• Title/Summary/Keyword: a sky view

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A Case Study on Field Campaign-Based Absolute Radiometric Calibration of the CAS500-1 Using Radiometric Tarp (Radiometric Tarp를 이용한 현장관측 기반의 차세대중형위성 1호 절대복사보정 사례 연구)

  • Woojin Jeon;Jong-Min Yeom;Jae-Heon Jung;Kyoung-Wook Jin;Kyung-Soo Han
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1273-1281
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    • 2023
  • Absolute radiometric calibration is a crucial process in converting the electromagnetic signals obtained from satellite sensors into physical quantities. It is performed to enhance the accuracy of satellite data, facilitate comparison and integration with other satellite datasets, and address changes in sensor characteristics over time or due to environmental conditions. In this study, field campaigns were conducted to perform vicarious calibration for the multispectral channels of the CAS500-1. Two valid field observations were obtained under clear-sky conditions, and the top-of-atmosphere (TOA) radiance was simulated using the MODerate resolution atmospheric TRANsmission 6 (MODTRAN 6) radiative transfer model. While a linear relationship was observed between the simulated TOA radiance of tarps and CAS500-1 digital numbers(DN), challenges such as a wide field of view and saturation in CAS500-1 imagery suggest the need for future refinement of the calibration coefficients. Nevertheless, this study represents the first attempt at absolute radiometric calibration for CAS500-1. Despite the challenges, it provides valuable insights for future research aiming to determine reliable coefficients for enhanced accuracy in CAS500-1's absolute radiometric calibration.

A Study of the Urban Tree Canopy Mean Radiant Temperature Mitigation Estimation (도시림의 여름철 평균복사온도 저감 추정 연구)

  • An, Seung Man;Son, Hak-gi;Lee, Kyoo-Seock;Yi, Chaeyeon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.1
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    • pp.93-106
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    • 2016
  • This study aimed to estimate and evaluate the thermal mitigation of the urban tree canopy on the summer outdoor environment by quantitative use of mean radiant temperature. This study applied the SOLWEIG model based $T_{mrt}$ comparison method by using both (1) urban tree canopy presence examples and (2) urban tree canopy absence examples as constructed from airborne LiDAR system based three-dimensional point cloud data. As a result, it was found that an urban tree canopy can provide a decrease in the entire domain averaged daily mean $T_{mrt}$ about $5^{\circ}C$ and that the difference can increase up to $33^{\circ}C$ depending both on sun position and site conditions. These results will enhance urban microclimate studies such as indices (e.g., wind speed, humidity, air temperature) and biometeorology (e.g., perceived temperature) and will be used to support forest based public green policy development.

Development of a UAV-Based Urban Thermal Comfort Assessment Method (UAV 기반 도시 공간의 열 쾌적성 평가기법 개발)

  • Seounghyeon Kim;Bonggeun Song;Kyunghun Park
    • Journal of the Korean Association of Geographic Information Studies
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    • v.27 no.2
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    • pp.61-77
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    • 2024
  • The purpose of this study was to develop a method for rapidly diagnosing urban thermal comfort using Unmanned Aerial Vehicle (UAV) based data. The research was conducted at Changwon National University's College of Engineering site and Yongji Park, both located in Changwon, Gyeongsangnam-do. Baseline data were collected using field measurements and UAVs. Specifically, the study calculated field measurement-based thermal comfort indices PET and UTCI, and used UAVs to create and analyze vegetation index (NDVI), sky view factor (SVF), and land surface temperature (LST) images. The results showed that UAV-predicted PET and UTCI had high correlations of 0.662 and 0.721, respectively, within a 1% significance level. The explanatory power of the prediction model was 43.8% for PET and 52.6% for UTCI, with RMSE values of 6.32℃ for PET and 3.16℃ for UTCI, indicating that UTCI is more suitable for UAV-based thermal comfort evaluation. The developed method offers significant time-saving advantages over traditional approaches and can be utilized for real-time urban thermal comfort assessment and mitigation planning

A Study on Efficient Sidewalk Green Space Development for Improving Urban Thermal Environments and Enhancing Pedestrian Comfort - Focused on the Derivation of Parameters for Design, and Proposing Methods for Green Space Creation - (도시열환경 개선 및 보행자 열 쾌적성 증대를 위한 효율적 가로녹지 조성방안 연구 - 계획 및 설계를 위한 매개변수 도출과 녹지조성 방법 제안을 중심으로 -)

