Multiobjective Imperialist Competitive Algorithm for Solving Nonlinear Constrained Optimization Problems

Nonlinear constrained optimization problem(NCOP) has been arisen in a diverse range of sciences such as portfolio, economic management, airspace engineering and intelligence system etc.In this paper, a new multiobjective imperialist competitive algorithm for solving NCOP is proposed.First, we review some existing excellent algorithms for solving NOCP; then, the nonlinear constrained optimization problem is transformed into a biobjective optimization problem. Second, in order to improve the diversity of evolution country swarm, and help the evolution country swarm to approach or land into the feasible region of the search space, three kinds of different methods of colony moving toward their relevant imperialist are given. Thirdly, the new operator for exchanging position of the imperialist and colony is given similar as a recombination operator in genetic algorithm to enrich the exploration and exploitation abilities of the proposed algorithm. Fourth, a local search method is also presented in order to accelerate the convergence speed. At last, the new approach is tested on thirteen well-known NP-hard nonlinear constrained optimization functions, and the experiment evidences suggest that the proposed method is robust, efficient, and generic when solving nonlinear constrained optimization problem. Compared with some other state-of-the-art algorithms, the proposed algorithm has remarkable advantages in terms of the best, mean, and worst objective function value and the standard deviations.     

散射区域加权压缩感知ISAR成像

压缩感知(compressive sensing,CS)理论为少量脉冲条件下实现高分辨逆合成孔径雷达(inverse synthetic aperture radar, ISAR)成像提供了新方法。然而由于CS的噪声敏感性,其成像易受到噪声污染;另外,少量脉冲条件下很难保证噪声参数估计精度,这进一步加剧了ISAR成像污染。针对这一问题,提出一种散射区域加权CS ISAR成像算法,利用目标散射区域信息对冗余字典中的基函数进行加权,修正CS重建算法以抑制噪声散斑。为提高噪声参数估计精度,对回波采样建立子序列矩阵,提出矩阵扰动理论噪声参数估计方法。实验结果表明,所提方法能够有效抑制噪声影响,提高低信噪比和少量脉冲条件下ISAR成像质量。     

虚拟试验设计中的序贯极大熵方法研究

针对包舍计算耗时仿真模型的虚拟试验预测模型建模过程，提出了一种序贯极大熵试验设计方法。通过调整高斯先验过程协方差函数，在预测模型误差较大区域序贯地增加新试验点，合理权衡试验点数目与预测模型精度。设计数学算例演示了序贯极大熵试验设计方法的效率，并证明优于一步法，适用于虚拟试验预测模型建模。     

AN AUTOMATED REFERENCE POINT-LIKE APPROACH FOR MULTICRITERIA SHORTEST PATH PROBLEMS

1. Introduction Nowadays the exponential and convergent development of informatics and telecommunications, including Internet, makes that, in many communication networks, important decisions of technical nature have to be made in short time periods or even in real-time. This is particularly relevant in the context of routing models involving the calculation and selection of routes (corresponding to loopless paths) for node to node traffic flows, which seek to optimize certain metric(s) while s…     

A NEW METHOD FOR FINDING MAJOR EFFICIENT SOLUTIONS AND MAJOR OPTIMAL SOLUTIONS OFDISCRETE MULTIOBJECTIVE PROGRAMMING

1.IntroductionThetermefficiencyisalsoknownasadmissibility,ornoninferiority.Itdepictsthemultiobjectiveprogrammingfromtheangleofsatisfaction.Majorefficiencyisbasedonthelawofmajority,whichhasbeenilitensivilyinvestigatedinpapers[1--3].Theprimaryconceptsaremajorefficientsolutionandmajoroptimalsolution.Considerthefollowingmultiobjectiveprogramming:whereXCR"isthefeasibleregion,f:X~ac,f(x)=(fi(x),f200,'',fm(x))",andfi:X~Risareal-valuedfunction,acandacareEuclideanspaces.oIntroducetwoconesetsHandH…     

基于分段模糊Lyapunov方法的离散模糊控制系统设计

针对应用公共Lyapunov函数方法和模糊Lyapunov函数方法判定离散T-S模糊控制系统稳定性存在的保守性和难度，在定义离散型分段模糊Lyapunov函数的基础上，应用并行分布补偿方法（PDC）设计出使模糊系统全局渐近稳定的拉制器，并提出和证明了一个新的判定用环离散T-S模糊系统稳定的充分条件，该条件降低了上述方法的保守性和难度。通过一个仿真例子验证了方法的有效性。     

