共查询到20条相似文献,搜索用时 31 毫秒
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David L 《Aerospace America》1996,34(3):28-33
A brief review of the status of space life sciences research is provided with an emphasis on the contributions this research has made to life here on Earth. Physiological effects of weightlessness are discussed along with methods of prevention or treatment. Several technologies are described which have resulted in advances in improved health care and in other industries. In addition, the impact of space life sciences research on women's health issues and on future space travel are discussed. 相似文献
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薛新东 《郑州航空工业管理学院学报(管理科学版)》2008,26(2):92-95
美国医疗保障体制处于不断改革之中。克林顿政府试图推动的改革方案的核心是引入社会保险的要素,建立一个雇主缴费型的强制性医疗计划,从而实现全民医疗保障覆盖。该方案由于受到社会各界的普遍反对而被国会否决。小布什政府主张从推广健康储蓄账户、引入联合健康计划、改革医疗责任事故相关法律制度和采用新信息技术来改革美国的医疗保障体制。其医疗改革方案注重通过制度创新来降低医疗保险费用和减少医疗费用的浪费。但改革的最终结果,尚取决于医疗储蓄账户的运行效果及其规模、病人能否具有评估医疗服务质量的能力以及改革方案能否真正、有效地控制费用上涨这几个问题的真正解决。 相似文献
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IEEE Standards for Prognostics and Health Management 总被引:1,自引:0,他引:1
Sheppard J.W. Kaufman M.A. Wilmer T.J. 《Aerospace and Electronic Systems Magazine, IEEE》2009,24(9):34-41
Recently operators of complex systems such as aircraft, power plants, and networks have been emphasizing the need for on-line health monitoring for purposes of maximizing operational availability and safety. The discipline of prognostics and health management (PHM) is being formalized to address the information management and prediction requirements for addressing these needs. Herein, we will explore how standards currently under development within the IEEE can be used to support PHM applications. Particular emphasis will be placed on the role of PHM and PHM-related standards with Department of Defense (DOD) automatic test systems-related research. 相似文献
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中国中小企业发展环境分析与政府政策支持体系的构建 总被引:3,自引:0,他引:3
李明 《郑州航空工业管理学院学报(管理科学版)》2008,26(5):27-33
中小企业发展受市场环境和政策环境的双重制约,无论是从市场环境还是从政策环境来看,中国中小企业都需要政府政策的大力支持。政府支持中小企业发展本质上是对市场的干预行为,应当以最大限度弥补市场失灵和尽可能避免自身失灵为标准。因此,政府中小企业政策支持体系应当摆脱以往单纯从企业融资、技术支持等具体环节着手的政策路径,从宏观角度深入分析市场环境和政策环境,针对市场和政策两个方面存在的主要问题,有针对性地构建起符合中国国情的政策支持体系。 相似文献
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This paper describes the latest trends in the IEEE 1394 (“firewireTM” or “iLinkTM”) standards and why it is becoming the connectivity standard of choice for automatic test applications. Why move to IEEE 1394, what are the possible risks with doing so, what are some of the myths associated with IEEE 1394 and a practical example of an automatic test application will all be presented with the prime emphasis on giving the latest information that will help you get IEEE 1394 integrated into your automatic test system 相似文献
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国内外智能制造的发展及对我国商用航空发动机发展的启示 总被引:1,自引:0,他引:1
多个国家在全球范围内部署了智能制造发展战略,建设航空发动机智能工厂是《中国制造2025》重点支持的方向。通过介绍国外商用航空发动机公司智能制造发展现状,探讨我国建设商用航空发动机智能工厂的关键问题,明确发展行业智能制造标准化工具,促进产品智能化改造,实现生产组织数字化、网络化、智能化是实现商用航空发动机智能制造的关键技术手段。 相似文献
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《Aerospace and Electronic Systems Magazine, IEEE》1988,3(3):12-16
The role of the professional engineering society in the career development of the engineer as he/she progresses through various stages of growth is examined. Beginning with the definition of an engineer, professional development is categorized in a four-stage model that begins at the apprentice level and ultimately culminates in the sponsor or director level. Civilian engineer career development at the Aeronautical Systems Division at Wright-Patterson Air Force Base is discussed in terms of the four-stage model. Key factors in career progression are enumerated. The role and impact of the professional society on an engineer's development is examined. The activities of the Engineering Management Society of the IEEE at the local level are reviewed. The critical role of government/industry/academic management policy on participation of their engineers in professional-society activities is debated 相似文献
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严碧峰 《西安航空技术高等专科学校学报》2007,25(6):38-40
经济适用房政策,是我国现阶段用来解决中低收入群体住房问题的有效措施。通过对经济适用房政策存在问题的分析,对如何完善经济适用房政策,解决中低收入群体的住房问题提出了界定购房对象、政策补贴、拓展二手房市场等建议。 相似文献
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针对传统强化学习算法在生成空战机动策略时存在收敛效率低、专家经验利用不足的问题,研究了基于生成对抗-近端策略优化的策略生成算法。算法采用判别器-策略-价值(DAC)网络框架,在近端策略优化(PPO)算法基础上,利用专家数据和环境交互数据训练判别器网络,并反馈调节策略网络,实现了约束策略向专家策略方向优化,提高了算法收敛效率和专家经验利用率。仿真环境为基于 JSBSim开源平台的 F-16飞机空气动力学模型。仿真结高,PPO果表明,本文算法收敛效率高于算法,生成的策略模型具备较好的智能性。 相似文献
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《Air & Space Europe》2000,2(3):41-44
Policy makers are confronted by a complex set of issues as they consider possible strategies for dealing with the problem of limiting the environmental impact of rapidly growing air traffic. To assist them in making an objective evaluation of different possible approaches, the Dutch AERO modelling system for policy analysis on global environmental issues has been developed. This article gives a broad account of AERO and some illustrations of its application. 相似文献
