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VKFQ:A Verifiable Keyword Frequency Query Framework with Local Differential Privacy in Blockchain
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作者 Youlin Ji Bo Yin Ke Gu 《Computers, Materials & Continua》 SCIE EI 2024年第3期4205-4223,共19页
With its untameable and traceable properties,blockchain technology has been widely used in the field of data sharing.How to preserve individual privacy while enabling efficient data queries is one of the primary issue... With its untameable and traceable properties,blockchain technology has been widely used in the field of data sharing.How to preserve individual privacy while enabling efficient data queries is one of the primary issues with secure data sharing.In this paper,we study verifiable keyword frequency(KF)queries with local differential privacy in blockchain.Both the numerical and the keyword attributes are present in data objects;the latter are sensitive and require privacy protection.However,prior studies in blockchain have the problem of trilemma in privacy protection and are unable to handle KF queries.We propose an efficient framework that protects data owners’privacy on keyword attributes while enabling quick and verifiable query processing for KF queries.The framework computes an estimate of a keyword’s frequency and is efficient in query time and verification object(VO)size.A utility-optimized local differential privacy technique is used for privacy protection.The data owner adds noise locally into data based on local differential privacy so that the attacker cannot infer the owner of the keywords while keeping the difference in the probability distribution of the KF within the privacy budget.We propose the VB-cm tree as the authenticated data structure(ADS).The VB-cm tree combines the Verkle tree and the Count-Min sketch(CM-sketch)to lower the VO size and query time.The VB-cm tree uses the vector commitment to verify the query results.The fixed-size CM-sketch,which summarizes the frequency of multiple keywords,is used to estimate the KF via hashing operations.We conduct an extensive evaluation of the proposed framework.The experimental results show that compared to theMerkle B+tree,the query time is reduced by 52.38%,and the VO size is reduced by more than one order of magnitude. 展开更多
关键词 SECURITY data sharing blockchain data query privacy protection
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Learned Distributed Query Optimizer:Architecture and Challenges
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作者 GAO Jun HAN Yinjun +2 位作者 LIN Yang MIAO Hao XU Mo 《ZTE Communications》 2024年第2期49-54,共6页
The query processing in distributed database management systems(DBMS)faces more challenges,such as more operators,and more factors in cost models and meta-data,than that in a single-node DMBS,in which query optimizati... The query processing in distributed database management systems(DBMS)faces more challenges,such as more operators,and more factors in cost models and meta-data,than that in a single-node DMBS,in which query optimization is already an NP-hard problem.Learned query optimizers(mainly in the single-node DBMS)receive attention due to its capability to capture data distributions and flexible ways to avoid hard-craft rules in refinement and adaptation to new hardware.In this paper,we focus on extensions of learned query optimizers to distributed DBMSs.Specifically,we propose one possible but general architecture of the learned query optimizer in the distributed context and highlight differences from the learned optimizer in the single-node ones.In addition,we discuss the challenges and possible solutions. 展开更多
关键词 distributed query processing query optimization learned query optimizer
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Query Expansion Based on Semantics and Statistics in Chinese Question Answering System 被引量:2
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作者 JIA Keliang PANG Xiuling +1 位作者 LI Zhinuo FAN Xiaozhong 《Wuhan University Journal of Natural Sciences》 CAS 2008年第4期505-508,共4页
In Chinese question answering system, because there is more semantic relation in questions than that in query words, the precision can be improved by expanding query while using natural language questions to retrieve ... In Chinese question answering system, because there is more semantic relation in questions than that in query words, the precision can be improved by expanding query while using natural language questions to retrieve documents. This paper proposes a new approach to query expansion based on semantics and statistics Firstly automatic relevance feedback method is used to generate a candidate expansion word set. Then the expanded query words are selected from the set based on the semantic similarity and seman- tic relevancy between the candidate words and the original words. Experiments show the new approach is effective for Web retrieval and out-performs the conventional expansion approaches. 展开更多
