5,160 research outputs found

    Judgment and Choice in Personnel Selection

    Get PDF
    [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

    Get PDF
    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

    Full text link
    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

    Full text link
    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

    Full text link
    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)

    Get PDF
    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

    Generalized Complex Spherical Harmonics, Frame Functions, and Gleason Theorem

    Full text link
    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\'

    A subalgebra of the Hardy algebra relevant in control theory and its algebraic-analytic properties

    Full text link
    We denote by A_0+AP_+ the Banach algebra of all complex-valued functions f defined in the closed right half plane, such that f is the sum of a holomorphic function vanishing at infinity and a ``causal'' almost periodic function. We give a complete description of the maximum ideal space M(A_0+AP_+) of A_0+AP_+. Using this description, we also establish the following results: (1) The corona theorem for A_0+AP_+. (2) M(A_0+AP_+) is contractible (which implies that A_0+AP_+ is a projective free ring). (3) A_0+AP_+ is not a GCD domain. (4) A_0+AP_+ is not a pre-Bezout domain. (5) A_0+AP_+ is not a coherent ring. The study of the above algebraic-anlaytic properties is motivated by applications in the frequency domain approach to linear control theory, where they play an important role in the stabilization problem.Comment: 17 page

    Adjointness Relations as a Criterion for Choosing an Inner Product

    Full text link
    This is a contribution to the forthcoming book "Canonical Gravity: {}From Classical to Quantum" edited by J. Ehlers and H. Friedrich. Ashtekar's criterion for choosing an inner product in the quantisation of constrained systems is discussed. An erroneous claim in a previous paper is corrected and a cautionary example is presented.Comment: 6 pages, MPA-AR-94-

    Optimal transfer of an unknown state via a bipartite operation

    Full text link
    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
    corecore