多用户多方式混合交通均衡变分模型及求解算法

在城市混合交通路网中,出行者通常根据自己的出行偏好选择自己的交通方式和出行路径. 考虑城市道路中不同交通方式之间的相互影响,把出行者按照时间价值划分为多个用户类型,每类出行者可选择自驾车、出租车或公交车方式出行. 为解决这个多交通模式相互影响的混合交通均衡分配问题,从交通需求的角度出发,基于BPR公式构造了城市混合交通网络的路段旅行时间函数,建立了多用户多方式混合交通均衡变分不等式模型,并设计了基于对角化技术与MSA方法的混合求解算法. 算例结果表明,高时间价值类出行者倾向于选择自驾车或出租车出行,低时间价值类出行者倾向于选择公交车出行.     

通行能力约束下的弹性需求交通投影动态演化模型

利用投影动态系统理论建立了具有路段通行能力约束的弹性需求交通网络动态演化模型.通过分析节点路段处交通流量与出行阻抗关系,揭示了出行者在网络局部对出行路线进行调整的决策过程,并分别建立了有通行能力约束的路段流量更新方程和弹性交通需求下的节点最短行程时间估计方程.通过在整个网络上整合上述两类方程,得到最终的交通网络投影动态...     

Modeling stochastic perception error in the mean-excess traffic equilibrium model

In this paper, we extend the α-reliable mean-excess traffic equilibrium (METE) model of Chen and Zhou (Transportation Research Part B 44(4), 2010, 493-513) by explicitly modeling the stochastic perception errors within the travelers’ route choice decision processes. In the METE model, each traveler not only considers a travel time budget for ensuring on-time arrival at a confidence level α, but also accounts for the impact of encountering worse travel times in the (1 − α) quantile of the distribution tail. Furthermore, due to the imperfect knowledge of the travel time variability particularly in congested networks without advanced traveler information systems, the travelers’ route choice decisions are based on the perceived travel time distribution rather than the actual travel time distribution. In order to compute the perceived mean-excess travel time, an approximation method based on moment analysis is developed. It involves using the conditional moment generation function to derive the perceived link travel time, the Cornish-Fisher Asymptotic Expansion to estimate the perceived travel time budget, and the Acerbi and Tasche Approximation to estimate the perceived mean-excess travel time. The proposed stochastic mean-excess traffic equilibrium (SMETE) model is formulated as a variational inequality (VI) problem, and solved by a route-based solution algorithm with the use of the modified alternating direction method. Numerical examples are also provided to illustrate the application of the proposed SMETE model and solution method.     

仿紧集上的一类新型广义双拟变分不等式

建立了一个新的极大极小不等式,并利用它研究了仿紧集上一类新型广义双拟变分不等式解的存在性问题.     

一个三角形中线不等式猜想的证明

采用三角形不等式中R—r—s方法,证明了作者多年前提出的一个有关三角形的猜想不等式,即有关中线ma,mb,mc与外接圆半径R以及内切圆半径r的不等式：1Ama＋1／mb＋1／mc≤2（1／R＋1／r）／3．     

跨性别语篇差异的体现及其成因

文化差异是导致交际失误的主要因素。性别差异也是造成交际失误的原因之一。男女之间存在不同的语篇系统,其差异主要体现在交际风格、意义的解释框架等方面。通过了解跨性别语篇差异的主要表现,分析产生差异的根源,有利于人们更有效地进行交际。在一定程度上,对于构建社会主义和谐社会具有重要的指导意义。     

Contributions by Women to Fisheries Economies: Insights from Five Maritime Countries

The contribution by women to fisheries economies globally continues to be overlooked, in part, because “fishing” is often narrowly defined as catching fish at sea, from a vessel, using specialized gears. Both men and women are involved in fisheries, but often in different roles and activities. Fisheries research, management, and policy have traditionally focused on direct, formal, and paid fishing activities—that are often dominated by men, ignoring those that are indirect, informal, and/or unpaid—where women are concentrated. This has led to a situation where men's and women's contributions to fisheries are not equally valued or even recognized and has resulted in women being largely excluded from fisheries decision-making processes. Here, we examine the contributions by women in the fisheries sector of five globally significant marine fishing countries—Mexico, Peru, Senegal, South Africa, and Vietnam. These countries each have strong links between livelihoods and marine capture fisheries, yet represent different geographic, socioeconomic, and governance contexts. Through a synthesis of existing data, case studies, and consultation with local experts, we found that the contribution by women to the fisheries of these five countries is substantial. However, this investigation also revealed major gaps in understanding of gender inequalities in the fisheries sector and the need for better gender-disaggregated data to inform fisheries policy.     

Bottema不等式的一个新加强

应用两个已知的几何不等式与反演变换,建立了一个强于Bottema不等式的新结果,给出了新结果的几个推论,指出了一个有趣的极值问题的结论,提出了一个未解决的问题与一个猜想.     

一个角平分线猜想不等式的证明

应用三角形一个重要的基本不等式,证明了有关三角形内角平分线之和的一个猜想不等式:设wa,wb,wc与s分别是三角形三条内角平分线和半周长,R,r分别为三角形的外接圆半径,则(wa wb wc)2s2 102Rr/5 66r2/5.指出了一个相关的值得进一步探讨的问题.     

三阶微分差分方程非线性边值问题的存在性与唯一性

利用微分不等式技巧研究了一类三阶微分差分方程的非线性边值问题,以二阶边值问题的已知结果为基础,建立了Volterra型积分微分差分非线性方程解的存在性,利用反证法获得了解的唯一性.同时,构造适当的上下解,得到了三阶微分差分方程解的存在性与唯一性.结果表明：这种技巧为其它边值问题的研究提出了崭新的思路.