home *** CD-ROM | disk | FTP | other *** search
- Xref: sparky or.general:765 pdx.general:1461 ogi.general:44
- Path: sparky!uunet!ogicse!ogicse.cse.ogi.edu!kelly
- From: kelly@ogicse.cse.ogi.edu (Kelly Atkinson)
- Newsgroups: or.general,pdx.general,ogi.general
- Subject: Computer Science Colloquia
- Message-ID: <48147@ogicse.ogi.edu>
- Date: 6 Jan 93 20:23:41 GMT
- Article-I.D.: ogicse.48147
- Sender: kelly@ogicse.ogi.edu
- Distribution: or
- Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR
- Lines: 118
-
-
- Oregon Graduate Institute
- Department of Computer Science and Engineering
-
- COLLOQUIUM SERIES
-
-
- -----------------------------------------------------------------------
- Issues in Scientific Computing Colloquium Series
- (Co-sponsored by OCATE)
-
- Applications Demand Class-Specific Optimizations:
- The C++ Compiler Can Do More
- Ian G. Angus, Boeing Computer Services
-
- Friday, January 15, 1993, 3:30 p.m.
- Main Seminar Room, OGI Administration Building
-
- So far C++ has made few inroads into the realm of scientific computing,
- which is still largely dominated by Fortran. Of the few attempts that have
- been made to apply C++ to numerically intensive codes, the results have
- often suffered from annoying performance problems. Examination of these
- problems suggests that they are unlikely to be solved by incremental
- improvements in compiler optimization technology.
-
- In this talk we will:
- * Motivate the discussion by describing a common efficiency problem
- that arises when numerical codes are programmed in C++.
- * Discuss some potential solution strategies that we believe to be
- viable in the near term, but not over the long term.
- * Introduce a minimal mechanism through which a compiler could
- solve these problems by loading class-specific optimizations on an as-
- needed basis. A simple interface that will enable this feature will be
- presented.
-
- While our immediate motivation is that of numerically intensive codes,
- our approach will be applicable to all application domains.
-
-
- -----------------------------------------------------------------------
- Getting At Information In Speech
- Hynek Hermansky, U S WEST Advanced Technologies
-
- Tuesday, January 19, 1992, 10:30 a.m.
- Main Seminar Room, OGI Administration Building
-
- Automatic recognition of speech aspires for automatic decoding of the
- linguistic information from speech. The task is complicated since, besides
- the linguistic information, speech carries information from many additional
- sources, such as the identity of talker or identity and quality of
- environment in which the speech was produced and over which it was
- transmitted. The resulting variability in speech is currently being handled
- by extensive training of recognizers on large databases which cover most
- sources of the anticipated variability.
-
- Database collection is expensive, and one can never be sure that all sources
- of variability are being covered. Our goal is to understand and to be able
- to model (and thus to alleviate) sources of harmful variability in speech.
- We discuss our recent techniques that are aimed at improving
- performance of recognizers in severe telecommunications environments.
- We are primarily guided by engineering considerations. Nevertheless we
- are arriving to solutions consistent with our knowledge of human
- information processing.
-
-
- -----------------------------------------------------------------------
- The Starburst Database Rule System: Language Design, Implementation
- and Applications
- Jennifer Widom, IBM Almaden Research Center
-
- Friday, January 22, 1992, 11:30 a.m.
- Room 102, OGI Computer Science and Engineering Bldg.
-
- This talk surveys our development of the Starburst Rule System, a
- production rules facility integrated into the Starburst extensible database
- system at the IBM Almaden Research Center. Database production rules
- allow definition of operations that are executed automatically whenever
- certain events occur or conditions are met, making the database system
- "active."
-
- The Starburst rule language is based on arbitrary database state
- transitions rather than tuple- or statement-level changes, yielding a clear
- and flexible execution semantics. The rule system was implemented
- rapidly using the extensibility features of Starburst; it is integrated into all
- aspects of query and transaction processing, including concurrency control,
- authorization, rollback, etc. Since production rules can be difficult to
- program, we have developed a number of methods for automatically
- generating database rule applications, including integrity constraints,
- materialized views, and deductive rules.
-
-
- -----------------------------------------------------------------------
- Language Issues in Software Specification and Development Colloquium
- Series
- (Co-sponsored by OCATE)
-
- Type Inference with Set Constraints
- Alex Aiken, IBM Almaden Research Center
-
- Friday, January 22, 1992, 3:30 p.m.
- Main Seminar Room, OGI Administration Building
-
- Set constraints are a simple extension of standard type languages. In
- addition to the usual type constructors, set constraints add the set
- operations (union, intersection, and a kind of negation) and constraints of
- the form "X is a subset of Y". This combination of inclusion constraints and
- set operations makes it possible to devise some very powerful type
- systems.
-
- While set constraints seem like a natural basis for type systems, the idea
- has not received much attention. This is partly because many algorithms
- on set constraints are computationally expensive, but also because
- progress has been slow on the central problem of solving systems of set
- constraints. In this talk, we present an algorithm for solving systems of
- set constraints and discuss its application to type inference. The talk will
- be illustrated with examples taken from our implementation of a type
- inference system based on solving systems of set constraints. This is joint
- work with Ed Wimmers.
-