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141.
Efficient structures for wideband digital receiver   总被引:1,自引:0,他引:1  
1 .INTRODUCTIONWith the development of high perfor mance ana-logue-to-digital converters ( ADC) , applicationspecific integrated circuit ( ASIC) devices anddigital signal processing ( DSP) technology , dig-ital receiver has increasingly become popular inrecent years[1 ~7]. The digital receiver is a typi-cal application of software radio in radar . Itsmain purpose is to move the digital conversionprocess closer to the antenna and execute mainfunctions on general hardware . But the sign…  相似文献   
142.
Sensor management based on fisher information gain   总被引:2,自引:0,他引:2  
1 .INTRODUCTIONSensor management can be described as a systemor process that provides automatic or semi-auto-matic control of a group of sensors[1]. The basicobjective of sensor management is to select rightsensors to do the right service on the right targetat right ti me based on external measurements orcriteria[2]. A variety of techniques have been pro-posed or appliedtothe area of sensor management .One of the first articles to apply opti mization tech-nique to sensor management is by …  相似文献   
143.
1 .INTRODUCTIONA mobile Ad hoc network refers to a temporal multi-hop autonomy system,whichis constituted by a groupof mobile nodes containing wireless send-receive equip-ments[1].It possesses manycharacteristics-fast-deploy-able,self-organized,acentric , movable and of multi-hop.It can be wildly applied to many fields ,such asnational defense,emergency and disaster ,scientificin-vestigation and exploration etc .,and uponthat ,it hasgreat prospects[1 ,3 6]. With the wide spread of mo-bile…  相似文献   
144.
1. INTRODUCTION Many researches have been made on automatic target recognition (ATR) from SAR images in the past few years. Lincoln Laboratory has developed a complete, end-to-end ATR system[1-4]. The whole system inclu- des three stages: detection (or prescreening), discri- mination and classification. In the detection stage, a two-parameter CFAR (constant false alarm rate) detector is used as a prescreener to select candidate targets in an SAR image on the basis of local brightne…  相似文献   
145.
1. INTRODUCTION Large-scale dynamic system theory has been intensi- vely studied during the past decade[1~3], but for fuzzy large-scale systems, namely large-scale systems comp- osed of a series of fuzzy subsystems, has been seldom done in literature. In Ref.[4], decentralized stabiliz- ation problem of fuzzy large-scale systems composed of a series of fuzzy subsystems was considered. Sufficient conditions for asymptotic stability of the fuzzy large-scale system and design methods of dec…  相似文献   
146.
1. INTRODUCTION Weapon equipments acquisition and demonstration has become more and more prominent in the informationalized war conditions while operational effectiveness evaluation is its core part. The compl- exity and uncertainty of weapon systems operational effectiveness evaluation make traditional analysis methods or expert evaluation methods less effective to solve problems. Simulation based operational effe- ctiveness evaluation is an efficient solution. The increased complexity o…  相似文献   
147.
星际推销员     
沃克推销的那种录音机外观很漂亮,铝合金和塑料的外壳,四四方方,结实美观.它被放在涂蜡的柜台上,在它周围故意放了一些难看的当地技术产品.别出心裁的销售技巧--他想,手里紧紧攥着他祖父传给他的公文包,似乎那是他的护身符.  相似文献   
148.
随着时间的推移,我们的世界似乎在不断地变小,不仅如此,新的发明创造也在向着更小更精细的方向发展。然而,这些“小玩意儿”在发展的道路上总会遭遇瓶颈,至少在以摩尔定律(Moore's Law)为准规则的计算世界会这样。如果根据英特尔公司(INTEL)创办人之一Gordon Moore的建议,即一个电脑芯片上所能容纳的晶体管数目每隔18~24个月增加一倍,那么一块硅片上  相似文献   
149.
Global warming: Take action or wait?   总被引:1,自引:0,他引:1  
Of all the changes wrought by human activity, the buildup in our atmosphere of the greenhouse gases, carbon dioxide, methane and nitrous oxide, has gener- ated the most contentious debate. Environmentalists warn that in the absence of firm action, over th…  相似文献   
150.
Based on results of nannofossil analysis and 10Be dating in ferromanganese crusts M1-1 and A1-1 (no nannofossils were found in it),from the western and central Pacific respectively,it is found that the crust growth ages from nannofossil biostrati-graphy agree well with those based on 10Be isotope analysis. Both crusts have three growth layers,and the oldest layer was deposited in Miocene at about 12.80 Ma. The maximum,minimum,and average growth rates of crust A1-1 (from the central Pacific) are 8.11,1.92 and 3.47 mm/Ma,and those of crust M1-1 (from the western Pacific) are 2.93,0.47,and 0.94 mm/Ma.  相似文献   
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