Research Info
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Current Projects:
For my dissertation, I used probabilistic transfer matrices to compute
circuit and system reliabilities implemented with electrostatic and
magnetic quantum-dot cellular automata (QCA) devices. My goal was to
identify the component error rates required to develop reliable
circuits. With this knowledge, we can then determine if components
with manufacturing defects may be feasible if device level redundancy
is used (i.e. thicker electrostatic QCA wires). To do this, I built a
new electrostatic QCA simulator and determined the reliability of
various electrostatic QCA straight wires given various levels of
device redundancy.
My post-doc research is likely to revolve around two or three major
topics. The first is on applications for magnetic QCA. Given how
clocking is expected to work in magnetic QCA, memory and systolic
architectures are the most promising applications. The second topic
will be on modeling energy usage in high-performance computing
systems. In particular, we are interested in how much energy is
required to deliver data to the processor in an exascale system (1000
petaflops). Lastly, we will be investigating different methods for
organizing memory in high-performance computing systems.
For reference, a basic introduction to electrostatic QCA can be
found on the QCADesigner website here. Magnetic QCA is similar in nature to
electrostatic QCA if you consider a single magnet to be roughly
equivalent to half of an electrostatic cell (differences occur in the
majority gates and vertical wire structures). Since QCA is a misnomer
for the magnetic implementation, the term nanomagnetic logic is being
utilized instead. A large number of papers (and references to many
more) can be found here.
My informal reflections from IWQCA 2009 (1st International
Workshop on QCA) can be found here. [PDF]
Research Interests:
- Nanoelectronic devices and architectures, particularly quantum-dot cellular automata (QCA)
- Defect and fault tolerant design and modeling
- High-performance computing systems
- Computer-aided design and electronic design automation
Note: I would highly encourage anyone with questions on
QCA and/or QCADesigner to join the Yahoo group qca_design and post
their question to that list. Links to the group page and joining the
mailing list can be found at www.qcadesigner.ca
QCADesigner Contributions:
- XML Based file format framework
- qca2xml -- Old to new file format converter
- More info on the above can be found here.
- Supervised an undergraduate (Dominic Antonelli) that wrote the digital logic simulation engine.
Note: The above contributions have not been introduced into the
release versions of QCADesigner at the discretion of its caretakers.
The XML file format components are included here and I may still have
a version of QCADesigner with a digital logic simulation method, but
I'm not certain. At the very least, I have a stand alone version of
the digital logic simulation engine.
Publications:
Under Review
- Timothy J. Dysart and Peter M. Kogge. Reliability Impact of
N-Modular Redundancy in Quantum-Dot Cellular Automata. IEEE Trans. on
Nanotechnology
Accepted for publication
- Timothy J. Dysart and Peter M. Kogge. Organizing Wires for
Reliability in Magnetic QCA. ACM Journal on
Emerging Technologies in Computing Systems
Journals
- Timothy J. Dysart and Peter M. Kogge. Analyzing the Inherent
Reliability of Moderately Sized Magnetic and Electrostatic QCA
Circuits via Probabilistic Transfer Matrices. IEEE Trans. on
VLSI Vol. 17, Num. 4, Apr. 2009. pp. 507-516 [On IEEE Xplore]
- Konrad Walus, Timothy J. Dysart, Graham A. Jullien,
Arief R. Budiman. QCADesigner: A Rapid Design and Simulation Tool for
Quantum-Dot Cellular Automata. IEEE Trans. on Nanotechnology,
Vol 3, Num. 1, March 2004. pp. 26-31 [On IEEE Xplore]
Refereed Workshops and Conferences
- Timothy J. Dysart and Peter M. Kogge. System Reliabilities when
Using Triple Modular Redundancy in Quantum-Dot Cellular Automata.
