Browsing by Author "Chen, Hao-Wei"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item The effect of the fast-ship option in retail supply chains(2011-01) Chen, Hao-WeiTo reduce loss of sales caused by demand uncertainty, retailers can offer a fast-ship option to customers who experience stockout. The fast-ship option is a common practice that serves as a secondary source of supply. When this option is offered, the supply chain partners arrange to have out-of-stock items shipped directly from the supplier to willing customers at no additional cost to the customers. The fast-ship option serves as a mechanism by which inventory risk can be shared between the retailer and the supplier. We investigate the retailer's and the supplier's interactions when the fast-ship option is offered under different scenarios. More specifically, we characterize the supplier's and the retailer's ordering policies and investigate how the supplier and the retailer react to different levels of participation for fast-ship orders. We also study how the supplier can manage its risk by using either price markup or supply commitment under different supply contract structures. In addition, when the fast-ship option is offered, we investigate how alliance or competition between retailers can affect the profitability of the supplier and retailers.Item Highway Cost Allocation and Determination of Heavy Freight Truck Permit Fees(Minnesota Department of Transportation, 2012-07) Gupta, Diwakar; Chen, Hao-WeiMinnesota Department of Transportation (MnDOT) and other state DOTs periodically carry out studies to assess how highway construction and maintenance (HCM) expenditures ought to be attributed to various vehicle classes. In parallel, each vehicle-class’ contribution to revenues from fuel and excise taxes and permit fees are calculated. Although, the latter are determined by the state legislature, the cost-to-revenue ratio helps inform MnDOT if changes to policy could be justified. A variety of methods have been developed to apportion HCM costs to different user classes. The purpose of this study was to evaluate pros and cons of different HCA methods and to identify/develop a methodology best suited for conditions in Minnesota. Researchers also carried out a highway cost allocation study (HCAS) using the latest data from Minnesota. In addition, the methodology developed in this project can be used to evaluate damage costs to the road system from permitting more than 80,000-lb gross vehicle weight trucks on Minnesota roads and the users’ willingness to pay for such permits.Item Improving Capacity Planning for Demand-Responsive Paratransit Services(Minnesota Department of Transportation, 2008-04) Gupta, Diwakar; Chen, Hao-Wei; Miller, Lisa; Surya, FajarraniThis report proposes and evaluates two ideas for improving efficiency and service quality of paratransit operations. For carrying out this analysis, the authors use data from Metro Mobility, the agency responsible for providing ADA-mandated transportation services in the Twin Cities. However, the underlying principles, mathematical models, and algorithms are applicable to a variety of similar transportation operations in urban and rural areas. The first idea is to re-optimize routes developed by Metro Mobility’s route-building software (a commercial product named Trapeze) at the end of each day of booking operations to reduce the total time it takes to serve booked trips. The second idea evaluates the selective use of non-dedicated vehicles and service providers (e.g. taxi services) for lowering operational costs. Mathematical models and computer algorithms are developed for each of these approaches. These are then tested on actual operational data obtained from Metro Mobility. The report shows that a conservative estimate of savings from re-optimization would be 5% of Metro Mobility’s operating costs. Additional savings from the use of taxi service would be in the hundreds of dollars per day. The actual magnitude of these savings would depend on the proportion of customers who agree to travel by taxi.