• 한국재료학회지
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• 제27권8호
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• pp.397-402
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• 2017

We used an etching process to control the line-width of screen printed Ag paste patterns. Ag paste was printed on anodized Al substrate to produce a high power LED. In general, Ag paste spreads or diffuses on anodized Al substrate in the process of screen printing; therefore, the line-width of the printed Ag paste pattern increases in contrast with the ideal line-width of the pattern. Smudges of Ag paste on anodized Al substrate were removed by neutral etching process without surface damage of the anodized Al substrate. Accordingly, the line-width of the printed Ag paste pattern was controlled as close as possible to the ideal line-width. When the etched Ag paste pattern was used as a seed layer for electroless Ni plating, the line width of the plated Ni film was similar to the line-width of the etched Ag paste pattern. Finally, in pattern formation by Ag paste screen printing, we found that the accuracy of the line-width of the pattern can be effectively improved by using an etching process before electroless Ni plating.

• 대한전자공학회논문지
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• 제25권5호
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• pp.495-500
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• 1988

The effectiveness of tri layer resist (TLR) technique is compared with that of single layer resist (SLR) technique in order to make a 0.8um pattern with the linewidth deviation of 10 percents. SLR technique is not appropriate to shape the micro-pattern on oxide and aluminum steps because of the standing wave effect and the light scattering effect in shaping the resist pattern. On the contrary, the uniform line with a width of 0.8um on oxide and aluminum steps can be formed by TLR technique, reducting such effects. The planarization and the light absorption coefficient of the bottom layer resist in TLR are optimized by exposing it to ultra violet light after baking it for 30min at 230\ulcorner. An uniform line with a width of 0.8um on oxide step is defined with the light absorption coefficient of 0.85 whereas that on aluminum step is defined with 0.95.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.305-309
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• 2010

Photopolymer films containing fluorescent anthracene polymer, polymethyleneanthracene (PMAn), were prepared with different concentrations of PMAn for holographic recording useful for security documents. The fluorescent photopolymer film showed enhanced fluorescent intensity due to the micro-separation which arose from grating formation and diffusion during photopolymerization. Experimental values of diffraction efficiency were well matched to the simulated values for photopolymers having different PMAn concentrations. Holography patterning was carried out using the fluorescent photopolymer under a photo-mask. A grating was confirmed using microscope techniques in the recorded area under the pattern. Importantly the recorded area showed enhanced fluorescence compared to the unrecorded part, allowing fluorescence patterns at micro scale along with the submicron grating pattern. The fluorescence pattern recorded on the photopolymer film provides additional readability of holographic reading and thus is useful for secure recording and reading of information.

• 한국정밀공학회지
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• 제5권4호
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• pp.32-38
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• 1988

Apaptive cintrol of machine tool is aimed to change cutting state satis- factorily without aid of a machine operator, if the cuting state is abnomal such as formation of tangled ribbon type chip, built-up edge and generation of chattering and so on. Among these the recognition of chip type is one of the most important since it has imlications relate to : 1. Safety of operator 2. Stoppage of work due to entanglment in tool and workpiece of chip 3. Problem of producted chip control In this paper the chip type is discriminatied by the pattern recognition technique. It is found that the power spectrum of cutting force for each chip type has it's own special pattern. Linear discriminant function for the recognition of the chip type is obtained by learning process. The discriminant function can be the basis of adaptive control for the rate of success of recognition by pattern recognition technique is at leasthigher than 83%.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.381-386
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• 1999

In machining with cutting tool inserts having complex chip groove shape, the flow, curl and breaking patterns of the chip are different than in flat-face type inserts. In the present work, an effort is made to understand the three basic phenomena occurring in a chip since its formation in machining with groove type and pattern type inserts. These are the initial chip flow, the subsequent development of up and side curl and the final chip breaking due to the development of torsional and banding stresses. In this paper, chip flow angle in a groove type and pattern type inserts. The expression for chip flow angle in groove type and pattern type insets is also verified experimentally using high speed filming techniques.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1486-1489
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• 2009

