带磨损因子的排序问题     

刘静  孙世杰 《温州大学学报(社会科学版)》2004,17(5):58-61

本考虑下述带磨损因子的排序问题：n个工件j，j=1，2，…，n，在同一台机器上依次加工，其所需的加工时间同它被开始加工的时间有关，越后加工其所需的加工时间越多；要求适当排列这n个工件的加工顺序，使目标函数值达最小．对加工全程、完工时间之和这两个目标函数中给出了相应条件下的最优算法．  相似文献   

海洋科技创新对海洋经济增长的门槛效应研究     

吴梵  高强  刘韬 《科技管理研究》2019,39(20)

在"科技强国"的背景下,基于2007-2016年中国沿海11省市面板数据,利用门槛模型考察海洋科技创新对海洋经济增长的门槛效应,分别以对外开放和金融发展为门槛变量,研究表明海洋科技创新对海洋经济增长有明显的双重门槛效应,并提出相应政策建议。  相似文献   

Optimal parametrization in numerical construction of curve   总被引：1，自引：0，他引：1  

E.B. Kuznetsov 《Journal of The Franklin Institute》2007,344(5):658-671

The application of the optimal parametric continuation method to constructing a solution set curve for a system of nonlinear algebraic or transcendental equations depending on a parameter is considered. There are discussed two approaches to solving this problem—the use of iterative methods and reduction to an initial value problem for a system of ordinary differential equations. The algorithm suggested in this paper can also be used for finding an appropriate initial approximation when solving a system of nonlinear algebraic or transcendental equations not depending on a parameter by an iterative method.  相似文献   

Numerical solutions of optimal control for linear time-varying systems with delays via hybrid functions     

Xing Tao Wang 《Journal of The Franklin Institute》2007,344(7):941-953

By applying hybrid functions of general block-pulse functions and Legendre polynomials, the linear-quadratic problem of linear time-varying systems with delays are transformed into the optimization problem of multivariate functions. The approximate solutions of the optimal control and state as well as the optimal value of the objective functional are derived. The numerical examples illustrate that the algorithms are valid.  相似文献   

南水北调东线受水区水资源优化配置模型   总被引：3，自引：0，他引：3  

张平  郑垂勇  赵敏 《资源科学》2006,28(5):88-94

南水北调东线工程是我国南水北调总体布局中的重要组成部分，对其水资源进行优化配置将缓解受水区的水资源短缺问题及促进该区域的社会经济发展。根据南水北调工程东线受水区的特点,将其划分为3个子区、5个用水部门，选用国内生产总值最大、区域总缺水量最小、区域重要污染物排放量最小为目标，以水源可供水量、水源至用户的输水能力、用户需水量、区域协调发展等为约束条件，结合水源供水次序系数、用户用水公平系数、需水量、水源供水量等参数，共同构成了该区域的水资源优化配置模型。通过对模型的计算结果进行分析发现,在2010年和2030年，南水北调东线工程受水区的各用水部门中，生活、环境、航运、工业用水都可以满足，只有农业用水出现短缺；南水北调工程东线受水区水资源利用与经济发展协调度较好，而经济发展与环境保护之间的协调较差，整个区域资源、经济、环境的协调性一般。  相似文献   

英语学习词典运用策略中的最佳输入   总被引：1，自引：0，他引：1  

杨晓蓉 《太原大学学报》2008,9(1):112-114

词典对于英语写作的重要性是不言而喻的,但很多英语学习者却很难有效地运用词典策略．将词典的运用策略与最佳输入相结合,可以进一步促进和提高英语学习的能力。  相似文献   

Optimal location and controller design of STATCOM for power system stability improvement using PSO     

Sidhartha Panda  Narayana Prasad Padhy 《Journal of The Franklin Institute》2008,345(2):166-181

