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961.
Recent developments in neuroelectronics are applied to aviation and airplane flight control instruments. Electromyographic control has been applied to flight simulations using the autopilot interface in order to use gestures to give bank and pitch commands to the autopilot. In other demonstrations, direct rate control was used to perform repeated successful landings and the damage-adaptive capability of inner-loop neural and propulsion-based controls was utilized. 相似文献
962.
The role of cross-cultural factors in long-duration international space missions was examined during an isolation study that simulated many of the conditions aboard the International Space Station. Methods: Interactions involving two heterogeneous crews and one homogeneous crew staying in isolation from 110 to 240 days were studied. Data consisted of post-isolation interviews with crewmembers, ground support personnel and management, observational data, and public statements by crewmembers. Data was analyzed using the techniques of linguistic anthropology and ethnography. Results: Sub-cultural (organizational and professional) differences played a larger role than national differences in causing misunderstandings in this study. Conversely, some misunderstandings and conflicts were escalated by participants falsely assuming cultural differences or similarities. Comparison between the two heterogeneous crews showed the importance of training, personality factors, and commander and language skills in preventing and alleviating cultural misunderstandings. Conclusion: The study revealed a number of ways that cultural differences, real as well as assumed, can play a role and interact with other, non-cultural, factors in causing and/or precipitating conflict situations. It is postulated that such difficulties can be avoided by selecting culturally adaptive crewmembers and by cross-cultural and language training. Also the crew composition and role of commander were found to be important in mitigating conflict situations. 相似文献
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964.
NASA下一世纪科学探索方式将基于廉价频繁的卫星发射,这些卫星将是轻型、低成本、高度自主的小卫星。通过“新世纪计划”(NMP),NASA准备创建一种新的高度综合的方法,对实现这些卫星目标的一系列技术进行开发和空间验证。要满足这些想象的任务要求,并突出降低寿命期成本的目标,对卫星设计、制造和操作各方面将提出挑战。本文集中讨论先进通信系统的体系结构和技术,这些都是NMP已明确的关键性能需求,也是空间验证计划当前选定的内容。这些系统主要分三大类:小型深空通信,极高码速率近地通信和短程通信。其应用包括:空—地链路,行星间飞行器及其着陆器和漫游年之间数据中继的航天器间链路,以及通过星间交叉链路和数据中继卫星的近地卫星通信。本文将从用途和关键性能参数(如质量、体积、效率和成本)来讨论射频(400MHz-32GHz)和光通信技术。 相似文献
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968.
Doetsch K 《Acta Astronautica》2005,57(2-8):661-675
The paper addresses the evolution of the Canadian Space Station Program between 1981 and 2003. Discussions with potential international partners, aimed at jointly developing the current International Space Station program, were initiated by NASA in 1982. Canada chose, through the further development of the technologies of Canadarm on the space shuttle, to provide and operate an advanced and comprehensive external robotics system for space station, and to use the space station for scientific and commercial purposes. The program was to become a corner-stone of the new Canadian Space Agency. The development phase of the Canadian Space Station Program has been completed and two of the three major elements are currently operational in space. 相似文献
969.
Pre-cometary ice located around star-forming regions contains molecules that are pre-biotic compounds or pre-biotic precursors. Molecular line surveys of hot cores provide information on the composition of the ice since it sublimates near these sites. We have combined a hydrostatic hot core model with a complex network of chemical reactions to calculate the time-dependent abundances of molecules, ions, and radicals. The model considers the interaction between the ice and gas phase. It is applied to the Orion hot core where high-mass star formation occurs, and to the solar-mass binary protostar system IRAS 16293-2422. Our calculations show that at the end of the hot core phase both star-forming sites produce the same prebiotic CN-bearing molecules. However, in the Orion hot core these molecules are formed in larger abundances. A comparison of the calculated values with the abundances derived from the observed line data requires a chemically unprocessed molecular cloud as the initial state of hot core evolution. Thus, it appears that these objects are formed at a much younger cloud stage than previously thought. This implies that the ice phase of the young clouds does not contain CN-bearing molecules in large abundances before the hot core has been formed. The pre-biotic molecules synthesized in hot cores cause a chemical enrichment in the gas phase and in the pre-cometary ice. This enrichment is thought to be an important extraterrestrial aspect of the formation of life on Earth and elsewhere. 相似文献
970.
根据费用与进度综合管理的思想,在给出了项目可调余度与计划余度的定义与量化表示的基础上,提出了应用香蕉曲线,考虑资金占用与计划余度两因素来制定与调整项目计划的优化模型及其启发式求解算法,该模型与算法适合于大中型项目初步制定后,在满足工期,资源,费用约束条件下的网络计划优化问题。 相似文献