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电子工作证系统是一个集计算机应用技术、信息系统建设和智能终端设备和非接触式智能卡应用于一体的综合型应用的系统工程.介绍了工作系统的特点、功能,并详细叙述了该系统在企业管理中的应用. 相似文献
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This paper presents a single-phase phase-locked loop (PLL) system which is primarily free from the double-frequency ripples from which the conventional PLL system suffers. The proposed PLL is then extended to reject the harmonic components from the input signal and to estimate the phase-angle and frequency of the distorted input signal with no error. Three units of the proposed PLL can be used in three-phase power systems, such as FACTS and HVDC converters, to estimate the phase-angles of the individual phases with no double-frequency ripples and without sensitivity to the presence of harmonics and inter-harmonics. This makes the proposed PLL unique and desirable for applications which demand highly accurate estimation of the phase-angle(s) and frequency. 相似文献
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鉴于目前电子门锁管理中存在时效性差、工作量大、工作效率低下等问题,本文提出了一种基于RFID手持式读写器的电子门锁实时管理系统,该系统利用手持式读写器的便携性好、存储数据量大、卡片读写稳定、可视化操作方便等优点来提高电子门锁管理系统的实时性,将手持式读写器和传统的功能卡两种管理方式相结合,从而满足酒店、宾馆、写字楼、高校宿舍等场合电子门锁对提高管理时效性和工作效率的要求,使电子门锁的管理更加安全、便捷、高效。 相似文献
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文章给出了一个由MIS和GIS相结合的配电网生产管理信息系统.介绍了用来完善MIS系统功能的GIS系统的相关技术以及主要功能,并描述了此系统的特色.实际使用表明,地理信息系统技术对于传统的电力工业有着积极的作用. 相似文献
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It is estimated that about 80% of all photovoltaic (PV) modules are used in stand-alone applications. Continuous power is obtained from PV systems by using a storage buffer, typically in the form of a lead acid battery. Batteries used in PV applications have different performance characteristics compared with batteries used in more traditional applications. In PV applications, lead acid batteries do not reach the cycle of lead acid batteries used in other applications such as uninterruptible power supplies or electric vehicles. The shortened battery life contributes significantly to the costs of a PV system. In some PV systems the battery accounts for more than 40% of the life cycle costs. An increase in the lifetime of the battery will result in improved reliability of the system and a significant reduction in operating costs. The life of a lead acid battery can be extended by avoiding critical operating conditions such as overcharge and deep discharge. This paper presents a battery management system for such applications 相似文献
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水情自动测报系统通信方式的选择,直接影响到系统的建设和维护成本及系统的可靠稳定性。为了给今后的水情自动测报系统建设提供一些参考依据,文章介绍了我国目前应用于水情自动测报系统的常用通信方式,分析各种通信方式在水情自动测报系统实际应用中的优缺点,并介绍了各种通信方式的典型系统,分析了这些通信方式在不同流域地区的水情自动测报系统中的应用选择效果。 相似文献
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Xiaohui Zhang Fiedler R. Popovich M. 《IEEE engineering in medicine and biology magazine》2004,23(1):58-64
The development of public health surveillance systems requires multidisciplinary knowledge and advanced technologies. Scientific Technologies Corp. has developed the NH Pharmaceutical Sales Surveillance (NHPSS) for the New Hampshire Department of Health and Human Services (NH DHHS). The NHPSS was developed as a distributed information system. In addition to the database server, enterprise application servers and the Web-browser-based user interface, its architecture features knowledgebase technology, a new dynamic system model with rule systems, and automated data analysis in supporting public health surveillance. Internet mapping was also embedded in the system to provide for spatial analysis. Since its pilot application, started in December of 2002 in the Bureau of Communicable Disease Control and Surveillance, NH DHHS, the NHPSS has assisted NH DHHS in successful detections of gastrointestinal and respiratory events. This article first introduces the methodology and the technology in the NHPSS development. Next, the system functionalities are introduced. Then, a new dynamic system model with a rule system for public health surveillance is described in detail. Finally its application and preliminary results are summarized. 相似文献
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Based on a discussion of channel characteristics and the design objective of a high overall link availability, it is shown that a frequency-hopping communication system using phase-shift-keying modulation can overcome the problems of the more traditional narrowband communication systems. The design parameters of such a system are then discussed. The performance is evaluated, and results of measurements in testbeds and on the power mains are presented 相似文献
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电力通信设备与电路综合查询系统 总被引:1,自引:0,他引:1
介绍了电力通信设备与电路综合查询系统,该系统采用了Visual FcxPro6.0数据库开发工具,结合实际运行要求及现存的一些问题,将本地区通信设备与业务电路有机地链接起来,提供了一个科学、实用的运行资料管理平台。 相似文献
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针对专用自动测试系统被测对象单一的问题,研制了一套通用电子干扰吊舱自动测试系统,可实现不同型号的电子干扰吊舱的自动测试.该系统硬件以测控计算机为核心,以基于GPIB总线和VXI总线的测试资源为组成部分,采用了接口适配器、测试资源可互换技术、多线程技术和防差错处理等方法提高系统的性能和可靠性.系统实现了测试结果文件的保存... 相似文献
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存在活动多余物是影响星载电子设备稳定性的主要因素。应用微粒碰撞噪声检测方法研制一种星载电子设备多余物自动检测系统,该系统采用风冷电磁式振动系统为多余物检测提供力学条件,通过数据采集卡把被测多余物信号采集至上位机处理,上位机采用脉冲提取、聚类分析、特征提取、神经网络等算法自动给出是否存在组件、是否存在多余物及其材质判别结果。所研制的星载电子设备多余物自动检测系统对多余物微粒及活动组件识别的准确度可达91%,对多余物材质识别的准确度可达90%。 相似文献
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对电子式互感器进行准确测量和校验是数字化变电站安全和稳定运行的重要保证.针对目前电子式互感器校验过程中存在的问题,提出了一套符合电子式互感器数字输出要求的校验方法和设计方案;引入基于准同步算法与DFT相结合的误差测量方法并对其实现过程进行了讨论,有效地抑制了因电网频率波动而导致的非同步采样对校验结果的影响.最后对校验方法的实现过程进行了仿真,实验结果表明,基于上述校验方法的电子式互感器校验系统能够满足测试的精度要求. 相似文献