Mainstream media play a crucial role in constructing the cultural memory of a city.This study used 319 short videos released by“Hi Chengdu,”a new media product of Chengdu Radio and Television,as samples.Based on the...Mainstream media play a crucial role in constructing the cultural memory of a city.This study used 319 short videos released by“Hi Chengdu,”a new media product of Chengdu Radio and Television,as samples.Based on the grounded theory,a research framework encompassing“content,technology,and discourse”was established to explore the paths through which mainstream media construct the cultural memory.Regarding content,this paper emphasized temporal and spatial contexts and urban spaces,delving deep into the themes of the cultural memory and vehicles for it.In terms of technology,this paper discussed the practice of leveraging audio/visual-mode discourse to stitch together the impressions of a city and evoke emotional resonance to create a“flow”of memory.As for discourse,this paper looked at the performance of a communication ritual to frame concepts and shape urban identity.It is essential to break free from conventional thinking and leverage local culture as the primary driving force to further boost a city’s productivity,in order to excel in cultural communication.展开更多
Broadcasting gateway equipment generally uses a method of simply switching to a spare input stream when a failure occurs in a main input stream.However,when the transmission environment is unstable,problems such as re...Broadcasting gateway equipment generally uses a method of simply switching to a spare input stream when a failure occurs in a main input stream.However,when the transmission environment is unstable,problems such as reduction in the lifespan of equipment due to frequent switching and interruption,delay,and stoppage of services may occur.Therefore,applying a machine learning(ML)method,which is possible to automatically judge and classify network-related service anomaly,and switch multi-input signals without dropping or changing signals by predicting or quickly determining the time of error occurrence for smooth stream switching when there are problems such as transmission errors,is required.In this paper,we propose an intelligent packet switching method based on the ML method of classification,which is one of the supervised learning methods,that presents the risk level of abnormal multi-stream occurring in broadcasting gateway equipment based on data.Furthermore,we subdivide the risk levels obtained from classification techniques into probabilities and then derive vectorized representative values for each attribute value of the collected input data and continuously update them.The obtained reference vector value is used for switching judgment through the cosine similarity value between input data obtained when a dangerous situation occurs.In the broadcasting gateway equipment to which the proposed method is applied,it is possible to perform more stable and smarter switching than before by solving problems of reliability and broadcasting accidents of the equipment and can maintain stable video streaming as well.展开更多
Taking the National Experimental Teaching Demonstration Center of the Central Academy of Drama as an example,this article explores the construction and development of the National Experimental Teaching Demonstration C...Taking the National Experimental Teaching Demonstration Center of the Central Academy of Drama as an example,this article explores the construction and development of the National Experimental Teaching Demonstration Center for the practical teaching of drama and film and television disciplines.The article first introduces the background and importance of the demonstration center and then analyzes in depth the construction content and achievements of the demonstration center from four aspects:practical teaching philosophy,practical teaching system,practical teaching resources,and practical teaching effects.Finally,the article summarizes the experience and shortcomings of the demonstration center and proposes future development directions and suggestions.展开更多
当前数字电视发展速度很快,在个别地方甚至已经开始逐步普及,但是由于经济,技术等原因,在电视广播领域,模拟电视广播还将在很长一段时间内占据主导地位.在不改变现有模拟电视广播系统的条件下,如何有效的提高视频图像的质量已经成为一...当前数字电视发展速度很快,在个别地方甚至已经开始逐步普及,但是由于经济,技术等原因,在电视广播领域,模拟电视广播还将在很长一段时间内占据主导地位.在不改变现有模拟电视广播系统的条件下,如何有效的提高视频图像的质量已经成为一个热门的话题.将数字解码技术用在改善传统的模拟电视广播质量上,用数字方法提高模拟视频的图像质量,和传统的模拟视频解码相比,解码性能较高,并且为后端数字视频处理提供优质视频源.对于模拟视频信号的解码系统,亮色分离和色度解调是视频解码的两个关键点.对于NTSC(national television system committee)制式的视频解码,当前已有的几种优质的解码算法中,亮色分离均用3D自适应梳状滤波,色度解调采用数字锁相环,均能实现优质的视频解码效果,但其共同点为算法复杂,硬件实现难度大,成本高.本文在深入研究NTSC制式编解码的基础上提出一种精简高效的数字解码方法,将传统的NTSC制式彩色全电视信号,通过高速高分辨率的FPGA(field programmable gate array)硬件采集系统转化为数字视频流,提出一种改进型自适应2D梳状滤波器进行亮色分离,相比3D梳状滤波器,在满足视频解码质量需要的基础上大幅度简化了算法,利用相位估计法恢复色同步副载波,相比数字锁相环,除简化了算法外,还避免了数字锁相环偶尔失锁的可能,且对前端视频数字化采集的采样率无特殊要求.解码后的视频分量信号可在数字视频设备上直接显示,并可为后端的数字视频图像处理等提供优质的数字视频信号源.该解码算法在MATLAB上模拟,具有解码后的图像质量良好,运算速度快和解码系统精简等特点.展开更多
