Voice quality prediction models and their application in VoIP networks

The primary aim of this paper is to present new models for objective, nonintrusive, prediction of voice quality for IP networks and to illustrate their application to voice quality monitoring and playout buffer control in VoIP networks. The contributions of the paper are threefold. First, we present a new methodology for developing perceptually accurate models for nonintrusive prediction of voice quality which avoids time-consuming subjective tests. The methodology is generic and as such it has wide applicability in multimedia applications. Second, based on the new methodology, we present efficient regression models for predicting conversational voice quality nonintrusively for four modern codecs (G.729, G.723.1, AMR and iLBC). Third, we illustrate the usefulness of the models in two main applications - voice quality prediction for real Internet VoIP traces and perceived quality-driven playout buffer optimization. For voice quality prediction, the results show that the models have accuracy close to the combined ITU PESQ/E-model method using real Internet traces (correlation coefficient over 0.98). For playout buffer optimization, the proposed buffer algorithm provides an optimum voice quality when compared to five other buffer algorithms for all the traces considered.     

核磁共振测井在东濮凹陷深层气评价中的应用

东濮凹陷深层气具有储层深、岩性细、致密、层薄、低孔隙度和低渗透率等特点。由于成岩作用的影响，电性曲线基值高，油气水层界限不分明，油气层与干层界限模糊，用常规的测井系列对深层气评价有一定的难度。笔者应用核磁共振技术从氢核的弛豫方面探测孔隙结构特点，分辨流体性质，并介绍了核磁测井在深层气解释评价方面的应用情况。     

A preference multi-objective optimization based on adaptive rank clone and differential evolution

Evolutionary multi-objective optimization (EMO) algorithms have been used in various real-world applications. However, most of the Pareto domination based multi-objective optimization evolutionary algorithms are not suitable for many-objective optimization. Recently, EMO algorithm incorporated decision maker’s preferences became a new trend for solving many-objective problems and showed a good performance. In this paper, we first use a new selection scheme and an adaptive rank based clone scheme to exploit the dynamic information of the online antibody population. Moreover, a special differential evolution (DE) scheme is combined with directional information by selecting parents for the DE calculation according to the ranks of individuals within a population. So the dominated solutions can learn the information of the non-dominated ones by using directional information. The proposed method has been extensively compared with two-archive algorithm, light beam search non-dominated sorting genetic algorithm II and preference rank immune memory clone selection algorithm over several benchmark multi-objective optimization problems with from two to ten objectives. The experimental results indicate that the proposed algorithm achieves competitive results.     

Challenges of future multimedia QoE monitoring for internet service providers

Multimedia Tools and Applications - The ever-increasing network traffic and user expectations at reduced cost make the delivery of high Quality of Experience (QoE) for multimedia services more...     

板坯连铸二冷段气水冷却控制系统改造

介绍了板坯连铸机二冷段气水冷却系统技术改造，在最佳参数数学模型基础上，用西门子模板，实现PLC自动控制。改造后拉速度提高37．5％，降低了能源消耗，提高了产品质量。     

基于socket的局域网聊天工具

本文主要是在简要介绍基于socket局域网聊天工具软件设计发展现状的基础上,通过软件开发平台来对基于socket的局域网聊天工具客户端进行设计。这一设计过程在文中进行多方面的综合说明:一方面着重对这款软件所具有的特点和功能进行说明,在此基础上补充说明其使用方法;另一方面则侧重于介绍这一聊天工具软件设计过程中所使用的相关技术和实现方法;最后综述改聊天工具软件设计的思路与方法。     

EFFECT OF Cr,Cu AND Co ON MAGNETOSTRICTION OF Fe-Si-B AMORPHOUS ALLOYS

The dependence of composition varied,especially C,Si,Cr,Cu and Co in four amorphousalloy systems Fe_(80-x)Cr_xSi_5B_(15).Fe_(80-x)Cr_xC_5B_(15).Fe_(80-x)Cu_xSi_5B_(15)and(Fe_(1-x)Co_x)_(82)Cu_(0.4)Si_(4.4)B_(13.2)upon their saturation magnetostriction at room temperature hasbeen studied.It was observed that the saturation magnetostriction of the alloys may be re-markably improved by small addition of Cu and Co.the peak value being up to 70×10~(-6)asx=0.02 in alloys(Fe_(1-x)Co_x)_(82)Cu_(0.4)Si_(4.4)B_(13.2).     

利用EMI成像测井资料评价锡林好来砂砾岩储集层

锡林好来地区沉积物多属近物源快速堆积,地层岩性复杂多变,发育的砂砾储层,具有层内（间）岩性非均质性强、物性差异大的特点,仅用常规测井资料进行砂砾岩储层评价遇到了较大的困难。文章介绍了利用EMI成像测井识别砂砾岩,并对岩心资料、常规测井资料深度进行”双标定”;研究储集层的”四性”关系,建立砂砾岩储层的解释模版及解释标准。研究成果在锡林好来砂砾岩油气层评价中,获得了重大突破。     

面积最大优先调度的预约回填算法

传统backfilling算法是在先来先服务基础上,将小作业回填到空闲CPU,以提高CPU利用率。该算法偏向小作业,大作业也会因为长期等待出现饥饿现象。当空闲CPU数无法满足算法中小作业回填要求时,系统仍有部分CPU闲置,难以更好地提高CPU利用率。本文中提出的算法以作业所需CPU数及预估运行时间构成的二维面积作为优先调度的条件,引入二级优先级和预约算法消除大作业的饥饿现象,减少回填作业CPU数,相应增加预估运行时间,更好提高CPU利用率。实验证明,该算法比传统backfilling算法在保证用户公平性,缩短作业平均响应时间及CPU利用率方面有所提高。     

一种新的差分进化约束优化算法

对于约束优化问题,目前提出的差分进化算法大多采用罚函数法,但此方法对罚参数有很强的依赖性.基于此,把约束优化问题中的约束条件当作一个目标函数,从而把约束优化问题转化为有两个目标函数的多目标优化问题.借鉴多目标优化中的Pareto的概念,对种群中的个体规定等级,便于在优胜劣汰过程中确定选择概率.同时,在算法陷入局部最优时,采用一种不可行解替换机制来提高算法搜索能力.对13个标准测试问题的测试结果表明,与动态惩罚函数的进化算法、可行性规则的差分进化算法、采用随机排序的进化策略以及人工免疫响应约束进化策略相比,新算法在求解精度上均具有一定的优势.