A cognitive relay network model is proposed, which is defined by a source, a destination, a cognitive relay node and a primary user. The source is assisted by the cognitive relay node which is allowed to coexist with ...A cognitive relay network model is proposed, which is defined by a source, a destination, a cognitive relay node and a primary user. The source is assisted by the cognitive relay node which is allowed to coexist with the primary user by imposing severe constraints on the transmission power so that the quality of service of the primary user is not degraded by the interference caused by the secondary user. The effect of the cognitive relay node on the proposed cognitive relay network model is studied by evaluating the outage probability under interference power constraints for different fading environments. A relay transmission scheme, namely, decode-and-forward is considered. For both the peak and average interference power constraints, the closed-form outage expressions are derived over different channel fading models. Finally, the analytical outage probability expressions are validated through simulations. The results indicate that the proposed model has better outage probability than direct transmission. It is also found that the outage probability decreases with the increase of interference power constraints. Meanwhile, the outage probability under the average interference power constraint is much less than that under the peak interference power constraint when the average interference power constraint is equal to the peak interference power constraint.展开更多
This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywo...This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R＆D information in Korea （human resources, project and outcome） and applying expertise calculation algorithm. In consideration of the characteristics of national R＆D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R＆D information.展开更多
This paper analyzes the emergence of new powers on the international scene and its relationship with natural resources. Divided into three parts, the paper first discusses the changes in the concept of natural resourc...This paper analyzes the emergence of new powers on the international scene and its relationship with natural resources. Divided into three parts, the paper first discusses the changes in the concept of natural resource. Then, the reasons that led to increased demand for them, and the consequences it generates. Finally, the text discusses possibilities of cooperation between emerging countries in search of new technologies, which should be based on renewable resources to change the present situation of unequal access and use natural resources in the world.展开更多
基金Supported by National Natural Science Foundation of China (No. 60972039, 60905040 and 60972041 )National High Technology Research and Development Program of China (No. 2009AA01Z241)+3 种基金National Postdoctoral Research Program (No. 20090451239)Important National Science and Technology Specific Projects of China (No. 2009ZX03003-006)Scientific Research Foundation of Nanjing University of Posts and Telecommunications (No. NY210006)Key Teaching Reform Foundation of NUPT (No. JG00210JX01)
文摘A cognitive relay network model is proposed, which is defined by a source, a destination, a cognitive relay node and a primary user. The source is assisted by the cognitive relay node which is allowed to coexist with the primary user by imposing severe constraints on the transmission power so that the quality of service of the primary user is not degraded by the interference caused by the secondary user. The effect of the cognitive relay node on the proposed cognitive relay network model is studied by evaluating the outage probability under interference power constraints for different fading environments. A relay transmission scheme, namely, decode-and-forward is considered. For both the peak and average interference power constraints, the closed-form outage expressions are derived over different channel fading models. Finally, the analytical outage probability expressions are validated through simulations. The results indicate that the proposed model has better outage probability than direct transmission. It is also found that the outage probability decreases with the increase of interference power constraints. Meanwhile, the outage probability under the average interference power constraint is much less than that under the peak interference power constraint when the average interference power constraint is equal to the peak interference power constraint.
基金Project(N-12-NM-LU01-C01) supported by Construction of NTIS (National Science & Technology Information Service) Program Funded by the National Science & Technology Commission (NSTC), Korea
文摘This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R＆D information in Korea （human resources, project and outcome） and applying expertise calculation algorithm. In consideration of the characteristics of national R＆D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R＆D information.
文摘This paper analyzes the emergence of new powers on the international scene and its relationship with natural resources. Divided into three parts, the paper first discusses the changes in the concept of natural resource. Then, the reasons that led to increased demand for them, and the consequences it generates. Finally, the text discusses possibilities of cooperation between emerging countries in search of new technologies, which should be based on renewable resources to change the present situation of unequal access and use natural resources in the world.
