• 제목/요약/키워드: Average radiation

검색결과 1,467건 처리시간 0.025초

Exploring Environmental Factors Affecting Strawberry Yield Using Pattern Recognition Techniques

  • 조완현;박유하;나명환;최돈우
    • 인터넷정보학회논문지
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    • 제20권1호
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    • pp.39-46
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    • 2019
  • This paper investigates the importance of various environmental factors that have a strong influence on strawberry yields grown in greenhouse using the pattern recognition methods. The environmental factors influencing the production of strawberries were six factors such as average inside temperature, average inside humidity, average $CO_2$ level, average soil temperature, cumulative solar radiation, and average illumination. The results of analyzing the observed data using Dynamic Time Warping (DTW) showed that the most significant factor influencing the strawberry production was average soil temperature, average inside humidity, and cumulative solar radiation. Second, the results of analyzing the observed data using Multidimensional Scaling (MDS) showed that the most influential factors on the strawberry yields, such as average $CO_2$ level, average inside humidity, and average illumination were differently given for each farms. However, these results are based on the distance in 3D space and can be deduced from the fact that there is not a large difference between these distances. Therefore, in order to increase the harvest of strawberries cultivated in the farms, it is necessary to manage the environmental factors such as thoroughly controlling the humidity and maintaining the concentration of $CO_2$ constantly by ventilation of the greenhouse.

한국 어린이를 위한 복사 공간에서의 투사 면적에 관한 연구 (Visible Project Area for Korean Child (Six Years Old) in Radiant Enclosures)

  • 손철수;최민권
    • 한국주거학회논문집
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    • 제11권4호
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    • pp.77-84
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    • 2000
  • The purpose of this paper is to find a visible project area for an average six year old Korean child in radiant enclosures having standing pose. The results using this method will be necessary to find effective radiation area, effective radiation area factor, form factor, and mean radiant temperature for an average six years old Korean child consists of 3012 triangles. The methods to find visible project area of an average six years old Korean at arbitrary view point will be presented. The visible project area for Korean child is needed for evaluating thermal comfort for six years old Korean child. The biggest visible project area of an average six years old Korean is $\textrm{cm}^2$$2.061.0\textrm{cm}^2$ at the view point of alfa 0.0 degree and beta 0.0 degree, and the smallest visible real area of an average six years old Korean is $567.1\textrm{cm}^2$ at the view point of alfa 15.0 degree and beta 90.0 degree.

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Penman식의 적용에 있어서 지역별 일사량 추정을 위한 계수의 산정 (A Calculation of the Coefficients for Estimating the Regional Radiation in Using the penman Equation)

  • 고희원;황은;김시원
    • 한국농공학회지
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    • 제31권4호
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    • pp.96-110
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    • 1989
  • To suggest the fundamental data for the estimation of crop evaportranspiration by the ca- lculated coefficients for estimating the radiation suitable to the different regions of korea in application of Penman equcation, the daily data such as sc(skycover), n(actual sunshine hours), N(possible sunshine hours), Rs(horizontal solar radiation) and Ra(extraterrestial solar radiation) for 10 years (from 1977 to 1986) collected from 19 meteorological stations were analysed. The results are summarized as follows : 1. The coefficients a, b and c for estimating the radiation taken by the regression method with the daily and monthly mean data of the skycover and the ratio of Rs to Ra were shown as a=0.619, b= -0.0202, c= -0.0023 and a=0.64, b=0.0377 c=0.0001 in ave- rage respectively. 2. The coefficients a and b for estimating the radiation analysed by the regression and arithmetic method from the daily ratio of sunshine hours and Rs to Ra were shown as a= 0.157, b= 0.529, and a=0.119, b= 0.726 in average, respectively. 3. The coefficients a and b for estimating the radiation calculated by the regression me- thod based on the monthly ratio of sunshine hours and radiation were shown as a=0. 319 and b= 0.557 in average. 4. The values of a and b for estimating the radiation taken from the relationship between the daily ratio of sunshine hours and radiation showed high significance level. 5. The standard deviation and the coefficient of variance between the radiation calculated from the coefficients by the regression and arithmetic method with the daily data and the actual radiation were analysed and compared to the results by the coefficients of the modified Penman method (a=0.18, b=0.55) and by those of the F.A.O inodified Penman method(a=0.25, b=0.5). The standard deviation and the coefficient of varia- nce by the regression method in this study showed the lowest value. 6. From the above results, it is suggested that regression method using the coefficients taken from the relationship between the ratio of sunshine hours and the ratio of radia- tion based on the daily data has the highest accuracy in estimating the radiation. 7. The average reference crop evapotranspiration estimating by the modified Penman me- thod using the coefficients a and b derived by the regression method from the daily meterological data was closer to the actual evapotsranspiration of grass measured in Suwon area than the estimated evapotranspiration by the modified Penman method and the F.A.O modified Penman method.

