published journal article

Short-Term Exposure to Ambient Air Pollution and Increased Emergency Room Visits for Skin Diseases in Beijing, China

Toxics

Publication Date

May 1, 2021

Author(s)

Wanzhou Wang, Wenlou Zhang, Jingjing Zhao, Hongyu Li, Jun Wu, Furong Deng, Qingbian Ma, Xinbiao Guo

Abstract

Skin diseases have become a global concern. This study aims to evaluate the associations between ambient air pollution and emergency room visits for skin diseases under the background of improving air quality in China. Based on 45,094 cases from a general hospital and fixed-site monitoring environmental data from 2014–2019 in Beijing, China, this study used generalized additive models with quasi-Poisson regression to estimate the exposure–health associations at lag 0–1 to lag 0–7. PM2.5 and NO2 exposure were associated with increased emergency room visits for total skin diseases (ICD10: L00-L99). Positive associations of PM2.5, PM10, O3 and NO2 with dermatitis/eczema (ICD-10: L20–30), as well as SO2 and NO2 with urticaria (ICD-10: L50) visits were also found. For instance, a 10 μg/m3 increase in PM2.5 was associated with increases of 0.7% (95%CI: 0.2%, 1.2%) in total skin diseases visits at lag 0–5 and 1.1% (95%CI: 0.6%, 1.7%) in dermatitis/eczema visits at lag 0–1, respectively. For PM2.5, PM10 and CO, stronger annual associations were typically observed in the high-pollution (2014) and low-pollution (2018/2019) years. For instance, a 10 μg/m3 increase in PM2.5 at lag 0–5 was associated with increases of 1.8% (95%CI: 1.0%, 2.6%) and 2.3% (95%CI: 0.4%, 4.3%) in total skin disease visits in 2014 and 2018, respectively. Our study emphasizes the necessity of controlling the potential health hazard of air pollutants on skin, although significant achievements in air quality control have been made in China.

Suggested Citation
Wanzhou Wang, Wenlou Zhang, Jingjing Zhao, Hongyu Li, Jun Wu, Furong Deng, Qingbian Ma and Xinbiao Guo (2021) “Short-Term Exposure to Ambient Air Pollution and Increased Emergency Room Visits for Skin Diseases in Beijing, China”, Toxics, 9(5), p. 108. Available at: 10.3390/toxics9050108.

conference paper

High coverage point-to-point transit: Local vehicle routing problem with genetic algorithms

2011 14th international IEEE conference on intelligent transportation systems (ITSC)

Publication Date

October 1, 2011

Author(s)

Suggested Citation
Jaeyoung Jung, R. Jayakrishnan and Doohee Nam (2011) “High coverage point-to-point transit: Local vehicle routing problem with genetic algorithms”, in 2011 14th international IEEE conference on intelligent transportation systems (ITSC). IEEE. Available at: 10.1109/itsc.2011.6082818.

published journal article

Performance Based Funding Allocation guidelines for Transit Operations in Los Angeles County

Transportation Research Record

Publication Date

January 1, 1982

Author(s)

Gordon (Pete) Fielding, Subhash R Mundle, Joe Misner

Abstract

During the last five years, transit performance indicators have been widely used in the transit industry. California and New York have used performance indicators to determine eligibility for funding. In Pennsylvania, transit performance measures have been used to provide incentive payments for superior performance, and in Michigan a detailed analysis of transit operations provides the basis for state managerial assistance. In Los Angeles County, nine transit operators, including Southern California Rapid Transit District, provide fixedroute transit service. Between 1977 and 1980, operating cost per vehicle hour increased from $28.52 to $38.76, a rate higher than the consumer price index for the Los Angeles area. In response to state legislation designed to maximize utilization of public subsidies for transit, the Los Angeles County Transportation Commission undertook the development of performance-based guidelines for allocating transit subsidies. The performance guidelines developed in cooperation with the local transit operators are presented here. In this program, service is classified into local and express categories. Seven indicators were chosen to monitor transit performance on a periodic basis. Three indicators were selected to establish standards to be achieved by all fixed-route service operators in Los Angeles County. Compliance with these standards will determine eligibility for discretionary funds (representing 5 percent of operating assistance) in the future. The methodology for quantifying loss of subsidy funds if an operator falls below the established standards is also described. The performance guidelines merit consideration for two reasons. First, they represent an attempt by a large metropolitan area to control transit costs, and second they initiate performance-based funding allocation rather than funding based on demographic characteristics or operating deficits. Both reasons are substantial advancements in the theory and application of performance-based guidelines to transit-financing issues.

