草图理解技术研究进展

本文概述了草图理解技术(包括草图识别和语义理解)的现状。首先，草图识别包括预处理和图形识别．根据各种图形处理机制，介绍了四种图形识别方法：基于笔划的、基于图元的、基于几何特征的、基于组合图形的。其次．深入分析了几个语义理解方法，一般包括三个环节：语义获取关系分析和高层应用。最后，本文提出了几何模型、用户模型和领域模型。讨论了草图理解中的主要问题并给出初步解决方案。     

采用快速图元匹配的手绘非规则军标识别

在线手绘非规则军标识别是基于草图的态势标绘系统的重要组成部分.针对非规则军标的图形线条可变性大的问题,提出一种结构化识别方法.首先定义并识别非规则军标草图的图元;然后用模糊方法描述图元间的拓扑关系,建立待识别样本与模板图形的图元匹配代价矩阵,并基于指派问题模型计算图形相似度;最后提出2种计算不完整的输入草图与模板图形相似度的方法.实验结果表明,文中方法是有效的.     

程序流程草图的存储表示及自动翻译算法

将手绘草图识别技术融于在线手绘程序流程草图的识别中,设计了一个存储图元的节点结构,提出基于上下文的在线手绘程序流程草图自动翻译算法,实现在线手绘程序流程草图的存储、识别和到C 语言代码的自动翻译和运行,实验证明该方法具有较高的识别效率。     

面向概念设计的组合图形草图识别方法

提出了一种面向机械产品概念设计的组合图形草图识别方法。将图形符号看作由多个单笔划图元构成的图形,首先识别出单个图元的类型并提取它们之间的空间位置关系;然后利用结构匹配法对标准图形结构进行定义,将用户绘制的图形与标准图形结构模板进行比较,筛选出结构相同的图形进行第一次图形过滤;再利用傅里叶形状描述子对图形形状进行描述,计算出图形形状相似度,筛选出形状相同的图形进行第二次过滤;最后将结构与形状两个特征相结合并运用到机械概念草图设计中,快速并准确地识别出机构运动副,实现机械结构的草图识别。     

数字集成电路初阶（四）

三、组合逻辑门电路实验(上) 在门电路中,我们已经学习了基本逻辑电路:与门、或门、非门以及较复杂的逻辑电路:或非门、与非门、异或门。以前都是利用一个独立的门进行实验的,来了解输入端电平高低的组合与输出端电平的逻辑关系。若把某些独立的门相互连接起来,组合后的逻辑关系又会是怎样的呢?在这一部分门电路实验中,将要了解组合门电路的逻辑运算有哪些基本定律,能够利用这些基本定律去分析组合门电路的逻辑功能,还能通过门     

基于草绘的机构识别及机构分析方法研究*

在概念设计阶段构造新型的支持创新过程的设计系统,对新产品的设计活动具有重要意义。在机械产品概念设计中将机构看成由图元构成的图形,提出一种面向概念设计的机构草图识别及分析方法,主要内容包括手绘草图输入及机构草图识别、机构方案运动分析。本文把手绘草图识别技术和机构运动相结合,通过对机构草图的识别以及机构的运动分析,实现在概念设计阶段对机构设计方案的评价分析。     

浅析CMOS逻辑门电路的应用模式

我们把基本逻辑运算的电子电路称之为逻辑门电路。在数字电路关系应用中,逻辑门电路中的门代表着基本逻辑关系的电路。在该文中,将重点分析CMOS逻辑门应用电路。     

基于C8051F500微控制器的逻辑门电路验证系统设计

为进一步优化逻辑门电路产品的验证与测试流程，基于C8051F500微控制器，提出一种逻辑门电路验证系统。系统综合运用微控制器技术、通信技术、计算机技术，可输出多路不同频率、相位的信号用作逻辑门电路激励，通过微控制器实时采集逻辑门电路的输出信号，也可在示波器上直接监测输出信号，准确验证与测试电路功能与性能。系统可用于测量与、或、非逻辑门电路及由其构成的其他逻辑门电路，适应性强，操作灵活方便，有助于简化实验人员操作流程。     

基于草图的人机交互技术研究进展

从草图识别和语义理解这两个方面对基于草图的人机交互技术的研究状况进行了分析和总结．对草图识别方法按其模式单元定义（笔划、图元、特征和组合图形）进行了分类和剖析;对草图语义理解所涉及的语义获取、语义解释和语义应用这三个关键问题及其解决方法进行了分析和阐述;并分别从基于草图的人机交互技术的几何模糊性、用户适应性和应用独旁性及其关系角度提出了这一领域的主要研究课题及其解决思路．     

传输门电路简化技术

利用传输门作开关,在数字、模拟电路中均得到广泛应用,单沟道和 CMOS 传输门用在动态电路中构成各种动态电路,使电路大大简化。本文叙述利用传输门简化静态电路,简化组合逻辑的技术,这种传输门电路简化技术,近年来在中、大规模集成电路特别是 CMOS 中、大规模电路中应用越来越多。     

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.     

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.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

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。