policy brief

Using a “Bathtub Model” to Analyze Travel Can Protect Privacy While Providing Valuable Insights

Policy Brief

UC-ITS-2022-45

Areas of Expertise

Abstract

Transportation agencies increasingly rely on detailed trip data to analyze traffic patterns and plan infrastructure improvements. However, traditional data collection methods require extensive personal information about travelers’ origins, destinations, and routes, raising serious privacy concerns. Current “big data” approaches can track individual movements with alarming precision, often without explicit consent. As privacy regulations tighten and public concerns grow, transportation planners need alternative methods that balance analytical needs with privacy protection. To address this challenge, the research team evaluated the “bathtub model” as a privacy-preserving alternative to traditional traffic data collection methods. This simple, network-level approach treats all trips in a region as part of one system. Instead of tracking each person’s path, a bathtub model represents trips by how much distance they have left to travel. This allows for analyzation of network performance while protecting privacy.

Suggested Citation
Wen-Long Jin and Joseph Lo (2025) Using a “Bathtub Model” to Analyze Travel Can Protect Privacy While Providing Valuable Insights. Policy Brief UC-ITS-2022-45. UC ITS / ITS-Irvine. Available at: https://doi.org/10.7922/G2D798TX (Accessed: November 3, 2025).

Phd Dissertation

Research universities as gateways: The expanding roles of higher education institutions and their contribution to economic development

Publication Date

September 30, 2021

Author(s)

Areas of Expertise

Abstract

The past 30 years have witnessed a gradual expansion in the missions of many universities, and in the ways in which they contribute to local and regional economic development. While teaching and research continue to serve as the foundational core of most university missions, increased attention has been afforded to how universities, by their presence and functions, influence the spatial geographies of neighborhoods, cities, and regions. This dissertation research explores the changing roles of research universities in small and medium-sized metropolitan areas with an emphasis on their impacts across the different geographical scales by investigating associations between university presence and (1) growth in foreign-born populations; (2) the attraction and retention of highly educated residents; and (3) student-driven neighborhood change dynamics. The findings of this dissertation extend previous studies emphasizing the increasing importance of higher education institutions to economic development activities at various scales. Results from metropolitan area level analyses demonstrate that counties with large research universities were associated with an increase in foreign-born residents following the 1990 Immigration and Naturalization Act, as well as an increase in highly educated residents in the 2000-2014 period. More specifically, while findings revealed that the presence of research universities generate significant spatial spillovers of highly educated residents from university host counties to metropolitan levels, there was little evidence of such spatially-explicit dynamics occurring amongst foreign-born residents. Furthermore, findings from neighborhood-level analyses indicated that proximity to large research university campuses may play an outsized role on the likelihood of neighborhoods undergoing studentification (i.e., student-driven neighborhood change) in the 2000-2014 period. These results may be indicative of a bifurcation of neighborhoods in university-dominant counties into wealthy and highly educated renter populations situated near the university campus, and relatively less wealthy and less educated homeowners residing on the further away from the campus or on the periphery of the county. By exploring university contributions beyond the spheres of research, teaching, and service contributions, this dissertation presents scholars, urban planners, and policymakers with a more comprehensive portrait of the relationship between universities and their host communities. The evidence of this work suggests that the evolving role of higher education institutions, including their role as gateways for new populations, should be reflected in policymaking which seeks to leverage the locational advantages of research universities for city building or revitalization efforts. Further, policymakers and planners should also be cognizant that scale matters when considering how higher education institutions can better serve their surrounding communities. The contributions of research universities should not be thought of as monolithic or uniform, but should rather be seen as presenting different opportunities and challenges at different geographical levels.

Suggested Citation
N Osutei (2021) Research universities as gateways: The expanding roles of higher education institutions and their contribution to economic development. PhD Dissertation. UC Irvine. Available at: https://escholarship.org/uc/item/5x68r902.

journal article preprint

Used Oil Policies to Protect the Environment: An Overview of Canadian Experiences

Abstract

We examine some consequences of dumping used oil in the environment and review some policies to foster used oil recycling. We then contrast policies adopted in the Canadian Prairie Provinces for managing used oil, used oil filters, and containers, with those put in place in the rest of Canada. Our analysis proposes that public-private partnerships relying on economic instruments and public education can be more effective for recycling used oil than public agencies relying mostly on regulations.