A television based multistatic radar system is described. The commercial television transmitter is used as the illuminator in the multistatic radar system. The reflected commercial television signals are measured by ...A television based multistatic radar system is described. The commercial television transmitter is used as the illuminator in the multistatic radar system. The reflected commercial television signals are measured by an array of sensors. A data processing scheme is developed that adapts to the poor signal processing ability. The innovation is focused on the construction of the observation space, which could reduce the non linearity error. The new method leads to better system stability than the traditional one. Monte Carlo simulation is utilized and compared with the traditional method.展开更多
Entertainment shows in the Arab world stand for something larger than pointless amusements shaped by producers to follow a set of marketing rules. They may be, at times, trivial or foolish but they always address the ...Entertainment shows in the Arab world stand for something larger than pointless amusements shaped by producers to follow a set of marketing rules. They may be, at times, trivial or foolish but they always address the uncertainties of collective and individual identities in a region boiling with struggles over meanings and knowledge. Because of the liberalization of the Arab television industries, they have successfully integrated the global market and are now elaborating new conventions inspired by both oriental and western references. In this paper, it will explore the depiction of Arab youth as a social construct meant to challenge the nationalistic representation of this ambiguous social category while, at the same time, promoting the regional debate over modernity, Arabism, and change.展开更多
请比较以下两个段落,哪个段落写得更好,表述内容更清楚?A. Fast-food dining, even within the home, is becoming a way of life for too many of us. Work schedules, individual organized activities, and television all limit the...请比较以下两个段落,哪个段落写得更好,表述内容更清楚?A. Fast-food dining, even within the home, is becoming a way of life for too many of us. Work schedules, individual organized activities, and television all limit the quantity and quality of mealtime interaction.展开更多
Background: Given the low levels of physical activity(PA) among adolescent girls in the US, there is a need to identify tools to motivate increased PA. Although there is limited evidence that adolescents transfer PA f...Background: Given the low levels of physical activity(PA) among adolescent girls in the US, there is a need to identify tools to motivate increased PA. Although there is limited evidence that adolescents transfer PA from one context to another, exergames(i.e., video games that require gross motor activity) may act as a gateway to promote overall PA outside game play. The purpose of this study was to examine potential transfer effects(i.e., influences on external behaviors and psychological constructs) of a 12-week exergaming intervention on adolescent girls' PA, screen time,and self-efficacy toward PA, as well as the intrinsic motivation of exergaming.Methods: Participants were 37 girls aged 14–18 years(65% African American, 35% white) who were overweight or obese(body mass index ≥ 85 th percentile) and were recruited from the community via school, physicians, news media, and social media websites. Adolescents were randomly assigned to a 12-week group exergaming intervention(thirty-six 60 min sessions of group-based dance exergaming in a research laboratory using Kinect for Xbox360(Microsoft Corporation, Redmond, WA, USA)) or to a no-treatment control group. Outcome variables included objectively measured PA(total) and self-reported leisure-time PA(discretionary time only) 1 week before vs. 1 week after the intervention; selected type and intensity of PA when placed in a gym setting for 30 min("cardio free choice"); screen time; self-efficacy toward PA; and intrinsic motivation toward exergaming.Results: Attendance at the exergaming sessions was high(80%). Compared with the control group, the intervention group self-reported an increase in PA(p = 0.035) and fewer hours watching television or videos(p = 0.01) after the intervention, but there were no significant differences in sedentary, light, moderate, or vigorous PA measured by accelerometry. The intervention group significantly improved self-efficacy toward PA(p = 0.028). The intervention group highly rated intrinsic motivation toward exergaming.Conclusion: Exergaming for 12 weeks was associated with positive impacts on adolescent girls' self-reported PA, television viewing, self-efficacy,and intrinsic motivation. Future research is warranted to leverage exergames as an enjoyable, motivating, and effective PA tool.展开更多
