In this paper, a novel multiple-user cooperative spectrum sensing (MCSS) scheme is proposed to achieve the spatial diversity gains for cognitive radio (CR) networks, where only the best relay, selected among all t...In this paper, a novel multiple-user cooperative spectrum sensing (MCSS) scheme is proposed to achieve the spatial diversity gains for cognitive radio (CR) networks, where only the best relay, selected among all the candidate relays in accordance with the quality of channel conditions, is utilized to cooperatively detect the primary user. Closed-form expressions of detection time for the traditional non-cooperative and the proposed MCSS schemes are derived over Rayleigh fading channels. In addition, numerical experimentations are conducted to make a performance comparison between the noncooperative sensing and our scheme. The result shows that by exploiting the multiple-user cooperation, the detection time is reduced greatly and moreover, diversity gains obtained by the MCSS scheme increase with a rise in the number of candidate relays.展开更多
In theory, sustainable forest management (SFM) puts public participation at the epicenter of the decision-making process. However, in reality, the situation is different. The growing importance of public participation...In theory, sustainable forest management (SFM) puts public participation at the epicenter of the decision-making process. However, in reality, the situation is different. The growing importance of public participation seems essential for the implementation of sustainable forest management. The aim of this study is to assess the implementation of a theoretical concept closely related to SFM, integrated land and resource management (ILRM). This Canadian concept aims to integrate many forest functions using participatory tools. Using semi-structured interviews with experts, we clarify our theoretical concept and adapt it to reality. Our results show that better communication between stakeholders is necessary. It is also important to increase the flexibility of the timber harvest system and adapted forest zoning should be considered. A new concept, the forest culture, seems to be a key element that needs to be considered upstream of forest management. A new</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">definition</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">of ILRM is proposed</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in order to better</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">reach social values.展开更多
基金Supported by the Postgraduate Innovation Program of Scientific Research of Jiangsu Province (Grant Nos. CX08B 080Z, CX09B 150Z)the National Natural Science Foundation of China (Grant No. 60972039)+2 种基金the Key Project of Natural Science Funding of Jiangsu Province (Grant No. BK2007729)the National High-Tech Research & Development Program of China (Grant No. 2009AA01Z241)the Major Development Program of Jiangsu Educational Committee (Grant No. 06KJA51001)
文摘In this paper, a novel multiple-user cooperative spectrum sensing (MCSS) scheme is proposed to achieve the spatial diversity gains for cognitive radio (CR) networks, where only the best relay, selected among all the candidate relays in accordance with the quality of channel conditions, is utilized to cooperatively detect the primary user. Closed-form expressions of detection time for the traditional non-cooperative and the proposed MCSS schemes are derived over Rayleigh fading channels. In addition, numerical experimentations are conducted to make a performance comparison between the noncooperative sensing and our scheme. The result shows that by exploiting the multiple-user cooperation, the detection time is reduced greatly and moreover, diversity gains obtained by the MCSS scheme increase with a rise in the number of candidate relays.
文摘In theory, sustainable forest management (SFM) puts public participation at the epicenter of the decision-making process. However, in reality, the situation is different. The growing importance of public participation seems essential for the implementation of sustainable forest management. The aim of this study is to assess the implementation of a theoretical concept closely related to SFM, integrated land and resource management (ILRM). This Canadian concept aims to integrate many forest functions using participatory tools. Using semi-structured interviews with experts, we clarify our theoretical concept and adapt it to reality. Our results show that better communication between stakeholders is necessary. It is also important to increase the flexibility of the timber harvest system and adapted forest zoning should be considered. A new concept, the forest culture, seems to be a key element that needs to be considered upstream of forest management. A new</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">definition</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">of ILRM is proposed</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in order to better</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">reach social values.