关于(a,a,b)类型的三维除数问题

本文研究（ａ,ａ,ｂ）类型的三维除数问题,通过把此问题和熟知的Ｄｉｒｉｃｈｌｅｔ问题相联系并估计余项的新形式,我们得到了更好的结果。     

Solution of the problems of a perforated disk,a conical bar,and a flat wedge of nonlinear viscoelastic material in pure shear,torsion, and bending,respectively

Exact solutions and approximations have been obtained for the problems of a disk with an opening twisted by opposite moments uniformly distributed over the inner and outer surfaces and of a conical bar twisted by a moment applied at the vertex of the cone. An approximate solution has been found for the problem of a flat wedge bent by pressure uniformly distributed along one of its sides. The disk is made of nonlinear viscoelastic material. In [1] it was proposed that problems for such a material be solved by the method of approximations. The rheological law of the nonlinear viscoelastic material of the cone and the wedge in Laplace—Carson transforms is the relation of the theory of small elastoplastic deformations with a power law of strain hardening.Institute of Electronic Engineering, Moscow. Translated from Mekhanika Polimerov, No. 6, pp. 1071–1076, November–December, 1971.     

Discontinuous dynamics of a non-linear, self-excited, friction-induced, periodically forced oscillator

The discontinuous dynamics of a non-linear, friction-induced, periodically forced oscillator is studied. The analytical conditions for motion switchability at the velocity boundary in such a nonlinear oscillator are developed to understand the motion switching mechanism. Using such analytical conditions of motion switching, numerical predictions of the switching scenarios varying with excitation frequency and amplitude are carried out, and the parameter maps for specific periodic motions are presented. Chaotic and periodic motions are illustrated through phase planes and switching sections for a better understanding of motion mechanism of the nonlinear friction oscillator. The periodic motions with switching in such a nonlinear, frictional oscillator cannot be obtained from the traditional analysis (e.g., perturbation and harmonic balance method).     

From a Nonlinear, Nonconvex Variational Problem to a Linear, Convex Formulation

   Abstract. We propose a general approach to deal with nonlinear, nonconvex variational problems based on a reformulation of the problem resulting in an optimization problem with linear cost functional and convex constraints. As a first step we explicitly explore these ideas to some one-dimensional variational problems and obtain specific conclusions of an analytical and numerical nature.     

System of Laplace equations in a half-space with a free interface,capillary-gravitational waves,bifurcation, and symmetry

We study the stability of branching solutions of a system of two nonlinearly perturbed Laplace equations in a half-space with two differential relations on the interface. This system describes the motion of a two-layer fluid. To construct and study the related branching systems, methods of group analysis of differential equations (RZhMat 1978 11B883K, RZhMat 1983 11A813K) and the S. Lie-L.V. Ovsyannikov technique of invariants and invariant manifolds are used.     

From a Nonlinear, Nonconvex Variational Problem to a Linear, Convex Formulation

Abstract. We propose a general approach to deal with nonlinear, nonconvex variational problems based on a reformulation of the problem resulting in an optimization problem with linear cost functional and convex constraints. As a first step we explicitly explore these ideas to some one-dimensional variational problems and obtain specific conclusions of an analytical and numerical nature.     

On a paper of Krupchyk, Tarkhanov, and Tuomela

We compare the above-mentioned article with the content of a previous publication.     

Analysis of a single-stage,single-product,stochastic, MRP-controlled assembly system

This paper models a single-stage, single-product, stochastic assembly system, operating according to an Materials Requirements Planning controlled (MRP) ordering philosophy. It deals explicitly with the underlying stochastic process that describes the end-product inventory position, enabling production lead times to be treated as independent and generally distributed random variables. The inventory position process is identified as a Markov renewal process, and this structure is exploited to determine system performance measures such as average inventory level, average backorder level, and the probability distribution of the end-product inventory position. An example, which demonstrates the type of analysis possible, focuses on quantifying the effect of kitting on the availability of end-products.     

