分布式加速事务处理引擎技术及实现

数据库加速引擎是位于企业级数据库应用和数据库服务器之间,使用标准接口与底层数据库服务器通信,采用集群方式实现并行处理而不依赖于集成硬件,具有通用性的软件加速系统,能适应对性能要求较高的OLTP应用.系统采用多个工作线索对数据操作请求进行分发,并利用数据分片技术在子站点上处理操作请求,通过并发控制和一维Hash分片在站点间实现负载平衡.通过测试比较证明,该系统具有高性价比和良好的可扩展性等特点,因而具有广阔的应用前景.     

高性能服务器底层网络通信模块的设计方法

在对I／O完成端口进行底层封装的基础上,提出一种具有高性能的、可扩展性的通用网络通信模块设计方案。该方案采用多种系统性能优化技术,如线程池、对象池和环形缓存区等。该模块在Win32平台上用C＋＋开发完成,经过严格的压力和性能测试后,实验结果表明该模块能够支持海量并发连接,具有较高的数据吞吐量,在实际项目应用中也取得了良好的表现。     

进程隐藏的相关问题研究

通过构建若干典型实例,对Windows环境下主流进程隐藏技术进行了分析,包括APIHOOK、远程线程注入DLL和远程线程注入代码,并以此为基础,探索了增强加载程序隐蔽性的技术途径以及提高进程隐藏编码效率的方法。     

分布式实时嵌入式中间件的调度体系

在实时CORBA1.2的基础上扩展了一种分布式调度体系,这种调度体系可以获取全局信息,从而本地调度器可以获得更加准确的调度信息.这里只讨论本地调度器使用截止期调度策略的情况,因此这种调度器可以使得分布式任务在截止期之前完成的可能性增大.如果本地调度器使用其他的调度算法,可以在这种体系中给出相应的机制来提供更准确的调度信息.文中主要描述了这种调度体系的设计与实现.     

Smart manufacturing process and system automation – A critical review of the standards and envisioned scenarios

Smart manufacturing is arriving. It promises a future of mass-producing highly personalized products via responsive autonomous manufacturing operations at a competitive cost. Of utmost importance, smart manufacturing requires end-to-end integration of intra-business and inter-business manufacturing processes and systems. Such end-to-end integration relies on standards-compliant and interoperable interfaces between different manufacturing stages and systems. In this paper, we present a comprehensive review of the current landscape of manufacturing automation standards, with a focus on end-to-end integrated manufacturing processes and systems towards mass personalization and responsive factory automation. First, we present an authentic vision of smart manufacturing and the unique needs for next-generation manufacturing automation. A comprehensive review of existing standards for enabling manufacturing process automation and manufacturing system automation is presented. Subsequently, focusing on meeting changing demands of efficient production of highly personalized products, we detail several future-proofing manufacturing automation scenarios via integrating various existing standards. We believe that existing automation standards have provided a solid foundation for developing smart manufacturing solutions. Faster, broader and deeper implementation of smart manufacturing automation can be anticipated via the dissemination, adoption, and improvement of relevant standards in a need-driven approach.     

接触扫描法测量圆柱螺纹量规中径的测量不确定度评定

依据JJF 1345-2012《圆柱螺纹量规校准规范》和GB/T 28703-2012《圆柱螺纹检测方法》,圆柱螺纹量规可用二维螺纹量规扫描仪进行多参数自动测量,其测量方法为接触扫描法。即通过测针沿被测螺纹轴向剖面轮廓进行二维接触扫描,获取被测螺纹轴向剖面轮廓的二维坐标信息,由计算软件算出被测螺纹各参数的测得值。针对用接触扫描法测量的圆柱螺纹量规中径,建立测量模型,分析主要测量不确定度来源,对中径测量的不确定度进行合理的评估。     

如何用Java回调和线程实现异步调用

异步调用是一种非阻塞式调用方式,用于在处理比较耗时的任务时保证程序性能不受到影响。实现异步调用的关键在于要解决三个技术问题,它们分别是程序阻塞问题、异步消息的传递问题和超时问题。本文介绍的开发方法和步骤采用并发线程、回调机制和计时器圆满地解决了异步调用的技术难题。     

挤压内螺纹在电子产品中的应用研究

通信电子设备中,铝合金屏蔽盒在电磁屏蔽中起到了举足轻重的作用,应用较为广泛。用普通加工方法在铝合金屏蔽盒上加工小螺孔时,易出现螺纹烂牙、丝锥粘牙,并经常出现“滑扣”问题。通过大量的试验,对挤压螺纹加工工艺方法进行了研究,突破了常规加工的传统习惯,改善了螺纹的联结强度,进一步提高了通信电子设备的可靠性,并推广应用到其它有色金属加工和黑色金属薄板料螺孔加工。其适用性广泛,在通信电子设备中应用前景广阔。     

铜管屏蔽绝缘母线的特点和应用

在大型变配电设施中,铜管屏蔽绝缘母线已逐步取代矩形截面母线作为主变二次侧与配电设施之间的联接导体。介绍了铜管屏蔽绝缘母线及其主要部件的结构,阐述了铜管屏蔽绝缘母线的电气性能和特点及其电气考核标准,并以铜管屏蔽绝缘母线在本企业应用的实例,指出在安装、运行中应当注意的一些问题。     

New procedure to increase the accuracy of interfacial tension measurements obtained by breaking thread method

The breaking thread method has been widely used to measure interfacial tension between molten polymers. However, various factors can introduce errors in the breaking thread measurements and is very difficult to obtain accurate values of interfacial tension. In this work a new procedure to enhance the accuracy of the breaking thread method is proposed. It consists of using Tomotika's original theory and Tjahjadi's et al. numerical simulation of the evaluation of a breaking thread simultaneously to identify fibers with residual stresses. These fibers should not be considered for breaking thread experiment. Also, a new experimental procedure for polymer pairs that cannot normally be tested using breaking thread method is presented. Using these two new procedures the interfacial tension between polypropylene and polystyrene and between polypropylene and polycarbonate was evaluated for temperatures ranging from 200 to 240 °C. It was shown that the accuracy of the method was increased by 28% when compared to the result obtained using one of the both theories, Tomotika or Tjahjadi et al, independently. The results of interfacial tension between polypropylene and polystyrene and between polypropylene and polycarbonate corroborated the results obtained using other methods.