2,686 research outputs found

    Towards a generalisation of formal concept analysis for data mining purposes

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    In this paper we justify the need for a generalisation of Formal Concept Analysis for the purpose of data mining and begin the synthesis of such theory. For that purpose, we first review semirings and semimodules over semirings as the appropriate objects to use in abstracting the Boolean algebra and the notion of extents and intents, respectively. We later bring to bear powerful theorems developed in the field of linear algebra over idempotent semimodules to try to build a Fundamental Theorem for K-Formal Concept Analysis, where K is a type of idempotent semiring. Finally, we try to put Formal Concept Analysis in new perspective by considering it as a concrete instance of the theory developed

    Ergodic and Nonergodic Anomalous Diffusion in Coupled Stochastic Processes

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    Inspired by problems in biochemical kinetics, we study statistical properties of an overdamped Langevin process whose friction coefficient depends on the state of a similar, unobserved process. Integrating out the latter, we derive the long time behaviour of the mean square displacement. Anomalous diffusion is found. Since the diffusion exponent can not be predicted using a simple scaling argument, anomalous scaling appears as well. We also find that the coupling can lead to ergodic or non-ergodic behaviour of the studied process. We compare our theoretical predictions with numerical simulations and find an excellent agreement. The findings caution against treating biochemical systems coupled with unobserved dynamical degrees of freedom by means of standard, diffusive Langevin descriptions

    FOOD SAFETY INNOVATION IN THE UNITED STATES: EVIDENCE FROM THE MEAT INDUSTRY

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    Recent industry innovations improving the safety of the Nation's meat supply range from new pathogen tests, high-tech equipment, and supply chain management systems, to new surveillance networks. Despite these and other improvements, the market incentives that motivate private firms to invest in innovation seem to be fairly weak. Results from an ERS survey of U.S. meat and poultry slaughter and processing plants and two case studies of innovation in the U.S. beef industry reveal that the industry has developed a number of mechanisms to overcome that weakness and to stimulate investment in food safety innovation. Industry experience suggests that government policy can increase food safety innovation by reducing informational asymmetries and strengthening the ability of innovating firms to appropriate the benefits of their investments.Food safety, innovation, meat, asymmetric information, Beef Steam Pasteurization System, Bacterial Pathogen Sampling and Testing Program, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

    Methods of tropical optimization in rating alternatives based on pairwise comparisons

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    We apply methods of tropical optimization to handle problems of rating alternatives on the basis of the log-Chebyshev approximation of pairwise comparison matrices. We derive a direct solution in a closed form, and investigate the obtained solution when it is not unique. Provided the approximation problem yields a set of score vectors, rather than a unique (up to a constant factor) one, we find those vectors in the set, which least and most differentiate between the alternatives with the highest and lowest scores, and thus can be representative of the entire solution.Comment: 9 pages, presented at the Annual Intern. Conf. of the German Operations Research Society (GOR), Helmut Schmidt University Hamburg, Germany, August 30 - September 2, 201

    Non-Life Insurance Pricing: Multi Agents Model

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    We use the maximum entropy principle for pricing the non-life insurance and recover the B\"{u}hlmann results for the economic premium principle. The concept of economic equilibrium is revised in this respect.Comment: 6 pages, revtex

    Fuzzy hh-ideals of hemirings

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    A characterization of an hh-hemiregular hemiring in terms of a fuzzy hh-ideal is provided. Some properties of prime fuzzy hh-ideals of hh-hemiregular hemirings are investigated. It is proved that a fuzzy subset ζ\zeta of a hemiring SS is a prime fuzzy left (right) hh-ideal of SS if and only if ζ\zeta is two-valued, ζ(0)=1\zeta(0) = 1, and the set of all xx in SS such that ζ(x)=1\zeta(x) = 1 is a prime (left) right hh-ideal of SS. Finally, the similar properties for maximal fuzzy left (right) hh-ideals of hemirings are considered
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