1,206 research outputs found

    'The time where the British took the lead is over': ethical aspects of writing in complex research partnerships

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    Writing reflects some of the different characteristics of the language being used and of the people who are communicating. The present paper focusses on the internal written communication in international and inter-disciplinary research projects. Using a case study of an international public health research project, it argues that the authorship and the languages used in internal project communication are not neutral but help to generate or reinforce power hierarchies. Within research partnerships, language thus raises ethical issues that have so far been neglected. Current ethics guidelines often focus on interactions between scientists and participants of social research and clinical trials, with less attention paid to the interactions among the scientists themselves. Describing all the different project phases based on writing within a research project, the paper distinguishes different influences on the distribution of power that emerge through a focus on written communication. The focus of the present paper is to illuminate the issues of ethics, power and the dimensions of hierarchy, physical location and native versus non-native English speakers that arise from paying attention to such communications

    Denoising Autoencoders for fast Combinatorial Black Box Optimization

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    Estimation of Distribution Algorithms (EDAs) require flexible probability models that can be efficiently learned and sampled. Autoencoders (AE) are generative stochastic networks with these desired properties. We integrate a special type of AE, the Denoising Autoencoder (DAE), into an EDA and evaluate the performance of DAE-EDA on several combinatorial optimization problems with a single objective. We asses the number of fitness evaluations as well as the required CPU times. We compare the results to the performance to the Bayesian Optimization Algorithm (BOA) and RBM-EDA, another EDA which is based on a generative neural network which has proven competitive with BOA. For the considered problem instances, DAE-EDA is considerably faster than BOA and RBM-EDA, sometimes by orders of magnitude. The number of fitness evaluations is higher than for BOA, but competitive with RBM-EDA. These results show that DAEs can be useful tools for problems with low but non-negligible fitness evaluation costs.Comment: corrected typos and small inconsistencie

    An analysis of the local optima storage capacity of Hopfield network based fitness function models

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    A Hopfield Neural Network (HNN) with a new weight update rule can be treated as a second order Estimation of Distribution Algorithm (EDA) or Fitness Function Model (FFM) for solving optimisation problems. The HNN models promising solutions and has a capacity for storing a certain number of local optima as low energy attractors. Solutions are generated by sampling the patterns stored in the attractors. The number of attractors a network can store (its capacity) has an impact on solution diversity and, consequently solution quality. This paper introduces two new HNN learning rules and presents the Hopfield EDA (HEDA), which learns weight values from samples of the fitness function. It investigates the attractor storage capacity of the HEDA and shows it to be equal to that known in the literature for a standard HNN. The relationship between HEDA capacity and linkage order is also investigated

    A Study on Multimemetic Estimation of Distribution Algorithms

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    PPSN 2014, LNCS 8672, pp. 322-331Multimemetic algorithms (MMAs) are memetic algorithms in which memes (interpreted as non-genetic expressions of problem solving strategies) are explicitly represented and evolved alongside genotypes. This process is commonly approached using the standard genetic procedures of recombination and mutation to manipulate directly information at the memetic level. We consider an alternative approach based on the use of estimation of distribution algorithms to carry on this self-adaptive memetic optimization process. We study the application of different EDAs to this end, and provide an extensive experimental evaluation. It is shown that elitism is essential to achieve top performance, and that elitist versions of multimemetic EDAs using bivariate probabilistic models are capable of outperforming genetic MMAs.This work is partially supported by MICINN project ANYSELF (TIN2011-28627-C04-01), by Junta de Andalucía project DNEMESIS (P10-TIC-6083) and by Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

    A review on probabilistic graphical models in evolutionary computation

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    Thanks to their inherent properties, probabilistic graphical models are one of the prime candidates for machine learning and decision making tasks especially in uncertain domains. Their capabilities, like representation, inference and learning, if used effectively, can greatly help to build intelligent systems that are able to act accordingly in different problem domains. Evolutionary algorithms is one such discipline that has employed probabilistic graphical models to improve the search for optimal solutions in complex problems. This paper shows how probabilistic graphical models have been used in evolutionary algorithms to improve their performance in solving complex problems. Specifically, we give a survey of probabilistic model building-based evolutionary algorithms, called estimation of distribution algorithms, and compare different methods for probabilistic modeling in these algorithms

    A review of estimation of distribution algorithms in bioinformatics

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    Evolutionary search algorithms have become an essential asset in the algorithmic toolbox for solving high-dimensional optimization problems in across a broad range of bioinformatics problems. Genetic algorithms, the most well-known and representative evolutionary search technique, have been the subject of the major part of such applications. Estimation of distribution algorithms (EDAs) offer a novel evolutionary paradigm that constitutes a natural and attractive alternative to genetic algorithms. They make use of a probabilistic model, learnt from the promising solutions, to guide the search process. In this paper, we set out a basic taxonomy of EDA techniques, underlining the nature and complexity of the probabilistic model of each EDA variant. We review a set of innovative works that make use of EDA techniques to solve challenging bioinformatics problems, emphasizing the EDA paradigm's potential for further research in this domain

    Stressors and Coping Strategies in Esports: A Systematic Review

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    In this systematic review, we provide an overview of stressors and coping strategies in esports, emphasizing the goal of informing applied practice and guiding future research. Guided by the PRISMA guidelines and employing the SPIDER framework, we synthesize findings from 19 studies. Performance stressors such as defeat and performance pressure were prominently observed, followed by team, organizational, and then personal stressors. Coping strategies, aligned with Nicholls et al. (2016), demonstrate internal regulation was the most frequently reported, followed by mastery coping, while goal withdrawal strategies were less frequently reported. Comparing esports to traditional sports highlights the role of stressors such as social media and equipment challenges in esports. However, personal stressors remain relatively unexplored. The review also identifies research gaps in stressor appraisal and communal coping strategies. Future research could delve into personal stressors, considering a wide array of psychological factors, and employing dynamic methodologies. Practical implications revolve around tailored interventions, promoting open communication, mastery coping techniques, and holistic well-being strategies. This review provides a broader understanding of esports stressors and coping strategies, offering a starting point for targeted interventions aimed at enhancing performance and well-being in the distinctive competitive landscape of esports

    Recombination operators and selection strategies for evolutionary Markov Chain Monte Carlo algorithms

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    Markov Chain Monte Carlo (MCMC) methods are often used to sample from intractable target distributions. Some MCMC variants aim to improve the performance by running a population of MCMC chains. In this paper, we investigate the use of techniques from Evolutionary Computation (EC) to design population-based MCMC algorithms that exchange useful information between the individual chains. We investigate how one can ensure that the resulting class of algorithms, called Evolutionary MCMC (EMCMC), samples from the target distribution as expected from any MCMC algorithm. We analytically and experimentally show—using examples from discrete search spaces—that the proposed EMCMCs can outperform standard MCMCs by exploiting common partial structures between the more likely individual states. The MCMC chains in the population interact through recombination and selection. We analyze the required properties of recombination operators and acceptance (or selection) rules in EMCMCs. An important issue is how to preserve the detailed balance property which is a sufficient condition for an irreducible and aperiodic EMCMC to converge to a given target distribution. Transferring EC techniques to population-based MCMCs should be done with care. For instance, we prove that EMCMC algorithms with an elitist acceptance rule do not sample the target distribution correctly
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