4 research outputs found

    Query processing in temporal object-oriented databases

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    This PhD thesis is concerned with historical data management in the context of objectoriented databases. An extensible approach has been explored to processing temporal object queries within a uniform query framework. By the uniform framework, we mean temporal queries can be processed within the existing object-oriented framework that is extended from relational framework, by extending the existing query processing techniques and strategies developed for OODBs and RDBs. The unified model of OODBs and RDBs in UmSQL/X has been adopted as a basis for this purpose. A temporal object data model is thereby defined by incorporating a time dimension into this unified model of OODBs and RDBs to form temporal relational-like cubes but with the addition of aggregation and inheritance hierarchies. A query algebra, that accesses objects through these associations of aggregation, inheritance and timereference, is then defined as a general query model /language. Due to the extensive features of our data model and reducibility of the algebra, a layered structure of query processor is presented that provides a uniforrn framework for processing temporal object queries. Within the uniform framework, query transformation is carried out based on a set of transformation rules identified that includes the known relational and object rules plus those pertaining to the time dimension. To evaluate a temporal query involving a path with timereference, a strategy of decomposition is proposed. That is, evaluation of an enhanced path, which is defined to extend a path with time-reference, is decomposed by initially dividing the path into two sub-paths: one containing the time-stamped class that can be optimized by making use of the ordering information of temporal data and another an ordinary sub-path (without time-stamped classes) which can be further decomposed and evaluated using different algorithms. The intermediate results of traversing the two sub-paths are then joined together to create the query output. Algorithms for processing the decomposed query components, i. e., time-related operation algorithms, four join algorithms (nested-loop forward join, sort-merge forward join, nested-loop reverse join and sort-merge reverse join) and their modifications, have been presented with cost analysis and implemented with stream processing techniques using C++. Simulation results are also provided. Both cost analysis and simulation show the effects of time on the query processing algorithms: the join time cost is linearly increased with the expansion in the number of time-epochs (time-dimension in the case of a regular TS). It is also shown that using heuristics that make use of time information can lead to a significant time cost saving. Query processing with incomplete temporal data has also been discussed

    Integrated information model for managing the product introduction process

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    The thesis proposes an integrated product introduction (PI) information model for managing the product introduction process in an efficient manner. Through the process of product introduction, ideas and needs are converted to the information from which technical systems and products can be made and sold. Two critical factors for its success are the management of the product introduction activities, and the quality and functionality of its output (i.e. the product) which itself depends on the quality of the PI process. The process is as effective as the decisions made within it, and as efficient as the speed with which the information required for each decision is made available. In order to improve the efficiency of the management of the project in meeting its diverse targets (project time, project cost, product cost and uparrow product functionality), a model that integrates the targets would be essential in relating the activities of the project to their outcomes. Existing information models in related areas such as design, product development, project management, computer aided design and manufacturing consider some of these targets, but not all of them simultaneously. Especially product functionality is not considered along with the other targets of the PI project. The project introduction information includes managerial and technical information and complex associations among these two categories. Its representation places a challenging and novel set of demands on database technology as it is evolving, distributed and heterogeneous. Existing information models do not address the link between the managerial and technical information, and their continual evolution. Based on a detailed analysis of its nature and content, the thesis presents a three dimensional model of the product introduction information from three related but different viewpoints:- (1) entity-relationship or objects, (2) intra-layer integration and (3) evolution, each capturing important aspects of the PI information, but all required for a complete description. The overall three dimensional information model includes the following layers:- from view 1 - product functionality, process or project, product introduction resources, product and information map; from view 2 - node, relationship, and organisation; from view 3 - meta-model, data model, and data. Each model describes one aspect of the product introduction information but contains references to the others. The building blocks of the information model are described using schema definitions

