• 제어로봇시스템학회논문지
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• 제8권1호
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• pp.37-45
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• 2002

A method of measuring the length of defects on the wall and restructuring the defect image is proposed based on the estimation algorithm of a camera orientation, which uses the declination angle of a laser slit beam. The estimation algorithm of the horizontally inclined angle of CCD camera adopts a 3-dimensional coordinate transformation of the image plane where both the laser beam and the original image of the defects exist. The estimation equation is obtained by using the information of the beam projected on the wall and the parameters of this equation are experimentally obtained. With this algorithm, the original image of the defect can be reconstructed as an image normal to the wall. From the result of a series of experiments, the measuring accuracy of the defect is measured within 0.5% error bound of real defect size under 30 degree of the horizontally inclined angle. The proposed algorithm provides the method of reconstructing the image taken at any arbitrary horizontally inclined angle as the image normal as the wall and thus, it enables the accurate measurement of the defect lengths by using a single camera and a laser slit beam.

• 대한치과교정학회지
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• 제14권1호
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• pp.151-160
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• 1984

This study was designed to get the informations of the mesiodistal axial inclinations of the posterior teeth and of the relationships between these and other angular measurements of facial bony structures in normal occlusion and malocclusion groups using lateral roentgenocephalograms. The subjects consisted of 73 normal occlusions (31 males 42 females), 38 Class II Division 1 malocclusions (17 males 21 females) and 47 Class III malocclusions (19 males 28 females). The findings of this study are as follows : 1. In mandible, the posterior teeth axes of Class II Division 1 malocclusion group were inclined more mesially and those of Class III malocclusion group were inclined more distally than normal occlusion group. In maxilla, Class II Division 1 malocclusion group showed more distal inclination and Class III malocclusion group showed more mesial inclinaton of 1st, 2nd premolars and more distal inclination of 1st, 2nd molars than those of the normal occlusion group. 2. There was a tendency for teeth axes to maintain nearly the same inclination in relation to occlusal plane irrespective of various OMA and OPA in each group. 3. F M A, P M A and O P A were the largest in Class II Division 1 malocclusion group and O M A, GoA were the largest in Class 111 malocclusion group. 4. There were high correlationships between mandibular teeth inclinations related to mandibular plane and 4 angular measurements except OPA, and between maxillary teeth inclinations related to palatal plane and OPA.

• 대한기계학회논문집A
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• 제34권9호
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• pp.1287-1292
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• 2010

본 연구에서는 균열선단 주위의 응력장을 균열선단으로부터 떨어진 일직선상에서 유한요소법에 의해 계산된 광탄성 등색프린지 차수와 급수형 등각사상 맵핑함수를 이용하여 해석하였다. 해석된 광탄성 응력장을 실제의 광탄성프린지와 비교하였다. 정성적인 비교가 용이하도록 디지털 영상처리에 의해 등색프린지 패턴을 2 배로 증식시키고, 증식된 프린지를 다시 세선처리하여 서로 비교하였다. 유한요소법으로 계산된 프린지 차수를 이용한 하이브리드 응력장 해석에 의해 계산된 프린지와 광탄성 실험에 의한 실제의 프린지를 정성적이고 정량적인 비교를 하였다. 입력된 변위와 계산된 변위의 퍼센트 오차는 18 개의 데이터 모두 6.0% 이하로 서로 일치하였다. 또한 하이브리드 기법에 의한 정규화시킨 응력확대계수 $K_I$ 및 $K_{II}$는 유한요소법과 경험식으로 계산된 값에 근접하였다.

