We investigate the expressive power of different fragments of higher-order logics over finite relational structures (or equivalently, relational databases) with special emphasis in higher-order logics of order greater than or equal three. Our main results concern the study of the effect on the expressive power of higher-order logics, of simultaneously bounding the arity of the higher-order variables and the alternation of quantifiers. Let AAi(r,m) be the class of (i + 1)-th order logic formulae where all quantifiers are grouped together at the beginning of the formulae, forming m alternating blocks of consecutive existential and universal quantifiers, and such that the maximal-arity (a generalization of the concept of arity, not just the maximal of the arities of the quantified variables) of the higher-order variables is bounded by r. Note that, the order of the quantifiers in the prefix may be mixed. We show that, for every i [greater than or equal to] 1, the resulting AAi hierarchy of formulae of (i + 1)-th order logic is proper. This extends a result by Makowsky and Pnueli who proved that the same hierarchy in second-order logic is proper. In both cases the strategy used to prove the results consists in considering the set AUTOSAT(F) of formulae in a given logic F which, represented as finite structures, satisfy themselves. We then use a similar strategy to prove that the classes of [Sigma superscript i subscript m union Pi superscript i subscript m] formulae in which the higher-order variables of all orders up to i+1 have maximal-arity at most r, also induce a proper hierarchy in each higher-order logic of order i [greater than or equal to] 3. It is not known whether the correspondent hierarchy in second-order logic is proper. Using the concept of finite model truth definitions introduced by M. Mostowski, we give a sufficient condition for that to be the case. We also study the complexity of the set AUTOSAT(F) and show that when F is one of the prenex fragments [Sigma superscript 1 subscript m] of second-order logic, it follows that AUTOSAT(F) becomes a complete problem for the corresponding prenex fragment [Sigma superscript 2 subscript m] of third-order logic. Finally, aiming to provide the background for a future line of research in higher-order logics, we take a closer look to the restricted second-order logic SO[superscript w] introduced by Dawar. We further investigate its connection with the concept of relational complexity studied by Abiteboul, Vardi and Vianu. Dawar showed that the existential fragment of SO[superscript w] is equivalent to the nondeterministic inflationary fixed-point logic NFP. Since NFP captures relational NP, it follows that the existential fragment of SO[superscript w] captures relational NP. We give a direct proof, in the style of the proof of Fagin’s theorem, of this fact. We then define formally the concept of relational machine with relational oracle and prove the exact correspondence between the prenex fragments of SO[superscript w] and the levels of the relational polynomial-time hierarchy. This allows us to stablish a direct connection between the relational polynomial hierarchy and SO without using the Abiteboul and Vianu normal form for relational machines.

The quality of Machine Translation (MT) can often be poor due to it appearing incoherent and lacking in fluency. These problems consist of word ordering, awkward use of words and grammar, and translating text too literally. However we should not consider translations such as these failures until we have done our best to enhance their quality, or more simply, their fluency. In the same way various processes can be applied to touch up a photograph, various processes can also be applied to touch up a translation. This research outlines the improvement of MT quality through the application of Fluency Enhancement (FE), which is a process we have created that reforms and evaluates text to enhance its fluency. We have tested our FE process on our own MT system which operates on what we call the SAM fundamentals, which are as follows: Simplicity - to be simple in design in order to be portable across different languages pairs, Adaptability - to compensate for the evolution of language, and Multiplicity - to determine a final set of translations from as many candidate translations as possible. Based on our research, the SAM fundamentals are the key to developing a successful MT system, and are what have piloted the success of our FE process.