The optimal location of a static synchronous compensator (STATCOM) and its coordinated design with power system stabilizers (PSSs) for power system stability improvement are presented in this paper. First, the location of STATCOM to improve transient stability is formulated as an optimization problem and particle swarm optimization (PSO) is employed to search for its optimal location. Then, coordinated design problem of STATCOM-based controller with multiple PSS is formulated as an optimization problem and optimal controller parameters are obtained using PSO. A two-area test system is used to show the effectiveness of the proposed approach for determining the optimal location and controller parameters for power system stability improvement. The nonlinear simulation results show that optimally located STATCOM improves the transient stability and coordinated design of STATCOM-based controller and PSSs improve greatly the system damping. Finally, the coordinated design problem is extended to a four-machine two-area system and the results show that the inter-area and local modes of oscillations are well damped with the proposed PSO-optimized controllers.  相似文献   

Bond graph formulation of an optimal control problem for linear time invariant systems   总被引：1，自引：0，他引：1  

Wilfrid Marquis-Favre  Omar Mouhib 《Journal of The Franklin Institute》2008,345(4):349-373

A recent communication has proposed a conjectural procedure for representing a category of optimal control problems in bond graph language [W. Marquis-Favre, B. Chereji, D. Thomasset, S. Scavarda, Bond graph representation of an optimal control problem: the dc motor example, in: ICBGM’05 International Conference of Bond Graph Modelling and Simulation, New Orleans, USA, January 23-27, 2005, pp. 239-244]. This paper aims at providing a fundamental theory for proving the effectiveness of this procedure. The class of problem that the procedure can deal with has been extended. Its application was formerly restricted to linear time invariant siso system. The systems considered now are linear time invariant mimo systems. The optimization objective is the minimization of dissipation and input. The developments concerning the optimal control problem are based on the Pontryagin maximum principle and the proof of the effectiveness of the procedure makes a broad use of the port-Hamiltonian concept. As a result, the bond graph representation of the given optimization problem enables the analytical system, which provides the optimal solution, to be derived. The work presented in this paper is the first step in research with perspectives towards formulating dynamic optimization problems in bond graph and, towards coupling this formulation with a sizing methodology using bond graph language and a state-space inverse model approach. This sizing methodology, however, is not the topic of this paper and thus is not presented here.  相似文献   

流域水土资源优化配置的几种方法比较   总被引：9，自引：0，他引：9  

耿艳辉  闵庆文  成升魁 《资源科学》2007,29(2):188-193

目前关于流域水土资源优化配置研究的特点表现为：对单项的水、土资源优化配置研究较多,把两者结合起来的研究较少;分别从宏观和微观两个尺度研究的较多,将两种尺度结合起来研究的较少;越来越重视资源配置模式下的生态系统服务功能状况及其能否满足特定区域可持续发展的需要;研究方法逐渐由定性向定量化转变,在定量研究中,较多使用一般线性规划、灰色线性规划、动态规划、多目标决策和系统动力学等方法;越来越重视以3S技术为基础,结合专业模型进行模拟,为水土资源配置和管理提供高质量的科学决策支持,但目前还没有建立完善的区域性的支持系统。通过重点对水土资源优化配置的定量化方法进行比较分析,今后的研究应当重视：①进一步完善流域水土资源优化配置的理论与方法,特别是与区域特点相结合,利用系统科学等多种学科的理论和方法实现宏观尺度上的优化配置;②加强GIS技术与定量模型的契合;③着力解决若干重要的科学和实践问题,如： 特定地区生态效益的量化、生态效益与经济效益比例的确定、生态需水量的理论与方法、森林植被的水文效应、农业节水与水资源管理关键技术等;④开发建立流域水土资源优化的决策支持系统。  相似文献   

缴费确定型企业年金最优投资策略研究     

叶燕程  高随祥 《中国科学院大学学报》2007,24(2):149-153

本文利用随机控制理论研究缴费确定型企业年金的最优投资策略,分别在固定缴费和随机缴费情形下,建立基于给付损失最小化的企业年金最优投资模型,通过求解HJB方程得到最优投资策略和给付水平的显式解,并对固定缴费时的最优策略进行蒙特卡洛仿真模拟.  相似文献