• Title/Summary/Keyword: Large-Surface

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Calculation of Soil Moisture and Evapotranspiration of KLDAS applying Ground-Observed Meteorological Data (지상관측 기상자료를 적용한 KLDAS(Korea Land Data Assimilation System)의 토양수분·증발산량 산출)

  • Park, Gwangha;Kye, Changwoo;Lee, Kyungtae;Yu, Wansik;Hwang, Eui-ho;Kang, Dohyuk
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1611-1623
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    • 2021
  • Thisstudy demonstratessoil moisture and evapotranspiration performance using Korea Land Data Assimilation System (KLDAS) under Korea Land Information System (KLIS). Spin-up was repeated 8 times in 2018. In addition, low-resolution and high-resolution meteorological data were generated using meteorological data observed by Korea Meteorological Administration (KMA), Rural Development Administration (RDA), Korea Rural Community Corporation (KRC), Korea Hydro & Nuclear Power Co.,Ltd. (KHNP), Korea Water Resources Corporation (K-water), and Ministry of Environment (ME), and applied to KLDAS. And, to confirm the degree of accuracy improvement of Korea Low spatial resolution (hereafter, K-Low; 0.125°) and Korea High spatial resolution (hereafter, K-High; 0.01°), soil moisture and evapotranspiration to which Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and ASOS-Spatial (ASOS-S) used in the previous study were applied were evaluated together. As a result, optimization of the initial boundary condition requires 2 time (58 point), 3 time (6 point), and 6 time (3 point) spin-up for soil moisture. In the case of evapotranspiration, 1 time (58 point) and 2 time (58 point) spin-ups are required. In the case of soil moisture to which MERRA-2, ASOS-S, K-Low, and K-High were applied, the mean of R2 were 0.615, 0.601, 0.594, and 0.664, respectively, and in the case of evapotranspiration, the mean of R2 were 0.531, 0.495, 0.656, and 0.677, respectively, indicating the accuracy of K-High was rated as the highest. The accuracy of KLDAS can be improved by securing a large number of ground observation data through the results of this study and generating high-resolution grid-type meteorological data. However, if the meteorological condition at each point is not sufficiently taken into account when converting the point data into a grid, the accuracy is rather lowered. For a further study, it is expected that higher quality data can be produced by generating and applying grid-type meteorological data using the parameter setting of IDW or other interpolation techniques.

Topographic Factors Computation in Island: A Comparison of Different Open Source GIS Programs (오픈소스 GIS 프로그램의 지형인자 계산 비교: 도서지역 경사도와 지형습윤지수 중심으로)

  • Lee, Bora;Lee, Ho-Sang;Lee, Gwang-Soo
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.903-916
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    • 2021
  • An area's topography refers to the shape of the earth's surface, described by its elevation, slope, and aspect, among other features. The topographical conditions determine energy flowsthat move water and energy from higher to lower elevations, such as how much solar energy will be received and how much wind or rain will affect it. Another common factor, the topographic wetness index (TWI), is a calculation in digital elevation models of the tendency to accumulate water per slope and unit area, and is one of the most widely referenced hydrologic topographic factors, which helps explain the location of forest vegetation. Analyses of topographical factors can be calculated using a geographic information system (GIS) program based on digital elevation model (DEM) data. Recently, a large number of free open source software (FOSS) GIS programs are available and developed for researchers, industries, and governments. FOSS GIS programs provide opportunitiesfor flexible algorithms customized forspecific user needs. The majority of biodiversity in island areas exists at about 20% higher elevations than in land ecosystems, playing an important role in ecological processes and therefore of high ecological value. However, island areas are vulnerable to disturbances and damage, such as through climate change, environmental pollution, development, and human intervention, and lacks systematic investigation due to geographical limitations (e.g. remoteness; difficulty to access). More than 4,000 of Korea's islands are within a few hours of its coast, and 88% are uninhabited, with 52% of them forested. The forest ecosystems of islands have fewer encounters with human interaction than on land, and therefore most of the topographical conditions are formed naturally and affected more directly by weather conditions or the environment. Therefore, the analysis of forest topography in island areas can be done more precisely than on its land counterparts, and therefore has become a major focus of attention in Korea. This study is focused on calculating the performance of different topographical factors using FOSS GIS programs. The test area is the island forests in Korea's south and the DEM of the target area was processed with GRASS GIS and SAGA GIS. The final slopes and TWI maps were produced as comparisons of the differences between topographic factor calculations of each respective FOSS GIS program. Finally, the merits of each FOSS GIS program used to calculate the topographic factors is discussed.

