Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

The shear strength, elastic moduli and plastic strain characteristics of scaled-down ballast materials are investigated by use of the parallel gradation technique. Uniformly graded ballast materials chosen for the investigation are limestone, basalt and steel-slag. Steel-slag is a byproduct material of Eregli Iron and Steel Works, which is suitable to meet the durability test requirements as well as the electrical resistivity and the waste contaminants regulatory level. Conventional triaxial testing at a strain rate of 0.4 mm/min is used to obtain these characteristics for the scaled-down materials with a diameter of 100 mm specimen under a confining stress of 35 kPa, 70 kPa and 105 kPa / whereas that of only 35 kPa is used to characterize the accumulated plastic strain. The angle of internal friction, f, and the apparent cohesion, c, may be conservatively taken to be 42o and 35 kPa for all materials. The elastic moduli values for all materials may be predicted within an adequate estimate for the engineering purposes by using the power law parameters, K and n, determined for L-9.5 (D50 = 12.7 mm), the coarsest gradation tested for limestone. K with a reference pressure, pr = 1 kPa and n values for L-9.5, respectively, are 4365 and 0.636 for initial / 8511 and 0.419 for secant / 25704 and 0.430 for unloading-reloading elastic moduli. The unloading-reloading moduli increased, as the number of cycles increased. An increase in unloading-reloading modulus at N = 20 obtained was roughly 15% for scaled-down limestone / 10% for the basalt / and 5% for the steel-slag. The plastic strain after first cycle, &amp / #949 / 1, and the plastic strain coefficient, C can be represented as a function of mean particle size for each material type. For the limestone, basalt and steel-slag prototype size, D50 = 45 mm, &amp / #949 / 1 values of 0.59, 0.43 and 0.75 and C values of 0.54, 1.42 and 0.74 are predicted, respectively.

Há alguns anos, a necessidade de armazenar a história das informações e o período no qual as mesmas são válidas ou não no mundo real, está crescendo. As próprias leis vigentes no país fazem com que isto seja uma necessidade quando, por exemplo, criam uma tabela de tempo de validade para o armazenamento de documentos fiscais ou de recursos humanos. Neste âmbito destaca-se a importância do estudo de modelos de dados temporais que gerenciem este tipo de informação. Tais modelos definem a forma como as informações são organizadas, mantidas e recuperadas. A implementação destes modelos, entretanto, é realizada sobre bancos de dados (BD) convencionais, uma vez que ainda não existe um BD totalmente temporal. O mapeamento de um modelo temporal sobre um convencional não impede que sejam satisfeitas todas as necessidades de representação temporal, desde que seja realizado de forma coerente. As diferentes informações temporais que podem ser utilizadas para a representação de tempo são o tempo de transação e o tempo de validade. Quando se deseja uma representação completa da realidade, utilizam-se bancos de dados bitemporais, através dos quais é possível recuperar todas as informações passadas, presentes e futuras. Este trabalho apresenta o mapeamento de um modelo de dados bitemporal (modelo TF-ORM) para um SGBD convencional (Oracle). Este mapeamento compreende, além das informações temporais, todas as características do modelo, dentre as quais: classes e papéis, mensagens, regras, propriedades dinâmicas e estáticas. É apresentada, ainda, a definição de um gerenciador temporal, o qual busca automatizar o que é implementado. Complementando o estudo realizado, são apresentadas sugestões de operações a serem realizadas pelos desenvolvedores de aplicações temporais quando da manutenção das informações. As operações de inserção, atualização e remoção em uma base temporal são analisadas, independente do tipo de BD temporal implementado. Um estudo de caso é apresentado para validar todas as definições realizadas. / The need for storing the information’s history and the period in which they are still valid in the real world has been growing in the last few years. The very existing laws in the country make it necessary when, for instance, a validity temporal table is created for storing business or human resources documents. Therefore, the study of temporal data models which manage this kind of information has become very important. Such models define the way in which the information is organized, kept and recovered. The implementation of these models, though, is carried out over conventional data bases (DB), once there is no a totally temporal DB. The mapping of a temporal model over a conventional one allows all of its requirements to be met, as long as it is made coherently. The different temporal information that can be used for time representation are the transaction time and the validity time. Whenever a complete representation of the reality is wanted, bitemporal databases are used. These bases make it possible to recover all the past information as well as present and future information. This work presents the mapping of a temporal data model (TF-ORM model) for a conventional DBMS (Oracle). Besides the temporal information, this mapping comprehends all the model’s characteristics, such as: classes and roles, messages, rules, dynamic and static properties. It is also presented a definition of a temporal manager which aims at automating what is implemented. In addition to this study, suggestions of operations to be carried out by the developers of temporal applications for the maintenance of the information are presented. The operations of inserting, updating and removing on temporal base are analyzed, apart from the kind of DB implemented. A case study is presented in order to validate all the definitions made.

