The cost of COTS

Fairchild Defense, a division of Orbital Sciences Corporation, has been a pioneer in the use of Commercial-Off-The-Shelf (COTS) hardware, software, and tools in military equipment. Fairchild has developed a cost and schedule effective approach to the use of COTS elements. This paper discusses Fairchild's experience with the use of COTS in military equipment and special considerations imposed because of the military environment     

基于CATS面向信号的TPS开发设计

本文介绍了CATS测试系统开发平台,以及在该平台上进行TPS开发过程,并以数字万用表资源测量某LRU的输出电压为例,详细介绍了面向信号的测试程序开发步骤,实现了在基于CATS平台下面向信号的TPS的开发,为解决航空电子装备的LRU维修问题提供一种可行的研究思路。     

国外货架电子产品在军用装备研制中的质量控制

介绍了国外货架电子产品的特点,说明了货架电子产品选型的考虑因素,并强调了加强入库检验和环境应力筛选及深入开展可靠性工作的重要性.     

Developing a visual component library for a graphical programmingplatform using object orientation

The development of virtual instruments (VIs) is bringing a great revolution to the fields of automated testing and measurement. It is accelerating the integration of measurement systems and is promoting instrument standardization, modularization and generalization. A graphical programming platform for automated testing is one of the most important applications of VI technology, and it provides users with an intuitive and friendly programming environment. The visual component library (VCL) is the key part of such graphical programming platforms. The research reported in this paper makes full use of the advantages of the object-oriented methodology to develop the visual VI components for a graphical programming platform. By setting up two base classes for all the VI components, various VIs can be efficiently developed     

基于有限元方法的防热瓦损伤分析

防热系统是可重复使用运载器安全飞行的重要保障,而对受损防热结构进行传热特性分析是实现其健康监控的基础.本文针对典型的可重复使用陶瓷防热瓦,建立其有限元传热学分析模型,在考虑气动加热、辐射散热以及防热瓦与飞行器蒙皮之间的传热三种因素的基础上,分别模拟了单片防热瓦在正常情况和发生表面涂层损伤或冲击损伤情况下的传热情况,并进一步分析了两种损伤对于防热瓦温度分布的影响.结果表明,冲击损伤对防热瓦的影响比表层损伤明显严重,可能导致防热瓦底层结构的温度过高而产生严重后果.本文在讨论相应的损伤监测的测点布置原则后建议对防热系统进行多层次的温度监测.     

Use of service history for certification credit for COTS [avionic software]

Much has been written in the last ten years about how the use of commercial-off-the-shelf (COTS) components would revolutionize the aerospace industry avionics, communication, navigation, surveillance/air traffic management (CNS/ATM) as well as global air traffic management (GATM). Civil aviation authorities around the world have been faced with numerous requests to certify aircraft containing increasing percentages of COTS components, much of it never designed or intended for use in the safety critical environment of an aircraft. Product service history is one method for demonstrating that such software is acceptable for use. In theory, product service history would seem to be a fairly simple concept, both to understand and to apply. However, in practice, such use has proven extremely problematic, as questions of how to measure the historic performance and the relevance of the provided data have surfaced. This paper elaborates a research effort funded by the United States Federal Aviation Administration to collect, analyze, and synthesize what is known and understood about applying product service history. The effort is limited to the topic of software product service history as applied in the certification of airborne systems and equipment.     

Sustainment of legacy automatic test systems: lessons learned on TPS transportability

Sustainment of legacy automatic test systems (ATS) saves cost through the re-use of software and hardware. The ATS consists of the automatic test equipment (ATE), the test program sets (TPSs), and associated software. The associated software includes the architecture the TPSs run on, known as the control software or test station test executive. In some cases, to sustain the legacy ATS, it is more practical to develop a replacement ATE with the latest instrumentation, often in the form of commercial off-the-shelf (COTS) hardware and software. The existing TPSs, including their hardware and test programs, then need to be transported, or translated, to the new test station. In order to understand how to sustain a legacy ATS by translating TPSs, one must realize the full architecture of the legacy ATS to be replaced. It must be understood that TPS transportability does not only include translating the original TPS from an existing language (such as ATLAS) to a new language (such as "C") to run on a new test station, but includes transporting the run-time environment created by the legacy ATS. This paper examines the similarities and differences of legacy ATE and modern COTS ATE architectures, how the ATS testing philosophy impacts the ease of TPS transportability from legacy ATE to modern-day platforms, and what SEI has done to address the issues that arise out of TPS transportability.     

