• 한국생산제조학회지
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• 제19권4호
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• pp.455-461
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• 2010

Automated magnetic abrasive polishing which can be applied after machining of the mold on a machine tool without unloading is very effective for finishing a complicated injection mold surface. This study aims to realize one step polishing of free form surface with the same machine tool. For this purpose, magnetic flux density according to the change of curvature radii was simulated for selecting polishing conditions and experimental verification was performed with a complicated mold of aluminum alloy. As a result, it was seen by the simulation that the magnetic flux density at a gradual curvature of the mold was higher than at a steep curvature and the higher magnetic flux density produced the better surface roughness in the experimentation. The deviation for the surface roughness of the mold decreased on the whole and the uniform mold surface was obtained after the automated magnetic abrasive polishing.

• 대한통합의학회지
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• 제7권3호
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• pp.197-204
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• 2019

Purpose: The purpose of this study was to investigate the effects of the plank exercise to strengthen the core muscles on the muscle thickness of external and internal obliques and transverse abdominis muscle depending on the form of the support surface. Methods: This study was randomized to 12 males and 12 females in their 20s and conducted three times a week for 4 weeks. The subjects were divided into the two groups and performed flank exercise on a stable surface (stable surface group) and an unstable surface (unstable surface group). A mat was used as a stable surface, and an TOGU used as a unstable surface. Results : In both stable and unstable surface, the thickness changes of the transverse abdominis and external and internal oblique muscle increased (p<.05). In the unstable surface, there was a greater increase in the thickness change of the transverse abdominis and external oblique muscles in the flank exercise than in the stable surface (p.<05). Among them, the greatest increase was found in the external abdominal muscle (p<.05). Conclusion : This study found that the flank exercise was more effective in strengthening the abdominal muscles on an unstable surface, when compared with the outcomes on a stable one. It is also thought to have the most effect on the muscle activity of the external oblique muscle on unstable surface.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.91-91
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• 2011

The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

• 비파괴검사학회지
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• 제33권2호
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• pp.154-159
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• 2013

본 논문은 마운트의 형상 정밀도와 볼트의 체결력에 따라 마운트에 고정되는 반사경에 발생되는 응력과 변형량에 대해 연구하였다. 일반적인 반사광학계에 사용되는 고정밀 반사경은 볼트나 접착제로 마운트에 조립되는데 이러한 경우 볼트의 체결력과 접착제의 접착력으로 인해 발생하는 장력이 반사경면을 뒤틀리게 한다. 또한 반사경과 마운트를 조립한 후 반사경에 접촉되는 마운트의 표면 형상 정밀도에 따라 반사경면이 뒤틀려서 형상 정밀도가 변한다. 본 논문에서는 유한요소법을 이용한 구조 해석을 통해 반사경과 접촉되는 마운트의 형상 정밀도와 볼트의 체결력에 의해 고정밀 반사경의 반사경면에 발생되는 응력분포와 뒤틀림 변형량에 대해 연구하였다.

• 한국정밀공학회지
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• 제20권10호
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• pp.31-40
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• 2003

In this paper, optimal cutting condition to minimize the form error in side wall machining with a flat end mill is studied. Cutting forces and tool deflection are calculated considering surface shape generated by the previous cutting such as roughing. Using the form error prediction method from tool deflection, optimal cutting condition considering form accuracy is investigated. Also, the effects of tool teeth number, tool geometry and cutting conditions on form error are analyzed. The characteristics and the difference of generated surface shape in up and down milling are discussed and over-cut free condition in up milling is presented. Form error reduction method through successive up and down milling is also suggested. The effectiveness and usefulness of the presented method are verified from a series of cutting experiments under various cutting conditions. It is confirmed that form error prediction from tool deflection in side wall machining can be used in optimal cutting condition selection and real time surface error simulation for CAD/CAM systems. This study also contributes to cutting process optimization for the improvement of form accuracy especially in precision die and mold manufacturing.