Objective To test the effect of television viewing on pediatric obesity in urban China. Methods Stratified multistage cluster random sampling method was used for subjects selection. Nine thousand three hundred and fif...Objective To test the effect of television viewing on pediatric obesity in urban China. Methods Stratified multistage cluster random sampling method was used for subjects selection. Nine thousand three hundred and fifty-six children, as well as their parents, were investigated. Questionnaire survey was used for data collection. Children's weights and heights were measured in the clinic of the investigated kindergartens or schools by trained investigators following the standardized procedure. Results The percentages of children and adolescents who watched television less than 1 h, 1-2 h, 2-3 h and more than 3 h daily were 32.5%, 46.0%, 15.4% and 6.1%, respectively, while the prevalence of obesity was 10.9%, 11.8%, 13.2% and 15.1%, respectively. Each hourly increment of television viewing was associated with 1 %-2% increase in the prevalence of obesity. Conclusions Time spent watching television is directly related to an increase risk of obesity, television viewing time is an independent factor for pediatric obesity.展开更多
Objective The purpose of this study was to explore how obesity was covered in television news in China, including the trends over time and the characteristics of obesity-related news. Methods The frame analysis was ad...Objective The purpose of this study was to explore how obesity was covered in television news in China, including the trends over time and the characteristics of obesity-related news. Methods The frame analysis was adopted to assess the content of obesity-related news broadcasted in China Central Television (CCTV) from 1982 to 2009. To investigate the characteristics of the news, the obesity-related news was divided into subgroups according to populations concerned, as well as the period in which the news was broadcasted. The differences between subgroups were examined. Results A total of 1 599 pieces of news reported obesity, in which 1 278 pieces (79.92%) aired in "wealthy" period (2006-2009). More news was concerned with adults (1 134, 70.92%). "Individual behavior" dominated most of the cause frames (389, 24.33%), solution frames (522, 32.65%), and responsibility frames (860, 53.78%). There was more news mentioning individual factors in news aired in "wealthy" period and news concerning children. The coverage of social-structure causes was higher in news concerning children, while the coverage of social-structure solutions was higher in news concerning children and news aired in "wealthy" period. Conclusion Although the coverage of obesity was modest, it showed an incremental trend as the economy grew. Obesity was mostly depicted as an individual problem in terms of responsibility, causes and solutions.展开更多
The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relati...The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relative positions and the reasons for the side peaks are analyzed and a new algorithm for side peaks suppression is proposed in this paper. The algorithm, in consideration of the characteristics of the structure of the frame, can eliminate the side peaks completely in the valid Doppler observation interval by setting the reference signals to zero at equal intervals. Both the simulative and experimental results show that this algorithm can improve the performance of target detection of the passive radar based on DTTB signal.展开更多
With the great commercial success of several IPTV (internet protocal television) applications, PPLive has received more and more attention from both industry and academia. At present, PPLive system is one of the most ...With the great commercial success of several IPTV (internet protocal television) applications, PPLive has received more and more attention from both industry and academia. At present, PPLive system is one of the most popular instances of IPTV applications which attract a large number of users across the globe; however, the dramatic rise in popularity makes it more likely to become a vulnerable target. The main contribution of this work is twofold. Firstly, a dedicated distributed crawler system was proposed and its crawling performance was analyzed, which was used to evaluate the impact of pollution attack in P2P live streaming system. The measurement results reveal that the crawler system with distributed architecture could capture PPLive overlay snapshots with more efficient way than previous crawlers. To the best of our knowledge, our study work is the first to employ distributed architecture idea to design crawler system and discuss the crawling performance of capturing accurate overlay snapshots for P2P live streaming system. Secondly, a feasible and effective pollution architecture was proposed to deploy content pollution attack in a real-world P2P live streaming system called PPLive, and deeply evaluate the impact of pollution attack from following five aspects:dynamic evolution of participating users, user lifetime characteristics, user connectivity-performance, dynamic evolution of uploading polluted chunks and dynamic evolution of pollution ratio. Specifically, the experiment results show that a single polluter is capable of compromising all the system and its destructiveness is severe.展开更多
As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliabilit...As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme.展开更多
In this paper, I described the methods that I used for the creation of Xlets, which are Java applets that are developed for the IDTV environment;and the methods for online data retrieval and processing that I utilized...In this paper, I described the methods that I used for the creation of Xlets, which are Java applets that are developed for the IDTV environment;and the methods for online data retrieval and processing that I utilized in these Xlets. The themes that I chose for the Xlets of the IDTV applications are Earthquake and Tsunami Early Warning;Recent Seismic Activity Report;and Emergency Services. The online data regarding the Recent Seismic Activity Report application are provided by the Kandilli Observatory and Earthquake Research Institute (KOERI) of Bogazici University in Istanbul;while the online data for the Earthquake and Tsunami Early Warning and the Emergency Services applications are provided by the Godoro website which I used for storing (and retrieving by the Xlets) the earthquake and tsunami early warning simulation data, and the DVB network subscriber data (such as name and address information) for utilizing in the Emergency Services (Police, Ambulance and Fire Department) application. I have focused on the methodologies to use digital television as an efficient medium to convey timely and useful information regarding seismic warning data to the public, which forms the main research topic of this paper.展开更多
In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting fun...In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting function, which is obtained by block-based moving object detection and motion estimation with variable block sizes. Experimental results show that the proposed algorithm improves the temporal consistency of the depth video and reduces by about 38% both the flickering artefact in the synthesized view and the number of coding bits for depth video coding.展开更多
学英语的人对When-词并不觉得陌生,但when有一用法却很特殊且多数词典均未涉及。请看下列句子: 1.I was thinking of this when I heard my name called. 2.He was just about to dive when he saw the shark. 3.I was watching the tel...学英语的人对When-词并不觉得陌生,但when有一用法却很特殊且多数词典均未涉及。请看下列句子: 1.I was thinking of this when I heard my name called. 2.He was just about to dive when he saw the shark. 3.I was watching the television,when suddenly the lights went out. 4.One evening little Hans was sitting near the fire whne he heard a loud knock at the door. 这些句子里的when其用法有哪些特殊之处?本文将从语义、语法和汉译处理三方面分析其特征。为分析方便起见,下文将位于when前面的分句叫做when前分句(pre—when clause),简称when前句,将位于when后面的分句叫做when后分句(post—when clause),简称when后句。展开更多
With the development of the economy,film and television education has gradually received more and more attention.With the rapid development of new media technologies,there are still some problems in film and televisio...With the development of the economy,film and television education has gradually received more and more attention.With the rapid development of new media technologies,there are still some problems in film and television education in the new media environment.This paper mainly analyzes the problems faced by film and television education in the new media environment,and the development direction of film and television education in the new media era,and explores the forms of film and television education and film industry integration.展开更多
