Tree-based access methods for spatial databases: implementation andperformance evaluation

Experiences with the implementation of the cell tree dynamic access method for spatial databases are reported, and the results of an experimental performance comparison with the R-tree of A. Guttman (1984) and with the R-tree of T. Sellis et al. (1987) are given. Cell tree design and implementation are discussed. Although the cell tree often requires more storage space and more CPU time to answer a search query, it usually obtains the results with a lower number of disk accesses than the two rival structures     

Design of a Java spatial extension for relational databases

Jaspa (Java Spatial) is a novel spatial extension for relational database management systems (RDBMSs). It is the result of a research project that aims to accomplish two goals: firstly, to fill the absence in the Free and Open Source Software (FOSS) world of a solid Java-based alternative to PostGIS, the leading spatial extension written in C. Secondly, to exploit the advantages of Java and the Java geospatial libraries over C in terms of portability and easiness to extend. Java programming for geospatial purposes is a flowering field and similar solutions to Jaspa have recently appeared, but none of them can equate with PostGIS due to lack of functionalities. Jaspa currently implements almost all PostGIS functionality. The next step will be the enrichment of the software with more sophisticated features: storage of spatial data in a topological structure within the RDBMS, cluster tolerance and geodetic functionalities. Jaspa is being developed at the Department of Cartographic Engineering, Geodesy and Photogrammetry of the Universidad Politécnica de Valencia and it has been published under an Open Source license on the OSOR.eu repository. This paper has been written by its creators with the aim of introducing users to its main capabilities.     

分布式Oracle监控系统的设计与实现

为了保障大规模多库系统的连续高效运行,针对当前普遍使用的Oracle数据库,设计并实现了一个分布式监控系统DMSO.采用灵活的监控策略配置、多层次多粒度内容呈现等方法,在低开销的基础上,系统能够对物理上分布的多个Oracle数据库进行不问断的集中式监控,对监控所得的实时信息进行判断,并对可能发生的问题进行预警;此外为了协助解决问题.系统还提供了一定的远程处理功能.实验结果和型号项目中的实际应用在一定程度上验证了系统设计实现技术的有效性.     

Using compressed index structures for processing moving objects in large spatio-temporal databases

This paper develops a novel, compressed B⁺-tree based indexing scheme that supports the processing of moving objects in one-, two-, and multi- dimensional spaces. The past, current, and anticipated future trajectories of movements are fully indexed and well organized. No parameterized functions and geometric representations are introduced in our data model so that update operations are not required and the maintenance of index structures can be accomplished by basic insertion and deletion operations. The proposed method has two contributions. First, the spatial and temporal attributes of trajectories are accurately preserved and well organized into compact index structures with very efficient memory space utilization and storage requirement. Second, index maintenance overheads are more economical and query performance is more responsive than those of conventional methods. Both analytical and empirical studies show that our proposed indexing scheme outperforms the TPR-tree.     

Intelligent fuzzy queries for multimedia databases

Multimedia databases have emerged to cope up with the huge amount of multimedia data, which comes up as a result of technological advancement. However, more intelligent techniques are required to satisfy different query requirements of multimedia users. This study extends the query capability of a multimedia database through the integration of a fuzzy rule‐based system. In addition to fuzzy semantic rules, which deduce new information from the data stored in the database, fuzzy spatial and temporal relations, which are inherent to multimedia applications, are defined in the rule‐based system. Users can formulate fuzzy semantic, spatial, temporal, and spatiotemporal queries, resulting in the deduction of new information using the rules defined in the rule‐based system. With some practical examples, the paper presents how a fuzzy rule‐based system integrated to a fuzzy multimedia database improves the query capabilities of the database system intelligently. © 2011 Wiley Periodicals, Inc.     

Formal approach for reengineering fuzzy XML in fuzzy object-oriented databases

Since semi-structured documents (e.g., XML) could benefit greatly from database support and more specifically from object-oriented (OO) database management systems, we study the methodology of reengineering XML to object-oriented databases when database migration occurs in this paper. In particular, considering the need of processing the imprecise and uncertain information existing in practical applications, we investigate the problem of migrating fuzzy XML to fuzzy object-oriented databases. To find the object-oriented schema that best describes the existing fuzzy XML schema (DTD), we devise a comprehensive approach centering on a set of mapping rules. Such reengineering practices could not only provide a significant consolidation of the interoperability between fuzzy OO and fuzzy XML modeling techniques, but also develop the practical design methodology for fuzzy OO databases.     

