• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.529-530
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• 2006

Manufacturing industry is changing rapidly. Prototyping with rapid manufacturing is a part of every business in many companies and prototypes are used efficiently as a part of the production development process. Sheet metal forming has traditionally been a technology area where prototyping has been extremely expensive and efficient options for low volume have been limited. This paper describes the process for incremental sheet forming technologies to make the prototype for a brake dust shield of vehicles, which includes the remodeling method to make a base mold and tool path for sheet metal forming and 5-axes laser cutting machine to trim the prototype product.

• 한국의류산업학회지
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• 제6권5호
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• pp.648-654
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• 2004

The purpose of this study was to develops of brassiere pattern for middle school students (15 ages ${\mp}$ 3). In order to design a brassiere pattern, the body surface shell was used as the basic pattern. The foundation pattern and the four-piece brassiere pattern with wire were designed and sewed. The results of this study can be summarized as follows. 1. The foundation pattern of the size 75A was proved proper for the body by the wearing tests. Each angle and length of the parts on the base line of the breasts played an important role on setting the pattern. 2. As based on the body surface shell extracted from a plaster mold, the cups of brassiere pattern were applied to the body surface shell, and full side stretch -wings were applied to 8% reduced body size. 3. As the result of the wearing test, the excellence of the experimental brassiere was recognized objectively, with high marks in all the items of clothing compensation, body motion, clothing pressure and breasts growth. The experimental brassiere was covering the whole breasts to cope with change according to breasts growth, It was designed to support the breasts firmly, not to press the middle part of them. Simultaneously, this has the advantages that satisfy a characteristic of a figure and the purpose of putting it on.

• 대한안전경영과학회지
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• 제15권2호
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• pp.71-77
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• 2013

The accident which is caused by the press work remains a Permanent obstacle in worker's hand or arms, the disaster ratio is high and the fatal case is many. Mainly Like this accident occurs because the hand to enter with inside of the press die, therefore, basic countermeasure is the safety press. In order to prevent access to mechanical moving part by the hand or any part of the body, it is important to making a safety die design Structurally. It presents the design of the safety press die with suitable structure in the Product's attribute which it had shown in samples, There is a possibility of being difficult because the attribute of safety die design that had present all the productions from research does not agree each other. but because the representative process which is used most at sample had designed, If you were imitates with safety die design base which is presented from this research, It comes to be thought to be the part which can are used at the various sides.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.43-46
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• 2005

Micro molding technology is a promising mass production technology for polymer based microstructures. Mass production technologies such as the micro injection/compression molding, hot embossing, and micro reaction molding are already in use. In the present study, we have developed a numerical analysis system to simulate three-dimensional non-isothermal cavity filling for hot embossing, with a special emphasis on the free surface capturing. Precise free surface capturing has been successfully accomplished with the level set method, which is solved by means of the Runge-Kutta discontinuous Galerkin (RKDG) method. The RKDG method turns out to be excellent from the viewpoint of both numerical stability and accuracy of volume conservation. The Stokes equations are solved by the stabilized finite element method using the equal order tri-linear interpolation function. To prevent possible numerical oscillation in temperature Held we employ the streamline upwind Petrov-Galerkin (SUPG) method. With the developed code we investigated the detailed change of free surface shape in time during the mold filling. In the filling simulation of a simple rectangular cavity with repeating protruded parts, we find out that filling patterns are significantly influenced by the geometric characteristics such as the thickness of base plate and the aspect ratio and pitch of repeating microstructures. The numerical analysis system enables us to understand the basic flow and material deformation taking place during the cavity filling stage in microstructure fabrications.

• 열처리공학회지
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• 제10권1호
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• pp.20-29
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• 1997

Pure copper is widely used for base material for electrical and electronic parts because of its good electrical conductivity. However, it has such a low strength that various alloying elements are added to copper to increase its strength. Nevertheless, alloying elements which exist as solid solution elements in copper matrix severely reduce the electrical conductivity. The reduction of electrical conductivity can be minimized and the strengthening can be maximized by TMT(Thermo-Mechanical Treatment) in copper alloys. In this research, the effects of TMT on mechanical and electrical properties of Cu-Ni-Al-Si-P, Cu-Ni-Al-Si-P-Zr and Cu-Ni-Si-P-Ti alloys aged at various temperatures were investigated. The Cu alloy with Ti showed the hardness of Hv 225, electrical conductivity of 59.8%IACS, tensile strength of 572MPa and elongation of 6.4%.

