CGL Meeting Agenda

Wednesday, January 31, 1996


Location:
DC 1304
Time:
12:30 PM
Chair:
Saar Friedman

1. Adoption of the Agenda - additions or deletions

2. Coffee Hour

Coffee hour this week:
Don Dragomatz
Coffee hour next week:
???

3. Next meeting

Date:
February 7, 1996
Location:
DC 1304
Time:
12:30 PM
Chair:
Ryan Gunther
Technical presentation:
Ed Dengler

4. Forthcoming

Chairs:
  1. Fabrice Jaubert
  2. Rick Kazman
  3. Gilles Khouzam
Tech Presenters:
  1. Don Dragomatz
  2. Saar Friedman
  3. Ryan Gunther

5. Technical Presentations

Presenter:
Matthew Davidchuk
Title: Efficient collision detection
Abstract:
Collision detection is a fundamental problem in solid modeling, robotics, animation, and computer-simulated environments. I will briefly discuss a collision detection library which implements algorithms based on the coherence of objects being modelled.

6. General Discussion Items

7. Action List

8. Director's Meeting

9. Seminars


DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

SYMBOLIC COMPUTATION SEMINAR

                    -Thursday, February 1, 1996

Ernst Joachim Weniger, Dept of Applied Math, will speak
on   ``Nonlinear   sequence   transformations  for  the
summation of strongly divergent series.''

TIME:                3:30-4:30 p.m.

ROOM:                DC 1304

ABSTRACT

Sequence  transformations,  which  transform  a  slowly
                                         oo
convergent  or  divergent  sequence  {s }    into a new
                                       n n=0
                oo
sequence   {s ' }     with  hopefully  better  numerical
             n n=0
properties, are principal tools to overcome convergence
problems   [C. Brezinski   and   M. Redivo  Zaglia,
Extrapolation    methods   (North-Holland, Amsterdam,
-------------    -------
1991)].  Some  sequence  transformations are presented,
which  use  explicit  remainder estimates and which are
consequently  particularly  suited for the summation of
strongly  divergent series [E.J. Weniger, Comput. Phys.
Rep. 10 (1989), 189 - 371].

Some  examples  from  special  function theory and from
quantum  mechanical  perturbation  theory are presented
which  show  that  divergent series can be used for the
computation of the functions they represent if they are
combined  with  sequence  transformations  of  the kind
mentioned above.

For  example,  it  is  shown  that the so-called strong
coupling expansion

          (m)           1/(m+1)    oo   (m)    -2n/(m+1)
         E   (BETA)=BETA       ,sum    K   BETA 
                                   n=0  n

                                   (m)
for   the  ground  state  energy  E    (BETA)  of  an  the
anharmonic oscillator described by the Hamiltonians

               ^ (m)       ^2 ^2       ^ 2m
               H    (BETA)=p +x + BETA x   , m=2,3,4

can  be  constructed  from  the strongly divergent weak
coupling expansion

                  (m)           oo   (m)    n
                 E   (BETA)= sum    b   BETA  .
                                n=0  n



==================================================================


DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

DATABASE SEMINAR

                    -Friday, February 2, 1996

Weiye  Zhang, graduate student, Dept. Comp. Sci., Univ.
Waterloo,  will  speak  ``SQL  Predicate  Conversion in
Multidatabase Systems''.

TIME:                2:00-3:00 p.m.

ROOM:                DC 1331

ABSTRACT

In  a  multidatabase system, the local database systems
may   use  different  character  sets.  The  difference
between  the  collating sequences of the character sets
results  in  the semantic difference of queries. When a
query  moves  among these local systems, the predicates
of the query have to be converted to keep the semantics
consistent.  This  talk  presents a general solution of
the  SQL  predicate  conversion based on the difference
between  the  collating  sequences. Since the converted
predicates   are   usually  complicated,  we  introduce
several   techniques   for   predicate  simplification.
Imprecise  queries  and simplification optimization are
the major concern in our current research.

