• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.378-381
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• 2009

As a Joule-heat source, a conductive Mo layer was used to crystallize amorphous silicon for AMOLED backplanes. This Joule-heating induced crystallization (JIC) process could produce poly-Si having a grain size ranging from tens of nanometers to greater than several micrometers. Here, the blanket (single-shot whole-plane) crystallization could be achieved on the $2^{nd}$ and the $4^{th}$ generation glass substrate.

• 전기의세계
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• v.20 no.3
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• pp.17-26
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• 1971

An experimental design of magnetic amplifiers and their characteristics in steady state are presented. A saturable reactor model having 2KVA capacity was designed, using Z-10 grain-oriented silicon steel which is commonly used in power transformers. Experimental and theoretical analysis show that the experimental results are in good agreement with the equal ampere-turns law. In addition to the saturable reactor, the self-saturated magnetic amplifiers of 0.4VA and 5VA capacity, using 50% Ni-Fe alloy cores having rectangular hysteresis loops were designed. Control characteristic curves of these amplifiers show high ampere-turn gain enough to be used for voltage controllers under load and non-contact magnetic switches of the rated capacity.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.66-76
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• 2017

This paper is concerned with investigating the plastic material properties of steel plate formed by line heating method, and is aimed at implementing more rational design considering the accidental limit states such as collision or grounding. For the present study, line heating test for marine grade steel plate has been carried out with varying plate thickness and heating speed, and then microscopic examination and tensile test have been carried out. From the microscopic, it is found that the grain refined zones like ferrite and pearlite are formed all around the heat affected zone. From the tensile test results, it is seen that yield strength, tensile strength, fracture strain, hardening exponent and strength coefficient vary with plate thickness and heat input quantity. The formulae relating the material properties and heat input parameter should be, therefore, derived for the design purpose considering the accidental impact loading. This paper ends with describing the extension of the present study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.9
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• pp.1001-1009
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• 1992

In this paper, the standard A earth station antenna was designed by using the shaping techniques and also manufactured for I NTELSAT satellite. The designed antenna Is C-band shaped casse grain antenna with the diameter of 18m. The wide-angle radaiation patterns wholly satisfied CCIR Recommendation of sidelobe envelope line of 29-25 logo. The whole radiatlon characteristics satisfied the design specifications.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.79-85
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• 2017

Vickers hardness is an important material in the design and reliability is required. Therefore, these values are very important as the basic data for design, manufacture and development, and the identification of quantitative probability distribution characteristics such as mean and dispersion is a very important parameter in design. In this study, Vickers hardness was measured after artificially heat-treated in the temperature range 753K, where chrome depletion near the grain boundary occurred for three kinds of stainless steels, and the Vickers hardness were evaluated. From the results, Vickers hardness increased with increasing heat treatment temperature. In Weibull distribution for Vickers hardness, the dispersion of STS310S at 813K and 873K was small, and the dispersion of STS316L at 753K, 933K and 993K was small. Also, STS347H exhibited the lowest dispersion at 753K in three kinds of stainless steels. The scale parameter increased with increasing heat treatment temperature in three kinds of stainless steels.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.317-325
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• 2009

On the ground of that toy as for infants is an important tool for education as well as play and furthermore it has a great influences on their growth and development, the present study intends to analyze the characteristics of the infant-oriented toys made of wood, the environment-friendly material. Object of the study includes the infants aged 2 to 7, and the wooden toy not only in domestic also international cases are investigated and analyzed from the point of function and design in particular, and the infant-oriented wooden toy is finally characterized. The wooden toys are classified in 5 items according to functions. There are toy helping a physical development like small muscles, toy improving the creativity, toy assisting language learning like Korean & English, toy contributing to number understanding and counting, and toy for imitation of social roles. The characteristics of the wooden toy are that the natural color & grain of wood are shown first, and also the natural texture & aroma of wood are felt secondly, and geometric design and shape are often presented thirdly, and recycling is available fourthly, and it is expensive finally. In order to revitalize the wooden toys lagging behind the cheap and diverse toys made of plastic, it is highly needed that development of the environment-friendly painting, unique design, marketing strategy of enterprises and use of domestic wood material.