23rd IEEE International Symposium on Defect and Fault Tolerance in VLSI
Systems (DFT '08). Oct. 1-3, 2008. [On IEEE Xplore]
- Timothy J. Dysart, Daniel J. Lohmer, Peter M. Kogge. Yield
Estimation of Molecular QCA Memory Structures with Geometric
Analysis. IEEE International Workshop on Design and Test of
Nano Devices, Circuits and Systems (NDCS). Sept. 29-30, 2008. [On IEEE Xplore]
- Timothy J. Dysart and Peter M. Kogge. Comparing the Reliability
of PLA and Custom Logic Implementations of a QCA Adder. IEEE
International Workshop on Design and Test of Nano Devices, Circuits
and Systems (NDCS). Sept. 29-30, 2008. [On IEEE Xplore]
- Timothy J. Dysart and Peter M. Kogge. Probabilistic Analysis of
a Molecular Quantum-Dot Cellular Automata Adder. 22nd IEEE
International Symposium on Defect and Fault Tolerance in VLSI Systems
(DFT '07). Rome, Italy. September 26-28, 2007. [On IEEE Xplore]
- Timothy J. Dysart and Peter M. Kogge. Probabilistic Analysis of a
Quantum-Dot Cellular Automata Multiplier Implemented in Different
Technologies. 4th Non-Silicon Computing Workshop in conjunction with
the 34th International Symposium on Computer Architecture and FCRC
2007. San Diego, CA. June 9, 2007. [PDF]
- Timothy J. Dysart, Peter M. Kogge, Craig S. Lent, and Mo Liu. An
Analysis of Missing Cell Defects in Quantum-Dot Cellular Automata.
IEEE International Workshop on Design and Test of Defect-Tolerant
Nanoscale Architectures (NANOARCH '05) in conjunction with the VLSI
Test Symposium. Palm Springs, CA. May 1, 2005. [PDF]
- Sarah E. Frost, Timothy J. Dysart, Peter M. Kogge, and Craig S.
Lent. Carbon Nanotubes for Quantum-Dot Cellular Automata Clocking.
4th IEEE Conf. on Nanotechnology. Munich, Germany. August 17-19,
2004. [On IEEE Xplore]
- Dominic A. Antonelli, Danny Z. Chen, Timothy J. Dysart, Xiaobo
S. Hu, Andrew B. Kahng, Peter M. Kogge, Richard C. Murphy, and Michael
T. Niemier. Quantum-Dot Cellular Automata (QCA) Circuit Partitioning:
Problem Modeling and Solutions. 41st Design Automation Conference.
San Diego, CA. June 7-11, 2004. [On IEEE Xplore]
- Timothy J. Dysart, Branden J. Moore, Lambert Schaelicke, Peter
M. Kogge. Cache Implications of Aggressively Pipelined High
Performance Microprocessors. IEEE International Symposium on
Performance Analysis of Systems and Software (ISPASS-2004). Austin,
Texas. March 10-12, 2004. [On IEEE Xplore]
- Timothy J. Dysart and Peter M. Kogge. Strategy and Prototype
Tool for Doing Fault Modeling in a Nanotechnology. 3rd IEEE Conf. on
Nanotechnology. San Francisco, CA. Aug. 12-14, 2003. [On IEEE Xplore]
Other Workshops, Technical Reports, and Thesis
- Timothy J. Dysart. Implementing a Generic Three State Coherence Vector
Model for QCA. White paper, 2009. [PDF]
- Timothy J. Dysart. It's All About the Signal Routing:
Understanding the Reliability of QCA Circuits and Systems.
Ph.D. Dissertation, 2009. [PDF]
- Timothy J. Dysart, Daniel J. Lohmer, Peter M. Kogge. Missing Cell
Patterns Causing Circuit Failures In Densely Packed Molecular QCA
Wires. TR 2008-08, Dept. of Computer Science and Engineering,
University of Notre Dame. [PDF]
- Timothy J. Dysart. Defect Properties and Design Tools for
Quantum Dot Cellular Automata. Master's Thesis, 2005. [PDF]
- Timothy J. Dysart and Peter M. Kogge. XML Based File Format for
QCADesigner. TR 2004-26, Dept. of Computer Science and Engineering,
University of Notre Dame. [PDF]
- Konrad Walus, Timothy J. Dysart, Graham A. Jullien,
Arief R. Budiman. QCADesigner: A Rapid Design and Simulation Tool for
Quantum-Dot Cellular Automata. 2nd International Workshop on Quantum
Dots for Quantum Computing and Classical Size Effect Circuits
(IWQDQC). Notre Dame, IN. Aug. 7-9, 2003. Note: Extended version
published in IEEE Trans. on Nanotechnology
Undergraduate projects supervised:
- Jorge Vendries: Parallelization of a statistical mechanical QCA
simulator. Summer/Fall 2008
- Daniel Lohmer: Geometric analysis of QCA wires (Workshop paper published). Spring 2008
- Jared Sylvester: CAD tools for QCA. Academic year 2004-2005
- Dominic Antonelli: Digital logic simulator for QCADesigner. Summer
2003