• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.83-86
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• 2001

In injection molding, short shot is one of the frequent and fatal defects. Experts of injection molding usually adjust process conditions such as injection time, mold temperature, and melt temperature because it is the most economic way in time and cost. However it is a difficult task to find appropriate process conditions for troubleshooting of short shot as injection molding process is a highly nonlinear system and process conditions are coupled. In this paper, a fuzzy neural network(FNN) has been applied to injection molding process to shorten troubleshooting time of short shot. Based on melt temperature and fill time, a reasonable initial mold temperature is recommended by the FNN, and then the mold temperature is inputted to injection molding process. Depending on injection molding result, specifically the insufficient quantity of an injection molded part, an appropriate mold temperature is recommend repeatedly through the FNN.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.183-188
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• 2003

Non-molding and welding line happen by the assembly of gas at the connector terminal. There is not good phenomenon of burr by increasing the over injection pressure, the temperatures of die and resin to prevent from them. Therefore, the connector mold to apply the vacuum molding system is developed in this study. The vacuum pressure is controlled systematically with the optimum conditions in the important ingredients of injection molding that are the temperatures of melting resin and die and cooling condition. The badness in charging is cleared by making a vacuum to non-charging part of the deep bottom part of each cavity. And the vacuum system to reduce the cycle time is applied as the study envelopment of molding work. So, the good product and the productivity improvement can be obtained in this study.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.95-100
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• 2004

Plastics is used to produce precise parts with an inclusion of a reinforcement material such as glass fiber or carbon fiber to improve the dimension accuracy. The plastic goods can be produced with inaccurate dimensions, low mechanical strength, or residual stress due to the over packing of cavity inside, if the filling balance of melt resin is not accomplished. To overcome this problem, it is necessary to design the runner system with the geometrical balance at the mold design stage. However, even if the balanced runner system is achieved, a severe filling imbalance is observed practically in a multi-cavity mold. In this study, experiments were performed with Taguchi method to achieve the filling balance in multi-cavity mold with a symmetric runner system, by the use of pure PA and PA with glass fiber 33%. The experimental results were investigated to understand the effect of related molding factors on the filling imbalance for two resins.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.569-571
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• 2010

In this paper, we develop a vision inspection system for inspecting flaws on plastic products such as insufficient moldings, spots, scratches. The inspection algorithm for this system consist of image binarization for curved structure of plastic products, image noise removal using morphology operation, labeling methods for candidate regions and image filtering and calibration method for flaw inspection. In order to improve its performance, we also develop fast image processing algorithm based on GUI. To verify the effectiveness of this system, we conducted evaluation for the system accuracy and the inspection algorithm processing time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4145-4150
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• 2010

This research aims to design on an automatic machine vision system to replace eye inspection of alternator spool which is one of the key automotive parts. The alternator spool, plastic extrusion part would have various defects like unfinished, crack and burr. Through the design failure examples the optimized fast machine vision system will be designed to inspect all spools also focuses on the low cost machine for the middle sized company as 2'nd automotive supplier. 3-dimensional design softwares of Pro-Engineer & CATIA were used and the system were built based on the design. The system will contribute to satisfy the cycle time and can inspect each part in an absolutely accurate method, which is sufficient for industrial applications.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.403-404
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• 2020

본 논문에서는 단일 2-level 3-leg 전압형 인버터를 사용하여 직렬 연결된 3상 및 단상 표면부착형 영구자석 동기전동기(SPMSM)를 가변속 운전하는 기법을 제안한다. 일반적으로 두 영구자석 동기전동기를 독립적으로 가변속 운전하기 위해서는 각각의 인버터가 필요하지만, 본 논문은 옵셋(Offset) 전압을 사용한 전압 펄스 폭 변조(PWM) 방식으로 인버터를 제어하여 단일 인버터를 사용한 3상 및 단상 전동기 동시 운전이 가능하다. 제안된 방식은 전력용 반도체 소자 수를 줄여 전동기 구동시스템의 가격을 절감시킬 수 있으며, PLECS 시뮬레이션을 통하여 제안된 토폴로지의 유효성을 검증하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.610-615
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• 2016

