共查询到20条相似文献,搜索用时 15 毫秒
1.
We study Chaney's and Ben-Tal-Zowe's second-order directional derivatives with applications in minimization problem for max-functions
of the formh(x): = max {f(x, τ); τ ∈T},where T is a compact metricspace. We improve Kawasaki's result on necessary condition for such functions in the minimization
problem. 相似文献
2.
We consider a dynamic mean-risk problem, where the risk constraint is given by the Average Value–at–Risk. As financial market
we choose a discrete-time binomial model which allows for explicit solutions. Problems where the risk constraint on the final
wealth is replaced by intermediate risk constraints are also considered. The problems are solved with the help of the theory
of Markov decision models and a Lagrangian approach. 相似文献
3.
Bass Richard F.; Burdzy Krzysztof; Chen Zhen-Qing 《Proceedings London Mathematical Society》2008,96(2):273-311
We study the solution to the Robin boundary problem for theLaplacian in a Euclidean domain. We present some families offractal domains where the infimum of the solution to the mixedDirichlet–Robin boundary problem is greater than 0, andsome other families of domains where it is equal to 0. We alsogive a new result on trap domains defined in Burdzy,Chen and Marshall (Math. Z.), that is, domains where reflectingBrownian motion takes a long time to reach the center of thedomain. 相似文献
4.
Janina A. Brenner Sándor P. Fekete Jan C. van der Veen 《Mathematical Methods of Operations Research》2009,69(2):281-296
We consider a special case of the directed subgraph homeomorphism or topological minor problem, where the host graph has a
specific regular structure. Given an acyclic directed pattern graph, we are looking for a host graph of minimal height which
still allows for an embedding. This problem has applications in compiler design for certain coarse-grain reconfigurable architectures.
In this application domain, the task is to simultaneously schedule, bind and route a so-called data-flow graph, where vertices represent operations and arcs stand for data dependencies between the operations, given an orthogonal
grid structure of reconfigurable processing elements (PEs) that have restricted communication abilities. We show that the
problem of simultaneously scheduling, binding and routing is NP-complete by describing a logic engine reduction from NAE-3-SAT.
This result holds even when the input graph is a directed tree with maximum indegree two. We also give a |V|3/2-approximation algorithm.
J. A. Brenner’s research supported by the DFG Research Center Matheon “Mathematics for key technologies”.
J. C. van der Veen’s research supported by DFG Focus Program 1148, “Reconfigurable Architectures”, Grants FE 407/8-1 and FE
407/8-2. 相似文献
5.
V. E. Mosyagin 《Siberian Advances in Mathematics》2020,30(1):26-42
We consider the random process at − v+(pt) + v−(−qt), t ∈ (−∞, −), where v− and v+ are independent standard Poisson processes if t ≥ 0 and v−(t) = v+(t) = 0 if t < 0. Under certain conditions on the parameters a, p, and q, we study the distribution function G = G(x) of the time of attaining the maximum for a trajectory of this process. In the present article, we find an exact asymptotics for the tails of G. We also find a connection between this problem and the statistical problem of estimation of an unknown discontinuity point of a density function. 相似文献
6.
L. Stupelis 《Lithuanian Mathematical Journal》2000,40(2):176-196
In the present paper we consider one initial boundary-value problem for a system of equations of magnetohydrodynamics in the
case where it is necessary to take into account the displacement currents in the Maxwell system of equations. We prove a local
(in time) unique solvability of this problem in the Sobolev spaces.
Translated from Lietuvos Matematikos Rinkinys, Vol. 40, No. 2, pp. 228–254, April–June, 2000.
Translated by R. Lapinskas 相似文献
7.
We consider the problem of finding the nearest point in a polyhedral cone C={x∈R
n
:D
x≤0} to a given point b∈R
n
, where D∈R
m×n
. This problem can be formulated as a convex quadratic programming problem with special structure. We study the structure
of this problem and its relationship with the nearest point problem in a pos cone through the concept of polar cones. We then
use this relationship to design an efficient algorithm for solving the problem, and carry out computational experiments to
evaluate its effectiveness. Our computational results show that our proposed algorithm is more efficient than other existing
algorithms for solving this problem. 相似文献
8.
G. A. Chechkin 《Journal of Mathematical Sciences》2006,135(6):3485-3521
We study the asymptotic behavior of eigenelements of boundary value problems in a domain Ω ⊂ ℝd, d ⩾ 3, with rapidly alternating type of boundary conditions. The density is equal to 1 outside tiny domains and is equal
to ε−m inside them, where ε is a small parameter. These domains (concentrated masses) of diameter εa are located on the boundary
at a positive distance of order O(ε) from each other, where a = const. The Dirichlet boundary condition is on parts of ∂Ω that are tangent to concentrated masses, and the Neumann boundary condition
is stated outside concentrated masses. We construct the limit (homogenized) operator, prove the convergence of eigenelements
of the original problem to the eigenelements of the limit (homogenized) problem in the case m ⩾ 2, and estimate the difference
between the eigenelements. Bibliography: 79 titles. Illustrations: 4 figures.
__________
Translated from Problemy Matematicheskogo Analiza, No. 32, 2006, pp. 45–75. 相似文献
9.
Miloš Zlámal 《Annali di Matematica Pura ed Applicata》1962,57(1):143-150
Summary We consider the Dirichlet problem for the equation Lε(u) ≡ uxx+ɛuyy++A(x, y)ux−B(y)uy+C(x, y)u=F(x, y) where B(y)>0 and ɛ is a small positive parameter. An asymptotic formula is proved, from which it follows
that in a suitable part of the domain of definition u(x, y, ɛ)→U(x, y) as ɛ→0+, where U(x, y) is the solution of the corresponding
boundary - value problem for the reduced equation L0(U)≡Uxx+A(x, y)Ux−B(y)U+C(x, y)U=F(x, y).
