• Title/Summary/Keyword: High altitude

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Analysis of Optical Characteristic Near the Cloud Base of Before Precipitation Over the Yeongdong Region in Winter (영동지역 겨울철 스캔라이다로 관측된 강수 이전 운저 인근 수상체의 광학 특성 분석)

  • Nam, Hyoung-Gu;Kim, Yoo-Jun;Kim, Seon-Jeong;Lee, Jin-Hwa;Kim, Geon-Tea;An, Bo-Yeong;Shim, Jae-Kwan;Jeon, Gye-hak;Choi, Byoung-Choel;Kim, Byung-Gon
    • Korean Journal of Remote Sensing
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    • v.34 no.2_1
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    • pp.237-248
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    • 2018
  • The vertical distribution of hydrometeor before precipitation near the cloud base has been analyzed using a scanning lidar, rawinsonde data, and Cloud-Resolving Storm Simulator (CReSS). This study mostly focuses on 13 Desember 2016 only. The typical synoptic pattern of lake-effect snowstorm induced easterly in the Yeongdong region. Clouds generated due to high temperature difference between 850 hPa and sea surface (SST) penentrated in the Yeongdong region along with northerly and northeasterly, which eventually resulted precipitation. The cloud base height before the precipitation changed from 750 m to 1,280 m, which was in agreement with that from ceilometer at Sokcho. However, ceilometer tended to detect the cloud base 50 m ~ 100 m below strong signal of lidar backscattering coefficient. As a result, the depolarization ratio increased vertically while the backscattering coefficient decreased about 1,010 m~1,200 m above the ground. Lidar signal might be interpreted to be attenuated with the penetration depth of the cloud layer with of nonspherical hydrometeor (snow, ice cloud). An increase in backscattering signal and a decrease in depolarization ratio occured in the layer of 800 to 1,010 m, probably being associated with an increase in non-spherical particles. There seemed to be a shallow liquid layer with a low depolarization ratio (<0.1) in the layer of 850~900 m. As the altitude increases in the 680 m~850 m, the backscattering coefficient and depolarization ratio increase at the same time. In this range of height, the maximum value (0.6) is displayed. Such a result can be inferred that the nonspherical hydrometeor are distributed by a low density. At this time, the depolarization ratio and the backscattering coefficient did not increase under observed melting layer of 680 m. The lidar has a disadvantage that it is difficult for its beam to penetrate deep into clouds due to attenuation problem. However it is promising to distinguish hydrometeor morphology by utilizing the depolarization ratio and the backscattering coefficient, since its vertical high resolution (2.5 m) enable us to analyze detailed cloud microphysics. It would contribute to understanding cloud microphysics of cold clouds and snowfall when remote sensings including lidar, radar, and in-situ measurements could be timely utilized altogether.

Carbon Monoxide Dispersion in an Urban Area Simulated by a CFD Model Coupled to the WRF-Chem Model (WRF-Chem 모델과 결합된 CFD 모델을 활용한 도시 지역의 일산화탄소 확산 연구)

  • Kwon, A-Rum;Park, Soo-Jin;Kang, Geon;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.36 no.5_1
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    • pp.679-692
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    • 2020
  • We coupled a CFD model to the WRF-Chem model (WRF-CFD model) and investigated the characteristics of flows and carbon monoxide (CO) distributions in a building-congested district. We validated the simulated results against the measured wind speeds, wind directions, and CO concentrations. The WRF-Chem model simulated the winds from southwesterly to southeasterly, overestimating the measured wind speeds. The statistical validation showed that the WRF-CFD model simulated the measured wind speeds more realistically than the WRF-Chem model. The WRF-Chem model significantly underestimated the measured CO concentrations, and the WRF-CFD model improved the CO concentration prediction. Based on the statistical validation results, the WRF-CFD model improved the performance in predicting the CO concentrations by taking complicatedly distributed buildings and mobiles sources of CO into account. At 04 KST on May 22, there was a downdraft around the AQMS, and airflow with a relatively low CO concentration was advected from the upper layer. Resultantly, the CO concentration was lower at the AQMS than the surrounding area. At 15 KST on May 22, there was an updraft around the AQMS. This resulted in a slightly higher CO concentration than the surroundings. The WRF-CFD model transported CO emitted from the mobile sources to the AQMS measurement altitude, well reproducing the measured CO concentration. At 18 KST on May 22, the WRF-CFD model simulated high CO concentrations because of high CO emission, broad updraft area, and an increase in turbulent diffusion cause by wind-shear increase near the ground.

