A prototype for spatial information services based on J2EE

J2EE (Java 2 Platform , Enterprise Edition) is a kind of architecture that simplifies the development ,design and management of multilevel enterprise solution. The spatial middlewares based on J2EE can easily resolve the problems which the traditional Geographic Information Systems (GIS) now have to face wit,such as transplantability,stability, easy maintainability and many more. This paper first introduces some conceptions and principles about J2EE,spatial middleware. then proposes a concrete J2EE-based solution of spatial middleware,namely SISP AS,which develops on JBoss(an open sources application server of J2EE) and uses the SISP spatial database. SISP AS follows Open GIS specifications,and implements a subset of OGC services. it improves interrperability and commonality by using XML/GML for communication and data transmission,resolves the transmission efficiency problem of large spatial data by using raster pyramid and vector pyramid. Finally,the related work will be presented. Notably, the experiments on this prototype system can proves that it is available to manage,distribute and share large scale spatial data by using SISP AS.     

递归(分片)仿射分形插值数值模拟与盒维数研究

分析了Barnsley M F的经典文献中递归仿射分形插值的数值模拟问题，利用Matlab与随机迭代算法，给出了递归仿射分形插值算例的随机迭代算法，得到相应分形插值曲线。递归仿射分形插值把较长的原像区间Ji′=［xl,xm］压缩映射到更短的像区间Ji=［xi－1,xi］时，有3种情况:(1) JiJi′; (2) JiJi′且Ji∩Ji′=Φ;(3) JiJi′，但是Ji∩Ji′≠Φ。根据递归仿射分形插值与分片分形插值，对以上3种情形进行了随机迭代数值模拟，给出了算法流程与详细的程序代码，这些数值分析是对分形插值理论的补充。最后，利用粒子群最优化算法给出仿射分形插值函数的盒维数最优解。     

幂矩阵的秩展开公式

设A是n级复数矩阵，E←可逆矩阵T，使A^m=Tdiag[J1^m，J2^m，…，J2^m]T^-1,其中：Ji（i=1，2，…，s）是初等因子（λ-λi）^ri所对应的若当块，并且∑i=1sri=n，借助等式rankA^m=∑i=1srankJi^m，利用rankJi^m的特点，分别从A是否可逆两个角度及幂指数m的不同取值范围，给出了幂矩阵A^m的秩rankA^m的展开公式。     

RMg2Ni9(R=Ca,La)合金的电子结构与稳定性的第一原理研究

利用第一原理赝势平面波方法计算了C aM g2N i9,L aM g2N i9贮氢合金的电子结构,分析了合金中原子间的相互作用以及对合金稳定性的影响.结果表明:L aM g2N i9中N i-N i间的作用比C aM g2N i9中相应的原子间的作用强,使得C aM g2N i9比L aM g2N i9易于完成由N i-N i键到N i-H的转移,是导致L aM g2N i9合金吸氢量比C aM g2N i9合金吸氢量少的原因之一.     

A Voronoi-based spatial algebra for spatial relations

Spatial relation between spatial objects is a very important topic for spatial reasoning, query and analysis in geographical information systems (GIS). The most popular models in current use have fundamental deficiencies in theory. In this paper, a generic algebra for spatial relations is presented, in which (i) appropriate operators from set operators (i.e. union, intersection, difference, difference by, symmetric difference, etc.) are utilized to distinguish the spatial relations between neighboring spatial objects; (ii) three types of values are used for the computational results of set operations-content, dimension and number of connected components; and (iii) a spatial object is treated as a whole but the Voronoi region of an object is employed to enhance its interaction with its neighbours. This algebra overcomes the shortcomings of the existing models and it can effectively describe the relations of spatial objects.     

J-Boolean like环

本文首先引进了Boolean-like环的一类新的扩张J-Boolean like环,即对任意环R中元素a,b都有（a-a2）（b-b2）∈J（R）,这里J（R）为环R的Jacobson根,则环R称为J-Boolean like环.证明了两个定理分别为（1）设D是一个环,C是D的一个子环,R[D,C]是一个J-Boolean like环（a）C,D是J-Boolean like环,（b）J2（C）J（D）.（2）如果B/J（B）是Boolean环,并且B[i]={a＋bi｜i2=ui＋η,a,b,u,η∈B},那么B[i]是J-Boolean like环当且仅当uη∈J（B）.     

