软启动器在电气控制系统中的应用

主要采用一个SFR-M011-3软启动器实现两台电动机的起动控制，将两台电动机分别起动。当第一台电动机起动后，才能够对第二台电动机进行启动。启动完成后，两台电动机互不干扰。并通过故障设置，达到技能训练的目的。整个控制过程由组态软件进行监控。     

新型三相异步电动机软启动器的设计

针对三相异步电动机采用降压启动方法存在的二次电流冲击问题,文章提出了一种新型三相异步电动机软启动器的设计方案,详细介绍了该软启动器的硬件及软件设计。该软启动器采用80C196KC单片机和电力电子技术自动调节电动机输入电压,结构简单、参数容易调整且电动机启动过程平稳。实验结果表明,该软启动器可根据要求设置不同的起始电压和启动时间完成电动机的软启动任务。     

单片机在交流电机软启动器中的应用

介绍了一种交流电机软启动器的硬件组成和软件程序设计，该系统以AT89C52单片机为核心，通过对电动机启动过程中的晶闸管调压调速，实现电动机的平滑启动。根据用户的不同需求，可以设置不同的启动时间、启动电流和启动转矩，同时实现断电数据存储。     

基于BP神经网络的电机转矩软测量研究

本文将在化工领域广泛使用的软测量技术应用来进行异步电机转矩测量。根据感应电动机的数学模型，提出了仅用葶于神经网络的电机定子电流的电磁转矩辨识方法，实现异步电机转矩的软测量。用改进的BP算法对神经网络进行学习和训练，构建了适合电机转矩观测的多层前馈神经网络，仿真研究表明：基于神经网络的电机转矩辨识模型具有良好的性能。     

水泵群软启动控制系统设计及轻载调压节能分析

根据水泵电动机轴输出功率与转速的立方成正比的关系,文章分析了软启动器在水泵电动机轻载调压降速运行时的节能效果,给出了一种由2台软启动器共同控制实现水泵群软启动的控制方案,同时2台软启动器起到了相互备用的效果。     

海洋平台吊机软启动器设计应用与优化研究

软启动器作为大型电动机常采用的启停控制装置之一,越来越多地应用到海洋钻井生产过程中。该文从电动机启停特点、软启动器控制方式、接线,并结合海洋钻井平台吊机的设计思路及应用来分析,结合现场相关故障维修实例对软启动器升级改造方案进行了研究。     

基于ARM和CPLD的三相异步电动机智能软启动器的设计

介绍了一种三相异步电动机智能软启动器的设计方案。该软启动器以ARM芯片LPC2364为控制核心,采用大规模可编程逻辑器件EPM7128SLC84-15作为逻辑信号处理电路,可通过Modbus现场总线与上位机通信;能对不同功率的三相异步电动机进行转距等多种方式的软启动,并通过实时监控电动机的各项运行指标实现二十余种电动机保护。实际运行结果表明,该智能软启动器运行稳定,操作简便,抗干扰能力强,且扩展方便。     

基于MATLAB的晶闸管电动机软启动系统仿真

构建晶闸管电动机软启动器的计算机仿真模型,利用SIMULINK/stateflow仿真工具对其进行动态仿真,并取得较理想的仿真结果.表明了用SIMULINK平台对软启动器软启过程进行仿真分析是一种方便高效实用的方法,同时验证了电动机软启动的启动性能远远优于直接启动.     

ABB软启动器的应用

本文介绍了鼠龙式电动机常见启动方式及启动特性,就ABB软启动器的启动特点、保护特性、软停止特性及运用等几方面进行重点阐述。     

基于C8051F040单片机的软启动器设计

针对煤矿井下刮板输送机和粉碎机因启动电流大而损害电动机、影响其他设备正常运行的问题,采用C8051F040单片机控制晶闸管通断的方案设计了一种软启动器,介绍了该软启动器的总体结构,软硬件设计方案,以及电压斜坡启动、限流启动、电压突跳+电压斜坡启动、电压突跳+限流启动4种启动方式;对该软启动器的硬件电路进行测试,测试波形正确,验证了电路设计的合理性;以限流启动方式对该软启动器进行测试,结果表明该软启动器能够有效降低三相异步电动机的启动电流。     

计算机病毒的研究分析与防控

随着计算机技术的迅速发展以及计算机应用领域的日益扩大,计算机病毒随之而来并迅速蔓延扩张,几乎已遍及社会的各个领域,显然地,计算机病毒已成了计算机技术和以计算机为核心的社会信息化进程发展到一定阶段的必然产物,有过计算机接触史的人几乎都会碰到它.计算机病毒给计算机系统造成的巨大破坏和潜在威胁已经给人们的生活,工作和学习带来了极大的不便.为此,为保障计算机系统以及信息传递的安全,对计算机病毒的研究分析显得尤为重要,防控计算机病毒更是迫不及待,着重从计算机病毒的特点、分类、传播途径,以及易感染程序为切入点来进行研究分析,进而探讨有关计算机病毒的防控方法与措施.     