Decomposition of Eco-friendly Liquid Propellants over Platinum/Hexaaluminate Pellet Catalysts (백금/헥사알루미네이트 펠렛 촉매를 이용한 친환경 액체 추진제 분해)

  • Jo, Hyeonmin;You, Dalsan;Kim, Munjeong;Woo, Jaegyu;Jung, Kyeong Youl;Jo, Young Min;Jeon, Jong-Ki
    • Clean Technology
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    • v.24 no.4
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    • pp.371-379
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    • 2018
  • The objective of this study is to develop a platinum/hexaaluminate pellet catalyst for the decomposition of eco-friendly liquid propellant. Pellet catalysts using hexaaluminate prepared by ultrasonic spray pyrolysis as a support and platinum as an active metal were prepared by two methods. In the case of the pellet catalyst formed by loading the platinum precursor onto the hexaaluminate powder and then adding the binder (M1 method catalyst), the mesopores were well developed in the catalyst after calcination at $550^{\circ}C$. However, when this catalyst was calcined at $1,200^{\circ}C$, the mesopores almost collapsed and only a few macropores existed. On the other hand, in the case of a catalyst in which platinum was supported on pellets after the pellet was produced by extrusion of hexaaluminate (M2 method catalyst), the surface area and the mesopores were well maintained even after calcination at $1,200^{\circ}C$. Also, the catalyst prepared by the M2 method showed better heat resistance in terms of platinum dispersion. The effects of preparation method and calcination temperature of Pt/hexaaluminate pellet catalysts on the decomposition of liquid propellant composed mainly of ammonium dinitramide (ADN) or hydroxyl ammonium nitrate (HAN) were investigated. It was confirmed that the decomposition onset temperature during the decomposition of ADN- or HAN- based liquid propellant could be reduced significantly by using Pt/hexaaluminate pellet catalysts. Especially, in the case of the catalyst prepared by the M2 method, the decomposition onset temperature did not show a large change even when the calcination temperature was raised at $1,200^{\circ}C$. Therefore, it was confirmed that Pt/ hexaaluminate pellet catalyst prepared by M2 method has heat resistance and potential as a catalyst for the decomposition of the eco-friendly liquid propellants.

Exposure and Risk Assessments of Multimedia of Arsenic in the Environment (환경 중 비소의 매체통합 노출평가 및 위해성평가 연구)

  • Sim, Ki-Tae;Kim, Dong-Hoon;Lee, Jaewoo;Lee, Chae-Hong;Park, Soyeon;Seok, Kwang-Seol;Kim, Younghee
    • Journal of Environmental Impact Assessment
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    • v.28 no.2
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    • pp.152-168
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    • 2019
  • The element arsenic, which is abundant in the Earth's crust, is used for various industrial purposes including materials for disease treatment and household goods. Various human activities, such as the disposal of soil waste, metal mining and smelting, and combustion of fossil fuels, have caused the pollution of the environment with arsenic. Recently, guidelines for arsenic in rice have been adopted by the Korean ministry of food and drug safety to prevent health risks based on rice consumption. Because of the exposure to arsenic and its accumulation in the human body through various channels, such as air inhalation, skin contact, ingestion of drinking water, and food consumption, integrated multimedia risk assessment is required to adopt appropriate risk management policies. Therefore, integrated human health risk assessment was carried out in this study using integrated exposure assessment based on multimedia (e.g., air, water, and soil) and multi-route (e.g., oral, inhalation, and dermal) scenarios. The results show that oral uptake via drinking water is the most common pathway of arsenic into the human body, accounting for 57%-96% of the total arsenic exposure. Among various age groups, the highest exposures to arsenic were observed in infants because the body weight of infants is low and the surface areas of infant bodies are large. Based on the results of the exposure assessment, the cancer and non-cancer risks were calculated. The cancer risk for CTE and RME is in the range of 2.3E-05 to 6.7E-05 and thus is negligible because it does not exceed the cancer probability of 1.0E-04 for all age groups. On the other hand, the cancer risk for RME varies from 6.4E-05 to 1.8E-04 and from 1.3E-04 to 1.8E-04 for infants and preschool children, exceeding the excess cancer risk of 1.0E-04. The non-cancer risks range from 5.4E-02 to 1.9E-01 and from 1.5E-01 to 6.8E-01, respectively. They do not exceed the hazard index 1 for all scenarios and all ages.