Reciprocal Cloaking Algorithm for Spatial K-Anonymity

Mobile devices with global positioning capabilities allow users to retrieve points of interest (POI) in their proximity. Due to the nature of spatial queries, location-based service (LBS) needs the user position in order to process requests. On the other hand, revealing exact user locations to LBS may pinpoint their identities and breach their privacy. Spatial K-anonymity (SKA) exploits the concept of K-anonymity in order to protect the identity of users from location-based attacks. However, existing reciprocal methods rely on a specialized data structure. In contrast, a reciprocal algorithm was proposed using existing spatial index on the user locations. At the same time, an adjusted median splits algorithm was provided. Finally, according to effectiveness (i.e., anonymizing spatial region size) and efficiency (i.e., construction cost), the experimental results verify that the proposed methods have better performance. Moreover, since using employ general-purpose spatial indices, the proposed method supports conventional spatial queries as well.     

青霉素的发现者弗莱明

2、·lt小。‘≯:叫代,。、?:爿妣☆的儿浆}"j特》jlj珥玖l刈i戈Ii乍力‘[ni n0 f5络.偏爱,li物、化。、≯:J_』J蛛 他成绩优蚌.、≯忠。’;:J≮.20岁缪人伦敦簪f屿HlJ I延院附J戚l必’’≯:院.从此踏逊J,1必。、:::的I!{i}t1:0 4、九救i卉协病D!的过袱l}1,弗求…发现,lIl】:缺乏柑效的}『【【辆药.协,敛f止人lfi伤∞伤¨溃烂,被地微胶,甚至痛苦地纯上这、触目惊心的事实他他十分难过。 5、“·f戍”结乘r 1919年.1 J J,弗策H月川到爷且5Ⅲl矧觉,卜嘤研究抗菌学,强烈n0黄任感,驱使他要找到一种x·r人体无害叉能有效地遏制以至消灭有i…     

整数线性规划问题的截去法

一、引言 整数线性规划的基本问题是,给定实数a_(ij),b_i,c_j,i∈I=,j∈J,在满足限制的向量(x_1,x_2,……,x_n)的集合上,把线性函数极大化。如J′=J,称为完全整数规划问题,否则称为部分整数规划问题。     

钢绳芯胶带接头状况的漏磁成像检测原理

通过将钢绳芯胶带磁化至饱和并在胶带表面测量接头产生的漏磁场b(I,J) ,获得基于二值化离散磁偶极子阵列 q(i,j)的接头状况成像方法 ,q(i,j)的磁荷量为 0和 1 ,由方程 {b(I,J) } ={k(I,J,i,j) } { q(i,j) }经线性反演求解得到 ,{k(I,J,i,j) }是 (I×J)× (i×j)维矩阵 ,由测量点和磁偶极子的空间位置关系决定 .方程的求解采用基于约束的最小二乘方法 ,约束包括接头处的b(I,J)必定大于某一量值且磁荷量一定不为负值     

WebGIS的技术分析及实现

分析了WebGIS的各种实现技术，指出它们各自的优点和缺点；针对使用Java的实现方案,结合Sun公司提出的J2EE技术规范，提出了一种基于J2EE的WebGIS实现的体系结构。     

基于J2EE高速公路网络地理信息系统平台研究

探讨了基于J2EE（Java 2 Enterprise Edition）的高速公路网络地理信息系统（webGIS）平台架构及其关键技术，包括高速公路空间数据组织和设计。WebGIS中间件技术，数据库连接池技术，高速公路WebGiS的动态分段技术等．建立了高速公路WebGIS地理信息平台，以惠河高速公路管理为例，介绍了地理信息平台的功能和应用，验证了文中的各种技术与方法．     

基于J2EE的WebGIS实现技术研究

在分析比较现有WebGIS体系结构及主要实现技术的基础上,提出了基于J2EE的WebGIS实现方法。     

Design and implementation of highway distress and preventive measures decision support system based on WebGIS 

A highway distress and preventive measures decision support system based on WebGIS and J2EE architecture were studied, and the key issues for the system are presented. Such issues as spatial data and attribute data organization, technology of enhancing user experience, database connection pool were investigated. The feasibility of the theories and methods were tested through the system.     

