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31.
We show that the tenure lengths for managers of sport teams follow a power law distribution with an exponent between 2 and 3. We develop a simple theoretical model which replicates this result. The model demonstrates that the empirical phenomenon can be understood as the macroscopic outcome of pairwise interactions among managers in a league, threshold effects in managerial performance evaluation, competitive market forces, and luck at the microscopic level. 相似文献
32.
D. Fong J. H. Hamilton A. V. Ramayya J. K. Hwang C. Goodin K. Li J. Kormicki J. O. Rasmussen Y. X. Luo S. C. Wu I. Y. Lee A. V. Daniel G. M. Ter-Akopian G. S. Popeko A. S. Fomichev A. M. Rodin Yu. Ts. Oganessian M. Jandel J. Kliman L. Krupa J. D. Cole M. A. Stoyer R. Donangelo W. C. Ma 《Physics of Atomic Nuclei》2006,69(7):1161-1167
The hot bimodal fission of 252Cf is reexamined with new high-statistics data. We constructed a γ-γ-γ coincidence cube for binary fission and LCP-gated γ-γ matrix for ternary fission. By identifying the secondary fission fragments from their γ-ray transitions, we measured the yields for various fission splits. The normal neutron yield distribution is found to be
Gaussian for Xe-Ru. However, the binary fission split of Ba-Mo is found to exhibit a bimodal neutron distribution with the
“hot mode” corresponding to ≈3.1% of the total yield. In α ternary fission, the first measurements of yields for specific fission splits are presented. The Te-α-Ru and Xe-α-Mo neutron yields fit well with a single mode, but the Ba-α-Zr split shows evidence for an enhanced hot mode with an intensity of ≈13.8% of the normal mode.
The text was submitted by the authors in English. 相似文献
33.
The European Physical Journal C - The CMS experiment&;nbsp;[1] uses a general purpose detector designed for detecting the diverse signatures associated with Higgs production and new physics... 相似文献
34.
We prove a Tauberian theorem for Walsh series of two variables, and use it to obtain several results about uniqueness of Cesàro summable double Walsh series. Namely, we show that up to sets of measure zero, Cesàro summability of double Walsh series is the same as convergence of the square dyadic partial sums and, under a suitable growth condition, that uniqueness holds for Cesàro summable double Walsh series. 相似文献
35.
Rafał Bocian Thorsten Holm Andrzej Skowroński 《Central European Journal of Mathematics》2004,2(1):67-75
Auslander’s representation dimension measures how far a finite dimensional algebra is away from being of finite representation
type. In [1], M. Auslander proved that a finite dimensional algebra A is of finite representation type if and only if the representation dimension of A is at most 2. Recently, R. Rouquier proved that there are finite dimensional algebras of an arbitrarily large finite representation
dimension. One of the exciting open problems is to show that all finite dimensional algebras of tame representation type have
representation dimension at most 3. We prove that this is true for all domestic weakly symmetric algebras over algebraically
closed fields having simply connected Galois coverings. 相似文献
36.
Let G be a set of n points in general
position (i.e., no three points are on a line)
in the plane, and let C be a caterpillar on n vertices.
We show that one can always find a rectilinear embedding of C in the plane
such that the vertices of C are the points of G and no two edges of C
go to parallel segments. This proves a conjecture of
Robert E. Jamison. 相似文献
37.
We consider noncommutative line bundles associated with the Hopf fibrations of SUq(2) over all Podle? spheres and with a locally trivial Hopf fibration of S3pq. These bundles are given as finitely generated projective modules associated via 1-dimensional representations of U(1) with Galois-type extensions encoding the principal fibrations of SUq(2) and S3pq. We show that the Chern numbers of these modules coincide with the winding numbers of representations defining them. To cite this article: P.M. Hajac et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003). 相似文献
38.
A robust and efficient adaptive reweighted estimator of multivariate location and scatter 总被引:1,自引:0,他引:1
Daniel Gervini 《Journal of multivariate analysis》2003,84(1):116-144
This article proposes a reweighted estimator of multivariate location and scatter, with weights adaptively computed from the data. Its breakdown point and asymptotic behavior under elliptical distributions are established. This adaptive estimator is able to attain simultaneously the maximum possible breakdown point for affine equivariant estimators and full asymptotic efficiency at the multivariate normal distribution. For the special case of hard-rejection weights and the MCD as initial estimator, it is shown to be more efficient than its non-adaptive counterpart for a broad range of heavy-tailed elliptical distributions. A Monte Carlo study shows that the adaptive estimator is as robust as its non-adaptive relative for several types of bias-inducing contaminations, while it is remarkably more efficient under normality for sample sizes as small as 200. 相似文献
39.
The existence of a Nash equilibrium in the undiscounted repeated two-person game of incomplete information on one side is
established. The proof depends on a new topological result resembling in some respect the Borsuk-Ulam theorem. 相似文献
40.
We derive the incompressible and compressible k–ε model for locally homogeneous turbulence. The model is rigorously derived on formal mathematical grounds using the MPP modelling technique. This lets us calculate by either analytical or numerical means the closure constants of the model. To cite this article: T. Chacón Rebollo, D. Franco Coronil, C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献