• 한국운동역학회지
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• 제14권1호
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• pp.13-26
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• 2004

The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to preflight of salto forward straight 3/2 turn motion between skillers and less-skillers. four S-VHS video cameras operating at 60Hz were used to record the performances. Five elite male gymnasts were participated in this study as subjects. Three-dimensional coordinates of 21 body landmarks during each trial were collected using a Direct Linear Transformation method. The raw 3-D coordinates of the 21 body landmarks were smoothed using a second order lowpass, recursive Butterworth digital filter and a cutoff frequency of 10Hz. Load cells attached on the beneath of a board were used to attain the kinetic variables. It was found that the more angular momentum in the longitudinal axis, the less vertical velocity and these angular momentum effected the height of peak in the preflight. Also, it was revealed that the larger angular momentum in the medio-lateral axis was rather than it in the longitudinal axis to increase vertical height and rotation force of the body. For the reaction force of springboard, the vertical and the horizontal reaction force were 16.52BW and 3.45BW, respectively. It was found that the higher value of the vertical reaction force induced the faster vertical velocity and the higher an ar momentum. of the whole body center of gravity.

• 방송공학회논문지
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• 제26권3호
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• pp.258-268
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• 2021

포인트 클라우드 콘텐츠는 3차원 포인트로 실제 객체를 나타내는 몰입형 콘텐츠이다. 포인트 클라우드 데이터를 획득하거나 포인트 클라우드 데이터를 인코딩 및 디코딩하는 과정에서 포인트 클라우드 콘텐츠의 해상도가 저하될 수 있다. 본 논문에서는 프레임 간 정합을 통해 순차적으로 포인트 클라우드 콘텐츠의 해상도를 점진적으로 향상시키는 방법을 제안한다. 포인트 클라우드 데이터를 정합하기 위해 ICP(Iterative Closest Point) 알고리즘이 일반적으로 사용된다. 기존 ICP 알고리즘은 강체를 변환할 수 있지만 포인트 클라우드 콘텐츠와 같이 로컬에서 서로 다른 방향으로 모션 벡터를 갖는 비 강체에 대해서는 변환이 불가능하다는 단점이 있다. 현재 프레임의 포인트 클라우드와 이전 프레임 사이의 포인트를 쌍을 만들고 만들어진 쌍의 움직임양을 계산하여 보상해주는 방법으로 기존 ICP 정합에서의 한계를 극복하였다. 이러한 방식으로 프레임 사이에 포인트를 정합하는 과정을 통해 기하학적 움직임이 있는 포인트 클라우드 콘텐츠의 해상도가 향상됨을 보였다.

• 한국임상수의학회지
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• 제19권1호
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• pp.49-54
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• 2002

Korean safflower (Carthami Flos) seed has been known to have healing effects on both bone fracture and osteoporosis. On the base of such a notice, this experiment was carried out to explore the effects of safflower seed on bone formation and bone repair. In addition, the healing mechanism was evaluated by analysing serum after feeding the seed to experimental. animals. The effect of Korean safflower seed were evaluated with 40 rats,3-month old. Forty Sprague-Dawley rats composed of 20 male and 20 female were underwent unilateral tibial defect and then fastened with unilateral fixators. The operated rats were divided into two groups depending on the composition of diet, such as positive control group fed normal diet (C-OP group) and safflower seed group fed 30% of safflower seed diet and 70% of normal diet (S-OP group). Postoperative radiographys were taken once in 2 weeks to evaluate callus formation for operated groups. In addition, a possible protein spots involved in bone recovery were examined using 2-Dimensional Gel Electrophoresis (2-DE). The comparison of the radiography between C-OP and S-OP group were showed that the safflower seed diet appeared to stimulate the formation of callus in the rat. On the images of 2-BE, it was able to identify possible five protein spots, having pl from 4 to 5 and molecular weight range from 24 to 26 kDa, involved in bone formation and repair, since no differing protein spots were found the two between groups except the five spots. No differences were observed between two groups before operation, but clear and bigger protein spots were observed from the S-OP group compared with C-OP group on 6 and 9 weeks post operation. These protein spots were, however, showed similar sizes and densities between two groups in 12 weeks later. The transformation of protein spots was suggested that these protein spots were involved in bone formation and recovery, in addition safflower seed might induce the formation of factors and activate these factors. In conclusion, this study suggest that safflower seed influence a variety of factors in the course of bone formation or the periods of remedy.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5148-5154
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• 2012

