Continuity and random dynamics of the non-autonomous stochastic FitzHugh–Nagumo system on RN

In this article, we use the so-called difference estimate method to investigate the continuity and random dynamics of the non-autonomous stochastic FitzHugh–Nagumo system with a general nonlinearity. Firstly, under weak assumptions on the noise coefficient, we prove the existence of a pullback attractor in $L^2\left({\mathbb{R}}^N\right)\times L^2\left({\mathbb{R}}^N\right)$ by using the tail estimate method and a certain compact embedding on bounded domains. Secondly, although the difference of the first component of solutions possesses at most $p$-times integrability where $p$ is the growth exponent of the nonlinearity, we overcome the absence of higher-order integrability and establish the continuity of solutions in $(L^p\left({\mathbb{R}}^N\right)\cap H^1\left({\mathbb{R}}^N\right))\times L^2\left({\mathbb{R}}^N\right)$ with respect to the initial values belonging to $L^2\left({\mathbb{R}}^N\right)\times L^2\left({\mathbb{R}}^N\right)$. As an application of the result on the continuity, the existence of a pullback attractor in $(L^p\left({\mathbb{R}}^N\right)\cap H^1\left({\mathbb{R}}^N\right))\times L^2\left({\mathbb{R}}^N\right)$ is proved for arbitrary $N\ge 1$ and $p>2$.     

Conservation laws of (3+α)-dimensional time-fractional diffusion equation

The concept of Lie–Backlund symmetry plays a fundamental role in applied mathematics. It is clear that in order to find conservation laws for a given partial differential equations (PDEs) or fractional differential equations (FDEs) by using Lagrangian function, firstly, we need to obtain the symmetries of the considered equation.Fractional derivation is an efficient tool for interpretation of mathematical methods. Many applications of fractional calculus can be found in various fields of sciences as physics (classic, quantum mechanics and thermodynamics), biology, economics, engineering and etc. So in this paper, we present some effective application of fractional derivatives such as fractional symmetries and fractional conservation laws by fractional calculations. In the sequel, we obtain our results in order to find conservation laws of the time-fractional equation in some special cases.     

线性时变参数系统切换输出反馈控制

考虑时变参数系统的切换H_∞控制问题.提出了由参数触发的切换策略,由此在最小驻留时间的限制下,将线性时变参数系统分解为若干具有范数有界不确定性的子系统.利用多Lyapunov函数方法分别设计各子系统的输出动态反馈控制器,使在切换策略驱动下构成的闭环系统满足H_∞控制性能.仿真算例完整地实现了理论方法,并验证了其有效性.

     

Resonant soliton and complexiton solutions for (3+1)-dimensional Boiti–Leon–Manna–Pempinelli equation

In this letter, the linear superposition principle is used to discuss the $(3+1)$-dimensional Boiti–Leon–Manna–Pempinelli equation with bilinear derivatives. As a result, we obtain new resonant soliton and complexiton solutions by discussing two different cases involved the parameters. These solutions are a class of $N$-wave solutions of linear combinations of exponential traveling waves.     

基于划分时滞区间的一类Cohen-Grossberg神经网络的鲁棒稳定性

研究一类具有时变时滞及参数不确性的Cohen-Grossberg神经网络的鲁棒稳定性问题.应用划分时滞区间的思想构造了一个新的Lyapunov泛函,并以线性矩阵不等式的形式给出了平衡点全局鲁棒稳定性判据,新判据放松了时变时滞变化率必须小于1的限制.仿真结果进一步证明了所得结论的有效性.

     

浅谈建筑施工噪声污染及防治方法 2012年10月9日

建筑工程现场施工的噪声污染很严重,给附近居民的身体健康以及周围的环境造成严重的损失,而且由于建筑施工现场的作业周期比较长,作业量非常大,建筑工程施工现场的噪音污染延续时间就比较长,由于城市的建筑物都比较密集,所以噪声传播速度很快,给人们的身体健康和心理健康造成的影响会比较大,建筑工程施工现场的噪声污染主要来源于一些大型机械设备和设施在作业时候发出的声音,由于建筑施工现场作业工具一般都是大型的机械设备和设施,所以噪声污染是必不可免的,尤其是传统的建筑工程施工现场的大型机械设备和设施的噪声污染,本文主要讲述了建筑工程施工的噪音污染的现状;建筑工程施工的噪音对人体健康产生不良的影响;建筑工程施工的噪声控制的管理对策与建议.     

