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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.
391

The 3rd international IEEE scientific conference on physics and control (PhysCon 2007) : September 3rd-7th 2007 at the University of Potsdam

January 2007 (has links)
During the last few years there was a tremendous growth of scientific activities in the fields related to both Physics and Control theory: nonlinear dynamics, micro- and nanotechnologies, self-organization and complexity, etc. New horizons were opened and new exciting applications emerged. Experts with different backgrounds starting to work together need more opportunities for information exchange to improve mutual understanding and cooperation. The Conference "Physics and Control 2007" is the third international conference focusing on the borderland between Physics and Control with emphasis on both theory and applications. With its 2007 address at Potsdam, Germany, the conference is located for the first time outside of Russia. The major goal of the Conference is to bring together researchers from different scientific communities and to gain some general and unified perspectives in the studies of controlled systems in physics, engineering, chemistry, biology and other natural sciences. We hope that the Conference helps experts in control theory to get acquainted with new interesting problems, and helps experts in physics and related fields to know more about ideas and tools from the modern control theory.
392

Narrating Entrepreneurship: a Complexity Adaptive System Perspective

Lin, Shao-yi 13 August 2007 (has links)
In the past, most entrepreneurship researches were constructed on static, unilateral, single-level perspectives. They were used to adopt logic positivism as methodology so that it¡¦s hard to see the dynamic process of entrepreneurship. In this paper, I avoid following such paradigm and seek a novel solution in entrepreneurship study. I adopt complexity adaptive system (CAS) as a new theoretical perspective and narrative inquiry as a fresh methodology. In this way, entrepreneurship is viewed as a dynamic process, and all the accounts are arranged in four entrepreneurship stories: ¡§The first step : far from equilibrium¡¨, ¡§Strange attractors : vision and core capability¡¨, ¡§Dawn of the chaos : self-organization¡¨, and ¡§The pattern accompanied innovation: emergence¡¨. Through the lens of CAS, this research expresses that successful entrepreneurship is simply not the result of perfect planning in advance or opportunity identification. In fact, entrepreneurs try to enact self-organizing through interactions with the outsiders and finally generate innovation. Organizations should view chaos as normal condition thus they can keep evolution to survive. With these metaphors, the research attempt to inspire entrepreneurs and make their entrepreneurship come off.
393

Det är enklare i teorin...Om skolutveckling i praktiken : En fallstudie av ett skolutvecklingsprojekt i en gymnasieskola

von Schantz Lundgren, Inger January 2008 (has links)
This dissertation is a case study dealing with a school development project that took place in an upper secondary school as a result of a merger of two schools with different cultures. The project used a method called “Frirumsmodellen” and was planned to be conducted in three steps. The first was to carry out a cultural analysis in order to map the preconditions to start a school development project. The second was to carry out concrete actions and finally study eventual effects from such activities by doing a second cultural analysis. My role was to be a supervisor in the school development work, but at the same time study how this work was conducted and its impact in the ordinary school day. The dissertation takes its departure in the fact that schools are political governed. The mission of schools is never neutral; it is always an expression of behind laying social forces, ideologies and ideals of the contemporary society. Of this reason, there is a close connection between the macro political level and the micro political level. Another point of departure is the transition from a modern to a post modern society that gives the character to the changes that take place in schools. Steering of schools has partly been treated as a technical implementation problem. Schools contain on going conflicts between different interest groups that, more or less regularly, end up in educational reforms. These reforms generate school development activities in the single school. Undoubtedly, this makes school development to a complex process. At a rather late stage of the study I decided not to fulfil my task to follow the original plan. I instead let the school development project as a model to be in focus. The over all purpose was formulated: How is it possible to understand what happened in the school development project in the Falkgymnasiet and why was it not possible to carry it out as it was said in the project plan? To interpret what took place during the project I did create an interpretation frame of implementation and complexity theory that also made it possible to critically scrutinise the “Frirumsmodellen”. Already in an early stage of the process it was obvious that the “Frirumsmodellen” did not supply any tools to use and it became disconnected from the project. The project in it selves was marginalised and made invisible. The headmaster used the situation to change things she thought were important to develop. As a result, things happened, but most of the involved people did not at first hand connect this to the project. It is, of course, difficult in detail to say what caused what. The complexity theory successively made the hidden patterns revealed, hidden unofficial potentates visible, as well as unpredictable conditions that generated reactions from the personnel in front of a development work. Together this was rather efficient obstacles for not changing this school. I also discuss school development and implementation problems on a general level, for example, the possibility to transform a top-down initiated project to be bottom-up driven and using project as a tool for school development work. It was obvious that headmasters and teachers must be prepared to handle the ideological dimensions of problems schools have to face. Consequently, development work is about making problems visible and to handle these in the intersection point between the intentions of educational policies, pedagogical researchers, school administrators, headmasters, teachers and pupils. The ideological dimension also contains an existential issue. Do I as a teacher share the intentions for the development work? If not, how must I act?
394

