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SUNMONTUEWEDTHUFRISAT
Events for April 22, 2009
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Meet USC
Wed, Apr 22, 2009
Viterbi School of Engineering Undergraduate Admission
Workshops & Infosessions
This half day program is designed for prospective freshmen and family members. Meet USC includes an information session on the University and the Admission process; a student led walking tour of campus and a meeting with us in the Viterbi School. Meet USC is designed to answer all of your questions about USC, the application process and financial aid.Reservations are required for Meet USC. This program occurs twice, once at 9:00 a.m. and again at 1:00 p.m. Please visit http://www.usc.edu/admission/undergraduate/visit/meet_usc.html to check availability and make an appointment. Be sure to list an Engineering major as your "intended major" on the webform!
Location: USC Admission Center
Audiences: Prospective Freshmen and Family Members - RESERVATIONS REQUIRED
Contact: Viterbi Admission
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Fading Model, MIMO Channel Generation, and Spectrum Sensing in Wireless Communications
Wed, Apr 22, 2009 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Wei-Ho Chung, UCLAAbstract: We investigate the fading channel modelling, MIMO channel generation, and spectrum detection for wireless communications. We propose the modified hidden semi-Markov model (MHSMM) for modeling the flat fading envelope process. The MHSMM incorporate the time-variant statistics of the envelope process in a single model, which facilitates computations of the envelope probability density function and the autocorrelation function. We propose and demonstrate the parameter estimation scheme by simulated and experimental data.Diversity techniques for various communication and MIMO systems exploit the spatial and temporal diversity attributes to mitigate the ill effects of the fading channels. We propose a unified approach capable of generating correlated flat-fading envelope processes with the desired auto-correlation functions, cross-correlation functions, and probability density functions (pdfs). The proposed approach utilizes the Gaussian vector autoregressive process and the inverse transform sampling techniques. Comparing to the past research focusing on generating fading channels of the same family, the novelty of the proposed approach is its capability to generate fading processes of heterogeneous pdfs.Sensor networks have been shown to be useful in diverse applications. One of the important applications is the collaborative detection based on multiple sensors to increase the detection performance. To exploit the spectrum holes in the cognitive radios, we consider the collaborative spectrum sensing by sensor networks in the likelihood ratio test (LRT) frameworks. We provide explicit algorithms to solve the LRT fusion rules, the probability of false alarm, and the probability of detection for the fusion center. We will discuss the single-sensor detection and collaborative detections of multiple sensors under various fading channels.Biography: Wei-Ho Chung was born in Kaohsiung, Taiwan, in 1978. He received the B.Sc. and M.Sc. degrees in Electrical Engineering from National Taiwan University, Taipei City, Taiwan, in 2000 and 2002 respectively. Since 2005, he has been with the Electrical Engineering Department at University of California, Los Angeles, where he obtained the Ph.D. degree in 2009. From 2002 to 2005, he was a system engineer at ChungHwa Telecommunications Company, where he worked on data networks. In 2008, he was an intern working on CDMA systems in Qualcomm, Inc. Since 2007, he has been a Teaching Assistant at UCLA. His research interests include communications, signal processing, and networks.For more information, please contact Wei-Ho Chung(whc@ee.ucla.edu).
Papers available at http://whc13.bol.ucla.edu/Host: Andreas Molisch, molisch@usc.edu, EEB 530, x04670Location: Hughes Aircraft Electrical Engineering Center (EEB) - 539
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
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A Quantitative Monitoring Approach for Assessing Tunnel Safety ...
Wed, Apr 22, 2009 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Using a Strain-Based TechniqueSpeaker: Dr. Si-hyun Park,Project Manager, Tunnel Division,
Korea Infrastructure Safety & Technology Corporation.
Goyang-City, Kyunggi-Province, KoreaABSRACT:This presentation discusses a method for the safety assessment of tunnel structures by using the values of measured displacements. Unlike stress measurements, the displacement measurements during the construction of a tunnel have advantages such as simple instrumentation, easy measurements (daily measurements), and economic efficiency. The safety of tunnels has been previously evaluated by using empirical control criteria for the displacement in the construction of tunnels. However, these control criteria have not been validated and do not provide consistent information during the construction phase of tunnels. This presentation introduces the concept of the critical strain for tunnel safety assessment by measuring the displacement instead of the stress-based values. The basic concept behind the critical strain approach was proposed several years ago. However, the concept of critical strain has not been widely applied in the field of the tunnels because until now the concept has not had a convincing engineering interpretation either at the theoretical or the mathematical level. The aim of this presentation is to: (1) compare and collect the control criteria to be used as tools for the measurement and management of the construction of a tunnel, (2) provide an overview the engineering interpretation of the critical strain, using results from prior studies, (3) verify the engineering interpretation of the critical strain, and (4) assess tunnel safety quantitatively by using the measured displacement values. It will be shown that the concept of critical strain can be validated by physical interpretation and be subsequently applied for the safety assessment during the construction of tunnels.Location: Kaprielian Hall (KAP) - 209 (on WebEx)
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
