基于RS与GIS的典型地区土地利用/覆盖变化研究——以三江源生态环境重点保护区玛多县为例

典型地区和脆弱区的土地利用/覆盖变化是区域性研究的重要内容。三江源地区是国家级自然保护区,生态系统异常敏感和脆弱。以典型地区玛多县为案例,基于RS和GIS技术,系统研究了该地区土地利用/覆盖变化及其对景观格局的影响,探讨了生态环境演化过程,可为更广泛的区域性综合提供基础。研究发现:①10 a间,该地区湿地、水体和天然草地明显减少,湿地减少比例达到36.63%,大于6 hm²的湖泊减少近半数;沙地,裸地和盐碱地等明显增加,草地退化、沙漠化严重;②天然草地、裸地、沙地、水体、湿地和盐碱地之间的类型转化较为明显,且与水资源又有密切的关系。③多样性、均匀性指数和景观异质程度提高,土地趋于多样化和均匀化;裸地、沙地优势度增加,湿地、水体和天然草地优势度减少;整体破碎化程度呈缓慢减少趋势,而湿地、沙地破碎度增加。④综合土地利用动态度为0.98,天然草地、裸地、湿地、沙地动态面积变化较大。⑤研究区的土地利用/覆盖变化将深刻影响该地区的生态过程,同时还将影响三江源地区的水源涵养和供给。     

Disassembly sequence structure graphs: An optimal approach for multiple-target selective disassembly sequence planning

Modern green products must be easy to disassemble. Specific target components must be accessed and removed for repair, reuse, recycling, or remanufacturing. Prior studies describe various methods for removing selective targets from a product. However, solution quality, model complexity, and searching time have not been considered thoroughly. The goal of this study is to improve solution quality, minimize model complexity, and reduce searching time. To achieve the goal, this study introduces a new ‘disassembly sequence structure graph’ (DSSG) model for multiple-target selective disassembly sequence planning, an approach for creating DSSGs, and methods for searching DSSGs. The DSSG model contains a minimum set of parts that must be removed to remove selected targets, with an order and direction for removing each part. The approach uses expert rules to choose parts, part order, and part disassembly directions, based upon physical constraints. The searching methods use rules to remove all parts, in order, from the DSSG. The DSSG approach is an optimal approach. The approach creates a high quality minimum-size model, in minimum time. The approach finds high quality, practical, realistic, physically feasible solutions, in minimum time. The solutions are optimized for number of removed parts, part order, part disassembly directions, and reorientations. The solutions remove parts in practical order. The solutions remove parts in realistic directions. The solutions consider contact, motion, and fastener constraints. The study also presents eight new design rules. The study results can be used to improve the product design process, increase product life-cycle quality, and reduce product environmental impact.     

某型飞机空中加受油训练模拟器的研制

根据加受油模拟训练的实际需求,提出了某型飞机空中加受油训练模拟器的功能,设计了模拟器的体系结构,并说明了模拟器模拟座舱、飞行仿真、伞套运动、运动平台、信号采控、操纵负荷、视景、教员控制台、计算机网络、音响通讯等分系统的实现。该模拟器采用实物与图像相结合的半实物仿真方式,空中对接环节临场感强、效果逼真,对实装飞行帮助很大,受训飞行员对该模拟器评价较好。该模拟器的投入使用,对提高仿真训练的质量效益,促进部队战斗力建设具有十分重要的价值和意义。     

图学在人类文明进展中的作用研究

摘 要：世界5大文明中心古老的文字都起源于图,图在人类文明进展中起很大作用并占重要地位。论述了古汉语象形文字、古埃及象形文字、古印度印章象形文字、中美洲玛雅象形文字、苏美尔楔形文字等世界文明中心文字的起源与图的关系。认为图学在人类文明进展中的核心作用是由“灵魂、主体、精髓、基础”构成的。物质形态与宇宙同生并存,图学具有叙述苍穹变化规律、承载人类文明信息、展示人类创新文明的重要功能。图学发展伴随着人类文明的过去、现在和未来,当代图学要真正承担起认识世界、传承文明、创新理论、咨政育人、服务社会、创新文化的神圣职责。     

短信技术在大型整流装置远程监测系统中的应用

针对整流装置运行环境恶劣、故障率高和维护困难的特点,在分析了GSM网络特点的基础上,基于短消息(short messagesystem)技术开发一个远程监控与故障诊断系统;该系统由客户端和服务器组成,客户端负责采集数据、下达指令。服务器软件采用组态的方式开发,实现整流装置的在线监控、故障诊断报警、数据综合管理等。服务器与客户机之间采用SMS短消息进行远程通信;该监控系统具有使用方便、成本低等特点。该系统已成功应用于工业现场。     

