105 resultados para Roger Holland
Resumo:
Internet gambling presents substantial new challenges to governments and regulatory agencies. Existing approaches to betting, lotteries and gaming are limited by the nature of Internet technology, and the international nature of the activity. Particular aspects of Internet gambling are considered, and the conclusion is reached that prohibition is an ineffectual alternative, and that licensing of gambling services providers is the appropriate approach. Copyright © 2001 John Wiley & Sons, Ltd.
Resumo:
Despite apparent overwhelming benefits, implementation of the Household Responsibility System (HRS) in China contained a number of flaws. The Two-Farmland System (TFS), which originated in Pingdu City in Shandong Province, sought to address the twin problems of land fragmentation and economies of size. A stochastic frontier production function analysis that isolates the impacts of land allocation reforms suggests that the TFS increased efficiency by around 7%. This article highlights the need for empirical analysis to assess objectively the merits or otherwise of particular reforms. (C) 2002 Elsevier Science Inc. All rights reserved.
Resumo:
We show that stochastic electrodynamics and quantum mechanics give quantitatively different predictions for the quantum nondemolition (QND) correlations in travelling wave second harmonic generation. Using phase space methods and stochastic integration, we calculate correlations in both the positive-P and truncated Wigner representations, the latter being equivalent to the semi-classical theory of stochastic electrodynamics. We show that the semiclassical results are different in the regions where the system performs best in relation to the QND criteria, and that they significantly overestimate the performance in these regions. (C) 2001 Published by Elsevier Science B.V.
Resumo:
Under certain circumstances, external stimuli will elicit an involuntary shift of spatial attention, referred to as attentional capture. According to the contingent involuntary orienting account (Folk, Remington, & Johnston, 1992), capture is conditioned by top-down factors that set attention to respond involuntarily to stimulus properties relevant to one's behavioral goals. Evidence for this comes from spatial cuing studies showing that a spatial cuing effect is observed only when cues have goal-relevant properties. Here, we examine alternative, decision-level explanations of the spatial cuing effect that attribute evidence of capture to postpresentation delays in the voluntary allocation of attention, rather than to on-line involuntary shifts in direct response to the cue. In three spatial cuing experiments, delayed-allocation accounts were tested by examining whether items at the cued location were preferentially processed. The experiments provide evidence that costs and benefits in spatial cuing experiments do reflect the on-line capture of attention. The implications of these results for models of attentional control are discussed.
Resumo:
By exhibiting a violation of a novel form of the Bell-CHSH inequality, Żukowski has recently established that the quantum correlations exploited in the standard perfect teleportation protocol cannot be recovered by any local hidden variables model. In the case of imperfect teleportation, we show that a violation of a generalized form of Żukowski's teleportation inequality can only occur if the channel state, considered by itself, already violates a Bell-CHSH inequality. On the other hand, the fact that the channel state violates a Bell-CHSH inequality is not sufficient to imply a violation of Żukowski's teleportation inequality (or any of its generalizations). The implication does hold, however, if the fidelity of the teleportation exceeds ≈ 0.90. © 2001 Elsevier Science B.V. All rights reserved.
Resumo:
This note gives a theory of state transition matrices for linear systems of fuzzy differential equations. This is used to give a fuzzy version of the classical variation of constants formula. A simple example of a time-independent control system is used to illustrate the methods. While similar problems to the crisp case arise for time-dependent systems, in time-independent cases the calculations are elementary solutions of eigenvalue-eigenvector problems. In particular, for nonnegative or nonpositive matrices, the problems at each level set, can easily be solved in MATLAB to give the level sets of the fuzzy solution. (C) 2002 Elsevier Science B.V. All rights reserved.
Resumo:
We introduce an integrable model for two coupled BCS systems through a solution of the Yang-Baxter equation associated with the Lie algebra su(4). By employing the algebraic Bethe ansatz, we determine the exact solution for the energy spectrum. An asymptotic analysis is conducted to determine the leading terms in the ground state energy, the gap and some one point correlation functions at zero temperature. (C) 2002 Published by Elsevier Science B.V.