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Projecting the impact of the coronavirus disease-2019 pandemic on childhood obesity in the United States: A microsimulation model

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Journal of Sport and Health Science 2020年第4期9卷 302-312页

作者： Ruopeng An Brown School Washington University in St.LouisSt.LouisMO 63130USA

Purpose:The coronavirus disease-2019(COVID-19)pandemic in the United States led to nationwide stay-at-home orders and school closures.Declines in energy expenditure resulting from canceled physical education classes and reduced physical activity may elevate childhood obesity risk.This study estimated the impact of COVID-19 on childhood obesity.Methods:A microsimulation model simulated the trajectory of a nationally representative kindergarten cohort’s body mass index z-scores and childhood obesity prevalence from April 2020 to March 2021 under the control scenario without COVID-19 and under the 4 alternative scenarios with COVID-19—Scenario 1:2-month nationwide school closure in April and May 2020;Scenario 2:Scenario 1 followed by a 10%reduction in daily physical activity in the summer from June to August;Scenario 3:Scenario 2 followed by 2-month school closure in September and October;and Scenario 4:Scenario 3 followed by an additional 2-month school closure in November and December.Results:Relative to the control scenario without COVID-19,Scenarios 1,2,3,and 4 were associated with an increase in the mean body mass index z-scores by 0.056(95%confidence interval(95%CI):0.0550.056),0.084(95%CI:0.0840.085),0.141(95%CI:0.1400.142),and 0.198(95%CI:0.1970.199),respectively,and an increase in childhood obesity prevalence by 0.640(95%CI:0.5150.765),0.972(95%CI:0.8191.126),1.676(95%CI:1.4751.877),and 2.373(95%CI:2.1352.612)percentage points,respectively.Compared to girls and non-Hispanic whites and Asians,the impact of COVID-19 on childhood obesity was modestly larger among boys and non-Hispanic blacks and Hispanics,respectively.Conclusion:Public health interventions are urgently called to promote an active lifestyle and engagement in physical activity among children to mitigate the adverse impact of COVID-19 on unhealthy weight gains and childhood obesity.

关键词： Childhood obesity Coronavirus COVID-19 microsimulation Physical activity

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Assessment of traffic performance measures and safety based on driver age and experience:A microsimulation based analysis for an unsignalized T-intersection

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第5期6卷 455-469页

作者： Mehmet Baran Ulak Eren Erman Ozguven Ren Moses Thobias Sando Walter Boot Yassir AbdelRazig John Olusegun Sobanjo Department of Civil and Engineering Stony Brook University Stony Brook NY 11794 USA Department of Civil and Environmental Engineering FAMU-FSU College of Engineering Tallahassee FL 32310 USA School of Engineering College of Computing Engineering and Construction University of North Florida Jacksonville FL 32224 USA Department of Psychology Florida State University Tallahassee FL 32306 USA

Traffic safety and performance measures such as crash risk and queue lengths or travel times are influenced by several important factors including those related to environment,human,and roadway design,especially at intersections.Previous research has studied different aspects related to these factors,yet these characteristics are not fully investigated with a focus on age and experience of drivers.In this paper,we investigate this issue by using a two-phase approach via a case study application on a critical T-intersection in the City of Tallahassee,Florida.The first phase includes a scenario-based microsimulation analysis through the use of a microscopic simulation software,namely VISSIM,to illustrate the variations in traffic performance measures with respect to driver compositions of different age groups in the traffic stream.A variety of scenarios is created where the driving characteristics are provided as inputs to these scenarios in terms of decision making and risk taking.This is also supported by a sensitivity analysis conducted based on the driver composition in the traffic.The second phase includes the analysis of microsimulation outputs via a tool developed by Federal Highway Administration tool,namely the Surrogate Safety Assessment Model(SSAM),in order to determine the traffic conflicts that occur in each scenario.These conflicts are also compared with real-life crash data for validation purposes.Results show that(a) the differences in risk perception that affect driving behavior might be significant in influencing traffic safety and performance measures,and(b) the proposed approach is considerably successful in simulating the actual crash conflict points.

