published journal article
Stability and bifurcation in network traffic flow: A Poincaré map approach
Transportation Research Part B: Methodological
Publication Date
November 1, 2013
Area of Expertise: Unspecified
conference paper
Android UI deception revisited: Attacks and defenses
Lecture notes in computer science (including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics)
Publication Date
January 1, 2017
Author(s)
E. Fernandes, Qi Alfred Chen, J. Paupore, G. Essl, J.A. Halderman, Z.M. Mao, A. Prakash
Suggested Citation
E. Fernandes, Q.A. Chen, J. Paupore, G. Essl, J.A. Halderman, Z.M. Mao and A. Prakash (2017) “Android UI deception revisited: Attacks and defenses”, in Lecture notes in computer science (including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics), pp. 41–59. Available at: 10.1007/978-3-662-54970-4_3. conference paper
How do they get by without cars in california?: Travel characteristics of voluntarily and involuntarily carless households
Proceedings of the 98th annual meeting of the transportation research board
Publication Date
January 1, 2019
Author(s)
Abstract
In spite of their increasing number in the U.S., our understanding of the travel behavior of households who do not own motor vehicles (labeled â??carlessâ?? herein) is sketchy. The goal of this paper is to start filling this gap for California. The authors perform parametric and non-parametric tests to analyze trip data from the 2012 California Household Travel Survey (CHTS) after classifying carless households as voluntarily carless, involuntarily carless, or unclassifiable based on a CHTS question that inquires why a carless household does not own any motor vehicle. The authors find substantial differences between voluntarily and involuntarily carless households. Compared to their voluntarily carless peers, involuntarily carless households travel less frequently, their trips are longer and they take more time, partly because their environment is not as well adapted to their needs. They also walk/bike less, depend more on transit, and when they travel by motor vehicle, occupancy is typically higher. Their median travel time is also longer, but remarkably, it is similar for voluntarily carless and motorized households. Overall, involuntarily carless households are less mobile, which may contribute to a more isolated lifestyle with a lower degree of well-being. Compared to motorized households, carless households rely a lot less on motor vehicles and much more on transit, walking, and biking. They also take less than half as many trips and their median trip distance is less than half as short. This study is a first step toward better understanding the transportation patterns of carless households.
Suggested Citation
Suman K. Mitra and Jean-Daniel M. Saphores (2019) “How do they get by without cars in california?: Travel characteristics of voluntarily and involuntarily carless households”, in Proceedings of the 98th annual meeting of the transportation research board, p. 7p. conference paper
MitM attack by name collision: Cause analysis and vulnerability assessment in the new gTLD era
2016 IEEE symposium on security and privacy (SP)
Publication Date
May 1, 2016
Author(s)
Qi Alfred Chen, Eric Osterweil, Matthew Thomas, Z. Morley Mao
Suggested Citation
Qi Alfred Chen, Eric Osterweil, Matthew Thomas and Z. Morley Mao (2016) “MitM attack by name collision: Cause analysis and vulnerability assessment in the new gTLD era”, in 2016 IEEE symposium on security and privacy (SP). IEEE, pp. 675–690. Available at: 10.1109/sp.2016.46.Preprint Journal Article
Decarbonizing Aviation: Cash-for-Clunkers in the Airline Industry
Publication Date
March 1, 2024
Author(s)
Jan Brueckner, Matthew E. Kahn, Jerry Nickelsburg
Abstract
The durability of the transportation capital stock slows down the pace of decarbonization since newer vintages feature cutting-edge technology. If older vintages were to be retired sooner, the social cost of travel would decline. This paper analyzes and explores the viability of a potential cash-for-clunkers program for the airline industry, which would help to hasten decarbonization of US aviation. Our estimation and calculations show that airlines can be induced to scrap rather than sell older planes upon retirement with a payment that is less than the forgone carbon damage, yielding net social benefits.
