粒子群算法在物流中心选址中的应用

物流中心选址是物流系统规划中的重要决策问题。为了快速得到合理的物流中心选址方案,针对问题的特点给出了选址问题的模型,提出了以最小化物流成本为目标函数的粒子群优化算法,开发了模型求解的MATLAB程序,并将算法应用于求解工厂仓库选址和废弃物回收中转站选址问题。实例求解结果表明,该算法求解选址问题的性能优于精确重心法,具有良好的搜索性能和实用性。     

基于GIS优化Dijkstra算法在物流中心选址中的研究*

基于传统的Dijkstra算法,提出了一种采用二叉堆结构和网络边存储模型的优化Dijkstra算法.实验结果表明:优化后的算法是切实有效的,将其应用到物流中心选址中得到了较满意的选址方案.     

基于改进遗传算法的物流中心选址优化

根据物流中心选址问题的特点和要求,在运输成本和运输时间最优的基础上,构造了选址问题的数学模型。给出了一种改进遗传算法的求解方法,其中由于适应度函数与各物流中心对应的需求分配情况密切相关,用拉格朗日松弛法来解决对于特定位置的物流中心服务需求分配的子问题。遗传算子采用线性凸组合的杂交方式、强弱两种变异方式以及进化（?滋+λ）选择方式,从而有效地避免算法的早熟现象,可防止其很快收敛到局部最优解。实例求解表明,该算法可以有效、快速地求得物流中心选址问题的全局最优解。     

GIS下物流节点选址模型

在物流行业运转的过程中,物流中心占据了非常重要的地位,它是商品流通过程中的一个重要枢纽.物流中心在管理货物的过程中需要经过运输、仓储、搬运、运输、配送、订单处理和信息处理等操作过程.物流中心高速运转首先要解决的就是物流中心的选址问题.物流中心的选址必定要考虑到地理条件,针对目标区域内有地理阻断进行物流中心选址进行了研究和探讨.通过研究分析有效地解决了单一物流中心选址问题.     

物流中心选址与动态运输路线选择的研究

物流配送过程中主要有两个环节,一是配送对象的选择,另一个是配送路线的设计.物流中心选址应以物流系统和社会经济效益为目标,用系统学理论和系统工程方法,综合考虑多种因素,对物流中心位置进行科学的研究和决策.在地理信息系统(GIS)现代信息技术应用于物流中心选址基础上,分析了物流配送选址中满足最小覆盖圆的一种基于Voronoi图的设施选址优化算法.针对以往交通路线选择是在一个假设的道路交通条件不变的背景下,根据实时动态交通条件进行路线选择,将智能运输系统(ITS)应用于动态路线选择.     

物流中心选址的神经网络集成模型研究

针对在建立物流中心选址模型中,单个人工神经网络模型难以确定参数、容易产生“过拟合”等问题,提出一种神经网络二次集成模型,利用Bootstrap可重复采样技术得到不同的训练集来训练产生不同的个体神经网络,采用粒子群优化算法结合个体输出获得神经网络集成,并在此基础上将集成视为个体再次结合。实验结果表明,该模型易于设计且能够提高泛化能力。     

冷链物流多层级配送中心连续选址模型构建

传统物流配送中心选址方法在设计过程中并没有考虑到要将选址问题进行转化,无法获得最优选址结果.为改善上述问题,构建了一种冷链物流多层级配送中心连续选址模型.设计配送中心选址流程,设置配送费用最少与配送时长最短的目标函数及相关约束条件,并将连续选址问题转换为多源Weber问题,采用启发式算法对其进行求解,根据备选策略数量,...     

PBIL算法求解物流中心选址优化问题

物流中心的合理布局对整个物流系统的效益有着决定性的影响。通过对物流中心选址问题相关特点和要求进行研究,我们以建设成本和运行费用最优为目标构造了选址问题的数学模型,设计了基于PBIL的物流中心选址优化算法,并进行了算法的实现和测试。测试表明,该算法计算速度快、稳定性好,对约束条件增减具有良好的适应性。最后,提出了该算法的学习概率修正参数动态变化方法,测试表明通过该方法可有效提高算法的收敛速度和寻优能力。     

模糊聚类遗传算法在军事装备物流中心选址中的应用

在分析军事装备物流中心选址问题基础上,构建了模糊聚类和遗传算法的混合算法模型,核心技术是把模糊聚类网络模型融合到遗传算法种群构建中,可以有效地避免遗传算法易出现早熟的现象,验证了算法具有很好的鲁棒性和可信度,仿真结果能够为决策者科学正确的选址提供一定的参考.     

