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1.
The importance of considering computer security as part of the software quality assurance practice is discussed. Issues that point to the need for integration of quality assurance and computer security disciplines are raised. To address some of these issues, the NASA Automated Information Security (AIS) program is presented as a model that may be used for improving interactions between the quality assurance and computer security community of professionals. The information presented does not comprise an answer to documenting all computer security interactions with quality assurance, but it does present a currently working baseline model and can serve as a basis for future research and discussion  相似文献   

2.
The modern digital computer is rapidly permeating all areas of our highly industrialized society-from agriculture to education-from process control to zoology. Printing and publishing and allied fields involved in graphic communications have been changing rapidly in this decade as the digital computer and associated peripheral devices have made rapid inroads in the graphic communications process. This paper describes the nature of the impact which the digital computer has had, and is making, upon today's graphic communications, particularly upon the editing and composition functions. A prediction of future impact is also presented.  相似文献   

3.
张林瑞 《航空学报》1991,12(12):628-630
由于复合材料结构件的各向异性和层合性,使得复合材料结构的设计、分析要比金属复杂得多,工作最也要大得多,有些工作甚至是手工计算所不能胜任的,必须依靠计算机。因此,近十几年来复合材料的计算机程序迅速地被开发出来。虽然列入《复合材料设计手册》的程序有36个,但在编写过程中涉及的程序有60多个。本文仅就其中的一些做一粗浅的评介。  相似文献   

4.
随着计算机技术的飞速发展,传统总线已远远无法满足目前和未来高性能计算机系统的I/O性能需求。介绍了一种新的基于包交换的I/O互连技术——RapidIO。通过介绍RapidIO协议规范以及将RapidIO和几种新兴高性能I/O互连技术(PCIExpress等)的对比,指出了RapidIO在满足高性能计算机系统的I/O性能需求方面的优势,最后给出了RapidIO验证模型并对验证结果进行了分析.  相似文献   

5.
军用计算机热管理综述   总被引:1,自引:0,他引:1  
在电子设备面临的所有挑战中,热管理对电子设备可靠性影响最大。军用计算机是一种关键的军用电子设备,它对热管理的要求也更苛刻。良好的热管理是电子设备以及军用计算机的正常可靠工作的重要条件。首先介绍了常用的空气冷却和传导冷却方法,并对军用计算机热管理的通用要求进行了详细介绍。为了满足军用计算机热密度迅速增加的要求,对射流冷却进行了介绍。为了统一现有的各种冷却方法,介绍了冷却标准-VITA48的相关内容。最后分析了军用计算机热管理未来的冷却方式。  相似文献   

6.
Advanced electronic navigation systems will be required for future merchant ship operations involving minimum crew manning. These systems will rely on some form of electronic chart, which will require continual and timely updating with the latest correction information. This paper describes a newly developed chart correction computer system capable of automatically updating electronic charts via satellite data transfers. The system can provide a direct computer data link between a shipboard computer and the Defense Mapping Agency's Automated Notice to Mariners System.  相似文献   

7.
分析了计算机系统设计思路与系统结构的发展趋势,进而对如何建立高性能的飞行参数记录系统结构进行了研究,并对采用这一结构模型的飞参系统的未来发展提出了几点看法。  相似文献   

8.
先进客机设计中油耗指标的分解方法   总被引:1,自引:0,他引:1  
先进客机最重要指标之一是油耗指标。研究一种将油耗指标进一步分解为更为具体的发动机的耗油率指标、客机的升阻比指标和使用空重指标的方法。以典型中程客机为例,应用分段解析方法建立客机飞行剖面的燃油量计算程序。应用计算程序分别分析了发动机的耗油率、客机的升阻比和使用空重的变化对油耗的影响。在此基础上,对发动机的耗油率、客机的升阻比和使用空重的指标进行规划,以满足先进客机油耗指标的要求。研究结果为未来客机确定出合理的升阻比、耗油率和使用空重的指标提供了参考。  相似文献   

9.
制图教学新思路   总被引:6,自引:0,他引:6  
本提出了一个有效的教学方法:机械制图和计算机绘图同步教学,通过同步教学,可以取得良好的教学效果,为学生适应社会发展奠定坚实基础。  相似文献   

10.
In this paper we describe the Logic Designer's Apprentice (LDA). The LDA is a knowledge-based computer program (an ``expert system') that designs digital electronic circuits. The LDA extends existing CAD/CAE capabilities by providing a computer aid to the design process, supplementing those that assist the drafting, layout, and simulation processes. It seeks to ensure that appropriate testability (and in the future, other ``ility') features are incorporated during the earliest stages of design in accord with the guidelines defined for Integrated Diagnostics. We discuss issues relevant to the engineering development of other knowledge-based tools needed for Integrated Diagnostics including tool selection and choice of knowledge representation.  相似文献   

11.
虚拟现实技术在CAD中的应用   总被引:1,自引:0,他引:1  
随着计算机技术的不断发展,信息技术不断融合到传统制造业中,虚拟设计/虚拟制造概念的出现受到学术界和企业界的广泛重视,成为研究的热点.阐述了将三维鼠标、立体眼镜原理及数据手套与CAD/CAM技术相结合在具有开放源代码的CAD系统上,将CAD数据模型转换为虚拟场景,保存为VRML格式,实现场景编辑的可视化,可从任意角度观察产品的设计效果.  相似文献   

