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
In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interact...In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interaction design mode used is still mainly based on the interaction mode for young groups,and is not designed for elderly users.Therefore,a design method for optimizing the interaction interface of live broadcasting platform for elderly users was proposed in this study.Firstly,the case study method and Delphi expert survey method were used to determine the design needs of elderly users and the design mode was analysed.Secondly,the orthogonal design principle was used to design a test sample of the interactive interface of live broadcasting platform applicable for the elderly users,and then a user evaluation system was established to calculate the weights of the design elements using hierarchical analysis,and then the predictive relationship between the design mode of the interactive interface of live broadcasting platform and the elderly users was established by Quantitative Theory I.Finally,Genetic Algorithm was applied to generate the optimized design scheme.The results showed that the design method based on the Genetic Algorithm and the combination of Quantitative Theory can scientifically and effectively optimize the design of the interactive interface of the live broadcasting platform for the elderly users,and improve the experience of the elderly users.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
In order to improve the performance and reliability of the radio and televisio transmission system and prowide users with a better audiovisual experience,this paper first analyzes the advantages of microwave in radio ...In order to improve the performance and reliability of the radio and televisio transmission system and prowide users with a better audiovisual experience,this paper first analyzes the advantages of microwave in radio and television transmitters,and further elaborates the radio and television transmission system.Through the reasonable configuration and appication of microwave equipment,the performance and reliability of radio and television transmission system can be improved,and the stable transmission of radio and television signals can be ensured.展开更多
With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become widespread.Therefore,this study aims to investigate the wireless covert communication in the two...With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become widespread.Therefore,this study aims to investigate the wireless covert communication in the two-user cooperative multi-antenna broadcast channel.We focus on the issue that the deteriorated reliability and undetectability are mainly affected by the transmission power.To tackle this issue,we design a scheme based on beamforming to increase the reliability and undetectability of wireless covert communication in the multi-antenna broadcast channel.We first modeled and analyzed the cooperative multi-antenna broadcasting system,and put forward the target question.Then we use the SCA(successive convex approximation)algorithm to transform the target problem into a series of convex subproblems.Then the convex problems are solved and the covert channel capacity is calculated.In order to verify the effectiveness of the scheme,we conducted simulation verification.The simulation results show that the proposed beamforming scheme can effectively improve the reliability and undetectability of covert communication in multi-antenna broadcast channels.展开更多
Degraded broadcast channels(DBC) are a typical multiuser communication scenario, Semantic communications over DBC still lack in-depth research. In this paper, we design a semantic communications approach based on mult...Degraded broadcast channels(DBC) are a typical multiuser communication scenario, Semantic communications over DBC still lack in-depth research. In this paper, we design a semantic communications approach based on multi-user semantic fusion for wireless image transmission over DBC. The transmitter extracts semantic features for two users separately and then effectively fuses them for broadcasting by leveraging semantic similarity. Unlike traditional allocation of time, power, or bandwidth, the semantic fusion scheme can dynamically control the weight of the semantic features of the two users to balance their performance. Considering the different channel state information(CSI) of both users over DBC,a DBC-Aware method is developed that embeds the CSI of both users into the joint source-channel coding encoder and fusion module to adapt to the channel.Experimental results show that the proposed system outperforms the traditional broadcasting schemes.展开更多
We consider an image semantic communication system in a time-varying fading Gaussian MIMO channel,with a finite number of channel states.A deep learning-aided broadcast approach scheme is proposed to benefit the adapt...We consider an image semantic communication system in a time-varying fading Gaussian MIMO channel,with a finite number of channel states.A deep learning-aided broadcast approach scheme is proposed to benefit the adaptive semantic transmission in terms of different channel states.We combine the classic broadcast approach with the image transformer to implement this adaptive joint source and channel coding(JSCC)scheme.Specifically,we utilize the neural network(NN)to jointly optimize the hierarchical image compression and superposition code mapping within this scheme.The learned transformers and codebooks allow recovering of the image with an adaptive quality and low error rate at the receiver side,in each channel state.The simulation results exhibit our proposed scheme can dynamically adapt the coding to the current channel state and outperform some existing intelligent schemes with the fixed coding block.展开更多
In this paper, we conduct research on the development direction of traditional broadcast television movie media under background of new media and lnternet. In recent years, with the computer technology network communi...In this paper, we conduct research on the development direction of traditional broadcast television movie media under background of new media and lnternet. In recent years, with the computer technology network communication technology and constant innovation rapid development of digital technology, digital new media got rapid development. Under the digital new media industry has gradually become the core industry of 21 st century knowledge economy and the new economic growth point. But there are still some problems in the digital of new media development. How to treat these problems to take effective countermeasures is vital to healthy development of the new media. Our research proposes corresponding guidance and the perspective on the development orientation which acts as the paradigm and the guideline.展开更多
