面向节能的单/多列车优化决策问题

主要研究了单/多列车运行优化控制问题.首先建立了面向节能的单列车能耗优化模型,采用节能控制策略对模型进行求解,得出节能运行的速度距离曲线;其次对多列车多区段的节能运行进行优化控制设计,以再生能量利用最大化为目标,分别建立多列车能耗优化通用模型和高峰/非高峰情形下优化模型,利用模拟退火算法求解模型,得出使总能耗最低的列车运行方案;最后针对晚点情况下追踪运行的多列车运行优化控制问题,分别建立随机和非随机晚点情况下实时控制模型,求解得到耗能最少的列车运行曲线.     

以能耗最低为目标的列车调控方案研究

研究的是以能耗最低为目标的单、多列车优化调控方案问题.首先根据列车运行的各个阶段的分析,构建以运行能耗最低为目标的非线性规划模型,采用逐步迭代算法进行求解,得到的最佳运行模式为无惰行运行,相应的最小能耗为12.47kwh.对于无高峰期的多列车节能运行控制问题,建立了以回收能量最多为目标的0-1非线性规划模型,得到发车间隔为578.86s、575.59s和760.89s,并以此规律循环33轮的发车间隔时间表,使得能量回收最大为250.57kwh,回收率为19.66%.对于存在早晚高峰的情形,建立了以回收能量最多为目标的5阶段0.1非线性规划模型,求出了全天的最优发车方案.     

2015年全国研究生数学建模竞赛D题的赛后评述

2015年全国研究生数学建模竞赛D题是"面向节能的单/多列车优化决策问题",题中包括3个问题:单列车节能运行优化控制、多列车节能运行优化控制问题、列车延误后运行优化控制问题.分别对这三个问题做一些评述.     

面向节能的单/多列车优化控制研究

主要研究了以节能为目标的单/多列车优化控制问题.对于单列车,建立了以最小化牵引耗能为目标的优化控制模型.采用了逐步修正法对模型进行求解,计算结果表明每公里牵引耗能仅为7.8 kWh.对于多列车,建立了以停车时间为决策变量,最大化再生能量利用为目标的多列车优化控制模型,并采用遗传算法进行了求解.计算结果表明,模型能够节省大约25%-30%的牵引耗能.最后对实际运行中可能出现的延误,给出相应的调整策略,并对其进行了蒙特卡罗模拟.     

中央空调系统节能设计与运行控制策略研究

根据大型商场中央空调系统运行原理,建立了商场"冷负荷需求模型",提出了节能设计与节能运行控制策略.假设人流或室外温度在一定范围内变化,对商场"冷负荷需求模型"进行误差分析.以某大型商场实际运行数据为例,求出某商场人流与电器设备的冷负荷,给出其误差范围,并验证了模型合理性.以保持商场内部温度尽可能稳定且节能为目标,在冷冻水、冷却水流量以及制冷机运行台数等约束条件下,建立多目标规划模型;并进行求解分析,给出优化控制策略.利用模型按"日"计算出夏季合理基准冷负荷;求出在商场设定温度提高1度时,其合理基准冷负荷减少量.     

突发事件条件下列车运行k-最短路模糊蚁群算法

突发事件造成铁路线路区间的通过能力受损,在成网条件下,铁路行车调度指挥工作客观上需要搜索列车运行k-最短路。根据突发事件的影响程度设定区间距离的事故等级系数,针对突发事件的模糊性定义了模糊隶属度函数,得到了突发事件条件下模糊区间距离;考虑列车模糊停站时分对运行径路的影响,将列车的模糊停站时分转化为广义距离;将模糊区间距离与广义距离应用到突发事件条件下铁路路网构建中,很好地处理了突发事件条件下路网信息的不确定性问题。在应用蚁群算法求解最短路径的基础上,引入了C-enough概念,将其应用于搜索突发事件条件下k-最短路径问题中。以我国部分路网为例,与传统的Dijkstra算法对比验证了模糊蚁群算法的高效性和实用性,可为列车运行调度指挥提供一定的借鉴。     

基于管网测压点的变频恒压供水优化方法研究

本文根据管网和水泵的运行曲线,阐明了供水系统的变频调速节能原理,研究了基于城市供水管网测压点的分时变频恒压供水优化方法与模型,并对该方法在某自来水公司的应用节能效果及经济效益进行了分析.     

货运列车的编组调度问题

主要通过建立组合优化的模型,将原问题等价为一个TSP问题,运用遗传算法来求解.问题一:以到达场列车解体次序为决策变量,车辆"中时"最小为目标,分阶段建立组合优化模型;问题二:在问题一的基础上将含有军用车辆的列车和含有去向目的站点S1车辆的列车优先考虑解体,得到解编方案;问题三,将待解编列车的范围向后延伸2小时;问题四,将到达场列车中去向目的站点S1和S2以远的车辆分别排在目的站点E 3和E 4以南之间;问题五,由于编组完成的列车都能及时发出,当排完前一时段留下的车辆后,对于当前时段到达的列车采用随到随解策略进行解编;问题六,给出改进编组调度方案的建议和意见.     

系统安全运行约束下的动态环境经济调度

文章研究风电入网情况下系统安全运行的动态环境经济调度问题.基于风电预测误差,权衡效益和系统运行风险,建立了购买可中断负荷(interruptible load,IL)的经济调度优化模型.新模型的目标函数考虑了传统火电机组能耗成本、环境成本、阀点效应成本和可中断负荷补偿成本.系统运行约束上,采用条件风险价值(conditional value-at-risk,CVaR)刻画因风电间歇性和随机性导致的系统不安全运行风险,结合火电机组出力和多时间段爬坡限制建立了系统的安全运行约束.模型的求解上,采用罚函数方法、光滑化技术和样本平均方法相结合,提出了一类新的随机优化算法;IEEE-30节点系统测试了模型和算法的有效性.     

基于峰谷分时电价机制的节能发电调度优化模型

为减少能源消耗,电力工业在发电侧推行节能发电调度,而在用电侧则施行需求侧管理。事实上,发电侧与用电侧可以通过联合优化实现更好的节能效果。峰谷分时电价将改变原有系统负荷的分布,发电侧机组发电调度的安排将随之改变,发电煤耗水平也将相应地变动。有鉴于此,首先分别构建了需求侧峰谷分时电价响应分析模型以及发电侧节能发电调度的机组组合模型;其次,为了实现分时电价响应向机组煤耗效益的传递,以机组发电煤耗与启停煤耗最少为目标构建了需求侧与发电侧的联合优化模型;最后,通过算例分析发掘模型的节能效益,借助GAMS求解上述模型,优化结果表明分时电价的优化将有助于改进发电侧的节能调度效果,同时将实现一定的环境效益。     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

Qualitative Analysis of Bifurcating Solutions in the Lengyel-Epstein Model

One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the＇living world. In his seminal paper ＂The Chemical Basis of Morphogenesis＂, Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates（1990） on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing＇s prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

(0,1 ;0)-INTERPOLATION ON INFINITE INTERVAL (-∞, +∞)

In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].