Marketing Your Intangible Future : Tangibilization of Retirement Savings at Handelsbanken and Swedbank

Larsson, Emelie, Södersten, Marianne January 2008 (has links)
The purpose of this study is to investigate how individual retirement savings are made tangible for potential customers. As case companies we have studied the marketing strategies of Handelsbanken and Swedbank. We use Miller and Foust’s classification of services by intangibility based on attributes and benefits and Tarn’s four strategy marketing-based model in order to find out how the retirement savings are made tangible. We find that the attributes and benefits that are used to define retirement savings depend on how the service is affiliated to life-insurance or banking services. Intangibility is coped by simplifying the products by lifting forward salient features. Complexity is overcome by explanation. Putting emphasis on flexibility is a mean to cope with the uncertainty of future income.
395

Effects of Temperature on the Kinetic Isotope Effects for Proton and Hydride Transfers in the Active Site Variant of Choline Oxidase Ser101Ala

Uluisik, Rizvan C 23 May 2013 (has links)
Choline oxidase catalyzes the oxidation of choline to glycine betaine. The reaction includes betaine aldehyde as an intermediate. FAD is reduced by the alcohol substrate, betaine aldehyde intermediate and oxidized by molecular oxygen to give hydrogen peroxide. In this study, the Ser101Ala variant of choline oxidase was prepared to elucidate the contribution of the hydroxyl group of Ser101 in the proton and hydride transfer reactions for proper preorganization and reorganization of the active site towards quantum mechanical tunneling. The thermodynamic parameters associated with the enzyme-catalyzed OH and CH bond cleavages and the temperature dependence of the associated solvent and substrate kinetic isotope effects were investigated using a stopped-flow spectrophotometer. The proton and hydride transfer have been shown to be occurring via quantum tunneling in CHO-S101A enzyme.
396

On the Complexity of Finding Spanner Paths

Nilsson, Mikael January 2013 (has links)
We study the complexity of finding so called spanner paths between arbitrary nodes in Euclidean graphs. We study both general Euclidean graphs and a special type of graphs called Integer Graphs. The problem is proven NP-complete for general Euclidean graphs with non-constant stretches (e.g. (2n)^(3/2) where n denotes the number of nodes in the graph). An algorithm solving the problem in O(2^(0.822n)) is presented. Integer graphs are simpler and for these special cases a better algorithm is presented. By using a partial order of so called Images the algorithm solves the spanner path problem using O(2^(c(\log n)^2)) time, where c is a constant depending only on the stretch.
397

Expansion, Random Graphs and the Automatizability of Resolution

Zabawa, Daniel Michael 25 July 2008 (has links)
We explore the relationships between the computational problem of recognizing expander graphs, and the problem of efficiently approximating proof length in the well-known system of \emph{resolution}. This program builds upon known connections between graph expansion and resolution lower bounds. A proof system $P$ is \emph{(quasi-)automatizable} if there is a search algorithm which finds a $P$-proof of a given formula $f$ in time (quasi)polynomial in the length of a shortest $P$-proof of $f$. It is open whether resolution is (quasi-)automatizable. We prove several conditional non-automatizability results for resolution modulo new conjectures concerning the complexity of identifying bipartite expander graphs. Our reductions use a natural family of formulas and exploit the well-known relationships between expansion and length of resolution proofs. Our hardness assumptions are unsupported; we survey known results as progress towards establishing their plausibility. The major contribution is a conditional hardness result for the quasi-automatizability of resolution.
398