关键词 Chinese question answering system query expansion relevance feedback semantic similarity semantic relevancy
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Banian: A Cross-Platform Interactive Query System for Structured Big Data 被引量:2
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作者 Tao Xu Dongsheng Wang Guodong Liu 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2015年第1期62-71,共10页
The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB le... The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB level structured data called Banian. Banian overcomes the storage structure limitation of relational database and effectively integrates interactive query with large-scale storage management. It provides a uniform query interface for cross-platform datasets and thus shows favorable compatibility and scalability. Banian's system architecture mainly includes three layers:(1) a storage layer using HDFS for the distributed storage of massive data;(2) a scheduling and execution layer employing the splitting and scheduling technology of parallel database; and(3)an application layer providing a cross-platform query interface and supporting standard SQL. We evaluate Banian using PB level Internet data and the TPC-H benchmark. The results show that when compared with Hive, Banian improves the query performance to a maximum of 30 times and achieves better scalability and concurrency. 展开更多
关键词 big data interactive query relational database HDFS cross platform
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GIS Chinese Query System Based on CBR
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作者 XU Aiping LIN Guang HUANG Yuan 《Wuhan University Journal of Natural Sciences》 CAS 2009年第5期399-403,共5页
In this paper, the method of tmderstanding GIS Chinese query based on CBR (case-based reasoning) is proposed. The CaseBase is designed on the grammar rule of Chinese query sentences, the cases that pick up the chara... In this paper, the method of tmderstanding GIS Chinese query based on CBR (case-based reasoning) is proposed. The CaseBase is designed on the grammar rule of Chinese query sentences, the cases that pick up the character of standard query language (SQL) and are expressed in form semantics. In retrieval, the concepts of target comparability, structure comparability and individual comparability are given. The algorithm of case retrieval searches first the case of structure comparability and then individual comparability. The SQL reasoning algorithm that first parses form semantics, then reasons on structure comparability, and finally reasons on individual comparability is realized. In the actual GIS, the structure comparability and individual comparability are tested respectively. The experiment results show that the strategy of CBR is correct and feasible. With the size of CaseBase increasing through studies, the CaseBase will eventually be perfected. The effect of retrieval and reasoning will become better and better. 展开更多
关键词 Chinese query case-based reasoning(CBR) Case- Base case retrieval comparability
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Semantic Query Mechanism on Peer to Peer XML-Based Information Systems
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作者 JIANG Min HUANG Yi +1 位作者 GU Jinguang HE Guiming 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第3期525-528,共4页
To enable accessing web information at semantic level, this paper develops a semantic query rewriting mechanism on peer to peer XISs with complex ontology mapping technology. It discusses the patterns of complex ontol... To enable accessing web information at semantic level, this paper develops a semantic query rewriting mechanism on peer to peer XISs with complex ontology mapping technology. It discusses the patterns of complex ontology mappings at first, and the ontology-based query mechanism in peer to peer environment. The extension of XML query algebra and XML query rewriting mechanism are dissussed in detail. 展开更多
关键词 ONTOLOGY query rewriting P2P XML-based information systems
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Query Optimization Framework for Graph Database in Cloud Dew Environment
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作者 Tahir Alyas Ali Alzahrani +3 位作者 Yazed Alsaawy Khalid Alissa Qaiser Abbas Nadia Tabassum 《Computers, Materials & Continua》 SCIE EI 2023年第1期2317-2330,共14页
