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71.
Dmitry I. Belov Ronald D. Armstrong 《Computational Optimization and Applications》2006,33(2-3):319-332
This paper introduces a novel approach for extracting the maximum number of non-overlapping test forms from a large collection
of overlapping test sections assembled from a given item bank. The approach involves solving maximum set packing problems
(MSPs). A branch-and-bound MSP algorithm is developed along with techniques adapted from constraint programming to estimate
lower and upper bounds on the optimal MSP solution. The algorithm is general and can be applied in other applications including
combinatorial auctions. The results of computer simulations and experiments with an operational item bank are presented.
An erratum to this article is available at . 相似文献
72.
73.
Treschev DV 《Chaos (Woodbury, N.Y.)》1996,6(1):6-14
Exponentially small separatrix splitting for a pendulum with rapidly oscillating suspension point and for the standard Chirikov map is studied by means of a new averaging method, which is a continuous version of the Neishtadt averaging procedure. An asymptotic formula for the rate of the separatrix splitting is obtained. (c) 1996 American Institute of Physics. 相似文献
74.
Dmitry Beliaev Fredrik Johansson Viklund 《Communications in Mathematical Physics》2013,320(2):379-394
Simmons and Cardy recently predicted a formula for the probability that the chordal SLE8/3 path passes to the left of two points in the upper half-plane. In this paper we give a rigorous proof of their formula. Starting from this result, we derive explicit expressions for several natural connectivity functions for SLE8/3 bubbles conditioned to be of macroscopic size. By passing to a limit with such a bubble we construct a certain chordal restriction measure and in this way obtain a proof of a formula for the probability that two given points are between two commuting SLE8/3 paths. The one-point version of this result has been predicted by Gamsa and Cardy. Finally, we derive an integral formula for the second moment of the area of an SLE8/3 bubble conditioned to have radius 1. We evaluate the area integral numerically and relate its value to a hypothesis that the area follows the Airy distribution. 相似文献
75.
Sergey M. Ramodanov Valentin A. Tenenev Dmitry V. Treschev 《Regular and Chaotic Dynamics》2012,17(6):547-558
We study the system of a 2D rigid body moving in an unbounded volume of incompressible, vortex-free perfect fluid which is at rest at infinity. The body is equipped with a gyrostat and a so-called Flettner rotor. Due to the latter the body is subject to a lifting force (Magnus effect). The rotational velocities of the gyrostat and the rotor are assumed to be known functions of time (control inputs). The equations of motion are presented in the form of the Kirchhoff equations. The integrals of motion are given in the case of piecewise continuous control. Using these integrals we obtain a (reduced) system of first-order differential equations on the configuration space. Then an optimal control problem for several types of the inputs is solved using genetic algorithms. 相似文献
76.
Dmitry Ioffe 《Letters in Mathematical Physics》1996,37(2):137-143
We give a simple proof that the limit Ising Gibbs measure with free boundary conditions on the Bethe lattice with the forward branching ratio k2 is extremal if and only if is less or equal to the spin glass transition value, given by tanh(
c
SG
= 1/k.The work was partially supported by the NSF grant DMS 9504513. 相似文献
77.
78.
Maksim Zalkovskij Radu Malureanu Christian Kremers Dmitry N. Chigrin Andey Novitsky Sergei Zhukovsky Peter T. Tang Peter U. Jepsen Andrei V. Lavrinenko 《Laser \u0026amp; Photonics Reviews》2013,7(5):810-817
A planar Babinet‐inverted dimer metamaterial possessing strong optical activity is proposed and characterized. An original fabrication method to produce large area (up to several cm2) freely suspended flexible metallic membranes is implemented to fabricate the metamaterial. Its optical properties are characterized by terahertz time‐domain spectroscopy, revealing anisotropic transmission with high optical activity. A simple coupled resonator model is applied to explain the principal optical features of the dimers, with predictive power of positions and number of resonances through a parametrical model. The model is validated for correct polarization‐dependent quantitative results on the optical activity in transmission spectra. The fabrication method presented in this work as well as the slit dimer design has great potential for exploitation in terahertz optics. 相似文献
79.
Peter?EbenfeltEmail author Bernhard?Lamel Dmitry?Zaitsev 《Geometric And Functional Analysis》2003,13(3):546-573
We show that germs of local real-analytic CR automorphisms of a
real-analytic hypersurface M in
$\mathbb{C}$2 at a point
p M
are uniquelydetermined by their jets of some finite order at
p if and only if M is
not Levi-flat near p. This seems to be the first necessary and sufficient
result on finite jet determination and the first result of this kind in
the infinite type case.If M is of finite type at p,
we prove a stronger assertion: the local real-analytic
CR automorphisms of M fixing p
are analytically parametrized (and hence uniquely determined)
by their 2-jets at p.
This result is optimal since the automorphisms of the unit sphere are
not determined by their 1-jets at a point of the sphere. The finite
type condition is necessary since otherwise the needed jet order can
be arbitrarily high [Kow1,2], [Z2]. Moreover, we show, by an example,
that determination by 2-jets fails for finite type hypersurfaces already
in $\mathbb{C)$3.We also give an application to the dynamics of germs of local
biholomorphisms of $\mathbb{C)$2. 相似文献
80.
Ignacio Llatser Christian Kremers Albert Cabellos-Aparicio Josep Miquel Jornet Eduard Alarcón Dmitry N. Chigrin 《Photonics and Nanostructures》2012,10(4):353-358
The scattering of terahertz radiation on a graphene-based nano-patch antenna is numerically analyzed. The extinction cross section of the nano-antenna supported by silicon and silicon dioxide substrates of different thickness are calculated. Scattering resonances in the terahertz band are identified as Fabry–Perot resonances of surface plasmon polaritons supported by the graphene film. A strong tunability of the antenna resonances via electrostatic bias is numerically demonstrated, opening perspectives to design tunable graphene-based nano-antennas. These antennas are envisaged to enable wireless communications at the nanoscale. 相似文献