Suggested Citation
Gordon J Fielding, Subhash R Mundle and Joe Misner (1982) “Performance Based Funding Allocation guidelines for Transit Operations in Los Angeles County”, Transportation Research Record, (857), pp. 14--18. Available at: https://onlinepubs.trb.org/Onlinepubs/trr/1982/857/857-003.pdf.

research report

Review current methods for allocating average weekday mobile source emissions to weekend days

Abstract

This report provides a review of the California Air Resources Board’s current method for adjusting estimated emissions from on-road motor vehicles. These estimates are a critical feature of CARB’s air quality modeling efforts, which are an important tool for maintaining and improving California’s air quality. The central approach of the method adjusts “average weekday” emissions estimates using fac- tors derived from measurements of diurnal and day-of-week variations in multi-class vehicle ac- tivity provided by Caltrans from automated vehicle classifer (AVC) data. The diurnal factors are used to adjust the inputs to the Direct Travel Improvment Model (DTIM), which provides gridded, hourly estimates that are assumed to represent general spatio-temporal emissions patterns on an average weekday. The day-of-week factors are used to adjust the average weekday county-wide emissions estimates produced by EMFAC, CARB’s tool for estimating emissions from on-road ve- hicles. The day specific spatio-temporal DTIM patterns are then used to produce hourly, gridded emissions from the county-wide EMFAC totals. The body of this report begins with a review the general methodology in the context of the broader model. It continues with a review of the SAS programs that compute the diurnal and day-of-week factors from Caltrans AVC data. We conclude with some recommendations for how the method might be improved over the near-term and long term.

Suggested Citation
Craig R Rindt, James E Marca and Will W Recker (2012) Review current methods for allocating average weekday mobile source emissions to weekend days. Final Report. Available at: https://escholarship.org/uc/item/4vd249bf.

conference paper

Towards Driving-Oriented Metric for Lane Detection Models

Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition

Publication Date

January 1, 2022
Suggested Citation
Takami Sato and Qi Alfred Chen (2022) “Towards Driving-Oriented Metric for Lane Detection Models”. Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 17153–17162. Available at: https://openaccess.thecvf.com/content/CVPR2022/html/Sato_Towards_Driving-Oriented_Metric_for_Lane_Detection_Models_CVPR_2022_paper.html (Accessed: October 5, 2023).

published journal article

The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model

Journal of Power Sources

Publication Date

December 1, 2011
Suggested Citation
Ghazal Razeghi, Tim Brown and G. Scott Samuelsen (2011) “The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model”, Journal of Power Sources, 196(23), pp. 10387–10394. Available at: 10.1016/j.jpowsour.2011.08.043.

working paper

Part-Time Operators in Public Transit: Experiences and Prospects

Publication Date

April 1, 1985

Working Paper

UCI-ITS-WP-85-3

Areas of Expertise

Abstract

Most U.S. transit agencies have begun to use part-time operators as a means to reduce operating cost. This report, based on five case studies, evaluates the cost savings and organizational impacts associated with this change. Results indicate that cost savings have been small but significant in situations where peak service expansion occurred. But where the schedule was static, contract protections for existing operators have made it difficult to use part-time labor, and hence savings were small or insignificant. We find that in transit agencies with highly peaked schedules, part-time operators (PTOs) save money for two reasons: they improve schedule efficiency (the ratio of hours-paid to hours-worked), and their wages and fringe benefits are lower than those of full time operators. In agencies with relatively flat schedules the only savings is from lower wages and fringes, and it is possible that this kind of “two-tier” wage system may be bargained away over time. We find that for agencies with flat or static schedules, it may be more effective to concentrate on alternative strategies such as absenteeism control and extraboard staffing which may be more beneficial and easier to implement. On the organizational side, we find no unusual costs associated with use of PTOs. They have proven to be as reliable, or even more so, than full time operators; they have not created unusual supervisory costs, and there have been relatively few problems between part-time and full-time operators. We also find that instead of creating a permanent force of PTOs, as had been anticipated, most of the PTOs that were hired really wanted full-time work.

