课题

In 1952, W. Ross Ashby, a cybernetician interested in how machines could learn, wrote," does not specify in detail how a kitten shall catch a mouse, but provides a learning mechanism and a tendency to play, so that it is the mouse which teaches the kitten the finer points of how to catch mice."

Ross Ashby （2），一个对机器可以如何学习的课题感兴趣的控制论工作者写道："并没有具体规定小猫如何抓老鼠，但是提供学习机制和演练的趋向，是老鼠将捕鼠的要领教给了小猫。"

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

Catchment economy should not stay on the research of a task only merely, and should put into practice.

流域经济不应该仅仅只停留在一个课题的研究上，而应该付诸行动。

This research through surveys, analysis of China's catering industry chain research training.

本次课题研究通过调查、分析的方法对我国连锁餐饮业培训进行研究。

Objective To observe and evaluate the exact effect and relative mechanism about external treatment of catgut implantation at acupuncture point on cyclomastopathy and to discuss the possible functional mechanism of it.

研究目的：本课题通过观察穴位埋线疗法治疗乳腺增生病的临床疗效，探讨外治法治疗乳腺增生病的可能机制。

The study of field emission cathode is always the key project in this field.

场致发射阴极的研究是该领域内贯穿始终的关键课题。

In this paper,similar products system design Based on CBR technology is discussed.

本课题对基于实例推理的相似产品系统设计方法进行了研究和探讨。

The former, such as "Celestial Empire's collapse - the Opium War re-study" break full of nationalist sentiment in the failure of the Qing empire reduced to misuse of a traitor, loyal model was demoted from the social system, a high degree of contrast to the study of this topic pushed to the an unprecedented new level.

前者如《天朝的崩溃--鸦片战争再研究》冲破饱含民族主义情绪的把清帝国失败归结为误用奸臣、忠臣遭贬的模式，从社会制度对比的高度，把这一课题的研究推到前所未有的新水平。

The fluidity or viscosity of cell surfaces is an extremely complex subject, and the degree of viscosity has to be appropriate for the function of the cell.

流动性或粘度的细胞表面是一个极其复杂的课题，和程度的粘度要适当的功能细胞。

Finally, we expound the applications of the wireless location technology in the cellular system and point out some topics about wireless location which will be studied in the following days.

最后，阐述了蜂窝系统中无线定位的应用，提出了无线定位技术有待进一步研究的课题。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。