Performance Prediction of Packet Mobile Communication through Wireless Multipath Fading Channel Modeling

This paper presents a software simulator applicable to multipath fading channels in urban environments of mobile communication networks. The simulator is constructed by a two-state Markov model and several statistical models for simulating the characterizations of different environments. A core idea of the simulator is to construct a Rice distribution-based multipath fading module produced by a modified Gans Doppler power spectrum,and in combination with a Markov model to predict the time-dependent characteristics of packet in different radio circumstances. It can simply predict the packet performance of the future channel and evaluate the relations between the radio channel and the modulation schemes,error control protocols and channel coding. Simulation results demonstrate that it is a reliable and efficient method.     

Research on group expandable optimization decision-making model for construction programme choice

Aiming at the decision-making problem of construction programme choice,this paper advanced a new group expandable optimization decision-making model.Various factors were comprehensively considered,and the new multi-attribute evaluation index system was established.Based on the assumption that decision-makers were rational,this paper formed a group of rational preferences through extracting the personal preferences pertinently,so the decision-makers position matrix was determined.The decision-makers position matrix integrated values given by group decision-makers to construction programme comprised a matrix,of which the entropy theory for datamining was adopted in this paper to determine the attribute weights.A decision was made by using the extension decision method.Eventually,the feasibility and practicability of the model were verified by the example.     

The effect of α-helix comformation on interaction between model oligopeptides and polymers

The study of interactions between peptides and synthetic polymers has aroused considerable interest recently. In the present paper, the interaction mechanism between adsorbent DMAPAM and two peptides, VVRGCTWW（V8） and CTWW（C4）, was investigated at molecular level by NMR and molecular stimulation. The results demonstrated that the conformation of oligopeptides played a vital role in their adsorption capacity on the adsorbent. Weak interactions could incorporate with each other between V8 and DMAPAM because there was a hydrophobic cleavage in o-helix conformation of V8. So the ad- sorption capacity of DMAPAM to V8 was higher. This was significant to explore the interaction mechanism between peptides and biomaterials.     

Tool life modeling for evaluating the effects of cutting speed and reinforcements on the machining of particle reinforced metal matrix composites

The wear of cutting tools in the machining of 2024Al alloy composites reinforced with Al₂O₃ particles using varying sizes and volume fractions of particles up to 23.3vol% was investigated by a turning process using coated carbide tools K10 and TP30 at different cutting speeds. Machining tests were performed with a plan of experiments based on the Taguchi method. The tool life model was developed in terms of cutting speed, size, and volume fraction of particles by multiple linear regressions. The analysis of variance (ANOVA) was also employed to carry out the effects of these parameters on the cutting tool life. The test results show that the tool life decreases with the increase of cutting speed for both cutting tools K10 and TP30, and the tool life of the K10 tool is significantly longer than that of the TP30 tool. For the tool life, cutting speed is found to be the most effective factor followed by particle content and particle size, respectively. The predicted tool life of cutting tools is found to be in very good agreement with the experimentally observed ones.     

LASER INDUCED THERMAL LENS EFFECT

The thermal lens effect has emerged in recent years as a novel, highly sensitive tool for the study of the very weak molecular absorption of light energy. This paper discusses the theory and technique of the thermal lens measurement. Some applications of the thermal lens measurement are described. A mode-mismatched dual-beam thermal lens experimental arrangement with a modulated probe beam, designed by the authors, for trace analysis is presented, and its detection limit was found to be 4.1×10~(-7) for Cu(Ⅱ)in ethanol and 80 mW excitation power.     

Evaluation of Metal Fatigue Problems Using Qualitative Reasoning Approach

Fatigue failures are often encountered in steel structures under heavy cyclic loadings. This paper presents metal fatigue problems in structural engineering using outcomes of recent advancements in numerical qualitative reasoning. Qualitative reasoning provides an effective and sound technique for solving complex and uncertain scenarios, regardless of the uncertainty or linearity of the design parameters and their constraints. This paper introduces the algorithms behind a software platform, built upon numerical qualitative reasoning for engineering applications. The software expresses the results of the analysis in variable ranges and diagrams showing a two-dimensional design space. The capability of representing design parameters and outcomes in solution spaces provides a practical way for engineers to leverage their existing knowledge and experience. Case studies in metal fatigue design are given to reflect on the capability of qualitative reasoning in engineering applications.     