We investigate the expressive power of different fragments of higher-order logics over finite relational structures (or equivalently, relational databases) with special emphasis in higher-order logics of order greater than or equal three. Our main results concern the study of the effect on the expressive power of higher-order logics, of simultaneously bounding the arity of the higher-order variables and the alternation of quantifiers. Let AAi(r,m) be the class of (i + 1)-th order logic formulae where all quantifiers are grouped together at the beginning of the formulae, forming m alternating blocks of consecutive existential and universal quantifiers, and such that the maximal-arity (a generalization of the concept of arity, not just the maximal of the arities of the quantified variables) of the higher-order variables is bounded by r. Note that, the order of the quantifiers in the prefix may be mixed. We show that, for every i [greater than or equal to] 1, the resulting AAi hierarchy of formulae of (i + 1)-th order logic is proper. This extends a result by Makowsky and Pnueli who proved that the same hierarchy in second-order logic is proper. In both cases the strategy used to prove the results consists in considering the set AUTOSAT(F) of formulae in a given logic F which, represented as finite structures, satisfy themselves. We then use a similar strategy to prove that the classes of [Sigma superscript i subscript m union Pi superscript i subscript m] formulae in which the higher-order variables of all orders up to i+1 have maximal-arity at most r, also induce a proper hierarchy in each higher-order logic of order i [greater than or equal to] 3. It is not known whether the correspondent hierarchy in second-order logic is proper. Using the concept of finite model truth definitions introduced by M. Mostowski, we give a sufficient condition for that to be the case. We also study the complexity of the set AUTOSAT(F) and show that when F is one of the prenex fragments [Sigma superscript 1 subscript m] of second-order logic, it follows that AUTOSAT(F) becomes a complete problem for the corresponding prenex fragment [Sigma superscript 2 subscript m] of third-order logic. Finally, aiming to provide the background for a future line of research in higher-order logics, we take a closer look to the restricted second-order logic SO[superscript w] introduced by Dawar. We further investigate its connection with the concept of relational complexity studied by Abiteboul, Vardi and Vianu. Dawar showed that the existential fragment of SO[superscript w] is equivalent to the nondeterministic inflationary fixed-point logic NFP. Since NFP captures relational NP, it follows that the existential fragment of SO[superscript w] captures relational NP. We give a direct proof, in the style of the proof of Fagin’s theorem, of this fact. We then define formally the concept of relational machine with relational oracle and prove the exact correspondence between the prenex fragments of SO[superscript w] and the levels of the relational polynomial-time hierarchy. This allows us to stablish a direct connection between the relational polynomial hierarchy and SO without using the Abiteboul and Vianu normal form for relational machines.

We investigate the expressive power of different fragments of higher-order logics over finite relational structures (or equivalently, relational databases) with special emphasis in higher-order logics of order greater than or equal three. Our main results concern the study of the effect on the expressive power of higher-order logics, of simultaneously bounding the arity of the higher-order variables and the alternation of quantifiers. Let AAi(r,m) be the class of (i + 1)-th order logic formulae where all quantifiers are grouped together at the beginning of the formulae, forming m alternating blocks of consecutive existential and universal quantifiers, and such that the maximal-arity (a generalization of the concept of arity, not just the maximal of the arities of the quantified variables) of the higher-order variables is bounded by r. Note that, the order of the quantifiers in the prefix may be mixed. We show that, for every i [greater than or equal to] 1, the resulting AAi hierarchy of formulae of (i + 1)-th order logic is proper. This extends a result by Makowsky and Pnueli who proved that the same hierarchy in second-order logic is proper. In both cases the strategy used to prove the results consists in considering the set AUTOSAT(F) of formulae in a given logic F which, represented as finite structures, satisfy themselves. We then use a similar strategy to prove that the classes of [Sigma superscript i subscript m union Pi superscript i subscript m] formulae in which the higher-order variables of all orders up to i+1 have maximal-arity at most r, also induce a proper hierarchy in each higher-order logic of order i [greater than or equal to] 3. It is not known whether the correspondent hierarchy in second-order logic is proper. Using the concept of finite model truth definitions introduced by M. Mostowski, we give a sufficient condition for that to be the case. We also study the complexity of the set AUTOSAT(F) and show that when F is one of the prenex fragments [Sigma superscript 1 subscript m] of second-order logic, it follows that AUTOSAT(F) becomes a complete problem for the corresponding prenex fragment [Sigma superscript 2 subscript m] of third-order logic. Finally, aiming to provide the background for a future line of research in higher-order logics, we take a closer look to the restricted second-order logic SO[superscript w] introduced by Dawar. We further investigate its connection with the concept of relational complexity studied by Abiteboul, Vardi and Vianu. Dawar showed that the existential fragment of SO[superscript w] is equivalent to the nondeterministic inflationary fixed-point logic NFP. Since NFP captures relational NP, it follows that the existential fragment of SO[superscript w] captures relational NP. We give a direct proof, in the style of the proof of Fagin’s theorem, of this fact. We then define formally the concept of relational machine with relational oracle and prove the exact correspondence between the prenex fragments of SO[superscript w] and the levels of the relational polynomial-time hierarchy. This allows us to stablish a direct connection between the relational polynomial hierarchy and SO without using the Abiteboul and Vianu normal form for relational machines.