Authenticated indexing for outsourced spatial databases

In spatial database outsourcing, a data owner delegates its data management tasks to a location-based service (LBS), which indexes the data with an authenticated data structure (ADS). The LBS receives queries (ranges, nearest neighbors) originating from several clients/subscribers. Each query initiates the computation of a verification object (VO) based on the ADS. The VO is returned to the client that can verify the result correctness using the public key of the owner. Our first contribution is the MR-tree, a space-efficient ADS that supports fast query processing and verification. Our second contribution is the MR*-tree, a modified version of the MR-tree, which significantly reduces the VO size through a novel embedding technique. Finally, whereas most ADSs must be constructed and maintained by the owner, we outsource the MR- and MR*-tree construction and maintenance to the LBS, thus relieving the owner from this computationally intensive task.     

实时数据库混合索引机制的设计与实现

在卫星地面设备监控中,需要将大量实时数据实时地存进数据库并提供实时查询。针对实时数据和Judy array数字树的特点,提出了一种基于内存映射文件的位图分配法,然后设计了一种哈希表、B+树和Judy array混合索引机制。通过大量记录的插入和查询,结果表明位图分配法能避免大量不可利用的内存碎片的产生,结合内存位图分配法的混合索引机制也为应用程序提供了实时的索引插入和查询。     

面向对象的嵌入式GIS空间数据模型设计与实现

利用面向对象技术,将嵌入式GIS系统抽象为元素模型、要素模型、地图表示/表现模型、地理数据计算/分析模型、空间数据压缩/索引模型和Web服务支持模型,讨论分析模型的设计、其间的组织关系、管理方式和实现机制,并对模型的应用和存在的问题进行简要阐述。     

Reasoning of fuzzy relational databases with fuzzy ontologies

A significant interest developed regarding the problem of describing databases with expressive knowledge representation techniques in recent years, so that database reasoning may be handled intelligently. Therefore, it is possible and meaningful to investigate how to reason on fuzzy relational databases (FRDBs) with fuzzy ontologies. In this paper, we first propose a formal approach and an automated tool for constructing fuzzy ontologies from FRDBs, and then we study how to reason on FRDBs with constructed fuzzy ontologies. First, we give their respective formal definitions of FRDBs and fuzzy Web Ontology Language (OWL) ontologies. On the basis of this, we propose a formal approach that can directly transform an FRDB (including its schema and data information) into a fuzzy OWL ontology (consisting of the fuzzy ontology structure and instance). Furthermore, following the proposed approach, we implement a prototype construction tool called FRDB2FOnto. Finally, based on the constructed fuzzy OWL ontologies, we investigate how to reason on FRDBs (e.g., consistency, satisfiability, subsumption, and redundancy) through the reasoning mechanism of fuzzy OWL ontologies, so that the reasoning of FRDBs may be done automatically by means of the existing fuzzy ontology reasoner.© 2012 Wiley Periodicals, Inc.     

空域精细可扩展编码预处理器的设计和实现

为了更好地运用空域精细可扩展编码算法,提出了一种编码预处理器的设计方案。该方案占用较少的外部存储空间缓存帧数据,充分利用数据操作之间的并行性和流水性,生成视频数据的多描述码流。仿真结果表明,该方案能满足空域精细可扩展编码算法的功能和实时性要求。     

支持多线程的空间数据GSQL解析器设计与实现*

为了使基于ingres扩展的空间数据库支持多线程空间数据上传和下载,设计实现了一个支持多线程的GSQL解析器。在分析PostGIS解析器的基础上,通过全局变量封装,实现解析器对多线程的支持。为了提高GSQL解析器的效率,提出并实现了可变长内存池管理机制。通过验证,GSQL解析器在多线程上传和下载空间数据时性能优良,而且使用可变长的内存池管理机制大幅度提高了GSQL解析器的时空效率。     

