published journal article
Do state affordable housing appeals systems backfire? A natural experiment
Housing Policy Debate
Publication Date
October 1, 2017
Archives: Research Products
working paper
Specification Issues in Models of Population and Employment Growth
Publication Date
December 1, 2001
Author(s)
Areas of Expertise
Abstract
Spatial econometric adaptations of population and employment growth models have been used to study the employment impacts of urban rail transit (Bollinger and Ihlanfeldt, 1997), the links between urban and rural development (Henry, Barkley, and Bao, 1997; Schmitt and Henry, 2000), and causality between intra-metropolitan population and employment location (Boarnet, 1994b). Yet the literature has so far given limited attention to two specification issues that are fundamental to the performance of spatial econometric population and employment growth models. First, the weight matrix, which defines how geographic units of observation relate to one another, must be defined a priori, and alternative versions of the weight matrix have rarely been consistently compared. Second, most recent population-employment growth models are lagged adjustment models, yet the estimated lag parameters often imply that the system does not adjust to a long-run equilibrium, violating one of the maintained hypotheses of the lagged adjustment approach. This paper analyzes those three specification issues, and provides insight into both the validity of various econometric practices that have been common in recent literature and the stability of econometric population and employment growth models when typical assumptions and approaches are changed.
conference paper
Characterization of sector clock biases in cellular CDMA systems
Proceedings of the 29th international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2016)
Publication Date
November 1, 2016
Author(s)
Suggested Citation
Joe Khalife and Zaher M. Kassas (2016) “Characterization of sector clock biases in cellular CDMA systems”, in Proceedings of the 29th international technical meeting of the satellite division of the institute of navigation (ION GNSS+ 2016). Institute of Navigation, pp. 2281–2285. Available at: 10.33012/2016.14731. conference paper
Methodology for determining the best use of road management equipment (Case study: 18 regional offices in south korea)
Proceedings of the 92nd annual meeting of the transportation research board
Publication Date
January 1, 2013
Author(s)
Choong Heon Yang, Amelia Regan, In Soo Kim
Abstract
This paper presents a methodology for determining the best use of road fleet/equipment management. The main purpose of this research is to aid public agencies with road fleet/equipment management within a given budget. In order to demonstrate the value of this approach, a case study using data collected for eighteen regional offices of the South Korean Ministry of Land, Transport and Maritime Affairs were examined. These offices use a computerized system called KAMIS to monitor both the use and condition of road fleet/equipment systematically. This system records the operational history and monitors the current condition of road fleet/equipment management. Road agencies might also want to know whether they currently have sufficient fleet/equipment to handle their actual work, but KAMIS does not provide that type of information. Thus, a methodology uses operational records for road fleet/equipment management, and two evaluation indicators has been developed. Based on the results of the author methodology, fleet/equipment can be classified into several groups: 1) frequently used and important, 2) relatively less used and important, 3) barely used and low importance, and 4) frequently used and low importance. These data can be used by regional offices to effectively lend and borrow fleet/equipment for both long and short term use. Such measures will help save money for the purchase and maintenance of road fleet/equipment. While the study focuses on a specific case study, the decision analysis method can easily be applied by similar decision makers in other countries.
Suggested Citation
Choong Heon Yang, Amelia C. Regan and In Soo Kim (2013) “Methodology for determining the best use of road management equipment (Case study: 18 regional offices in south korea)”, in Proceedings of the 92nd annual meeting of the transportation research board, p. 17p. published journal article
A phase-reconstruction technique for low-power centimeter-accurate mobile positioning
IEEE Transactions on Signal Processing
Publication Date
May 1, 2014
Author(s)
K.M. Pesyna, Zaher Kassas, R.W. Heath Jr., T.E. Humphreys
Suggested Citation
K.M. Pesyna, Z.M. Kassas, R.W. Heath Jr. and T.E. Humphreys (2014) “A phase-reconstruction technique for low-power centimeter-accurate mobile positioning”, IEEE Transactions on Signal Processing, 62(10), pp. 2595–2610. Available at: 10.1109/tsp.2014.2311967. Phd Dissertation
Predicting activity types from GPS and GIS data
Publication Date
January 1, 2006
Author(s)
Abstract
Current travel forecasting models have had limited sensitivity to policy decisions. One of the primary challenges with travel forecasting models (both experimental and those implemented) is limitations in the data. The primary data source, the daily travel diary, is limited in both accuracy and sample size. The daily travel diary has known problems with underreporting, time inaccuracies, respondent fatigue, and other human errors. Global positioning systems (GPS) have been recently used to supplement the daily travel diary. As GPS becomes more accurate, reliable, and cost effective, could it entirely replace the daily travel diary? A number of efforts have used GPS data for route choice studies and to supplement daily travel diaries by providing more accurate time data, and determining under-reporting rates. GPS is also used in computer assisted daily travel diaries, reminding respondents of activities they may have forgotten to report. GPS devices record times and locations of each activity and the trips between those activities. To use GPS data to replace the daily travel diary one need only predict the activity types. The goal of this research is to develop and test a model to predict activity types based solely on: (1) GPS data from devices placed on the individual’s vehicle or person, (2) Land use data, such as location type, expressed as GIS data, and (3) Demographic data for the individual and the household. This thesis summarizes models developed using discriminant analysis and classification/regression trees. The models predicted in which of 26 different activity types the individual participated. Accuracy for out of home activities for the best model was 63%. When combed with the activity of being at home (which can be accurately predicted if we know the individuals home location) an accuracy of 79% was achieved (72% if you consider that GPS data may miss as much as 10% of trips). Since travel diaries have been known to underreport trips by as much as 25%, GPS data with the model developed can be very competitive. It is even more appealing considering the time inaccuracies and human error associated with travel diaries.
