conference paper

Dynamic Tests of a Time-Space Model of Complex Travel Behavior

Travel Behavior Research, International Association of Travel Behavior

Publication Date

September 1, 1987

Abstract

In the research presented here, an attempt is made to analyze the entire daily activity pattern simultaneously in terms of its space, time, and activity category dimensions. The focus of the research is on developing procedures for the dynamic analysis of possible changes in activity patterns that may result from or lead to changes in the characteristics of the household. The intent is to trace the daily activity patterns of groups of travelers that have undergone significant change during multiple points in time, in a manner that will shed some light on both the nature and extent of associated changes in travel behavior. To check on the reliability of the modeling process and to understand its peculiarities, complementary analyses of pattern attributes, and time-series analyses of patterns were performed on the same data set. Results from these complementary analyses are briefly outlined here, and it is hoped that these results aid in placing the present approach in the perspective of the rich legacy of previous work.

Suggested Citation
Will Recker, Thomas F. Golob, Michael G. McNally and John D. Leonard (1987) “Dynamic Tests of a Time-Space Model of Complex Travel Behavior”. Travel Behavior Research, International Association of Travel Behavior, pp. 27–40.

published journal article

The perceived psychological benefits of third places for university students before and after COVID-19 lockdowns

Cities

Publication Date

October 1, 2024

Author(s)

Abstract

The impact of COVID-19 in the relationship between consumer-facing businesses and health and well-being remains understudied. In response, we utilized mixed methods to examine the perceived psychological benefits of urban parks and consumer-facing businesses among students from the University of California, Irvine before and after the COVID-19 lockdown. Overall, findings from photo-based close-ended questions indicated no significant disparity in perceived restorative quality, sentiment, and preference for urban third places before and after COVID-19 lockdowns. However, crowded third places exhibited a notable decline in sentiment and preference for third spaces following the COVID-19 lockdowns. Inductive content analysis of open-ended questions indicated a rise in visits to eating/drinking establishments and shops/stores post-COVID-19 lockdowns and a shift towards outdoor venues for activities. Findings support policy and planning efforts that promote healthy communities by maximizing the benefit of third places.

Suggested Citation
Narae Lee and Douglas Houston (2024) “The perceived psychological benefits of third places for university students before and after COVID-19 lockdowns”, Cities, 153, p. 105299. Available at: 10.1016/j.cities.2024.105299.

conference paper

Factors influencing alternative fuel adoption decisions in heavy-duty vehicle fleets in California

The 98th annual meeting of the transportation research board

Publication Date

January 1, 2019

Abstract

Alternative fuel adoption by heavy-duty vehicle (HDV) fleets can bring substantial benefits to both current local communities and future generations by reducing air pollutants and greenhouse gas emissions. A better understanding of HDV fleet operator perspectives towards alternative fuels can serve as the basis for developing effective policy suggestions that aim to accelerate the diffusion of these innovative technologies throughout the entire vehicle market. This study attempts to identify the factors that have influenced the decision for alternative fuel adoption or non-adoption made by HDV fleet operators in California. Through 18 in-depth qualitative interviews, a total of 25 adoption and 41 non-adoption cases were investigated across various alternative fuel options. Content analysis of the interview data yielded that the primary and most common factors comprised functional suitability, environmental consciousness, availability of vehicles, and regulations. Other important but less common factors were overall costs, vehicle purchase price, fuel price, fuel infrastructure, vehicle reliability and safety, contracts with municipalities, and financial incentives. Based on the key factors identified, testable propositions were developed and seven major hypotheses are presented. The study results help gain a better grasp of the demand-side aspects of alternative fuel adoption in the HDV sector in California.

Suggested Citation
Youngeun Bae, Suman Kumar Mitra, Craig Ross Rindt and Stephen G. Ritchie (2019) “Factors influencing alternative fuel adoption decisions in heavy-duty vehicle fleets in California”, in The 98th annual meeting of the transportation research board.

conference paper

Evaluation of relative clock stability in cellular networks

Proceedings of the 30th international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2017)

Publication Date

November 1, 2017
Suggested Citation
Joe J. Khalife and Zaher M. Kassas (2017) “Evaluation of relative clock stability in cellular networks”, in Proceedings of the 30th international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2017). Institute of Navigation, pp. 2554–2559. Available at: 10.33012/2017.15221.

published journal article

Daily activity pattern recognition by using support vector machines with multiple classes

Transportation Research Part B: Methodological

Publication Date

December 1, 2013
Suggested Citation
Mahdieh Allahviranloo and Will Recker (2013) “Daily activity pattern recognition by using support vector machines with multiple classes”, Transportation Research Part B: Methodological, 58, pp. 16–43. Available at: 10.1016/j.trb.2013.09.008.

working paper

Strategic Hydrogen Refueling Station Locations Analysis with Scheduling and Routing Considerations of Individual Vehicles

