This paper investigates the social-aware cooperation(SAC) among mobile terminals(MTs), motivated by the fact that modern smart devices have much improved context awareness. Aware of the social ties, the cooperative ne...This paper investigates the social-aware cooperation(SAC) among mobile terminals(MTs), motivated by the fact that modern smart devices have much improved context awareness. Aware of the social ties, the cooperative network contains two layers of property: social and physical. In order to observe how the social awareness benefit the cooperation performance, we first formulate the social ties between MTs into parameters that can describe the cooperative behaviors by taking the mobility feature into account, defined as the conviction-approval-suspicion(CAS) model. Limited by the processing capability, partner selection is of great practical significance. To this end, the social-aware partner selection strategy is analyzed, and a significant superiority is observed compared to social-unaware selection. By analyzing the cooperative throughput, an explicit relationship between the degrees-of-freedom gain and the social-physical property is finally derived. Simulation results validate the theoretical analysis.展开更多
This paper proposes a joint network-channel codingbased on turbo codes for user cooperation. The scenario under consideration is one in which two ＂partners＂--UE1 and UE2---cooperate in transmitting information to th...This paper proposes a joint network-channel codingbased on turbo codes for user cooperation. The scenario under consideration is one in which two ＂partners＂--UE1 and UE2---cooperate in transmitting information to the base station （BS）. Each partner transmits both locally generated information and the relayed information that originated at the other partner. The local information and relayed information are jointly network-channel coded to form a superimposed codeword, and the adjacent codewords transmitted in turn by the two partners are tightly correlative like a chain. It is shown via simulation that the proposed scheme achieves full diversity gain compared with the other user cooperation schemes, including those based on coded cooperation and distributed space-time coded cooperation.展开更多
Social relationships formed within a network of interacting group members can have a profound impact on an indi- vidual＇s behavior and fitness. However, we have little understanding of how individuals perceive their ...Social relationships formed within a network of interacting group members can have a profound impact on an indi- vidual＇s behavior and fitness. However, we have little understanding of how individuals perceive their relationships and how this perception relates to our external measures of interactions. We investigated the perception of affiliative and agonistic relation- ships at both the dyadic and emergent social levels in two captive groups of monk parakeets （Myiopsitta monachus, n = 21 and 19） using social network analysis and playback experiments. At the dyadic social scale, individuals directed less aggression to- wards their strong affiliative partners and more aggression towards non-partner neighbors.At the emergent social scale, there was no association between relationships in different social contexts and an individual＇s dominance rank did not correlate with its popularity rank. Playback response pattems were mainly driven by relationships in affiliative social contexts at the dyadic scale. In both groups, individual responses to playback experiments were significantly affected by strong affiliative relationships at the dyadic social scale, albeit in different directions in the two groups. Response pattems were also affected by affiliative relation- ships at the emergent social scale, but only in one of the two groups. Within affiliative relationships, those at the dyadic social scale were perceived by individuals in both groups, but those at the emergent social scale only affected responses in one group. These results provide preliminary evidence that relationships in affiliative social contexts may be perceived as more important than agonistic relationships in captive monk parakeet groups. Our approach could be used in a wide range of social species and comparative analyses could provide important insight into how individuals perceive relationships across social contexts and social scales [Current Zoology 61 （1）： 55-69, 2015].展开更多
基金supported by the National Basic Research Program of China (2013CB329001)the National Natural Science Foundation of China (61132002, 61201186)
文摘This paper investigates the social-aware cooperation(SAC) among mobile terminals(MTs), motivated by the fact that modern smart devices have much improved context awareness. Aware of the social ties, the cooperative network contains two layers of property: social and physical. In order to observe how the social awareness benefit the cooperation performance, we first formulate the social ties between MTs into parameters that can describe the cooperative behaviors by taking the mobility feature into account, defined as the conviction-approval-suspicion(CAS) model. Limited by the processing capability, partner selection is of great practical significance. To this end, the social-aware partner selection strategy is analyzed, and a significant superiority is observed compared to social-unaware selection. By analyzing the cooperative throughput, an explicit relationship between the degrees-of-freedom gain and the social-physical property is finally derived. Simulation results validate the theoretical analysis.
文摘This paper proposes a joint network-channel codingbased on turbo codes for user cooperation. The scenario under consideration is one in which two ＂partners＂--UE1 and UE2---cooperate in transmitting information to the base station （BS）. Each partner transmits both locally generated information and the relayed information that originated at the other partner. The local information and relayed information are jointly network-channel coded to form a superimposed codeword, and the adjacent codewords transmitted in turn by the two partners are tightly correlative like a chain. It is shown via simulation that the proposed scheme achieves full diversity gain compared with the other user cooperation schemes, including those based on coded cooperation and distributed space-time coded cooperation.
文摘Social relationships formed within a network of interacting group members can have a profound impact on an indi- vidual＇s behavior and fitness. However, we have little understanding of how individuals perceive their relationships and how this perception relates to our external measures of interactions. We investigated the perception of affiliative and agonistic relation- ships at both the dyadic and emergent social levels in two captive groups of monk parakeets （Myiopsitta monachus, n = 21 and 19） using social network analysis and playback experiments. At the dyadic social scale, individuals directed less aggression to- wards their strong affiliative partners and more aggression towards non-partner neighbors.At the emergent social scale, there was no association between relationships in different social contexts and an individual＇s dominance rank did not correlate with its popularity rank. Playback response pattems were mainly driven by relationships in affiliative social contexts at the dyadic scale. In both groups, individual responses to playback experiments were significantly affected by strong affiliative relationships at the dyadic social scale, albeit in different directions in the two groups. Response pattems were also affected by affiliative relation- ships at the emergent social scale, but only in one of the two groups. Within affiliative relationships, those at the dyadic social scale were perceived by individuals in both groups, but those at the emergent social scale only affected responses in one group. These results provide preliminary evidence that relationships in affiliative social contexts may be perceived as more important than agonistic relationships in captive monk parakeet groups. Our approach could be used in a wide range of social species and comparative analyses could provide important insight into how individuals perceive relationships across social contexts and social scales [Current Zoology 61 （1）： 55-69, 2015].
