• 한국컴퓨터정보학회논문지
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• 제21권10호
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• pp.11-19
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• 2016

The size of a display is large, The form becoming various of that do not apply to previous methods of gaze tracking and if setup gaze-track-camera above display, can solve the problem of size or height of display. However, This method can not use of infrared illumination information of reflected cornea using previous methods. In this paper, Robust pupil detecting method for eye's occlusion, corner point of inner eye and center of pupil, and using the face pose information proposes a method for calculating the simply position of the gaze. In the proposed method, capture the frame for gaze tracking that according to position of person transform camera mode of wide or narrow angle. If detect the face exist in field of view(FOV) in wide mode of camera, transform narrow mode of camera calculating position of face. The frame captured in narrow mode of camera include gaze direction information of person in long distance. The method for calculating the gaze direction consist of face pose estimation and gaze direction calculating step. Face pose estimation is estimated by mapping between feature point of detected face and 3D model. To calculate gaze direction the first, perform ellipse detect using splitting from iris edge information of pupil and if occlusion of pupil, estimate position of pupil with deformable template. Then using center of pupil and corner point of inner eye, face pose information calculate gaze position at display. In the experiment, proposed gaze tracking algorithm in this paper solve the constraints that form of a display, to calculate effectively gaze direction of person in the long distance using single camera, demonstrate in experiments by distance.

• 대한관절경학회지
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• 제7권2호
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• pp.127-136
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• 2003

슬관절 후외측방 불안정성은 전방 및 후방 십자인대 손상과 흔히 동반되며 이 동반된 손상은 심각한 기능적 불안정성 및 관절 연골의 변성을 초래하게된다. 슬관절의 후외측 구조물 손상이 있는 경우 적절한 치료 없이 전방 및 후방 십자인대 재건술만 시행할 경우 십자인대 재건술이 실패하게된다. 이를 방지하기 위해 자세한 이학적 검사, 방사선 검사를 시행하여야하며 하지정열축 및 보행 형태를 평가하여야 한다. 급성 후외측방 구조물의 3등급 단독 손상이나 동반 손상에서는 3주이내에 일차 봉합을 하거나, 봉합이 어려울 경우 보강수술이나 재건수술을 시행하는 것이 좋다. 후방 및 후외측방 재건술에서 다양한 수술 방법 중 적절한 방법을 선택하여 동시에 시행하거나 2단계 재건수술을 가능한 빨리 시행하여야 한다. 만약 만성 후외측 불안정성 슬관절에서 내반 정열이 있으면서 varus thrust gait가 있는 경우 외측 연부조직 재건술로는 해결하기가 어려우므로 먼저 외반 절골술을 시행하여야 하고 약 6개월 뒤에 후외측 불안정성을 재평가하여 이후 연부조직 재건술을 시행할 수도 있다.

• 한국측량학회지
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• 제17권4호
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• pp.421-429
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• 1999

21세기에는 전 세계인구의 70%가 도시에서 생활할 것으로 예상되며, 이러한 도시화는 도시관리를 위해 GIS와 더불어 건물 DEM과 정사투영영상에 대한 요구가 증대될 것이다. 건물 DEM을 생성하기 위해서는 건물의 형태를 나타내는 경계선을 검출해야 한다. 이를 위해서 일반적으로 자동과 반자동 건물 추출법을 사용한다. 그러나 자동 검출법을 항공사진에 직접 적용하면 지붕의 색깔이나 그림자 그리고 주변의 나무 등 때문에 정확한 건물 경계선을 추출하기 매우 어렵다. 이러한 문제점을 극복하기 위해 본 연구에서는 반자동 건물 추출법을 제시하였다. 건물 지붕의 색깔이 균일할 경우 지붕의 한 부분을 마우스로 클릭하여 건물경계를 찾도록 하였으며, 균일하지 않은 경우 건물의 모서리 부분을 클릭하여 건물 모서리점을 검출하도록 프로그램을 개발하였다. 건물 DEM은 영상정합에 의해 계산된 건물 높이와 건물 경계선을 이용하여 생성하였다.

• 전자공학회논문지C
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• 제36C권9호
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• pp.28-43
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• 1999

본 논문에서는 다중칩 모듈 설계를 위한 gridless 배선 방법을 제안한다. 제안하는 배선 방법에서는 배선상태를 표현하기 위해 배선격자 (grid) 대신 corner stitching 자료구조를 사용함으로써 핀들의 위치 제한을 없애고, 네트의 특성에 맞는 와이어 폭을 선택할 수 있다. 또한 비아보다 그 폭이 작은 와이어들로 인해 남는 공간을 다른 네트의 배선에 이용하여 배선영역을 최대한 낭비 없이 이용한다. 배선격자를 사용하지 않는 배선방법은 배선격자를 기반으로 하는 배선 방법에 배해 복잡하고 어렵다. 더구나 다중칩 모듈과 같이 배선 영역이 크고 배선층의 갯수가 많은 배선 문제일 경우 배선 속도는 배선 가능성을 결정하는 중요한 요소가 된다. 그러나 제안하는 배선 방법은 빠른 속도가 증명된 SEGRA의 배선 알고리즘과 효율적인 자료구조의 특성을 적절히 이용함으로써 배선격자를 기반으로 하는 배선 방법 보다 빠른 속도와 그리 떨어지지 않는 배선 결과를 보인다.

