Este trabalho apresenta uma proposta para o compartilhamento de dados entre bases de dados orientadas a objetos, em ambientes de desenvolvimento de projetos. O processo de compartilhamento e realizado através de três fases: separação, evolução e integração de dados. Esta forma de compartilhamento atua através de vínculos entre os objetos de base original com a base produto. Foram definidos seis tipos de vínculos, que são estabelecidos no processo de separação: apenas leitura, isolado, flagrante, mutuamente exclusivo, independente e on-line. Com isso, ambas as bases, respeitando as limitações impostas pelo tipo de vinculo entre as mesmas, podem evoluir separadamente e depois de um determinado tempo realizarem, se conveniente, um processo de reintegração. O processo de compartilhamento de dados tem por unidade de gerenciamento os objetos, compostos de base de dados. Os conceitos apresentados podem ser universalmente aplicados, em qualquer base de dados que efetue gerenciamento sobre a composição de seus objetos. Neste trabalho os conceitos de compartilhamento de dados são exemplificados através do modelo de dados SIRIUS. / This work presents a technique to share data stored in an object-oriented databases aimed at design environments. Three process enable the sharing of data between databases: separation, evolution and data integration. Whenever a block of data need to be shared between original and product database, it is spread among both, resulting in two block: one in the original database, and another in the receiver one, identified as the product of the sharing process. During the evolution phase of the sharing process, these blocks are not required to be kept identical. Six types of links to drive the updates were defined: read only, isolated, snapshot, mutually exclusive, independent and on-line. The original and product databases, both restricted by rules imposed by the type of links, can evolve alone. After a while they may enter into an reintegration process, which uses the composite objects as the control units. The presented concepts can be applied to any data model supporting composite objects. The SIRIUS datamodel is used to exemplify those concepts.

Este trabalho apresenta um meta-modelo conceitual de dados para ser usado como ferramenta concetual para a construção de modelos de dados, obedecendo a determinados padrões. Ele é baseado em um metamodelo que permite a instanciação de modelos de dados. Para isso, identificaram-se as abstrações de dados fundamentais utilizadas em modelos de dados em geral: as abstrações de classificação, de associação e de generalização, e a partir delas foi construído um metamodelo que permite a representação de outros modelos de dados. O metamodelo modela os construtores semânticos de um determinado modelo de dados definindo diversas parametrizações das abstrações utilizadas nesse modelo, possivelmente em múltiplas ocorrêncas da mesma abstração num mesmo modelo. Considera-se uma ocorrência de parametrização como a identificação das restrições que envolvem uma abstração e a atribuição de valores a essas restrições, delimitando as possibilidades de cada restrição. Com esse conceito foi estabelecido um arcabouço conceitual que define uma estrutura precisa para cada construtor do metamodelo. A parametrização foi exemplificada pela aplicação ao Modelo Entidade-Relacionamento original, e na construção de um modelo orientado a objetos concebido para atender a necessidades bem especificadas, definidas a priori (atender às necessidades de aplicações de projeto e engenharia e aplicações científicas) que é denominado Modelo SIRIUS. / A set of conceptual constructions was developed to be used as a \"conceptual tool\" aiming the representation or construction of other data models. The result is a Data Meta-Model, which can be used as a reference standard for the construction of other data models. The Meta-model is based on the identification of the fundamental data abstractions used in the existing data models. It is shown that the fundamental abstractions are the classification, the association and the generalization ones. The Meta-model permits the definition of the semantic constructors of each data model the parameterization of the fundamental abstractions used in each constructor of the model. An abstraction is parameterized by collecting its set of restrictions and by setting each restriction with a particular value. Therefore, the same abstraction can generate several distinct abstraction instances. In the same way, several abstraction instances of distinct fundamental abstractions can be associated to build each each semantic constructor of the target data model. This process is exemplified using two case studies. First, it is used to represent the Entity-Relationship Model. Thereafter, it is used to construct a new data model, aiming at supporting the requirements of computer-aided engineering design and of scientific applications. The new data model is named SIRIUS, and incorporates the fundamental abstractions instantiated into semantic constructors tailored to the needs of those domains.