广告设计教学实践与探讨 2012年10月9日

平面广告设计专业教学要“以人为本,充分发挥专业教师的主导作用,体现学生的主体地位”的素质教育已成为当今学校教学的主旋律.在广告设计教学课堂教学中应做到“以生为本”,充分相信学生,高度尊重学生,全面依靠学生,把学习的主动权交给学生,课堂上给学生提供了足够大的自主学习的空间,让学生在自主、动手、合作、探究、交往的氛围中去获取知识,把学生的学习潜能激发出来.倡导“低入”、“先做后学,先会后学”、“先学后教”、“以学定教”、“小组合作学习”的广告设计教学课堂.在现代艺术教育的学科建设中应该占有重要的位置.本文的主旨就是从建立顺应经济社会发展的教育教学理念为方向,分析提升广告设计教学存在的一些问题,提出了一些实践方法和设想.从多个方面对广告设计教学进行初步的探讨,希望能对以后的实践及教学起到一定的促进作用和参考价值.     

一种辨识Wiener-Hammerstein模型的新方法

针对非线性Wiener-Hammerstein模型,提出利用粒子群优化算法对非线性模型进行辨识的新方法.该方法的基本思想是将非线性系统的辨识问题转化为参数空间上的优化问题;然后采用粒子群优化算法获得该优化问题的解.为了进一步增强粒子群优化算法的辨识性能,提出利用一种混合粒子群优化算法.最后,仿真结果验证了该方法的有效性和可行性.

     

Towards Proof Planning for ω

This paper describes the proof planning system _ω⁺ for the meta theorem prover for LF implemented in Twelf. The main contributions include a formal system that approximates the flow of information between assumptions and goals within a meta proof, a set of inference rules to reason about those approximations, and a soundness proof that guarantees that the proof planner does not reject promising proof states. Proof planning in _ω⁺ is decidable.     

Design of optimal reduced order filters

This paper shows that the design of a reduced order optimal filter is equivalent to a frequency weighted norm model reduction problem.     

(2+1)-dimensional ZK–Burgers equation with the generalized beta effect and its exact solitary solution

The (1 ＋1)-dimensional mathematical model had been extensively derived to describe Rossby solitary waves in a line in the past few decades. But as is well known, the (1 ＋1)-dimensional model cannot reflect the generation and evolution of Rossby solitary waves in a plane. In this paper, a (2 ＋1)-dimensional nonlinear Zakharov–Kuznetsov–Burgers equation is derived to describe the evolution of Rossby wave amplitude by using methods of multiple scales and perturbation expansions from the quasi-geostrophic potential vorticity equations with the generalized beta effect. The effects of the generalized beta and dissipation are presented by the Zakharov–Kuznetsov–Burgers equation. We also obtain the new solitary solution of the Zakharov–Kuznetsov equation when the dissipation is absent with the help of the Bernoulli equation, which is different from the common classical solitary solution. Based on the solution, the features of the variable coefficient are discussed by geometric figures Meanwhile, the approximate solitary solution of Zakharov–Kuznetsov–Burgers equation is given by using the homotopy perturbation method. And the amplitude of solitary waves changing with time is depicted by figures. Undoubtedly, these solitary solutions will extend previous results and better help to explain the feature of Rossby solitary waves.     

A sensitivity study of the Navier–Stokes-α model

We present a sensitivity study of the Navier Stokes-$\alpha$ model with respect to perturbations of the differential filter length $\alpha$. The parameter-sensitivity is evaluated using the sensitivity equations method. Once formulated, the sensitivity equations are discretized and computed alongside the NS$\alpha$ model using the same finite elements in space, and Crank–Nicolson in time. We provide a complete stability analysis of the scheme, along with the results of several benchmark problems in both 2D and 3D. We further demonstrate a practical technique to utilize sensitivity calculations to determine the reliability of the NS$\alpha$ model in problem-specific settings. Lastly, we investigate the sensitivity and reliability of important functionals of the velocity and pressure solutions.     

