CTS Events
November 14, 2012

Dr. Nebiyou Tilahun, UPP, presents a seminar entitled "An agent based model of origin destination estimation (ADOBE)" Wednesday, November 14th at 4:00 pm in Rm 1127 SEO


November 7, 2012

Mr. Thomas Murtha, CMAP, will address the CTS-IGERT community at 4:00 p.m. in Room 1127 SEO.


October 24, 2012

Please join us in welcoming Dr. Bo Zou, CME, on Wednesday, October 24th, Room 1127 SEO, 4:00 p.m.


CTS Happenings
September 25, 2012

Award Received by Joshua Auld, CTS-IGERT alumnus.


April 20, 2012

Congratulations to James Biagioni, CTS Fellow and CS PhD candidate, winner of the Dean's Scholar award.


January 2, 2012

James Biagioni, CTS Fellow, receives "Best Presentation Award" at SenSys2011


July 30, 2010

Dr. Ouri Wolfson, Dr. Phillip Yu, and Leon Stenneth, CS student and CTS Associate, recently had a paper accepted to the 6th IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob 2010).


June 13, 2012

Please welcome Dr. Ethan Ying-en Ge, Associate Professor, Dalian University of Technology, China
Wednesday, June 13th at 4:00 p.m. in Room 1127 SEO

Until a few years ago, dynamic user equilibrium (DUE) and dynamic user optimum (DUO) were still interchangeable in investigating the dynamic traffic assignment (DTA) problem. A tolerance-based DUO and DUO with variable tolerance were recently proposed as alternative definitions of DUO, which distinguishes DUO from DUE. The former relies on a pre-chosen fixed tolerance, hence it can be termed DUO with fixed tolerance. At DUO with fixed or variable tolerance, the tolerances reflect the differences in travel costs between used paths of an origin-destination (OD) pair. Since DUE bears no differences in travel costs between used paths of an OD pair, it can be termed DUO with zero tolerance. It is necessary to investigate the relationships between the three concepts and implications for DTA modeling. This talk first compares the three alternative definitions of DUO and discusses their relationships. Secondly, the existence conditions of these DUO solutions are simply compared and discussed by means of three examples. A key conclusion is that DUO with variable tolerance must exist even when the other two may not. In addition, when the tolerances at DUO with fixed or variable tolerances are equal to zero, the solution must be a DUE solution. Furthermore, DUE is a special case of DUO with variable tolerance; since the tolerance in the concept of DUO with variable tolerance is an endogenous variable, if a DUE solution exists, an efficient method for solving for DUO with variable tolerance should directly find such a DUE solution. However, how to analytically model DUO with variable tolerance in a general but not ad hoc manner, including solving and implementation, seems not to be an easy problem to resolve.

Dr. Ying-en Ge obtained his first two degrees in mathematics and then was awarded a PhD in transportation planning and management in 1999 in Tongji University, Shanghai. He did his post-doc research at the University of California at Davis and then moved to the UK to work at three universities, i.e. University of Ulster, Queen's University of Belfast, and Edinburgh Napier University. He also worked as a senior analyst at an urban, regional and transportation planning consulting firm for 1.5 years. He moved back to China in the Spring 2010 and took up a professorship at the Dalian University of Technology. He has worked on traffic flow analysis and its applications on single roads and on road networks for more than 10 years and published nearly 40 scholarly papers, including those in major transportation journals as Transportation Science, Transportation Research Part B and Networks & Spatial Economics.

Hosted by: Dr. Jane Lin, CME