基于MSP430F149的网络心电系统设计

本文提出了一个便携式可连网的心电仪的设计方案.通过选择合适的器件,使所设计的心电系统不仅完成预期的功能要求,而且达到最佳性价比.并对所选择的器件特征和使用方法做了详细的介绍.     

基于CCD相机的光纤器件透过率测试

提出了利用单积分球和CCD相机对光纤器件透过率进行测量的方案。采用积分球产生漫射光,分别对积分球口的漫射光和放置光纤器件后的透射光光通量进行测试,再通过图像处理软件对所采集的图片处理,以求光纤器件的整体透过率。介绍了系统的光学设计和CCD镜头的选择,通过样品求得其透过率为60.04%。此系统操作方便,测试结果客观、准确,还可以实现对光纤器件的局部透过率、桶枕形失真、分辨力等技术参数的测量。     

非接触式温度测量系统中固体摄像器件的选择

非接触式温度测量由于不受被测对象的条件限制,具有十分优越的特点。如何选择能符合温度测量要求的固体摄像器件是值得重视的问题。基于辐射理论和CCD器件成像原理,指出了辐射式测温系统中的固体摄像器件必须具备的性能和选择CCD摄像器件时应考虑的主要问题。     

重离子加速器相幅稳定系统的恒温子系统设计

文章主要阐述了重离子加速器相幅稳定系统的恒温子系统的硬件设计。首先介绍恒温子系统的组成与工作原理;其次介绍硬件电路设计及相关器件选型,包括热电制冷片的选择、温度传感器的选择、核心控制芯片的选择、风扇检测与控制电路的设计及相关器件选择、电流和电压的检测电路的设计及相关器件选择和功率放大电路的设计;最后论述了恒温子系统的试验测试结果及其分析等。     

微器件自动装配系统的定标和操纵策略

主要研究了自动微器件装配系统的定标技术和操纵策略两个问题.在加入了尺度因子优化步骤之后,一种基于Tsai两步法的自定标方法实现了亚微米级的定标精度,并且获得了更加可信的定标角度参数.这种定标方法应用于微器件装配系统中并可以实现高精度的微器件定位.除了精确定标之外,我们还应该选择合适的工作环境来控制粘附力的大小来提高微器件操纵成功率,选择合适的夹持和释放方式来提高微器件操纵效率和释放位置精度,选择一种安全简单的移动路径来缩短移动时间.实验表明,我们的自动微器件装配系统可以在10 s内完成一个器件的定位和移动操作,并实现数微米的释放位置精度.     

提升中大功率——IMV—实达UPS使用IGBT镜像技术剖析

在线式 UPS 的结构主要由将输入交流电经整流滤波后转换为直流电的整流器和将直流电转换成交流电输出的逆变器所组成,而逆变器采用何种器件直接关系到 UPS 的输出性能。进入九十年代,随着 IGBT 制造工艺的日益完善及性能提高,大多数 UPS 厂家均选择 IGBT 作为逆变器的功率器件。     

低功耗手持多媒体终端硬件平台的研究

通过选择低功耗器件,特别是高效率DC/DC变换器,合理进行电路板布线,优化结构级设计,进行系统级功率管理,从而延长电池工作时间。根据多媒体终端的要求,选择了许多新工艺器件,极大地降低了系统功耗。     

计及电流能量的PMSM FOC系统中功率器件老化监测方法

为了研究永磁同步电机系统中功率器件老化的状态监测技术,以永磁同步电机磁场定向控制策略为例,分析了功率器件老化后的运行机理,提出一种计及电流能量监测功率器件老化状态的方法。首先采集不同老化状态下的工作电流,提取稳定状态下相同周期的电流数据做能量运算,通过差值比较得到老化功率器件所在桥臂;其次根据变形公式对电流正负数据做处理得到具体老化区间;最后通过仿真实验得到功率器件老化状态监测指标。结果表明,所提方法能够实现永磁同步电机系统中功率器件老化状态的在线监测,且方法简单、成本低、响应速度快,从而避免了功率器件进一步老化所引发的系统故障,提高了整个系统的安全性和可靠性。     

磁致伸缩器件及其应用研究

介绍了磁致伸缩材料的最新研究方向 ,阐述了磁致伸缩器件在换能传感、驱动及频率控制等方面的应用及近年来所取得的最新成果 ,分析了磁致伸缩器件与应用在上述领域的压电陶瓷器件相比所具有的优点 ,展望了其未来发展趋势     

