异质多智能体系统的自适应点对点拟一致性控制

考虑了各层内部节点和两层网络间对应节点都是异质的,设计了 自适应的一致性控制协议,并分别研究了线性多智能体系统和非线性多智能体系统两种情形.针对线性异质多智能体系统,利用线性矩阵不等式和稳定性方法证明了两层网络节点之间可以实现点对点拟一致性;针对具有Lipschitz型动力学的非线性异质多智能体系统,也给出了两层网络节...     

离散时间异质多智能体系统的一致性控制

针对由一阶智能体和二阶智能体组成的离散异质多智能体系统,研究其一致性问题.设计无通信时延和具有有界通信时延时的分布式一致性协议,通过将系统转化为自治的离散时间线性时不变系统,运用矩阵理论和代数图论方法,分析得到系统实现一致性的充分条件.获得的充分条件与采样周期、控制参数和系统的拓扑结构有关.证明了系统的一致性不受有界通信时延影响.数值仿真结果验证了理论结果的正确性.     

异质多智能体系统的编队控制

目的研究异质多智能体系统的编队控制问题。方法基于图论和李雅普诺夫直接方法进行研究。结果针对由一阶和二阶积分器智能体构成的异质多智能体系统,给出了一种基于一致性的时变编队控制协议。结论证明了使用上述协议的异质多智能体系统能够解决编队控制问题。     

多智能体一致性的随机镇定研究

本文给出多智能体随机一致性的数学描述,模拟了环境噪声对多智能体系统一致性的影响,并提出一种运用随机噪声控制多智能体系统的方法。仿真结果表明,添加满足一定条件的随机噪声控制可以令在没有噪声干扰情况下非一致性的多智能体系统达到随机一致性镇定。最后对多智能体的随机一致性镇定进行理论分析,并得到满足控制要求的随机噪声强度的大致下界。所提出的多智能体协调控制方法具有系统能耗小、控制性能更佳的特点。     

基于观测的事件触发主从多智能体系统的一致性

研究基于事件触发观测的一般线性多智能体系统的主从一致性问题.首先,基于多智能体系统提出输出事件触发控制协议,研究多智能体的真实状态与估计状态的一致性问题;其次,提出分布式自适应事件触发控制方案,通过应用Lyapunov稳定性理论和线性矩阵不等式证明主从多智能体的一致性,并排除Zeno行为;最后,数值算例说明理论结果的有...     

具有和不具有非线性动态的二阶时滞多智能体系统的领导跟随一致性(英文)

研究了带有时滞的二阶多智能体系统的领导跟随一致性问题.所给定的领导者不仅位置和速度保持变化,而且带有时滞.首先,为了跟踪这样一个具有非线性动态的领导者,对于每一个智能体给出了基于邻域的分布式控制器,基于Lyapunov-Razumikhin理论,获得了二阶多智能体系统达到领导跟随一致性的充分条件.另外,讨论了领导者和每个智能体都不具有非线性动态的一致性问题,得到了使得多智能体系统达到一致性的充分条件.最后,给出的仿真结果表明了所获定理的有效性.     

基于事件触发策略的连续多智能体系统一致性综述

多智能体系统信息量庞大,对多智能体系统事件触发一致性的研究有利于降低资源的消耗,减少智能体之间的信息交互.本文综述了基于不同事件触发策略的连续多智能体系统一致性的研究现状.首先,简单阐述了多智能体系统的研究历史,并探讨了基于事件触发策略的多智能体一致性研究的意义.随后,从动力学行为、控制协议以及事件触发条件等角度出发,概述现阶段连续多智能体系统的事件触发一致性研究进展.最后,给出了尚未解决的问题和未来值得关注的研究方向,如优化问题、输出反馈等,为下一步研究奠定基础.     

l步信息脉冲牵引控制的多智能体一致性分析

应用矩阵论和代数图论,分析l步信息脉冲牵引控制的多智能体一致性问题。把具有单个脉冲控制器的多智能体的一致性系统推广到只对一个智能体实施l步信息脉冲牵引控制的系统。在通讯拓扑是无向连通图的情况下,给出使多智能体达到一致性的一个充分条件。选择恰当的l有助于减少使多智能体系统达到一致性所需的脉冲次数。最后,仿真实例验证了理论结果。     

具有时滞状态导数反馈的一阶多智能体系统的收敛速度分析

对于一阶多智能体系统,提出一类具有加权项的时滞状态导数反馈一致性协议,研究在无向通讯拓扑下多智能体系统实现一致性的收敛速度。给出了多智能体系统在一致性协议下的闭环形式,并利用拉普拉斯矩阵将其转化成紧凑形式;利用矩阵理论,分析反馈强度对闭环形式极点的影响,证明当多智能体系统为超临界时滞多智能体系统时,引入适当的反馈强度可以提高多智能体系统实现一致性的收敛速度;数值仿真验证了结果的有效性。     

具有测量噪声的时滞多智能体系统的一致性问题

为研究噪声和时滞对多智能体系统平均一致性产生的影响,建立了具有测量噪声的时滞多智能体系统的模型,利用随机微分方程的稳定性理论,得到了多智能体系统以概率1实现平均一致性的充分条件。针对时滞和噪声对多智能体系统一致性行为的影响进行了仿真实验,验证了理论结果的正确性。     

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.     

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.