Elements inter-diffusion in the turning of wear-resistance aluminum bronze

Inter-diffusion of elements between the tool and the workpiece during the turning of aluminum bronze using high-speed steel and cemented carbide tools have been studied. The tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novel high strength, wear-resistance aluminum bronze without coolant and lubricant. Adhesion of workpiece materials was found on all tools' surface. The diffusion couples made of tool materials and aluminum bronze were prepared to simulate the inter-diffusion during the machining. The results obtained from tool wear samples were compared with those obtained from diffusion couples. Strong inter-diffusion between the tool materials and the aluminum bronze was observed in all samples. It is concluded that diffusion plays a significant role in the tool wear mechanism.     

Robust PCA-Based Abnormal Traffic Flow Pattern Isolation and Loop Detector Fault Detection

One key function of intelligent transportation systems is to automatically detect abnormal traffic phenomena and to help further investigations of the cause of the abnormality. This paper describes a robust principal components analysis （RPCA）-based abnormal traffic flow pattern isolation and loop detector fault detection method. The results show that RPCA is a useful tool to distinguish regular traffic flow from abnormal traffic flow patterns caused by accidents and loop detector faults. This approach gives an effective traffic flow data pre-processing method to reduce the human effort in finding potential loop detector faults. The method can also be used to further investigate the causes of the abnormality.     

Craniometrical evidence for population admixture between Eastern and Western Eurasians in Bronze Age southwest Xinjiang

Xinjiang,the most northwest provincial administrative area of China,was the area where the oriental people met the occidental.The populations in Xinjiang exhibit very high genetic diversity.Previous study revealed that the eastern Xinjiang populations of the Bronze Age were mixed by the Eastern and the Western Eurasians.However,few studies have been performed to reveal when the population admixture started and how far to the west it reached.In this paper,we studied 148 craniofacial traits of 18 skulls from the Bronze Age Liushui graveyard in Khotan(Keriya County) in the southwest of Xinjiang.Seventeen craniometrical parameters of the Khotan samples were then compared with those of other ancient samples from around Xinjiang using dendrogram cluster analysis,principal components analysis,and multidimensional scaling.The results indicated that population sample of Liushui graveyard was mixed by the Western and Eastern Eurasians with about 79% contribution from the east.Therefore,we demonstrated that population admixture between east and west Eurasia can be traced back to as early as 1000 BC in southwest Xinjiang.     

社会网络分析中的机器学习技术综述

机器学习是智能数据分析的有力工具,可以对社会网络数据进行建模。文中讨论了机器学习技术在社会网络分析(Social Network Analysis,简称SNA)领域中的应用,尤其综述了对象分类、链接预测、群体检测等SNA子任务中的机器学习技术。此外,还分析了在SNA中使用机器学习技术所面临的若干问题和挑战,最后给出了SNA中机器学习技术的研究前景。     

线性广义系统的D型迭代学习控制

根据误差收敛准则,提出了线性广义系统的迭代学习控制算法,利用矩阵理论及不等式技巧给出了线性定常广义系统在D型学习律作用下的迭代控制收敛性结果,这一结果是全新的,其对时变系统也成立;另外,针对线性定常广义离散时间系统,给出了一种通过最优化目标函数确定控制器参数的设计方法.     