A prototype for spatial information services based on J2EE

J2EE (Java 2 Platform , Enterprise Edition) is a kind of architecture that simplifies the development ,design and management of multilevel enterprise solution. The spatial middlewares based on J2EE can easily resolve the problems which the traditional Geographic Information Systems (GIS) now have to face with, such as transplantability, stability, easy maintainability and many more. This paper first introduces some conceptions and principles about J2EE, spatial middleware, then proposes a concrete J2EE-based solution of spatial middleware, namely SISP AS, which develops on JBoss(an open sources application server of J2EE) and uses the SISP spatial database. SISP AS follows Open GIS specifications, and implements a subset of OGC services, it improves interoperability and commonality by using XML/GML for communication and data transmission, resolves the transmission efficiency problem of large spatial data by using raster pyramid and vector pyramid. Finally, the related work will be presented. Notably, the experiments on this prototype system can proves that it is available to manage, distribute and share large scale spatial data by using SISP AS.     

A prototype for spatial information services based on J2EE

J2EE (Java 2 Platform , Enterprise Edition) is a kind of architecture that simplifies the development ,design and management of multilevel enterprise solution. The spatial middlewares based on J2EE can easily resolve the problems which the traditional Geographic Information Systems (GIS) now have to face with, such as transplantability,stability, easy maintainability and many more. This paper first introduces some conceptions and principles about J2EE, spatial middleware. then proposes a concrete J2EE-based solution of spatial middleware, namely SISP AS, which develops on JBoss(an open sources application server of J2EE) and uses the SISP spatial database. SISP AS follows Open GIS specifications, and implements a subset of OGC services. it improves interoperability and commonality by using XML/GML for communication and data transmission, resolves the transmission efficiency problem of large spatial data by using raster pyramid and vector pyramid. Finally, the related work will be presented. Notably,the experiments on this prototype system can proves that it is available to manage,distribute and share large scale spatial data by using SISP AS.     

Design and implementation of highway distress and preventive measures decision support system based on WebGIS

A highway distress and preventive measures decision support system based on WebGIS and J2EE architecture were studied, and the key issues for the system are presented. Such issues as spatial data and attribute data organization, technology of enhancing user experience, database connection pool were investigated. The feasibility of the theories and methods were tested through the system.     

基于J2EE的WebGIS的模型研究

网络地理信息系统(WebGIS)是当前GIS技术研究热点,实现WebGIS系统的方法有许多种,这里在比较多种WEBGIS开发方法的同时提出了基于J2EE体系结构的WebGIS开发模型,并且列举了该模型的优势.     

J2EE平台WebGIS设计技术探讨

针对传统WebGIs设计方法的局限性，利用Java平台无关性的优点，为拓展GIS在电子政务中的应用，提出了基于J2EE平台的Browser／server模式的分布式解决方案，并以一个城市电子地图为例，着重探讨了J2EE平台上采用中间件（MapXtrerne）设计和架构应用于电子政务的WebGIS的思想，主要包括客户端的选择、功能考虑以及服务器端的结构设计等，并据此提供了一个原型．该原型的建立及其设计的思想方法对于其他更为复杂的WebGIS的开发具有借鉴意义．     

一种基于组件的多层WebGIS模型的设计与实现

针对WebGIS中存在的系统不稳定、难以扩展及可维护性差等问题,提出一种基于组件的多层WebGIS模型,并论述了如何基于J2EE框架实现该体系结构。实际的系统设计与开发工作表明,基于新体系结构的WebGIS具有较好的集成性与可扩展性,从而缩短了开发周期,降低了开发成本。