Ting Lei (雷霆) 博士，美国堪萨斯大学地理与大气科学系助理教授。主讲课程包括网络分析和空间优化、空间数据库、地理信息系统及遥感图像处理等。雷教授的研究领域涉及空间优化技术的方法和模型，及其在交通、物流、城市规划、环境资源管理中的应用。雷教授在 European Journal of Operational Research (影响因子：3.806), Transportation Research Part E (影响因子：4.253), International Journal of Geographic Information Science (影响因子：3.545) Annals of the Association of American Geographers (影响因子：3.810), Geographical Analysis (影响因子：1.955), Landscape Ecology (影响因子：4.349) 等杂志上发表学术论文20篇，文章引用次数430次，H指数10.
Location optimization and modeling: a unified model
Location-allocation modeling is an important area of research in spatial optimization and GIScience. It involves identifying the optimal location for facilities that serve a set of spatially distributed demands. Each demand can be assigned to one or more facilities based on factors such as shortest distance, minimum transport cost, capacity and server availability, among others. Location-allocation models have been used in different planning activities involving emergency response service, firefighting, forestry, nature reserve design, transportation planning and other planning problems in the public and private sectors (ReVelle et al. 1970).
Since the early developments in location modeling over 50 years ago, a large number of location-allocation models have been developed to address a wide range of location problems in transportation, planning and other fields. The p-median problem and three other classic location models are widely deemed as the four fundamental location problems. Many location problems in the literature are extensions and variants of the four fundamental models. However, even the fundamental location models are linked to one another, and it has been demonstrated that some of the fundamental models are special cases of the p-median problem. In this talk, we follow this line of research and describe a new unified median location problem called the Vector Assignment Ordered Median Problem (VAOMP) that unifies the four classic location problems among others. We also discuss solution approaches to the unified location model.