3,263 research outputs found

    Book Review: governance in pacific Asia: political economy and development from Japan to Burma

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    In his latest book, Peter Ferdinand discusses the increasing economic integration of the Pacific Asian region as well as its impact on global affairs. Kent Deng is impressed by the breadth of the book’s coverage and the way it rethinks the once narrowly conceived boundaries of Asia

    Merits and Qualms of Work Fluctuations in Classical Fluctuation Theorems

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    Work is one of the most basic notion in statistical mechanics, with work fluctuation theorems being one central topic in nanoscale thermodynamics. With Hamiltonian chaos commonly thought to provide a foundation for classical statistical mechanics, here we present general salient results regarding how (classical) Hamiltonian chaos generically impacts on nonequilibrium work fluctuations. For isolated chaotic systems prepared with a microcanonical distribution, work fluctuations are minimized and vanish altogether in adiabatic work protocols. For isolated chaotic systems prepared at an initial canonical distribution at inverse temperature β\beta, work fluctuations depicted by the variance of eβWe^{-\beta W} are also minimized by adiabatic work protocols. This general result indicates that if the variance of eβWe^{-\beta W} diverges for an adiabatic work protocol, then it diverges for all nonadiabatic work protocols sharing the same initial and final Hamiltonians. How such divergence explicitly impacts on the efficiency of using the Jarzynski's equality to simulate free energy differences is studied in a Sinai model. Our general insights shall boost studies in nanoscale thermodynamics and are of fundamental importance in designing useful work protocols.Comment: 11 pages, 5 figures, close to published versio

    Deformed Jarzynski Equality

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    The well-known Jarzynski equality, often written in the form eβΔF=eβWe^{-\beta\Delta F}=\langle e^{-\beta W}\rangle, provides a non-equilibrium means to measure the free energy difference ΔF\Delta F of a system at the same inverse temperature β\beta based on an ensemble average of non-equilibrium work WW. The accuracy of Jarzynski's measurement scheme was known to be determined by the variance of exponential work, denoted as var(eβW){\rm var}\left(e^{-\beta W}\right). However, it was recently found that var(eβW){\rm var}\left(e^{-\beta W}\right) can systematically diverge in both classical and quantum cases. Such divergence will necessarily pose a challenge in the applications of Jarzynski equality because it may dramatically reduce the efficiency in determining ΔF\Delta F. In this work, we present a deformed Jarzynski equality for both classical and quantum non-equilibrium statistics, in efforts to reuse experimental data that already suffers from a diverging var(eβW){\rm var}\left(e^{-\beta W}\right). The main feature of our deformed Jarzynski equality is that it connects free energies at different temperatures and it may still work efficiently subject to a diverging var(eβW){\rm var}\left(e^{-\beta W}\right). The conditions for applying our deformed Jarzynski equality may be met in experimental and computational situations. If so, then there is no need to redesign experimental or simulation methods. Furthermore, using the deformed Jarzynski equality, we exemplify the distinct behaviors of classical and quantum work fluctuations for the case of a time-dependent driven harmonic oscillator dynamics and provide insights into the essential performance differences between classical and quantum Jarzynski equalities.Comment: 24 pages, 1 figure, accepted version to appear in Entropy (Special Issue on "Quantum Thermodynamics"

    A ripple reduction method for a two stages battery charger with multi-winding transformer using notch filter

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    This paper presents a two-stage battery charger consisting of a bridgeless Totem-pole power factor correction (TP-PFC) circuit and a full bridge converter with a multi-winding transformer. By using this transformer the cell equalizing operation can be achieved with no additional circuitry. In addition, a double-line frequency ripple reduction method is proposed to address the low frequency current ripples issues existing in both primary and secondary winding of the transformer which is caused by the voltage ripples across the intermediate DC link bus. Control and analysis of the converter at different operation modes is illustrated in detail and simulation results validate the effectiveness of the proposed converter and control algorithm

    DISCRETE AND CONTINUOUS TIME MODELS FOR FARM CREDIT MIGRATION ANALYSIS

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    This paper introduces two continuous time models, i.e. time homogenous and non-homogenous Markov chain models, for analyzing farm credit migration as alternatives to the traditional discrete time model cohort method. Results illustrate that the two continuous time models provide more detailed, accurate and reliable estimates of farm credit migration rates than the discrete time model. Metric comparisons among the three transition matrices show that the imposition of the potentially unrealistic assumption of time homogeneity still produces more accurate estimates of farm credit migration rates, although the equally reliable figures under the non-homogenous time model seem more plausible given the greater relevance and applicability of the latter model to farm business conditions.Agricultural Finance,

    REMOTE HEALTH MONITORING: FALL DETECTION

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    Falling is a serious health issue among the elderly population; it can result in critical injuries like hip fractures. Immobilization caused by injury or unconsciousness means that the victim cannot summon help themselves. With elderly who live alone, not being found for hours after a fall is quite common and drastically increases the significance of fall-induced injuries. With an aging Baby Boomer population, the incidence of falls will only rise in the next few decades. The objective of this paper is to design and create a fall detection system. The system consists of a monitoring device that links wirelessly with a laptop. The device is able to accurately distinguish between fall and non-fall

    Applying RDA to digital resources metadata

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    This presentation will describe how Resource Description and Access (RDA) has been applied in cataloging, updating, and migrating digital resources at the University of Central Florida Libraries. Presenters will explain the similarities and differences of using RDA to catalog traditional serials in an Integrated Library System (ILS) and digitized serials and serial analytics in a Content Management System (CMS). Examples will be used to illustrate the issues of using RDA in conjunction with other metadata standards such as Dublin Core (DC) and Metadata Object Description Schema (MODS) to catalog digital resources including digitized newspapers and monographs, such as: relating RDA core elements to the DC and MODS fields; treating analytical description; transcribing newspaper information; applying roles and vocabularies as specified in RDA; exhibiting work, expression, and manifestation relationship; and describing designator relationships. It will also address the typical changes made to convert old records to RDA in migrating them to new systems. This session will help catalogers and metadata librarians react to the changing cataloging rules and apply them in their daily work

    Metadata Guide for STARS

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