• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.490-498
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• 2010

The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW(Ver. 5.2) in order to solve the process-problems of K company relating to air-traps and short-shots. The former occurs at the cavity edge of torque-rod-bush and the latter takes place for the injection molding of dynamic dampers. As a result the process problem relating to air traps was solved by optimizing edge-angle and the number of gates to prevent the flow congestion of flow-front and to make the flow-front movement unaffected by congestion. For dynamic dampers of K company the unmolded flaw caused by their unfilled cavity was corrected by installing the air-vent at the confronting locations of both upstream and downstream of flow-front where air traps frequently occur. Besides the unmolded flaws were rectified by altering the position of gate from the upper to the middle or by increasing the number of gates. Thus the process problems of K company relating to air-traps and short-shots of torque-rod-bush and dynamic dampers, respectively, were solved by proper altering of mold design with process simulation of rubber injection molding.

• Composites Research
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• v.24 no.6
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• pp.31-36
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• 2011

According to the evaluation on GMT-sheet by molding conditions, fiber projection on the moldings surface was investigated. Fiber projection is one of the major defects on moldings surface due to matrix shrinkage. That is, fiber projection happens from different shrinkage of matrix and glass fiber. Height of fiber projection from moldings surface becomes smaller when molding pressure is higher during holding pressure and cooling process. Height of fiber projection is dominantly affected by molding pressure. With consideration of molding pressure, the formation of surface unevenness and change in fiber projection height was elucidated. In addition, coating layer is effective to suppress surface defects, and there is no fiber projection or crack in case that coating is applied. Coating layer improves surface roughness up to the level of the polypropylene which is a single material.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.613-620
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• 2009

It is necessary to develop a system of judging whether or not the parts are defective easily at low cost, especially in a small scale factory which manufactures a large variety of products in small amounts. To develop such system, we require to recognize objects using human's cognitive ability under various circumstances. Human's high intelligence originates mostly from neocortex of human brain. The HTM theory, which is proposed by Jeff Hopkins, is one of the recent researches to model the operation principle of neocortex. In this paper we developed PRESM (Parts image REcognition System for small scale Manufacturing industry) system based on the HTM theory to judge badness of manufactured products. As a result of application to the real field of workplace environments we identified the superiority of our recognition system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.793-799
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• 2007

Generally, a semiconductor chip measured with a few micro units is captured by line scan camera for higher inspection accuracy. However, the faulty inspection requires an exact boundary detection algorithm, because it is very sensitive to scan speed and lighting conditions. In this paper we propose boundary detection with subpixel edge detection in order to increase the accuracy of bump faulty detection on chips. The bump edge is detected by first derivative to four directions from bump center point and the exact edge positions are searched by the subpixel method. Also, the exact bump boundary to calculate the actual bump size is computed by LSM(Least Squares Method) to minimize errors since the bump size is varied such as bump protrusion, bump bridge, and bump discoloration. Experimental results exhibit that the proposed algorithm shows large improvement comparable to the other conventional boundary detection algorithms.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.329-336
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• 2009

This experiment was carried out to know adaptability and forage production and quality of corn hybrid for silage at paddy field from 2007 to 2008 at Chungnam province. Growth, forage production and quality of silage corn showed more well drained condition than poorly drained condition at paddy field. Among growth characteristics, 'Kwangpyongok' and 'DK697' hybrids were somewhat strong for waterlogging, then and good at stay green, lodging, disease and insect resistance. Fresh yield of 'DK697' hybrid at poorly drained paddy field was the highest as 32,610 kg per ha among corn hybrids. The dry yield of 'P32P75' hybrid at poorly drained paddy field was the highest as 14,910 kg per ha The result of this study showed that 'P32P75', 'DK697', 'Kangdaok' and 'Kwangpyongok' hybrids had good growth characters and forage productivity at poorly drained paddy field and dry matter yield at poorly drained paddy field was 65.6% level compared with well drained paddy field.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.323-336
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• 2003

