The introduction of on-demand ride-hailing platforms totally changed the way people commute. In recent years, several firms entered this market to directly compete with traditional taxi companies. Some of these online platforms offer a carpooling service in which several passengers heading in the

Portfolio risk measurement under the nested setting is a challenging computational problem, and has received increasing attention in recent years. This nested setting often requires mark-to-market reevaluation of the portfolio for a large number of possible scenarios of risk factors up to a future

We consider a new ranking and selection problem in which the performance of each alternative depends on some observable random covariates. The best alternative is thus not constant but depends on the values of the covariates. Assuming a linear model that relates the mean performance of an

We consider a dynamic pricing problem where the firm tries to maximize the profit upon selling a product over the course of T periods. We do not assume decision maker’s foreknowledge on the demand. Traditionally, the cost is fixed and the problem may be formulated as a multi armed bandit problem,

In this paper, we study the dynamic pricing and availability decisions of a firm that repeatedly introduces new generations of a product over time. Customers are strategic and are affected by two types of scarcity effects----direct scarcity effect and relative scarcity effect. Firm-induced scarcity

Over the past few decades, global metapopulation epidemic simulations built with worldwide air-transportation data have been the main tool for studying how epidemics spread from the origin to other parts of the world (e.g. for pandemic influenza, SARS and Ebola). However, it remains unclear how

This work is motivated by the appointment booking of specialist services at the ambulatory care center (ACC) in a major public hospital in Hong Kong. We study scheduling policies in a healthcare system in which patients' waiting times for medical consultations are governed by the Hong Kong Hospital

We consider the problem of allocating daily hospital service capacity among several types of elective surgical procedures. Our focus is on the interaction between two major constraining hospital resources: operating room and recovery bed capacity. In our model, each type of surgical procedure has

We study stochastic optimization problems with decisions truncated by random variables. The technical difficulty is that the optimization problems may not be convex programs due to the truncation. We develop a transformation technique to convert the original non-convex problems to equivalent convex

Opponents of pollution regulation claim that regulations choke businesses, hurt welfare and destroy economic growth. Do pollution regulations in fact hurt producers and the economy? To address this question, we develop an integrated production-pollution-abatement model, and study two popular