To meet the challenges of ubiquitous computing, ambient technologies and an increasingly older population, researchers have been trying to break away from traditional modes of interaction. A history of studies over th...To meet the challenges of ubiquitous computing, ambient technologies and an increasingly older population, researchers have been trying to break away from traditional modes of interaction. A history of studies over the past 30 years reported in this paper suggests that Gesture Controlled User Interfaces (GCUI) now provide realistic and affordable opportunities, which may be appropriate for older and disabled people. We have developed a GCUI prototype application, called Open Gesture, to help users carry out everyday activities such as making phone calls, controlling their television and performing mathematical calculations. Open Gesture uses simple hand gestures to perform a diverse range of tasks via a television interface. This paper describes Open Gesture and reports its usability evaluation. We conclude that this inclusive technology offers some potential to improve the independence and quality of life of older and disabled users along with general users, although there remain significant challenges to be overcome.展开更多
Phrasal verbs,such as look after,look forward to,look through,etc.,account for a large per-centage in English vocabulary,and they are even more difficult than single words for.English learn-ers to learn.For one reason...Phrasal verbs,such as look after,look forward to,look through,etc.,account for a large per-centage in English vocabulary,and they are even more difficult than single words for.English learn-ers to learn.For one reason,they are of a large quantity by formation.By looking throughWebster’s Third New International Dictionary(1961),we can see how colorful the forms of展开更多
文摘Mainstream media play a crucial role in constructing the cultural memory of a city.This study used 319 short videos released by“Hi Chengdu,”a new media product of Chengdu Radio and Television,as samples.Based on the grounded theory,a research framework encompassing“content,technology,and discourse”was established to explore the paths through which mainstream media construct the cultural memory.Regarding content,this paper emphasized temporal and spatial contexts and urban spaces,delving deep into the themes of the cultural memory and vehicles for it.In terms of technology,this paper discussed the practice of leveraging audio/visual-mode discourse to stitch together the impressions of a city and evoke emotional resonance to create a“flow”of memory.As for discourse,this paper looked at the performance of a communication ritual to frame concepts and shape urban identity.It is essential to break free from conventional thinking and leverage local culture as the primary driving force to further boost a city’s productivity,in order to excel in cultural communication.
基金This work was supported by a research grant from Seoul Women’s University(2023-0183).
文摘Broadcasting gateway equipment generally uses a method of simply switching to a spare input stream when a failure occurs in a main input stream.However,when the transmission environment is unstable,problems such as reduction in the lifespan of equipment due to frequent switching and interruption,delay,and stoppage of services may occur.Therefore,applying a machine learning(ML)method,which is possible to automatically judge and classify network-related service anomaly,and switch multi-input signals without dropping or changing signals by predicting or quickly determining the time of error occurrence for smooth stream switching when there are problems such as transmission errors,is required.In this paper,we propose an intelligent packet switching method based on the ML method of classification,which is one of the supervised learning methods,that presents the risk level of abnormal multi-stream occurring in broadcasting gateway equipment based on data.Furthermore,we subdivide the risk levels obtained from classification techniques into probabilities and then derive vectorized representative values for each attribute value of the collected input data and continuously update them.The obtained reference vector value is used for switching judgment through the cosine similarity value between input data obtained when a dangerous situation occurs.In the broadcasting gateway equipment to which the proposed method is applied,it is possible to perform more stable and smarter switching than before by solving problems of reliability and broadcasting accidents of the equipment and can maintain stable video streaming as well.
文摘Taking the National Experimental Teaching Demonstration Center of the Central Academy of Drama as an example,this article explores the construction and development of the National Experimental Teaching Demonstration Center for the practical teaching of drama and film and television disciplines.The article first introduces the background and importance of the demonstration center and then analyzes in depth the construction content and achievements of the demonstration center from four aspects:practical teaching philosophy,practical teaching system,practical teaching resources,and practical teaching effects.Finally,the article summarizes the experience and shortcomings of the demonstration center and proposes future development directions and suggestions.