  • Park, Ju-Hyeon;Eum, Jeong-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.2
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    • pp.21-38
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    • 2024
  • This study aims to establish an efficient street green area to improve the urban thermal environment and enhance pedestrian thermal comfort. Specifically, This study identified parameters applicable to green space planning and design, analyzed thermal environment mitigation mechanisms for each parameter, and, based on these findings, proposed methods for tree species selection and planting in green space planning and design. To achieve this, 61 papers were selected through a four-stage process from both domestic and foreign sources. The selected papers were analyzed, and the following main results were derived: In open street canyons with high stress levels due to low aspect ratios and high sky view factors(SVF), broadleaf trees with wide crown widths, low trunk heights, high leaf area index(LAI), and high crown heights were found effective in reducing heat, thereby increasing the amount and quality of shade. In contrast, in deep and narrow street canyons with relatively low heat stress due to high aspect ratios and low SVF, broad-leaved trees with narrow crown widths, high trunks, low crown heights, and low LAI were effective in reducing heat by enhancing ventilation. This study can serve as fundamental data for establishing standards for street green spaces to improve the thermal environment of street canyons and enhance thermal comfort of pedestrians. Additionally, it can be valuable when selecting the location and prioritizing street green spaces. Moreover, it is anticipated to be a foundational resource for creating guidelines for green space planning and design in response to climate change.

Simulation Analysis of GPS Reception Environment of Unified Control Points Using GIS (GIS를 이용한 통합기준점의 GPS 수신환경 모의 분석)

  • Kim, Tae Woo;Yun, Hong Sik;Kim, Kwang Bae;Jung, Woon Chul
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.609-616
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    • 2017
  • National Geographic Information Institute has established a plan that preoccupies UCPs (Unified Control Points) at 2~3km intervals in urban areas by considering the distance between existing UCPs by satellite images and aerial photographs in 2015. In this study, we discussed the method of selecting the locations of optimal UCPs by simulating GPS reception environment in candidate sites for UCPs using GIS. For this purpose, we selected new candidate sites for installing UCPs using satellite images and aerial photographs, and analyzed the GPS reception environment by calculating the visibility distance from buildings around UCPs using GIS skyline analysis. The number of and the arrangement of visible satellites that are capable of GPS satellite reception from the viewpoint of sky view were showed by GIS skyline analysis. Quality evaluation results of GPS observation data were compared with average PDOP calculated from hourly PDOP and TEQC in two points of Sungkyunkwan University during 8 hours. As a result of GPS reception environment using GIS, if the PDOP increases, the data acquisition rate is lowed, and the multipath error and the cycle slip are increased. Thus, this study verified that the quality of GPS observation data can be secured by constructing three-dimensional spatial information and simulating PDOP when preoccupying multiple UCPs using GIS.

Status Report of the NISS and SPHEREx Missions

  • Jeong, Woong-Seob;Park, Sung-Joon;Moon, Bongkon;Lee, Dae-Hee;Park, Won-Kee;Lee, Duk-Hang;Ko, Kyeongyeon;Pyo, Jeonghyun;Kim, Il-Joong;Park, Youngsik;Nam, Ukwon;Kim, Minjin;Ko, Jongwan;Im, Myungshin;Lee, Hyung Mok;Lee, Jeong-Eun;Shin, Goo-Hwan;Chae, Jangsoo;Matsumoto, Toshio
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.58.2-58.2
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    • 2016
  • The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument optimized to the first small satellite of NEXTSat series. The capability of both imaging and low spectral resolution spectroscopy with the Field of View of $2{\times}2deg.$ in the near-infrared range from 0.9 to $3.8{\mu}m$ is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. The Flight Model of the NISS is being developed and tested. After an integration into NEXTSat-1, it will be tested under the space environment. The NISS will be launched in 2017 and it will be operated during 2 years. As an extension of the NISS, SPEHREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) is the NASA SMEX (SMall EXploration) mission proposed together with KASI (PI Institute: Caltech). It will perform an all-sky near-infrared spectral survey to probe the origin of our Universe; explore the origin and evolution of galaxies, and explore whether planets around other stars could harbor life. The SPHEREx is designed to have wider FoV of $3.5{\times}7deg.$ as well as wider spectral range from 0.7 to $4.8{\mu}m$. After passing the first selection process, SPHEREx is under the Phase-A study. The final selection will be made in the end of 2016. Here, we report the current status of the NISS and SPHEREx missions.

