Adapting node-place model to predict and monitor COVID-19 footprints and transmission risks

The node-place model has been widely used to classify and evaluate transit stations,which sheds light on individuals’travel behaviors and supports urban planning through effectively integrating land use and transportation development.This study adapts this model to investigate whether and how node,place,and mobility would be associated with the transmission risks and presences of the local COVID-19 cases in a city.Moreover,the unique metric drawn from detailed visit history of the infected,i.e.,the COVID-19 footprints,is proposed and exploited.This study then empirically uses the adapted model to examine the station-level factors affecting the local COVID-19 footprints.The model accounts for traditional measures of the node and place as well as actual human mobility patterns associated with the node and place.It finds that stations with high node,place,and human mobility indices normally have more COVID-19 footprints in proximity.A multivariate regression is fitted to see whether and to what degree different indices and indicators can predict the COVID-19 footprints.The results indicate that many of the place,node,and human mobility indicators significantly impact the concentration of COVID-19 footprints.These are useful for policy-makers to predict and monitor hotspots for COVID-19 and other pandemics’transmission.

Sustainable transportation in the US： A review of proposals, policies, and programs since 2000

This paper reviews the research, policy proposals and recommendations, implemented policies, and programs on sustainable transportation since 2000, with regional focus on the US, using the UK （related to the European Union if appropriate）, and Canada as references. The paper finds that the concept of sustainable transportation has been given increased attention in all places. There are significant variances between the research, policy proposal, and implementation. Efforts made towards sustainable transportation, and the focus of the efforts at entities within and outside the US also vary notably. As a whole, the US did more research on sustainable transportation than the reference countries and it even undertook several studies of sustainable transportation practices in West Europe. The US federal government is less aggressive than its foreign counterparts in marketing and implementing sustainable transporta- tion. This is evidenced by a lack of overarching federal policy （mandate） on and a universal working definition for sustainable transportation, and absence of a gateway and dedicated website to market and disseminate the idea of sustainable development in general and sustainable transportation in particular.

Mobile-Source GHG Modeling Institutions and Capacities in China:Findings Based on Structured Interviews and On-Line Surveys

This paper provides an overview of practices of mobile-source greenhouse gas(GHG) modeling in China and related data sharing issues. It is based on structured phone interviews and two on-line surveys conducted in 2011 and finds that most cities have transportation-land use models but that few have mobile-source GHG models. A group of entities housed in the government have the strongest GHG modeling capacities and dominate the relevant consulting market. Data hoarding of public entities is the biggest barrier for entities without government ties to compete in the market. The reasons for data hoarding include government concerns over political implications of data release, a tradition of data hoarding, and a lack of confidence in reliability and accuracy of the data.

Quick fabrication of aeronautical complicated structural parts based on stereolithography

Investment casting based on stereolithography(SL)has the characteristics of short production cycle and low cost,which is especially suitable for fabricating complex aeronautical parts without metal dies.But there are some problems during the fabrication process,such as low surface accuracy caused by the staircases of resin prototype,shell cracking caused by higher thermal stress during the sintering process and so on.Taking an engine turbine stator as a fabrication example,the surface accuracy of resin prototype under the effect of coating method was investigated using the laser confocal microscopy;what’s more,both theoretical analysis and finite element analysis(FEA)were combined and compared to reveal the thermal stress field of ceramic shell during pyrolyzing and sintering process under different situation.It was founded that the surface staircases of the resin prototype was eliminated and the surface quality was improved after coating process,the thermal stress was decreased and shell cracking was avoided by sintering the ceramic shell with the inner hollow resin prototype under the heating rate of 51C/min.The result showed that,the metal turbine stator had high dimensional accuracy of CT4-CT6 and had a good surface finish within Ra 3.2.