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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

AKDB-Tree: An Adjustable KDB-tree for Efficiently Supporting Nearest Neighbor Queries in P2P Systems

Liu, Hung-ze 06 July 2008 (has links)
In the future, more data intensive applications, such as P2P auction networks, P2P job--search networks, P2P multi--player games, will require the capability to respond to more complex queries such as the nearest neighbor queries involving numerous data types. For the problem of answering nearest neighbor queries (NN query) for spatial region data in the P2P environment, a quadtree-based structure probably is a good choice. However, the quadtree stores the data in the leaf nodes, resulting in the load unbalance and expensive cost of any query. The MX--CIF quadtree can solve this problem. The MX--CIF quadtree has three properties: controlling efficiently the height of the tree, reducing load unbalance, and reducing the NNquery scope with controlling the value of the radius. Although the P2P MX--CIF quadtree can do the NN query efficiently, it still has some problems as follows: low accuracy of the nearest neighbor query, the expensive cost of the tree construction, the high search cost of the NN query, and load unbalance. In fact, the index structures for the region data can also work for the point data which can be considered as the degenerated case of the region data. Therefore, the KDB--tree which is a well-known algorithm for the point data can be used to reduce load unbalance, but it has the same problem as the quadtree. The data is stored only in the leaf nodes of the KDB--tree. In this thesis, we propose an Adjustable KDB--tree (AKDB--tree) to improve this situation for the P2P system. The AKDB--tree has five properties: reducing load unbalance, low cost of the tree construction, storing the data in the internal nodes and leaf nodes, high accuracy and low search cost of the NN query. The Chord system is a well--known structured P2P system in which the data search is performed by a hash function, instead of flooding used in most of the unstructured P2P system. Since the Chord system is a hash approach, it is easy to deal with peers joining/exiting. Besides, in order to combine AKDB--tree with the Chord system, we design the IDs of the nodes in the AKDB--tree. Each node is hashed to the Chord system by the ID. The IDs can be used to differentiate the edge node in the AKDB-tree is a vertical edge or a horizontal edge and the relative position of two nodes in the 2D space. And, we can calculate the related edge of a region in the 2D space according to the ID of the region. As discussed above, we make use of the property of IDs to reduce the search cost of the NN query by a wide margin. In our simulation study, we compare our method with the P2P MX--CIF quadtree by considering five performance measures under four different situations of the P2P MX--CIF quadtree. From our simulation results, for the NN query, our AKDB-tree can provide the higher accuracy and lower search cost than the P2P MX--CIF quadtree. For the problem of load, our AKDB-tree is more balance than the P2P MX--CIF quadtree. For the time of the tree construction, our AKDB-tree needs shorter time than the P2P MX--CIF quadtree.
372

XML as a Format for Representation and Manipulation of Data from Radar Communications

Alfredsson, Anders January 2001 (has links)
<p>XML was designed to be a new standard for marking up data on the web. However, as a result of its extensible and flexible properties, XML is now being used more and more for other purposes than was originally intended. Today XML is prompting an approach more focused on data exchange, between different applications inside companies or even between cooperating businesses.</p><p>Businesses are showing interest in using XML as an integral part of their work. Ericsson Microwave Systems (EMW) is a company that sees XML as a conceivable solution to problems in the work with radar communications. An approach towards a solution based on a relational database system has earlier been analysed.</p><p>In this project we present an investigation of the work at EMW, and identification and documentation of the problems in the radar communication work. Also, the requirements and expectations that EMW has on XML are presented. Moreover, an analysis has been made to decide to what extent XML could be used to solve the problems of EMW. The analysis was conducted by elucidating the problems and possibilities of XML compared to the previous approach for solving the problems at EMW, which was based on using a relational database management system.</p><p>The analysis shows that XML has good features for representing hierarchically structured data, as in the EMW case. It is also shown that XML is good for data integration purposes. Furthermore, the analysis shows that XML, due to its self-describing and weak typing nature, is inappropriate to use in the data semantics and integrity problem context of EMW. However, it also shows that the new XML Schema standard could be used as a complement to the core XML standard, to partially solve the semantics problems.</p>
373

Semantos : a semantically smart information query language

Crous, Theodorus. January 2008 (has links)
Thesis (M.Sc.(Computer Science))--University of Pretoria, 2008. / Includes bibliographical references (leaves 99-116).
374

