949 resultados para Two-person zero-sum games


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A deep theoretical analysis of the graph cut image segmentation framework presented in this paper simultaneously translates into important contributions in several directions. The most important practical contribution of this work is a full theoretical description, and implementation, of a novel powerful segmentation algorithm, GC(max). The output of GC(max) coincides with a version of a segmentation algorithm known as Iterative Relative Fuzzy Connectedness, IRFC. However, GC(max) is considerably faster than the classic IRFC algorithm, which we prove theoretically and show experimentally. Specifically, we prove that, in the worst case scenario, the GC(max) algorithm runs in linear time with respect to the variable M=|C|+|Z|, where |C| is the image scene size and |Z| is the size of the allowable range, Z, of the associated weight/affinity function. For most implementations, Z is identical to the set of allowable image intensity values, and its size can be treated as small with respect to |C|, meaning that O(M)=O(|C|). In such a situation, GC(max) runs in linear time with respect to the image size |C|. We show that the output of GC(max) constitutes a solution of a graph cut energy minimization problem, in which the energy is defined as the a"" (a) norm ayenF (P) ayen(a) of the map F (P) that associates, with every element e from the boundary of an object P, its weight w(e). This formulation brings IRFC algorithms to the realm of the graph cut energy minimizers, with energy functions ayenF (P) ayen (q) for qa[1,a]. Of these, the best known minimization problem is for the energy ayenF (P) ayen(1), which is solved by the classic min-cut/max-flow algorithm, referred to often as the Graph Cut algorithm. We notice that a minimization problem for ayenF (P) ayen (q) , qa[1,a), is identical to that for ayenF (P) ayen(1), when the original weight function w is replaced by w (q) . Thus, any algorithm GC(sum) solving the ayenF (P) ayen(1) minimization problem, solves also one for ayenF (P) ayen (q) with qa[1,a), so just two algorithms, GC(sum) and GC(max), are enough to solve all ayenF (P) ayen (q) -minimization problems. We also show that, for any fixed weight assignment, the solutions of the ayenF (P) ayen (q) -minimization problems converge to a solution of the ayenF (P) ayen(a)-minimization problem (ayenF (P) ayen(a)=lim (q -> a)ayenF (P) ayen (q) is not enough to deduce that). An experimental comparison of the performance of GC(max) and GC(sum) algorithms is included. This concentrates on comparing the actual (as opposed to provable worst scenario) algorithms' running time, as well as the influence of the choice of the seeds on the output.

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OBJECTIVE: To examine the Young's modulus of the human amniotic membranes, as well as its relationship to gestational age. To determine whether cellular and material-related parameters affect this modulus. STUDY DESIGN: In a prospective study at the Obstetric outpatient clinic of the University Hospital Zurich Young's modulus, thickness and mesenchymal:epithelial cell ratio of amniotic membranes of preterm (N=23) and term (N=40) placentae were examined. Significance (P<0.05) was calculated with the Mann-Whitney two-sample rank sum test and Wilcoxon signed rank test, while correlations were made using the Spearman's correlation. RESULTS: The Young's modulus of preterm amniotic membranes was significantly higher than that of term membranes. It varied within the same amniotic membrane. The thickness of the amnion in both preterm and term membranes did not differ significantly. The thinner the preterm and term amniotic membranes, the higher the Young's modulus was. There was no relation to the mesenchymal:epithelial cell ratio in the amnion. CONCLUSIONS: Preterm amniotic membranes are stiffer than term amniotic membranes. Tentatively, we hypothesise that there may be a correlation between the extracellular matrix components and the elastic properties of the membrane.

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Health literacy (HL) is context-specific. In public health and health promotion, HL in the private realm refers to individuals' knowledge and skills to prevent disease and to promote health in everyday life. However, there is a scarcity of measurement tools explicitly geared to private realm contexts. Our aim was to develop and test a short survey tool that captures different dimensions of HL in the context of family and friends. We used cross-sectional data from the Swiss Federal Surveys of Adolescents from 2010 to 2011, comprising 7983 males and 366 females between 18 and 25 years. HL was assessed through a set of eight items (self-reports). We used principal component analysis to explore the underlying factor structure among these items in the male sample and confirmatory factor analysis to verify the factor structure in the female sample. The results showed that the tested item set represented dimensions of functional, interactive and critical HL. Two sub-dimensions, understanding versus finding health-relevant information, denoted functional HL. Interactive and critical HL were each represented with two items. A sum score based on all eight items (Cronbach's α: 0.64) showed expected positive associations with own and parental education among males and females (p < 0.05). The short item set appears to be a feasible measurement tool to assess HL in the private realm. Its broader application in survey studies may help to improve our understanding of how this form of HL is distributed in the general population.

