Multi-texture-model for Water Extraction Based on Remote Sensing Image
Hua WANG, Li PAN, Hong ZHENG
School of Remote Sensing and Information & Engineering, Wuhan University 129 Luoyu Road,
Wuhan 430079,P.R.China
School of Electronic Information, Wuhan University 129 Luoyu Road, Wuhan 430079,P.R.China
Abstract:
In this paper, a multi-texture-model for water extraction based on remote sensing imagery is proposed. The model is applied to extract inland water (including wide river, lake and reservoir)from high-resolution panchromatic images. Firstly directional variance is used to find river regions, and then grain table is adopted to avoid noise including objects that have similar directional variance characteristic as water surfaces. The experiment result shows that the proposed method provides an effective way for water extraction.
1. Introduction
The recognition of water from remote sensing image has drawn considerable attention in recent yeas. A large number of publications about water extraction appeared and various approaches for water extraction have been proposed. Zhou developed a descriptive model for automatic extraction of water based on spectral characteristics[1]. Barton applied channel 4 for NOAA/AVHRR to extract water[2]. Du proposed a approach for water extraction from SPOT-5 based on decision tree algorithm[3]. Li recognized and monitored clear water from MODIS[4]. Wu extracted water from Quick Bird image and used active contour model to obtain accurate position of river bank[5]; In order to extract water from high-spatial remote sensing images, He used wavelet technique to expend the information and cleaned main noise of the images, and then presented multi-window linearity reserve technique to conserve linear water[6].
Recently, most research work on water extraction was forced on automatic recognition of water from remote sensing images based on spectral characteristics. However, there are some disadvantages of these methods: (1) The resolution of image used for water extraction is low. The minimum size of recognizable object is depended on the spatial resolution of sensor. Therefore it is difficult to obtain accurate position of water boundary. (2) Due to the characteristic of water itself and the sensor applied, in certain channels the spectral features of different objects are equilibrated. The equilibration leads to the phenomena of “different objects same image” or“different images same object”, which results in noise objects included in extraction result.
In this paper, a multi-texture-model for water extraction based on remote sensing is proposed. The model is applied to extract inland water (including wide river, lake and reservoir) from
high-resolution panchromatic image. Firstly directional variance is applied to find river regions, and then grain table is adopted to avoid noise including objects that have similar directional variance characteristic as water surfaces. The experiment result shows that the proposed method provides an effective way for water extraction.
This paper is organized as follows. In Section 2, the directional variance model adopted is introduced. Then, fusion of proposed grain table model with directional variance model is discussed in Section 3.The experimental results of the proposed multi-texture-model and comparative studies with single models are given in Section 4. We conclude this paper in Section 5.
2. Directional Variance Model
The aim of our research is to extract water larger than 100m2from panchromatic images. As shown in Figure 2(a), the research objects can be divided into three classes: wide river, lake and reservoir, which all represent as region in high-resolution imageries. The objects of background can be divided into two classes: building and cropland, which also represent as region.In panchromatic imagery, wide river has a similar gray level to building and cropland, though the mean gray
of lake and reservoir is much lower than the background objects. Conventional methods for water extraction based on spectral characteristics are not effective in the situation. In the meantime, water body defines homogeneous areas whereas building and cropland correspond to heterogeneous regions. Therefore, we take into account the homogeneity of the image to separate wide river, lake and reservoir from background instead. To characterize the difference of homogeneity between water body and the other types of areas, we use a textual operator: the directional variance.
2.1. The Directional Variance Operator
The operator is derived from those defined by Guerin & Maitre and Airault & Jamet[10]. As shown in Figure1, the directional variance consists in computing, for each pixel M of the image, the variance of the gray levels of the image on several direction of a circle whose center is M and radius is R. Then, the direction with the highest variance value is kept. Its direction defines the direction for which image is the most heterogeneous, locally. Its variance value is the directional variance value of the pixel M.
