I am an assistant professor in the Division of Geriatric Medicine and Gerontology, Department of Medicine at Johns Hopkins University School of Medicine and a core faculty at the Center on Aging and Health. My research is primarily focused on data analytics for objective physical activity measurements and their association with health outcomes. I am a lead investigator on several projects including recognition and quantification of walking from raw accelerometry data. Methods are motivated by and applied to several large studies of activity. I develop methods for big data produced by wearable devices and create reproducible, robust, and scalable analytical pipelines for human activity. These projects require a combination of statistical methods, computational approaches, and digital signal processing tools that are specific to wearable computing data, which are non stationary, high resolution, and heterogeneous.