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Radiation Exposure Reduction in APR1400

  • Bae, C.J.;Hwang, H.R.;Matteson, D.M.
    • Journal of Radiation Protection and Research
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    • 제28권2호
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    • pp.127-135
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    • 2003
  • The primary contributors to the total occupational radiation exposure in operating nuclear power plants are operation and maintenance activities doting refueling outages. The Advanced Power Reactor 1400 (APR1400) includes a number of design improvements and plans to utilize advanced maintenance methods and robotics to minimize the annual collective dose. The major radiation exposure reduction features implemented in APR1400 are a permanent refueling pool seal, quick opening transfer tube blind flange, improved hydrogen peroxide injection at shutdown, improved permanent steam generator work platforms, and more effective temporary shielding. The estimated average annual occupational radiation exposure for APR1400 based on the reference plant experience and an engineering judgment is determined to be in the order of 0.4 man-Sv, which is well within the design goal of 1 man-Sv. The basis of this average annual occupational radiation exposure estimation is an eighteen (18) month fuel cycle with maintenance performed to steam generators and reactor coolant pumps during refueling outage. The outage duration is assumed to be 28 days. The outage work is to be performed on a 24 hour per day basis, seven (7) days a week with overlapping twelve (12) hour work shifts. The occupational radiation exposure for APR1400 is also determined by an alternate method which consists of estimating radiation exposures expected for the major activities during the refueling outage. The major outage activities that cause the majority of the total radiation exposure during refueling outage such as fuel handling, reactor coolant pump maintenance, steam generator inspection and maintenance, reactor vessel head area maintenance, decontamination, and ICI & instrumentation maintenance activities are evaluated at a task level. The calculated value using this method is in close agreement with the value of 0.4 man-Sv, that has been determined based on the experience aid engineering judgement. Therefore, with the As Low As Reasonably Achievable (ALARA) advanced design features incorporated in the design, APR1400 design is to meet its design goal with sufficient margin, that is, more than a factor of two (2), if operated on art eighteen (18) month fuel cycle.

Exposure of the Population in the United States to Ionizing Radiation

  • Carter Melvin W.;Oliver Robert W.
    • Journal of Radiation Protection and Research
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    • 제12권2호
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    • pp.37-50
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    • 1987
  • The exposure of the population in the United States to ionizing radiation has recently been evaluated by the National Council on Radiation Protection and Measurements (NCRP). This was done by constituting six organizational groups to address various phases of the work and the results of this work are summarized in this article. The article is based on the report, by the same title, which is scheduled for publication by the NCRP in September, 1987. The six organizational groups are titled Radiation Exposure from Consumer Products, Natural Background Radiation, Radiation Associated with Medical Examinations, Radiation Received by Radiation Employees, Public Exposure from Nuclear Power, and Exposure from Miscellaneous Environmental Sources. These titles are descriptive of the subject areas covered by each of these separate groups. The data evaluated are for the years 1977-1984 with the majority of the data being for the period 1980-1982. Summary information is presented and discussed for the number of people exposed to given sources, the effective dose equivalent, the average effective dose equivalent to the U.S. population, and the genetically significant dose equivalent. The average annual effective dose equivalent from all sources to the U.S. population is approximately 3.6 mSv (360 mrem). Exposures to natural sources make the largest contribution to this total. Radon and radon decay products contribute 2.0 mSv (200 mrem) whereas the other naturally occurring radionuclides contribute 1.0 mSv (100 mrem). Among man-made or enhanced sources, medical exposures make the largest additional contributions, namely 0.39 mSv (39 mrem) for diagnosis and 0.14 mSv (14 mrem) for nuclear medicine. It was not possible to evaluate exposures for therapy. Most of the other sources of population exposure, including nuclear power and consumer products, are minor. A possible exception would be the use of tobacco products. These exposures are discussed in relation to a negligible individual risk level of $10{\mu}Sv/y$ (1 mrem/y). The NCRP considers exposures below the negligible individual risk level as trivial and as such should be dismissed.