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IEEEl394是一种具有支持等时传输和异步传输的特点的高速串行数据总线,目前已在航天器载荷试验数据传输中得到良好应用,但在未来大型空间飞行器载荷试验信息传输的应用中仍存在重量功耗开销大、传输距离和速率有限等问题.光纤通道作为一种具有良好兼容性、可靠性高、低时延、传输距离远和传输速率高等优点的先进总线技术,可为上层协议提供通用的高速率数据传输通道.基于IEEEl394和光纤通道的基本特性,给出了一种适用于空间载荷试验信息系统的FC-1394桥接方案,并为基于IEEE1394和光纤通道协议映射的空间信息系统数据网络互连提供了一种解决方案. 相似文献
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针对近年来有关中国民航运输业的相关理论研究成果,系统分析了其产业属性与市场结构、民航运输业的产业政策选择、民航运输业市场价格等热点研究领域的研究成果.基于对既有研究成果的综述,就今后研究的进一步发展方向从理论、方法的角度进行了若干展望. 相似文献
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Yiwei WANG Christian GOGU Nicolas BINAUD Christian BES Raphael T.HAFTKA Nam H.KIM 《中国航空学报》2017,30(3)
Airframe maintenance is traditionally performed at scheduled maintenance stops.The decision to repair a fuselage panel is based on a fixed crack size threshold,which allows to ensure the aircraft safety until the next scheduled maintenance stop.With progress in sensor technology and data processing techniques,structural health monitoring (SHM) systems are increasingly being considered in the aviation industry.SHM systems track the aircraft health state continuously,lead ing to the possibility of planning maintenance based on an actual state of aircraft rather than on a fixed schedule.This paper builds upon a model-based prognostics framework that the authors developed in their previous work,which couples the Extended Kalman filter (EKF) with a first order perturbation (FOP) method.By using the information given by this prognostics method,a novel cost driven predictive maintenance (CDPM) policy is proposed,which ensures the aircraft safety while minimizing the maintenance cost.The proposed policy is formally derived based on the trade-off between probabilities of occurrence of scheduled and unscheduled maintenance.A numerical case study simulating the maintenance process of an entire fleet of aircrafts is imple mented.Under the condition of assuring the same safety level,the CDPM is compared in terms of cost with two other maintenance policies:scheduled maintenance and threshold based SHM maintenance.The comparison results show CDPM could lead to significant cost savings. 相似文献
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Anuja MahashabdePhilip Wolfe Akshay AshokChristopher Dorbian Qinxian HeAlice Fan Stephen LukachkoAleksandra Mozdzanowska Christoph WollersheimSteven R.H. Barrett Maryalice LockeIan A. Waitz 《Progress in Aerospace Sciences》2011,47(1):15-52
With the projected growth in demand for commercial aviation, many anticipate increased environmental impacts associated with noise, air quality, and climate change. Therefore, decision-makers and stakeholders are seeking policies, technologies, and operational procedures that balance environmental and economic interests. The main objective of this paper is to address shortcomings in current decision-making practices for aviation environmental policies. We review knowledge of the noise, air quality, and climate impacts of aviation, and demonstrate how including environmental impact assessment and quantifying uncertainties can enable a more comprehensive evaluation of aviation environmental policies. A comparison is presented between the cost-effectiveness analysis currently used for aviation environmental policy decision-making and an illustrative cost-benefit analysis. We focus on assessing a subset of the engine NOX emissions certification stringency options considered at the eighth meeting of the International Civil Aviation Organization’s Committee on Aviation Environmental Protection. The FAA Aviation environmental Portfolio Management Tool (APMT) is employed to conduct the policy assessments. We show that different conclusions may be drawn about the same policy options depending on whether benefits and interdependencies are estimated in terms of health and welfare impacts versus changes in NOX emissions inventories as is the typical practice. We also show that these conclusions are sensitive to a variety of modeling uncertainties. While our more comprehensive analysis makes the best policy option less clear, it represents a more accurate characterization of the scientific and economic uncertainties underlying impacts and the policy choices. 相似文献
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Government contracts mandate specifications and standards of specific issues and dates; Government/industry practice involves continuing update of materials, processes, and components documents. These different approaches create hardships in major system procurements, due to long duration of the procurement cycle. Examples of inconsistencies among documents governing electronic systems are discussed and tabulated. Modification of the ?Defense Standardization Manual 4120.3-M? is recommended, to provide a consistent and practicable Department of Defense policy. 相似文献