Реферат: Computer History Essay Research Paper ABSTRACTCurrent neural

of processing the absolute value of the illumination at each point on an object, and required

a very powerful computer.(Thompson 249-250). The analysis required measurements be taken over

a massive number of sample locations on the object, and so, it required the computing power of a

massive digital computer to analyze the data.

The professors believe that to replicate the function of the human retina they can use a neural

network modeled with a similar biological structure of the eye, rather than simply using massive

computer power. Their chip utilizes an analog computer which is less powerful than the previous

digital computers. They compensated for the reduced computing power by employing a far more

sophisticated neural network to interpret the signals from the electronic eye. They modeled the

network in their silicon chip based on the top three layers of the retina which are the best

understood portions of the eye.(250) These are the photoreceptors, horizontal cells, and bipolar cells.

The electronic photoreceptors, which make up the first layer, are like the rod and cone cells in the eye.

Their job is to accept incoming light and transform it into electrical signals. In the second

layer, horizontal cells use a neural network technique by interconnecting the horizontal cells

and the bipolar cells of the third layer. The connected cells then evaluate the estimated

reliability of the other cells and give a weighted average of the potentials of the cells

around it. Nearby cells are given the most weight and far cells less weight.(251)

This technique is very important to this process because of the dynamic nature of image

processing. If the image is accepted without testing its probable accuracy, the likelihood

of image distortion would increase as the image changed.

The silicon chip that the two professors developed contains about 2,500 pixels? photoreceptors

and their associated image-processing circuitry. The chip has circuitry that allows a professor

to focus on each pixel individually or to observe the whole scene on a monitor. The professors

stated in their paper, “The behavior of the adaptive retina is remarkably similar to that of

biological systems” (qtd in Thompon 251).

The retina was first tested by changing the light intensity of just one single pixel while the

intensity of the surrounding cells was kept at a constant level. The design of the neural network

caused the response of the surrounding pixels to react in the same manner as in biological retinas.

They state that, “In digital systems, data and computational operations must be converted into