Browsing by Author "LIN, SH"

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A HYBRID NEURAL-NETWORK FOR IMAGE CLASSIFICATION
(1995)
HSU, KY
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LIN, SH
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電子物理學系
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光電工程學系
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Department of Electrophysics
Principles of the photorefractive perceptron learning algorithm are described. The influences of the finite response time and hologram erasure of the photorefractive gratings on the convergence property of the photorefractive perceptron learning are discussed. A novel neural network which could resolve these constraints is presented. It is a hybrid system which utilizes the photorefractive holographic gratings to implement the inner product between the input image and the interconnection matrix. A personal computer is used for storing the interconnection matrix and the updating procedure, and it also functions as a feedback means during the learning phase. After training the weight vectors are recorded in the volume hologram of an optical processor. This novel method combines the advantages of the massive parallelism of optical systems and the programmability of electronic computers. Experimental results of image classification are presented. It shows that the system could correctly classify the input patterns into one of the two groups after training on four examples in each group during successive iterations. The system has been extended to perform multi-category image classification.
CONDITIONAL CONVERGENCE OF PHOTOREFRACTIVE PERCEPTRON LEARNING
(1993-12-15)
HSU, KY
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LIN, SH
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YEH, P
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光電工程學系
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Department of Photonics
We consider the convergence characteristics of a perceptron learning algorithm, taking into account the decay of photorefractive holograms during the process of interconnection weight changes. As a result of the hologram erasure, the convergence of the learning process is dependent on the exposure time during the weight changes. A mathematical proof of the conditional convergence, as well as computer simulations of the photorefractive perceptrons, is presented and discussed.
INTRAMOLECULAR DIELS-ALDER REACTION OF FURANS WITH ALLENYL ETHERS - HIGH EFFECT OF THE CHAIN-LENGTH ON THE STRUCTURE AND REACTIVITY OF THE CYCLOADDUCTS
(1994-07-01)
WU, HJ
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LIN, SH
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LIN, CC
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交大名義發表
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應用化學系
The structure and reactivity of the cycloadducts of the title reaction were found to be highly dependent on the chain length between the furan diene and the allenyl ether dienophile. Reaction of the propargyl ether (2) with t-BuOK in t-BuOH at 85-degrees-C for 3 h gave a mixture of the cycloadducts (3) and (4) in 90% yield, which were transferred to the benzo derivatives (5), (6) and (7). Treatment of the propargyl ether (8) with t-BuoK in t-BuOH at 85-degrees-C for 5 h gave the products (9) and (10) in a ratio of 8:1 in 65% yield, no detectable amount of the cycloadduct (8b) was obtained. Refluxing of the propargyl ether (13) with t-BuOK in t-BuOH at 85-degrees-C for 4 h gave the allenyl ether (14). Heating 14 in DMSO at 15-degrees-C for 12 h still did not give 15.
OPTICAL RESTORATION OF PHOTOREFRACTIVE HOLOGRAMS THROUGH SELF-ENHANCED DIFFRACTION
(1995-02-01)
CAMPBELL, S
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YEH, PC
;
GU, C
;
LIN, SH
;
CHENG, CJ
For the first time to our knowledge, we demonstrate the use of self-enhanced diffraction to optically restore weak dynamic volume holograms. This restoration process is achieved through the use of a novel beam-toggling scheme that significantly enhances the steady-state diffraction efficiency of volume index gratings stored in photorefractive media. Experiments demonstrating and confirming theory are presented and discussed.
REAL-TIME IMAGE PROCESSING USING PHOTOREFRACTIVE CRYSTALS
(1994)
HSU, KY
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LIN, SH
;
HSIEH, TC
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光電工程學系
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Department of Photonics