Changes of Sedimentary Environment in the Tidal Flat of the Dammed Yeongsan River Estuary, Southwestern Coast of Korea (영산강 하구 갯벌의 퇴적환경 변화)

  • Kim, Young-Gil;Lee, Myong Sun;Chang, Jin Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.6
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    • pp.687-697
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    • 2019
  • By monitoring sediment grain size and level variation of tidal flat surface for 6 years (2005-2011), and also by mooring TISDOS (tidal-flat sediment dynamics observation system) on the low intertidal flat in 2008, we investigated the sedimentary environment of tidal flat in the dammed Yeongsan River Estuary. The tidal flat of the Yeongsan River Estuary lost 82 % of its area because of coastal development projects, and a narrow tidal flat below mean sea level now remains. Most of the tidal flat sediments are composed of silt up to 70-94 %, and show the characteristics of clay deficiency and silt dominance. This is closely related with the coastal development, which led to the destruction of high tidal flats where most mud settled, and the modification of tidal current patterns. Moreover, the estuarine tidal-flat sediments reveal seasonal variation. They are coarse with abundant silt during windy autumn to spring, fine with abundant clay during the less-windy and high-discharge summer. This phenomenon indicates that the behavior of sediment particles on the low intertidal flats of the Yeongsan River Estuary is influenced by wind waves for silt and fresh water discharge and the tidal process for clay. Monitoring results of the altitude of tidal flat surface showed that the study area had eroded at an average rate of -2.6 cm/y during the period of 2005-2011, and also that an unusual deposition with a rate of 4 cm/y occurred in 2010. The erosion can be explained by an increased tidal amplitude and a strengthened ebb-dominant tidal asymmetry after the construction of an estuary dike and the Yeongam Kumho Seawall. The deposition in 2010 seems to have been closely related to the mass production of suspended materials from dredging of the estuary.

Consumer Intention to Purchase Domestic/Foreign Brand Jeans;Beliefs, Attitude, and Individual Characteristics. (국내 및 외국 상표 청바지의 구매의도에 따른 평가기준에 대한 신념과 추구이미지 및 의복태도의 차이연구)

  • 고애란
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.2
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    • pp.263-272
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    • 1994
  • The purpose of this study was to identify factors that might distinguish those who have a high level of Intention to purchase each of domestic, foreign designer and national brand jeans from those who have a low intention in terms of evaluative criteria belief, ideal jeans image and clothing altitude. The sample consisted of 198 male and 197 female students from five universities in Seoul. The questionnnaire consisted of 50 seven-point semantic differential scales dealing with evaluative criteria and ideal jeans image, beliefs about and intention to purchase domestic, foreign designer and foreign national brand jeans and 25 Likert type clothing attitude scales. Based on a series of t-tests the results showed that color and design were the most influencing factor among the evaluative criteria belief, regardless of brand type, while durability, accessory, sewing were the least. Sexy image, brand consciousnees and fashion interest were the important factor that distinguish high intention to purchase group fro)m low intention to purchase group.

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A Study on the Forest Vegetation of Odaesan National Park, Korea (오대산국립공원 삼림식생에 관한 연구)

  • Kim, Chang-Hwan;Oh, Jang-Geun;Lee, Nam-Sook;Choi, Young-Eun;Song, Myoung-Jun
    • Korean Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.61-67
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    • 2015
  • This study, which was conducted from Apr. 2013 to Jan. 2014, was carried out as part of a project of making a more detailed ecological zoning map with 1/5,000 scale. The necessity of electronic vegetation map with large scale has arisen in order to make the best use of basic research findings on resource monitoring of National Parks and to enhance efficiency in National Park management. In order to improve accuracy and speed of vegetation research process, the data base for vegetation research was categorized into five groups, namely broad-leaved forest, coniferous forest, mixed forest, rock vegetation and miscellaneous one. And then a vegetation map for vegetation research was created for the research on the site. What is in the database for vegetation research and the vegetation map reflecting findings from vegetation research showed similar distribution rate for broad-leaved forest with 71.965% and 71.184%, respectively. The distribution rate of coniferous forest (16.010%, 15.747%), mixed forest (10.619%, 12.085%), and rock vegetation (0.015%, 0.002%) did not have much difference. In a detailed vegetation map reflecting vegetation research findings, the broad-leaved mountain forest was the most widely distributed with 60.096% based on the physiognomy classification. It was followed by mountain coniferous forest (16.332%), mountain valley forest (15.887%), and plantation forest (3.558%) As for vegetation conservation classification evaluated in the national park, grade I and grade II areas took up 200.44 km2, 61.80% and 108.80 km2, 33.55% respectively. The combined area of these two amounts to 95.35%, making this area the first grade area in ecological nature status. This means that this area is highly worth preserving its vegetation. The high rate of grade I area such as climax forests, unique vegetation, and subalpine vegetation seems to be attributable to diverse innate characteristics of Odaesan National Park, high altitude, low level of artificial disturbance, the subalpine zone formed on the ridge of the mountain top, and their vegetation formation, which reflects climatic and geological characteristics, despite continuous disturbance by mountain climbing.