2.2. Extraction of water based on directional variance
According to the definition of the operator, the minimum acreage of recognizable water body is depended on the length of radius R. We have chosen a length of 10 pixels for 1m resolution. The directional variances of the five typical training samples (wide river, lake, reservoir, building and cropland) have been computed and the statistical comparison is summarized in Table1. The overall average of water directional variance is lower than the objects of background.Nevertheless, the directional variance of cropland is similar to wide river with overlapping potion over 90%.In
high-resolution panchromatic imagery, details inside wide river, such as boat, wave, etc, are represented clearly which result in the heterogeneous of water. In the meantime, the textures of parts of building (for example, roof ) and cropland are rather fine. In a small window, these potions define homogeneous areas with similar directional variance as wide river. The result is improved if we chosen a length of 100 pixels. The statistical comparison is shown in Table2. If the length of radius is large enough, directional variance of building is higher than other objects obviously with no overlapping portion; the difference between cropland and wide river is increased while the overlapping potion is decreased. However, increasing the radius leads to two problems which are outlined as follow:
1) The size of recognizable water body increases;therefore water which has small acreage (for example narrow river) can not be detected.
2) The position of water bank is not accurate although the spatial resolution of imagery is rather high.
Hence, in this paper, a multi-texture-model is presented and two texture models are fused to extract water from panchromatic images. Firstly, we chose a radius of 10 pixels to extract water based on directional variance; and then, grain table is adopted to avoid noise including parts of building and cropland that have similar directional variance characteristic as water surface.
3. Multi-texture-model
In high-resolution imagery, cropland and building represents structural characteristic. According to this characteristic, grain analysis is adopted for further research on the original extraction based on directional variance. The grain table histogram is able to represent structural characteristic of the research object, which can be applied to recognize many kinds of different objects [12].
3.1. Extraction of water fused by grain table
The grain table histograms of the five typical training samples (wide river, lake, reservoir, building and cropland) are computed and correlation coefficients between them are summarized in Table3. Correlation coefficients between water classes are over 85%, however, correlation coefficients between water classes and background classes are lower than 65%.Hence, we compare the correlation coefficients of regions in extraction image base on directional variance with three water samples and two background samples respectively. If the region has a higher correlation coefficient with background classes, it will be marked background and wiped off[13].
4.Experimental Results
We run the algorithm on several high-resolution panchromatic images. In Figure2.(a), we have been considering an aerial photograph(6126×4800) of a region in Wuhan, China, the resolution of which is 1m,including building, cropland, wide river( Changjiang river), lake, reservoir and cropland. The results of extraction based on directional variance with radius of 10 pixels is displayed in Figure2.(b), and clearly, water has been detected completely, whereas parts of building and cropland are included as noise objects in the result. Water extraction using directional variance with radius of 100 pixels is displayed in Figure2.(c)with correctness over 95%, however, small lakes are missed and the position of bank is not as accurate as Figure2.(b). Finally, in Figure2.(d), the result of Figure2.(b) is fused by grain table analysis, so that the correctness and completeness of extraction are both over 90%.
5. Conclusions
Based on textural analysis of water in high-resolution panchromatic imagery, a multi-texture-model is presented for water extraction.The experimental results proved that the approach is efficient for inland water (including wide river, lake and reservoir) extraction. As the complexity and diversity of water, the rate of recognition of our algorithm fluctuates. Furthermore, the method is supervised which needs a lot of human interference to obtain training samples. Therefore, there are problems to be solved in future:
1) Our further work should be extensible to multispectral remote sensing images.
2) To decrease human interference, old vector will be applied to obtain training samples instead. 6. Acknowledgments
The work was supported by the National Key Technology R&D Program of China under grant No.2006BAB10B01.
