• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.214-217
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• 2000

To help the blind to find the information easily on World Wide Web, this research has tried to develop the device which enables us to convert HTML for the general into HTML for the blind. This program consists of the items as follows: 1. Web Robot to gather the internet browser and the general HTML. 2. Restoring DB by Parsing process 3. Multimedia editor for the use of web DB to add the literal and acoustic description to the editing function. 4. Convertor which gathers the DB and then changes into HTML for the blind. This project is designed to make it easy for the manager to establish the web site for the blind. We expect that this program will basically help the blind to overcome the inequality in the common information.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2309-2310
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• 2008

The surface made of dielectric materials can therefore become probable sites for damaging electrostatic discharges. Thanks to a specially equipped chamber, the spatial environment can be reproduced experimentally in the laboratory. In this paper, the behavior of high energy electrons injected in polymers such as PolyMethylMetaAcrylate (PMMA) and Kpton is studied. Results obtained by surface potential technique, pulse-electro acoustic device and a cell based on the split Faraday cup system are analyzed and discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.3
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• pp.32-38
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• 2004

Recently, the system of high speed milling(HSM) is widely used for reducing the operation time and maximizing efficiency of work. The most research of high speed milling system is still leaves much to be desired. Specially the research of mass pocket high speed processing with high precision is the first and probably the last. So this paper showed mass pocket processing of high precision with a duralumin and then confirmed a cause of inferior goods through the CAD/CAM pattern simulation and experimentation. And this paper showed high speed processing system reduce the rate of inferior from this optimal pattern.

• Speech Sciences
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• v.3
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• pp.50-56
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• 1998

Frequency transposition (FT) hearing system was designed for individuals with little or no residual hearing at high frequencies. This device compresses and shifts the wide-band, high frequency acoustic energy where important features for speech perception are concentrated to the audible, lower range of frequencies. The usefulness of the FT system was investigated for 12 patients (7 children and 5 adults) with severe-to-profound sensorineural hearing losses compared with conventional hearing aids. Results suggest that the hearing impaired can benefit from the FT system with appropriate selection criteria and auditory (re)habilitation program.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.1014-1018
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• 2005

The purpose of this study is to obtain strong bond strength at the interface between piezoelectric substrates and semiconductor thin films to be applied for the manufacture of high-performance acoustic wave semiconductor coupled device. For this purpose, we have compared and examined the effects of different surface treatment methods on hydrophile properties at the surface of the piezoelectric substrates. Moreover, we have observed the effect of microwave and laser on the elimination of water molecules at the interface. As for the piezoelectric substrates, dry method for surface treatment was found to be superior in the control of hydrophilicity of the surface compared to wet method. On the other hand, both microwave and laser were found to be effective in the elimination of water molecules in the interface.

• Journal of the Korean Ceramic Society
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• v.43 no.9 s.292
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• pp.527-531
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• 2006

In order to study the influence of post-annealing treatment on the frequency characteristics of the Li doped ZnO(Li:ZnO) FBAR(Film Bulk Acoustic Resonator) device, we investigated the material and electrical properties of Li:ZnO films in the annealing temperature range from 300 to $500^{\circ}C$. In our samples, as annealing temperature was increased, Li:ZnO films showed the improvement of high c-axis orientation and resistance value with relieved stress and low surface roughness. In addition to, the return loss in the frequency property of fabricated FBAR was improved by annealing treatment from 24.9 to 29.8dB. From experimental results, the optimum post-annealing temperature for FBAR is $500^{\circ}C$ and it can obtain excellent Li:ZnO FBAR performance with stronger c-axis orientation, smoother surface, relieved stress, and lower loss factor.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.49-51
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• 2005

The single phase switched reluctance motor(SRM) has many merits in practical appliance because it has simple operating drive and control system, very high energy density per unit volume comparing with three phase SRM. But it has also problems to need a starting device and to generate the torque ripple. One of the major problems is a torque ripple which causes increased undesirable acoustic noise and speed ripple. This paper describes an approach to determine a rotor type to minimize the torque ripple.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.167-170
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• 2003

This paper presents the results of a series of performance tests for the Stilting cryocooler. A free piston and free displacer(FPFD) Stilting cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM. Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stilting cryocooler is designed, manufactured and fabricated, and performance characteristics for the vibration, acoustic noise, EMI and leak rate are evaluated. Vibration outputs are measured to 20KHz for compressor and expander, respectively. And, the objective of noise test is a noise level, less than 30㏈ at 5 m. EMI tests are carried out according to the standard MIL-STD-461C tests RE01 and RE02. Leak test for the Stilting cryocooler is performed by bombing method.

• Earthquakes and Structures
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• v.9 no.3
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• pp.577-601
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• 2015

The thermomagnetic effect on plane wave propagation at the liquid-solid interface with nonclassical thermoelasticity is investigated. It is assumed that liquid-solid half-space is under initial stress. Numerical computations are performed for the developed amplitude ratios of P, SV and thermal waves under Cattaneo-Lord-Shulman theory, Green-Lindsay theory and classical thermoelasticity. The system of developed equations is solved by the application of the MATLAB software at different angles of incidence for Green and Lindsay model. The effect of initial stress and magnetic field in the lower half-space are discussed and comparison is made in LS, GL and CT models of thermoelasticity. In the absence of magnetic field, the obtained results are in agreement with the same results obtained by the relevant authors. This study would be useful for magneto-thermoelastic acoustic device field.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.12
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• pp.92-98
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• 1998

In this paper, we implemented an angularly multiplexed volume holographic memory system using an AOD that is controlled electronically, with rapid access time(10$mutextrm{s}$) and accurate repeatability of the reference beam. First we designed an AOD-based angular multiplexing system without the frequency compensation of the object beam, and magnified the deflection angle of AOD through the combination of lens so that we increased the storage capacity up to six times. Finally fifty-one images were stored experimentally in a photorefractive material of 1㎤ Fe:LiNbO$_3$.