Phd Dissertation

Human-centered computing and the future of work : lessons from mechanical turk and turkopticon, 2008-2015

Publication Date

June 30, 2015

Areas of Expertise

Abstract

Online labor markets such as Amazon Mechanical Turk (AMT), Uber, and TaskRabbit are contributing to rapid changes in the nature of work for hundreds of thousands of workers. These markets create significant new economic opportunities, but most currently treat workers as second-class citizens. Take-home pay is often low compared to similar work in traditional employment arrangements, and workers have limited means of influencing market design or management practice. This makes it hard for workers to create reliable livelihoods from the opportunities these markets present. This dissertation uses AMT, an online labor market for small information tasks, as a case through which to examine the consequences of treating workers as second-class citizens, to argue that future platform designs and management practices should treat workers as central stakeholders, and to develop theory and method for doing so. The central argument of the dissertation is that workers’ concerns should be more substantively and systematically addressed in the design and operation of online labor markets. Five messages elaborate this argument. First, in online labor markets, some workers are casual or transient, while others are professionals, providing significant and reliable value to customers and relying on income earned in the market to meet basic needs. Second, workers who rely on income earned through online labor markets should be considered first-class stakeholders, alongside customers and shareholders. Third, workers in online labor markets are rarely the narrowly self-interested profit maximizers of classical economic theory. Workers can be better understood as “situatedly rational” actors: human beings with incomplete information and finite cognitive capabilities whose actions and preferences are shaped by many factors, including rules, norms, and expectations. Fourth, online labor markets are not monolithic, perfectly competitive markets but parts of polycentric economic systems composed of complexly interlinked action situations characterized by imperfect competition and incomplete information. Fifth, institutions supporting crowd work research should develop an interdisciplinary practice-oriented agenda to understand the consequences of current online labor market designs and practices, and to develop new designs and practices that incorporate workers who rely on market income as central stakeholders.

Suggested Citation
MICHAEL SILBERMAN (2015) Human-centered computing and the future of work : lessons from mechanical turk and turkopticon, 2008-2015. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991017757829704701.

conference paper

Bridging the Binary Analysis Gap: A Cross-Compiler Dataset and Neural Framework for Industrial Control Systems

Proceedings of the 31st ACM SIGKDD Conference on Knowledge Discovery and Data Mining V.2

Publication Date

August 3, 2025

Author(s)

Yonatan G. Achamyeleh, Shih-Yuan Yu, Gustavo Q. Araya, Mohammad Al Faruque

Areas of Expertise

Abstract

Industrial Control Systems (ICS) rely heavily on Programmable Logic Controllers (PLCs) to manage critical infrastructure, yet analyzing PLC executables remains challenging due to diverse proprietary compilers and limited access to source code.To bridge this gap, we introduce PLC-BEAD, a comprehensive dataset containing 2431 compiled binaries from 700+ PLC programs across four major industrial compilers (CoDeSys, GEB, OpenPLC-V2, OpenPLC-V3). This novel dataset uniquely pairs each binary with its original Structured Text source code and standardized functionality labels, enabling both binary-level and source-level analysis. We demonstrate the dataset’s utility through PLCEmbed, a transformer-based framework for binary code analysis that achieves 93% accuracy in compiler provenance identification and 42% accuracy in fine-grained functionality classification across 22 industrial control categories. Through comprehensive ablation studies, we analyze how compiler optimization levels, code patterns, and class distributions influence model performance. We provide detailed documentation of the dataset creation process, labeling taxonomy, and benchmark protocols to ensure reproducibility. Both PLC-BEAD and PLCEmbed are released as open-source resources to foster research in PLC security, reverse engineering, and ICS forensics, establishing new baselines for data-driven approaches to industrial cybersecurity.

Suggested Citation
Yonatan G. Achamyeleh, Shih-Yuan Yu, Gustavo Q. Araya and Mohammad A. Al Faruque (2025) “Bridging the Binary Analysis Gap: A Cross-Compiler Dataset and Neural Framework for Industrial Control Systems”, in Proceedings of the 31st ACM SIGKDD Conference on Knowledge Discovery and Data Mining V.2. New York, NY, USA: Association for Computing Machinery (KDD '25), pp. 5260–5269. Available at: 10.1145/3711896.3737373.

Preprint Journal Article

Priority Queue Formulation of Agent-Based Bathtub Model for Network Trip Flows in the Relative Space

Abstract

Agent-based models have been extensively used to simulate the behavior of travelers in transportation systems because they allow for realistic and versatile modeling of interactions. However, traditional agent-based models suffer from high computational costs and rely on tracking physical locations, raising privacy concerns. This paper proposes an efficient formulation for the agent-based bathtub model (AB2M) in the relative space, where each agent’s trajectory is represented by a time series of the remaining distance to its destination. The AB2M can be understood as a microscopic model that tracks individual trips’ initiation, progression, and completion and is an exact numerical solution of the bathtub model for generic (time-dependent) trip distance distributions. The model can be solved for a deterministic set of trips with a given demand pattern (defined by the start time of each trip and its distance), or it can be used to run Monte Carlo simulations to capture the average behavior and variation stochastic demand patterns, described by probabilistic distributions of trip distances and departure times. To enhance the computational efficiency, we introduce a priority queue formulation, eliminating the need to update trip positions at each time step and allowing us to run large-scale scenarios with millions of individual trips in seconds. We systematically explore the scaling properties and discuss the introduction of biases and numerical errors. The systematic exploration of scaling properties of the modeling of individual agents in the relative space with the AB2M further enhances its applicability to large-scale transportation systems and opens up opportunities for studying travel time reliability, scheduling, and mode choices.

