恒温混水阀在燃气热水器系统中应用的实验研究

随着国民经济的快速发展,种类繁多的热水器得到了更广泛的推广。但很多消费者在使用过程中发现热水器出现忽冷忽热,恒温保持时间较短的缺陷。研究在燃气热水器中加入恒温混水阀测试系统,在实际使用的环境中,在恒温混水阀的温度调大时,其对燃气热水器的影响不大,在恒温混水阀温度调小时,影响则比较大,更严重的情况会造成燃气热水器熄火、重新点燃,实验显示,燃气热水器的流量产生和出水温度深受恒温混水阀的温度影响。     

燃气热水器性能自动检测系统的研制

介绍一种用８０３１单片机控制的燃气热水器性能自动检测系统，该系统利用多路传感器检测燃气热水器气阀气密性、水路系统的耐压性能、热水产率等。能实现自动、快速的数据采集、处理，并具有检测精度高、准确性好、效率高等优点     

一种燃气热水器的温控装置

在普通燃气热水器上配置单片机,实现水温自动控制,能使用户方便地设定热水的温度.     

基于ST72F324的强排式燃气热水器控制系统

意法(ST)半导体公司的ST系列单片机近年来刚被引入我国,其在综合性能方面有一定特色,其中ST72F324是一款性价比很高的8位flash单片机.本方案充分利用了ST72F324的各种资源,简化了硬件设计,为燃气式热水器控制器提供了一种低成本高可靠性的解决方案.     

恒温瓦斯检测模型动态分析及控制

恒温检测是通过控制检测元件中的电流达到控制元件工作温度的目的.检测电流会随着温度的波动而波动,普通恒温检测电路通过闭环控制需要经过很长时间才能达到稳定.为解决长时间振荡问题,在恒温瓦斯检测原理及载体催化元件性能分析的基础上,建立了恒温瓦斯检测的数学模型并设计出一种PID控制器.其控制效果明显好于闭环控制.仿真及实验结果表明,带PID控制器的恒温瓦斯检测系统只需3 s便能检测出瓦斯浓度,其稳定性和快速性明显优于一般恒温瓦斯检测系统.     

大家谈家电我的热水器

现代都市生活节奏的加快，辛苦劳作一天的我们已经疲惫不堪，如何缓解疲劳——回到家中能舒舒服服地洗上一个热水澡可是良方之一，这样的感觉你我都知道吧。这时一个称心如意的热水器就显得越发重要了，它能让你更轻松，更省事。现在是燃气热水器、电热水器、太阳能热水器三分天下。那么究竟选那种热水器好呢？“大家谈家电”就请已经拥有此类热水器的读者来谈谈使用感受。[编者按]     

双桥恒温式燃气检测方法①

恒温式燃气检测方法是使载体催化传感元件在工作中,始终处于一定温度的一种检测燃气的新技术。它与传统的变阻检测法相比,具有量程宽、响应快、稳定性强等优点;但对环境温度影响测值问题,在单电桥的条件下不易克服。妨碍了这一新技术的推广。为此,提出了双桥电路,获得满意的结果,具有良好的应用前景。     

TCP Veno协议的性能分析与评价

TCP Veno协议综合了TCP Reno和TCP Vegas的特点,通过对慢启动,拥塞避免和快速恢复算法的改进,使TCP协议在无线网络环境下性能有了较大的改善.为求更加客观和直观的展示Veno的性能,在NS-2环境下对TCP Veno和几种不同版本的TCP协议进行了对比分析.结果显示,TCP Veno协议在无线环境中表现优良,尤其是链路差错率较高的情况下,TCPVeno的性能较其它版本的TCP协议为好,改善了无线环境中因随机丢包而引起的网络性能下降情况.     

基于半导体制冷技术的恒温控制仿真

基于半导体制冷技术,针对航天、军事、医疗、生物制品、车载等特殊有限工作空间的独特需求,设计了体积小、成本低、性能高、结构合理紧凑、功耗低且节能环保的微型半导体温控箱箱体,并对温控箱的温度及变化速率等各种参数能够实时精确控制,为高性能生物制剂、功能材料等的实验室制备方法以及性能研究提供技术支撑。本文选用TEC-12706半导体制冷片并进行了半导体制冷原理进行验证实验。半导体恒温箱采用强制对流方式,提高了储藏室空气之间的热交换率,由此在距离储藏室内胆一定距离的三维空间区域形成一个恒温控制区,该区域内温度均匀无差异,且能迅速响应半导体片的温度切换。仿真表明,该系统具有结构简单、控制精度高、可靠性好、性能稳定等优点,具有广泛的应用前景。     

炼焦生产过程控制系统的多层性能评估策略

针对炼焦生产过程分层递阶智能集成控制系统,提出一种多层性能评估策略.讨论了由炼焦过程经济性能、焦炉加热燃烧控制系统性能和专家分析模块三部分组成的多层性能评估策略的结构、功能和所用技术.用焦炭产量预测模型、炼焦过程能耗预测模型、基于模型预测控制的性能评估方法以及专家分析方法实现了炼焦生产过程控制系统的多层性能评估.所提出的性能评估策略成功应用于炼焦生产全流程智能集成优化控制仿真实验平台上,取得了明显的应用成效.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

