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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.
51

Sucessão geracional na agricultura familiar : valores, motivações e influências que orientam as decisões dos atores

Panno, Fernando January 2016 (has links)
A presente tese tem por objetivo analisar as decisões dos agricultores familiares de Frederico Westphalen/RS com relação à sucessão geracional nas suas propriedades, sob a ótica da teoria da decisão e orientações de valor, elencando os diferentes fatores que influenciam sucessores e sucedidos nesse processo. Para alcançar este propósito, além de análises bibliográficas e documentais acerca do tema e suas nuances, teorias balizadoras e elaboração de uma construção histórica dos sistemas agrários do campo empírico, considerando o papel de pessoas e instituições nessa construção, foi aplicado um questionário a 50 potenciais sucessores e a 50 sucedidos, buscando compreender os direcionamentos decisórios destes atores sobre sucessão. Os dados coletados a campo, entre os meses de julho e setembro de 2015, foram tabulados com o suporte estatístico do programa Statistical Package for the Social Science (SPSS), gerando cruzamentos e informações relevantes acerca do tema e suas relações com o futuro das propriedades rurais familiares. O estudo mostra que a abertura de possibilidades e alternativas de aprimoramento acadêmico dos potenciais sucessores, mesmo em áreas agrícolas, tem oportunizado uma gama de escolhas profissionais que contribui para o constante desinteresse pela sucessão. A postura dos pais nessas situações também é condicionante para que o filho desperte ou não o interesse pela propriedade e tenha uma preparação adequada para assumi-la, sendo o incentivo dos sucedidos visto como um condicionador importante nas decisões dos potenciais sucessores O estudo aponta também para uma necessidade de pensar a sucessão geracional como um processo e não como uma decisão pontual. A participação dos filhos nas decisões cotidianas da propriedade, bem como na divisão dos resultados financeiros e das responsabilidades, mostram-se fatores determinantes para que esse processo aconteça. Além de delinear e analisar fatores influenciadores das decisões dos atores, o estudo classifica potenciais sucessores e sucedidos dentro das orientações de valor de Ruth Gasson (1973) – instrumental, social, expressiva e intrínseca. Comparando as orientações de pais e filhos, tem-se uma importante diferença de percepção. Assim, tem-se nas variáveis que influenciam o processo decisório dos atores e suas percepções e orientações de valor, atreladas à importância da agricultura familiar, como base de sustentação econômica e social local, a justificativa para que se estruturem alternativas viáveis em prol da manutenção do jovem no campo. / The aim of this thesis is to analyze the decisions of family farmers of Frederico Westphalen / RS regarding the generational succession in their properties, from the point of view of decision theory and value orientations, listing the different factors that influence successors and successors in this process. In order to achieve this purpose, besides bibliographical and documentary analyzes about the theme and its nuances, beacon theories and elaboration of a historical construction of the agrarian systems of the empirical field, considering the role of people and institutions in this construction, a questionnaire was applied to 50 potential successors and 50 family farmers, seeking to understand the decision making process direction of these actors over succession. The data collected in the field between July and September 2015 were tabulated with statistical support from the Statistical Package for the Social Science (SPSS), generating crosses and relevant information about the theme and its relations with the future of the properties rural areas. The study shows that the opening of possibilities and alternatives for academic improvement of potential successors, even in agricultural areas, has provided a range of professional choices that contributes to the constant lack of interest in succession. The parents attitude in these situations is also a condition for the child to arouse or not the interest for the property and to have adequate preparation to assume it, being the incentive of the successes seen as an important conditioner in the decisions of the potential successors The study also points to a need to think of generational succession as a process and not as a one off decision. The participation of the children in the daily decisions of the property, as well as in the division of the financial results and the responsibilities, are determining factors for this process to happen. In addition to outlining and analyzing factors influencing actors' decisions, the study ranks potential successors and succeeded within Ruth Gasson (1973) value orientations - instrumental, social, expressive, and intrinsic. Comparing the orientations of parents and children, one has an important difference of perception. Thus, the variables influencing the decision-making process of the actors and their perceptions and value orientations, linked to the importance of family agriculture, as a basis for local economic and social support, are the justification for structuring viable alternatives for maintenance the young man in the field.
52

Rational Fools: (Ir)rational Choices of Humans, Rhesus Macaques, and Capuchin Monkeys in Dynamic Stochastic Environments

