LASCA: Featured Projects
- Computer network emulation,
Srinidhi Varadarajan,
Computer Science.
- The continuing exponential growth of the Internet has resulted in rapid proliferation
of new network protocols. Protocol interactions have become vastly more complex and it is
no longer possible to analyze their runtime behavior in small experimental testbeds.
Furthermore, critical network protocols are highly distributed in nature.
The complexity of router software, the backbone of Internet communication, requires
large-scale testbeds to verify scalability and validate correctness.
The reseach goal of this project is to enable the systematic study of network applications
and protocols through the development of a scalable network emulation testbed.
To achieve this goal, we are building a new network emulation system called the
Open Network Emulator (ONE), based on a novel compiler directed framework that supports
both simulation and direct code execution paradigms.
This integration of paradigms, which often have opposing requirements, enables a new
dimension in verification and validation of network protocols.
Event-driven simulation models can now be validated through their interaction with
real-world code counterparts. Our compiler directed strategy provides a modular
framework that includes support for automatic checkpointing and recovery,
without application support.
Our compiler directed strategy for generating composable code objects also enables
existing non-OO codes to use the power of grid computing environments.
Support for transparent checkpointing and recovery enables large scientific simulation
codes to use optimistic parallel discrete event simulation (PDES) algorithms without
modification.
Support for runtime code migration enables new dynamic load balancing algorithms that
are of use to large-scale parallel computation.
For more information, visit the
Computing Systems Research Lab.
- Grid computing,
Dennis Kafura and
Cal Ribbens,
Computer Science.
- The goal of this project is to establish a campus-wide computational grid
at Virginia Tech. The group is working with LASCA affiliates with large-scale
computing needs to access a variety of computing resources from around the
university---in some cases leveraging unused cycles on workstations, in other
cases combining multiple clusters and SMPs in order to run extremely large
parallel codes. Research projects pursued by this group include
privilege management and authorization, scheduling, runtime algorithm
selection, automatic job checkpointing and migration, and configurable resource
brokering. For more information, visit the
Grid-Computing Research Group.
- Molecular electronics,
Massimiliano Di Ventra,
Physics.
-
Prof. Di Ventra's research focuses on using first-principles atomistic
calculations to predict the electronic, optical and transport properties
of materials. He is a pioneer of transport calculations in molecular
devices from first principles. This includes the investigation of
fundamental phenomena at the atomic level, e.g., electromigration
and temperature effects. His recent work also includes the study of the
transport properties of nanotubes, their metal contacts and field-effect
behavior, thin-film oxidation of wide-gap materials like SiC, and the
improvement of the SiC-SiO2 interface via NO annealing.
- Molecular modeling---protein structure and function,
David Bevan,
Biochemistry.
-
Prof. Bevan is working to isolate and
characterize proteins with the ultimate goal of
modeling the dynamics and interactions of the proteins that serve as the
basis of their function. For
example, his group has isolated a protein from cyanobacteria that is called
cyanoglobin. It is a heme-containing protein that binds oxygen reversibly,
and it functions in some capacity in nitrogen fixation.
The kinetics of ligand binding to cyanoglobin have been defined, and
a three-dimensional model of the structure of the protein
has recently been developed.
Other topics of interest include a study of
the beta-glucosidases and the application of
molecular modeling to the study of endocrine disruptors and to
an analysis of the structure and dynamics of DNA.
- Molecular statics and dynamics,
Diana Farkas,
Materials Science & Engineering.
- Prof. Farkas research
concentrates on theoretical studies of extended defect
structure in novel ordered intermetallic alloys, with emphasis on
predicting mechanical behavior. Using various computer simulation techniques,
she studies the atomic structure of grain boundaries and dislocation cores
in these materials and the
interaction of dislocations and grain boundaries.
The goal is to contribute to the understanding of the
mechanical behavior of these alloys in both single crystal and
polycrystalline form and to be able to suggest
ways to improve their ductility.
Her research encompasses state-of-the-art work
in atomistic micro-mechanical and continuum level computational work
in the areas of material deformation and fracture,
wave propagation, and visualization.
- Seismic modelling --- waves in complex media,
Matthias Imhof, Geological Sciences.
- Prof. Imhof's work focuses on simulating the propagation of acoustic and elastic
waves in complex media and the interpretation of seismic experiments.
Computation of synthetic seismograms is essential for designing seismic
experiments, data processing tools, and interpretation schemes. Dr. Imhof is
developing new simulation algorithms based on the finite-difference and
boundary-element methods. A current example is the simulation of elastic waves
in media with embedded fractures or cavities. With regard to data
interpretation, Dr. Imhof is developing a full-waveform tomographic algorithm to
infer the subsurface from both reflected and transmitted seismic signals. In
addition to deterministic inversion, he is also working on estimating local
second-order statistics of subsurface heterogeneity from seismic data and the
construction of compatible heterogeneity models.
Last updated 12/12/02
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