講者：Shou, Haochang (壽昊暢) 副教授 (Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine)
時間：113年3月21日（星期四）13:00
地點：台大新生教學館403教室
講題：Statistical modeling for physical activity distributional objects assessed via wearable sensor devices
摘要：Wearable devices such as accelerometers enable the continuous and objective measurement of physical activity and sleep, which has shown to link with psychological and physiological health. They offer significant potentials to supplant traditional clinical markers in observational and interventional studies. In recent years, there are increasing interests to appropriately model the daily physical activity distribution as multivariate complex object data summarized as probability densities, histograms, or quantile functions. Traditional statistical methods often fail to apply when the data are sampled from an arbitrary non-Euclidean metric space. In this talk, we will introduce wearable device data and its applications in mobile health research, and discuss some of our recent work on modeling physical activity distributional objects. In particular, we developed a structural equation model with a random quantile function as the mediator to study the indirect mediation effect through physical activity. Our method was applied to a randomized trial to investigate the mediation effect of physical activity on the causal path between flexible duty-hour policies and the sleep related outcomes among internal medicine residents.