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High impact strength poly(phenylene oxide)-polyamide blends can be prepared by chemically coupling the two components and incorporating a rubbery impact modifier in the resin. The resulting materials exhibit a distinctive morphology in which the rubber is selectively incorporated in the dispersed poly(phenylene oxide) phase. In this paper both the structure and toughening mechanisms in these blends are examined. An analysis of their deformation behaviour is presented in a companion paper.  相似文献   
84.
Curve-skeleton properties, applications, and algorithms   总被引:7,自引:0,他引:7  
Curve-skeletons are thinned 1D representations of 3D objects useful for many visualization tasks including virtual navigation, reduced-model formulation, visualization improvement, animation, etc. There are many algorithms in the literature describing extraction methodologies for different applications; however, it is unclear how general and robust they are. In this paper, we provide an overview of many curve-skeleton applications and compile a set of desired properties of such representations. We also give a taxonomy of methods and analyze the advantages and drawbacks of each class of algorithms  相似文献   
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This paper describes a technique to animate three-dimensional sampled volumes. The technique gives the animator the ability to treat volumes as if they were standard polygonal models and to use all of the standard animation/motion capture tools on volumetric data. A volumetric skeleton is computed from a volumetric model using a multi-resolution thinning procedure. The volumetric skeleton is centered in the object and accurately represents the shape of the object. The thinning process is reversible in that the volumetric model can be reconstructed from the volumetric skeleton. The volumetric skeleton is then connected and imported into a standard graphics animation package for animation. The animated skeleton is used for reconstruction, which essentially recreates a deformed volume around the deformed skeleton. Polygons are never computed and the entire process remains in the volumetric domain. This technique is demonstrated on one of the most complex 3D datasets, the Visible Male, resulting in actual “human animation”.  相似文献   
87.
Document understanding, the interpretation of a document from its image form, is a technology area which benefits greatly from the integration of natural language processing with image processing. We have developed a prototype of an Intelligent Document Understanding System (IDUS) which employs several technologies: image processing, optical character recognition, document structure analysis and text understanding in a cooperative fashion. This paper discusses those areas of research during development of IDUS where we have found the most benefit from the integration of natural language processing and image processing: document structure analysis, optical character recognition (OCR) correction, and text analysis. We also discuss two applications which are supported by IDUS: text retrieval and automatic generation of hypertext links  相似文献   
88.
Genetic algorithms are a technique for search and optimization based on the Darwinian principle of natural selection. They are iterative search procedures that maintain a population of candidate solutions. The best or most fit solutions in that population are then used as the basis for the next generation of solutions. The next generation is formed using the genetic operators reproduction, crossover, and mutation. Genetic algorithms have been successfully applied to engineering search and optimization problems. This paper presents a discussion of the basic theory of genetic algorithms and presents a genetic algorithm solution of a lumber cutting optimization problem. Dimensional lumber is assigned a grade that represents its physical properties. A grade is assigned to every board segment of a specific length. The board is then cut in various locations in order to maximize its value, A genetic algorithm was used to determine the cutting patterns that would maximize the board value.  相似文献   
89.
Hypermedia technologies have been available for about a decade. Beginning with Douglas Engelbart, researchers have become interested in applying hypermedia concepts and technologies to software development. This paper assesses this symbiosis between hypermedia and software development as described by research contributions; by our count, more than one hundred articles. To date, no collection of, or guide to, this literature has been published. A number of significant contributions are classified, described, and appraised — providing a guide into what has been a rich but perhaps under-reported research area. Hypermedia has made significant contributions to software development in three primary areas: coping with massive amounts of information associated with software development projects; establishing and maintaining linkages between various types of software engineering documents; and enabling development engineers to record, document, and preserve knowledge about development thoughts, processes and rationale. These contributions may help direct the focus of future research towards building on, combining and assessing the resulting contributions. A research agenda is proposed along these lines.  相似文献   
90.
Although e-commerce adoption and customers’ initial purchasing behavior have been well studied in the literature, repeat purchase intention and its antecedents remain understudied. This study proposes a model to understand the extent to which trust mediates the effects of vendor-specific factors on customers’ intention to repurchase from an online vendor. The model was tested and validated in two different country settings. We found that trust fully mediates the relationships between perceived reputation, perceived capability of order fulfillment, and repurchasing intention, and partially mediates the relationship between perceived website quality and repurchasing intention in both countries. Moreover, multi-group analysis reveals no significant between-country differences of the model with regards to the antecedents and outcomes of trust, except the effect of reputation on trust. Academic and practical implications and future research are discussed.  相似文献   
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