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치과 X선발생장치 및 방어에 관한 조사연구 (A LIMITED SURVEY OF DENTAL X-RAY UNITS AND PROTECTION IN KOREA)

  • 박태원
    • 치과방사선
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    • 제10권1호
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    • pp.57-61
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    • 1980
  • In dental roentgenograph it is of mutual benefit to the patient and the dentist to use the minimum amount of radiation capable of producing roentgenograms with maximum interprtive informations. Recent increases in the number of diagnostic x-ray examinations made in this country have caused attention to be paid to the quantity of radiation delivered to the population and operator. The purposes of this study was to assess the quality of dental x-ray units, the amount of films, the average processing procedures and the radiation protection methods in korea. The results were as following: 1. Most of radiation generating system were used in low voltage such as 60Kvp, 10㎃. 2. High sensitivity films such as 'D' group of Kodak or Rinn were mainly used and average 14.7 films used per weeks. 3. Some dentists practiced visual processing technic in simple dark room, and others used instant films. 4. 68.26% of patient held the film themselves, but 27.30% were assisted by dentists film holding. 5. In radiation protection method, 7.85% of dentists had protection equipments such as protective barrier, 2.73% wore protective apron, 27.9% made it a rules to avoid beam, and 7.51% used to maintain a distance from the radiation source.

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남한의 태양에너지 자원 정밀조사 (A Detailed Investigation of Solar Radiation Resources in South Korea)

  • 조덕기;윤창열;김광득;강용혁
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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    • pp.59-62
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    • 2011
  • The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at 16 different locations in Korea and for the more detailed analysis, images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth I s surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. From the results, the measured data has been collected at 16 different stations and estimated using satellite at 23 different stations over the South Korea from 1982 to 2000. The Result of analysis shows that the armual-average daily global radiation on the horizontal surface is $3.56kWh/m^2/day$ and Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.27 to +3.65% from the measured values.

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TRNSYS를 이용한 지역별 고정형 태양광모듈 배치안 검토 (A Study on the Optimum Selection of Placing Photovoltaic Module In the Metropolitan City Using a TRNSYS)

  • 박성현;서장후
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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    • pp.297-302
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    • 2011
  • In this study, used Trnsys and will apply metropolitan city distinguishes, fixations and BIPV systems the photovoltaic module arrangement environment which receives solar radiation quantity plentifully from the case design process which and most the outcome value simulation did analyzed. The climate data uses each metropolitan city distinguishes 20 average weather data, With measured values of horizontal solar radiation. The error scope appeared with 0.1%~6.7%. Variable of module arrangement Azimuth and angle of inclination of module and comparison group Module on due south direction angle of inclination $45^{\circ}$ day time set with the yearly average solar radiation quantity which receives. The result When the case comparison group which arranges a solar storehouse module with optimum environment and comparing until the minimum 1.4% - maximum 10.9% the solar radiation quantity difference appears with the thing, metropolitan city distinguishes considers the case solar radiation quantity which will arrange a photovoltaic module and that must establish with optimum environment judges.

