• 제목/요약/키워드: Total radiation

검색결과 2,254건 처리시간 0.026초

선량강도 조절법을 이용한 방사선치료에서 총선량에 관한 고찰 (A Study of Total Dose in Intensity Modulation Radiation Therapy)

  • 김성규
    • 한국의학물리학회지:의학물리
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    • 제11권1호
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    • pp.85-90
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    • 2000
  • 방사선치료에서 치료의 효과는 총선량, 치료회수, 1회 조사선량 등에 의해서 결정된다. 선량강도조절법을 사용하여 방사선치료를 행할 때 치료회수나 1회 조사선량을 고려하여 총선량에 미치는 효과를 살펴보고자 한다. 방사선치료의 목적은 암조직에는 충분한 선량을 조사하면서 주위 정상 조직에는 최소한의 선량을 조사되게 하여 치료성적의 향상으로 암환자의 생존율과 삶의 질을 높이는데 목적이 있다. 이러한 문제를 해결하기 위하여 많은 연구자들이 여러 가지 방법으로 해결하고자 노력한 결과 CT의 영상을 치료계획에 이용할 수 있게 되어 three dimensional conformal radiation therapy(3DCRT)를 개발하였다. 선량강도조절법을 시행하여 총선량을 75, 80, 85, 90Gy를 조사할 때, 처음부터 선량강도조절법을 사용하여 치료하는 경우와 일차적으로 45Gy를 조사하고 boost를 조사할 때 나머지 선량을 선량강도조절 법으로 사용하는 것을 TDF 환산법을 사용하여 비교하였다. 처음부터 선량강도조절법으로 치료할 경우에는 총선량에서 약 12.5 - 15 Gy 정도 감해서 조사하여야 하는 것으로 나타났다.

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온실의 광환경 분석을 위한 기초실험 (The Basic Experiments for Analysis of Solar Radiation Environemnts in Greenhouse)

  • 이현우;이석건;김길동;이종원
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.434-438
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    • 1999
  • It was neede to know the amount of PAR to predict the growth of crops, and the quantity of total radiation to control the temperature by shading screen in the greenhouse. Experiments have been conducted to determine the correlation between the hourly PAR and total solar radiation the transmisson of PAR and total solar radiaiton oat canopy location, and the relationship between the illuminaance and total solar radiation. Additional experiments are needed to confirm thses experimental results.

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플라스틱 하우스의 직달(直達) 및 산란(散亂) 일사량(日射量) 해석(解析) (Analysis of Direct and Diffuse Radiation in Plastic Greenhouse)

  • 고학균;김문기;김용현
    • 태양에너지
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    • 제9권3호
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    • pp.13-24
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    • 1989
  • Direct and diffuse components of solar radiation were measured inside and outside a single-span plastic greenhouse. To analyze the direct solar radiation inside the plastic greenhouse, the cross-section of the greenhouse was assumed to be circular. Then the direct solar radiation transmitted into the greenhouse was calculated theoretically, and compared with the experimental measurements. The results are summarized as follows: (1) The transmissivities of total solar radiation were about 65% on cloudy days and 50% on clear days. For cloudy days, the transmissivity of the total solar radiation was regarded as the transmissivity of sky diffuse radiation. (2) The ratio of the inside effective scattered component of direct solar radiation to the diffuse radiation was 60-65%. (3) It appeared that the seasonal variation of the transmissivity of total solar radiation was adversely affected by the transmissivity of direct solar radiation and the effective scattered coefficient. But the effect of the transmissivity of direct solar radiation was dominant factor. (4) Computer simulation showed that the inside direct solar radiation was decreased as the floor of the plastic greenhouse was higher. (5) The predicted value of the inside direct solar radiation was 3.3% to 29.0% higher than the measured value.

