针对复杂非均匀水下环境中目标检测问题,提出了一种基于背景统计特性的鲁棒声呐恒虚警(Background Statistical Characteristics based Robust Sonar Target Constant False Alarm Ratio,BSCR-CFAR)检测算法。该算法将自动删除平均级检...针对复杂非均匀水下环境中目标检测问题,提出了一种基于背景统计特性的鲁棒声呐恒虚警(Background Statistical Characteristics based Robust Sonar Target Constant False Alarm Ratio,BSCR-CFAR)检测算法。该算法将自动删除平均级检测(Automatic Censored Mean Level Detection,ACMLD)和排序统计恒虚警(Order Statistic CFAR,OS-CFAR)检测算法引入可变指数恒虚警(Variability Index CFAR,VI-CFAR)检测算法中,并通过评估背景特性,自适应选择更匹配的CFAR检测方法。仿真和声呐实测数据分析结果表明,相比较单元平均恒虚警(Cell Average CFAR,CA-CFAR)、单元平均选大恒虚警(Greatest of CFAR,GO-CFAR)、单元平均选小恒虚警(Smallest of CFAR,SO-CFAR)和OS-CFAR、VI-CFAR等检测算法,该算法在混响边缘、混响区、单/多强离散干扰等典型非均匀背景下的恒虚警检测保持了良好的鲁棒性。展开更多
For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background mod...For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background model kept a sample of intensity values for each pixel in the image and used this sample to estimate the probability density function of the pixel intensity. The density function was estimated using a new Marr wavelet kernel density estimation technique. Since this approach was quite general, the model could approximate any distribution for the pixel intensity without any assumptions about the underlying distribution shape. The background and current frame were transformed in the binary discrete wavelet domain, and background subtraction was performed in each sub-band. After obtaining the foreground, shadow was eliminated by an edge detection method. Experimental results show that the proposed method produces good results with much lower computational complexity and effectively extracts the moving objects with accuracy ratio higher than 90%, indicating that the proposed method is an effective algorithm for intelligent transportation system.展开更多
Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a provin...Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a province located in a low-latitude plateau,this work analyzes the climatic characteristics and the corresponding large-scale circulation patterns related to the western North Pacific westward moving TCs(WMTCs).Its impacts on the rainfall in the Yunnan Plateau are studied.Results show that WMTCs happen almost every year,mainly from July to September.It shows a downward trend in decadal variation.Nearly the entire Yunnan area is affected by them but the eastern part experiences the most severe influences.Most of the WMTCs migrate from the South China Sea,primarily make landfall in Hainan and Guangdong and enter the Northern Bay.The tracks of these typhoons can be classified into five categories,in which the most significant impact results from those making landfall in Guangdong.All categories of the tropical cyclones can induce province-wide heavy rainfall in Yunnan.Super typhoons bring about the heaviest and most extensive rainfall over the low-latitude plateau while the associated circulation pattern is marked with a dominant 500 hPa meridional circulation at middle latitudes,an active monsoon depression and Intertropical Convection Zone(ITCZ) at low latitudes and a westward-located South Asia High at 100 hPa,which is favorable for tropical cyclones to travel westward.WMTCs tend to go westward into the interior part of China if the subtropical high extends its westernmost ridge point to the northeast of Yunnan,or expands its periphery anti-cyclonic circulation to the Tibetan Plateau,or merges with the Qinghai-Tibetan high.展开更多
The focus of this study is the critical analysis of data related to Hispanic males and criminality, Factors, such as marital status, income level, age, and police contact, are measureable entities that are at the core...The focus of this study is the critical analysis of data related to Hispanic males and criminality, Factors, such as marital status, income level, age, and police contact, are measureable entities that are at the core of the statistical ,analysis, A cross-disciplinary approach provides a cultural context for the statistical world of numbers, The socially conflicting terms of masculinity and maleness will lead to a discussion of macho behavior and criminaliW, Macho behavior, often interpreted as aggressive, may arouse police suspicion, In this case, the police will stop Hispanic males because of their behavior, not necessarily because they committed a crime, This study will show that the cycle of poverty prevents Hispanic males of low-income families from contacting with the police, whereas uneducated Hispanic males must confirm their masculinity in a criminal behavior, CriminaliW, often associated with violence as machismo, is the social over compensation for a male inferiority complex that finds its origin in the Spanish conquest of South America,展开更多
This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on ...This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on the skewness-kurtosis test. In the end, a multivariate Gaussian distribution mathematical expression of background clutter image is given.展开更多
