Summary: | 博士 === 中原大學 === 工業與系統工程研究所 === 102 === The development and improvement of technology and economy has brought comfort and convenience to people, resulting in improved quality of life. People’s reliance on electricity has made its sources essential, and the demand for it has risen rapidly. While the world faces dwindling supplies of energy, every nation in the world is actively developing natural energy sources and new alternative energy sources. Although solar power, wind power, and geothermal power can be seen as sustainable ways to produce energy, large scale production of these resources has both technical and financial limitations. Hydroelectricity is considered a natural resource and is a mature, cost-effective technology. In the process of producing renewable hydroelectric energy, plants all over the world are facing the problem of reservoir sediment. If this sediment is removed but not properly disposed of, it can become a secondary pollutant. This study proposes a way to resolve this problem through reuse and recycling.
In the case study, using a green design based on the Design for Six Sigma (DFSS) process, reservoir sediment and the masonry waste from the construction industry are combined with cement and a curing agent. The resulting mixture is not sintered, but is molded under high pressure. After 28 days of natural curing, the result is a high strength, non-sintered cured brick. This product is a new walling material that fulfills the objectives of environmental protection, energy conservation, and waste recycling. It also meets the need to develop a circular economy, protect ecosystems, and promote sustainable development.
In this study, two integrated vendor-buyer inventory models with and without backordering for the brick production case study are also presented. A random fraction of defective items is produced by the vendor who implements a 100% inspection to screen and scrap defective units by multiple disposals during the production period. We derive the optimal production batch, the number of shipments and the number of defective item disposed in order to minimize the integrated inventory cost. The examples illustrate the solution procedure and analyze the sensitivity of the optimal policies with respect to changes in some system parameters.
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