Vidyut Samanta

Illumimote: Multimodal and High-Fidelity Light Sensor Module for Wireless Sensor Networks

We describe the system requirements, design, system integration, and performance evaluation of the Illumimote, a new light-sensing module for wireless sensor networks. The Illumimote supports three different light-sensing modalities: incident light intensity, color intensities, and incident light angle (the angle of ray arrival from the strongest source); and two situational sensing modalities: attitude and temperature. The Illumimote achieves high performance, comparable to commercial light meters, while conforming to the size and energy constraints imposed by its application in wireless sensor networks. We evaluated the performance of our Illumimote for light intensity, color temperature, and incident light angle measurements and verified the function of the attitude sensor. The Illumimote consumes about 90 mW when all features on board are activated. We describe our design and the experiment design for the performance evaluation.

Impact of Video Encoding Parameters on Dynamic Video Transcoding

Currently there are a wide variety of devices with different screen resolutions, color support, processing power, and network connectivity, capable of receiving streaming video from the Internet. In order to serve different multimedia content to all these devices, middleware proxy servers which transcode content to fit different types of devices are becoming popular. In this paper, we present result of several tests conducted with different combination of video encoding parameters and show their impact on network, CPU and energy resource usage of a transcoding server. For this purpose, we implemented a dynamic video trancoding server, which enables dynamic changes in different trancoding parameters during a video streaming session