1,541,868 research outputs found

    An Exponential Lower Bound for the Runtime of the cGA on Jump Functions

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    In the first runtime analysis of an estimation-of-distribution algorithm (EDA) on the multi-modal jump function class, Hasen\"ohrl and Sutton (GECCO 2018) proved that the runtime of the compact genetic algorithm with suitable parameter choice on jump functions with high probability is at most polynomial (in the dimension) if the jump size is at most logarithmic (in the dimension), and is at most exponential in the jump size if the jump size is super-logarithmic. The exponential runtime guarantee was achieved with a hypothetical population size that is also exponential in the jump size. Consequently, this setting cannot lead to a better runtime. In this work, we show that any choice of the hypothetical population size leads to a runtime that, with high probability, is at least exponential in the jump size. This result might be the first non-trivial exponential lower bound for EDAs that holds for arbitrary parameter settings.Comment: To appear in the Proceedings of FOGA 2019. arXiv admin note: text overlap with arXiv:1903.1098

    Universal Social Orderings

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    We propose the concept of a universal social ordering, defined on the set of pairs of an allocation and a preference profile of any finite population. It is meant to unify evaluations and comparisons of social states with populations of possibly different sizes with various characteristics. The universal social ordering not only evaluates policy options for a given population but also compares social welfare across populations, as in international or intertemporal comparisons of living standards. It also makes it possible to evaluate policy options which affect the size of the population or the preferences of its members. We study how to extend the theory of social choice in order to select such orderings on a rigorous axiomatic basis. Key ingredients in this analysis are attitudes with respect to population size and the bases of interpersonal comparisons.social choice, universal social orderings, maximin principle, interpersonal comparisons

    Universal Social Orderings

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    We propose the concept of a universal social ordering, defined on the set of pairs of an allocation and a preference profile of any finite population. It is meant to unify evaluations and comparisons of social states with populations of possibly different sizes with various characteristics. The universal social ordering not only evaluates policy options for a given population but also compares social welfare across populations, as in international or intertemporal comparisons of living standards. It also makes it possible to evaluate policy options which affect the size of the population or the preferences of its members. We study how to extend the theory of social choice in order to select such orderings on a rigorous axiomatic basis. Key ingredients in this analysis are attitudes with respect to population size and the bases of interpersonal comparisons.social choice, universal social orderings, maximin principle, interpersonal comparisons

    Phase Transition in Sexual Reproduction and Biological Evolution

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    Using Monte Carlo model of biological evolution we have discovered that populations can switch between two different strategies of their genomes' evolution; Darwinian purifying selection and complementing the haplotypes. The first one is exploited in the large panmictic populations while the second one in the small highly inbred populations. The choice depends on the crossover frequency. There is a power law relation between the critical value of crossover frequency and the size of panmictic population. Under the constant inbreeding this critical value of crossover does not depend on the population size and has a character of phase transition. Close to this value sympatric speciation is observed.Comment: 13 pages, 8 figure

    Defining Demographic Change in Locational Planning Problems

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    Since population, which actually represents demand in any organised or rearranged service system, is the final target and recipient of every planning strategy or policy action, the success of locational analysis and the locational planning process, is largely determined upon the decision makers' ability to estimate the study area's future population size and distribution. Such estimations can be demographically achieved through the analysis and extrapolation into the future of carefully measured birth, death and migration rates according to observed trends and tendencies of the relevant socio-economic factors that affect them. As opposed to traditional generalisations and recent practices, which deal with population as a whole, the approach presented in this paper focuses on each individual's attitude towards the issue of intended births, which when aggregated formulate a fertility rate. More specifically, certain socio-economic characteristics, based on questionnaire data, are analysed using discrete choice models in order to estimate the prospective family-size desires. In this respect, a birth-rate choice model is derived through the assessment of the expected number of children to be born in a household during a specific time period and with regard to its socio-economic identity. Moreover, modifications of the above characteristics generate alternative family-size scenarios and thus differing population forecasts, which in turn can lead to unforeseen solution strategies and thus a more sophisticated and pragmatic decision-making process when dealing with facility-location problems both in the public and the private sector.Locational Planning; Discrete Choice models; Population Projections; Greece

    Land use and mobility

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    This paper analyses the effects of land use characteristics on mode choice and carownership. The study is based on a large sample of individuals from the National TravelSurvey of Great Britain for the years 1989-91 and 1999-2001. Land use characteristics aredefined as population density, size of the municipality, accessibility to public transport andlocal amenities, such as shops and services. Mode choice (shares of total travel by car,public transport and walking) and car ownership are modelled using multinomial andbinomial logit models respectively, which include a large number of socio-economicfactors (income, age, gender, household structure and employment status) as well as landuse indicators. The estimation results strongly support the importance of the land usefactors considered on mode choice and car ownership

    Variable population welfare and poverty orderings satisfying replication properties

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    We discuss and compare the variable population axioms of Critical Level (CL) and Population Replication Invariance (PRI) introduced in the economic and philosophical literature for evaluating distributions with different population size. We provide a common framework for analyzing these competing views considering a strengthening of the Population Replication Principle (PRP) based on Dalton's (1920) "principle of proportionate additions to persons" that requires an ordering defined over populations of the same size to be invariant w.r.t. replication of the distributions. The strong version of PRP extends the invariance condition to hold also when distributions of different population size are compared. We suggest ethically meaningful general specifications of the invariance requirement underlying the Strong PRP and characterize the associated classes of parameterized evaluation functions that include CL principles and PRI properties. Moreover, we identify a general class of evaluation functions satisfying the Strong PRP: the social evaluation ordering will be represented by the simple formula considering the product of the population size times a strictly monotonic function of the Equally Distributed Equivalent Income (EDEI). Interesting ethical properties are shown to be associated with the shape of the function transforming the EDEI. Implications for poverty measurement are investigated.Variable Population Social Choice, Population Replication, Welfare Measurement, Poverty Measurement.

    Nash and Wardrop equilibria in aggregative games with coupling constraints

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    We consider the framework of aggregative games, in which the cost function of each agent depends on his own strategy and on the average population strategy. As first contribution, we investigate the relations between the concepts of Nash and Wardrop equilibrium. By exploiting a characterization of the two equilibria as solutions of variational inequalities, we bound their distance with a decreasing function of the population size. As second contribution, we propose two decentralized algorithms that converge to such equilibria and are capable of coping with constraints coupling the strategies of different agents. Finally, we study the applications of charging of electric vehicles and of route choice on a road network.Comment: IEEE Trans. on Automatic Control (Accepted without changes). The first three authors contributed equall
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