The Study on Restoration & Repair of the Seated Stone Statue of Buddha in the Samreoung Valley of Mt. Namsan (경주 남산 삼릉계 석불좌상 보존 및 복원 연구)

  • Jeong, Min Ho;Ji, Sung Jin
    • Korean Journal of Heritage: History & Science
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    • v.43 no.3
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    • pp.242-281
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    • 2010
  • There are a large number of Buddhist cultural relics in Mt. Namsan. The cultural relics carry the spirit of people of Shila who dream of Buddhist Elysium and the establishment of Buddhist nation. In the valley and the top of the mountain and on various rock cliff, stone statues of Buddha and stone pagodas stand in harmony with nature. For that reason, Mt. Namsan is called an open-air museum. And it played an important role in establishing 'The UNESCO World Heritage' status for Gyeongdju in December 2000. But sadly, there are many stone relics that have eroded away and damaged from collapsing in the passage of time. The seated stone statue of Buddha in Samreoung valley of Mt. Namsan is one of them. It was created between the 8th and 9th century, and restored without much care nor extensive historical research in 1923. As a result, The face of the Buddha remained with concrete mortar and its nimbus fallen backward and destroyed. Therefore, restoration and repair as well as creation of a statue environment for the statue were urgent. So we immediately started in restoration and repair. First, through the archaeological excavation around the stone Buddha, we carried the stone Buddha on the original position. In order to restore the statues to its original glory created by the Unified Shila Dynasty, we created a restoration plan in corporation with art historians and historians, then restored the jaw and the damage nimbus. Second, we made the weathering & damage map of the stone Buddha. In order to prevent second damage, we cleaned the surface of contaminants with distilled water. Third, we studied restoration method to prevent artificial damage. We recreated parts of his face and halo. Then each parts of the statue were restored to their original position. In the whole process of restoration, we tried to use traditional techniques.

Global Ocean Data Assimilation and Prediction System in KMA: Description and Assessment (기상청 전지구 해양자료동화시스템(GODAPS): 개요 및 검증)

  • Chang, Pil-Hun;Hwang, Seung-On;Choo, Sung-Ho;Lee, Johan;Lee, Sang-Min;Boo, Kyung-On
    • Atmosphere
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    • v.31 no.2
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    • pp.229-240
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    • 2021
  • The Global Ocean Data Assimilation and Prediction System (GODAPS) in operation at the KMA (Korea Meteorological Administration) is introduced. GODAPS consists of ocean model, ice model, and 3-d variational ocean data assimilation system. GODAPS assimilates conventional and satellite observations for sea surface temperature and height, observations of sea-ice concentration, as well as temperature and salinity profiles for the ocean using a 24-hour data assimilation window. It finally produces ocean analysis fields with a resolution of 0.25 ORCA (tripolar) grid and 75-layer in depth. This analysis is used for providing a boundary condition for the atmospheric model of the KMA Global Seasonal Forecasting System version 5 (GloSea5) in addition to monitoring on the global ocean and ice. For the purpose of evaluating the quality of ocean analysis produced by GODAPS, a one-year data assimilation experiment was performed. Assimilation of global observing system in GODAPS results in producing improved analysis and forecast fields with reduced error in terms of RMSE of innovation and analysis increment. In addition, comparison with an unassimilated experiment shows a mostly positive impact, especially over the region with large oceanic variability.

An Inquiry into the Iron Seated Buddha Excavated from Pocheon in the National Museum of Korea (국립중앙박물관 소장 포천 출토 철조여래좌상에 대한 소고)

