27,304 research outputs found

    Finite Form of the Quintuple Product Identity

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    The celebrated quintuple product identity follows surprisingly from an almost-trivial algebraic identity, which is the limiting case of the terminating q-Dixon formula.Comment: 1 pag

    Pilot interaction with automated airborne decision making systems

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    An investigation was made of interaction between a human pilot and automated on-board decision making systems. Research was initiated on the topic of pilot problem solving in automated and semi-automated flight management systems and attempts were made to develop a model of human decision making in a multi-task situation. A study was made of allocation of responsibility between human and computer, and discussed were various pilot performance parameters with varying degrees of automation. Optimal allocation of responsibility between human and computer was considered and some theoretical results found in the literature were presented. The pilot as a problem solver was discussed. Finally the design of displays, controls, procedures, and computer aids for problem solving tasks in automated and semi-automated systems was considered

    Electric Vehicle Charging Station Placement: Formulation, Complexity, and Solutions

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    To enhance environmental sustainability, many countries will electrify their transportation systems in their future smart city plans. So the number of electric vehicles (EVs) running in a city will grow significantly. There are many ways to re-charge EVs' batteries and charging stations will be considered as the main source of energy. The locations of charging stations are critical; they should not only be pervasive enough such that an EV anywhere can easily access a charging station within its driving range, but also widely spread so that EVs can cruise around the whole city upon being re-charged. Based on these new perspectives, we formulate the Electric Vehicle Charging Station Placement Problem (EVCSPP) in this paper. We prove that the problem is non-deterministic polynomial-time hard. We also propose four solution methods to tackle EVCSPP and evaluate their performance on various artificial and practical cases. As verified by the simulation results, the methods have their own characteristics and they are suitable for different situations depending on the requirements for solution quality, algorithmic efficiency, problem size, nature of the algorithm, and existence of system prerequisite.Comment: Submitted to IEEE Transactions on Smart Grid, revise

    Photoemission Spectroscopy of Magnetic and Non-magnetic Impurities on the Surface of the Bi2_2Se3_3 Topological Insulator

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    Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses back-scattering and protects the coherence of these states in the presence of non-magnetic scatterers. In contrast, magnetic scatterers should open the back- scattering channel via the spin-flip processes and degrade the state's coherence. We present angle-resolved photoemission spectroscopy studies of the electronic structure and the scattering rates upon adsorption of various magnetic and non-magnetic impurities on the surface of Bi2_2Se3_3, a model topological insulator. We reveal a remarkable insensitivity of the topological surface state to both non-magnetic and magnetic impurities in the low impurity concentration regime. Scattering channels open up with the emergence of hexagonal warping in the high-doping regime, irrespective of the impurity's magnetic moment.Comment: 5 pages, 4 figure

    Transmission of Sex Preferences Across Generations: The Allocation of Educational Resources Among Siblings

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    The purpose of this paper is to test whether there is an intergenerational transmission of gender preferences in educational resource allocation among children. The unique data set of Taiwan’s Panel Study of Family Dynamics project provides us a rich 3-generation education information and allows us to probe into this question. We performed our analysis along two directions: the first is to see whether the society as a whole has any macro change in gender-specific education achievement, and the second is to see whether there is any within-lineage transmission of gender preferences across generations. After carefully reviewing the education system and societal characteristics in Taiwan, we set up an empirical model to estimate and test the hypotheses of intergenerational transmission of gender preferences. We also perform various statistical analyses to support our findings, e.g. contraposition of a proposition. As far as the macro pattern is concerned, we found that although there is a clear tendency of differential treatment against females in the old generation, this tendency is significantly weakened and nearly vanishes in the young generation. Furthermore, the supporting effect of senior siblings in the old generation becomes a crowding (resource-dilution) effect in the young generation. However, within each micro lineage, there is a mild “habitus” effect in gender-specific educational resource allocation in the sense that parents who had the experience of gender-specific differential treatment tend to treat their children in a similar fashion. Moreover, this mild habitus effect is stronger for female respondents (who were the deprived group) than for male respondents (who were the privileged group).
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