December 2011 - talks - lists.cs.princeton.edu

Jimin Song FPO
by Melissa M. Lawson 14 Dec '11

14 Dec '11

Jimin Song will present her FPO on Monday December 19 at 2PM in Room 402. The members of her committee are: Mona Singh, advisor; Olga Troyanskaya and Tom Funkhouser, readers; Bernard Chazelle and Andrea LaPaugh, nonreaders. A copy of her thesis, "Network-based analysis of protein function", is on display in Room 310. Everyone is invited to attend her talk.

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W Kim preFPO
by Melissa M. Lawson 12 Dec '11

12 Dec '11

Wonho Kim will present his preFPO on Friday December 16 at 4PM in Room 402. The members of his committee are: Vivek Pai, advisor; Larry Peterson and Michael Freedman, readers; Jennifer Rexford and David Walker, nonreaders. Everyone is invited to attend his talk. His abstract follows below. ---------------------- Title: Understanding Resource Usage and Performance in Wide-area Distributed Systems Many Internet services employ wide-area frameworks to deliver exponentially growing network traffic to end-users with low response time. These systems typically leverage a large number of servers distributed to the edges of the Internet, which makes the systems difficult to design and manage. In this thesis, we examine resource usage and the performance of remote synchronization in wide-area systems. To support the development of new network services on a global scale, the next generation of federated testbeds are under active development, but very little is known about resource usage in the shared infrastructures. We conduct an extensive study of the usage profiles in PlanetLab that we collected for six years by running CoMon, a PlanetLab monitoring service. We examine various aspects of node-level behavior as well as experiment-centric behavior, and describe their implications for resource management in the federated testbeds. We find that the usage is much different from shared compute clusters, that conventional wisdom does not hold for PlanetLab, and that several properties of PlanetLab as a network testbed are largely responsible for this difference. We also present a latency-sensitive file synchronizer, Lsync, that can be used as synchronization building block for wide-are distributed systems where latency matters. While many distributed systems depend on fast data synchronization for coordinating remote nodes, current data dissemination systems focus on efficiency for open client populations, rather than focusing on completion latency for a known set of nodes. In examining this problem, we find that optimizing for latency produces strategies radically different from existing distribution tools, and can dramatically reduce latency across a wide range of scenarios. Lsync performs novel node selection, scheduling, and adaptive policy switching that dynamically chooses the best synchronization method using information available at runtime. Our evaluation results show that Lsync reduces latency by more than a factor of 14 compared to a widely used synchronization tool, and makes most remote nodes fully synchronized even under frequent file updates.

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11am talk today on secure provenance in distributed systems in room 402
by Jennifer Rexford 12 Dec '11

12 Dec '11

Speaker: Wenchao Zhou, U. Penn Title: Secure Provenance in Distributed Systems Date/time: 11am-noon Monday December 12 Room: 402 Abstract: Operators of distributed systems often find themselves needing to answer forensic questions, to perform a variety of managerial tasks including fault detection, system debugging, accountability enforcement, and attack analysis. In this talk, we present Secure Provenance, a novel approach that provides the fundamental functionality required for answering such forensic questions -- the capability to "explain'' the existence (or change) of a certain distributed system state at a given time in a potentially adversarial environment. We show that it is both possible and practical to efficiently and scalably maintain and query provenance in a distributed fashion, where provenance maintenance and querying are modeled as recursive continuous queries over distributed relations. We then propose enhancements to the provenance model that allow operators to reliably query provenance information in adversarial environments. Our extensions incorporate tamper-evident properties which provide the guarantee that operators can eventually detect the presence of compromised nodes that lie or falsely implicate correct nodes. Finally, we present ongoing efforts that consider privacy protection of sensitive information in provenance maintenance and querying, and discuss our work in the context of our longer term vision towards provably secure distributed systems.

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11am-noon Mon Dec 12 talk on secure provenance in distributed systems
by Jennifer Rexford 08 Dec '11

08 Dec '11

Speaker: Wenchao Zhou, U. Penn Title: Secure Provenance in Distributed Systems Date/time: 11am-noon Monday December 12 Room: 402 Abstract: Operators of distributed systems often find themselves needing to answer forensic questions, to perform a variety of managerial tasks including fault detection, system debugging, accountability enforcement, and attack analysis. In this talk, we present Secure Provenance, a novel approach that provides the fundamental functionality required for answering such forensic questions -- the capability to "explain'' the existence (or change) of a certain distributed system state at a given time in a potentially adversarial environment. We show that it is both possible and practical to efficiently and scalably maintain and query provenance in a distributed fashion, where provenance maintenance and querying are modeled as recursive continuous queries over distributed relations. We then propose enhancements to the provenance model that allow operators to reliably query provenance information in adversarial environments. Our extensions incorporate tamper-evident properties which provide the guarantee that operators can eventually detect the presence of compromised nodes that lie or falsely implicate correct nodes. Finally, we present ongoing efforts that consider privacy protection of sensitive information in provenance maintenance and querying, and discuss our work in the context of our longer term vision towards provably secure distributed systems.

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Colloquium Speaker Celine Latulipe Mon Dec 5- 4:30pm
by Nicole E. Wagenblast 05 Dec '11

05 Dec '11

Expressive Interaction and the Evaluation of Creativity Support Celine Latulipe, University of North Carolina at Charlotte Monday, December 5, 2011, 4:30pm Computer Science Small Auditorium (Room 105) Visionaries in Computer Science have long seen the computer as a tool to augment our intellect. However, while it is relatively straightforward to measure the impact of a tool or technique on task efficiency for well-defined tasks, it is much more difficult to measure computers' impact on higher-level cognitive processes, such as creativity. In my own research in Human-Computer Interaction, I create novel interaction techniques, but run up against the problem of trying to evaluate how these tools impact higher-level processes such as creativity, expressiveness and exploration. In this talk, I briefly present a variety of interaction techniques that I have developed, and I then describe a new survey metric, the Creativity Support Index (CSI), that we have developed to help researchers and designers evaluate the level of creativity support provided by these types of systems, tools or interfaces. I will then present some current results using EEG and machine learning to classify the creative experience with more specific, temporal granularity. I present this work within the context of my longer term goal to develop a suite of tools that provide both stronger analytical power and a general framework for evaluating computational support for creative activities, engagement and aesthetic experience. Dr. Celine Latulipe has a PhD in Computer Science from the University of Waterloo in Canada. She is an Assistant Professor of Human-Computer Interaction in the Department of Software and Information Systems in the College of Computing and Informatics at UNC Charlotte. Dr. Latulipe has long been fascinated by two-handed interaction in the real world, and the absence of it in the human-computer interface. She has developed numerous individual and collaborative two-handed interaction techniques and these have blossomed into a more general exploration of creative expression. Dr. Latulipe works on projects with choreographers, dancers, artists and theatre producers to better understand creative work in practice and how technology may play a role in supporting and evaluating creative work practices. Currently, Dr. Latulipe is working on many projects, including the NSF CreativeIT-funded Dance.Draw project, which has received national media attention.

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