基于MicrosoftSQLServer2000的全文搜索功能构建Web搜索应用程序

MicrosoftSQLServer2000的全文搜索功能，可以对在非结构化文本数据上生成的索引执行快速、灵活的查询。本文介绍了如何充分利用使用MicrosoftSQLServer2000的全文搜索功能，可以快速实现一个简单、功能强大的Web搜索应用程序。     

On structuring proof search for first order linear logic

Full first-order linear logic can be presented as an abstract logic programming language in Miller's system Forum, which yields a sensible operational interpretation in the ‘proof search as computation’ paradigm. However, Forum still has to deal with syntactic details that would normally be ignored by a reasonable operational semantics. In this respect, Forum improves on Gentzen systems for linear logic by restricting the language and the form of inference rules. We further improve on Forum by restricting the class of formulae allowed, in a system we call G-Forum, which is still equivalent to full first-order linear logic. The only formulae allowed in G-Forum have the same shape as Forum sequents: the restriction does not diminish expressiveness and makes G-Forum amenable to proof theoretic analysis. G-Forum consists of two (big) inference rules, for which we show a cut elimination procedure. This does not need to appeal to finer detail in formulae and sequents than is provided by G-Forum, thus successfully testing the internal symmetries of our system.     

Adaptive Probabilistic Search Over Unstructured Peer-to-Peer Computing Systems

A challenging problem that confronts unstructured peer-to-peer (P2P) computing systems is how to provide efficient support to locate desired files. This paper addresses this problem by using some quantitative information in the form of probabilistic knowledge. Two types of probabilistic knowledge are considered in this paper: overlap between topics shared in the network and coverage of topics at each individual peer. Based on the probabilistic knowledge, this paper proposes an adaptive probabilistic search algorithm that can efficiently support file locating operation in the unstructured P2P network. Then, an update algorithm is devised to keep the freshness of the probabilistic knowledge of individual peers by taking advantage of feedback from the previous user queries. Finally, some extensive experiments are conducted to evaluate the efficiency and effectiveness of the proposed method. This work is partially supported by the National Natural Science Foundation of China under grant No. 60496325 and 60496327 and MoE Doctorate Subject Program under project No. 20030246023, and this work was done when the first author was visiting University of California at Berkeley.     

应用DataReader对象实现数据库查询

在ADO.NET数据模型中,DataReader对象具有内存占用少、数据检索效率高等优点。MSFlexGrid数据表格则控制灵活、界面简洁。因此,以DataReader对象获取数据,并在MSFlexGrid表格中浏览之,无疑是设计数据库查询程序时的一种上佳选择。     

论搜索引擎

本文介绍在Internet上进行信息搜索的搜索引擎的概念、原理、现状、使用、发展趋势及评价标准,并提供了一些常用的优秀国内外搜索引擎供大家参考。     

On-orbit servicing: a time-dependent, moving-target traveling salesman problem

The robotic capability of maintaining and repairing space assets, on‐orbit servicing (OOS), has the potential to change the way spacecraft are designed, manufactured and operated. The most common OOS mission concept envisions an orbital “depot”, where consumables and spare parts for spacecraft will be stored. A “servicing platform”, based at this depot, will be used to service a number of client spacecraft and then return to the depot for resupply. We model OOS as a time‐dependent, moving‐target traveling salesman problem and present an algorithm for minimizing the total amount of energy or time required for OOS operations.     

Some approaches to improve tree-based nearest neighbour search algorithms

Nearest neighbour search is a widely used technique in pattern recognition. During the last three decades a large number of fast algorithms have been proposed. In this work we are interested in algorithms that can be used with any dissimilarity function provided that it fits the mathematical notion of distance.Some of such algorithms organize, in preprocessing time, the data in a tree structure that is traversed in search time to find the nearest neighbour. The speedup is obtained using some pruning rules that avoid the traversal of some parts of the tree.In this work two new decomposition methods to build the tree and three new pruning rules are explored. The behaviour of our proposal is studied through experiments with synthetic and real data.     

SiCp/Al复合材料的制备方法及研究方向

SiCp/Al是颗粒增强铝基复合材料中研究较多、应用较广泛的一种。文中综述了SiCp/Al复合材料的制备方法,并简述了今后的研究方向。     

著名中文搜索引擎评析

概述了搜索引擎的工作原理,并通过检索实例对著名的中文搜索引擎做了评析。     

氯化丁基吡啶/AlCl_3离子液体催化体系中富马酸二甲酯合成过程优化

在氯化丁基吡啶与AlCl3 组成的离子液体催化体系中 ,顺丁烯二酸酐与甲醇反应 ,生成富马酸二甲酯 .采用单纯型优化方法对催化剂用量 ,反应时间、反应原料摩尔比进行了优化 .实验结果表明氯化丁基吡啶与AlCl3 组成的离子液体具有异构化和酯化两种催化作用 .在优化条件下m(催化剂 )∶m(顺丁烯二酸酐 ) =0 .0 7∶1 ;n(甲醇 )∶n(顺丁烯二酸酐 ) =1 .1∶1 ,反应时间 3h,反应温度 65℃ ,富马酸二甲酯的收率达到 92 % .