共查询到20条相似文献,搜索用时 31 毫秒
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在传统的数据库安全性技术的基础上,根据供电企业综合统计系统实际情况,对报表的显示作了改进,并提出了一种针对报表及菜单功能的用户管理和权限维护方案,该方案在某市供电公司综合统计管理信息系统中得以成功应用。 相似文献
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基于PSoC及Cyfi无线通信技术,设计了一种智能车窗控制系统方案,具有无线控制车窗升降、车窗防夹手等功能。实验结果表明,该方案具有设计简单灵活、操作方便、功耗低、抗干扰等特点,可作为一种无线智能控制方案应用于汽车电子领域。 相似文献
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针对居民社区公共门窗管理不及时,耗费大量人力资源,且效率较低等问题,设计了一款基于STM32单片机的居民社区门窗禁控制系统.在传统的门禁控制系统的基础上,系统利用Zigbee无线传感网技术,实现门窗禁控制器之间的无线通讯.管理用户可以通过以太网远程控制系统,系统也可以根据传感器监测到的环境数据实现自动调节.同时,尝试采用一种基于频率捷变的分布式自适应干扰技术,解决系统在居民居住环境中遇到的Wifi网络信号干扰问题.最后,通过测试表明,该系统运行稳定,具有广泛的应用前景. 相似文献
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Badri Narayan Subudhi 《Pattern recognition letters》2011,32(15):2097-2108
This article addresses a problem of moving object detection by combining two kinds of segmentation schemes: temporal and spatial. It has been found that consideration of a global thresholding approach for temporal segmentation, where the threshold value is obtained by considering the histogram of the difference image corresponding to two frames, does not produce good result for moving object detection. This is due to the fact that the pixels in the lower end of the histogram are not identified as changed pixels (but they actually correspond to the changed regions). Hence there is an effect on object background classification. In this article, we propose a local histogram thresholding scheme to segment the difference image by dividing it into a number of small non-overlapping regions/windows and thresholding each window separately. The window/block size is determined by measuring the entropy content of it. The segmented regions from each window are combined to find the (entire) segmented image. This thresholded difference image is called the change detection mask (CDM) and represent the changed regions corresponding to the moving objects in the given image frame. The difference image is generated by considering the label information of the pixels from the spatially segmented output of two image frames. We have used a Markov Random Field (MRF) model for image modeling and the maximum a posteriori probability (MAP) estimation (for spatial segmentation) is done by a combination of simulated annealing (SA) and iterated conditional mode (ICM) algorithms. It has been observed that the entropy based adaptive window selection scheme yields better results for moving object detection with less effect on object background (mis) classification. The effectiveness of the proposed scheme is successfully tested over three video sequences. 相似文献
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基于角色实现窗口按钮级通用动态权限管理 总被引:1,自引:1,他引:1
比较现有MIS系统中权限管理存在的缺陷,提出了基于角色实现窗口按钮级通用动态权限管理的方案,通过精心设计数据库和程序模块.实现了权限管理的通用性、动态性以及细化到窗口按钮的功能。 相似文献
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药品生产质量文件的计算机管理 总被引:1,自引:0,他引:1
文章阐明了药品生产质量文件的作用、分类、主要管理过程及采用计算机管理的必要性,介绍了作者开发的GMP质量文件管理软件系统的设计方案与主要特点,为制药企业质量文件的管理提供了一种科学、规范且高效的方法。 相似文献
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黄良峰 《电脑编程技巧与维护》2012,(22):37-39
介绍了RFID技术的概念,RFID的系统组成与工作原理,分析了现行图书馆文献管理系统存在的问题,探讨了RFID智能系统的优势,给出了利用RFID技术对现行的图书馆文献管理系统进行改良的方案,为实现数字化图书馆管理奠定了良好的基础。 相似文献
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李强 《自动化技术与应用》2013,(11):111-114
针对一些环境恶劣的工业生产现场或不易使用有线传输的场合,提出了一种集中管理,基于AVR和ZigBee技术的分布式温度实时动态无线遥感和控制方案.选用PT100温度传感器对检测点温度进行精确测量,AVR单片机对数据进行处理并利用ZigBee网络无线传输至上位机,window GUI记录温度实时变化并采取相应控制措施.系统具有低功耗、低成本、自组织的特性,且有自动和手动可选的控制方式,实现对环境温度的高效智能化测控. 相似文献
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文章提出了一种新的基于身份的盲签名方案,该方案具有盲签名的特性,保证了签名接受者信息的保密性,采用基于身份的数字签名,大大减少了基于证书的公钥体制中的公钥证书管理成本。 相似文献
