Constrained Weapon–Target Assignment: Enhanced Very Large Scale Neighborhood Search Algorithm

Optimization problems solved using very large scale neighborhood (VLSN) search algorithms include scheduling problems, the capacitated minimum spanning tree problem, the traveling salesman problem, and weapon-target assignment (WTA). This correspondence paper presents an enhanced VLSN search algorithm for obtaining feasible solutions and constructing improvement graphs. This enhanced VLSN search algorithm solves the constrained WTA (CWTA) problem, in which the number of interceptors available to each weapon and the number of interceptors allowed to fire at each target have upper bounds. The proposed enhanced VLSN search algorithm can solve a CWTA problem with 100 targets and 100 weapons (where the upper bound on the number of interceptors for each weapon is one and both the lower and upper bounds on the number of interceptors for each target are equal to one) within an average of 3 s. This study demonstrates that the proposed Enhanced VLSN is superior to existing approaches.     

Heuristics for a multiperiod inventory routing problem with production decisions

Manufacturers who resupply a large number of retailers on a periodic basis continually struggle with the question of how to formulate a replenishment strategy. This paper presents a comparative analysis of a series of heuristics for an inventory routing problem (IRP) that arises in a manufacturing supply chain. The IRP is formulated as a mixed integer program with the objective of maximizing the net benefits associated with making deliveries in a specific time period to a widely dispersed set of customers. It is assumed that inventory can accumulate at the customer sites, but that all demand must be met without backlogging. Because optimal solutions were not within reach of exact methods, a two-step procedure was developed that first estimates daily delivery quantities and then solves a vehicle routing problem for each day of the planning horizon. As part of the methodology, a linear program is used to determine which days it is necessary to make at least some deliveries to avoid stockouts.The IRP is investigated in the context of an integrated production–inventory–distribution–routing problem (PIDRP). The full model takes into account production decisions and inventory flow balance in each period. For the computations, a previously developed branch-and-price algorithm is used that requires the solution of multiple IRPs (one in each period) to generate columns for the master problem. Testing showed that PIDRP instances with up to eight time periods and 50 customers can be solved within 1 h. This level of performance could not be matched by either CPLEX or an exact version of the branch-and-price algorithm.     

拒绝服务攻击下的多输入多输出非线性系统无模型自适应控制

针对多输入多输出(MIMO)非线性离散时间系统,研究系统遭受拒绝服务(DoS)攻击和随机发生数据包丢失下的控制问题.首先采用两个独立的伯努利分布对周期性DoS攻击和随机发生的数据包丢失进行建模.其次结合DoS攻击设计无模型自适应控制(MFAC)算法,进而通过理论分析和数学推导证明所提算法的收敛性.并且通过结合先前时刻数...     

基于改进蚁群算法的多约束QoS路由优化研究

本文建立了多约束QoS路由模型，并对基本蚁群算法的信息素更新策略进行了改进，提出了一种基于改追蚁群算法的多约束QoS路由优化算法，实例计算结果证明了算法的有效性。     

区间粒子算法与线源反问题求解

目前国内外对线源反问题数值求解尚没有一种成熟有效的算法。本文在研究区间搜索算法基础上,提出了一种新的求解算法—区间粒子算法(Range Particle Algorithm)来求解线源反问题。首先简要介绍了线源反问题的求解特点,并根据线源方程建立了反问题求解的目标函数;其次基于该目标函数,设计了区间粒子算法来求解,探讨了算法实现的基本步骤和参数调整问题;最后通过模拟数据和实测数据分别检验了该算法求解的效果,结果表明区间粒子算法求解精度高、收敛速度快和计算稳定,在线源反问题数值求解中是适用的。     

一种新算法在ECT图像重建中的应用研究

为了解决大残量、小残量或零残量问题和普通迭代方法收敛速度慢的问题,引入NL2SOL优化算法,并与GaussNewton法相结合,提出了一种多项式加速的正则化迭代电容层析成像算法.在介绍12电极电容层析成像系统基本原理的基础上,给出了该算法的数学模型,并利用谱分析对该算法的收敛性进行了证明.仿真实验验证了该算法满足收敛条件且重建图像误差小,在电容层析成像应用中具有可行性.     

