A New Approach for Solving Nonlinear Equations Systems

This paper proposes a new perspective for solving systems of complex nonlinear equations by simply viewing them as a multiobjective optimization problem. Every equation in the system represents an objective function whose goal is to minimize the difference between the right and left terms of the corresponding equation. An evolutionary computation technique is applied to solve the problem obtained by transforming the system into a multiobjective optimization problem. The results obtained are compared with a very new technique that is considered as efficient and is also compared with some of the standard techniques that are used for solving nonlinear equations systems. Several well-known and difficult applications (such as interval arithmetic benchmark, kinematic application, neuropsychology application, combustion application, and chemical equilibrium application) are considered for testing the performance of the new approach. Empirical results reveal that the proposed approach is able to deal with high-dimensional equations systems.     

A Homotopy Approach to Solving Nonlinear Rational Expectation Problems

Many numerical methods have been developed in an attempt to find solutions to nonlinear rational expectations models. Because these algorithms are numerical in nature, they rely heavily on computing power and take sizeable cycles to solve. In this paper we present a numerical tool known as homotopy theory that can be applied to these methods. Homotopy theory reduces the computing time associated with an iterative algorithm by using a rational expectation problem with known solutions and transforming it into the problem at hand. If this transformation is performed slowly, homotopy theory also helps the global convergence properties of the numerical algorithm. We apply homotopy theory to Den Haan and Marcet's Parameterized Expectation Approach to show how homotopies improve the computing speed and global convergence properties of this algorithm.     

A New Approach to Solving Data Clusterization Problems

A new approach to solving some problems of cluster analysis is proposed, which reduces a multi-dimensional problem to a one-dimensional one.     

求解一类非线性整数规划的新方法

针对一类非线性整数规划问题，通过构造直接高散搜索方向提出了一种十分有效的算法。     

A Neural Network for Solving Nonlinear Programming Problems

A neural network for solving convex nonlinear programming problems is proposed in this paper. The distinguishing features of the proposed network are that the primal and dual problems can be solved simultaneously, all necessary and sufficient optimality conditions are incorporated, and no penalty parameter is involved. Based on Lyapunov, LaSalle and set stability theories, we prove strictly an important theoretical result that, for an arbitrary initial point, the trajectory of the proposed network does converge to the set of its equilibrium points, regardless of whether a convex nonlinear programming problem has unique or infinitely many optimal solutions. Numerical simulation results also show that the proposed network is feasible and efficient. In addition, a general method for transforming non-linear programming problems into unconstrained problems is also proposed. ID="A1" Correspondence and offprint requests to: Dr Z Chen, Department of Electronic Engineering, Brunel University, Uxbridge, Middle-sex, UK     

A Robust Algorithm for Solving Nonlinear Programming Problems

In this paper, we introduce a new algorithm for solving nonlinear programming (NLP) problems. It is an extension of Guo's algorithm [1] which possesses enhanced capabilities for solving NLP problems. These capabilities include: a) extending the variable subspace, b) adding a search process over subspaces and normalized constraints, c) using an adaptive penalty function, and d) adding the ability to deal with integer NLP problems, 0-1 NLP problems, and mixed-integer NLP problems which have equality constraints. These four enhancements increase the capabilities of the algorithm to solve nonlinear programming problems in a more robust and universal way. This paper will present results of numerical experiments which show that the new algorithm is not only more robust and universal than its competitors, but also its performance level is higher than any others in the literature.     

A Connectionist Approach for Solving Large Constraint Satisfaction Problems

An efficient neural network technique is presented for the solution of binary constraint satisfaction problems. The method is based on the application of a double-update technique to the operation of the discrete Hopfield-type neural network that can be constructed for the solution of such problems. This operation scheme ensures that the network moves only between consistent states, such that each problem variable is assigned exactly one value, and leads to a fast and efficient search of the problem state space. Extensions of the proposed method are considered in order to include several optimisation criteria in the search. Experimental results concerning many real-size instances of the Radio Links Frequency Assignment Problem demonstrate very good performance.     

一种求解3-SAT问题的新方法

可满足性问题(SatisfiabilityProblem,SAT)是计算科学的典型问题之一,目前有DP算法、SAT1.3算法和遗传算法等多种求解方法。文章根据Kennedy和Eberhart提出的二进制粒子群优化算法(BinaryParticleSwarmOptimizers),基于局部随机搜索策略,给出了一种求解3-SAT问题的新方法:基于局部随机搜索的改进二进制粒子群优化算法(ModifedBinaryParticleSwarmOptimizersBasedonlocalstochasticsearch,简称MBPSO)。数值实验表明,对于随机产生的3-SAT问题测试实例,该算法是一种高效实用的新方法。     

Solving Nonlinear Constrained Minimization Problems with a New Interval Valued Function

The paper represents a continuation of the work the author previously published in this journal for unconstrained problems. An interval (box) valued function, the so-called zone function, is introduced in the first section. The next section uses the new notion for finding global minima of continuous multivariate real functions over a set given by nonlinear inequality constraints. Two numerical examples are presented in the third section. The second numerical example gives a better approximation to a welded tubular structure problem than one that has appeared in the literature.     

A New Formulation Approach for Location-Routing Problems

A Location-Routing Problem (LRP) combines two difficult problems, facility location and vehicle routing, and as such it is inherently hard to solve. In this paper, we propose a different formulation approach than the common arc-based product-flow (Arc-BPF) approach in the literature. We associate product amounts to the nodes of the network resulting in a node-based product-flow (Node-BPF) formulation. Our main objective is to develop LRP models with fewer constraints and variables, which can be solved more efficiently. To introduce the proposed approach, we reformulate a complex four-index Arc-BPF LRP model from the literature as a three-index Node-BPF model, which computationally outperforms the former. We then introduce a heuristic method.     

