Do e-scooters fill mobility gaps and promote equity before and during COVID-19? A spatiotemporal analysis using open big data (preprint)

The growing popularity of e-scooters and their rapid expansion across urban streets has attracted widespread attention. A major policy question is whether e-scooters substitute existing mobility options or fill the service gaps left by them. This study addresses this question by analyzing the spatiotemporal patterns of e-scooter service availability and use in Washington DC, focusing on their spatial relationships with public transit and bikesharing. Results from an analysis of three open big datasets suggest that e-scooters have both competing and complementary effects on transit and bikesharing services. The supply of e-scooters significantly overlaps with the service areas of transit and bikesharing, and we classify a majority of e-scooter trips as substitutes to transit and bikesharing uses. A travel-time-based analysis further reveals that when choosing e-scooters over transit, travelers pay a price premium and save some travel time. The price premium is greater during the COVID-19 pandemic but the associated travel-time savings are smaller. This implies that public health considerations rather than time-cost tradeoffs are the main driver for many to choose e-scooters over transit during COVID. In addition, we find that e-scooters complement bikesharing and transit by providing services to underserved neighborhoods. A sizeable proportion (about 10 percent) of e-scooter trips are taken to connect with the rail services. Future research may combine the big-data-based analysis presented here with traditional methods to further shed light on the interactions between e-scooter services, bikesharing, and public transit.

Infections Forecasting and Intervention Effect Evaluation for COVID-19 via a Data-Driven Markov Process and Heterogeneous Simulation (preprint)

The Coronavirus Disease 2019 (COVID-19) pandemic has caused tremendous amount of deaths and a devastating impact on the economic development all over the world. Thus, it is paramount to control its further transmission, for which purpose it is necessary to find the mechanism of its transmission process and evaluate the effect of different control strategies. To deal with these issues, we describe the transmission of COVID-19 as an explosive Markov process with four parameters. The state transitions of the proposed Markov process can clearly disclose the terrible explosion and complex heterogeneity of COVID-19. Based on this, we further propose a simulation approach with heterogeneous infections. Experimentations show that our approach can closely track the real transmission process of COVID-19, disclose its transmission mechanism, and forecast the transmission under different non-drug intervention strategies. More importantly, our approach can helpfully develop effective strategies for controlling COVID-19 and appropriately compare their control effect in different countries/cities.

The impact of the Covid-19 crisis on scholarly publishing in China

This paper describes actions recently taken by the government, scholarly publishers, and researchers to face the COVID-19 challenge in China. By promulgating new policies and funding new programs, the Chinese government at all levels has provided huge support for research on COVID-19. Guided by the new policies, Chinese scholarly book publishers have published 124 new titles on the subject of the coronavirus. Journal publishers have put out numerous calls for papers and launched open access platforms for COVID-19 research. Chinese researchers have produced 2021 English-language papers and 2837 Chinese papers on COVID-19. These activities have the potential to affect scholarly publishing in China and around the world in multiple ways: 1) by establishing a more reasonable academic evaluation system in China;2) by bringing about a more balanced relationship between Chinese scholarly publishers' profit motive and their commitment to social welfare;and 3) by altering the communication channels that Chinese researchers use and the publishing choices they make.