Date: 3^rd December, 2019

Time: 10:00 – 11:30 a.m.

Venue: Room1002, Administration Building, Zijingang Campus, Zhejiang University.

【Speaker Introduction】：Hua Cheng is a PhD candidate in Operations Research at Yale Business School. He holds a master's degree in statistics and data science from Yale University, a bachelor’s degree in computer engineering from Shanghai Jiaotong University, a bachelor’s degree in industrial engineering from the University of Michigan, and a second degree in mathematics.

【Lecture Abstract】：We focus on modeling and evaluating a novel emergency service system in which cross-trained fire-medics respond to both fire calls and medical emergencies. Fire demand in the U.S. has decreased dramatically in the last three decades, while emergency medical calls have surged. With this changing landscape, cities are under pressure to reduce their budgets by closing fire stations. We show that a better alternative would be to implement a fire-medic system in terms of cost savings and response time performance. We develop an exact spatial queuing model and two approximation methods, the second of which has linear complexity and can be used to solve three-state problems of any size. This paper is the first to develop a fast algorithm for general three-state spatial queuing problems. In several constructed examples, performance errors are less than 1% compared to exact values. We apply our method to the fire-medic system in St. Paul, MN. and find the errors between predicted and actual average response times are less than 2%. We show, in St. Paul, the traditional system would require 33% more personnel than the fire-medic system to achieve the same mean response times. We believe the fire-medic approach and our modeling have widespread applicability to other cities.