变频调速恒压供水系统新方法

针对当前多数恒压供水系统水泵运行状态单一、不能自动完成多台水泵循环工作,影响水泵使用寿命且使其它水泵长期停歇造成资源浪费的问题。提出了采用支持图形化逻辑电路编程的LOGO!可编程控制器,依据增泵条件和减泵条件,实现了变频恒压供水系统多泵自动循环工作和定时自动切换的控制功能。实际运行结果表明,该方法控制有效,系统运行稳定可靠、功能完善。     

基于水泵轴功率的变频恒压供水系统泵组控制研究

变频恒压供水系统能够根据水负荷变化自动调节水泵转速或切换水泵运行的台数,有效节约了电能,同时实现了水泵的软启动。通过分析变频恒压供水系统特点,提出基于水泵轴功率的变频恒压供水系统泵组控制方式,设计了一套以可编程逻辑控制器PLC为控制核心,结合变频调速技术和PID调节等技术的自动恒压变频供水系统。该供水系统能够有效地避免人为操作的复杂性且控制简单可靠。     

变频调速控制技术应用一例

提出了125MW／135MW机组凝泵、疏水泵采用变频改造的方案以及对除氧器水位和凝汽器水位的多变量智能控制方法。     

变频调速在电厂低加疏水系统中的应用

以湛江电厂低加疏水系统变频改造为例,介绍电机变频改造的具体控制方案,并分析运行效果和经济效益.     

水厂水泵组计算机优化调度与控制

本文分析水泵组运行的工况特性，探讨一个二级泵站的计算机优化调度方案、水泵变频节能控制的原理和方法。     

变频调速技术在水泵控制系统中的应用

介绍了水泵变频调速控制系统的节能原理、系统结构及节能效果。系统运行结果表明：水泵采用变频调速控制,节能效果显著,具有明显的经济效益和社会效益。     

基于DSP控制的变频自动恒压供水系统设计

针对供水企业降低水泵的能耗和维护成本，设计了一种基于DSP变频自动恒压供水系统。采用TMS320F240 DSP和一台160kW大功率变频器控制三台大功率水泵电机实现对某水厂的变频自动恒压供水控制；详细分析了其硬件组成和DSP编程原理。实验运行表明，此系统运行稳定可靠、稳压精度高、节能效果明显，具有很好的经济效益。     

基于PLC和变频器串行通讯的变频恒压供水系统

介绍了一种基于PLC和变频器采用串行总线方式通讯的变频恒压供水系统的构成和工作原理。系统采用变频调速方式自动调节水泵电机转速，保持供水压力的恒定，在用水低谷时投入小流量泵，降低电能损耗。变频器故障时仍能自动运行．保证不间断供水，同时故障消除后能自启动，实现无人值守全自动运行。     

多泵自动循环切换恒压供水变频调速系统

本文采用变频调速方式自动调节水泵转速或加、减泵。自动完成泵组软启动及无冲击切换,使水压平稳过渡。变频器故障时系统仍可运行,保证不间断供水。系统断电恢复后可自启动。并详细说明系统硬件构成、软件设计、工作原理、运行方式、参数整定等．系统主要采用三菱PLC和西门子变频,来实现所需要的功能．     

低加疏水泵调节控制改造

2×330MW机组低加疏水泵原设计为节流调节方式,把节流调节改为变频调节,改造后不但机组的经济性和可靠性有所提高,而且平均节电率达65%.     

论团队精神在高校设计专业人才培养中的重要性

近几年来,无论是学校还是社会在谈到大学生素质时,常常会涉及诸如缺乏创新能力、知识面狭窄、缺乏独立生活的能力、缺乏团队精神、心理承受力有限等问题。本文将结合教学实践和相关调查从社会需求与学生对团队精神认知之间的矛盾、设计与团队精神的关系入手,探讨如何培养高校设计专业学生团队精神以适应知识经济时代社会对设计人才需求的问题。     

Compatibility in Interpretation of Relations in EuroWordNet

This paper describes how the Euro WordNet project established a maximum level of consensus in the interpretation of relations, without loosing the possibility of encoding language-specific lexicalizations. Problematic cases arise due to the fact that each site re-used different resources and because the core vocabulary of the wordnets show complex properties. Many of these cases are discussed with respect to language internal and equivalence relations. Possible solutions are given in the form of additional criteria.     

