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SUNMONTUEWEDTHUFRISAT
Events for April 25, 2007
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Optimization of maintenance and replacement policies for a system of heterogeneous infrastructure fa
Wed, Apr 25, 2007 @ 12:00 PM - 01:30 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
(( SPEAKER ))Dr. SAMER MADANAT, Institute of Transportation Studies (ITS), University of California, Berkeley(( ABSTRACT ))This research addresses the determination of optimal maintenance and replacement policies for a system of heterogeneous facilities. The problem of optimizing maintenance and replacement policies at the system level is formulated in a reliability-based framework, based on policies that are optimal at the facility level. The facility-level policies are determined using a finite-state, finite horizon Markov decision process in which the state of the Markov chain contains information on the history of maintenance and deterioration.Optimality conditions for the continuous-case system-level problem are derived and explained intuitively. A numerical study shows that the results obtained in the discrete-case implementation of the solution are valid approximations of the continuous-case results. The computational efficiency of the system-level solution makes the formulation suitable for systems of realistic sizes.Bio: Samer Madanat is the Xenel Distinguished Professor in the Department of Civil & Environmental Engineering, and the Director of the Institute of Transportation Studies at the University of California at Berkeley.He received a B.Sc. in Civil Engineering from the University of Jordan in 1986, and a M.S and Ph.D. in Transportation Systems from MIT in 1988 and 1991 respectively.His research and teaching interests are in the area of Transportation Infrastructure Management, with an emphasis on modeling facility performance and the development of optimal management policies under uncertainty. He has published extensively in refereed archival journals and conference proceedings.In 2000, he received the Science and Technology grant from the University of California Office of the President, an award given annually to one faculty member in the UC system. Since 2001, he has served as the Editor-in-Chief of the ASCE Journal of Infrastructure Systems. Several of his former students are faculty members at universities in the US and abroad.
Location: Ralph And Goldy Lewis Hall (RGL) - -215
Audiences: Everyone Is Invited
Contact: Masako Okamoto
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Particulate Matter Emitted By Vehicles in Freeway and Roadway Tunnel Environments:
Wed, Apr 25, 2007 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
(( SPEAKER ))DR. MICHAEL D. GELLER, Department of Civil and Environmental Engineering, USC(( ABSTRACT ))Individual organic compounds such as hopanes and steranes (originating in lube oil), selected polycyclic aromatic compounds (PAHs) (generated via combustion), and trace metals found in particulate emissions from vehicles have proven useful in source apportionment of ambient particulate matter.Currently, little ambient data exists for a majority of these species. Three sampling campaigns have been carried out in four different environments with similar ambient conditions: a gasoline only freeway, a heavy-duty diesel influenced freeway (~20% diesel), a gasoline only tunnel, and a mixed-vehicle (~4% diesel) tunnel.Trace organic species in the ultrafine (Very good agreement is observed between CA-110 (gasoline freeway) and light duty vehicle tunnel emission factors as well as I-710 (~20% diesel freeway) measurements and corresponding reconstructed emission factors from the tunnel for selected species. This study demonstrates the effective use of CO2-estimated dilution to associate assorted vehicle-emitted PM bound compounds in distinct vehicle-dominated environments.
Location: Kaprielian Hall (KAP) - -203
Audiences: Everyone Is Invited
Contact: Masako Okamoto
