• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (B)
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• pp.814-816
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• 2004

본 논문에서는 웨이블릿을 이용한 알고리즘으로 얼굴을 검출하고 검출된 얼굴을 움직이는 Pan-Tilt 카메라상에서 추적하는 방법을 제안하고자 한다. 우리는 얼굴 검출을 위해 다섯 종류의 간단한 웨이블릿을 사용하여 특징을 추출하였고 AdaBoost(Adaptive Boosting) 알고리즘을 이용한 계층적 분류기를 통하여 추출된 특징들 중에서 얼굴을 검출하는데 강인한 특징들만을 모았다. 이렇게 만들어진 특징집합들을 이용하여 입력받은 영상에서 초당 20프레임의 실시간으로 얼굴을 검출하였고 영상에서 얼굴 위치와 Pan-Tilt 카메라 위치를 계산하여 실시간으로 움직임을 추적하는데 성공하였다.

• 항공우주시스템공학회지
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• 제1권2호
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• pp.27-36
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• 2007

The Damage Tolerant Design is developed to help alleviate structural failure and cracking problems in aerospace structures. Recently, the Damage Tolerant Design is required and recommended for most of aircraft design. In this paper, the damage tolerant design is applied to tilt rotor UAV. First of all, the fatigue load spectrum for the tilt rotor UAV is developed and fatigue analysis is performed for the flaperon joint which has FCL (fatigue critical location). Tilt rotor UAV has two modes: helicopter mode when UAV is taking off and landing; fixed wing mode when the tilt rotor UAV is cruising. To make fatigue load spectrum, FELIX is used for helicopter mode. TWIST is used for fixed wing mode. Fatigue analysis of flaperon joint is performed using fatigue load spectrum. E-N curve approach is used for picking crack initiation point. The LEFM(Linear Elastic Fracture Method) is considered for analyzing crack growth or propagation. Finally, including the crack initiation and propagation, the fatigue life is evaluated. Therefore the Damage Tolerant Design can be done.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.821-825
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• 2005

Tilt rotor aircraft was developed for satisfying VSTOL (vertical short take off and landing) capability and cruise performance. However the noise generated by tilt rotor system causes one of the most serious problems. In this paper, noise characteristics of tilt rotor system in hovering flight are predicted by using free wake method and Lowson's formula. The flow field of the tilt rotor is simulated by using time marching free wake method, and the free field acoustic pressure is calculated through Lowson's formula. The predicted results are compared with experimental data at various observing positions. In the near field, they show good agreement with experimental data regardless of rotating speed and collective pitch angles of 6, 8 and 10 degree, although there are some discrepancies between prediction and experiment in the far field and at the rotating axis in the near field. It seems that the reason of these discrepancies is difference of unsteady force fluctuation between experiment and calculation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.979-984
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• 2005

In this study, we suggest a tilt rotor aircraft and attempt to apply a nonlinear model matching control method for its maneuver. The proposed method is very simple and useful to construct the control law for the complicated nonlinear system such as aircraft motion.

• The Journal of Korean Physical Therapy
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• 제25권2호
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• pp.71-75
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• 2013

Purpose: Although use of a tilt table is recommended in clinical practice, there are no published guidelines regarding pressure and inclination for tilt table use. The aim of the current study was to assess the changes of pressure on sacrum and buttock according to different inclination of the tilt table in healthy subjects. Methods: Thirty two healthy subjects participated in this study. Subjects were positioned supine on the tilt table and safety straps were secured across the chest, pelvic, and knee with sufficient tension to prevent the subjects from falling. Pressure and peak pressure of sacrum and buttock were measured using pressure mapping system with the tilt table standing at $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$, and $85^{\circ}$ inclination. Results: A significant decrease in the pressure of sacrum and buttock was achieved by increasing tilt table inclination (p<0.05): $0^{\circ}{\sim}15^{\circ}$ (8.16%), $15^{\circ}{\sim}30^{\circ}$ (8.02%), $30^{\circ}{\sim}45^{\circ}$ (11.61%), $45^{\circ}{\sim}60^{\circ}$ (16.18%), $60^{\circ}{\sim}75^{\circ}$ (16%), and $75^{\circ}{\sim}85^{\circ}$ (11.48%). A significant decrease in the peak pressure was achieved by increasing tilt table inclination (p<0.05): $30^{\circ}{\sim}45^{\circ}$ (9.91%), $45^{\circ}{\sim}60^{\circ}$ (19.24%), $60^{\circ}{\sim}75^{\circ}$ (19.93%), and $75^{\circ}{\sim}85^{\circ}$ (11.48%). No significant peak pressure change was observed in $0^{\circ}{\sim}15^{\circ}$, $15^{\circ}{\sim}30^{\circ}$ tilt table inclination (p>0.05). Conclusion: The results of this study showed that the pressure of sacrum and buttock were decreased according to increasing tilt table inclination in healthy subjects. Guidelines are needed in order to optimize patient safety and overall outcome for tilt table standing.

