A Modified Gravity p-Median Model for Optimizing Facility Locations
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Zhuolin Tao
,
Qingjing Zheng
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.
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Articles in the same Issue
- Co-evolution: A New Perspective for Business Model Innovation
- Solving the Observing and Downloading Integrated Scheduling Problem of Earth Observation Satellite with a Quantum Genetic Algorithm
- A Modified Gravity p-Median Model for Optimizing Facility Locations
- Real-Time Pricing for Smart Grid with Multiple Companies and Multiple Users Using Two-Stage Optimization
- Optimization Analysis on Dynamic Reduction Algorithm
- Finding Cut-Edges and the Minimum Spanning Tree via Semi-Tensor Product Approach
- A New Design of Electrical Impedance Tomography Sensor System for Pulmonary Disease Diagnosis