Invariant analysis and conservation laws of (2+1) dimensional time-fractional ZK–BBM equation in gravity water waves

This paper intends to make an in-depth study on the symmetry properties and conservation laws of the ($2+1$) dimensional time fractional Zakharov–Kuznetsov–Benjamin–Bona–Mahony (ZK–BBM) equation with Riemann–Liouville fractional derivative. Symmetry properties have been investigated here via Lie symmetry analysis method. In view of Erdélyi-Kober fractional differential operator, the reduction of ($2+1$) dimensional time fractional ZK–BBM equation has been done into fractional ordinary differential equation. To analyse the conservation laws, new theorem of conservation law has been proposed here for constructing the new conserved vectors for ($2+1$) dimensional time fractional ZK–BBM equation with the help of formal Lagrangian.     

RBF神经网络参数估计的两种混合优化算法

基于全局搜索的进化算法和一种局部搜索算法———结构化的非线性参数优化方法（ＳＮＰＯＭ）,提出两种混合的优化算法来估计ＲＢＦ神经网络中的参数：１）初始化一定数目的种群作为ＳＮＰＯＭ 的初始值得到其适应值,通过选择、交叉和替换策略来更新种群;２）采用进化算法运行一定的代数,从最终群体中选取一些个体进一步用ＳＮＰＯＭ来优化．这两种混合优化算法的本质是用进化算法为ＳＮＰＯＭ 搜寻最优初始值,以得到全局最优解．仿真实验结果表明,该混合算法比单独使用进化算法或ＳＮＰＯＭ 更优,且优于其他一些算法．

     

软件人群在入侵检测系统中的协调控制

在深入研究大系统控制理论,人工智能和“软件人”智能检测技术的基础上,采用先进的分布式体系结构,提出一种基于“软件人”群(MSM)的智能入侵检测协商模型.模型采取无控制中心的“软件人”群体结构,避免了单个中心分析器带来的单点失效问题.每个数据采集部件,检测部件和分析部件都是独立的单元,不仅实现了数据采集的分布化,而且将入侵检测和实时响应分布化,提高了系统的健壮性,真正实现了分布式检测的思想.

     

Rational and semi-rational solutions of the y-nonlocal Davey–Stewartson I equation

The nonlocal Davey–Stewartson (DS) I equation with a parity-time-symmetric potential with respect to the $y$-direction, which is called the $y$-nonlocal DS I equation, is a two-dimensional analogue of the nonlocal nonlinear Schrödinger (NLS) equation. The multi-breather solutions for the $y$-nonlocal DS I equation are derived by using the Hirota bilinear method. Lump-type solutions and hybrid solutions consisting of lumps sitting on periodic line waves are generated by long wave limits of the obtained soliton solutions. Also, various types of analytical solutions for the nonlocal NLS equation with negative nonlinearity, including both the Akhmediev breathers and the Peregrine rogue waves sitting on periodic line waves, can be generated with appropriate constraints on the parameters of the obtained exact solutions of the $y$-nonlocal DS I equation. Particularly, we show that a family of hybrid solitons describing the Peregrine rogue wave that coexists with the Akhmediev breather, both of them sitting on a spatially-periodic background can be thus obtained.     

Downside-risk控制下的供应链收益共享契约设计研究

运用Downside-risk约束,对一个两阶供应链模型中风险规避型零售商与其上游风险中性供应商之间的协调进行契约设计和建模,在供应链收益共享契约下风险约束得到满足,并且供应商和零售商的利润均得到了提高.同时,供应链收益共享契约得到有效设计时,风险中性方可为风险规避方提供相应的风险保护,满足其风险约束,可产生更多的利润,以更好地协调供应链.算例分析验证了该结论的有效性.

     

含不可控变迁的Petri网监控器设计

在基于Petri网建模的含不可控事件的离散事件系统监控器设计中,当给定的控制目标为Parikh矢量约束时,提出通过转换矩阵R将不可控变迁导致的非法不等式约束变换为允许约束,并求得相应监控器.构造矩阵方程求解R,通过矩阵方程的相容性判断R的存在性,并给出利用广义逆矩阵求解R的算法,得到对应的允许约束和监控器.同时提出代价函数,用于寻找控制观测代价最小的监控器.最后通过实例验证了该算法的正确性和有效性.