考虑姿态禁忌约束的航天器安全姿态跟踪控制

针对航天器姿态跟踪过程中的姿态约束问题,提出了一种基于势函数的安全姿态机动控制算法。与姿态定点机动的姿态约束问题不同,引入误差四元数和误差角速度,建立了航天器姿态跟踪误差模型。采用四元数描述了姿态禁忌区域,并根据禁止姿态最小允许角构造了一种新的规避高斯势函数。利用规避势函数和吸引势函数得到安全姿态机动控制器,对于无扰动和有扰动的情况分别分析了闭环控制系统的Lyapunov稳定性。最后,对于有约束的姿态跟踪情况进行了计算机数值仿真。仿真结果表明,所提出的控制方法既能实现姿态跟踪的目的,又能确保航天器在机动过程中不会进入姿态禁忌区域。     

An affine scaling derivative-free trust region method with interior backtracking technique for bounded-constrained nonlinear programming

This paper proposes an arlene scaling derivative-free trust region method with interior backtracking technique for bounded-constrained nonlinear programming. This method is designed to get a stationary point for such a problem with polynomial interpolation models instead of the objective function in trust region subproblem. Combined with both trust region strategy and line search technique, at each iteration, the affine scaling derivative-free trust region subproblem generates a backtracking direction in order to obtain a new accepted interior feasible step. Global convergence and fast local convergence properties are established under some reasonable conditions. Some numerical results are also given to show the effectiveness of the proposed algorithm.     

城市居住空间分异仿真模型框架研究

城市居住空间分异研究中传统的基于微分方程的建模方法难以描述城市空间格局形成中所表现出来的复杂的时空变化，以及形成的原因。基于多智能体的“从下而上”的建模方法为研究城市空间结构提供了新的思路。以城市居住空间分异现象的仿真模拟为例，采用PEAs描述物理世界模型，ERA方案构建面向对象的逻辑模型，Swarm实现仿真。提出的PEAS-ERA-SWARM多智能体建模与实现的方法，可以使研究人员快速构建高质量、可维护的多智能体仿真应用。     

单纯形法优化PID参数的新途径

本文探讨了一种优化PID参数的新途径,即直接作单纯形各顶点所对应的PID控制器的单位阶跃响应曲线,以此曲线的优劣来代替解析目标函数的值,作为寻优的标准。把该方法用于一加热炉的主控制器设计,结果令人满意。     

直接数据域迭代空时自适应处理方法

针对常规空时自适应处理(space-time adaptive processing, STAP)在机载雷达非均匀杂波环境下杂波抑制性能下降的问题,提出一种直接数据域(direct data domain, DDD)迭代空时自适应处理方法。首先利用数据的特殊结构和空时谱的稀疏性引入一种新的迭代自适应(iterative adaptive approach, IAA)空时二维谱估计算法,然后在获得待检测单元空时谱分布的基础上重构无孔径损失的协方差矩阵,最后根据目标信号在空时平面的分布特点,提出一种新的目标剔除算法对协方差矩阵进行修正,以避免目标自相消。仿真实验结果表明,在存在3%阵列误差的情况下,所提方法在旁瓣杂波区的改善因子比传统直接数据域方法高出约10 dB、比多普勒平移法高出约5 dB。     

SIMPLE COMPUTING OF THE CUSTOMER LIFETIME VALUE:A FIXED LOCAL-OPTIMAL POLICY APPROACH

In this paper,we present a new method for finding a fixed local-optimal policy for computing the customer lifetime value.The method is developed for a class of ergodic controllable finite Markov chains.We propose an approach based on a non-converging state-value function that fluctuates（increases and decreases） between states of the dynamic process.We prove that it is possible to represent that function in a recursive format using a one-step-ahead fixed-optimal policy.Then,we provide an analytical formula for the numerical realization of the fixed local-optimal strategy.We also present a second approach based on linear programming,to solve the same problem,that implement the c-variable method for making the problem computationally tractable.At the end,we show that these two approaches are related：after a finite number of iterations our proposed approach converges to same result as the linear programming method.We also present a non-traditional approach for ergodicity verification.The validity of the proposed methods is successfully demonstrated theoretically and,by simulated credit-card marketing experiments computing the customer lifetime value for both an optimization and a game theory approach.     