Recently, the development of tunnel reinforcement method has been required relating to the shallow tunnelling in soft ground. In this study, the improvement method on tunnel stability is proposed by evaluating the efficiency of face reinforcement which enables to control extrusion of advance core, however, it is often neglected in urban tunnelling under the poor ground conditions. Systematic pre-confinement ahead of the face improves the tunnel stability, subsequently, displacement of the crown and surface settlement can be restrained by proper method. 3-dimensional numerical analysis including horizontal reinforcement modelling on a face is applied to estimate the behaviour of a tunnel in relation to the ground and reinforcement conditions. Consequently, extrusion at the face decreases significantly after using the horizontal reinforcement and the effect of reinforcement is much increased in case of applying the supplemental reinforcement ahead of the face together. Especially, confinement effect around the tunnel and the core is proved by means of the core reinforcement in poor ground conditions.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.420-429
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• 2006

In the zoom lens of digital still cameras with the variation of the image plane generated by various symmetric error factors such as curvature, thickness and refractive index error of each lens surface about the optic axis, we induce a theoretical condition to fix constantly the image plane by translating the compensator group of the zoom lens by using the Gaussian bracket. We confirm the validity of this condition by using three examples of general zoom lens types with 3, 4, and 5 groups, respectively. When these error factors are randomly changed within the range of tolerance according to the Monte Carlo method, we verify that the distributions of the degree of moving of the compensator are normal distributions at three zoom lens types. From capability analysis using these results, we theoretically propose the method estimating the standard deviation, that is, sigma-level, as a function of the maximum movement of the compensator.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.71-73
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• 1995

시금치는 명아주과로서 고온 장일 조건하에서 추대가 촉진되고 고온에는 극히 생육이 약하여 $25^{\circ}C$ 이상이 되면 생육장해나 병충해가 만연한다. 이러한 생육특성으로 고온, 건조, 장일과 같은 불량 환경조건이 가중되는 여름철 수확재배는 대단히 어렵다. 따라서 매년 여름철에 입하되는 양은 절대적으로 부족하며 그 중에서도 특히 7월-9월에는 대단히 고가이다. 본 실험은 여름철 평지에서도 양질의 시금치를 대량생산할 수 있는 기술 확립을 위한 연구로 여름철 온실의 재배시기별 차광효과를 구명코자 실시하였다. (중략)

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.83-86
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• 2004

본 연구의 목적은, CAE(Computer Aided Engineering) 기술과 동시설계(Concurrent Design) 방식을 활용하여 0.3mm 정밀박판금형을 설계, 제작하는 것이다. 박판 성형은 기존의 사출성형제품에 비하여 훨씬 얇은 제품을 성형하는 것이기 때문에 수지의 충전 불량 제품의 변형, 과다 내부응력 등 많은 문제점들이 발생한다. 이런 문제점들을 해결하기 위하여 본 연구에서는 컴퓨터 시뮬레이션을 통한 최적성형조건을 찾아내고자 시도하였으며 도출된 조건을 금형설계 및 성형에 적용시킴으로써 최소한의 시행오차를 통한 고부가가치 제품을 성형하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.88-88
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• 2011

최근 소비자의 생활수준이 향상되면서 섬유제품에 대한 기술적인 요구가 증가하고 있는데 그 중에서도 기모제품을 응용한 원단에 대한 요구가 급격히 증가하고 있다. 특히 기모원단은 기모공정 후 원단에 존재하는 기모유연제를 처리하기 위해 정련공정을 거쳐야 하는데 대부분의 염색공장에서는 이를 무시한 채 염색을 하고 있다. 이 때문에 잔존하는 기모유연제에 의해 염색 불량을 발생하게 된다. 기모원단에서 정련공정을 생략할 수 있다면, 공정의 단축으로 인한 Cost 절감 효과뿐만 아니라 폐수 부하량도 감소하는 등 시장 및 환경적인 측면에서 동시에 경쟁력을 가질 수 있게 된다. 본 연구에서는 (주)한송인더스트리에서 생분해성을 가지는 환경친화형 기모유연제를 개발하여 이를 염색공정 중 함께 처리함으로써 전체 공정을 단축하고, 개발한 친환경 기모유연제가 염색성에 영향을 미치지 않는 것을 확인하였다. 또한 기존 유연제와 개발된 유연제를 염색공정에서 동일한 조건으로 처리 하였을 때, 기존 유연제 처리 시료는 표면의 불순물과 Oil의 잔존으로 흡습성이 떨어져 균염성 떨어졌고, 염색된 원단에서도 염색불량을 확인할 수 있었다.