Asia
Single-Iteration Threshold Hamming Networks
Meilijson, Isaac, Ruppin, Eytan, Sipper, Moshe
The HN calculates the Hamming distance between the input pattern and each memory pattern, and selects the memory with the smallest distance. It is composed of two subnets: The similarity subnet, consisting of an n-neuron input layer connected with an m-neuron memory layer, calculates the number of equal bits between the input and each memory pattern. The winner-take-all (WTA) subnet, consisting of a fully connected m-neuron topology, selects the memory neuron that best matches the input pattern.
Learning Curves, Model Selection and Complexity of Neural Networks
Murata, Noboru, Yoshizawa, Shuji, Amari, Shun-ichi
Learning curves show how a neural network is improved as the number of t.raiuing examples increases and how it is related to the network complexity. The present paper clarifies asymptotic properties and their relation of t.wo learning curves, one concerning the predictive loss or generalization loss and the other the training loss. The result gives a natural definition of the complexity of a neural network. Moreover, it provides a new criterion of model selection.
Physiologically Based Speech Synthesis
Hirayama, Makoto, Vatikiotis-Bateson, Eric, Honda, Kiyoshi, Koike, Yasuharu, Kawato, Mitsuo
This study demonstrates a paradigm for modeling speech production based on neural networks. Using physiological data from speech utterances, a neural network learns the forward dynamics relating motor commands to muscles and the ensuing articulator behavior that allows articulator trajectories to be generated from motor commands constrained by phoneme input strings and global performance parameters. From these movement trajectories, a second neural network generates PARCOR parameters that are then used to synthesize the speech acoustics.
A Parallel Gradient Descent Method for Learning in Analog VLSI Neural Networks
Alspector, J., Meir, R., Yuhas, B., Jayakumar, A., Lippe, D.
Typical methods for gradient descent in neural network learning involve calculation of derivatives based on a detailed knowledge of the network model. This requires extensive, time consuming calculations for each pattern presentation and high precision that makes it difficult to implement in VLSI. We present here a perturbation technique that measures, not calculates, the gradient. Since the technique uses the actual network as a measuring device, errors in modeling neuron activation and synaptic weights do not cause errors in gradient descent. The method is parallel in nature and easy to implement in VLSI. We describe the theory of such an algorithm, an analysis of its domain of applicability, some simulations using it and an outline of a hardware implementation.
A Neural Network that Learns to Interpret Myocardial Planar Thallium Scintigrams
Rosenberg, Charles, Erel, Jacob, Atlan, Henri
The planar thallium-201 myocardial perfusion scintigram is a widely used diagnostic technique for detecting and estimating the risk of coronary artery disease. Neural networks learned to interpret 100 thallium scintigrams asdetermined by individual expert ratings. Standard error backpropagation wascompared to standard LMS, and LMS combined with one layer of RBF units.
Learning Curves, Model Selection and Complexity of Neural Networks
Murata, Noboru, Yoshizawa, Shuji, Amari, Shun-ichi
Learning curves show how a neural network is improved as the number of t.raiuing examples increases and how it is related to the network complexity. The present paper clarifies asymptotic properties and their relation of t.wo learning curves, one concerning the predictive loss or generalization loss and the other the training loss. The result gives a natural definition of the complexity of a neural network. Moreover, it provides a new criterion of model selection.
Integration of Visual and Somatosensory Information for Preshaping Hand in Grasping Movements
Uno, Yoji, Fukumura, Naohiro, Suzuki, Ryoji, Kawato, Mitsuo
The primate brain must solve two important problems in grasping movements. Thefirst problem concerns the recognition of grasped objects: specifically, how does the brain integrate visual and motor information on a grasped object? The second problem concerns hand shape planning: specifically, how does the brain design the hand configuration suited to the shape of the object and the manipulation task? A neural network model that solves these problems has been developed.
A dynamical model of priming and repetition blindness
Bavelier, Daphne, Jordan, Michael I.
We describe a model of visual word recognition that accounts for several aspects of the temporal processing of sequences of briefly presented words. The model utilizes a new representation for written words,based on dynamic time warping and multidimensional scaling. The visual input passes through cascaded perceptual, comparison, anddetection stages. We describe how these dynamical processes can account for several aspects of word recognition, including repetitionpriming and repetition blindness.