Watzek, Julia 01 May 2017 (has links)
Human and animal decision-making is known to violate rational expectations in a variety of contexts. Statistical structures of real-world environments may account for such seemingly irrational behavior. In a computerized experiment, 16 capuchins, 7 rhesus monkeys, and 30 humans chose between up to three options of different value. The options disappeared and became available again with different probabilities. Subjects overwhelmingly chose transitively (A>B, B>C, and A>C) in the control condition, where doing so maximized overall gain. However, most subjects also adhered to transitivity in the test condition, where it was suboptimal but led to negligible losses compared to the optimal strategy. Only a few of the capuchins were able to maximize long-term gain by violating transitivity. Adhering to rational choice principles may facilitate the formation of near-optimal decision rules when short- and long-term goals align. Such cognitive shortcuts may have evolved to preserve mental resources.
53

Simulating interactions among multiple characters

Shum, Pak Ho January 2010 (has links)
In this thesis, we attack a challenging problem in the field of character animation: synthesizing interactions among multiple virtual characters in real-time. Although there are heavy demands in the gaming and animation industries, no systemic solution has been proposed due to the difficulties to model the complex behaviors of the characters. We represent the continuous interactions among characters as a discrete Markov Decision Process, and design a general objective function to evaluate the immediate rewards of launching an action. By applying game theory such as tree expansion and min-max search, the optimal actions that benefit the character the most in the future are selected. The simulated characters can interact competitively while achieving the requests from animators cooperatively. Since the interactions between two characters depend on a lot of criteria, it is difficult to exhaustively precompute the optimal actions for all variations of these criteria. We design an off-policy approach that samples and precomputes only meaningful interactions. With the precomputed policy, the optimal movements under different situations can be evaluated in real-time. To simulate the interactions for a large number of characters with minimal computational overhead, we propose a method to precompute short durations of interactions between two characters as connectable patches. The patches are concatenated spatially to generate interactions with multiple characters, and temporally to generate longer interactions. Based on the optional instructions given by the animators, our system automatically applies concatenations to create a huge scene of interacting crowd. We demonstrate our system by creating scenes with high quality interactions. On one hand, our algorithm can automatically generate artistic scenes of interactions such as the fighting scenes in movies that involve hundreds of characters. On the other hand, it can create controllable, intelligent characters that interact with the opponents for real-time applications such as 3D computer games.
54

An Examination of the College Decision-Making Process of High School Students in Rural Vermont: A Cross-Case Analysis

Reidel, Jon 01 January 2018 (has links)
Earning a college degree has been shown to have a number of positive socioeconomic impacts on individuals and society as a whole. Although researchers acknowledge that the decision to attend college is a complex process involving multiple factors, studies have focused primarily on individual reasons as part of a linear college choice paradigm. Individual obstacles to college attendance that consistently emerge in this strand of research include academic preparation, socioeconomic status, cost, family background, parental influence, motivation, and guidance counselor support (Harris & Halpin, 2002). College attendance rates are particularly low among students living in rural areas. Nationwide, only 59 percent of students from rural America choose to attend college, compared to 62 percent of their urban counterparts and 67 percent of students from suburban areas. (National Student Clearinghouse, 2015). The purpose of this study was to examine the college decision-making process of high school students in rural Vermont to better understand why fewer than 61 percent choose to attend college, despite more than 90 percent aspiring to do so at some point during their K-12 academic career (VSAC, 2016). A qualitative ethnographic case study approach was used to provide a unique student-focused perspective on the complexities of the college-decision making process as they go through it during their senior year of high school. A series of in-depth interviews were conducted with 10 students at two rural high schools throughout their senior year as they wrestled with an influx of information from multiple sources creating a series of pushes and pulls from guidance counselors, family members and friends with varying motives. Individual case study analyses were conducted on the following three groups of students based on their level of commitment to attend college at the start of their senior year: College Confident, College Considering and College Conflicted. A cross-case analysis of those three groups was also conducted. The result is a detailed account of how students in each group internalized and acted upon new information about their post-secondary plans, which depended heavily on when they received it, who they received it from and its quality. In most cases, the experience proved to be a frustrating, convoluted process that waxed and waned with each new piece of information. Ultimately, students made final college-going decisions based heavily on a combination of information that was not always accurate, sometimes misleading, and on the advice of at least one parent they perceived as having their best interest in mind.
55