Suggested Citation
Kenneth M. Chomitz, Genevieve Giuliano and Charles A. Lave (1985) Part-Time Operators in Public Transit: Experiences and Prospects. Working Paper UCI-ITS-WP-85-3. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/1jm5106j.

conference paper

UAV integrity monitoring measure improvement using terrestrial signals of opportunity

Proceedings of the 32nd international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2019)

Publication Date

October 1, 2019

Author(s)

Mahdi Maaref, Zaher Kassas
Suggested Citation
Mahdi Maaref and Zaher M. Kassas (2019) “UAV integrity monitoring measure improvement using terrestrial signals of opportunity”, in Proceedings of the 32nd international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2019). Institute of Navigation, pp. 3045–3056. Available at: 10.33012/2019.17009.

published journal article

Business Churning and Neighborhood Instability: Is There a Link?

International Regional Science Review

Publication Date

January 12, 2023

Author(s)

Jae Hong Kim, Kevin Kane, Young-An Kim, John R. Hipp

Abstract

Much of the work concerning economic dynamism has focused on its aggregate-level implications, while there have been rising concerns about business displacement at the community or neighborhood level. In this article, we analyze this important (restructuring) process using detailed establishment-level business information and explore how it manifests itself across space within the Los Angeles—Long Beach—Santa Ana, CA Urbanized Area. We also investigate the association between business churning and neighborhood-level housing vacancy rates to understand the implications of dramatic changes in the business landscape. We find that housing vacancies are more likely to increase in urban neighborhoods with a higher establishment death rate, while the creation of new businesses can mitigate the association to some extent. We also detect substantial variation across decades not only in the spatial distribution of business churning but also in its association with housing vacancy rates, suggesting the evolving nature of business dynamics and their implications.

Suggested Citation
Jae Hong Kim, Kevin Kane, Young-An Kim and John R. Hipp (2023) “Business Churning and Neighborhood Instability: Is There a Link?”, International Regional Science Review, p. 01600176221145873. Available at: 10.1177/01600176221145873.

published journal article

Valuing Sequences of Lives Lost or Saved Over Time: Preference for Uniform Sequences

Decision Analysis

Publication Date

March 1, 2020

Author(s)

Jeffery L. Guyse, Robin Keller, Candice H. Huynh

Abstract

Policymakers often make decisions involving human-mortality risks and monetary outcomes that span across different time periods and horizons. Many projects or environmental-regulation policies involving risks to life, such as toxic exposures, are experienced over time. The preferences of individuals on lives lost or saved over time should be understood to implement effective policies. Using a within-subject survey design, we investigated our participants’ elicited preferences (in the form of ratings) for sequences of lives saved or lost over time at the participant level. The design of our study allowed us to directly observe the possible preference patterns of negative time discounting or a preference for spreading from the responses. Additionally, we embedded factors associated with three other prevalent anomalies of intertemporal choice (gain/loss asymmetry, short/long asymmetry, and the absolute magnitude effect) into our study for control. We find that our participants exhibit three of the anomalies: preference for spreading, absolute magnitude effect, and short/long-term asymmetry. Furthermore, fitting the data collected, Loewenstein and Prelec’s model for the valuation of sequences of outcomes allowed for a more thorough understanding of the factors influencing the individual participants’ preferences. Based on the results, the standard discounting model does not accurately reflect the value that some people place on sequences of mortality outcomes. Preferences for uniform sequences should be considered in policymaking rather than applying the standard discounting model.

Suggested Citation
Jeffery L. Guyse, L. Robin Keller and Candice H. Huynh (2020) “Valuing Sequences of Lives Lost or Saved Over Time: Preference for Uniform Sequences”, Decision Analysis, 17(1), pp. 24–38. Available at: 10.1287/deca.2019.0397.