• Annual Conference of KIPS
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• 2017.04a
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• pp.573-576
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• 2017

본 연구는 홍삼 등급판정 과정에서 내부 조직 치밀도 분석을 위해 의료 영상 분석 방법을 이용하여 적외선 영상 측정기기를 개발하였다. 기존 홍삼 내부분석방법은 수동으로 암실환경에서 강한 조명을 홍삼에 투과하여 사람 눈으로 직접 판별하는 과정을 거친다. 이러한 기존 검사 과정은 작업 비효율성과 불균일한 검사기준으로 제품 품질 신뢰도 저하의 단점을 가져온다. 이러한 문제점을 해결하기 위해 본 연구는 적외선 조명환경에서 자동 측정이 가능한 홍삼 내부 측정기기를 개발하였다. 개발된 장치는 홍삼의 빛 투과 특성을 응용한 920nm 파장대역의 적외선 조명기구, 조명 제어회로, 적외선 대역 촬영이 가능한 영상 측정 카메라 장치, $0.9^{\circ}$의 간격으로 $360^{\circ}$ 홍삼 영상취득이 가능한 회전 엑츄에이터로 구성이 된다. 본 연구에서 제안 하는 홍삼 단층 영상분석 방법은, 홍삼을 $0.9^{\circ}$ 간격으로 회전시키어 $360^{\circ}$ 홍삼 내부영상을 취득하여 라돈 변환(Radon transform)을 통해 사이노그램(Sinogram)으로 재구성 하였으며, 역 라돈 변환(Inverse Radon transform)을 통해 단층 영상복원(Back-projection)알고리즘을 구현하였다. 이 결과 홍삼을 절단하지 않고 홍삼 내부 단면영상 획득이 가능하였으며 내공(內空), 내백(內白)의 유무를 판단하고 직경을 파악할 수 있었다. 이를 토대로 등급 판별 공식을 산출하면 신뢰성 있는 홍삼 등급 자동화 측정기기를 개발할 수 있을 것으로 기대된다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.243-250
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• 2014

Fiber-optic cables towed by underwater vehicles have an important role in enhancing the mission capability of a mother ship. In general, fiber optic cables are unwound in water for securing unwinding stability and preventing unwinding-related problems. Therefore, in this study, the numerically simulated result is verified against the experimental result in water, and the cable-unwinding motion is predicted based on the increase in unwinding velocity. The experimental apparatus is composed of a water tank and a winder, and a high-speed camera is used for photographing the cable-unwinding motion. The numerical result defined in the Cartesian coordinate system is solved using a transient-state unwinding equation of motion. The numerical result agrees well with the experimental result, and it can predict cable-unwinding behaviors in according to an increase in the unwinding velocity.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.4
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• pp.313-318
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• 2014

In this paper, we propose a method for correcting the measurement axis twist that occurs in the process of wearing and each estimation method of joint in which the inertial measurement unit based in health arm by the method of operation upper limb rehabilitation equipment of hemiplegic patients. In order to verify the proposed method, it is fitted with a inertial measurement unit of the upper arm and forearm of the experimenter left arm, verified by comparing actual joint angle is detected by photographing the arbitrary posture, the angle that the estimated joint. Then, it was verified by comparing the applied front / rear techniques for correcting the measurement axis twist. A result of the experiment, before applying the measurement axis twist correction, joint, after but each match rate showed a weak concordance rate in 89.16% and were corrected, measurement axis twist, each concordance rate of joint agreement of 93.28% I understand that it has been 4.12% improvement in the rate.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.9-14
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• 1999

The effect of operating condition was studied experimently on the characteristics of twin sprays ejected from two airblast atomizers, within the range of the mass air-fuel ratio 1.36∼3.54. Water and nitrogen gas were used as test fluids for the experiments. Spray characteristics of liquid spray were measured with measurement of mass distribution and instantaneous image of the spray cone. Experimental results show that the maximum specify of the distribution were lowered but distributed over the larger area when the ROA ratio increased, Center of mass position did not change with increasing water mass flow, Increase of the nozzle distance has an small effect on mass distribution of interaction area but distributed over the larger area. It was also conformed that the effect of interaction near central point of collision decreased with the increase of the ROA ratio on interaction area from comparison using superposition method

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.33-38
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• 2012