浅谈计算机多媒体技术在教学中的应用

对多媒体教学的意义和重要性进行了研究，重点研究了搞好多媒体教学应注意的几个问题：优越的多媒体教学演示方式：简便灵活的模拟教学活动；智能型的人一机结合交互式教学；多媒体教学设计促进教学创新；普及与提高。正确处理好这几个关系是搞好多媒体教学的关键。     

氧化铝厂设备管理信息系统的设计及应用

根据氧化铝厂生产工艺及设备管理的特点,分析了氧化铝厂设备管理的现状及存在的问题。针对设备管理信息系统的现状需求,将信息技术与管理技术相结合,确立了系统的目标,设计了设备管理信息系统的结构以及功能模型。系统由设备管理子系统、设备采购子系统、固定资产子系统、工程项目管理子系统组成,并分析了子系统及主要功能模块间的数据流,给出了系统的信息模型及系统的软硬件及网络平台设计方案．对实施应用后的效益进行了分析。     

Computer networking at the National Computing Centre

The National Computing Centre installed a microcomputer-based local area network in 1981. The paper reviews the operation of this network since its implementation. The configuration of the network and the facilities it provides are described. The justification for such a network is examined, and the objectives of the installation are listed. The criteria on which the network was chosen are discussed, and implementation, training and support are described. The applications of the network are examined, along with user reaction, the impact on work and the benefits achieved. Problems and limitations of the network are also discussed.     

联合收割机脱粒滚筒恒速智能控制器设计

研究了轴流式联合收割机的控制问题,给出了联合收割机脱粒滚筒的数学模型,介绍了基于模式识别的智能控制原理,建立了联合收割机脱粒滚筒恒速控制模型,设计了基于模式识别的智能恒速控制器.应用Matlab/Simulink进行了控制器仿真,其结果表明,将基于模式识别的智能控制应用于联合收割机脱粒滚筒的恒速控制,其过渡过程平稳、响应速度快、无超调、无振荡并且无稳态误差.     

危险品运输领域网络化指纹认证系统

该系统是对基于网络的指纹认证系统的研究和开发,主要应用于危险品运输领域,对危险品运输人员进行基于网络的指纹识别认证。整个系统采用C/S(客户/服务器)架构,服务器端采用SQLSERVER数据库系统,客户端应用程序在MSVB60集成环境下开发完成,指纹采集设备选用UareU2000指纹采集仪,指纹的识别算法及功能集成在ActiveX控件模块内。系统的开发采用了多项先进技术,涉及到指纹图像处理与识别技术、远程数据访问技术、ActiveX技术及大型数据库的开发。     

微型动力机电系统研究进展与关键问题分析

阐述了微型动力机电系统的研究现状和进展,介绍了最新实验研究和分析结果.分析了微型动力机电系统所面临的关键问题与解决方法.微型动力机电系统具有重量轻、储能大、寿命长、性能高、成本低、排放低、电压稳定等优点,具有广阔的应用前景,将会对科技、社会和经济产生重要影响.     

Design and analysis of area efficient QCA based reversible logic gates

The CMOS technology has been plagued by several problems in past one decade. The ever increasing power dissipation is the major problem in CMOS circuits and systems. The reversible computing has potential to overcome this problem and reversible logic circuits serve as the backbone in quantum computing. The reversible computing also offers fault diagnostic features. Quantum-dot cellular automata (QCA) nanotechnology owing to its unique features like very high operating frequency, extremely low power dissipation, and nanoscale feature size is emerging as a promising candidate to replace CMOS technology. This paper presents design and performance analysis of area efficient QCA based Feynman, Toffoli, and Fredkin universal reversible logic gates. The proposed designs of QCA reversible Feynman, Toffoli, and Fredkin reversible gates utilize 39.62, 21.05, and 24.74% less number of QCA cells as compared to previous best designs. The rectangular layout area of proposed QCA based Feynman, Toffoli, and Fredkin gates are 52, 28.10, and 40.23%, respectively less than previous best designs. The optimized designs are realized employing 5-input majority gates to make proposed designs more compact and area efficient. The major advantage is that the optimized layouts of reversible gates did not utilize any rotated, translated QCA cells, and offer single layer accessibility to their inputs and outputs. The proposed efficient layouts did not employ any coplanar or multi-layer wire crossovers. The energy dissipation results have been computed for proposed area efficient reversible gates and thermal layouts are generated using accurate QCAPro power estimator tool. The functionality of presented designs has been performed in QCADesigner version 2.0.3 tool.     

Developing land administration in Cambodia

Presently, Cambodia struggles with an ineffective land administration. The enormity of land problems and the insecurity of tenure is a concrete obstacle, for up to 90% of the population. The government has no means of land management through the existing land register at its disposal. The creation of a clear land policy and a land management system are seen as crucial steps towards restoring law and order. In terms of land register performance, a training program is recommended as a short-term solution to improvement. The systematic registration is presented as a long-term solution to the clarification of the situation on land and to the introduction of the security of tenure. The developed method for systematic land registration in rural Cambodia consists of six parts: public information, adjudication, demarcation, surveying, documentation and appeal. The area by area, parcel by parcel and one parcel–one visit principles are applied. The 2 years' test results are encouraging. The method works well, problems are rare and the desire for secured land titles, among the landholders, is high. The main hindrance is represented by the ambiguous legislation. The estimated cost of the first registration with the method is about 15 US$ per parcel including aerial photography, orthophoto production, systematic registration and title issurance. The evaluation demonstrated that the method is capable of facilitating the general objectives of land registration. It strongly promotes the strategic goals of the Finnish development co-operation.     