面向空间目标交汇的多拦截器最优部署算法

对空间目标的交汇拦截是现代空天防御体系部署的关键环节, 而其核心优化控制问题为实现交汇次数的最大化. 本文针对一类多个拦截器与空间目标交汇的最优问题, 提出了同时优化拦截器初始部署位置和机动过程中加速度的最优控制策略. 首先, 建立了同时考虑了部署地域和动力学约束的交汇次数最大化的最优控制模型. 进一步, 给出了拦截器与目标可交汇的必要条件以及最优加速度输入设计, 进而使得将最优控制问题转为拦截器部署位置的优化问题. 最后, 严格给出了各个拦截器最优部署位置的具体计算过程.     

A maritime inventory routing problem: Practical approach

Despite of the practicality of the motivation of the inventory routing problem (IRP), there are few successful implementation stories of IRP based decision support systems which utilize optimization algorithms. Besides the fact that the IRP is an extremely challenging optimization problem, simplifications and assumptions made in the definition of typical IRP in the literature make it even more difficult to take advantage of the developed technologies for IRP in practice. This paper introduces a flexible modeling framework for IRP, which can accommodate various practical features. A simple algorithmic framework of an optimization based heuristic method is also proposed. A case study on a practical maritime inventory routing problem (MIRP) shows that the proposed modeling and algorithmic framework is flexible and effective enough to be a choice of model and solution method for practical inventory routing problems.     

遗传算法在圆度误差评定中的应用

针对传统最小二乘圆优化算法评定圆度误差局部收敛的问题,提出基于遗传算法的圆度误差评定方法。介绍了遗传算法基本原理和运算流程,在建立最小二乘圆数学模型的基础上,推导出待优化的目标函数,并详细描述了基于遗传算法的圆度评定优化步骤。实例计算结果表明该算法能比传统优化算法收敛到更精确的解,并具有较高的稳定性,能有效地克服局部收敛的问题。     

Dantzig–Wolfe and block coordinate-descent decomposition in large-scale integrated refinery-planning

The integrated refinery-planning (IRP), an instrumental problem in the petroleum industry, is made of several subsystems, each of them involving a large number of decisions. Despite the complexity of the overall planning problem, this work presents a mathematical model of the refinery operations characterized by complete horizontal integration of subsystems from crude oil purchase through to product distribution. This is the main contribution from a modelling point of view. The IRP, with a planning horizon ranging from 2 to 300 days, results in a large-scale linear programming (LP) problem of up to one million constraints, 2.5 million variables and 59 millions of nonzeroes in the constraint matrix. Large instances become computationally challenging for generic state-of-the-art LP solvers, such as CPLEX. To avoid this drawback, after the identification of the nonzero structure of the constraints matrix, structure-exploiting techniques such as Dantzig–Wolfe and block coordinate-descent decomposition were applied to IRP. It was also observed that interior-point methods are far more efficient than simplex ones in large IRP instances. These were the main contributions from the optimization viewpoint. A set of realistic instances were dealt with generic algorithms and these two decomposition methods. In particular the block coordinate-descent heuristic, with a reverse order of the subsystems, appeared as a promising approach for very large integrated refinery problems, obtaining either the optimal or an approximate feasible solution in all the instances tested.     