  • Kang, Kunwoo
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.96
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    • pp.209-223
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    • 2019
  • The Iron Seated Buddha sculpture in the National Museum of Korea had long sat unregistered in storage at the museum. However, a new accession number "bon9976" has recently been assigned to it. This sculpture was excavated from the neighborhood of Heungnyongsa Temple in Baekun-ri, Yidong-myeon, Pocheon-gun, Gyeonggi-do Province together with another Iron Seated Buddha sculpture(bon9975) called "Iron Buddha from Pocheon." A comparison and examination of Gelatin Dry Plate and official documents from the Joseon Government-General Museum during the Japanese occupation period have revealed that these two Iron Buddha sculptures were transferred to the Museum of the Government-General of Korea on December 17, 1925. The Iron Seated Buddha sculpture(bon9976) has a height of 105 centimeters, width at the shoulders of 57 centimeters, and width at the knee of 77 centimeters. The Buddha is wearing a robe with rippling drapery folds and the right shoulder exposed. He is seated in the position called gilsangjwa(the seat of good fortune) in which the left foot is placed over the right thigh. The features of the Buddha's oval face are prominently sculpted. The voluminous cheeks, eye sockets in a large oval shape, slanted eyes, short nose, and plump lips can also be found in other ninth-century Iron Seated Buddha sculptures at Silsangsa Temple in Namwon, Jeollanam-do Province, Hancheonsa Temple in Yecheon, Gyeongsangbuk-do Province, and Samhwasa Temple in Donghae-si, Gangwon-do Province. Moreover, its crossed legs, robe exposing the right shoulder, and rippling drapery folds suggest that this sculpture might have been modeled after the main Buddha sculpture of the Seokguram Grotto from the eighth century. The identity of this Iron Seated Buddha can be determined using the Gelatin Dry Plate(M442-2, M442-7). In them, the Buddha has its right palm facing upwards and holds a medicine jar on its left palm. Until now, the Iron Seated Bhaiṣajyagura(Medicine) Buddha(bon1970) excavated from Wonju has been considered the sole example of an iron Medicine Buddha sculpture. However, this newly registered Iron Seated Buddha turns out to be a Medicine Buddha holding a medicine jar. Furthermore, it serves as valuable material since traces of gilding and lacquering clearly remain on its surface. This Iron Seated Buddha sculpture (bon9976) is presumed to have been produced around the ninth century under the influence of Esoteric Buddhism by the Monk Doseon(827~898), a disciple of the Monk Hyecheol, to protect the temple and help the country overcome geographical shortcomings. According to the records stored at Naewonsa Temple(later Heungnyongsa Temple), Doseon selected three significant sites, including Baegunsan Mountain, built "protector" temples, created the Bhaisajyagura Buddha triad, and enshrined them at the temples. Moreover, the inscription on the stele on the restoration of Seonamsa Temple states that Doseon constructed temples and produced iron Buddha sculptures to help the country surmount certain geographical shortcomings. Heungnyongsa Temple is located in Dopyeong-ri, Yidong-myeon, Pocheon-si, Gyeonggi-do Province. This region appears to have been related to rituals directed to the Medicine Buddha since Yaksa Temple(literally, "the temple of medicine") was built here during the Goryeo Dynasty, and the Yaksa Temple site with its three-story stone pagoda and Yaksadong Valley still exist in Dopyeong-ri.

Utility and Care Patterns of Lotus Shown in Classic Poetries and Proses, Painting (고전 시문과 회화를 통해 본 연(Nelumbonucifera)의 활용과 애호 행태)

  • Kim, Myung-Hee;Hong, Hyoung-Soon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.1-13
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    • 2011
  • The purpose of this study is to consider practical examples of the method of utilizing plant material 'lotus' used by the ancients, and the value and meaning they wanted to get from it. The method of this study to do this is descriptive study to consider and interpret poem and painting reflecting impression and concept world of lotus. Summary of this study is as follows. First, ornamental value of lotus could be divided in effect of group plant and detail value held by the flower, the leaves and the stem. Especially, group plant lotus in large site provides unique landscape differentiated form other flowering plants. As well, another feature of lotus is its high ornamental value spread in detail elements including the flower, the leaves, the stem and the lotus seed. Second, fragrance expressed 'Hyang-won-ik-cheong(香遠益淸)' is an important charm of lotus. Lotus was utilized as olfactory element providing fragrance. The ancients considered lotus fragrance not only for enjoy but as symbolic object comparing noble man's dignity so that they expressed it in poem and painting. Third, lotus was utilized as acoustical element. That is, the sound of raindrops harmonizing the surface of water and wide lotus leaves was called 'hearing lotus fond and rain', enjoying it as classic grace. Fourth, summer play lotus sightseeing was called mind wash up meaning 'washing the mind polluted by the mundane world'. Such poetic taste was widely enjoyed by various classes from general public to royal family. Besides, poetic taste related with lotus is the method of drinking alcohol using the feature of big lotus leave and vacant stem, called 'Beog-tong-ju(碧筒酒)'. And in the Joseon dynasty period, when the distinction between the man and the woman influenced by Confucian, lotus seed and 'lotus collecting song' was important sign to express romance between man and woman. Lotus has been enamored by wide classes transcending cultural background as thought and religion since ancient times. Due to such reasons, various symbolic meaning of lotus and planting examples related to religious facilities as temples could not be considered in various manner is limitation of this study, and which is research project for the future.