• 소성∙가공
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• 제10권4호
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• pp.302-310
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• 2001

The twisting and extrusion process of the product with involute helical fin from the round billet is developed by the upper bound analysis. The twisting of extruded product is caused by the twisted inclined die surface connecting the die enterance section and the die exit section linearly. In the analysis, the internal shear surface is defined as the curved twisted plane from the twisting of die surface and the shear work is calculated by the consumption of shear energy. The increase rate of angular velocity is determined by the minimization of plastic work. The angular velocity of die exit can be controlled by the land length and the length of inclined die. The alular velocity assums to be increased linearly by the axial distance from the die enterance to the die exit. The results of the analysis show that the angular velocity of the extruded product increases with the die twisting angle, the reduction of area, and decreases with the die length, the friction constant.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.179-184
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• 1995

A new cutting parameter is defined in the spherical part of ball end-mill cutter. A series of slot cutting experiments were carried out to obtain the cutting parameter. The cutter contact area is expressed as the grid posiotion in the cutting plane using Z map. The cutting forces in each grid are calculated and saved as force map, prior to the average cutting forces calculation. The cutting force, in the arbitrary cutting area, can be easily calculated by summing up the cutting forces of the engaged grid in the force map. This model was verified in the inclined surface cutting by cutting test of a cylindrical part.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.3-7
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• 2009

The amount of incident rays over inclination according to direction has been widely utilized as important data in installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

• 한국전산유체공학회지
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• 제14권3호
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• pp.9-15
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• 2009

Numerical investigation has been carried out for laminar flow past an inclined square cylinder in cross freestream. In particular, inclination of a square cylinder with respect to the main flow direction can cause sudden shift of the separation points to other edges, resulting in drastic change of flow-induced forces on the cylinder such as Strouhal number (St) of vortex shedding, drag and lift forces on the cylinder, depending upon the inclination angle. Collecting all the numerical results obtained, we propose contour diagrams of drag/lift coefficients and Strouhal number on an Re-Angle plane. This study would be the first step towards understanding flow-induced forces on cylindrical structures under a strong gust of wind from the viewpoint of wind hazards.

• 한국태양에너지학회 논문집
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• 제29권2호
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• pp.47-54
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• 2009

The amount of incident rays over inclination according to direction has been widely utilized as important data m installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

• Geomechanics and Engineering
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• 제12권6호
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• pp.1021-1046
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• 2017

The assessment of slope stability is an essential task in geotechnical engineering. In this paper, a three-dimensional (3D) finite element analysis (FEA) was employed to investigate the performance of different shear pin arrangements to increase the stability of a soil block resting on an inclined plane with a low-interface friction plane. In the numerical models, the soil block was modeled by volume elements with linear elastic perfectly plastic material in a drained condition, while the shear pins were modeled by volume elements with linear elastic material. Interface elements were used along the bedding plane (bedding interface element) and around the shear pins (shear pin interface element) to simulate the soil-structure interaction. Bedding interface elements were used to capture the shear sliding of the soil on the low-interface friction plane while shear pin interface elements were used to model the shear bonding of the soil around the pins. A failure analysis was performed by means of the gravity loading method. The results of the 3D FEA with the numerical models were compared to those with the physical models for all cases. The effects of the number of shear pins, the shear pin locations, the different shear pin arrangements, the thickness and the width of the soil block and the associated failure mechanisms were discussed.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.815-827
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• 2014

본 연구는 복근의 정적 지구력 평가 도구로서의 등척성 버티기 방법의 타당성을 검증하고 최적의 적용 각도를 결정해내기 위해 수행되었다. 92명(남 68명, 여 24명)의 피험자가 자발적으로 실험에 참여하여 다음과 같은 결과를 얻었다. 유산소 역량과 근지구력 역량 사이의 상관성은 남성에서보다 여성에게서 더 높게 나타났으며 등척성 버티기의 수행 시간과 윗몸일으키기의 반복 횟수 사이에 정적인 상관관계를 나타냈다. 또한 40도의 경사도를 적용 시 30도 및 50도와 비교해 근지구력과의 가장 높은 상관성을 나타냈다. 이와 같은 결과를 통해 복근지구력의 평가 도구로서의 등척성 버티기 방법이 요부의 잠재적 상해 위험을 지닌 것으로 보고되고 있는 윗몸일으키기 방법을 대체할 수 있는 대안으로 사용될 수 있으며 적용 시 40도의 각도를 적용하는 것이 적절하다는 결론을 내릴 수 있었다. 서로 다른 연령 및 체력 상태에 따른 최적의 적용 각도에 대해서는 후속 연구를 통해 밝혀져야 할 것이다.