基于PLC的温室温度控制系统设计

基于PLC控制器,采用多功能智能传感器为监测部件,通过PID控制算法设计温室温度控制系统,系统包含主控制单元、数据采集单元、执行单元和数据显示单元。数据采集单元采集温室温度信息,经AD转换模块把模拟信号转换成数字信号并传递给主控制单元,主控制单元根据内部程序驱动执行单元。显示单元基于Node-RED平台设计,可以通过网络远程实时显示温室温度信息。实验验证了该系统的有效性。     

基于VB的计算机并行数据采集系统

结合化学气相沉积(CVD)金刚石膜设备温度检测系统的实例,分析了计算机并行口的EPP接口协议,介绍了计算机并行口数据输入模式的设置方法,论述了采用VB语言程序来实现通过计算机并行口采集8位并行数据的技术,并给出了对数据进行采集、转换、显示、报警等处理的相关程序。     

单片机系统Flash存储器在系统编程设计

介绍了AM29F010B的编程要求,结合M68HC11上电自动引导功能,针对发动机控制单元设计中编程的问题,提供了一种Flash存储器在系统编程的方案,并给出了相应环节的程序流程图和部分操作的程序示例。笔者将该方法应用于发动机控制系统中,实现了将程序代码在线写入Flash存储器的功能。     

对技术间断点的影响及成功跨越的分析

当技术范式发生转变新旧技术进行转换时,两种技术发展的S曲线间会出现一个间断点,企业要保持长期竞争优势,必须成功地完成技术转换,跨越这一间断.本文论述了技术间断对企业的影响,分析了众多企业跨越失败的原因,并对如何顺利进行新旧技术转换提出建议.     

解析变频技术在煤矿提升机中的应用

传统意义上,在煤矿提升机的运行过程当中,使用流调速系统下的转子串电阻调速方案存在大量的不足与缺陷,而变频技术则在节能、运行可靠以及提高循环次数方面效果显著。本文结合A煤矿提升机实际情况,研究了变频技术引入下的整个提升机调速系统改造方案,并就改造下的效果进行了研究,望能够进一步提高提升机的运行质量。     

帅小伙的电力花开

一个身穿南网工作服的帅气小伙屏息凝气轻敲着鼠标,眼镜片上不断闪现电脑屏幕上的串串程序代码,这一幕仿佛《窃听风云》中的场景,同样的惊心,一样的动魄。原来,这是8月22日在广西崇左供电局举行的桂西南供电网信息专业运维技能竞赛实操现场,而这个帅气的小伙,在这个群英荟萃的大舞台通过努力最终斩获了个人第二的好成绩,他就是崇左供电局凭祥供电公司唯一一名信息专业员梁聪.     

电脑使汽车遍身布满传感器

现代汽车技术中融入了大量的计算机控制技术，极大地丰富了汽车的控制内容，明显地提高了汽车的控制技术，使汽车具有了相当的智能，计算机控制系统已经成为汽车不可或缺的有机组成部分。汽车计算机控制系统的性能首先取决于获取的与控制过程有关的工作变量和参数的精度，传感器就是将温度、压力、速度、位置、流量和氧气浓度等物理量转换成相应的电信号的转换装置。因此，它构成了汽车计算机系统的重要组成部分。一、 温度传感器温度是汽车计算机控制系统的重要输入变量，特别是在发动机控制系统中，冷却液温度和进气温度直接关系到喷油量…     

红外在线测温系统

该系统是由红外测温技术、同步扫描技术、高速信号采集处理、实时图像处理软件设计等高技术集成的智能机电一体化测温产品。系统的核心部件——高速非接触式红外测温仪，主要是通过被测物体向外发射红外辐射能量进行检测，并通过内部一个高速旋转的光学系统收集被测物体发出的红外辐射能量，经内部电路转换处理，每秒可连续采集1250个位置点的温度，以实现大面积、精确、实时在线温度测量。该系统具有响应时间短（μs级）、检测扫描速度高、温度采样准确等优点，且具备自动跟踪线扫描及温度校正功能。可广泛应用于建材、电力、冶金、轻工等工业领域，尤其适用于高温、多粉尘、腐蚀性气体环境下对物体的监测，对工业生产的质量保证、节能降耗、提高生产效率、保障安全生产具有重要作用。     

铁路牵引电机状态检测技术

采用ALL-TEST检测仪,对铁路系统使用的电力机车电机进行状态检测,逐步形成了相关的测试方法、程序及标准.     

输气站场埋地管道开挖检测技术分析

根据西部管道新疆输油气分公司每年对埋地管道全开挖的检测与评价,分析其开挖检测程序和技术要求,并对输气站阴极保护系统、管道本体(内外表面)、管道焊缝缺陷、管道防腐层、进行全面开挖(分段、分区进行)的技术分析。     

基于WAP的学生信息查询系统的设计与实现

对WAP编程原理及其关键实现技术作了详细介绍,包括WAP服务器的配置、WAP的基础语言WML及其开发方式,并对基于WAP学生查询系统进行了详细设计,给出了程序实现的核心源代码。     

Vertical Ownership,Program Network Carriage,and Tier Positioning in Cable Television: An Empirical Study

Using a 2004 cross-sectional database of digital cable systems in the U.S., we provide new evidence that the effects of vertical ownership ties between systems and programming suppliers persist in spite of extensive channel capacity expansion, as well as new competition from direct broadcast satellites. Focusing on four program network groups (basic outdoor entertainment, basic cartoon, basic movie, and premium movie), we generally find that integrated cable systems carry their affiliated networks more frequently and carry unaffiliated rival networks less frequently—a pattern identified by previous studies using data prior to DBS or the capacity expansion effects of digital cable. We also find that integrated systems that do carry rival networks often position them on digital tiers having more limited subscriber access, a pattern not investigated in previous studies.     