基于三维的起重葫芦CAD应用开发研究

起重葫芦产品 CAD系统的研究开发在国内属于空白领域。文章提出了 CA D系统的开发原则和总体框架结构设计形式 ,论述了 CAD系统的方案设计、分析计算、三维零部件造型和模拟装配干涉校验等各个功能模块的内容 .基于以上内容完成了 CAD系统的开发。 CAD系统在行业的应用中取得了较好的技术经济效益。     

大学生学习风格与二语习得的关系及启示

通过对476名大学生进行了有关学习风格的问卷调查,对学习风格量表进行了验证,表明其具有良好的信度和效度。利用该量表对大学生的主要学习类型进行了描述和人口统计学变量上的差异检验和回归分析,并考察了大学生不同学习风格与英语学习成绩之间的皮尔逊相关关系。统计分析结果表明听觉型、外向型、纵观全局型、归纳型和场依赖型的学习风格与其英语学习成绩呈显著正相关,说明具有这些学习风格的大学生其二语成绩更好。     

基于合作学习理论的英语自主学习平台研究与设计

自主学习对培养学生语言学习能力和认知水平有极大的促进作用,作者发现学生在使用学院购买的自主学习平台过程中由于缺少有效监督和学习形式枯燥,并没有达到预期目的.设计并实现了一套基于合作学习理论的自主学习平台,该平台利用信息技术将学生单独自主学习改为小组学习,有利于提高学生积极性和学习效果,文中详细分析了该平台工作流程和各个功能模块,并给出了运行效果图.     

校园教育辅助类虚拟学习社区知识共享的社会网络分析

以莆田学院天空教室为研究对象,借助UCINET对该虚拟学习社区的社会网络密度、社区结构以及中心性进行分析。研究发现:整体网络结构松散,成员间联系疏离,互动交流较少,教师在社区中占据重要位置,学生间的知识共享有限。针对这些问题,提出重视虚拟学习社区的运用和模块功能建设,引导学生积极参与社区互动交流,进行有效知识贡献以提高知识共享程度。     

Study of Chunks Input Approach

This paper is to describe and investigate Chunks (Lexical Phrases) Input Approach in vocabulary learning strategies by means of achievement tests, questionnaire surveys and interviews. The study is to reveal how different learners combine different vocabulary learning strategies in their learning process. With the data collected, the author of this paper discusses and summarizes learners' individual differences in selecting vocabulary learning strategies with the hope of giving new insights into English teaching and learning.     

信息化环境下计算机课程中开展混合式学习的教学模式探索

本文探讨了信息化环境下如何充分利用传统课堂和信息化虚拟课堂双重教学空间在《计算机基础》课程中开展混合式学习,通过将教学过程分为基础理论知识模块、上机操作模块、数据库项目设计模块和学习评价模块四大模块,并在不同的模块中分别采用不同的适宜的教学方式,达到了激发学生学习兴趣,培养学生探究协作能力、实践创新能力,提高教学效果的目的。     

通过PET-CT图像纹理特征预测软组织肉瘤转移性

提出了一种针对软组织肉瘤转移性预测的辅助诊断方法,该方法通过对患者的FDG-PET和CT诊断图像进行纹理特征分析,共提取了105个特征,其中包括灰度共生矩阵的24个特征和其他81个灰度等级的特征,分别利用支持向量机、K近邻和随机森林等机器学习算法建立预测模型,并采用网格搜索法对其参数进行优化.最后使用留一交叉验证法对各模型进行验证.通过评估各模型性能,选择支持向量机作为最终预测模型,得到了80%的平均精确度.此外,该模型的敏感度达到81%,特异性达到79%,表明该模型预测结果具有一定的可靠性,可以对STS进行辅助诊断并通过更好的适应性治疗来改善患者的预后.     

PCA-FA： Applying Supervised Learning to Analyze Gene Expression Data

In previous gene expression data analyses, supervised learning has mainly focused on the classification of attribute data, such as the different experimental conditions, different known classes of the same tumor and sex, However, supervised learning classification is not suitable for interval-scaled attributes such as age and survival outcome of cancer patients, For this problem, this paper proposed a new method by combining two well-known methods: principal component analysis (PCA) and Fisher analysis (FA). The method, PCA-FA, realizes supervised learning with two types of attributes (nominal attributes and intervalscaled attributes). The fuzzy FA was introduced to model the interval-scaled attributes. In this paper, an approximate linear relationship between gene expression data of lung adenocarcinoma patients and survival outcome is successfully revealed by PCA-TA.