比较原理

On the base of the search model"s analyze, this article analyze and discuss the principle and implement of the fashion Search Engine"s several technology, for example Innernet"s Building, Chinese Syncopate, Auto-Briers Building, the Search Result"s Rank and Several Level Intellective Search Agent.Now, full-text search is a mature technology. Its searchs the all and the one is success. But its accuracy is lack. In fact, the two technologies(Chinese Syncopate and Auto-Briers Building) should be broke through. To Chinese Syncopate, this paper brings forward a new technology that the partial adjust will be brought into effect after the Chinese is syncopated and the notional document brief is put forward to Auto-Briefs Building.

本文在对检索模型分析的基础上，重点对当前流行的搜索引擎中的几大技术(知识库的建立、中文切分、自动文摘的生成、检索结果的排序、多级智能检索代理的实现)的原理、实现进行了分析和探讨；目前，全文本搜索技术作为一种比较成熟的技术，其查全率方面已经做得比较好，但它的查询精度确有待进一步提高，究其原因是："中文切分"和"自动文摘的生成"这二项技术有待突破，本文中，对"中文切分"提出了切分算法加局部调整技术，对"自动文摘的生成"提出了"概念化的文档摘要"，以期能够起到抛砖引玉的作用。

The phylogeny and applied prospect of MES are summarized in the paper. The principle of this system is analyzed from the point of view of acoustics. The surveying and filtering technology of auxiliary parameters, sounding data and the theory of image form, backscatter strength data processing, are researched deeply in the paper. The optimal model of velocity of sound is given. For sound ray tracing, some methods of correction of sound ray curve are developed. At the same time, an ideal model of sound ray tracing is proved and given. The GPS technology is applied for the determination of tide, attitude of vessel. Moreover, some methods are given. As an important topic, the systematic error is discussed in the paper. Some filtering methods are researched in this paper. Based on the current methods of image processing, the procedure and methods are tested and given that adapt to sonar image processing.

本文研究的工作是在总结多波束声纳测深系统的发展历史、应用前景的基础上，从声学角度分析了多波束系统的工作原理；对多波束辅助参数的测定和滤波方法、测深数据的滤波方法、多波束声纳图像的形成机理、图像处理以及最终应用等作了比较深入的研究；得出了适合于多波束精密深度计算的最优声速模型和声线改正模型；提出了 GPS 载波相位定位技术用于多波束辅助参数测量的思想、算法，改善了多波束系统的作业模式；系统地分析了深度数据的误差来源和类型，首次将系统误差作为影响测深精度的主要因素给以研究，并给出了削弱系统误差的方法，提高了深度数据的质量；对多波束声纳图像的形成、处理方法进行了细致的研究，给出了适合多波束图像处理的算法和流程，并从理论和实践上对声纳图像的应用进行了比较全面的研究。

To deal with the problem that Electrostatic Separation of waste circuit board is high in purity, whereas relatively low in output/capacity,we developed multi-cylinder electrostatic separator and waste circuit winnower which is developed on the principle that the specific gravities of copper powder/grain and plastics are remarkable different..

另外针静电分离对废旧电路覆铜板的分离纯度高而产量比较小，我公司开发的多滚筒静电分离机和根据粉碎后的电路板中铜粉与环氧树脂粉的密度比重差距比较大的原理研制的废旧电路板气流分选机解决了分离产量问题。

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

On the basis of its elementary principle,we suggested a kinetic equation to describe the reaction procedure,Wamp=[Ntarg×(1+P) n1 +0.5×Cenz×U×P×Ceactive×-Ntarg×(1+n×P)]×Cu×M.

我们根据PCR技术的基本原理提出了比较完整、比较准确地描述PCR扩增技术的动力学数学模型，使PCR技术的理论研究达到了

The working methods and principles of the ditching machine coming from home and abroad are analyzed and compared in this paper. By combining the present planting style of rape in the southern area of our country and the large scale usage of small rotary cultivation machine, the advantages and disadvantages of ditching mode between former and post-position are compared. Finally, the ditching components of disc pattern are designed by adopting the post-position to realize the mechanization of ditching in rape planting.

本文分析比较了国内外开沟机械的工作方法和原理，结合我国南方现有油菜种植方式及现有小型旋耕机大量使用的现状，比较了前置和后置式开沟方式的优缺点，采用后置式开沟方式设计圆盘式开沟部件，实现油菜种植机械化开沟和覆土。

Firstly, the thesis discusses the principles and framework of E-commerce, and introduces the architecture key techniques advantages of mobile Agent systems. It also compares a few known mobile agent developing platforms, especially IBMs Aglets. Secondly, after analyzing the Aglets system, we have devised and developed a intelligent E-Commerce prototype system using Java, Jsp, Servlet JDBC and MVC design pattern based on Agelts platform.

本文首先论述了电子商务的基本原理及其系统结构，对移动Agent系统的体系结构、关键技术、技术优势、安全性方面作了完整的介绍，并对几个比较著名的移动Agent开发平台进行了比较分析，然后着重研究了IBM的移动代理平台Aglets，并以Aglets为开发平台结合其它技术，设计开发了一个智能商务系统原型。

Analysis is done systematically to the philosophy of electronic clearers of both optical and capacitance types regarding their difference in-between.

系统分析了新型光电式和电容式电子清纱器的基本原理，比较了其清纱性能的差别，并对国内外不同型号新型电子清纱器作了比较与介绍。

My thesis aims to do some research about trust management comprehensively, analyze its framework and principles of operations. For the important issue of trust management—the certificate chain discovery, some thorough research will be done to try to find a better searching algorithm.

本文旨在比较全面、系统地对信任管理理论进行研究，分析其框架结构和运行原理，对信任管理理论的关键问题——证书链的发现问题做比较深入的探讨，找到一种相对较完善的证书链发现算法。

Every sub-circuit is designed reasonably according to the principle and character of PWM switching converter, such as: bandgap, error amplifier, oscillator, narrow pulse generator, saw tooth generator, PWM comparator, PWM modulator, output stage, OCP circuit and low voltage comparator.

根据PWM开关电源的原理和特点，合理地设计了各个子电路，其中包括：带隙基准源、误差放大器、振荡器、窄波发生器、锯齿波发生器、PWM比较器、PWM脉冲调整器、输出级电路、过流保护电路和低压比较器等。

I am sure after a few weeks of adaptation and familiarization I will have no difficulty in functioning on a daily basis in an English speaking society or in participating fully in graduate studies.

在大学的三年的学习生活不仅给予我自身的充实，更重要的是磨练和培养了我较强的自觉能力和严谨，踏实的作风以及不怕困难的精神，对未来充满了信心！

As the first volcanoes erupted, one of the gases that bellowed out was steam.

在第一批火山喷发时，喷出的气体之一就是水蒸汽。