Zhengwen He

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This paper involves the multi-mode project payment scheduling problem where the activities can be performed with one of several discrete modes and the objective is to assign activities’ modes and progress payments so as to maximize the net present value of the contractor under the constraint of project deadline. Using the event-based method the basic model(More)
This paper involves the multi-mode project payment scheduling problem with bonus–penalty structure where activities can be performed with several modes and a bonus–penalty structure exists at the deadline of the project. In the problem the decisions on when to schedule events and payments, the magnitude of each payment, and the performing mode of each(More)
Rheumatoid arthritis (RA) is a complex and not fully understood autoimmune disease associated with multijoint damage. The main effector cells, the synovial fibroblasts, are apoptosis resistant and hyperplastic which indicate that autophagy level is high in synovial tissue. Real-time PCR, immunocytochemistry, and western blotting were used in this paper to(More)
This paper offers insights into how the bullwhip effect in two parallel supply chains with interacting price-sensitive demands is affected in contrast to the situation of a single product in a serial supply chain. In particular, this research studies two parallel supply chains, each consisting of a manufacturer and a retailer, and the external demand for a(More)
Based on the distribution of the project financing cost over the contractor and the client, this paper involves the project payment scheduling problem from a joint perspective of the two parties. In the problem, the project financing cost is defined as the expense for raising money from the outside or the opportunity cost of the capital devoted into the(More)
Reverse logistics, which is induced by various forms of used products and materials, has received growing attention throughout this decade. In a highly competitive environment, the service level is an important criterion for reverse logistics network design. However, most previous studies about product returns only focused on the total cost of the reverse(More)