考虑通道总能耗的城际列车运行速度优化研究

在考虑不同运输方式竞争关系的基础上,探讨了能力约束下的通道客流分配方法.以乘客出行总费用及通道运营总成本最小为目标,构建了城际列车运行速度非线性优化模型,并采用遗传算法对模型进行求解.算例结果表明,模型能够有效求解含限速区间的城际列车运行速度优化问题,且随限速区间运行速度的下降,非限速区间最优运行速度呈缓慢上升趋势;对于短距离通道而言,可开行较高运行速度的城际列车,以吸引客流;而对于中距离通道而言,可适度降低城际列车运行速度,减少运营能耗.     

面向OD客流的高速列车开行方案的优化

满足旅客出行需求的列车开行方案能够更好地吸引客流，提高高速铁路的核心竞争力.以最大化经济收益和最小化出行费用为目标函数，以高速铁路开行方案为研究对象，以旅客出行需求等作为约束条件，将列车开行方案与OD客流量结合起来，同时考虑旅客的购票心理和列车购票的时效性，建立了一种基于动态客流的列车开行方案的多目标优化模型，并设计一种基于个体信息和改进变异算子的多目标差分(SG-MOSaDE)算法进行求解.以广州市某线路为例进行实验，结果表明，优化后的开行方案不仅最大化满足了旅客出行需求，而且在提高铁路部门经济收益的同时降低了旅客的出行花费，并且优化后的列车总停站次数较原来有所下降，停站方案更加均衡.     

城际列车开行方案的客运量预测及评价

从铁路运输企业的角度,由分析影响旅客列车客运量因素入手,利用灰色理论建立铁路旅客列车开行方案的客运量GM(1,h)预测模型,构建评价其经营效果(经济效益和经营风险)的计算方法.以沪宁线为背景,预测城际列车开行方案的客运量,并对其经济效益和盈亏平衡点分析计算,为铁路运输企业设计旅客列车开行方案提供科学依据.     

需求导向的广珠城际铁路列车停站方案优化设计

本文根据广珠城际铁路客流特点,以旅客的总旅行时间最小为目标函数,考虑客流节点服务频率、单列列车停站次数、车站能力和列车运输能力约束,构建了广珠城际铁路列车停站方案优化模型,并设计遗传算法进行求解.算例分析表明,相比于现有方案,优化方案各等级节点服务频率分别减少了4.88％、7.41％、33.33％,各等级节点间平均服务...     

城际列车的概念及其开行条件

城际列车是在世界铁路客运发展趋势的宏观背景下 ,结合我国铁路客运改革的需要 ,推出的更能适应市场、满足经济和社会发展的旅客列车新品种 .分析了国内外城际列车运行状况 ,并根据我国铁路客运现状 ,提出了城际列车的概念 ,着重分析了城际列车的开行在区域范围、运输能力以及车底设备 (包括车门数量及宽度、车底板高度等 )方面的条件 ,探讨了城际列车在运行距离、列对密度、旅行速度以及服务质量方面的要求 .最后 ,指出了城际列车的发展需要经历 2个时期 (即既有线运行时期和未来客运专线运行时期 )、5个阶段 (起步阶段、初级阶段、中级阶段、高级阶段以及理想阶段 ) .从而为优化沪宁杭城际列车既有运行方案奠定了理论基础     

基于灵活编组的轨道交通列车开行方案优化方法

针对城市轨道交通全日客流时间分布不均衡特性下的列车开行方案优化问题,从乘客广义出行成本和企业运营成本角度,考虑列车满载率对牵引能耗成本的影响,利用数学规划方法构建基于灵活编组模式下的多目标列车开行方案优化模型,并提出四阶段求解算法.以某城市轨道交通线路为对象进行案例分析,对比传统固定编组列车开行方案,基于灵活编组的列车开行方案使乘客广义出行费用和企业运营成本分别减少了14.6％和11.0％.结果表明:该方法能有效实现既有固定编组条件下,列车开行方案难以达到的乘客出行费用和企业运营成本双赢目标,可为我国城市轨道交通新型运输组织方案的制定提供新方法.     

区域性城际列车开行方案的研究

基于对城际客运市场的调查分析,探讨了城际列车的种类及其承担客流比率等客运产品设计的基本问题,优化了现行列车开行方案的确定方法,提出了分层次确定开行方案的新模型,并以沪宁城际轨道交通为例进行计算分析,得出了可行、实用的开行方案.     

基于遗传算法的列车开行方案优化

根据列车停站方案的4种模式,建立了列车开行方案双层规划模型.上层以总的运营费用最小和未服务的旅客数量最少为目标进行停站方案和开行频次的优化;给定停站方案和开行频次后,下层以服务旅客数量最大和旅客总的旅行时间最小为目标,建立了客流分配的混合整数规划.基于GA的开行方案优化算法实现了停站方案生成与客流分配循环反馈优化.最后以台湾高铁为实例分析,验证了本文模型和算法的有效性.     

动车所选址和列车开行方案编制协同优化

在列车开行方案现有研究成果基础上,考虑动车所选址对列车始发/终到站选择的影响,以列车运行成本、动车所建设成本、动车组出入动车所的空驶成本为优化目标,提出动车所选址与列车开行方案协同优化模型.根据模型特点,采用拉格朗日松弛技术对复杂约束进行松弛,将原问题分解为客流路径分配子问题和列车开行及动车所选址子问题,以珠三角城际网络为案例背景对模型和算法进行验证.计算结果表明:在不考虑动车所与其直接关联车站间空驶里程时,与初始方案相比,优化方案的动车组出入动车所产生的空驶里程降低了56 160列·km,减少了1组车底;与对比方案相比,动车组出入动车所产生的空驶里程降低了13 250列·km,增加了3组车底.通过分析不同服务水平下的列车开行方案与动车所选址方案的联动关系,验证了将两者协同优化的必要性.     

铁路货运直达列车运行线优化选择模型与算法

确定列车运行线是编制列车运行图的重要内容之一,优化列车运行线选择对于加快铁路货物送达速度,压缩铁路车辆周转时间具有重要意义.本文以两个技术站之间开行的直达列车为研究对象,基于不同列车的等级,研究了考虑列车等级权重的列车运行线优化选择方法.以各列车在途中停留时间加权值的总和最小化为优化目标,建立了直达列车运行线选择的0-1整数规划模型,并在此基础上设计了粒子群算法对模型进行优化求解.最后,通过算例分析,验证了优化数学模型和求解算法的有效性,为铁路货运直达列车的运输组织提供参考依据.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.