基于EtherCAT和LabVIEW的风洞安全联锁及状态监测系统设计

安全联锁与状态监控系统是保障风洞运行安全的重要系统,基于EtherCAT环网实现了风洞联锁和监控信号的实时、可靠采集,构建了多网络融合的联锁与状态监控系统。介绍了系统的硬件组成和软件总体功能,利用TwinCAT2设计下位机安全联锁软件,实现了吹风前和吹风过程中的联锁策略,保障了风洞运行安全;基于LabVIEW开发了状态监测软件,通过TCP/IP、OPC等多种通信协议实现了多网络数据利用,利用LabVIEW DSC多个子模块实现了数据存储与查询功能,利于数据溯源。应用结果表面,系统具有良好的实时性和可靠性,功能完备、界面友好,在使用过程中有效保证了风洞及设备安全,并为设备性能分析提供有效分析手段。     

Application of optimal control theory to flexible robotic manipulations

The dynamic equatios of a single link flexible robotic manipulator and the measurements are formulated. The observer and the control law are derived based on optimal control theory. The numerical results of several cases obtained through computer simulation are presented here. The issues of nonlinearity and sampling rate, and the effects of gravity, white noises, and damping are investigated. The feasibility of real-time control of flexible robotic manipulators is discussed.     

Distributed implementations of communicating objects

The paper presents the design and implementation of a CSP-based object-oriented system. The system consists of a specification model, Communicating-object, and a prototype system, C-OBJECT, supporting the model. The objects execute in a set of parallel processes called actions. The dynamic communicating objects exchange messages by both data transmissions and function invocations. The C-OBJECT prototype is constructed in a MIMD architecture (32-node transputer) with C++ which is composed of two parts: network configuration and a Communicating-object service subsystem (library) providing various levels of message-passing primitives. The initial prototype with good performance has shown its availability for C and C++ programming. The integrated system facilitates application software with tools of specification, design and implementation.     

AutoCAD智能评判系统的开发

介绍了建立在AutoCAD平台上的工程图学智能评判系统的架构，分析了智能评判的原理、方式及算法，并开发了一套基于AutoCAD的工程图学智能评判系统。系统能对AutoCAD图形中的直线、圆、圆弧、文本等进行评判。     

水电站大坝碾压混凝土温控措施应用研究

象鼻岭水电站位于贵州省威宁县与云南省会泽县交界处的牛栏江上,水库坝高141.5m,碾压混凝土工程量为81.93万m3,地处暖温带高原季风气候,受季风、地形、低纬的影响形成复杂多变的气候特征。象鼻岭水电站大坝是目前世界上第二高碾压混凝土双曲拱坝,大坝具有工程具有规模大、技术含量高、施工要求高等特点。大坝碾压混凝土温控问题十分突出,成为质量和进度的控制关键。针对象鼻岭水电站水文气象条件、工程施工特点及大坝碾压混凝土温度控制标准,为防止建筑物有害裂缝发生,对碾压混凝土浇筑的温度控制施工技术进行了系统的研究,突破了传统的碾压混凝土温控理念,大胆采用优化混凝土配合比、降低入仓温度、通水冷却、视频监控等新工艺、新技术进行碾压混凝土温度控制,取得良好的温控效果,使碾压混凝土的施工质量得到了更可靠的保证,为类似工程项目提供借鉴和指导。     

磁能驱动微型泵的性能实验研究

在电磁场驱动原理的基础上,设计并研制了一种磁能驱动的微型泵。微型泵包括进／出液管、扩散管／喷管、驱动薄膜、腔体、电磁线圈和永磁体。微型泵的整体尺寸约为Ф11mm×4mm,腔室半径为5mm,深2mm。利用正交实验方法,对微型泵的性能进行了测试。在电压为4V、驱动薄膜厚度为6μm、频率为5Hz方波脉冲的最佳实验条件下,微型泵的最大泵送流速约为0．21mL／min。     

移动网格路由协议MMRP的研究与模拟

Ad Hoc具有网络无中心,多跳等技术特点,选取移动网格路由协议(the Mobile Mesh Routing Protocol,以下简称MMRP)作为Ad Hoc网络的研究内容,通过对该协议路由机制的分析,在移动PC上模拟协议的运行,实现了Ad Hoc多跳,自组织的功能。实验结果表明:MMRP是一种健壮的、有效的移动Ad Hoc路由协议。