Há alguns anos, a necessidade de armazenar a história das informações e o período no qual as mesmas são válidas ou não no mundo real, está crescendo. As próprias leis vigentes no país fazem com que isto seja uma necessidade quando, por exemplo, criam uma tabela de tempo de validade para o armazenamento de documentos fiscais ou de recursos humanos. Neste âmbito destaca-se a importância do estudo de modelos de dados temporais que gerenciem este tipo de informação. Tais modelos definem a forma como as informações são organizadas, mantidas e recuperadas. A implementação destes modelos, entretanto, é realizada sobre bancos de dados (BD) convencionais, uma vez que ainda não existe um BD totalmente temporal. O mapeamento de um modelo temporal sobre um convencional não impede que sejam satisfeitas todas as necessidades de representação temporal, desde que seja realizado de forma coerente. As diferentes informações temporais que podem ser utilizadas para a representação de tempo são o tempo de transação e o tempo de validade. Quando se deseja uma representação completa da realidade, utilizam-se bancos de dados bitemporais, através dos quais é possível recuperar todas as informações passadas, presentes e futuras. Este trabalho apresenta o mapeamento de um modelo de dados bitemporal (modelo TF-ORM) para um SGBD convencional (Oracle). Este mapeamento compreende, além das informações temporais, todas as características do modelo, dentre as quais: classes e papéis, mensagens, regras, propriedades dinâmicas e estáticas. É apresentada, ainda, a definição de um gerenciador temporal, o qual busca automatizar o que é implementado. Complementando o estudo realizado, são apresentadas sugestões de operações a serem realizadas pelos desenvolvedores de aplicações temporais quando da manutenção das informações. As operações de inserção, atualização e remoção em uma base temporal são analisadas, independente do tipo de BD temporal implementado. Um estudo de caso é apresentado para validar todas as definições realizadas. / The need for storing the information’s history and the period in which they are still valid in the real world has been growing in the last few years. The very existing laws in the country make it necessary when, for instance, a validity temporal table is created for storing business or human resources documents. Therefore, the study of temporal data models which manage this kind of information has become very important. Such models define the way in which the information is organized, kept and recovered. The implementation of these models, though, is carried out over conventional data bases (DB), once there is no a totally temporal DB. The mapping of a temporal model over a conventional one allows all of its requirements to be met, as long as it is made coherently. The different temporal information that can be used for time representation are the transaction time and the validity time. Whenever a complete representation of the reality is wanted, bitemporal databases are used. These bases make it possible to recover all the past information as well as present and future information. This work presents the mapping of a temporal data model (TF-ORM model) for a conventional DBMS (Oracle). Besides the temporal information, this mapping comprehends all the model’s characteristics, such as: classes and roles, messages, rules, dynamic and static properties. It is also presented a definition of a temporal manager which aims at automating what is implemented. In addition to this study, suggestions of operations to be carried out by the developers of temporal applications for the maintenance of the information are presented. The operations of inserting, updating and removing on temporal base are analyzed, apart from the kind of DB implemented. A case study is presented in order to validate all the definitions made.