Suggested Citation
Irene Martinez and Wen-long Jin (2023) “Priority Queue Formulation of Agent-Based Bathtub Model for Network Trip Flows in the Relative Space”. arXiv. Available at: 10.48550/arXiv.2309.01970.

working paper

Used Oil Policies to Protect the Environment: An Overview of Canadian Experiences

Publication Date

September 1, 2001

Working Paper

UCI-ITS-WP-01-5, UCTC 666

Areas of Expertise

Abstract

We examine some consequences of dumping used oil in the environment and review some policies to foster used oil recycling. We then contrast policies adopted in the Canadian Prairie Provinces for managing used oil, used oil filters, and containers, with those put in place in the rest of Canada. Our analysis proposes that public-private partnerships relying on economic instruments and public education can be more effective for recycling used oil than public agencies relying mostly on regulations.

Suggested Citation
Hilary Nixon and Jean-Daniel Saphores (2001) Used Oil Policies to Protect the Environment: An Overview of Canadian Experiences. Working Paper UCI-ITS-WP-01-5, UCTC 666. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/8x15b0x7.

working paper

Impacts of Motor Vehicle Operation on Water Quality in the United States - Clean-up Costs and Policies

Publication Date

January 1, 2007

Abstract

This paper investigates the costs of controlling some of the environmental impacts of motor vehicle transportation on groundwater and on surface waters. We estimate that annualized costs of cleaning-up leaking underground storage tanks range from $0.8 billion to $2.1 billion per year over ten years. Annualized costs of controlling highway runoff from principal arterials in the US are much larger: they range from $2.9 billion to $15.6 billion per year over 20 years (1.6% to 8.3% of annualized highway transportation expenditures.) Some causes of non-point source pollution were unintentionally created by regulations or could be addressed by simple design changes of motor vehicles. A review of applicable measures suggests that effective policies should combine economic incentives, information campaigns, and enforcement, coupled with preventive environmental measures. In general, preventing water pollution from motor vehicles would be much cheaper than cleaning it up.

Phd Dissertation

Electronic waste management in California : consumer attitudes toward recycling, advanced recycling fees, "green" electronics, and willingness to pay for e-waste recycling

Publication Date

June 30, 2006

Author(s)

Areas of Expertise

Suggested Citation
Hilary Nixon (2006) Electronic waste management in California : consumer attitudes toward recycling, advanced recycling fees, "green" electronics, and willingness to pay for e-waste recycling. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991034707529704701.

Phd Dissertation

Economic analysis of aircraft and airport noise regulations

Publication Date

January 1, 2006

Author(s)

Abstract

The aviation industry has sought to address the negative externality of aircraft noise using a variety of approaches, but there has been little theoretical work to date encompassing both the market implications and the social optimality of air transportation noise policy. This dissertation develops simple theoretical models to analyze the effects of noise regulation on an airline’s scheduling, aircraft ‘quietness’, and airfare choices. Monopolistic and duopolistic airline competition are modelled, and two types of noise limits are considered: maximum cumulative noise from aircraft operations and noise per aircraft operation. As expected, tighter noise limits, which reduce community exposure to noise, also cause airlines to reduce service frequency and raise fares, which hurts consumers. Welfare analysis investigates the social optimality of noise regulation, taking into account the social cost of exposing airport communities to noise damage, as well as consumer surplus and airline profit. Numerical simulations show that the type of noise limit has a significant effect on the magnitude of the first-best and second-best optimal solutions for service frequency, cumulative noise, and aircraft size and level of quietness. Furthermore, the numerical analyses suggest that under the more realistic second-best case, the cumulative noise limit might be a preferable policy instrument over the per-aircraft noise limit. In the monopoly’s parameter space exploration, welfare is found to be slightly higher, cumulative noise is lower, and the fare is slightly lower when the planner controls cumulative noise rather than per-aircraft noise. In the duopoly case, when the per-aircraft limit yields greater welfare than the cumulative limit, the per-aircraft limit offers only modest welfare gains above the levels achieved with the cumulative limit. But when the cumulative limit yields greater welfare than the per-aircraft limit, the cumulative limit offers substantial welfare gains above the levels achieved with the per-aircraft limit. The effects of noise taxation and the optimal level of noise taxes are also investigated with the duopoly model; the analysis shows equivalence between noise taxation and the cumulative noise limit.

Suggested Citation
Raquel Girvin (2006) Economic analysis of aircraft and airport noise regulations. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/74dcdl/alma991035092979904701 (Accessed: October 14, 2023).