Publication Date

September 5, 2012

Working Paper

UCI-ITS-WP-12-2

Abstract

Set Covering problems find the optimal provision of service locations while guaranteeing an acceptable level of accessibility for every demand points in a given area. Other than reliance on static,exogenously-imposed accessibility measures, these problems either exclude substantive infrastructure-vehicle interactions or only include fragmented infrastructure-vehicle interactions related to the routing considerations of households seeking refueling service as a requirement of performing routine, daily activities. Here, we address this problem by coupling a Location-Routing Problem (LRP) that uses the set covering model as a location strategy to the Household Activity Pattern Problem (HAPP) as the mixed integer scheduling and routing model that optimizes households’ participation in out-of-home activities. The problem addressed includes multiple decision makers: the public/private sector as the service provider, and the collection of individual households that make their own routing decisions to perform a given set of “out-of-home activities” together with a visit to one of the service locations. A solution method that does not necessarily require the full information of the coverage matrix is developed to reduce the number of HAPPs that needs to be solved. The performance of the algorithm, as well as comparison of the results to the set covering model, is presented. Although the application is focused on identifying the optimal locations of Hydrogen Fuel Cell Vehicle (HFCV) refueling stations, this proposed formulation can be used as a facility location strategy for any service activity that is generally toured with other activities.

Suggested Citation
Jee Eun Kang and Will W. Recker (2012) Strategic Hydrogen Refueling Station Locations Analysis with Scheduling and Routing Considerations of Individual Vehicles. Working Paper UCI-ITS-WP-12-2. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/9bf4j0xn.

published journal article

An evaluation tool for advanced traffic information and management systems in urban networks

Transportation Research Part C: Emerging Technologies

Publication Date

September 1, 1994

Author(s)

R. (Jay) Jayakrishnan, Hani Mahmassani, Ta-Yin Hu
Suggested Citation
R. Jayakrishnan, Hani S. Mahmassani and Ta-Yin Hu (1994) “An evaluation tool for advanced traffic information and management systems in urban networks”, Transportation Research Part C: Emerging Technologies, 2(3), pp. 129–147. Available at: 10.1016/0968-090X(94)90005-1.

published journal article

Mathematical logic in the modeling of control systems

IFAC Proceedings Volumes

Publication Date

January 1, 2006

Author(s)

Yannis Pavlis, Will Recker
Suggested Citation
Yannis Pavlis and Will Recker (2006) “Mathematical logic in the modeling of control systems”, IFAC Proceedings Volumes, 39(12), pp. 491–496. Available at: 10.3182/20060829-3-nl-2908.00085.

Preprint Journal Article

On Robustness of Lane Detection Models to Physical-World Adversarial Attacks in Autonomous Driving

Publication Date

July 6, 2021

Report Number

arXiv:2107.02488

Abstract

After the 2017 TuSimple Lane Detection Challenge, its evaluation based on accuracy and F1 score has become the de facto standard to measure the performance of lane detection methods. In this work, we conduct the first large-scale empirical study to evaluate the robustness of state-of-the-art lane detection methods under physical-world adversarial attacks in autonomous driving. We evaluate 4 major types of lane detection approaches with the conventional evaluation and end-to-end evaluation in autonomous driving scenarios and then discuss the security proprieties of each lane detection model. We demonstrate that the conventional evaluation fails to reflect the robustness in end-to-end autonomous driving scenarios. Our results show that the most robust model on the conventional metrics is the least robust in the end-to-end evaluation. Although the competition dataset and its metrics have played a substantial role in developing performant lane detection methods along with the rapid development of deep neural networks, the conventional evaluation is becoming obsolete and the gap between the metrics and practicality is critical. We hope that our study will help the community make further progress in building a more comprehensive framework to evaluate lane detection models.

Suggested Citation
Takami Sato and Qi Alfred Chen (2021) “On Robustness of Lane Detection Models to Physical-World Adversarial Attacks in Autonomous Driving”. arXiv. Available at: http://arxiv.org/abs/2107.02488 (Accessed: October 11, 2023).

working paper

Regulation by Prices and by Command

Publication Date

June 1, 1995

Associated Project

Working Paper

UCI-ITS-WP-95-11, UCTC 276

Areas of Expertise

Abstract

Standard economic theory states that regulation by price is more efficient than regulation by command and control. Exceptions may arise of regulators have good knowledge of the supply curve. In practice, though, governments usually regulate by command and control, and do so when there is uncertainty about the technology of supply. We show that government may prefer to regulate by command and control when it cares about the investment decisions of a firm.

Suggested Citation
Amihai Glazer and Charles Lave (1995) Regulation by Prices and by Command. Working Paper UCI-ITS-WP-95-11, UCTC 276. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/6bs9v6wk.