基于移动终端的主动预约式智能公交调度系统

针对我国城市近郊区公交系统智能化水平低、居民出行便捷性差等交通现状,在综合分析现有需求响应式交通系统(DRT)特点的基础上,结合互联网主动预约技术与车辆智能定位技术,提出了一种基于移动终端的主动预约式智能公交调度系统。将互联网移动终端、总调度控制中心与公交车辆作为一个整体系统,以乘客预约候车总人数与乘客最长等待时间为决策变量,通过引入相关阈值建立了基于乘客需求的发车间隔优化模型,并给出了发车时间间隔的求解方法。研究结果表明:与常规公交系统相比,基于移动终端的主动预约式智能公交调度系统能够有效地解决我国城市近郊公交运行效率低、乘客候车时间长、出行困难等交通问题,对于提高公交的便捷性与智能化水平具有积极的现实意义。     

城市外围非高峰期实时预约公交系统研究

针对居住在城市外围的人们在非高峰期出行时,公交系统的运营效率及运营成本与乘客等待公交时间的矛盾问题,本文提出了一种基于网约车思想利用手机APP实时预约公交的系统模式。在新请求出现时实时预约公交调度系统会先根据公交系统服务阈值筛选出符合条件的公交,再利用启发式最短路径算法为距离新请求点由近至远的公交依次进行响应路径规划,并结合响应判断函数计算对应公交的响应效益,然后指派首个效益为正的公交作为新请求的响应公交,最后调度系统会将响应公交的信息实时反馈到乘客APP。本文以重庆市外围地区的169路公交为研究对象,验证实时预约公交系统的可实施性,并得出该系统模式在城市外围非高峰期可以进一步完善公交运营系统且满足乘客出行需求。     

城市轨道交通换乘常规公交时间优化模型

为探究城市轨道交通换乘常规公交的时间优化模型,以上海市晚高峰时段地铁6号线金桥站换乘874线路公交车为例,利用统计分析软件,分析客流到站时间,得到对数正态分布;并在此基础上建立乘客候车时间模型,运用调查所得数据设置模型各参数值;最后以乘客候车时间最少为目标函数,利用遗传算法求解得到874线路公交车优化后的到站时间.结果表明:利用时间优化模型求得的874线路公交车发车时间与优化前的发车时间相比,乘客的候车时间平均每人节约约52.8 s,有效提高了人们的出行效率.     

可变线路式公交的两阶段车辆调度模型

针对可变线路式公交设计了一种可同时处理预约需求和实时需求的两阶段车辆调度模型.第1阶段模型以预约需求为服务对象,建立了以乘客出行成本和车辆运营成本最小为目标的路径优化模型,采用模拟退火算法对模型进行求解,获得车辆初始行驶路径方案.第2阶段模型以实时需求为服务目标,在原定行驶路径方案上利用启发式插入算法将4类乘客排入车辆行车计划中.基于实例的仿真试验验证了两阶段车辆调度模型的可行性,结果表明:通过提高乘客预约出行比例的方式可提升系统性能,本例中当乘客需求量达到25人/h、预约出行比例达到70%时,系统整体性能相较于纯动态需求条件下提升近10%.     

基于服务可靠性的公交到站时刻表编排与评价

建立了利用公交历史数据进行公交到站时刻表编排的优化模型,以提升乘客按时刻表出行的搭乘成功率,减少等待时间,改善出行体验。首先,提出了服务可靠性的概念来表示乘客根据时刻表候车能成功搭乘的概率,并基于此引入了历史百分位到站时刻作为参考时刻;然后综合考虑等待时间、运行时间等约束条件,以最大化服务可靠性构建了到站时刻表编排模型,并利用乘客搭乘成功率、平均等待时间等指标来对模型进行评估。最后,选取广州市某公交线路进行了实例验证,并与传统方法进行了对比分析。结果表明,模型编排的到站时刻表能明显提高乘客的搭乘率,减少乘客平均等待时间。     

公共交通智能化调度系统实时网络优化模型与方法的研究

公共交通智能化管理系统的核心是公共交通智能化调度系统.智能化调度系统可以动态地获取实时公共交通信息,实现对公交车辆的实时监控和调度,是公共交通实现现代化管理的重要标志,能够完成乘客在出行时达到最优换乘.本文研究了城市公交交通智能化调度系统实时网络优化模型的建立与实施,旨在推动我国智能公交系统的快速发展.     

基于公交运行数据的到站时间填充方法

公交实时到站数据是乘客出行行为分析的基础,但是现有公交运行数据存在到站时间缺失问题。以公交实时到站数据为基础,结合公交车辆的运行特性以及拥堵传播特性,建立考虑多因素加权的多项式插值方法,对公交车辆的到站缺失数据进行填补。填补后的到站时间能够更详细地描述车辆运行过程,得到更精确的车辆到站间隔。应用该方法对北京市地面公交运行数据进行补全,得到了修正的时刻表,并对公交运行间隔与串车现象进行分析。     

基于公交运行数据的到站时间填充方法

公交实时到站数据是乘客出行行为分析的基础,但是现有公交运行数据存在到站时间缺失问题。以公交实时到站数据为基础,结合公交车辆的运行特性以及拥堵传播特性,建立考虑多因素加权的多项式插值方法,对公交车辆的到站缺失数据进行填补。填补后的到站时间能够更详细地描述车辆运行过程,得到更精确的车辆到站间隔。应用该方法对北京市地面公交运行数据进行补全,得到了修正的时刻表,并对公交运行间隔与串车现象进行分析。     

智能公交动态调度优化模型

利用先进的技术和设备实现公交的优化调度,充分满足人们的出行需要,是智能公交系统发展的目标.然而近年来中国智能公交发展在一定程度上出现过于追求先进性、忽略实用性、运营效果不理想、动态调度尚待充分开发等问题.结合中国智能公交系统现状,通过对智能公交调度系统和调度特点深入分析,在GPS定位、通信、计算机等技术的支持下,将动态交通状态信息与车辆定位信息有效融合,将智能化算法引入到公交运营调度中,建立了基于实时动态数据,兼顾乘客满意度和企业效益的动态调度优化模型.并且阐述了模型数据的自动采集方法、模型Matlab程式化的解法.结果表明,该模型可以显著提高公交车辆满载率、缩短乘客等车时间和减少车辆总班次,优化调度效果明显.     

人员稀疏地区柔性公交区域特性的研究

传统意义上的公交系统具有固定的路线和时刻表,造成需求量较低的地区调度上的灵活性较差,不能满足人们出行的需求。通过阐述一种新的柔性公交车搭乘方法,融合了传统公交系统的低成本性和需求响应公交的灵活性,在保持原有公交路线行进方向的情况下,采用无返回最近插入算法,拓展了公交路线的宽度,通过减少乘客来去候车时间,减少所有乘客出行的总时间,便于人们出行,对于出行不便者意义重大。     

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.