一种异地容灾系统的状态监控方法

针对异地容灾系统提出了一种基于Internet的状态监控方法,即聚类时间触发状态监控方法.该方法能很好地将各种监控对象进行整合,可有效地对各个监控对象的运行状态进行实时监控,并可对状态监控数据进行提取和分析.该方法能很好地适应异地容灾系统结构庞大、本地和远程多台服务器、多段网络、多容灾任务的情况.     

深腾2600新型网络服务器系统

“深腾2600新型网络服务器系统”面向国家信息化建设的应用需求，以集群架构组织计算资源，以存储区域网络进行数据存储，实现了统一管理、高性能存储、负载均衡、服务容错、存储容灾、并行数据访问及智能电源管理等功能，     

一种分布式动态负载均衡调度算法

目前计算机应用服务系统经常采用集群系统,负载均衡调度是集群系统的关键。在通用负载均衡调度算法的基础上,提出一种分布式动态负载均衡调度算法.该算法动态收集、统计和分析服务器的信息,以此为根据完成服务器负载均衡的任务,能够实现集群正常调度.在此基础上,采取分布式调度的策略,提高负载均衡调度的效率、性能,以使其对业务系统整体性能的影响最小。     

一种多点网络异地数据备份恢复方法

为了解决容灾系统中单个备份服务器带来的性能瓶颈,本文提出了一种多点网络异地数据备份恢复方法MRDBR.该方法实时监控逻辑卷的数据变化,将监控到的数据变化记录通过海量缓存发送至多个备份服务器进行写重放,完成对本地数据的多点备份.在灾难发生后,根据备份服务器的负载情况,从各备份服务器对任务的差异数据进行并发恢复,并动态调整各备份源的恢复任务,最后在本地进行数据拼合,完成快速恢复.实验证明,该方法具有多点备份、性能稳定、恢复速度快等优点.     

基于服务器负载状况分类的负载均衡调度算法

针对云端集群负载均衡问题和现有负载均衡算法的优缺点,提出了一种基于服务器负载状况分类的负载均衡算法.通过每阶段采集负载信息,实时掌握节点状态,停止重负载节点接收任务,降低中负载节点集合接收的负载,相应地增加轻负载节点集合的负载,以达到负载均衡效果.同时采用集合的形式很好的避免了大量负载涌入某一指标最优的节点,能够更好地实现均衡,提高系统的吞吐率.结果表明:该算法可以有效地避免云端集群负载发生倾斜,使系统在长时间的运行过程中达到动态的负载均衡.     

分布式文件系统K-DFS的设计与实现

设计并实现了一个可应用于CNGrid(中国国家网格)的分布式文件系统——K-DFS(Keda分布文件系统),该系统可以管理大量的存储节点并同时向多用户提供远程文件访问服务.K-DFS通过跟踪器的监控和管理,有效地解决了多存储节点的访问和同步问题,并实现了负载均衡的功能,避免数据集中于少量存储服务器中.通过副本冗余存储技术,K-DFS保障了远程文件的安全性,有效防止了由于存储节点宕机导致的文件丢失问题.同时,K-DFS具有良好的可扩展性,可以动态地增加存储节点,支持Windows和Linux平台的多种应用,特别适合各种以文件为载体的网络服务.     

一种基于动态可分配比的服务器负载均衡算法

负载均衡是服务器集群技术研究的重点,为了解决分配不均的问题,综合考虑集群中各节点性能、负载情况、传输代价、网络随机任务等各方因素而提出了一种基于动态可分配比的负载均衡算法.基于动态可分配比的算法由一张动态的描述各节点负载情况的全局表动态生成一张候选节点表,并在该表中找出负载最轻的节点完成任务.通过仿真实验发现该算法思路简洁,实现简单,并在解决服务器负载均衡方面有明显效果.     

物联网环境下负载均衡的低代价云存储数据副本分布

为满足物联网终端结点移动性和数据访问实时性要求,根据云存储中副本分布与访问的模式,提出结合数据访问点位置和访问频率,具有低访问代价的存储服务器选取方法.考虑负载对访问代价的影响,通过动态更新代价矩阵,提出负载均衡机制.研究结果表明:该方法在最少副本数目的前提下,将副本分配到与访问情况相适应的具有较低访问代价的存储服务器上,可有效减少数据访问开销,并避免副本集中分布,保证各存储服务器的负载均衡,更适合于物联网环境中云存储数据管理.     

数字化图书馆的容灾系统设计

数字化图书馆的容灾系统可以在灾难事故中有效地保护其数据资源和服务的连续性,远程容灾系统是容灾方式的最佳选择.在构建容灾系统时,除考虑安全因素外,还应关注其数据管理、存储、传输及效率等内容,为此,本文探讨了容灾系统的软、硬件结构模型.     

云中心基于Nginx的动态权重负载均衡算法

为了解决云中心的服务器端在高并发情况下各节点的负载失衡问题,在对负载均衡技术Nginx自带的负载均衡策略和主流的负载均衡策略进行研究、分析的基础上,提出了一种动态调节权重的负载均衡策略.该策略基于加权轮询策略进行改进,同时考虑服务器的本身硬件性能与工作时的负载情况,设计了静态权值和动态权值的计算方法,将两者结合得到节点最终权值.静态权值主要考虑了各服务器的硬件性能情况,动态权值的计算则是收集各后端服务器节点工作时的CPU利用率、内存利用率、网络性能情况及磁盘I/O等性能情况,由此,动态地调节各后端服务器节点权重.测试结果表明,相较于原加权轮询算法,该算法在高并发情况下的响应时间和实际并发数等方面表现更好.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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