非线性不等式与等式约束的多目标规划问题的区间极大熵方法

利用极大熵方法将带多个非线性不等式约束和多个非线性等式约束的多目标规划问题变为两个非线性不等式约束的单个可微的目标函数优化问题,并结合区间分析知识给出一种新的解决多目标规划问题的区间方法.     

解非线性规划的凝聚函数法

本文提出求解非线性规划的一种新方法,称为凝聚函数法。首先用“极大值”约凍代替原约束集合,把原来的多约束优化问题变为一个不可微的单约束优化问题;然后利用代理约束概念和最大熵原理导出一个可微函数,并以此逼近不可微的极大值函数,将原问题化为一个可微的单约束优化问题.在此基础上,我们构造了一个乘子惩罚函数算法。该算法具有收敛稳定、速度快和易于计算机实现等优点,特别适于求解含大量约束的非线性规划问题。     

求解约束优化问题的一种新的遗传算法

提出一种新的求解约束优化问题的遗传算法,算法通过重新定义可行解与不可行解的适应度函数分别对它们进行选择,有效避免了惩罚函数法引入参数所带来的困难,重新设计的交叉算子使得算法对解空间的寻优范围扩大了.数值实验结果表明算法具有较好的鲁棒性,且对最优解位于约束边界上的一类问题具有很大优势.     

0-1线性规划的连续化及其遗传算法解法

将0-1离散规划通过一个非线性等式约束表示为[0,1]区间上等价的连续变量非线性规划列式.对非线性等式约束的问题进行了两种方法的处理.第一种方法使用乘子法,第二种方法将非线性的等式约束近似为一个非线性的不等式约束,均利用遗传算法程序GENOCOP进行了求解.对多个算例进行了计算,结果表明了该方法的可行性和有效性.     

带新NCP函数的Lagrangian乘子方法

在经营管理、工程设计、科学研究、军事指挥等方面普遍存在着最优化问题,而实际问题中出现的绝大多数问题都被归纳为非线性规划问题之中。作为带等式、不等式约束的复杂事例,最优化问题的求解向来较为繁琐、困难。适当条件下,非线性互补函数(NCP)可以与约束优化问题相结合,其中NCP函数的无约束极小解对应原约束问题的解及其乘子。本文提出了一类新的NCP函数用于解决等式和不等式约束非线性规划问题,结合新的NCP函数构造了增广Lagrangian函数。在适当假设条件下,证明了增广Lagrangian函数与原问题的解之间的一一对应关系。同时构造了相应算法,并证明了该算法的收敛性和有效性。     

解非线性规划问题的非参数罚函数多目标正交遗传算法

对非线性规划问题的处理通常采用罚函数法,使用罚函数法的困难在于参数的选取.本文提出了一种解非线性规划问题非参数罚函数多目标正交遗传算法,对违反约束的个体进行动态的惩罚以保持群体中不可行解的一定比例,从而不但有效增加种群的多样性,而且避免了传统的过度惩罚缺陷,使群体更好地向最优解逼近.数据实验表明该算法对带约束的非线性规划问题求解是非常有效的.     

基于一类光滑函数法求解选址问题

选址问题是组合优化中一类有着重要理论意义和广泛实际背景的问题.在利用数学模型解决这类问题时经常会遇到非线性L_1问题,也就是不可微优化问题.为了解决这类问题,构造了适合于选址问题的一类新的光滑函数,并对这类光滑函数进行了性质描述,然后在此基础上提出了基于有效集法进行优化求解的计算步骤.最后,以实例证明了这类光滑函数应用在选址问题的优化求解上是有效的.     

构造非线性差分方程精确解的一种方法

在齐次平衡法、试探函数法的基础上,给出指数函数所组成的两种试探函数法,并借助符号计算系统Mathematica构造了Hybrid-Lattice系统、mKdV差分微分方程、Ablowitz-Ladik.Lattice6系统等非线性离散系统的新的精确孤波解.     

求解非线性互补问题一个新的Jacobian光滑化方法

本文构造了非线性互补问题一个新的光滑逼近函数,分析了该函数的一些基本性质.利用这一新的光滑逼近函数建立了求解非线性互补问题的一个Jacobi光滑化方法,并证明了在适当的条件下这一算法是全局及局部超线性收敛的.数值结果表明该方法是有效的.     

解非线性互补问题的积分水平集方法

本文考虑有约束的非线性互补问题的全局最优化问题,在文《IntegralGlobalOptimizationMethodforSolutionofNonlinearComplementarityproblem》和《一种修正的求总极值的积分一水平集方法》的基础上,给出了一种修正的求约束总极值的积分一水平集方法,它同样具有修正的求总极值的积分一水平集方法的两个特点：1）每一步需要构造一个新的函数,而且它与原目标函数具有相同的总极值;2）避免了郑权算法在一般情况下,由于水平集不易求得而造成难以求出水平的困难,并证明了算法的收敛性     

Reliability stochastic optimization for a series system with interval component reliability via genetic algorithm

This paper deals with chance constraints based reliability stochastic optimization problem in the series system. This problem can be formulated as a nonlinear integer programming problem of maximizing the overall system reliability under chance constraints due to resources. The assumption of traditional reliability optimization problem is that the reliability of a component is known as a fixed quantity which lies in the open interval (0, 1). However, in real life situations, the reliability of an individual component may vary due to some realistic factors and it is sensible to treat this as a positive imprecise number and this imprecise number is represented by an interval valued number. In this work, we have formulated the reliability optimization problem as a chance constraints based reliability stochastic optimization problem with interval valued reliabilities of components. Then, the chance constraints of the problem are converted into the equivalent deterministic form. The transformed problem has been formulated as an unconstrained integer programming problem with interval coefficients by Big-M penalty technique. Then to solve this problem, we have developed a real coded genetic algorithm (GA) for integer variables with tournament selection, uniform crossover and one-neighborhood mutation. To illustrate the model two numerical examples have been solved by our developed GA. Finally to study the stability of our developed GA with respect to the different GA parameters, sensitivity analyses have been done graphically.     

