• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.326-326
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• 2010

우주환경에서 임무를 수행하는 인공위성의 경우, 조립, 시험, 운용시점까지 위성 표면에 흡착되는 오염물질을 최소화하기 위하여 전 기간 동안 세심한 주의를 기울여야 한다. 위성표면에 흡착된 미세한 오염물질은, 고진공 및 고온, 극저온이 반복되는 가혹한 우주환경 속에서 위성의 성능저하 및 효율의 손실을 가져올 수 있다. 예를 들어 위성 표면에 떨어진 입자오염은 별 추적 장치의 오류를 발생시킴에 따른 위성 자세제어의 실패를 가져올 수도 있고, 표면에 흡착된 분자 오염은 렌즈, 미러, 윈도우 등의 광학기기 및 주요 민감 표면에 작용하여 광학적 특성과 열제어 성능의 저하를 가져올 수 있다. 위성의 조립 및 시험을 관장하는 한국항공우주연구원에서는 위성의 오염물질에 대한 노출을 최소화하기 위해, 오염측정이 이루어지는 청정실을 운용하고 있는데, 본 논문에서는 청정실 및 진공챔버 내의 부유입자측정, 표면입자오염측정, 표면분자오염측정법을 소개하고 오염측정 결과에 대한 분석을 수행하였다.

• Proceedings of the KSLP Conference
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• 1998.11a
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• pp.187-187
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• 1998

위식도 역류 질환의 전형적인 증상에 반하여 인후두에서 나타나는 애성, 만성 기침, 헛기침, 인후두 이물감등의 비전형적인 증상에 대해 최근 관심이 높아지고 있다. 특히 애성이 주된 증상으로 나타나는 경우 일부에서 후두 후방에 점막의 비후 소견이나 육아종을 보이기도 하지만 많은 경우 후두내 기질적 병변을 찾기 어려울 때가 많으므로 의식도 역류 질환과 연관된 애성으로 진단하기 위해서는 자세한 병력 파악 및 이학적 검진, 그리고 위식도 역류 진단을 위한 검사 둥이 요구된다. 저자들은 인후두 이물감을 주소로 내원하여 위식도 역류 검사상 위식도 역류 질환으로 판명되었던 환자 중 애성이 동반된 환자 20례에 대하여 치료전 음성 검사를 시행하였으며 일반적인 치료 후 8주째 추적 검사를 시행하여 그 결과를 문헌 고찰과 함께 보고하고자 한다. (중략)

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.335-337
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• 2012

전투공간 시뮬레이션 결과를 가시화할 뿐 아니라 시나리오 가시화 중에 사용자가 선택한 엔티티의 상세한 관찰을 제공하기 위해 스테레오 3D 모델 뷰어를 개발하여 가시화 시스템의 프로토타입을 구성하였다. 전투공간 가시화를 위해서는 가시화 스프트웨어인 SIMDIS를 사용하였다. 사용자는 시뮬레이션 가시화 스크린 상에서 엔티티를 선택할 수 있으며, 이 엔티티의 자세한 관찰은 스테레오 3D 모델 뷰어에 가시화 된다. 모델 뷰어는 사용자에게 엔티티 관찰 시 몰입감과 인지도를 향상시키기 위하여 헤드 트래킹 기술을 적용하였다. 사용자의 위치를 추적하기 위해서는 깊이 카메라를 이용하였으며, 획득한 깊이 영상을 통해 실시간 사용자 헤드 트래킹을 적용하였다. 구현된 시스템은 SIMDIS를 이용한 전투공간 시뮬레이션 가시화와 스테레오 3D 뷰어를 각각 가시화하기 위하여 2D 디스플레이와 3D TV를 사용하였다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.374-377
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• 2004

동영상 강의는 시간이나 장소 등에 크게 구애받지 않고 인터넷을 통하여 쉽게 이용할 수 있는 간편한 학습방법중의 하나이다. 그러나 학습자의 학습자세와 태도에 따라 학습효과는 매우 다를 수 있는 문제점을 가지고 있다. 본 논문에서는 입력영상으로부터 학습자의 얼굴정보를 입력받아 주기적으로 탐색하여 학습자의 강의에 대한 집중도와 충실도를 평가하는 시스템을 제안하고자 하였다. 먼저 입력영상의 분할된 중심영역으로부터 학습자의 얼굴을 포함하는 신체정보를 입력받아 사용하였으며, 빠르고 효율적인 얼굴영역의 추출을 위하여 피부색상(skin-color)정보와 얼굴의 지역적 특성을 이용하는 방법을 사용하였다. 또한 주기적으로 입력되는 영상의 빠른 얼굴추적을 위하여 설정된 영역들로부터 구성되는 블록들의 위치와 구성정보를 이용한 블록탐색 기법을 사용하였다.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.313-318
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• 1986

