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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Effective Distribution Theory

Dahlgren, Fredrik January 2007 (has links)
<p>In this thesis we introduce and study a notion of effectivity (or computability) for test functions and for distributions. This is done using the theory of effective (Scott-Ershov) domains and effective domain representations.</p><p>To be able to construct effective domain representations of the spaces of test functions considered in distribution theory we need to develop the theory of admissible domain representations over countable pseudobases. This is done in the first paper of the thesis. To construct an effective domain representation of the space of distributions, we introduce and develop a notion of partial continuous function on domains. This is done in the second paper of the thesis. In the third paper we apply the results from the first two papers to develop an effective theory of distributions using effective domains. We prove that the vector space operations on each space, as well as the standard embeddings into the space of distributions effectivise. We also prove that the Fourier transform (as well as its inverse) on the space of tempered distributions is effective. Finally, we show how to use convolution to compute primitives on the space of distributions. In the last paper we investigate the effective properties of a structure theorem for the space of distributions with compact support. We show that each of the four characterisations of the class of compactly supported distributions in the structure theorem gives rise to an effective domain representation of the space. We then use effective reductions (and Turing-reductions) to study the reducibility properties of these four representations. We prove that three of the four representations are effectively equivalent, and furthermore, that all four representations are Turing-equivalent. Finally, we consider a similar structure theorem for the space of distributions supported at 0.</p>
12

Effective Distribution Theory

Dahlgren, Fredrik January 2007 (has links)
In this thesis we introduce and study a notion of effectivity (or computability) for test functions and for distributions. This is done using the theory of effective (Scott-Ershov) domains and effective domain representations. To be able to construct effective domain representations of the spaces of test functions considered in distribution theory we need to develop the theory of admissible domain representations over countable pseudobases. This is done in the first paper of the thesis. To construct an effective domain representation of the space of distributions, we introduce and develop a notion of partial continuous function on domains. This is done in the second paper of the thesis. In the third paper we apply the results from the first two papers to develop an effective theory of distributions using effective domains. We prove that the vector space operations on each space, as well as the standard embeddings into the space of distributions effectivise. We also prove that the Fourier transform (as well as its inverse) on the space of tempered distributions is effective. Finally, we show how to use convolution to compute primitives on the space of distributions. In the last paper we investigate the effective properties of a structure theorem for the space of distributions with compact support. We show that each of the four characterisations of the class of compactly supported distributions in the structure theorem gives rise to an effective domain representation of the space. We then use effective reductions (and Turing-reductions) to study the reducibility properties of these four representations. We prove that three of the four representations are effectively equivalent, and furthermore, that all four representations are Turing-equivalent. Finally, we consider a similar structure theorem for the space of distributions supported at 0.
13

Topological domain theory

Battenfeld, Ingo January 2008 (has links)
This thesis presents Topological Domain Theory as a powerful and flexible framework for denotational semantics. Topological Domain Theory models a wide range of type constructions and can interpret many computational features. Furthermore, it has close connections to established frameworks for denotational semantics, as well as to well-studied mathematical theories, such as topology and computable analysis. We begin by describing the categories of Topological Domain Theory, and their categorical structure. In particular, we recover the basic constructions of domain theory, such as products, function spaces, fixed points and recursive types, in the context of Topological Domain Theory. As a central contribution, we give a detailed account of how computational effects can be modelled in Topological Domain Theory. Following recent work of Plotkin and Power, who proposed to construct effect monads via free algebra functors, this is done by showing that free algebras for a large class of parametrised equational theories exist in Topological Domain Theory. These parametrised equational theories are expressive enough to generate most of the standard examples of effect monads. Moreover, the free algebras in Topological Domain Theory are obtained by an explicit inductive construction, using only basic topological and set-theoretical principles. We also give a comparison of Topological and Classical Domain Theory. The category of omega-continuous dcpos embeds into Topological Domain Theory, and we prove that this embedding preserves the basic domain-theoretic constructions in most cases. We show that the classical powerdomain constructions on omega-continuous dcpos, including the probabilistic powerdomain, can be recovered in Topological Domain Theory. Finally, we give a synthetic account of Topological Domain Theory. We show that Topological Domain Theory is a specific model of Synthetic Domain Theory in the realizability topos over Scott's graph model. We give internal characterisations of the categories of Topological Domain Theory in this realizability topos, and prove the corresponding categories to be internally complete and weakly small. This enables us to show that Topological Domain Theory can model the polymorphic lambda-calculus, and to obtain a richer collection of free algebras than those constructed earlier. In summary, this thesis shows that Topological Domain Theory supports a wide range of semantic constructions, including the standard domain-theoretic constructions, computational effects and polymorphism, all within a single setting.
14