根据遥感图象的多纹理模型相关的水抽取
Hua WANG, Li PAN, Hong ZHENG
School of Remote Sensing and Information & Engineering, Wuhan University 129 Luoyu Road,
Wuhan 430079,P.R.China
School of Electronic Information, Wuhan University 129 Luoyu Road, Wuhan 430079,P.R.China
文摘：
在本文中，提议了一个多纹理模型为根据遥感成像的水提取。而且运用模型从高分辨率泛色图象提取内陆水域(包括宽河、湖和水库)。首先定向变化用于发现河地区，五谷桌然后被采
取避免噪声包括有相似的定向变化特征当水表面的对象。实验结果表示，提出的方法为水提取提供有效方式。
1．简介
在最近这些年，水的图像测量识别是作为一个相当值得关注的问题。有大量的关于水的抽提的出版物涌现，以及关与水的抽提的多种方法被大量的提出。周朝曾经发展过一个基于光谱特征的描述型的自动抽取模型。巴顿在NOAA/AVHRR应用下用来抽取液体。Du被提议于从SPOT-5基于决策树运算法则来逐步进行水的抽取。Li认可了并且从MODIS监测出了清楚的水。Wu利用从飞的很快的鸟的图象中抽取水的流体特性并运用运动等高模型来获取河岸的准确位置。为了从高空间遥感图象提取水的特性，他使用小波技术扩展信息并且消除了图象的主要噪声，然后利用被提出的多窗口线性预留技术保存线性水。
最近，在水抽取的多数研究工作是牵强的在水的自动识别从根据光谱特性的遥感图象的过程。然而，有这些方法的有些缺点：(1) 用于水抽取的图象的决议是低的。可辩识的对象的极小的大小取决于传感器的空间分辨率。所以获得水边界限的准确位置是难的。(2) 由于水自身的特征和传感器被用于在某些渠道应用的不同的对象的特点被均衡化。这种平衡带来了“不同的对象现象同样图象”或“不同的图象同样对象”的现象，导致在提取结果包括了噪声对象。
在本文，一个基于细微的感觉的水抽取的多纹理模型被最终提议。运用模型从高分辨率泛色图象提取内陆水域(包括宽河、湖和水库)的范围内进行。首先定向变化的趋势被应用于发现河地区，然后颗粒表格的方法被采取于避免噪声包括有相似的定向变化特征当水表面的对象。实验结果表示，这些被提出的方法都很好的为水提取提供有效方式。
本文接下来要讨论的问题有：在第2部分，将介绍被采取的定向变化模型。然后，在部分3会提出的颗粒表格法模型的融合与定向变化模型在提出的多纹理模型.其中实验性结果会被谈论，并且在第4部分将给出比较研究同唯一的模型。最后，我们在第5部分结束本文。2．定向变化模型
我们的研究的目标大于100m2from泛色图象将提取水。如图2 (a)所显示，研究对象可以被划分成三类：宽河、湖和水库，所有在高分辨率成像都会被代表作为区域。背景对象可以被划分成二类：大厦和农田，也将会代表作为区域。在泛色成像，宽河有相似的灰级级别的图像，并且农田，这个背景对象可能会比湖和水库的灰度低。常规方法为：根据光谱特性的水抽取是不是有效的情况下所决定。同时，水本体也定义了同类的区域，而修造和农田则可以对应于各种不同的地区。
所以，我们考虑到图象的同质性则从背景上改为分离成宽河、湖和水库。要描绘同质性区别在水本身和其他区域类型之间的不同，我们使用一个本文里讲到操作：定向变化。
2.1. 定向变化的操作
这些操作的过程都是源于从Guerin& Maitre和Airault & Jamet定义的那些结论中找到的。如Figure1所显示，定向变化在计算其中救包括为图象，图象的灰级的变化的每个映像点M 都是以m为圆心，并且半径是R的弧线的几个不同指导方向上进行的。然后，方向以最高的变化价值被保留。它的方向当地定义了图象是最异向的方向。它的变化价值就是映像点M.的定向变化价值。
2.2. 基于定向变化理论上的抽取水过程
根据操作流程的定义，可辩识的水本体的极小的面积也取决于半径R的长度。我们选择了10个映像点的长度为1m决议。五个典型的测试样品(宽河、湖、水库、大厦和农田)的定向变化将会在Table1被计算了和统计来进行比较总结。整体平均水定向变化将有可能低于背景对象。然而，农田的定向变化对于宽河是相似的，并且重叠的部分超过90%。在高分辨率泛色导致不同种的水的成像，细节在宽河里面显示出来，例如小船、波浪等等，都可以清楚
地表示出来。同时，大厦的部分纹理(例如，屋顶)和农田是相当完整的。在一个小窗口里，这些部分定义了同类的区域以相似的定向转变成宽河。这个改进结果就是如我们选上的100个映像点的长度。统计的比较已经在Table2显示了。如果半径的长度足够大的时候，大厦的定向变化其他对象明显地高于其他没有重叠的部分; 而与农田和宽河之间的区别，当重叠的部分被减少时，相应的也会增加。然而，增加半径导致被概述和跟随的会产生二个问题：
1) 可认识的水本体增量的大小; 例如可能有一些有面积的水(狭窄的河)不可能被查出。
2) 岸边的位置不是准确的，虽然成像的空间分辨率可能还是相当高。
因此，在本文，多纹理模型被提出，并且二个纹理模型被熔化从泛色图象提取水。首先，我们选择半径10个映像点是基于定向变化抽取水；然后，颗粒表格模型
被采取避免噪声包括有相似的定向变化特征作为水表面的相关大厦和农田的部分。
3. 多纹理模型
在高分辨率成像的领域，农田和大厦代表了大部分结构特征。根据这个特征，颗粒分析将会为对根据定向变化的原始的提取的数据进一步研究所采取而进行下去。颗粒表格模型直方图就是能代表研究对象的结构特征，并且可以被应用认可于许多不同种类的对象。
3.1. 由颗粒表格所解决的水的抽取模型
在表格3中五个典型的测试样品(宽河、湖、水库、大厦和农田)的颗粒表格模型直方图将会被计算，并且在他们之间作相关系数的总结。在水类之间相关系数为85%，然而，在水类和背景类之间相关系数将有可能低于65%。因此，我们在提取图象基数范围内的相关系数将会在定向变化与各自三个水样已经两个背景样品之间作比较。如果在此范围内有一个更高的相关系数与背景类，那么它将是被标记的背景和抹去。
4. 实验的结果
我们在几个高分辨率泛色图象运用算法进行运算。在Figure2.(a)，我们在中国的武汉，决议将被设为一张空中相片(6126×4800)的一个区域，并且决定用1m来作为标准，包括大厦，宽河(长江)，湖、农田水库和农田。根据定向变化的提取的结果与半径10个映像点在Figure2.(b)被显示，和清楚地表示水完全地被查出了，而大厦和农田的部分包括当噪声对象在结果。水提取使用定向变化
与半径100个映像点在Figure2(c)中被显示。并且以正确性95%为标准，然而，小湖将会背错过，并且银行的位置不是一样准确的象Figure2.(b)。终于，在Figure2.(d)，结果的Figure2.(b)由颗粒表格分析所解决，因此提取的正确性和完整性两个90%。
5. 结论
基于对水的质地分析在高分辨率泛色成像，多纹理模型为水抽取被提出。实验性结果证明，方法为内陆水域(包括宽河、湖和水库)提取是高效率的。作为水的复杂性和变化性，我们的算法得到了公认的率动摇。此外，需要很多人的干涉得到训练样品的方法被监督。所以，下面列出有今后将要解决的问题：
1) 我们的进一步工作应该是延伸性的到多光谱遥感图象。
2) 要减少人的干涉，将运用住得一些老传播媒介改进而得到新的测试样品。
6. 鸣谢
在津贴No.2006BAB10B01之下的由中国的全国重要技术R&D节目支持的工作。
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