Suggested Citation
Patrick Tracy McGowen (2006) Predicting activity types from GPS and GIS data. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/74dcdl/alma991035093161304701 (Accessed: October 14, 2023). conference paper
Vision-based two-factor authentication & localization scheme for autonomous vehicles
Third International Workshop on Automotive and Autonomous Vehicle Security (AutoSec) 2021 (part of NDSS)
Publication Date
January 1, 2021
Author(s)
Anas Alsoliman, Marco Levorato, Qi Alfred Chen
Suggested Citation
Anas Alsoliman, Marco Levorato and A. Chen (2021) “Vision-based two-factor authentication & localization scheme for autonomous vehicles”, in Third International Workshop on Automotive and Autonomous Vehicle Security (AutoSec) 2021 (part of NDSS). Available at: https://par.nsf.gov/servlets/purl/10215804 (Accessed: October 11, 2023). conference paper
DOES ONLINE SHOPPING REDUCE TRAVEL? Evidence from the 2017 National Household Travel Survey
100th Transportation Research Board (TRB) Annual Meeting
Publication Date
January 1, 2021
Author(s)
Suggested Citation
Lu Xu and Jean-Daniel Saphores (2021) “DOES ONLINE SHOPPING REDUCE TRAVEL? Evidence from the 2017 National Household Travel Survey”. 100th Transportation Research Board (TRB) Annual Meeting, Washington, DC. working paper
Standard Transportation Forecasting Techniques: How They Fail
Publication Date
September 1, 1984
Author(s)
Abstract
The decade of the 1980s is proving to be a critical one for transportation system choices. Our transportation infrastructure is on the verge of collapse in many areas. Boston’s rail system. New York’s subway. Connecticut’s highway bridges. and aging urban freeways in the nation’s major cities. are all in dire need of rehabilitation. At the same time. funds are being solicited for new projects. most of which have been on the drawing board for more than a decade. These include interstate highway projects. as well as rail transit projects in major cities throughout the country. In view of the massive investment our current “wish list” of projects implies. it is appropriate to examine the justification for these investments and the way we forecast the need for them.
Suggested Citation
Genevieve Giuliano (1984) Standard Transportation Forecasting Techniques: How They Fail. Working Paper UCI-ITS-WP-84-5. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/32w6b00q. Phd Dissertation
Capacity modeling for multimodal freight transportation networks
Publication Date
January 1, 2005
Author(s)
Areas of Expertise
Abstract
Since the early 1990’s, public policies for transportation planning have evolved towards modally balanced transportation systems, requiring planning agencies to more precisely evaluate the capacity of their transportation systems, considering all feasible modes as well as low-cost capacity improvements. However, existing methods for capacity analysis are limited to either an individual facility or a single mode network, and thus appear insufficient for multimodal systems capacity analysis. This dissertation presents an advanced method for capacity assessment that can serve as an analytical tool for strategic planning of freight transportation systems, particularly from a multimodal perspective. The multimodal network capacity model proposed in this research takes a mathematical form of a nonlinear bi-level optimization problem with an embedded user equilibrium network assignment problem at its lower level. The bi-level problem, referred to as the MNCP model in this thesis, is comprehensive in the sense that many crucial factors are incorporated including multiple modes and commodities, behavioral aspects of network users, external factors, as well as the physical and operational conditions of a network. The numerical tests designed to illustrate the application of the proposed MNCP model indicate that the algorithm developed for solving the bi-level problem has been successfully implemented. These results show the capability of the model not only to estimate the capacity of a multimodal network, but also to identify the capacity gaps over all individual facilities in the network, including intermodal facilities. By incorporating more precise capacity measures into the planning process, planning agencies would benefit from the MNCP model in articulating investment priorities across all transportation modes, thus achieving their goal of developing sustainable transportation systems in a cost-effective manner.