Solving the Bipartite Subgraph Problem Using Genetic Algorithm with Conditional Genetic Operators

Bipartite subgraph problem is an important example of a class of combinatorial optimization problems. It has many important applications in modeling matching problem, modern coding theory, communication network, and computer science. The goal of this NP-complete problem is to find a bipartite subgraph with maximum number of edges of the given graph. In this paper, for efficiently solving the problem, we propose a genetic algorithm-based approach in which the genetic operators are performed based on the condition instead of probability. The proposed algorithm is tested on a large number of instances, and the experimental results show that the proposed algorithm is superior to its competitors. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

关于国际科技合作专家管理系统的构想

该系统将专家信息和项目成果相对应,多网联通,资源共享,实现了对专家库、项目成果库的精确管理,可及时全方位对国际科技合作专家进行查询、统计、分析.本系统以人性化设计、个性化服务、标准化操作等先进的设计理念为指导思想,充分利用Internet发展的最新技术,融合了信息管理技术与数据库技术,实现了对专家库、项目成果库的精确管理.     

基于PDA的水调信息移动查询系统

基于个人数字助理（PDA）的水调信息移动查询系统采用TCP/IP通信机制,PDA终端通过通用分组无线电业务（GPRS）接入水调内部网络,通过WebService提供数据服务实现对水调信息的移动查询。该系统已应用到福建电网水调系统中,为水库调度决策提供了及时有效的信息技术支持,大大提高了水库调度的快速反应能力和工作效率。     

Incomplete data management: a survey

Incomplete data accompanies our life processes and covers almost all fields of scientific studies, as a result of delivery failure, no power of battery, accidental loss, etc. However, how to model, index, and query incomplete data incurs big challenges. For example, the queries struggling with incomplete data usually have dissatisfying query results due to the improper incompleteness handling methods. In this paper, we systematically review the management of incomplete data, including modelling, indexing, querying, and handling methods in terms of incomplete data. We also overview several application scenarios of incomplete data, and summarize the existing systems related to incomplete data. It is our hope that this survey could provide insights to the database community on how incomplete data is managed, and inspire database researchers to develop more advanced processing techniques and tools to cope with the issues resulting from incomplete data in the real world.     

RDF partitioning for scalable SPARQL query processing

The volume of RDF data increases dramatically within recent years, while cloud computing platforms like Hadoop are supposed to be a good choice for processing queries over huge data sets for their wonderful scalability. Previous work on evaluating SPARQL queries with Hadoop mainly focus on reducing the number of joins through careful split of HDFS files and algorithms for generating Map/Reduce jobs. However, the way of partitioning RDF data could also affect system performance. Specifically, a good partitioning solution would greatly reduce or even totally avoid cross-node joins, and significantly cut down the cost in query evaluation. Based on HadoopDB, this work processes SPARQL queries in a hybrid architecture, where Map/Reduce takes charge of the computing tasks, and RDF query engines like RDF-3X store the data and execute join operations. According to the analysis of query workloads, this work proposes a novel algorithm for automatically partitioning RDF data and an approximate solution to physically place the partitions in order to reduce data redundancy. It also discusses how to make a good trade-off between query evaluation efficiency and data redundancy. All of these proposed approaches have been evaluated by extensive experiments over large RDF data sets.     

一种个性化查询扩展方法

针对当前主流web搜索引擎存在信息检索个性化效果差和信息检索的精确率低等缺点, 通过对已有方法的技术改进, 介绍了一种基于用户历史兴趣网页和历史查询词相结合的个性化查询扩展方法。当用户在搜索引擎上输入查询词时,能根据学习到的当前用户兴趣模型动态判定用户潜在兴趣和计算词间相关度,并将恰当的扩展查询词组提交给搜索引擎,从而实现不同用户输入同一查询词能返回不同检索结果的目的。实验验证了算法的有效性,检索精确率也比原方法有明显提高。     

一种内外网隔离的证书查询方案设计与实现

LDAP协议广泛应用于网络信息资源查询和证书目录查询,然而在有些场合,证书的查询端和证书目录服务器之间有网络隔离设备,不能直接采用公开的远程目录访问协议来进行证书查询。设计和实现了一种内外网隔离的证书查询方案,既不用修改LDAP协议,又能够防止恶意用户非法获取证书。     

基于k-频繁子图聚类的二分图匿名方法

针对以二分图形式发布的社会网络隐私泄露问题,提出了一种面向敏感边识别攻击的社会网络二分图匿名方法。在已有k-安全分组的理论基础上,结合二分图的稀疏性和敏感边识别攻击形式,分别提出了正单向、逆单向以及完全（c1,c2）-安全性原则,并在此基础上,形式化地定义了一类抗敏感边识别攻击的社会网络二分图安全匿名问题;同时,还提出了一种基于k-频繁子图聚类的二分图划分算法和一种基于二分图（c1,c2）-安全性的匿名算法来保证发布二分图的安全性。实验结果表明,该算法在与已有方法相当时间开销的前提下,能产生更小的信息损失度,有效地抵制了敏感边识别攻击,实现了二分图的安全发布。     

一种面向专业搜索引擎的查询推荐算法

根据专业搜索引擎的特点,提出了一种新颖的基于词语共现与HITS算法的查询推荐算法QR-CH（Query Recommendation algorithm based on word Co-occurrence and HITS algorithm）。该算法一方面利用HITS算法对基于词语共现筛选出的关联词按语义关联性进行排序,选取排序靠前的关联词作为推荐词,提高了推荐词与原查询词的相关性;另一方面使用HITS算法排序关联文档,从查询结果文档集的角度来判断推荐是否冗余,降低了推荐词的冗余性。该算法将推荐相关的信息存储到知识树中,利用知识树实现查询推荐。实验结果表明QR-CH算法在推荐词的相关性和冗余词的判断方面均优于文献中已有的类似算法。     

针对Kriging插值结果的空间查询方法

Kriging插值方法及其各种改进模型已被广泛应用,但由于其插值结果是栅格形式,因此不利于与矢量数据叠加分析。为了更加便捷地使用插值结果,在衡量Voronoi图和最小外接矩形特点的基础上,提出了适用于Kriging插值结果的数据结构及空间查询方法。查询某一点位的特征值时,先通过区域的最小外接矩形初步判断出该位置可能存在的区域,进而逐一判断点与所选区域的空间关系,根据点所在区域的属性值得到该点位的特征值。该方法实现了对Kriging插值结果的空间查询,其正确性通过某露天矿的实际运行数据得到了验证。实验结果表明,该方法的查询效率控制在毫秒级,能够满足矿区车载终端程序及类似应用的需求。