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931.
932.
We study the motion of a Brownian particle which interacts with a stationary obstacle in two dimensions. The Brownian particle acquires drift proportionally to the time spent on the boundary of the obstacle. The system approaches equilibrium, and the equilibrium distribution for the location and drift magnitude has the product form. The distribution for the location is uniform, while the drift distribution depends on the shape of the obstacle, resembling a gamma function for the circular or elliptic obstacle. 相似文献
933.
934.
Muhammad Aslam Noor 《Journal of Mathematical Analysis and Applications》2006,324(2):1417-1428
In this paper, we introduce and analyze a new class of equilibrium problems known as general hemiequilibrium problems. It is shown that this class includes hemiequilibrium problems, hemivariational inequalities and complementarity problems as special cases. We use the auxiliary principle techniques to suggest some iterative-type methods for solving multivalued hemiequilibrium problems. We also analyze the convergence analysis of these new iterative methods under some mild conditions. As special cases, we obtain several new and known methods for solving variational inequalities and equilibrium problems. 相似文献
935.
This paper introduces a polynomial combinatorial optimization algorithm for the dynamic user optimal problem. The approach
can efficiently solve single destination networks and can be potentially extended to heuristically solve multidestinational
networks. In the model, traffic is propagated according to sound traffic flow theoretical models rather than link exit functions;
thereby allowing link queue evolution to be modeled more precisely. The algorithm is designed, proven, implemented and computationally
tested. 相似文献
936.
937.
S. Duhot R. Mélin 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(2):257-266
The three-dimensional bimodal random-field Ising model
is investigated using the N-fold version of the Wang-Landau
algorithm. The essential energy subspaces are determined by the
recently developed critical minimum energy subspace technique, and
two implementations of this scheme are utilized. The random fields
are obtained from a bimodal discrete (±Δ) distribution,
and we study the model for various values of the disorder strength
Δ, Δ=0.5,1,1.5 and 2, on cubic lattices with
linear sizes L=4–24. We extract information for the probability
distributions of the specific heat peaks over samples of random
fields. This permits us to obtain the phase diagram and present
the finite-size behavior of the specific heat. The question of
saturation of the specific heat is re-examined and it is shown
that the open problem of universality for the random-field Ising
model is strongly influenced by the lack of self-averaging of the
model. This property appears to be substantially depended on the
disorder strength. 相似文献
938.
Many problems in the field of computational biology consist of the analysis of so-called gene-expression data. The successful application of approximation and optimization techniques, dynamical systems, algorithms and the utilization of the underlying combinatorial structures lead to a better understanding in that field. For the concrete example of gene-expression data we extend an algorithm, which exploits discrete information. This is lying in extremal points of polyhedra, which grow step by step, up to a possible stopping.We study gene-expression data in time, mathematically model it by a time-continuous system, and time-discretize this system. By our algorithm we compute the regions of stability and instability. We give a motivating introduction from genetics, present biological and mathematical interpretations of (in)stability, point out structural frontiers and give an outlook to future research. 相似文献
939.
The rotational spectrum of phosphaethene (CH2PH) was reinvestigated. One hundred and nineteen new lines were measured in the submillimeter range from 500 to 650 GHz. The determination of the centrifugal distortion constants is significantly improved. As the molecule is close to symmetric prolate top, both reduction A and S were compared. The equilibrium structure has been derived from experimental ground state rotational constants and ab initio rovibrational interaction parameters. This semi-experimental structure is in excellent agreement with the ab initio structure calculated at the CCSD(T) level of theory using a basis set of quintuple-zeta quality and a core correlation correction. The structure of CH2PH was compared to that of CH2NH which was also determined for this goal. It is found that the semi-experimental structure of CH2NH is less accurate than the ab initio structure. It is also found that the methylene group is much more asymmetric in CH2NH than in CH2PH. 相似文献
940.
J. Jestin L.-T. Lee M. Privat G. Zalczer 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,24(4):541-547
Using neutron reflectivity, we directly and self-consistently obtained all the parameters of the critical adsorption profile
of three critical mixtures (n-hexane+perfluorohexane, deuterated methanol+cyclohexane and methanol+deuterated cyclohexane)
assuming only a Liu-Fisher form for the profile. The characteristic exponent and the amplitude ratio which can be deduced
from the neutron spectra alone are in good agreement with one another, with ellipsometric data and with theoretical values.
Owing to auxiliary measurements of coexistence curves and correlation lengths, we could also check the amplitude of the intermediate
and distal parts of the profile with good agreements for the methanol cyclohexane mixtures only. The adsorbed amount is much
greater in the n-hexane+perfluorohexane mixture where both the power-law amplitude and the characteristic length of the profile
are affected.
Received 30 May 2001 相似文献