• 대한기계학회논문집A
• /
• 제30권11호
• /
• pp.1425-1432
• /
• 2006

Coating layers on a coated sheet steel frequently affect distributions of strain rate of sheets and deteriorate the frictional characteristics between sheets and tools in sheet metal forming. Thus, it is important to identify the deformation behavior of these coatings to ensure the success of the sheet forming operation. In this study, the technique using nano-indentation test, FE-simulation and Artificial Neural Network(ANN) were proposed to determine the power law stress-strain behavior of coating layer and the power law behavior of extracted coating layers was examined using FE-simulation of drawing and nano-indentation process. Also, deep drawing test was performed to estimate the formability and frictional characteristic of coated sheet, which was calculated using the linear relationship between drawing force and blank holding force obtained from the deep drawing test. FE-simulations of the drawing process were respectively carried out for single-behavior FE-model having one stress-strain behavior and for layer-behavior FE-model which consist of coating and substrate separately. The results of simulations showed that layer-behavior model can predict drawing forces with more accuracy in comparison with single-behavior model. Also, mean friction coefficients used in FE-simulation signify the value that can occur maximum drawing force in a drawing test.

• 대한물리의학회지
• /
• 제15권2호
• /
• pp.49-56
• /
• 2020

PURPOSE: This study examined the difference in muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in maneuver. METHODS: This study was conducted on 15 healthy males and eight females who were attending D University in Busan. This experiment was conducted after 15 minutes of abdominal drawing-in training using a pressure biofeedback unit before the experiment, and the difference in the muscle activity of the trunk and legs during flat walking with or without an abdominal drawing-in technique was investigated. Surface electromyography was used, and the electrode attachment site was the right sternocleidomastoid muscle, splenius capitis muscle, rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, erector spinae muscle, vastus medialis muscle, and vastus lateralis muscle (TM DTS, Noraxon, USA). The data were analyzed statistically using a paired t-test on SPSS version 18.0 (IBM). RESULTS: The muscle activity of the rectus abdominis muscle, external abdominal oblique muscle, transverse abdominis muscle, vastus medialis muscle were increased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). Moreover, muscle activity of the erector spinae muscle was decreased significantly and maintained more than walking without maintaining an abdominal drawing-in maneuver (p < .05). CONCLUSION: Maintaining an abdominal drawing-in maneuver during flat walking is more effective during walking training.

• 대한건축학회논문집:계획계
• /
• 제35권9호
• /
• pp.89-99
• /
• 2019

In the representation of buildings with continuous changes in the curved shape of the surface, countless plans or sections are required, or none of the traditional drawings can explain the geometry of it. In other words, in no case can an ordinary drawing achieve the efficient and clear communication capability which is inherent function of the drawings. As a result, the current architects are introducing their own way of drawing technique which is developed in accordance with a specific curved shape, construction method or company resources, but this is not what can be applied to other cases because it has not been ever shared or agreed in the industry. In this process, the drawing or construction of curved building has been recognized as the exclusive property of a specific expert, or the design and construction without the in-depth understanding of the technology have resulted in the appearance of poor buildings. Therefore, this study aims to present an elements and method that can convey shape information more effectively and clearly in the drawing representation of non-linear buildings and, thus, contributes to lowering the barriers to entry into the field by providing the information to be easily applied to related projects. In order to attain this goal, the drawings of recently completed projects of free form building are analyzed to reveal the method used to effectively express the shape information of the building and to derive new drawing elements that have not been applied to the existing drawings.

• 대한기계학회논문집A
• /
• 제24권1호
• /
• pp.87-93
• /
• 2000

Warm, forming technique which is one of the new forming technologies to improve formability of sheet metal is applied to the cylindrical cup drawing of stainless-aluminum. clad sheets. In experiments the temperature of die and blank holder is varied from room temperature to 18$0^{\circ}C$, while the punch is cooled by circulation of coolant to increase the fracture strength of workpiece on the punch corner area. Test materials chosen for experiments are STS304-A1050-STS304, STS304-A1050-STS430 clad sheets and A1050-0 aluminum sheet. Teflon film as a lubricant is used on both sides of a workpiece. The limit drawing ratio as well as quality of drawn cups(distribution of thickness and hardness)are investigated and validity of warm drawing process is also discussed.

• 한국산업융합학회 논문집
• /
• 제23권1호
• /
• pp.57-64
• /
• 2020

The construction market became generally opened to overseas and the domestic construction industry has competed with the international construction enterprise of which technical knowledge is superior. In order to compete with the international construction companies, domestic construction industry needs more continuous promotions on the research and development for improving the level of technique of the construction engineering to meet the international norm. This study aims to suggest the better standards of engineering output such as drawings and specifications to correspond the changing integration system and bidding system in preparation for growing international competition. The study starts with comparison and analyses of domestic and international methods and standards for preparing design drawings. And it continues to delve into actual drawing preparation practices, especially focusing on the ones for road and subway construction. Finally, the study presents a better way of the standardization of the main drawings such as general plan, longitudinal drawing, cross section, structural drawings and temporary structure for new bidding systems of historical cost estimation and whole specification tender and for promotion of international competitiveness.

