面向对象的交互式三维布局仿真系统OO3DP

本文详细描述了一个利用面向对象技术建立的交互式三维空间实体布局仿真系统。该系统的主要目的有两个:一是为用户布局提供一个计算机仿真环境,以代替以往的实物模型布局系统;二是为集成化智能三维实体布局系统提供一种开放式的面向对象的交互式界面及集成基础结构。     

面向对象的电阻应变虚拟测试系统设计与实现

提出了基于虚拟仪器技术的电阻应变虚拟测试系统的体系结构和功能模型,建立了电阻应变虚拟测试应用软件的面向对象模型,并介绍了采用LabVIEW的虚拟测试应用软件的实现方法.所提出的虚拟测试应用软件模型以及子虚拟仪器通用性强,可移植用于其他机械量虚拟测试系统和面向先进制造系统质量检测集成测试环境等的研究开发.     

面向对象的交互式三维布局仿真系统003DP

本文详细描述了一个利用面向对象技术建立的交互式三维空间实体布局仿真系统,该系统的主要目的有两个:一是为用户布局提供一个计算机仿真环境,以代替以往的实物模型布局系统;二是为集成化智能三维实体布局系统提供一种开放式的面向对象的交互式界面及集成基础结构。     

面向对象与STEP技术相结合的信息建膜方法研究

计算机集成制造系统（ＣＩＭＳ）的关键在于信息集成与信息交换。而信息模型的建立是实现ＣＩＭＳ信息完整而一致地描述与交换的重要基础性工作。本文基于ＳＴＥＰ思想，在分析传统建模方法和面向对象（０－０）建模方法的基础上，提出了将０—０技术与ＳＴＥＰ技术相结合的信息建模方法。     

面向对象的交互式三维布局仿真系统003DP

本文详细描述了一个利用面向对象技术建立的交互式三维空间实体布局仿真系统。该系统的主要目的有两个:一是为用户布局提供一个计算机仿真环境,以代替以往的实物模型布局系统;二是为集成化智能三维实体布局系统提供一种开放式的面向对象的交互式界面及集成基础结构。     

基于面向对象Petri网的工作流建模及性能分析

工作流技术作为一种过程建模和过程管理的核心技术,在计算机应用领域获得了迅速的发展。介绍了工作流技术;提出了将面向对象建模技术融入Petri网模型所形成的面向对象Petri网,并讨论了建立基于面向对象Petri网的工作流模型的步骤;运用面向对象Petri网建立了某制造企业的产品方案处理流程的工作流模型,并运用性能等价公式对工作流模型的性能进行了分析。     

基于XML的CAD/CAPP/CAM信息集成技术

在比较目前几种流行的系统集成技术的基础上 ,通过采用基于特征、面向对象的方法为产品几何数据和非几何数据建立信息模型 ,结合以计算机内部模型表达的产品定义数据 ,提出了一种基于 XML 标准的信息集成解决方案 ,并首次将 JDOM技术和 XQL查询技术珠联璧合地结合在一起实现对 XML文档高效地访问、操作 .该方案以灵活的数据模式、可重用的信息模块、易扩展的数据接口有效地、可靠地解决产品在设计和制造过程中信息的交换和共享 .     

面向制造过程的CAQ系统研究

计算机辅助质量系统是企业进行质量管理强有力的工具。文中阐述了CAQ系统的基本思想及其综合集成功能结构,分析了制造过程的主要质量职能。在此基础上,建立了面向制造过程的CAQ系统的功能模型,开发了原型系统,并结合实例进行了说明。     

面向对象着色Petri网的板级电子产品拟实制造系统

基于面向对象着色Petri网(OCPN)模型，结合面向对象方法和Petri网，建立了板级电子产品拟实制造系统(VMS)的仿真模型，开发了VMS软件，并给出了仿真结果。     

VM及其在过程控制系统中的应用

虚拟制造系统ＶＭ是通过计算机模型和仿真技术模拟实现产品生产和信息处理过程，它首先在离散型制造系统中得到广泛应用，本文根据过程控制系统自身的特点，把虚拟过程控制系统同计算机集散型控制系统结合起来，建立了建模、控制、优化与仿真计算机集成化环境，并把制浆造纸生产线各工段的动态数学模型和静态数学模型及控制算法输入到集成环境中，建立了制浆造纸生产线模拟系统，仿真结束和实际运行验证了它的有效性     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.