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This paper presents a micro-model of knowledge creation and transfer in a small group of people. Our model incorporates two key aspects of the cooperative process of knowledge creation: (i) heterogeneity of people in their state of knowledge is essential for successful cooperation in the joint creation of new ideas, while (ii) the very process of cooperative knowledge creation a¤ects the heterogeneity of people through the accumulation of knowledge in common. The model features myopic agents in a pure externality model of interaction. In the two person case, we show that the equilibrium process tends to result in the accumulation of too much knowledge in common compared to the most productive state. Unlike the two-person case, in the four person case we show that the equilibrium process of knowledge creation may converge to the most productive state. Equilibrium paths are found analytically, and they are a discontinuous function of initial heterogeneity.

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Chronic communal conflicts resemble the prisoner’s dilemma. Both communities prefer peace to war. But neither trusts the other, viewing the other’s gain as its own loss, so potentially shared interests often go unrealized. Achieving positive-sum outcomes from apparently zero-sum struggles requires a kind of riskembracing leadership. To succeed leaders must: a) see power relations as potentially positive-sum; b) strengthen negotiating adversaries instead of weakening them; and c) demonstrate hope for a positive future and take great personal risks to achieve it. Such leadership is exemplified by Nelson Mandela and F.W. de Klerk in the South African democratic transition. To illuminate the strategic dilemmas Mandela and de Klerk faced, we examine the work of Robert Axelrod, Thomas Schelling, and Josep Colomer, who highlight important dimensions of the problem but underplay the role of risk-embracing leadership. Finally we discuss leadership successes and failures in the Northern Ireland settlement and the Israeli-Palestinian conflict.

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Russia in 2004 politely rejected the offer to become a participant in the European Neighbourhood Policy, preferring instead to pursue bilateral relations with the EU under the heading of ‘strategic partnership’. Five years later, its officials first reacted with concern to the ENP’s eastern dimension, the Eastern Partnership initiative. Quickly, however, having become convinced that the project would not amount to much, their concern gave way to indifference and derision. Furthermore, Russian representatives have failed to support idealistic or romantic notions of commonality in the area between Russia and the EU, shunned the terminology of ‘common European neighbourhood’ and replaced it in EU-Russian documents with the bland reference to ‘regions adjacent to the EU and Russian borders’. Internally, the term of the ‘near abroad’ was the official designation of the area in the Yeltsin era, and unofficially it is still in use today. As the terminological contortions suggest, Moscow officials consider the EU’s eastern neighbours as part of a Russian sphere of influence and interest. Assurances to the contrary notwithstanding, they look at the EU-Russia relationship as a ‘zero-sum game’ in which the gain of one party is the loss of the other. EU attempts to persuade the Russian power elite to regard cooperation in the common neighbourhood not as a competitive game but providing ‘win-win’ opportunities have been to no avail. In fact, conceptual approaches and practical policies conducted vis-à-vis the three Western CIS countries (Belarus, Ukraine and Moldova) and the southern Caucasus (Georgia, Armenia and Azerbaijan) confirm that, from Moscow’s perspective, processes of democratisation, liberalisation and integration with Western institutions in that region are contrary to Russian interests. In each and every case, therefore, the area’s ‘frozen conflicts’ have not been regarded by the Kremlin as an opportunity to promote stability and prosperity in the countries concerned but as an instrument to prevent European choices in their domestic and foreign policy. The current ‘reset’ in Russia’s relations with the United States and the ‘modernisation partnership’ with the EU have as yet failed to produce an impact on Russia’s policies in ‘its’ neighbourhood. The EU is nevertheless well advised to maintain its course of attempting to engage that country constructively, including in the common neighbourhood. However, its leverage is small. For any reorientation to occur in Moscow towards perceptions and policies of mutual benefit in the region, much would depend on Russia’s internal development.

