37 research outputs found

    A tandem evolutionary algorithm for identifying causal rules from complex data

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    We propose a new evolutionary approach for discovering causal rules in complex classification problems from batch data. Key aspects include (a) the use of a hypergeometric probability mass function as a principled statistic for assessing fitness that quantifies the probability that the observed association between a given clause and target class is due to chance, taking into account the size of the dataset, the amount of missing data, and the distribution of outcome categories, (b) tandem age-layered evolutionary algorithms for evolving parsimonious archives of conjunctive clauses, and disjunctions of these conjunctions, each of which have probabilistically significant associations with outcome classes, and (c) separate archive bins for clauses of different orders, with dynamically adjusted order-specific thresholds. The method is validated on majority-on and multiplexer benchmark problems exhibiting various combinations of heterogeneity, epistasis, overlap, noise in class associations, missing data, extraneous features, and imbalanced classes. We also validate on a more realistic synthetic genome dataset with heterogeneity, epistasis, extraneous features, and noise. In all synthetic epistatic benchmarks, we consistently recover the true causal rule sets used to generate the data. Finally, we discuss an application to a complex real-world survey dataset designed to inform possible ecohealth interventions for Chagas disease

    Analysis of a consumer survey on plug-in hybrid electric vehicles

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    Plug-in Hybrid Electric Vehicles (PHEVs) show potential to reduce greenhouse gas (GHG) emissions, increase fuel efficiency, and offer driving ranges that are not limited by battery capacity. However, these benefits will not be realized if consumers do not adopt this new technology. Several agent-based models have been developed to model potential market penetration of PHEVs, but gaps in the available data limit the usefulness of these models. To address this, we administered a survey to 1000 stated US residents, using Amazon Mechanical Turk, to better understand factors influencing the potential for PHEV market penetration. Our analysis of the survey results reveals quantitative patterns and correlations that extend the existing literature. For example, respondents who felt most strongly about reducing US transportation energy consumption and cutting greenhouse gas emissions had, respectively, 71 and 44 times greater odds of saying they would consider purchasing a compact PHEV than those who felt least strongly about these issues. However, even the most inclined to consider a compact PHEV were not generally willing to pay more than a few thousand US dollars extra for the sticker price. Consistent with prior research, we found that financial and battery-related concerns remain major obstacles to widespread PHEV market penetration. We discuss how our results help to inform agent-based models of PHEV market penetration, governmental policies, and manufacturer pricing and marketing strategies to promote consumer adoption of PHEVs. © 2014 The Authors

    Reversibilidade de bens na concessão do serviço telefônico fixo comutado : uma análise crítica na perspectiva da Teoria Responsiva da Regulação

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    Dissertação (mestrado)—Universidade de Brasília, Faculdade de Direito, Curso de Pós-Graduação em Direito, 2017.A presente dissertação investiga as possíveis consequências de mutações paradigmáticas do direito administrativo no contorno jurídico de um instituto considerado, tradicionalmente, intrínseco às concessões de serviço de telecomunicações: a reversão de bens. O estudo evidencia a relação das alterações doutrinárias dos institutos jurídicos do direito administrativo com a persistência dos bens reversíveis nas concessões de serviços de telecomunicações. Destarte, a linha investigativa do trabalho identifica se o instituto da reversibilidade de bens na concessão de serviço público de telecomunicações é, ainda, a única ou melhor forma de se atingir os fins por ele visados, em especial a continuidade do serviço. Em relação ao marco teórico, adotou-se a teoria responsiva da regulação, tal como concebida por Ian Ayres e John Braithwaite no livro Responsive Regulation: Transcending the Deregulation Debate, de 1992, e desdobramentos de pesquisas posteriores. A pesquisa inicia com investigação sobre o novo papel a ser desempenhado pela Administração Pública em sua atuação em geral e, especificamente, no âmbito regulatório. Em seguida, propõe-se a adoção da teoria responsiva da regulação como modelagem teórica adequada para conciliar uma nova forma de atuação administrativa com a proteção dos interesses públicos. Após um aprofundamento sobre as principais proposições da teoria responsiva, foram analisados a doutrina e o arcabouço normativo sobre o tema dos bens reversíveis no setor de telecomunicações, propondo-se, ao final, uma crítica à regulamentação atual e fornecendo-se uma possível modelagem que seguisse os ditames da teoria responsiva da regulação.This study investigates the possible consequences of paradigmatic changes in Administrative Law in the legal context of an institute considered, at least traditionally, intrinsic to telecommunications service in Brazil: the reversal to the public domain or to a new service provider of assets owned by the current service provider. It is intended to highlight the relationship between the doctrinal changes in the legal institutes of Administrative Law and the persistence of the reversible assets in telecommunications service. Thus, the investigative line of the work will seek to know if the institute of the reversibility of asset in public telecommunications services is still the only or the better way to achieve its goals, especially the continuity of the service, from the perspective of the theory of responsive regulation, as conceived by Ian Ayres and John Braithwaite in the book Responsive Regulation: Transcending the Deregulation Debate, 1992. The research begins with developments on the new role to be played by the Public Administration, not least in the regulatory arena. Next, the study tackles the appropriateness of the theory of responsive regulation to reconcile a new form of administrative action with the protection of public interests. After that the main propositions of the theory of responsive regulation, the doctrine and the normative framework on the subject of reversible assets in the telecommunications sector were analyzed. Finally, a critique of current state of the art of the regulation and proposals providing a possible modeling that follows the dictates of the Responsive Theory of Regulation were made

    Parameterizing Pair Approximations for Takeover Dynamics

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    Pair approximations have often been used to predict equilibrium conditions in spatially-explicit epidemiological and ecological systems. In this work, we investigate whether this method can be used to approximate takeover dynamics in spatially structured evolutionary algorithms. Our results show that the pair approximation, as originally formulated, is insufficient for approximating pre-equibilibrium dynamics, since it does not properly account for the interaction between the size and shape of the local neighborhood and the population size. After parameterizing the pair approximation to account for these influences, we demonstrate that the resulting system of differential equations can serve as a general and rapid approximator for takeover dynamics on a variety of spatially-explicit regular interaction topologies with varying population sizes. Strengths, limitations, and potential applications of the pair approximation to evolutionary computation are discussed

    Team Learning for Healthcare Quality Improvement

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