• Title/Summary/Keyword: desert

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A Study on the Outbreak and Transport Processes of the Severe Asian Dust Event Observed in March 2010 (2010년 3월 극심한 황사사례의 발생 및 수송과정에 관한 연구)

  • Kim, Sukwoo;Song, Sang-Keun;Han, Seung-Bum
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.3
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    • pp.256-271
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    • 2016
  • The source and transport of the severe Asian dust event (ADE) recently observed in the Korean peninsula were analyzed based on observations (surface weather charts and satellite data) and modeling study (WRF-CMAQ modeling systems). The ADE occurred on 20-21 March 2010 in South Korea with very high $PM_{10}$ concentrations (up to approximately $3,000{\mu}g/m^3$ in Daegu and Jeju). The dominant meteorological conditions affecting the dust outbreak and transport processes were found to be associated with the two synoptic features: (1) strong airflows (i.e., westerlies) induced by a strong pressure gradient resulting from a dense isobar pattern (west-high and east-low) between Tuva Republic and Mongolia and (2) a rapid movement of the strong westerlies merged with airflows generated near Gobi Desert and Inner Mongolia. The merged strong westerlies with a low pressure played a pivotal role in the huge amount of AD and its transport height of 5-8 km. The time and location of dust emissions calculated in the source regions were similar to those observed in the weather charts and satellite image. The ADE simulation mostly showed agreement in the patterns and the concentration levels of modeled dust (including $PM_{10}$) with those of the observations.

Fabrication of a Hybrid Superhydrophobic/superhydrophilic Surface for Water Collection: Gravure Offset Printing & Colloidal Lithography (수분수집을 위한 초발수/초친수 복합 표면 제작: 그라비아 옵셋 프린팅과 콜로이달 리소그래피 공정)

  • Ji, Seung-Muk;Kim, In-Young;Kim, Eun-Hee;Jung, Jie-Un;Kim, Wan-Doo;Lim, Hyun-Eui
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.1
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    • pp.19-24
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    • 2012
  • We demonstrate the desert beetle back mimicking hybrid superhydrophilic/superhydrophobic patterned surface by using the combination method of colloidal lithography and gravure offset printing for nano and micro patterning, respectively. The two methods are cost-effective and industrially available techniques compared to the other nano/micro patterning methods. To verify the water collecting function of the hybrid surface, the water condensation behavior is investigated on the chilled surface in ambient temperature and high humidity. Due to the synergetic effect of drop and film wise condensation, the hybrid superhydrophobic/superhydrophilic surface shows the higher efficiency than one of single wettability surfaces. The work is underway to get the good patterns of hybrid surfaces for water collecting from the dew or fog.

Sea Level Fluctuation in the Yellow Sea Basin (황해 분지의 해수면 변동)

  • PARK, YONG AHN;KHIM, BOO KEUN;ZHAO, SONGLING
    • 한국해양학회지
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    • v.29 no.1
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    • pp.42-49
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    • 1994
  • A series of radiocarbon dating from intertidal, subtidal, and inner continental shelf deposits investigated along the west coast of Korea as well as from its offshore sea floor (namely, the eastern Yellow Sea Basin) how (1) the Holocene sea level rise, i.e., the ecstatic sea-level history during the oxygen isotope stage 1, and (2) pre-Holocene sea-level fluctuations during the oxygen isotope stages 2 and 3. Marine geophysical investigations in the Yellow Sea reported a possible development of desert and loses deposits due to dieselization under the cold and dry climate during the Last Glacial Maximum. The Kanweoldo deposit overlain unconformably by the Holocene intertidal deposits, which is mainly exposed along the tidal channels and intertidal flats in the Cheonsu Bay, the west coast of Korea, shows the characteristic cryogenic structure (cryoturbation). Such cryoturbation structure of the Kanweoldo deposit appears to indicate the cold and dry climate under the ecstatic sea-level paleoshoreline standing before and after of the pre-Holocene interstitial period (about 30000 y BP is suggested and its shoreline curve is constructed.

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Screening of Tomato Cultivars Resistant to Root-knot Nematode, Meloidogyne incognita (고구마 뿌리혹선충 저항성 토마토 품종 스크리닝)

  • Kim, Hyeong-Hwan;Cho, Myoung-Rae;Kang, Taek-Joon;Jung, Jae-A;Han, You-Kyoung
    • Research in Plant Disease
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    • v.16 no.3
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    • pp.294-298
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    • 2010
  • Thirty-two tomato cultivars, eleven cherry tomato cultivars and eight rootstock tomato cultivars were inoculated with Meloidogyne incognita, to evaluate tomato cultivars for resistance against root-knot nematodes. One tomato cultivar, Homerunking was proved to be resistant while eight cultivars such as Regendsummer, Regend, Sunmyung, Pinktop, Top3, Delice, Tasha and Lilyance were moderately resistant to the root-knot nematodes. Five cherry tomato cultivars (Tenten, Desert, Redstar, Veryking and Arigatto) showed moderate resistance and one cultivar (Redcherry) was resistant to root-knot nematodes. In eight rootstock tomato cultivars, two cultivars (Bukinghagae, Special) were resistant and five cultivars (B-blocking, Solution, Dongbanja and Greenpower) were moderate.