ADALM Pluto is a software-defined radio product.Based on theoretical analysis,this paper designs a Frequency Modulation(FM)broadcast receiving system using ADALM Pluto as a wireless receiver on the Simulink platform.T...ADALM Pluto is a software-defined radio product.Based on theoretical analysis,this paper designs a Frequency Modulation(FM)broadcast receiving system using ADALM Pluto as a wireless receiver on the Simulink platform.The simulation results show that the theoretical analysis is correct and the parameter settings are reasonable,and the Software-Defined Radio(SDR)has the characteristics of high performance,high ease of use,and low cost.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
In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. ...In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. By the learning ability of the NN and the closely approximate unknown function to any degree of desired accuracy,the input-output mapping relationship between coordinates and the measurement data of time of arrival (TOA) and time difference of arrival (TDOA) is established. A real-time learning algorithm based on the extended Kalman filter (EKF) is used to train the multilayer perceptron (MLP) network by treating the linkweights of a network as the states of the nonlinear dynamic system. Since the EKF-based learning algorithm approximately gives the minimum variance estimate of the linkweights,the convergence is improved in comparison with the backwards error propagation (BP) algorithm. Numerical results illustrate thatthe proposedalgorithmcanachieve enhanced accuracy,and the performance ofthe algorithmis betterthanthat of the BP-based NN algorithm and the least squares (LS) algorithm in the NLOS environments. Moreover,this location method does not depend on a particular distribution of the NLOS error and does not need line-of-sight ( LOS ) or NLOS identification.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
Wireless sensor networks (WSNs) consist of sensor nodes that broadcast a message within a network. Efficient broadcasting is a key requirement in sensor networks and has been a focal point of research over the last ...Wireless sensor networks (WSNs) consist of sensor nodes that broadcast a message within a network. Efficient broadcasting is a key requirement in sensor networks and has been a focal point of research over the last few years. There are many challenging tasks in the network, including redundancy control and sensor node localization that mainly depend on broadcasting. In this paper, we propose a broadcasting algorithm to control redundancy and improve localization (BACRIL) in WSNs. The proposed algorithm incorporates the benefits of the gossip protocol for optimizing message broadcasting within the network. Simulation results show a controlled level of redundancy, which is up to 57.6% if the number of sensor nodes deployed in a 500 m×500 m area are increased from 50 to 500.展开更多
In this paper, we propose a classical secret broadcasting and splitting joint protocol in a quantum scenario. With those genuinely entangled states, the boss can always broadcast some of his secrets and split some oth...In this paper, we propose a classical secret broadcasting and splitting joint protocol in a quantum scenario. With those genuinely entangled states, the boss can always broadcast some of his secrets and split some others to multi- receivers at the same time. The efficiency of the joint protocol is also compared with that of two separate ones which realise classical secret broadcasting and classical secret splitting respectively, and based on the comparison we can see the promising advantage of our joint protocol is that it can realise the two tasks more efficiently and more conveniently.展开更多
Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial ...Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.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
Broadcasting is a fundamental operation in any wireless networks, more so in wireless ad hoc sensor networks, where each sensor node has limited transmission range as well as battery power. Although broadcasting in wi...Broadcasting is a fundamental operation in any wireless networks, more so in wireless ad hoc sensor networks, where each sensor node has limited transmission range as well as battery power. Although broadcasting in wireless ad hoc sensor networks has many advantages but it can cause serious problems like-broadcast storm, which could cause a lot of contention, redundant retransmission, collision and most importantly, drain immense amount of energy from limited battery powered sensor nodes. In this work, our objective is to reduce the number of retransmission and energy consumption of sensor nodes by using the duty cycle property of wireless ad hoc sensor networks. We propose a preamble-based broadcasting technique for wireless ad hoc sensor networks. We show that in dense wireless ad hoc sensor networks a small size preamble can give maximum network-wide data dissemination rather than using the large preamble, which will only consume immense amount of energy during packet reception.展开更多
Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits....Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits. The normal digital TV receiver can only receive and decode the pay TV programs scrambled by one specific CAS. In this paper, the authors proposed a smartcard conditional access interface (SCAI) scheme in order to make the digital TV receiver be a common receiving platform independent of any specific CAS employed at the broadcasting head-end. As a result, it only needs to include a common condi-tional access software package (CCAP) without any requirement of hardware modification in the receiver. Comparison between the two mentioned DVB-CI-based schemes showed that the cost of such kind receiver is greatly reduced. The main design points of the proposed scheme and its reference implementation’s architecture are presented in this paper. This scheme is also one of the candidate national standards for Chinese digital TV broadcasting industry.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
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.
