中央研究院 資訊科學研究所

Transportation activity surveys investigate when, where and how people travel in urban areas to provide information necessary for urban transportation planning. Such surveys are conducted through conventional questionnaires and travel diaries. However, the conventional surveys are problematic and error-prone. We are developing a smartphone-based transportation activity survey system to replace the traditional surveys. The smartphones are used to collect GPS, GSM, accelerometer and other contextual information for place detection, trajectory tracking and transportation mode detection. Our smartphone based survey system is designed to seamlessly capture the daily transportation activity profiles of users, including their modes of transportation and places they visit. In this talk, we will discuss the design and implementation of the transportation activity survey system. We present the design of the mobile applications, based on the Android and iOS platforms, to improve the quality of the sensing data and reduce the energy required for data collection. We give an overview of the survey web application to enable users to validate their activities and trips. We highlight the design of the high-performance backend system for managing and processing the huge volume of sensor data, and its preliminary performance and scalability analysis. We also present the data analysis techniques for stop detection and transportation mode detection. A full prototype of the system has been developed and is being used to support the Singapore Land Transport Authority's (LTA) Travel Survey 2012, involving at least 1000 volunteer smartphone users.

Fang-Jing Wu is a Research Fellow in Nanyang Technological University, Singapore. She received her B.S. degree in Mathematics from Fu Jen Catholic University Taiwan in 2001, M.S.

degree in Computer Science and Information Engineering from National Chiao-Tung University Taiwan in 2004, and Ph.D. degree in Computer Science from National Chiao-Tung University, Taiwan in 2011. Her current research interests include cyber-physical systems, pervasive computing, and participatory sensing, sensor networks, and wireless and mobile networks.