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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.
191

Koncepce libertariánského paternalismu v rekodifikaci českého soukromého práva. / The concept of libertarian paternalism in the recodification of Czech private law.

Mičková, Barbora January 2015 (has links)
The master thesis The concept of libertarian paternalism in the recodification of Czech private law introduces a concept that works as an efficient synthesis of two different approaches to the relationship between the individual and the state: liberalism and paternalism. Libertarian paternalism deals mainly with the default system setting and setting of the recommendations and mechanism that are helpful in the decision making process of an individual as well as the whole society. The master thesis defines this concept, its main attributes and its tradition in the behavioral economics as well as its means and limits. The thesis shows how the use of this concept provides cheap and effective tools for nudging human decisions and behavior. The libertarian paternalistic approach in the law regulation is demonstrated in the new civil recodification, especially Civil Code 2012 as the fundamental act of civil law. The master thesis uses interdisciplinary approach to the topic, applying the perspectives of philosophy of law, economy, psychology and sociology.
192

Essays in Behavioral Finance / Essais en Finance

Benamar, Hedi 04 July 2014 (has links)
Cette thèse consiste en trois chapitres distincts. Dans le premier chapitre, je teste l'hypothèse selon laquelle le format d'affichage de l'information financière affecte les décisions des investisseurs individuels. Je montre qu'un affichage plus efficace permet aux individus de mieux gérer leurs ordres à cours limité en minimisant le risque de sélection adverse encouru en utilisant ces ordres. Cela suggère que les investisseurs individuels ont une rationalité limitée. Dans le second chapitre, je teste si les stratégies de trading apporteuses de liquidité peuvent générer des profits, après coûts de transactions, pour les traders actifs qui les implémentent. Je montre que seuls les individus situés dans le plus haut décile de performance peuvent battre le marché de façon persistante en utilisant des stratégies hautement contrariantes qui nécessitent l'utilisation massive d'ordres à cours limité. Les limites-à-l'arbitrage semblent expliquer ce phénomène. Dans le troisième chapitre, j'étudie les stratégies des individus autour des annonces de résultats. Je montre que les allers-retours qui sont implémentés un jour avant une annonce génèrent en moyenne des profits plus élevés et sont plus courts en durée que ceux implémentés en temps normal. Les individus clôturent leurs positions gagnantes le jour de l'annonce, ce qui peut ralentir l'ajustement des prix suite à l'annonce. / This thesis is made of three distinct chapters. In the first chapter, I test whether the display format of financial information matters for the individual investor. I find that a more efficient information display allows investors to increase returns on their limit orders, because it becomes easier for them to mitigate the risk of adverse selection when trading with those orders. My findings suggest that retail investors have bounded rationality. In the second chapter I test whether liquidity provision to the market can be a profitable strategy, after fees, for active retail investors. I find that only individuals ranked in the top decile of performance can persistently beat the market using highly contrarian limit order strategies. Limits-to-arbitrage seem to explain why these top retail investors exploit trading opportunities before other more sophisticated arbitrageurs. In the third chapter, I study the retail trading strategies around stock earnings announcements. I find that round-trips started one day before an announcement are more profitable and much shorter in duration than those started during the non-announcement period. Retails reverse their winning trades on the event date, which can slow down the adjustment of prices to new information.
193

Desenvolvimento de técnicas eficientes de programação linear na utilização de metaheurísticas para o problema de planejamento da expansão de sistemas de transmissão /

