University of Manitoba

“Quantile Regression with Nominated Samples: An example in Osteoporosis Analysis”

Date: Thursday, September 27, 2018
Time: 2:45 a.m.
Location: P230 Duff Roblin

In this talk, we study quantile regression analysis with maxima or minima nomination sampling designs. These designs are often used to obtain more representative samples from the tails of the underlying distribution using the easy to access rank information during the sampling process. We propose new loss functions to incorporate the rank information of nominated samples in the estimation process. Also, we provide an alternative approach that translates estimation problems with nominated samples to corresponding problems under simple random sampling (SRS). Strategies are given to choose proper nomination sampling designs for a given population quantile. Numerical studies show that quantile regression models with maxima (or minima) nominated samples have higher relative efficiencies compared with their counterparts under SRS for analyzing the upper (or lower) tail quantiles of the distribution of the response variable. Results are then implemented on a large cohort study in the Canadian province of Manitoba to analyze quantiles of bone mineral density using available covariates. We show that in some cases, methods based on nomination sampling designs require about one‐tenth of the sample used in SRS to estimate the lower or upper tail conditional quantiles with comparable mean squared errors. This is a dramatic reduction in time and cost compared with the usual SRS approach.

This is a work in collaboration with Ayilara Olawale and Bill Leslie.

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Congratulations to our October, 2018 graduates: Jenna Tichon (Ph.D.), Kanika Grover (M.Sc.), Mohammed Kamso (M.Sc.), Inesh Munaweera Arachchilage (M.Sc.), Joynob Siddiqua (M.Sc.), Shamsia Sobhan (M.Sc.).

Important Dates

September 19: Course Add Date - the last date to add a course in the revision period

September 19: Deadline to Apply Online to Graduate for February 2019 (most students)

October 3: Fee Payment Deadline Fall Term

Upcoming Seminars

Statistics seminar: Bo Li: “Spatially Varying Autoregressive Models for Prediction of New HIV Diagnoses” — Thursday, September 20 at 2:45 p.m., P230 Duff Roblin.

Statistics seminar: Mohammad Jafari Jozani: “Quantile Regression with Nominated Samples: An example in Osteoporosis Analysis” — Thursday, September 27 at 2:45 a.m., P230 Duff Roblin.

Statistics seminar: Yuliya Martsynyuk — Thursday, October 4 at 2:45 a.m., P230 Duff Roblin.

Statistics seminar: Darja Barr: “Evidence Driven Best Practices for Teaching the Mathematical Sciences” — Thursday, October 11 at 2:45 a.m., P230 Duff Roblin.

Where are they now?

Taraneh Abarin, Ph.D. (2009)

Yanqing Yi, Ph.D. (2008)