Intensity and phase statistics of multilook polarimetric andinterferometric SAR imagery

Polarimetric and interferometric SAR data are frequently multilook processed for speckle reduction and data compression. The statistical characteristics of multilook data are quite different from those of single-look data. The authors investigate the statistics of their intensity and phase. Probability density function (PDF's) of the multilook phase difference, magnitude of complex product, and intensity and amplitude ratios between two components of the scattering matrix are derived, and expressed in closed forms. The PDF's depend on the complex correlation coefficient and the number of looks. Comparisons of these theoretically derived PDF's are made to measurements from NASA/JPL AIRSAR data. The results of this paper can be applied to feature classification using polarimetric SAR and to the estimation of decorrelation effects of the interferometric SAR     

细腻、饱满、让家庭影院同样美声A.R.T MONOLITH-3.1喇叭线

前些日子,我收到一卷由代理商寄来杂志社测评用喇叭线。当打开线材的包装箱才发现这是一个来自意大利的新品牌,名叫A.R.T,型号为MONOLITH-3.1。由于线材是散线,长度很长,完全可以用于视听室内的家庭影院音箱系统布线。同时,散线最大的优势就是长度能够根据自己的需要进行购买,且购买同等长度的情况下,散线甚至可以裸线连接,从而省掉了接线端子,比成品线来得便宜。因此,非常适合用在家庭影院音箱系统又或者传统的Hi-Fi系统之中。关于家庭影院音箱的线材选用方面,有人认为家庭影院音箱对线材的要求不高,再加上绝大部分的发烧友都受到经济条件的限制,他们一般都不会采用售价几百块钱一米的发烧线材来进行布线。而事实上,使用高端的发烧线材确实会对整个系统的声音的提升起到帮助。这次我有这么一个难得的机会可以使用这些线材进行布线,当然要好好地试玩一番。     

Interactive neural-network-assisted screening. An economic assessment

OBJECTIVE: To apply clinical effectiveness estimates of interactive, neural network-assisted (INNA) screening to economic cervical cancer screening models to assess the economic impact of using this technology. STUDY DESIGN: Estimates of the sensitivity of INNA screening were drawn from a recently completed comprehensive synthesis of the INNA literature and applied to the Computer Model for Designing CANcer ConTROL Programs-based Cervical Cancer Screen economic model. The economic analysis was conducted from a modified payer perspective using costs borne by payers combined with patient deductibles and copayments. Costs of treating cervical cancer were updated to 1997 values using the medical care component of the Consumer Price Index. The model was run for a cohort of women starting at age 20 and screened on a triennial schedule through age 75. RESULTS: In the primary analysis (sensitivity of unassisted manual examination assumed to be 85%), the ratios found in this investigation varied from approximately $35,000 to $80,000 per life year saved, with the preponderance of ratios < $50,000 per life year saved. These results were sensitive to estimates of sensitivity of unassisted manual screening but not to estimates of treatment costs. CONCLUSION: This investigation applied accuracy data on INNA rescreening to a model of the cost-effectiveness of cervical cancer screening. The results support the use of INNA rescreening as an appropriate expenditure of resources to identify missed cases of cervical epithelial abnormalities and potential cervical cancer.     

小房间影院发烧友的重播利器——鉴赏Atlantic Technology(亚特兰大)1200家庭影院音箱系统

对于玩AV的发烧友来说,往往需要一间足够大的聆听空间才能容纳多只大型的音箱、多台放大器、大型的投影机以及投影幕等AV器材,从而获得专业电影院般震撼的音效。但是,对于只有小房间的消费者来说,这些条件或许对于他们来讲是遥不可及的事情。有见及此,以生产专业剧院扬声器为主的Atlantic Technology公司为此推出了一系列家用式的家庭影院音箱,其中1200音箱系统就是为了对应小房间用户而开发的音箱系统。该系统运用了8200e和6200e等旗舰产品的一些技术,使它拥有着优秀的声音     

更平衡、更稳重、更强劲 AudioQuest(线圣)CV-8DBS音箱线

使用导体:单支(PSC )精密高纯度光面铜导体×8长度:2.5m附件:银金属抛光布参考价格:7000元/对咨询电话:0571-88393776网址:www.audioquest.com优点:声音温暖、平衡度高,低频力度强劲,能量丰富,而且还附赠银金属抛光布,方便用家对插头进行清洁。期待:价格稍稍合理一些。     

丰富饱满的能量,快速敏捷的反应 XTZ 99W 12.18 ICE

XTZ推出的99W12.18 ICE低音炮实际上是在原来被动版99W12.18P的基础上内置了一台输出功率达515W的ICEPower放大模组而产生的。使用ICEPower放大模组的原因是取其优秀的低频特性以及超高的转换效能,在长时间工作下都能保持低发热量,对于需要处于长时间大功率状态下工作的超低音音箱来说是十分有利的。与此同时,合理的市场定价也令它在市场上占有相当的优势。