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.     

美国地缘环境解析及其对中国的启示

 基于地缘环境理论，构建了地缘环境解析框架，从地理环境、地缘关系、地缘结构和地缘空间4个层次对美国地缘环境的动态变化进行了系统的解析。地理环境赋予美国有利的地理位置、优越的地理条件、绝对的地缘优势和拥有世界权力的可能。美国的地缘关系在其发展过程中呈现出对抗、竞争、合作、同盟等多种形式。地缘结构具有重要功能，倒三角结构、多极结构、两极结构、一超多强结构带给美国地缘政治、地缘经济、地缘文化等方面的地位、权力和利益，美国面对中国崛起的地缘理念结构亟需更新。美国主要的地缘空间横跨北美洲、亚洲及欧洲，可划分为腹地、核心地缘空间、海洋地缘空间和外围地缘支点。进入21世纪，美国的国内、国际环境正在发生深刻变化，其对外关系与地缘战略也呈现出新一轮的变动和调整，以适应新的地缘环境。中国在和平崛起过程中可以通过建设潜在的印度洋通道、构建互利共赢的“朋友圈”、制定自身发展的地缘战略等手段积极塑造自身的地缘环境，破解错综复杂的地缘环境问题，维护中国地缘安全。     

高温影响杂交水稻开花结实的生理生化基础初探

本文研究了人工气候箱内不同温度处理的水稻叶片中,叶绿素、糖和磷的含量及花药中游离氨基酸的含量与杂交水稻开花结实的关系。考察了不同温度处理下.杂交水稻的结实率。     

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     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

远程教育试卷系统的开发

电化教学领域中，基于网络的多媒体课件制作已成为实现远程教学模式的核心问题。为适应网络环境下远程教育的需要，以《微机原理与接口技术试卷生成系统》网络多媒体课件为例，结合CAI软件框架与相关网络技术，提出了实现多媒体信息网络发布的新想法与关键技术。     

采空区地表斜坡变形破坏类型及其运动机制

论述了采空区地表斜坡变形和破坏的地质现象，类型及其运动机制，斜坡在采空区覆岩移动的环境下，岩体发生塌落、倾倒、拱屈、弯曲和滑动等。它们各有其成因，力学特点和运动机制，对评定采空区地表斜坡稳定性是不可少的。     

支持EAI基于JMS的企业级协同消息通信工具的实现

面向企业应用系统集成,基于Java消息服务,研究企业级协同消息通信工具的实现技术.在J2EE核心技术的基础上,提出以企业JavaBean和Java消息服务为核心服务器,一切消息通信基于消息模式的系统架构,以解决企业级即时消息通信工具和其他信息系统集成难的问题;为了提高性能及系统可靠性,提出了核心服务器集群的方式.     

三昧:佛教审美感悟的主要形式

佛教对中国古代学创作和审美产生了巨大影响，这已经是不争的问题。而在感应外物的心理知觉上与学审美究竟有何内在联系及区别，则又大多语焉不详，或详而无纲、油水分离。笔从佛教教义中拈出“三昧”两个字，深入探寻佛教审美感悟的主要方式，分析它与庄子“心斋”及俗人梦幻的同异，这对中国古代学审美理论的梳理和建构都有重要意义。     

框架结构倒塌过程中的动力学分析

用刚度的概念只能分析框架未破坏时的变形和位移，文中运用惯性的概念解决了框架破坏后的运动分析，利用动力学中力与加速度的关系以及碰撞原理，可求出框架各部分的位移，从而可动态描述框架破坏后直至其完全倒塌在地面的全过程。