Primary aldosteronism is a disease that the stimulus for the excessive aldosterone production resides within the adrenal gland. It was first described by conn in 1955. And many cases were reported by physicians at present in the world. But it is relatively rare in Korea, probably due to lack of attension and medical facilities. Only about 13 cases have been reported at present. The clinical, biochemical features in 1 case of primary aldosteranism caused by adrenal hyperplasia that was diagnosed at Yeungnam University Hospital was observed and the following result were obtained. 1. Clinical feature: The present case was 27-year-old woman who was admitted due to general weakness and easy fatigability. The above mensioned chief complaints occurred 8 months prior to admission when she delivered of second baby by cesarian section. Symptoms such as above chief complaints, intermittent muscle paralysis and cramping were noticed. Trousseau's sign was also present. The average blood pressure ranged from 170/90 to 200/120. 2. Biochemical abnormalities: Severe hypokalemia lower than 2.5 mEq/L was presented and 24 hours urine potassium showed markedly increased urinary loss.(228 mEq/day). Plasma renin activity was decreased under normal range with furosemide administration.(Basal renin; 0.01ng/ml/hr, stimulated renin 0.12ng/ml/hr). Saline suppression test revealed markedly elevated levels of aldosterone higher than normal range. (Basal aldosterone; 320.68pg/ml stimulated aldosterone; 451.86pg/ml). And posture test showed decreased plasma renin activity and increased plasma aldosterone level. - PRA(ng/ml/hr)=Bsal: 0.05(0.15~2.33), Stimulated: 0.22(1.31~3.95) - Aldosterone(pg/ml)=Bsal: 242.77(10~160), Stimulated: 432.09(40~310) 3. Adrenal CT scan revealed no abnormal findings. 4. Treatment and course: Spironolactone was given at OPD with regular follow-up. Her blood pressure ranged from 150/90 to 160/100 and symptoms were improved. The effect of treatment was satisfactory and further follow up would be performed.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.5
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• pp.444-450
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• 2015

The accuracy of small and low cost CCD camera is insufficient to provide data for precisely tracking unmanned aerial vehicles(UAVs). This study shows how UAV can hover on a human targeted tracking object by using CCD camera rather than imprecise GPS data. To realize this, UAVs need to recognize their attitude and position in known environment as well as unknown environment. Moreover, it is necessary for their localization to occur naturally. It is desirable for an UAV to estimate of his attitude by environment recognition for UAV hovering, as one of the best important problems. In this paper, we describe a method for the attitude of an UAV using image information of a maker on the floor. This method combines the observed position from GPS sensors and the estimated attitude from the images captured by a fixed camera to estimate an UAV. Using the a priori known path of an UAV in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a marker on the floor and the estimated UAV's attitude. Since the equations are based on the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the UAV. The Kalman filter scheme is applied for this method. its performance is verified by the image processing results and the experiment.

• Journal of the Korea Computer Graphics Society
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• v.21 no.2
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• pp.11-20
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• 2015

We present a new interactive technique for directing the motion sequences of an animated character by dragging its specific body part to a desired location in the three-dimensional virtual environment via a hand motion tracking device. The motion sequences of our character is synthesized by reordering subsequences of captured motion data based on a well-known graph representation. For each new input location, our system samples the space of possible future states by unrolling the graph into a spatial search tree, and retrieves one of the states at which the dragged body part of the character gets closer to the input location. We minimize the difference between each pair of successively retrieved states, so that the user is able to anticipate which states will be found by varying the input location, and resultantly, to quickly reach the desired states. The usefulness of our method is demonstrated through experiments with breakdance, boxing, and basketball motion data.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.76-82
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• 2006

The Mission Control System for KOMPSAT-2 was developed by ETRI and is being operated at Satellite Control Center at KARI to monitor and control KOMPSAT-2 (KOrea Multi-Purpose Satellite) which was launched in July 28th, 2006. MCE provides the functions such as telemetry reception and processing, telecommand generation and transmission, satellite tracking and ranging, orbit prediction and determination, attitude maneuver planning, satellite simulation, etc. KOMPSAT-2 is the successor of KOMPSAT-1 which is an earth-observation satellite. KOMPSAT-2 has higher resolution image taking ability due to MSC (Multi Spectral Camera) payload in the satellite and precise orbit and attitude determination by Mission Control System. It can produce one meter resolution image compared to six meter resolution image by KOMPSAT-1.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1575-1591
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• 2008

In this paper, we propose a new method detecting foot motion capture in order to overlap in realtime foot's 3D virtual model from stereo cameras. In order to overlap foot's virtual model at the same position of the foot, a process of the foot's joint detection to regularly track the foot's joint motion is necessary, and accurate register both foot's virtual model and user's foot in complicated motion is most important problem in this technology. In this paper, we propose a dynamic registration using two types of marker groups. A plane information of the ground handles the relationship between foot's virtual model and user's foot and obtains foot's pose and location. Foot's rotation is predicted by two attached marker groups according to instep of center framework. Consequently, we had implemented our proposed system and estimated the accuracy of the proposed method using various experiments.

• Journal of Advanced Navigation Technology
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• v.23 no.4
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• pp.289-295
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• 2019

Maritime back-up navigation system in port approach requires a horizontal accuracy of 10 meters in IALA (International Association of Lighthouse Authorities) recommendations. eLoran which is a best back-up navigation system that satisfies accuracy requirement has poor navigation performance depending signal environments. Especially, noise caused by multipath and electronic devices around eLoran antenna affects navigation performance. In this paper, Ship based Navigation Back-up system using UAV on Interference is designed to satisfy horizontal accuracy requirement. To improve the eLoran signal environment, UAVs are equipped with camera, IMU sensor and eLoran antenna and receivers. This proposed system is designed to receive eLoran signal through UAV-based receiver and control UAV's position and attitude within Landmark around area. The ship-based positioning using eLoran signal, vision and attitude information received from UAV satisfy resilient and robust navigation requirements.