分布式三环网络传输延迟

分布式三环网络是至少具有一个环结构的网络，利用层图模型，首先用整数分拆的方法重新给出了一般环网络直径的上界，重点研究了三环网络，给出其直径的上界，并给出N不太大时，三环网络取得最优的一个条件。     

宽网科技：数字视频资讯系统能为上海市民带来些什么？

数字视频资讯系统，是一个方便、灵活的数字平台，它为有线电视网络服务商和小区网络服务商抓住新的产业机遇，提供了一个不可多得的便利条件。它好比是一个功能齐备的舞台，凭借它，网络服务商们可以演出无数精彩的好戏。     

浅论计算机“安全”下的网络犯罪

21世纪是一个以计算机网络为核心的信息时代，网络化、信息化、数字化是21世纪的时代特征，网络不仅给我们带来了网络电视、E-MAIL、电子商务、虚拟现实、数字地球的同时，也带来了网络黑客、网络色情和网络诈骗，这些新形式的网络犯罪已经成为一个社会问题。     

网络文明与高校育人新思路

网络的发展标志着人类文明的新进展，人类正在进入一个网络文明的时代。网络的出现是人类历史上的一次革命，计算机网络的迅速发展，为人类开启了一个崭新的世界。网络的发展对经济的推动作用是巨大的。网络是现代文明的标志。同时．网络的发展给青年学生带来的负面影响也是多方面的。我们应用辩证的观点去研究网络的发展，兴利除弊，扬长避短，探索网络条件下高校育人的新思路。     

NESP:一种可扩展的通用网络测量系统平台

建立一个可扩展的、通用的网络测量平台是全面了解大规模网络行为的基础。提出了网络测量系统平台NESP的体系结构，给出了NESP的功能流程及模块分类并讨论了关键实现技术。基于NESP，实现了一个大型网络监视测量系统MMS，该系统整合了多种流测量工具并运行了多种网络测量应用。实践表明，NESP是一个可扩展的、通用的网络测量平台。     

Ad hoc网络安全模型的研究

Adhoc网络作为一种无线移动网络正成为网络研究的一个热点。而且由于它的若干特点，使得Adhoc网络在军事领域受到广泛的重视，并正在逐步应用于商业领域。但安全问题却是Adhoc网络的一个弱点。根据RSA密码体制和门限数字签名方案，提出了一种门限RSA数字签名方案，并在此基础上提出了一种基于信任分散的Adhoc网络安全模型。该安全模型对建立一个安全的Adhoc网络有着一定的意义。     

分布式网络应用系统管理开发方法的研究

分析了对网络应用系统进行管理的必要性，结合当前网络技术发展的趋势，提出了一个网络应用系统管理模型，为开发分布式网络应用系统管理工具提供了一个切实可行的方法。     

树状网络上代理服务器逆优化问题

通常的代理服务器选址问题是在给定的网络上，如何合理地放置代理服务器，使得整个网络的最大时延最小或总花费最小，其实在实际中会很自然地碰到它的一类逆优化问题，就是当代理服务器已在给定的网络上放置好且不能移动时，如何改进网络（如增加网络带宽，提高服务器的负载能力、处理速度等），使得改进后的网络运行更有效。本文研究在一个已放置了P个代理服务器的树状网络上，如何在不超过预算的情况下，使用户到代理服务器的最大时延最小的逆优化问题，给出了一个多项式时阎算法，并通过一个实例验证了该算法的可行性。     

网络对青少年的负面影响及防治措施

一、网络对青少年的危害 1．“网络黄潮”、“色情文化”给青少年的身心健康以极大的摧残，使部分青少年深受其害，不能自拔，从而走上违法犯罪的道路。我们大家都知道网络是一个信息宝库，也是一个信息垃圾场。据有关专家调查，网络上非学术信息中47％与色情有关。     

局域网互连设备及应用

网络互连是计算机网络研究的重要课题。近年来，由于局域网的广泛应用，在一个机构内往往存在多个局域网。一个孤立的局域网其资源和作用范围都有限，随着局域网技术的发展和网络应用的扩大，出现了将多个局域网连为一个整体的要求，即通过网络互连来实现更大范围的通信与...     

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.