==================================================================

DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

DATABASE SEMINAR

                    -Friday, February 2, 1996

Professor   L.   Kerschberg,   Director,   Center   for
Information  Systems  Integration  and Evolution Chair,
Department   of   Information   and   Software  Systems
Engineering   School   of  Information  Technology  and
Engineering, George Mason University will speak on ``The
Engineering  of Large-Scale Data-Intensive Information
Systems''.

TIME:                10:30 a.m. - 11:30 a.m.

ROOM:                DC 1331

ABSTRACT

Large-scale  data-intensive information systems require

architectures  that  allow  them  to  evolve over their
life-time. In this presentation we present a case study
of  an  architectural  design  study  of  NASA's  Earth
Observing  System Data and Information System (EOSDIS).
This  is  presently the largest US government-sponsored
science project.

The  architecture describes the multiple facets of this
complex  data  and information system: data acquisition
and  storage,  product scheduling and generation, meta-
data  and  knowledge  representation and management, as
well as information access, retrieval and distribution.

A  federated  client-server  software  architecture  is
developed  to  support EOSDIS. Client software presents
an  integrated  view of information resources through a
collection   of   active,  intelligent  thesauri  which
constitute an "information web."

Information  integration and mediation services support
user  subscription  services  for  data  products,  the
distribution  of  large  quantities  of  data,  and the
production  of  value-added  data  products.  Moreover,
intelligent    and    cooperative   query   formulation
strategies  are  used  to  assist users in browsing and
retrieving   large  data  sets,  which  may  reside  in
multiple heterogeneous information systems.

Specialized    servers    handle   meta-data,   product
generation, product storage and product distribution. A
data   warehouse  concept  is  proposed  to  store  and
distribute  popular  data  products, while "Info Marts"
develop  value-added data products for specialized user
communities  such  as  global  change research, weather
forecasting, and K-12 educational materials.

Biographical Sketch for Dr. Larry Kerschberg

Larry  Kerschberg  is  Professor  and  Chairman  of the
Department   of   Information   and   Software  Systems
Engineering in the School of Information Technology and
Engineering  at  George  Mason  University.  He is also
Director   of   the   Center  for  Information  Systems
Integration and Evolution. Professor Kerschberg holds a
Ph.D.  in Systems Engineering from Case Western Reserve
University, an M.Sc. in Electrical Engineering from the
University  of Wisconsin-Madison, and a B.Sc. degree in
Engineering Science from Case Institute of Technology.

Dr.  Kerschberg's  research is in the areas of data and
knowledge   models,   database   design,   active  data
dictionaries,  distributed  query  processing,  object-
oriented   systems,  software  architecture,  knowledge
discovery in databases and expert database systems. His
current    research    projects   include   Information
Integration   and   Interchange:  A  Federated  Systems
Approach  as  well as Knowledge Discovery in Databases,
both  sponsored  by ARPA, Sustaining Engineering - Life
Cycle  Support  for  Evolutionary Software Development,
sponsored by NASA.

He recently served as a Co-Principal Investigator on an
interdisciplinary  team consisting of Earth Scientists,
Information  Scientists,  and  Computer  Scientists who
formulated  a  hardware  and  software architecture for
NASA's Earth Observing System, called Mission to Planet
Earth.

Dr.  Kerschberg  serves as Coordinating Editor-in-Chief
of  the  Journal of Intelligent Information Systems. He
served   as   General  Chair  of  the  ACM  SIGMOD/PODS
Conference  held  in Washington, D.C., in May 1993. Dr.
Kerschberg organized and has served as Program Chairman
of  both the First and Second International Conferences
on Expert Database Systems. These conferences helped to
provide impetus for ongoing research in the integration
of  artificial  intelligence and database technologies.
He  is  past  Chairman  of  the IEEE Computer Society's
Technical Committee on Data Engineering.




10. Lab Cleanup (until 1:30 or 5 minutes)