본 논문은 포환던지기 여자 기록보유자의 실제 경기에서 포환과 신체 무게중심의 운동학적 특성을 분석하는데 있다. 이를 위해 2대의 비디오카메라를 이용하여 촬영 한 후, 3차원 영상분석을 위해 DLT 방법을 이용하였으며, 자료 분석을 위해 Kwon3D 프로그램을 이용하였다. 그 결과는 다음과 같다. 첫째, 포환의 투사 속도와 투사 높이는 각각 13.73 m/s, 198.6 cm(신장비 119%)로 선행연구들과 비교했을 때, 최적의 수행을 한 것으로 판단되나 투사 각도는 $34^{\circ}$로 다소 작게 나타났다. 둘째, 신체 무게중심의 이동은 글라이드 구간에서 투사 방향으로의 이동이 필요하며, 딜리버리 구간에서 신체 무게중심의 상하 이동을 제어해야 한다. 셋째, 릴리즈 순간 신체 무게중심의 좌우방향과 상하방향의 흔들림 없이 정확한 타이밍에 포환이 투사되어야 한다.

• 한국운동역학회지
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• 제13권3호
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• pp.293-309
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• 2003

The purpose of this study was to analyze the kinematic variables of the right-straight punch(RSP) in boxing with three-dimensional analysis technical methods. The subjects are boxers who have been playing in national boxing representative team and the RSP is their special favorite technique, The right-straight punches were filmed on 16mm video cameras(30frames/sec.) The kinematic variables were temporal, postural and center of gravity(COG). The mean and the standard deviation of variables have been obtained and used as basic factors for examining characteristics of the RSP by out-boxers. From the data analysis and discussion, the following conclusions have been drawn. 1) Temporal variables It is a significant characteristic that LDJ and KDM s' the amount of elapsed time(EF) needed for both an attack and a defense were similar : ET for stretch-out of attack-arm was $0.52{\pm}0.04\;sec$. and return was $0.54{\pm}0.01\;sec$. Therefore, a defense motion is as important as an attack motion. 2) Posture variables When the subjects performed a RSP, the significant characteristic of the ankle angle was that it wasn't completely returned to the original position after stretching-out. Therefore it is necessary to do supplementary exercises, such as side steps, to move the center of gravity more effectively. The hee angle was not fully stretched either. In regard to the hip angle, it should be rotated with all strength to harmonize with the direction of movement. 3) Center of Gravity(COG) variables When both LDJ and KDM performed a RSP, a significant characteristic was the transformation of sagittal view rather than transverse or frontal views.

• 대한토목학회논문집
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• 제26권6D호
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• pp.1025-1032
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• 2006

고해상도 위성의 센서모형화는 도면화와 지형공간정보(Geo-spatial Information System)의 응용을 위해서는 필수적인 단계이다. 영상과 대상물과의 기하학적인 관계를 규정하는 센서모형은 크게 엄밀(rigorous)센서모형화와 간략(approximate)센서모형화의 두 가지로 나눌 수 있다. 엄밀센서모형화는 위성의 실제적인 촬영기하를 고려한 것으로 센서의 내외부적인 특성을 알고 있어야 하는 반면에 간략센서모형화 방법은 영상취득기하의 종합적인 이해나 센서의 내외부적인 특성정보를 필요로 하지 않기 때문에 사진측량 커뮤니티에서 많은 관심이 증대되고 있다. 본 연구에서는 고해상도 위성영상의 3차원 위치결정에 이용되고 있는 엄밀센서모형과 다양한 간략센서모형에 대해 비교연구를 수행하였으며 위성영상의 이용목적에 따른 적합한 모형화 방법을 제안하였다. IKONOS 위성영상을 이용한 사례연구를 통하여 엄밀센서모형과 간략센서모형에 대한 비교연구를 수행하였으며, 수집 가능한 지상기준점에 따른 위치정확도를 평가하였다. 간략센서모형화 방법 중에서 편의보정된 다항식비례모형(bias compensated RFM)이 가장 우수하였으며 개량평행투영모형(modified parallel projection)과 평행-중심투영모형(parallel-perspective model)은 적은 수의 기준점을 이용하여 센서모형화가 가능하였다. 또한 간략센서모형화 방법 중 부등각사상변환(affine transformation)은 고해상도 위성의 수평위치결정과 영상간의 등록에 활용가능하다.

