80,842 research outputs found

    Maximum Likelihood-based Online Adaptation of Hyper-parameters in CMA-ES

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    The Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is widely accepted as a robust derivative-free continuous optimization algorithm for non-linear and non-convex optimization problems. CMA-ES is well known to be almost parameterless, meaning that only one hyper-parameter, the population size, is proposed to be tuned by the user. In this paper, we propose a principled approach called self-CMA-ES to achieve the online adaptation of CMA-ES hyper-parameters in order to improve its overall performance. Experimental results show that for larger-than-default population size, the default settings of hyper-parameters of CMA-ES are far from being optimal, and that self-CMA-ES allows for dynamically approaching optimal settings.Comment: 13th International Conference on Parallel Problem Solving from Nature (PPSN 2014) (2014

    International Copyright: An Unorthodox Analysis American Association of Law Schools\u27 Intellectual Property Section\u27s Symposium on Compliance with the TRIPS Agreement

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    Professor Hansen reviews the development of copyright from its traditional domestic orientation to the modern emphasis on globalization and harmonization. His commentary analogizes modem trends in international copyright to religious equivalents. He notes that the current players include a secular priesthood (the traditional copyright bar and academics), agnostics and atheists (newer academics and lawyers, particularly those concerned with technology and the culture of the public domain) and missionaries (whose task it is to increase copyright protection around the world and who are primarily driven by trade considerations). The copyright crusade has been driven by this last group. The author compares the task of Increasing copyright protection In newly industrialized and developing countries to the conversion of any group to a new religion. The missionaries, primarily from the United States and the European Union, have the choice of seeking voluntary or involuntary conversions. He augurs that the prospects for voluntary conversion are slim and that coercion will continue to be used against newly industrialized and developing nations when copyright protection is at stake

    Introduction

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    Gray Market Goods: A Lighter Shade of Black Symposium: The Controversy over the Importation of Gray Market Goods: Is a Resolution Forthcoming

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    If a street vendor offers a famous brand-name product for a substantially lower price than one would expect, the average consumer\u27s initial reaction might be that the product had been stolen or was hot - a product of the black market. While such discounted goods might indeed be stolen, sophisticated consumers have come to expect similar discounts in stores and mail-order houses throughout the country on goods not from the black market but rather from the gray market. These products, naturally enough, are called gray market goods or simply gray goods. Gray goods are brand-name products manufactured abroad which bear an authentic trademark authorized by the owner of the trademark in the market for which the goods are intended. The owner of the trademark is usually foreign. These goods are normally intended for markets outside the United States at the time of manufacture. At some point, however, the gray goods are diverted or imported into the United States for the purpose of competing with the U.S. trademark owner\u27s authorized goods. Historically, the importation of gray goods was rare and sporadic. As a consequence, the U.S. Customs Service\u27s regulations which permit their importation were ignored. Gray goods, as a legal topic, were confined to the backwaters of antitrust and intellectual property law. In the last few years, however, the importation of gray goods has become a growth industry and has generated numerous lawsuits and commentaries. While the initial growth in the gray market was spurred by the very high value of the U.S. dollar in international currency markets, it appears that now a permanent gray market network has developed that will make the subject of gray-goods importation one of importance for years to come regardless of the value of the dollar

    Inference on Treatment Effects After Selection Amongst High-Dimensional Controls

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    We propose robust methods for inference on the effect of a treatment variable on a scalar outcome in the presence of very many controls. Our setting is a partially linear model with possibly non-Gaussian and heteroscedastic disturbances. Our analysis allows the number of controls to be much larger than the sample size. To make informative inference feasible, we require the model to be approximately sparse; that is, we require that the effect of confounding factors can be controlled for up to a small approximation error by conditioning on a relatively small number of controls whose identities are unknown. The latter condition makes it possible to estimate the treatment effect by selecting approximately the right set of controls. We develop a novel estimation and uniformly valid inference method for the treatment effect in this setting, called the "post-double-selection" method. Our results apply to Lasso-type methods used for covariate selection as well as to any other model selection method that is able to find a sparse model with good approximation properties. The main attractive feature of our method is that it allows for imperfect selection of the controls and provides confidence intervals that are valid uniformly across a large class of models. In contrast, standard post-model selection estimators fail to provide uniform inference even in simple cases with a small, fixed number of controls. Thus our method resolves the problem of uniform inference after model selection for a large, interesting class of models. We illustrate the use of the developed methods with numerical simulations and an application to the effect of abortion on crime rates

    Ionization of NO at high temperature

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    Space vehicles flying through the atmosphere at high speed are known to excite a complex set of chemical reactions in the atmospheric gases, ranging from simple vibrational excitation to dissociation, atom exchange, electronic excitation, ionization, and charge exchange. Simple arguments are developed for the temperature dependence of the reactions leading to ionization of NO, including the effect of vibrational electronic thermal nonequilibrium. NO ionization is the most important source of electrons at intermediate temperatures and at higher temperatures provides the trigger electrons that ionize atoms. Based on these arguments, recommendations are made for formulae which fit observed experimental results, and which include a dependence on both a heavy particle temperature and different vibration electron temperatures. In addition, these expressions will presumably provide the most reliable extrapolation of experimental results to much higher temperatures

    Viscosity and thermal conductivity of model Jupiter atmospheres

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    The viscosity and thermal conductivity coefficient are estimated for three models of the atmosphere of Jupiter: a heavy model consisting of 22% helium and 78% hydrogen, a nominal model consisting of 11% helium and 89% hydrogen, and a light model consisting of pure hydrogen. The effect of trace elements is neglected. Linearized approximations are used for the transport coefficients of the mixtures; these are found to be in almost constant ratio to the values for pure hydrogen, independent of temperature. Short Basic language programs for computing the coefficients are listed
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