眼科病床配置的优化模型及其计算机模拟

为了实现资源的高效利用,采用排队论思想,建立了眼科病床合理配置的优化模型,并用计算机模拟的方法对模型进行了检验,根据历史数据,求得五类病人被分配到的病床比例为19%、24%、21%、10%、26%,所得结果与实际吻合较好,优化模型对病床的合理配置具有一定的借鉴意义.     

病床安排模型及其评价指标体系的改进——以某医院眼科住院部为例

首先建立了一套较为合理的评价指标体系用以评价病床安排模型的优劣,然后根据某医院眼科部门对5种不同疾病治疗的实际情况,从分析现有模型存在的问题出发,优化出新的病床安排模型．最后,本文运用Matlab软件和已有数据对该模型进行模拟,并使用已建立的评价指标体系对两个模型进行比较分析．     

奥运临时超市选址的优化模型

首先依据问卷调查的数据,分析了年龄结构、购物需求、出行、用餐方式之间的关系,然后进一步用逐步回归方法找出了对顾客消费额影响较大的因素为年龄结构、性别结构.以此为依据测算出20个商区的人流量的百分比分布,其中人流量最大的节点依次为:A6,B6,C4.对于各商区的人流量先折换成实际购物的标准人,然后以此作为超市规模的确定标准建模求解,建立以商业营利最大为目标,超市分布均衡及满足购物需求为约束的整数规划的选址模型,确定了在不同超市规模下,A、B、C三区应拥有的超市个数及各超市的具体所在.     

基于Q-过程和随机模拟的病床安排方案

本文设计的一个新的住院病床安排方案,可用来取代传统的FCFS(先到先得)规则.患者在等候队列中的优先级将基于病情和手术的紧急程度.本文把患者的入住情况转化为经典的M/M/N排队论问题,利用可逆Q-过程的性质以及经典排队论的结果,得到各类疾病患者的平均逗留时间以及所需床位数的先验估计.根据独立Poisson过程的性质确定排队过程的Q-矩阵,从而作出相应的先验估计和具体表达式.在若干约束条件的基础上,利用C++编程求得最优病床分配方案.本文建立的评价指标体系,通过计算机随机模拟,证明了在多种情形下,该模型较FCFS(先到先得)规则更具优势.     

研究生录取的优化模型

把研究生录取分解为师生间的评价问题和师生间配对最优化的问题.建立了师生相互评价的指标体系和量化评价指标的计算模型,以满意度计量评价结果,提出了相互满意度的概念,建立了使师生配对达到整体总满意度最大的整数规划优化模型.根据建立的模型,解决了具体的研究生录取问题.所建立的模型具有较强的实用性、可操作性和可扩展性.     

解决医院病床安排问题的线性规划方法

本文研究了医院病床安排问题,在综合考虑病人等待入院和等待手术期间产生费用的前提下,建立了病床安排问题的线性规划模型。利用该模型,可以得到使病人平均等待费用最低的入院顺序。通过实例计算显示,利用本文模型得到的结果与利用传统的先到先服务原则安排的结果相比,病人等待手术的平均时间大约缩短了50%,等待费用大约降低了50%。     

油田增产措施合理规划的优化模型研究

在考虑均衡使用增产措施的前提下,以油田规划期内增产措施5年的产油量最大为目标,以增产措施的产油量下限、产水量和费用的上限、增产措施的工作量上限为约束条件建立了规划期内增产措施产油量最大的整数线性优化模型,并运用LINDO6.1对模型编程求解和分析,给油田规划提供一个很好的参照.     

带启动时间的Geom/Geom/1多重工作休假排队

本文中研究了一个带有启动时间的Geom/Geom/1多重工作休假排队模型。服务台在休假期间,不停止服务,而是以较低的服务率为顾客提供服务。运用拟生灭过程和矩阵几何解的方法,给出了该模型的稳态队长分布,并求出了平均队长以及顾客的平均逗留时间。     

地面搜索优化方案的模型建立

对一块长为11200 m,宽为7200m的平地矩形区域,运用最优化数学理论,寻求最佳搜索路径.若20人一组搜索,运用整数规划方法建立模型并求解出最短搜索时间为49.03 h;若要在48 h内完成搜索,运用线性规划方法改进模型并求得最少需22人.     

考虑医院病床数的SIR模型的分支分析

建立了具有标准发生率且考虑医院病床数的SIR模型,并对其性态进行了分析.通过分析,发现R_0不再是疾病流行的阈值,并且当医院的病床数小到一定值时模型就会出现后向分支和鞍结点分支.通过数值模拟可以看出当病床数b减少时,模型会呈现出一系列复杂的动力学性态,如:Hopf分支,BT分支和同宿轨分支.通过对模型的研究与分析可以看出医院的病床数是一个极其重要的因素,当R01时,通过增加医院的病床数是可以消灭疾病的;当R_01时通过增加病床数可以使得疾病得到控制不会出现一些复杂的发展趋势.     

Parameterized algorithmics for linear arrangement problems

We discuss different variants of linear arrangement problems from a parameterized perspective. More specifically, we concentrate on developing simple search tree algorithms for these problems. Despite this simplicity, the analysis of the algorithms is often rather intricate. For the newly introduced problem linear arrangement by deleting edges, we also show how to derive a small problem kernel.     

