Research on the underground logistics system (ULS) has been carried out for nearly 30 years, but the description of the global research network, research trends, and the discussion of advanced theories and practices have not been systematically reviewed so far. The concept of public freight has expanded a new development direction: metro-based underground logistics system (M-ULS). The purpose of this paper is to analyze this new model by taking underground logistics and public freight as the research object. We performed statistical analyses of 222 references and constructed three kinds of visualized bibliographic information experiments for regional collaboration, authorship collaboration, and keywords co-occurrence. Based on the scientometrics results, the evolution path of the literature evolution was drawn. We used cluster-analysis-based taxonomy to structure the recent relevant literature. According to the comprehensive review, the research stays in the theoretical research stage, mainly focusing on system concept and planning, traffic organization, and network operation. There is still a lack of discussion on engineering quantification and application implementation. Finally, this study highlights some brief ideas, discussions, and potential suggestions for future research. This bibliometric research is expected to provide researchers and practitioners with a panoramic description and in-depth understanding of ULS and M-ULS research.

Content Delivery Network (CDN) technology is one of the core technologies for performance optimization of mobile WEB applications, but it often encounters bottlenecks in video storage. In this paper, based on studying the basic technical model of distributed real-time transcoding CDN, we propose an overall technical architecture of a distributed real-time transcoding CDN system, present the business process of distributed real-time transcoding CDN resource negotiation in the model, design a resource storage policy model and algorithm, including the hot storage ratio resource storage value evaluation method and storage resource allocation algorithm. Through simulation experiments, we verify the technical efficiency of the distributed real-time transcoding CDN system by simulation experiments.