Engineering Commons^™

Optimal Allocation Of Blood Products, Godson A. Tetteh

Dissertations

The high cost of collection and the short shelf life of apheresis platelets demand efficient inventory management to reduce outdates and shortages. Apheresis platelets are licensed for seven days, and blood centers are keen on knowing the consequences of various product collection and distribution strategies. To reduce outdates, inventory managers typically distribute the older units first, thereby following first-in first-out (FIFO) policy; however, hospital blood banks would prefer that the blood center issues out the freshest units first, equivalent to a last-in first-out (LIFO) policy. This study addresses the optimal distribution policy to achieve a desired outdate, shortage and average …

Multiclass Intermodal Network Model : The Use Of Combined Model On System Evaluations, Yi Deng

Dissertations

United States transportation policy has generally addressed the negative economic and social effects of the standpoint of individual transportation modes and local government involvement. Therefore, there has been an increased focus on the development of intermodal transportation. Integrating the modes and using each of them to its best advantage are strategies to optimize the existing resources and to create new capabilities.

According to the literature review performed in this research, the research in intermodal transportation system evaluation is far from mature. Most transportation performance measurements are focused on one mode rather than a whole network. In practice, the data necessary …

Optimized Scheduling Of Highway Work Zones, Yimin Tang

Dissertations

Highway maintenance activities usually require lane closures and disrupt traffic operations. Because of budget constraints, project deadlines, and the resulting traffic impact, the objective of this dissertation is to improve the efficiencies of traffic operation and maintenance work, and minimize the total project cost (i.e., agency cost and road user cost) by optimizing work zone schedules.

This dissertation focuses on the maintenance projects on multiple-lane highways. The objective total cost function is formulated while considering a discrete maintenance time-cost function and time-dependent traffic diversions. However, the work zone scheduling problem is a combinatorial optimization problem and difficult to solve analytically. …