再制造系统的库存控制研究

分析了再制造系统库存控制的特点，提出了两个简单有效的库存控制策略：PUSH策略和PULL策略，比较了不同参数条件下传统制造过程和混合系统中库存控制分别采用PUSH策略和PULL策略情况下系统的平均生产费用，结果对于生产实践具有一定的指导意义．     

移动计算环境下多信道并行广播策略

在移动计算环境中,数据广播已成为数据发布和获取的重要手段.为适应信息量的不断增大,使一个用户请求一次能访问多个数据项,提出了一种移动环境下的多信道并行广播模型.在多信道广播中采用高效的数据调度策略,使得该模型大量减少了移动客户机的访问时间,同时又保证了电量消耗没有大幅增加.最后通过仿真试验表明该广播模型有效地提高了移动数据广播的性能.     

移动计算环境中数据广播调度算法的研究

在移动计算机环境中,数据广播是一种发布数据的重要途径,能有效支持对具有公共访问兴趣的热点数据的访问。数据广播的一个首要问题是如何调度待广播的数据,优化数据广播的访问时间和调谐时间。通过比较数据广播的平坦调度与非平坦调度,说明多盘调度的优越性,并且提出一种基于Zipf法则的多盘调度算法。该算法具有可操作性好、性能优异、实用性强的优点,性能接近理论最优访问时间。     

基于区块链的无线体域网数据云存储完整性研究

针对无线体域网数据云存储的安全问题,设计了基于区块链的访问控制框架,框架通过区块链技术与数字签名相结合控制用户的访问请求;通过区块存储访问请求及其数字签名,利用改进的Raft算法保证节点间的区块链一致.其次,设计了有序数组和Merkle树相结合的方式存储数据,哈希表和Merkle树相结合的方式存储数据的访问请求;再次,提出针对无线体域网数据的完整性验证方案.最后,对区块链的一致性、数据完整性验证方案进行实验.结果表明,提出的框架能使各用户节点协同对访问请求进行控制,并且均能验证数据的完整性.     

数据广播中基于访问记录的数据替换算法

非对称通信环境下,服务器数据广播是一种比较实用的技术,而其移动客户端cache的管理,由于移动环境的限制,传统的LRU算法和理想的LIX算法都存在缺陷。提州了一种基于历史访问记录的数据替换算法。其中,无向概率图上的筛选过程．算法简单,复杂度小。试验表明,此算法明显改善cache命中率和平均响应时间。     

异构型非对称数据访问的ASN.1解决方案

针对企业单位普遍存在异构型计算机网络的信息孤岛问题 ,分析ASN 1标准和数据库访问中的几个关键技术 ,提出了一种以ASN 1为基础、以单项数据广播的数据共享方案 .该方案由服务器端和客户端组成 ,服务器负责数据库的访问 ,并按照XML配置文件定时接收数据 ,且为数据库提供了一种高级访问接口 .服务器端与客户端之间采用ASN 1编码标准和用户数据报协议 (UDP)进行通信 ,其中应答方向的数据传输由UDP协议负责 ,请求方向的数据传输采用人工的方式 .这种新方法解决了异构型计算机网络中的数据访问问题 ,具有简便、安全、易操作和成本低的优点 ,具有广阔的应用前景     

政务云中心数据存储架构与智能存取技术

政务系统是一种联机分析处理/联机事务处理(OLAP/OLTP)的混合型系统,通过分析政务云数据中心架构特征,针对传统存储模型所造成的网络与I/O瓶颈问题,在Oracle Exadata基础上,针对集中式社会服务特点,提出了云数据中心的垂直一体化的存储体系架构与多项智能存取技术,提供了若干关键优化访问算法,可支持云数据中心对快速增长的海量数据的有效管理,并最大程度地提高数据访问效率.对具有高负载混合型的政务应用系统,可提高数10~100倍的存取性能.     

基于需求的数据广播调度

随着通讯、互连网以及移动技术的发展,数据广播逐渐成为一种流行的数据传播方式。在结合了数据广播和传统的客户/服务器模式优点的基础上,产生了新的数据传播方式,基于需求的数据广播。设计基于需求的数据广播系统的关键在于广播调度算法。本文介绍了基于需求的数据广播的系统结构和性能衡量标准,并分析了基本的广播调度算法,抢占式调度算法以及实时调度算法。     

移动云计算嵌套式两阶段博弈计算卸载算法

移动云计算中,移动设备需要决定哪些应用部分卸载至云端处理,即计算卸载决策问题。针对这一问题,提出了一种嵌套式两阶段博弈算法。第一阶段中,移动设备决策其服务请求至云端处理的部分;第二阶段中,云端系统根据所有移动设备的服务请求到达率决策服务请求处理的资源分配。移动设备的目标是最小化功耗和服务请求响应时间,而云端系统的目标是最大化收益。基于向后归纳原则,利用凸优化方法求解了嵌套式两阶段博弈过程中移动设备和云端系统的最优策略,并证明算法可以产生唯一Nash均衡解。实验结果表明,比较基准算法,嵌套式两阶段博弈算法可以使移动设备同步降低平均功耗和平均服务请求响应时间分别约21. 8%和31. 9%。     

对象存储系统中基于负载均衡的设备选择算法

为解决大规模海量存储系统中用户数据访问过程中出现的系统负载不均衡现象,深入分析了对象存储节点的负载特征,提出一种对象存储设备的选择算法,检测和计算各个对象存储设备的实时负载信息,并依此从中选择当前负载较低的设备进行数据访问.测试和仿真结果均表明:对于I/O请求中写请求占主导的负载,该算法实现了负载的均衡分布,消除了单点过载,缩短了系统响应时间.该算法不仅适用于写请求到达时的设备选择,也适用于重要数据的备份选择以及链式MDS中后继节点的选择,具有较广的应用范围.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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