A novel quasi-oppositional chaotic antlion optimizer for global optimization

This paper proposes a novel quasi-oppositional chaotic antlion optimizer (ALO) (QOCALO) for solving global optimization problems. ALO is a population based algorithm motivated by the unique hunting behavior of antlions in nature and exhibits strong influence in solving global and engineering optimization problems. In the proposed QOCALO algorithm of the present work, the initial population is generated using the quasi-opposition based learning (QOBL) and the concept of QOBL based generation jumping is utilized inside the main searching strategy of the proposed algorithm. Utilization of QOBL ensures better convergence speed of the proposed algorithm and it also provides better exploration of the search space. Alongside the QOBL, a chaotic local search (CLS) is also incorporated in the proposed QOCALO algorithm. The CLS guides local search around the global best solution that provides better exploitation of the search space. Thus, a better trade-off between exploration and exploitation holds for the proposed algorithm which makes it robust. It is observed that the proposed algorithm offers better results than the original ALO in terms of solution quality and convergence speed. The proposed QOCALO algorithm is implemented and tested, successfully, on nineteen mathematical benchmark test functions of varying complexities and the experimental results are compared to those offered by the basic ALO and some other recently developed nature inspired algorithms. The efficacy of the proposed algorithm is further utilized to solve three real world engineering optimization problems viz. (a) the placement and sizing problem of distributed generators in radial distribution networks, (b) the congestion management problem in power transmission system and (c) the optimal design of pressure vessel.     

带投资约束P-中位问题的混合蚁群算法

将投资限制引入经典约束p-中位问题,提出带投资的约束P-中位问题,该问题更适用于交通、物流等领域的设施选址。在深入分析带投资约束P-中位问题的数学模型的基础上,首先提出了适用于该问题求解的局部搜索策略;其次,将局部搜索策略与拉格朗日启发式算法和蚁群算法相结合,设计了求解该问题的拉格朗日混合蚁群算法。实验结果表明：带投资的约束P-中位问题能够根据投资金额规划不同的投资方案;且提出的混合蚁群算法较大程度上提高了蚁群算法和拉格朗日启发式算法的求解精度,具有较好的收敛性。     

改进遗传算法在磁性材料组炉优化问题中的应用

牌号、交货日期、优先级、需求量等是磁性材料生产工单的属性,计划员需要依据上述属性寻求最优的生产工单组合以最小化生产成本并提高生产效率.针对磁性材料企业人工组炉存在的组炉时间长,组炉结果不优化问题.本文建立了磁性材料生产工单组炉优化模型.提出将该组炉问题转化为伪旅行商问题,并采用一种改进遗传算法求解.染色体编码采用从1到N的自然数编码方式,并设计一种基于最早完工日期规则的初始种群产生方法.引入精英选择策略和改进的贪心三交叉算子,优化遗传算法收敛速度和精度;引入逆转算子,提高遗传算法全局搜索能力.基于实际生产数据的仿真实验表明,建立的磁性材料组炉优化模型是合适的,所提改进算法是有效的.     

一维下料的改进遗传算法优化

针对一维下料优化问题,在对一维下料方案数学模型分析的基础上,提出了基于改进遗传算法的优化求解方案。主要思想是把零件的一个顺序作为一种下料方案,定义了遗传算法中的关键问题:编码、解码方法、遗传算子和适应度函数的定义。该算法设计了一种新颖的遗传算子,包括顺序交叉算子、线性变异算子、扩展选择算子。根据这一算法开发出了一维下料方案的优化系统。实际应用表明,该算法逼近理论最优值,而且收敛速度快,较好地解决了一维下料问题。     

带时间窗和服务顺序约束的多需求车辆路径问题

研究顾客具有多种需求,分别需要由不同类型车辆提供服务,且同一顾客多种需求的服务时间具有固定先后顺序的车辆路径问题.在考虑各个顾客需求的服务时间窗,同一顾客不同需求的服务顺序、服务时间间隔,以及各种车型的车容量及最大行驶时间等约束的前提下,以满足顾客多种需求的车辆运行成本和等待成本之和极小化为目标,建立混合整数规划模型.进一步设计求解模型的联合优化遗传算法,并利用车辆路径问题的标准测试集构造具有两种需求的测试算例,分别利用所提出的联合优化遗传算法与文献中的两阶段遗传算法进行模拟计算与分析,验证所提出算法的有效性.将经典的单一需求车辆路径问题推广到多种需求的情形,建立带约束的多需求车辆路径问题的数学模型并设计求解模型的有效算法,为解决实际问题提供了决策依据.     

