• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.280-281
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• 2017

본 논문에서는 기존의 배풍기 효율을 높이고 크기를 줄이기 위해 임펠러의 속도를 높이는 설계에 관한 연구다. 임펠러 속도는 5500rpm으로 증가시키고 크기는 320mm에서 250mm로 줄였으며 효율과 최대 풍량을 향상키기기 위해 임펠러의 Hub/Tip 비율을 줄이며, 날개각도에 변화를 주는 방식을 제안한다. Hub/Tip 비율이 줄어들면 유량이 통과하는 면적이 넓어지게 되는 효과를 얻게 되고, 임펠러 중심거리에 따른 날개 각도를 변화시키면 풍압과 풍량이 달라지는 효과를 얻게 되어 동일한 rpm으로 회전하는 배풍기의 효율을 높일 수 있다. 설계된 구동용 SRM과 임펠러의 설계에 따른 운전 특성을 시뮬레이션을 통해 해석하고자 한다.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.159-177
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• 2002

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle and the angular velocity of the air born phase and understand the control mechanism of the high-bar movement, the somersault, the double somersault, the double somersault with full twist. For this study seven well trained university gymnastic volunteered, Zatsiorky and Seluyanov(1983, 1985)'s sixteen segment system anatomical model was used for this study. For the movement analysis three dimensional cinematographical method(Arial Performance Analysis System : APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 5.1 graphical profromming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and angular velocity were defined. As a result of this study 1. As the rotation of the body increased in the air born phase the projection angle of the CM of the total increased, this resulted the increased of the max hight of the CM. 2. In three dimensional angular velocity the Z axis(vertical direction) projection angular velocity increased as the rotation of the body increased in the airborn phase, but the Y axis and the X axis projection angular velocity did not show significant differences. 3. As the rotation of the body increased in the air born phase the angular movement of the shoulder and the hip showed significant change. These movement act as the starter in the preparation phase. 4. The somersault angle, the twist angle, the tilt angle of the upper body related to the global reference frame in the releas phase the average somersault angle of the three types of high-bar movement was $57.7^{\circ}$, $38.8^{\circ}$, $39.7^{\circ}$, the average tilt angle was $-1.5^{\circ}$, $-5.4^{\circ}$, $-8.4^{\circ}$, the average twist angle was $13.4^{\circ}$, $10.6^{\circ}$, $23.3^{\circ}$. This result showed that the somersault with full twist had the largest movement.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.225-229
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• 2020

Recently, convolutional neural network (CNN) have been showed outstanding performance in the field of image recognition, image processing and computer vision, etc. In this paper, we propose a CNN-based image rotation correction algorithm as a solution to image rotation problem, which is one of the factors that reduce the recognition rate in image recognition system using CNN. In this paper, we trained our deep learning model with Leeds Sports Pose dataset to extract the information of the rotated angle, which is randomly set in specific range. The trained model is evaluated with mean absolute error (MAE) value over 100 test data images, and it is obtained 4.5951.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.1-8
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• 1999

This paper presents a new algorithm for surface segmentation and feature description. In the first stage of proposed algorithm, the signature of an edge image of object is extracted. The signature technique represents a surface using the distance from the mass center to the boundary of the image as a function of angle rotating counterclockwise. If there exists a range in the angle axis where more than two signatures form a closed curve, we can conclude there is a surface inside the range. Using this feature of the signature, surface can be segmented. The surface features such as number of vertices, number of edges, convex and type of surface can also be extracted from segmented surfaces. This algorithm has distinguished advantages; it can easily recover the lost part in the edge image using the curve fitting method; it extracts surface features correctly regardless of the rotation of the surface in 3-D space.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.6
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• pp.1-9
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• 2010

In this paper, we propose a hi-speed/low-power Extended QRD-RLS(QR-Decomposition Recursive Least Squares) equalizer with systolic array structure. In the conventional systolic array structure, vector mode CORDIC on the boundary cell calculates angle of input vector, and the rotation mode CORDIC on the internal cell rotates vector. But, in the proposed structure, it is shown that implementation complexity can be reduced using the rotation direction of vector mode CORDIC and rotation mode CORDIC. Furthermore, calculation time can be reduced by 1/2 since vector mode and rotation mode CORDIC operate at the same time. Through HDL coding and chip implementation, it is shown that implementation area is reduced by 23.8% compared with one of conventional structure.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.547-557
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• 2014