• Journal of Biosystems Engineering
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• v.19 no.1
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• pp.22-32
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• 1994

The combine harvester is considered as an important but complicated and costly machine. The appropriate size of combine has to be developed to use efficiently in Korea. But the combine is such a complicated machine that a complete design model to develop a new type is impossible without understanding the relationship between each factor. The combine capacity is generally limited by the cleaning shoe performance. So a design model for a cleaning shoe has to be developed first for the complete combine design. The objective of this research was to develop a cleaning model of head-feeding combine to predict grain separation from chaff and broken straw on a sieve. A developed physically based model can explain the situation which can happen during separation process. A test apparatus based on the field going machine was developed. The test materials were paddy rice and barley. The data obtained were analyzed by the hand and the video camera. The developed model was verified as an adequate model through the test with $R^2$ of 0.934 and 0.837. The model can be used to evaluate design and operation alternatives of combine and also applied to the automatic control of separation unit of combine with a loss monitering sensors.

• Journal of the Korea Furniture Society
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• v.25 no.1
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• pp.1-10
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• 2014

The First bentwood chairs in the world, called "winsor chairs" were made by British craftsman in the 17th century. Since then, from the start of NO.14 using solid bentwood by 19th-century German Michael Thonet, furniture making techniques such as Bent knee, Y-leg, X-leg- were developed based on Llaminated bentwood made by Alvar Aalto of Finland in the 20th century. In the 20th century Charles Eames of the United States studied Molded plywood, using plywood to produce a variety of furniture and during the 17~20 century a variety of Bentwood were developed. Coming into the 21st century, American Matthias Pliessnig and Phil Seaton worked with past Bentwood designs, developing Bentwood further by adapting Bentwood's know-how and IT technology. Science and technology evolved and Reholz of Germany developed technology which can mold three-dimensional wood using a new matarial called 3D-veneer, In the past only plastic or metal could be moulded 3 dimensional but now beautiful wood grain patterns can be molded by utilizing this technology. Also this is comparable with the past two-dimensional molding technology. In this Sustainable Design techniauses era, Bentwood fused with IT technology has great potential as a high-tech and eco-friendly techniche.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.190-194
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• 2007

The forging process design and microstructure evolution for gas turbine disk of a Waspaloy is investigated in this study. Parameters related to deformation are die and preform geometry, and forging temperature of die and workpiece. Die and preform design are considered to reduce the forging load, and to avoid the forging defects. Blocker and finisher dies for multistage forging are designed and the initial billet geometry is determined. The control of hot forging parameters such as strain, strain rate and temperature also is important because the microstructure change in hot working affects the mechanical properties. The dynamic recrystallization evolution has been studied in the temperature range 900-$1200^{\circ}C$ and strain rate range 0.01-1.0s-1 using hot compression tests. Modeling equations are required represent the flow curve, recrystallized grain size, recrystallized volume fraction by various tests. In this study, we used to thermo-viscoplastic finite element modeling equation of DEFORM-2D to predict the microstructure change evolution during thermo-mechanical processing. The microstructure is updated during the entire thermal and deformation processes in forging.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.2
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• pp.12-19
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• 2022

Propellant grains with embedded metal wires have been used for enhancement of burning rate while maintaining high loading density. For the performance design of a solid rocket motor using propellant grain with embedded metal wires, burn-back analysis is required according to number, location, arrangement angle of metal wires, and augmentation ratio of the propellant burning rate near a wire region. In this study, a numerical method to quickly calculate a burning surface area was developed in response to the design change of the propellant grain with embedded metal wires. The burning surface area derived from the developed method was compared with the results of a CAD program. Error rate decreased as the radial size of the grid decreased. Analysis for characteristics of burning surface area was performed according to the number and location of metal wires, the initial and final phases were shortened and the steady-state phase was increased when the number of metal wires increased. When arranging the metal wires at different radii, the burning surface area rapidly increased in the initial phase and sharply decreased in the final phase compared to the case where the metal wires were disposed in the same radius.