Supporting configurability and real time in RTD channels

Network communication services that can be configured to customize functionality provide significant advantages over monolithic versions, but can be difficult to construct if the services must also provide real‐time guarantees on message delivery. This paper describes how practical issues related to the combination of configurability and real time have been addressed in real‐time dependable (RTD) channels, a communication abstraction that has been prototyped using the Cactus system. The architecture and implementation of RTD channels are described, including facilities for translating an application's quality of service requirements into configuration‐specific resource requirements, and an admission control architecture that uses system‐wide information to determine whether sufficient resources exist to create new channels. In addition, the results of experiments that demonstrate that the desired channel properties—including real‐time guarantees—are provided for various configurations are presented. Finally, practical problems and lessons learned from implementing RTD channels on the general‐purpose MK 7.3 Mach operating system are discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

A Feasibility Study of Automated Natural Language Requirements Analysis in Market-Driven Development

In market-driven software development there is a strong need for support to handle congestion in the requirements engineering process, which may occur as the demand for short time-to-market is combined with a rapid arrival of new requirements from many different sources. Automated analysis of the continuous flow of incoming requirements provides an opportunity to increase the efficiency of the requirements engineering process. This paper presents empirical evaluations of the benefit of automated similarity analysis of textual requirements, where existing information retrieval techniques are used to statistically measure requirements similarity. The results show that automated analysis of similarity among textual requirements is a promising technique that may provide effective support in identifying relationships between requirements.     

空间科学用COTS元器件的质量与可靠性保证研究

商用货架(COTS)元器件具有高性能、低成本、易采购和短货期等优点,但是,在有高可靠性要求的空间领域使用存在一定的风险。为了探索COTS元器件空间应用的可行性,对几种空间科学用COTS元器件质量保证过程中出现的问题进行了研究,分析了问题机理,以及可能造成的失效。根据环境剖面和元器件特点,制定了有针对性的元器件质量保证方案,预计了COTS元器件质量保证后在空间应用的可靠性,并通过环境与可靠性试验得到验证,结果证明COTS元器件的空间应用是可行的。     

A market-driven requirements engineering process: Results from an industrial process improvement programme

In market-driven software evolution, the objective of a requirements engineering process include the envisioning and fostering of new requirements on existing packaged software products in a way that ensures competitiveness in the marketplace. This paper describes an industrial, market-driven requirements engineering process which incorporates continuous requirements elicitation and prioritisation together with expert cost estimation as a basis for release planning. The company has gained a measurable improvement in delivery precision and product quality of their packaged software. The described process will act as a baseline against which promising new techniques can be evaluated in the continuation of the improvement programme.     

机载高分辨率加固LCD显示器的设计

为了实现机载显示器高分辨率、大屏幕显示的目的,选用商用货架产品（COTS）,采用切割、拼接技术以及加固技术,对液晶屏进行了深入研究和设计。结果表明,在不损失分辨率和显示效果的情况下,该方法拼接屏显示器的拼接物理缝小于1.5 mm,分辨率达到3200×1200,完全实现了大屏幕超宽双屏显示的目的。该方法具有实用、成本低以及通用化的特点,完全能够满足低成本军用机载高分辨率LCD显示器的使用要求。     

组件及其复用技术研究

软件复用是软件工程学科的一个研究的热点 ,也是解决软件危机的有效途径之一。随着 Internet应用技术的发展 ,网络环境下的软件复用变得越来越重要 ,网络环境下的软件复用可以通过面向 Agent的方法实现 ,由 Agent自主地搜索、匹配所需要的组件     

基于商用现货的高分辨卫星微振动抑制系统设计

提出了通过合理选取和改进商用现货(COTS)的振动参数对振动部件安装位置进行优化的方法,以解决带有高分辨率光学载荷的小卫星微振动抑制问题。与其他隔振系统设计方法不同,所提方法不需对振动机理建模,而是直接通过振动部件微振动特性分析,选取合适的COTS隔振产品并对参数进行微调;利用Newmark法对蜂窝夹层结构进行动力学响应分析,得到了振动部件的合理安装位置,取得了较好的隔振效果。仿真、振动实验和飞行数据表明,振动部件在敏感频段的微振动抑制率达到90%,整星地面测量微振动引起的次镜角位移不超过0.04″,卫星在轨微振动环境能够满足相机使用要求。所提出的微振动抑制系统设计方法为后续工程实践提供了参考。     

Combining disparate sources of information in the safety assessment of software-based systems

The main topic of the paper is a discussion on how to combine disparate sources of information in the safety assessment of software-based systems. This is based on experience gained through the licensing process of a programmable system in the Swedish nuclear power plant Ringhals, where a guideline for reviewing software in safety-related systems was applied. One lesson learned from this activity is that the approval of a programmable safety critical system, in particular one which is based on Commercial-Off-The-Shelf software, is based on a combination of disparate sources of information. This combination of information is made in a diagrammatic framework. An emerging methodology to combine information about disparate evidences in a systematic way is based on Bayesian Belief Networks. The objective is to show the link between basic information and the confidence one can have in a system.     

综合航空电子系统新技术研究

首先回顾了战斗机综合航空电子系统的发展过程，分析了下一代战斗机综合航空电子系统所应具备的主要特征，最后探讨了在下一代综合航空电子系统中将会运用的3种新技术。     

基于COTS的人工耳蜗体外语音处理器设计与实现

人工耳蜗是目前治疗深度或重度耳蜗性聋的唯一有效的办法,由体外语音处理器和植入体组成。介绍了一种基于商用现货原则（COTS,Commercial-Off-The-Shelf）的低功耗人工耳蜗体外语音处理器的设计与实现：系统选用低功耗立体声A/D芯片CS53L21实现前端处理和采集语音信号;利用通用16位定点DSP芯片TMS320VC5502实现语音处理CIS算法;借用RFID射频芯片MLX90121向植入体传输能量并与其进行双向数据通信。