A nonlinear interval number programming method for uncertain optimization problems

In this paper, a method is suggested to solve the nonlinear interval number programming problem with uncertain coefficients both in nonlinear objective function and nonlinear constraints. Based on an order relation of interval number, the uncertain objective function is transformed into two deterministic objective functions, in which the robustness of design is considered. Through a modified possibility degree, the uncertain inequality and equality constraints are changed to deterministic inequality constraints. The two objective functions are converted into a single-objective problem through the linear combination method, and the deterministic inequality constraints are treated with the penalty function method. The intergeneration projection genetic algorithm is employed to solve the finally obtained deterministic and non-constraint optimization problem. Two numerical examples are investigated to demonstrate the effectiveness of the present method.     

An Algorithm of Global Optimization for Rational Functions with Rational Constraints

To solve a system of nonlinear equations, Wu wen-tsun introduced a new formative elimination method. Based on Wu's method and the theory of nonlinear programming, we here propose a global optimization algorithm for nonlinear programming with rational objective function and rational constraints. The algorithm is already programmed and the test results are satisfactory with respect to precision and reliability.     

一个解非线性0-1整数规划问题基于罚函数的混合粒子群优化算法

利用罚函数思想把非线性0-1整数规划问题转化为无约束最优化问题,然后把粒子群优化和罚函数方法结合构造出一个基于罚函数的混合粒子群优化算法,数值结果表明所提出的算法是有效的.     

非线性半定规划的逐次线性化柔性惩罚法

针对非线性不等式约束半定规划问题提出一种新的逐次线性化方法, 新算法既不要求罚函数单调下降, 也不使用过滤技巧, 尝试步的接受准则仅仅依赖于目标函数和约束违反度, 罚函数中对应于成功迭代点的罚因子不需要单调增加. 新算法或者要求违反约束度量有足够改善, 或者在约束违反度的一个合理范围内要求目标函数值充分下降, 在通常假设条件下, 分析了新算法的适定性及全局收敛性. 最后, 给出了非线性半定规划问题的数值试验结果, 结果表明了新算法的有效性.     

A nonlinear programming approach to a very large hydroelectric system optimization

A large scale hydroelectric system optimization is considered and solved by using a non-linear programming method. The largest numerical case involves approximately 6 000 variables, 4 000 linear equations, 11 000 linear and nonlinear inequality constraints and a nonlinear objective function. The solution method is based on

1. partial elimination of independent variables by solving linear equations,
2. essentially unconstrained optimization of a compound function that consists of the objective function, nonlinear inequality constraints and part of the linear inequality constraints. The compound function is obtained via penalty formulation.

The algorithm takes full advantage of the problem's structure and provides useful solutions for real life problems that, in general, are defined over empty feasible regions.     

Sequential Systems of Linear Equations Algorithm for Nonlinear Optimization Problems with General Constraints

In Ref. 1, a new superlinearly convergent algorithm of sequential systems of linear equations (SSLE) for nonlinear optimization problems with inequality constraints was proposed. At each iteration, this new algorithm only needs to solve four systems of linear equations having the same coefficient matrix, which is much less than the amount of computation required for existing SQP algorithms. Moreover, unlike the quadratic programming subproblems of the SQP algorithms (which may not have a solution), the subproblems of the SSLE algorithm are always solvable. In Ref. 2, it is shown that the new algorithm can also be used to deal with nonlinear optimization problems having both equality and inequality constraints, by solving an auxiliary problem. But the algorithm of Ref. 2 has to perform a pivoting operation to adjust the penalty parameter per iteration. In this paper, we improve the work of Ref. 2 and present a new algorithm of sequential systems of linear equations for general nonlinear optimization problems. This new algorithm preserves the advantages of the SSLE algorithms, while at the same time overcoming the aforementioned shortcomings. Some numerical results are also reported.     

A gradient projection-multiplier method for nonlinear programming

This paper describes a gradient projection-multiplier method for solving the general nonlinear programming problem. The algorithm poses a sequence of unconstrained optimization problems which are solved using a new projection-like formula to define the search directions. The unconstrained minimization of the augmented objective function determines points where the gradient of the Lagrangian function is zero. Points satisfying the constraints are located by applying an unconstrained algorithm to a penalty function. New estimates of the Lagrange multipliers and basis constraints are made at points satisfying either a Lagrangian condition or a constraint satisfaction condition. The penalty weight is increased only to prevent cycling. The numerical effectiveness of the algorithm is demonstrated on a set of test problems.The author gratefully acknowledges the helpful suggestions of W. H. Ailor, J. L. Searcy, and D. A. Schermerhorn during the preparation of this paper. The author would also like to thank D. M. Himmelblau for supplying a number of interesting test problems.     

A feasible direction method for the semidefinite program with box constraints

In this paper, we try to solve the semidefinite program with box constraints. Since the traditional projection method for constrained optimization with box constraints is not suitable to the semidefinite constraints, we present a new algorithm based on the feasible direction method. In the paper, we discuss two cases: the objective function in semidefinite programming is linear and nonlinear, respectively. We establish the convergence of our algorithm, and report the numerical experiments which show the effectiveness of the algorithm.