关键词： Traffic safety Driver age and experience Traffic performance microsimulation VISSIM T-intersections

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Spatial microsimulation modeling for residential energy demand of England in an uncertain future

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Geo-Spatial Information Science 2014年第3期17卷 153-169页

作者： Chengchao ZUO Mark BIRKIN Nicolas MALLESON School of Geography University of LeedsLeedsWest Yorkshire LS29JTUK

High quality infrastructure is crucial to economic success and the sustainability of society.Infrastructures for services,such as transport,energy,and water supply,also have long lead times,and therefore require effective long-term planning.In this paper,we report on work undertaken as part of the UK Infrastructure Transitions Research Consortium to construct long-term models of demographic change which can help to inform infrastructure planning for transport,energy,and water as well as IT and waste.A set of demographic microsimulation models(MSM),which are spatially disaggregate to the geography of UK Local Authorities,provides a high level of detail for understanding the drivers of changing patterns of demand.However,although robust forecasting models are required to support projections based on the notion of‘predict-and-provide,’the potential for behavioral adaptation is also an important consideration in this context.In this paper,we therefore establish a framework for linkage of a MSM of household composition,with behavior relating to the consumption of energy.We will investigate variations in household energy consumption within and between different household groups.An appropriate range of household types will be defined through the application of decision trees to consumption data from a detailed survey produced by the UK Department of Energy and Climate Change.From this,analysis conclusions will be drawn about the impact of changing demographics at both household and individual level,and about the potential effect of behavioral adjustments for different household groups.

关键词： spatial modeling microsimulation energy consumption demographic modeling

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The Impacts of COVID-19 on Migrants,Remittances,and Poverty in China:A microsimulation Analysis

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China & World Economy 2021年第6期29卷 4-33页

作者： Yumei Zhang Yue Zhan Xinshen Diao Kevin Z.Chen Sherman Robinson Institute of Agricultural Economics and Development Chinese Academy of Agricultural SciencesChina International Food Policy Research Institute(IFPRI) China China Academy for Rural Development Zhejiang UniversityChina

Chinese migrant workers are very exposed to the shocks caused by the COVID-19 pandemic.Falling remittances adversely affect their families who rely on remittance incomes.The impacts of COVID-19 on migrants and remittance-receiving households are assessed using a nationally representative household dataset and a microsimulation model.We found about 70 percent of migrant workers lost part of their wage income during the pandemic lockdown period and rural migrants working in small and medium enterprises were affected the most.This led to about 50 percent of remittance-receiving households being affected adversely by falling remittances,and the average decline in such income was more than 45 percent.Nearly 13 percent of pre-pandemic nonpoor remittance-receiving households could fall into poverty,raising the poverty rate among remittancereceiving households by 4 percentage points.Many households that were poor prior to the pandemic became more impoverished.The results indicate that social protection programs targeting vulnerable migrants and their families at home are important.

关键词： China COVID-19 microsimulation migrants and remittances poverty

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Calibration methodology for microscopic traffic simulation models of land ports of entry along the US-Mexico border

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第3期11卷 40-59页

作者： David Salgado Peter T.Martin Abhisek Mudgal Rafael M.Aldrete Texas A&M Transportation Institute 4050 Rio Bravo Drive Suite 212El Paso 79912USA New Mexico State University Engineering Complex II Rm.215Las Cruces 88003USA Indian Institute of Technology(BHU)Civil Engineering Department Varanasi 221011 Uttar PradeshIndia

Non-commercial Land Ports of Entry(LPOEs)are unique transportation facilities controlling the ingress and egress of passenger vehicles from Mexico to the United States and vice versa.The calibration of microscopic traffic simulation models of non-commercial LPOEs requires a deep understanding of operational processes and driving behavior at these facilities.This paper provides a methodology to guide modelers in calibrating microscopic traffic simulation models of non-commercial LPOEs.The methodology establishes a common framework for modeling operational processes and traffic operations.Moreover,the methodology includes the value of four state variables that characterizes operations of passenger vehicles at non-commercial LPOEs.These variables are speed,acceleration,deceleration,and headway.The authors evaluated this methodology using the Otay Mesa non-commercial LPOE as a case study.Results showed that this methodology could be potentially used to model non-commercial LPOEs along the US-Mexico border and other border regions worldwide.

