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| Modeling Visual
Recognition and Online Linear Discriminant Analysis |
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Shuji Yoshizawa*1,Hiroshi
Mizoguchi*2
*1Saitama University,*2Tokyo University
of Science
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Aiming development of brain-oriented recognition and decision technologies,
our group has studied three subjects.
The first subject is modeling of brain information processing; its goal
is understanding of information processing mechanism in the brain with neuron
level and neural network level. We have clarify the mechanisms of synaptic
regulation and proposed multiplicative spike-timing-dependent synaptic plasticity
(STDP) rules which can achieve synaptic regulation. We have also investigated
the property of the connection which is required for realization of the
qualitative results shown by the psycho-physical experiments on the binocular
rivalry.
The second subject is the study on recognition technology. Only from a two-dimensional
movie, we can recognize three dimensional positions and motions of a person
in it. Though the mechanism of that ability is not known completely, we
have a conjecture that a model of human body is built in the brain and it
is applied to two-dimensional images so that natural motions can be estimated.
According to this strategy, we have tried estimation of three-dimensional
motions based on positions of characteristic body points which are detected
from two-dimensional movies. In experiments on qualitative properties for
the case that noises are added to the detected positions, an interesting
behavior is observed; unless the noises are so large that no candidate of
three-dimensional posture remains, naturalness of estimated motion has little
dependence on the amount of noises.
The third subject is the study on discrimination technology. The brain can
learn new things and it has adaptability to change of situations during
the learning. It can also extract useful components for its decision from
high-dimensional input data. In order to develop discrimination technologies
which have the above nature, we have constructed online linear discriminant
analysis (OLDA) and related techniques. In addition to theoretical investigation
of them, we have also built several vision systems as applications of them,
face recognition system, arbitrary pattern recognition system, human walking
pitch extraction system based on visual tracking of person's heel, and so
on.
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