制冷设备在线自动质量检测系统

针对制冷设备生产过程中质量检测手段的落后状况,遵从产品质量检测的原则,提出了产品在线自动质量检测的设计方案：详细介绍了采用两级计算机控制的方法,在冰柜生产过程中质量自动检测系统的实现方案,给出了检测线的结构和布局、两级计算机的功能划分、数据结构、通讯数据格式和最终运行结果。该系统已经应用到实际项目中,取得了良好的应用效果。     

990WS—Ⅱ工作站加固技术

本文着重从结构设计、热设计和电磁屏蔽三方面介绍了990WS-Ⅱ工作站的加固技术,并提出了在热设计中采用半导体制冷技术的关键所在。990WS-Ⅱ工作站是我所以SPARC工作站为主机,引进商业机芯LX模块进行后天加固而成,目前已通过各项例行试验,已形成系列产品。     

利用人工神经网络技术实现智能控制

本文研究一种利用人工神经网络(ANN)技术实现智能控制的方法,介绍一个基于 ANN 的冰柜温度智能控制系统及其有关性能。这一系统以一个事先经过培训的多层感知器为核心,动态地调整冰柜内部的温度,使其适应外界环境和各种不可观测的噪音干扰,维持在希望的范围内。实践表明,ANN 技术适应智能控制的要求,具有许多潜在能力。     

冰箱性能自动测试系统

介绍一种冰箱、冷柜基本性能自动测试的计算机系统.该系统根据国家标准要求设计,可用于技术监督部门对冰箱、冷柜进行抽样型式试验和生产厂家的出厂检验与产品开发试验.     

制冷与空调产品性能测试系统开发

为加强制冷空调产品的性能检测,保证制冷空调产品向高效、节能的方向发展.按照国家标准,开发了多功能制冷与空调产品性能测试系统,分析了该试验台的工作原理,介绍了测控系统的软、硬件设计方案,重点对该测控系统软件设计中采用的多线程和动态链接库技术作了论述.运行结果表明,该性能测试系统功能齐全,工作可靠.     

制冷仿真实训系统

针对目前制冷企业技能培训的教学手段落后与制冷企业自动化管理水平普遍较低的现象。开发了制冷仿真软件1．0。该文首先阐明了软件的功能定位，并对开发工具MCGS的特点与运行机理作了讨论；通过制冷压缩机仿真模型的建立。重点分析了制冷仿真系统的建模方法——以各个设备为对象、对于不同的蒸发系统以热平衡和质平衡为主线，建立系统数学模型；对各个对象的传质与传热基理，在不违背制冷工艺变化规律的前提下，作恰当地较大简化，在此基础上使系统能动态地仿真其变化规律；最后对软件的各部分组成与功能作了介绍。     

光电探测系统多学科分布式仿真平台设计

针对光电探测产品系统级验证和评估的需要,设计开发了一个多学科分布式仿真平台。通过搭建仿真运行支撑环境、紧密集成光电探测涉及的各学科工具软件,构建了包括目标大气系统、光学系统、探测器系统、信号处理系统、控制系统以及监测评估系统的虚拟试验可配置运行环境。重点介绍了运行支撑环境的设计,并给出了各学科工具软件的集成方法,最后讨论了仿真平台下虚拟MRTD试验系统和虚拟外场试验系统的搭建。     

制冷空调试验平台远程监控系统中的ActiveX

针对目前的全自动制冷空调试验平台监控系统缺乏远程调试、远程监控、远程故障检测和分析等能力，提出了一种基于Internet的制冷空调试验平台监控系统，对系统的基本构架、系统服务器端与客户端ActiveX技术的实现进行了设计，利用ASP和ActiveX控件技术实现动态发布和在线监控的功能，最后论述采用ActiveX技术的网络安全问题。通过ActiveX技术的应用增强了系统的可扩展性，方便了系统的升级与维护。     

飞机电源试验数字式测试系统

介绍应用于地面飞机电源试验系统的计算机测控系统,同样适于工频电源系统的试验,介绍了该系统的硬件结构及工作原理.经过实际使用证明运行可靠,试验自动化程度高使用方便等特点.     

冰箱、冰柜、冷库温度检测系统问世

由湖南省计算技术研究所研制的冰箱冰柜冷库温度检测系统具有测量精度高＼检测速度快、性能可靠＼抗干扰能力强、安装调试方便、操作维护容易等优点。本温度检测系统由一台微机、多台温度检测仪和感温头组成。系统的联结采用了光电隔离技术。就本系统而言，它既可用作日抽检数台样机的温度检查，又可满足日产数千台的冰箱冰柜生产厂的老化测试。该检测系统的温度测量范围一50℃～＋120℃，误差仅为主O．2℃。本系统在硬件不变的情况下，换上冷库、冷冻加工厂的测量控温软件，即可用于冷库、冷冻加工厂的温度检测和自动控制。冰箱、冰柜、冷…     

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.