Short correctness proofs for two self-stabilizing algorithms under the distributed daemon model

The distributed daemon model introduced by Burns in 1987 is a natural generalization of the central daemon model introduced by Dijkstra in 1974. In this paper, we show that a well-known shortest path algorithm is self-stabilizing under the distributed daemon model. Although this result has been proven only recently, the correctness proof provided here is from a different point of view and is much more concise. We also show that Bruell et al.’s center-finding algorithm is actually self-stabilizing under the distributed daemon model. Finally, we compute the worst-case stabilization times of the two algorithms under the distributed daemon model.     

Analysis on global exponential robust stability of reaction-diffusion neural networks with S-type distributed delays

To avoid the unstable phenomena caused by time delays and perturbations, we investigate the sufficient conditions to ensure the global exponential robust stability with a convergence rate for the reaction-diffusion neural networks with S-type distributed delays. Because S-type distributed delays lead to some difficulty, we also introduce a new generalized Halanay inequality and a novel method-system-approximation method into the qualitative research of neural networks. Moreover, the sufficient criteria provided here, which are rather accessible and feasible, have wider adaptive range.     

Optimal Control Problem Governed by Semilinear Parabolic Equation and its Algorithm

In this paper, an optimal control problem governed by semilinear parabolic equation which involves the control variable acting on forcing term and coefficients appearing in the higher order derivative terms is formulated and analyzed. The strong variation method, due originally to Mayne et al to solve the optimal control problem of a lumped parameter system, is extended to solve an optimal control problem governed by semilinear parabolic equation, a necessary condition is obtained, the strong variation algorithm for this optimal control problem is presented, and the corresponding convergence result of the algorithm is verified.     

基于分布参数模型的CO_2蒸发器结构参数研究

在设计工况下,建立了用于跨临界二氧化碳热泵热水器的套管式蒸发器的稳态分布参数模型,对其结构参数进行了敏感性分析,指出了它们的合理变化范围:管内套1根管时,内管外径应至少大于11.00mm,低于13.00mm,外管内径应在20.00mm以上,23.00mm以下;管内套多根管时,以管内套3根管的性能为最优。优化设计结果对开发二氧化碳蒸发器产品具有一定的指导意义。     

Convergence of Distributed Optimal Controls on the Internal Energy in Mixed Elliptic Problems when the Heat Transfer Coefficient Goes to Infinity

We consider a steady-state heat conduction problem P _α with mixed boundary conditions for the Poisson equation depending on a positive parameter α , which represents the heat transfer coefficient on a portion Γ ₁ of the boundary of a given bounded domain in R ⁿ . We formulate distributed optimal control problems over the internal energy g for each α . We prove that the optimal control g_ op _α and its corresponding system u_ g_ op _α α and adjoint p_ g_ op _α α states for each α are strongly convergent to g _op , u_ g _op and p _ g _op , respectively, in adequate functional spaces. We also prove that these limit functions are respectively the optimal control, and the system and adjoint states corresponding to another distributed optimal control problem for the same Poisson equation with a different boundary condition on the portion Γ ₁ . We use the fixed point and elliptic variational inequality theories.     

Direct simulation of the motion of neutrally buoyant balls in a three-dimensional Poiseuille flow

In a previous article the authors introduced a Lagrange multiplier based fictitious domain method. Their goal in the present article is to apply a generalization of the above method to: (i) the numerical simulation of the motion of neutrally buoyant particles in a three-dimensional Poiseuille flow; (ii) study – via direct numerical simulations – the migration of neutrally buoyant balls in the tube Poiseuille flow of an incompressible Newtonian viscous fluid. Simulations made with one and several particles show that, as expected, the Segré–Silberberg effect takes place. To cite this article: T.-W. Pan, R. Glowinski, C. R. Mecanique 333 (2005).     

基于微机械陀螺的MIMU关键技术

针对基于微机械陀螺的MIMU关键技术，对其进行研究和解决。参加美国JDAM性能指标和导航精度要求，计算陀螺性能参数：采用多级大容量的滤波器及有源电流限制电路，同时电源的输入端接入EMC滤波器，以提高电磁兼容性，并能抵抗浪涌和拉偏的能力；DSP实现信号实时采集，采用高次多项式拟合预处理去除数据野值；根据GJB729评估方法，利用利用蒙特卡罗方法仿真进行精度评估；最后按照GJB813进行可靠性分析。     

Bifurcation and stability analysis of a neural network model with distributed delays

In this paper, the dynamics of a generalized two-neuron model with self-connections and distributed delays are investigated, together with the stability of the equilibrium. In particular, the conditions under which the Hopf bifurcation occurs at the equilibrium are obtained for the weak kernel. This means that a family of periodic solutions bifurcates from the equilibrium when the bifurcation parameter exceeds a critical value. Explicit algorithms for determining the stability of the bifurcating periodic solutions and the direction of the Hopf bifurcation are derived by using the theory of normal form and center manifold [20]. Some numerical simulations are given to illustrate the effectiveness of the results found. The obtained results are new and they complement previously known results.This work was supported by the National Natural Science Foundation of China under Grants 60574043 and 60373067, the Natural Science Foundation of Jiangsu Province, China under Grants BK2003053.     

边坡变形的分布式光纤监测模拟试验研究

布里渊散射光时域反射测量技术(BOTDR)作为一项新型光电传感监测技术,因其具有良好的抗干扰、长距离、可植入性和分布式监测的特点而被广泛应用于结构工程健康监测中。而直接将光纤布设在土体中则存在变形协调性差、易折断及空间定位难等问题。本次研究通过室内小比例尺模型试验,分别将光纤植入土工布和土工格栅等柔性复合材料中并一起铺设在边坡模型不同深度处,利用BOTDR监测边坡在外荷作用下的变形特征。试验结果表明,布设在土工格栅中的光纤稳定性最好; 土工布中的光纤变形协调性和敏感性优于土工格栅; 通过合理布置光纤能够对异常应变进行较为准确的识别和定位。试验初步验证了该方法应用于土质边坡变形监测的可行性。