Righetto, Edison. January 2010 (has links)
Resumo: Neste trabalho apresenta-se uma estratégia de programação linear especializada para resolver, de forma eficiente, o problema de planejamento da expansão de sistemas de transmissão de energia elétrica usando o algoritmo de busca em vizinhança variável (VNS). O modelo matem'atico para este problema é um modelo de programação linear inteira mista. A solução deste modelo através de metaheurísticas, dependendo do sistema elétrico sob análise, pode exigir a solução de centenas de milhares de problemas de programação linear (PL) que exigem elevado esforço computacional e consomem a maior parte do tempo de CPU exigido pela metaheurística. A ideia fundamental deste artigo consiste em identificar soluções básicas adequadas para iniciar o processo de solução do problema de planejamento da transmissão e os inúmeros problemas de PL exigidos pela metaheurística, fazendo que os problemas de PL sejam resolvidos de forma eficiente computacionalmente. A solução básica adequada consiste na definição uma base dual factível específica para o problema que permite que novos problemas de PL resultantes das alterações de alguns parâmetros do problema de planejamento possam ser resolvidos usando um algoritmo dual simplex canalizado. A metodologia proposta foi validada e testada em um sistema de médio porte / Abstract: This paper presents a linear programming expert strategy to solve efficiently the energy transmission network expansion planning problem using the variable neighborhood search algorithm (VNS). The mathematical model used is a mixed integer linear programming problem. Solution of this model using different metaheuristics, depending on the electrical system under analysis, may require hundreds of thousands of linear programming problems (LP) which require high computational effort and consume almost all of the CPU time required by the metaheuristic. The basic idea of this paper is to identify appropriate basic solutions which help to start the process and speed up the solution of the many subsequent subproblems generated during a typical run, solving the LP problems efficiently. The starting basic solution is defined as an appropriate dual feasible basis for the specific problem, new LP problems resulting from changes in some parameters of the planning problem are solved using a bounded dual simplex algorithm. The proposed methodology was validated and tested in a system of medium size / Orientador: Rubén Augusto Romero Lázaro / Coorientador: Jose Roberto Sanches Mantovani / Banca: Anna Diva Plasencia Lotufo / Banca: Carlos Roberto Minussi / Banca: Antônio César Baleeiro Alves / Banca: Marcos Julio Rider Flores / Doutor
194

Demand for genetically modified food : theory and empirical findings

Kaye-Blake, William January 2006 (has links)
As economies develop, novel products are created and markets for these products arise. Genetically modified food (GMF) is an example of such a novel product and provides economists with the opportunity to investigate an infant market. Of particular interest with GMF is the impact of consumer reactions on the market. The response of consumers to GMF and their willingness to pay for it has emerged as an important factor in the development of this technology. This research investigates these consumer responses. Prior research suggests that two aspects of consumer behaviour may be relevant for the GMF market. First, consumers may react differently to different types of GMF, so that some products are potentially more economically viable. Secondly, some consumers appear to prefer not having GMF at all. Consumer behaviour is often framed according to neoclassical economic theory. Consumer preferences over goods and the attributes of those goods are generally held to have certain properties. The aspects of consumers' reactions to GMF noted above, however, may be in conflict with two properties of preferences in neoclassical theory. First, preferences over food attributes are not separable, but may interact with each other. Secondly, some consumers may have preferences regarding GMF that are not continuous. As a result, aggregate impacts of introducing GMF may be difficult to measure, which raises a third issue for investigation, aggregation. Finally, an alternative model of consumer behaviour is bounded rationality, which theorises that choices may be discontinuous as a result of specific protocols. It also suggests that consumers seek to make good-enough choices, rather than attempting to maximise their satisfaction. Thus, optimisation or maximisation is the fourth issue considered in this thesis. In order to investigate these properties of consumers' preferences, a choice experiment survey was developed. The strength of a choice experiment for examining these issues is its focus on the impact of each product attribute on a respondent's choices. Thus, it may be possible to identify potentially discontinuous choice patterns and to identify choices affected by interactions between GM technology and other food attributes. Results from a neoclassical analysis of the survey data suggest that some consumers consider the type of benefit created with GM technology in making their choices. In addition, one-quarter to one-half of respondents may have had discontinuous preferences with respect to GMF. Reactions to GMF appear related to respondents' attitudes, but not to socio-economic or demographic descriptors. As a result, aggregate measures of the impact of GMF may not fully account for consumers' responses. A boundedly rational model also has reasonable goodness of fit, and may provide a different perspective on consumer behaviour. It is hoped that the results of this research provide a better understanding of consumer behaviour regarding GMF and, by extension, of the process of consumer adoption of novel products. It is further hoped that this attempt to incorporate choice protocols into discrete choice analysis will provide a useful example for further research.
195

