492 research outputs found
Parallel software tool for decomposing and meshing of 3d structures
An algorithm for automatic parallel generation of three-dimensional unstructured computational meshes based on geometrical domain decomposition is proposed in this paper. Software package build upon proposed algorithm is described. Several practical examples of mesh generation on multiprocessor computational systems are given. It is shown that developed parallel algorithm enables us to reduce mesh generation time significantly (dozens of times). Moreover, it easily produces meshes with number of elements of order 5 · 107, construction of those on a single CPU is problematic. Questions of time consumption, efficiency of computations and quality of generated meshes are also considered
Applying multiobjective evolutionary algorithms in industrial projects
During the recent years, multiobjective evolutionary algorithms have matured as a flexible optimization tool which can be used in various areas of reallife applications. Practical experiences showed that typically the algorithms need an essential adaptation to the specific problem for a successful application. Considering these requirements, we discuss various issues of the design and application of multiobjective evolutionary algorithms to real-life optimization problems. In particular, questions on problem-specific data structures and evolutionary operators and the determination of method parameters are treated. As a major issue, the handling of infeasible intermediate solutions is pointed out. Three application examples in the areas of constrained global optimization (electronic circuit design), semi-infinite programming (design centering problems), and discrete optimization (project scheduling) are discussed
Fuzzy Logic
Fuzzy Logic is becoming an essential method of solving problems in all domains. It gives tremendous impact on the design of autonomous intelligent systems. The purpose of this book is to introduce Hybrid Algorithms, Techniques, and Implementations of Fuzzy Logic. The book consists of thirteen chapters highlighting models and principles of fuzzy logic and issues on its techniques and implementations. The intended readers of this book are engineers, researchers, and graduate students interested in fuzzy logic systems
A comprehensive part model and graphical schema representation for object-oriented databases
Part-whole modeling plays an important role in the development of database schemata in data-intensive application domains such as manufacturing, design, computer graphics. text document processing, and so on. Object-oriented databases (OODBs) have been targeted for use in such areas. Thus, it is essential that OODBs incorporate a part relationship as one of their modeling primitives. In this dissertation, we present a comprehensive OODB part model which expands the boundaries of OODB part-whole modeling along three fronts. First, it identifies and codifies new semantics for the OODB part relationship. Second, it provides two novel realizations for part relationships and their associated modeling constructs in the context of OODB data models. Third. it, provides an extensive graphical notation for the development of OODB schemata.
The heart of the part model is a part relationship that imposes part-whole interaction on the instances of an OODB. The part relationship is divided into four characteristic dimensions: (1) exclusive/shared. (2) cardinality/ordinality, (3) dependency. and (A) value propagation. The latter forms the basis for the definition of derived attributes in a part hierarchy.
To demonstrate the viability of our part model, we present two novel realizations for it in the context of existing OODBs. The first realizes the part relationship as an object class and utilizes only a basic set of OODB constructs. The second realization, an implementation of which is described in this dissertation, uses the unique metaclass mechanism of the VODAK Model Language (VML). This implementation shows that our part model can be incorporated into an existing OODB without having to rewrite a substantial subsystem of the OODB, and it also shows that the VML metaclass facility can indeed support extensions in terms of new semantic relationships.
To facilitate the creation of part-whole schemata, we introduce an extensive graphical notation for the part relationship and its associated constructs. This notation complements our more general OODB graphical schema representation which includes symbols for classes, attributes. methods. and a variety of relationships. OO-dini, a graphical schema editor that employs our notation and supports conversion of the graphical schema into textual formats, is also discussed
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Modelling information usage and decision processes in new product introductions : an information-processing perspective.
The objective of this study is to understand the problem solving process used in new product introductions, and other unstructured business problems. I hope this understanding will contribute to improved decision support systems. Based on Cognitive psychology theories (in particular, Anderson, 1983, 1987), a set of propositions were outlined and investigated by using a computer model. One application of the expert system shell, used here, is to try to model the expert\u27s knowledge. The shell is used to develop a system that simulates the expert\u27s approach to problem solving. The differences between this application and expert system development, are: (i) the focus is on trying to understand the mind of the expert, instead of trying to replace him; and (ii) the problem area is ill-structured, instead of narrow and well-defined. The introduction of new products into markets is an example of an ill-structured problem, in a business setting. In particular, identifying opportunities is to create new products--their future growth and competitiveness often depends on this. The method adopted, computer simulation, has both advantages and limitations. The advantages include: (i) in-depth analysis of the problem-solving process; (ii) operationalizing the theory; and (iii) producing a program that can act as a research vehicle for future projects. The limitations are: (i) small sample size; (ii) lack of clear-cut validation procedures; and (iii) dependence on shell features. The findings, for the most part, supported the propositions (i) The expert model clearly had more procedural knowledge than the textbook model. This supports the proceduralization theory of skill acquisition. (ii) Reasoning by analogy was used by both expert and novices. The use of weak methods by the expert does not support the theory. (iii) The expert adopted a forward reasoning strategy within a task agenda. This supports the hierarchical goal structure theory of Anderson. (iv) The use of soft information was also observed
The nature and evaluation of commercial expert system building tools, revision 1
This memorandum reviews the factors that constitute an Expert System Building Tool (ESBT) and evaluates current tools in terms of these factors. Evaluation of these tools is based on their structure and their alternative forms of knowledge representation, inference mechanisms and developer end-user interfaces. Next, functional capabilities, such as diagnosis and design, are related to alternative forms of mechanization. The characteristics and capabilities of existing commercial tools are then reviewed in terms of these criteria
Rationality and metacognition in non-human animals
The project of understanding rationality in non-human animals faces a number of conceptual and methodological difficulties. The present chapter defends the view that it is counterproductive to rely on the human folk psychological idiom in animal cognition studies. Instead, it approaches the subject on the basis of dynamic- evolutionary considerations. Concepts from control theory can be used to frame the problem in the most general terms. The specific selective pressures exerted on agents endowed with information-processing capacities are analysed. It is hypothesized that metacognition offers an evolutionary stable response to the various demands of the internal and external flows of information in a competitive environment. Metacognition provides a form of process-reflexivity that can, but does not have to be redeployed through metarepresentations. Finally the claim that rationality so conceived involves normativity is discussed
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