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In this study, a blended synchronous learning environment (BSLE) was designed from pedagogical, social and technical perspectives. It was created for a group of master's students to attend lessons in the classroom and at the same time allow a few of them to join the identical sessions using video conferencing from different sites. The purpose of the study was to describe the guiding principles for pedagogical, social and technical designs and specific strategies applied, and identify the students' learning experiences and perceptions of the environment. Results showed that the BSLE could extend certain features of classroom instruction to the online students and they had equivalent learning experiences. They also liked the flexibility and convenience of attending lessons via video conferencing. This study further found that smooth and clear audio communication, redesign of certain learning activities and the quality of audio were crucial for the BSLE to be useful in practice.

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This study investigated a blended synchronous learning environment (BSLE), which was designed for a group of master's students taking a course at a teacher education institute. The BSLE was created for the majority of the students to attend the course face-to-face and at the same time allowed the rest to join the identical sessions using videoconferencing from different locations. The purpose of the study was to find out what learning experiences and perceptions the students had with regard to the design and implementation of the BSLE. Results show that the BSLE could extend certain features of the face-to-face classroom instruction to the online students and the students liked the flexibility and convenience of attending lessons via the twoway videoconferencing at remote sites. This study further identified that smooth communication between online students and the instructor and between the online students and classroom students, the engagement of the online students and the redesign of certain instructional activities, balanced attention from the instructor to the classroom students as well as the online students and the quality of the audio were crucial for the environment to be effective.

In wireless sensor networks (WSNs), many applications require a high reliability for the sensing data forwarding to sink. Due to the lossy nature of wireless channels, achieving reliable communication through multihop forwarding can be very challenging. Broadcast technology is an effective way to improve the communication reliability so that the data can be received by multiple receiver nodes. As long as the data of any one of the receiver nodes is transmitted to the sink, the data can be transmitted successfully. In this paper, a cross-layer optimization protocol named Adaptive transmission Power control based Reliable data Forwarding (APRF) scheme by using broadcast technology is proposed to improve the reliability of network and reduce communication delay. The main contributions of this paper are as follows: (1) for general data aggregation sensor networks, through the theoretical analysis, the energy consumption characteristics of the network are obtained. (2) According to the case that the energy consumption of nearsink area is high and that in far-sink area is low, a cross-layer optimization method is adopted, which can effectively improve the data communication by increasing the transmission power of the remaining energy nodes. (3) Since the reliability of communication is improved by increasing the transmission power of the node, the number of retransmissions of the data packet is reduced, so that the delay of the packet reaching the sink node is reduced. The theoretical and experimental results show that, applying APRF scheme under initial transmission power of 0 dBm, although the lifetime dropped by 13.77%, delay could be reduced by 40.37%, network reliability could be reduced by 10.08%, and volume of data arriving at sink increased by 10.08% compared with retransmission-only mechanism.