• 대한치과보철학회지
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• 제16권1호
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• pp.32-37
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• 1978

The purpose of this study was to apply the position, the form and the angle of the attrition in the natural maxillary central incisors shown on the labial surface to the artificial teeth in the field of prosthetic dentistry. So we should exactly alter the molds of artificial teeth in individual cases in order to make artificial teeth more natural. 226 extracted teeth of the maxillary central incisors were chosen as materials. I have exactly examined the teeth with a magnifying glass and a circular graduator under concentrated light. The observation brought me the following results: 1) The attrition was most prevailing at the range from the mesial angle to the middle part of cutting edge in the left maxillary central incisor, and distal angle of cutting edge in the right maxillary central incisor. 2) On the attrite form of both angles, the angulated form was more than 4 times as frequent as rounded form in the mesial angle, and almost equal in the distal angle. 3) On the attrite form of cutting edge, mesial attrite form including mesial angle was most frequent in the left maxillary central incisor, and distal attrite form including distal angle in the right maxillary central incisor. 4) The angle made by the labial surface and the attrite surface was about $39^{\circ}$, and more than 70% of the total examined teeth were included at the range from $31^{\circ}\;to\;50^{\circ}$. 5) None attrite form at the cutting edge was about 12% and completely attrite form at the cutting edge was about 27% of examined teeth.

• 한국의류학회지
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• 제18권5호
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• pp.646-660
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• 1994

The purpose of this study was to investigate the difference of the visual evaluation about Clothing form and the surface image of detail. This study consists of pre-experiment for selecting the method of expression among detail which shows difference of the image and main experiment for identifying the clothing image as clothing form and the suface image of detial. Main experiment is made of factorial design for three variables-clothing form (H-line, A-line, V-line, X-line), detail (frill, tape), direction (width, length). Questionaire consists of 24 semantic differential scale expressing clothing form and detail. The subjects were 100 female students majoring in clothing and textile.7he data were analyzed by Frequencey, Factor analysis, Anova, scheffe's test and MCA method. The major findings were; 1) The image of clothing form and the surface image of detail were composed of 5 factors; attractiveness, prettiness, attention, modern, young. 2) For the visual evaluation of clothing form as the surface image of detail, there were significant differences in prettiness and attention factors. For the pretty and attentive image, we should express by the image of frill. 3) For the visual evaluation of the image of detail as clothing forms variation, there were significant difference in prettiness by A-line and X-line. 4) For the effect of clothing form and the surface image of detail, main effect was significant in attractiveness, prettiness, attention, modern factor. For the pretty image of clothing, it will be expressed by the image of frill and A-line, X-line. For the attentive image of clothing, it will be expressed by the image of frill and V-line. For the modern image of clothing, it will be expressed by the image of tape and V-line.

• 한국기계가공학회지
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• 제4권2호
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• pp.10-15
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• 2005

For the development of compensation machining program, ultra precision grinding used in ultra precision machine and corrective machining was studied. We explored a new rough grinding technique on optical material such as zerodur. The facility used is a polishing machine with a custom grinding module and a range of diamond resin bond wheel. Surface roughness and form accuracy are measured by surface measurement equipment(Form Talysurf series2). Our compensation machining program has complied with a target of producing surface roughness better than $0.05{\mu}m$ Ra and form accuracy of around $0.05{\mu}m$ Rt and has been unveiled as a work-hour model.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.123-126
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• 2009

This study is analyzed the effects of the number of use of aluminum form surface coating material on surface quality of concrete. The results can be summarized as follows. Surface roughness showed larger values with increase in the number of use. Values were larger in UP and AL compared to PE. While found to have bad influence on concrete surface quality, PA and W showed most excellent values for roughness. The number of surface pores increased with increasing number of use, and the number of pores on concrete surface was reduced by applying a remover. In terms of type of surface coating material, PA and W showed smallest number of pores in comparison to PE. In order to comprehensively improve surface quality of concrete, parallel use of PA coating material and remover is deemed most appropriate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.879-880
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• 2010