Suggested Citation
Jan K. Brueckner, Matthew E. Kahn and Jerry Nickelsburg (2024) “Decarbonizing Aviation: Cash-for-Clunkers in the Airline Industry”. National Bureau of Economic Research (Working Paper Series). Available at: 10.3386/w32205. published journal article
Residential mobility of low-income, subsidized households: A synthesis of explanatory frameworks
Housing Studies
Publication Date
October 1, 2016
Author(s)
Victoria Basolo, Anaid Yerena
Suggested Citation
Victoria Basolo and Anaid Yerena (2016) “Residential mobility of low-income, subsidized households: A synthesis of explanatory frameworks”, Housing Studies, 32(6), pp. 841–862. Available at: 10.1080/02673037.2016.1240762. published journal article
Exposure measurement error in air pollution studies: the impact of shared, multiplicative measurement error on epidemiological health risk estimates
Air Quality, Atmosphere & Health
Publication Date
June 1, 2020
Author(s)
Mariam S. Girguis, Lianfa Li, Fred Lurmann, Jun Wu, Carrie Breton, Frank Gilliland, Daniel Stram, Rima Habre
Abstract
Spatiotemporal air pollution models are increasingly being used to estimate health effects in epidemiological studies. Although such exposure prediction models typically result in improved spatial and temporal resolution of air pollution predictions, they remain subject to shared measurement error, a type of measurement error common in spatiotemporal exposure models which occurs when measurement error is not independent of exposures. A fundamental challenge of exposure measurement error in air pollution assessment is the strong correlation and sometimes identical (shared) error of exposure estimates across geographic space and time. When exposure estimates with shared measurement error are used to estimate health risk in epidemiological analyses, complex errors are potentially introduced, resulting in biased epidemiological conclusions. We demonstrate the influence of using a three-stage spatiotemporal exposure prediction model and introduce formal methods of shared, multiplicative measurement error (SMME) correction of epidemiological health risk estimates. Using our three-stage ensemble learning-based nitrogen oxides (NOx) exposure prediction model, we quantified SMME. We conducted an epidemiological analysis of wheeze risk in relation to NOx exposure among school-aged children. To demonstrate the incremental influence of exposure modeling stage, we iteratively estimated the health risk using assigned exposure predictions from each stage of the NOx model. We then determined the impact of SMME on the variance of health risk estimates under various scenarios. Depending on the stage of the spatiotemporal exposure model used, we found that wheeze odds ratio ranged from 1.16 to 1.28 for an interquartile range increase in NOx. With each additional stage of exposure modeling, the health effect estimate moved further away from the null (OR = 1). When corrected for observed SMME, the health effects confidence intervals slightly lengthened, but our epidemiological conclusions were not altered. When the variance estimate was corrected for the potential “worst case scenario” of SMME, the standard error further increased, having a meaningful influence on epidemiological conclusions. Our framework can be expanded and used to understand the implications of using exposure predictions subject to shared measurement error in future health investigations.