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원자력 및 핵의학 분야용 Total RMS (Radiation Monitoring System)의 설계 (Design of Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine)

  • 고태영;이주현;이승호
    • 전기전자학회논문지
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    • 제21권2호
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    • pp.158-161
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    • 2017
  • 본 논문에서는 원자력 및 핵의학 분야용 Total RMS(Radiation Monitoring System)를 제안한다. 제안하는 시스템은 Stack Monitor, Area Monitor, Water(Liquid) Monitor 등을 하나의 시스템으로 확장 및 제어할 수 있는 장비로 각 방사선 검출기에서 측정된 신호를 통합 모니터링 할 수 있다. 제안하는 시스템은 해당 방사선을 검출하는 Sensor Module, 방사선 검출 위치에 인접한 곳에서 방사선량을 디스플레이 하는 Display Unit, 검출된 방사선량이 위험 수준에 도달시 경보를 알리는 Alarm Unit, 각 모니터링에서 측정된 방사선량들을 취합하고 저장하여 원격 감시 시스템에 내용을 전달하는 Main Hub, 원격지에서 측정된 방사선량 상태를 일목요연하게 디스플레이 하는 RMS Monitoring Unit 등으로 구성된다. 제안된 원자력 및 핵의학 분야용 Total RMS의 성능을 평가하기 위하여 공인시험기관에서 실험한 결과, 측정 불확도가 8.5%이하로 측정되어 국제 표준인 ${\pm}15%$ 이하에서 정상동작 됨이 확인되었다.

접수 원통형 구조물의 표면 진동속도를 이용한 총 방사음향파워 계산 (Estimation of Total Acoustic Radiation Power of Submerged Circular Cylindrical Structure Using Surface Vibration Velocity)

  • 한승진;이종주;강명환;배수룡;정우진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.236-239
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    • 2014
  • Most naval underwater weapon system can be simplified to a circular cylindrical structure which has vibrating machineries inside. In order to predict efficiently the total acoustic radiation power of cylindrical structure, surface velocity is measured and radiation efficiency of surface element is calculated. Then, they are substituted to the surface pressure in the simplified Helmholtz integral equation which assumes acoustic far-field and plane-wave approximation at the surface. Surface velocity and total acoustic radiation power for a submerged cylinder are measured in water-tank. In this example, it is found that total acoustic power output obtained from the prediction is in good agreement with that of measurement in mid-high frequency range.

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강릉 지역에서 자동 전운량 장비와 GWNU 태양 복사 모델을 이용한 지표면 일사량 분석 (An Analysis of Global Solar Radiation using the GWNU Solar Radiation Model and Automated Total Cloud Cover Instrument in Gangneung Region)

  • 박혜인;조일성;김부요;지준범;이규태
    • 한국지구과학회지
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    • 제38권2호
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    • pp.129-140
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    • 2017
  • 이 연구에서는 지표 관측 자료와 위성 자료 그리고 GWNU 단층 복사 모델을 이용하여 맑은 상태의 전천 일사량을 계산하였으며, 전운량에 따라 관측 및 모델의 일사량 값을 비교 분석하였다. 연구 자료는 2012년 강릉원주대학교 복사 관측소의 전천 일사량, 기온, 기압, 습도, 에어로졸 등의 관측 자료와 OMI 센서의 오존전량 자료 그리고 구름의 유무 및 전운량을 판단하기 위하여 자동 전운량 장비인 Skyview 자료를 이용하였다. 전운량이 0 할인 맑은 날의 경우 관측 값과 모델 값이 0.98로 높은 상관계수를 나타내었으나 RMSE가 $36.62Wm^{-2}$로 비교적 높게 나타났다. 이는 Skyview 장비가 얇은 구름이나 박무 및 연무 등의 기상상태를 판단하지 못하였기 때문이다. 흐린 날의 경우 구름의 영향을 보정하기 위해 전운량과 두 값의 차에 대한 비율을 이용한 회귀식을 복사 모델에 적용하였으며, 장비의 오탐지를 제외한 경우 상관계수가 0.92로 높은 상관성을 보였으나 RMSE가 $99.50Wm^{-2}$으로 높은 값을 보였다. 더 정확한 분석을 위해서는 직달 성분의 차폐 유무 및 구름 광학 두께를 포함한 다양한 구름 요소의 추가적인 분석이 요구된다. 이 연구결과는 분 또는 시간에 따른 일사량을 산출하여 일사량이 관측되지 않는 지역에서 유용하게 사용될 수 있다.

