摘要:

The aim of the paper is to apply some recent results on regularization of Lagrangians to the case of second order Lagrangians corresponding to 3rd order Euler‐Lagrange equations. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814742

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

A variational principle for the first order mechanical systems subjected to general nonholonomic constraints is presented, providing the (reduced) nonholonomic motion equations in a form of constraint Euler‐Lagrange equations. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814743

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In this work, Fredholm joint spectrum of noncommuting operator family which generates nilpotent Lie algebra is defined and investigated some properties of it. The joint spectrum ofais defined to be the set &sgr;F(a) of those &lgr; ∈Cnfor which the complexKos(a− &lgr;,X) whose co‐homology spaces are not of finite dimension. It is proved that &sgr;F(a) is a compact set inCn. Polynomial spectral mapping theorem with respect to polynomials in noncommuting variables is proved such thatP(&sgr;F(a)) ⊂ &sgr;F(P(a)). © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814744

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

A necessary and sufficient condition is obtained for oscillation of bounded solutions of second order impulsive delay differential equations of the form(r(t)x′(t))′ + p(t)f(x(&tgr;(t))) = 0, t ≠ &thgr;i, &Dgr;(r(&thgr;i)x′(&thgr;i)) + big(x(&sgr;(&thgr;i))) = 0, i ∈ Z, &Dgr;x(&thgr;i) = 0. An example is also inserted to illustrate the effect of impulses on the oscillatory behavior of the solutions. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814745

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

The role played by coercive inequalities in the study of local boundary‐value problems for parabolic and elliptic differential equations is well known ( see, e.g.,[14],[21]). In present paper we consider the nonlocal boundary‐value problems for parabolic and elliptic differential equations. The coercive inequalities for the solution of these nonlocal boundary‐value problems are presented. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814746

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

It is well known that the KdV equation describes the behavior of ion‐acoustic waves in a cold plasma. In the presence of negative ions, if their concentration satisfies a certain condition (critical concentration) the relevant equation is the modified KdV equation. The transition between these two regimes is studied from several points of view. The multiple scales analysis is extended to higher order and the role played by the next equations in the corresponding hierarchies KdV and mKdV is discussed. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814747

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

In the last three decades, there has been significant interest in using mean field theory of statistical physics for combinatorial optimization. This has led to the development of powerful optimization techniques such as neural networks (NNs), simulated annealing (SA), and mean field annealing (MFA). MFA replaces the stochastic nature of SA with a set of deterministic equations named as mean field equations. The mean field equations depend on the energy function of the NNs and are solved at each temperature during the annealing process of SA. MFA advances to the optimal solution in a fundamentally different way than stochastic methods. The use of mean field techniques for the combinatorial optimization problems are reviewed in this study. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814748

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

Primal dual Interior Point Methods (IPMs) generate points that lie in the neighborhood of the central trajectory. The key ingredient of the primal dual IPMs is the parameterization of the central trajectory. A new approach to the parameterization of the central trajectory is presented. Instead of parameterizing the central trajectory by the barrier parameter, it is parameterized by the time by describing a continuous dynamical system. Specifically, a new update rule based on the solution of an ordinary differential equation for the barrier parameter of the primal dual IPMs is presented. The resulting ordinary differential equation combined with the first order Karush‐Kuhn‐Tucker (KKT) conditions, which are algebraic equations, are called differential algebraic equations (DAEs). By solving DAEs, we find an optimal solution to the given problem. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814749

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

After a short introduction in the Nambu‐Poisson dynamics (NPD), some applications of NPD in the (in)finite‐dimensional models are considered. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814750

出版商:AIP    

年代:1904

数据来源: AIP

摘要:

We previously proposed a method tor the study of the relaxation phenomena in the activation and inactivation gates of ion channels present in the excitable membranes of neurons. In order to study the relaxation phenomena, the assumption is made that the activation and inactivation gate order parameters can be treated as fluxes and forces. In the present paper, we extend the previous model as including an ensemble of gating particles, and apply it for T‐type calcium channel in thalamic relay neurons. It is found that kinetic equations are characterized by two relaxation times. The kinetic coefficients are determined for its empirical model. We also determine the kinetic coefficients of linear and nonlinear thermodynamic models for the same T‐type calcium channel, and compare them with the empirical ones. © 2004 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1814751

出版商:AIP    

年代:1904

数据来源: AIP