五、外文资料翻译 Stress and Strain 1.Introduction to Mechanics of Materials Mechanics of materials is a branch of applied mechanics that deals with the behavior of solid bodies subjected to various types of loading. It is a field of study that i s known by a variety of names, including “strength of materials” and “mechanics of deformable bodies”. The solid bodies considered in this book include axially-loaded bars, shafts, beams, and columns, as well as structures that are assemblies of these components. Usually the objective of our analysis will be the determination of the stresses, strains, and deformations produced by the loads; if these quantities can be found for all values of load up to the failure load, then we will have obtained a complete picture of the mechanics behavior of the body. Theoretical analyses and experimental results have equally important roles in the study of mechanics of materials . On many occasion we will make logical derivations to obtain formulas and equations for predicting mechanics behavior, but at the same time we must recognize that these formulas cannot be used in a realistic way unless certain properties of the been made in the laboratory. Also , many problems of importance in engineering cannot be handled efficiently by theoretical means, and experimental measurements become a practical necessity. The historical development of mechanics of materials is a fascinating blend of both theory and experiment, with experiments pointing the way to useful results in some instances and with theory doing so in others①. Such famous men as Leonardo da Vinci(1452-1519) and Galileo Galilei (1564-1642) made experiments to adequate to determine the strength of wires , bars , and beams , although they did not develop any adequate theo ries (by today’s standards ) to explain their test results . By contrast , the famous mathematician Leonhard Euler(1707-1783) developed the mathematical theory any of columns and calculated the critical load of a column in 1744 , long before any experimental evidence existed to show the significance of his results ②. Thus , Euler’s theoretical results remained unused for many years, although today they form the basis of column theory. The importance of combining theoretical derivations with experimentally determined properties of materials will be evident theoretical derivations with experimentally determined properties of materials will be evident as we proceed with
华北电力大学科技学院 毕业设计（论文）附件 外文文献翻译 学号：121912020115姓名：彭钰钊 所在系别：动力工程系专业班级：测控技术与仪器12K1指导教师：李冰 原文标题：Infrared Remote Control System Abstract 2016 年 4 月 19 日
红外遥控系统 摘要 红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术，被众多的硬件和软件平台所支持。红外收发器产品具有成本低，小型化，传输速率快，点对点安全传输，不受电磁干扰等特点，可以实现信息在不同产品之间快速、方便、安全地交换与传送，在短距离无线传输方面拥有十分明显的优势。红外遥控收发系统的设计在具有很高的实用价值，目前红外收发器产品在可携式产品中的应用潜力很大。全世界约有1亿5千万台设备采用红外技术，在电子产品和工业设备、医疗设备等领域广泛使用。绝大多数笔记本电脑和手机都配置红外收发器接口。随着红外数据传输技术更加成熟、成本下降，红外收发器在短距离通讯领域必将得到更广泛的应用。 本系统的设计目的是用红外线作为传输媒质来传输用户的操作信息并由接收电路解调出原始信号，主要用到编码芯片和解码芯片对信号进行调制与解调，其中编码芯片用的是台湾生产的PT2262，解码芯片是PT2272。主要工作原理是：利用编码键盘可以为PT2262提供的输入信息，PT2262对输入的信息进行编码并加载到38KHZ的载波上并调制红外发射二极管并辐射到空间，然后再由接收系统接收到发射的信号并解调出原始信息，由PT2272对原信号进行解码以驱动相应的电路完成用户的操作要求。 关键字：红外线；编码；解码；LM386；红外收发器。 1 绪论
New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.
