Yasuyuki Funahashi

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A neural network model was formulated to describe the spatiotemporal properties of the photoreceptor and horizontal cell responses to light in the vertebrate retina. The model consists of two layers, one of which represents the photoreceptor syncytium and the other the horizontal cell syncytium. Each syncytium is an array of elemental neurons, each of which(More)
This paper analyzes grasp stability of two objects in two dimensions. In the previous researches on the grasp stability, the number of grasped objects is restricted to 1. For efficiency of tasks, multiple objects had better been grasped and manipulated by a robot hand. In order to design stable grasp, grasp stability of multiple objects must be(More)
A linear analogue network model is proposed to describe the neuronal circuit of the outer retina consisting of cones, horizontal cells, and bipolar cells. The model reflects previous physiological findings on the spatial response properties of these neurons to dim illumination and is expressed by physiological mechanisms, i.e., membrane conductances,(More)
We propose a new method for analyzing the stability of grasps. The characteristic points in this paper are to consider the curvature of both hand and object at contact points and the grasp with friction and frictionless contact. From this analysis, it is shown that the grasp using round fingers is more stable than using sharp fingers. Moreover, we establish(More)
We propose an equivalent circuit model of a discrete formulation to describe the interaction between the red cone syncytium and the H1 horizontal cell syncytium in lower vertebrate retinas. Analytical solutions of the model provide intuitive understandings of spatio-temporal properties of light-induced responses in reference to membrane impedance, strength(More)