一种基于能量受限的移动 sink 数据收集策略

针对无线传感器网络中基于移动sink的节能数据收集问题,综合考虑传感器节点和移动sink的能耗,提出一种基于能量受限的移动sink数据收集策略（DC-ECMS）。 DC-ECMS包括3个阶段：①采用图论中最小支配集思想构建sink的驻留点;②采用蚁群算法规划sink访问驻留点的巡游路径;③sink沿规划路径周期性进行数据收集。仿真实验结果表明,DC-ECMS可有效延长网络寿命和提高网络的能量利用率,并且可扩展为多个sink进行数据收集,进一步延长网络寿命。     

无线传感网中移动采集节点的路径优化研究

针对具有单一移动采集节点的无线传感网,考虑数据采集的相关因素对移动采集节点路径规划的影响,建立了基于移动采集节点单位时间内采集的数据总量最大化的数据采集路径规划数学模型,并设计了模拟退火算法对该问题进行了求解。实验仿真证明,文中设计的数据采集策略可以大大地提高移动采集节点的数据采集效率,最大化地发挥移动采集节点的功能,减小无线传感网络中静态传感器节点的通信负载,优化网络生存时间。     

激励机制改进蚁群优化算法用于全局路径规划

为提高优化算法搜索能力,分析了基本蚁群优化算法和心理学家斯金纳的强化激励方法的基本原理,将正、负激励原理应用于改进基本蚁群优化算法,提出了基于激励机制的改进蚁群算法,并给出了其数学描述。将改进的算法应用于求解旅行商问题和避碰约束下的最短路径规划问题,并与基本算法进行比较。仿真试验显示,改进的蚁群算法有效搜索到最短路径,实现全局路径优化。由于采用了激励机制,使得种群中所有个体都能够积极向最优解移动,从而更快地找到最优解,其较之基本蚁群算法具有较快的收敛速度,整体性能优越,能够应用于求解路径规划等问题。     

正定二次规划的投影最小二乘算法

提出了正定二次规划问题的投影最小二乘算法．该算法先求目标函数无约束优化问题的解，再将此解逐次投影到有效约束的边界．迭代过程中不断更新有效约束，最终得到问题的有效约束集，进而得到问题的解．将该算法应用到FIR滤波器的约束最小二乘设计中，算法分析及约束FIR滤波器的设计例子都表明该算法的计算量远小于目前最流行的二次规划算法——有效集方法．     

空间众包中在线路径规划算法

工作者的路径规划问题是空间众包中一个重要的研究内容。当前路径规划问题的研究主要集中在离线情形下,然而在线情形下的路径规划更符合现实需求。因此,该文从众包物流和共享巴士等典型空间众包平台中提取出了一个在线路径规划问题——空间众包中终点固定的在线路径规划问题。首先研究了Euclidean空间上的路径规划问题,提出了基于粒子群的在线粒子群路径规划算法,该算法通过在线追踪最优解来进行路径规划,同时,提出了基于k近邻的在线局部粒子群路径规划算法。还研究了面向路网的路径规划问题,提出了加权最短路径边界索引和路网上的在线局部粒子群路径规划算法。最后,通过真实数据上的大量实验验证了上述算法的有效性和高效性,其中在线局部粒子群路径规划算法拥有更好的效果。     

双层多目标规划问题的Pareto有效解

研究双层多目标规划问题，提出了“双级Ｐａｒｃｔｏ有效解”和“带权数双级Ｐａｒｃｔｏ有效解”的概念，建立了对应的最优性条件．利用这些条件，我们可以设计求解双层多目标规划问题的算法．     

生物质资源库存-路径整合优化问题研究

库存和路径是供应链中两个重要决策问题。本研究旨在整合优化生物质资源供应链中的设施库存和车辆路径，将总成本降至最低。本研究在优化供应链中车辆路径规划问题时，加入对设施库存问题的考虑，通过对两个问题的整合优化来减少牛鞭效应的影响。针对整合出的生物质资源供应链库存-路径优化问题建立混合整数规划模型。由于问题的计算复杂度较高，导致求解问题会消耗大量时间，为此开发混合启发式算法(HHS)实现高效决策。通过算例测试验证了模型及算法的可行性，计算结果可应用于实际的生物质资源供应链库存和路径。CPLEX精确解和HHS算法近似解的比较表明HHS算法可求得十分接近精确解的近似解且更加高效。     

基于时延受限的移动sink环境下能量高效的数据融合算法

基于移动sink的无线传感器网络环境下的数据收集方案能有效提升网络性能,但在实时性要求较高的应用中,很难同时兼顾时延与数据的收集效率.该文提出了一种考虑时延受限条件下能量高效的移动sink数据收集策略.首先,根据时延约束和网络整体能耗效率优化为目标,对移动sink的最佳驻留点集合进行求解.然后,提出了一种基于驻留点优先级的路径优化选择方法,得到移动sink经过驻留点的最短路径.仿真实验结果表明,与已有算法相比,该文提出的数据收集策略能最大限度的减小时延,并延长网络的生命周期.     

一种基于无性繁殖遗传算法的多移动节点路径规划方法

针对利用多个移动节点采集散布在固定区域内固定传感器节点上的信息时的路径规划问题,提出了一种基于无性繁殖的遗传算法.该遗传算法采用了二分染色体编码方案和随机联赛选择算子,并分别对染色体第一部分和第二部分提出了优化机制以扩大解空间的搜索能力,增加种群的多样性.仿真实验结果表明:针对总路线最短优先、路径均衡优先和最短完成时间优先3种路径选择策略,该算法均取得较好结果.     

一种基于移动代理的Ad Hoc网络入侵检测方法

根据AdHoc网络的特点，提出了一种基于移动代理的AdHoc网络中的入侵检测方法．该方法能够同时检测主机行为和网络行为．由于AdHoc网络无法在网关或交换机处收集网络数据，作为检测网络行为的数据来源，该方法采用了一种分布式算法，选择数目很少的节点收集网络数据、检测网络行为，减少了其它节点的系统资源和电量的消耗．     

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.