3,215 research outputs found

    Power-law behavior and condensation phenomena in disordered urn models

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    We investigate equilibrium statistical properties of urn models with disorder. Two urn models are proposed; one belongs to the Ehrenfest class, and the other corresponds to the Monkey class. These models are introduced from the view point of the power-law behavior and randomness; it is clarified that quenched random parameters play an important role in generating power-law behavior. We evaluate the occupation probability P(k)P(k) with which an urn has kk balls by using the concept of statistical physics of disordered systems. In the disordered urn model belonging to the Monkey class, we find that above critical density ρc\rho_\mathrm{c} for a given temperature, condensation phenomenon occurs and the occupation probability changes its scaling behavior from an exponential-law to a heavy tailed power-law in large kk regime. We also discuss an interpretation of our results for explaining of macro-economy, in particular, emergence of wealth differentials.Comment: 16pages, 9figures, using iopart.cls, 2 new figures were adde

    Migration of Nurses in the EU, the UK, and Japan : Regulatory Bodies and Push-Pull Factors in the International Mobility of Skilled Practitioners

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    This paper examines the regulatory characteristics of the EU, the UK, and Japan concerning the accepting of nurses from overseas, by focusing on the interests of regulatory bodies and policies to promote or mitigate the impact of push-pull factors on the inflow of nurses. These cases show that verifying qualifications, assessing language skills, and admitting work permits are important, instant, and effective measures through which regulatory bodies can promote or mitigate the impact of push-pull factors on the inflow of nurses into their territories. The EU and the UK studies revealed that further research is required concerning the discrimination which is prohibited under EU law. Compared to Europe, Japan's Economic Partnership Agreement (EPA) is a full-course regulatory arrangement that covers issues ranging from quantitative restriction, refusal of mutual recognition, refusal of verification of qualification valid in other countries, and language proficiency to work permit, due to ambivalent interests in a single regulatory framework.migration of nurses, the EU, the UK, Japan's EPA, regulatory bodies

    Infinite-range transverse field Ising models and quantum computation

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    We present a brief review on information processing, computing and inference via quantum fluctuation, and clarify the relationship between the probabilistic information processing and theory of quantum spin glasses through the analysis of the infinite-range model. We also argue several issues to be solved for the future direction in the research field.Comment: 13 pages, 6 figures, using svjour.cls, to appear in EPJ-Special Topic

    The European Community's Power in the Financing for Development Initiatives

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    In order to examine the nature of the power that the EC wields, this paper focuses specifically on its productive power. This paper examines whether and, if so, to what extent, the EC contributed to the financing for development by identifying the problems, formulating solutions, and persuading others to accept these solutions. The process through which the financing for development initiatives decides upon relevant issues and how the EC engages with these issues makes it clear that the EC should not be regarded as a genuine productive power because it was not the sole trigger that prompted the definition of problems or the formulation of solutions. Nonetheless, it should be regarded as a significantly influential driving force in the financing for development, in terms of its contribution to defining problems and formulating solutions. The EC's role in encouraging commitment to the financing for development initiative and persuading others to accept this commitment shows that the EC can be regarded as an entity wielding some form of productive power. However, further study is required to understand the extent to which the EC can really influence the behaviors of states. This study also reveals that the EC can execute productive power only when permitted or delegated to do so by other bodies and its member states. These facts, which are exhibited in this paper, help clarify the context in which international organizations execute power.The EC, financing for development, power of international organizations, productive power

    Waiting time analysis of foreign currency exchange rates: Beyond the renewal-reward theorem

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    We evaluate the average waiting time between observing the price of financial markets and the next price change, especially in an on-line foreign exchange trading service for individual customers via the internet. Basic technical idea of our present work is dependent on the so-called renewal-reward theorem. Assuming that stochastic processes of the market price changes could be regarded as a renewal process, we use the theorem to calculate the average waiting time of the process. In the conventional derivation of the theorem, it is apparently hard to evaluate the higher order moments of the waiting time. To overcome this type of difficulties, we attempt to derive the waiting time distribution Omega(s) directly for arbitrary time interval distribution (first passage time distribution) of the stochastic process P_{W}(tau) and observation time distribution P_{O}(t) of customers. Our analysis enables us to evaluate not only the first moment (the average waiting time) but also any order of the higher moments of the waiting time. Moreover, in our formalism, it is possible to model the observation of the price on the internet by the customers in terms of the observation time distribution P_{O}(t). We apply our analysis to the stochastic process of the on-line foreign exchange rate for individual customers from the Sony bank and compare the moments with the empirical data analysis.Comment: 8pages, 11figures, using IEEEtran.cl