Bounded Rationality and Exemplar Models

Persson, Magnus January 2003 (has links)
<p>Bounded rationality is the study of how human cognition with limited capacity is adapted to handle the complex information structures in the environment. This thesis argues that in order to understand the bounded rationality of decision processes, it is necessary to develop decision theories that are computational process models based upon basic cognitive and perceptual mechanisms. The main goal of this thesis is to show that models of perceptual categorization based on the storage of exemplars and retrieval of similar exemplars whenever a new object is encountered (D. L. Medin & M. M. Schaffer, 1978), can be an important contribution to theories of decision making. Study I proposed, PROBEX (PROBabilities from Exemplars), a model for inferences from generic knowledge. It is a “lazy” algorithm that presumes no pre-computed abstractions. In a computer simulation it was found to be a powerful decision strategy, and it was possible to fit the model to human data in a psychologically plausible way. Study II was a theoretical investigation that found that PROBEX was very robust in conditions where the decision maker has very little information, and that it worked well even under the worst circumstances. Study III empirically tested if humans can learn to use exemplar based or one reason decision making strategies (G. Gigerenzer, P. Todd, & the ABC Research Group, 1999) where it is appropriate in a two-alternative choice task. Experiment 1 used cue structure and presentation format as independent variables, and participants easily used one reason strategies if the decision task presented the information as normal text. The participants were only able to use exemplars if they were presented as short strings of letters. Experiment 2 failed to accelerate learning of exemplar use during the decision phase, by prior exposure to exemplars in a similar task. In conclusion, this thesis supports that there are at least two modes of decision making, which are boundedly rational if they are used in the appropriate context. Exemplar strategies may, contrary to study II, only be used late in learning, and the conditions for learning need to be investigated further.</p>
196

Combining the vortex-in-cell and parallel fast multipole methods for efficient domain decomposition simulations : DNS and LES approaches

Cocle, Roger 24 August 2007 (has links)
This thesis is concerned with the numerical simulation of high Reynolds number, three-dimensional, incompressible flows in open domains. Many problems treated in Computational Fluid Dynamics (CFD) occur in free space: e.g., external aerodynamics past vehicles, bluff bodies or aircraft; shear flows such as shear layers or jets. In observing all these flows, we can remark that they are often unsteady, appear chaotic with the presence of a large range of eddies, and are mainly dominated by convection. For years, it was shown that Lagrangian Vortex Element Methods (VEM) are particularly well appropriate for simulating such flows. In VEM, two approaches are classically used for solving the Poisson equation. The first one is the Biot-Savart approach where the Poisson equation is solved using the Green's function approach. The unbounded domain is thus implicitly taken into account. In that case, Parallel Fast Multipole (PFM) solvers are usually used. The second approach is the Vortex-In-Cell (VIC) method where the Poisson equation is solved on a grid using fast grid solvers. This requires to impose boundary conditions or to assume periodicity. An important difference is that fast grid solvers are much faster than fast multipole solvers. We here combine these two approaches by taking the advantages of each one and, eventually, we obtain an efficient VIC-PFM method to solve incompressible flows in open domain. The major interest of this combination is its computational efficiency: compared to the PFM solver used alone, the VIC-PFM combination is 15 to 20 times faster. The second major advantage is the possibility to run Large Eddy Simulations (LES) at high Reynolds number. Indeed, as a part of the operations are done in an Eulerian way (i.e. on the VIC grid), all the existing subgrid scale (SGS) models used in classical Eulerian codes, including the recent "multiscale" models, can be easily implemented.
197

Combining the vortex-in-cell and parallel fast multipole methods for efficient domain decomposition simulations : DNS and LES approaches

