Select a calendar:
Filter January Events by Event Type:
SUNMONTUEWEDTHUFRISAT
Events for January 29, 2010
-
Advanced Nanoelectromechanical Devices and Systems
Fri, Jan 29, 2010 @ 02:00 PM - 03:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Abstract:
Nanoscale devices with mechanical degrees of freedom offer compelling characteristics that make them not only interesting tools for fundamental studies, but also intriguing candidates for technological applications. In particular, nanoelectromechanical systems (NEMS) vibrating in their resonant modes provide promising opportunities and advantages for developing novel sensors and transducers, in the previously inaccessible regimes. This seminar will describe my research interests, efforts, and thoughts in advanced NEMS engineering, with a central theme of how to innovate and advance today's primitive nanostructures into functional devices and integrated systems with high performance. I will first briefly overview the fundamentals of NEMS devices enabled by the state-of-the-art nanofabrication techniques (both top-down and bottom-up). I will then focus on two specific technological thrusts. One is to demonstrate that engineering of NEMS resonators and signal transduction, in very-high and ultra-high frequency (VHF/UHF) ranges, has enabled single-biomolecule sensing in real time, and the prototyping of NEMS-based mass spectrometry for future proteomics. Second is to show novel, high-performance silicon nanowire NEMS based on a hybrid top-down/bottom-up technique. This new device technology has opened up the opportunities for monolithic integration at large scale; and has led to self-sensing nanowire NEMS gas analyzers that are now being manufactured using industrial SOI technology. Next, I shall briefly introduce and highlight some latest milestones such as the nascent radio-frequency (RF) NEMS for frequency control and timing, NEMS based logic devices, and their very-large-scale integration (VLSI). Finally, I will discuss the tremendous opportunities created by such explorations that transcend boundaries of traditional disciplines. I will show my perspective on future fundamental and technological research, and possibilities for novel devices in emerging applications. Biography:
Philip Feng is a staff scientist at California Institute of Technology (Caltech), affiliated with the Kavli Nanoscience Institute, where he has also been serving as a co-principal investigator since 2008. He obtained his Ph.D. from Caltech in 2007 for developing ultra-high-frequency nanoelectromechanical systems (NEMS) with low-noise technologies. He has since been leading a small team of engineers and applied physicists to advance NEMS and other device-related technologies for sensing, signal processing and computing. He has been privileged to deliver invited lectures at several peer-reviewed international conferences. He has served on IEEE frequency control technical committee and also served as a frequent reviewer for more than fifteen high-impact multidisciplinary and IEEE journals.Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: Hazel Xavier
-
Crosscorrelation of $m$-sequences and related topics
Fri, Jan 29, 2010 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Tor Helleseth,
University of BergenAbstract: Sequences with good correlation properties are important in many communication systems, for example in Code-Division Multiple-Access systems(CDMA). Many sequence families in practical use involve maximal-length (or $m$)-sequences as part of their construction. Therefore the crosscorrelation of $m$-sequences has been a classical and ongoing research problem for more than 40 years.In this talk an updated overview of the crosscorrelation of $m$-sequences will be given. The status of what is presently known including recent results involving exponential sums and Dickson polynomials will be presented. Open problems and several conjectures will also be pointed out. Several of the problems have also been considered and significantly inspired by researchers from USC during several decades.Biography: Tor Helleseth received the Cand. Real. and Dr. Philos. degrees in mathematics from the University of Bergen, Bergen, Norway, in 1971 and 1979, respectively. From 1973 to 1980 he was a Research Assistant at the Department of Mathematics, University of Bergen. From 1981 to 1984 he was at the Chief Headquarters of Defense in Norway. Since 1984 he has been a Professor at the Department of Informatics at the University
of Bergen.During the academic years 1977-1978 and 1992-1993 he was on sabbatical leave at the University of Southern California, Los Angeles, and during 1979-1980 he was a Research fellow at the Eindhoven University of Technology, The Netherlands. His research interests include coding theory, cryptology and discrete mathematics. He has published more than 100 journal papers including more than 70 in the IEEE Transactions in Information Theory.From 1991 to 1993 he served as an Associate Editor for Coding Theory for IEEE Transactions on Information Theory. He is on the editorial board of Designs, Codes and Cryptography and Cryptography and Communications: Discrete Structures, Boolean Functions and Sequences. He was Program Chairman for Eurocrypt'93 and for the IEEE Information Theory Workshop in 1997 in Longyearbyen, Norway. He was a Program Co-Chairman for SETA04 in Seoul and SETA06 in Beijing. He was also a Program Co-Chairman for the IEEE Information Theory Workshop in Solstrand, Norway in 2007. He was serving on the Board of Governors for the IEEE Information Theory Society 2007-2009. In 1997 he was elected an IEEE Fellow for his contributions to coding theory and cryptography. In 2004 he was elected member of Norsk Videnskaps-Akademi.Host: Gerhard Kramer, gkramer@usc.edu, EEB 536, x07229
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
-
Disorder-immune slow light with topological electromagnetic modes
Fri, Jan 29, 2010 @ 04:00 PM - 05:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
University Calendar
Speaker: Dr. Zheng Wang, MITAbstract: Chiral edge states were discovered around 30 years ago in quantum Hall effects in 2D electron gas. They are the underlying mechanism that supports dissipationless transport of electrons in quantum Hall systems and quantum spin Hall systems. Although they were only observed in fermionic systems, such as electrons in graphene, our work experimentally demonstrates, for the first time, that chiral edge states also exist for photonic systems.Light can be confined and routed using structures known as waveguides. The slimmest waveguides, known as "single-mode waveguides", allow light to propagate only in one spatial configuration either in forward or backward direction. Using photonic chiral edge states, we can force light to propagate only in one spatial configuration and only in one direction, essentially creating "half-mode waveguides".When the possibility of traveling backwards is eliminated, light exhibits fascinating and unparalleled properties. For instance, scattering can be completely suppressed, even in the presence of very large disorder. With a waveguide highly tolerant to large imperfection, a wide range of practical applications from electromagnetic isolation, to slow light and optical buffering may benefit.Biography: Dr. Zheng Wang is currently a postdoctoral researcher at the Massachusetts Institute of Technology. He received his PhD in Applied Physics from Stanford University in 2006.
Location: Frank R. Seaver Science Center (SSC) - 319
Audiences: Everyone Is Invited
Contact: Michelle Povinelli