关键词： Land port of entry microsimulation calibration traffic models car-following models state variables

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Video-based trajectory extraction with deep learning for High-Granularity Highway Simulation(HIGH-SIM)

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Communications in Transportation Research 2021年第1期1卷 111-120页

作者： Xiaowei Shi Dongfang Zhao Handong Yao Xiaopeng Li David K.Hale Amir Ghiasi Department of Civil and Environmental Engineering University of South FloridaTampaFL33620United States Leidos IncSaxton Transportation Operation LaboratoryMcLean22101VirginiaUnited States

High-granularity vehicle trajectory data can help researchers develop traffic simulation models,understand traffic flow characteristics,and thus propose insightful strategies for road traffic management.This paper proposes a novel vehicle trajectory extraction method that can extract high-granularity vehicle trajectories from aerial videos.The proposed method includes video calibration,vehicle detection and tracking,lane marking identification,and vehicle motion characteristics calculation.In particular,the authors propose a Monte-Carlo-based lane marking identification approach to identify each vehicle's lane.This is a challenging problem for vehicle trajectory extraction,especially when the aerial videos are taken from a high altitude.The authors applied the proposed method to extract vehicle trajectories from several high-resolution aerial videos recorded from helicopters.The extracted dataset is named by the High-Granularity Highway Simulation(HIGH-SIM)vehicle trajectory dataset.To demonstrate the effectiveness of the proposed method and understand the quality of the HIGHSIM dataset,we compared the HIGH-SIM dataset with a well-known dataset,the NGSIM US-101 dataset,regarding the accuracy and consistency aspects.The comparison results showed that the HIGH-SIM dataset has more reasonable speed and acceleration distributions than the NGSIM US-101 dataset.Also,the internal and platoon consistencies of the HIGH-SIM dataset give lower errors compared to the NGSIM US-101 dataset.To benefit future research,the authors have published the HIGH-SIM dataset online for public use.

关键词： Video analytics Image processing Vehicle trajectory extraction Deep learning microsimulation

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D-MELD risk capping improves post-transplant and overall mortality under markov microsimulation

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World Journal of Transplantation 2014年第3期4卷 206-215页

作者： Jeffrey B Halldorson Robert L Carithers Jr Renuka Bhattacharya Ramasamy Bakthavatsalam Iris W Liou Andre A Dick Jorge D Reyes James D Perkins Division of Transplant Surgery Department of Surgery University of California San Diego CA 92103-8401 United States Division of Transplantation Department of Surgery University of Washington Seattle WA 98195 United States Division of Gastroenterology Department of Medicine University of Washington Seattle WA 98195 United States

AIM: To hypothesize that the product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age(D-MELD) risk capping ± Rule 14 could improve post liver transplant and overall survival after listing.METHODS: Probabilities derived from the United Network for Organ Sharing database between 2002 and 2004 were used to simulate potential outcomes for all patients listed for transplantation. The Markov simula-tion was then modified by screening matches using a 1200 or 1600 D-MELD risk cap ± allowing transplants for Model for End-Stage Liver Disease(MELD) ≤ 14(Rule 14). The differential impact of the rule changes was assessed.RESULTS: The Markov simulation accurately reproduced overall and post transplant survival. A 1200 D-MELD risk cap improved post-transplant survival. Both the 1200 and 1600 risk caps improved overall survival for waitlisted patients. The addition of Rule 14 further improved post transplant and overall survival by redistribution of donor livers to recipients in higher MELD subgroups. The mechanism for improved overall and post-transplant survival after listing was due to shifting a larger percentage of transplants to the moderate MELD score subgroup(MELD 15-29) while also ensuring that high MELD recipients have livers of high quality to achieve excellent post transplant survival.CONCLUSION: A 1200 D-MELD risk cap + Rule 14 provided the greatest overall benefit primarily by focusing liver transplantation towards the moderate MELD recipient.

关键词： Liver transplantation The product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age Donor/recipient matching Markov microsimulation Model for End-Stage Liver Disease Donor age

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