A LEO Satellite performs automatic initial operations by FSW after separation from a launch vehicle. After initial operation by FSW is finished, preparation for normal operation is performed by ground during bus initial activation and checkout phase. First of all, we check state of health of the satellite including solar array deployment status. After then, each unit of spacecraft bus is activated and checked. After activation and checkout of every units used for normal operation, we check maneuver performance for imaging mission and orbit maintenance performance. Because the Bus IAC is performed during limited ground contact time, every detailed procedure must be designed considering ground contact. Therefore, the Bus IAC procedure is separated into several parts based on ground contact duration. In addition, the procedures for every possible operation including expected situation as results of IAC procedures and unexpected contingency situation must be prepared. The contingency operation is also designed based on ground contact duration. The LEO satellite was successfully launched and the Bus IAC was successfully performed. In this paper, we explain design concepts and execution results of Bus IAC.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.99-107
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• 1991

The purpose of this study was to decide the proper projection angle that could avoid the superimposition of the petrous portion of temporal bone and posterior clinoid process in cephalometric lateral and basal view of the 10 dry skulls and to analyze the reproducibility of a modified Accurad-100 head holder device from Denar Co. and a cephalostat head holder in 30 transcranial radiographs of the dry skull. The results were obtained as follows: The vertical angle was 24.5±4.1° and the horizontal angle was 3.0 ±5.7°. The distances between arbitrary 3 points which were on the TMJ area were as follows: AB 16.76±0.27㎜, BC 8.79±0.18㎜ in the transcranial radiographs using modified Accurad-100 head holder, AB 29.03±0.14㎜, AC 19.95±0.24㎜, BC 10.08±0.07㎜ in the transcranial radiographs using cephalostat.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.65-70
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• 2018

Computed tomography system is widely used on various fields because section image of an object can be acquired. During several step to obtain section image, artifacts by many error factors can be added on the image. Ring artifact induced by the CT system is examined in this study. A test phantom of $512{\times}512$ size was constructed numerically, and the ring artifact was investigated by the algebraic reconstruction technique. The computer program was realized using Visual C++ under the fan beam geometry with projections of 720 and detector pixel of 1,280. The generation of ring artifact was verified by applying different detection efficiency on detector pixels. The ring intensity became large as increasing the ring value, and the ring artifacts were strongly emphasized near the center of the reconstructed image. The ring artifact may be eliminated by tracking the position of ring artifact on the reconstructed image and by calibrating the detector pixel.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.275-282
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• 2006

This study was conducted laboratory flume tests to identify landslide features and flow characteristics of debris using a flume test equipment. Under the several test conditions dependent on rainfall intensity and slope angle, the authors measured pore water pressure, slope failure and displacement, spreading area of debris on a regular time interval. The test processes were also recorded by video cameras and digital still cameras. According to the test results, pore water pressures have trends of direct proportion to the rainfall intensity and the slope angle, resulting in high potential of landslide triggering. The spreading area of debris is also increased with the slope angle and the rainfall intensity as well as the rainfall duration.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.293-300
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• 2009

The rotorcraft-based unmanned aerial vehicle(UAV) capable of performing close-range surveillance and reconnaissance has been developed. Trade studies on mission feasibility led to the adoption of a coaxial rotorcraft with twin rotors counter-rotating in one axis and driven by electric motors. A commercial off-the-shelf flight control computer(FCC) and a radio frequency modem were adopted for autonomous navigation. In order to achieve an aerial view, commercial charge-coupled device camera was also integrated into the vehicle. The performance of the completed vehicle was proved with manual flight test, and mission capability was verified through waypoint navigation flight after being equipped with FCC. This paper treats the whole process of design and system integration for development of the coaxial rotorcraft UAV.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1239-1244
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• 2013

In the field of clinical medicine and research, the analysis of such as protein and DNA at the molecular level and even at the cell level are necessary for disease diagnosis and treatment. In many cases, a real time image of samples is needed for the accurate analysis and manipulation of samples since experimental samples are degenerated with time. In this research, a three-dimensional fluorescence microscope device was developed for taking images of protein and DNA inside a single cell and the server-client based image analysis system was made for an integrated management of the real-time images taken from the microscope device. The system consists of a fluorescent measurement device, the associated software and a client program on smartphone. The developed system allows doctors or experimental managers to receive and look at the real-time experimental images taken from the samples of patients anywhere in the emergency, to analyze results and to instantly diagnose the disease and to transfer the results to the patients. As a result, the system is able to be utilized in the implementation of ubiquitous health as well.