In this paper, the temporal different characteristics between the target and background pixels are used to detect dim moving targets in the slow-evolving complex background. A local and global variance filter on tempo...In this paper, the temporal different characteristics between the target and background pixels are used to detect dim moving targets in the slow-evolving complex background. A local and global variance filter on temporal profiles is presented that addresses the temporal characteristics of the target and background pixels to eliminate the large variation of background temporal profiles. Firstly, the temporal behaviors of different types of image pixels of practical infrared scenes are analyzed.Then, the new local and global variance filter is proposed. The baseline of the fluctuation level of background temporal profiles is obtained by using the local and global variance filter. The height of the target pulse signal is extracted by subtracting the baseline from the original temporal profiles. Finally, a new target detection criterion is designed. The proposed method is applied to detect dim and small targets in practical infrared sequence images. The experimental results show that the proposed algorithm has good detection performance for dim moving small targets in the complex background.展开更多
Twitter is a micro-blogging application, which is commonly used as a way for individuals to maintain social connections. Social scientists have also begun using Twitter as a data source for understanding more about hu...Twitter is a micro-blogging application, which is commonly used as a way for individuals to maintain social connections. Social scientists have also begun using Twitter as a data source for understanding more about human interactions. There is very little research about Twitter’s utility for monitoring health related attitudes, beliefs and behaviors. The purpose of this study was to examine the extent to which individuals tweeted about problem drinking, and to identify if such tweets corresponded with time periods when problem drinking was likely to occur. Data from this study came from tweets originating in one of 9 randomly selected states, one from each of the nine census geographies in the US. Twitter’s API was used to collect tweets during the month of October 2010, and again during the time period surrounding New Year’s Eve 2010. Keywords were selected which indicated problem-drinking behaviors, and tweets were coded for the presence or absence of these keywords. Twitter users were most likely to tweet about problem drinking on Friday, Saturday and Sunday during the hours from 10 pm to 2 am. Tweets originating during the New Year’s Eve holiday (0.53%) were twice as common when compared to tweets during weekends in the month of October (0.34%). Twitter may be a valid data source for social scientists, given that tweets about problem drinking corresponded with expected time periods of actual problem drinking. Furthermore, tweets that mention problem drinking may be problematic for public health if they establish incorrect normative beliefs that such behaviors are acceptable and expected. Social norms interventions may be an effective tool in correcting misperceptions related to problem drinking by informing Twitter followers that problem drinking behaveiors are not normative.展开更多
基金National Natural Science Foundation of China(61774120)
文摘In this paper, the temporal different characteristics between the target and background pixels are used to detect dim moving targets in the slow-evolving complex background. A local and global variance filter on temporal profiles is presented that addresses the temporal characteristics of the target and background pixels to eliminate the large variation of background temporal profiles. Firstly, the temporal behaviors of different types of image pixels of practical infrared scenes are analyzed.Then, the new local and global variance filter is proposed. The baseline of the fluctuation level of background temporal profiles is obtained by using the local and global variance filter. The height of the target pulse signal is extracted by subtracting the baseline from the original temporal profiles. Finally, a new target detection criterion is designed. The proposed method is applied to detect dim and small targets in practical infrared sequence images. The experimental results show that the proposed algorithm has good detection performance for dim moving small targets in the complex background.
文摘Twitter is a micro-blogging application, which is commonly used as a way for individuals to maintain social connections. Social scientists have also begun using Twitter as a data source for understanding more about human interactions. There is very little research about Twitter’s utility for monitoring health related attitudes, beliefs and behaviors. The purpose of this study was to examine the extent to which individuals tweeted about problem drinking, and to identify if such tweets corresponded with time periods when problem drinking was likely to occur. Data from this study came from tweets originating in one of 9 randomly selected states, one from each of the nine census geographies in the US. Twitter’s API was used to collect tweets during the month of October 2010, and again during the time period surrounding New Year’s Eve 2010. Keywords were selected which indicated problem-drinking behaviors, and tweets were coded for the presence or absence of these keywords. Twitter users were most likely to tweet about problem drinking on Friday, Saturday and Sunday during the hours from 10 pm to 2 am. Tweets originating during the New Year’s Eve holiday (0.53%) were twice as common when compared to tweets during weekends in the month of October (0.34%). Twitter may be a valid data source for social scientists, given that tweets about problem drinking corresponded with expected time periods of actual problem drinking. Furthermore, tweets that mention problem drinking may be problematic for public health if they establish incorrect normative beliefs that such behaviors are acceptable and expected. Social norms interventions may be an effective tool in correcting misperceptions related to problem drinking by informing Twitter followers that problem drinking behaveiors are not normative.
