面向云工作流的两阶段资源调度方法

为提高云计算系统的资源利用率,优化系统性能,同时兼顾用户的服务质量(Qo S)需求约束,文中结合云计算和工作流建立了云工作流系统,给出了具有两个调度阶段的系统资源调度模型.在第1阶段中,考虑了Qo S的时间及价格约束、工作流内各个任务之间的依赖关系以及各个任务所产生的中间数据的处理,提出了改进的粒子群优化(MPSO)算法,并利用Pareto获得最优解,以提高调度效率;在第2阶段中,考虑了资源在主机上的分配情况,提出了具有负载感知的调度策略,根据系统的负载情况进行资源调度,以提高系统的资源利用率.实验结果表明:在云工作流系统的资源优化调度中,与经典的异构最早完成时间算法、单目标优化的遗传算法相比,MPSO算法的任务执行速度更快、资源利用率更高,能满足用户的Qo S需求;具有负载感知的调度策略能更有效地根据负载情况进行调度,提高任务执行的效率和资源利用率.     

基于预留带宽门限和传输等级的带宽分配算法

针对异构无线网络融合环境下多业务传输资源分配问题,提出一种基于预留带宽门限和业务传输等级自适应的分布式带宽分配算法.根据移动终端多宿主传输特性和异构网络分布式资源管理模型,通过构建传输业务的网络效用函数,在传输等级Qo S需求和业务容量约束条件下,将其建模成凸优化问题;根据用户业务请求接入变化,自适应的调整预留带宽门限和业务传输等级,采用动态优化的迭代算法求得最优带宽分配矩阵.仿真结果显示,所提算法在保证网络低的通信开销和满足Qo S需求基础上,达到最大化网络的效用函数和降低业务呼叫阻塞概率的效果.     

基于PSO和SA混合优化的智能容错QoS路由机制

由于网络的异构性、移动性和不稳定性等特点导致网络在发生故障时连接的可靠性变差,不能满足用户服务质量(quality of service,Qo S)需求,因此网络需要具有保证Qo S的容错路由能力.为此提出基于粒子群优化(particle swarm optimization,PSO)和模拟退火(simulated annealing,SA)混合优化的容错Qo S路由机制.考虑到网络环境的动态性,引入模糊数学和概率论定量刻画网络模型,采用共享风险链路组(shared risk link group,SRLG)分离和共享通路的预防式保护策略建立备份路径,使其端到端可靠性、代价和路径Qo S评价值达到最优.仿真结果表明,所提出的容错路由机制具有良好的路由有效性、故障恢复率和资源利用率,是可行和有效的.     

实时多任务异构云计算平台负载均衡算法

针对组成云计算平台各节点之间软件环境存在异构性及数据分布不均匀等原因而导致云计算平台在处理大量任务时往往出现节点负载不均衡的问题,提出了解决异构云计算平台负载均衡方法与相关算法.研究首先统计云计算平台提供的各类服务的平均资源消耗,结合任务分配给指定节点后运行时长和资源占用情况,预测评估某一时刻节点上任务剩余资源消耗需求总量既剩余负载总量;各节点按周期反馈实际任务负载情况,及时修正任务负载信息;最后综合考虑节点各项性能,预测各节点负载评估值,并将待分配任务分发给最适合的节点.实验结果表明,该算法具有可行性并在实时多任务异构云计算平台负载均衡方面具有一定优势.     

基于分簇的无线多媒体传感器网络QoS多径路由

针对无线多媒体传感器网络应用,提出基于分簇的Qo S多径路由算法。该算法首先建立分层网络拓扑,然后基于改进蚁群算法实现Qo S多径路由。网络分层时,根据多媒体传感节点的有向性设计分簇算法,实现簇内数据融合以减少冗余数据。数据传输阶段,提出基于蚁群优化的Qo S多径路由算法以满足多约束的Qo S需求。仿真结果表明,与Ant Sens Net等路由协议相比,该算法有效降低网络负载,延长网络生命期。     

基于边缘云的动态和抢占式任务卸载调度算法研究

边缘云计算系统被广泛用于支持各种计算服务。针对边缘云计算环境中的任务卸载调度问题,考虑边缘云系统下的动态性和抢占式任务卸载调度,提出一个基于贪婪模拟退火启发式算法的在线卸载框架(SAOF),根据任务所需的传输延迟以及计算时间,进行周期性的卸载和调度计算,考虑独立任务的随机到达性和资源的异构性,动态地将新到达的任务分配到合适的目的地(边缘服务器或云服务器),并根据每个任务的延迟敏感性,抢占式地为其分配计算资源,使所有任务的总加权响应时间最小化。最后,在多组参数组合下生成测试实例并进行性能评估实验,将SAOF算法与3种优秀的卸载调度优化算法(Selfish算法、Nearest算法和OnDisc算法)进行对比,实验结果表明,SAOF算法能更有效降低所有任务的总加权响应时间。     

云计算下异构数据集成模型的构建

为使用户能够将现有的应用系统向云计算环境迁移,将原有的异构数据处理无缝的映射为云计算环境下通用的数据服务和行为,从云计算和云存储的理论和模型出发,面向大规模的数据密集应用,针对各种异构数据库存储系统和云存储系统,构建云计算环境下异构数据模型,为用户提供透明、统一的异构数据集成和访问接口服务。实践证明:云计算下基于本体的异构数据集成模型的构建,可以为云计算环境下各业务应用提供统一的数据管理和处理方法,方便、快捷地实现异构数据统一的检索与查询以及业务应用所处理的各种异构数据之间实质性关联与映射。     

移动Internet中端到端QoS保证的准入及资源分配策略

目前对移动 Internet上服务质量 ( Qo S)的保证方法 ,大多没有考虑端到端 Qo S保证及准入与资源预留的结合 .文中提出了一种准入及资源预留策略 ,将应用服务分为三类 ,对其中两类服务同时考虑移动主机本地资源信息和移动范围内的资源信息 ,并改进资源预留协议 ( RSVP)来在相应 IP流路径上的所有网络节点进行准入控制和资源预留分配 ,从而达到移动 Internet上的端到端Qo S控制的目的 .仿真结果表明 ,该策略有效降低了服务的切换失败概率 ,保证了端到端 Qo S     

移动Internet中端到端QoS保证的准入及资源分配策略

目前对移动 Internet上服务质量 (Qo S)的保证方法 ,大都没有考虑端到端 Qo S保证及准入与资源预留的结合 .文中提出了一种准入及资源预留策略 ,将应用服务分为三类 ,对其中两类服务同时考虑移动主机本地资源信息和移动范围内的资源信息 ,并改进资源预留协议 (RSVP)来在相应 IP流路径上的所有网络节点进行准入控制和资源预留分配 ,从而达到移动 Internet上的端到端 Qo S控制的目的 .仿真结果表明 ,该策略有效降低了服务的切换失败概率 ,保证了端到端 Qo S.     

不确定QoS信息下的web服务选择方法研究

针对web服务选择中存在Qo S属性信息不确定性的问题,在分析Qo S属性描述的基础上,提出一种不确定Qo S信息下的web服务选择方法,该方法分别从区间型和模糊型两方面考虑不确定Qo S信息,基于有序加权平均(OWA)算子实现区间型Qo S属性的确定化,使用联系数分析和量化web服务的模糊Qo S属性,并在此基础上设计不确定Qo S下的web服务选择模型.实验结果证实该选择算法的有效性和可行性.     

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.