• Title/Summary/Keyword: Direct solar radiation

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Study on Improvement of Signal to Noise Ratio for HgI2 Radiation Conversion Sensor Using Blocking Layer (Blocking layer 적용을 통한 HgI2 방사선 변환센서의 신호대 잡음비 향상에 관한 연구)

  • Park, Ji-Koon;Yoon, In-Chan;Choi, Su-Rim;Yoon, Ju-Sun;Lee, Young-Kyu;Kang, Sang-Sik
    • Journal of the Korean Society of Radiology
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    • v.5 no.2
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    • pp.97-101
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    • 2011
  • In this study, the basic research verifying possibility of applications as radiology image sensor in Digital Radiography was performed, the radiology image sensor was fabricated using double layer technique tio decrease dark current. High efficiency material in substitution for a-Se have been studied as a direct method of imaging detector in Digital Radiography to decrease dark current by using Hetero junction already used as solar cell, semiconductor. Particle-In-Binder method is used to fabricate radiology image sensor because it has a lot of advantages such as fabrication convenient, high yield, suitability for large area sensor. But high leakage current is one of main problem in PIB method. To make up for the weak points, double layer technique is used, and it is considered that high efficient digital radiation sensor can be fabricated with easy and convenient process. In this study, electrical properties such as leakage current, sensitivity is measured to evaluate double layer radiation sensor material.

Daylight Assessment of Venetian Blind by Shading Heights and Slat Angles (베네시안 블라인드의 높이와 슬랫각도 조절에 따른 계절별 실내주광분포 분석)

  • Shin, Hwa-Young;Kim, Gon;Kim, Jeong Tai
    • KIEAE Journal
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    • v.11 no.2
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    • pp.105-111
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    • 2011
  • Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

Spatial Analysis of Skin Cancer Incidence in Iran

  • Pakzad, Reza;Ghoncheh, Mahshid;Pournamdar, Zahra;Pakzad, Iraj;Momenimovahed, Zohre;Salehiniya, Hamid;Towhidi, Farhad;Makhsosi, Behnam Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.33-37
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    • 2016
  • Skin cancer is one of the most common cancers worldwide, including in Iran. Variations in its incidence rate among geographical areas are due to various contributing factors. Since there has been a lack of studies on this topic in our country, the present spatial analysis of skin cancer incidence in Iran in 2009 was conducted using data from the cancer registry system for the country. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi), high-risk areas were drawn. Provinces that were 1.9 SD higher or lower than the national average were considered hot spots or cold spots, with significance at the level of 0.05. In 2009, a total of 9,964 cases of skin cancer occurred, 3,696 in women and 6,268 in men (standardized incidence rates of 15.8 and 22.6, respectively). The results of the study showed that in men and women, the disease demonstrated high incidence in the central provinces and desert regions. In women, Yazd Province and in men, Qom Province had significant hot spots (p <0.05). While Isfahan, Markazi, Tehran and Kurdistan provinces were expected to be hot spots, the differences from the national average were not significant at the 0.05 level. As well, the provinces of Sistan Va Baluchistan, Kerman, and Hormozgan were identified as cold or low-risk disease regions (p <0.05). The central provinces of the country due to hot weather conditions, more solar radiation, and closer vicinity to the central desert of Iran demonstrated higher incidence rates for skin cancer, so further epidemiological studies into the etiology and early detection are essential in these areas.

Effects of Aerosol Optical Properties on Upward Shortwave Flux in the Presence of Aerosol and Cloud layers (구름과 에어로솔의 혼재시 에어로솔의 광학특성이 상향 단파 복사에 미치는 영향)

  • Lee, Kwon-Ho
    • Korean Journal of Remote Sensing
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    • v.33 no.3
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    • pp.301-311
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    • 2017
  • Aerosol optical properties as well as vertical location of layer can alter the radiative balance of the Earth by reflecting and absorbing solar radiation. In this study, radiative transfer model (RTM) and satellite-based analysis have been used to quantify the top-of-atmosphere (TOA) radiative effect of aerosol layers in the cloudy atmosphere of the northeast Asia. RTM simulation results show that the atmospheric warming effect of aerosols increases with their height in the presence of underlying cloud layer. This relationship is higher for stronger absorbing aerosols and higher surface albedo condition. Over study region ($20-50^{\circ}N$, $110-140^{\circ}E$) and aerosol event cases, it is possible to qualitatively identify absorbing aerosol effects in the presence of clouds by combining the UV Absorbing Aerosol Index (AAI) derived from Total Ozone Mapping Spectrometer (TOMS), cloud parameters derived from the Moderate Resolution Imaging Spectro-radiometer (MODIS), with TOA Upward Shortwave Flux (USF) from the Clouds and the Earth's Radiant Energy System (CERES). As the regional-mean radiative effect of aerosols, 6 - 26 % lower the USF between aerosols and cloud cover is taken into account. These results demonstrate the importance of estimation for the accurate quantification of aerosol's direct and indirect effect.

A Way for Creating Human Bioclimatic Maps using Human Thermal Sensation (Comfort) and Applying the Maps to Urban and Landscape Planning and Design (인간 열환경 지수를 이용한 생기후지도 작성 및 도시·조경계획 및 디자인에의 적용방안)

  • Park, Soo-Kuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.1
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    • pp.21-33
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    • 2013
  • The purpose of this study is to find applicabilities of human bioclimatic maps, using human thermal sensation(comfort) in summer, with microclimatic in situ data and computer simulation results at the study site of downtown Daegu. This includes the central business district(CBD) area and two urban parks, the Debt Redemption Movement Memorial Park and the 2.28 Park, for urban and landscape planning and design. Climatic data and urban setting information for the analysis of human thermal sensation were obtained from in situ measurement and the geographic information system data. As a result, the CBD had higher air temperature than the parks when the wind speed was low. Relative humidities were opposite to the air temperature. Especially, same directional streets with local wind direction had lower air temperature than streets perpendicular to the wind direction. The most important climatic variable of human thermal sensation in summer was direct beam solar radiation. Also, creating shadow areas would be the most relevant method for modifying hot thermal environments in urban areas. The most effective method of creating shadow patterns was making a tree shadow over a pergola, and the second best one was making a tree shadow on the front of north directional building walls. Moreover, how to plant trees for creating shadow patterns was important as well as what kind of trees should be planted. The results of human thermal sensation were warm to very hot at sunny areas and neutral to warm at shaded ones. At the sunny areas, wide, squared shape areas had a little bit higher thermal sensation than those of narrow streets. The albedo change of building walls 0.15 and ground surface 0.1 could change 1/6 of a sensation level at the shaded areas and 1/3 at the sunny ones. These microclimatic approaches will be useful to find appropriate methods for modifying thermal environments in urban areas.