基于Qt的航电仿真系统记录回放模块设计

针对航电仿真系统对仿真数据进行事后分析的应用需求,结合模块化设计思想,提出了一种基于Qt的航电仿真系统记录回放模块的设计方案。利用Qt的信号与槽机制,简化设计思路、精简代码量的同时,增强了该模块的功能性与可重用性。Qt的跨平台特性,为该模块搭载到其他领域的类似工程应用提供了可能。经过仿真平台的验证,该模块符合用户需求,...     

Development of modular electrical systems

Modular systems provide the ability to achieve product variety through the combination and standardization of components. A methodology that combines system modeling, integration analysis, and optimization techniques for development of modular systems is presented. The approach optimizes integration and interactions of system elements and creates functional and physical modules for the electrical system. The Hatley/Pirbhai methodology (1987) is used for modeling functional requirements of a system. The model defines system interfaces (interactions) to support its functions. Once the interactions among functions are identified, an incidence matrix of the interfaces is developed. A clustering algorithm is developed to identify clusters in the incidence matrix, group the functions, and create modules. A Hatley/Pirbhai architecture model is developed to represent modular system design. A detailed discussion on the importance of system modeling in design of modular systems and on the constraints that limit development of modular vehicle systems is also presented. The approach presented is systematic and can be used to support product development and decision-making in engineering design     

ASP modules: cost-effective building-blocks for real-time DSP systems

ASP (Associative String Processor) architecture and support software provide the base technology for the development of versatile, replaceable, and highly compact building-blocks for the simple construction of modular real-time DSP systems, offering step-function improvements in cost-performance, application flexibility, reliability, and ease of maintenance. Based on a fully programmable and fault-tolerant homogeneous computational architecture, emerging from research at Brunel University and being developed by Aspex Microsystems, ASP modules offer cost-effective support of a particularly wide range of DSP applications, by mapping application data structures to a common string representation supporting content-addressing, parallel processing and a reconfigurable inter-processor communication network. Moreover, by exploiting state-of-the-art microelectronics and packaging technologies, the ASP modules achieve processor packing-densities which are more ussually associated with memory components. Indeed, the ASP has been designed to benefit from the inevitable VLSI-to-ULSI-to-WSI technological trend, with a fully integrated simply scalable, and defect/fault-tolerant processor interconnection strategy. The architecture, software, and implementation of ASP modules are discussed, and the paper indicates that the potential of a peak performance of 1 TOPS (i.e., 1E12 operations (e.g., 12-bit adds) per second) with an input-output bandwidth of 3,200 Mbytes/second could be achieved with only 10 ASP modules, within less than a cubic-foot, dissipating 1 KW, and for less than $1M.     

IEEE's Posix: making progress

The status of the interface standards within the IEEE Portable Operating System Interface (Posix) environment (the x in Posix denotes the Unix operating system origin of this effort) is discussed. The open system standards within the Posix activity are expected to resolve the portability and interoperability problems and to open the door to a major new industry of standard software components, or modules. From these components, users will be able to build and modify larger systems to suit their evolving needs, eliminating the need to produce several versions of an application program to accommodate operating systems with different file system structures and network interfaces. Details of the Posix Open Systems Environment (OSE) application program interfaces are examined to show how standards can be used in constructing portable software     

A Composite Software Design for the Electronic Switching System

This paper describes a process to achieve modular software for switching systems in a way similar to hardware design manufacturing the components first, then constructing a system using the components needed. To reduce the software maintenance cost in the case of changing switching functions, the following factors were studied: 1) modularity corresponding to divided switching functions; 2) interface standardization among the modules; 3) software structure applicable to different systems. In the trial manufacture for the data switching system, the authors were able to reduce manpower required for designing and debugging, and were able to obtain a structural simplicity and modular portability to other switching systems.     

The use of service level agreements in tactical military coalition force networks

Tactical military coalition force IP networks will have to offer quality of service. Service level agreements and service level specifications are important elements of the QoS architecture in civilian networks. However, SLAs/SLSs in military coalition networks should not be applied in the same fashion as in a commercial network. Our contribution is to identify the useful role SLAs/SLSs can play in network engineering and QoS management of tactical coalition force networks. The SLS definition needs to be more detailed than for a commercial SLS, and its monitoring must be performed on a finer timescale than in comparable commercial networks. The security architecture of military coalition networks may also restrict the monitoring and SLA management. Finally, we sketch a measurement-based approach showing how SLSs can be used in tactical military coalition force networks to support both call admission control and network engineering. Parts of this analysis include a discussion of SLSs and the proposed NATO standards for tactical communications network.     