• 소성∙가공
• /
• 제11권8호
• /
• pp.668-675
• /
• 2002

The circles deform into various shape during deformation, the major and minor axes of which indicate the direction of the major and minor principal strains. Likewise, the measured dimensions are used to determine the major and minor principal strain magnitudes. This circular grid technique of measuring strains can be used to diagnose the causes of necking and fracture in industrial practice and to investigate whether these defects were caused by material property variation, changes in lubrication, of incorrect press settings. In non-axisymmetric deep drawing, three modes of forming regimes are found: draw, stretch, plane strain. The stretch mode for non-axisymmetric deep drawing could be defined when the major and minor strains are positive. The draw mode could be defined when the major strain is positive and minor strain is negative, and plane strain mode could be defined when the major strain is positive and minor strain is zero. Through experiments the draw mode was shown on the wall and flange are one of a drawn cup, while the plane strain and the stretch mode were on the punch head and the punch corner area respectively, We observed that the punch load of elliptical deep drawing was decreased according to increase of die corner radius and the thickness deformation of minor side was more large than major side.

• Journal of Computational Design and Engineering
• /
• 제3권3호
• /
• pp.286-294
• /
• 2016

In this paper we present an efficient technique for sketch-based 3D modeling using automatically extracted image features. Creating a 3D model often requires a drawing of irregular shapes composed of curved lines as a starting point but it is difficult to hand-draw such lines without introducing awkward bumps and edges along the lines. We propose an automatic alignment of a user's hand-drawn sketch lines to the contour lines of an image, facilitating a considerable level of ease with which the user can carelessly continue sketching while the system intelligently snaps the sketch lines to a background image contour, no longer requiring the strenuous effort and stress of trying to make a perfect line during the modeling task. This interactive technique seamlessly combines the efficiency and perception of the human user with the accuracy of computational power, applied to the domain of 3D modeling where the utmost precision of on-screen drawing has been one of the hurdles of the task hitherto considered a job requiring a highly skilled and careful manipulation by the user. We provide several examples to demonstrate the accuracy and efficiency of the method with which complex shapes were achieved easily and quickly in the interactive outline drawing task.

• 한국HCI학회:학술대회논문집
• /
• 한국HCI학회 2008년도 학술대회 1부
• /
• pp.103-108
• /
• 2008

3 차원 공간 모델링을 하기 위한 스케치 시스템의 경우, 3 차원 공간상의 입력 장치를 이용하는 것이 디자이너의 의도를 가장 정확하게 표현할 수 있다. 하지만, 3 차원 공간상의 스케치는 공간 입력 장치의 디자이너 사용에 따라 오차가 방생할 수 있다. 이러한 오차를 줄이기 위하여 디자이너가 일반적으로 사용해 온 드로잉 방식인 다중의 스트로크를 데이터로 사용하여 의도한 모델링을 수행하게 된다. 다중의 스트로크를 실시간으로 처리하기 위해 공간상에 정의된 격자를 이용한 모델링 방식을 사용하였다. 곡면을 구성하기 위한 격자간의 관계 및 다중의 스트로크를 처리하기 위한 주변 격자간의 관계를 정리하고, 이를 이용한 스케치 시스템을 구현하였다.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
• /
• pp.235-237
• /
• 2006

비사실적렌더링(NPR-Non Photorealistic Rendering) 기법은 현재 다양한 미술 소재를 가지고 3차원 표현에 활발히 이용되고 있다. 하지만 소재의 이용 범위에 있어서 동양적인 회화 기법들은 목탄, 유채, 연필 등 서양화 기법에 미치지 못한다. 동양화 회화 표현 중 담채화는 동양화에서, 묽게 갠 먹이나 잉크, 그림물감 등으로 수채화 위에 가볍게 한 겹 칠한 그림이다. 본 논문에서는 이러한 수묵 담채화 표현과 비사실적 렌더링의 개념을 결합한 새로운 영상 표현 기법을 3D 애니메이션 프로그램 Alias MAYA의 스크립트 언어인 MEL(MAYA Embeded Language)을 이용하여 구현하였다.

• 조명전기설비학회논문지
• /
• 제26권7호
• /
• pp.23-29
• /
• 2012

A single line diagram is a graphic user interface to represent electrical connectivity between power equipments in distribution automation systems. This paper proposes a new single line auto-drawing technique based on the service oriented architecture. Web service, CIM(Common Information Model) and SVG(Scalable Vector Graphics) are adopted to implement SOA concept. A web service demo system was established which is configured with the service provider, consumer and broker to verify the feasibility of this study.