在广州甚至广东的住宅小区电气设计中,一般都会涉及到小区的高低压供配电系统的设计.如10kV高压配电系统图,低压配电系统图等等图纸一大堆.然而在真正实施过程中,供电部门(尤其是供电公司指定的所谓电力设计小公司)根本将这些图纸作为一回事,按其电脑里原有的电子档图纸将数据稍作改动以及断路器按其所好换个厂家名称便美其名曰设计(可笑不?),拿出来的图纸根本无法满足电气设计的设计意图,致使严重存在以下问题:(也不知道是职业道德问题还是根本一窍不通) 1.跟原设计的电气系统货不对板,存在与低压开关柜后出线回路严重冲突,对实际施工造成严重阻碍,经常要求设计单位改动原有电气系统图才能满足它的要求(垄断的没话说). 2.对消防负荷和非消防负荷的供电(主要在高层建筑里)应严格分回路(从母线段)都不清楚,将消防负荷和非消防负荷按一个回路出线(尤其是将电梯和消防电梯,地下室的动力合在一起等等,有的甚至将楼顶消防风机和梯间照明合在一个回路,以一个表计量). 3.系统接地保护接地型式由原设计的TN-S系统竟曲解成"TN-S-C-S"系统(室内的还需要做TN-C,好玩吧?),严格的按照所谓的"三相四线制"再做重复接地来实施,导致后续施工中存在重复浪费资源以及安全隐患等等问题.. ............................(违反建筑电气设计规范等等问题实在不好意思一一例举,给那帮人留点混饭吃的面子算了) 总之吧,在通过图纸审查后的电气设计图纸在这帮人的眼里根本不知何物,经常是完工后的高低压供配电系统已是面目全非了,能有百分之五十的保留已经是谢天谢地了. 所以.我觉得:住宅建筑电气设计,让供电部门走!大不了留点位置,让他供几个必需回路的电,爱怎么折腾让他自个怎么折腾去.. Guangzhou, Guangdong, even in the electrical design of residential quarters, generally involving high-low cell power supply system design. 10kV power distribution systems, such as maps, drawings, etc. low-voltage distribution system map a lot. But in the real implementation of the process, the power sector (especially the so-called power supply design company appointed a small company) did these drawings for one thing, according to computer drawings of the original electronic file data to make a little change, and circuit breakers by their the name of another manufacturer will be sounding good design (ridiculously?), drawing out the design simply can not meet the electrical design intent, resulting in a serious following problems: (do not know or not know nothing about ethical issues) 1. With the original design of the electrical system not meeting board, the existence and low voltage switchgear circuit after qualifying serious conflicts seriously hinder the actual construction, often require changes to the original design unit plans to meet its electrical system requirements (monopoly impress ). 2. On the fire load and fire load of non-supply (mainly in high-rise building in) should be strictly sub-loop (from the bus segment) are not clear, the fire load and fire load of non-qualifying press of a circuit (especially the elevator and fire elevator, basement, etc.
哈尔滨工业大学毕业设计（论文） 英文原文（原文也可以直接将PDF版打印） ASSESSING CREDIT OR DETERMINING QUANTITY? THE EVOLVING ROLE OF RATING AGENCIES Lynnette D. Purda* This version: April 21, 2011 Abstract Over the past ten years, credit rating agencies have come under intense criticism from both practitioners and academics, first for their failure to identify problems resulting in bankruptcies at Enron and Worldcom and second for providing overly optimistic ratings for structured finance products. While many investors question the value of rating agencies in light of these criticisms, they have proven remarkably resilient. This paper provides a brief background on how rating agencies secured competitive advantages in evaluating credit quality. It then reviews the empirical evidence on the information content of ratings given these advantages. I argue that the information content of ratings stems from two intertwined sources: 1) information related to credit quality and 2) information related to the firm’s ability to access debt. Based on this evidence, I suggest that the dominant role for ratings today is as a benchmark for financial contracting. In this way, ratings remain influential in establishing the supply and demand of debt securities. 译文 评级机构的发展的作用评估信用还是决定数量？ 本文：2011.4.21 摘要 在过去的十年，信用评级机构一直处于来自实践者和学者的激烈的批评中，首先他们未能发现问题，导致安然和世通破产；其次对结构性金融产品提供过于乐观的评级。虽然许多投资者因为这些批评对评级机构的价值提出了质疑，但他们仍然被证明是相当有活力的。这篇文章首先在评估机构如何在信用评级质量中获得竞争优势提供一个简单地背景介绍，然后考虑到这些优势回顾了一些信息内容方面的评级经验证据。个人认为信息内容的评级来自两种交织在一起（错综复杂）的来源：1）和信贷质量相关的信息；2)和公司获取债务资本能力相关的信息。以此为据，我建议当前评级的主导作用是作为基准的金融收缩。以这种方式，在建立债券的供应和需求方面评级仍然是有效的。 - -1
