In this research project, we analyse the presence of video on the websites of regional television stations in Spain, and study the use of different internet-related audiovisual content viewing and distribution technol...In this research project, we analyse the presence of video on the websites of regional television stations in Spain, and study the use of different internet-related audiovisual content viewing and distribution technologies. The current television model is undergoing a deep-rooted change, and its future depends, to a large extent, on its presence in cyberspace. For the purposes of this study, we selected the internet homepages of the 12 regional radio-television stations which together make up the Spanish Federation of Regional Radio and Television Organizations (FORTA). The aim was to carry out a research project using content analysis techniques.展开更多
The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challengi...The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challenging and this is the focus of this paper. In this paper, the eavesdropper is hidden from the macro base stations. To relax the unpractical assumption on the channel state information on eavesdropper, a localization based algorithm is first given. Then a joint resource allocation algorithm is proposed in our work, which simultaneously considers physical layer security, cross-tier interference and joint optimization of power and subcarriers under fairness requirements. It is revealed in our work that the considered optimization problem can be efficiently solved relying on convex optimization theory and the Lagrangian dual decomposition method is exploited to solve the considered problem effectively. Moreover, in each iteration the closed-form optimal resource allocation solutions can be obtained based on the Karush-Kuhn-Tucker(KKT) conditions. Finally, the simulation results are given to show the performance advantages of the proposed algorithm.展开更多
In this paper,we consider a wireless ad hoc network consisting of multiple source nodes transmitting to their respective destinations,where an eavesdropper attempts to intercept their transmissions.We propose an optim...In this paper,we consider a wireless ad hoc network consisting of multiple source nodes transmitting to their respective destinations,where an eavesdropper attempts to intercept their transmissions.We propose an optimal transmission scheduling scheme to defend against the eavesdropper,where a source node having the highest secrecy rate is scheduled to access the wireless medium for transmitting to its destination in an opportunistic manner.To be specific,the secrecy rate between a pair of the source and destination in the presence of an eavesdropper varies temporally due to the wireless fading effect.The proposed optimal transmission scheduling scheme opportunistically selects a source node with the highest secrecy rate to transmit its data for the sake of maximizing the security of the ad hoc network against eavesdropping attacks.For comparison purposes,we also consider the conventional round-robin scheduling as a benchmark,where multiple source nodes take turns in accessing their shared wireless medium for transmitting to their respective destinations.We derive closed-form secrecy outage probability expressions of both the round-robin scheduling and the proposed optimal scheduling schemes over Rayleigh fading environments.Numerical results show that the proposed transmission scheduling scheme outperforms the conventional round-robin method in terms of its secrecy outage probability.Additionally,upon increasing the number of source-destination pairs,the secrecy outage probability of the round-robin scheme keeps unchanged,whereas the secrecy outage performance of the proposed transmission scheduling significantly improves,showing the security benefits of exploiting transmission scheduling for protecting wireless ad hoc networks against eavesdropping.展开更多
Since 1958 the United States Watson research center designed the world' s first computer teaching system, the history of computer technology in education has lasted for over 40 years, with the beginning of digitized ...Since 1958 the United States Watson research center designed the world' s first computer teaching system, the history of computer technology in education has lasted for over 40 years, with the beginning of digitized audio and global network as a symbol of the information age, the rapid development of multimedia network technology' s application crosses various fields, like other areas, foreign language teaching also benefit. January 2004, Department of Higher Education issued a "College English Curriculum Requirements" (Trial), which clearly states: "It should make full use of opportunities of multimedia, network technology development which is brought about by the introduction of new teaching model to improve the original teachers' single classroom teaching mode. The new model should be based on modern information technology support, especially network technology, the English teaching towards individualized learning, independent of time and place restrictions learning, active learning direction. "展开更多
