• 대한전자공학회논문지SP
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• 제42권2호
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• pp.101-112
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• 2005

사람이 두 눈을 통하여 3차원 공간을 지각하는 것과 같이 두 대의 카메라로부터 얻어진 스테레오 영상을 이용하여 3차원 정보를 얻을 수 있다. 스테레오 영상은 많은 데이터량을 가지기 때문에 최근 수년간 디지털 비디오 압축 기술의 발전과 함께 스테레오 영상을 효율적으로 압축하기 위한 기술이 개발되고 있다. 스테레오 영상을 압축하고 3차원 정보를 추출하는데 이용되는 양안차 추정은 일반적으로 두 스테레오 영상의 화소 간의 밝기 차이를 이용한다. 하지만 두 카메라의 초점거리, 방향, 상대적 위치, 조리개에 의해 입사되는 빛의 양 등의 미세한 차이에도 스테레오 영상 간의 밝기차가 발생한다. 밝기차가 있는 스테레오 영상은 부정확한 양안차 벡터와 이에 따른 낮은 압축 효율과 같은 문제점을 발생시킬 수 있다. 따라서 이런 스테레오 영상 간의 밝기차를 사전에 보상한 후 압축함으로써 압축의 효율을 높이고, 또한 재생 시 두 눈을 통하여 들어오는 서로 다른 시각 정보로 인한 눈과 두뇌의 피로를 덜어 줄 수 있다. 본 논문에서는 간단하면서도 효율적인 전처리 방법으로 전역 밝기 보상과 국부지역 밝기 보상 및 계층적 밝기 보상을 제안한다 실험결과는 제안된 보상 방법이 효율적으로 스테레오 영상을 압축하는 것을 보여준다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제10권7호
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• pp.279-286
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• 2021

최근 COVID-19 확산 방지를 위한 공공장소에서는 최소 1m 이상을 유지하는 물리적 거리두기 정책을 실행하고 있다. 본 논문에서는 드론과 CCTV가 취득한 스테레오 영상에서 실시간으로 사람들 간의 거리를 추정하는 방법과 추정된 거리에서 1m 이내의 객체를 인식하는 자동화 시스템을 제안한다. 기존의 CCTV를 이용하여 다중 객체 간의 거리 추정에 사용되었던 방법의 문제점으로는 한 대의 CCTV만을 이용하여 객체의 3차원 정보를 얻지 못한다는 것이다. 선, 후행하거나 겹쳐진 사람 간의 거리를 구하기 위해서는 3차원 정보가 필요하기 때문이다. 또한, 일반적인 Detected Bounding Box를 사용하여 영역 안에서 사람이 존재하는 정확한 좌표를 얻지 못한다. 따라서 사람이 존재하는 정확한 위치 정보를 얻기 위해 스켈레톤 추출하여 관절 키포인트의 2차원 좌표를 획득한 후, Stereo Vision을 이용한 카메라 캘리브레이션을 적용하여 3차원 좌표로 변환한다. 3차원으로 변환된 관절 키포인트의 중심좌표를 계산하고 객체 간 사이의 거리를 추정한다. 3차원 좌표의 정확성과 객체(사람) 간의 거리 추정 실험을 수행한 결과, 1m 이내에 존재하는 다수의 사람 간의 거리 추정에서 0.098m 이내 평균오차를 보였다.

• 천문학논총
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• 제24권1호
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• pp.53-64
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• 2009

MIRIS is the main payload of the STSAT-3 (Science and Technology Satellite 3) and the first infrared space telescope for astronomical observation in Korea. MIRIS space observation camera (SOC) covers the observation wavelength from $0.9{\mu}m$ to $2.0{\mu}m$ with a wide field of view $3.67^{\circ}\times3.67^{\circ}$. The PICNIC HgCdTe detector in a cold box is cooled down below 100K by a micro Stirling cooler of which cooling capacity is 220mW at 77K. MIRIS SOC adopts passive cooling technique to chill the telescope below 200 K by pointing to the deep space (3K). The cooling mechanism employs a radiator, a Winston cone baffle, a thermal shield, MLI (Multi Layer Insulation) of 30 layers, and GFRP (Glass Fiber Reinforced Plastic) pipe support in the system. Optomechanical analysis was made in order to estimate and compensate possible stresses from the thermal contraction of mounting parts at cryogenic temperatures. Finite Element Analysis (FEA) of mechanical structure was also conducted to ensure safety and stability in launching environments and in orbit. MIRIS SOC will mainly perform Galactic plane survey with narrow band filters (Pa $\alpha$ and Pa $\alpha$ continuum) and CIB (Cosmic Infrared Background) observation with wide band filters (I and H) driven by a cryogenic stepping motor.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.727-731
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• 2009