We investigate the expressive power of different fragments of higher-order logics over finite relational structures (or equivalently, relational databases) with special emphasis in higher-order logics of order greater than or equal three. Our main results concern the study of the effect on the expressive power of higher-order logics, of simultaneously bounding the arity of the higher-order variables and the alternation of quantifiers. Let AAi(r,m) be the class of (i + 1)-th order logic formulae where all quantifiers are grouped together at the beginning of the formulae, forming m alternating blocks of consecutive existential and universal quantifiers, and such that the maximal-arity (a generalization of the concept of arity, not just the maximal of the arities of the quantified variables) of the higher-order variables is bounded by r. Note that, the order of the quantifiers in the prefix may be mixed. We show that, for every i [greater than or equal to] 1, the resulting AAi hierarchy of formulae of (i + 1)-th order logic is proper. This extends a result by Makowsky and Pnueli who proved that the same hierarchy in second-order logic is proper. In both cases the strategy used to prove the results consists in considering the set AUTOSAT(F) of formulae in a given logic F which, represented as finite structures, satisfy themselves. We then use a similar strategy to prove that the classes of [Sigma superscript i subscript m union Pi superscript i subscript m] formulae in which the higher-order variables of all orders up to i+1 have maximal-arity at most r, also induce a proper hierarchy in each higher-order logic of order i [greater than or equal to] 3. It is not known whether the correspondent hierarchy in second-order logic is proper. Using the concept of finite model truth definitions introduced by M. Mostowski, we give a sufficient condition for that to be the case. We also study the complexity of the set AUTOSAT(F) and show that when F is one of the prenex fragments [Sigma superscript 1 subscript m] of second-order logic, it follows that AUTOSAT(F) becomes a complete problem for the corresponding prenex fragment [Sigma superscript 2 subscript m] of third-order logic. Finally, aiming to provide the background for a future line of research in higher-order logics, we take a closer look to the restricted second-order logic SO[superscript w] introduced by Dawar. We further investigate its connection with the concept of relational complexity studied by Abiteboul, Vardi and Vianu. Dawar showed that the existential fragment of SO[superscript w] is equivalent to the nondeterministic inflationary fixed-point logic NFP. Since NFP captures relational NP, it follows that the existential fragment of SO[superscript w] captures relational NP. We give a direct proof, in the style of the proof of Fagin’s theorem, of this fact. We then define formally the concept of relational machine with relational oracle and prove the exact correspondence between the prenex fragments of SO[superscript w] and the levels of the relational polynomial-time hierarchy. This allows us to stablish a direct connection between the relational polynomial hierarchy and SO without using the Abiteboul and Vianu normal form for relational machines.

