基于数据挖掘的路网交通拥堵特征分析

交通拥堵的发生通常导致道路通行能力的下降和交通瓶颈的形成,对城市的经济和环境造成影响。对此利用大数据技术挖掘交通数据,通过聚类分析方法,构建交通指数数据集,进而对城市路网交通拥堵进行定量分析。研究表明,路网拥堵在工作日和周末存在差异,周数据具有周期性,在空间上总体呈现由点向线再到面的拥堵扩散过程。依据拥堵的时空特征,分析了路网的拓扑结构和流量的复杂性,为城市的可持续发展和交通优化提供一定的支持。     

基于交通指数云图的宏观交通流分析方法综述

基于交通流分析在智能交通研究和应用中的重要性,聚焦路网交通流分析方法的回顾,综述了宏观尺度的路网交通流分析方法的研究现状.从微观、中观、宏观3个方面梳理了交通流分析方法的基本类型;重点阐述了宏观交通流分析中的交通拥堵指数的基本概念及其计算方法;随后基于交通拥堵指数提出交通指数云图的概念;最后对基于交通指数云图的路网交通流分析进行了讨论,并对其发展和应用前景进行了展望.     

独山县年度土地利用变更调查数据分析

选取独山县为研究对象,利用独山县2013—2017年度土地变更调查数据,首先分析独山县土地利用现状及变化特征,在此基础上,对独山县土地利用转移进行分析,通过分析独山县2013—2017年转移矩阵,得出独山县土地利用变化趋势及年度土地利用变更调查的局限性,对下一步开展年度土地利用变更调查提出展望。     

全球变暖背景下青岛市不同强度降水特征及趋势分析

基于带"结"并考虑序列自相关的改进Mann-kendall检验方法,对1961～2013年的青岛降水对全球变暖的响应及趋势特征进行了分析。研究发现,青岛年均降水量为709mm,夏季降水占到57.37%,降水主要集中在中雨、大雨和暴雨,共占到全年降水量的73.14%;夜间全年降水比白天多近100mm,并且降水差异主要集中于高强度降水,夏季和冬季表现尤为显著。全年降水总体有不显著的下降和集中化趋势,但具体指标及四季变化有升有降。不同强度降水指标的年度变化趋势中,除去大雨降水量表现出不显著的增加趋势,其余直接降水指标均呈下降或无明显变化趋势,与之相对的白天干旱指数则呈极显著增加趋势。     

基于TPI数据的交通拥堵状况时空特征分析——以青岛市为例

基于交通运行指数数据,针对城市商圈交通,从区间特性、时间维度及时空演变等相关角度对青岛市的交通拥堵状况进行系列特征分析。通过对交通运行指数数据进行统计分析,筛选出最具典型的五大商圈。结合五大商圈的特点,分析交通拥堵的时空特征:拥堵最严重的往往是南部沿海地区;交通拥堵大多集中在7:30—9:30,17:00—19:00;并且在工作日与休息日和一天中的不同时刻,不同商圈呈现出不同的变化趋势。通过分析青岛市商圈的拥堵现状、原因及其变化规律,对缓解城市拥堵问题具有重要意义,为青岛市的城市规划提出针对性建议。     

基于 HP 滤波对山东省潜在产出和产出缺口的实证分析

利用HP滤波对山东省季度GDP数据进行研究,并用Eviews软件对潜在产出和产出缺口进行分析,得出经济增长的变化趋势。     

安徽省马鞍山市区域环境功能评价

本文提出利用环境功能指数对城市环境功能区的环境功能进行评估，设计了相应的评估方法。对马鞍山市七个环境功能区的环境功能进行了评估，分析讨论了各功能区的环境功能变化趋势，并提出相应的对策与建议。此项研究为马鞍山市合理利用土地、制订生态规划，使城市建设与环境保护协调发展提供依据。     

地质体的三维形态分析方法与应用

针对隐伏矿体立体定量预测中复杂形态地质体的空间分析问题,利用数学形态学和欧氏距离变换理论,提出基于三维栅格模型的地质体三维形态定量分析的方法.利用开闭滤波或闭开滤波的数学形态学变换,构建地质体表面形态趋势的提取算法;将形态滤波、欧氏距离变换、全局集合运算结合起来,建立地质体形态起伏定量分析及分级提取模型;采用基于欧氏距离场的计算模型,提出地质体表面与趋势面夹角的提取方法.在建立地质体三维栅格模型的基础上,将地质体三维形态定量分析方法应用于安徽铜陵凤凰山矿田的新屋里岩体分析,实现地质控矿因素指标的定量提取.研究结果表明:采用该方法对地质体进行形态分析,可计算出地质体的各种形态参数,并提取出地质控矿因素量化指标,能有效地应用于隐伏矿体立体定量预测.     

基于路径交通拥堵指数的危险废物回收模型研究

针对交通拥堵对危险废物运输中的成本和风险的影响,引入路径交通拥堵指数,建立了时变道路系统中基于交通拥堵指数的危险废物回收双目标优化模型,并对传统蚁群算法中启发式因子计算公式进行了改进,提出了改进的蚁群算法对模型求解,最后以某环保公司危险废物回收问题为背景进行了案例分析。结果表明,不同出发时间和车辆使用模式对帕累托最优解有显著影响,最短路径不一定是耗能最少的行车路线。本文提出的模型和算法可为决策者制定调度方案提供参考。     

西宁市昆仑桥下大转盘及南关街丁字路口交通优化方案

该文主要是针对西宁市昆仑桥下转盘改造及交通渠化,以缓解交通拥堵现象,利用平面交叉口通行能力理论研究方法对其进行计算分析,从而提出了合理可行的交通优化方案。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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