12.
飞行仿真技术的发展与展望   总被引:13,自引:0,他引:13  
飞行仿真技术是系统仿真,计算机和航空等多领域相结合的产物,简要回顾了飞行仿真技术的发展历程,阐述了现阶段飞行仿真技术的应用现状,并对未来飞行仿真技术的发展趋势进行了简单的介绍。  相似文献   

13.
虚拟现实技术及其应用   总被引:10,自引:0,他引:10  
虚拟现实技术是当今最为流行的计算机技术之一 ,本文对虚拟现实的历史、发展、概况进行了必要的介绍 ,同时讲述了虚拟现实技术的基本特点。介绍了虚拟现实系统的构成及其基本的应用与今后发展的趋势。最后针对当前的实际情况 ,提出了今后应该做的工作。  相似文献   

14.
陈健 《洪都科技》2003,(4):33-36
多媒体技术的出现改变了传统计算机在人们心目中“专业化”的印象。多媒体教育软件的出现不仅对现在教育手段是一种冲击,而且将对人们的教育观念产生深远的影响。在众多的教学软件中,鱼目混珠,水平参差不齐。教学软件能否体现教学设计是一个十分关键的问题。一个教学软件如能较好地体现出教学设计,该软件就是一个较成功的教学软件。  相似文献   

15.
《中国航空学报》2020,33(3):956-964
A feasible guidance scheme with impact time constraint is proposed for attacking a stationary target by missiles with time-varying velocity. The main idea is to replace the constant velocity with the future mean velocity; therefore, the existing time-to-go estimation algorithm of the proportional navigation guidance law can be improved to adapt to varying conditions. In order to obtain the prediction of the velocity profile, the velocity differential equation to the downrange is derived, which can be numerically integrated between the current downrange and the target position by the on-board computer. Then, a third-order polynomial is introduced to fit the velocity profile in order to calculate the future mean velocity. At the beginning of each guidance loop, the future mean velocity is predicted and the time-to-go information is updated, based on which a novel biased proportional navigation guidance law is established to achieve the impact time constraint. Finally, numerical simulation results verified the effectiveness of the time-to-go estimation algorithm and the proposed law.  相似文献   

16.
The design of an integrated Russian-VLF/Omega receiver implemented on a TMS320C30-microprocessor-based SPECTRUM plug-in board installed in a PC-compatible portable computer is presented. The system also requires an external antenna, pre-amp, and frequency reference. The SPECTRUM board digitizes the RF signal to 16 b and then digitally mixes with the sines and cosines of the three Russian frequencies plus 10.2, 11-1/3, and 13.6 kHz. The mixer outputs are low-pass filtered, and the comb filters are implemented for the respective epochs. The computer accesses and processes the comb filter outputs, calculating and logging signal phase and amplitude. The design allows for easy future expansion to include unique and VLF communication frequencies  相似文献   

17.
This article traces the evolution of long range jet transport aircraft over the 50 years since Kuechemann founded the journal Progress in Aerospace Sciences. The article is particularly focused on transonic aerodynamics. During Kuechemann's life time a good qualitative understanding had been achieved of transonic flow and swept wing design, but transonic flow remained intractable to quantitative prediction. During the last 50 years this situation has been completely transformed by the introduction of sophisticated numerical algorithms and an astonishing increase in the available computational power, with the consequence that aerodynamic design is now carried out largely by computer simulation. Moreover developments in aerodynamic shape optimization based on control theory enable a competitive swept wing to be designed in just two simulations, as illustrated in the article. While the external appearance of long range jet aircraft has not changed much, advances in information technology have actually transformed the entire design and manufacturing process through parallel advances in computer aided design (CAD), computational structural mechanics (CSM) and multidisciplinary optimization (MDO). They have also transformed aircraft operations through the adoption of digital fly-by-wire and advanced navigational techniques.  相似文献   

18.
首先对民用飞机发动机反推力装置的出现、作用、工作原理以及最新的发展趋势进行了简要而系统的阐述。对液压反推力装置作动系统和电反推力装置作动系统的构架和控制原理进行权衡分析,阐述了其在研制中应该注意的问题和考虑的因素,并对今后工作的开展提出了意见。  相似文献   

19.
Computer requirements for future space missions are developed and three different approaches to multiprocessing computer organizations are presented. These approaches are shown to have considerable advantages over conventional computers for advanced space missions. Reliability requirements also are assessed by a simulation method and shown to be attainable for long-duration missions.  相似文献   

20.
The concept and physics of a most peculiar glass (called NASTYGLASS) suffering from the video equivalent of audio cross-over distortion are discussed, and a simple mathematical model developed. The model is used as the basis for a computer simulation of how things would look when viewed through a NASTYGLASS window. Some computer-generated, TV-displayed images of `Einstein-in-NASTYGLASS' are included. Finally, future research is proposed, research that just might lead to a Nobel prize in medicine or physiology!  相似文献   

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