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The objectives of the European Union (EU) and the United States (US) for the countries of the Balkan region are generally assumed to be complementary. They both stress and condition their support and assistance on the progress that these countries make with regards to economic modernization, build-up of social institutions, and respect for international law. However, this rhetoric doesn't always match the facts on the ground. Often, instead of dealing with a cohesive set of policy recommendations, the countries in the region are faced with contradictory alternatives and zero-sum choices. The debate over the development of the International Criminal Court (ICC) was such a case. It centered on whether the countries in the region should exempt US personnel from the jurisdiction of the Court while in the country and thus rendering them immune from prosecution for any crimes committed for which the US courts were not willing or able to take any action. The final outcome was mixed. Three of the countries - Croatia, Serbia (and Montenegro), and Slovenia - decided not to give in to US pressure, while the remaining three - Albania, Bosnia and Herzegovina, and Macedonia - ignored the pleas and threats of the EU and of the various international non-governmental organizations and decided to sign Bilateral Immunity Agreements (BIAs) with the US. How can one explain such divergent outcomes? I argue that the credibility of actors involved played an important role in determining whether threats coming from the US or the EU were more credible, thus tipping the scales in favor of signing BIAs with the US. However, the issue of threat credibility serves only to narrow down the choices of actors. Further determination of the outcome necessitates a look at the nature of the security context in which these countries exist and operate.

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Introduction. Russia’s annexation of the Crimea and subsequent meddling in Ukraine does not constitute a game-changer. It is just a reminder that at least since the war with Georgia in 2008 Russia has been and still is playing the same game: a “game of zones”, aimed at (re)establishing an exclusive sphere of influence. Many of us Europeans had forgotten that, or had pushed it to the back of our minds, preferring to believe that we were not engaged in a zero-sum game in our eastern neighbourhood. While we were dealing with Ukraine, we tended also to forget the crises still going on in our southern neighbourhood, in Libya, Mali, Syria and now Iraq. Spilling over from Syria, extremist militias may establish their own “zone” in the Middle East, which would de-stabilize the entire region. In order to prevent that game-changer from materializing, another game-changer may be necessary: a rapprochement with Iran. Europe must assume responsibility for security in its entire neighbourhood, both east and south. The challenge is great – but so are Europe’s means.

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Thesis (Ph.D.)--University of Washington, 2016-06

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The use of simulation games as a pedagogic method is well established though its effective use is context-driven. This study adds to the increasing growing body of empirical evidence of the effectiveness of simulation games but more importantly emphasises why by explaining the instructional design implemented reflecting best practices. This multi-method study finds evidence that student learning was enhanced through the use of simulation games, reflected in the two key themes; simulation games as a catalyst for learning and simulation games as a vehicle for learning. In so doing the research provides one of the few empirically based studies that support simulation games in enhancing learning and, more importantly, contextualizes the enhancement in terms of the instructional design of the curriculum. This research should prove valuable for those with an academic interest in the use of simulation games and management educators who use, or are considering its use. Further, the findings contribute to the academic debate concerning the effective implementation of simulation game-based training in business and management education.

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International travel has significant implications on the study of architecture. This study analyzed ways in which undergraduate and graduate students benefited from the experience of international travel and study abroad. Taken from the perspective of 15 individuals who were currently or had been architecture students at the University of Miami and Florida International University or who were alumni of the University of Florida and Syracuse University, the research explored how international travel and study abroad enhanced their awareness and understanding of architecture, and how it complemented their architecture curricula. This study also addressed a more personal aspect of international travel in order to learn how the experience and exposure to foreign cultures had positively influenced the personal and professional development of the participants.^ Participants’ individual and two-person semi-structured interviews about study abroad experiences were electronically recorded and transcribed for analysis. A second interview was conducted with five of the participants to obtain feedback concerning the accuracy of the transcripts and the interpretation of the data. Sketch journals and design projects were also analyzed from five participants and used as data for the purposes of better understanding what these individuals learned and experienced as part of their study abroad.^ Findings indicated that study abroad experiences helped to broaden student understanding about architecture and urban development. These experiences also opened the possibilities of creative and professional expression. For many, this was the most important aspect of their education as architects because it heightened their interest in architecture. These individuals talked about how they had the opportunity to experience contemporary and ancient buildings that they had learned about in their history and design classes on their home campuses. In terms of personal and professional development, many of the participants remarked that they became more independent and self-reliant because of their study abroad experiences. They also displayed a sense of global awareness and were interested in the cultures of their host nations. The study abroad experiences also had a lasting influence on their professional development.^

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The use of simulation games as a pedagogic method is well established though its effective use is context-driven. This study adds to the increasing growing body of empirical evidence of the effectiveness of simulation games but more importantly emphasises why by explaining the instructional design implemented reflecting best practices. This multimethod study finds evidence that student learning was enhanced through the use of simulation games, reflected in the two key themes; simulation games as a catalyst for learning and simulation games as a vehicle for learning. In so doing the research provides one of the few empirically based studies that support simulation games in enhancing learning and, more importantly, contextualizes the enhancement in terms of the instructional design of the curriculum. This research should prove valuable for those with an academic interest in the use of simulation games and management educators who use, or are considering its use. Further, the findings contribute to the academic debate concerning the effective implementation of simulation game-based training in business and management education.