Development of three-phase switch-mode rectifier using single-phase modules

This paper presents a three-phase (3/spl phi/) switch-mode rectifier (SMR) consisting of three 1 /spl phi/ SMRs, two center-tapped autotransformers and three changeover switches. The ac input sides of three modules are /spl Delta/-connected, and their dc output sides are connected in parallel. As any one module fault occurs, the remaining two modules becomes modified T-connected and continuously perform three-phase rectification with good line drawn power quality. When two constituted 1/spl phi/ modules are faulted, the proposed 3/spl phi/ SMR will be operated as 1/spl phi/ SMR. The quantitative and robust voltage regulation controls for the developed SMR are made to consider the effects of changes of system parameters, operating condition, and number of connected modules.     

高校图书馆期刊订阅与服务

核心期刊论文数量已成为评估高校科研实力的重要指标，也是教师岗位评定、定岗定级的重要依据。高校的主要功能是人才培养，包括教师学术水平的提高，教学与科研能力的培养等。作为重要导向的核心期刊论文，其期刊采购标准与学术水平应与高校的目标相一致。高校图书馆的期刊订阅与服务也需紧紧围绕这一目标，服务于教师的教学与科研。因此按学院学科发展规划，建立符合学院学科发展的期刊订阅与评估体系至关重要。     

高校数字化图书馆建设的几个问题

通过对国内外图书馆自动化发展的过程分析，结合沈阳航空工业学院(以下简称沈航)图书馆自动化建设的基本状况，利用结构图的方法．阐述了沈阳航空工业学院自动化系统各功能模块的主要作用以及存在的不足。随着计算机技术、网络通讯技术和海量存储技术等高新技术的迅猛发展，图书馆正由传统模式向数字化方向发展，数字化图书馆将成为21世纪图书馆的半壁江山。最后提出了未来数字化图书馆特点及模式。     

Analysis tools for the evaluation of maintenance software

Test packages written for built-in test (BIT) and mobile automatic test equipment (ATE) systems for the forward support of electronic and thermal imaging equipment used by the British Army are currently scrutinized and subjected to objective tests by test package evaluation and acceptance teams (TPEATs) before being accepted for field use. This is a time-consuming and costly exercise that can result in the rejection of unsuitable software. The result of such rejection on equipment logistics is for reaching, since the hardware will enter service without adequate maintenance support. In an attempt to address this problem a suite of programs aimed at assisting the verification and validation activities of the TPEAT at every stage of the software life cycle from requirements analysis through to testing and acceptance is being devised. The development of these tools is discussed     

营销技巧在图书馆参考咨询服务中的应用

新的信息环境对图书馆的参考咨询服务提出了新的要求,将市场营销的理念引入到图书馆的参考咨询服务中,提出了在新信息环境下图书馆如何利用营销技巧进行参考咨询服务。     

UML在图书馆管理系统建模中的应用

以图书馆管理系统项目的开发为背景，探讨了UML在图书馆管理系统中的应用问题，在对系统进行需求分析的基础上，采用CASE建模工具构建了系统的用户需求模型、对象结构模型、行为模型和实现模型。     

LVDT刀具在线检测仪在超精密车削加工中的应用

介绍了一种LVDT刀具在线检测仪,用于超精密车削中刀具的精密对刀及刀尖圆弧半径测量。重点介绍了该装置的工作原理、组成部分及在超精密车削中的具体应用。     

Development of a 1m-normal-incidence-EUV telescope

Astrophysical plasmas at temperatures in the range (0.5–5)×10⁵ K that occur e.g. in interstellar space, in the extended atmospheres around stars of essentially all spectral types, including the numerous late-type stars with low photospheric temperatures, and in the atmospheres of highly evolved stars, can best be studied at extreme ultraviolet wavelengths where they release the bulk of their energy. We report here the current development status of a 1m-normal-incidence-EUV-telescope that will be flown on an ARIES rocket to observe the spectra of nearby stars in the 350 – 700 mm range.     

Development of a SAR digital system

A data acquisition system for an airborne SAR (Synthetic Aperture Radar) was designed and implemented. DSP is used for the first time in the implementation of a SAR data acquisition system. A novel precision programmable timer using the DDS (Direct Digital Synthesis) technique was designed, built, and successfully tested to provide increased flexibility, reliability and stability     

Excitation control of a synchronous generator using a lookup table

A scheme involving the use of a lookup table is developed for the excitation control of a synchronous generator. The proposed control scheme, generator speed deviation, and acceleration deviation are taken as the input signals. These input signals are sampled and converted to linguistic terms before they are fed into the controller. The controller generates the desired output (control) signal by using a set of production rules (if-then rules) that are based on previous experience to relate the input signals to the output. The output signal is converted from linguistic terms to a numerical value before it is sent to the excitation system of the synchronous machine. To demonstrate the effectiveness of the proposed control scheme, digital simulations of a synchronous generator subject to a three-phase fault under different operating conditions were performed. It was found that the controller can improve the dynamic performance of a synchronous generator over a wide range of operating conditions. Since the controller does not require model identification, it is computationally efficient and is suitable for online excitation control, using a microcomputer