https://www.doczj.com/doc/6713656690.html,/finance/company/consumer.html Consumer finance company The consumer finance division of the SG group of France has become highly active within India. They plan to offer finance for vehicles and two-wheelers to consumers, aiming to provide close to Rs. 400 billion in India in the next few years of its operations. The SG group is also dealing in stock broking, asset management, investment banking, private banking, information technology and business processing. SG group has ventured into the rapidly growing consumer credit market in India, and have plans to construct a headquarters at Kolkata. The AIG Group has been approved by the RBI to set up a non-banking finance company (NBFC). AIG seeks to introduce its consumer finance and asset management businesses in India. AIG Capital India plans to emphasize credit cards, mortgage financing, consumer durable financing and personal loans. Leading Indian and international concerns like the HSBC, Deutsche Bank, Goldman Sachs, Barclays and HDFC Bank are also waiting to be approved by the Reserve Bank of India to initiate similar operations. AIG is presently involved in insurance and financial services in more than one hundred countries. The affiliates of the AIG Group also provide retirement and asset management services all over the world. Many international companies have been looking at NBFC business because of the growing consumer finance market. Unlike foreign banks, there are no strictures on branch openings for the NBFCs. GE Consumer Finance is a section of General Electric. It is responsible for looking after the retail finance operations. GE Consumer Finance also governs the GE Capital Asia. Outside the United States, GE Consumer Finance performs its operations under the GE Money brand. GE Consumer Finance currently offers financial services in more than fifty countries. The company deals in credit cards, personal finance, mortgages and automobile solutions. It has a client base of more than 118 million customers throughout the world
英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,
International Journal of Minerals, Metallurgy and Materials Volume 17, Number 4, August 2010, Page 500 DOI: 10.1007/s12613-010-0348-y Corresponding author: Zhuan Li E-mail: li_zhuan@https://www.doczj.com/doc/6713656690.html, ? University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010 Preparation and properties of C/C-SiC brake composites fabricated by warm compacted-in situ reaction Zhuan Li, Peng Xiao, and Xiang Xiong State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China (Received: 12 August 2009; revised: 28 August 2009; accepted: 2 September 2009) Abstract: Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by the warm compacted-in situ reaction. The microstructure, mechanical properties, tribological properties, and