基于熵的瓶颈运输问题的动态规划解

建立了关于时间(路程)的瓶颈运输问题的动态规划模型,并利用熵作为工具,解决了物品运输过程中所用时间长短的界问题,进而给出易于处理的瓶颈运输问题的动态规划模型。最后给出一个实例说明该方法的实用性和有效性。     

m维瓶颈指派问题的动态规划模型

m维瓶颈指派问题：把m个人指派到n项工作上（m〉n），要求每人只做一件工作，已知每人做每件工作的效益，问题是如何把m人划分成n组m1,m2,…，mn，∑j=1 mj=m，让mj组人去做第j件工作，可使效益最低的一组效益达到最大。本文对此问题建立了动态规划模型，并利用黄金分割律作为工具给出了动态规划模型的解。最后，文章给出一个算例以说明该方法的可行性和有效性。     

m维瓶颈指派问题的动态规划模型

m维瓶颈指派问题:把m个人指派到n项工作上(m>n),要求每人只做一件工作,已知每人做每件工作的效益,问题是如何把m人划分成n组m1,m2,…,mn,nΣj=1mj=m,让mj组人去做第j件工作,可使效益最低的一组效益达到最大。本文对此问题建立了动态规划模型,并利用黄金分割律作为工具给出了动态规划模型的解。最后,文章给出一个算例以说明该方法的可行性和有效性。     

紧急救援下障碍空间分析技术的应用

灾害紧急救援提出了对地理信息技术新的急迫要求:即动态GIS中的动态数据模型和"0"初始化计算问题,障碍空间路径规划问题、"安全岛"问题——障碍空间最大(小)间隙问题、与安全区的k阶邻近问题,本文给出了这些问题的解决途径和解算实例。     

用正行列式解瓶颈指派问题

用正行列式作为工具，给出了瓶颈指派问题新的解法，并利用正行列式的值求出了瓶颈指派问题的全部最优解。最后通过一个实例说明该算法的实用和有效性。     

车辆路径问题:从时间地理学的视角

车辆路径问题具有典型的时空分布特征,受到众多时空约束条件的制约。在车辆路径规划中,综合考虑时间和空间因素是非常必要的。本文从时间地理学这一全新的视角来研究车辆路径问题,提出一套完整的时间地理学分析框架,阐述了时间地理学的基本概念,提出了车辆路径问题中的时空约束、时空路径、时空棱柱、时空可达性、时空距离等概念,并给出了图示或定量化的度量方法。论文提出的时空距离度量方法综合考虑了顾客在空间位置和时间窗口2个方面的特征,可更科学地判定顾客之间的"邻近性"。论文通过设计一种求解大规模软时间窗车辆路径问题的算法,证明了时空距离的价值,并展望了时间地理学在求解动态车辆路径规划问题、移动设施路径规划问题等方面的应用。本文的贡献在于,通过时间地理学所提供的一系列概念和方法,实现了在统一的框架下同时考虑车辆路径问题(VRP)的时间和空间特征的构想,挖掘了传统时间地理学理论在车辆路径领域中的应用潜力,这将有利于更快或者更好地求解VRP问题。     

交通流量分析与实时最优控制

通过将车流量的增大或减小转化为路长权重的变化。将交通流量的动态问题转化为静态问题，用解决最短路问题的Dijkstra方法，给出交通流量实时最优控制的可行性模型及其有效算法。     

基于路段-路口联合建模的对偶图卷积网络的行程时间估计方法

估计给定路径的行程时间在许多城市交通系统中起着重要作用，例如导航、路线规划和拼车等。然而，现有的大多数工作都侧重于对路段或交叉路口进行单独建模，这并不能准确估计行驶时间，因为交叉路口和路段作为路径的基本要素不仅各自包含多样化的空间属性和时间动态，而且它们之间还具备较强的耦合相关性。为了解决上述问题，本论文提出了一种新颖的端到端深度学习框架，即面向行程时间估计的对偶图卷积网络（DGCN-TTE）来对交叉路口和路段进行联合建模。具体来说，这个模型采用对偶图卷积方法来捕获路口和路段的复杂关系，其中构建节点图来刻画路口之间的相关性，构建边图来表征路段之间的交互特征。为了捕捉空间和时间特征的联合关系，模型中还引入了一种在捕捉时间依赖性的同时结合了从多个邻域范围内整合多尺度空间关系的时空学习模块。本论文通过对3个真实世界的轨迹数据集上的充分的实验来评估提出的DGCN-TTE模型，结果表明该模型显著优于现有的方法，评估指标相比于次优方法最多可以获得超过10%的提升。     

反演奇异模型的参数估计的通用公式

将大地测量反演问题中的线性模型，综合为一般模型，称为反演奇异模型。运用最小二乘统一理论给出了反演奇异模型的参数和单位权方差通用估计公式，给出了这种模型的验前验后方差一致性检验方法。讨论了反演参数估计的有关问题。     

多层建筑空间的分层最优路径算法实现

由于多层建筑空间相对于室外环境存在按楼层分层的三维空间特性,在室内路径分析中需考虑楼层空间位置信息对最优路径规划的影响,而传统基于节点之间的网络连通拓扑模型的最优路径规划方法并没有空间概念,不能很好地应用于室内路径分析。为此,针对室内最优路径规划问题,基于多层建筑空间的层次特性,采用分层结构化的方法,提出结构化动态网络分析模式,实现了室内分层最优路径算法。该算法将各楼层路网和楼层连接均视为独立结构,根据停靠点的楼层分布情况,逐楼层动态构建跨越2个楼层的结构化网络模型并以该网络模型进行跨楼层的路径分析,从而得到多层建筑空间中遍历所有停靠点的最优路径。试验结果表明：相比传统最优路径算法,该算法在路径规划结果更加合理的情况下,时间效率有明显提高;另外,结构化动态网络分析模式可根据需求定义不同的楼层转换规则,更具灵活性。该算法可应用于城市大型公共建筑中,让室内路径分析与室外路径分析进行对接,使路径分析更科学、全面、合理。     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied     

Advances in Polar Science CONTENTS(Volume 25,2014)

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Guide to Authors： Journal of Mountain Science

<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.     

Journal of Mountain Science(JMS)

<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by     

Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.     

Author Index for Journal of Mountain Science Volume 11,2014,pp 1-1656

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