A Modified Gravity p-Median Model for Optimizing Facility Locations
A Modified Gravity p-Median Model for Optimizing Facility Locations
复制标题
用于优化设施位置的修正重力 p 中值模型
DOI：
10.21078/jssi-2018-421-14
复制
发表时间：
2018
期刊：
影响因子：
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通讯作者：
Hui Kong
中科院分区：
文献类型：
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作者：
Zhuolin Tao;Qingjing Zheng;Hui Kong
摘要重力p-中位数模型是对广泛使用的p-中位数模型的一个重要改进。然而，它在实证应用中的有效性仍然存在争议。以前的研究甚至怀疑重力p中位数模型的意义。本文以深圳市三级医院为例，通过将重力p-中位数模型与p-中位数模型的差异分解为重力规则和变量吸引，重新检验了两种模型的差异。本研究还提出了一种改进的重力p-中位数模型，通过引入距离阈值。实证结果支持了重力p-中位数模型的有效性，也揭示了只有当候选设施位置的吸引力是可变的时，重力p-中位数模型才会导致与p-中位数模型不同的结果。本文还讨论了改进的重力p-中值模型与重力p-中值模型之间的差异。此外，研究了距离衰减参数和距离阈值对解的影响。结果表明：距离衰减参数越大，最优设施分布越分散，平均出行时间越小;距离阈值越小，设施空间公平性越好。所提出的方法也可以应用于其他类型的设施或在其他领域的研究。
Abstract The gravity p-median model is an important improvement to the widely-used p-median model. However, there is still a debate on its validity in empirical applications. Previous studies even doubt the significance of the gravity p-median model. Using a case study of tertiary hospitals in Shenzhen, China, this study re-examines the difference between the gravity p-median model with the p-median model, by decomposing the difference between the two models into gravity rule and variant attraction. This study also proposes a modified gravity p-median model by incorporating a distance threshold. The empirical results support the validity of the gravity p-median model, and also reveal that only when the attractions of candidate facility locations are variable will the gravity p-median model lead to different results with the p-median model. The difference between the modified gravity p-median model and the gravity p-median model is also examined. Moreover, the impacts of the distance-decay parameter and distance threshold on solutions are investigated. Results indicate that a larger distance-decay parameter tends to result in a more dispersed distribution of optimal facilities and a smaller average travel time, and a smaller distance threshold can better promote the spatial equity of facilities. The proposed method can also be applied in studies of other types of facilities or in other areas.