published journal article
Archives: Research Products
conference paper
The Tracer Data Collection System: Implementation and Operational Experience
Transportation Research Board 82nd Annual Meeting
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Associated Project
Author(s)
Suggested Citation
James E Marca, Craig R Rindt and Michael G McNally (2002) “The Tracer Data Collection System: Implementation and Operational Experience”, in Transportation Research Board 82nd Annual Meeting. Available at: https://escholarship.org/uc/item/3826k93v.presentation
Periodicity Detection of Simulated Traffic Data and Calibration of Network Fundamental Diagrams in Signalized Road Networks
Publication Date
Author(s)
Suggested Citation
Ximeng Fan and Wenlong Jin (2021) “Periodicity Detection of Simulated Traffic Data and Calibration of Network Fundamental Diagrams in Signalized Road Networks”. 100th TRB Annual Meeting.published journal article
Essays in honor of Kenneth a. Small
Journal of Urban Economics
Publication Date
Author(s)
Suggested Citation
Jan K. Brueckner (2007) “Essays in honor of Kenneth a. Small”, Journal of Urban Economics, 62(2), p. 161. Available at: 10.1016/j.jue.2007.07.001.working paper
Product Differentiation on Roads: Constrained Congestion Pricing with Heterogeneous Users
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Author(s)
Working Paper
Areas of Expertise
Abstract
We explore the properties of various types of public and private pricing on a congested road network, with heterogeneous users and allowing for elastic demand. Heterogeneity is represented by a continuum of values of time. The network allows us to model certain features of real-world significance: pricing restrictions on either complementary or substitute links, as well as interactions between different user groups on shared links (e.g. in city centers). We find that revenue-maximizing pricing, whether restricted or unrestricted; but this difference is mitigated by the product differentiation made possible with heterogeneous users. Product differentiation also produces some unexpected distributional effects: those hurt most by pricing may be people with moderate rather than low values of time, and first-best pricing can cause congestion levels to increase for some users compared to no pricing. Ignoring heterogeneity causes the welfare benefits of a policy close to one currently being used, namely second-best pricing of one of two parallel links, to be dramatically underestimated. Unlike first-best policies, second-best policies are in danger of losing much of their potential effectiveness if heterogeneity is ignored when setting toll levels.
Suggested Citation
Erik T. Verhoef and Kenneth A. Small (2002) Product Differentiation on Roads: Constrained Congestion Pricing with Heterogeneous Users. Working Paper UCI-ITS-WP-02-10, UCTC 656. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/2sb2x5xp.conference paper
A model-based design of cyber-physical energy systems
2014 19th asia and south pacific design automation conference (ASP-DAC)
Publication Date
Author(s)
Suggested Citation
Mohammad Abdullah Al Faruque and Fereidoun Ahourai (2014) “A model-based design of cyber-physical energy systems”, in 2014 19th asia and south pacific design automation conference (ASP-DAC). IEEE, pp. 97–104. Available at: 10.1109/aspdac.2014.6742873.published journal article
Stochastic modeling and real-time prediction of vehicular lane-changing behavior
Transportation Research Part B: Methodological
Publication Date
Author(s)
Suggested Citation
Jiuh-Biing Sheu and Stephen G. Ritchie (2001) “Stochastic modeling and real-time prediction of vehicular lane-changing behavior”, Transportation Research Part B: Methodological, 35(7), pp. 695–716.published journal article
Adaptive Data Fusion for State Estimation and Control of Power Grids Under Attack
IEEE Transactions on Industrial Informatics
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Author(s)
Abstract
Current power system state estimation and control methods are susceptible to false data injection attacks (FDIAs), which introduce faulty measurements throughout the grid that decrease grid stability. Fusing sensor measurements can reduce errors in state estimation, and data-driven approaches have been increasingly used for defense against FDIAs. However, current methods often lack adaptability and focus only on detection while failing to address attack effects on estimation and control. This work proposes AstroFusion, an adaptive data fusion framework that makes power grid state estimation and control more resilient to attacks. AstroFusion employs deep multilayer perceptrons to identify which sensors may be under attack and adaptively selects from an ensemble of data-driven models to improve the state estimation. This work is the first to characterize the performance of autonomous power grid controllers in the presence of varying attacks. Results are shown on IEEE 14-bus, IEEE 36-bus, and IEEE 118-bus systems.
Suggested Citation
Trier Mortlock and Mohammad Abdullah Al Faruque (2024) “Adaptive Data Fusion for State Estimation and Control of Power Grids Under Attack”, IEEE Transactions on Industrial Informatics, 20(9), pp. 11115–11126. Available at: 10.1109/TII.2024.3399885.Phd Dissertation
Online Advertising: A Large Scale Computing Perspective
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Author(s)
Areas of Expertise
Abstract
Online advertising is emerging as a primary industry for major computer science companies such as Facebook, Google, Microsoft and Yahoo!. From a computing perspective, we face challenges to match the best ads to suitable users within fast enough response times on the massive industrial Petabyte scale of data. In this thesis, centered on computational problems related to online ad problems, the main contributions are: to provide a new statistical model for ad response prediction; a new parallel computing algorithm for model inference; a new optimization method in an online stochastic environment; and exploration and exploitation for ad selection in time-varying dynamic systems. First, we introduce a Bayesian Regression Model for click through rate prediction, and develop and parallelize learning and inference algorithms in the distributed Hadoop Map-Reduce framework. Then, we propose a Multi-Core Gibbs Sampling. Our exact parallel inference achieves near linear speedup in the complex statistical models on 1.8 million news articles from over 20 years of the New York Times. Moreover, we develop a voted Dual Average method for online classification, derive the training and generalization error bounds, and achieve state-of-the-art performance in parsing reranking. Finally, we discuss the exploration and exploitation in a more realistic scenario under a time-varying environment. We introduce different discount factors (e.g. exponential decay) according to the underlying dynamics; and consequently our algorithm is able to trade-off exploration and exploitation adaptively.
Suggested Citation
Tianbing Xu (2013) Online Advertising: A Large Scale Computing Perspective. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991034281349704701 (Accessed: October 13, 2023).working paper
The Relationship Between an Option Space and Drivers' Indecision
Publication Date
Author(s)
Abstract
A traffic signal is a substantially different traffic sign compared with othe traffic devices. The uniqueness of traffic signals is manifested in their displaying an alternate message and not a constant one. The transition period from one message to another creates a decision problem for drivers. An inappropriate decision might create a risk of a rear-end collision. This article presents a disaggregate behavioral model for drivers’ decision when the green light ends. It is demans trated, and supported by field data, that a large option zone increases the indecision of drivers. The increase in indecision creates a greater risk of rear-end collisions, as experienced at many intersections. The influence of distance from the intersection and of approach speed on drivers’ decision is examined through the model.