新型联动报警系统

提出对传统报警系统改进的办法:用PC机作为主机,用AT89S52单片机作为从机,采用RS485总线型网络系统。该系统的特点:(1)不仅主机可以呼叫从机,从机在必要时可以主动呼叫主机,避免了从机只能等待主机轮询访问的弊端,从而提高了系统实时性和可靠性;(2)由于报警的时间毕竟很少,因此没有必要让主机无休止地轮询访问各个从机。而且轮询的方式效率很低,主机未必能从多台从机中立刻定位到报警的那台从机。     

Computer use and the gender gap: The issue of access, use, motivation, and performance

Since the beginning of computerization, it has been of interest whether there are differential effects on computer behavior, in particular in terms of computer access, computer use, and motivational variables, such as computer self-efficacy. The current research addresses the questions if the gender-related differences in this respect persist to the present day and if there is also a difference in actual performance characteristics. A sample of 48 university students (23 male) was administered a technology self-efficacy questionnaire, a survey on computer access, recorded a user diary, and turned in a computer task. Results show that the gender gap is closing as far as computer access and self-efficacy are concerned. Also, female and male students report comparable amounts of computer usage for their studies. User behavior appears to be gender-specific as males spend more time at the computer for personal purposes. There is also some evidence that male students outperform female students at a computer task (remastering of Power-Point slides). Conclusions for creating computer-based learning environments are discussed.     

试论计算机多媒体技术的应用

曾几何时,当计算机不再只为计算庞大的数据而生;曾几何时当计算机成为了家电下乡产品中的一员,而被定义为普通家用电器时,你是否觉得计算机在你我的生活之中几乎无孔不入呢?人们越来越接受计算机,将其视为必备日常家电,是因为计算机强大的功能。计算机不再只跟数字打交道,它几乎深入了我们生活的方方面面,可以说小到开门七件事,大到宇宙和国防都少不了计算机的身影。计算机最拿手的除了数据运算以外,就是它的多媒体处理能力了,以下就这方面进行一番探讨。     

结合自身特色，创新计算机文化基础课教学思路

通过计算机一级考试与计算机文化基础课之间的关系,以及计算机文化基础课的教学现状和问题的分析,提出结合自身特色,创新计算机文化基础课教学的思路。     

改进机房管理提高教学质量

在计算机技术迅猛发展的信息时代,学习并掌握一定的计算机知识已显得尤为重要,上机实践更是重中之重。目前计算机理论课与实践课相分离的教学方式存在不少问题,可对机房现有设备进行改进,使其成为教学实践两用机房,让理论实践完美结合,提高教学质量,更好的服务于教学。     

浅议计算机机房管理长效机制建设

如何发挥计算机机房的最大作用,如何科学有效的管理计算机机房,如何建立计算机机房管理的长效机制,这些都是计算机机房管理人员需要尽快解决的问题。     

Wearable computing: toward humanistic intelligence

Over the past 20 years, wearable computing has emerged as the perfect tool for embodying humanistic intelligence (HI). HI is intelligence that arises when a human is part of the feedback loop of a computational process in which the human and computer are inextricably intertwined. It is common in the field of human-computer interaction to think of the human and computer as separate entities. (indeed, the term "HCI" emphasizes this separateness by treating the human and computer as different entities that interact.) However, in HI theory, we prefer not to think of the wearer and the computer with its associated I/O apparatus as separate entities. Instead, we regard the computer as a second brain and its sensory modalities as additional senses, in which synthetic synesthesia merges with the wearer's senses. When a wearable computer functions in a successful embodiment of HI, the computer uses the human's mind and body as one of its peripherals, just as the human uses the computer as a peripheral. This reciprocal relationship is at the heart of HI.     

浅析计算机网络中硬件的故障与维护

计算机网络已普及到大部分企业,如何保养和维护好企业的计算机网络硬件,并且及时地解决计算机网络硬件故障,最大限度地保证企业计算机网络的高效和安全,成为了每个计算机网络硬件管理者关心的问题。本文将从计算机网络硬件的基本常识入手,论述了计算机网络常见的硬件故障,最后提出了计算机网络硬件维护的常用方法。     

Computer usage and the validity of self-assessed computer competence among first-year business students

This study evaluates the reliability of self-assessment as a measure of computer competence. This evaluation is carried out in response to recent research which has employed self-reported ratings as the sole indicator of students’ computer competence. To evaluate the reliability of self-assessed computer competence, the scores achieved by students in self-assessed computer competence tests are compared with scores achieved in objective tests. The results reveal a statistically significantly over-estimation of computer competence among the students surveyed. Furthermore, reported pre-university computer experience in terms of home and school use and formal IT education does not affect this result. The findings call into question the validity of using self-assessment as a measure of computer competence. More generally, the study also provides an up-to-date picture of self-reported computer usage and IT experience among pre-university students from New Zealand and South-east Asia and contrasts these findings with those from previous research.