文摘当前数字电视发展速度很快,在个别地方甚至已经开始逐步普及,但是由于经济,技术等原因,在电视广播领域,模拟电视广播还将在很长一段时间内占据主导地位.在不改变现有模拟电视广播系统的条件下,如何有效的提高视频图像的质量已经成为一个热门的话题.将数字解码技术用在改善传统的模拟电视广播质量上,用数字方法提高模拟视频的图像质量,和传统的模拟视频解码相比,解码性能较高,并且为后端数字视频处理提供优质视频源.对于模拟视频信号的解码系统,亮色分离和色度解调是视频解码的两个关键点.对于NTSC(national television system committee)制式的视频解码,当前已有的几种优质的解码算法中,亮色分离均用3D自适应梳状滤波,色度解调采用数字锁相环,均能实现优质的视频解码效果,但其共同点为算法复杂,硬件实现难度大,成本高.本文在深入研究NTSC制式编解码的基础上提出一种精简高效的数字解码方法,将传统的NTSC制式彩色全电视信号,通过高速高分辨率的FPGA(field programmable gate array)硬件采集系统转化为数字视频流,提出一种改进型自适应2D梳状滤波器进行亮色分离,相比3D梳状滤波器,在满足视频解码质量需要的基础上大幅度简化了算法,利用相位估计法恢复色同步副载波,相比数字锁相环,除简化了算法外,还避免了数字锁相环偶尔失锁的可能,且对前端视频数字化采集的采样率无特殊要求.解码后的视频分量信号可在数字视频设备上直接显示,并可为后端的数字视频图像处理等提供优质的数字视频信号源.该解码算法在MATLAB上模拟,具有解码后的图像质量良好,运算速度快和解码系统精简等特点.
文摘A television based multistatic radar system is described. The commercial television transmitter is used as the illuminator in the multistatic radar system. The reflected commercial television signals are measured by an array of sensors. A data processing scheme is developed that adapts to the poor signal processing ability. The innovation is focused on the construction of the observation space, which could reduce the non linearity error. The new method leads to better system stability than the traditional one. Monte Carlo simulation is utilized and compared with the traditional method.
文摘Entertainment shows in the Arab world stand for something larger than pointless amusements shaped by producers to follow a set of marketing rules. They may be, at times, trivial or foolish but they always address the uncertainties of collective and individual identities in a region boiling with struggles over meanings and knowledge. Because of the liberalization of the Arab television industries, they have successfully integrated the global market and are now elaborating new conventions inspired by both oriental and western references. In this paper, it will explore the depiction of Arab youth as a social construct meant to challenge the nationalistic representation of this ambiguous social category while, at the same time, promoting the regional debate over modernity, Arabism, and change.
文摘请比较以下两个段落,哪个段落写得更好,表述内容更清楚?A. Fast-food dining, even within the home, is becoming a way of life for too many of us. Work schedules, individual organized activities, and television all limit the quantity and quality of mealtime interaction.
基金AES and PTK are supported,in part,by the U54 GM104940 grant from the National Institute of General Medical Sciences of the US National Institutes of Health,which funds the Louisiana Clinical&Translational Science CenterPTK is supported,in part,by the Marie Edana Corcoran Endowed Chair in Pediatric Obesity and Diabetespartially supported by Nutrition Obesity Research Center Grant#P30DK072476 entitled“Nutritional Programming:Environmental and Molecular Interactions”
文摘Background: Given the low levels of physical activity(PA) among adolescent girls in the US, there is a need to identify tools to motivate increased PA. Although there is limited evidence that adolescents transfer PA from one context to another, exergames(i.e., video games that require gross motor activity) may act as a gateway to promote overall PA outside game play. The purpose of this study was to examine potential transfer effects(i.e., influences on external behaviors and psychological constructs) of a 12-week exergaming intervention on adolescent girls' PA, screen time,and self-efficacy toward PA, as well as the intrinsic motivation of exergaming.Methods: Participants were 37 girls aged 14–18 years(65% African American, 35% white) who were overweight or obese(body mass index ≥ 85 th percentile) and were recruited from the community via school, physicians, news media, and social media websites. Adolescents were randomly assigned to a 12-week group exergaming intervention(thirty-six 60 min sessions of group-based dance exergaming in a research laboratory using Kinect for Xbox360(Microsoft Corporation, Redmond, WA, USA)) or to a no-treatment control group. Outcome variables included objectively measured PA(total) and self-reported leisure-time PA(discretionary time only) 1 week before vs. 1 week after the intervention; selected type and intensity of PA when placed in a gym setting for 30 min("cardio free choice"); screen time; self-efficacy toward PA; and intrinsic motivation toward exergaming.Results: Attendance at the exergaming sessions was high(80%). Compared with the control group, the intervention group self-reported an increase in PA(p = 0.035) and fewer hours watching television or videos(p = 0.01) after the intervention, but there were no significant differences in sedentary, light, moderate, or vigorous PA measured by accelerometry. The intervention group significantly improved self-efficacy toward PA(p = 0.028). The intervention group highly rated intrinsic motivation toward exergaming.Conclusion: Exergaming for 12 weeks was associated with positive impacts on adolescent girls' self-reported PA, television viewing, self-efficacy,and intrinsic motivation. Future research is warranted to leverage exergames as an enjoyable, motivating, and effective PA tool.