Cocle, Roger 24 August 2007 (has links)
This thesis is concerned with the numerical simulation of high Reynolds number, three-dimensional, incompressible flows in open domains. Many problems treated in Computational Fluid Dynamics (CFD) occur in free space: e.g., external aerodynamics past vehicles, bluff bodies or aircraft; shear flows such as shear layers or jets. In observing all these flows, we can remark that they are often unsteady, appear chaotic with the presence of a large range of eddies, and are mainly dominated by convection. For years, it was shown that Lagrangian Vortex Element Methods (VEM) are particularly well appropriate for simulating such flows. In VEM, two approaches are classically used for solving the Poisson equation. The first one is the Biot-Savart approach where the Poisson equation is solved using the Green's function approach. The unbounded domain is thus implicitly taken into account. In that case, Parallel Fast Multipole (PFM) solvers are usually used. The second approach is the Vortex-In-Cell (VIC) method where the Poisson equation is solved on a grid using fast grid solvers. This requires to impose boundary conditions or to assume periodicity. An important difference is that fast grid solvers are much faster than fast multipole solvers. We here combine these two approaches by taking the advantages of each one and, eventually, we obtain an efficient VIC-PFM method to solve incompressible flows in open domain. The major interest of this combination is its computational efficiency: compared to the PFM solver used alone, the VIC-PFM combination is 15 to 20 times faster. The second major advantage is the possibility to run Large Eddy Simulations (LES) at high Reynolds number. Indeed, as a part of the operations are done in an Eulerian way (i.e. on the VIC grid), all the existing subgrid scale (SGS) models used in classical Eulerian codes, including the recent "multiscale" models, can be easily implemented.
198

Bounded Rationality and Exemplar Models

Persson, Magnus January 2003 (has links)
Bounded rationality is the study of how human cognition with limited capacity is adapted to handle the complex information structures in the environment. This thesis argues that in order to understand the bounded rationality of decision processes, it is necessary to develop decision theories that are computational process models based upon basic cognitive and perceptual mechanisms. The main goal of this thesis is to show that models of perceptual categorization based on the storage of exemplars and retrieval of similar exemplars whenever a new object is encountered (D. L. Medin &amp; M. M. Schaffer, 1978), can be an important contribution to theories of decision making. Study I proposed, PROBEX (PROBabilities from Exemplars), a model for inferences from generic knowledge. It is a “lazy” algorithm that presumes no pre-computed abstractions. In a computer simulation it was found to be a powerful decision strategy, and it was possible to fit the model to human data in a psychologically plausible way. Study II was a theoretical investigation that found that PROBEX was very robust in conditions where the decision maker has very little information, and that it worked well even under the worst circumstances. Study III empirically tested if humans can learn to use exemplar based or one reason decision making strategies (G. Gigerenzer, P. Todd, &amp; the ABC Research Group, 1999) where it is appropriate in a two-alternative choice task. Experiment 1 used cue structure and presentation format as independent variables, and participants easily used one reason strategies if the decision task presented the information as normal text. The participants were only able to use exemplars if they were presented as short strings of letters. Experiment 2 failed to accelerate learning of exemplar use during the decision phase, by prior exposure to exemplars in a similar task. In conclusion, this thesis supports that there are at least two modes of decision making, which are boundedly rational if they are used in the appropriate context. Exemplar strategies may, contrary to study II, only be used late in learning, and the conditions for learning need to be investigated further.
199

Stabilization of Discrete-time Systems With Bounded Control Inputs

Jamak, Anes January 2000 (has links)
In this paper we examine the stabilization of LTI discrete-time systems with control input constraints in the form of saturation nonlinearities. This kind of constraint is usually introduced to simulate the effect of actuator limitations. Since global controllability can not be assumed in the presence of constrained control, the controllable regions and their characterizations are analyzed first. We present an efficient algorithm for finding controllable regions in terms of their boundary hyperplanes (inequality constraints). A previously open question about the exact number of irredundant boundary hyperplanes is also resolved here. The main result of this research is a time-optimal nonlinear controller which stabilizes the system on its controllable region. We give analgorithm for on-line computation of control which is also implementable for high-order systems. Simulation results show superior response even in the presence of disturbances.
200

Stabilization of Discrete-time Systems With Bounded Control Inputs

Jamak, Anes January 2000 (has links)
In this paper we examine the stabilization of LTI discrete-time systems with control input constraints in the form of saturation nonlinearities. This kind of constraint is usually introduced to simulate the effect of actuator limitations. Since global controllability can not be assumed in the presence of constrained control, the controllable regions and their characterizations are analyzed first. We present an efficient algorithm for finding controllable regions in terms of their boundary hyperplanes (inequality constraints). A previously open question about the exact number of irredundant boundary hyperplanes is also resolved here. The main result of this research is a time-optimal nonlinear controller which stabilizes the system on its controllable region. We give analgorithm for on-line computation of control which is also implementable for high-order systems. Simulation results show superior response even in the presence of disturbances.

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