working paper

Micro-simulation Modeling Approach to Applications of On-line Simulation and Data Fusion

Abstract

This report summarizes research work conducted under TO4143 at the California PATH ATMS Center at the University of California, Irvine. This project has two tasks: Functionality enhancements of the PARAMICS simulation model through API programming for the on-line simulation application; On-line data fusion algorithm for a better section travel time estimation based on point detector data and probe vehicle data. In order to conduct these two tasks, we complete the following two related studies, which are the basis of the two tasks of this project: Development of the capability-enhanced PARAMICS simulation environment through API programming; Calibration and validation of microscopic simulation models.

research report

Large-Scale Traffic Simulation Through Distributed Computing of Paramics

Publication Date

October 1, 2004

Author(s)

Final Report

UCB-ITS-PRR-2004-42

Abstract

Simulation modeling is an increasingly popular and effective tool for analyzing transportation problems, which are not amendable to study by other means. We examine the need for parallel or distributed simulation approaches from the need for computational speed-ups, availability of options towards that, and then at the need to distribute the effort to develop network simulation contexts and datasets. After an overview of the general techniques for the distributed discrete-event simulation and previous efforts on the distributed traffic simulation, we present the general architecture of the proposed distributed modeling framework. Two categories of modeling strategies, namely, light global control / independent subnets vs. heavy global control / coordinated subnets are described. We have implemented the distributed scheme of light global control / independent subnets and the implemented details, such as communication techniques and vehicle transferring across the boundary of two subnets are discussed. Unlike the previous studies using the dedicated high performance machines, our efforts are to utilize the low-cost networked PCs that are commonly available. By using the API supported by off-the-shelf Paramics software, we are able to distribute the computational load of microscopic simulation to multiple single-processor PCs without access the proprietary source codes of the simulation program. Performance testing and analysis of the implemented prototype demonstrate that the proposed framework is very promising.

Suggested Citation
Henry X. Liu, Wenteng Ma, R. Jayakrishnan and Will Recker (2004) Large-Scale Traffic Simulation Through Distributed Computing of Paramics. Final Report UCB-ITS-PRR-2004-42. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/4h1451bn.

Research Report: Resource Paper an Attitudinal Models

presentation

Clustering and Optimizing Transit Requests for Scalable Shortest-Path Routing

Publication Date

October 24, 2025

Author(s)

Luke Li
Suggested Citation
Luke Li (2025) “Clustering and Optimizing Transit Requests for Scalable Shortest-Path Routing”. 2025 Emerging Scholars Transportation Research Showcase II, ITS-Irvine, 24 October. Available at: https://youtu.be/W6lpxBvg1Ck?t=3969.

published journal article

SURVEY DATA RELIABILITY EFFECTS ON RESULTS OF CONSUMER PREFERENCE ANALYSES.

Advances in Consumer Research

Publication Date

January 1, 1979

Author(s)

Abraham D. Horowitz, Thomas Golob

Abstract

Mail panel survey respondents were resurveyed to assess data reliability. Aggregate measures of evaluations toward hypothetical new products were found to be reliable. However, certain respondents were unreliable, and decision criteria were developed for identifying such respondents when resurvey data are unavailable. The effects on data analyses results of eliminating potentially unreliable respondents from the survey sample were investigated. The magnitude of the effects depended upon the type of analyses conducted.

Suggested Citation
Abraham D. Horowitz and Thomas F. Golob (1979) “SURVEY DATA RELIABILITY EFFECTS ON RESULTS OF CONSUMER PREFERENCE ANALYSES.”, Advances in Consumer Research, 6(1), p. 532. Available at: https://openurl.ebsco.com/EPDB%3Agcd%3A1%3A8512833/detailv2?sid=ebsco%3Aplink%3Ascholar&id=ebsco%3Agcd%3A6604733&crl=c.

conference paper

A Comparison of Time-use for Telecommuters, Potential Telecommuters, and Commuters during the COVID-19 Pandemic

101st Annual Meeting of the Transportation Research Board

Publication Date

January 1, 2022
Suggested Citation
Rezwana Rafiq and Michael G. McNally (2022) “A Comparison of Time-use for Telecommuters, Potential Telecommuters, and Commuters during the COVID-19 Pandemic”. 101st Annual Meeting of the Transportation Research Board.

published journal article

Run-time scheduling framework for event-driven applications on a GPU-Based embedded system

IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst.

Publication Date

January 1, 2016

Author(s)

Haeseung Lee, Mohammad Al Faruque

Abstract

Graphics processing units (GPUs) have been employed in the critical path of applications in embedded systems due to the GPUs’ programmability, high-performance, and low power consumption. State-of-the-art GPUs have the capability to process multiple GPU workloads concurrently. Moreover, GPU-based embedded systems have been considered to be essential because of the increased number of throughput-oriented applications and system events. However, existing application scheduling frameworks on a GPU do not have enough flexibility to handle the dynamic behavior of the event-driven applications. This is because in the existing scheduling frameworks: 1) only temporal preemption is considered and 2) one application occupies the GPU at a time. In order to tackle these problems, we propose a novel run-time scheduling framework that considers both temporal and spatial preemptions concurrently. We demonstrate the capability and novelty of our framework compared to the existing scheduling frameworks with realistic benchmark applications and with different execution scenarios. Experimental results show that our scheduling framework is able to guarantee up to 1.37 times as many applications compared to other scheduling frameworks. Moreover, the total amount of timing violation is decreased by up to 54.57%.

Suggested Citation
Haeseung Lee and Mohammad Abdullah Al Faruque (2016) “Run-time scheduling framework for event-driven applications on a GPU-Based embedded system”, IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst., 35(12), pp. 1956–1967. Available at: 10.1109/tcad.2016.2547916.

Phd Dissertation

Activity-based travel analysis in the wireless information age

Suggested Citation
JAMES E. MARCA (2002) Activity-based travel analysis in the wireless information age. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991008196379704701.

published journal article

Stowage and Deployment of a Viscoelastic Orthotropic Carbon-Fiber Composite Tape Spring

Journal of Spacecraft and Rockets

Publication Date

January 1, 2018

Author(s)

Elisa Borowski, Eslam M. Soliman, Arafat I. Khan, Mahmoud M. Reda Taha

Abstract

Strain energy deployable composite structures offer spacecraft designs reduced payload and compact volume. One of the greatest advantages presented by deployable composite structures arises from their ability to maintain high-strain configurations for extended periods of stowage. Because of the viscoelastic nature of the polymer matrix, the stowed composite structure undergoes stress relaxation that results in a decrease of the energy available for deployment. This paper focuses on a three-layered (±45 deg plain weave/0 deg unidirectional/±45 deg plain weave) carbon-fiber-reinforced polymer composite deployable structure, known as a tape spring. Stress relaxation testing was used to define the viscoelastic behavior of the epoxy matrix. Experimental long-term stowage and deployment testing was performed on the (±45/0/±45 deg) tape spring specimens. Finite element simulations considering viscoelastic, orthotropic stress relaxation were developed to predict the effects of stress relaxation on the deployment of a (±45/0/±45 deg) tape spring.

Suggested Citation
Elisa C. Borowski, Eslam M. Soliman, Arafat I. Khan and Mahmoud M. Reda Taha (2018) “Stowage and Deployment of a Viscoelastic Orthotropic Carbon-Fiber Composite Tape Spring”, Journal of Spacecraft and Rockets, 55(4), pp. 829–840. Available at: 10.2514/1.A33960.