• 제목/요약/키워드: Total radiation

검색결과 2,228건 처리시간 0.033초

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

  • 김성규
    • Progress in Medical Physics
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    • 제11권1호
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    • pp.85-90
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    • 2000
  • In radiation therapy, the effects of radiation are decided total dose, total treatment times and number of radiation dose fractions. We considered that total dose, total treatment times and number of radiation dose fractions in intensity modulation radiation therapy(IMRT) infuence tumor cell killing. The goal of three dimensional conformal radiation therapy(3DCRT) in radiation therapy is to conform the partial distribution of the prescribed radiation dose to the precise 3D configuration of the tumor, and at the same time, to minimize the dose to the surrounding normal tissues. To optimize treatment volume of tumor, treatment volume will be same tumor volume. All IMRT compare to conventional treatment plus boost IMRT when total dose irradiated 75 - 90 Gy. Because of biological effect, total dose are decreased 12.5 - l5Gy in all IMRT.

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

  • 이현우;이석건;김길동;이종원
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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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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Analysis of Direct and Diffuse Radiation in Plastic Greenhouse (플라스틱 하우스의 직달(直達) 및 산란(散亂) 일사량(日射量) 해석(解析))

  • Koh, Hak-Kyun;Kim, Moon-Ki;Kim, Yong-Hyeon
    • Solar Energy
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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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Design of Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine (원자력 및 핵의학 분야용 Total RMS (Radiation Monitoring System)의 설계)

  • Ko, Tae-Young;Lee, Joo-Hyun;Lee, Seung-Ho
    • Journal of IKEEE
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    • 제21권2호
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    • pp.158-161
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    • 2017
  • In this paper, we propose Total RMS(Radiation Monitoring System) for nuclear and nuclear medicine. The proposed system can expand and control Stack Monitor, Area Monitor, and Water(Liquid) Monitor into one system, and can monitor the signals measured by each radiation detector in an integrated manner. The proposed system consists of a sensor module that detects the radiation, a display unit that displays the radiation dose near the radiation detection location, an alarm unit that reports the alarm when the detected radiation dose reaches the danger level, A Main Hub for collecting and storing the contents to the remote monitoring system, and an RMS Monitoring Unit for clearly displaying the measured radiation dose at the remote site. In order to evaluate the performance of Total RMS for the proposed nuclear and nuclear medicine field, it is confirmed that the measurement uncertainty is less than 8.5% and it operates normally within ${\pm}15%$ of the international standard.

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

  • Han, Seungjin;Lee, Jongju;Kang, Myunghwan;Bae, Sooryong;Jung, Woojin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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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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An Analysis of Global Solar Radiation using the GWNU Solar Radiation Model and Automated Total Cloud Cover Instrument in Gangneung Region (강릉 지역에서 자동 전운량 장비와 GWNU 태양 복사 모델을 이용한 지표면 일사량 분석)

  • Park, Hye-In;Zo, Il-Sung;Kim, Bu-Yo;Jee, Joon-Bum;Lee, Kyu-Tae
    • Journal of the Korean earth science society
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    • 제38권2호
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    • pp.129-140
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    • 2017
  • Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.

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

  • 김광현;성명훈;이창호;전상준;고태용
    • Korean Journal of Bronchoesophagology
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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
    • The Bulletin of The Korean Astronomical Society
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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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