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MIRIS: Science Programs

  • Jeong, Woong-Seob;Matsumoto, Toshio;Seon, Kwangil;Pyo, Jeonghyun;Lee, Dae-Hee;Park, Youngsik;Ree, Chang Hee;Moon, Bongkon;Park, Sung-Joon;Nam, Uk-Won;Park, Jang-Hyun;Lee, Duk-Hang;Cha, Sang-Mok;Lee, Sungho;Yuk, In-Soo;Ahn, Kyungjin;Cho, Jungyeon;Lee, Hyung Mok;Han, Wonyong
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.97.2-97.2
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    • 2012
  • The main payload of Science and Technology Satellite 3 (STSAT-3), Multipurpose InfraRed Imaging System (MIRIS) is the first Korean infrared space mission to explore the near-infrared sky with a small astronomical instrument developed by KASI. The 8-cm passively cooled telescope with a wide field of view (3.67 deg. ${\times}$ 3.67 deg.) will be operated in the wavelength range from 0.9 to $2{\mu}m$. It will carry out wide-band imaging and the Paschen-${\alpha}$ emission line survey. After the calibration of MIRIS in our laboratory, MIRIS has been delivered to SaTReC and successfully assembled into the STSAT-3. The main purposes of MIRIS are to perform the observation of Cosmic Infrared Background (CIB) at two wide spectral bands (I and H band) and to survey the Galactic plane at $1.88{\mu}m$ wavelength, the Paschen-${\alpha}$ emission line. CIB observation enables us to reveal the nature of degree-scale CIB fluctuation detected by the IRTS (Infrared Telescope in Space) mission and to measure the absolute CIB level. The MIRIS will continuously monitor the seasonal variation of the zodiacal light towards the both north and south ecliptic poles for the purpose of calibration as well as the effective removal of zodiacal light. The Pashen-${\alpha}$ emission line survey of Galactic plane helps us to understand the origin of Warm Ionized Medium (WIM) and to find the physical properties of interstellar turbulence related to star formation. Here, we also discuss the observation plan with MIRIS.

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MIRIS Science Missions

  • Jeong, Woong-Seob;Matsumoto, Toshio;Seon, Kwang-Il;Lee, Dae-Hee;Ree, Chang-Hee;Park, Young-Sik;Nam, Uk-Won;Pyo, Jeong-Hyun;Moon, Bong-Kon;Park, Sung-Joon;Cha, Sang-Mok;Park, Jang-Hyun;Lee, Duk-Hang;Lee, Sung-Ho;Yuk, In-Soo;Ahn, Kyung-Jin;Cho, Jung-Yeon;Lee, Hyung-Mok;Han, Won-Yong
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.26.4-27
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    • 2010
  • The main payload of STSAT-3 (Science and Technology Satellite 3), MIRIS (Multipurpose InfraRed Imaging System) is the first Korean infrared space mission to explore the near-infrared sky with a small astronomical instrument, which is being developed by KASI. The 8-cm passively cooled telescope with a wide field of view (3.67 deg. $\times$ 3.67 deg.) will be operated in the wavelength range from 0.9 to $2{\mu}m$. It will carry out wide field imaging and the emission line survey. The main purposes of MIRIS are to perform the Cosmic Infrared Background (CIB) observation at two wide spectral bands (I and H band) and to survey the Galactic plane at $1.88{\mu}m$ wavelength, the Paschen-$\alpha$ emission line. CIB observation enables us to reveal the nature of degreescale CIB fluctuation detected by the IRTS (Infrared Telescope in Space) mission and to measure the absolute CIB level. The Pashen-$\alpha$ emission line survey of Galactic plane helps us to understand the origin of Warm Ionized Medium (WIM) and to find the physical properties of interstellar turbulence related to star formation. Here, we also discuss the observation plan with MIRIS.