一种基于功能表的可视化器件编程方案的探索与实现

为改善集成电路测试仪对器件编程和建库的效率,根据可视化和易于用户编程的要求提出了一种方案,并用填写器件功能表的方式成功予以实现。本文叙述了方案的选择确定,研究了对各种不同的数字器件运用功能表的编程方法,说明了器件编程效益的明显提高及程序在可移植性和标准化方面的进展,并进而探讨了可编程逻辑器件的编程自动化及模拟器件的可视化编程问题。     

Expert system verification and validation: a survey and tutorial

Assuring the quality of an expert system is critical. A poor quality system may make costly errors resulting in considerable damage to the user or owner of the system, such as financial loss or human suffering. Hence verification and validation, methods and techniques aimed at ensuring quality, are fundamentally important. This paper surveys the issues, methods and techniques for verifying and validating expert systems. Approaches to defining the quality of a system are discussed, drawing upon work in both computing and the model building disciplines, which leads to definitions of verification and validation and the associated concepts of credibility, assessment and evaluation. An approach to verification based upon the detection of anomalies is presented, and related to the concepts of consistency, completeness, correctness and redundancy. Automated tools for expert system verification are reviewed. Considerable attention is then given to the issues in structuring the validation process, particularly the establishment of the criteria by which the system is judged, the need to maintain objectivity, and the concept of reliability. This is followed by a review of validation methods for validating both the components of a system and the system as a whole, and includes examples of some useful statistical methods. Management of the verification and validation process is then considered, and it is seen that the location of methods for verification and validation in the development life-cycle is of prime importance.     

Web与数据库互连技术的探讨

随着Internet/Intranet的迅猛发展,基于Web的数据应用需求日益扩大。这个应用主要表现为3个层次:信息共享与发布、信息存取以及企业业务处理。这三者均与数据库的支持有着密切的联系。随着应用的深入和趋于复杂,对数据库访问的功能和性能要求就越高。如何满足用户动态查询数据库的要求便成了亟待解决的问题,Web数据库的开发不仅仅是HTML的开发,还涉及到与数据库交互要使用的程序设计语言及技术。其中关键技术之一就是如何将数据库与Web互连,以达到最佳的服务性能。文中将就Web与数据库互连技术进行探讨。为了更好地说明一种技术,给出了一个应用实例。     

Cyberspace as a generator of changes in the aggressive-victim role

The interaction of adolescents’ presential and cyberspace contexts accentuates the emergence of the aggressive-victim role. This profile takes on new dimensions as a result of the many combinations involved in the co-existence of bullying and cyberbullying. The twofold object of the present work was to: (i) determine the prevalence of victim-aggressive in the various forms that this role might be found in the context of bullying and cyberbullying; and (ii) explore the synergistic relationship established between the type and frequency of the abuse suffered and the type and frequency of the aggression perpetrated. The sample consisted of 1648 adolescents of from 12 to 16 years in age. The instrument used to acquire the data was a questionnaire. The results revealed the existence of four categories of aggressive victims: traditional aggressive-victims, aggressivecybervictims, cyberaggresive-victims, and cyberaggresive-cybervictims. The types of bullying suffered and perpetrated were found to be directly related and the frequencies of these two classes of attack were positively correlated. This allows one to predict the cyberspace and presential behaviour that will be displayed by adolescents who are being subjected to certain types of bullying and cyberbullying.     

基于Authorware与Office兼容性课件制作技术研究

对Office及Authorware做了深入的研究和分析,Office有其应用简单、覆盖面广的特点,而课件制作工具Authorware有其交互性强和对多媒体元素较好控制的特性,将两者结合起来,能够制作出操作便捷、使用广范的课件。     

Real-world effectiveness of Ergonomic methods

The way ahead with the practical development and application of Ergonomic methods is through a better anticipation and appreciation of changes to system effectiveness and human work that will be incurred through the introduction of new technologies to the workplace. These improvements will involve an improved awareness by the system of the working context and environment. The argued future is with improvements in the handling and use of knowledge by systems. The development of suitable Ergonomics methods, or the careful adaptation of existing methods, should accompany any technological revolution. Moreover, future methods are needed that are specifically developed to be applicable to the real time study of work considering both work context and the amalgamation of results from the use of many diverse methods throughout the design and development life cycle of a system. Part of this process will be a necessary complementation of both quantitative and qualitative methods and guidelines. Another focus should be on creating improved Ergonomics participation within multidisciplinary system design and development environments throughout the system's life cycle. Only through this avenue can Ergonomics show a consistent and valued contribution to quality design and its development. In parallel to such a contribution will be an acceptance by other engineering disciplines, managers, and customers that such an application of Ergonomics is cost effective.     

