一种基于图像熵及分形维矢量的图像检索技术

在基于内容的图像检索系统中,图像的抽象描述和特征提取是要解决的关键问题之一.提出了一种利用低维数据有效表示图像特征的基于图像熵及位面图序列分形维矢量的图像检索方法,实现了快速有效的图像检索.     

一种基于小波突出点颜色及空间分布熵的图像检索方法

分析了基于兴趣点的图像检索方法的缺点，提出了一种基于小波突出点的图像检索新方法．该方法在小波域提取突出点，这些突出点既表示了全局变化也表示了局部变化；然后以小波突出点为线索，设计了基于小波突出点的颜色分布熵，既利用了小波突出点的局部特征，又考虑了小波突出点的空间分布结构；用图像间的颜色分布熵来度量图像间的相似性．该检索算法不但保证了对图像旋转、平移鲁棒性，而且克服了传统直方图没有空间位置的缺陷．实验结果表明，该方法对图像检索是有效的．     

一个图像检索模型及其应用

给出一个用于图像数据库系统的图像检索模型，这个模型不仅可以用来作为描述和比较图像检索方法的一般框架，也可以作为实现图像检索机制的参考结构。作为应用实例，也为了评价现有的各种图像检索手段，并且应用这个模型对多种图像检索方法进行了分析与比较。     

基于内容的图像检索技术

综合视觉特性,基于内容的图像检索图像特征提取的关键是图像低层视觉特征的提取技术,内容主要包括图像的颜色特征、形状特征以及颜色的空间分布特征,采用线性组合以及加权颜色空间分布熵四种方法来提高图像信息熵和空间分布熵进行图像检索的性能。     

基于颜色布局的压缩图像检索研究

图像检索技术是多媒体应用中的关键技术.文章针对JPEG压缩图像,结合MPEG-7中建议的颜色布局描述符,提出一种带相关反馈的基于DCT域的快速图像检索方法;该方法只需要熵解码(部分解码),可提高图像特征提取的速度、节省存储空间;实验结果表明,此方法具有检索效率高、检索效果好的特点.     

一种基于LSI的图像语义检索技术

探讨如何将LSI技术应用于图像检索中，以实现基于语义的图像检索的技术途径，给出了一种新的图像索引方法，它使用灰色模型GM（1，1）对图像的像素值进行模型化处理，并且使用模型参数的概率分布来描述图像，在此基础上，详细讨论了将隐含主义索引应用于图像检索中的具体方法，并给出了相应的算法，最后，给出了实验结果和尚需进一步研究的问题。     

基于非下采样Contourlet信息熵的纹理图像检索

提出了一种基于非下采样Contourlet信息熵的纹理图像检索新方法.首先对原始图像进行三层非下采样Contourlet分解;然后计算各个子带的能量,并对其进行排序、合并,得到纹理直方图;最后以纹理直方图为概率密度函数,并用改进的信息熵方法求得函数的熵,以此作为纹理特征进行检索.实验结果表明,该方法与当前基于多分辨率的纹理图像检索方法相比具有更高的查全率和查准率.     

基于Web的服装图像检索系统

提出了基于Web的服装图像检索方法，用ASP实现了对服装图像数据进行检索与浏览等功能。     

基于空间数据结构的图像检索

提出了用图像联合特征取代单一的图像特征表示内容的模型，通过把图像的相似性定义在欧氏空间，引入了空间数据索引结构，针对图像联合特征的高维性，提出用X树空间结构来索引图像联合特征从而实现对图像内容进行检索的方法，通过实验比较，证明该方法的检索不仅视觉效果良好，而且检索效率也明显提高。     

基于颜色的图像检索

论述了基于颜色的图像检索方法，对颜色空间的选择、颜色的量化以及颜色的相似测试进行了讨论。在此基础上，对两种典型的基于颜色的图像检索方法的特点、关键技术的实现方法以及存在的问题进行了详细的分析和比较。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。