A Learning Approach To Obtain Efficient Testing Strategies In Medical Diagnosis

Fakih, Saif 15 March 2004 (has links)
Determining the most efficient use of diagnostic tests is one of the complex issues facing the medical practitioners. It is generally accepted that excessive use of tests is common practice in medical diagnosis. Many tests are performed even though the incremental knowledge gained does not affect the course of diagnosis. With the soaring cost of healthcare in the US, there is a critical need for cutting costs of diagnostic tests, while achieving a higher level of diagnostic accuracy. Various decision making tools assisting physicians in diagnosis management have been presented to the literature. One such method, called analytical hierarchy process, utilize a multilevel structure of decision criterion for sequential pair wise comparison of available test choices. Many of the decision-analytic methods are based on Bayes' theory and decision trees. These methods use threshold treatment probabilities and performance characteristics of the tests, such as true-positive rate and false-positive rates, to choose among the available alternatives. Sequential testing approaches tend to elongate the diagnosis process, whereas the parallel testing approach generally involves higher number of tests. This research is focused on developing a machine learning based methodology for finding an efficient testing strategy for medical diagnosis. The method, based on the patient parameters (both observed and tested), recommends test(s) with the objective of optimizing a measure of performance for the diagnosis process. The performance measure is a combined cost of the testing, the risk and discomfort associated with the tests and the time taken to reach diagnosis. The performance measure also considers the diagnostic ability of the tests. The methodology is developed combining tools from the fields of data mining (rough set theory, in particular), utility theory, Markov decision processes (MDP), and reinforcement learning (RL). The rough set theory is used in extracting diagnostic information in the form of rules from the medical databases. Utility theory is used to bring three non-homogenous measures (cost of testing, risk and discomfort and diagnostic ability) into one cost based measure of performance. The MDP framework along with an RL algorithm facilitates obtaining efficient testing strategies. The methodology is implemented on a sample problem of diagnosing Solitary Pulmonary Nodule (SPN). The results obtained are compared with those from four other approaches. It is shown that the RL based methodology holds significant promise in improving the performance of diagnostic process.
56

Car Purchasing Behavior in Beijing : - An Empirical Investigation

Bai, Xuan, Dongyan, Liu January 2008 (has links)
<p>This study aims to give an overview on young Chinese consumers’ car purchase behavior. The results show that car purchasing decision is an important decision for most of Chinese. Consumers get information from different channels. The results of this study also tells us that Chinese consumers take “safety” as the most important characteristic and take “value for money” as the second most important and “riding comfort” as the third important characteristic. Chinese consumers take “after-sale maintenance” and “exterior design/size” as the forth most important factors when making the purchase decision. For “exterior design/size”, it indicates that Chinese people are status-seeking and Chinese people prefer to choose a bigger car with a good appearance (Mian Zi Che) to show their good social status and want to get respects from others. Chinese consumers put the least importance on resale value that is because second hand car market is not well developed in China.</p>
57

Decision Making under Uncertainty and Complexity : A study of young investors’ decision to buy warrants / Beslutsfattande under osäkerhet och komplexitet

Karlsson, Marie, Kraufvelin, Linda January 2009 (has links)
<p><strong>Background:</strong> A warrant is a derivative that is normally issued over stocks. During the last financial crisis, the trading of warrants reached new records. The high leverage and the complexity of the product make the warrant a risky investment. Financial products such as warrants therefore imply a significant purchase decision for an individual and the consequences of making a poorly thought-out choice can be of considerable importance. Financial products require a high degree of involvement since the decision process is characterized by uncertainty of outcome and complexity of the product. Traditional theories on consumer decision making build on the assumptions of self-interest and rationality. In the context of financial services, the rationality of the decision process has been questioned within the field of behavioral economics, a field that suggests that the consumer is unable to make rational decisions as well as comparative judgments.</p><p><strong>Purpose: </strong>With a theoretical basis in the traditional consumer decision process, the purpose of this thesis is to examine and describe the decision making of young investors that buy warrants.</p><p><strong>Methodology:</strong> The study can be described as abdicative, since the subject of this thesis is based on an empirical problem observed in reality as well as based on existing theories on the subject. The thesis is furthermore a mixed qualitative and quantitative study. The empirical information was gathered using an Internet survey that was sent out to young investors that are members or are connected to financial associations or societies at different universities.</p><p><strong>Results:</strong> The study is considered to show that the decision making of young investors can be described as neither optimal nor rational when buying warrants. The respondents seldom seem to make efficient and as rational decisions as the traditional decision process model implies. Instead, individual characteristics and attitudes of the young investors affect their decision making.</p>
58