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O presente trabalho está vinculado ao Programa de Pós-Graduação em Educação Ambiental - PPGEA/FURG e tem como tema a Educação Ambiental, a Educação Física e os Jogos Cooperativos no contexto escolar, com o objetivo de repensar a prática de Educação Física na escola a partir do desenvolvimento dos jogos cooperativos. A Educação Física é uma disciplina inserida no espaço escolar caracterizada pela presença dos esportes competitivos como conteúdo dominante e a Educação Ambiental é uma prática social que considera outros modos de constituição de relações sociais que estejam para além da lógica perspectivada pelo capitalismo e tão presente na prática dos jogos competitivos realizada nas aulas de Educação Física. A pesquisa insere-se numa perspectiva qualitativa tendo como suporte metodológico a pesquisa-ação. Ocorreu na Escola Municipal de Ensino Fundamental Mate Amargo, onde a pesquisadora possui vínculo. Os sujeitos da pesquisa foram os alunos de uma turma da referida escola e a partir do questionamento ?quais os significados atribuídos aos jogos cooperativos pelos estudantes da turma 71 - sétima série (no ano de 2012 e oitava série em 2013) da Escola Municipal de Ensino Fundamental Mate Amargo, desenvolveu-se esta pesquisa. A produção dos dados ocorreu por meio da proposição de jogos cooperativos e semi-cooperativos com registros escritos dos sujeitos da pesquisa após as vivências, escrita no diário de campo da pesquisadora e a produção de uma história das aulas de Educação Física realizada pelos referidos alunos. Como instrumento de análise foi utilizado a análise textual discursiva (ATD) proposta por Moraes e Galliazzi (2007) o qual se constitui por diversas etapas num movimento recursivo de compreensão do fenômeno investigado. A partir dos dados analisados emergiram duas categorias de análise: a primeira intitula-se ?Jogos e suas múltiplas faces: o resgate do lúdico? onde foi possível analisar as percepções dos alunos diante de tais jogos, os sentimentos que surgiram, suas opiniões e aprendizados. Evidenciouse ainda o potencial lúdico existente nestes jogos propostos. A segunda denomina-se "Entre a competição e a cooperação", e são expressas suas percepções acerca destes dois elementos no jogo, demonstrando que em alguns momentos a competição se evidencia revelando talvez, as próprias vivências dos alunos em seu cotidiano, e por vezes a cooperação se anuncia confirmando a possibilidade desses jogos em impulsionar e desenvolver sentimentos de coletividade, cooperação e sentido de grupo nos sujeitos da pesquisa permitindo o encaminhamento do significado atribuído por eles aos jogos cooperativos como atividades que propiciaram momentos de diversão e prazer, acompanhados de situações em que possibilitou o exercício da cooperação, percepção do outro e da coletividade. Como aporte teórico, deu-se ênfase a autores como Loureiro (2006; 2009), Guimarães (1995;2007), Bracht (1992;2009), Orlick (1978) Brown (2002) Brotto (2001). A pesquisa mostrou que os jogos cooperativos propiciaram a emergência de atitudes cooperativas e a percepção do outro, como também foi possível apreender pelas análises um clima de diversão e prazer sentido e expressado por eles confirmando o potencial lúdico existente nestes jogos.

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Part 18: Optimization in Collaborative Networks

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We compute the leading radiative correction to the Casimir force between two parallel plates in the lambdaPhi(4) theory. Dirichlet and periodic boundary conditions are considered. A heuristic approach, in which the Casimir energy is computed as the sum of one-loop corrected zero-point energies, is shown to yield incorrect results, but we show how to amend it. The technique is then used in the case of periodic boundary conditions to construct a perturbative expansion which is free of infrared singularities in the massless limit. In this case we also compute the next-to-leading order radiative correction, which turns out to be proportional to lambda(3/2).