基于面向方面MDA的实时系统开发方法

实时系统有许多难以处理的横切整个系统的非功能需求。针对以上问题,提出基于面向方面模型驱动架构的实时系统开发方法。该方法在设计阶段将系统的非功能需求从功能需求中分离出,以降低系统开发的复杂性,提高系统的可重用性、可维护性和横切关注点的模块化程度。通过应用实例证明该方法是有效的。     

基于MDA和可执行形式化的可信软件设计

提出基于模型驱动架构的软件开发过程,利用可执行形式化规范,有效提高软件开发效率和可测试性,并通过基于可执行规范的运行时监控技术保证系统行为的可信性,降低由于软件测试阶段遗留的错误以及系统受到非法入侵所带来的风险。     

基于SCA的遗留系统移植研究与实现

针对传统遗留系统在面向服务计算移植过程中存在的重复性和多样性问题,提出一种基于服务组件框架（SCA）的遗留系统移植方案,将遗留系统移植到SCA组件系统中,通过python扩展生成器生成可以被该脚本调用的模块,在硬件平台上进行模拟,实验结果表明,该方案是可行的,能够避免因面向服务实现形式的差异而造成的重复移植。     

设计模式在民航信息平台中的应用

为了在面向服务设计中有效提高系统的灵活性、敏捷性,以民航综合信息平台为背景,使用设计模式构建面向服务的应用系统。针对民航综合信息平台的核心服务设计,提出服务接口和服务网关2种面向服务的设计模式,将其实现在应用系统中,以验证设计模式在面向服务系统设计中的有效性。     

基于MIPS指令集的超标量和超长指令字混合架构处理器设计

针对嵌入式和移动设备对处理器高性能低功耗日趋强烈的要求,提出一种基于MIPS指令集的顺序超标量和超长指令字混合架构处理器设计方案,便于以同构多核架构代替目前业界普遍采用的CPU与DSP异构结构,降低功耗面积,同时以VLIW模式获得较好的DSP性能。在PD（Processor Designer）平台下以LISA语言建立处理器的周期精度软件模拟器,通用性能和DSP性能分别由dhrystone、coremark基准测试程序及EEMBC的telecom测试程序进行验证。测试结果表明该设计以较低的硬件开销通过混合架构获得较高的数字信号处理性能,在高性能低功耗的处理器应用场景中拥有良好的适用性。     

深度学习应用技术研究

本文针对深度学习应用技术进行了研究性综述。详细阐述了RBM（Restricted Boltzmann Machine）逐层预训练后再用BP（back-propagation）微调的深度学习贪婪层训练方法,对比分析了BP算法中三种梯度下降的方式,建议在线学习系统,采用随机梯度下降,静态离线学习系统采用随机小批量梯度下降;归纳总结了深度学习深层结构特征,并推荐了目前最受欢迎的5层深度网络结构设计方法。分析了前馈神经网络非线性激活函数的必要性及常用的激活函数优点,并推荐ReLU （rectified linear units）激活函数。最后简要概括了深度CNNs(Convolutional Neural Networks), 深度RNNs(recurrent neural networks), LSTM(long short-termmemory networks)等新型深度网络的特点及应用场景,并归纳总结了当前深度学习可能的发展方向。     

基于AADL的航电构型控制系统的建模分析

针对航电系统的不同构型仿真、系统加改装的验证,为了使构型控制系统可以根据应用需求可靠转换,以满足系统结构能够可靠重构的需求,采用先进的建模语言AADL(结构化分析设计语言)完成了对航电构型控制系统的建模设计。结合AADL对航电构型控制系统进行了详细的分析,展示了该系统的特征与关键技术,体现了此系统的工作原理与内部结构。该模型可以表达系统的功能与非功能约束,实现了系统级的组件建模策略,层次化地描述了系统的架构。     

浅谈《计算机系统结构》课程教学的改革

《计算机系统结构》课程对于计算机专业的学生系统地掌握计算机软硬件知识非常重要。通过该课程的学习,可以加深学生对计算机整体知识的理解．提高学生分析和设计计算机系统的能力。目前这门课程在国内教学上还存在教学内容相对落后、与实际应用联系程度不高、对课程实验环节不够重视等问题。结合对这门课程教学的实际感悟,分析该门课程的教学现状,并提出相应的改进措施。     

Adaptable Decentralized Service Oriented Architecture

In the Service Oriented Architecture (SOA), BPEL specified business processes are executed by non-scalable centralized orchestration engines. In order to address the scalability issue, decentralized orchestration engines are applied, which decentralize BPEL processes into static fragments at design time without considering runtime requirements. The fragments are then encapsulated into runtime components such as agents. There are a variety of attitudes towards workflow decentralization; however, only a few of them produce adaptable fragments with runtime environment. In this paper, producing runtime adaptable fragments is presented in two aspects. The first one is frequent-path adaptability that is equal to finding closely interrelated activities and encapsulating them in the same fragment to omit the communication cost of the activities. Another aspect is proportional-fragment adaptability, which is analogous to the proportionality of produced fragments with number of workflow engine machines. It extenuates the internal communication among the fragments on the same machine. An ever-changing runtime environment along with the mentioned adaptability aspects may result in producing a variety of process versions at runtime. Thus, an Adaptable and Decentralized Workflow Execution Framework (ADWEF) is introduced that proposes an abstraction of adaptable decentralization in the SOA orchestration layer. Furthermore, ADWEF architectures Type-1 and Type-2 are presented to support the execution of fragments created by two decentralization methods, which produce customized fragments known as Hierarchical Process Decentralization (HPD) and Hierarchical Intelligent Process Decentralization (HIPD). However, mapping the current system conditions to a suitable decentralization method is considered as future work. Evaluations of the ADWEF decentralization methods substantiate both adaptability aspects and demonstrate a range of improvements in response-time, throughput, and bandwidth-usage compared to previous methods.     

A top-down strategy to reverse architecting execution views for a large and complex software-intensive system: An experience report

This article is an experience report about the application of a top-down strategy to use and embed an architecture reconstruction approach in the incremental software development process of the Philips MRI scanner, a representative large and complex software-intensive system. The approach is an iterative process to construct execution views without being overwhelmed by the system size and complexity. An execution view contains architectural information that describes what the software of a software-intensive system does at runtime and how it does this. The application of the strategy is illustrated with a case study, the construction of an up-to-date execution view for the start-up process of the Philips MRI scanner. The construction of this view helped the development organization to quickly reduce about 30% the start-up time of the scanner, and set up a new system benchmark for assuring the system performance through future evolution steps. The report provides detailed information about the application of the top-down strategy, including how it supports top-down analysis, communication within the development organization, and the aspects that influence the use of the top-down strategy in other contexts.