冷链物流同时送取货车辆路径优化

针对冷链物流同时送取货车辆路径优化问题,分析冷链物流配送中的车辆固定成本、行驶成本、制冷成本和货损成本等成本构成,以总成本最小化为目标,将冷链物流配送的送货和取货业务综合到每一个客户节点,建立单个配送中心和多个客户节点的冷链物流配送车辆路径优化模型,并采用遗传算法进行求解,算例分析验证了所建模型和设计算法的适用性和可行性,结果表明优化后的同时送取货车辆配送方案能够降低配送成本,提高配送效率,研究结论对冷链物流配送决策具有重要的参考价值.     

第3方冷链物流配送路径优化研究

根据冷链物流配送具有的特殊性,进一步探索冷链物流配送优化研究的方案.在保证货物不超载的情况下,建立以一个冷链配送中心、多个顾客的冷链物流的配送数学模型,用改进遗传算法加以分析求解,并采用Matlab软件对算法进行编程,最后通过算例进行验证.得到如下结论:利用改进遗传算法得到的最优配送路线优于标准遗传算法求解结果.     

考虑碳排放的冷链物流配送路径优化研究

针对日益严峻的环境问题,有别于以往普通冷链物流配路径研究仅考虑满足客户满意度以及各项总成本最小的要求,在普通冷链物流配送过程中引入碳排放,将碳排放转化成相应的经济效益,形成一个考虑碳排放成本的冷链物流配送路径优化数学模型.在求解优化数学模型中,采用蚁群启发式算法,利用Matalab进行编码求解,最后通过实例来验证模型和算法的可行性与有效性,结果表明:考虑碳排放的冷链物流配送路径总成本降低,比不考虑碳排放的传统冷链物流配送更具有现实意义.     

不确定运行时间环境下的车辆调度问题及启发式算法

考虑到物流公司或者配送中心车辆实际运行过程中时间的不确定性,提出了配送服务线路包含时间窗口、车辆容量约束的随机规划模型,以最小化车辆运行成本同时尽可能降低所服务顾客的不满意度.同时,又稍作改进给出了平均-风险模型,由于VRP问题是NP难的,给出了一种基于禁忌搜索的启发式算法,并以北京市13个点的为例,给出求解结果.     

冷链低碳物流配送路径优化的细菌觅食—蚁群算法研究

冷链物流的绿色发展已成为国家十三五发展的热点,在分析冷链物流配送环节各种成本基础上,以车载容量和时间窗为约束,构建综合总成本最小化的冷链低碳物流配送路径优化模型.将细菌觅食算法中的复制操作和趋向操作引入基本蚁群算法中,改善了算法的收敛效率和全局搜索能力,提出了细菌觅食一蚁群算法用于求解冷链低碳物流配送路径优化模型.通过实例仿真表明,在求解冷链低碳物流配送路径优化模型方面,细菌觅食—蚁群算法能够以更高的效率寻找到更低的综合总成本,验证了改进算法的合理性和有效性.     

蝙蝠算法在物流配送车辆路径优化问题中的应用

车辆路径问题(Vehicle Routing Problem,VRP)是组合优化问题中一个典型的NP难题.蝙蝠算法(Bat Algorithm,BA)是一种新型的智能优化算法,尚未被应用到求解VRP问题中去.根据物流配送中VRP问题的数学模型及其具体特征,设计了求解VRP问题的蝙蝠算法,并通过仿真实例和与其他算法进行比较的方式验证了蝙蝠算法求解VRP问题的有效性与可行性.     

改进蚁群算法优化周期性车辆路径问题

周期性车辆路径问题(PVRP)是标准车辆路径问题(VRP)的扩展,PVRP将配送期由单一配送期延伸到T(T＞1)期,因此,PVRP需要优化每个配送期的顾客组合和配送路径。由于PVRP是一个内嵌VRP的问题,其比标准VRP问题更加复杂,难于求解。本文采用蚁群算法对PVRP进行求解,并提出采用两种改进措施——多维信息素的运用和基于扫描法的局部优化方法来提高算法的性能。最后,通过9个经典PVRP算例对该算法进行了数据实验,结果表明本文提出的改进蚁群算法求解PVRP问题是可行有效的,同时也表明两种改进措施可以显著提高算法的性能。     

贪婪随机自适应蝙蝠算法在车辆路径问题中的应用

车辆路径问题(Vehicle Routing Problem,VRP)在物流与供应链领域是一个非常有研究价值的NP-Hard问题.蝙蝠算法(Bat Algorithm,BA)是一种新兴的智能优化算法,有着广阔的应用前景.然而它不能直接用于求解离散问题,并且如同大多数智能优化算法一样,容易陷入局部最优,后期收敛速度慢.本文针对VRP问题的具体特性,重新定义了蝙蝠的编码方式并利用GRASP启发式算法生成蝙蝠算法初始种群来改进算法,然后应用于求解VRP问题.     

带时效性约束的配送中心多源选址问题研究

应用启发式算法求解带时效性约束的多源选址问题.分析物流配送的时效性问题,建立带时效性约束的配送中心多源选址模型.构造两步启发式算法:1)借助传统迭代算法,求解物流服务分配矩阵,把多源选址问题转化为单源选址问题;2)基于M ATLAB函数,设计优化程序,计算带时效性约束的单源选址模型.并给出算例,验证模型和算法的可行性.研究表明两步启发式算法是求解带时效性约束的物流配送中心多源连续选址问题的有效算法.     

基于最大最小蚂蚁系统的物流配送中心选址算法的研究

提出了一种基于信息素自适应调节的最大最小蚂蚁系统的多物流配送中心选址算法,利用改进的蚁群算法的路径寻优机制结合蚂蚁聚集尸体的行为模式,根据物流配送总成本最低的原则将各配送点与候选配送中心进行聚类,合理选择配送中心。将已有物流配送模型进行拓展,加入经营管理成本。分别利用基本蚁群聚类算法和改进的蚁群聚类算法对配送中心选址进行仿真,实验结果表明在解决大规模配送中心选址问题时,改进的算法在解的质量和收敛速度方面明显优于基本蚁群聚类算法。     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by     

Bounds for the zeros of polynomials

Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 ＜β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 ＜α≤ 1).     

Jacobi polynomials used to invert the laplace transform

Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f（u） of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.