To Enrico Bompiani on his scientific Jubilee. 相似文献
10.
In this paper, we outline an impulse stochastic control formulation for pricing variable annuities with a guaranteed minimum
withdrawal benefit (GMWB) assuming the policyholder is allowed to withdraw funds continuously. We develop a numerical scheme
for solving the Hamilton–Jacobi–Bellman (HJB) variational inequality corresponding to the impulse control problem. We prove
the convergence of our scheme to the viscosity solution of the continuous withdrawal problem, provided a strong comparison
result holds. The scheme can be easily generalized to price discrete withdrawal contracts. Numerical experiments are conducted,
which show a region where the optimal control appears to be non-unique. 相似文献
11.
In a domain with free boundary, we establish conditions for the existence and uniqueness of a solution of the inverse problem
of finding the time-dependent coefficient of heat conductivity. We study the case of strong degeneration where the unknown
coefficient tends to zero as t → +0 as a power function t
β
, where β ≥ 1.
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 61, No. 1, pp. 28–43, January, 2009. 相似文献
12.
On the Representation Ring of a Quiver 总被引:1,自引:0,他引:1
Martin Herschend 《Algebras and Representation Theory》2009,12(6):513-541
13.
We establish exact-order bilateral estimates for the size of the support of a solution of the Cauchy problem for a doubly
nonlinear parabolic equation with anisotropic degeneration in the case where the initial data are finite and have finite mass.
__________
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 58, No. 11, pp. 1477–1486, November, 2006. 相似文献
14.
Carlo Toffalori 《Archive for Mathematical Logic》1998,37(2):127-142
We show undecidability for lattices over a group ring where has a cyclic subgroup of order for some odd prime . Then we discuss the decision problem for -lattices where is a cyclic group of order 8, and we point out that a positive answer implies – in some sense – the solution of the “wild
undecidable” conjecture.
Received November 15, 1995 相似文献
15.
An analytic solution is found for the problem on the behavior of a collisional plasma in a variable external electric field.
We elucidate the structure of the screened electric field and investigate the case where the frequency of the external field
is close to the plasma oscillation frequency (resonance). We show that there are two near-surface layers where the behavior
of the screened field differs essentially.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 147, No. 3, pp. 487–502, June, 2006. 相似文献
16.
Massimo Grossi Angela Pistoia Juncheng Wei 《Calculus of Variations and Partial Differential Equations》2000,11(2):143-175
We study a perturbed semilinear problem with Neumann boundary condition
where is a bounded smooth domain of , , , if or if and is the unit outward normal at the boundary of . We show that for any fixed positive integer K any “suitable” critical point of the function
generates a family of multiple interior spike solutions, whose local maximum points tend to as tends to zero.
Received March 7, 1999 / Accepted October 1, 1999 / Published online April 6, 2000 相似文献
17.
Qiang Zhen Johan S. H. van Leeuwaarden Charles Knessl 《Mathematical Methods of Operations Research》2010,72(3):453-476
We consider the processor sharing M/M/1-PS queue which also models balking. A customer that arrives and sees n others in the system “balks” (i.e., decides not to enter) with probability 1−b
n
. If b
n
is inversely proportional to n + 1, we obtain explicit expressions for a tagged customer’s sojourn time distribution. We consider both the conditional distribution,
conditioned on the number of other customers present when the tagged customer arrives, as well as the unconditional distribution.
We then evaluate the results in various asymptotic limits. These include large time (tail behavior) and/or large n, lightly loaded systems where the arrival rate λ → 0, and heavily loaded systems where λ → ∞. We find that the asymptotic
structure for the problem with balking is much different from the standard M/M/1-PS queue. We also discuss a perturbation method for deriving the asymptotics, which should apply to more general balking
functions. 相似文献
18.
Younghwan In 《International Journal of Game Theory》2006,34(1):79-90
We extend the results of van Damme et al. (1990) and Muthoo (1991) to two bilateral multi-issue bargaining)procedures with complete information and endogenous agenda, where each issue is associated with a finite set of alternatives. We show that in the first procedure (issue-by-issue bargaining), the stationary subgame perfect equilibria alone may support a large multiplicity of inefficient agreements. Confronting a recent study, the results for the second procedure imply that it is not necessary to appeal to “strictly controversial” issues in a bargaining problem in order to find multiplicity and delay in agreements 相似文献
19.
We study the problem of evaluation of the probability of ruin of an insurance company for infinitely many steps in the case
where the company can invest its capital to bank deposits at any time. As a distribution of the amounts of claims to the insurance
company, we use the gamma-distribution with the parameters n and α.
__________
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 59, No. 4, pp. 447–457, April, 2007. 相似文献
20.
G. P. Galdi K. Pileckas A. L. Silvestre 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2007,8(4):994-1007
We show that in an unsteady Poiseuille flow of a Navier–Stokes fluid in an infinite straight pipe of constant cross-section,
σ, the flow rate, F(t), and the axial pressure drop, q(t), are related, at each time t, by a linear Volterra integral equation of the second type, where the kernel depends only upon t and σ. One significant consequence of this result is that it allows us to prove that the inverse parabolic problem of finding a
Poiseuille flow corresponding to a given F(t) is equivalent to the resolution of the classical initial-boundary value problem for the heat equation. 相似文献