The GA-ANN method for determining calculation parameters for deep excavation

This paper presents a new method (GA-ANN) developed by combining genetic algorithm (GA) and artificial neural networks (ANN) for determining parameters of soils and retaining walls of deep excavation. This method has the advantages of nonlinear projection of neural networks, networks reasoning, prediction and good overall characteristics. it was first used for back analysis of the problem of mechanics parameters for excavation. Case studies showed that the GA-ANN method is effective and practical for back analysis of determining parameters. Project supported by NSFC(5973860) and National Civil Defence fund of China     

“丝绸之路经济带”贸易联系网络结构研究?--基于省区尺度和国家尺度的社会网络分析

选择中国西部的9省区和18个相关国家,基于两个不同的空间尺度（省区尺度和国家尺度）构建“丝绸之路经济带”贸易空间关联网络,采用1997年、2002年、2007年、2012年4个时间断面的贸易数据,利用社会网络分析方法,绘制可视化网络结构拓扑图,并对关联网络的拓扑学特征进行定量分析。结果表明：省区尺度的贸易网络密度呈现先增后减的趋势,而国家尺度的贸易网络密度则保持稳定增加;四川、重庆处于省区尺度贸易网络中心地位,陕西、宁夏、青海则处于边缘地位,新疆、甘肃逐渐向边缘移动,云南、广西则逐渐向中心移动;欧洲国家大都处于国家尺度贸易网络中心地位,而中亚五国处于边缘地位,中国的地位跃升趋势最为明显;省区尺度贸易网络内存在5个凝聚子群,国家尺度贸易网络内存在9个凝聚子群;省区尺度网络的贸易联系基本平衡,而国家尺度网络的贸易联系具有明显的核心边缘结构。应加强区域合作,以创新驱动发展,优化网络组团结构,充分发挥网络核心的辐射作用,推动区域经济一体化进程,实现“经济带”区域共同发展。     

社会网络嵌入性视角的创新型企业文化作用机制研究

企业持续创新的动力来源于创新型企业文化.创新型企业文化可以增强员工工作满足感,提高员工的创造表现行为和工作绩效.促进企业组织创新.人们的经济行为又是嵌入于社会网络之中的.从社会网络嵌入性视角出发,将社会网络理论引入到企业文化理论研究中,首先分析了什么是创新型企业文化和社会网络嵌入性,然后对创新型企业文化、员工所嵌入的社会网络和员工的创造表现行为之间的关系进行了分析,在此基础上构建了基于社会网络的创新型企业文化的作用机制模型.研究发现,创新型企业文化通过作用于员工个体的社会网络作用于员工的心理和决策,从而使员工产生创造性表现行为.     

一种基于AODV路由协议的改进算法

Ad hoc Network无线局域网络又称自组网络,是将移动性扩展到无线领域中的自治系统,它有自己特定的路由选择协议.本文探讨了一种基于AODV路由协议(Ad hoc On-demand Distant Vector)的改进算法并利用GloMoSim软件仿真并分析Ad Hoc网络改进前后两种按需路由协议.     

Actor diversity and interactions in the development of banana hybrid varieties in Uganda: implications for technology uptake

Purpose: We examine the nature of networks through which new hybrid banana varieties (HBVs) in Uganda are developed, and how different actors engage in the technology development process.

Design/methodology/approach: We collected the data through 20 key informant interviews and 5 focus group discussions with actors involved in the process. We analysed the data with NVivo and Social Network Analysis software.

Findings: The process of developing HBVs involves many actors with a diversity of roles and interests. The network density was 29.4, implying existence of only 29.4% of the possible direct linkages. Strong ties mainly existed among research-oriented actors, with other actors in the periphery.

Practical implications: The current position of smallholder farmers and other non-research actors inhibits their influence on decisions in the technology development process. We recommend that smallholder farmers should be empowered through better organization so that they can influence the process of developing HBVs. Researchers, supported with appropriate policies, should engage more with actors in the intermediary, enterprise and support service domains for a more vibrant agricultural research system.

Theoretical implications: Application of the systems approach to technology development requires a dynamic process that supports involvement of a diverse range of actors. However, close attention to context is important in dealing with issues of power asymmetries and determining to what extent various actors engage in the process.

Originality/value: This work contributes to literature on systems approaches to agricultural and rural development. The paper demonstrates that actor diversity and interactions are critical in technology development and uptake.     

人工神经网络及其应用

主要讲述了人工神经网络的特征、基础知识和分类。进一步说明了人工神经网络学习和训练,模型的建立过程。最后指出了其应用领域。     

粗糙集和神经网络在文本分类中的应用研究

把粗糙集与神经网络结合,应用于文本分类,可以充分发挥两种方法的优势,取长补短,粗糙集理论可以有效地对样本集进行约简,从而简化了神经网络的结构,减少了网络的训练次数,学习速度和分类精度明显提高,并用仿真实验验证了此方法的有效性.     

On exploiting propagation delays for passive target localization using bearings-only measurements

For many cases, target localization accuracy can significantly improve by accounting for the propagation delay between the target source and the sensors. This paper considers when it is advantageous to compensate for the propagation delay for the case of a network of nodes where each node consists of an array of sensors. Each node calculates a direction of arrival (DOA) from the raw data, and these DOAs are combined to localize the target. First, we consider the case when no prior data are given and the localization occurs using DOA measurements from a single snapshot. Such localization methods are necessary to initiate a target track. Finally, we investigate the case where an extended Kalman filter is used to aggregate measurements over multiple snapshots.     

一种基于无线传感网的概率分发时间同步算法

针对无线传感器网络的DMTS时间同步算法,提出一种基于概率分发的改进算法P—DMTS算法,算法以动态变化的概率发送同步报文,大幅降低了广播同步报文的冗余度,有效节省了网络能耗．最后通过仿真实验验证P—DMTS算法,结果表明该算法对于能耗要求较高,但同步精度要求不是很高的无线传感器网络具有广泛的适用性．     

Scholars in an increasingly open and digital world: imagined audiences and their impact on scholars’ online participation

This study investigates the audiences that scholars imagine encountering online and the ways in which these audiences impact scholars’ online participation and presentation of self. Prior research suggests that imagined audiences affect what users share and how they present themselves on social media, but little research has examined this topic in the context of faculty members and doctoral students (i.e., scholars). An analysis of interviews with 16 scholars shows that imagined audiences span the personal–professional continuum. Further, most scholars imagined their online audiences as known and familiar. Though many recognized collapsed contexts as problematic, several others appeared more comfortable with audience collapse than prior literature suggests. Findings also suggest that scholars’ conceptualizations of their audiences differ from those of their universities, principally in that scholars imagine their audiences as communities rather than as venues for attracting professional attention.