• 제목/요약/키워드: TLD

검색결과 362건 처리시간 0.035초

A Real-time Face Tracking Algorithm using Improved CamShift with Depth Information

  • Lee, Jun-Hwan;Jung, Hyun-jo;Yoo, Jisang
    • Journal of Electrical Engineering and Technology
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    • 제12권5호
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    • pp.2067-2078
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    • 2017
  • In this paper, a new face tracking algorithm is proposed. The CamShift (Continuously adaptive mean SHIFT) algorithm shows unstable tracking when there exist objects with similar color to that of face in the background. This drawback of the CamShift is resolved by the proposed algorithm using Kinect's pixel-by-pixel depth information and the skin detection method to extract candidate skin regions in HSV color space. Additionally, even when the target face is disappeared, or occluded, the proposed algorithm makes it robust to this occlusion by the feature point matching. Through experimental results, it is shown that the proposed algorithm is superior in tracking performance to that of existing TLD (Tracking-Learning-Detection) algorithm, and offers faster processing speed. Also, it overcomes all the existing shortfalls of CamShift with almost comparable processing time.

$MgB_4O_7$ 열형광체의 제작과 X선의 선량측정에 관한 연구 (A Study on the Preparation of $MgB_4O_7$ Thermoluminescent Phosphors and X-ray Dosimetry)

  • 송재흥;노경석;이덕규;구효근
    • 대한방사선기술학회지:방사선기술과학
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    • 제21권2호
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    • pp.47-52
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    • 1998
  • Tissue-equivalent $MgB_4O_7$ TL phosphors were prepared and the effects of Lantanides series activators on TLD properties of the phosphors were studied. The glow curve of TLD increased TL intensity and the peak temperature is low that is, the heating rate is $10^{\circ}C/sec$. The activation energy of the main peak estimated by the peak shape method. By these methods, the estimated activation energies were $0.76{\sim}1.55eV$ respectively. The TL phosphors prepared in this work may be utilized to radiation sensor elements because of this high sensitivity to X-ray.

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CORVUS Planning System를 사용한 세기조절방사선치료 시 환자치료의 정확성에 대한 검증

  • 김명세;김성규
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2005년도 제30회 춘계학술대회
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    • pp.39-41
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    • 2005
  • 본 연구에서는 두경부암 환자에게 세기조절 방사선치료계획을 수립한 후 환자 위치의 정확한 재현성과 치료선량의 정확한 전달을 위한 정도관리를 본원에 설치되어 있는 21ex 선형가속기와 세기조절방사선치료계획 장치인 CORVUS 시스템을 사용하였다. 세기조절 방사선치료계획을 QA 아크릴 팬텀으로 옮겨 계산된 계산치가 1.50 Gy였으며, 같은 조건으로 QA 아크릴 팬텀을 설치하여 측정한 선량은 1.485 Gy였으며, TLD에서의 측정치는 1.483 Gy였다. 측정치의 비교에서 이온챔버와 TLD에서 각각 1.0%, 1.2%의 차이를 보여 세기조절방사선치료의 환자 적용에의 적합성을 확인하였다. 나아가 환자치료시 정확하게 치료되고 있는지에 대한 검정과정을 개발하였다.

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내부 슬로싱 현상을 이용한 사각상자 형태의 부유체 Sway 거동 모사에 대한 수치적 고찰 (Numerical study of sway motion of a rectangular floating body with inner sloshing phenomena)

  • 하민호;정철웅
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
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    • pp.161-165
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    • 2013
  • In this paper, possibility of controlling motion of a floating structure using a tuned liquid damper (TLD) is numerically investigated. A TLD is a tank partially filled with liquid. Sloshing phenomena of liquid inside a tank can suppress movement of the tank subject to external excitations at specific frequency. The effects of sloshing phenomena inside a rectangular floating body on its sway motion are investigated by varying excitation frequency. First, a grid-refinement study is carried out to ensure validity of grid independent numerical solutions using present numerical techniques. Then, sway motion of the floating body subjected to wave with five different frequencies are simulated. The normalized amplitudes of sway motion of the target floating body are compared over the frequency, for cases with and without water inside the floating body. It is shown that the motion of the floating body can be minimized by matching the sloshing natural frequency to excitation frequency.

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고에너지 전자선의 흡수선량 측정에 있어서 TLD의 유용성 (Measurement of Absorbed Dose for High Energy Electron using $CaSO_4:Tm$ - PTFE TLD)

  • 박명환;김도성
    • 대한방사선기술학회지:방사선기술과학
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    • 제23권1호
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    • pp.97-101
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    • 2000
  • In this study, the highly sensitive $CaSO_4:Tm$-PTFE TLDs has been fabricated for the purpose of measurement of high energy electron. $CaSO_4:Tm$ phosphor powder was mixed with polytetrafluoroethylene(PTFE) powder and moulded in a disk type(diameter 8.5 mm. thickness $90\;mg/cm^2$) by cold pressing. The absorbed dose distribution and ranges for high energy electron were measured by using the $CaSO_4:Tm$-PTFE TLDs. The ranges determined were $R_{100}=14.5mm$, $R_{50}=24.1mm$ and $R_P=31.8mm$, respectively and the beam flatness, the variation of relative dose in 80% of the field size, was 4.5%. The fabricated $CaSO_4:Tm$-PTFE TLDs nay be utilized in radiation dosimetry for personal, absorbed dose and environmental monitoring.

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전악치근단방사선사진촬영, 파노라마방사선사진촬영 및 협각단층촬영시의 흡수선량 (Absorbed Dose in the Full-mouth Periapical Radiography, Panoramic Radiography, and Zonography)

  • 최순철;최항문
    • 치과방사선
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    • 제29권1호
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    • pp.255-260
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    • 1999
  • Purpose: The objective of this study was to evaluate the possibility of substitution of the zonography for the full-mouth periapical radiography in aspect of radiation protection. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses at brain, skin above the TMJ. parotid gland. bone marrow in the mandibular body. and thyroid gland during the full-mouth periapical radiography. panoramic radiography. and zonography were measured. Resul ts: From the zonography. the absorbed doses to the brain. the skin over the TMJ. and the parotid gland were relatively high. but the absorbed doses to the bone marrow in the mandibular body and. especially. the thyroid gland were very low. Conclusion: The zonography can be an alternative to the full-mouth periapical radiography in aspect of radiation protection.

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