空间故障网络的柔性逻辑描述

为使空间故障网络(space fault network, SFN)描述系统故障演化过程(system fault evolution process, SFEP)时能蕴含信息的不确定性和演化特征,克服因素、数据和演化本身的不确定性,提出使用柔性逻辑对SFN进行描述和改造。首先论述了SFN存在的问题和使用柔性逻辑解决这些问题的可能性。使用柔性逻辑描述SFN,应从SFN的最基本单元、事件发生关系、SFN结构方面进行。给出了SFN中与、或和传递关系的柔性逻辑表示。在柔性逻辑条件下给出了SFN的关系组,进而得到SFN最终事件状态的柔性逻辑表示。实例结果蕴含了SFEP中各事件、因素和演化过程之间的柔性逻辑关系及其不确定性,为SFEP的智能化研究提供了新方法论和理论基础。     

Dynamics analysis for a novel 6-DoF parallel manipulator I with three planar limbs

A novel 6-DoF parallel manipulator I with three planar limbs is proposed and its dynamics is analyzed systematically. First, its characteristics and DoF are analyzed and calculated. Second, the formulae for solving kinematics of the moving platform and the planar limbs are derived. Third, the formulae for solving the inertial wrench applied on the planar limbs and the moving platform are derived, and dynamics formula is derived for solving dynamic active forces applied onto the planar limbs. Fourth, a singularity of the proposed parallel manipulator is determined and analyzed. Fifth, an analytic example is given for solving the kinetostatics and dynamics of the proposed parallel manipulator, and the solved results are analyzed and verified by the simulation mechanism. Finally, a workspace is constructed and analyzed by comparing with an existing 6-DoF parallel manipulator.     

Environmental ergonomics: a review of principles, methods and models

A review of the principles, methods and models used in environmental ergonomics is provided in terms of the effects of heat and cold, vibration, noise and light on the health, comfort and performance of people. Environmental ergonomics is an integral part of the discipline of ergonomics and should be viewed and practised from that perspective. Humans do not respond to the environment in a way monotonically related to direct measures of the physical environment. There are human characteristics which determine human sensitivities and responses. Practical methods for assessing responses to individual environmental components are presented as well as responses to ‘total’ environments and current and proposed International Standards concerned with the ergonomics of the physical environment.     

元宇宙中区块链的应用与展望

元宇宙是虚拟数字世界与真实物理世界无缝融合的新生态,近来引发了各界的广泛关注。区块链、人工智能、虚拟现实/增强现实及传感技术、移动通信及泛在计算等各种新型互联网技术愈发成熟,使元宇宙的进一步发展成为可能。关于元宇宙的研究主要涉及产业项目、基础设施、关键技术、隐私安全等方面,这些研究虽然涉及区块链技术,但未具体指出区块链应用于元宇宙的优势及具体应用方式。区块链技术不仅可以为元宇宙提供开放自由的去中心化环境,而且可以为其提供公平合理的数字资产分配机制。主要从区块链赋能元宇宙中数字身份和数字资产管理的角度出发,分析了元宇宙的发展历程和特征,讨论了元宇宙发展所需核心技术及面临的挑战。同时研究了区块链的关键技术,并从区块链的本质特征及与其他技术融合优势两个方面对区块链应用于元宇宙做可行性分析。进一步提出元宇宙生态体系架构,重点详细分析了基于区块链的自我主权身份管理模型、区块链-非同质化通证（NFT,non-fungible token）工作流程及其在元宇宙中的应用。结合区块链和元宇宙的最新研究进展,从基础设施、通信和计算资源管理机制、监管与隐私保护以及区块链可扩展和互操作性4个方面指出区块链应用...     

面向移动互联网的统一通信会议

统一通信是指把计算机技术与传统通信相互融合的一种通信模式,利用先进的技术打破当前通信手段中以设备和网络为中心的限制,使人们只要通过最常使用的通信工具和应用,就可以便捷高效地在企业内部与同事、客户及合作伙伴沟通.本文以现有的企业统一通信的项目为背景,主要研究了会议的模块.对会议模块进行了设计,并相应的介绍了有关的MQTT协议和电话会议多媒体会议的流程与原理.最后再对自己的设计与研究进行了实验,最终实现了电话会议通话和多媒体会议通信的功能.