Subgroups,of Chevalley groups over a locally finite field,defined by a family of additive subgroups

It is proved that every elementary carpet of nonzero additive subgroups which is associated with a Chevalley group of a Lie rank exceeding one over a locally finite field coincides, up to conjugation by a diagonal element, with a carpetwhose additive subgroups are equal to some chosen subfield of the ground field. A similar result is obtained for a full matrix carpet (a full net).     

On a problem with a boundary condition of the second kind,a complex-valued coefficient,and a spectral parameter in the other boundary condition

We study a classical problem that arises in the analysis of natural vibrations of a loaded string with a free endpoint. We assume that the coefficient occurring in the boundary condition of the third kind with a spectral parameter instead of a physical parameter can take complex values. We discuss the traditional aspects of the completeness, minimality, and basis property of the system of root functions. Special attention is paid to the structure of root subspaces.     

A linear system of differential equations with small parameter at a part of derivatives,a deviation of the argument,and a turning point

For a system of differential equations with small parameter at a part of derivatives, a linear deviation of the argument, and a turning point, we obtained conditions, under which its solutions are solutions of a system of differential equations with small parameter at a part of derivatives such that its matrices possess the asymptotic expansions at |ε| ≤ ε₀ with the coefficients holomorphic at |x| ≤ x ₀ . The existence and the infinite differentiability of a solution of the system of differential equations with small parameter at a part of derivatives and with a linear deviation of the argument in the presence of a turning point are proved.     

A New Construction of Central Relative (p a , p a , p a , 1)-Difference Sets

Semiregular relative difference sets (RDS) in a finite group E which avoid a central subgroup C are equivalent to orthogonal cocycles. For example, every abelian semiregular RDS must arise from a symmetric orthogonal cocycle, and vice versa. Here, we introduce a new construction for central (p ^a , p ^a , p ^a , 1)-RDS which derives from a novel type of orthogonal cocycle, an LP cocycle, defined in terms of a linearised permutation (LP) polynomial and multiplication in a finite presemifield. The construction yields many new non-abelian (p ^a , p ^a , p ^a , 1)-RDS. We show that the subset of the LP cocycles defined by the identity LP polynomial and multiplication in a commutative semifield determines the known abelian (p ^a , p ^a , p ^a , 1)-RDS, and give a second new construction using presemifields.We use this cohomological approach to identify equivalence classes of central (p ^a , p ^a , p ^a , 1)-RDS with elementary abelian C and E/C. We show that for p = 2, a 3 and p = 3, a 2, every central (p ^a , p ^a , p ^a , 1)-RDS is equivalent to one arising from an LP cocycle, and list them all by equivalence class. For p = 2, a = 4, we list the 32 distinct equivalence classes which arise from field multiplication. We prove that, for any p, there are at least a equivalence classes of central (p ^a , p ^a , p ^a , 1)-RDS, of which one is abelian and a – 1 are non-abelian.     

A reducing of a chaotic movement to a periodic orbit,of a micro-electro-mechanical system,by using an optimal linear control design

This paper analyzes the non-linear dynamics, with a chaotic behavior of a particular micro-electro-mechanical system. We used a technique of the optimal linear control for reducing the irregular (chaotic) oscillatory movement of the non-linear systems to a periodic orbit. We use the mathematical model of a (MEMS) proposed by Luo and Wang.     

Thermoelastic state of a medium,containing a thermally insulated ellipsoidal cavity,when subjected to a uniform heat flow

This article examines a problem of static thermoelasticity for an isotropic medium with an ellipsoidal cavity. The orientation of the cavity relative to the heat flow is assumed to be arbitrary. The solution of the problem is constructed in closed form and is expressed through incomplete elliptic integrals of the first and second kinds. In cases when the ellipsoid degenerates into a spheroid or sphere, the stress-strain state can be written in elementary functions of the ellipsoidal coordinate.Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 19, pp. 46–50, 1988.     