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Transmission control protocol (TCP) has been recognized as the most important transport-layer protocol for the Internet. It is distinguished by its reliable transmission, flow control, and congestion control. However, the issue of fair bandwidth-sharing among competing flows was not properly addressed in TCP. As web-based applications and interactive applications grow more popular, the number of short-lived flows conveyed on the Internet continues to rise. With conventional TCP, short-lived flows will be unable to obtain a fair share of available bandwidth. As a result, short-lived flows will suffer from longer delays and a lower service rate. It is essential for the Internet to come up with an effective solution to this problem in order to accommodate the new traffic patterns.With a more equitable sharing of bottleneck bandwidth as its goal, a stateless queue management scheme featuring early drop maximum (EDM) is developed and presented in this article. The fundamental idea is to drop packets from those flows having more than an equal share of bandwidth. The congestion window size of a TCP sender is carried in the options field on each packet. The proposed scheme will be exercised on routers and make its decision on packet dropping according to the congestion windows. In case of link congestion, the queued packet with the largest congestion window will be dropped from the queue. This will lower the sending rate of its sender and release part of the occupied bandwidth for the use of other competing flows. By so doing, the entire system will approach an equilibrium point with a rapid and fair distribution of bandwidth. As a stateless approach, the proposed scheme inherits numerous advantages in implementation and scalability.Extensive simulations were conducted to verify the feasibility and the effectiveness of the proposed approach. As revealed in the simulation results, the proposed scheme outperforms existing stateless techniques, including Drop-Tail and Random Early Drop, in many respects, such as a fairer sharing of available bandwidth and a shorter response time for short-lived flows. 相似文献
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针对目前无线寻呼基站管理中存在的问题,介绍了一种基于C/S结构的无线寻呼基站监控系统的设计和实施方法,对其工作原理和关键技术进行了详细的说明。并就该工程的复杂性及其发展方向进行了探讨。 相似文献
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针对钢铁企业能源管理最基本的供配电系统以及供配电系统改造的内容作了较为详细的介绍。根据供配电系统的变电站现场配置情况,提出了供配电系统的3种改造方案,并就每种改造方案在什么情况下采用以及需要注意的事项进行探讨。 相似文献
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本文针对传统的火力发电企业设备缺陷管理方法存在的诸多问题,如处理效率低、准确性差、历史经验及数据未得到有效利用等提出一种基于知识图谱技术的系统化解决方案。通过构建一种基于知识图谱的设备全寿命周期管理系统,可以在设备缺陷闭环管理中,有效实现设备维修辅助决策,通过设备维修历史、缺陷记录的自动分析,为运维人员提供优化的检修策略。本文首先简单介绍了整体技术方案及背景,接着对系统的整体设计及架构和功能进行了阐述,然后对系统的整体实现进行了详细说明,最后总结本文的工作,并讨论了存在的问题及未来的优化方向。希望本文能为国内火电企业建设类似系统提供一定的参考借鉴。 相似文献
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《Control Engineering Practice》2007,15(2):177-186
This paper is concerned with the design of improved active queue management (AQM) control schemes for time-delay systems taking into account explicitly the presence of delays in the controller design. A robust controller coping with uncertainties on the network parameters such as round-trip time and load variations is proposed. This is based on an appropriate robust reduction method for time-delay systems. A robust observer for time-delay systems is used to estimate online the average transmission window resulting in a robust output feedback stabilization scheme for AQM. The resulting control law is validated and tested firstly through numerical simulations and then pseudo-experimentally by network simulator (NS-2). 相似文献