방사선 치료 환자에서의 Provox 사용 (The effect of Radiation Therapy on the Use of Proven Prosthesis in Laryngectomees)

  • 김광현;성명훈;이창호;전상준;고태용
    • 대한기관식도과학회지
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    • 제4권2호
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    • pp.177-181
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    • 1998
  • Provox is now widely used for voice rehabilitation for total laryngectomized patient because of its low airway resistance and easiness for phonation. This study was designed to reveal the influence of radiation therapy on Proven complications. Forty-four patients who underwent total laryngectomy were grouped into group A (no radiation), group B(radiation and then Provox insertion), group C(Proven insertion and then radiation). Provox complications were leakage, granulation tissue formation, malfunction and infection. The average survival time of Provox was longer in group C (9.2 me) than group A(8.6 m) or group B (7.3 me), but no statistical significance was found. The first time of Provox change was 10.2, 8.6 and 9.7 months respectively. The incidence of complication was not significantly different among groups. The cases of Provox remeval due to shunt failure were 5, 4 and 2 respectively. Even though a significant statistically difference was not found partialy due to the small numbers of patients, a special caution should be exercised in inserting Provox to prevent a serious complication for the patients who had a history of previous radiation.

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Recent Advances in Radiation-Hardened Sensor Readout Integrated Circuits

  • Um, Minseong;Ro, Duckhoon;Kang, Myounggon;Chang, Ik Joon;Lee, Hyung-Min
    • Journal of Semiconductor Engineering
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    • 제1권3호
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    • pp.81-87
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    • 2020
  • An instrumentation amplifier (IA) and an analog-to-digital converter (ADC) are essential circuit blocks for accurate and robust sensor readout systems. This paper introduces recent advances in radiation-hardening by design (RHBD) techniques applied for the sensor readout integrated circuits (IC), e.g., the three-op-amp IA and the successive-approximation register (SAR) ADC, operating against total ionizing dose (TID) and singe event effect (SEE) in harsh radiation environments. The radiation-hardened IA utilized TID monitoring and adaptive reference control to compensate for transistor parameter variations due to radiation effects. The radiation-hardened SAR ADC adopts delay-based double-feedback flip-flops to prevent soft errors which flips the data bits. Radiation-hardened IA and ADC were verified through compact model simulation, and fabricated CMOS chips were measured in radiation facilities to confirm their radiation tolerance.

Implementation of a Radiation-hardened I-gate n-MOSFET and Analysis of its TID(Total Ionizing Dose) Effects

  • Lee, Min-Woong;Lee, Nam-Ho;Jeong, Sang-Hun;Kim, Sung-Mi;Cho, Seong-Ik
    • Journal of Electrical Engineering and Technology
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    • 제12권4호
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    • pp.1619-1626
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    • 2017
  • Electronic components that are used in high-level radiation environment require a semiconductor device having a radiation-hardened characteristic. In this paper, we proposed a radiation-hardened I-gate n-MOSFET (n-type Metal Oxide Semiconductors Field Effect Transistors) using a layout modification technique only. The proposed I-gate n-MOSFET structure is modified as an I-shaped gate poly in order to mitigate a radiation-induced leakage current in the standard n-MOSFET structure. For verification of its radiation-hardened characteristic, the M&S (Modeling and Simulation) of the 3D (3-Dimension) structure is performed by TCAD (Technology Computer Aided Design) tool. In addition, we carried out an evaluation test using a $Co^{60}$ gamma-ray source of 10kGy(Si)/h. As a result, we have confirmed the radiation-hardened level up to a total ionizing dose of 20kGy(Si).

Effects of radiation-modulated cooling on the momentum transfer from stellar feedback

  • Na, Chongsam;Kimm, Taysun
    • 천문학회보
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    • 제44권1호
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    • pp.70.2-70.2
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    • 2019
  • Strong radiation fields can change the ionization state of metals and hence cooling rates. In order to understand their effects on the momentum transfer from radiation and supernova feedback, we perform a suite of radiation-hydrodynamic simulations with radiation-modulated metal cooling. For this purpose, we pre-tabulate the metal cooling rates for a variety of spectral shapes and flux levels with the spectral synthesis code, Cloudy, and accurately determine the rates based on the local radiation field strength. We find that the inclusion of the radiation-modulated metal cooling decreases the total radial momentum produced by photo-ionization heating by a factor of ~3 due to enhanced cooling at temperature T~10^3-4 K. The amount of momentum transferred from the subsequent SN explosions, however, turns out to be little affected by radiation, as the main cooling agents at T~10^5-6 K are only destroyed by soft X-ray radiation which is generally weak. We further discuss the total momentum budget in various conditions.

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