Fuzzy modelling of static system optimum traffic assignment problem having multi origin-destination pair

Traffic congestion is an unpreventable problem to avoid in a transportation network and it has negative effects on traffic accident, time wasting, traffic delay and safety problem. Besides, in transportation networks, drivers do not want to deal with traffic jam while traversing between specified origin-destination pair. Therefore, traffic assignment (TA) is imperative to improve traffic management, transportation safety, time, and cost savings. System Optimum Traffic Assignment Problem (SOTAP) is a kind of TA model which aims to minimize the total system travel time on the network, and satisfies the flow conservation constraints. To model the SOTAP more realistically, the imprecise parameters can be taken as fuzzy. Therefore, in this paper, we focus on converting the conventional SOTAP to a fuzzy quadratic programming problem (QPP) which is named System Optimum Fuzzy Traffic Assignment Problem (SOFTAP). Here, link travel time is expressed with BPR function as generally used in the literature by converting to fuzzy except link-dependent parameters. Thus, the nonlinear objective function of SOFTAP is expressed in terms of fuzzy link flows and fuzzy link travel times. A solution approach from the literature is modified to the reconstructed SOFTAP.     

基于经济新常态的长春市水资源开发利用潜力评价

以长春市为研究对象,基于未来经济处于新常态的发展态势,构建包含水资源、社会、经济、生态环境4个子系统的评价指标体系,并确定各指标的评价等级标准;基于模糊数学理论以及层次分析法构建包括目标层、准则层、指标层的3层模糊综合评价模型,以2015年为现状水平年,应用模型对长春市水资源开发利用潜力进行综合评价。结果表明:长春市水资源开发利用程度处于中等偏上水平,各辖区水资源开发利用规模不平衡,可通过产业结构调整提高全市用水效率,为经济持续增长提供保障。     

基于效应的随机灰规划模型和应用

为了解决同时含有随机因素和灰色因素的不确定规划问题,通过结合区间灰数所属区间两个端点的随机性,给出随机区间灰数和随机区间灰函数的定义,提出了随机灰规划模型。通过综合效应函数理论用随机变量期望值和方差综合量化表示灰数所属区间的两个端点值。应用该理论对综合量化后的两个端点值继续进行综合量化,从而将随机灰规划转化为确定型规划问题。应用遗传算法进行求解。通过综合效应函数的理念,综合随机变量的期望和方差,同时综合区间灰数的区间因素,将随机灰规划数学模型转化为确定型规划模型即基于效应的随机灰规划模型。通过选取不同的综合效应函数,得到了关于不同决策意识下的随机灰规划的最优解。这个方法可为决策者进行不确定决策提供参考。     

Economic interpretations of DEA

Research on productive efficiency at the firm level has developed as an important and active strand of research the last decades, both within operations research, management science and economics. Two apparently different definitions of efficiency are examined, but it is shown that when both estimation methods are based on solving linear programming problems the definitions of efficiency are identical. The purpose of the paper is to give the basic ideas of efficiency analyses using DEA as a tool for researchers not so familiar with efficiency analysis and DEA. The concept of shadow prices is given special attention.     

基于模糊意见集中排序法的建筑工程资格预审

建筑工程资格预审无论对业主还是对承包商都至关重要，根据建筑工程的特点，在目前普遍采用的资格预审评价方法的基础之上，总结了进行资格预审的评价指标体系，并提出了基于模糊数学意见集中排序法的建筑工程资格预审方法。     

企业知识管理绩效综合评价案例研究

知识管理是现代企业管理的重要内容。正确分析和评价企业的知识管理绩效，对于促进企业知识管理、提高企业知识管理水平以及增强企业竞争优势，具有重要的现实意义。文章构建了企业知识管理绩效评价的指标体系，并运用模糊综合评价模型对企业知识管理绩效进行了综合评价。     

烧结模糊控制系统的设计与实现

设计了一个烧结模糊控制系统，进而构建了一个基于模糊控制的自适应脉宽控制器，对煤气阀、换向阀开关时间进行控制；利用模糊控制器的模糊推理能力来实现煤气阀门开度在线调整，以达到优化控制的目的。运行结果表明，这种控制器与常规比值控制器相比可以取得较好的控制效果。     

基于方程组的新型模糊时序分析

基于线性方程组的模糊时间序列分析是一种新颖的方法,但根据二次规划求得的参数存在两个不可调和的矛盾,即模糊中值序列和模糊距度序列不同时得到很好的拟合。为此文章考虑利用一种新的模糊时间序列分析的方法,即将模糊中值和模糊跨度分别建模。并给出了实例。     

Application of multi-factor hierarchical fuzzy comprehensive evaluation model in risk assessment of gas exploration

This article classified gas exploration risk on the basis of the characteristics of oil-gas exploration investment projects, which are internal systems risk and external non-systemic risk. It described each classification specifically and introduced the basic principles and mathematical model of the multi-factor hierarchical fuzzy comprehensive judgment in detail, and then researched the conducts the risk of the gas exploration with examples.     

面向对象程序设计教学改革与实践

指出了面向对象程序设计教学中存在的问题,针对问题提出了改革措施：采用案例式教学,加强实践教学管理,结合BB教学平台辅助教学。不断提高学生学习的自觉性和主动性,成为教学改革的重要研究内容。