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Events for March 31, 2009
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Delay-Limited Cooperative Communication with Reliability Constraints in Wireless Networks
Tue, Mar 31, 2009 @ 02:00 PM - 03:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Rahul Urgaonkar
USC PhD. StudentAbstract: We investigate optimal resource allocation for delay-limited cooperative communication in mobile ad-hoc networks. Motivated by real-time applications that have stringent delay constraints, we develop dynamic cooperation strategies that make optimal use of network resources to achieve a target outage probability (reliability) for each user subject to average power constraints. Using the technique of Lyapunov optimization, we first present a general framework to solve this problem and then derive quasi-closed form solutions for several cooperative protocols proposed in the literature (such as Amplify-and-Forward, Decode-and-Forward, etc.). Our work is the first to treat the problem of delay-limited cooperative communication with reliability constraints in a stochastic network characterized by fading channels, node mobility, and random packet arrivals, where opportunistic cooperation decisions are required.Biography: Rahul Urgaonkar obtained the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology (IIT) Bombay in 2002 and the M.S. degree in Electrical Engineering from the University of Southern California, Los Angeles in 2005. He is currently a PhD student in Electrical Engineering at USC. His research interests are in the areas of stochastic network optimization, resource allocation, and scheduling in next generation Wireless Networks.Relevant papers: R. Urgaonkar and M. J. Neely, "Delay-limited Cooperative Communication with Reliability Constraints in Wireless Networks," IEEE INFOCOM, Mini-conference, Rio de Janeiro, Brazil, April 2009Link: http://www-scf.usc.edu/~urgaonka/papers/coop_comm_infocom09.pdfHost: Michael Neely, mjneely@usc.edu, EEB 520, x03505Location: Hughes Aircraft Electrical Engineering Center (EEB) - 539
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
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From Game Characters to Game Companions: Practice, Anticipation, and Embodiment
Tue, Mar 31, 2009 @ 04:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Speaker: Guy Hoffman
Host: Prof. Gerard Medioni Abstract:
Aiming to make computer game agents more engaging and longer-lasting, I propose the notion of "game companions", based on three notions: (a) viewing game play as a collaborative activity, highly coordinated with a human player; (b) modeling practice to improve the agents' skills over time; and (c) moving game characters into the physical world, in the form of personal robots. Framed within an overall methodology that optimizes for engagement instead of efficiency, this talk introduces computational models for two aspects of practice: anticipation and embodiment, and their implementation on game agents and collaborative robots. First, I present an extension to Markov Decision Processes, modeling anticipation for agents collaborating with humans. I discuss the implementation of the model on a game character, which adapts to a human collaborator through repetition. I demonstrate the effect of anticipation on repetitive teamwork by showing this agent to be more efficient and fluent, and to seem significantly more committed and contributing to the team, as rated by human players. Then, I extend this discrete state/action model to a cognitively plausible embodied framework operating on continuous sensory input and performing real-world motor activity. Based on recent neuro- psychological findings supporting an embodied view of cognition, I model practice as priming perceptual simulation and affecting Hebbian learning. Implemented on two robots, I show this framework to have significant effects on both the efficiency of a human-robot team, and on human subjects' perception of the robot's intelligence, fluency, and even gender. With our aims set on long-term engaging interaction with artificial agents, these systems' capacity to physically practice with humans may hold a key to the kind of efficient and satisfying performance that humans are accustomed to from each other. Biography:
Guy Hoffman is a postdoctoral research associate at the Georgia Institute of Technology Center for Music Technology. Prior, he was a postdoctoral associate at MIT. Hoffman holds a Ph.D. from the MIT Media Lab in the field of Human-Robot Interaction and an M.Sc. in Computer Science from Tel Aviv University. His research investigates practice, anticipation, and joint action between humans and artificial agents, with the aim of designing agents that display more fluent behavior with their human partners. Other research interests include theater and musical performance robots as well as non-anthropomorphic agent design. His robot AUR won the 2007 IEEE International Robot Design Competition; he was animation and software lead on the 2008 World Expo Digital Water Pavilion, one of TIME magazine's "Best Inventions of 2007"; his research has been covered in the international press, including the New York Times, Süddeutsche Zeitung, and Science; Hoffman has held several senior research and product development positions in the Israeli software technology industry; and his work in animation, data visualization, architecture, theater, and new media art has been internationally published and exhibited.Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Colloquia