We investigate the expressive power of different fragments of higher-order logics over finite relational structures (or equivalently, relational databases) with special emphasis in higher-order logics of order greater than or equal three. Our main results concern the study of the effect on the expressive power of higher-order logics, of simultaneously bounding the arity of the higher-order variables and the alternation of quantifiers. Let AAi(r,m) be the class of (i + 1)-th order logic formulae where all quantifiers are grouped together at the beginning of the formulae, forming m alternating blocks of consecutive existential and universal quantifiers, and such that the maximal-arity (a generalization of the concept of arity, not just the maximal of the arities of the quantified variables) of the higher-order variables is bounded by r. Note that, the order of the quantifiers in the prefix may be mixed. We show that, for every i [greater than or equal to] 1, the resulting AAi hierarchy of formulae of (i + 1)-th order logic is proper. This extends a result by Makowsky and Pnueli who proved that the same hierarchy in second-order logic is proper. In both cases the strategy used to prove the results consists in considering the set AUTOSAT(F) of formulae in a given logic F which, represented as finite structures, satisfy themselves. We then use a similar strategy to prove that the classes of [Sigma superscript i subscript m union Pi superscript i subscript m] formulae in which the higher-order variables of all orders up to i+1 have maximal-arity at most r, also induce a proper hierarchy in each higher-order logic of order i [greater than or equal to] 3. It is not known whether the correspondent hierarchy in second-order logic is proper. Using the concept of finite model truth definitions introduced by M. Mostowski, we give a sufficient condition for that to be the case. We also study the complexity of the set AUTOSAT(F) and show that when F is one of the prenex fragments [Sigma superscript 1 subscript m] of second-order logic, it follows that AUTOSAT(F) becomes a complete problem for the corresponding prenex fragment [Sigma superscript 2 subscript m] of third-order logic. Finally, aiming to provide the background for a future line of research in higher-order logics, we take a closer look to the restricted second-order logic SO[superscript w] introduced by Dawar. We further investigate its connection with the concept of relational complexity studied by Abiteboul, Vardi and Vianu. Dawar showed that the existential fragment of SO[superscript w] is equivalent to the nondeterministic inflationary fixed-point logic NFP. Since NFP captures relational NP, it follows that the existential fragment of SO[superscript w] captures relational NP. We give a direct proof, in the style of the proof of Fagin’s theorem, of this fact. We then define formally the concept of relational machine with relational oracle and prove the exact correspondence between the prenex fragments of SO[superscript w] and the levels of the relational polynomial-time hierarchy. This allows us to stablish a direct connection between the relational polynomial hierarchy and SO without using the Abiteboul and Vianu normal form for relational machines.

Among student modelling researches, domain-independent student models have usually been a rarity. They are valued because of reusability and economy. The demand on domain-independent student models is further increased by the need to stay competitive in the so-called knowledge economy nowadays and the widespread practice of lifelong learning. On the other hand, the popularity of student-oriented pedagogy triggers the need to provide cognitive support in virtual learning environments which in turn requires student models that create cognitive profiles of students. This study offers an innovative student modelling approach called cognitive trait model (CTM) to address both the needs mentioned above. CTM is a domain-independent and persistent student model that goes beyond traditional concept of student model. It is capable of taking the role of a learning companion who knows about the cognitive traits of the student and can supply this information when the student first starts using a new learning system. The behaviour of the students in the learning systems can then be used to update CTM. Three cognitive traits are included in the CTM in this study, they are working memory capacity, inductive reasoning ability and divergent associative learning. For the three cognitive traits, their domain-independence and persistence are studied and defined, their characteristics are examined, and behaviour patterns that can be used to indicate them are extracted. In this study, a learning system is developed to gather behaviour data of students. Several web-based psychometric tools are also developed to gather the psychometric data about the three cognitive traits of students. In the evaluations, Cognitive trait modelling is then applied on the behaviour data and the results are compared with the psychometric data. The findings prove the effectiveness of CTM and reveal important insights about the three cognitive traits.

