移动计算环境下结构化存储查询优化算法的设计

移动结构化存储问题一直以来是移动PC产品研究的热点问题。为了更好地处理移动计算环境下断接等问题,采用多元连接的查询优化算法进行了设计。首先在理论上设计了改进算法在并行连接操作的优势及特点,同时利用Socket实现了移动Agent和服务器Agent的网络通信;并完成了移动环境下的无线网络模拟平台设计。实验结果表明改进算法传送到指定站点的集中装配消耗时间显著减少,在表属性列限制条件较多时,改进算法的总代价与普通算法相比明显要少,并行连接最多时改进的算法可以确保总代价最小。研究对移动数据存储的稳定性改进具有一定的意义。     

基于改进单神经元梯度学习的无线网络主动队列管理

考虑传统网络拥塞控制忽略了网络拥塞的持续状态, 引入将数据包到达链路速率作为控制器输入的方案, 得到一种改进单神经元梯度学习(improves single neuron gradient learning, ISNGL)的主动队列管理算法. ISNGL 算法采用梯度学习动态调整网络参数, 并在此基础上对收敛速度和稳定性加以改进, 提出带有位移参数的新激活函数和带有权值调整的动量项的改进方法, 最后通过 NS2 网络仿真软件在无线网络的拓扑模型上进行仿真分析, 结果表明 ISNGL 算法在无线网络环境下拥有良好的拥塞控制能力.     

一种单宿主用户异构无线网络选择算法

异构无线网络的资源管理是异构无线网络的关键技术之一.针对异构无线网络环境下的单宿主用户,提出了一种单宿主的网络选择算法.该算法在用户端利用层次分析法(AHP)确定网络属性的权重,然后利用逼近理想解法(TOPSIS)选择最优网络.仿真结果表明,该算法可有效降低系统阻塞率.同时能够更好保证高优先级用户的接入质量.     

退避算法改进及其在矿山物联网应用研究

针对智慧矿山建设中,数据在无线传输过程存在的传输速率低、覆盖范围不足及稳定性差等问题,将退避算法应用到矿山物联网中,来提升无线网络的性能.而目前常用的退避算法由于缺乏适应能力,无法满足网络环境的变化.因此,对退避算法进行改进,引入一个竞争窗口的门限值CWt,来划分网络环境的负载情况,并采用对应的退避策略以适应变化的网络环境.实验结果表明,采用改进的退避算法对网络进行优化后,矿山物联网的性能有了显著提升.     

流量分布路由在无线网络中的应用

介绍了无线网络的概念、特点,以及无线局域网的协议标准和常见的无线网络的应用设备,并对流量分布路由在无线网络中的应用进行探讨,通过高速路由表查找算法及其改进流量分布路由让无线网络速度得到了提高.     

异构无线网络负载超前转移的负载均衡技术研究

文章分析了以多属性决策理论中简单加权算法(SAW)为代表的普通切换算法负载对比呼叫到达率(CAR)滞后的特性,针对异构无线网络垂直切换负载滞后造成负载不均衡现象,首先,建立异构无线网络,使用时间序列建立(SARIMA)模型预测网络呼叫到达率,根据预测呼叫到达率,引导业务切换和超前转移业务带宽,形成改进的(TSAW)算法,仿真结果表明TSAW算法克服了SAW算法负载滞后特性,使网络负载均衡特性变好.     

一种基于QoS的无线分组调度算法

提出了一种适用于无线网络的分组调度算法动态概率优先级(DynamicProbabilistic Priority,DPP)调度算法.DPP调度算法采用动态的优先级分配策略,满足了不同业务的QoS需求.另外,DPP算法在网络出现差错时,动态地调整带宽分配,使得网络中的带宽得到有效的利用,提高了系统的吞吐量,保证了算法的公平性.理论分析和仿真试验表明,在无线网络环境中,该算法具有更好的性能.     

改进Markov过程的异构无线网络垂直切换算法

针对当前异构无线网络垂直切换算法存在切换次数多, 服务质量难以满足实际应用需要的问题, 以获得更优的异构无线网络服务质量为目标, 提出一种基于改进Markov过程的异构无线网络垂直切换算法. 首先, 建立异构无线网络整体性能评价指标体系, 然后采用灰色关联分析法确定网络整体性能评价指标的权重值, 最后利用Markov决策过程对异构无线网络的状态进行预测, 选择最优的接入网络, 并通过异构无线网络垂直切换的仿真对比实验测试和分析其性能. 实验结果表明, 相对其他异构无线网络垂直切换算法, 该算法可降低平均切换次数, 避免了频繁切换现象的发生, 大幅度减少了网络数据传输的丢包率, 改善了用户满意度, 获得了更高的服务质量.     

基于频谱系数和比例公平算法的网络调度优化策略

针对传统比例公平的无线网络资源调度优化策略无法有效保证用户的公平性, 存在无线网络通信系统资源利用率低等缺陷, 设计一种基于频谱系数和比例公平算法的无线网络通信系统资源调度优化策略, 以解决当前无线网络通信系统资源优化调度过程中存在的问题. 首先建立无线网络通信系统的信道模型, 通过自适应遗传算法确定合理的频谱系数; 然后根据比例公平算法计算调度优先级, 将无线网络通信系统的资源分配给用户, 并针对传统比例公平算法的不足进行改进; 最后在MATLAB 2016平台上对无线网络通信系统的性能进行分析. 结果表明, 该策略可更好地保证用户使用资源的公平性, 提升了无线网络通信系统的吞吐量, 改善了无线网络通信系统的资源利用率.     

一种新的SCTP对ST检测机制

针对无线网络高误码率、时延抖动大等特点,提出了一种新的SCTP检测算法-FRTO(快速重发超时),该算法使用了TCP中的基本思想,其主要改进是:①当收到第一个确认信息后,只发送一个新的数据报;②改进了SCTP的慢启动和拥塞避免算法.对算法进行了仿真研究,仿真结论证明了带有FRTO的SCTP在性能上优于现有的Eifel检测机制和复制的最高传输序列号(DHPTSN)检测机制.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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