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간 종양의 방사선치료에서 위내용적과 종양 위치 간의 관계 (Relationship between Stomach Volume and Tumor Location in Radiation Treatment for Hepatic Tumors)

  • 전미진;이창걸;이익재;최원훈;최윤선;신동봉;김종대;김세준;하진숙;조윤진
    • 대한방사선치료학회지
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    • 제22권2호
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    • pp.75-83
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    • 2010
  • 목 적: 간과 간 내에 생긴 암이 위내의 크기, 위치변화에 따라 종양의 위치변화와 경향성을 평가하기 위함이다. 방법 및 고찰: 2009년 3월부터 2010년 4월까지 강남세브란스병원을 내원한 간 종양을 가진 환자 중 CT-simulation (컴퓨터 단층촬영을 이용한 모의치료)을 하기 전 2주 내에 컴퓨터단층촬영이나 양전자컴퓨터단층촬영영상을 가진 환자 9명을 대상으로 하였으며, CT-simulation는 6시간 공복을 유지하고, 영상융합을 위한 컴퓨터단층촬영이나 양전자컴퓨터단층촬영은 촬영직전에 240~260 cc 가량의 물을 섭취하도록 하였다. 두 종류의 영상은 RTP (Radiation Treatment Planning, Pinnacle 8.0 h)에서 각각 환자의 뼈 구조를 중심으로 영상융합을 하였다. 결 과: 물 섭취양은 240~260 cc로 일정하였으나 물 섭취 후 위장의 크기는 259.3 cc부터 495.4 cc로 다양하였으며, 두 가지 다른 상태에서 찍은 컴퓨터단층촬영들에서 나타난 위장의 부피변화는 개인의 차이는 있지만, 평균 130 cc 정도의 부피증가가 측정되었으며, 이는 평균 174%의 증가에 해당된다. 종합적인 종양 중심점의 절대거리는 0.52 cm에서 3.04 cm으로 평균 1.52 cm의 움직임을 보였으며, 머리-다리(Cranial-Caudal)방향으로는 0.1 cm에서 1.35 cm으로 평균 0.44 cm의 움직임을 보였고, 왼-오른(Left-Right)방향으로는 0.05 cm에서 2.75 cm으로 평균 1.22 cm의 움직임을 보였고, 배-등(Ventral-Dorsal)방향으로는 0.05 cm에서 1.85 cm으로 평균 0.33 cm의 움직임을 보였다. 결 론: 개인차가 커서 위장의 운동을 관찰하여 종양의 움직임을 예측하는 것은 힘들지만 위장이 채워짐에 따라, 복잡한 경로를 통해 간 종양의 위치가 오른쪽으로 치우치는 것이 관찰되었다. 이에 간종양 치료 시 치료 정확도를 확보하기 위하여 공복상태를 유도하는 것을 권장한다. 반면 공복상태가 어려울 경우 환자의 위장의 부피와 움직임을 측정하여 치료계획 시 간 종양의 움직임을 고려하여 방사선 치료를 할 것을 권장한다.

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Feasibility of Fabricating Variable Density Phantoms Using 3D Printing for Quality Assurance (QA) in Radiotherapy

  • Oh, Se An;Kim, Min Jeong;Kang, Ji Su;Hwang, Hyeon Seok;Kim, Young Jin;Kim, Seong Hoon;Park, Jae Won;Yea, Ji Woon;Kim, Sung Kyu
    • 한국의학물리학회지:의학물리
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    • 제28권3호
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    • pp.106-110
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    • 2017
  • The variable density phantom fabricated with varying the infill values of 3D printer to provide more accurate dose verification of radiation treatments. A total of 20 samples of rectangular shape were fabricated by using the $Finebot^{TM}$ (AnyWorks; Korea) Z420 model ($width{\times}length{\times}height=50mm{\times}50mm{\times}10mm$) varying the infill value from 5% to 100%. The samples were scanned with 1-mm thickness using a Philips Big Bore Brilliance CT Scanner (Philips Medical, Eindhoven, Netherlands). The average Hounsfield Unit (HU) measured by the region of interest (ROI) on the transversal CT images. The average HU and the infill values of the 3D printer measured through the 2D area profile measurement method exhibited a strong linear relationship (adjusted R-square=0.99563) in which the average HU changed from -926.8 to 36.7, while the infill values varied from 5% to 100%. This study showed the feasibility fabricating variable density phantoms using the 3D printer with FDM (Fused Deposition Modeling)-type and PLA (Poly Lactic Acid) materials.