A New Approach to Solving Equivalence Problem

An application of a new method for the equivalence recognition in a computation model whose objects are labeled directed graphs is illustrated by the example of multitape automata. The paper is focused on general ideas of the method discussed. An algorithm that recognizes equivalence of multitape automata with disjoint loops is described in detail.     

非线性方程组求解的一种新方法

针对现有的非线性方程组求解方法不能同时收敛到所有解的问题,提出了一种混合小生境遗传算法的求解新方法.采用确定性拥挤小生境创造出种群的小生境进化环境,克服遗传算法的遗传漂移现象,维持种群的多样性,使算法能同时收敛到多个解;以拟牛顿算法作为遗传算法的局部搜索算子进行精确搜索,进一步提高算法收敛速度和精度.选择了几组典型的多解非线性方程组进行了求解验证,结果表明所设计的混合小生境遗传算法能在解的定义域内同时收敛到所有解,收敛速度快、精度高,是求解非线性方程组全局解的一种有效方法.     

A New Evolutionary Algorithm for Solving Many-Objective Optimization Problems

In this paper, we focus on the study of evolutionary algorithms for solving multiobjective optimization problems with a large number of objectives. First, a comparative study of a newly developed dynamical multiobjective evolutionary algorithm (DMOEA) and some modern algorithms, such as the indicator-based evolutionary algorithm, multiple single objective Pareto sampling, and nondominated sorting genetic algorithm II, is presented by employing the convergence metric and relative hypervolume metric. For three scalable test problems (namely, DTLZ1, DTLZ2, and DTLZ6), which represent some of the most difficult problems studied in the literature, the DMOEA shows good performance in both converging to the true Pareto-optimal front and maintaining a widely distributed set of solutions. Second, a new definition of optimality (namely, L-optimality) is proposed in this paper, which not only takes into account the number of improved objective values but also considers the values of improved objective functions if all objectives have the same importance. We prove that L-optimal solutions are subsets of Pareto-optimal solutions. Finally, the new algorithm based on L-optimality (namely, MDMOEA) is developed, and simulation and comparative results indicate that well-distributed L-optimal solutions can be obtained by utilizing the MDMOEA but cannot be achieved by applying L-optimality to make a posteriori selection within the huge Pareto nondominated solutions. We can conclude that our new algorithm is suitable to tackle many-objective problems.      

A New Varying-Parameter Design Formula for Solving Time-Varying Problems

Neural Processing Letters - A novel finite-time convergent zeroing neural network (ZNN) based on varying gain parameter for solving time-varying (TV) problems is presented. The model is based on...     

Mapping Forests: A Comprehensive Approach for Nonlinear Mapping Problems

A new and robust mapping approach is proposed entitled mapping forests (MFs) for computer vision applications based on regression transformations. Mapping forests relies on learning nonlinear mappings deduced from pairs of source and target training data, and improves the performance of mappings by enabling nonlinear transformations using forests. In contrast to previous approaches, it provides automatically selected mappings, which are naturally nonlinear. MF can provide accurate nonlinear transformations to compensate the gap of linear mappings or can generalize the nonlinear mappings with constraint kernels. In our experiments, we demonstrate that the proposed MF approach is not only on a par or better than linear mapping approaches and the state-of-the-art, but also is very time efficient, which makes it an attractive choice for real-time applications. We evaluated the efficiency and performance of the MF approach using the BU3DFE and Multi-PIE datasets for multi-view facial expression recognition application, and Set5, Set14 and SuperTex136 datasets for single image super-resolution application.     

不等式约束的非线性规划混合遗传算法

针对带不等式约束的非线性规划问题,提出了一个混合遗传算法。该算法分为全局探测和局部开采两个阶段,全局探测阶段是通过在有潜力的小生境内嵌入单纯形搜索,快速确定有前景的区域;而局部开采阶段则是在最有前景的区域进行单纯形搜索。该算法增强了局部搜索能力并同时保持种群的多样性,有效地解决了遗传算法的过早收敛和局部搜索能力弱的问题。典型非线性规划算例验证了混合算法的效率、精度和可靠性。     

一种用于解决非线性滤波问题的新型粒子滤波算法

粒子滤波算法受到许多领域的研究人员的重视,该算法的主要思想是使用一个带有权值的粒子集合来表示系统的后验概率密度.在扩展卡尔曼滤波和Unscented卡尔曼滤波算法的基础上,该文提出一种新型粒子滤波算法.首先用Unscented卡尔曼滤波器产生系统的状态估计,然后用扩展卡尔曼滤波器重复这一过程并产生系统在k时刻的最终状态估计.在实验中,针对非线性程度不同的两种系统,分别采用5种粒子滤波算法进行实验.结果证明,文中所提出的算法的各方面性能都明显优于其他4种粒子滤波算法.     

基于遗传算法的非线性方程组求解

针对目前求解非线性方程组所采用的牛顿法及其变形算法存在的运算量大、求解速度慢的问题,提出了一个求解非线性方程组近似解的通用遗传算法。该算法主要采用求解目标函数极小值的思想,并结合遗传算法并行搜索的特点,通过选择和设置适当的父体选择策略、杂交算子、变异算子等参数,使算法取得了较高的收敛速度和精度。实验结果表明,该方法明显优于传统方法,并具有运算速度快、精度高、通用性好的特点。     

异构计算——求解超级问题的新途径

异构计算是近年来并行处理领域中新的研究热点。它的思想是充分利用一组汪同结构的高性能计算机求解含有不同并行性的超级问题。文中分析了异构计算的背景及特点，讨论了当前存在的问题。