Knowledge-based approach to domain modeling: Application to nasa''s payload operations control centers

Several institutions in industry and academia are pursuing research efforts in domain modeling to address unresolved issues in software reuse. To demonstrate the concepts of domain modeling and software reuse, a prototype software engineering environment is being developed at George Mason University to support the creation of domain models and the generation of target system specifications. This prototype environment, which is application domain independent, consists of an integrated set of commercial off-the-shelf software tools and custom-developed software tools. This paper describes the knowledge-based tool that has been developed as part of the environment to generate target system specifications from a domain model. This knowledge-based approach to domain modeling has been applied to NASA's Payload Operations Control Center (POCC) domain.     

Plastic-encapsulated microcircuit reliability andcost-effectiveness study

This study evaluates the reliability and cost-effectiveness of using commercial plastic-encapsulated microcircuits (PEM) in a typical military system, with a view to increasing their acceptability in military applications. The cost comparison indicates an average 6-fold decrease in cost when commercial devices are used. Assurance testing did not reveal any special problems with commercial parts. Thus, if commercial PEM were proven to be sufficiently reliable for an intended military application, large cost savings would be gained by using them instead of hermetic packages. The 4.5 sigma enhanced inspection program and the process-control methods suggested here would enhance the manufacturing yield of the PLGR (precision lightweight global positioning system receiver) by encouraging improvements in the manufacturing process while simultaneously cutting the cost of a 100% rescreen to qualify the final product. Neither the requirements assurance tests (including the step-stress test-analyze-and-fix test), nor the reliability demonstration test, nor the operational test, showed more failures than are typical for any new development, and no problems unique to PEM were observed. Thus, the use of PEM did not lead to any special problems that caused PLGR-use specifications to be violated. Complete failure analysis of the isolated parts is in progress, and the results will help to understand the specific reliability issues involved with the use of PEM in military systems. These issues can then be addressed to improve the acceptability of such devices in future military applications     

Modular specification and verification of XTP

The transfer protocol framework supports the formal specification and verification of data transfer protocols. It consists of generic specification modules and theorems. Compositions of specification module instances result in well-structured specifications which describe a protocol, the medium used, and the service provided by means of TLA formulas. The protocol verification is based on the proof of the logical implication between protocol and service specification. Due to the modular structuring of the specifications, this proof can be decomposed into a set of subimplications which correspond directly to theorems of the framework. Therefore, the development of formal specifications as well as the protocol verification can be reduced to the instantiation and arrangement of framework elements. The flexibility of the framework opens its application for a broad spectrum of data transfer protocols. We outline the principles of the framework and concentrate on its application to the high-speed transfer protocol XTP. Because of the framework support, the formal modeling and analysis of this modern and function-rich protocol was manageable and identifies deficiencies of the current protocol definition clearly.     

软件无线电技术在卫通终端中的应用

根据软件无线电技术的思想,提出了一种依托通用的可编程硬件平台,以各种软件模块实现不同标准信号通信的多速率、多模式的卫星通信终端的设计。详细讨论了该设备的软、硬件结构设计,并对所涉及的开放式的总线结构、宽带A/D、D/A转换技术、高速数字信号处理技术、功能软件模块化编程设计等关键技术进行了分析。     

一种OPNET网络仿真与实物终端的互联实现

针对网络研究中纯数学网络仿真建模难以保证准确度的问题,研究了基于OPNET软件的网络半实物仿真模型。讨论了半实物仿真系统的构成,分析了系统各模块的功能,提出了OPNET半实物仿真系统的模块化设计方案,详细讨论了半实物仿真硬件处理接口单元和软件处理接口单元的实现,并分析了仿真系统的运行结果。通过实例证明半实物仿真在网络研究中具有技术优势。     

基于EAI的多层分布式应用与实现

针对目前大型企业各类应用迅速增加但应用之间缺乏有效通信的问题,采用企业应 用集成(EAI)技术,提出了4层分布式应用体系结构,实现流程自动化和松耦合的应用集成.文中首先从EAI技术和常见解决方案出发,详细阐述了表示层、企业门户、EAI总线层和数据源层的功能及软件结构,并结合电信业务运营支撑系统的实际需求,给出了J2EE平台下的应用实例开发.利用组件和容器的技术构建企业门户,通过工作流和企业Java组件(EJB)技术实现EAI总线,借助资源适配器完成应用之间的互连互通.该系统现已投入实际运行,取得了良好的应用效果.     