基于改进损失函数的YOLOv3网络

为了提高卷积神经网络在目标检测的精度,本文提出了一种基于改进损失函数的YOLOv3网络.该网络模型应用一种新的损失函数Tan-Squared Error （TSE）,将原有的平方和损失（Sum Squared Error,SSE）函数进行转化,能更好地计算连续变量的损失;TSE能有效减低Sigmoid函数梯度消失的影响,使模型收敛更加快速.在VOC数据集上的实验结果表明,与原网络模型的表现相比,利用TSE有效提高了检测精度,且收敛更加快速.     

一种解决非光滑伪凸优化问题的新型神经网络

针对带有不等式约束条件的非光滑伪凸优化问题，提出了一种基于微分包含理论的新型递归神经网络模型，根据目标函数与约束条件设计出随着状态向量变化而变化的罚函数，使得神经网络的状态向量始终朝着可行域方向运动，确保神经网络状态向量可在有限时间内进入可行域，最终收敛到原始优化问题的最优解。最后，用两个仿真实验用来验证神经网络的有效性与准确性。与现有神经网络相比，它是一种新型的神经网络模型，模型结构简单，无需计算精确的罚因子，最重要的是无需可行域有界。     

A recurrent neural network for nonlinear optimization with a continuously differentiable objective function and bound constraints

This paper presents a continuous-time recurrent neural-network model for nonlinear optimization with any continuously differentiable objective function and bound constraints. Quadratic optimization with bound constraints is a special problem which can be solved by the recurrent neural network. The proposed recurrent neural network has the following characteristics. 1) It is regular in the sense that any optimum of the objective function with bound constraints is also an equilibrium point of the neural network. If the objective function to be minimized is convex, then the recurrent neural network is complete in the sense that the set of optima of the function with bound constraints coincides with the set of equilibria of the neural network. 2) The recurrent neural network is primal and quasiconvergent in the sense that its trajectory cannot escape from the feasible region and will converge to the set of equilibria of the neural network for any initial point in the feasible bound region. 3) The recurrent neural network has an attractivity property in the sense that its trajectory will eventually converge to the feasible region for any initial states even at outside of the bounded feasible region. 4) For minimizing any strictly convex quadratic objective function subject to bound constraints, the recurrent neural network is globally exponentially stable for almost any positive network parameters. Simulation results are given to demonstrate the convergence and performance of the proposed recurrent neural network for nonlinear optimization with bound constraints.     

Green logistic vehicle routing problem: Routing light delivery vehicles in urban areas using a neuro-fuzzy model

Today’s growth in the level of traffic in cities is leading to both congestion and environmental pollution (exhaust emissions and noise), as well as increased costs. Traffic congestion makes cities less pleasant places to live in, a particular problem being the negative impact on health as a result of increased exhaust emissions. In addition to these emissions, another major effect of transport which can lead to serious health problems is noise (EEA, 2013a, 2013b). There is a strong tendency in the world towards the development of “clean” motor vehicles that do not pollute the environment, that is, that do not emit harmful substances in their exhaust fumes and which create less noise without causing other types of pollution. The growth in the influence of transport on the environment has resulted in planners formulating procedures which take into account the effect of traffic on the quality of life in urban areas. This paper presents a model for the routing of light delivery vehicles by logistics operators. The model presented takes into account the fact that logistics operators have a limited number of environmentally friendly vehicles (EFV) available to them. When defining a route, EFV vehicles and environmentally unfriendly vehicles (EUV) are considered separately. For solving the problem of routing in the model, an adaptive neural network was used which was trained by a simulated annealing algorithm. An adaptive neural network was used for assessing the performance of the network branches. The input parameters of the neural network were the logistics operating costs and environmental parameters (exhaust emissions and noise) for the given vehicle route. Each of the input parameters of the neural network was thoroughly examined. The input parameters were broken down into elements which further describe the state of the environment, noise and logistics operating costs. After obtaining the performance of the network links for calculating the route for EFV and EUV vehicles a modified Clark–Wright algorithm was used. The proposed model was tested on a network which simulates the conditions in the very centre of Belgrade. All of the input parameters of the model were obtained on the basis of 40 automatic measuring stations for monitoring the air quality (SEA, 2012).     

