Exploring Regional Variation in Spatial Language Using Spatially Stratified Web-Sampled Route Direction Documents

Spatial language, such as route directions, can be analyzed to shed light on how humans communicate and conceptualize spatial knowledge. This article details a computational linguistic approach using route directions to study regional variations in spatial language. We developed a web-sourcing approach to collect human-generated route direction documents on a geographical scale. Specifically, we built the Spatially strAtified Route Direction (SARD) Corpus through automated scraping, classifying, and georeferencing of route directions. Based on semantic categories of cardinal and relative direction terms, the analysis of the SARD Corpus reveals significant differences and patterns on both national (United States, United Kingdom, and Australia) and regional (contiguous U.S. states) levels. Combining computational linguistics and georeferencing approaches offers the potential for extending classic spatial linguistic studies.     

基于FMS和J2EE的视频会议系统的研究

探讨了基于FMS（Flash Media Server）和J2EE技术的B/S结构视频会议系统的设计及实现,整体采用J2EE技术,使用FMS作为视频流媒体服务器。设计分析了系统的整体架构及各功能模块,采用Web Services技术解决了流媒体服务器的访问控制,利用远程共享对象实现视频流的切换。相比传统的C/S结构以及硬件视频会议系统,具有容易部署、成本低以及容易与现有企业应用系统、OA系统集成的优点。     

我国消费信贷市场的困境与对策

在消费信贷快速发展的同时,受消费信贷操作规范性不够、居民承贷能力较弱等多种客观因素的影响,我国消费信贷的发展空间受到严重的制约。为大力开拓消费信贷市场,在健全社会保障体系的同时,应完善消费信贷相应的配套政策措施。文章分别从承贷能力、运行机制、社会保障、法律环境等五个方面分析了目前我国消费信贷制度中存在的问题与弊端,并有针对性地提出了改革与完善我国消费信贷制度的措施与政策建议。     

基于主题模型的结构化Web服务发现机制

提出了基于主题模型(topic model)的结构化Web服务发现机制.利用LDA(Latent Dirichlet Allocation)生成概率模型,将Web服务(Web service)建模为结构化文本文档.一个文档视作主题的概率分布,主题又由关键词的概率分布组成,从而提供基于主题的Web服务检索.同时,利用Web服务的结构化特性,将Web服务描述文档表示为有向无环图,利用n阶谱核测量Web服务文档的相似度,实现Web服务结构化信息的发现.通过实验分析对比,基于主题模型的结构化Web服务发现机制有效提高了Web服务发现的效率和精确率.      

Workspace,stiffness analysis and design optimization of coupled active-passive multilink cable-driven space robots for on-orbit services

The use of space robots (SRs) for on-orbit services (OOSs) has been a hot research topic in recent years. However, the space unstructured environment (i.e.: confined spaces, multiple obstacles, and strong radiation interference) has greatly restricted the application of SRs. The coupled active-passive multilink cable-driven space robot (CAP-MCDSR) has the characteristics of slim body, flexible movement, and electromechanical separation, which is very suitable for extreme space environments. However, the dynamic and stiffness modeling of CAP-MCDSRs is challenging, due to the complex coupling among the active cables, passive cables, joints, and the end-effector. To deal with these problems, this paper proposes a workspace, stiffness analysis and design optimization method for such type of MCDSRs. Firstly, the multi-coupling kinematics relationships among the joint, cables and the end-effector are established. Based on hybrid series-parallel characteristics, the improved coupled active–passive (CAP) dynamic equation is derived. Then, the maximum workspace, the maximum stiffness, and the minimum cable tension are resolved, among them, the overall stiffness is the superposition of the stiffness produced by the active and the passive cable. Furthermore, the workspace, the stiffness, and the cable tension are analyzed by using the nonlinear optimization method (NOPM). Finally, an 8-DOF CAP-MCDSR experiment system is built to verify the proposed modeling and trajectory tracking methods. The proposed modeling and analysis results are very useful for practical space applications, such as designing a new CAP-MCDSR, or utilizing an existing CAP-MCDSR system.