A heuristic method for the inventory routing and pricing problem in a supply chain

The inventory routing problem (IRP) in a supply chain (SC) is to determine delivery routes from suppliers to some geographically dispersed retailers and inventory policy for retailers. In the past, the pricing and demand decisions seem ignored and assumed known in most IRP researches. Since the pricing decision affects the demand decision and then both inventory and routing decisions, it should be considered in the IRP simultaneously to achieve the objective of maximal profit in the supply chain. In this paper, a mathematical model for the inventory routing and pricing problem (IRPP) is proposed. Since the solution for this model is an NP (non-polynomial) problem, a heuristic method, tabu search adopting different neighborhood search approaches, is used to obtain the optimal solution. The proposed heuristic method was compared with two other methods considering the IRPP separately. The experimental results indicate that the proposed method is better than the two other methods in terms of average profit.     

Modeling and solving mixed-model assembly line balancing problem with setups. Part I: A mixed integer linear programming model

This paper is the first one of the two papers entitled “modeling and solving mixed-model assembly line balancing problem with setups”, which has the aim of developing the mathematical programming formulation of the problem and solving it with a hybrid meta-heuristic approach. In this current part, a mixed-integer linear mathematical programming (MILP) model for mixed-model assembly line balancing problem with setups is developed. The proposed MILP model considers some particular features of the real world problems such as parallel workstations, zoning constraints, and sequence dependent setup times between tasks, which is an actual framework in assembly line balancing problems. The main endeavor of Part-I is to formulate the sequence dependent setup times between tasks in type-I mixed-model assembly line balancing problem. The proposed model considers the setups between the tasks of the same model and the setups because of the model switches in any workstation. The capability of our MILP is tested through a set of computational experiments. Part-II tackles the problem with a multiple colony hybrid bees algorithm. A set of computational experiments is also carried out for the proposed approach in Part-II.     

Considering lost sale in inventory routing problems for perishable goods

This paper presents a mathematical model for an inventory routing problem (IRP). The model is especially designed for allocating the stock of perishable goods. It is assumed that the age of the perishable inventory has a negative impact on the demand of end customers and a percentage of the demand is considered as lost sale. The proposed model balances the transportation cost, the cost of inventory holding and lost sale. In addition to the usual inventory routing constraints, we consider the cost of lost sale as a linear or an exponential function of the inventory age. The proposed model is solved to optimality for small instances and is used to obtain lower bounds for larger instances. We have also devised an efficient meta-heuristic algorithm to find good solutions for this class of problems based on Simulated Annealing (SA) and Tabu Search (TS). Computational results indicate that, for small problems, the average optimality gaps are less than 10.9% and 13.4% using linear and exponential lost sale functions, respectively. Furthermore, we show that the optimality gaps found by CPLEX grow exponentially with the problem size while those obtained by the proposed meta-heuristic algorithm increase linearly.     

空间机器人随机故障容错规划的蜜蜂算法

本文为解决复杂的随机规划问题设计了一种基于随机模拟的混沌量子蜜蜂算法,证明了该算法的收敛 性,并分析了算法的收敛速度．分析6 自由度空间机器人系统的不确定性,采用基于微分变换法进行误差分析,建 立了随机数学规划模型．为涉及故障前后运动学与动力学约束限制的容错轨迹规划,以加权最小驱动力矩为优化性 能指标,采用混沌量子蜜蜂算法求解全部工作时间中机械臂故障前后的最优轨迹．通过降低异常关节的运动速度来 降低故障关节力矩,保证机械臂在发生故障后具有较高的操作能力．案例研究验证了该算法的有效性、稳定性及准 确性．     

基于正交差异混合演化算法的制造资源选择

对制造资源的选择问题进行分析,并建立数学模型,提出一种适合求解该问题的正交差异混合演化算法。该算法使用子空间收缩技术和多子竞争策略,使收敛速度得到明显提高。实验结果表明,与其他算法相比,该混合演化算法在解的质量、稳定性和收敛速度方面均具有较好的性能。