内容审查在网站再设计中的应用探析

随着IT技术的发展,许多企事业单位都开发了自己的网站。但随着时间的推移,经常需要对网站进行优化。在对网站进行内容审查市,可从客户对网站内容的看法、分析网站内容、重新规划网站内容、对网站原先内容重新优化四个方面进行。对企事业单位进一步提升网站的知名度有较强的指导意义。     

Provision of Records Created in Networked Environments in the Curricula of Institutions of Higher Learning in Africa

The importance of curriculum development on archives and records management in the digital era, especially on the African continent, cannot be overemphasized. While many universities in the global hub have included studies on all aspects of archives and records management programs with many emphasizing records created in networked environments, the same cannot be said about universities on the African continent. In Africa, education and training of archives and records professionals can be traced back several decades. Archives and records practitioners in Africa’s different countries have, over the years, taken varying paths to attain their professional qualifications. This study outlines progress on an ongoing study by InterPARES Trust Africa Team that examines the curricula in different African educational institutions and investigates the extent to which they address the increasingly complex environment that includes the management of digital records in networked environments. It is hoped that the study will inform curriculum development and review in the area of digital records at the institutions of higher learning in Africa.     

PIAnO在白车身轻量化设计上的应用

以某SUV车型的白车身为研究对象,采用高效的实验设计和优化软件PIAnO,综合考虑其模态、刚度、40%偏置碰和侧碰等性能进行轻量化设计。确定并优化设计变量,对白车身刚度和模态性能进行近似建模。提出分段优化方案并进行仿真验证,得到的白车身质量减少11.93 kg,下降3.08%。将该轻量化白车身的100%正碰、强度、IPI和NTF性能进行验证,满足设计要求,证明基于PIAnO的白车身轻量化策略行之有效。     

SVM法在虚拟仪器非线性校准中的应用

在构建虚拟仪器系统时,非线性误差是值得考虑的一个问题,本文主要是为了解决这方面的问题.文中首先介绍了虚拟仪器非线性校准的基本原理,接着分析了支持向量机回归模型,并通过采用遗传算法来优化支持向量机的参数.以便建立基于优化的支持向量机非线性校准模型.最后,通过构建一个简单的虚拟仪器数据采集校准系统的实验来验证这种校准方法的有效性,实验结果表明,这种方法是可行的.而且测量精度有了显著提高.     

移动IP隧道技术在Linux下的实现*

移动IP为移动主机在移动过程中保持其通信不间断提供了实现方法,隧道技术是移动IP的关键技术之一,当通信节点向移动节点发送数据报时,需要使用到隧道技术。介绍了移动IP中隧道技术的基本原理,并给出了一种在Linux系统下的实现方法,对于移动IP相关软件的研究和开发具有一定的借鉴作用。     

Rendezvous in networks in spite of delay faults

Two mobile agents, starting from different nodes of an unknown network, have to meet at a node. Agents move in synchronous rounds using a deterministic algorithm. Each agent has a different label, which it can use in the execution of the algorithm, but it does not know the label of the other agent. Agents do not know any bound on the size of the network. In each round an agent decides if it remains idle or if it wants to move to one of the adjacent nodes. Agents are subject to delay faults: if an agent incurs a fault in a given round, it remains in the current node, regardless of its decision. If it planned to move and the fault happened, the agent is aware of it. We consider three scenarios of fault distribution: random (independently in each round and for each agent with constant probability \(0<p<1\)), unbounded adversarial (the adversary can delay an agent for an arbitrary finite number of consecutive rounds) and bounded adversarial (the adversary can delay an agent for at most c consecutive rounds, where c is unknown to the agents). The quality measure of a rendezvous algorithm is its cost, which is the total number of edge traversals. For random faults, we show an algorithm with cost polynomial in the size n of the network and polylogarithmic in the larger label L, which achieves rendezvous with very high probability in arbitrary networks. By contrast, for unbounded adversarial faults we show that rendezvous is not possible, even in the class of rings. Under this scenario we give a rendezvous algorithm with cost \(O(n\ell )\), where \(\ell \) is the smaller label, working in arbitrary trees, and we show that \(\varOmega (\ell )\) is the lower bound on rendezvous cost, even for the two-node tree. For bounded adversarial faults, we give a rendezvous algorithm working for arbitrary networks, with cost polynomial in n, and logarithmic in the bound c and in the larger label L.