二元关系传递性的矩阵判别法

判断一个二元关系是否具有传递性,用定义与关系图的方法比较繁琐,利用关系矩阵判断其传递性,能避免繁琐的过程。利用矩形判别法、三角形判别法、十字型判别法,使可传递关系得到的判别变得既直观又迅速。     

有限集上二元关系传递性的矩阵判别法

通过对二元关系的关系矩阵元素特征的观察和对Warshall算法的深入研究，得出了3种判断有限集上的二元关系是否具备传递性的矩阵判别法：逻辑相加判别法、逻辑乘方比较判别法、打圈画叉判别法．     

一种语言判断矩阵不一致性的修正方法

文章研究了语言判断矩阵不一致性的修正方法。首先利用0-1型排列偏好关系矩阵是否是标准0-1型排列矩阵,得出语言判断矩阵是否具有满意一致性;若不具有满意一致性,通过改变0-1型排列偏好关系矩阵的元素值来修正方案两两比较时出现的循环现象,使其成为标准0-1型排列矩阵;最后给出实例验证这种方法的合理性和有效性。     

基于衡平矩阵的二元关系传递性的判别法

直接根据文献[1-3]中的离散数学教材中的二元关系传递性定义,有时很难判定。通过研究突破了二元关系传递性定义的局限性,通过引入衡平矩阵的概念,给出一个二元关系具有传递性的充要条件是它的关系矩阵为衡平矩阵,并给出了利用衡平矩阵判定二元关系具有传递性的几种方法,使对传递性的判别直观、形象、方便、快捷。     

致判断矩阵与一致模糊矩阵的关系

通过对一致判断矩阵与一致模糊矩阵的关系研究证明一致判断矩阵与一致模糊矩阵一样具有中分传递性,符合人类决策思维的一致性;运用模糊层次分析法决策会造成判断信息、一致性及累积优势度的损失.     

一致判断矩阵与一致模糊矩阵的关系

通过对一致判断矩阵与一致模糊矩阵的关系研究证明：一致判断矩阵与一致模糊矩阵一样具有中分传递性,符合人类决策思维的一致性;运用模糊层次分析法决策会造成判断信息、一致性及累积优势度的损失．     

一类衡平矩阵的判定与应用

给出了判定0-1矩阵为衡平矩阵的几种方法。因为每一个0-1矩阵对应一个二元关系的关系矩阵,从而给出了利用衡平矩阵判定二元关系具有传递性的几种方法。     

用面向对象的方法和计算机分析关系的传递性

关系传递性的特征比较复杂，本文给出的两种方法，分别可以从关系图和关系矩阵中判断关系的传递性，特别是用面向对象的方法判断关系的传递性，不仅简单、直观、实用而且准确。     

布尔矩阵与关系性质的判断

本文用布尔矩阵理论的方法对关系及其性质作了系统的论述，并给出了判断关系的可传递性的一个很方便的布尔矩阵方法。     

二元关系传递性与反传递性的判定

本文给出了关系运算法、关系图法、关系矩阵法、关系复合矩阵法判定二元关系的传递性和反传递性,分析了传递性和反传递性之间的联系,并建立了判定传递性和反传递性的算法,最后利用C语言编程实现.     

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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.     

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     

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。