空域反转阵导向最小方差波束形成

文章研究了基于空域反转阵（Spatial Reversion Array,SRVA）的导向最小方差（Steered Minimum Variance,STMV）波束形成方法。根据空域反转阵的原理将均匀线阵列的快拍进行空间反转,再与原阵列快拍卷积,得到孔径扩大近一倍的空域反转阵,提高阵列性能。将同样的方法用于构造空域反转阵的导向向量,实现其导向最小方差（SRVA-STMV）波束形成。仿真和海试试验结果表明,相较于常规的STMV波束形成,空域反转阵STMV波束形成能够获得更窄的主瓣、更低的旁瓣、更高的输出信干噪比以及更好的多目标分辨能力。     

基于UML状态图的面向方面软件建模

该文基于UML状态图对缓存并发读写问题进行面向方面的建模,把系统的同步和调度分离出来,建模为方面。该方法有效解决了面向对象中功能和代码混乱的现象,也提高了系统模块的可复用性。     

基于情感词典扩展技术的网络舆情倾向性分析

随着Web2.0时代的到来,网络已逐渐成为反映社会舆情的重要载体之一,网络舆情发现及网民的观点和倾向性挖掘也成为新的研究热点,但是目前尚无有效反应网民对热点事件或话题总体态度的舆情分析系统.本文针对网民关于话题评论简单、数目众多的特点,应用HowNet和NTUSD两种资源对现有情感词典进行扩展,建立了一个新的、具有倾向程度的情感词典.基于扩展的情感词典,开发了一个半自动化网络舆情分析系统.该系统能够为用户提供更加细致、准确的评论倾向性分析结果.     

轮廓曲线的LoG变换及图像共变区域的检测

本文将LoG (Laplacian of Gaussian)变换应用到轮廓曲线上, 其范数的平方具有稳健的曲率特性, 由此构造了轮廓角点的响应函数; 在此基础上, 结合轮廓LoG所检测的角点和角点邻域内轮廓方向的尺度共变性设计了一种新的关于旋转和尺度共变的特征区域检测算法. 最后, 利用相关度准则对多组受干扰的图像进行特征共变区域匹配, 实验结果验证了所提出的共变特征区域检测算法具有计算简单、容易实现和较强的鲁棒性等特点.     

An empirical study of the factors affecting social network service use

Social network services are emerging as a promising IT-based business, with some services already being provided commercially such as Facebook, Cyworld and Xiaonei. However, it is not yet clear which potential audience groups will be key social network service participants. Moreover, the process showing how an individual actually decides to start using a social network service may be somewhat different from current web-based community services. Hence, the aims of this paper are twofold. First, we empirically examine how individual characteristics affect actual user acceptance of social network services. To examine these individual characteristics, we apply a Technology Acceptance Model (TAM) to construct an amended model that focuses on three individual differences: social identity, altruism and telepresence, and one perceived construct: the perceived encouragement, imported from psychology-based research. Next, we examine if the users’ perception to see a target social network service as human relationship-oriented service or as a task-oriented service could be a moderator between perceived constructs and actual use. As a result, we discover that the perceived encouragement and perceived orientation are significant constructs that affect actual use of social network services.     

A novel AR-based robot programming and path planning methodology

This paper discusses the benefits of applying Augmented Reality (AR) to facilitate intuitive robot programming, and presents a novel methodology for planning collision-free paths for an n degree-of-freedom (DOF) manipulator in an unknown environment. The targeted applications are where the end-effector is constrained to move along a visible 3D path/curve, which position is unknown, at a particular orientation with respect to the path, such as arc welding and laser cutting. The methodology is interactive as the human is involved in obtaining the 3D data points of the desired curve to be followed through performing a number of demonstrations, defining the free space relevant to the task, and planning the orientations of the end-effector along the curve. A Piecewise Linear Parameterization (PLP) algorithm is used to parameterize the data points using an interactively generated piecewise linear approximation of the desired curve. A curve learning method based on Bayesian neural networks and reparameterization is used to learn and generate 3D parametric curves from the parameterized data points. Finally, the orientation of the end-effector along the learnt curve is planned with the aid of AR. Two case studies are presented and discussed.     

基于无线传感器网络的井下人员定位方法的研究

近年来,随着无线传感器技术的成熟,以及基于无线传感器网络的定位技术的发展,不少学者提出了基于无线传感器技术的煤矿井下人员定位方法,本文对其中部分方法进行了分析,发现其中存在的一些不足。     

基于自然景观资源的环境艺术设计之定位

当前,随着环境问题的日益突出,要求加强对环境的保护、修复和美化已成为人们实践活动中的一个关键内容,而与解决环境问题紧密相关的环境艺术设计更是责任重大,尤其是在资源型城市(如矿山、油田、旅游区等),要尝试探索如何充分理解自然生态系统运行规律和自然美学价值,宏观地赋予环境艺术设计新的内涵和价值,在功能、形式、生态、经济和人文诸多因素中谋求环境与人的平衡。     

基于Hadoop的Web日志挖掘

基于单一节点的数据挖掘系统在挖掘Web海量数据源时存在计算瓶颈,针对该问题,利用云计算的分布式处理和虚拟化技术的优势,设计一种基于云计算的Hadoop集群框架的Web日志分析平台,提出一种能够在云计算环境中进行分布式处理的混合算法。为进一步验证该平台的高效性,在该平台上利用改进后的算法挖掘Web日志中用户的偏爱访问路径。实验结果表明,在集群中运用分布式算法处理大量的Web日志文件,可以明显提高Web数据挖掘的效率。     

Keeping up-to-date with information technology: Testing a model of technological knowledge renewal effectiveness for IT professionals

In a rapidly changing IT environment, IT professionals need to keep abreast of technological knowledge. We examined how well this is achieved by developing a motivational model of “technological knowledge renewal effectiveness.” We hypothesized that (1) renewal effectiveness was influenced by the IT professional's career orientation, perceived IT dynamism, tolerance of ambiguity, delegation; and (2) that this positively affected both intrinsic and extrinsic job satisfaction. Survey data from 126 IT professionals was used to test the hypotheses. The results generally supported the research model. We discussed the implications of these results in both research and practice.