wear mechanism of C/C-SiC composites at different brake speeds were investigated. The results indicate that the composites are composed of 58wt% C, 37wt% SiC, and 5wt% Si. The density and open porosity are 2.0 g·cm–3 and 10%, respectively. The C/C-SiC brake composites exhibit good mechanical properties. The flexural strength can reach up to 160 MPa, and the impact strength can reach 2.5 kJ·m–2. The C/C-SiC brake composites show excellent tribological performances. The friction coefficient is between 0.57 and 0.67 at the brake speeds from 8 to 24 m·s?1. The brake is stable, and the wear rate is less than 2.02×10?6 cm3·J?1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems. Keywords: C/C-SiC; ceramic matrix composites; tribological properties; microstructure [This work was financially supported by the National High-Tech Research and Development Program of China (No.2006AA03Z560) and the Graduate Degree Thesis Innovation Foundation of Central South University (No.2008yb019).] 温压-原位反应法制备C / C-SiC刹车复合材料的工艺和性能 李专，肖鹏，熊翔 粉末冶金国家重点实验室，中南大学，湖南长沙410083，中国（收稿日期：2009年8月12日修订：2009年8月28日;接受日期：2009年9月2日） 摘要：采用温压?原位反应法制备炭纤维增强炭和碳化硅双基体(C/C-SiC)复合材
文献翻译 原文 Combining JSP and Servlets The technology of JSP and Servlet is the most important technology which use Java technology to exploit request of server, and it is also the standard which exploit business application .Java developers prefer to use it for a variety of reasons, one of which is already familiar with the Java language for the development of this technology are easy to learn Java to the other is "a preparation, run everywhere" to bring the concept of Web applications, To achieve a "one-prepared everywhere realized." And more importantly, if followed some of the principles of good design, it can be said of separating and content to create high-quality, reusable, easy to maintain and modify the application. For example, if the document in HTML embedded Java code too much (script), will lead the developed application is extremely complex, difficult to read, it is not easy reuse, but also for future maintenance and modification will also cause difficulties. In fact, CSDN the JSP / Servlet forum, can often see some questions, the code is very long, can logic is not very clear, a large number of HTML and Java code mixed together. This is the random development of the defects. Early dynamic pages mainly CGI (Common Gateway Interface, public Gateway Interface) technology, you can use different languages of the CGI programs, such as VB, C / C + + or Delphi, and so on. Though the technology of CGI is developed and powerful, because of difficulties in programming, and low efficiency, modify complex shortcomings, it is gradually being replaced by the trend. Of all the new technology, JSP / Servlet with more efficient and easy to program, more powerful, more secure and has a good portability, they have been many people believe that the future is the most dynamic site of the future development of technology. Similar to CGI, Servlet support request / response model. When a customer submit a request to the server, the server presented the request Servlet, Servlet responsible for handling requests and generate a response, and then gave the server, and then from the server sent to