Topological entanglement complexity of systems of polygons and walks in tubes

Atapour, Mahshid 09 September 2008
In this thesis, motivated by modelling polymers, the topological entanglement complexity of systems of two self-avoiding polygons (2SAPs), stretched polygons and systems of self-avoiding walks (SSAWs) in a tubular sublattice of Z3 are investigated. In particular, knotting and linking probabilities are used to measure a polygonfs selfentanglement and its entanglement with other polygons respectively. For the case of 2SAPs, it is established that the homological linking probability goes to one at least as fast as 1-O(n^(-1/2)) and that the topological linking probability goes to one exponentially rapidly as n, the size of the 2SAP, goes to infinity. For the case of stretched polygons, used to model ring polymers under the influence of an external force f, it is shown that, no matter the strength or direction of the external force, the knotting probability goes to one exponentially as n, the size of the polygon, goes to infinity. Associating a two-component link to each stretched polygon, it is also proved that the topological linking probability goes to unity exponentially fast as n→∞. Furthermore, a set of entangled chains confined to a tube is modelled by a system of self- and mutually avoiding walks (SSAW). It is shown that there exists a positive number γ such that the probability that an SSAW of size n has entanglement complexity (EC), as defined in this thesis, greater than γn approaches one exponentially as n→∞. It is also established that EC of an SSAW is bounded above by a linear function of its size. Using a transfer-matrix approach, the asymptotic form of the free energy for the SSAW model is also obtained and the average edge-density for span m SSAWs is proved to approach a constant as m→∞. Hence, it is shown that EC is a ggoodh measure of entanglement complexity for dense polymer systems modelled by SSAWs, in particular, because EC increases linearly with system size, as the size of the system goes to infinity.
399

Samarbete och lärande : Om friktion, uppgifters komplexitet och erfarenhetsutbyten i samarbete / Cooperation and Learning : About friction, the complexity of tasks, and exchange of experience in cooperation

Stedt, Lisbeth January 2013 (has links)
This thesis highlights collaboration among secondary school teachers as an example of employees' possibilities to learn from each other in collaboration. The purpose of the thesis is to throw light upon how employees shape conditions for cooperation, and the importance these conditions have for their possibilities to exchange experiences and influence each other’s task understanding, i.e., their possibilities to learn from each other through collaboration. The thesis’ theoretical bases are action theory and constructivism. The study uses a case-study approach, and involves a combination of participant observation and interviewing techniques. The starting point was to identify factors that appeared to assist or hinder the exchange of experience. One conclusion is that the division of labour seems to have been central to how conditions are shaped and is the basis for teachers' possibilities for experience-exchange. The combination of a common, physical context, and the friction between the teachers’ actions, seems to promote experience-exchange between teachers and contribute to the possibility to learn from each other. Friction could be seen as the basis for teachers’ need to achieve consensus and coordinate action, since friction is a hindrance. Consequently, friction entails both obstacles and opportunities for coordination and learning. The conditions giving rise to frictions that are overcome seem to be shaped by the way teachers divide the work. Tasks with a high degree of complexity seldom cause friction, which is avoided in these contexts through individual labour. Friction seems to occur and be overcome more frequently during cooperation on easier tasks. Teachers' attempts to collaborate on complex tasks, and simultaneously divide work individually, seem to increase the risk of insurmountable friction arising, from power-related and communication barriers.
400

Expansion, Random Graphs and the Automatizability of Resolution

Zabawa, Daniel Michael 25 July 2008 (has links)
We explore the relationships between the computational problem of recognizing expander graphs, and the problem of efficiently approximating proof length in the well-known system of \emph{resolution}. This program builds upon known connections between graph expansion and resolution lower bounds. A proof system $P$ is \emph{(quasi-)automatizable} if there is a search algorithm which finds a $P$-proof of a given formula $f$ in time (quasi)polynomial in the length of a shortest $P$-proof of $f$. It is open whether resolution is (quasi-)automatizable. We prove several conditional non-automatizability results for resolution modulo new conjectures concerning the complexity of identifying bipartite expander graphs. Our reductions use a natural family of formulas and exploit the well-known relationships between expansion and length of resolution proofs. Our hardness assumptions are unsupported; we survey known results as progress towards establishing their plausibility. The major contribution is a conditional hardness result for the quasi-automatizability of resolution.

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