基金This research was funded by "Danone Institute China Diet Nutrition Research & Communication Grant".
文摘Objective To test the effect of television viewing on pediatric obesity in urban China. Methods Stratified multistage cluster random sampling method was used for subjects selection. Nine thousand three hundred and fifty-six children, as well as their parents, were investigated. Questionnaire survey was used for data collection. Children's weights and heights were measured in the clinic of the investigated kindergartens or schools by trained investigators following the standardized procedure. Results The percentages of children and adolescents who watched television less than 1 h, 1-2 h, 2-3 h and more than 3 h daily were 32.5%, 46.0%, 15.4% and 6.1%, respectively, while the prevalence of obesity was 10.9%, 11.8%, 13.2% and 15.1%, respectively. Each hourly increment of television viewing was associated with 1 %-2% increase in the prevalence of obesity. Conclusions Time spent watching television is directly related to an increase risk of obesity, television viewing time is an independent factor for pediatric obesity.
文摘Objective The purpose of this study was to explore how obesity was covered in television news in China, including the trends over time and the characteristics of obesity-related news. Methods The frame analysis was adopted to assess the content of obesity-related news broadcasted in China Central Television (CCTV) from 1982 to 2009. To investigate the characteristics of the news, the obesity-related news was divided into subgroups according to populations concerned, as well as the period in which the news was broadcasted. The differences between subgroups were examined. Results A total of 1 599 pieces of news reported obesity, in which 1 278 pieces (79.92%) aired in "wealthy" period (2006-2009). More news was concerned with adults (1 134, 70.92%). "Individual behavior" dominated most of the cause frames (389, 24.33%), solution frames (522, 32.65%), and responsibility frames (860, 53.78%). There was more news mentioning individual factors in news aired in "wealthy" period and news concerning children. The coverage of social-structure causes was higher in news concerning children, while the coverage of social-structure solutions was higher in news concerning children and news aired in "wealthy" period. Conclusion Although the coverage of obesity was modest, it showed an incremental trend as the economy grew. Obesity was mostly depicted as an individual problem in terms of responsibility, causes and solutions.
文摘The ambiguity function of Chinese standard Digital Television Terrestrial Broadcasting (DTTB) signals for passive radar contains one main peak and many side peaks. The side peaks may cause the false alarms. The relative positions and the reasons for the side peaks are analyzed and a new algorithm for side peaks suppression is proposed in this paper. The algorithm, in consideration of the characteristics of the structure of the frame, can eliminate the side peaks completely in the valid Doppler observation interval by setting the reference signals to zero at equal intervals. Both the simulative and experimental results show that this algorithm can improve the performance of target detection of the passive radar based on DTTB signal.
基金Project(2007CB311106) supported by National Basic Research Program of ChinaProject(242-2009A82) supported by National Information Security Special Plan Program of China
文摘With the great commercial success of several IPTV (internet protocal television) applications, PPLive has received more and more attention from both industry and academia. At present, PPLive system is one of the most popular instances of IPTV applications which attract a large number of users across the globe; however, the dramatic rise in popularity makes it more likely to become a vulnerable target. The main contribution of this work is twofold. Firstly, a dedicated distributed crawler system was proposed and its crawling performance was analyzed, which was used to evaluate the impact of pollution attack in P2P live streaming system. The measurement results reveal that the crawler system with distributed architecture could capture PPLive overlay snapshots with more efficient way than previous crawlers. To the best of our knowledge, our study work is the first to employ distributed architecture idea to design crawler system and discuss the crawling performance of capturing accurate overlay snapshots for P2P live streaming system. Secondly, a feasible and effective pollution architecture was proposed to deploy content pollution attack in a real-world P2P live streaming system called PPLive, and deeply evaluate the impact of pollution attack from following five aspects:dynamic evolution of participating users, user lifetime characteristics, user connectivity-performance, dynamic evolution of uploading polluted chunks and dynamic evolution of pollution ratio. Specifically, the experiment results show that a single polluter is capable of compromising all the system and its destructiveness is severe.
