3,755 research outputs found

    Judgment and Choice in Personnel Selection

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    [Excerpt] Imagine that you have set out to buy a used car. You examine eight cars before making your choice, test driving some of them and rejecting others at first glance (due for example to excessive rust). A researcher asks you to rate each of the eight cars in terms of overall quality. The researcher proceeds to sharply criticize you for carrying out an unsystematic search process. Your failure to test-drive every car and to ask the same questions to the dealers about each car has caused you to do a poor job of rank-ordering the cars. You respond that, since you could only afford one car, you had no interest in rank-ordering or in assigning ratings to the entire set of cars. It seems unfair to be criticized for poor performance of a task which was unrelated to your original mission of buying the best used car available. This paper explores the possibility that a similar misspecification of the goals of employee selection has caused researchers to criticize selectors for behavior which may not adversely affect the goal of hiring the best individual from among a group of candidates

    Preference Reversals in Personnel Selection

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    Preference reversals, in which one alternative is preferred in a choice task while another alternative is preferred in a judgment task, may occur in personnel selection. If so, the candidate who is assigned the highest predictor score may not be the candidate the selector would have chosen. Previous research does not clearly indicate the rate of preference reversals that are likely to occur in personnel selection. A simulated selection task carried out by 157 managers revealed near-zero levels of preference reversals. Implications for decision theory and personnel selection research are discussed

    Brownian semistationary processes and conditional full support

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    In this note, we study the infinite-dimensional conditional laws of Brownian semistationary processes. Motivated by the fact that these processes are typically not semimartingales, we present sufficient conditions ensuring that a Brownian semistationary process has conditional full support, a property introduced by Guasoni, R\'asonyi, and Schachermayer [Ann. Appl. Probab., 18 (2008) pp. 491--520]. By the results of Guasoni, R\'asonyi, and Schachermayer, this property has two important implications. It ensures, firstly, that the process admits no free lunches under proportional transaction costs, and secondly, that it can be approximated pathwise (in the sup norm) by semimartingales that admit equivalent martingale measures.Comment: 7 page

    Operator ordering and Classical soliton path in Two-dimensional N=2 supersymmetry with Kahler potential

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    We investigate a 2-dimensional N=2 supersymmetric model which consists of n chiral superfields with Kahler potential. When we define quantum observables, we are always plagued by operator ordering problem. Among various ways to fix the operator order, we rely upon the supersymmetry. We demonstrate that the correct operator order is given by requiring the super Poincare algebra by carrying out the canonical Dirac bracket quantization. This is shown to be also true when the supersymmetry algebra has a central extension by the presence of topological soliton. It is also shown that the path of soliton is a straight line in the complex plane of superpotential W and triangular mass inequality holds. And a half of supersymmetry is broken by the presence of soliton.Comment: 13 pages, typos correcte

    Fundamental Limits on the Speed of Evolution of Quantum States

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    This paper reports on some new inequalities of Margolus-Levitin-Mandelstam-Tamm-type involving the speed of quantum evolution between two orthogonal pure states. The clear determinant of the qualitative behavior of this time scale is the statistics of the energy spectrum. An often-overlooked correspondence between the real-time behavior of a quantum system and the statistical mechanics of a transformed (imaginary-time) thermodynamic system appears promising as a source of qualitative insights into the quantum dynamics.Comment: 6 pages, 1 eps figur

    Comparison of surface iodination methods by electron microscopic autoradiography applied in vitro to different life-stages of Dipetalonema vitae (Filarioidea)

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    Different stages of Dipetalonema viteae (males, females, microfilariae, and 3rd-stage larvae) have been iodinated in vitro under physiological conditions by chloroglycoluril, lactoperoxidase or chloramine T. The concentrations of the catalysts were correlated with the viability of the worms. Localization of the label with the different iodination methods had been visualized by electron microscopical autoradiography. Chloroglycoluril-mediated iodination is predominantly localized on the filarial cuticle. Lactoperoxidase-catalysed iodination is less specific and chloramine T catalyses iodination in a gradient decreasing from the cuticle to inner structures. It is necessary to visualize the labelling by electron microscopical autoradiography prior to biochemical and immunological experiments to avoid the extraction of structures iodinated by leakage of the catalyst into sub-cuticular region

    Optimal transfer of an unknown state via a bipartite operation

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    A fundamental task in quantum information science is to transfer an unknown state from particle AA to particle BB (often in remote space locations) by using a bipartite quantum operation EAB\mathcal{E}^{AB}. We suggest the power of EAB\mathcal{E}^{AB} for quantum state transfer (QST) to be the maximal average probability of QST over the initial states of particle BB and the identifications of the state vectors between AA and BB. We find the QST power of a bipartite quantum operations satisfies four desired properties between two dd-dimensional Hilbert spaces. When AA and BB are qubits, the analytical expressions of the QST power is given. In particular, we obtain the exact results of the QST power for a general two-qubit unitary transformation.Comment: 6 pages, 1 figur

    Generalized Complex Spherical Harmonics, Frame Functions, and Gleason Theorem

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    Consider a finite dimensional complex Hilbert space \cH, with dim(\cH) \geq 3, define \bS(\cH):= \{x\in \cH \:|\: ||x||=1\}, and let \nu_\cH be the unique regular Borel positive measure invariant under the action of the unitary operators in \cH, with \nu_\cH(\bS(\cH))=1. We prove that if a complex frame function f : \bS(\cH)\to \bC satisfies f \in \cL^2(\bS(\cH), \nu_\cH), then it verifies Gleason's statement: There is a unique linear operator A: \cH \to \cH such that f(u)=f(u) = for every u \in \bS(\cH). AA is Hermitean when ff is real. No boundedness requirement is thus assumed on ff {\em a priori}.Comment: 9 pages, Accepted for publication in Ann. H. Poincar\'

    Power of unentangled measurements on two antiparallel spins

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    We consider a pair of antiparallel spins polarized in a random direction to encode quantum information. We wish to extract as much information as possible on the polarization direction attainable by an unentangled measurement, i.e., by a measurement, whose outcomes are associated with product states. We develop analytically the upper bound 0.7935 bits to the Shannon mutual information obtainable by an unentangled measurement, which is definitely less than the value 0.8664 bits attained by an entangled measurement. This proves our main result, that not every ensemble of product states can be optimally distinguished by an unentangled measurement, if the measure of distinguishability is defined in the sense of Shannon. We also present results from numerical calculations and discuss briefly the case of parallel spins.Comment: Latex file, 18 pages, 1 figure; published versio

    On the support of the Ashtekar-Lewandowski measure

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    We show that the Ashtekar-Isham extension of the classical configuration space of Yang-Mills theories (i.e. the moduli space of connections) is (topologically and measure-theoretically) the projective limit of a family of finite dimensional spaces associated with arbitrary finite lattices. These results are then used to prove that the classical configuration space is contained in a zero measure subset of this extension with respect to the diffeomorphism invariant Ashtekar-Lewandowski measure. Much as in scalar field theory, this implies that states in the quantum theory associated with this measure can be realized as functions on the ``extended" configuration space.Comment: 22 pages, Tex, Preprint CGPG-94/3-
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