En underrättelsefunktion som ska hantera en motståndare i en komplex och dynamisk miljö ställs inför en svår uppgift. Möjligheterna till framgång ökar om flera olika inhämtningsmetoder nyttjas i kombinerade underrättelseoperationer. En av svårigheterna utgörs av att hitta en balans mellan en centraliserad respektive en decentraliserad underrättelsefunktion. Fördelarna med en centraliserad underrättelsefunktion där ett system av underrättelsesystem skapas kan svårligen uppnås fullt ut samtidigt som de förband som är mottagare av underrättelserna leds med ledningsmetoden uppdragstaktik och är decentraliserade. En paradox uppstår. Centralisering kontra decentralisering är en organisatorisk fråga. Henry Mintzbergs organisationsteori beskriver fem olika organisationstyper, som har olika fördelar i olika miljöer. Om den teorin är giltig för underrättelsefunktionen, så skulle kunskapen därom öka möjligheterna till att ur en organisatorisk synvinkel skapa optimala underrättelseförband i framtiden. Mintzbergs organisationsteori prövas i undersökningen på tre olika fall från Afghanistan, Irak respektive Mali. Teoriprövningen har resulterat i att Mintzbergs organisationsteori inte har kunnat falsifieras. En underrättelsefunktion som verkar i en komplex och dynamisk miljö fungerar optimalt om den är organiserad enligt organisationstypen adhokrati, vilken är decentraliserad och växlar mellan att vara organiserad funktionsvis och mot marknad. Den dominerande koordineringsmekanismen utgörs av ömsesidig anpassning. Det uppnås genom utbredd samverkan, förtroendeskapande åtgärder samt att de ingående enheterna är välutbildade och samtränade.

Há alguns anos, a necessidade de armazenar a história das informações e o período no qual as mesmas são válidas ou não no mundo real, está crescendo. As próprias leis vigentes no país fazem com que isto seja uma necessidade quando, por exemplo, criam uma tabela de tempo de validade para o armazenamento de documentos fiscais ou de recursos humanos. Neste âmbito destaca-se a importância do estudo de modelos de dados temporais que gerenciem este tipo de informação. Tais modelos definem a forma como as informações são organizadas, mantidas e recuperadas. A implementação destes modelos, entretanto, é realizada sobre bancos de dados (BD) convencionais, uma vez que ainda não existe um BD totalmente temporal. O mapeamento de um modelo temporal sobre um convencional não impede que sejam satisfeitas todas as necessidades de representação temporal, desde que seja realizado de forma coerente. As diferentes informações temporais que podem ser utilizadas para a representação de tempo são o tempo de transação e o tempo de validade. Quando se deseja uma representação completa da realidade, utilizam-se bancos de dados bitemporais, através dos quais é possível recuperar todas as informações passadas, presentes e futuras. Este trabalho apresenta o mapeamento de um modelo de dados bitemporal (modelo TF-ORM) para um SGBD convencional (Oracle). Este mapeamento compreende, além das informações temporais, todas as características do modelo, dentre as quais: classes e papéis, mensagens, regras, propriedades dinâmicas e estáticas. É apresentada, ainda, a definição de um gerenciador temporal, o qual busca automatizar o que é implementado. Complementando o estudo realizado, são apresentadas sugestões de operações a serem realizadas pelos desenvolvedores de aplicações temporais quando da manutenção das informações. As operações de inserção, atualização e remoção em uma base temporal são analisadas, independente do tipo de BD temporal implementado. Um estudo de caso é apresentado para validar todas as definições realizadas. / The need for storing the information’s history and the period in which they are still valid in the real world has been growing in the last few years. The very existing laws in the country make it necessary when, for instance, a validity temporal table is created for storing business or human resources documents. Therefore, the study of temporal data models which manage this kind of information has become very important. Such models define the way in which the information is organized, kept and recovered. The implementation of these models, though, is carried out over conventional data bases (DB), once there is no a totally temporal DB. The mapping of a temporal model over a conventional one allows all of its requirements to be met, as long as it is made coherently. The different temporal information that can be used for time representation are the transaction time and the validity time. Whenever a complete representation of the reality is wanted, bitemporal databases are used. These bases make it possible to recover all the past information as well as present and future information. This work presents the mapping of a temporal data model (TF-ORM model) for a conventional DBMS (Oracle). Besides the temporal information, this mapping comprehends all the model’s characteristics, such as: classes and roles, messages, rules, dynamic and static properties. It is also presented a definition of a temporal manager which aims at automating what is implemented. In addition to this study, suggestions of operations to be carried out by the developers of temporal applications for the maintenance of the information are presented. The operations of inserting, updating and removing on temporal base are analyzed, apart from the kind of DB implemented. A case study is presented in order to validate all the definitions made.

