Representation and Estimation Method for Technical Station Capacity Based on Three-Parameter Interval Gray Numbers

Capacity is an important index to measure the production efficiency of railway technical station, in order to reflect capacity scalability and improve measurement accuracy, the applicability of three parameter interval and universal grey number for capacity representation was analyzed. The three parameter interval was used to guarantee the capacity value range of upper and lower bounds, the universal grey number was introduced to reduce the possible interval expansion caused by capacity calculation, and then the concepts of contraction capacity, balance capacity and relaxation capacity were proposed based on the operation state. After comparing various interval estimation methods, Jackknife-after-Bootstrap (JAB) interval estimation method was used to determine the lower and upper limit on capacity. A case of Zhengzhoubei Marshalling Station shows that the interval width determined by the capacity representation and estimation method based on three-parameter interval gray number is smaller, and the interval position is more accurate compared with the original fixed value representation on capacity. The calculated confidence interval is [9.6933, 10.2043], the interval width is 0.511 when the confidence level is 95%; Similarly, when it is 90%, the calculated confidence interval is [9.7358, 10.1653], and the interval width is 0.429. The contraction of carrying capacity in Zhengzhoubei railway station is 0.99, the relaxation is 1.01, and the contraction of resorting capacity is 0.94, the relaxation is 1.07, which indicates that the capacity measurement results show certain relaxation and contraction phenomenon.