基于函数cotx变换的灰色建模方法

在对原始序列经过标准化处理的基础上提出经函数cotx变换来提高离散数据序列光滑度的方法，并从理论上证明了离散数据序列经过这种变换后可以大大提高光滑度且比“对数函数”法及“幂函数”法更加有效。文末把其用在客运量的预测中，此应用实例表明了本文提出方法的有效性。     

地海交界环境与其上方双目标复合散射的混合算法研究

采用蒙特卡罗方法建立地海交界分区域复合粗糙面模型,陆地区域采用高斯谱模拟,近海海面区域采用基于变浅系数的北海海浪工程(joint North Sea wave project, JONSWAP)谱模拟;提出了基于分形理论的边界赋形方法,并运用多种反正切权函数处理实现了线型、月牙型、峡谷型和分形型边界的地海交界环境;基于矩量法和基尔霍夫近似的混合算法研究了地海交界环境与其上方双目标的复合电磁散射特性,对比了双目标分别位于两种典型环境和地海交界环境上方时的复合散射系数曲线,研究了复合散射系数随入射角、陆地区域参数、海面参数、边界形状、双目标参数及双目标类型的变化情况,并做了详细分析与讨论。结果表明该混合算法的高效性和准确性,数值仿真结果对地海交界环境上方目标的探测、遥感及成像具有借鉴意义。     

Adjustable entropy function method for support vector machine

Based on KKT complementary condition in optimization theory, an unconstrained non-differential optimization model for support vector machine is proposed. An adjustable entropy function method is given to deal with the proposed optimization problem and the Newton algorithm is used to figure out the optimal solution. The proposed method can find an optimal solution with a relatively small parameter p, which avoids the numerical overflow in the traditional entropy function methods. It is a new approach to solve support vector machine. The theoretical analysis and experimental results illustrate the feasibility and efficiency of the proposed algorithm.     

过程系统寻优新方法——非线性映射主轴分析法

对于实际过程系统的寻优，大都是多维的非线性优化问题，寻求一种全局稳定最优数值解的方法，一直是人们关注的课题．本文应用人工神经网络的拓扑映射技术，提出非线性映射主轴分析法．这种新方法将一个多维空间的非线性问题降维映射到二维平面，籍目标函数等值分布曲线的分析，决策出最优点或最优区域，通过逆映射运算可将其还原到多维空间用原始变量表示．从本文的例证可见，这种方法直观、简便、有效、得出的最优解准确、可靠     

模拟电路单—故障的模糊神经网络诊断方法

本文提出了利用模糊神经网络进行模拟电路故障诊断的方法。该方法根据模式识别原理,利用建立在神经网络中的模糊特征库,推断出故障特征对各元件故障的隶属程度,并指示元件参数的变化趋势。这一方法为解决模拟电路及一些含有非线性元件的电路的故障诊断问题提供了一种新方法。     

Prescribed Performance Finite-Time Tracking Control for Uncertain Nonlinear Systems

This work investigates the finite-time tracking control problem for a class of uncertain strict-feedback nonlinear systems from a new perspective. First, a novel concept called finite-time performance function(FTPF) is defined. Further, a new sufficient condition of finite-time stability is derived and the tracking error can converge to a predefined region within a finite-time interval. The design process of the proposed technique is simpler. Finally, four simulation examples are carried out to illustrate the effectiveness of presented method.     

Computer-aided design of classical linear compensators with application to aerospace

A new Matlab function based on a versatile compensator design approach is developed. This function allows design of lead-lag, PID, proportional plus rate feedback, proportional-integral plus rate feedback, and nth order linear compensators. The primary inputs to this function are the plant transfer function and the desired closedloop behavior in terms of an nth order transfer function. The output is the particular compensator parameters. The unified design approach is primarily based on minimizing a mean-squared error type objective function. This minimization gives the compensator parameters in terms of a set of linear simultaneous algebraic equations. This solution method requires the user to input such parameters as the lower and upper limits of frequency range of interest; such parameters are automatically determined by the use of numerical optimization. The design method and the associated software are demonstrated by solving a flexible satellite problem, and the results are compared with those obtained by two other methods reported in the open literatures.     

基于人-机-网络一体化的综合集成管理支持系统研究

以综合集成方法为指导,在提出面向复杂管理系统的综合集成管理思想的基础上,着重研究了采用以人为主导、人-机-网络一体化的技术路线,构建人-机-网络一体化支持系统以及系统的组成与结构、功能与技术内涵,并进一步探讨和建立了综合集成管理支持系统应用的概念框架.