The aim of this study was to understand the effects of skin pigmentation on physiological parameters of thermoregulation and grazing behaviour of dairy goats in a hot and humid climate. The study used 26 crossbred Saanen yearling goats (95% Saanen+5% Local Hair Breed). The animals were raised at semi-intensive private farms in Adana (36 59'N, 35 18'E). Groups were selected 2 d before the start of observations. Goats were categorized as predominantly pigmented (P) skin and unpigmented (UP) skin. All observations and measurements were collected on grassland during the grazing period of June and July 2007 (60 d). Air temperature and relative humidity were recorded at 10 min intervals by a portable data logger. The physiological data (rectal temperature, respiration and pulse rate, and skin temperatures from head and udder) were recorded twice weekly in the morning (07:00-08:00); at midday (13:00-14:00); and in the evening (18:00-19:00). Additionally, the activity of the animals was observed and classified (eating, ruminating, drinking, standing, walking, lying) for 12 h during the day twice weekly, using a portable camera system linked directly to a computer. Panting behaviour was also observed. According to the THI values, the experimental goats were subjected to stressful conditions. The pigmented goats had significantly lower rectal temperatures (39.68 vs. $29.89^{\circ}C$), pulse rate (74.08 vs. 84.10 beat/min) and respiration rate (65.65 vs. 88.23 breath/min.) compared with unpigmented goats at midday when the THI exceeded 92. The rectal, head and udder temperatures, pulse and respiration rates of the non-pigmented group exceeded $40^{\circ}C$, $37^{\circ}C$, $37.5^{\circ}C$, 84 beats/min and 78 breaths/min, respectively. Higher activity was observed among pigmented compared with unpigmented goats. Unpigmented goats grazed (4.3 vs. 5.6 h), ruminated (2.0 vs. 2.4 h), and stood (0.8 vs. 1.2 h) less, but lay down (2.2 vs. 1.8 h) more than pigmented goats. The data obtained in this experiment support the hypothesis that unpigmented goats are more adversely affected by climatic stress, likely due to their decreased activity and increased water consumption, as demonstrated by previous studies.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2430-2434
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• 2005

Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

• 한국응급구조학회지
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• 제13권2호
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• pp.87-98
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• 2009

Purpose : This study set out to compare the educational effects of a video self-instruction program for child CPR education on childcare teachers by applying the 2006 KACPR Guideline. By adopting the nonequivalent control group posttest quasi-experimental design, the study examined the educational effects on a group that did not receive instructions from the instructor, another group that received his instructions, and the other group that received an extra three-minute practice training session in addition to instructions. Methods : Data were gathered from August 6 to 18, 2008. As for research tools, the Knowledge Instrument of CPR by Connolly (2006) was used along with the National Practice Test Protocol for C1ass 1 Emergency Medical Technicians (2007) and Common Protocol for CPR (2006) to examine the performance of child CPR. By shooting the guide screen of $Resusci^{(R)}$ Junior CPR Manikin of Leardal with a video camera and using the Skill Guide Checklist of the Common Protocol for CPR (2006), the subjects' technical accuracy of chi1d CPR was evaluated. There were three subject groups: 29 childcare teachers randomly assigned to received the video self-instruction program training for chi1d CPR and no instructions from the instructor made up the control group; 22 childcare teachers randomly assigned to received the program training and instructions from the instructor made up experiment group I; 23 childcare teachers randomly assigned to received an extra three-minute practice training session in addition to the program training and the instructions made up experiment group II. The gathered data were analyzed with SPSS/PC+ (Version 14.0) in frequency, percentage, $X^2$-test, ANOVA, Scheffe test. Results : 1) There were no statistically significant differences (F=1.030, p=.362) among the groups in terms of knowledge scores after the child CPR education. 2) There were statistically significant differences (F=13.625, p=.000) among the groups in terms of performance abilities after the child CPR education. 3) There were no statistically significant differences (F=1.610, p=.207) among the groups in terms of technical accuracy of mouth-to-mouth resuscitation after the child CPR education 4) There were no statistically significant differences (F=1.484, p=.234) among the groups in terms of technical accuracy of chest compression after the child CPR education. Conclusion : The results indicate that childcare teachers can improve their performance abilities in child CPR when the instructors are active with their instructions and extra practice hours are secured through a VSI program. It's also needed to provide education with increasing concentration ratio about the items of lower knowledge points in order to help the teachers learn the accurate theory of child CPR. And there should be VSI programs of diverse conditions to increase the effects of child CPR training among childcare teachers.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2003년도 제27회 추계학술대회
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• pp.67-67
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• 2003

