solve this nonlinear optimization problem. Thirdly, object-oriented programming and design patterns are adopted to design and implement the software framework. Lastly, numerical example is used to verify the presented method. This software, "SuperBeam" for short, is released for free and does speed up the conceptual design of automobile body. (C) 2013 Elsevier Ltd. All rights reserved.
We describe implementation of a modular system of computer codes for inversion of electromagnetic geophysical data, referred to as ModEM. The system is constructed with a fine level of modular granularity, with basic ...
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We describe implementation of a modular system of computer codes for inversion of electromagnetic geophysical data, referred to as ModEM. The system is constructed with a fine level of modular granularity, with basic components of the inversion - forward modeling, sensitivity computations, inversion search algorithms, model parametrization and regularization, data functionals - interchangeable, reusable and readily extensible. Modular sensitivity computations and generic interfaces to parallelized inversion algorithms provide a ready framework for rapid implementation of new applications or inversion algorithms. We illustrate the code's versatility and capabilities for code reuse through implementation of 3D magnetotelluric (MT) and controlled-source EM (CSEM) inversions, using essentially the same components. (C) 2014 Elsevier Ltd. All rights reserved.
Semantic Web applications share a large portion of development effort with database-driven Web applications. Existing approaches for development of these database-driven applications cannot be directly applied to Sema...
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Semantic Web applications share a large portion of development effort with database-driven Web applications. Existing approaches for development of these database-driven applications cannot be directly applied to Semantic Web data due to differences in the underlying data model. We develop a mapping approach that embeds Semantic Web data into object-oriented languages and thereby enables reuse of existing Web application frameworks. We analyse the relation between the Semantic Web and the Web, and survey the typical data access patterns in Semantic Web applications. We discuss the mismatch between object-oriented programming languages and Semantic Web data, for example in the semantics of class membership, inheritance relations, and object conformance to schemas. We present ActiveRDF, an object-oriented API for managing RDF data that offers full manipulation and querying of RDF data, does not rely on a schema and fully conforms to RDF( S) semantics. ActiveRDF can be used with different RDF data stores: adapters have been implemented to generic SPARQL endpoints, Sesame, Jena, Redland and YARS and new adapters can be added easily. We demonstrate the usage of ActiveRDF and its integration with the popular Ruby on Rails framework which enables rapid development of Semantic Web applications. (c) 2008 Elsevier B. V. All rights reserved.
Simulation-based optimization for industrial process lines is discussed in this paper. Our approach combines multidisciplinary modeling, modern sensitivity analysis methodology as well as multiobjective optimization b...
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Simulation-based optimization for industrial process lines is discussed in this paper. Our approach combines multidisciplinary modeling, modern sensitivity analysis methodology as well as multiobjective optimization by means of object-oriented software design principles. As a result, a simulation and optimization approach that can be extended and modified due to users' needs can be developed. Our approach is illustrated by a real-world example from papermaking industry.
The aim of this paper is to describe an efficient method to connect two independent softwares so as to jointly use best qualities of each software around a complex problem solved by the finite element emethod (FEM). T...
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The aim of this paper is to describe an efficient method to connect two independent softwares so as to jointly use best qualities of each software around a complex problem solved by the finite element emethod (FEM). This connection makes it possible to extend quickly and easily the applicability of new models developed in academic softwares, by their simultaneous use with commercial softwares. This is particularly interesting when these models are vey difficult to implement directly in commercial softwares. Most of the commercial FEM applications allow users to add additional features, physical models or boundary conditions via a programing interface. Within these user routines, access to internal data structures is possible, either through subroutine parameters and global variables, or via internal modules for reading and storing data. We use these capabilities to link the commercial software ABAQUS and an academic object-oriented C++ software HEREZH++, via the user-defined mechanical material behaviour (Umat). In this interface, HEREZH++ computes the mechanical behaviour of material and the code coupling performs a communication procedure between ABAQUS and HEREZH++. This paper describes this architecture which allows to implement easily original behaviour law and an interface written in c/C++. Several test samples are presented to show the efficiency and accuracy of the proposed implementations concernning the computational time. In particular, an industrial test is carried out with an original behaviour model of clasto-viscohysteresis which would have been very difficult to implement directly in ABAQUS. (c) 2008 Elsevier Ltd. All rights reserved.
作者：
Xu, DXNanjing Univ
Dept Comp Sci & Technol State Key Lab Novel Software Technol Nanjing 210093 Peoples R China
This article presents an object-oriented logic framework, I,KO, for the dependable development of knowledge based systems. Based on logical objects which are viewed as abstractions with states, constraints, behaviors ...
