Distinguished Lecture Series: Fall 2004

• November 19: Eric Horvitz
  Title: Cognitive Models in Computing: Results and Directions
  Location and time: Shaffer 3, 10:45 am
  
  Abstract: I will present research on harnessing statistical methods to model properties of human attention and memory--and on harnessing such cognitive models in computing applications. I will focus first on the construction of predictive models of workload and interruptability. I will review user studies of disruptions in computing settings, and discuss the Priorities, BusyBody, and Notification Platform projects. Then, I will turn to efforts to build probabilistic models of memory landmarks, reviewing work on the MemoryLens project. I will present several prototype applications to demonstrate how such models can be applied. Finally, I will discuss longer-term directions with the use of probabilistic methods to model multiple aspects of human cognition.
  
  Bio: Eric Horvitz is a Senior Researcher at Microsoft Research, where he manages the Adaptive Systems and Interaction group. His interests include principles of sensing, learning, and reasoning under uncertainty, and applications of probability and utility in problem solving, communications, and human-computer interaction. He is an Associate Editor of the Journal of the ACM, Chairman of the Association for Uncertainty in Artificial Intelligence, and serves on the Naval Research Advisory Committee (NRAC). He has been elected a Councilor and Fellow of the American Association for Artificial Intelligence. He received PhD and MD degrees from Stanford University.
  
  More information is available at: http://research.microsoft.com/~horvitz
  
  
• November 18: Jennifer Rexford
  Title: Stable Internet Routing Without Global Coordination
  Location and time: Shaffer 3, 10:45 am
  
  Abstract: The Border Gateway Protocol (BGP) allows an autonomous system (AS) to apply diverse local policies for selecting routes and propagating reachability information to other domains. However, BGP permits ASes to have conflicting policies that can lead to routing instability. This talk proposes a set of guidelines for an AS to follow in setting its routing policies, without requiring coordination with other ASes. Our approach exploits the Internet's hierarchical structure and the commercial relationships between ASes to impose a partial order on the set of routes to each destination. The guidelines conform to conventional traffic-engineering practices of ISPs, and provide each AS with significant flexibility in selecting its local policies. Furthermore, the guidelines ensure route convergence even under changes in the topology and routing policies. Drawing on a formal model of BGP, we prove that following our proposed policy guidelines guarantees route convergence. We also describe how our methodology can be applied to new types of relationships between ASes, how to verify the hierarchical AS relationships, and how to realize our policy guidelines. Our approach has significant practical value since it preserves the ability of each AS to apply complex local policies without divulging its BGP configurations to others. The end of the talk briefly summarizes follow-up studies that have built on this work.
  
  
• October 21: David Chaum
  Title: Secret-Ballot Receipts:True Voter-Verifiable Elections
  Location and time: Shaffer 3, 10:45 am
  
  Abstract: A new kind of receipt sets a far higher standard of security by letting voters verify correctness of the election outcome?even if all election computers and records were to be compromised.
  
  In the voting booth, the voter can see his or her choices clearly indicated on the receipt. After taking it out of the booth, the voter can use it to ensure that the votes it contains are included correctly in the final tally. But, because the choices are safely encrypted before it can be removed from the booth, the receipt cannot be used to show others how the voter voted.
  
  Several ways to realize such receipts will be described. Some are well suited to be added on to current touch-screen voting machines. A very simple type will be introduced that is similar in use to current optical scan voting systems.