• Wind and Structures
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• 제34권1호
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• pp.43-58
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• 2022

The BARC flow is studied via Direct Numerical Simulation at a relatively low turbulent Reynolds number, with focus on the geometrical representation of the leading-edge (LE) corners. The study contributes to further our understanding of the discrepancies between existing numerical and experimental BARC data. In a first part, rounded LE corners with small curvature radii are considered. Results show that a small amount of rounding does not lead to abrupt changes of the mean fields, but that the effects increase with the curvature radius. The shear layer separates from the rounded LE at a lower angle, which reduces the size of the main recirculating region over the cylinder side. In contrast, the longitudinal size of the recirculating region behind the trailing edge (TE) increases, as the TE shear layer is accelerated. The effect of the curvature radii on the turbulent kinetic energy and on its production, dissipation and transport are addressed. The present results should be contrasted with the recent work of Rocchio et al. (2020), who found via implicit Large-Eddy Simulations at larger Reynolds numbers that even a small curvature radius leads to significant changes of the mean flow. In a second part, the LE corners are fully sharp and the exact analytical solution of the Stokes problem in the neighbourhood of the corners is used to locally restore the solution accuracy degraded by the singularity. Changes in the mean flow reveal that the analytical correction leads to streamlines that better follow the corners. The flow separates from the LE with a lower angle, resulting in a slightly smaller recirculating region. The corner-correction approach is valuable in general, and is expected to help developing high-quality numerical simulations at the high Reynolds numbers typical of the experiments with reasonable meshing requirements.

• 대한기계학회논문집A
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• 제24권6호
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• pp.1565-1574
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• 2000

Surface edge crack subjected to contact stresses is analysed. A punch with corner radii is considered to press the semi-infinite plane. Partial slip problem is solved when a shear force is applied to the punch. Dislocation density function method is used to solve the present mixed mode crack problem. The crack length of positive K1 is examined, which is affected by the ratio of the flat portion to the total width of the punch. Surface traction during one cycle of the shear force is evaluated to simulate the fretting condition. The compliance change of the contact surface is also investigated during the shear cycle. It is found that the crack grows during only a part of the cycle, which may be termed as effective period of crack growing. A design method for restraining the fretting failure is discussed, from which recommendable geometry of the punch is suggested.

• Steel and Composite Structures
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• 제28권6호
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• pp.655-670
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• 2018

A coupled method, that combines the Ritz method and the finite element (FE) method, is proposed to solve the vibration problem of rectangular thin and thick plates with general boundary conditions. The eigenvalue partial differential equation(s) of the plate is (are) first reduced to a set of eigenvalue ordinary differential equations by the application of the Ritz method. The resulting eigenvalue differential equations are then reduced to an eigenvalue algebraic equation system using the finite element method. The natural boundary conditions of the plate problem including the free edge and free corner boundary conditions are also implemented in a simple and accurate manner. Various boundary conditions including simply supported, clamped and free boundary conditions are considered. Comparisons with existing numerical and analytical solutions show that the proposed mixed method can produce highly accurate results for the problems considered using a small number of Ritz terms and finite elements. The proposed mixed Ritz-FE formulation is also compared with the mixed FE-Ritz formulation which has been recently proposed by the present author and his co-author. It is found that the proposed mixed Ritz-FE formulation is more efficient than the mixed FE-Ritz formulation for free vibration analysis of rectangular plates with Levy-type boundary conditions.

• 한국전산구조공학회논문집
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• 제22권5호
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• pp.439-444
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• 2009

본 논문에서는 경계요소법의 평면 접촉해석에 사용될 수 있는 효율적인 접촉면 검출 알고리즘을 제시하였다. 접촉면 검출 알고리즘을 경계요소법에 적용하기 위하여, 경계요소법이 가지는 자료구조를 분석하였다. 경계요소법의 특징 중 하나인 모퉁이 문제를 고려하여 전역검색, 지역검색, 접촉관계식 설정의 3단계로 접촉면 검출기법을 구현하였다. 전역검색은 접촉 주요소, 부요소 개념을 도입하였으며, 지역검색에 있어서는 공간분할기법인 사지트리를 이용하였다. 접촉관계식의 설정을 위하여 요소수준에서 절점의 접촉여부를 검토하고 최종계의 방정식에 구속조건을 할당하도록 하였다. 제시된 알고리즘을 이용한 프로그램의 정확성과 효율성을 입증하기 위하여 수치해석을 실시하여 결과를 비교하였다.

• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.384-391
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• 1998

When a device is mounted on the PCB, it is impossible to have zero defects due to many unpredictable problems. Among these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). It is obvious that given the complexity of the inspection task, the efficiency of a human inspection is questionable. Thus, new technologies for inspection of SMD(Surface Mounting Device) should be explored. An example of such technologies is the Automated Visual Inspection(AVI), wherein the vision system plays a key role to correct this problem. In implementing vision system, high-speed and high-precision are indispensable for practical purposes. In this paper, a new algorithm based on the Radon transform which uses a projection technique to inspect the FIC(Flat Integrated Circuit) device is proposed. The proposed algorithm is compared with other algorithms by measuring the position error(center and angle) and the processing time for the device image, characterized by line scan camera.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.48-51
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• 1997

This paper presents the algorithm of FIC inspection in chip mounter. When device is mounted on the PCB, it is impossible to get zero defects since there are many problems which can not be predicted. Of these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). In this paper, we proposed a new algorithm based on the Radon transform which uses a projection to inspect the FIC(Flat Integrated Circuit) device and compared this method with other algorithms. We measured the position error and applied this algorithm to our image processing board which is characterized by line scan camera. We compared speed and accuracy in our board.