• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.840-843
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• 2016

원호는 산업 환경에서 객체의 검출 및 인식에 매우 유용한 특성이다. 본 논문에서는 새로운 원호 검색 방법을 제안한다. 원호 검출은 중점과 원호의 반지름, 두 개의 호 끝점이 필요하다. 제안하는 새로운 검출 방법은 호를 따라 지정한 세 점을 이용하여 가장 좋은 부분을 결정한다. 최소자승법을 적용하여 원호의 최적점과 중점 그리고 반지름을 얻는다. 남은 모서리 점들의 거리와 반지름은 원호의 두 끝점을 찾는데 이용된다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.399-404
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• 2001

In CNC machining, a 3D(3-dimension) linear segment and a 2D(2-dimension) circular arc are general forms given by CAD/CAM system. Generally, the 2D circular arc machining is processed using dividing into some linear segments. A 3D circular arc also don't exist in the standard form of NC data. This paper present a algorithm and method for real-time machining of a circular arc(not only the 2D one, but also the 3D one). The 3D circular arc machining is based on the 2D circular arc machining. It only needs making a new coordinate system, converting given 3D points(a start point, a end point, and a center point of a 3D circular arc) into points of the new coordinate system, and processing a inverse transformation about a interpolated point. The proposed algorithm was implemented and simulated on PC system. It was confirmed to give a gcod result.

• 한국안전학회지
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• 제14권4호
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• pp.28-36
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• 1999

In this paper, A circular arc crackered plate in biaxially stretched sheets was investigated in the boundary element method. The applications of fracture mechanics have traditionally concentrated on crack problems under an mode I, straight crack. However, many service failures occur from growth of cracks subjected to mixed mode loadings. A rectangular plate with arc crack or slanted central crack, under biaxial tensile loading, was treated analytically and also solved numerically. The Results from BEM applying different loading conditions, crack length (a/W), arc angle($\alpha$) are presented and discussed. The stress intensity factors are evaluated by the techniques of the J-integral. The decomposition method, used to decouple the stress intensity factors in mixed mode problems, is implemented by a considering a small circular contour path around each crack tip. The BIE method was successfully applied to a circular arc crackerd plate problem, also slanted centre cracked plate under mixed mode.

• International Journal of Fluid Machinery and Systems
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• 제10권1호
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• pp.63-75
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• 2017

Many axial fans have circular arc blades with constant thickness. It is still a challenging task to calculate their performance, i.e. to predict how large their pressure rise and pressure losses are. For this task a need for cascade data exists. Therefore, the designer needs a method which works quickly for design purposes. In the present contribution a design method for such cascades consisting of circular arc blades with constant thickness is described. It is based on a singularity method which is combined with a CFD-data-based flow loss model. The flow loss model uses CFD-data to predict the total pressure losses. An interpolation method for the CFD-data are applied and described in detail. Data of measurements are used to validate the CFD-data and parameter variations are conducted. The parameter variations include the variation of the camber angle, pitch chord ratio and the Reynolds number. Additionally, flow patterns of two dimensional cascades consisting of circular arc blades with constant thickness are shown.

• 대한기계학회논문집
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• 제11권2호
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• pp.198-204
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• 1987

본 논문에서는 전보에서 창성된 인벌류우트-원호합성치형기어에 있어서 Hertz 식에 의하여 치면접촉응력을 구하고 유한요소법에 의하여 이뿌리응력을 계산하였다. 그리고 같은 제원의 표준 인벌류우트 치형기어와 비교하였다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권9호
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• pp.868-877
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• 2005

호는 패턴인식에 있어서 매우 중요한 특징으로 간주된다. 이 논문에서는 기하학적 분석을 이용하여 2차원 곡선으로부터 호를 추출하고 그 호의 중심과 반지름을 계산하는 방법을 제시한다. 제안된 방법에 의해 추출된 호는 원래의 곡선으로부터 거리오차가 항상 허용치 이내의 값을 만족한다. 제안된 방법이 부드럽게 연결된 2차원 곡선이나 잡음이 심한 2차원 곡선 내에 있는 호의 추출에도 유용함을 실험으로 확인하였다.

• 대한기계학회논문집
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• 제10권6호
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• pp.870-875
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• 1986

본 연구에서는 랙의 이끝부분을 full-rounded tip으로 설계한 후, 이에 의하 여 창성되는 피니언의 이뿌리곡선을 구하여 전체치형을 완성하였다. 그리고 합성치 형기어의 미끄름율, 유효이뿌리원에서의 공칭굽힘응력과 두쌍접촉호의 길이대 원호부 분접촉호의 길이의 비인 접촉계수를 해석적인 방법으로 구하였다.또한 이들 특성들 과 물림율등 제특성을 비교.검토하여 공구압력각, 인벌류우트부분의 크기를 나타내는 물림각 및 원호반경등의 변화에 대한 제특성의 변화를 고려한 합성치형의 성능을 향상 시킬 수 있는 설계방법을 구하였으며, 합성치형과 표준인버류우트치형을 비교하였다.

• Structural Engineering and Mechanics
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• 제43권4호
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• pp.439-448
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• 2012

This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권2호
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• pp.151-161
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• 2016

In this paper, we present a $C^3$ quartic B-spline approximation of circular arcs. The Hausdorff distance between the $C^3$ quartic B-spline curve and the circular arc is obtained in closed form. Using this error analysis, we show that the approximation order of our approximation method is six. For a given circular arc and error tolerance we find the $C^3$ quartic B-spline curve having the minimum number of control points within the tolerance. The algorithm yielding the $C^3$ quartic B-spline approximation of a circular arc is also presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.523-526
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• 2000

This paper performs the motion analysis for a disk cam and a follower mechanism using a circular arc method, a coordinate transformation method and an instant velocity method in order to find a contact point between the cam and the follower. Based on the proposed method, the displacement and the velocity are calculated by using the geometric relationships of the cam mechanism. Also, the acceleration is determined on using the central difference method. As the results, this paper presents the original curve and the analyzed curve for the motion analysis of the disk cam for an example.