Lattice point counts for the Shi arrangement and other affinographic hyperplane arrangements

Hyperplanes of the form xj=xi+c are called affinographic. For an affinographic hyperplane arrangement in Rn, such as the Shi arrangement, we study the function f(m) that counts integral points in n[1,m] that do not lie in any hyperplane of the arrangement. We show that f(m) is a piecewise polynomial function of positive integers m, composed of terms that appear gradually as m increases. Our approach is to convert the problem to one of counting integral proper colorations of a rooted integral gain graph.An application is to interval coloring in which the interval of available colors for vertex vi has the form [hi+1,m].A related problem takes colors modulo m; the number of proper modular colorations is a different piecewise polynomial that for large m becomes the characteristic polynomial of the arrangement (by which means Athanasiadis previously obtained that polynomial). We also study this function for all positive moduli.     

考虑不完全检测的冲击模型最优维修策略

针对制造系统中设备检测不完全的情形,研究基于不完全检测的冲击模型的周期检测、维修联合策略．通过定期检测获知系统的劣化状态以进行必要的预防性维修．在假设系统是退化的且有k个不同故障状态的条件下,以最小化系统运行成本为目标,以检测周期T、系统更换前故障次数Ⅳ为联合决策变量,利用更新过程理论建立了系统平均费用率C（T,N）的数学模型,并且给出最优联合策略的数值算法．最后借助数值例子演示了该模型,分析了检测水平对系统运行成本的影响．     

New relationships for multi-neighborhood search for the minimum linear arrangement problem

We develop a series of theorems about the graph structure of the classical Minimum Linear Arrangement (MinLA) problem which disclose properties that can be exploited by Multi-Neighborhood Search (MNS) algorithms. As a foundation, we differentiate between swaps of labels attached to adjacent and non-adjacent nodes to create two new neighborhood classes, and show how our theorems yield efficient algorithms for updating key arrays used by local search procedures. In addition, we introduce a class of neighborhoods called set-based neighborhoods supported by a theorem that identifies solutions (labelings) for the MinLA problem in polynomial time that dominate exponential numbers of alternative solutions. The component neighborhoods within this new neighborhood class can be applied in various sequences in conjunction with the first two new neighborhoods introduced. Our results also apply to problems with objectives different than those of MinLA. Finally, our results make it possible to exploit the new neighborhoods according to the user's choice of MNS protocols and alternative local search algorithms.     

一类二阶非线性泛函微分方程的振动性

本文讨论二阶非线性泛函微分方程(a(t)y′(t))′+p(t)y′(t-τ(t))-q(t)f(y(t))=0,t≥t₀,(1)(a(t)y′(t))′-p(t)y′(t+τ(t))-q(t)f(y(t))=0,t≥t₀,(2)获得了方程(1)和(2)振动的充分性判据,推广和改进了已知的一些结果.     

Ordering optimal deductible allocations for stochastic arrangement increasing risks

The insurer usually solicits the insured through granting a certain amount of deductible to multiple risks according to his/her own will. Due to the nonlinear nature of the concerned optimization problem, in the literature on the optimal allocations of deductibles researchers usually assume independence or comonotonicity among concerned risks and ignore the impact due to frequency. In this study we build two sufficient conditions for the decreasing optimal allocation of deductibles, relaxing the stochastic arrangement increasing or right tail weakly stochastic arrangement increasing discount factors in Cai and Wei (2014, Theorems 6.3 and 6.6) to the conditionally upper orthant arrangement increasing or weak conditionally upper orthant arrangement increasing frequencies.     

Numerical method for solving an inverse problem for a population model

The inverse problem of determining the growth rate coefficient of biological objects from additional information on their time-dependent density is considered. Two nonlinear integral equations are derived for the unknown coefficient, which is determined on part of its domain from one equation and on the remaining part from the other equation. The nonlinear integral equations are solved by iterative methods. The convergence conditions for the iterative methods are formulated, and results of numerical experiments are presented.     

Oscillation criteria for nonlinear second order differential equations with damping

Summary Using the integral average method, we give some new oscillation criteria for the second order differential equation with damped term (a(t)Ψ(x(t))K(x'(t)))'+p(t)K(x'(t))+q(t)f(x(t))=0, t<span style='font-size:10.0pt; font-family:"Lucida Sans Unicode"'>≧t₀. These results improve and generalize the oscillation criteria in<span lang=EN-US style='font-size:10.0pt;mso-ansi-language:EN-US'>[1], because they eliminate both the differentiability of p(t) and the sign of p(t), q(t). As a consequence, improvements of Sobol's type oscillation criteria are obtained.     

A note on the existence of positive bounded solutions for an epidemic model

In this short note, we establish an existence and uniqueness theorem about a positive bounded solution for a nonlinear infinite delay integral equation, which arises in some epidemic problems. As one can see, our main result can deal with some cases, to which many previous results cannot be applied. In addition, we show that our main result can also be applied to a Lasota–Wazewska model.     

城市交通信号实时控制问题

以车辆平均延误时间最小为目标,建立单交叉口和线状区域的多交叉口信号实时配置的优化模型,结合外点罚函数法和模式搜索法求解,解决函数的不可微问题,算法简单可行.