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Nicky Rogge Richard Simper Marijn Verschelde Maximilian Hall 《European Journal of Operational Research》2015
This paper fills a noticeable gap in the current economic and penology literature by proposing new performance-enhancing policies based on an efficiency analysis of a sample of male prisons in England and Wales over the period 2009/10. In addition, we advance the empirical literature by integrating the managerialism of four strategic functions of prisons, employment and accommodation, capacity utilization, quality of life in prison and the rehabilitation and re-offending of prisoners. We find that by estimating multiple models focussing on these different areas some prisons are more efficient than other establishments. In terms of policy, it is therefore necessary to consider not just an overall performance metric for individual prisons, as currently undertaken annually by the UK Ministry of Justice, but to look into the administration and managerialism of their main functions in both a business and public policy perspective. Indeed, it is further necessary to view prisons together and not as single entities, so as to obtain a best practice frontier for the different operations that management undertakes in English and Welsh prisons. 相似文献
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Saunders has recently claimed that “identical quantum particles” with an anti-symmetric state (fermions) are weakly discernible objects, just like irreflexively related ordinary objects in situations with perfect symmetry (Black’s spheres, for example). Weakly
discernible objects have all their qualitative properties in common but nevertheless differ from each other by virtue of (a
generalized version of) Leibniz’s principle, since they stand in relations an entity cannot have to itself. This notion of
weak discernibility has been criticized as question begging, but we defend and accept it for classical cases likes Black’s
spheres. We argue, however, that the quantum mechanical case is different. Here the application of the notion of weak discernibility
indeed is question begging and in conflict with standard interpretational ideas. We conclude that the introduction of the conceptual
resource of weak discernibility does not change the interpretational status quo in quantum mechanics. 相似文献
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The effective potential for an on-shell BRST invariant gluon-ghost condensate of mass dimension 2 in the Curci-Ferrari gauge in SU(N) Yang-Mills is analysed by combining the local composite operator technique with the algebraic renormalization. We pay attention to the gauge parameter independence of the vacuum energy obtained in the considered framework and discuss the Landau gauge as an interesting special case. 相似文献
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M.A.L. Capri D. Dudal V.E.R. Lemes R.F. Sobreiro S.P. Sorella R. Thibes H. Verschelde 《The European Physical Journal C - Particles and Fields》2007,52(2):459-476
We prove that the nonlocal gauge invariant mass dimension 2 operator Fμν(D2)-1Fμν can be consistently added to the Gribov–Zwanziger action, which implements the restriction of the path integral’s domain
of integration to the first Gribov region when the Landau gauge is considered. We identify a local polynomial action and prove
the renormalizability to all orders of perturbation theory by employing the algebraic renormalization formalism. Furthermore,
we also pay attention to the breaking of the BRST invariance, and to the consequences that this has for the Slavnov–Taylor
identity.
PACS 11.15.-q; 11.15.Tk 相似文献
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A new quantization method for solitons is proposed, which is based on a straightforward application of pathintegral techniques. There is no zero mode problem and the intricacies of the canonical approach (the Dirac theory of constrained systems) are avoided. 相似文献
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Homotopy continuation methods can be applied to compute all finite solutions to a given polynomial system. Computations will be performed more efficiently if the symmetric structure of the system can be exploited. This paper presents the construction of a symmetric homotopy. Using this homotopy, only the paths according to the generating solutions have to be traced during continuation. 相似文献
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It has been shown by Bogdanova and Boukliev [1] that there exist a ternary [38,5,24] code and a ternary [37,5,23] code. But it is unknown whether or not there exist a ternary [39,6,24] code and a ternary [38,6,23] code. The purpose of this paper is to prove that (1) there is no ternary [39,6,24] code and (2) there is no ternary [38,6,23] code using the nonexistence of ternary [39,6,24] codes. Since it is known (cf. Brouwer and Sloane [2] and Hamada and Watamori [14]) that (i) n3(6,23) = 38> or 39 and d3(38,6) = 22 or 23 and (ii) n3(6,24) = 39 or 40 and d3(39,6) = 23 or 24, this implies that n3(6,23) = 39, d3(38,6) = 22, n3(6,24) = 40 and d3(39,6) = 23, where n3<>(k,d) and d<>3(n,k) denote the smallest value of n and the largest value of d, respectively, for which there exists an [n,k,d] code over the Galois field GF(3). 相似文献
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Rolf MP Hofman MB Kuijer JP Pai VM Greiser A van Rossum AC Heethaar RM 《Magnetic resonance imaging》2009,27(3):385-392
Multiecho phase-contrast steady-state free precession (PC-SSFP) is a recently introduced sequence for flow quantification. In this multiecho approach, a phase reference and a velocity-encoded readout were acquired at different echo times after a single excitation. In this study, the sequence is validated in vitro for stationary flow. Subsequently, the sequence was evaluated on cardiac output measurements in vivo for through-plane flow in comparison to regular single gradient echo velocity quantification [phase-contrast spoiled gradient echo (PC-GE)]. In vitro results agreed with regular flow meters (RMS 0.1 cm/s). Cardiac output measurements with multiecho PC-SSFP on 10 healthy subjects gave on average the same results as the standard PC-GE. However, the limits of repeatability of PC-SSFP were significantly larger than those of PC-GE (2 l/min and 0.5 l/min, respectively, P=.001). The multiecho approach introduced some specific problems in vivo. The difference in echo times made the velocity maps sensitive for water-fat shifts and B(0)-drifts, which in turn made velocity offset correction problematic. Also, the addition of a single bipolar gradient cancelled the flow compensated nature of the SSFP sequence. In combination with the prolonged TR, this resulted in flow artifacts caused by high and pulsatile through-plane flow, affecting repeatability. Given the significantly lower repeatability of PC-SSFP, cardiac output in turn is less reliable, thus impairing the use of multiecho PC-SSFP. 相似文献