The study investigated the use of Facebook as an educational tool as well as the influence of Facebook integration into blended learning environment on English pronunciation teaching and learning activities. The subjects for the study consisted of 30 students who were the first-year English majors at Thai Nguyen University of Education. They were divided into two groups: the experimental group and the traditional group. Besides, there was a student teacher from the same university to be the subject of the experimental group. A combination of qualitative, quantitative and experimental approaches was employed to collect data and students’ views on this model. This allowed the researcher to get hold of a transformation in students’ pronunciation competence and their attitudes towards a blended format with supporting a social networking site (Facebook). The findings of the study indicate that Facebook retains outstanding features to offer a professional online course for English pronunciation learning, such as live lectures, group discussions, schedule events and etc. Furthermore, Facebook benefits the teachers in managing students’ learning autonomy so that the teacher is likely to grasp the ability of individuals in a short time. However, the use of Facebook still remains obstacles in the path of carrying out English pronunciation activities, and when putting it into blended-learning, the model handles these obstacles and limitations in the current learning and teaching of English pronunciation as well.

We put forward a joint optimization algorithm for relay selection and source & relay power allocations under lineof-sight (LoS) and non-LoS mixed conditions for both power saving and robustness enhancement in practical cooperative multicast millimeter-wave (mmWave) wireless personal area networks (WPANs). Firstly, a novel beam training protocol capable of overhearing is devised to filter relay candidates with non-LoS links and avoid relays selection for LoS paths through feedback 1-bit channel amplitude information (CAI). Secondly, we provide the problem formulation that minimizes the maximum total transmit power consumption under constraints of maximum tolerable outage probability and limited power. As these two problems are coupled together, the formulation is non-convex with extremely high complexity of finding optimal solution. By introducing relaxation method and Lagrange multipliers algorithm, we propose an optimal approach to reduce complexity while maintaining reasonable performance, and derive a closed-form expression of optimal joint relay selection and power allocation. Lastly, simulation results indicate significant improvements both on outage probability and power consumption performances over the existing sum transmit power minimization algorithm.

This paper presents a non-cooperative method to maximize the throughput of a set of distributed links in wireless MIMO ad hoc networks. The space-time power scheduling in each link is built into a non-cooperative game where its utility function is identified and maximized. The link quality is introduced into the pricing function in order to obtain Pareto improvement. The gradient projection methods are compared with the proposed game theoretic approach by simulations, and the results show that the proposed method provides a distributed scheduling of resources with low computational complexity and without significantly sacrificing the network throughput.I.

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