Manufacturing features represent area of interest on the machinable surface of a part, which can provide a unique set of removable volumes from part. Feature description in standard for exchange of product(STEP) AP224...Manufacturing features represent area of interest on the machinable surface of a part, which can provide a unique set of removable volumes from part. Feature description in standard for exchange of product(STEP) AP224 is an efficient neutral format for the development of feature based process planning. Process planning information of features can be converted to numerical control(NC)code to have complete manufacturing information of part. STEP-NC code provides an efficient manufacturing information model compared to G-M codes. In this work, an interface is developed for extraction of feature information available in AP224(AIM) format and the ruled-based approach is used to select different process planning parameters. A graphical user interface(GUI) is developed for the interface for displaying features information as represented in AP224 file. Furthermore, the interface generates STEP-NC code in AP238 format. The developed interface has three modules. 1) Module I: Reading interface for STEP AP224 file and development of GUI. 2)Module II: Selection of feature based process planning parameters. 3) Module III: Writing interface for STEP-NC(AP238). The developed interface has been implemented in Java through Java standard data access interface(JSDAITM). The generated STEP-NC AP238 code for the test part has been successfully simulated on STEP-NC Machine TM, an AP238 simulator. This article also provides an in-depth view of application interpreted model(AIM) representation format of STEP for AP224 and AP238.展开更多
目前数据中心规模迅速扩大和网络带宽大幅度提升,传统软件网络协议栈的处理器开销较大,并且难以满足众多数据中心应用程序在吞吐、延迟等方面的需求.远程直接内存访问(remote direct memory access,RDMA)技术采用零拷贝、内核旁路和处...目前数据中心规模迅速扩大和网络带宽大幅度提升,传统软件网络协议栈的处理器开销较大,并且难以满足众多数据中心应用程序在吞吐、延迟等方面的需求.远程直接内存访问(remote direct memory access,RDMA)技术采用零拷贝、内核旁路和处理器功能卸载等思想,能够高带宽、低延迟地读写远端主机内存数据.兼容以太网的RDMA技术正在数据中心领域展开应用,以太网RDMA网卡作为主要功能承载设备,对其部署发挥重要作用.综述从架构、优化和实现评估3个方面进行分析:1)对以太网RDMA网卡的通用架构进行了总结,并对其关键功能部件进行了介绍;2)重点阐述了存储资源、可靠传输和应用相关3方面的优化技术,包括面向网卡缓存资源的连接可扩展性和面向主机内存资源的注册访问优化,面向有损以太网实现可靠传输的拥塞控制、流量控制和重传机制优化,面向分布式存储中不同存储类型、数据库系统、云存储系统以及面向数据中心应用的多租户性能隔离、安全性、可编程性等方面的优化工作;3)调研了不同实现方式、评估方式.最后,给出总结和展望.展开更多
文摘Manufacturing features represent area of interest on the machinable surface of a part, which can provide a unique set of removable volumes from part. Feature description in standard for exchange of product(STEP) AP224 is an efficient neutral format for the development of feature based process planning. Process planning information of features can be converted to numerical control(NC)code to have complete manufacturing information of part. STEP-NC code provides an efficient manufacturing information model compared to G-M codes. In this work, an interface is developed for extraction of feature information available in AP224(AIM) format and the ruled-based approach is used to select different process planning parameters. A graphical user interface(GUI) is developed for the interface for displaying features information as represented in AP224 file. Furthermore, the interface generates STEP-NC code in AP238 format. The developed interface has three modules. 1) Module I: Reading interface for STEP AP224 file and development of GUI. 2)Module II: Selection of feature based process planning parameters. 3) Module III: Writing interface for STEP-NC(AP238). The developed interface has been implemented in Java through Java standard data access interface(JSDAITM). The generated STEP-NC AP238 code for the test part has been successfully simulated on STEP-NC Machine TM, an AP238 simulator. This article also provides an in-depth view of application interpreted model(AIM) representation format of STEP for AP224 and AP238.
文摘目前数据中心规模迅速扩大和网络带宽大幅度提升,传统软件网络协议栈的处理器开销较大,并且难以满足众多数据中心应用程序在吞吐、延迟等方面的需求.远程直接内存访问(remote direct memory access,RDMA)技术采用零拷贝、内核旁路和处理器功能卸载等思想,能够高带宽、低延迟地读写远端主机内存数据.兼容以太网的RDMA技术正在数据中心领域展开应用,以太网RDMA网卡作为主要功能承载设备,对其部署发挥重要作用.综述从架构、优化和实现评估3个方面进行分析:1)对以太网RDMA网卡的通用架构进行了总结,并对其关键功能部件进行了介绍;2)重点阐述了存储资源、可靠传输和应用相关3方面的优化技术,包括面向网卡缓存资源的连接可扩展性和面向主机内存资源的注册访问优化,面向有损以太网实现可靠传输的拥塞控制、流量控制和重传机制优化,面向分布式存储中不同存储类型、数据库系统、云存储系统以及面向数据中心应用的多租户性能隔离、安全性、可编程性等方面的优化工作;3)调研了不同实现方式、评估方式.最后,给出总结和展望.
