有机/无机纳米复合材料的研究进展

近年来纳米科技得到了迅速发展,由无机纳米粒子与聚合物复合制备的有机/无机纳米复合材料成为现代材料科技发展的重要方向.概述了有机/无机纳米复合材料的制备方法和性能特点;介绍了有机/无机纳米复合材料的应用领域,最后对它的发展前景进行了展望.     

Improvement of Fracture Toughness Lanthanum Zirconate

Thermalbarriercoatings(TBCs)havefoundan increasingnumberofapplicationsinprotectinghigh temperaturemetalliccomponents,forexample,TBCsaredepositedontransitionpieces,combustion lines,first stagebladesandvanes,andotherhot pathcomponentsofgasturbineseithertoincreasethe inlettemperaturewithaconsequentimprovementof theefficiencyortoreducetherequirementsfora coolingsystem[1].Thereareseveralceramicsthat havebeenevaluatedasTBCmaterials[2].Lanthanum zirconatewasrecentlyproposedasapromisingTBC materia…     

MATLAB与Java的联合应用研究

科学与工程领域经常涉及网络环境下的工程计算问题。MATLAB具有很强的数值计算能力,Java是目前普遍使用的网络应用开发工具。本文研究了工程计算问题中的MATLAB与Java联合途径,提出二者联合应用的三种方法。研究与应用表明,这些方法能够将MATLAB的运算能力与Java的网络开发功能结合起来,实现二者的优势互补,拓宽应用领域,增强应用程序的处理能力,很好地解决网络环境下的工程计算问题。由于三种方法各有所长,在实际应用中要根据具体问题和要求的不同进行合适的选择。     

数据挖掘:建模、算法、应用和系统

数据挖掘是20世纪末逐渐形成的一个多学科交叉领域,目前已经广泛成功地应用在金融、零售、医药、通讯、电子工程、航空、旅馆等有大量数据和深度分析需求的领域。文中对数据挖掘的建模、算法、应用和软件工具进行了综述,给出了数据挖掘的定义、范畴和特点,以及数据挖掘的数据集的各种实际情况;总结了数据挖掘在实际应用时的基本步骤和过程;对数据挖掘在各种应用问题上的任务和建模进行了讨论;列举了目前数据挖掘领域中主要流行的算法,并对算法设计需要考虑的问题进行了简要的分析;综述了目前数据挖掘算法在一些领域的应用;较全面地叙述了目前数据挖掘软件工具性能及其开发商情况;最后,对数据挖掘的发展前景和方向进行了展望。     

CASE-BASED REASONING AND KNOWLEDGE DISCOVERY IN MEDICAL APPLICATIONS WITH TIME SERIES

This paper discusses the role and integration of knowledge discovery (KD) in case-based reasoning (CBR) systems. The general view is that KD is complementary to the task of knowledge retaining and it can be treated as a separate process outside the traditional CBR cycle. Unlike knowledge retaining that is mostly related to case-specific experience, KD aims at the elicitation of new knowledge that is more general and valuable for improving the different CBR substeps. KD for CBR is exemplified by a real application scenario in medicine in which time series of patterns are to be analyzed and classified. As single pattern cannot convey sufficient information in the application, sequences of patterns are more adequate. Hence it is advantageous if sequences of patterns and their co-occurrence with categories can be discovered. Evaluation with cases containing series classified into a number of categories and injected with indicator sequences shows that the approach is able to identify these key sequences. In a clinical applica-tion and a case library that is representative of the real world, these key sequences would improve the classification ability and may spawn clinical research to explain the co-occurrence between certain sequences and classes.     

Client-Centric Adaptive Scheduling of Service-Oriented Applications

The paper proposes a client-centric computing model that allows for adaptive execution of service-oriented applications. The model can flexibly dispatch application tasks to the client side and the network side, dynamically adjust an execution scheme to adapt to environmental changes, and thus is expected to achieve better scalability, higher performance and more controllable privacy. Scheduling algorithms and the rescheduling strategies are proposed for the model. Experiments show that with the model the performance of service-oriented application execution can be improved.     

An empirical examination of a process-oriented IT business success model

The value of information technology (IT) to modern organizations is almost undeniable. However, the determination of that value has been elusive in research and practice. We used a process-oriented research model developed using two streams of IT research to examine the value of IT in business organizations. One stream is characterized by examining how IT and non-IT variables affect other so-called IT success variables. The second stream is commonly referred to as IT business value, defined as the contribution of IT to firm performance. The resulting research model is referred to in our paper as the IT business success model. Data was collected from 225 top IS executives in fairly large organizations to empirically examine several hypotheses derived from theory concerning the causal nature of the IT business success model. A set of measures for the IT business success model was developed through an intense investigation of the IT literature. The measures were tested for validity and reliability using confirmatory factor analysis. The hypotheses that resulted from past research and conceptually illustrated in the research model were assessed using structural equation analysis. The implications of these findings and the limitations of the study are discussed in an effort to contribute to building a process-oriented theory base for IT business success at the organizational level of analysis.     

基于整体映射的不规则三维模型多细节层次描述

针对无孔洞、有边界的不规则三维模型，提出一种整体映射的多细节层次描述方法：先通过整体映射变换，将三维网格无遮挡、均匀地映射到平面正方形中；再通过正方形中初始网格的自动细化和重采样，得到所需的网格简化模型；获取不同层次简化模型，从而构建多细节层次描述。相对于传统的几何元素删除型网格简化局部型算法，以及新近的基于几何图像描述的整体型算法，该方法算法快速、简单、稳定，描述效果也较好。     

联机分析处理中的非规则维建模

预聚集技术通过预先计算并保存原始数据上的查询结果以实现联机分析处理系统的快速查询响应能力．然而，在实际应用中，许多非规则维的结构难以使用传统多维模型进行建模，从而影响了预聚集技术的使用．为此，基于子级别到父级别的部分映射定义级别之间的部分序关系，进而提出了一个支持非覆盖、非映上等非规则雏中维级别关系建模的维模型．同时，在维模型基础上，定义了支持非规则维的立方体模型以及典型的联机分析处理操作．多维模型与关系模式的转换定义和实例分析证明了该多维模型可以实现对各种非规则维的建模支持，保证了预聚集技术在联机分析处理中的使用．     

GEAMAS: A Generic Architecture for Agent-Oriented Simulations of Complex Processes

This paper's object is to present the results of the GEAMAS project which aims at modeling and simulating natural complex systems. GEAMAS is a generic architecture of agents used to study the behavior emergence in such systems. It is a multiagent program meant to develop simulation applications. Modeling complex systems requires to reduce, to organize the system complexity and to describe suitable components. Complexity of the system can then be tackled with an agent-oriented approach, where interactions lead to a global behavior. This approach helps in understanding how non-determinist behavior can emerge from interactions between agents, which is near of self-organized criticality used to explain natural phenomena. In the Applied Artificial Intelligence context, this paper presents an agent software architecture using a model of agent. This architecture is composed of three abstract levels over which the complexity is distributed and reduced. The architecture is implemented in ReActalk, an open agent-oriented development tool, which was developed on top of Smalltalk-80. To illustrate our purpose and to validate the architecture, a simulation program to help in predicting volcanic eruptions was investigated. This program was run over a period of one year and has given many satisfying results unattainable up to there with more classical approaches.