The query optimizer uses cost-based optimization to create an execution plan with the least cost,which also consumes the least amount of resources.The challenge of query optimization for relational database systems is... The query optimizer uses cost-based optimization to create an execution plan with the least cost,which also consumes the least amount of resources.The challenge of query optimization for relational database systems is a combinatorial optimization problem,which renders exhaustive search impossible as query sizes rise.Increases in CPU performance have surpassed main memory,and disk access speeds in recent decades,allowing data compression to be used—strategies for improving database performance systems.For performance enhancement,compression and query optimization are the two most factors.Compression reduces the volume of data,whereas query optimization minimizes execution time.Compressing the database reduces memory requirement,data takes less time to load into memory,fewer buffer missing occur,and the size of intermediate results is more diminutive.This paper performed query optimization on the graph database in a cloud dew environment by considering,which requires less time to execute a query.The factors compression and query optimization improve the performance of the databases.This research compares the performance of MySQL and Neo4j databases in terms of memory usage and execution time running on cloud dew servers. 展开更多
关键词 query optimization compression cloud dew DECOMPRESSION graph database
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Application of Recursive Query on Structured Query Language Server
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作者 荀雪莲 ABHIJIT Sen 姚志强 《Journal of Donghua University(English Edition)》 CAS 2023年第1期68-73,共6页
The advantage of recursive programming is that it is very easy to write and it only requires very few lines of code if done correctly.Structured query language(SQL)is a database language and is used to manipulate data... The advantage of recursive programming is that it is very easy to write and it only requires very few lines of code if done correctly.Structured query language(SQL)is a database language and is used to manipulate data.In Microsoft SQL Server 2000,recursive queries are implemented to retrieve data which is presented in a hierarchical format,but this way has its disadvantages.Common table expression(CTE)construction introduced in Microsoft SQL Server 2005 provides the significant advantage of being able to reference itself to create a recursive CTE.Hierarchical data structures,organizational charts and other parent-child table relationship reports can easily benefit from the use of recursive CTEs.The recursive query is illustrated and implemented on some simple hierarchical data.In addition,one business case study is brought forward and the solution using recursive query based on CTE is shown.At the same time,stored procedures are programmed to do the recursion in SQL.Test results show that recursive queries based on CTEs bring us the chance to create much more complex queries while retaining a much simpler syntax. 展开更多
关键词 structured query language(SQL)server common table expression(CTE) recursive query stored procedure hierarchical data
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Visible-infrared person re-identification using query related cluster
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作者 赵倩倩 WU Hanxiao +2 位作者 HUANG Linhan ZHU Jianqing ZENG Huanqiang 《High Technology Letters》 EI CAS 2023年第2期194-205,共12页
Visible-infrared person re-identification(VIPR), is a cross-modal retrieval task that searches a target from a gallery captured by cameras of different spectrums.The severe challenge for VIPR is the large intra-class ... Visible-infrared person re-identification(VIPR), is a cross-modal retrieval task that searches a target from a gallery captured by cameras of different spectrums.The severe challenge for VIPR is the large intra-class variation caused by the modal discrepancy between visible and infrared images.For that, this paper proposes a query related cluster(QRC) method for VIPR.Firstly, this paper uses an attention mechanism to calculate the similarity relation between a visible query and infrared images with the same identity in the gallery.Secondly, those infrared images with the same query images are aggregated by using the similarity relation to form a dynamic clustering center corresponding to the query image.Thirdly, QRC loss function is designed to enlarge the similarity between the query image and its dynamic cluster center to achieve query related clustering, so as to compact the intra-class variations.Consequently, in the proposed QRC method, each query has its own dynamic clustering center, which can well characterize intra-class variations in VIPR.Experimental results demonstrate that the proposed QRC method is superior to many state-of-the-art approaches, acquiring a 90.77% rank-1 identification rate on the RegDB dataset. 展开更多
关键词 query related cluster(QRC) cross-modality visible-infrared person re-identification(VIPR) video surveillance
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基于改进Deformable DETR的无人机视频流车辆目标检测算法
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作者 江志鹏 王自全 +4 位作者 张永生 于英 程彬彬 赵龙海 张梦唯 《计算机工程与科学》 CSCD 北大核心 2024年第1期91-101,共11页
针对无人机视频流检测中小目标数量多、因图像传输质量较低而导致的上下文语义信息不充分、传统算法融合特征推理速度慢、数据集类别样本不均衡导致的训练效果差等问题,提出一种基于改进Deformable DETR的无人机视频流车辆目标检测算法... 针对无人机视频流检测中小目标数量多、因图像传输质量较低而导致的上下文语义信息不充分、传统算法融合特征推理速度慢、数据集类别样本不均衡导致的训练效果差等问题,提出一种基于改进Deformable DETR的无人机视频流车辆目标检测算法。在模型结构方面,该算法设计了跨尺度特征融合模块以增大感受野,提升小目标检测能力,并采用针对object_query的挤压-激励模块提升关键目标的响应值,减少重要目标的漏检与错检率;在数据处理方面,使用了在线困难样本挖掘技术,改善数据集中类别样本分布不均的问题。在UAVDT数据集上进行了实验,实验结果表明,改进后的算法相较于基线算法在平均检测精度上提升了1.5%,在小目标检测精度上提升了0.8%,并在保持参数量较少增长的情况下,维持了原有的检测速度。 展开更多