Diverse accessories are used in automobiles, such as navigation systems, front and rear cameras, spoilers, and sun visors. Sun visors block sunlight so that drivers can drive safely with a better view, and they are used in many automobile designs. However, when large plastic products are manufactured using injection molding, there are many difficulties that develop, like weld lines, short shots, flow marks, imperfections, and distortion. In this study, a CAE simulation was conducted based on previous results to predict potential problems in the injection molding of large products. The flow characteristics up to complete charge for the melting resins were captured using a computer-aided engineering simulation. The temperature departure on the front part of a flow was about $10^{\circ}C$ and very stable. The practical ejecting time of the cold runner was about 70 seconds in the simulation. Finally, the capability of a suitable injection machine was calculated and recommended by prediction of the injection pressure and the die clamping force.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.10a
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• pp.19-22
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• 2003

통발어업은 어구 조작을 위한 선박 의존도가 적고, 어구를 예인하지 않아 배의 속력이나 기관 마력을 그다지 크게 할 필요성이 없으므로 유류 사용량이 적으며, 저인망이나 연승 등으로 조업이 곤란한 기복이 심한 해저나 심해에서도 조업이 가능하다는 장점이 있다. 본 연구실에서는 통발 어구에 대해 미성어를 탈출하게 하여 보호하고, 성숙한 개체만을 선택적으로 어획할 수 있는 자원관리형 통발 어구어법 개발에 관한 연구가 수행 중에 있으며, 현장실험을 통해 어구에 대한 어획선택성, 자원상태와 어획강도 등에 관한 연구를 수행하고 있다. (중략)

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.5
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• pp.684-693
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• 1999

한국과 미국의 사이클 선수들이 선호하는 사이클복에 대하여 조사하였으며 착용실태 파악을 위한 설문조사는 1997년 8월-10월 사이에 한국과 미국에서 동시에 실시하였고 총 145명 (한국인=79명, 미국인 =66명)의 설문결과가 데이터 분석에 이용되었다 설문내용은 인적사항 사이클복에 대한인식 및 계절에 따라 선호하는 스타일 등에 대해 35문항으로 구성되어 있으며 질문형식은 그림형과 서술형으로 나누어 작성하였다. 데이터는 빈도와 백분율로 비교하였고 {{{{ chi ^2 }} 와 Fisher's exact 방법을 이용하여 그 결과를 고찰하였다. 한국인 사이클 선수들의 Rohrer 지수는 한국 표준 체위조사의 같은 나이 집단의 수치와 거의 차이가 없으며미국인 남자 사이클 선수는 같은 나이 집단의 미국 군인들을 위한 체위조사 결과보다 낮은 수치를 나타냈다. 한국의 여자 사이클 선수들 중 79.6%가 사이클복이 시합이나 훈련중 기록향상에 영향을 미친다고 응답하였다. 대부분의 미국인 사ㅣ클 선수들은 그들이 착용한 사이클복에 만족하고 있으며 상하가 분리된 스타일을 선호하였다, 한국과 미국의 사이클 선수들은 jersey 의 경우 round neckline에 stand collar가 있는 스타일을 좋아하며 jersey 와 shorts 모두 몸에 꼭 맞는 스타일을 선호하였다.

• Journal of Korea Water Resources Association
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• v.43 no.4
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• pp.353-365
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• 2010

Generally, river discharge is measured at flood forecasting points, upstream dam points, large rivers, and important points over a basin, and it is hard to estimate discharge of medium or small stream and small catchment. Physically based rainfall-runoff model with geographical parameters can simulate discharge at all the points within a basin with optimized parameters for a point in the basin. In this study, GRM (Grid based Rainfall-runoff Model) calibrated at the outlet is applied. The discharge at upstream point is estimated and the possibility of model regionalisation is examined for ungauged catchment of small or medium stream within a river system. Wicheon and Boksu watershed in Nakdonggang (Riv.) and Yudeungcheon (Riv.) respectively are selected. The discharge at Miseong and Sindae station is simulated with the parameters estimated at Museong and Boksu station. The results of Miseong and Sindae station show good agreement with observed hydrographs in peak discharge and peak time and consistently linear relationships with high correlations in discharge volume, peak discharge, and peak time. And it shows GRM could be applied to estimate discharge at ungauged catchments along a river system.