Computer-assisted language leaming is a trend in the language teaching field of the 21st century and it is also advocated by the latest college English curriculum requirements. To test this model, we've conducted an ...Computer-assisted language leaming is a trend in the language teaching field of the 21st century and it is also advocated by the latest college English curriculum requirements. To test this model, we've conducted an experiment on a campus-network-based listening and speaking course with 869 students from the NAAU since the 2005-2006 academic years. It has been proved that the new model enjoys great advantages over the conventional teacher-and-recorder teaching, though it is not thoroughly free from limitations or problems. On the one hand, this new model may provide students with authentic language sample, richer materials, interactive platform, friendly context, ect; on the other hand, factors such as costly hardware and software, non-stopping changes, lack of talents and inadequate funds are all preventing it from playing its role to full extent. Thus counter measures should be taken as soon as possible to break the bottleneck restricting the model from further development.展开更多
Among the human users of the Internet of Things,the hearing-impaired is a special group of people for whom normal information expression forms,such as voice and video are unaccessible,and most of them have some diffic...Among the human users of the Internet of Things,the hearing-impaired is a special group of people for whom normal information expression forms,such as voice and video are unaccessible,and most of them have some difficulty in understanding information in text form.The hearing-impaired are accustomed to receiving information expressed in sign language.For this situation,a new information expression form for the Internet of Things oriented toward the hearing-impaired is proposed in this paper,and the new expression is based on sign language video synthesis.Under the sign synthesis frame,three modules are necessary:constructing database,searching for appropriate sign language video units and transition units,and generating interpolated frames.With this method,text information could be transformed into sign language expression for the hearing-impaired.展开更多
To further increase the throughput of wireless multi-hop networks,a distributed scheduling method is proposed,which takes physical interference model into account.It is assumed that nodes in the network can perform ph...To further increase the throughput of wireless multi-hop networks,a distributed scheduling method is proposed,which takes physical interference model into account.It is assumed that nodes in the network can perform physical carrier sensing,and the carrier sensing range can be set to different values.In the traditional carrier sensing mechanism,the carrier sensing range is computed under the protocol interference model,which is not accurate.Here the optimal carrier sensing range with physical interference model is achieved.Each sending node implements the distributed approach in three phases at each time slot,and all the concurrent transmissions are interference free.Good performance can be achieved under this scheduling approach.The approximation ratio of the distributed method to the optimal one is also proved.展开更多
文摘In this research project, we analyse the presence of video on the websites of regional television stations in Spain, and study the use of different internet-related audiovisual content viewing and distribution technologies. The current television model is undergoing a deep-rooted change, and its future depends, to a large extent, on its presence in cyberspace. For the purposes of this study, we selected the internet homepages of the 12 regional radio-television stations which together make up the Spanish Federation of Regional Radio and Television Organizations (FORTA). The aim was to carry out a research project using content analysis techniques.
基金supported by the National Natural Science Foundation of China under Grant No.61371075the 863 project SS2015AA011306
文摘The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challenging and this is the focus of this paper. In this paper, the eavesdropper is hidden from the macro base stations. To relax the unpractical assumption on the channel state information on eavesdropper, a localization based algorithm is first given. Then a joint resource allocation algorithm is proposed in our work, which simultaneously considers physical layer security, cross-tier interference and joint optimization of power and subcarriers under fairness requirements. It is revealed in our work that the considered optimization problem can be efficiently solved relying on convex optimization theory and the Lagrangian dual decomposition method is exploited to solve the considered problem effectively. Moreover, in each iteration the closed-form optimal resource allocation solutions can be obtained based on the Karush-Kuhn-Tucker(KKT) conditions. Finally, the simulation results are given to show the performance advantages of the proposed algorithm.
