基于归纳式学习法的通勤交通满意度指标研究

以评价通勤者对交通系统满意度为目的,建立通勤交通满意度指标.以问卷形式采集数据,采用归纳式学习方法,分析通勤者满意度等级与通勤时间之间的相关信息,得到以大于0.5证据权的出行时间区间为代表值的满意度指标.其中,通勤时间区间10～30 min为出行者最满意的通勤时间代表值.此结论从一个角度说明交通出行行为具有“可达性”与“移动性”的双重价值.     

基于改进熵的土地利用混合度对非通勤行为的影响

为研究土地利用混合度对非通勤行为的影响,提出改进熵模型定量描述土地利用混合度,并深入分析土地利用混合度对非通勤者出行距离和出行方式选择的影响.结合甘肃省天水市2015年居民出行调查数据,构建土地利用混合度与非通勤者出行距离的关系模型,并利用MNL模型研究土地利用混合度对非通勤者出行方式选择的影响.结果表明:与传统熵指标相比,改进熵指标对非通勤者出行距离的解释性更强;利用STATA软件标定MNL模型参数并进行弹性分析,进一步表明改进熵指标对居民出行行为的解释性优良,合理的土地利用布局有助于引导居民选择非机动化出行方式.研究结果对城市规划和交通政策的制定具有指导意义.     

基于位置服务大数据的粤港澳大湾区通勤标度特征分析

城市群是中国发展的重要增长极点和核心节点,城市群交通一体化是推进城市群协调发展的首要任务之一,而对城市群内多种交通出行模式的充分认识是实现这一目标的重要基础。该文基于位置服务大数据,以粤港澳大湾区“9+2”城市群为例,分析了城市群内部通勤出行标度特征的一致性与差异性,得到以下结果：粤港澳大湾区的市内通勤仍占主导地位,但部分区域存在相当规模的跨市通勤;粤港澳大湾区通勤联系的“概率-距离”分布具有指数标度特征;对各城市而言,市内通勤的标度参数比跨市通勤更大,意味着市内通勤者对距离更加敏感;标度参数可以进一步反映交通与土地利用联系的紧密程度,进而为政策制定提供参考。     

基于30 min通勤可达范围的居住区分类及特征指标

以上海市15个居住区通勤出行调查数据为基础,确定合理的单次通勤出行时间预算目标值为30min.利用电子地图应用程序编程接口(API)二次开发和地理信息系统(GIS)技术绘制居住区居民使用小汽车、轨道交通、常规公交方式30min通勤活动空间可达范围.从30min通勤可达范围交通系统配置角度,分析居住区通勤可达范围差异产生原因.重点对居住区公共交通30min通勤可达范围内各类提供工作岗位的设施点密度、被调查者上班地点落在该范围比例、使用小汽车通勤出行比例之间的相关性进行分析.提出分类居住区的针对性交通改善策略.     

基于出行态度的自行车通勤出行市场划分

为识别自行车通勤出行中不同出行者选择偏好的差异,针对基于出行态度的自行车通勤出行市场进行划分.根据南京市居民通勤出行问卷调查,采用结构方程模型从29个观测变量中提取出若干态度潜变量,分析了出行偏好态度变量间的相关性,并采用K-means聚类方法对自行车通勤出行市场进行划分.根据选择自行车通勤出行意愿、对固定出行时刻需求、对出行舒适度需求及环保意识4类态度变量将自行车通勤出行市场划分为6个子市场,同一子市场内个人选择自行车出行意愿近似,不同子市场间选择意愿明显不同.分析了每个子市场内个人通勤出行态度特征以及自行车方式选择特征,针对每个子市场提出了相应政策以引导自行车通勤出行方式的选择.     

通勤可达范围的居住区分类及特征指标

本文以上海市15个居住区通勤出行调查数据为基础,确定合理的单次通勤出行时间预算目标值为30分钟。利用电子地图API二次开发和GIS技术绘制居住区居民使用小汽车、轨道交通、常规公交方式30min通勤活动空间可达范围。从30min通勤可达范围交通系统配置角度,分析居住区通勤可达范围差异产生原因。重点对居住区公共交通30min通勤可达范围内各类提供工作岗位的设施点密度、被调查者上班地点落在该范围比例、使用小汽车通勤出行比例之间的相关性进行分析。提出分类居住区针对性交通改善策略。     

通勤出行中停车换乘选择行为分析与建模

针对通勤出行研究驾车者的停车换乘选择行为,选取上海市典型停车换乘站对驾车通勤者与公共交通通勤者进行了RP(revealed preference)调查与SP(stated preference)调查,基于调查数据分析了选择停车换乘与否的影响因素,并针对道路交通通畅、堵塞2种状态分别建立了是否停车换乘的二项Logit模型.模型结果显示低收入的年轻人更倾向于选择停车换乘;交通状态堵塞时是否有老人或小孩等家庭特征显著影响停车换乘选择行为;模型还揭示了通畅时通勤者更关注出行费用,而堵塞时通勤者更关注出行时耗和舒适性,并分析了时间和费用敏感度对停车换乘选择概率的影响及其差异.     

基于网络广义极值模型的居住地和通勤方式同时选择模型研究

基于随机效用最大化理论, 选取个人属性、社会经济属性、出行特性和土地利用属性因素为联合选择模型影响变量, 以居住地区位选择集合和通勤出行方式选择集合的组合作为模型的选择项, 构建居住和出行方式联合选择的网络广义极值模型, 刻画日益增长的交通拥堵情况的影响变化及其在不同的就业地模式下对居住再选址和出行方式转变的潜在影响, 从微观角度研究居住就业与城市通勤交通出行关系。利用 Biogeme 软件, 对模型参数进行估计和检验, 同时对模型进行弹性分析, 分析不同影响因素的变化引起的方式选择概率的变化。结果表明, 相比郊区的通勤者, 中心区的通勤者对出行时间的增加更为敏感, 更易于改变出行方式和居住区位, 以抵消交通拥挤引起的负效用。     

城市通勤出行链模式选择行为研究

通勤出行是城市居民最基本和最重要的出行,对其进行研究是进行交通规划、设计与管理的一项不可缺少的基础工作,因此本文开展了基于2008年东莞城市居民出行调查数据和多项Logistic模型建立居民通勤出行链模式选择模型的研究工作。本文中的通勤出行链模式选择模型将通勤出行链模式细分为五类（HWH、HWHWH、HWH＋、HWHWH＋、HW＋WH）,并考虑了出行方式对出行链模式的影响作用。通过对模型结果的分析,总结了通勤出行链模式的显著影响因素以及通勤出行链模式选择中的特征。研究内容对于建立基于活动的交通需求预测模型、制定交通管理政策具有重要借鉴作用。     

通勤出行时间与方式选择

针对不同方式通勤出行者在出行时间上的差异性,从通勤出行方式对通勤出行时间的影响出发,将通勤出行方式选择和出行时间选择纳入同一模型系统,建立由离散选择模型和线性回归模型组成的离散 连续模型,对通勤出行方式和出行时间选择及其相互影响模式进行了深入分析.研究表明,通勤出行方式对出行时间选择有显著影响,通勤者年龄、性别及其家庭成员结构、工作活动属性及通勤途中的非工作活动安排等都是出行方式和出行时间选择的重要影响因素.本研究对准确预测通勤出行选择行为及其对交通管理工作的影响有重要意义.     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.