Micro wall is fabricated using iterative screen printing that it is able to fabricate the pattern as low cost, simple process, formation of pattern at large area on the various substrates. In the process of micro wall fabrication using screen printing, the printing result with pressure change in process and improvement of surface roughness using hydrophillic plasma treatment are included. Height of micro wall increase linearly and precision of iteration is very high. Error rate of printed pattern width is very high, but change rate of width is under 10 %. Fabricated micro pattern have minimum width $48.75{\mu}m$ and maximum height $75.45{\mu}m$ with aspect ratio 1.55.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권3호
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• pp.321-330
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• 2020

Data classification and clustering is one of the most common applications of the machine learning. In this paper, we aim to provide the insight of the classification for Turing pattern image, which has high nonlinearity, with feature engineering using the machine learning without a multi-layered algorithm. For a given image data X whose fixel values are defined in [-1, 1], X - X³ and ∇X would be more meaningful feature than X to represent the interface and bulk region for a complex pattern image data. Therefore, we use X - X³ and ∇X in the neural network and clustering algorithm to classification. The results validate the feasibility of the proposed approach.

• 대한지리학회지
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• 제35권1호
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• pp.17-38
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• 2000

The marine terraces often offer come important clues to understand the topographic development during the Quaternary and the present landforms in korea. We examined the mechanism of the marine terraces formation along the coast from Samjung-Ri(community), Guryongpo-Eup(county) to Haseo-Ri, Yangnam-Myun(county), Gyungju-Si(city). Among the various but unique factors of the given coastal environment, which should contribute to the marine terraces formation together, we focused on five possible factors for the present stydy. Geologic difference in bedrocks, protrusion degree of coastiline, topological relief of sea-bottom, fluvial characteristics on land, and pattern of the waves appeared to act cooperatibely on the terrace formation of Southeastem coast in korea, while the fluvial characteristics seemed play a significant but localized role in it. Wide distribution of middle surfaces on the coast of Samjungri-Janggilri could be due to the concentration of the high waves and the weakness of the Tertiary volcanic rocks. For the sporadic distribution of the terraces on the coast of Gupungri-Gyewonri, it seemed attributable to the erosion -susceptible weak bedrock, the coastline of inner bay, shallow sea-bottom with the gentle relief, and other fluvial characteristics with the low divides. Together with the geologic difference in bedrock, other factors including protrusion degree of coast, topological relief of sea-bottom, and the transportation loads by the stream Daejongchon are believed to act cooperatively on the mechanism of the marine terraces formation on the coast of Duwonri-Upchonri.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.126-131
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• 2003

The acceptance test of KTX has been performed in Korea. During the test, lateral vibration of carbody over the accepted value called sway was found. KTX has 20 car trainset formation whose trailer cars are linked by articulate bogies. So this study is performed to see the effects of long trainset formation on vehicle dynamics and the train stability by 20 car vehicle model. Firstly the reliable vehicle model which shows well the tendencies appeared in the tests on the high speed test line is required to find the cause of lateral vibration and the countermeasure. Vehicle model was made .for the. analysis with VAMPIRE. The analysis results show that secondary air spring lateral stiffness is the most significant parameter to cause carbody lateral vibration. Mode analysis results show that the least damped mode shape is similar to the vibration pattern shown in the tests that the amplitude of the motion increases along the train set and decreases in the tail part. For the case of short train formation with 7 or 10cars, sway does not happen. But in the case of longer train formation with 16 or 20 cars, sway was found.

• 한국균학회지
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• 제26권2호통권85호
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• pp.187-193
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• 1998

팽이버섯균주의 분열자의 생성원인을 구명하기 위하여 균사생장시의 배지종류, 배양온도, 배양기간, pH, 및 $CO_2$ 농도별로 균사생장정도와 분열자 생성수를 조사하여 본 결과, 저온시 균사의 분화가 제대로 일어나지 않아 균사가 완전히 생장하지 못했던 경우를 제외하고는 균사생장이 불량한 조건에서 분열자의 생성은 많았으며, 최적조건에서는 분열자의 생성량이 적었다. 이핵균주로부터 유래된 분열자를 발아시켜 얻은 단핵균주의 교배형은 모두 한 가지의 교배형의 핵을 가졌으며, 모균주에 미치는 영향을 조사하기 위하여 19개의 분열자균주를 모균주와 Di-Mon교배를 실시한 결과 모균주에 비해 교배균주의 70%는 공시균주에 비하여 균사생장이 늦고 수량이 적었으며 Di-Mon 교배균주 중 한 균주는 동위효소 pattern에서도 차이를 나타내었다.