CGL Meeting Agenda - 2000.09.06

September 6th, 2000

Location:
DC1304
Time:
1:30 p.m.
Chair:
Tim Lahey :-)

1. Adoption of the Agenda - additions or deletions

2. Coffee Hour

Coffee hour last week:
          Eric Hall
Coffee hour this week:
??
Coffee hour next week:
??

3. Next meeting

Date:
Wednesday, September 13th, 2000
Location:
DC1304
Time:
1:30 p.m.
Chair:
Josée Lajoie :-)
Technical presentation:
Patrick Gilhuly :-)

4. Forthcoming

Chair:
  1. Marryat Ma (September 20th) :-)
  2. Vincent Ma (September 27th) :-)
  3. Stephen Mann (October 4th) :-)
Tech Presenters:
  1. Eric Hall (September 20th) :-)
  2. Tim Lahey (September 27th) :-)
  3. Josée Lajoie (October 4th) :-)

5. Technical Presentation

Presenter:

 

 
 
 

Teresa Ge :-)
 
 

Title:

 

 

Solving Inverse Kinematics Constraint Problems for Highly Articulated Models
 

Abstract:

 

 

I will talk about inverse kinematic problems, different techniques to do
singular value decomposition for a matrix, and object avoidance methods
in a redundant system.
 

6. General Discussion Items

7. Action List

8. Director's Meeting

9. Seminars

Master's Thesis Presentation
Computer Science
Friday, 8 September 2000 at 10:30AM
DC1304

Analyzing Multi-Threaded Program Performance with uProfiler
Dorota Zak
Computer Science, University of Waterloo

Threads are widely supported by many operating systems and languages to allow concurrency
in both uni-processor and multi-processor architectures. They can be used as a program
 structuring tool in the uni-processor environment or to accelerate the execution of an
application in the multi-processor environment. Unfortunately, the actual behaviour of a
multi-threaded program is often quite different from expectations and frequently does not
achieve desired performance.

Since good performance is important to users and performance tuning is not easy,
programmers need profiling tools to help them understand program execution and find its hot
spots and bottlenecks. Profiling tools usually contain several metrics to let users select a
metric or metrics that provide the best understanding of a program's run-time behaviour.

This talk describes the design and implementation of a profiler, called uProfiler, for the
uC++ user-level thread library that can execute in uni-processor and multi-processor
shared-memory environments. Four new built-in metrics are presented, each characterizing
various aspects of program behaviour, giving users an opportunity to view an execution from
 different perspectives.

UNIVERSITY OF WATERLOO
FACULTY OF MATHEMATICS
BROKEN SYMMETRY IN NONLINEAR WAVES, BILLIARDS AND DICE
DATE:   Tuesday, September 12, 2000
TIME:   2:30 p.m.
PLACE:  MC 5136
SPEAKER:Dr. Frank Berkshire
        Imperial College of Science, Technology and Medicine
        London, UK

Abstract

Symmetries correspond to conservation laws and, if there is a sufficient
number of them, then dynamics is ordered, in physical, biological chemical,
economic.....  systems.

When this full symmetry is broken, any conservation laws that remain may
prevent dynamical collapse to a singularity and/or inhibit the emergence
and development of chaos.

Examples featured in this lecture should include:

(1)     The cubic Schrodinger equation, which is ordered for the case of
one space dimension plus time (with soliton solutions), exhibits a
'blow-up' singularity in higher dimensions for suitable initial data. There
is a direct parallel with total collapse in the classical gravitational
n-body problem and possible applications to other wave systems.

(2)     Order and chaos in idealised billiards systems are  dependent on
the shape of the enclosure and any resulting symmetries.

(3)     The dynamical evolution of the motion of a die moving chaotically
is too sensitive to predict, but the stochastic consequences of broken
symmetry are quantifiable.

10. Lab Cleanup