一个扩展的CCS

诉微分算子ＣＣＳ（Ｃａｌｃｌｕｓ ｏｆ Ｃｏｍｍｕｎｉ－ｃａｔｉｎｇ Ｓｙｓｔｅｍｓ）是由英国爱丁堡大学计算机科学系的ＲｏｂｉｎＭｉｌｎｅｒ首先提出的。ＣＣＳ是一个在数学上完整的理论算子系统,可以作为计算机通讯系统的基本理论模型。我们先简要说明一个ＣＣＳ的内容。我们所作的工作是在理论上扩充地的ＣＣＳ,使得我们的ＣＣＳ更为一般化。在我们的观战看来,ＲｏｂｉｎＭｉｂｅｒ的ＣＣＳ只不过是我们的ＣＣＳ的一     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

An Analysis of the Criteria for Evaluating Adequate Theories of Computation

This paper deals with the question: What are the criteria that an adequate theory of computation has to meet? (1) Smith’s answer: it has to meet the empirical criterion (i.e. doing justice to computational practice), the conceptual criterion (i.e. explaining all the underlying concepts) and the cognitive criterion (i.e. providing solid grounds for computationalism). (2) Piccinini’s answer: it has to meet the objectivity criterion (i.e. identifying computation as a matter of fact), the explanation criterion (i.e. explaining the computer’s behaviour), the right things compute criterion, the miscomputation criterion (i.e. accounting for malfunctions), the taxonomy criterion (i.e. distinguishing between different classes of computers) and the empirical criterion. (3) Von Neumann’s answer: it has to meet the precision and reliability of computers criterion, the single error criterion (i.e. addressing the impacts of errors) and the distinction between analogue and digital computers criterion. (4) “Everything” computes answer: it has to meet the implementation theory criterion by properly explaining the notion of implementation.     

FTDSS：高容错分布式共享存储机制

Computerized data has become critical to the survival of an enterprise. Company must have a strategy for recovering their data should data lose. RAID is a popular mechanism to offer good fault-tolerance. But RAID can notwork well when one more disks fail. In this paper, we present an efficient Network-based high High-Tolerance Dis-tributed Shared Storage mechanism called FTDSS. FTDSS makes use of disk space of node in Network to build alarge pubhc shared storage space. Users can read/write their file from/to the public storage space from node of net-work. Physically File is stored in each node in form of data fragment or XOR verify fragment. Because of redundant XOR fragments, file is available even when two more nodes fail. FTDSS realize distant redundant srorage. At last,this paper use experiment to prove that FTDSS can offer high. fault-tolerance and advanced performance.     

一种面向查询的多文档摘要方法

面向查询的多文档摘要技术有两个难点 第一,为了保证摘要与查询密切相关,容易造成摘要内容重复,不够全面;第二,原始查询难以完整描述查询意图,需进行查询扩展,而现有查询扩展方法多依赖于外部语义资源。针对以上问题,该文提出一种面向查询的多文档摘要方法,利用主题分析技术识别出当前主题下的子主题,综合考虑句子所在的子主题与查询的相关度以及子主题的重要度两方面因素来选择摘要句,并根据词语在子主题之间的共现信息,在不使用任何外部知识的情况下,进行查询扩展。在DUC2006评测语料上的实验结果表明,与Baseline系统相比,该系统取得了更高的ROUGE评价值,基于子主题的查询扩展方法则进一步提高了摘要的质量。     

Existential foundations of the composition paradigm

The theses of existonness, compoundness, and polyadness are proved. The consistency of these theses with the reversibility principle is founded. Existential foundations of the composition paradigm are constructed. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 3–12, March–April 2008.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Autonomous programmable DNA nanorobotic devices using DNAzymes

A major challenge in nanoscience is the design of synthetic molecular devices that run autonomously (that is, without externally mediated changes per work-cycle) and are programmable (that is, their behavior can be modified without complete redesign of the device). DNA-based synthetic molecular devices have the advantage of being relatively simple to design and engineer, due to the predictable secondary structure of DNA nanostructures and the well-established biochemistry used to manipulate DNA nanostructures. However, ideally we would like to minimize the use of protein enzymes in the design of a DNA-based synthetic molecular device. We present the design of a class of DNA-based molecular devices using DNAzyme. These DNAzyme-based devices are autonomous, programmable, and further require no protein enzymes. The basic principle involved is inspired by a simple but ingenious molecular device due to Tian et al. [Y. Tian, Y. He, Y. Chen, P. Yin, C. Mao, A DNAzyme that walks processively and autonomously along a one-dimensional track, Angew. Chem. Intl. Ed. 44 (2005) 4355–4358] that used DNAzyme to traverse on a DNA nanostructure, but was not programmable in the sense defined above (it did not execute computations).     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.