• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.225-229
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• 2003

When hot strip is trimmed in the side trimming process at the entry side of tandem cold rolling mill, due to bad quality of trimming face and burr, product quality(saw ear)becomes so bad that it causes drop of yield and claim from customers. Therefore, it was examined that applying ultrasonic vibration is an effective method to improve quality of strip trimming face and decrease burr magnitude by decreasing shear force acting between strip trimming face and knife in side trimming process of cold rolling.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.101-108
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• 2004

It is very important to diagnose state of knife and strip cutting face in real time in the side trimming process due to improvement of quality of trimming face. In this study, diagnosis system for knife and strip cutting face was developed. CCD camera was installed at the both side of strip in the entry of burr masher roll. This system offer to operator the diagnosis result that was analyzed image obtained from CCD camera. As a result, bad quality of trimming face is decreased below 1/10 and knife breakage is detected $100\%$.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.29-34
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• 2006

In this paper, the mechanical characteristics of ultrasonic cold forged technology (UCFT) used for the trimming knife and the effects of ultrasonic vibration energy (UVE) into the trimming process on the state of the strip cutting face were studied. And a diagnosis system to quality control for trimming knife and strip cutting face was developed and installed in plant. By the plant application of UCFT, service life of knife was more increased over 100% than that of conventional knife. And using the developed diagnosis system, the knife breakage and saw ear have been perfectly detected and quality control of trimming face is obtained effectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 금형가공 심포지엄
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• pp.144-147
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• 2002

In this study, springback analysis of side rear member is carried out. Side rear member is one of the parts which shows severe springback problems. Forming, trimming, flanging and springback stages can be analyzed successively. From forming analysis, we identified the possible spots in which tearing may occur and can prevent failure. In springback analysis we used the boundary conditions same as applied to the blank on the checker so that the computational result can be compared with experimental one. Form .the comparison, springback analysis can yield relatively good results in a qualitative sense. However, in order to get good deformation result quantitatively, there still remains unsettled tasks in the forming analysis with very small die radius. It is found that we have to develop the element with better bending characteristics and precise contact treatment.

• 한국기계가공학회지
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• 제15권5호
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• pp.93-99
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• 2016

The trimming process is required for satisfying the dimensions of a final product in the hot stamping process. In general, the mechanical trimming or laser trimming process is applied after hot stamping. However, these processes have several disadvantages such as short tool life and low productivity. Therefore, in this study, the optimal trimless blank shape for the hot stamping process of a sill side was designed to remove the trimming process after hot stamping. In order to design the trimless blank, numerical analysis was performed. Firstly, CFD analysis was carried out to predict the cooling temperature and holding time of the hot stamping process. Then, the optimal trimless blank shape was determined through FE analysis. The effectiveness of the designed trimless blank shape was verified through a hot stamping experiment at an actual industrial site.

• 한국기계가공학회지
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• 제14권4호
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• pp.146-150
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• 2015

Steel is produced through the steel-making process with a desired shape by a rolling press. Scrap is removed according to the sheet edge to improve the quality of the product. This machine is called a side trimmer. This study aimed to develop a side trimmer for automatically changing the width of the trimming knife without line stopping. This machine consists of a housing opening device and a turning device. The measuring technologies of sheet width, trimming knife rotation angle, and knife gap for increasing the control accuracy. This experiment was conducted to evaluate the performance of the developed technologies. It was reduced by 10% compared with the operation time of the conventional method.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.710-716
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• 2005

A total of 21 patients were operated. Via a columellar labial incision, the upper lateral cartilages were separated from the septum. A submucous resection of the septal cartilage was carried out. After rasping the convex lateral nasal wall of the unaffected side, a low-to-low lateral nasal osteotomy was conducted. Along the deviated dorsal line at the bony vault passing the submucous tunnel, a paramedian nasal osteotomy was performed. The convex side of the nasal bone flap was contoured by rasping. The convex side of the "T"-shaped dorsal septum was trimmed. A total direct septal extension graft of the septal cartilage was done and the alar cartilages were suspended to it. The postoperative results were evaluated by photogrammetric analysis processed by a "neon glow" filter in Adobe Photoshop. The distance from the nasal midline to the most deflective point at 5 levels was measured, and the proportion indices were obtained in regard to intercanthal distance. The results revealed improvement in all levels (p < 0.05), although not perfect. In summary, this technique can result in a clinically good-looking in spite of a slight deflection that still exists

• 대한기계학회논문집
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• 제15권1호
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• pp.376-385
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• 1991

본 연구에서는 그루브의 각도에 따라 그루브 에징을 한 형상과 상사하게 가상 의 슬라브를 제작하여 오버랩에 영향을 미치는 압연인자들을 분석하고 그 영향을 검토 함으로써 최적 G 롤의 각도를 결정하였고, 최적인 G 롤의 형상으로 에저를 제작하여 G 에징량에 따른 오버랩량의 변화를 고찰하였다.

• 소성∙가공
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• 제15권4호
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• pp.281-288
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• 2006

Most of automobile member parts experience severe springback problems because of their complicated shape and high yielding strength. Now it becomes imperative to develop an effective method to resolve these problems. However, there remain several obstacles to get accurate estimation of dimensional shape. Especially the effective algorithms to simulate sheet metal forming processes including drawing, trimming, flanging and springback is demanded for the multi stage simulation of automobile member parts. In this study, for the purpose of accurate springback calculation, a simulation program which is robust in springback analysis is developed. Favorable enhancement in computation time for springback analysis by using latest equation solving technique and robust solution convergence by continuation method are achieved with the program. In analysis, the multi processes of rear side member are simulated to verify the system. For the evaluation of springback accuracy practically, all conditions including boundary conditions for springback analysis and inspection conditions for dimensional accuracy are applied. The springback results of simulations show good agreement with the experiments.

• 한국식품영양학회지
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• 제19권3호
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• pp.332-341
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• 2006

The goal of this study was to determine a method of reducing food wastes in the dietary home lifestyle. Statistical analyses were conducted of 491 questionnaires answered by housekeepers living in Daejeon city. The data were analyzed by SAS program and the results are summarized as follows. Among the respondents, 51.53% answered that they purchased the foods in consideration of the family number, 60.45% that they occasionally throw away foods because the date of expiry had passed, i.e., the foods threw away by mistake of storage, 68.23% that they make side dishes at a time for three meals in a day, 52.95% that they make three or four kinds of side dishes, 82.28% that they prepared meals according to the favorite foods of the family, 48.04% that they left food at home, and 47.32% that they threw away foods because too many foods had been prepared. The major reasons for food wastes at home were listed as meal leftovers (32.72%), vegetable trimming (31.29%), and non-planned purchase (25.77 %). The perception of housekeepers on the reduction of food waste were listed as the preparation of accurate meal quantity (50.92%), planned purchase (28.31%), development of recycling foods (14.05%), and reduction of side dishes (6.72%). Further reduction of food wastes of dietary home lifestyle can be summarized to emphasize the preparation of accurate meal quantity, planned purchase, development of recycling foods, and reduction of side dishes. In addition, studies should be conducted to examine the systematic administration method and standard education for the reduction of food wastes.