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451.
Data fusion algorithm based on state and attribute parameter 总被引:1,自引:0,他引:1
Aquestionthathasbeenconcernedformanyyearsinthemultitargettrackingfieldishowtoreducethecomputationalcomplexityofdataassociatio... 相似文献
452.
郭文君 《西安航空技术高等专科学校学报》2008,26(1):33-34
目的正确分析、准确判断空气压缩机的常见故障。方法通过观察、测量、试验等方法判断故障部位和类型。结果故障主要是活塞环严重磨损、活门密封性降低、偏心轮扭断、润滑油路堵塞和活门严重故障等。结论迅速快捷地排除空压机故障。 相似文献
453.
Yongheng Zhao Yanxia Zhang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(12):1955-1959
The automated classification of objects from large catalogs or survey projects is an important task in many astronomical surveys. Faced with various classification algorithms, astronomers should select the method according to their requirements. Here we describe several kinds of decision trees for finding active objects by multi-wavelength data, such as REPTree, Random Tree, Decision Stump, Random Forest, J48, NBTree, AdTree. All decision tree approaches investigated are in the WEKA package. The classification performance of the methods is presented. In the process of classification by decision tree methods, the classification rules are easily obtained, moreover these rules are clear and easy to understand for astronomers. As a result, astronomers are inclined to prefer and apply them, thus know which attributes are important to discriminate celestial objects. The experimental results show that when various decision trees are applied in discriminating active objects (quasars, BL Lac objects and active galaxies) from non-active objects (stars and galaxies), ADTree is the best only in terms of accuracy, Decision Stump is the best only considering speed, J48 is the optimal choice considering both accuracy and speed. 相似文献
454.
SQL Server数据复制在自来水数据库系统中的实现 总被引:2,自引:0,他引:2
介绍了Microson SQL Server数据复制的概念、工作原理和拓扑结构,并结合自来水公司的业务特点和应用需求,提出了适合企业业务发展的分布式系统解决方案. 相似文献
455.
456.
M. Nelson W.F. DempsterJ.P. Allen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(5):675-683
Development of reliable and robust strategies for long-term life support for planetary exploration must be built from real-time experimentation to verify and improve system components. Also critical is incorporating a range of viable options to handle potential short-term life system imbalances. This paper revisits some of the conceptual framework for a Mars base prototype which has been developed by the authors along with others previously advanced (“Mars on Earth®”) in the light of three years of experimentation in the Laboratory Biosphere, further investigation of system alternatives and the advent of other innovative engineering and agri-ecosystem approaches. Several experiments with candidate space agriculture crops have demonstrated the higher productivity possible with elevated light levels and improved environmental controls. For example, crops of sweet potatoes exceeded original Mars base prototype projections by an average of 46% (53% for best crop) ultradwarf (Apogee) wheat by 9% (23% for best crop), pinto bean by 13% (31% for best crop). These production levels, although they may be increased with further optimization of lighting regimes, environmental parameters, crop density etc. offer evidence that a soil-based system can be as productive as the hydroponic systems which have dominated space life support scenarios and research. But soil also offers distinct advantages: the capability to be created on the Moon or Mars using in situ space resources, reduces long-term reliance on consumables and imported resources, and more readily recycling and incorporating crew and crop waste products. In addition, a living soil contains a complex microbial ecosystem which helps prevent the buildup of trace gases or compounds, and thus assist with air and water purification. The atmospheric dynamics of these crops were studied in the Laboratory Biosphere adding to the database necessary for managing the mixed stands of crops essential for supplying a nutritionally adequate diet in space. This paper explores some of the challenges of small bioregenerative life support: air-sealing and facility architecture/design, balance of short-term variations of carbon dioxide and oxygen through staggered plantings, options for additional atmospheric buffers and sinks, lighting/energy efficiency engineering, crop and waste product recycling approaches, and human factor considerations in the design and operation of a Mars base. An “Earth to Mars” project, forging the ability to live sustainably in space (as on Earth) requires continued research and testing of these components and integrated subsystems; and developing a step-by-step learning process. 相似文献
457.
"余度数据总线电气隔离度测试"是检验在数据总线和余度电缆之间存在电气耦合度的大小.通过对数据总线屏蔽层在接地与不接地状态下的电气隔离度测试,分析了"有传输活动"电缆对"无传输活动"电缆干扰的特征,阐述了电缆屏蔽层的良好接地是确保余度数据总线电气隔离度满足要求的关键. 相似文献
458.
459.
提高长线传输数字波形质量的技术措施 总被引:2,自引:0,他引:2
从两方面论述数字编码波形在长线上传输的影响因素及其改善措施。通过分析并经实验表明,长线的分布电容影响通常居诸因素之首位。改进长线驱动电路,在一定程度上,可改善其传输波形之质量。另外,可利用长线传输波形的同时,还传输供总线接口电路需要的电源能量,满足总线浮空隔离的要求,有效地抑制了共模干扰。此项技术适用于远距多路串行总线的数据采集系统。 相似文献
460.
<正> 大后掠机翼翼尖挂导弹对外界干扰的动力响应很灵敏,这种干扰主要来自随机不稳定气流或各种突加载荷。为保证安全和防止导弹失控,摸清其响应值非常必要;除理论计算外,对可能遇到的不平稳气流和突加载荷在翼尖导弹上的动力响应进行了空测,并用频谱分析和功率谱密度分析处理了空测数据,制订了翼尖导弹振动与冲击试验谱,进行了地面试验与空中打靶试验,获得了满意结果。 相似文献