Materialized view matching and compensation for SQL/XML and Xquery /

Hoppe, Andrzej. January 2008 (has links)
Thesis (M.Sc.)--York University, 2008. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 147-152). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR38782
375

Structural join : processing algorithms and size estimation /

Wang, Wei. January 2004 (has links)
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 107-120). Also available in electronic version. Access restricted to campus users.
376

XCQ : a framework for XML compression and querying /

Lam, Wai-Yeung. January 2003 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 142-147). Also available in electronic version. Access restricted to campus users.
377

Systematic testing using test summaries : effective and efficient testing of relational applications

Abdul Khalek, Shadi 31 January 2012 (has links)
This dissertation presents a novel methodology based on test summaries, which characterize desired tests as constraints written in a mixed imperative and declarative notation, for automated systematic testing of relational applications, such as relational database engines. The methodology has at its basis two novel techniques for effective and efficient testing: (1) mixed-constraint solving, which provides systematic generation of inputs characterized by mixed-constraints using translations among different data domains; and (2) clustered test execution, which optimizes execution of test suites by leveraging similarities in execution traces of different tests using abstract-level undo operations, which allow common segments of partial traces to be executed only once and the execution results to be shared across those tests. A prototype embodiment of the methodology enables a novel approach for systematic testing of commonly used database engines, where test summaries describe (1) input SQL queries, (2) input database tables, and (3) expected output of query execution. An experimental evaluation using the prototype demonstrates its efficacy in systematic testing of relational applications, including Oracle 11g, and finding bugs in them. / text
378

Enhanced Query Data Recorder (EQDR) - A Next Generation Network Recorder Built Around iNET Standards

Wigent, Mark A., Mazzario, Andrea M. 10 1900 (has links)
ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / The Enhanced Query Data Recorder (EQDR) has been developed under the Test Resource Management Center's (TRMC) Spectrum Efficient Technologies (SET) T&E S&T program. The EQDR is a network flight recorder built around the iNET standards and which is intended to meet the future needs of the networked telemetry environment. The EQDR is designed to support the "fetch" of recorded test data during a test without interruption to the ongoing recording of data from the test article vehicle network. The key benefits of the network data recorder as implemented in the EQDR are increased flexibility and efficiency of test in an environment with increasing demands on spectrum available for telemetered data. EQDR enables retrieval of individual recorded parameters on an as-needed basis. Having the flexibility to send data only when it is required rather than throughout the duration of the test significantly increases the efficiency with which limited spectrum resources are used. EQDR enables parametric-level data retrieval, based not only on time interval and data source, but also on the content of the recorded data messages. EQDR enables selective, efficient retrieval of individual parameters using indexes derived from the actual values of recorded data.
379

Spectrum Savings from High Performance Network Recording and Playback Onboard the Test Article

Wigent, Mark A., Mazzario, Andrea M. 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / The Test Resource Management Center's (TRMC) Spectrum Efficient Technologies (SET) S&T program is sponsoring development of the Enhanced Query Data Recorder (EQDR), a network flight recorder that is intended to meet the future needs of the networked telemetry environment. EQDR is designed to support the "fetch" of recorded test data during a test without interrupting the ongoing recording of data from the test article vehicle network. The key benefits of the network data recorder as implemented in EQDR are increased flexibility and efficiency of test in an environment with increasing demands on spectrum available for telemetered data. EQDR enables retrieval of individual recorded parameters on an as-needed basis. Having the flexibility to send data only when it is required rather than throughout the duration of the test significantly increases the efficiency with which limited spectrum resources are used. EQDR enables parametric-level data retrieval, based not only on time interval and data source, but also on the content of the recorded data messages. EQDR enables selective, efficient retrieval of individual parameters using indexes derived from the actual values of recorded data. This paper describes the design of EQDR and the benefits of selective data storage and retrieval in the application of networked telemetry. In addition it describes the performance of the EQDR in terms of data recording and data retrieval rates when implemented on single board computers designed for use in the aeronautical test environment with size, weight, and power constraints.
380

Functional Query Languages with Categorical Types

Wisnesky, Ryan 25 February 2014 (has links)
We study three category-theoretic types in the context of functional query languages (typed lambda-calculi extended with additional operations for bulk data processing). The types we study are: / Engineering and Applied Sciences

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