一种基于蚁群算法的多媒体网络多播路由算法

为了克服蚁群算法（Ant Colony Optimization,ACO）收敛速度慢，易限于局部最小点等缺陷，对ACO进行了改进，在每次循环结束时，保留最优解，自适应地改变挥发度系数，引入遗传算法的交叉算子，提出了一种基于ACO的有时延约束的多播路由算法模型。仿真结果表明，基于改进ACO的多播路由算法模型 可以稳定地获得优于现有启发式算法的解，是一种有效的多播路算法，该算法也适用于并行执行和应用。     

分簇式ad hoc多播路由的超图法

在大规模的ad hoc网络中,设计分簇式路由算法可以解决节点数目增长带来的可扩展性问题.给出分簇式多播算法的超图模型,提出基于Steiner超树模型的ad hoc多播路由的集中式算法和分布式算法,并对两种算法的复杂度和通信开销做出分析.     

自适应粒子群优化的AdHoc网络多播路由算法

针对AdHoc网络中带QoS约束的多播路由问题,提出了一种自适应粒子群优化的AdHoc网络多播路由算法（APs0）,将微粒在解空间中的飞行搜索过程映射为多播树的树形变换过程．构建了AdHoc网络中QoS多播网络模型,采用罚函数处理约束条件来设计适应度函数．描述了APSO算法求解AdHoe网络多播路由问题的实现过程,将QoS多播路由优化问题转化为整数计算问题．仿真结果表明：该算法能快速地找到针对AdHoc网络中满足qos要求的最优多播树,尤其在大规模网络下更能显示该算法的有效性和可靠性．     

一种能量负载均衡的自组织网络多播路由协议

在分析基于共享树的Ad Hoc网络多播路由协议MAODV的基础上,结合能量模型,提出了一种Ad Hoc网络基于节点能量负载均衡的多播路由协议——ELBMRP.算法分析显示,在不增加算法复杂性的前提下,ELBMRP明显地改善了MAODV协议的延时特性,节点的能量消耗比较均衡,一方面降低了系统的能耗,另一方面有效地延长了网络的存活时间,比较好地解决了Ad Hoc网络能量和延时相互矛盾的问题.     

一种多约束的应用层组播路由算法

由于IP多播在应用上的困难。应用层网络作为多播服务平台逐步被人们认可。针对实时多媒体应用对带宽需求和时延约束的特性，提出了一种新的构造应用层最小直径多播树的启发式算法PCT，该算法结合深度可调的广度优先搜索策略，根据带宽和时延的策略函数选择既满足要求又节约网络资源的路径。实验表明该算法能够有效地降低多播树的直径，减少多播树时延并具有广泛的适应性。     

通信网络中QOS多播路由技术研究

给出了多约束QoS组播路由的问题模型,分析论述了多约束QoS组播路由优化的约束树算法和遗传算法、蚁群算法、免疫算法等智能化算法,对QoS约束的多播路由技术的进一步研究进行了展望。     

应用层多播技术的分析与研究

针对现有多播协议均忽略代价不对称性建立共享多播树这一问题,分析并设计了一种基于源端建立多播树的算法,并实现了与之相关的支持轻量级应用的应用层多播协议.基于本协议开发了一套应用层多播聊天程序,并在校园网上进行了实验.结果表明,所设计的应用层多播机制能有效地支持小规模的多播通信.     

基于ACO的LEO卫星网络路由研究

为了解决低轨卫星网络动态拓扑路由问题,通过更改蚁群优化(Ant Colony Optimization,ACO)算法结构以及信息素更新策略进行调整,提出一种适合LEO卫星网络的具有多QoS约束条件的ACO路由算法.这种路由算法能够根据LEO卫星网络中业务流量分布的变化对网络最优路径做出调整、均衡网络负载、避免拥塞,实现多种QoS指标的联合最优.仿真结果表明:在网络接近满负荷的情况下,路由算法在保证业务QoS需求的同时,使网络资源得到了充分利用.     

移动自组网的多约束QoS多播路由最优算法

在多播应用中,应当确保多种网络服务质量(Qos).针对移动自组网多播通信业务工程,本文给出了一个基于遗传算法的多约束最优化路由算法(MQMGA),该算法能够优化最大链路利用、节省多播树开销、保持长寿命路径选择、减少平均延迟和端对端最大延迟.仿真实验结果表明,该算法有效,能够提高多播通信业务工程的性能,易于评价移动自组网的路由稳定性.     

基于链路可共享性的多播路由算法

基于链路可共享性,提出一个快速有效的时延约束多播路由算法SBMR.该算法首先计算各链路的可共享性,然后根据链路的可共享性,由大到小依次选择链路参与多播路由,最后由所选链路组成一棵低代价的多播树.实验结果表明,与多播路由KPP算法相比,本算法构建的多播树有72%比KPP算法构建的多播树更优,代价降低13%,启用的链路数减少9%,而且CPU时间减少15%.与多播路由DCSP算法相比,本算法以增加28%的CPU时间为代价,构建的82%的多播树比DCSP更优,代价降低15%,而且启用的链路数减少11%,达到了更好的链路共享.     

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).     

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.     

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.