Software to display and analyse DNA sequences is a crucial tool for bioinformatics research. The data of a DNA sequence has a relatively simple format but the length and sheer volume of data can create difficulties in navigation while maintaining overall context. This is one reason that current bioinformatics applications can be difficult to use. This research examines techniques for navigating through large single DNA sequences and their annotations. Navigation in DNA sequences is considered here in terms of the navigational activities: exploration, wayfinding and identifying objects. A process incorporating user-centred design was used to create prototypes involving panning and zooming of DNA sequences. This approach included a questionnaire to define the target users and their goals, an examination of existing bioinformatics applications to identify navigation designs, a heuristic evaluation of those designs, and a usability study of prototypes. Three designs for panning and five designs for zooming were selected for development. During usability testing, users were asked to perform common navigational activities using each of the designs. The “Connected View” design was found to be the most usable for panning while the “Zoom Slider” design was best for zooming and most useful zooming tool for tasks involving browsing. For some tasks the ability to zoom was unnecessary. The research provides important insights into the expectations that researchers have of bioinformatics applications and suitable methods for designing for that audience. The outcomes of this type of research can be used to help improve bioinformatics applications so that they will be truly usable by researchers.

Chacune des périodes de crise qu’a connue l’histoire contemporaine ont été jalonnées d’un ensemble de bouleversements sociaux que l’on pourrait appeler des innovations sociales. Elles rassemblent, dans un élan collectif et ascendant, une myriade de mouvements citoyens qui visent la réponse à des besoins sociaux non, ou peu satisfaits, par l’Etat et le marché. Par ailleurs, en s’appuyant sur un ensemble d’organisations de l’économie sociale et solidaire, elles poursuivent une quête de démocratisation de l’activité économique. Dès lors, c’est pour mieux comprendre ces phénomènes de transformation sociale que ce travail tente de mobiliser les sciences de l’information et de la communication. Autrement dit, dans une démarche exploratoire, il questionne le rôle de la communication dans les capacités de changement institutionnel porté par ces initiatives. Une première analyse théorique permet de mettre en lumière l’hétérogénéité du mouvement de l’innovation sociale chez les acteurs de l’économie sociale et solidaire. Elle souligne, dans ce cadre, la tendance de ces organisations à s’emparer de pratiques de communication stratégiques (marketing et management), bien qu’elles soient historiquement investies d’un rôle politique et symbolique, lui intimant la nécessité de s’emparer d’un répertoire plus critique de la communication. Par conséquent, une seconde analyse empirique, dont les fondements épistémologiques se retrouvent dans la théorie de la complexité d’Edgar Morin et dans une approche réflexive, montre que l’analyse des initiatives citoyennes doit s’appuyer sur les apports communicationnels tout autre. Plus précisément, différents niveaux d’analyses de la communication de ces acteurs permettent de mettre à jour les capacités transformatrices, ou isomorphiques, des initiatives socialement innovantes de l’économie sociale et solidaire. En conclusion, ce que nous dit cette étude, c’est que la transformation sociale en germe dans ces organisations ne peut s’analyser que par une approche praxéologique de la communication. En d’autres termes, la praxis communicationnelle, comme activité organisante de perspective partagée dans un espace public de proximité, est une activité typificatrice d’habitudes, vectrice de changement institutionnel. / Each periods of crisis in contemporary history has been marked by a series of social upheavals that could be called social innovations. They bring together, in a collective and ascending momentum, a myriad of citizen movements that aim at the response to social needs not very satisfied by the State and the market. Moreover, by relying on a set of organizations of the social and solidarity economy, they pursue a quest for democratization of economic activity. Therefore, is to better understand these phenomena of social transformation that this work tries to mobilize the information and communication sciences. In other words, in an exploratory approach, he questions the role of communication in the institutional capacity for change brought about by these initiatives. A first theoretical analysis allows to highlight the heterogeneity of the social innovation movement among social and solidarity economy actors. In this context, she underlines the tendency of these organizations to seize strategic communication practices (marketing and management), although they are historically invested with a political and symbolic role, telling her the need to seize a more critical repertory of communication. Consequently, a second empirical analysis, whose epistemological foundations are found in Edgar Morin's theory of complexity and in a reflexive approach, shows that the analysis of citizen initiatives must be based on very different communicational inputs. More precisely, different levels of communication analysis of these actors make it possible to update the transformative, or isomorphic, capacities of socially innovative initiatives of the social and solidarity economy. In conclusion, what this study tells us is that the social transformation that germinates in these organizations can only be analyzed through a praxeological approach to communication. In other words, communicative praxis, as an organizing activity of shared perspective in a public space of proximity, is a typifying activity of habits, vector of institutional change.