Abstract not available

Video database applications call for flexible and powerful modeling and querying facilities, which require an integration or interaction between database and knowledge base technologies. It is also necessary for many real life video database applications to incorporate uncertainty, which naturally occurs due to the complex and subjective semantic content of video data. In this thesis study, firstly, a fuzzy conceptual data model is introduced to represent the semantic content of video data. UML (Unified Modeling Language) is utilized and extended to represent uncertain information along with video specific properties at the conceptual level. Secondly, an intelligent fuzzy object-oriented database framework is presented for video database applications. The introduced fuzzy conceptual model is mapped to the presented framework, which is an adaptation of the previously proposed IFOOD architecture. The framework provides modeling and querying of complex and rich semantic content and knowledge of video data including uncertainty. Moreover, it allows (fuzzy) semantic, temporal, (fuzzy) spatial, hierarchical, regional and trajectory queries, based on the video data model. We think that the presented conceptual data model and framework can be adapted to any application domain related to video databases.

GLOBDATA is a project that aims to design and implement a middleware tool offering the abstraction of a global object database repository. This tool, called COPLA, supports transactional access to geographically distributed persistent objects independent of their location. Additionally, it supports replication of data according to different consistency criteria. For this purpose, COPLA implements a number of consistency protocols offering different tradeoffs between performance and fault-tolerance. This paper presents the analysis of one of two strong consistency protocols for the GLOBDATA system, the voting protocol. A protocol relies heavily on the use of atomic translation primitive as a building block to serialize conflicting transactions. The paper presents an in-depth description of the conceptual model using UML-based analysis of the protocol which later is used to define the PLA (piece-linear aggregates) model of the system, a discrete event-based simulation of the processes. As a result of the work, the PLA model is ready to be used to validate, verify and simulate various behavioral and performance characteristics of the model using mathematical proof techniques.

Modern data intensive applications, such as multimedia systems require the ability to store and manipulate complex data. The classical Database Management Systems (DBMS), such as relational databases, cannot support these types of applications efficiently. This dissertation presents the salient features of Object Database Management Systems (ODBMS) and Persistent Programming Languages (PPL), which have been developed to address the data management needs of these difficult applications. An 'impedance mismatch' problem occurs in the traditional DBMS because the data and computational aspects of the application are implemented using two different systems, that of query and programming language. PPL's provide facilities to cater for both persistent and transient data within the same language, hence avoiding the impedance mismatch problem. This dissertation presents a method of implementing a PPL by extending the language C++ with pre-compiled classes. The classes are first developed and then used to implement object persistence in two simple applications. / Computing / M. Sc. (Information Systems)

Este trabalho apresenta um meta-modelo conceitual de dados para ser usado como ferramenta concetual para a construção de modelos de dados, obedecendo a determinados padrões. Ele é baseado em um metamodelo que permite a instanciação de modelos de dados. Para isso, identificaram-se as abstrações de dados fundamentais utilizadas em modelos de dados em geral: as abstrações de classificação, de associação e de generalização, e a partir delas foi construído um metamodelo que permite a representação de outros modelos de dados. O metamodelo modela os construtores semânticos de um determinado modelo de dados definindo diversas parametrizações das abstrações utilizadas nesse modelo, possivelmente em múltiplas ocorrêncas da mesma abstração num mesmo modelo. Considera-se uma ocorrência de parametrização como a identificação das restrições que envolvem uma abstração e a atribuição de valores a essas restrições, delimitando as possibilidades de cada restrição. Com esse conceito foi estabelecido um arcabouço conceitual que define uma estrutura precisa para cada construtor do metamodelo. A parametrização foi exemplificada pela aplicação ao Modelo Entidade-Relacionamento original, e na construção de um modelo orientado a objetos concebido para atender a necessidades bem especificadas, definidas a priori (atender às necessidades de aplicações de projeto e engenharia e aplicações científicas) que é denominado Modelo SIRIUS. / A set of conceptual constructions was developed to be used as a \"conceptual tool\" aiming the representation or construction of other data models. The result is a Data Meta-Model, which can be used as a reference standard for the construction of other data models. The Meta-model is based on the identification of the fundamental data abstractions used in the existing data models. It is shown that the fundamental abstractions are the classification, the association and the generalization ones. The Meta-model permits the definition of the semantic constructors of each data model the parameterization of the fundamental abstractions used in each constructor of the model. An abstraction is parameterized by collecting its set of restrictions and by setting each restriction with a particular value. Therefore, the same abstraction can generate several distinct abstraction instances. In the same way, several abstraction instances of distinct fundamental abstractions can be associated to build each each semantic constructor of the target data model. This process is exemplified using two case studies. First, it is used to represent the Entity-Relationship Model. Thereafter, it is used to construct a new data model, aiming at supporting the requirements of computer-aided engineering design and of scientific applications. The new data model is named SIRIUS, and incorporates the fundamental abstractions instantiated into semantic constructors tailored to the needs of those domains.