文摘In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interaction design mode used is still mainly based on the interaction mode for young groups,and is not designed for elderly users.Therefore,a design method for optimizing the interaction interface of live broadcasting platform for elderly users was proposed in this study.Firstly,the case study method and Delphi expert survey method were used to determine the design needs of elderly users and the design mode was analysed.Secondly,the orthogonal design principle was used to design a test sample of the interactive interface of live broadcasting platform applicable for the elderly users,and then a user evaluation system was established to calculate the weights of the design elements using hierarchical analysis,and then the predictive relationship between the design mode of the interactive interface of live broadcasting platform and the elderly users was established by Quantitative Theory I.Finally,Genetic Algorithm was applied to generate the optimized design scheme.The results showed that the design method based on the Genetic Algorithm and the combination of Quantitative Theory can scientifically and effectively optimize the design of the interactive interface of the live broadcasting platform for the elderly users,and improve the experience of the elderly users.
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In order to improve the performance and reliability of the radio and televisio transmission system and prowide users with a better audiovisual experience,this paper first analyzes the advantages of microwave in radio and television transmitters,and further elaborates the radio and television transmission system.Through the reasonable configuration and appication of microwave equipment,the performance and reliability of radio and television transmission system can be improved,and the stable transmission of radio and television signals can be ensured.
基金supported by the National Natural Science Foundation of China(Grants No.U1836104,61772281,61702235,61801073,61931004,62072250).
文摘With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become widespread.Therefore,this study aims to investigate the wireless covert communication in the two-user cooperative multi-antenna broadcast channel.We focus on the issue that the deteriorated reliability and undetectability are mainly affected by the transmission power.To tackle this issue,we design a scheme based on beamforming to increase the reliability and undetectability of wireless covert communication in the multi-antenna broadcast channel.We first modeled and analyzed the cooperative multi-antenna broadcasting system,and put forward the target question.Then we use the SCA(successive convex approximation)algorithm to transform the target problem into a series of convex subproblems.Then the convex problems are solved and the covert channel capacity is calculated.In order to verify the effectiveness of the scheme,we conducted simulation verification.The simulation results show that the proposed beamforming scheme can effectively improve the reliability and undetectability of covert communication in multi-antenna broadcast channels.
基金supported in part by National Key R&D Project of China (2023YFB2906201)the National Natural Science Foundation of China (62222111, 62125108 and 62431015)the Fundamental Research Funds for the Central Universities。
文摘Degraded broadcast channels(DBC) are a typical multiuser communication scenario, Semantic communications over DBC still lack in-depth research. In this paper, we design a semantic communications approach based on multi-user semantic fusion for wireless image transmission over DBC. The transmitter extracts semantic features for two users separately and then effectively fuses them for broadcasting by leveraging semantic similarity. Unlike traditional allocation of time, power, or bandwidth, the semantic fusion scheme can dynamically control the weight of the semantic features of the two users to balance their performance. Considering the different channel state information(CSI) of both users over DBC,a DBC-Aware method is developed that embeds the CSI of both users into the joint source-channel coding encoder and fusion module to adapt to the channel.Experimental results show that the proposed system outperforms the traditional broadcasting schemes.
基金supported in part by the National Key R&D Project of China under Grant 2020YFA0712300National Natural Science Foundation of China under Grant NSFC-62231022,12031011supported in part by the NSF of China under Grant 62125108。
文摘We consider an image semantic communication system in a time-varying fading Gaussian MIMO channel,with a finite number of channel states.A deep learning-aided broadcast approach scheme is proposed to benefit the adaptive semantic transmission in terms of different channel states.We combine the classic broadcast approach with the image transformer to implement this adaptive joint source and channel coding(JSCC)scheme.Specifically,we utilize the neural network(NN)to jointly optimize the hierarchical image compression and superposition code mapping within this scheme.The learned transformers and codebooks allow recovering of the image with an adaptive quality and low error rate at the receiver side,in each channel state.The simulation results exhibit our proposed scheme can dynamically adapt the coding to the current channel state and outperform some existing intelligent schemes with the fixed coding block.
文摘In this paper, we conduct research on the development direction of traditional broadcast television movie media under background of new media and lnternet. In recent years, with the computer technology network communication technology and constant innovation rapid development of digital technology, digital new media got rapid development. Under the digital new media industry has gradually become the core industry of 21 st century knowledge economy and the new economic growth point. But there are still some problems in the digital of new media development. How to treat these problems to take effective countermeasures is vital to healthy development of the new media. Our research proposes corresponding guidance and the perspective on the development orientation which acts as the paradigm and the guideline.