Vegetation Structure of Vaccinium bracteatum Thunb. Habitat Area at A Valley of Southern Slope in Mt. Halla, Jeju Island (한라산 남사면 계곡 모새나무 자생지 일대의 식생구조)

  • Song, Jung-Min;Kim, Yunjung;Sun, Byung-Yun;Kim, Chul Hwan;Do, Seon-Gil;Song, Gwanpil
    • Korean Journal of Plant Resources
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    • v.26 no.5
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    • pp.589-596
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    • 2013
  • Vaccinium bracteatum Thunb. is an evergreen plant that belongs to the Genus Vaccinium distributed in Korea, and its fruit has been used for food by the common people and thus has a high possibility of commercialization. Therefore, the habitat environment and individual characteristics of V. bracteatum in Jeju Island were investigated to obtain the basic data for commercialization and preservation. The results showed that V. bracteatum is mostly distributed on the southern slope of Mt. Halla at an altitude of 100 to 500 m. V. bracteatum that occurred in the quadrat were total 30 individuals, which had an average height of 6.0 m, an average DBH of 7.8 cm, and an average number of trunk of 4.3. As for the community structure of the habitat, the average percentage of vegetation cover for the tree layer was 36%, while that for the subtree layer was 78%, which emphasized the importance of the subtree layer. The total number of species that occurred in the quadrat was 76. For the tree layer, total 10 species occurred, which include 2 species of evergreen coniferous trees, 3 species of evergreen broad-leaved trees, and 5 species of deciduous broad-leaved trees. For the subtree layer, total 24 species occurred, which include 1 species of evergreen coniferous tree, 11 species of evergreen broad-leaved trees, and 10 species of deciduous broad-leaved trees. Among these, Eurya japonica Thunb. was the species with a high relative contribution, which threatened V. bracteatum For the shrub layer, 27 species occurred including Cinnamomum japonicum Siebold, and for the herbaceous layer, 64 species occurred including Ardisia crenata Sims. The similarity between the habitats of V. bracteatum was very low, and it did not prefer a characteristic community. The V. bracteatum community around Shinrei stream was distributed on the surrounding area adjacent to the slope of the stream rather than the slope. There were a lot of basins, but the branches, which did not receive sunlight, had withered. It is thought that V. bracteatum would decline if the forest formation continues.

Sulforaphane and Total Phenolics Contents and Antioxidant Activity of Radish according to Genotype and Cultivation Location with Different Altitudes (재배지 고도에 따른 무 품종별 설포라판, 총페놀함량 및 항산화 특성)

  • Im, Ju-Sung;Lee, Eung-Ho;Lee, Jong-Nam;Kim, Ki-Deog;Kim, Hwa-Yeong;Kim, Myung-Jun
    • Horticultural Science & Technology
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    • v.28 no.3
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    • pp.335-342
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    • 2010
  • Sulforaphane (SFN) and total phenolics (TPC) contents and antioxidant activity (AA) were analyzed from 13 radish genotypes (Rhaphanus sativus L.), cultivated at 3 locations with different altitudes (Gangneung: asl 5 m, Jinbu: asl 550 m, and Daegwallyeong: asl 750 m). SFN varied greatly from 0.1 to $120.5{\mu}g{\cdot}g^{-1}$ in dry weight test and was significantly affected by location ($P{\leq}0.001$), genotype ($P{\leq}0.001$) and $location{\times}genotype$ interaction ($P{\leq}0.01$). Radishes, cultivated at Daegwallyeong site, showed higher SFN than those of other locations. Among different genotypes, the root of 'Black radish' and leaves of 'Purunmu' of Daegwallyeong had the highest SFN (107.8 and $120.5{\mu}g{\cdot}g^{-1}$, respectively). TPC in root was affected by genotype ($P{\leq}0.001$), and $location{\times}genotype$ interaction ($P{\leq}0.01$), but not by location. In leaves, TPC was affected by location ($P{\leq}0.01$), genotype ($P{\leq}0.001$), and $location{\times}genotype$ interaction ($P{\leq}0.001$). AA expressed as electron donating ability was significantly influenced by location, genotype and $location{\times}genotype$ interaction and correlated positively with TPC ($Pearson's$ $r$=0.897) in root. These results suggest that radish could be a good source of functional food and high altitude location such as Daegwallyeong has potential for the production of radish with high content of health promoting factors.

