Nectar Project applications
Video conferencing
The video conferencing system allows users sitting at their workstation to
communicate using voice and video over gigabit Nectar and other
networks. The systems includes a user interface that can be used to
control what network, protocol or bandwidth is used. The bandwidth is
controled by either changing the frame rate or the resolution of the
picture. The video conferencing system was developed by Kam Lee.
Medical imaging
The purpose of the medical imaging project is to render an image of the
brain, using MRI image slices, and to superimpose information about
functionality of parts of the brain. The resulting image can for example
be used by surgeons while preparing a patient for surgery. The first
part of the application, the computation of the volume rendered image
using a set of MRI images as inputs, has been finished. The application
uses three systems: iWarp extracts volume information from MRI images,
the PSC Cray does some data format conversion, and the paragon does the
final rendering. Gigabit Nectar is used for communication: communication
from iWarp to Cray runs as 40 MB/s sustained, while the Cray to Paragon
communication is currently limited by the Paragon HIPPI interface to 2
MB/s. The second part of the computation, the mapping of functional
information on the brain, is under development. It will use the PSC
Alpha cluster and a workstation.
The medical imaging application is an example of heterogeneous computing
application. The main motivation for using heterogeneous computing is
that the application consists of components that were developed
independently on different systems (iWarp, workstation cluster, ..).
Heterogeneous computing makes it possible to bring up the application
quickly, without having to port the components.
The medical imaging project is lead by Doug Noll.
Dome
Dome is a distributed objects system that can be used to distribute
applications over networks of workstations. It has been used to
distribute kernels of scientific computations, a molecular dynamics
code, and the evaluation of binary decision diagrams. Dome objects can
do transparent load balancing and architecture independent
checkpointing. BEE is used for monitoring.
Environmental modeling
The
environment modeling
application is used to evaluate policies for
environmental pollution control. It consists of a fronted, GEMS, and a
modeling program, called airshed. The system uses Nectar in two ways.
First, airshed can be invoked from GEMS on different systems over gigabit
Nectar.
Second, airshed has been distributed so that it can run on different
combinations of distributed systems, connected by gigabit Nectar.
DCABB
DCABB is a programming environment that supports the development and
execution of linear programming problems across clusters of
workstations. Programmers specify program elements for node evaluation,
prioritization of unevaluation nodes, termination detection, and cut
plane processing. The DCABB system uses these routines to implement a
distributed linear programming algorithm.
The DCABB environment is an example of an application-specific
programming environment. By focussing on a specific class of applications
it is possible to support a programming model with a high level of abstraction.
The DCABB environment was developed by Gautham Kudva and Joe Pekny
(Purdue).
prs@cs.cmu.edu. Last updated Oct 2, 1994