Suggested Citation
Mariam S. Girguis, Lianfa Li, Fred Lurmann, Jun Wu, Carrie Breton, Frank Gilliland, Daniel Stram and Rima Habre (2020) “Exposure measurement error in air pollution studies: the impact of shared, multiplicative measurement error on epidemiological health risk estimates”, Air Quality, Atmosphere & Health, 13(6), pp. 631–643. Available at: 10.1007/s11869-020-00826-6. published journal article
The role of extreme heat exposure on premature rupture of membranes in Southern California: A study from a large pregnancy cohort
Environment International
Publication Date
March 1, 2023
Author(s)
Anqi Jiao, Yi Sun, David A. Sacks, Chantal Avila, Vicki Chiu, John Molitor, Jiu-Chiuan Chen, Kelly T Sanders, John T Abatzoglou, Jeff Slezak, Tarik Benmarhnia, Darios Getahun, Jun Wu
Abstract
Background Significant mortality and morbidity in pregnant women and their offspring are linked to premature rupture of membranes (PROM). Epidemiological evidence for heat-related PROM risk is extremely limited. We investigated associations between acute heatwave exposure and spontaneous PROM. Methods We conducted this retrospective cohort study among mothers in Kaiser Permanente Southern California who experienced membrane ruptures during the warm season (May-September) from 2008 to 2018. Twelve definitions of heatwaves with different cut-off percentiles (75th, 90th, 95th, and 98th) and durations (≥ 2, 3, and 4 consecutive days) were developed using the daily maximum heat index, which incorporates both daily maximum temperature and minimum relative humidity in the last gestational week. Cox proportional hazards models were fitted separately for spontaneous PROM, term PROM (TPROM), and preterm PROM (PPROM) with zip codes as the random effect and gestational week as the temporal unit. Effect modification by air pollution (i.e., PM2.5 and NO2), climate adaptation measures (i.e., green space and air conditioning [AC] penetration), sociodemographic factors, and smoking behavior was examined. Results In total, we included 190,767 subjects with 16,490 (8.6%) spontaneous PROMs. We identified a 9–14% increase in PROM risks associated with less intense heatwaves. Similar patterns as PROM were found for TPROM and PPROM. The heat-related PROM risks were greater among mothers exposed to a higher level of PM2.5 during pregnancy, under 25 years old, with lower education and household income level, and who smoked. Even though climate adaptation factors were not statistically significant effect modifiers, mothers living with lower green space or lower AC penetration were at consistently higher heat-related PROM risks compared to their counterparts. Conclusion Using a rich and high-quality clinical database, we detected harmful heat exposure for spontaneous PROM in preterm and term deliveries. Some subgroups with specific characteristics were more susceptible to heat-related PROM risk.
Suggested Citation
Anqi Jiao, Yi Sun, David A. Sacks, Chantal Avila, Vicki Chiu, John Molitor, Jiu-Chiuan Chen, Kelly T Sanders, John T Abatzoglou, Jeff Slezak, Tarik Benmarhnia, Darios Getahun and Jun Wu (2023) “The role of extreme heat exposure on premature rupture of membranes in Southern California: A study from a large pregnancy cohort”, Environment International, 173, p. 107824. Available at: 10.1016/j.envint.2023.107824. published journal article
The automotive future belongs to fuel cells range, adaptability, and refueling time will ultimately put hydrogen fuel cells ahead of batteries
IEEE Spectrum
Publication Date
February 1, 2017
Author(s)
Suggested Citation
G. Scott Samuelsen (2017) “The automotive future belongs to fuel cells range, adaptability, and refueling time will ultimately put hydrogen fuel cells ahead of batteries”, IEEE Spectrum, 54(2), pp. 38–43. Available at: 10.1109/mspec.2017.7833504. conference paper
WIP: Infrared Laser Reflection Attack Against Traffic Sign Recognition Systems
ISOC Symposium on Vehicle Security and Privacy (VehicleSec)
Publication Date
January 1, 2023
Author(s)
Takami Sato, Sri Hrushikesh Bhupathiraju, Michael Clifford, Takeshi Sugawara, Qi Alfred Chen, Sara Rampazzi
Abstract
All vehicles must follow the rules that govern traffic behavior, regardless of whether the vehicles are human-driven or Connected, Autonomous Vehicles (CAVs). Road signs indicate locally active rules, such as speed limits and requirements to yield or stop. Recent research has demonstrated attacks, such as adding stickers or dark patches to signs, that cause CAV sign misinterpretation, resulting in potential safety issues. Humans can see and potentially defend against these attacks. But humans can not detect what they can not observe. We have developed the first physical-world attack against CAV traffic sign recognition systems that is invisible to humans. Utilizing Infrared Laser Reflection (ILR), we implement an attack that affects CAV cameras, but humans can not perceive. In this work, we formulate the threat model and requirements for an ILR-based sign perception attack. Next, we evaluate attack effectiveness against popular, CNNbased traffic sign recognition systems. We demonstrate a 100% success rate against stop and speed limit signs in our laboratory evaluation. Finally, we discuss the next steps in our research.