The aviation industry is growing rapidly and the carbon dioxide emissions from the industry are following in the same manner. Biofuels made from edible feedstock have had an impact on lowering the emissions but at the same time an impact on increasing food prices. There are a few alternative fuels on the market today (TF-SPK, HEFA-SPK) which work in a blend with the petroleum based fuels, reducing the emissions from the aircrafts. Biofuels from next generation biomass, also called advanced biomass, such as algae and lignin, seem likely to be a good substitute for the first generation biofuels. The advanced biofuels are relatively costly to produce. This is due to the many steps in the production process, which restricts the usage of these sorts of fuels in the aviation industry. There are some problems associated with a jet fuel produced from 100% biomass. This is because the jet fuel produced from biomass differs from the jet fuels used today, making it unsafe to use in modern day airplane engines. That is why it is important to find an alternative jet fuel based on biomass that has the same characteristics as the conventional jet fuel, to be able to use the same transportation and engines that are in use today. Otherwise the high cost of advanced bio-jet fuels will make them unusable.

Eine Übersicht über die Verfahren der Erweiterten Suche (TF,IDF, Stemming, Indexing, Klang von Wörtern) sowie Textkorrektur, dazu deskriptorenbasierte Beschreibung von Dokumenten und Abstracts. Es erfolgt eine Evaluierung dieser Verfahren anhand von ausgewählten XML-Metadaten aus dem MONARCH. Den Abschluß bildet eine Analyse zum Ist-Zustand des MONARCH, bezogen auf Qualität der verwendeten Metadaten und deren Nutzbarkeit für die Erweiterte Suche.

Vulnerable code may cause security breaches in software systems resulting in financial and reputation losses for the organizations in addition to loss of their customers’ confidential data. Delivering proper software security training to software developers is key to prevent such breaches. Conventional training methods do not take the code written by the developers over time into account, which makes these training sessions less effective. We propose a method for recommending computer–security training to help identify focused and narrow areas in which developers need training. The proposed method leverages the power of static analysis techniques, by using the flagged vulnerabilities in the source code as basis, to suggest the most appropriate training topics to different software developers. Moreover, it utilizes public vulnerability repositories as its knowledgebase to suggest community accepted solutions to different security problems. Such mitigation strategies are platform independent, giving further strength to the utility of the system. This research discussed the proposed architecture of the recommender system, case studies to validate the system architecture, tailored algorithms to improve the performance of the system, and human subject evaluation conducted to determine the usefulness of the system. Our evaluation suggests that the proposed system successfully retrieves relevant training articles from the public vulnerability repository. The human subjects found these articles to be suitable for training. The human subjects also found the proposed recommender system as effective as a commercial tool.

Mathematics is the science and study of quality, structure, space, and change. It seeks out patterns, formulates new conjectures, and establishes the truth by rigorous deduction from appropriately chosen axioms and definitions. The study of mathematics makes a person better at solving problems. It gives someone skills that (s)he can use across other subjects and apply in many different job roles. In the modern world, builders use mathematics every day to do their work, since construction workers add, subtract, divide, multiply, and work with fractions. It is obvious that mathematics is a major contributor to many areas of study. For this reason, retrieving, ranking, and recommending Math answers, which is an application of Math information retrieval (IR), deserves attention and recognition, since a reliable recommender system helps users find the relevant answers to Math questions and benefits all Math learners whenever they need help solve a Math problem, regardless of the time and place. Such a recommender system can enhance the learning experience and enrich the knowledge in Math of its users. We have developed MaRec, a recommender system that retrieves and ranks Math answers based on their textual content and embedded formulas in answering a Math question. MaRec (i) applies KL-divergence to rank the textual content of a potential answer A with respect to the textual content of a Math question Q, and (ii) together with the representation of the Math formulas in Q and A as XML trees determines their subtree matching scores in ranking A as an answer to Q. The design of MaRec is simple, since it does not require the training and test process mandated by machine learning-based Math IR systems, which is tedious to set up and time consuming to train the models. Conducted empirical studies show that MaRec significantly outperforms (i) three existing state-of-the-art MathIR systems based on an offline evaluation, and (ii) a top-of-the-line machine learning system based on an online performance analysis.