    Multimedia databases in managing the intangible cultural heritage

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    Motivacija za izradu ove doktorske disertacije je multimedijalna kolekcija koja je rezultat vi²egodi²njih terenskih istraºivanja istraºiva£a iz Balkanolo²kog instituta Srpske akademije nauka i umetnosti. Kolekcija se sastoji od materijala u vidu snimljenih intervjua, snimljenih raznih obi£aja, pridruºenih tekstualnih opisa (protokola) i brojnih drugih dokumenata. Predmet istraºivanja ove disertacije je prou£avanje mogu¢nosti i razvoj novih metoda kojima bi se zapo£elo re²avanje problema upravljanja nematerijalnim kulturnim nasle em Balkana. Podzadaci koji se tom prilikom otvaraju su razvoj adekvatnog dizajna i implementacije multimedijalne baze podataka nematerijalnog kulturnog nasle a koja bi odgovarala potrebama razli£itih vrsta korisnika, automatska semanti£ka anotacija protokola uz pomo¢ metoda obrade prirodnih jezika, kao osnova za polu-automatsku anotaciju multimedijalne kolekcije i uspe²nu pretragu po metapodacima koji su u skladu sa CIDOC CRM standardom, istraºivanje dodatnih mogu¢nosti pretrage ove kolekcije u cilju dobijanja novih znanja, kao i razvoj izabranih metoda. Glavni problem sa dostupnim metodama je u tome ²to jo² uvek nema dovoljno razvijene infrastrukture u kontekstu obrade teksta na prirodnom jeziku, organizacije i upravljanja u domenu kulturnog nasle a na prostoru Balkana i posebno za slu£aj srpskog jezika, koja bi se mogla efektivno koristiti za re²avanje postavljenog problema. Stoga, postoji izraºena potreba za razvojem metoda kojima bi se do²lo do odgovaraju¢eg re²enja. Za polu-automatsku anotaciju multimedijalnih materijala kori²¢ena je automatska semanti£ka anotacija protokola koji su pridruºeni materijalima. Ona je sprovedena metodama ekstrakcije informacija, prepoznavanja imenovanih entiteta i ekstrakcije tema, tehnikama zasnovanim na pravilima uz pomo¢ dodatnih resursa poput elektronskih re£nika, tezaurusa i re£nika re£i iz speci£nog domena. Za klasikaciju tekstualnih protokola u odnosu na tematiku, izvedeno je istraºivanje o metodama koje se mogu primeniti za re²avanje problema klasikacije tekstova na srpskom jeziku, i ponu ena je metoda koja je prilago ena speci£nom domenu koji se obra uje (nematerijalno kulturno nasle e), speci£nim problemima koji se re²avaju (klasikacija protokola u odnosu na tematiku) i srpskom jeziku, kao jednom od morfolo²ki bogatih jezika...The motivation for writing this doctoral dissertation is a multimedia collection that is the result of many years of eld research conducted by researchers from the Institute for Balkan studies of the Serbian Academy of Sciences and Arts. The collection consists of materials in the form of recorded interviews, various recorded customs, associated textual descriptions (protocols) and numerous other documents. The subject of research of this dissertation is the study of possibilities and the development of new methods that could be used as a starting point in solving the problem of managing the intangible cultural heritage of the Balkans. The subtasks that emerge in this endeavor are the development of adequate design and implementation of a multimedia database of intangible cultural heritage that would meet the needs of dierent types of users, automatic semantic annotation of protocols using natural language processing methods, as a basis for semi-automatic annotation of the multimedia collection, and successful search by metadata which comply with the CIDOC CRM standard, study of additional search possibilities of this collection in order to gain new knowledge, as well as development of selected methods. The main problem with the available methods is that there is still not enough developed infrastructure in the context of natural language processing, organization and management in the eld of cultural heritage in the Balkans and especially for the Serbian language, which could be eectively used to solve the proposed problem. There is thus a strong need to develop methods to reach an appropriate solution. For the semi-automatic annotation of multimedia materials, automatic semantic annotation of the protocols associated with the materials was used. It was carried out by methods of information extraction, recognition of named entities and topic extraction, using rule-based techniques with the help of additional resources such as electronic dictionaries, thesauri and vocabularies from a specic domain. To classify textual protocols in relation to the topic, research was conducted on methods that can be used to solve the problem of classifying texts in the Serbian language, and a method was oered that is adapted to the specic domain being processed (intangible cultural heritage), to the specic problems being solved (classi cation of protocols in relation to the topic) and to the Serbian language, as one of the morphologically rich languages..

    UniSQL's next-generation object-relational database management system

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