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This article presents an object-oriented logic framework, I,KO, for the dependable development of knowledge based systems. Based on logical objects which are viewed as abstractions with states, constraints, behaviors and nonmonotonic inheritance, a hybrid knowledge representation amalgamating rule, frame, semantics network and blackboard is available for both most structured end flat knowledge and requirements of knowledge based systems. After the iterations of specification modification and verification in terms of knowledge acquisition activities, prototypes are correctly formed. The LKO methodology, applying the concepts of rapid prototyping, top-down design and object-orientation, is designed to deal with changing and incomplete requirements and to provide multiple abstract models of the domain, where formal methods might be used at each abstract level. (C) 1998 Elsevier Science B.V. All rights reserved.
Developing interactive software systems with complex user interfaces has become increasingly common. Given this trend, it is important that new technology be based on flexible architectures that do not require develop...
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Developing interactive software systems with complex user interfaces has become increasingly common. Given this trend, it is important that new technology be based on flexible architectures that do not require developers to understand all the complexities inherent in a system. object-oriented frameworks provide an important enabling technology for reusing both the architecture and the functionality of software components. But frameworks typically have a steep learning curve since the user must understand the abstract design of the underlying framework as well as the object collaboration rules or contracts-which are often not apparent in the framework interface-prior to using the framework. In this article, the author describes her experience with developing an object-oriented framework for speech recognition applications that use IBM's ViaVoice speech recognition technology. Design patterns help to effectively communicate the internal framework design and reduce dependence on the documentation.
This paper presents techniques for solving systems of equations arising in finite element applications using a localized, tensor-based approach. The approach is localized in that a major part of the solution responsib...
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This paper presents techniques for solving systems of equations arising in finite element applications using a localized, tensor-based approach. The approach is localized in that a major part of the solution responsibility is delegated to vector degree-of-freedom objects, rather than residing solely in a global solver working on a monolithic data structure. The approach is tensor-based in that the fundamental quantities used for computation are considered to be second-order tensors. The localized data structure strategy provides the benefits of an efficient sparse and symmetric storage scheme without requiring complex implementation code. The tensor-based aspect of the approach can bring substantial performance benefits by increasing the granularity at which solution algorithms deal with their data. Java and C++ implementations of interactive finite element programs are used to demonstrate performance that is competitive with other available solvers, especially in the case of problems for which interactive analysis is feasible on commonly available hardware. (C) 2003 Elsevier Science Ltd. All rights reserved.
Alarm processing is a traditional feature of energy-management systems (EMS), and has not changed significantly over several generations of SCADA design. This paper describes two parts of a project between the Univers...
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Alarm processing is a traditional feature of energy-management systems (EMS), and has not changed significantly over several generations of SCADA design. This paper describes two parts of a project between the University of Dundee and Scottish Hydro-Electric pie (HE) on the use of an Artificial Intelligence system for alarm processing and fault diagnosis. The first part of the project was an overview and comparison study of three real-time object-oriented toolkits: Muse, Kappa and Nexpert object. The study is based on the capabilities of such toolkits to handle the power system alarm processing, integration with external programs and real-time databases, portability, price and execution speed. Some advantages and drawbacks of each toolkit are also pointed out. The second part of the project was the implementation of an object-oriented expert system using the KappaPC toolkit operating on a 486 IBM compatable PC under Microsoft Windows 3.1. The toolkit was chosen in the first part of the project, for the initial development of a prototype real-time alarm-processing and fault-diagnosis system. The structure of the object-oriented expert system captures the heuristic knowledge used for power system operation. The knowledge-base is automatically updated by the existing SCADA system as the power system's status changes. The paper also describes the features of the real-time object-oriented expert system;these include the need for fast, deep-level reasoning, easy maintainability of the object-oriented programming and the end user's interface.
At the conceptual design stage, simplified finite element (FE) model of body-in-white (BIW) structure focuses on its specific merit to provide early-stage predictions for detailed FE model of that. This paper exploits...
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At the conceptual design stage, simplified finite element (FE) model of body-in-white (BIW) structure focuses on its specific merit to provide early-stage predictions for detailed FE model of that. This paper exploits a semi-rigid beam element (SRBE) that consists of a beam element with two semi-rigid connections at the ends to simulate the flexibility of joint. Guyan reduction method condenses the SRBE as a super element. A special finite element software for structural modeling and analysis of BIW (SMAB) is developed in .NET framework. The Unified Modeling Language is employed to depict the classes and their relationship. The design patterns are identified and applied in the framework design to facilitate communication and system expansion. Microsoft DirectX and GDI+ implement graphics display of spatial BIW frame and planar thin-walled cross section. Based on multi-threaded technology in .NET, subspace iteration method is paralleled to speed up the mode analysis. As a result, the efficiency of the SRBE is demonstrated by a benchmarking automotive body. Multi-threaded parallel is effective and useful, especially for frequency optimization. (C) 2011 Elsevier Ltd. All rights reserved.
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