Design and implementation of the tree-based fuzzy logic controller

In this paper, a tree-based approach is proposed to design the fuzzy logic controller. Based on the proposed methodology, the fuzzy logic controller has the following merits: the fuzzy control rule can be extracted automatically from the input-output data of the system and the extraction process can be done in one-pass; owing to the fuzzy tree inference structure, the search spaces of the fuzzy inference process are largely reduced; the operation of the inference process can be simplified as a one-dimensional matrix operation because of the fuzzy tree approach; and the controller has regular and modular properties, so it is easy to be implemented by hardware. Furthermore, the proposed fuzzy tree approach has been applied to design the color reproduction system for verifying the proposed methodology. The color reproduction system is mainly used to obtain a color image through the printer that is identical to the original one. In addition to the software simulation, an FPGA is used to implement the prototype hardware system for real-time application. Experimental results show that the effect of color correction is quite good and that the prototype hardware system can operate correctly under the condition of 30 MHz clock rate.     

Modeling and querying fuzzy spatiotemporal databases

Modeling spatiotemporal data, in particular fuzzy and complex spatial objects representing geographic entities and relations, is a topic of great importance in geographic information systems, computer vision, environmental data management systems, etc. Because of complex requirements, it is challenging to represent spatiotemporal data and its features in databases and to effectively query them. This article presents a new approach to model and query the spatiotemporal data of fuzzy spatial and complex objects and/or spatial relations. In our case study, we use a meteorological database application in an intelligent database architecture, which combines an object-oriented database with a knowledgebase for modeling and querying spatiotemporal objects.     

Design and implementation of a hardware fuzzy inference system

This paper discusses the design of a dedicated hardware fuzzy inference system based on the generalized modus ponens (GMP) inference rule, the “mini” fuzzy implication function, the “max-min” fuzzy composition rule, and the center of gravity (COG) defuzzification method. As a special case, the implementation of a two-input (antecedents), one-output (consequent) fuzzy inference system based on the general design idea was implemented on a single field programmable gate array (FPGA) chip with an extra EPROM for defuzzification. Circuitry details and performance data are included. Additional issues such as extendibility and adaptability are also discussed.     

Design and implementation of a fuzzy inference system for supporting customer requirements

Efficient and effective response to the requirements of customers is a major performance indicator. Failure to satisfy customer requirements implies operational weaknesses in a company. These weaknesses will damage both the rights of customers and the reputation of the company. The traditional method of handling customer requirement for a machine tool manufacturer was dominated by manual process and subjective decision. In this study, we improved the operation process of handling customer requirement. The framework of a customer requirement information system (CRIS) for machine tool manufacturers was then analyzed, integrating rule-based fuzzy inference and expert systems, and a prototype system developed. The CRIS supports both customers and service personnel in providing a systematic way of fulfilling and analyzing customer requirements. The system was installed and operated in a machine tool manufacturer and the performance was found promising.     

Fuzzy relations and fuzzy relational databases

This paper deals with the connections existing between fuzzy set theory and fuzzy relational databases. Our new result dealing with fuzzy relations is how to calculate the greatest lower bound (glb) of two similarity relations. Our main contributions in fuzzy relational databases are establishing from fuzzy set theory what a fuzzy relational database should be (the result is both surprising and elegant), and making fuzzy relational databases even more robust.Our work in fuzzy relations and in fuzzy databases had led us into other interesting problems—two of which we mention in this paper. The first is primarily mathematical, and the second provides yet another connection between fuzzy set theory and artificial intelligence. In understanding similarity relations in terms of other fuzzy relations and in making fuzzy databases more robust, we work with closure and interior operators; we present some important properties of these operators. In establishing the connection between fuzzy set theory and artificial intelligence, we show that an abstraction on a set is in fact a partition on the set; that is, an abstraction defines an equivalence relation on the underlying set.     

用于化学专利标引的族性结构模板的设计与实现

对药物专利中族性结构进行标引是将专利文本信息转换成结构信息用于族性结构的匹配检索。本文根据国家知识产权局知识产权出版社数据研发中心提出的新的图形化标引语言GFL对近千余篇药物专利进行了标引。结合GFL的特点,统计分析药物专利中出现频率很高的结构片断,将这些结构片断的标引结果利用面向对象编程技术设计成一系列的族性模板,便于标引人员直接调用,有利于实现标引工作的半自动化。