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The Search for Study on the Construction Process and Changes in the Landscape Plants of the Pasanseodang ('파산서당'의 영건과정과 조경식물 변화상 탐색)

  • Joo, Been;Choi, Hayoung;Shin, Sangsup
    • Korean Journal of Heritage: History & Science
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    • v.51 no.1
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    • pp.48-65
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    • 2018
  • The authors of this paper aim to make a record of the construction process, its symbolic meaning, and the changes in the status of the landscape plants at the Pasanseodang according to the Report on the Pasanseodang written by Park Gyu-hyun in 1874. First, the construction of Samgahun Pavilion, which is located in Myo-ri, Habin-myun, Dalsung-gun, Daegu, took about 90 years and spanned the lifetimes of Park Sungsoo, an 11th-generation descendant of Park Paengnyun (1417~1456) through to Park Kyuhyun, a 14th-generation descendant. It was called the shape of dragon, with its head facing the tail (回龍顧尾形), in feng shui. Second, the village of Pahwoe was founded in 1769, the 45th year of the reign of King Yeongjo, by Park Sungsoo for the purpose of socializing with his friends at his thatched home, and was named after his own courtesy name (Samgahun). Park Kwangseok, the second son of Park Sungsoo, built the sarangchae in 1826 and the anchae in 1869 after his marriage (in 1783). Then, Park Kyuhyun, the grandson of Park Kwangseok, built the pond and planted it with lotus flowers, and built the Hayeopjeong in 1874. The Pasanseodang, as the precursor of the Hayeopjeong, may be related with the name of the hillside region behind Samgahun. Third, a quadrangular-shaped pond with a length of 21m and a width of 15m was also built and planted with lotus flowers. In the center of the pond is a small round island that reflects the world view of the Chosun dynasty, i.e. that the sky is round and the landmass is quadrangular. Meanwhile, the name of the Hayeopjeon reflects the value system of aristocrats who lived a life of leisure and artistic indulgence. They called the eastern room "Yeeyeonhun" (怡燕軒) and the western room "Mongyangjae" (蒙養齋), names which embody their wishes for a good life as a member of the nobility and a bright future for one's descendants. Fourth, in Confucian terms, the authors infer the points of view reflected in the kinds of trees that were planted according to Confucian norms (pine tree, lotus, bamboo), the living philosophy of sustainability (willow), the ideology of seclusion and the search for peace of mind (bamboo), and relief efforts for the poor and a life of practicality (chestnut, oak, wild walnut, lacquer). The authors assert that this way of planting trees was a highly effective design feature of landscape architecture that drew on the locational and symbolic significance of the Seodang. Fifth, the majority of the trees that were initially planted withered and were replaced with different species, except for the locust and lotus, at this point. Nevertheless, a review of the process of construction, symbolic meaning, and original architectural landscape of the Samgahun is of value in demonstrating the extended symbolic meaning of their descendants in terms of the practical loss of the function of the Seodang, the values of Feng Sui (red in the east, white in the west, based on the principles of Feng Sui), the function of repelling evils spirits (kalopanax, trifoliate orange), aesthetic and practical values (sweetbrier, apricot, pear, peach, and oriental oak trees), and the prosperity of the family and the timeless value of honest poverty (silk, crape myrtle, and yew trees).

Satisfaction Survey of Occupational Therapy Service at Specialized Child-care Centers for Disabled in Gyeongbuk (경북지역 장애아전문어린이집의 작업치료서비스에 대한 만족도 조사)

  • Kang, Suk-Gu;Lee, Chun-Yeop
    • The Journal of Korean society of community based occupational therapy
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    • v.5 no.1
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    • pp.55-62
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    • 2015
  • Objective : The purpose of this study was to investigate the satisfaction of occupational therapy service for parents of children with disabilities using specialized child-care centers for disabled in Gyeongbuk. Methods : The subjects of this study were 104 parents who have experience in occupational therapy at 14 specialized child-care centers for disabled in Gyeongbuk. A questionnaire was conducted from July, 2014 to March, 2015. Descriptive statistics of frequency, mean, standard deviation, and One-Way ANOVA study were used to analyze data. Results : Disabled children got occupational therapy at first when they were 3.25 years, on average. Duration of occupational therapy use were 31.84 month, on average. The subjects determined to got occupational therapy mostly through consultation nurseries(40.4%). Most of them got speech therapy(78.0%) other than receiving occupational therapy service, responded very necessary to occupational therapy(69.3%). Satisfaction of occupational therapy service were 4.49 point at attitude of occupational therapists, 4.36 point at occupational therapy program, and 4.26 point at environment of occupational therapy room. Attitude of occupational therapists were the highest satisfied. Conclusion : This study would contribute to effective and meaningful occupational therapy through objective view

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