A area de revisão de crenças estuda como agentes racionais mudam suas crencas ao receberem novas informações. O marco da area de revisão de crenças foi a publicacão do trabalho de Alchourron, Gardenfors e Makinson. Nesse trabalho conhecido como paradigma AGM foram denidos criterios de racionalidade para tipos de mudanca de crencas. Desde então, a área de revisão de crenças foi influenciada por diversas disciplinas como filosoa, computacão e direito. Paralelamente ao desenvolvimento da area de revisão de crenças, os últimos 20 anos foram marcados por um grande avanço no estudo das logicas de descrição. Tal avanço, impulsionado pelo desenvolvimento da web-semântica, levou a adoção de linguagens inspiradas em logicas de descrição (OWL) como padrão para se representar ontologias na web. Nessa tese tratamos do problema de aplicar a teoria da revisão de crenças a lógicas não clássicas e especialmente a logicas de descric~ao. Trabalhos recentes mostraram que o paradigma AGM e incompatvel com diversas logicas de descricão. Estendemos esses resultados mostrando outras lógicas que não são compatíveis com o paradigma AGM. Propomos formas de aplicar a teoria de revisão tanto em bases quanto em conjuntos de crencas a essas logicas. Alem disso, usamos algoritmos conhecidos da área de depuração de ontologias para implementar operações em bases de crenças. / Belief revision theory studies how rational agents change their beliefs after receiving new information. The most in uential work in this area is the paper of Alchourron, Gardenfors and Makinson. In this work, known as AGM paradigm rationality criteria for belief change were dened. Since then, the eld has been in uenced by many areas like philosophy, computer science and law. Parallel to the development of belief revision eld, in the past 20 years there was a huge grow in the study of description logics. The climax of this development was the adoption of OWL (a language based on description logics) as the standard language to represent ontologies on the web. In this work we deal with the problem of applying belief revision in to non-classical logics, specially description logics. Recent works showed that the AGM paradigm is not compliant with several description logics. We have extended this work by showing that other logics are not compliant with AGM paradigm. Furthermore, we propose alternative ways to apply belief revision techniques to these logics. Finally, we show that well known algorithms from the area of ontology debugging eld can be used to implement the proposed constructions.

DL-based ontologies have been widely used as knowledge infrastructures in knowledge management systems and on the Semantic Web. The development of efficient, sound and complete reasoning technologies has been a central topic in DL research. Recently, the paradigm shift from professional to novice users, and from standalone and static to inter-linked and dynamic applications raises new challenges: Can users build and evolve ontologies, both static and dynamic, with features provided by expressive DLs, while still enjoying e cient reasoning as in tractable DLs, without worrying too much about the quality (soundness and completeness) of results? To answer these challenges, this thesis investigates the problem of tractable and quality-guaranteed reasoning for ontologies in expressive DLs. The thesis develops syntactic approximation, a consequence-based reasoning procedure with worst-case PTime complexity, theoretically sound and empirically high-recall results, for ontologies constructed in DLs more expressive than any tractable DL. The thesis shows that a set of semantic completeness-guarantee conditions can be identifed to efficiently check if such a procedure is complete. Many ontologies tested in the thesis, including difficult ones for an off-the-shelf reasoner, satisfy such conditions. Furthermore, the thesis presents a stream reasoning mechanism to update reasoning results on dynamic ontologies without complete re-computation. Such a mechanism implements the Delete-and-Re-derive strategy with a truth maintenance system, and can help to reduce unnecessary over-deletion and re-derivation in stream reasoning and to improve its efficiency. As a whole, the thesis develops a worst-case tractable, guaranteed sound, conditionally complete and empirically high-recall reasoning solution for both static and dynamic ontologies in expressive DLs. Some techniques presented in the thesis can also be used to improve the performance and/or completeness of other existing reasoning solutions. The results can further be generalised and extended to support a wider range of knowledge representation formalisms, especially when a consequence-based algorithm is available.

