Feature-based ontological framework for semantic interoperability in product development

An essential requirement in integrating tasks in product development is to have a seamless exchange of product information through the entire product lifecycle. A key challenge in the integration is the exchange of shape semantics in terms of understandable labels and representations. A unified taxonomy is proposed to represent, classify, and extract shape features. This taxonomy is built using the Domain-Independent Form Feature (DIFF) model as the representation of features. All the shape features in a product model are classified under three main classes, namely, volumetric features, deformation features and free-form surface features. Shape feature ontology is developed using the unified taxonomy, which brings the shape features under a single reasoning framework. One-to-many reasoning framework is presented for mapping semantically equivalent information (label and representation) of the feature to be exchanged to target applications, and the reconstruction of the shape model automatically in that target application. An algorithm has been developed to extract the semantics of shape features and construct the model in the target application. The algorithm developed has been tested for shape models taken from literature and test cases are selected based on variations of topology and geometry. Results of exchanging product information are presented and discussed. Finally, the limitations of the proposed method for exchanging product information are explained.     

BIM在建设工程领域中的应用暨发展方向研究

BIM技术作为建筑业的一种新技术,具有可视化、模型化、优化型、协调性等特点,其正在成为市场的驱动力量。BIM环境下的信息互用对解决目前建筑业成本浪费和工期延误有很大的帮助。通过介绍BIM技术在建筑工程设计施工中的应用,分析BIM技术的应用现状、应用实践、应用热点等,指出了BIM随着市场化的发展,形成其特有的产业链。     

Asymmetric CPW-fed SRR patch antenna for WLAN/WiMAX applications

In this paper, a compact asymmetric coplanar waveguide (CPW) feed with split-ring resonator (SRR) is proposed to resonate at dual-band operations for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The asymmetric CPW-fed SRR patch (ACSP) antenna consists of a meander line, square-shaped split ring, and CPW ground plane. The proposed ACSP antenna resonates at two operating frequencies, namely, 2.48 GHz (2.4–2.74 GHz) and 3.49 GHz (3.25–3.64 GHz) with reflection coefficients (S₁₁) of −16.65 dB and −32.67 dB, respectively. The measured results agree closely with the simulation results of the proposed antenna.     

TD-LTE回传网络和时间同步解决方案研究

TD-LTE对回传网络在高带宽、低时延、横向转发、高精度时间同步地面传送等方面提出了更高要求。本文面向TD-LTE需求,结合中国移动的相关研究和测试,介绍大容量PTN,基于PTN的TD-LTE回传,PTN全面互通,OTN＋（L2/L3）PTN组网时间同步传送等关键技术解决方案。     

欧盟铁路车辆噪声技术要求的分析与研究

本文对欧盟铁路车辆噪声的技术法规（指令）、技术规范（TSI）、技术标准的制度体系进行了分析研究,对欧盟常规铁路噪声、高速铁路噪声的通过噪声、稳态噪声、起动噪声、驾驶室内部噪声的技术要求进行了详尽的分析,为提高我国铁路噪声控制技术水平和推进铁路车辆出口提供借鉴。     

基于网关的HLA-TENA互联研究

分布交互体系结构如DIS、HLA、TENA等解决了各自领域内的互操作问题,但体系结构间不一致的数据格式、不匹配的元模型和不同的仿真服务等因素阻碍了体系结构系统间的互操作。通用网关可将不同体系结构的仿真系统互联,通过通用数据交换模型实现异构系统间对象模型间的互操作,是当前最理想的互联方法。设计的通用网关架构包括接口服务、通用数据交换模型、模型映射模型和状态池,其中通用数据交换模型是网关具有通用性的关键。通过HLA-TENA原型系统的试验,验证了通用网关的性能,找到了影响网关性能的主要因素。     

中间件技术在异构与互操作环境中的应用研究

为了解决现代化企业信息系统由于分布性、可扩展性和可重用性导致的信息系统的结构设计复杂的问题,实现异构数据库间数据共享和互操作,采用中间件技术,简化了信息系统的开发,通过对CIS需求的分析和对中间件介绍．描述了基于J2EE中间件技术的CIS体系结构设计方案;特别是对于非结构化数据库和结构化数据库并存的异构环境,通过设计基于．Java技术的访问中间件模型,实现了异构数据库的互操作．