文摘针对复杂非均匀水下环境中目标检测问题,提出了一种基于背景统计特性的鲁棒声呐恒虚警(Background Statistical Characteristics based Robust Sonar Target Constant False Alarm Ratio,BSCR-CFAR)检测算法。该算法将自动删除平均级检测(Automatic Censored Mean Level Detection,ACMLD)和排序统计恒虚警(Order Statistic CFAR,OS-CFAR)检测算法引入可变指数恒虚警(Variability Index CFAR,VI-CFAR)检测算法中,并通过评估背景特性,自适应选择更匹配的CFAR检测方法。仿真和声呐实测数据分析结果表明,相比较单元平均恒虚警(Cell Average CFAR,CA-CFAR)、单元平均选大恒虚警(Greatest of CFAR,GO-CFAR)、单元平均选小恒虚警(Smallest of CFAR,SO-CFAR)和OS-CFAR、VI-CFAR等检测算法,该算法在混响边缘、混响区、单/多强离散干扰等典型非均匀背景下的恒虚警检测保持了良好的鲁棒性。
基金Project(60772080) supported by the National Natural Science Foundation of ChinaProject(3240120) supported by Tianjin Subway Safety System, Honeywell Limited, China
文摘For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background model kept a sample of intensity values for each pixel in the image and used this sample to estimate the probability density function of the pixel intensity. The density function was estimated using a new Marr wavelet kernel density estimation technique. Since this approach was quite general, the model could approximate any distribution for the pixel intensity without any assumptions about the underlying distribution shape. The background and current frame were transformed in the binary discrete wavelet domain, and background subtraction was performed in each sub-band. After obtaining the foreground, shadow was eliminated by an edge detection method. Experimental results show that the proposed method produces good results with much lower computational complexity and effectively extracts the moving objects with accuracy ratio higher than 90%, indicating that the proposed method is an effective algorithm for intelligent transportation system.
基金Key National Project for Fundamental Research and Development (2009CB421504)National Science Foundation of China (40975032)Special Project for Forecasters in Yunnan Meteorological Bureau (YB200901)
文摘Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a province located in a low-latitude plateau,this work analyzes the climatic characteristics and the corresponding large-scale circulation patterns related to the western North Pacific westward moving TCs(WMTCs).Its impacts on the rainfall in the Yunnan Plateau are studied.Results show that WMTCs happen almost every year,mainly from July to September.It shows a downward trend in decadal variation.Nearly the entire Yunnan area is affected by them but the eastern part experiences the most severe influences.Most of the WMTCs migrate from the South China Sea,primarily make landfall in Hainan and Guangdong and enter the Northern Bay.The tracks of these typhoons can be classified into five categories,in which the most significant impact results from those making landfall in Guangdong.All categories of the tropical cyclones can induce province-wide heavy rainfall in Yunnan.Super typhoons bring about the heaviest and most extensive rainfall over the low-latitude plateau while the associated circulation pattern is marked with a dominant 500 hPa meridional circulation at middle latitudes,an active monsoon depression and Intertropical Convection Zone(ITCZ) at low latitudes and a westward-located South Asia High at 100 hPa,which is favorable for tropical cyclones to travel westward.WMTCs tend to go westward into the interior part of China if the subtropical high extends its westernmost ridge point to the northeast of Yunnan,or expands its periphery anti-cyclonic circulation to the Tibetan Plateau,or merges with the Qinghai-Tibetan high.
文摘The focus of this study is the critical analysis of data related to Hispanic males and criminality, Factors, such as marital status, income level, age, and police contact, are measureable entities that are at the core of the statistical ,analysis, A cross-disciplinary approach provides a cultural context for the statistical world of numbers, The socially conflicting terms of masculinity and maleness will lead to a discussion of macho behavior and criminaliW, Macho behavior, often interpreted as aggressive, may arouse police suspicion, In this case, the police will stop Hispanic males because of their behavior, not necessarily because they committed a crime, This study will show that the cycle of poverty prevents Hispanic males of low-income families from contacting with the police, whereas uneducated Hispanic males must confirm their masculinity in a criminal behavior, CriminaliW, often associated with violence as machismo, is the social over compensation for a male inferiority complex that finds its origin in the Spanish conquest of South America,
文摘This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on the skewness-kurtosis test. In the end, a multivariate Gaussian distribution mathematical expression of background clutter image is given.