基于改进神经网络的非满载车辆路线优化模型

货物流通过程中,目前流行的车辆调度方式--基于简单的神经网络模型设计,造成运输成本的浪费。提出了一种基于改进神经网络的非满载车辆路线优化挖掘模型,来解决运输过程中的非满载车辆调度优化问题。改进的模型通过对非满载车辆时域长度和空域概率的加权、对神经网络稳定状态进行约束、建立非满载车辆起点和终点函数方程生成改进算法配送模型,并通过对新模型进行时间窗加权,合成了改进神经网络非满载车辆挖掘模式。仿真结果表明,该挖掘模型与传统的神经网络计算方法相比,能够提高非满载车辆路线选择效率和正确性,取得了较好的效果。     

基于变分不等式的多商品物流网络优化设计

为优化设计多级多商品流的物流网络,按网络状态把物流网络划分为静态网络和动态网络,分析了静态网络的基础设施建设和动态网络的物流活动问题,构建了可描述不同网络阶段的运营成本和建设成本函数,并且考虑了运营过程带来的环境污染问题,构建了治理费用函数。基于以上函数,建立以供给能力为约束条件,以总成本最小为目标的网络设计和重新设计模型,然后将模型转换为变分不等式问题,证明了所设计模型与变分不等式等价。最后通过算例,运用修正投影算法对模型进行数值演算和验证,得到了最优成本下的设施建设方案和物流组织方案。     

递归复合型模糊神经网络结构研究

针对一类能够有效引入过程先验知识的复合型模糊神经网络，研究了其动态结构． 通过对复合型模糊神经网络的函数网络的第二层引入动态递归环节，使其具有动态映射能力 ，实现了对动态系统的良好响应．本文采用了动态非线性模型对其进行仿真研究，结果 表明，对于处理动态非线性系统，此动态复合模糊神经网络较之静态网络在收敛速度、预测 精度和网络规模等方面都有较大的改善．     

Analysis of service satisfaction in web auction logistics service using a combination of Fruit fly optimization algorithm and general regression neural network

When constructing classification and prediction models, most researchers used genetic algorithm, particle swarm optimization algorithm, or ant colony optimization algorithm to optimize parameters of artificial neural network models in their previous studies. In this paper, a brand new approach using Fruit fly optimization algorithm (FOA) is adopted to optimize artificial neural network model. First, we carried out principal component regression on the results data of a questionnaire survey on logistics quality and service satisfaction of online auction sellers to construct our logistics quality and service satisfaction detection model. Relevant principal components in the principal component regression analysis results were selected for independent variables, and overall satisfaction level toward auction sellers’ logistics service as indicated in the questionnaire survey was selected as a dependent variable for sample data of this study. In the end, FOA-optimized general regression neural network (FOAGRNN), PSO-optimized general regression neural network (PSOGRNN), and other data mining techniques for ordinary general regression neural network were used to construct a logistics quality and service satisfaction detection model. In the study, 4–6 principal components in principal component regression analysis were selected as independent variables of the model. Analysis results of the study show that of the four data mining techniques, FOA-optimized GRNN model has the best detection capacity.     

一类非光滑非凸优化问题的神经网络方法

提出了解决一类带等式与不等式约束的非光滑非凸优化问题的神经网络模型。证明了当目标函数有下界时,神经网络的解轨迹在有限时间收敛到可行域。同时,神经网络的平衡点集与优化问题的关键点集一致,且神经网络最终收敛于优化问题的关键点集。与传统基于罚函数的神经网络模型不同,提出的模型无须计算罚因子。最后,通过仿真实验验证了所提出模型的有效性。     

泊松分布灰色理论在物流需求预测中的应用

研究物流需求预测准确度问题。物流需求预测中存在数据小以及非线性特点,使预测系统存在不确定性。为解决上述问题,提出了一种泊松分布的神经网络需求预测算法,采用泊松分布算法对物流的整体需求进行分类,然后采用灰色理论算法选择物流需求影响因子,对物流的需求进行实时预测,仿真结果表明,改进物流需求预测方法比传统的灰色理论预测模型以及BP神经网络具有更高的预测精确度,有效地提高了区域物流需求的预测准确度,具有一定的实际应用价值。     

BP神经网络在心理障碍诊断中的应用研究

以高校大学生常见心理疾病作为研究对象,充分利用L-M算法的全局寻优性及局部收敛性的特点对BP神经网络进行优化,建立基于改进的BP算法的心理诊断模型,实现简单的模式识别。仿真结果表明:该模型减少了训练迭代次数,缩短了训练时间,具有较高的准确性,应用该神经网络建立心理障碍诊断系统也是有效的。