A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and seco...

We investigate four problems on optimal resource allocation and cross-layer control in cognitive and cooperative wireless networks with time-varying channels. The first three problems consider different models and capabilities associated with cognition and cooperation in such networks. Specifically, the first problem focuses on the dynamic spectrum access model for cognitive radio networks and ...

The collaborative model developed by Clark and colleagues views language use as a process by which people collaborate to perform joint actions, not merely exchange information. Because language use is one fundamental way in which people engage in cooperative interaction, many aspects of the collaborative model might be fruitfully applied to the design of computer systems which support cooperati...

In order to improve the efficiency of spectrum resource usage and the capacity of wireless networks, cooperative relay techniques which utilize the vacant spectrum of primary users for secondary users’ data transmission have been applied in cognitive radio networks. Considering the dynamic time-varying vacant spectrum resources and achievable rate on different channels at relay nodes (RN), the ...

We propose an interactive edit web system, that is, users can edit and revise documents cooperatively and interactively. The Ie-web is constructed based on conceptions of special issue edit and pantographic issue edit. The goal of this study is not only developing cooperative document making system by many users, but research paper making system by mentors and other students. In recent years, c...

It is possible to realize systems supporting cooperative work among users in distance location utilizing recent network technology. Most current computer supported cooperative work (CSCW) systems, however, offer identical display views to all the users through video in order to simulate real world. We use database functions and non-video based communication tools to realize such cooperative wor...

As demands for limited natural resources increase, developing management institutions that ensure the sustainability of such resources is essential. Natural resources are Common Pool Resources (CPRs), managed under different noncooperative, cooperative, and externally imposed management frameworks. While early studies of non-cooperative CPR management suggest inevitable “tragedy of the commons,...

In this paper, a cooperative relaying system with α-proportional fair scheduling is proposed for multi-carrier systems. The cooperative relaying provides ’virtual’ MIMO through combining the signals from the source and the relay at the destination in addition to the advantage of the simple relaying which reduces path-loss attenuation in the air interface. We have adopted the α-proportional fair...