A produção científica de uma área do conhecimento aparece em diferentes formatos e é disponibilizada de forma essencialmente distribuída por entre revistas, anais, teses, dissertações e outros formatos característicos utilizados pela comunidade científica para a sistematização de seu discurso. Uma federação de bibliotecas digitais oferece uma arquitetura da informação que tem por finalidade facilitar a agregação de diferentes tipos de documentos disponibilizados, facilitando termos acesso a esses documentos, bem como a seus metadados descritores, formando, desse modo, verdadeiras estruturas de apoio ao desenvolvimento de pesquisas e análises científicas dos documentos que por ali circulam. Já a análise de redes sociais vem se mostrando um importante objeto de pesquisa da área da Ciência da Informação nas últimas décadas, tendo sido apropriada ainda de forma preliminar pela comunidade científica brasileira. Como forma de ampliar o conhecimento e experimentações com o uso da análise de redes sociais e identificar seu potencial analítico em relação ao que poderíamos coletar de informações de uma federação de bibliotecas digitais, tivemos por objetivo neste trabalho utilizar a análise de rede para mapear os padrões, tendências e estratégias de conectividade de dois planos de relacionamento entre pesquisadores: a coautoria em documentos oriundos de revistas científicas e a participação em bancas de defesas de teses e dissertações. Além disso, buscamos mapear as causas sociais e políticas dos padrões de rede identificados, colocando em evidência um uso crítico e contextualizado dos indicadores estruturais e dinâmicos de redes utilizados neste trabalho. Utilizamos como caso a biblioteca digital federada Univerciencia.org, uma biblioteca especializada na área de Ciências da Comunicação, tendo fornecido como fonte de dados 49 revistas científicas da área com 9864 documentos e 12 bibliotecas digitais de teses e dissertações com 1961 documentos. Os resultados apontam que os movimentos geradores e constituintes das redes sociais em nossos dois planos de análise são fortemente determinados por uma racionalidade característica da política científica do campo da Comunicação e da ciência de modo geral. / The scientific production of an area of knowledge appears in different formats and is available in a distributed mainly through journals, proceedings, theses, dissertations and other typical formats used by the scientific community for the systematization of his speech. A federation of digital libraries offers an information architecture that aims to facilitate the aggregation of different types of documents available, facilitating access to those documents and their metadata descriptors, forming thus real structures to support the development of research and analysis of scientific documents that circulate through there. The analysis of social networks has proven an important subject of research in the area of Information Science and in recent decades have been appropriate even in a preliminary way by the Brazilian scientific community. As a way to increase knowledge and experimentation with the use of social network analysis and identify his potential analytical, the objective of this work was use network analysis to map the patterns , trends and connectivity strategies between two planes of relation between researchers: co-authoring of documents from scientific journals and participation in defenses of theses and dissertations. Furthermore, we seek to map the social and political causes of network patterns identified, highlighting a critical use of structural and dynamic indicators. We use as case Univerciencia.org federated digital library, a library specialized in the field of Communication Sciences and provided as a source of data collected 49 scientific journals in the area with 9864 documents and 12 digital libraries of theses and dissertations with 1961 documents. The results show that the generative movements and constituents of social networks in our two levels of analysis are strongly determined by a characteristic rationality of science policy in the field of communication and science in general.