Decision Making under Uncertainty and Complexity : A study of young investors’ decision to buy warrants / Beslutsfattande under osäkerhet och komplexitet

Karlsson, Marie, Kraufvelin, Linda January 2009 (has links)
Background: A warrant is a derivative that is normally issued over stocks. During the last financial crisis, the trading of warrants reached new records. The high leverage and the complexity of the product make the warrant a risky investment. Financial products such as warrants therefore imply a significant purchase decision for an individual and the consequences of making a poorly thought-out choice can be of considerable importance. Financial products require a high degree of involvement since the decision process is characterized by uncertainty of outcome and complexity of the product. Traditional theories on consumer decision making build on the assumptions of self-interest and rationality. In the context of financial services, the rationality of the decision process has been questioned within the field of behavioral economics, a field that suggests that the consumer is unable to make rational decisions as well as comparative judgments. Purpose: With a theoretical basis in the traditional consumer decision process, the purpose of this thesis is to examine and describe the decision making of young investors that buy warrants. Methodology: The study can be described as abdicative, since the subject of this thesis is based on an empirical problem observed in reality as well as based on existing theories on the subject. The thesis is furthermore a mixed qualitative and quantitative study. The empirical information was gathered using an Internet survey that was sent out to young investors that are members or are connected to financial associations or societies at different universities. Results: The study is considered to show that the decision making of young investors can be described as neither optimal nor rational when buying warrants. The respondents seldom seem to make efficient and as rational decisions as the traditional decision process model implies. Instead, individual characteristics and attitudes of the young investors affect their decision making.
59

Dynamic Cooperative Secondary Access inHierarchical Spectrum Sharing Networks

Wang, Liping, Fodor, Viktoria Unknown Date (has links)
We consider a hierarchical spectrum sharing network consisting of a primary and a cognitive secondary transmitter-receiver pair, with non-backlogged traffic. The secondary transmitter may utilize cooperative transmission techniques to relay primary traffic while superimposing its own information, or transmit opportunistically when the primary user is idle. The secondary user meets a dilemma in this scenario. Choosing cooperation it can transmit a packet immediately even if the primary queue is not empty, but it has to bear the additional cost of relaying, since the primary performance needs to be guaranteed. To solve this dilemma we propose dynamic cooperative secondary access control that takes the state of the spectrum sharing network into account. We formulate the problem as a Markov Decision Process (MDP) and prove the existence of a stationary policy that is average cost optimal. Then we consider the scenario when the traffic and link statistics are not known at the secondary user, and propose to find the optimal transmission strategy using reinforcement learning. With extensive numerical evaluation, we demonstrate that dynamic cooperation with state aware sequential decision is very efficient in spectrum sharing systems with stochastic traffic, and show that dynamic cooperation is necessary for the secondary system to be able to adapt to changing load conditions or to changing available energy resource. Our results show, that learning based access control, with or without known primary buffer state, has close to optimal performance. / <p>QS 2013</p>
60

Bruksmakt och maktbruk : Robertsfors AB 1897-1968 / Decision-making and decision power : Robertsfors AB 1897-1968

Holmström, Per January 1988 (has links)
This thesis studies seven strategic decisions made in the family-owned forestry company Robertsfors AB, in Northern Sweden. During the present century Ro­bertsfors AB has developed from a patriarchally concern controlled into a capi­talistic industrial company. This also meant a radical change in the decision­making process. Two factors were decisive in this process: the managing direc­tor's values, and altered power relationships both within the company and exter­nally in relation to e g state and municipal authorities and labour market organi­zations. The patriarchal Seth M Kempe, managing director 1897-1927, placed greater value on the company's independence than on profitability, and he personally, after discussions with the production manager, made the strategic decisions to build a sulphite mill in 1902 and not to build a sulphate mill in 1918. He also had no confidence in outside experts. Maximum profits on paid up capital, quick decisions and delegation of re­sponsibility were the marks of the years 1928-1947, when Seth M Kempe's son Erik was managing director. The strategic decision to close down the sawmill in 1935 was made by the company board, while he himself made the decisions early in the 1940's to produce sulphite alcohol and to establish an impregnation works, and finally to close down the sulphite mill in 1948. Responsibility for the community and the company's work force increased in importance during the years 1948-1968, when Erik's brother Ragnar was man­aging director. Now the board once again had real power. Decision-making was based on negotiation and compromise between management, the board, union organizations and state authorities — which is reflected in the strategic decision of 1967 to rebuild the foundry. / digitalisering@umu

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