• 한국융합학회논문지
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• 제11권7호
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• pp.163-167
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• 2020

본 연구에서는 피스톤 헤드의 형상별 열응력해석을 진행하여 내구성이 있는 피스톤의 형상을 고찰하기 위한 연구를 진행하였다. 그 결과로서는 온도가 가해지는 부분에서부터 거리가 멀수록 낮은 온도를 볼 수 있다. 피스톤 헤드의 형상에 따라 열을 받는 면적이 다르기 때문에 피스톤 기둥 부분과 스커트부에 영향을 끼치게 된 점을 볼 수 있었다. 본 연구에서는 세 모델이 동일하게 피스톤 헤드의 중심부에서 가장 적은 응력이 나오는 것을 알 수 있었다. Model A는 다른 두 모델에 비해 항복이 발생하는 응력이 가장 작은 것을 알 수 있었다. Model B는 접시형 피스톤헤드로서 피스톤 헤드부가 오목한 형상으로 되어 있어 피스톤 헤드 중심부에서는 주변 부분에 영향을 가장 덜 끼치는 모델임을 알 수 있었다. Model C는 항복이 발생하게 되는 응력이 가장 크게 보였다. 또한 본 연구결과는 내구성이 있는 피스톤의 형상 설계에 유용하게 적용할 수 있다고 사료된다. 피스톤 헤드의 형상에 따른 열응력 해석을 적용함으로서, 본 연구가 미적인 융합에 부합된다고 사료된다.

• 대한한의학원전학회지
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• 제30권3호
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• pp.55-76
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• 2017

Objectives : The transition of the 29 diagrams of Heart originated from MingTangZangFuTu will be used to understand the shape of heart and the changes of people's understanding of heart. Methods : The 29 diagrams of Heart originated from MingTangZangFuTu are divided according to their shape elements (Heart itself, internal curvatures, structures above heart, wuzangxi, and excursus). Then its transitions are analyzed, and each shape element is compared to modern anatomy and its textual basis is searched. Results : The lengthy cylinderical organ situated above the heart is composed of upper part consisting with joints and the lower part void of joints. The upper part is Pyewan (such as the lungs) and fall into trachea. The lower part is Xinxi or Feixi which are either relative vein (or aorta) or left bronchus that passes behind the heart. This depiction of the structures around the heart can be considered to have composed by actual observance of a physical heart, a method that is similar to anatomy. However, the shape of the heart itself is described as a lotus flower that has not been bloomed, a depiction which finds its origin from Zhongguangbuzhu huangdineijing suwen (762). The three short curvatures inside the heart is described as Pericardium, influenced by Shisijingfahui (1341) in its depiction, or as sammo, influenced by Nanjing. Structures that are connected directly from the heart to spleen, kidney, and uterus are not found in modern anatomy. The saying in Excursus "All cords of five internal organs belong to heart" is based on Huatuoxuanmenneizhaotu, and this is changed to the saying cords of four internal organs belong to heart in Leijingtuyi for the first time. Conclusions : The authors of medical scriptures at the time did not have a method of direct observance when they were copying heart diagrams. Therefore, they made changes to the source material's diagram and excursus while being influenced by Nanjing, Huatuoxuanmenneizhaotu, and Shisijingfahui. Then the doctors' understandings with regards to the shape and function of heart were reflected during that process.

• 한국가구학회지
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• 제21권3호
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• pp.253-260
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• 2010

The drop handle in the Chosun-Dynasty played a role lifting up the cabinet and box which was attached to and besides this had the decoration function. The scope of this study should include the drop handles from the $18^{th}$ century up to now by investigating and analyzing their definition & function and furthermore the types of their designs. The object of the study was the drop handle having 2 golden fixing parts which are definitive difference from ring or loop, and the design typology of drop handle was concentrated on the handle part, and it can be classified in two types. The one is the figuration of bow, bat, bamboo, fish and bird and so on from the motive of nature on the handle part, and the other one is the drop handle of the simple ㄷ-shape, the temple-symbol shape or geometrical forms. According to the analysis of relics & literature from the past it was found that there were more quantitative nature-motive figurations than the geometrical forms. The nature-motive figurations were again classified in box-, bat-, cloud- bamboo-, fish- and bird-type, and the geometrical forms in ㄷ-shape, the temple-symbol shape and others. The cases applied to furniture are roughly divided into the front-attached type and the side-attached type. In comparison of the drop handle in the Chosun-Dynasty with that of modern times, ㄷ-shape and bow-type keep the long tradition of the drop handles despite of the constructive change partly. Ring-type is similar to the just ring or loop of the part and drop handle with one golden fixing part, while the knob-type shows almost same forms in the past as well as in the modern times. Which type among handles in the modern times has little connection with the past is the reclaimed type, and it was showed in the Chosun-Dynasty and also is showed up to now identically that the man-made hole on the front side of the drawer for the function as handle.