Sports clubs today are exposed to multiple, sometimes contradictory, forces and expectations. This study is about sports coaches and their problems with and experiences of multiple institutional logics in Swedish sports. The aim of the study was therefore to provide further knowledge about the relationship between sports coaches’ leadership and institutional complexity. The study focused on the context of football in northern Sweden. The research questions that were examined were about institutional pressures, legitimacy, institutional logics, sports clubs’ impact and coaches’ strategies to manage institutional complexity. The data was collected through the means of qualitative interviews with 12 active football coaches. The results showed that the football coaches experience multiple institutional pressures and legitimacy claims. The coaches engage with 4 different coexisting institutional logics depending on the situation. Despite the fact that the institutional complexity is institutionalized in the context, it is sometimes viewed as problematic due to lack of control and support by the sports clubs. This indicated that the coaches are relatively autonomous and free to plan the activities as they wish and pursue the goals they see appropriate. Furthermore, the sports clubs have an important role in helping the coaches manage the institutional complexity and provide guidelines.

Description logics (DLs) are knowledge representation formalisms with well-understood model-theoretic semantics and computational properties. The DL SROIQ provides the logical underpinning for the semantic web language OWL 2, which is quickly becoming the standard for knowledge representation on the web. A central component of most DL applications is an efficient and scalable reasoner, which provides services such as consistency testing and classification. Despite major advances in DL reasoning algorithms over the last decade, however, ontologies are still encountered in practice that cannot be handled by existing DL reasoners. We present a novel reasoning calculus for the description logic SROIQ which addresses two of the major sources of inefficiency present in the tableau-based reasoning calculi used in state-of-the-art reasoners: unnecessary nondeterminism and unnecessarily large model sizes. Further, we describe a new approach to classification which exploits partial information about the subsumption relation between concept names to reduce both the number of individual subsumption tests performed and the cost of working with large ontologies; our algorithm is applicable to the general problem of deducing a quasi-ordering from a sequence of binary comparisons. We also present techniques for extracting partial information about the subsumption relation from the models generated by constructive DL reasoning methods, such as our hypertableau calculus. Empirical results from a prototypical implementation demonstrate substantial performance improvements compared to existing algorithms and implementations.

We consider the problem of answering conjunctive queries over description logic knowledge bases via query rewriting. Given a conjunctive query Q and a TBox T, we compute a new query Q′ that incorporates the semantic consequences of T such that, for any ABox A, evaluating Q over T and A can be done by evaluating the new query Q′ over A alone. We present RQR—a novel resolution-based rewriting algorithm for the description logic ELHIO¬ that generalizes and extends existing approaches. RQR not only handles a spectrum of logics ranging from DL-Lite_core up to ELHIO¬, but it is worst-case optimal with respect to data complexity for all of these logics; moreover, given the form of the rewritten queries, their evaluation can be delegated to off-the-shelf (deductive) database systems. We use RQR to derive the novel complexity results that conjunctive query answering for ELHIO¬ and DL-Lite+ are, respectively, PTime and NLogSpace complete with respect to data complexity. In order to show the practicality of our approach, we present the results of an empirical evaluation. Our evaluation suggests that RQR, enhanced with various straightforward optimizations, can be successfully used in conjunction with a (deductive) database system in order to answer queries over knowledge bases in practice. Moreover, in spite of being a more general procedure, RQR will often produce significantly smaller rewritings than the standard query rewriting algorithm for the DL-Lite family of logics.

Institutional logics create order and stability. They organize interaction and prescribe how we should behave towards each other. Such logics have generally been regarded as exclusive, in the sense that an organizational field is always guided by a single institutional logic. If there are two or more institutional logics in one setting at the same time this will create conflicting demands and contradictions. So how do organizations and individuals that act in these settings, where different institutional logics do meet, cope with the conflicting demands?    This question is researched by studying actors who organize partnerships between corporations and non-profit organizations. Institutional logics have typically been studied at field level. My study follows a more recent literature strand focusing on individuals and their way of coping with conflicting institutional logics. In this thesis, interviews, text analysis and observations are used. The interviews were conducted with CSR managers of corporations, managers of corporate partners at non-profit organizations, CSR consultants, and project managers of intermediary organizations. These actors are working in an environment where conflicting institutional logics are played out. Using a narrative approach it is shown how these actors are aware of their institutional environment and its conflicts which requires them to constantly act as translators. The study shows that the actors organize an interplay between a market-logic and a social-welfare logic by bringing together the logics and establishing limits to what extent logics can be mixed. Thus, the actors can be understood as bilingual, rather than hybrids. Furthermore, it is argued that a narrative approach provides the possibility to understand institutional logics in empirical contexts as more present and visible than they are usually considered to be. The study concludes that bilingual actors balance conflicting demands and negotiate requirements set by institutional logics in their day-to-day work.  Settings where institutional logics meet can hence be understood as both a contradiction and an ongoing interplay.