Distribution and Species Prediction of Epilithic Diatom in the Geum River Basin, South Korea (금강권역 주요 하천의 돌 부착돌말류 분포 및 출현예측)

  • Cho, In-Hwan;Kim, Ha-Kyung;Choi, Man-Young;Kwon, Yong-Su;Hwang, Soon-Jin;Kim, Sang-Hoon;Kim, Baik-Ho
    • Korean Journal of Ecology and Environment
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    • v.48 no.3
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    • pp.153-167
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    • 2015
  • In order to understand the relationship between the distribution of epilithic diatoms and the habitual environments, land-use, water qualities, and epilithic diatoms were studied at 141 sampling sites in the midwestern stream of Korean peninsula (Geum river, Mangyeong river, Dongjin river, and Sapgyo river). The total 183 diatom taxa was appeared in the study, while the dominant species were found to be Nitzschia palea (10.9%) and Achnanthes convergens (8.4%). Based on the abundance of epilithic diatoms, a cluster analysis results indicate that the sampling sites divided the sampling sites into 4 groups (G) at the 25% level. In term of geographic and aquatic environments, G-I and -II accounted for the upper and mid streams of the Geum river, and had large forest areas and good in water quality. G-III accounted for farmland and urban, and high concentration nutrient levels (TN and TP) and electric conductivity. G-IV accounted for mostly farmland, and high levels in turbidity, BOD, nutrient and electric conductivity. CCA results showed that the saproxenous taxa Meridion circulare was the indicator species of G-I, which strongly influenced by altitude and forests. In G-II, the indifferent taxa Navicula cryptocephala was influenced by Chl-a, AFDM, and DO. In G-III and -IV, the indifferent taxa Fragilaria elliptica and saprophilous taxa Aulacoseira ambigua were influenced by electric conductivity, turbidity, and nutrient counts. Meanwhile, random forest results showed that the predicting factor of indicator species appearance in G-I, -II, and -III was found to be electric conductivity whereas in G-IV it was found to be turbidity. Collectively, the distribution of diatoms in the midwestern of Korean peninsula was found to depend more on the land-use and its subsequent water qualities than the inherent characteristics of the aquatic environment.

Variation of leaf morphology among 18 populations of Zelkova serrata Mak. (느티나무 18개 집단의 엽 형질 변이)

  • Kim, In-Sik;Kwon, Hae-Yun;Ryu, Keun-Ok;Choi, Hyung-Soon
    • Korean Journal of Breeding Science
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    • v.42 no.1
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    • pp.40-49
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    • 2010
  • This study was conducted to examine genetic variation on leaf characteristics of Zelkova serrata populations. Leaf samples were obtained from eighteen populations and fourteen leaf characteristics such as leaf blade length, leaf width, leaf area and etc. were measured. In all leaf characteristics, there were significant differences among populations and among individuals within population. Most variance of leaf characteristics was contributed to among individuals within population except for length from leaf base to maximum width (x3) and the ratio of x3 to leaf blade length (x10). The relatively high variations of leaf characteristics were found at Gurye, Jungeup and Gyungju populations while Youngwol, Cheongsong, Youngchun populations showed the lower variation. There was high correlation among leaf characteristics related to leaf size, but not among the variables of ratio between leaf characteristics. Length from leaf base to maximum width(x3) and the ratio of x3 to x10 showed significant positive correlation with latitude and altitude of populations, which reflect the differences of mean annual temperature among populations. Mean annual rainfall of populations showed negative correlation with leaf blade length, leaf width, length from apex to first serration and leaf area. Four principal components (PC) were deduced from principal component analysis, which explain the 88.5% of total variance of leaf characteristics. Leaf area, length from leaf base to maximum width, serration number and petiole length showed the highest contribution to PC1, PC2, PC3, PC4, respectively. According to cluster analysis, the populations of Z. serrata were divided into two groups, which reflect the difference of mean annual temperature between groups. Within group, however, specific tendency of clustering was not observed among populattions.

Analysis of Spatial Correlation between Surface Temperature and Absorbed Solar Radiation Using Drone - Focusing on Cool Roof Performance - (드론을 활용한 지표온도와 흡수일사 간 공간적 상관관계 분석 - 쿨루프 효과 분석을 중심으로 -)

  • Cho, Young-Il;Yoon, Donghyeon;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.38 no.6_2
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    • pp.1607-1622
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    • 2022
  • The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.