A method based on electronic structure calculation is proposed to predict the substitution behavior of elements in ordered intermetallics. The electronic structure of 20 alloying elements in TiAl is calculated using ...A method based on electronic structure calculation is proposed to predict the substitution behavior of elements in ordered intermetallics. The electronic structure of 20 alloying elements in TiAl is calculated using the DV-Xα cluster method The bond orders between alloying elements and surrounding atoms, Bo_Ti,Bo_Al, are used as parameters. Two lines on the Bo_Ti-Bo_Al diagram separate the elements into three groups. The elements located outside of the two lines substitute either Ti or Al atom regardless of the composition of TiAl. The substitution behavior of elements between the two lines will be affected by the Ti/Al ratio and the amount of alloying elements added Substituting sequence in multi-element alloy is discussed The prediction based on this method agrees well with the experimental results.展开更多
This paper provides an efficient and useful approach for demand estimation and assortment planning of cell phone cards in wireless communication industry. We use maximum likelihood estimation to estimate the primary d...This paper provides an efficient and useful approach for demand estimation and assortment planning of cell phone cards in wireless communication industry. We use maximum likelihood estimation to estimate the primary demand and substitution probability of each cell phone card based on historical sales data. This estimation model is nonlinear, so we transform it to a mixed integer linear programming model by logarithmic transformations and piecewise＇linear approximation. On the basis of the estimation results, we can make assortment planning. Considering the resource of cell phone cards is limited, we jointly optimize the assortment and quantity planning of cell phone cards. In numerical study, we apply our approach to a large mobile service provider in China and frod our approach can increase the revenue of this mobile service provider by 23.69%. Sensitivity analysis shows the mobile service provider should provide more assortments to increase revenue when the types of cell phone cards that can be assigned to each store are limited.展开更多
文摘A method based on electronic structure calculation is proposed to predict the substitution behavior of elements in ordered intermetallics. The electronic structure of 20 alloying elements in TiAl is calculated using the DV-Xα cluster method The bond orders between alloying elements and surrounding atoms, Bo_Ti,Bo_Al, are used as parameters. Two lines on the Bo_Ti-Bo_Al diagram separate the elements into three groups. The elements located outside of the two lines substitute either Ti or Al atom regardless of the composition of TiAl. The substitution behavior of elements between the two lines will be affected by the Ti/Al ratio and the amount of alloying elements added Substituting sequence in multi-element alloy is discussed The prediction based on this method agrees well with the experimental results.
基金This research was partially supported by the National Science Foundation of China [Grants 71401086, 71332005 and 71361130017].
文摘This paper provides an efficient and useful approach for demand estimation and assortment planning of cell phone cards in wireless communication industry. We use maximum likelihood estimation to estimate the primary demand and substitution probability of each cell phone card based on historical sales data. This estimation model is nonlinear, so we transform it to a mixed integer linear programming model by logarithmic transformations and piecewise＇linear approximation. On the basis of the estimation results, we can make assortment planning. Considering the resource of cell phone cards is limited, we jointly optimize the assortment and quantity planning of cell phone cards. In numerical study, we apply our approach to a large mobile service provider in China and frod our approach can increase the revenue of this mobile service provider by 23.69%. Sensitivity analysis shows the mobile service provider should provide more assortments to increase revenue when the types of cell phone cards that can be assigned to each store are limited.