• Design & Manufacturing
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• 제15권3호
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• pp.1-6
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• 2021

An artificial neural network model based on a deep learning algorithm is known to be more accurate than humans in image classification, but there is still a limit in the sense that there needs to be a lot of training data that can be called big data. Therefore, various techniques are being studied to build an artificial neural network model with high precision, even with small data. The transfer learning technique is assessed as an excellent alternative. As a result, the purpose of this study is to develop an artificial neural network system that can classify burr images of light guide plate products with 99% accuracy using transfer learning technique. Specifically, for the light guide plate product, 150 images of the normal product and the burr were taken at various angles, heights, positions, etc., respectively. Then, after the preprocessing of images such as thresholding and image augmentation, for a total of 3,300 images were generated. 2,970 images were separated for training, while the remaining 330 images were separated for model accuracy testing. For the transfer learning, a base model was developed using the NASNet-Large model that pre-trained 14 million ImageNet data. According to the final model accuracy test, the 99% accuracy in the image classification for training and test images was confirmed. Consequently, based on the results of this study, it is expected to help develop an integrated AI production management system by training not only the burr but also various defective images.

• Archives of Plastic Surgery
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• 제48권1호
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• pp.44-48
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• 2021

Previously reported nipple-areolar complex reconstruction (NAR) methods involve multiple incisions and wide skin redraping, which increase retraction forces and heighten the risk of nipple-areolar complex (NAC) flattening. We introduce a NAR method using the long V-Y advancement technique that can overcome these disadvantages. A V-shaped flap is designed with the width of the flap base 4-5 mm larger than the diameter of the normal nipple. The flap length is designed to be at least 2.5 times its width. Dissection is performed to the top of the artificial dermal matrix or muscle layer. The nipple is constructed with the same projection as the contralateral side by folding the elevated flap. The tip of the elevated flap is apposed in the middle of the donor defect to minimize the deformity during donor site closure. A 3-point skin suture is applied to the upper third of the folded flap to mold its shape. Using this long V-Y advancement technique, we successfully decreased skin tension in NAC flaps and improved the maintenance of reconstructed nipple projection. The long V-Y advancement technique provides an easy, simple NAR method, effectively maintaining longer nipple projections and reducing breast deformities, especially in Asian women with relatively large nipples.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1047-1053
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• 2022

The leaf spring for a truck absorbs shocks or vibrations from the road surface while driving with the elastic force of the material and prevents the shock from being transmitted to the vehicle body. It is subjected to cyclic stress, and fatigue fracture occurs frequently. This study analyzes fractured leaf spring from a 25 ton truck that has been operating for about a year. In the fractured portion, which is the origin of crack, inclusions were observed, and fatigue failure was caused by cyclic stress. In the stress calculation and FE analysis, the stress at the center of the leaf spring was obtained to be 54~65% of the yield strength of the base material and damaged material. It is most important to prevent the mixing of impurities in the steel manufacturing for leaf springs. The large stress portion of the leaf spring needs to introduce compressive residual stress by peening etc.

• Design & Manufacturing
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• 제16권2호
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• pp.13-19
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• 2022

Recently, electric vehicles are gaining popularity among many domestic and foreign users due to their eco-friendly advantages of reducing fine dust and environmental greenhouse gases. As the demand and supply of electric vehicles increase, the demand for electric vehicle charging infrastructure is also growing together. Many users are experiencing inconvenience due to poor charging infrastructure, which makes them hesitant to buy electric vehicles. Research on the user experience of chargers in apartment complexes, a common residential type in Korea, is being conducted somewhat, but research on the design of electric vehicle charging devices in public places is insufficient. The purpose of this research is to identify user requirements and complaints based on the product design of the electric vehicle charger in public places and propose a new electric vehicle product design concept that meets the requirements. The research method understood the charging base and status of electric vehicles in public places through literature research and examined and analyzed the characteristics and problems of product design cases that improved the charging problem of electric vehicles recently released in the market. It is intended to identify and analyze the problems of the charging device product design through user interviews, a qualitative research method, and based on this, it is intended to propose a user-centered product design concept that improves major complaints.