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant 61931015the Peng Cheng Laboratory under Grant PCL2021A10+1 种基金the Science,Technology and Innovation Commission of Shenzhen Municipality(No.JSGG20201103095805015)sponsored by Tsinghua University-Yunnan Mobile Digital TV Company Ltd.,Joint Research Center(JCICBN)。
文摘As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme.
文摘In this paper, I described the methods that I used for the creation of Xlets, which are Java applets that are developed for the IDTV environment;and the methods for online data retrieval and processing that I utilized in these Xlets. The themes that I chose for the Xlets of the IDTV applications are Earthquake and Tsunami Early Warning;Recent Seismic Activity Report;and Emergency Services. The online data regarding the Recent Seismic Activity Report application are provided by the Kandilli Observatory and Earthquake Research Institute (KOERI) of Bogazici University in Istanbul;while the online data for the Earthquake and Tsunami Early Warning and the Emergency Services applications are provided by the Godoro website which I used for storing (and retrieving by the Xlets) the earthquake and tsunami early warning simulation data, and the DVB network subscriber data (such as name and address information) for utilizing in the Emergency Services (Police, Ambulance and Fire Department) application. I have focused on the methodologies to use digital television as an efficient medium to convey timely and useful information regarding seismic warning data to the public, which forms the main research topic of this paper.
基金supported by the National Research Foundation of Korea Grant funded by the Korea Ministry of Science and Technology under Grant No. 2012-0009228
文摘In this paper, we propose a new algorithm for temporally consistent depth map estimation to generate three-dimensional video. The proposed algorithm adaptively computes the matching cost using a temporal weighting function, which is obtained by block-based moving object detection and motion estimation with variable block sizes. Experimental results show that the proposed algorithm improves the temporal consistency of the depth video and reduces by about 38% both the flickering artefact in the synthesized view and the number of coding bits for depth video coding.
文摘学英语的人对When-词并不觉得陌生,但when有一用法却很特殊且多数词典均未涉及。请看下列句子: 1.I was thinking of this when I heard my name called. 2.He was just about to dive when he saw the shark. 3.I was watching the television,when suddenly the lights went out. 4.One evening little Hans was sitting near the fire whne he heard a loud knock at the door. 这些句子里的when其用法有哪些特殊之处?本文将从语义、语法和汉译处理三方面分析其特征。为分析方便起见,下文将位于when前面的分句叫做when前分句(pre—when clause),简称when前句,将位于when后面的分句叫做when后分句(post—when clause),简称when后句。
文摘With the development of the economy,film and television education has gradually received more and more attention.With the rapid development of new media technologies,there are still some problems in film and television education in the new media environment.This paper mainly analyzes the problems faced by film and television education in the new media environment,and the development direction of film and television education in the new media era,and explores the forms of film and television education and film industry integration.
文摘To meet the challenges of ubiquitous computing, ambient technologies and an increasingly older population, researchers have been trying to break away from traditional modes of interaction. A history of studies over the past 30 years reported in this paper suggests that Gesture Controlled User Interfaces (GCUI) now provide realistic and affordable opportunities, which may be appropriate for older and disabled people. We have developed a GCUI prototype application, called Open Gesture, to help users carry out everyday activities such as making phone calls, controlling their television and performing mathematical calculations. Open Gesture uses simple hand gestures to perform a diverse range of tasks via a television interface. This paper describes Open Gesture and reports its usability evaluation. We conclude that this inclusive technology offers some potential to improve the independence and quality of life of older and disabled users along with general users, although there remain significant challenges to be overcome.
文摘Phrasal verbs,such as look after,look forward to,look through,etc.,account for a large per-centage in English vocabulary,and they are even more difficult than single words for.English learn-ers to learn.For one reason,they are of a large quantity by formation.By looking throughWebster’s Third New International Dictionary(1961),we can see how colorful the forms of