• 한국항해항만학회지
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• 제30권5호
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• pp.375-379
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• 2006

세일링요트의 추진시 횡류를 방지하기 위하여 선체 하부에 킬을 부착하게 되는데 이는 세일의 양력에 의한 횡흐름을 멈추게 하는 역할과 힐 모멘트를 없애고 복원력을 생기게 한다. 이는 안전성에 영향을 미치기 때문에 적절한 킬의 선택은 중요하다고 할 수 있다. 또한 킬 하부에 부가물의 부착은 발라스트 중량중심을 낮춤으로서 선체 복원력에 중요한 영향을 미치므로 킬에 대한 최적형상 도출은 매우 중요하다. 이에, 본 연구에서는 저항성능 향상을 위한 동일 침수표면적의 핀킬 하부 부가물에 따른 저항특성을 비교 실험하였다. 실험방법으로는 회류 수조를 이용하여 3가지 핀킬 하부 부가물 모형킬을 모형선에 부착하여 형상별 저항특성을 비교 분석하였다. 분석 결과에 따른 저항감소 최적 형상을 도출 하였다.

• 소성∙가공
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• 제14권5호
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• pp.439-443
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• 2005

Deep drawing and cold forging processes are combined to achieve near net shape forming of automotive part which has not only drum shape but also thickness variation. It is important to find out proper intermediate shape where two totally different forming methods should be joined seamlessly. In the course of development of the combined process, finite element analysis can be utilized effectively to decide optimal position for transferring from the sheet metal work to the bulk forming. Because machining process is eliminated, significant improvement in integrity, reliability, and durability of the part is expected. The developed process combination could be applied in real manufacturing process successfully.

• Journal of Welding and Joining
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• 제21권6호
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• pp.40-45
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• 2003

Steel members have advantages of resisting torsion and axial compression. In design, residual stresses at the welded joint of T-shape steel pipes are one of the most important points to be considered. In this paper, characteristics of residual stresses of welded joints are clarified by carrying out 3D non-steady heat conduction analysis and 3D thermal elastic-plastic FE-analysis. According to the results, the production mechanism of residual stresses at the welded joint of T-shape steel pipe is clarified. In this paper, circumferential stresses depended on thermal histories but axial and radial stresses were more dependent on geometrical shape than thermal histories. Residual stresses in the axial direction on the lower part of pipe member were tensile, controlled by geometrical shape. However, in case of middle part, residual stresses in all the directions were controlled by thermal histories.

• 한국시뮬레이션학회논문지
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• 제14권3호
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• pp.147-154
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• 2005

In conventional approaches such as a functinal approach or a parametric approach to online signature verification, which could not deal with the local shape of signature, much various important informations inherent in the local part of signature shape have been overlooked. In this paper, we try a structural approach in which a signature is represented as a structural form of handwriting primitives and the local parts along a signature handwriting can be selectively compared according to their discrimination power in the process of signature verification, As a result, the error rate is diminished in the case that the weights of subpattern units is applied into comparing process, which is the degree of discrimination power of local part. And also, the global variation and complexity of each signature extracted from the analysis of local shape is found useful in determining the decision threshold more precisely.

• 한국산업정보학회논문지
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• 제17권7호
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• pp.43-50
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• 2012

본 논문에서는 차량용 센터필러 부품의 성형공정에서 발생하는 스프링백 문제를 해결하기 위한 일환으로 기존 부품의 금형보정이력 정보를 체계적으로 데이터베이스화하였다. 기존 부품의 경우 과도한 스프링백 발생에 의한 형상정밀도 불량을 해결하기 위하여 3차의 금형 보정을 현장기술자의 작업에 의하여 수행하였으나, 보정값이 정량화되어 있지 못한 문제가 있었다. 본 논문에서는 기존 금형 보정과정의 결과를 유한요소해석을 통하여 정량적으로 분석하고 보정이 의도대로 이루어졌는지를 평가하는 데이터베이스를 구축하였다. 구축된 데이터베이스 정보를 활용하여 유사부품의 금형설계에 활용하였으며, 결과적으로 보정횟수를 감소시키고도 제품을 성공적으로 성형할 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.932-938
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• 2001

This study is concerned with the shape optimization of stem for the artificial hip prosthesis with unbonded cement mantle. The artificial hip prosthesis with unbonded cement mantle allows a stem to slip on cement mantle because of polished stem surface. Unbonded cement mantle type has several advantages compared with bonded cement mantle type, for example, small micro motion, preventing stress shielding and so on. In this study, 2-dimensional axisymmetric model was developed with considering characteristics of unbonded cement mantle. Moreover, optimal shape of stem was obtained by using feasible direction method. The objective of this optimization is maximizing supported vertical loading. The slip motion and stresses of stem, cement mantle and bone is used for constraints. The optimal shape which obtained by this study has slope of 0.15 in proximal part and maintains the width about 5mm in distal part In addition, simplified 3-dimensional analysis which applying optimal shape is carried out. The result of 3-dimensional analysis showed that optimal shape has some advantages for cement mantle stress. However, more realistic 3-dimensional analysis which including bending effect, complex geometries etc. is needed in further research.

• 한국기계연구소 소보
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• 통권19호
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• pp.149-154
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• 1989

Generally Cam-Follower systems consist of two elements: Cam is for rotating motion and follower for reciprocating motion. Depending on the shape of cam and type of follower, the motion of cam-follower system is determined. Thus design process and analysis process must be well defined. The design process means to find the coordinates of cam shape which can be defined the given motion of follower and the analysis process means to determine the motion curve of follower corresponding to the given cam based on the dimensions of a cam-follower system. This paper consists of two parts: One is development of a numerical method for design and analysis of cam-follower systems, the other is for development of a CAD program and its application. As the first part of the paper, an iterative contact method is proposed. This method can calculate the contact points between cam and roller and determine their contact angles iteratively. The second part of the paper presents the structure of a CAD program and its availability to the industrial applications.