Routing a mix of conventional,plug-in hybrid,and electric vehicles

We introduce an electric vehicle routing problem combining conventional, plug-in hybrid, and electric vehicles. Electric vehicles are constrained in their service range by their battery capacity, and may require time-consuming recharging operations at some specific locations. Plug-in hybrid vehicles have two engines, an internal combustion engine and an electric engine using a built-in rechargeable battery. These vehicles can avoid visits to recharging stations by switching to fossil fuel. However, this flexibility comes at the price of a generally higher consumption rate and utility cost.To solve this complex problem variant, we design a sophisticated metaheuristic which combines a genetic algorithm with local and large neighborhood search. All route evaluations, within the approach, are based on a layered optimization algorithm which combines labeling techniques and greedy evaluation policies to insert recharging stations visits in a fixed trip and select the fuel types. The metaheuristic is finally hybridized with an integer programming solver, over a set partitioning formulation, so as to recombine high-quality routes from the search history into better solutions. Extensive experimental analyses are conducted, highlighting the good performance of the algorithm and the contribution of each of its main components. Finally, we investigate the impact of fuel and energy cost on fleet composition decisions. Our experiments show that a careful use of a mixed fleet can significantly reduce operational costs in a large variety of price scenarios, in comparison with the use of a fleet composed of a single vehicle class.     

关于(a,a,b)类型的三维除数问题

本文研究了(a,a,b)类型的三维除数问题.当a＜b≤2a时,我们利用指数和的新估计得到了余项△(a,a,b;x)的较好估计.     

On the solution of a 2-D,parabolic, partial differential energy equation subjected to a nonlinear convective boundary condition via a simple solution for a uniform,Dirichlet boundary condition

Separate theoretical and numerical analyses have been conducted for the prediction of the mean bulk-and wall-temperatures of hot fluids flowing inside horizontal tubes. Heat transmission between the internal forced flow and the external free flow of the surrounding fluid occurs through the solid wall of the tube. The mathematical formulation of this problem is expressed in terms of a parabolic, partial differential equation with a temperature-dependent, nonlinear boundary condition of third kind. The aim of the article is to critically examine the thermal response of this kind of in-tube flows utilizing two different mathematical models: (a) a complete 2-D differential model and (b) a largely simplified 1-D lumped model. For the 1-D lumped model, streamwise-mean values for the internal Nusselt numbers and the circumferential-mean values for the external Nusselt numbers have been taken from standard correlations that appear in basic textbooks. The combination of both mean Nusselt numbers leads to the calculation of a mean, equivalent Nusselt number, which serves to regulate the thermal interaction between the perpendicular fluid streams. For the two models tested, the computed results consistently demonstrate that the simplistic 1-D lumped model provides accurate estimates of the mean bulk- and wall-temperatures, when compared with those computed with the rigorous 2-D differential model. The former is associated with hand calculations, whereas the latter inevitably necessitated a finite-difference methodology and a personal computer. © 1995 John Wiley & Sons, Inc.     

Contextualism on a pragmatic,not a skeptical,footing

Contextualism is supposed to explain why the following argument for skepticism seems plausible: (1) I don’t know that I am not a bodiless brain-in-a-vat (BIV); (2) If I know I have hands, then I know I am not a bodiless BIV; (3) Therefore, I do not know I have hands. Keith DeRose claims that (1) and (2) are “initially plausible.” I claim that (1) is initially plausible only because of an implicit argument that stands behind it; it is not intuitively plausible. The argument DeRose offers is based on the requirement of sensitivity, that is, on the idea that if you know something then you would not believe it if it were false. I criticize the sensitivity requirement thereby undercutting its support for (1) and the skeptical data that contextualism is meant to explain. While skepticism is not a plausible ground for contextualism, I argue that certain pragmatic considerations are. It’s plausible to think that to know something more evidence is required when more is at stake. The best way to handle skepticism is to criticize the arguments for it. We should not adopt contextualism as a means of accommodating skepticism even if there are other pragmatic reasons for being a contextualist about knowledge.     

On a Question of Glasby,Praeger, and Xia

A Jordan partition λ(m, n, p) = (λ₁, λ₂, … , λ _m ) is a partition of mn associated with the expression of a tensor V _m  ? V _n of indecomposable KG-modules into a sum of indecomposables, where K is a field of characteristic p and G a cyclic group of p-power order. It is standard if λ _i  = m + n ? 2i + 1 for all i. We answer a recent question of Glasby, Praeger, and Xia who asked for necessary and sufficient conditions for λ(m, n, p) to be standard.