Electronic
Systems
and
Signals
Research
Laboratory
Naveen Singla
Post-Doctoral Research Associate
Department of Electrical & Systems Engineering
Box 1127
Washington University
One Brookings Drive
St. Louis, MO 63130-4899
Laser Doppler Vibrometry Measures of Physiological Function:
Evaluation of Biometric Capabilities
This work entails the analysis of (heartbeat) signals that are measured at
the carotid artery using the remote-recording method of laser Doppler
vibrometry. The analysis is focussed on two things:
Discerning physiological activity - can the signal be used to detect
physiological activities functions such as heart-rate, blood-pressure,
arrhythmia, etc?
Evaluation of biometric capability - does the signal have features
that can be used as unique identifiers for humans?
Pattern recognition systems are being used in applications ranging from
speech recognition to spam filters to biometric systems. In addition to
these artificial systems, there exist biological pattern recognition
systems, the brain being the quintessential example. A theoretical
understanding of such systems goes a long way in explaining its
intricacies and complexities. In this work we have developed an
information-theoretic framework for pattern recognition systems and have
derived bounds on the number of patterns that can be reliably recognized
given memory and sensory constraints. The problem has interesting
connections to the distributed source coding problem. We have also
extended this work to systems that use successive recognition.
Click here
for more information.
Joint Equalization and Decoding Schemes for Advanced Recording Media
Doctoral dissertation: Joint
Equalization and Decoding for Two-Dimensional Intersymbol Interference
Channels
(pdf) (ps)
Data storage systems have relied primarily on designs based on storing
data on tracks. On magnetic media, input data are encoded and stored as
flux reversals on tracks, with decoding being based on standard algorithms
such as the Viterbi algorithm. Optical-disc recording uses a similar
storage paradigm. As data densities increase, fundamental limits for
recording on tracks are approached, and alternative data storage
technologies must be considered. Research in data storage systems is
shifting towards using two-dimensional storage paradigms. For such
paradigms the intersymbol interference is also two-dimensional. This
interference invalidates assumptions in the Viterbi and related algorithms
necessitating novel decoding strategies. We describe several approaches
for the design of encoding and decoding for data storage systems that have
two-dimensional intersymbol interference. Click here
for more information.
For a good tutorial introduction on the Viterbi
algorithm and its application to the decoding of convolutional codes.
"To choose one sock from each of infinitely many pairs of socks
requires the Axiom of Choice, but for shoes the Axiom is not needed."
--Bertrand Russell. Go to Axiom of
Choice for more information.