Este trabalho apresenta uma proposta para o compartilhamento de dados entre bases de dados orientadas a objetos, em ambientes de desenvolvimento de projetos. O processo de compartilhamento e realizado através de três fases: separação, evolução e integração de dados. Esta forma de compartilhamento atua através de vínculos entre os objetos de base original com a base produto. Foram definidos seis tipos de vínculos, que são estabelecidos no processo de separação: apenas leitura, isolado, flagrante, mutuamente exclusivo, independente e on-line. Com isso, ambas as bases, respeitando as limitações impostas pelo tipo de vinculo entre as mesmas, podem evoluir separadamente e depois de um determinado tempo realizarem, se conveniente, um processo de reintegração. O processo de compartilhamento de dados tem por unidade de gerenciamento os objetos, compostos de base de dados. Os conceitos apresentados podem ser universalmente aplicados, em qualquer base de dados que efetue gerenciamento sobre a composição de seus objetos. Neste trabalho os conceitos de compartilhamento de dados são exemplificados através do modelo de dados SIRIUS. / This work presents a technique to share data stored in an object-oriented databases aimed at design environments. Three process enable the sharing of data between databases: separation, evolution and data integration. Whenever a block of data need to be shared between original and product database, it is spread among both, resulting in two block: one in the original database, and another in the receiver one, identified as the product of the sharing process. During the evolution phase of the sharing process, these blocks are not required to be kept identical. Six types of links to drive the updates were defined: read only, isolated, snapshot, mutually exclusive, independent and on-line. The original and product databases, both restricted by rules imposed by the type of links, can evolve alone. After a while they may enter into an reintegration process, which uses the composite objects as the control units. The presented concepts can be applied to any data model supporting composite objects. The SIRIUS datamodel is used to exemplify those concepts.

No description available.