The aim for this study is to identify and analyze general trends, logics, and structures within the Swedish education system, and whether these are consistent with society's growing need for creative individuals. Furthermore, this study aims to identify possible tensions, paradoxes, and challenges regarding the role and function of creativity in relation to education. The aims have been approached by a problem-oriented method, based on a literature review as well as semi-structured interviews with key representatives of the Swedish education system. Overall the study has captured an international and national movement, where creativity in education on the basis of socio-economic, political, institutional, and individual embossed perspectives, has come to be a high priority. This development is based on a critique of today's knowledge-oriented education system, which is no longer considered compatible with today's society. The study has identified multidimensional barriers and opportunities for creativity in late modern education systems, and furthermore recognized creativity in education systems as an important aspect in how to address contemporary and future societal challenges.

Change is a timely issue across organisations, particularly since the start of the economic crisis, and especially within English local government. Yet, this question remains dominated by macro and micro explanatory models which tend to exclude conflict, mess and power in favour of enumerating universalistic steps or leadership factors for successful change. This thesis problematises this literature, drawing on Laclau and Mouffe’s (1985) political discourse theory and its mobilisation by critical management studies of organisational change. Three avenues are identified to further this literature. First, the organisation is analysed as an ongoing and fragile hegemonic project in which spaces are defined and consent must be constantly renewed. Second, the organisation is recast as a discursively constituted ‘site’ within a flat ontology, where change is not the result of some ‘bigger’ phenomena such as neo-liberalism or austerity, but instead is the product of situated articulations, disparate demands being mobilised as threats or opportunities requiring change. Finally, a third proposition articulates leadership in organisations as a set of multiple and changing practices, pragmatically deployed by organisational players. In exploring those avenues, a five-step ‘logics of critical explanation’ approach is deployed, characterising organisational change practices according to social (rules and norms), political (inclusions and exclusions), and fantasmatic (fears and hopes) logics (Glynos and Howarth, 2007). A nine month case study of an English County Council and its local strategic partnership’s organisational change project, Integrated Commissioning 2012 (IC 2012), is analysed to problematise the emergence, transformation and failure of practices of change in organisations. Rather than a set of factors or top-down causes and effects, this research demonstrates how change, organisations and leadership are best explained as discursive constructions, where a set of conditions drawn from a given site must be problematised. This research contributes to critical explanations of organisational change politics in three ways. First, by developing the concept of hegemony and hegemonic spaces, this thesis evidences how organisations and change are the result of ongoing struggles, consent being notably gathered by the constant refuelling of the fantasmatic appeal of change. Second, framing the organisation as a site generates a more complex, situated and dynamic understanding of the mobilisation of disparate demands within change discourses. Third, by considering leadership as a set of changing discursive practices and developing four situated dimensions of leadership in the case study, this research adds to critical leadership studies and discursive discussions of the role of individuals in organisational politics.

Real-world automated reasoning systems, based on classical logic, face logically inconsistent information, and they must cope with it. It is onerous to develop such systems because classical logic is explosive. Recently, progress has been made towards semantics that deal with logical inconsistency. However, such semantics was never analyzed in the aspect of inconsistency tolerant relational model. In our research work, we use an inconsistency and incompleteness tolerant relational model called "Paraconsistent Relational Model." The paraconsistent relational model is an extension of the ordinary relational model that can store, not only positive information but also negative information. Therefore, a piece of information in the paraconsistent relational model has four truth values: true, false, both, and unknown. However, the paraconsistent relational model cannot represent disjunctive information (disjunctive tuples). We then introduce an extended paraconsistent relational model called disjunctive paraconsistent relational model. By using both the models, we handle inconsistency - similar to the notion of quasi-classic logic or four-valued logic -- in deductive databases (logic programs with no functional symbols). In addition to handling inconsistencies in extended databases, we also apply inconsistent tolerant reasoning technique in semantic web knowledge bases. Specifically, we handle inconsistency assosciated with closed predicates in semantic web. We use again the paraconsistent approach to handle inconsistency. We further extend the same idea to description logic programs (combination of semantic web and logic programs) and introduce dl-relation to represent inconsistency associated with description logic programs.

The aim of this work is to use contemporary notation to build theory of Rosser logic, explain in detail its relation to Peano arithmetic, show its Kripke semantics and finally using plural self-reference show the proof of arithmetical completeness. In the last chapter we show some of the properties of Rosser sentences. Powered by TCPDF (www.tcpdf.org)