Meeting Agenda

Wednesday, 29 November 1995

Location:: DC 1304
Time:: 1:30 PM
Chair:: Leith Chan

1. Adoption of the Agenda - additions or deletions

2. Coffee Hour

Coffee hour this week:: Richard Bartels
Coffee hour next week:: ???

3. Next week's meeting

Date:: 6 December 1995
Location:: DC 1304
Time:: 1:30 PM
Chair:: Leo Chan
Technical presentation:: John Beatty

4. Forthcoming

Chairs:

Stewart Chao
Wilkin Chau
Bill Cowan
Matthew Davidchuk

Tech Presenters:

Ian Bell
Leith Chan
Leo Chan
Stewart Chao

5. Technical Presentation

Presenter:: Richard Bartels

Title:

Wavelets and Some Graphical Applications

Abstract:

Computer science has long used the storage of difference information for efficiency and economy of space. RCS, for example, stores file archives in terms of the original file plus successive file difference information. Run-length encoding achieves space economy in image storage by storing base pixels and pixel consistency information. Wavelets are a formalization of this idea for the storage of data, provided that:

the data items are elements of a vector space

the data is organized in a certain hierarchical fashion

differences are measured in the least-squares sense
Applications to graphics include cases for which the data is geometric (polygon data, subpolygon hierarchy, Euclidian distance), functional (radiosity, succesive intensity approximation, quadratic energy functional), and image (pixels, levels of detail, RMS difference).

In this talk we give a brief introduction to the concepts of wavelets and multiresolution analysis using 2D/3D Euclidian space as a simple example, followed by Haar wavelets and linear B-spline wavelets. We close with some samples from the current literature in which wavelets have been used for radiosity, hierarchical curves and surfaces, and image compression.

6. General Discussion Items

Richard: I would like to get the technical presentation abstract split out as a simple web page on its own, in the public area, with a link to it from the meetings web page as well as from the CGL home page.

7. Action List

Richard will co-ordinate a Side Effects visit in February.
Rob will co-ordinate the next UofT visit (they come here).
March looks good.

8. Director's Meeting

9. Seminars

              The Institute for Computer Research (ICR)
                               and
           The Centre for Advanced Studies in Finance
                     Present a Colloquium on

                      "Finance to Physics"


by:     Dr. Joseph F. Traub

of:     Department of Computer Science
        Columbia University

Date:   Thursday, November 30, 1995 
Time:   3:30 pm.
Place:  William G. Davis Computer Research Centre, Room 1302

Abstract:
The talk will consist of three parts.  Some  recent  results  and
open  problems in information-based complexity will be described.
Some of the results will be applied to the valuation of financial
derivatives, an important topic in mathematical finance.  The fi-
nal part of the talk considers whether it  is  possible  to  move
from  limitative results in formal systems (Goedel, Turing, Cook,
...) to limits in empirical science.  Are there  provable  limits
to what is knowable in physics and, more generally, in science?

_________________
Joseph Traub is the Edwin Howard Armstrong Professor of  Computer
Science at Columbia University and on the external faculty of the
Santa Fe Institute.  Previously, he was Head of the Computer Sci-
ence   Department   at  Carnegie-Mellon  University.  He  started
research in what is now called  information-based  complexity  in
1959.

Everyone is welcome.  Refreshments served.

                      Last research skills seminar

The last research skills seminar will be as follows:

Topic:   "Oral Presentations"
Speaker: Dr. Mary Neill, University of Western Ontario
Date:    ***Friday 1 December***
Time:    ***2:00--4:00***
Place:   MC5136

Note:    I will be taping this talk, for anyone who wishes to listen to
it afterwards.  Also, Dr. Neill will return in January for a second
seminar in which we will all get a chance to practise giving
presentations.

Note2:   Incredibly delicious refreshments (some of them imported!) will
be provided.



                    "Formal Software Engineering"

                           J.-Ch. Gre'goire
                      INRS-Te'le'communications
                              Montre'al

Well respected researchers in the field of software engineering have
claimed that formal methods would be the next breakthrough
technology. Yet, formal methods are as old as object orientedness, and
their millenium does not appear to be in sight. Whereas these
``methods'' have found a niche in safety critical system, their use is
very expensive, and they are not considered for software engineering
at large.

In this presentation, we shall clarify the terminology, describe the
languages, the tools and techniques available and present the
challenge of their integration in software engineering practice. We
shall see where the integration is possible, the benefits which can be
derived and the associated cost and risks. Finally, we will review the
challenges ahead.


                   Date: Friday, December 1, 1995.

                           Time: 11:00 a.m.

Place: University of Waterloo, Davis Centre, Room 1304 (ICR Seminar
       Room).