It is crucial to minimize setup errors of a cancer treatment machine using a high energy and to perform precise radiation therapy. Usually, port film has been used for verifying errors. The Korea Cancer Center Hospital (KCCH) has manufactured digital electronic portal imaging device (EPID) system to verify treatment machine errors as a Quality Assurance (Q.A) tool. This EPID was consisted of a metal/fluorescent screen, 45$^{\circ}$ mirror, a camera and an image grabber and could display the portal image with near real time KIRAMS has also made the acrylic phantom that has lead line of 1mm width for ligh/radiation field congruence verification and reference points phantom for using as an isocenter on portal image. We acquired portal images of 10$\times$10cm field size with this phantom by EPID and portal film rotating treatment head by 0.3$^{\circ}$, 0.6$^{\circ}$ and 0.9$^{\circ}$. To check field size, we acquired portal images with 18$\times$18cm, 19$\times$19cm and 20$\times$20cm field size with collimator angle 0$^{\circ}$ and 0.5$^{\circ}$ individually. We have performed Flatness comparison by displaying the line intensity from EPID and film images. The 0.6$^{\circ}$ shift of collimator angle was easily observed by edge detection of irradiated field size on EPID image. To the extent of one pixel (0.76mm) difference could be detected. We also have measured field size by finding optimal threshold value, finding isocenter, finding field edge and gauging distance between isocenter and edge. This EPID system could be used as a Q.A tool for checking field size, light/radiation congruence and flatness with a developed video based EPID.

• 천문학논총
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• 제32권1호
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• pp.225-230
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• 2017

The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z~1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field ($5.4deg^2$), using ~10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ~25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute significantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1< z <2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP field in 5 broad bands (g, r, i, z, and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate midIR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

• 한국정보통신학회논문지
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• 제7권3호
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• pp.568-576
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• 2003

본 논문에서는 계층적 탐색기법을 이용한 동적 배경에서의 이동물체 추적 알고리즘을 제안하였다. 제안한 알고리즘은 초기모델 생성단계와 이동물체 추적 단계로 구성되었으며, 이전프레임에 비해 이동 거리가 큰 경우에도 안정적으로 추적할 수 있었다. 그리고, 카메라의 흔들림과 추적물체의 3차원 운동으로 인한 형태 변화에도 전체 프레임에서 효과적으로 추적을 할 수 있었고, 이동물체의 정확한 위치를 검출하여 추적시간을 단축할 수 있었다. 정합모델과 윤곽선 영상에 사이에 이동물체의 유사도 판정은 Partial Hausdorff 거리를 이용하여 평가하였다. 제안한 알고리즘의 타당성 검토를 위해 도로에서 주행하는 차량을 대상으로 이동물체 검출 및 추적 실험을 한 결과 정합횟수는 평균 28.21회이고, 프레임 당 정합시간은 평균 53.21 ms로 제안한 알고리즘의 우수성을 입증하였다. 추적위치와 실체위치를 비교하여 그 평균 자승오차를 계산한 결과 E=1.148임을 알 수 있었다. 차량의 크기, 색상 및 형태가 다른 경우 도로의 색과 차이가 있는 차량들은 98.66%의 추적 성능을 나타냈으며, 검정색 또는 적색 등과 같은 차량은 흑백 영상에서 도로의 색과 유사하여 배경의 영향을 많이 받으므로 95.33%이었고, 전체 평균은 97%로 우수한 추적 성능을 나타내었다.

• 핵의학기술
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• 제15권2호
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• pp.60-64
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• 2011

Brain의 질병을 평가하는 유용한 검사방법 중의 하나인 brain perfusion SPECT는 환자의 움직임으로 인한 검사의 실패확률이 높아 one day method를 사용하지 못하고 two days method를 사용해야 하는 경우가 많다. 본 연구에서는 image registration을 사용하여 검사의 실패확률을 줄이고 one day method로 검사를 시행할 수 있는지 image registration을 적용할 경우 검사의 신뢰성을 알아보고자 하였다. Jaszczak phantom에 준비된 방사성동위원소 $^{99m}Tc$을 insert에 111 MBq/mL가 되도록 분배하여 넣고 나머지 background에 3,145 MBq/mL가 되도록 넣어 1:8의 비율로 phantom을 제작하고 Hoffman 2-D brain phantom과 cylindrical uniform phantom에는 111 MBq/mL가 되도록 만든다. 완성된 phantom은 기본 위치에서 frame 당 5 sec씩 총 120 frame을 획득하여 영상을 얻었다. 또 Phantom과 환자의 데이터를 가지고 original 영상과 registration 영상, registration 시행한 후에 original 영상을 subtraction한 영상과 registration하지 않은 영상에서 subtraction한 영상 간의 임의의 같은 위치에 ROI를 설정하고 영상에서 counts 차이를 알아보았다. 실험 결과 약간의 counts 차이를 보였으나 이것은 실험시간이 경과함에 따른 RI의 decay와 phantom의 구조물이 없는 cylindlical phantom에서 조차 약간의 counts의 차이를 보이는 바로 미루어 봤을 때 실험 결과 나온 counts의 차이는 적다고 할 수 있을 것이다. 따라서 registration을 활용하여 brain perfusion SPECT의 단점들을 개선하고 정확한 진단에 도움을 줄 수 있을 것으로 사료된다.