4,205 research outputs found

    Adaptive multimodal continuous ant colony optimization

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    Seeking multiple optima simultaneously, which multimodal optimization aims at, has attracted increasing attention but remains challenging. Taking advantage of ant colony optimization algorithms in preserving high diversity, this paper intends to extend ant colony optimization algorithms to deal with multimodal optimization. First, combined with current niching methods, an adaptive multimodal continuous ant colony optimization algorithm is introduced. In this algorithm, an adaptive parameter adjustment is developed, which takes the difference among niches into consideration. Second, to accelerate convergence, a differential evolution mutation operator is alternatively utilized to build base vectors for ants to construct new solutions. Then, to enhance the exploitation, a local search scheme based on Gaussian distribution is self-adaptively performed around the seeds of niches. Together, the proposed algorithm affords a good balance between exploration and exploitation. Extensive experiments on 20 widely used benchmark multimodal functions are conducted to investigate the influence of each algorithmic component and results are compared with several state-of-the-art multimodal algorithms and winners of competitions on multimodal optimization. These comparisons demonstrate the competitive efficiency and effectiveness of the proposed algorithm, especially in dealing with complex problems with high numbers of local optima

    A prescription of methodological guidelines for comparing bio-inspired optimization algorithms

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    Bio-inspired optimization (including Evolutionary Computation and Swarm Intelligence) is a growing research topic with many competitive bio-inspired algorithms being proposed every year. In such an active area, preparing a successful proposal of a new bio-inspired algorithm is not an easy task. Given the maturity of this research field, proposing a new optimization technique with innovative elements is no longer enough. Apart from the novelty, results reported by the authors should be proven to achieve a significant advance over previous outcomes from the state of the art. Unfortunately, not all new proposals deal with this requirement properly. Some of them fail to select appropriate benchmarks or reference algorithms to compare with. In other cases, the validation process carried out is not defined in a principled way (or is even not done at all). Consequently, the significance of the results presented in such studies cannot be guaranteed. In this work we review several recommendations in the literature and propose methodological guidelines to prepare a successful proposal, taking all these issues into account. We expect these guidelines to be useful not only for authors, but also for reviewers and editors along their assessment of new contributions to the field.This work was supported by grants from the Spanish Ministry of Science (TIN2016-8113-R, TIN2017-89517-P and TIN2017-83132-C2- 2-R) and Universidad Politécnica de Madrid (PINV-18-XEOGHQ-19- 4QTEBP). Eneko Osaba and Javier Del Ser-would also like to thank the Basque Government for its funding support through the ELKARTEK and EMAITEK programs. Javier Del Ser-receives funding support from the Consolidated Research Group MATHMODE (IT1294-19) granted by the Department of Education of the Basque Government

    Managament in a New and Experimentally Organized Economy

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    The parallel development of management theory and practice over three phases of economic development is surveyed; (1) the pre-oil crisis experience 1969-1975, (2) the post oil crisis sobering up through most of the 1990s and (3) the emergence of new global production organizations , blurring the notion of the firm to be managed. The external market circumstances of each period dictate different structures of business operations ; (a) a steady state and predictable environment, (b) crisis, inflation and disorderly markets and (c) new technology supporting a globally distributed production organization. As a consequence structural learning between the periods has been of limited value and often outright misleading. The influence of management theory on management practice and its origin in the received economic equilibrium model are discussed, and an alternative management theory based on the theory of the Experimentally Organized Economy (EOE) presented. The increased rate of failure among large firms is related to the increasing complexity of business decisions in globally distributed production and the decreased reliability of learning . It is concluded that successful management practice develops through experimentation in markets and that the best management education has been a varied career in many lines of business and in several companies.Competence bloc theory; Experimentally Organized Economy (EOE); Management theory; WAD theory; Firm Dynamics; Learning

    Measuring the Efficiency of an FCC Spectrum Auction

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    FCC spectrum auctions sell licenses to provide mobile phone service in designated geographic territories. We propose a method to structurally estimate the deterministic component of bidder valuations and apply it to the 1995–1996 C-block auction. We base our estimation of bidder values on a pairwise stability condition, which implies that two bidders cannot exchange licenses in a way that increases total surplus. Pairwise stability holds in many theoretical models of simultaneous ascending auctions, including some models of intimidatory collusion and demand reduction. Pairwise stability is also approximately satisfied in data that we examine from economic experiments. The lack of post-auction resale also suggests pairwise stability. Using our estimates of deterministic valuations, we measure the allocative efficiency of the C-block outcome.

    Economics of irrigation water management : a literature survey with focus on partial and general equilibrium models

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    Water policy is an important topic on the agenda of the international community, and efficiency and equity in the allocation of water have emerged as important factors to be considered. Water pricing can be used to mitigate both the quantity and quality dimensions of water scarcity. This paper reviews partial equilibrium models and general equilibrium models that are relevant to irrigation water management issues. The most widely discussed issues in these models are water markets and water pricing. The interrelationships between economic, cultural, social, and political aspects that are related to water policy make it difficult to provide a comprehensive policy analysis. General equilibrium models of irrigation water management allow incorporation of both the irrigation sector and the other sectors in the economy and analysis of policies affecting each of them and the interaction between them. In addition to being able to address sector and household specifications, production factors, time horizon, pricing policies, and institutions such as water markets, general equilibrium models allow the analysis of the impact of water policies on equity and poverty alleviation. The authors conclude that, although there has been a significant increase in efforts to analyzewater related problems, analytical and empirical research in the field is still deficient and more effort is needed to address them.Environmental Economics&Policies,Water Supply and Sanitation Governance and Institutions,Town Water Supply and Sanitation,Water Supply and Systems,Water Conservation
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