This paper presents a method for designing circular template used in similarity measurement for image registration. Circular template has translation and rotation invariant property, which results in correct matching of control points for image registration under the condition of translation and rotation between reference and sensed images. Circular template consisting of the pixels located on the multiple circumferences of the circles whose radii vary from zero to a certain distance, is converted to two-dimensional Discrete Polar Coordinate Matrix (DPCM), whose elements are the pixels of the circular template. For sensed image, the same type of circular template and DPCM are created by rotating the circular template repeatedly by a certain degree in the range between 0 and 360 degrees and then similarity is calculated using mutual information of the two DPCMs. The best match is determined when the mutual information for each rotation angle at each pixel in search area is maximum. The proposed algorithm was tested using KOMPSAT-2 images acquired at two different times and the results indicate high accurate matching performance under image rotation.

• Journal of the Korean Society of Radiology
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• v.4 no.2
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• pp.13-20
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• 2010

True lateral scapula image was very important to diagnosis the scapula fracture and dislocation induced by traumatic injury. The aim of this study was to know the patient rotation angle to be showing the scapula true lateral in korean. d Materials Thirty patients(22men, 8 women, mean ages 53.4)with scapular pain, had supine Anteroposterior projection taken with $30^{\circ}$, $40^{\circ}$, $45^{\circ}$ trunk rotation angle changing the manual angulation material. Radiographs were evaluated independently by 5 experienced observers(1 orthopedics surgery specialist, 1 diagnostic radiology specialist, 3 radiological technologist) They assessed overlap of vertebral border and axillary border of scapula as follows; Totally overlapping of vertebral border and axillary border is 4, partially overlapping is 3, not overlapping is 2 and oblique location with two borders is 1. All observers scored using by PACS monitor.$30^{\circ}$ trunk rotation was scored $1.53{\pm}0.39$, $40^{\circ}$ trunk rotation was scored $3.83{\pm}0.15$ and $45^{\circ}$ trunk rotation was scored $2.17{\pm}0.43$. There was no difference(p<0.05) between group of more than 100cm of the girth of the chest and group of less than 100cm. Similarly, men and women group showed no difference(p<0.05) with trunk rotation statistically. There was no result of trunk rotation angle to radiograph the true scapula lateral image up to date. This studies were summarized as follows; Adaptation of $40^{\circ}$ trunk rotation was the best to show the true scapula lateral image in korean. Our results were very useful to get the true scapula lateral images in clinic.

• Journal of KIISE:Software and Applications
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• v.34 no.10
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• pp.945-952
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• 2007

The face detection is a necessary first-step in the face recognition systems, with the purpose of localizing and extracting face regions from input images. But it is not a simple problem, because faces have many variations such as scale, rotation and lighting condition. In this paper, we propose a novel method to detect not only frontal faces but also partial rotated faces in still images. Firstly, we produce the eye candidates in the sub-regions of an input image to detect rotated faces. Secondly, the eye candidates are used to measure the angles of rotated faces. Thirdly, we are able to derotate the rotated face then put it to Bayesian classifier. We make an experiment with rotated multiracial face and show the good results in this paper.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.784-786
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• 2004

두개의 영상을 정합하는 것은 컴퓨터 비젼분야의 기본적인 과정 중의 한가지이다. 본 논문에서는 영상에서 간결하면서 많은 정보를 가지고 있는 선형특징들을 이용하여 회전각도와 위치변화에 관계없이 영상을 정합하는 방법을 제안한다. 영상에서 edge성분들을 추출하여 구조체로 구성하고 이를 이용하여 Hough공간에서 최대로 누적되는 변환 파라미터들을 추정하고, 후보 파라미터들에 대하여 다시 최적의 정합조건을 가지는 파라미터를 Hough기법을 사용하여 결정한다. 많은 연산양이 요구되기 때문에 전처리 과정을 사용하여 정확하고 빠른 정합을 유도한다

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.728-729
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• 2015

본 논문은 100kW급 차량 구동용 매입형 영구자석 동기전 동기의 회전자 형상에 따른 특성을 비교 분석하였다. 영구자석 사용량을 동일하게 유지하고, 자속장벽 길이와 자석의 각도를 설계변수로 하여 해석 모델을 선정하였다. 유한요소 해석을 통해 선정된 해석 모델의 평균 토크, 토크리플 특성을 비교, 분석하여 개선된 모델을 제시하였다.