• 대한토목학회논문집
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• 제11권1호
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• pp.177-188
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• 1991

해빈변형(海濱變形)은 주로 파랑(波浪)과 흐름의 작용을 받아 표사이동(漂砂移動)에 의하여 생긴다. 본 연구(硏究)는 표사이동이 주로 발생되는 천수역(淺水域)에서 해빈변형을 예측(豫測)할 수 있는 3차원(次元) 해빈변형(海濱變形) 수식모형(數式模型)을 개발(開發)하였다. 파랑변형(波浪變形)은 흐름과 파랑이 공존(共存)하는 경우의 모형을 개발하였고 흐름조건은 이안류(離岸流)가 존재하는 경우를 상정(想定)하였으며, 표사량(漂砂量) 산정식(算定式)은 Flux모형(模型)을 사용하였다. 본(本) 연구(硏究)의 모형을 일정(一定) 구배를 가진 해빈(海濱)에 적용해 본 바, Watanabe의 수치해석 결과와 정성적(定性的)으로 유사한 결과를 얻었으며, 해안구조물(海岸構造物)이 있는 경우에 해빈류(海濱流)의 계산이 가능한 해역(海域)에서는 본(本) 모형(模型)의 적용이 가능할 것으로 판단된다. 매개변수(媒介變數)들이 해빈변형에 미치는 영향은 입사파고(入射波高)가 클 때, 흐름이 강할 때, 저질입경(低質粒徑)이 작을 때, 해저(海低) 구배가 클 때 큰 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.746-751
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• 2003

A method of measuring the length of defects on the wall of the spent nuclear fuel pool using the image processing and a laser slit beam is proposed. Since the defect monitoring camera is suspended by a crane and hinged to the crane hook, the camera viewing direction can not be adjusted to the orientation that is exactly perpendicular to the wall. Thus, the image taken by the camera, which is horizontally rotated along the axis of the camera supporting beam, is distorted and thus, the precise length can not be measured. In this paper, by using the LASER slit beam generator, the horizontally rotated angle of the camera is estimated. Once the angle is obtained, the distorted image can be easily reconstructed to the image normal to the wall. The estimation algorithm adopts a 3-dimensional coordinate transformation of the image plane where both the laser slit 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 taken at arbitrary rotated angle can be reconstructed to an image normal to the wall. From the result of a series of experiments, the accuracy of the defect is measured within 0.6 and 1.3 % error bound of real defect size in the air and underwater, respectively under 30 degree of the inclined angle of the laser slit beam generator. Also, the error increases as the inclined angle increases upto 60 degree. Over this angle, the defect length can not be measured since the defect image disappears. The proposed algorithm enables the accurate measurement of the defect length only by using a single camera and a laser slit beam.

• 한국운동역학회지
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• 제15권2호
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• pp.129-138
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• 2005

The purpose of this study was to investigate the techniques used by long jumpers who recorded over 8meters in 2002 Busan Asian Game and 2003 Daegu Universiade. The kinematic characteristics from the last three stride to takeoff at the takeoff board were analyzed such as velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation procedure. The conclusion were as follows; 1. The height variation who recorded over 8 meters of center of gravity of the jumpers at the last stride was under 8cm. In order to record over 8meters the national long jumpers should have under 10cm height variation. 2. In the approach phase the horizontal velocity of the jumpers should reach to 10.5m/s in last three strides and 9.79m/s in touch down at take off board. 3. The horizontal velocity at take off board must have over 8.51m/s and the vertical velocity must have 3.75m/s simultaneously in order to record 8meters. 4. The forward body lean angle should have over 20degrees with pushing the take off board in forwarding movement. The appropriate body variation range ratio between take off and touch down should be 1.2 vs 1 and the trunk angle at touch down on the board should be close to the erect posture for higher body flight.

• 복식문화연구
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• 제23권5호
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• pp.737-754
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• 2015

The structural aesthetics of architecture are becoming an inspirational source for many fashion designers and have been reborn in structural fashion. This study planned to analyze the method of expression of structural aesthetics expressed in modern structural fashion design and the construction method to maximize such an effect on the basis of the construction characteristic of Santiago Calatrava as the representative architect of the structural aesthetic. According to the study, the structural aesthetics expressed in modern structural fashion design are as follows: 1) The symbolical formative aesthetic expressed by symbolical inference and analyzation; 2) the dynamic beauty of physic expressed by visual emphasis and dynamics; and 3) the asymmetric beauty of symmetry expressed by metastasis toward the boundary between balance and imbalance. In addition, to maximize structural aesthetics, we used repetition and a progressive technique based on rhythm, asymmetry, and incision-based variances, such as balance, polygon flux, and inference, and analyzation-based distortion as the structuring principle. The following expression methods for maximizing structural aesthetics were found: 1) symbolical and structural exaggeration of appearance; 2) detail technique expansion and material property diversification; and 3) the three-dimensional transformation of structure and shell expression. Structural fashion design was found to have maximized structural aesthetics by using such expression methods to secure artistic esthetics, destroy existing shapes and patterns, and create unique shapes.