Turnouts are an important part of railway infrastructure for two reasons: infrastructure andmaintenance. For the infrastructure they provide the flexibility to allow the formulation and branchingof railway network and for maintenance they consume a large part of maintenance budget and have aprominent place in maintenance planning policy and activities. This is because as a “mechanical object”,a turnout often experiences malfunctions. The problem becomes even more complicated, since a turnoutis composed of many different parts and each of them fails for very different reasons (e.g. switch bladesvs crossing part). This is reflected in the different needs for maintenance activities, as railways areforced to pour in excessive amounts of resources to carry out emergency repairs, or to carry outunnecessary scheduled maintenance works in turnouts, which do not need to be inspected or repaired.Therefore, it is difficult to plan and organize maintenance activities in turnouts in an efficient manner.This raises the question of whether malfunctions in turnouts can be predicted and used as informationfor the maintenance planning process in order to optimize it and develop it into a more reliablepreventive maintenance planning.The aim of this analysis is to attempt to model the probability of various malfunctions in turnouts asa function of their main geometric and operational characteristics by using logistic regression modelsand then input these results into the maintenance planning process in order to optimize it. First, it wasimportant to objectify the railway track system and the turnout components, both in terms of parts andinterrelationships. Furthermore, the process and basic elements of railway maintenance planning weredefined, as well as arguments that motivate a turn towards preventive maintenance planningmethodologies. This was done through a comprehensive literature study.The basis of this research was case studies, which described the relationship between geometricaland operational characteristics of turnouts and their wear, as well as risk-based modelling methods inrailway maintenance planning. To create the analysis model, data from turnouts in eastern regionprovided by the Swedish Transport Administration were used, both from the point of view of describingthe underlying causes of turnout malfunctions and to formulate an object-oriented database suitable forusing in logistic regression models. The goal was a logit model that calculated the malfunctionprobability of a turnout, which could be used directly into a maintenance planning framework, whichranked maintenance activities in turnouts.The results obtained showed that although the model suffers from low correlation, differentrelationships between input variables and different functional errors were established. Furthermore, thepotential of these analytical models and modeling structures was shown to be able to developpreventive, predictive railway maintenance plans, but further analysis of the data structure is required,especially regarding data quality. Finally, further possible research areas are presented. / Spårväxlar är viktiga delar av järnvägens infrastruktur av två orsaker: infrastruktur och underhåll.För infrastrukturen ger de möjlighet till flexibla tillåter de formulering och grenning av järnvägsnät ochför underhållet konsumerar de en stor del av underhållsbudgeten och de har en framträdande plats iunderhållsplaneringspolitiken och aktiviteterna. Detta beror på att som ett ”maskinellt objekt”, harspårväxeln ofta fel. Problemet blir ännu mer komplicerat, eftersom en spårväxel består av många olikadelar och var och en av dem bryts ner av mycket olika skäl (t.ex. tunganordning vs korsningsdel). Dettaåterspeglas i olika behov av underhållsaktiviteter. Eftersom järnvägarna tvingas hålla alltför storamängder resurser för att utföra akuta reparationer eller för att utföra onödiga schemalagdaunderhållsarbeten i spårväxlar, som inte behöver inspekteras eller repareras. Därför är det svårt attplanera och organisera underhållsaktiviteter för spårväxlarna på ett effektivt sätt. Detta ställer fråganom funktionsfel i spårväxlar kan förutsägas och användas som information till  underhållsplaneringsprocessen för att optimera den och utveckla den till en pålitligare förebyggandeunderhållsplanering.Syftet med denna analys är att försöka modellera sannolikheten för olika funktionsfel i spårväxlarsom en funktion av deras huvudsakliga geometriska och operativa egenskaper med användning avlogistiska regressionsmodeller och sedan mata dessa resultat in i underhållsplaneringsprocessen för attoptimera den. För det första var det viktigt att objektifiera järnvägsspårsystemet ochspårväxlarkomponenterna, både vad gäller delar och inbördes förhållanden. Dessutom definieradesprocessen och grundelementen i järnvägsunderhållsplaneringen, samt att argument som motiverarförändring till förebyggande underhållsplaneringsmetoder. Detta gjordes genom en omfattandelitteraturstudie.Grunden i denna analys var fallstudier, som beskrev förhållandet mellan geometriska ochoperationella egenskaper hos spårväxlar och deras förslitning samt riskbaserade modelleringsmetoder ijärnvägsunderhållsplanering. För att skapa analysmodellen användes data från spårväxlar i östraregionen som tillhandahölls av Trafikverket, både ur synpunkten att beskriva de underliggandeorsakerna till spårväxlarsfel och för att formulera en objektorienterad databas lämplig för användning ilogistiska regressionsmodeller. Målet var en logitmodell som beräknade sannolikheten för fel i enspårväxel, som kunde användas direkt i en underhållsplaneringsram, som rangordnar lämpigaunderhållsaktiviteter i spårväxlar.Erhållna resultat visade att även om modellen lider av låg korrelation, konstaterades olika sambandmellan ingående variabler och olika funktionsfel. Vidare visades potentialen hos dessa analysmodelleroch modelleringsstrukturer för att kunna utveckla förebyggande, förutsägbarajärnvägsunderhållsplaner, men det krävs troligtvis ytterligare analys av datastrukturen, specielltangående datakvaliteten. Slutligen presenteras ytterligare möjliga forskningsområden.