具有功能性反应和时滞的扩散捕食-食饵系统

考虑具有功能性反应和时滞的扩散捕食-食饵系统，其中食饵连两个斑块间具有一定的扩散系数，捕食者可以两个斑块中任意走动，我们讨论了系统的一致持久性和周期解的存在性及全局吸引性．     

Periodic-Group-Delay Dispersion Compensation Reduces Collision-Induced Timing Shifts in Dispersion-Managed Quasilinear Systems

Periodic-group-delay (PGD) dispersion-compensation modules have recently been proposed as mechanisms to alleviate collision-induced timing shifts in dispersion-managed (DM) systems. We obtain frequency and timing shifts in quasilinear DM systems with PGDs and show that significant reductions are achieved when even a small fraction of the total dispersion is compensated by PGDs.__________Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 144, No. 1, pp. 6–13, July, 2005.     

Permanence and periodicity of a delayed ratio-dependent predator-prey model with stage structure

A periodic ratio-dependent predator-prey model with time delays and stage structure for both prey and predator is investigated. It is assumed that immature individuals and mature individuals of each species are divided by a fixed age, and that immature predators do not have the ability to attack prey. Sufficient conditions are derived for the permanence and existence of positive periodic solutions of the model. Numerical simulations are presented to illustrate the feasibility of our main results.     

双层指派模型及算法

介绍了指派问题应用中出现的一种新类型——双层指派问题,建立了双层指派问题的数学模型,并提出了针对双层指派模型的算法,最后给出它在铁路客车车底周转运用中的实例.     

Necessary conditions for the neutral problem of Bolza with continuously varying time delay

This note uses Clarke's decoupling technique to obtain necessary conditions for the generalized problem of Bolza with Lipschitz continuously varying delay in both the state and velocity variables.     

含两时滞捕食-被捕食系统的稳定性及分歧

本文研究一类含两相异时滞的捕食－被捕食系统的稳定性及分歧。首先，我们讨论两相异时滞对系统唯一正平衡点的稳定性的影响，通过对系数与时滞有关的特征方程的分析，建立了一种稳定性判别性。其次，将一个时滞看成分歧参数，而另一个看作固定参数，我们证明了该系统具有HOPF分歧特性。最后，我们讨论了分歧解的稳定性。     

学习(记忆)支配空间模式的不规则外向星(Outstar)(英文)

1 IntroductionIn this paper, we study the long--time behavior of the fOl1owing systernwhere l = 1,' 't n5 n, rf, ri and r: are non-negative constants, aot a,? 6i,ci9 di, fi, gi, I0, Ii: R - [0, oc) are continuous functions and I0 and Ii arebounded.System (1. 1) models the evolution of a neural fletwork called outstar, whichconsists of a command neuron vo and input ncurons (v, ?'' ? v.). The short-term mernory trace of each neuron vi is denoted by x,(t) ? the 1ong--term mernorytrace from vo…     

带时滞的比率型的食物链系统的持久性和稳定性

A delayed three-species ratio-dependent predator-prey food-chain model without dominating instantaneous negative feedback is investigated. It is shown that the system is permanent under some appropriate conditions, and sufficient conditions are obtained for the local asymptotic stability of a positive equilibrium of the system.     

Unintended consequences of collocation: using agent-based modeling to untangle effects of communication delay and in-group favor

In studies about office arrangements that have individuals working from remote locations, researchers usually hypothesize advantages for collocators and disadvantages for remote workers. However, empirical findings have not shown consistent support for the hypothesis. We suspect that there are unintended consequences of collocation, which can offset well-recognized advantages of being collocated. To explain these unintended consequences, we developed a multi-agent model to complement our laboratory-based experiment. In the lab, collocated subjects did not perform better than the remote even though collocators had faster communication channels and in-group favor towards each other. Results from the multi-agent simulation suggested that in-group favoritism among collocators caused them to ignore some important resource exchange opportunities with remote individuals. Meanwhile, communication delay of remote subjects protected them from some falsely biased perception of resource availability. The two unintended consequences could offset the advantage of being collocated and diminish performance differences between collocators and remote workers. Results of this study help researchers and practitioners recognize the hidden costs of being collocated. They also demonstrate the value of coupling lab experiments with multi-agent simulation.

Stability properties of nonlinear stochastic impulsive systems with time delay

This article establishes mean square stability and stabilization for stochastic delay systems with impulses. Using Razumikhin methodology, two approaches, classical Lyapunov-based method and comparison principle, are proposed to develop sufficient conditions that guarantee the stability and stabilization properties. It is shown that if the continuous system is stable and the impulses are destabilizing, the impulses should not be applied frequently. On the other hand, if the continuous system is unstable, but the impulses are stabilizing, the impulses should occur frequently to compensate the continuous state growth. Numerical examples are also presented to clarify the proposed theoretical results.