Information retrieval (IR) systems provide individual remote access to centrally managed data. The current proliferation of personal computer systems, as well as advances in storage and communication technology, have ...
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The authors consider the optical implementation of learning networks using volume holographic interconnections in photorefractive crystals. The use of volume holograms permits the storage of a very large number of int...
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The authors consider the optical implementation of learning networks using volume holographic interconnections in photorefractive crystals. The use of volume holograms permits the storage of a very large number of interconnections per unit volume, and the use of photorefractive crystals permits the dynamic modification of these connections, thus allowing the implementation of learning algorithms. The authors first briefly review the major types of learning algorithms that are being used in neural network models. They then estimate the maximum number of holographic gratings that can simultaneously exist in a photorefractive crystal. Since in an optical implementation each grating corresponds to a separate interconnection between two neurons, this estimate gives the density of connections that are achievable. They consider how the modulation depth of each grating (or equivalently the strength of each connection) can be controlled through the implementation of learning algorithms. Two related issues are investigated: the optical architectures that implement different learning algorithms and the reconciliation of physical mechanisms that are involved in the recording of holograms in photorefractive crystals with the dynamics of the learning procedures in neural networks.
This paper describes the principle and the state of art in magnetooptical recording using amorphous rare earth-transition metal films. The physical principles involved are discussed. The importance of material prepara...
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ISBN:
(纸本)0878495568
This paper describes the principle and the state of art in magnetooptical recording using amorphous rare earth-transition metal films. The physical principles involved are discussed. The importance of material preparation is brought out. Finally several problems still facing this new technology which would dawn in the coming years are mentioned.
This article introduces some advances in vertical-recording technology which could lead the way to higher capacities and data rates on magnetic media than have been possible even with opticalstorage. A monopole-head ...
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This article introduces some advances in vertical-recording technology which could lead the way to higher capacities and data rates on magnetic media than have been possible even with opticalstorage. A monopole-head technology has already achieved track densities of 2,100 tracks/in. and linear densities of over 20,000 flux changes/in. - amounting to over 30 million bits/in. **2.
A physical implementation of a spin glass processor is proposed. Implicit in the design is capability for associative memory, fast associative access, and massive information storage. It is based primarily on implemen...
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A physical implementation of a spin glass processor is proposed. Implicit in the design is capability for associative memory, fast associative access, and massive information storage. It is based primarily on implementation of ideas from the Boltzmann machine. An amorphous magnetic material such as a spin glass film is 'trained' with the series of pattern vectors by locally laser-heating it in the magnetic field from an imposed input pattern until the spins become mobile and then allowing the magnetic spins of the system to seek an energy minimum. Simulations show that after repeated training sessions, an energy landscape is created that effectively stores and permits retrieval of pattern vectors from a set of given inputs. The techniques needed for storage and retrieval of the patterns, which are now available from optical disk technology, are described.
The suitability of RF sputtered amorphous barium titanate (a-BaTiO//3) films as dielectric coatings in thin film active display devices has been investigated in the present study. The band gap and refractive index hav...
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ISBN:
(纸本)0878495568
The suitability of RF sputtered amorphous barium titanate (a-BaTiO//3) films as dielectric coatings in thin film active display devices has been investigated in the present study. The band gap and refractive index have been evaluated from the optical transmission data in the wavelength region 200-900 nm. The films were highly transparent (approximately 90%) in the visible region. The room temperature dc conductivity 10** minus **1**2 OMEGA ** minus **1 multiplied by (times) cm** minus **1, dielectric constant 13. 8 (at 100 kHz) and breakdown field 1. 25 multiplied by 10**6 V/cm give a charge storage capacity 1. 5 mu C/cm**2. The high transparency and good charge storage capacity show promise for the application of amorphous BaTiO//3 films in dielectric coated active display devices.
Information retrieval (IR) systems provide individual remote access to centrally managed data. The current proliferation of personal computer systems, as well as advances in storage and communication technology, have ...
ISBN:
(纸本)9780897912327
Information retrieval (IR) systems provide individual remote access to centrally managed data. The current proliferation of personal computer systems, as well as advances in storage and communication technology, have created new possibilities for designing information systems which are easily accessible, economical, and responsive to user needs. This paper outlines methods of integrating personal computers (PCs) into large information systems, with emphasis on effective use of the storage and processing capabilities of these computers. In particular we discuss means for caching retrieved data at PC-equipped user sites, noting that caching in this environment poses unique problems. An event-driven simulation program is described which models information system operation. This simulator is being used to examine caching strategies. Some results of these studies are presented.
Philips' recent proposal for a new compact disk standard called CD-I has generated a considerable amount of confusion within the editorial community as well as the marketplace. While Philips explained the details ...
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Philips' recent proposal for a new compact disk standard called CD-I has generated a considerable amount of confusion within the editorial community as well as the marketplace. While Philips explained the details and potential of this new proposal at the First International CD-ROM conference sponsored by Microsoft, there are still many questions regarding how CD-ROM will coexist with CD-I. This article discusses this issue by explaining the evolution of the three compact disk standards - Compact Disk Audio, CD-ROM, and CD-I - and their present positions in the market place.
This conference proceedings contains 5 papers. The main subjects are optical disc storagetechnology, compact image storage by computers, electronically scanned micrographs, the recording and provision of image data f...
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This conference proceedings contains 5 papers. The main subjects are optical disc storagetechnology, compact image storage by computers, electronically scanned micrographs, the recording and provision of image data for satellites, and storage and retrieval of facial images.
Besides main memories, which are almost exclusively silicon semiconductor memories, the most important mass memories today are magnetic storage media with packing densities of approx. 10E6 bit/cm. Examples of this are...
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Besides main memories, which are almost exclusively silicon semiconductor memories, the most important mass memories today are magnetic storage media with packing densities of approx. 10E6 bit/cm. Examples of this are magnetic tapes and discs (floppy or hard discs). In 1985, a new mass memory system was introduced to the market. Based on the known technologies of Video Disk and Audio Compact Disk, an optical Read Only Memory was developed and introduced as CD - ROM. Since then, a rapid development in opticalstoragetechnology has taken place. This paper is intended to give a short overview of the most recent development in this field.
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