基金Jiangsu Excellent Engineer Education and Training Program 2.0 Professional Construction Project(Project No.46)Jiangsu University Brand Construction Project Phase II(Third Batch)Project(Project No.452)Teaching Construction and Reform Project of Sanjiang University(Project No.J23007).
文摘ADALM Pluto is a software-defined radio product.Based on theoretical analysis,this paper designs a Frequency Modulation(FM)broadcast receiving system using ADALM Pluto as a wireless receiver on the Simulink platform.The simulation results show that the theoretical analysis is correct and the parameter settings are reasonable,and the Software-Defined Radio(SDR)has the characteristics of high performance,high ease of use,and low cost.
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.
基金The National High Technology Research and Development Program of China (863 Program) (No.2008AA01Z227)the Cultivatable Fund of the Key Scientific and Technical Innovation Project of Ministry of Education of China (No.706028)
文摘In order to enhance the accuracy and reliability of wireless location under non-line-of-sight (NLOS) environments,a novel neural network (NN) location approach using the digital broadcasting signals is presented. By the learning ability of the NN and the closely approximate unknown function to any degree of desired accuracy,the input-output mapping relationship between coordinates and the measurement data of time of arrival (TOA) and time difference of arrival (TDOA) is established. A real-time learning algorithm based on the extended Kalman filter (EKF) is used to train the multilayer perceptron (MLP) network by treating the linkweights of a network as the states of the nonlinear dynamic system. Since the EKF-based learning algorithm approximately gives the minimum variance estimate of the linkweights,the convergence is improved in comparison with the backwards error propagation (BP) algorithm. Numerical results illustrate thatthe proposedalgorithmcanachieve enhanced accuracy,and the performance ofthe algorithmis betterthanthat of the BP-based NN algorithm and the least squares (LS) algorithm in the NLOS environments. Moreover,this location method does not depend on a particular distribution of the NLOS error and does not need line-of-sight ( LOS ) or NLOS identification.
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Wireless sensor networks (WSNs) consist of sensor nodes that broadcast a message within a network. Efficient broadcasting is a key requirement in sensor networks and has been a focal point of research over the last few years. There are many challenging tasks in the network, including redundancy control and sensor node localization that mainly depend on broadcasting. In this paper, we propose a broadcasting algorithm to control redundancy and improve localization (BACRIL) in WSNs. The proposed algorithm incorporates the benefits of the gossip protocol for optimizing message broadcasting within the network. Simulation results show a controlled level of redundancy, which is up to 57.6% if the number of sensor nodes deployed in a 500 m×500 m area are increased from 50 to 500.
文摘In this paper, we propose a classical secret broadcasting and splitting joint protocol in a quantum scenario. With those genuinely entangled states, the boss can always broadcast some of his secrets and split some others to multi- receivers at the same time. The efficiency of the joint protocol is also compared with that of two separate ones which realise classical secret broadcasting and classical secret splitting respectively, and based on the comparison we can see the promising advantage of our joint protocol is that it can realise the two tasks more efficiently and more conveniently.
文摘Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.
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Broadcasting is a fundamental operation in any wireless networks, more so in wireless ad hoc sensor networks, where each sensor node has limited transmission range as well as battery power. Although broadcasting in wireless ad hoc sensor networks has many advantages but it can cause serious problems like-broadcast storm, which could cause a lot of contention, redundant retransmission, collision and most importantly, drain immense amount of energy from limited battery powered sensor nodes. In this work, our objective is to reduce the number of retransmission and energy consumption of sensor nodes by using the duty cycle property of wireless ad hoc sensor networks. We propose a preamble-based broadcasting technique for wireless ad hoc sensor networks. We show that in dense wireless ad hoc sensor networks a small size preamble can give maximum network-wide data dissemination rather than using the large preamble, which will only consume immense amount of energy during packet reception.
基金Project (No. 200442) supported by the Electronics DevelopmentFoundation for the Key Industrialization Project of the Ministry of0Information Industry, China
文摘Conditional access system (CAS) is a key technical component in digital TV broadcasting through which TV op-erators manage the appropriate rights of different subscribers in order to protect their commercial benefits. The normal digital TV receiver can only receive and decode the pay TV programs scrambled by one specific CAS. In this paper, the authors proposed a smartcard conditional access interface (SCAI) scheme in order to make the digital TV receiver be a common receiving platform independent of any specific CAS employed at the broadcasting head-end. As a result, it only needs to include a common condi-tional access software package (CCAP) without any requirement of hardware modification in the receiver. Comparison between the two mentioned DVB-CI-based schemes showed that the cost of such kind receiver is greatly reduced. The main design points of the proposed scheme and its reference implementation’s architecture are presented in this paper. This scheme is also one of the candidate national standards for Chinese digital TV broadcasting industry.
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.