I develop and implement statistical methodology to solve for scientific problems. My major research interest is related to high dimensional and high through-put data collected by Wearable Devices (accelerometers, actigraphs, heart rate monitor, etc.). Recently, these devices have gained their popularity in both academia and industry; however, accurately analyzing data generated by them remains a big scientific challenge. Understanding this type of data, their distribution within person and in the population can help understand the association between these new measurements and human health.

My main area of expertise is related to data collection and analysis for objectively measured physical activity, sleep, and circadian rhythmicity using actigraphy, accelerometry etc. I develop novel statistical methodologies and collaborate on multiple scientific projects as well. Specifically, I am interested in the following directions:

  1. feature engineering for raw actigraphy data to summarize noisy and high dimensional physiological signal

  2. dimension reduction on high dimensional actigraphy data

  3. integrative analysis of features acquired from multiple domains/modalities/devices.

Scientific Interests: wearable devices and their applications in public health (e.g. mental health and aging) and clinical trials (diease assessment and monitoring), physical activity assessment, sleep, circadian rhythmicity.

Statistical Methods: feature engineering for accelerometry signals, dimension reduction, functional data analysis, integration of multiple modalities.

Selected Research Projects

Integration of data from domains of physical activity, sleep, and circadian rhythmicity: Implemented JIVE to jointly reduce the dimesnion of multivariate actigraphy features representing multiple domains of physical activity, sleep, and circadian rhythmicity to provide data driven features and inuition about the multi-modal data structure. (See here)

Novel Features to Quantify Activity Fragmentation: Developed between-state transition probabilities to quantify patterns of sedentary/active time accumulation studied their association with mortality in NHANES 2003-2006.

Processed the NHANES 2003 - 2006 Accelerometery Data: Processed NHANES 2003 - 2006 accelerometry data to a user-friendly data package. Provided analytical tutorial to conduct statistical analysis on NHANES accelerometry data. (See here, and package)

Collaborative Research Projects: multiple collaborative research projects including: monitoring hospitalized patients with various activity trackers, sleep fragmentation and its association with cognitive functions, circadian rhythmicity and its association with mortality etc.