基金supported by the Natural Science Foundation of Anhui Provincial Education Department under Grant No.KJ2013Z048the Natural Science Foundation of Anhui Provincial Colleges and Universities under Grant No.KJ2014A234
文摘In this paper,we consider a wireless ad hoc network consisting of multiple source nodes transmitting to their respective destinations,where an eavesdropper attempts to intercept their transmissions.We propose an optimal transmission scheduling scheme to defend against the eavesdropper,where a source node having the highest secrecy rate is scheduled to access the wireless medium for transmitting to its destination in an opportunistic manner.To be specific,the secrecy rate between a pair of the source and destination in the presence of an eavesdropper varies temporally due to the wireless fading effect.The proposed optimal transmission scheduling scheme opportunistically selects a source node with the highest secrecy rate to transmit its data for the sake of maximizing the security of the ad hoc network against eavesdropping attacks.For comparison purposes,we also consider the conventional round-robin scheduling as a benchmark,where multiple source nodes take turns in accessing their shared wireless medium for transmitting to their respective destinations.We derive closed-form secrecy outage probability expressions of both the round-robin scheduling and the proposed optimal scheduling schemes over Rayleigh fading environments.Numerical results show that the proposed transmission scheduling scheme outperforms the conventional round-robin method in terms of its secrecy outage probability.Additionally,upon increasing the number of source-destination pairs,the secrecy outage probability of the round-robin scheme keeps unchanged,whereas the secrecy outage performance of the proposed transmission scheduling significantly improves,showing the security benefits of exploiting transmission scheduling for protecting wireless ad hoc networks against eavesdropping.
文摘Since 1958 the United States Watson research center designed the world' s first computer teaching system, the history of computer technology in education has lasted for over 40 years, with the beginning of digitized audio and global network as a symbol of the information age, the rapid development of multimedia network technology' s application crosses various fields, like other areas, foreign language teaching also benefit. January 2004, Department of Higher Education issued a "College English Curriculum Requirements" (Trial), which clearly states: "It should make full use of opportunities of multimedia, network technology development which is brought about by the introduction of new teaching model to improve the original teachers' single classroom teaching mode. The new model should be based on modern information technology support, especially network technology, the English teaching towards individualized learning, independent of time and place restrictions learning, active learning direction. "
文摘Computer-assisted language leaming is a trend in the language teaching field of the 21st century and it is also advocated by the latest college English curriculum requirements. To test this model, we've conducted an experiment on a campus-network-based listening and speaking course with 869 students from the NAAU since the 2005-2006 academic years. It has been proved that the new model enjoys great advantages over the conventional teacher-and-recorder teaching, though it is not thoroughly free from limitations or problems. On the one hand, this new model may provide students with authentic language sample, richer materials, interactive platform, friendly context, ect; on the other hand, factors such as costly hardware and software, non-stopping changes, lack of talents and inadequate funds are all preventing it from playing its role to full extent. Thus counter measures should be taken as soon as possible to break the bottleneck restricting the model from further development.
基金supported by the National Natural Science Foundation of China(Nos.60825203,60973056,60973057,U0935004)National Technology Support Project(2007BAH13B01)+2 种基金Beijing Municipal Natural Science Foundation(4102009)Scientific Research Common Program of Beijing Municipal Commission of Education(KM200710005023)PHR(IHLB)
文摘Among the human users of the Internet of Things,the hearing-impaired is a special group of people for whom normal information expression forms,such as voice and video are unaccessible,and most of them have some difficulty in understanding information in text form.The hearing-impaired are accustomed to receiving information expressed in sign language.For this situation,a new information expression form for the Internet of Things oriented toward the hearing-impaired is proposed in this paper,and the new expression is based on sign language video synthesis.Under the sign synthesis frame,three modules are necessary:constructing database,searching for appropriate sign language video units and transition units,and generating interpolated frames.With this method,text information could be transformed into sign language expression for the hearing-impaired.
基金Supported by the National Basic Research Program of China(No.2007CB307105)the National Natural Science Foundation of China(No.60932005)
文摘To further increase the throughput of wireless multi-hop networks,a distributed scheduling method is proposed,which takes physical interference model into account.It is assumed that nodes in the network can perform physical carrier sensing,and the carrier sensing range can be set to different values.In the traditional carrier sensing mechanism,the carrier sensing range is computed under the protocol interference model,which is not accurate.Here the optimal carrier sensing range with physical interference model is achieved.Each sending node implements the distributed approach in three phases at each time slot,and all the concurrent transmissions are interference free.Good performance can be achieved under this scheduling approach.The approximation ratio of the distributed method to the optimal one is also proved.