关键词 Deformable DETR 目标检测 跨尺度特征融合模块 object query挤压-激励 在线难样本挖掘
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用Java来设计组件重用的Query方法 被引量:3
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作者 葛瀛龙 徐翀 +1 位作者 郑宁 胡昔祥 《计算机工程与应用》 CSCD 北大核心 2002年第20期103-106,共4页
文章所探讨的组件重用的Query方法是利用Java反射技术和Java数据库连接技术来完成叶数据库的查询操作。它将查询数据库的公共操作封装于一个组件中,使编程工作者在具体编程工作中能方便地重复使用它们,以求简化编程工作。
关键词 JAVA语言 设计 组件重用 query方法 EJB组件
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Semantic-based query processing for relational data integration 被引量:1
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作者 苗壮 张亚非 +2 位作者 王进鹏 陆建江 周波 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期22-25,共4页
To solve the query processing correctness problem for semantic-based relational data integration,the semantics of SAPRQL(simple protocol and RDF query language) queries is defined.In the course of query rewriting,al... To solve the query processing correctness problem for semantic-based relational data integration,the semantics of SAPRQL(simple protocol and RDF query language) queries is defined.In the course of query rewriting,all relative tables are found and decomposed into minimal connectable units.Minimal connectable units are joined according to semantic queries to produce the semantically correct query plans.Algorithms for query rewriting and transforming are presented.Computational complexity of the algorithms is discussed.Under the worst case,the query decomposing algorithm can be finished in O(n2) time and the query rewriting algorithm requires O(nm) time.And the performance of the algorithms is verified by experiments,and experimental results show that when the length of query is less than 8,the query processing algorithms can provide satisfactory performance. 展开更多
关键词 data integration relational database simple protocol and RDF query language(SPARQL) minimal connectable unit query processing
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Query Expansion for Chinese Information Retrieval by Using a Decaying Co-occurrence Model 被引量:3
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作者 贺宏朝 何丕廉 +1 位作者 高剑峰 黄昌宁 《Transactions of Tianjin University》 EI CAS 2002年第3期183-186,共4页
Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and re... Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and realized. The model is an extension of the traditional co-occurrence model by adding a decaying factor that decreases the mutual information when the distance between the terms increases. Experimental results on TREC-9 collections show this query expansion method results in significant improvements over the IR without query expansion. 展开更多
关键词 query expansion Chinese language information retrieval
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Optimization of RDF link traversal based query execution 被引量:2
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作者 朱艳琴 花岭 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期27-32,共6页
Aiming at the problem that only some types of SPARQL ( simple protocal and resource description framework query language) queries can be answered by using the current resource description framework link traversal ba... Aiming at the problem that only some types of SPARQL ( simple protocal and resource description framework query language) queries can be answered by using the current resource description framework link traversal based query execution (RDF-LTE) approach, this paper discusses how the execution order of the triple pattern affects the query results and cost based on concrete SPARQL queries, and analyzes two properties of the web of linked data, missing backward links and missing contingency solution. Then three heuristic principles for logic query plan optimization, namely, the filtered basic graph pattern (FBGP) principle, the triple pattern chain principle and the seed URIs principle, are proposed. The three principles contribute to decrease the intermediate solutions and increase the types of queries that can be answered. The effectiveness and feasibility of the proposed approach is evaluated. The experimental results show that more query results can be returned with less cost, thus enabling users to develop the full potential of the web of linked data. 展开更多
关键词 web of linked data resource description framework link traversal based query execution (RDF-LTE) SPARQL query query optimization
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APPROXIMATE QUERY AND CALCULATION OF RNN_k BASED ON VORONOI CELL 被引量:1
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作者 郝忠孝 李博涵 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2009年第2期154-161,共8页