• Applied Biological Chemistry
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• 제4권
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• pp.33-42
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• 1963

1. 탁주(濁酒)의 발효율(醱酵率)을 국자단용법(麴子單用法)($S_1$)과 국자(麴子) 및 미국혼용법(米麴混用法)($S_2$)으로 담금하여 비교(比較)하고 또한 탁주원료(濁酒原料)와 그 술덧중(中)의 일반성분(一般性分)의 소장(消長)을 분석(分析)하였다. 그 결과(結果) i. $S_2$가 $S_1$에 비(比)하여 다소(多少) 완만(緩慢)한 발효(醱酵)를 하였으나 잔당량(殘糖量)이 훨신 적고 또 총당량(總糖量)이 약(約) 10% 적은 담금이였는데도 주정생성량(酒精生成量)은 거이 같았다. ii. 담금후(後) $3{\sim}4$일(日만)에 $S_1$, $S_2$에서 모두 전주정생성량(全酒精生成量)의 80% 이상(以上)이 생성(生成)되었다. iii. pH는 담금시(時)에 $S_1$이 $6.0{\sim}6.2,\;S_2$가 $4.8{\sim}5.2$에서 $1{\sim}2$일후(日後)부터는 양자(兩者)가 다같이 $4.0{\sim}4.2$로 되어 이값을 계속유지(繼續維持)하였다. 2. Paper partition chromatography법(法)에 의(依)하여 탁주원료중(濁酒原料中)의 유기산(有機酸) 및 당류(糖類)를 검색(檢索)하였다. 그 결과(結果) i. 검출(檢出)된 주요(主要)한 유기산(有機酸)으로서는 백미(白米)에서 Fumaric, Malic, Succinie, Citric, Acetic acid등(等)과 국자(麴子)에서 Fumaric, Succinie, Acetic, Citric, malic, oxalic acid등(等)이고 미국(米麴)에서는 백미(白米)에서와 같았으나 특(特)히 Citric acid가 현저(顯著)히 증가(增加)되어 있었다. ii. 당류(糖類)로서는 백미(白米)에서 Glucose, Suorose, Fructose, 및 Raffinose, 미국(米麴)에서는 Glucose와 그리고 백미중(白米中)에 있었던 Sucrose가 없어지고 Isomaltose, Kojibiose및 Sakebiose라고 추측(推測)되는 3개(個)의 당(糖)이 검출(檢出)되었으며 국자(麴子)에서는 Xylose, Glucose, Fructose 및 Kojibiose라고 생각되는 당(糖)이 검출(檢出)되었다. 3. 술덧에서 p.p.c,법(法)에 의(依)하여 검출(檢出)된 주요(主要)한 유기산(有機酸)으로는 Lactic, Succinic, Acetic acid이었고 Citric acid는 $S_2$에서는 담금초(初)부터 검출(檢出)되었으나 $S_1$에서는 후기(後期)에가서 검출(檢出)되었으며 당(糖)은 원료중(原料中)에 없었던 것으로서 Isomaltotriose와 Panose라고 추측(推測)되는 2개(個)의 당(糖)이 검출(檢出)되고 Maltose는 담금후(後) 1일(日)째에서는 검출(檢出)되었으나 그후(後)부터는 검출(檢出)되지 않았으며 검출(檢出)된 당(糖)들 중(中)에서 Isomaltose라고 추측(推測)되는 것이 숙성시(熟成時)까지 가장 뚜렷이 나타났었다. 4. Somogyi법(法)에 의(依)하여 탁주원료중(濁酒原料中)의 당함량(糖含量)과 술덧중(中)의 당소장(糖消長)을 정량(定量)한 바 백미중(白米中)에서는 Sucrose Glucose, Raffinose Fructose, 의 순(順)으로 함유(含有)되여있었고, 국자(麴子)에서는, Fructose,와 Glucose가 거이 동량(同量)이었으며 미국(米麴)에서는 Glucose가 재래미중(在來米中)의 약(約) $25{\sim}30$배(倍)로 증가(增加)되었고 숙성말기(熟成末期)의 술덧중(中)에는 극소량(極少量)의 유리당(遊離糖)이 함유(含有)되여 있을뿐이였다.