# Image Classification of Parcel Boxes under the Underground Logistics System Using CNN MobileNet
## 1 Introduction  
Since 2019, the COVID-19 virus has spread globally and is having a large impact on every industry and on people's lives due to its unpredictable nature. With COVID-19, internet activity has become almost routine and people spend more time at home. In particular, the logistics industry is showing a markedly different pattern compared with before COVID-19. Due to the change in the logistics industry, the parcel shipping market has exponentially increased, and fast delivery services are operating. As a result, it is logistically difficult for supplies and circulation to meet the urban demand, especially in metropolitan areas. In fact, Korea's parcel shipping volume amounted to 3.37 billion parcels in 2020, which represented a growth rate of about 140% compared to 2012. The number of individual parcel service that were used also increased, with a frequency of 9.74 per person per month in 2020, which represented an increase of 56.5% from compared 2019, before COVID-19. In particular, about 70% of the parcel shipping volume is concentrated in metropolitan areas. This is associated with an increase in the entry of freight vehicles into the metropolitan area, and social and environmental costs, such as traffic congestion and environmental pollution, are also increasing. Therefore, there is an urgent need tointroduce a new urban logistics system to handle the increasing parcel shipping volume and to respond to the increasing number of freight vehicles in cities. As the parcel delivery market is rapidly growing around the world, research into the development of new logistics transport systems is being actively conducted to respond to the logistics demand and to build an eco-friendly system. [PERSON], [PERSON] et al. analyzed the quantitative relationship between system implementation and urban logistics performance under the metro-based urban logistics system (M-ULS) to respond to parcel shipping services in the post COVID-19 era [1]. [PERSON], [PERSON] et al. proposed a new urban logistics system that combined an existing freight vehicle with an urban subway system to efficiently transport goods from the suburbs to metropolitan areas. As a result, these authors conducted a pilot project and verified the effectiveness of the new urban logistics system [2]. [PERSON], [PERSON] et al. presented a strategy to transport freight using public transportation, and the possibility of a new public freight transportation system was verified three times using the Delphi method [3]. [PERSON], [PERSON] et al. pointed out that urban logistics systems mainly relied on land transportation and incurred problems, such as traffic congestion, environmental problems, and delivery delays. In order to solve this problem, this research proposed a ULS using an urban subway for fast, one-day delivery during times when the urban subway was not congested [4]. As in the above studies, a city logistics system using an underground system are already widely known as an eco-friendly and sustainable means of freight transportation, and efforts to build a freight transportation system using the underground space are continuing. Therefore, as shown in Figure 1. This research focused on a metro-based ULS as an environmentally-friendly, punctual, and mass-transportation option for parcel delivery. As shown in Figure 2, the operation procedure of a ULS starts at the railway freight yard. After the cargo is received, the parcel boxes are sorted and stored within the railway freight yard for an extended period. After that, the sorted parcel boxes are loaded into the subway freight carriages and then moved between the urban subway stations. Parcel boxes arriving at the designated station are moved to the ground subway station site to be sorted using a vertical transfer device, and after re-sorting for last-mile delivery, the final delivery was performed. Figure 1: Concept of underground logistics system.