出行效用连续分布的路径选择模型及其特性分析

出行者路径选择行为的建模对城市路网的规划和智能交通控制系统的研究具有重要意义.传统的基于期望效用理论的路径选择模型存在许多不足,而累计前景理论则可以比较真实的描述在不确定性情况下的决策过程,符合出行者有限理性的特点.本文以累计前景理论为基础,在路径出行效用连续随机分布的条件下对出行者的感知效用进行建模,并结合模型的变量对模型的特性进行了分析,最后通过实例对比分析了期望效用理论与累积前景理论,结果表明累积前景理论可以克服期望效用理论的许多不足,更好的描述出行者的决策过程.通过对参考点和路径效用分布的分析,为智能交通控制系统和仿真建模奠定了理论基础.     

风险路网环境下出行者路径选择决策建模对比分析

出行者路径选择问题一直是交通领域研究的热点.对给定交通环境下出行者决策结果的精确描述能够更好地诱导人们出行,提高出行者的出行效率.基于累积前景理论建立的风险路网环境下决策的描述性模型,更好地描述了出行者的实际出行行为.在假设出行者出发前已知各路径的出行时间概率分布的前提下,建立了基于累积前景理论的风险路网环境下出行者路径选择决策模型,并通过算例和实证调查证明了累积前景理论在描述出行者的实际出行行为上具有更大的优势.     

基于累积前景理论的日变交通配流模型

相比基于均衡原理所建立的网络均衡配流模型,日变交通配流模型能够描述网络系统的非均衡状态,因而具有更一般的适用性.针对基于期望效用理论的出行者路径选择模型的不足,采用累积前景理论获得了出行者具有参考点依赖特征的路径累积前景值.假设出行者是最大路径累积前景的追随者,利用不同路径累积前景的差异构建了网络系统路径流量交换模型,并据此建立了一个日变动态配流模型.通过一个算例网络对配流模型进行了验证,数值结果表明所提出的模型能够反映动态决策环境下出行者考虑随机风险的有限理性决策行为.     

基于时间价值的随机用户出行决策模型研究

出行者一次出行经历了是否出行、终点选择、交通方式选择、路径选择四个决策过程.首先考虑时间价值不同这个因素,给出了基于时间价值的广义费用;然后建立随机用户出行决策模型,该模型描述了出行者的四个出行决策行为,即模型的一阶条件与四个出行决策的条件等价;其次证明了模型的一阶条件满足出行决策条件,最后给出模型算法.由于考虑了时间价值这个因素,因而模型能更准确描述出行者的出行行为.     

基于博弈论的交通管理政策效用分析

研究了考虑管理盲区影响下的交通管理政策效用.指出交通系统中存在不受交通管理政策影响的管理盲区,并以公务用车为例进行建模分析.首先,分析了政府的交通管理决策目标与出行者的出行选择目标,以缓解交通阻塞、维持区域经济活力作为政府的目标函数,以出行选择效用最大化作为出行者的目标函数,应用Stackelberg博弈模型描述政府及出行者双方的动态博弈平衡.然后,对出行选择效用进行假定,分析了中心区发达与否条件下的模型输出,揭示了公务用车对交通管理政策效用的影响.研究结论显示,对于发达的中心区,公务用车出行比例越高,限制个体交通的管理政策能够起到的效果就越差,且其他出行方式选择的综合效用也会显著降低.     

考虑出行行为的地铁公交网络优化

为研究新建地铁开通后配套公交线路的调整,从出行行为角度出发对地铁公交网络进行优化调整.引入前景理论描述有限理性出行者的路线选择行为,假定出行者总是追逐出行收益前景值最大,以此为目标建立路线选择模型.通过测试网络对前景理论和效用理论下的路网平衡态进行分析,结果显示:各路线流量在前景理论下达到平衡态的时间多于在效用理论下达到平衡态的时间,且前者存在较明显的流量振荡;前景值改变阈值对平衡态流量的影响体现了出行者对不确定性的风险抵抗,更贴合实际情况,可依此确定最终的公交线路.     

出行者感知误差下目标导向型双属性用户均衡

提出了目标导向型双属性路径效用模型,用于分析随机交通网络中出行时间和出行时间可靠度两属性影响下出行者的路径选择行为,其中能够达到的目标决定了路径效用的大小。所提出的模型具有3个特点:一是考虑出行者感知误差,从而得到出行时间和出行时间可靠度的感知值;二是基于感知值的边际分布,采用Copula函数刻画感知值间的随机相关性;三是出行者为每个属性赋予特定目标,并且提出了目标间的相互作用,即互补关系。基于所提出的路径效用模型,进一步提出了考虑出行者感知误差的目标导向型双属性用户均衡模型,将其表示为变分不等式问题,采用连续平均算法对其进行求解。最后通过数值实验验证了出行者不同出行行为下的表现和算法的有效性,并对相关参数进行了敏感性分析。提出的模型拓展了出行者路径选择的研究范围。     

城市综合交通规划的组合模型

根据我国城市混合交通阻抗的特点，将出行者看作为出行的消费者，考虑出行者出行决策的同时性，以离散选择和随机效用理论为分析工具，研究了基于对称阻抗的交通风险出行，讫点，方式和路径随机选择的组合模型，根据最优化原理和Lagrange算子性质，证明了模型最优解满足出行，讫点，方式和路径选择平衡的条件，且最优解是唯一的，最后给出一个算例。     

基于分层Logit的多方式随机用户均衡分配模型

为了完善现有的交通分配模型,综合考虑出行者的方式选择与路径选择行为,建立了基于分层Logit的多方式随机用户均衡分配模型。首先,在多方式交通网络中,根据出行者出行决策的2个步骤,即首先选择合适的交通出行方式、然后选择该方式交通网络中的出行路径,采用分层Logit模型描述出行者的交通方式和路径联合选择行为。在建立的分层Logit模型中,出行效用与流量分布相互制约,出行效用受路网流量影响,而路网流量由效用所决定,最终要达到平衡。接着,构造了一个数学规划模型来求平衡解,证明数学规划模型的最优解与分层Logit模型的流量解等价,并进一步证明等价数学规划模型的目标函数是凸的,而约束集也是凸的,因此等价数学规划模型是一个凸规划问题,模型的解是唯一的。随后,给出了求解提出的基于分层Logit的多方式随机用户均衡分配模型改进的方向搜索算法步骤。最后,以含公交车和小汽车2种方式的方格形路网为算例,分析公交票价、出行者的时间价值和分层Logit模型的层间比例参数的变化对交通分配结果的影响。结果表明:公交车票价对流量分配的影响不大;公交需求量随出行者时间价值的增加而下降;当出行者的时间价值较低时,公交需求量随分层Logit模型的层间比例参数增加而增加,当出行者的时间价值较高时,公交需求量随分层Logit模型的层间比例参数的增加而减小。     

基于三参考点多属性决策的居民出行方式选择

针对不同方式之间的客观优势与不足以及每种出行方式本身内在特点,以多属性决策方法为基础,引入前景理论价值函数,从影响出行者出行方式选择的主要属性出发,提出基于三参考点的不确定多属性出行方式选择方法。考虑评价属性值的不确定性,采用区间数描述属性值;其次,采用模糊分析法刻画出行者对不同出行方式的偏爱程度。对比三参照点和单参照点两种情形下的各种出行方式的效用排序结果,分析表明该方法获得最优出行方式不仅考虑了各种出行方式之间的外在相对优势,又体现了不同出行方式内在努力程度及出行者对不同出行方式的偏爱。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that