模块化单片机实验系统的研制

本文介绍了一种模块化单片机实验系统的硬件设计、软件调试平台和实际应用效果。该装置舍弃了以前单片机实验仪复杂的监控程序,所有资源完全公开透明,模块多样化,能灵活组建多种实验及实训项目,让学生从软硬件两方面了解单片机设计应用的整个过程。实际应用表明,该装置可以改善学生的实践动手能力。     

Blocking in a system on a chip

With more and larger functions being implemented on a single piece of silicon, true systems on a chip are being created. At the physical level, this integration derives from progress in process technology. But from the circuit designers' viewpoint, tools and methods are less help than they might be. In effect, to construct a system on a chip means more than the integration of millions of transistors. A set of complicated and rapidly evolving technologies and standards for telecommunications, multimedia, and PCs must be mastered, too. Also, the software content of most electronic systems has been growing for several years and now often accounts for a major part of the final product and hence of the design effort. Since a system on a chip is a system, a design methodology for generating such complex ICs will frequently have to address the software as well as hardware needs. Further more, as the size and complexity of chips has grown, so too has the task of verification. Verifying the design of a chip containing a million gates of logic presents a formidable challenge of its own. The complexity of large designs calls for a shift in the design paradigm to one based on reusable, high-level building blocks. Currently, most functional blocks are created by hand and are seldom used again. Reusable blocks, though, are not enough. To deliver on the promise of more productivity and less time to market, designers need reinforcements-a methodology and tools with which to integrate the blocks efficiently, plus standards that support the creation of reusable blocks, their exchange, and their integration     

Integrated electronics in defense systems

The role played by the Department of Defense in the early development of integrated electronics is discussed and the current status of military application is summarized. The potential advantages of the new technology to military systems are outlined. These include improved reliability, savings in cost, improved maintenance and logistics supply, enhanced system effectiveness, design flexibility, shorter development/production leadtime and decreased size, and weight and power requirements. The paper concludes with a discussion of the question of military specifications and standards supporting the position that standardization in integrated circuits should for the present be limited to criteria for stating performance characteristics, methods of measuring characteristics and definitions and terminology.     

移动运营商需要新一代应用集成合作伙伴

随着中国移动通信的迅猛发展，运营商的业务支撑系统将面临机遇和挑战；满足用户数的不断增长，紧跟移动通信技术和互联技术的发展，遵循统一的技术规范，积极参与加入WTO后的市场竞争。另一方面，承担运营商业务支撑系统建设和完善的移动应用集成商，也应在软件产品、应用解决方案和应用集成等方面，不断提升和创新，向运营商提供全方位的服务支持和全优的工程管理。     

网络电视视频编解码主流标准的比较研究

网络电视视频编解码主流标准有MPEG-4、H.264与AVS等多种标准制式。本文在所用技术基础上从基本概念、技术特征差异分析和发展趋势等方面对这些标准进行了比较评价,并得出一些重要结论。对于我国网络电视标准选择的参考,是十分必要也是完全可行的。由于这些网络电视标准系统均未进入大规模商用,标准可能存在的一些问题和缺陷很难暴露,在这些标准的实施过程中也会逐步认识各种标准的不足之处。     

Analysis of deep submicron VLSI technological risks: A new qualification process for professional electronics

A large range of commercial deep submicron VLSI devices are used for avionic designs. Due to the scaling down, an ever higher level of integration and the use of new materials in foundries, the main failure mechanisms are changing while new ones appear. Lifetimes related to these failure mechanisms are suspected of being shorter and shorter so failure rate prediction becomes a great challenge for deep submicron (DSM) semiconductor reliability. We propose in this paper, a new approach based on technologies analysis in order to determine potential reliability risks regarding the specific use of DSM components for avionic applications.     

Software protection - Putting COTS back in the box

Off-the-shelf software is now a part of avionics design. But how do you stop third-party code from upsetting other parts of the system? Standards call for it to be boxed off. The avionics industry has witnessed a major shift toward integrated modular avionics (IMA) in recent years, and IMA architectures and standards are still evolving as they gain industry acceptance. This presents significant challenges for standards organisations, OEMs and commercial vendors alike. However it is clear that standards-based architectures, such as ARINC 653, will provide greater flexibility and portability and enable existing federated applications to be reused in an IMA environment