基于XML的网络资源描述和交换

基于网络的信息传递具有交流快、内容丰富、交互性强等特点．而可扩展性标记语言XML的发展，给网络带来了新的生机．为了使得网络资源的可重用性提高，使XML能更好地作为数据交换通用格式在各种应用场合得到广泛应用．本文结合一个开发实例探讨了如何应用XML组织和描述网络资源信息，并给出了基于XML的网络资源和交换的方法和过程．这种方法的使用可以使XML适用于对各类复杂数据形式的描述，在web的不同应用领域，尤其在电子商务应用领域发挥更大的作用、     

基于B—rep模型的特征CAD系统

提出了一种特征分离表达模式，将几何信息与特征参数信息分别表达在Ｂ－ｒｅｐ模型和参数化数据模型中，但又互相关联，可较为完备地表达零件各层次信息。讨论了特征关系的表达策略，提出了特征设计中有效性检验的必要性和算法。     

联邦数据库系统协商机制的设计和实现

联邦分布数据库系统支持异构自治和多库共享,为此,系统要解决的一个主要问题是协商机制的实现.本文论述了协商机制的结构、访问权限协商模型以及实现的主要步骤和技术,该机制具有灵活可扩充的联邦特点,可以方便地对系统进行剪裁.     

Does use-of-force simulation training in Canadian police agencies incorporate principles of effective training?

Numerous police agencies in Canada incorporate use-of-force simulation training into their overall instructional regime. A prominent theory of learning, known as cognitive load theory, suggests that in order for this training to be effective, instructional methods must facilitate the acquisition and automation of task-relevant schemas without overwhelming the limited processing capacity of the learner. In this article, several instructional effects, proposed and supported by the cognitive load literature, are discussed. These training effects operate by minimizing unnecessary cognitive demands, by drawing on instructional methods that enhance schema acquisition, and/or by carefully managing the inherent complexity of the to-be-learned material. The argument is advanced that although use-of-force simulation training may be able to capitalize on many of these effects, at present there is little evidence to suggest that it currently does. The authors conclude by discussing the urgent need to assess how the knowledge gained from cognitive load theory might serve to enhance the effectiveness of use-of-force simulation training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model independent assertions for integration of heterogeneous schemas

Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (DBAs) with a view definition language they can use to build the desired integrated schema. These techniques leave to the DBA the responsibility of appropriately restructuring schema elements from existing local schemas and of solving inter-schema conflicts. This paper investigates theassertion-based approach, in which the DBA's action is limited to pointing out corresponding elements in the schemas and to defining the nature of the correspondence in between. This methodology is capable of: ensuring better integration by taking into account additional semantic information (assertions about links); automatically solving structural conflicts; building the integrated schema without requiring conforming of initial schemas; applying integration rules to a variety of data models; and performing view as well as database integration. This paper presents the basic ideas underlying our approach and focuses on resolution of structural conflicts.     

基于属性相关表的关系模式全部候选关键字求法

本文提出了属性相关表这样一种新的概念，定义了相应的运算并研究了它的有关性质及定理，在此基础上提出了用属性相关表求关系模式全部主属性的等级，并给出了用主属性来组合关系模式全部候选关键字的算法，上述算法的时间复杂度均为Ｏ（ｎ＾２）。     

CAD^2B—一个计算机辅助数据库设计系统

本文介绍了一个用Ｔｕｒｂｏ Ｃ语言在ＡＳＴ－２８６机器上实现的计算机辅助数据库设计系统ＣＡＤ＾２Ｂ。该系统提供了人机交互的环境，供设计者进行概念模型设计，并自动完成从概念模型逻辑模型的映射，创建满足规范化要求的关系表。该系统采用的概念模型是引入了事件和时间的扩展了的实体关系模型。该模型既能充分反映应用环境的静态和动态语义，又是向关系模式转化的基础。     

基于XML异构数据库集成中间件的设计与实现

为了解决网络环境中异构数据库数据共享和协作问题,提出了基于XML中间件技术实现异构数据库之间信息交换模型.在此模型中对虚拟法或中介法模型进行改进设计了翻译器、集成器和转换器,分别用于数据获取、合并和格式转换.为了更精确地描述XML文件自身结构信息,实现了从DTD到XML Schema的转换.     

A framework for sharing product information across enterprises

Collaborative product commerce (CPC) is a newly emerging technology to support inter-enterprise collaboration through the product life-cycle. From the point of view of information technology, CPC is a software technology to integrate products, processes and resources of different enterprises using web technologies. In this paper, we propose a framework for integrating product information across enterprises, which is being developed by the Electronics and Telecommunications Research Institute (ETRI) as a part of a CPC project. The product metadata represented by an XML schema, which is compatible with the ISO STEP PDM (product Data Management) schema standard, is presented to semantically and schematically integrate distributed product information. Web services technologies are discussed to support the interoperability of application systems related to the product development, such as computer-aided design (CAD) and PDM, where most of these applications run in a distributed environment. Finally, we implement the framework to integrate distributed product information and application systems.     

汽车磁流变半主动悬架仿人智能控制研究

在建立整车动力学模型的基础上，设计了基于整车分姿态协调控制的仿人智能控制器。将汽车看成快速移动的机器人，把汽车运动姿态划分为八种姿态，对不同的运动姿态采用不同的控制模态，并在MATLAB平台上进行了仿真。选用某型号轿车作为试验车辆，用磁流变半主动悬架替代原车被动悬架，在多种条件下进行了实车道路试验，试验结果与仿真结果吻合，表明对整车进行分姿态协调控制是可行的。与被动悬架相比较，仿人智能控制可提高平顺性能近20％，能有效抑制车身的俯仰和侧倾运动，改善轮胎的接地性能，其控制效果优于对各悬架进行独立控制的天棚控制策略。