信息隐藏的检测技术研究

信息隐藏检测是信息隐藏技术的一个重要方面,文章首先引入了信息隐藏的检测技术的概念,从不同角度出发,将信息隐藏的检测技术划分为对比检测方法、盲检测方法、时空域检测方法、频域检测方法、基于签名的检测方法和基于统计的检测方法。在众多检测技术中,文章着重研究了RQP检测法、Farid检测法和基于计算免疫系统的盲检测方法,并结合水印技术介绍了一种基于小波变换的水印检测算法。最后指出信息隐藏的检测技术有待解决的问题,如检测结果的优化与融合技术。     

网络计划技术在项目管理中的应用

与IT技术结合的广义网络计划技术是现代管理学科中比较盛行的一种科学管理方法。文章通过l200kt／a柴油加氢项目的计划编制，来介绍网络计划技术在项目管理中的应用，采用这种技术，不仅在计划制定期间求得工期、资源、成本的优化，而且在计划的执行过程中，通过信息反馈，进行有效的监督、控制和调整，能够保证项目预定目标的实现。     

“技术壁垒”的反思考

本文对国外技术性贸易措施对我国对外贸易的影响进行反思,并就国内企业应该如何认识与对待国际贸易中的技术性贸易措施提出建设性建议。     

流动注射分析的发展及应用

综述了国内外流动注射分析的发展,以及流动注射分析与分光光度法、电化学分析法、发光分析法、原子光谱法等技术的联用状况。流动注射分析系统具有能实现对污染物的快速定量分析的优点,它与计算机技术的结合可实现环境监测过程中的自动、在线分析,这将成为今后流动注射分析的主要发展趋势。     

The Economics of Software Development by Pair Programmers

Evidence suggests that pair programmers–two programmers working collaboratively on the same design, algorithm, code, or test–perform substantially better than the two would working alone. Improved quality, teamwork, communication, knowledge management, and morale have been among the reported benefits of pair programming. This paper presents a comparative economic evaluation that strengthens the case for pair programming. The evaluation builds on the quantitative results of an empirical study conducted at the University of Utah. The evaluation is performed by interpreting these findings in the context of two different, idealized models of value realization. In the first model, consistent with the traditional waterfall process of software development, code produced by a development team is deployed in a single increment; its value is not realized until the full project completion. In the second model, consistent with agile software development processes such as Extreme Programming, code is produced and delivered in small increments; thus its value is realized in an equally incremental fashion. Under both models, our analysis demonstrates a distinct economic advantage of pair programmers over solo programmers. Based on these preliminary results, we recommend that organizations engaged in software development consider adopting pair programming as a practice that could improve their bottom line. To be able to perform quantitative analyses, several simplifying assumptions had to be made regarding alternative models of software development, the costs and benefits associated with these models, and how these costs and benefits are recognized. The implications of these assumptions are addressed in the paper.     

Evaluation of USDA's Broadband Loan Program: Impacts on broadband provision

Since 2002 the USDA's Broadband Loan Program has directed more than $1.8 billion in subsidized loans to help expand broadband access in under-served rural communities. Program eligibility criteria included having a population of 20,000 or fewer, having no prior access to broadband, and providing a minimum matching contribution of 15% by recipients of the loan. Loans were extended mainly to small telecommunications services firms at varying (subsidized) interest rates. We evaluate on the effectiveness of the Loan Program in increasing broadband availability in target locations. Specifically, we analyze whether loan receipt increases the number of broadband providers in a particular location, using various count panel methods. Our analysis is conducted at the ZIP code level over the period 1999–2008; it uses broadband provider data from the FCC's Form 477, and loan data from the Rural Utility Service (the implementing agency for the Broadband Loan Program). Results indicate that ZIP codes receiving broadband loans did in fact experience modest, statistically significant increases in the number of broadband providers vis-à-vis non-recipient locations; that average marginal effects on treated ZIP codes were approximately 0.092 additional broadband providers annually; and that these benefits accrued more towards rural locations than urban locations, in conformance with the intent of the program.     

MIS通用查询技术的设计与实现

分析了在MIS中研制通用查询技术的必要性和重要性,根据MIS的开发实践,介绍面向对象的通用查询程序,提供了实用的查询条件设置逻辑,大大提高了程序对业务需求变化的适用性。在MIS中对于要查询的数据,相关操作仅与其类型有关。因此,可以将它们独立出来,设计成通用的组件进行封装,通过面向对象的设计方法的继承机制,将它们集成到MIS中,以备各模块重用。本文结合军械维修器材管理与辅助决策系统的开发,介绍了它的设计方法和实现技术。