A Framework for the Coordination of Complex Systems’ Development

Taxén, Lars January 2003 (has links)
This study is about the coordination of complex systems’ development. A Framework has been designed and deployed by the author in the development practice of Ericsson, a major supplier of telecommunication systems on the global market. The main purpose of the study is to investigate the impacts on coordination from the Framework. The development projects are very large and subject to turbulent market conditions. Moreover, they have many participants (often several thousand), have tight time constraints and are distributed to many design centres all over the world. In these projects, coordination of the development is of crucial importance. The Framework is grounded in a tentative theory called the Activity Domain Theory, which in turn is based on the praxis philosophy. In this theory the interaction between the individual and her environment is mediated by signs. Coordination is conceived as a particular activity domain which provides coordination to the development projects. The coordination domain is gradually constructed by the actors in this domain by iteratively refining a conceptual model, a process model, a transition model, a stabilizing core and information system support. In this process individual knowledge, shared meaning and organizational artefacts evolve in a dialectical manner. The Framework has been introduced in the Ericsson development practice over a period of more than ten years. Between 1999 and 2002 approximately 140 main projects and sub-projects at Ericsson have been impacted by the Framework. These projects were distributed to more than 20 different development units around the world and were carried out in a fiercely turbulent environment. The findings indicate that the Framework has had a profound impact on the coordination of the development of the most complex nodes in the 3rd generation of mobile systems. The knowledge contributions include an account for the history of the Framework at Ericsson and an identification of elements which contribute to successful outcomes of development projects. / The electronic version of the printed dissertation is a corrected version where all spelling and grammatical errors are corrected. Errors in tables has been corrected as in the errata above.
15

Rektorsrollen : om skolledarskapets gestaltning / The Principal's role: a study of the formation of educational leadership

Svedberg, Lars January 2000 (has links)
The role of principals in public education in Sweden has during the last decade been subjected to a number of reforms and structural changes that is without parallel in modern history. For example, the number of principals has doubled, the turnover is considerable and, while in the past being a principal has been an occupation for men, now women are in the majority. The limited Swedish research that has been carried out indicates that principals have multidimensional tasks that are often contradictory. In addition, principals find themselves in a situation where administration dominates at the cost of a more curriculum-based leadership. A majority of these research studies employ a macro-perspective that tends to marginalise the intentions of the actors and the impact of education as a socially-constructed sensemaking process. This thesis examines the role of the principal. The theoretical framework employed in this study derives from social psychology. Within this framework the role of the principal is perceived to be constructed in the intersection of the different domains of public education. This role is then related to the notion of a public ethos based on sets of democratic values. The empirical basis of the investigation is a case study of all principals and their superintendent (director of education) in a smaller Swedish municipality. Data was gathered in a number of interviews that extended over a school-year. The results, in short, suggest that the role of principals is being redefined and can in this process be interpreted with different emphases, that the different domains interpret the role of the principal from different rationalities and that goal-steering and related issues get treated more or less as symbolic rituals. These results are then discussed from the point of different discourses and sensemaking processes in education. It is concluded that the role of the principal is constructed in a discursive intersection. This discussion is then contrasted with a view where principals' emotional labour is highlighted and related to the primary processes of schooling and the societal functions of education.
16