Reverse k nearest neighbor (RNNk) is a generalization of the reverse nearest neighbor problem and receives increasing attention recently in the spatial data index and query. RNNk query is to retrieve all the data po... Reverse k nearest neighbor (RNNk) is a generalization of the reverse nearest neighbor problem and receives increasing attention recently in the spatial data index and query. RNNk query is to retrieve all the data points which use a query point as one of their k nearest neighbors. To answer the RNNk of queries efficiently, the properties of the Voronoi cell and the space-dividing regions are applied. The RNNk of the given point can be found without computing its nearest neighbors every time by using the rank Voronoi cell. With the elementary RNNk query result, the candidate data points of reverse nearest neighbors can he further limited by the approximation with sweepline and the partial extension of query region Q. The approximate minimum average distance (AMAD) can be calculated by the approximate RNNk without the restriction of k. Experimental results indicate the efficiency and the effectiveness of the algorithm and the approximate method in three varied data distribution spaces. The approximate query and the calculation method with the high precision and the accurate recall are obtained by filtrating data and pruning the search space. 展开更多
关键词 computational geometry approximation query filtrating reverse k nearest neighbor (RNNk) Voronoi cell
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基于JQuery的自动完成功能的实现 被引量:3
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作者 王波 王瀚波 《三门峡职业技术学院学报》 2010年第3期102-106,共5页
当客户在利用Goolge或Baidu搜索引擎在网上搜索信息时,自动完成功能给大家带来了很大的便利。随着Ajax技术的迅速发展,自动完成功能在不同的框架中都得到了一定程度的实现。以某精密机械有限公司ERP系统的制定年业务计划模块为例,详细... 当客户在利用Goolge或Baidu搜索引擎在网上搜索信息时,自动完成功能给大家带来了很大的便利。随着Ajax技术的迅速发展,自动完成功能在不同的框架中都得到了一定程度的实现。以某精密机械有限公司ERP系统的制定年业务计划模块为例,详细介绍通过JQuery-aucomplete插件和基于文本的数据交换格式JSON实现基于JQuery的自动完成功能的方法。 展开更多
关键词 AJAX query JSON 自动完成
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Auto-expanded multi query examples technology in content-based image retrieval 被引量:1
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作者 王小玲 谢康林 《Journal of Southeast University(English Edition)》 EI CAS 2005年第3期287-292,共6页
In order to narrow the semantic gap existing in content-based image retrieval (CBIR),a novel retrieval technology called auto-extended multi query examples (AMQE) is proposed.It expands the single one query image ... In order to narrow the semantic gap existing in content-based image retrieval (CBIR),a novel retrieval technology called auto-extended multi query examples (AMQE) is proposed.It expands the single one query image used in traditional image retrieval into multi query examples so as to include more image features related with semantics.Retrieving images for each of the multi query examples and integrating the retrieval results,more relevant images can be obtained.The property of the recall-precision curve of a general retrieval algorithm and the K-means clustering method are used to realize the expansion according to the distance of image features of the initially retrieved images.The experimental results demonstrate that the AMQE technology can greatly improve the recall and precision of the original algorithms. 展开更多
关键词 content-based image retrieval SEMANTIC multi query examples K-means clustering
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Microsoft Query技术在医院统计分析中的应用 被引量:4
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作者 车永茂 汤荣 《中国医院统计》 2007年第2期146-147,共2页
目的介绍Microsoft Query技术在医院统计工作中的应用。方法利用Microsoft Query自定义查询条件,从医院数据库提取数据导出到Excel。结果无须编程,即可及时、准确、全面、动态地获取数据库中的数据,结合Excel进行分析,能更快、更好地提... 目的介绍Microsoft Query技术在医院统计工作中的应用。方法利用Microsoft Query自定义查询条件,从医院数据库提取数据导出到Excel。结果无须编程,即可及时、准确、全面、动态地获取数据库中的数据,结合Excel进行分析,能更快、更好地提供有价值的统计信息。结论Microsoft Query技术值得在医院统计工作中进一步推广应用。 展开更多
关键词 MICROSOFT query技术 数据库 统计分析
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在EXCEL中掌握ODBC、Query的应用 被引量:1
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作者 赵龙强 《上海会计》 北大核心 2003年第10期42-44,共3页
关键词 EXCEL ODBC query 电子表格 财会电算化培训 数据透视表
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Approximate querying between heterogeneous ontologies based on association matrix
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作者 康达周 徐宝文 +1 位作者 陆建江 汪鹏 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期1-5,共5页
An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in... An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in two ontologies. Then, a methodof rewriting queriesbased on the association matrix is presented to solve the ontology heterogeneity problem. Itrewrites the queries in one ontology to approximate queries in another ontology based on thesubsumption relations between concepts. The method also uses vectors to represent queries, and thencomputes the vectors with the association matrix; the disjoint relations between concepts can beconsidered by the results. It can get better approximations than the methods currently in use, whichdonot consider disjoint relations. The method can be processed by machines automatically. It issimple to implement and expected to run quite fast. 展开更多
关键词 semantic web information retrieval ONTOLOGY query association matrix
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