## SSS Abstracts |

This talk is in partial fulfillment of the speaking requirement.

In this talk, I will introduce our compiler techniques which remove an important limitation to program performance caused by stalls that are necessary for forwarding scalar values between threads in TLS execution. I will present dataflow algorithms for three increasingly aggressive instruction-scheduling techniques that reduce the critical forwarding path introduced by these stalls. The effectiveness of these techniques will be demonstrated by contrasting with related hardware-only approaches.

This talk is in partial fulfillment of the speaking requirement.

This talk presents an unsupervised learning approach to non-English stemming. The stemming model is based on statistical machine translation and it uses an English stemmer and a small (10K sentences) parallel corpus as its sole training resources. A parallel corpus is a collection of sentence pairs with the same meaning but in different languages (i.e. United Nations proceedings, bilingual newspapers, the Bible). Monolingual, unannotated text in the target language is readily available and can be used to further improve the stemmer by allowing it to adapt to a desired domain or genre.

Examples and results will be given for Arabic, but the approach is applicable to any language that needs affix removal. Our resource-frugal approach results in 87.5% agreement with a proprietary Arabic stemmer built using rules, suffix and prefix lists, and human annotated text.

This is joint work with Scott McCarley while at IBM TJ Watson (Summer 2002).

This talk is in partial fulfillment of the speaking requirement.

In this talk I will present a formal definition of a stegosystem; give strong definitions of steganographic security against passive and active adversaries; and present constructions which provably satisfy these definitions, under the assumption that pseudorandom function families exist.

This talk is in partial fulfillment of the speaking requirement.

This talk is in partial fulfillment of the speaking requirement.

In this talk, I will present a calculus for probabilistic languages, which extends the traditional lambda calculus. In our calculus, every expression denotes a probability distribution yet evaluates to a regular value. The most notable feature of our calculus is that it is founded upon sampling functions, which map the unit interval to probability domains. As a consequence, we achieve a unified representation scheme for all types of probability distributions. I will also present preliminary evidence that probabilistic languages based upon our calculus are viable in applications involving massive probabilistic computation.

The development of the calculus also engendered new research topics. For instance, we have developed a structural formulation of the intuitionistic modal logic S4 with an intersection connective, which is employed in the type system for the calculus. I will briefly discuss these new research topics.

This talk is in partial fulfillment of the speaking requirement.

In this talk I will limit the discussion to an M/GI/1 queue. For the M/GI/1/PS queue all jobs (large or small) are slowed down by the same factor in expectation. Because the slowdown (response time divided by job size) is the same for all job sizes, the PS policy is often referred to as a fair policy. I will show that all work conserving scheduling policies have the same performance as PS with respect to large jobs. In particular, I will show that the slowdown as job size tends to infinity under any work conserving policy is at most that of PS almost surely; even for policies that clearly bias against large jobs.

This talk is in partial fulfillment of the speaking requirement.