Sapflux Measurement Database Using Granier's Heat Dissipation Method and Heat Pulse Method (수액류 측정 데이터베이스: 그래니어(Granier) 센서 열손실탐침법(Heat Dissipation Method)과 열파동법(Heat Pulse Method)을 이용한 수액류 측정)

  • Lee, Minsu;Park, Juhan;Cho, Sungsik;Moon, Minkyu;Ryu, Daun;Lee, Hoontaek;Lee, Hojin;Kim, Sookyung;Kim, Taekyung;Byeon, Siyeon;Jeon, Jihyun;Bhusal, Narayan;Kim, Hyun Seok
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.22 no.4
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    • pp.327-339
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    • 2020
  • Transpiration is the movement of water into the atmosphere through leaf stomata of plant, and it accounts for more than half of evapotranspiration from the land surface. The measurements of transpiration could be conducted in various ways including eddy covariance and water balance method etc. However, the transpiration measurements of individual trees are necessary to quantify and compare the water use of each species and individual component within stands. For the measurement of the transpiration by individual tree, the thermometric methods such as heat dissipation and heat pulse methods are widely used. However, it is difficult and labor consuming to maintain the transpiration measurements of individual trees in a wide range area and especially for long-term experiment. Therefore, the sharing of sapflow data through database should be useful to promote the studies on transpiration and water balance for large spatial scale. In this paper, we present sap flow database, which have Granier type sap flux data from 18 Korean pine (Pinus koraiensis) since 2011 and 16 (Quercus aliena) since 2013 in Mt.Taehwa Seoul National University forest and 18 needle fir (Abies holophylla), seven (Quercus serrata), three (Carpinus laxiflora and C. cordata each since 2013 in Gwangneung. In addition, the database includes the sapling transpiration of nine species (Prunus sargentii, Larix kaempferii, Quercus accutisima, Pinus densiflora, Fraxinus rhynchophylla, Chamecypans obtuse, P. koraiensis, Betulla platyphylla, A. holophylla, Pinus thunbergii), which were measured using heat pulse method since 2018. We believe this is the first database to share the sapflux data in Rep. of Korea, and we wish our database to be used by other researchers and contribute a variety of researches in this field.

Re-conservation of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration Excavated from Tomb No. 55 at the Dalseong Ancient Tomb Complex in Daegu and a Study of Its Production Method (대구 달성 55호분 출토 삼엽문이자태도의 재보존처리와 제작 기법 연구)

  • Lee, Huisung;Huh, Ilkwon;Ro, Jihyun;Park, Seungwon
    • Conservation Science in Museum
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    • v.24
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    • pp.1-16
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    • 2020
  • This paper presents the process of re-conservation and the results of research on the production method of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration, one of the excavation findings from Tomb No. 55 in the Dalseong Ancient Tomb Complex in Daegu. This iron sword is a double weapon with two large swords housed within a single sheath. Four smaller swords are attached to the surface of the sheath, two on the upper portion and the other two below. It is the only such two-in-one weapon excavated intact thus far from an ancient Korean tomb. The records show that it underwent conservation treatment twice in the past. In this study, it was subjected to conservation treatment again to replace the stiffener in some cracking areas, and its material, composition, and production method were analyzed by CT, XRF analysis, and stereoscopic microscopy. The sword is mainly made of copper, but the golden component contains both gold and mercury, which suggests that the copper was plated in gold using mercury amalgamation. The examination of the production methods indicates that it was intended more to demonstrate the authority of its owner rather than to serve any practical use. The two upper small swords on the sheath were made in the same manner as the main swords, and the two small lower swords were cut from a single metal sheet. The sheath was made by cutting two metal sheets. Supports were used to attach the two small swords to the upper portion of the sheath, while the lower portion of the sheath was slit to allow the other two small swords to be inserted into it. The ring pommels of the main swords have a three-pointed leaf decoration. As for the other designs, the handle of the main sword features a series of semicircles, the decorative bands on the sheath have waves in dots, and the fish tail of the sheath shows diagonal lines of dots.