Contributions to Pointfree Topology and Apartness Spaces

Hedin, Anton January 2011 (has links)
The work in this thesis contains some contributions to constructive point-free topology and the theory of apartness spaces. The first two papers deal with constructive domain theory using formal topology. In Paper I we focus on the notion of a domain representation of a formal space as a way to introduce generalized points of the represented space, whereas we in Paper II give a constructive and point-free treatment of the domain theoretic approach to differential calculus. The last two papers are of a slightly different nature but still concern constructive topology. In paper III we consider a measure theoretic covering theorem from various constructive angles in both point-set and point-free topology. We prove a point-free version of the theorem. In Paper IV we deal with issues of impredicativity in the theory of apartness spaces. We introduce a notion of set-presented apartness relation which enables a predicative treatment of basic constructions of point-set apartness spaces.
17

Topological and Computational Models for Fuzzy Metric Spaces via Domain Theory

RICARTE MORENO, LUIS-ALBERTO 23 December 2013 (has links)
This doctoral thesis is devoted to investigate the problem of establishing connections between Domain Theory and the theory of fuzzy metric spaces, in the sense of Kramosil and Michalek, by means of the notion of a formal ball, and then constructing topological and computational models for (complete) fuzzy metric spaces. The antecedents of this research are mainly the well-known articles of A. Edalat and R. Heckmann [A computational model for metric spaces, Theoret- ical Computer Science 193 (1998), 53-73], and R. Heckmann [Approximation of metric spaces by partial metric spaces, Applied Categorical Structures 7 (1999), 71-83], where the authors obtained nice and direct links between Do- main Theory and the theory of metric spaces - two crucial tools in the study of denotational semantics - by using formal balls. Since every metric induces a fuzzy metric (the so-called standard fuzzy metric), the problem of extending Edalat and Heckmann's works to the fuzzy framework arises in a natural way. In our study we essentially propose two di erent approaches. For the rst one, valid for those fuzzy metric spaces whose continuous t-norm is the minimum, we introduce a new notion of fuzzy metric completeness (the so-called standard completeness) that allows us to construct a (topological) model that includes the classical theory as a special case. The second one, valid for those fuzzy metric spaces whose continuous t-norm is greater or equal than the Lukasiewicz t-norm, allows us to construct, among other satisfactory results, a fuzzy quasi-metric on the continuous domain of formal balls whose restriction to the set of maximal elements is isometric to the given fuzzy metric. Thus we obtain a computational model for complete fuzzy metric spaces. We also prove some new xed point theorems in complete fuzzy metric spaces with versions to the intuitionistic case and the ordered case, respec- tively. Finally, we discuss the problem of extending the obtained results to the asymmetric framework. / Ricarte Moreno, L. (2013). Topological and Computational Models for Fuzzy Metric Spaces via Domain Theory [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34670 / TESIS
18

Utan samverkan är det inte möjligt : En kvalitativ studie om samverkan i det lokala brottsförebyggande arbetet mot ungdomskriminalitet / Without cooperation it´s not possible : A qualitative study on cooperation in the local crime prevention work against juvenile delinquency

Dimberg, William, Baydono, Natacha January 2022 (has links)
Juvenile delinquency is a recurring and currently discussed topic in today's media, and studies indicate that in the last few years there has been an increase in reports of juvenile delinquency to the social services. Researcher shows that a key factor in preventing youths’ involvement in crime is to take early preventative actions. It also appears that one important condition within preventive work is cooperation, and major parts of their contributions today consist of cooperation between different actors. The aim of this essay is to study how actors in the district of Teleborg in Växjö municipality cooperate in the preventive work against juvenile delinquency. By an empirical study of cooperation in Teleborg, we hope to be able to find a complete understanding and be able to raise any obstacles as well as success factors with the cooperation. This study is based on seven active actors in Teleborg, where each one of them are aiming towards keeping the youth away from juvenile delinquency. The result of the study proves that within Teleborg, there are various factors that encourage and inhibit the current cooperation. There are general and more organizational obstacles. Furthermore, it also appears when the cooperation is actualized, and what factors that are conductive within the preventive work.
19

Formally Verified Samplers From Discrete Probabilistic Programs

Bagnall, Alexander 05 June 2023 (has links)
No description available.
20

Formal Concepts and Applications

Shen, Gongqin 15 July 2005 (has links)
No description available.

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