• 공학교육연구
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• 제17권5호
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• pp.17-22
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• 2014

Unmanned aerial vehicles (UAVs) that have been recently commercialized can largely be divided into fixed-wing aircraft and rotor aircraft by their styles and flight characteristics. Although the fixed-wing aircraft represents higher power efficiency, higher speed, longer flight distance and larger loading weight than the rotor aircraft, they have a disadvantage of requiring a space for take-off and landing. On the other hand, the rotor aircraft can implement vertical take-off and landing (VTOL) and represents various flight modes (hovering, steep bank turns and low-speed flights). But they require both precision take-off control and attitude control. In this study, we used a quad-tilt rotor UAV to combine advantages in both the fixed-wing aircraft and the rotor aircraft. The quad-tilt rotor (QTR) system was designed and constructed by adding a tilt device with a servo motor to a general quad-rotor vehicle.

• 한국정밀공학회지
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• 제30권3호
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• pp.331-339
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• 2013

The Interest in disease prevention and rehabilitation is increasing depending on increase of patients with spinal. This is being developed using the spine stabilization device is being studied. So far studies have only evaluated the effect on trunk stabilization exercises but analysis of human movement patterns for active movement and passive movement did not. We assessed the muscle activity of trunk and leg muscle during passive and active tilt mode on eight tilt directions at tilt angle of $30^{\circ}$ using 3-D dynamic postural balance training system. We performed experimental study on the muscular activities of trunk muscle about rectus abdominis, external obliques, latissimus dorsi, erector spinae, and leg muscle about rectus femoris, Biceps femoris, Tibialis Anterior, gastrocnemius. As a result, muscle activation was different depending on the direction of movement and pattern. The results indicate that various patterns of spinal stabilization exercise system could be applied to an effective training of chronic low back pain patients.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.764-769
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• 2003

The paper introduces a development result for displacement measurement system of multiple moving objects based on image processing technique. The image processing method adopts inertia moment theory for obtaining the centroid of the targets and basic processing algorithms of gray, binary, closing, labeling and etc. To get precise displacement measurement in spite of multiple moving targets, a CCD camera with zoom is used and the position of camera is changed by a pan/tilt system. The fiducial marks on the fixed positions are used as the sensing points for the image processing to recognize the position errors in directions of X -Y coordinates. The precise alignment device is pan /tilt of X - Y type and the pan/tilt is controlled by DC servomotors which are driven by 80c196kc microprocessor based controller. The centers of the fiducial marks are obtained by a inertia moment method. By applying the developed precise position control system for multiple targets, the displacement of multiple moving targets are detected automatically and are stored in the database system in a real time. By using database system and internet, displacement data can be confirmed at a great distance and analyzed. The developed system shows the effectiveness such that it realizes the precision about 0.12mm in the position control of X -Y coordinates.

• 제어로봇시스템학회논문지
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• 제10권8호
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• pp.673-679
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• 2004

In this paper, we develop the displacement measurement system of multiple moving objects based on image processing techniques. The image processing method adopts inertia moment theory for obtaining the centroid measurement of the targets and basic processing algorithm of gray, binary, closing, labeling and so on. To get precise displacement measurement in spite of multiple moving targets, a CGD camera with zoom is used and the position of camera is changed by a pan/tilt system. The fiducial marks on the fixed positions are used as the sensing points for the image processing to recognize the position errors in direction of XY-coordinates. The precise alignment device is pan/tilt of XY-type and the pan/tilt is controlled by DC servomotors which are driven by a microprocessor. Morover, the centers of fiducial marks are obtainted by an inertia moment method. By applying the developed precise position control system for multiple targets, the displacement of multiple moving targets are detected automatically and are also stored in the database system in a real time. By using database system and internet, the displacement datum can be confirmed at a great distance and analyzed. Finally, the effectiveness of developed system is shown in experimental results and realized the precision about 0.12[mm] in the position control of XY-coordinates.

• 한국컴퓨터정보학회논문지
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• 제19권12호
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• pp.31-37
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• 2014

본 연구논문에서는 고해상도 적외선 센서장비에서 조립오차에 의해 저하된 성능을 보완하기 위해 적외선 센서장비의 구성품인 렌즈조립체, 축거울 및 검출기의 민감도 분석을 통해 성능에 미치는 영향성을 확인하였고, 이를 보정하기 위해 검출기의 틸트 메커니즘 적용 방안에 대한 연구를 하였다. 검출기 틸트 메커니즘에는 장착면에 shim을 적용하여 tilt하는 방식인 Shim plate 방식과 tilt screw를 조정하여 검출면의 tilt를 조정하는 Tilting 나사 방식, 마지막으로 마이크로미터를 장착하여 정량적인 데이터를 획득할 수 있는 마이크로미터 헤드 방식으로 3가지 방식이 검토 되었다. 검토 결과 사용자의 조절이 용이하고 부피가 크지 않으며 실시간으로 영상을 보면서 조절이 가능한 Tilting 나사 방식을 적용하였으며, 실험결과 고해상도 영상을 획득할 수 있었으며 고해상도 영상획득을 구현하기 위한 장비에 적용이 필요한 기술임을 확인하였다.