Comparison of Two Semi-Empirical BRDF algorithms using SPOT/VGT

  • Lee, Chang Suk;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.29 no.3
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    • pp.307-314
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    • 2013
  • The Bidirectional Reflectance Distribution (BRD) effect is critical to interpret the surface information using remotely sensed data. This effect was caused by geometric relationship between sensor, target and solar that is inevitable effect for data of optical sensor. To remove the BRD effect, semi-empirical BRDF models are widely used. It is faster to calculate than physical models and demanded less observation than empirical models. In this study, Ross-Li kernel and Roujean kernel were used respectively in National Aeronautics and Space Administration (NASA) and European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) that are used to compare each other. The semi-empirical model consists of three parts which are isotropic, geometric and volumetric scattering. Each part contained physical kernel and empirical coefficients that were calculated by statistical method. Red and NIR channel of SPOT/VEGETATION product were used to compute Nadir BRDF Adjusted Reflectance (NBAR) over East Asia area from January 2009 to December 2009. S1 product was provided by VITO that was conducted atmospheric correction using Simplified Method of Atmospheric Correction (SMAC). NBAR was calculated using corrected reflectance of red and NIR. Previous study has revealed that Roujean geometric kernel had unphysical values in large zenith angles. We extracted empirical coefficients in three parts and normalized reflectance to compare both BRDF models. Two points located forest in Korea peninsular and bare land in Gobi desert were selected for comparison. As results of time series analysis, both models showed similar reflectance change pattern and reasonable values. Whereas in case of empirical coefficients comparison, different changes pattern of values were showed in isotropic coefficients.

Interaction between different nitrogen fertilizer levels and maize-bean intercropping patterns

  • Sadeghi, Hossein;Kazemeini, Seyed Abdolreza
    • Journal of Ecology and Environment
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    • v.35 no.4
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    • pp.269-277
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    • 2012
  • In order to investigate the effects of different maize-bean intercropping patterns, and of nitrogen fertilizers on morphological and yield related traits, a factorial study based on Randomized Complete Block Design (RCBD) was performed during the 2010 and 2011 growing seasons in a research filed of Shiraz University, Iran. The first factor of the study was seven different ratios of Maize-Bean intercropping system (Maize sole cropping, Bean sole cropping, and intercropping of maize/bean at the ratios of 1/3, 1/1, 2/3, 3/2 and 3/1) and the second factor was three nitrogen (N) fertilizer application levels (0, 100 and 200 kg N/ha). Results showed that with respect to increasing the levels of N fertilizer, the yield of bean sole cropping decreased but the yield of maize sole cropping increased. On the other hand, in intercropping systems with N fertilizer application, the yield of both crops increased. Results of total land equivalent ratio (LER) for both crops showed that the highest LER value under both 100 and 200 kg N/ha application was that of M1B1 (1 seed of maize after 1 seed of bean, consecutively, on a row with same distance). Under no N fertilizer application the highest LER value was that of M2B3 (2 seeds of maize after 3 seeds of bean, consecutively, on a row with same distance). Overall, it can be concluded that M1B1 is the best intercropping pattern in maize-bean intercropping systems and that the application of N fertilizer can be effective within practical settings of intercropping agriculture, resulting in higher yields.

A Study on the Costume of Loulan - Centered Around Interrelationship with Ancient Korean Costume - (누란(樓蘭) 복식 연구 - 고대 한국복식과의 상관관계를 중심으로 -)

  • Chae, Keum-Seok;Kim, Eun-Kyoung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.18 no.3
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    • pp.197-211
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    • 2016
  • Loulan was an ancient kingdom located on the northeast of the Taklamakan Desert, a diverging point between the north and south of Silk Road, on the east of the current Turpan, from the 2nd century BC and the 7th century A.D, absorbing and propagating culture of both sides through active trade. Meanwhile, as many previous research investigations suggest the early trade between Korea and the countries bordering on Western China, characteristics of Loulan costume have been found to have similarity to those of ancient Korean costume. Also, it can be compared to costume in other surrounding regions. Therefore, it is a highly valuable region in researching ancient costume. This study examined the historical background of Loulan and its relationship with ancient Korea, analyzed the clothes found in historic sites of Louland and Niya, and compared costume elements of Loulan and those of Korea. The result of the study shows that first, the Loulan Jeogori was based on the Jikryeonggyoim, with Chaksu, narrow sleeves and the length coming between below the chest and above the bottom, and the line decoration and waist belt were very similar to Korean costumes, as well as the Banryeong, curved collar and Bansu, short sleeves. Second, the types of pants included Gunggo, characterized by closed bottom and many creases, and Daegugo, wide-leg trousers, which are very similar in shape to the Korean Shilla lay sculpture, Stele To Martyr Yi Ch'a-don, Yangjikgongdo and Wangheedo. Third, in accessories as well, the Jowu stuck on the Gwanmo is similar in the shapes to Korean costume.

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Forecast Sensitivity Analysis of An Asian Dust Event occurred on 6-8 May 2007 in Korea (2007년 5월 6-8일 황사 현상의 예측 민감도 분석)

  • Kim, Hyun Mee;Kay, Jun Kyung
    • Atmosphere
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    • v.20 no.4
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    • pp.399-414
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    • 2010
  • Sand and dust storm in East Asia, so called Asian dust, is a seasonal meteorological phenomenon. Mostly in spring, dust particles blown into atmosphere in the arid area over northern China desert and Manchuria are transported to East Asia by prevailing flows. An Asian dust event occurred on 6-8 May 2007 is chosen to investigate how sensitive the Asian dust transport forecast to the initial condition uncertainties and to interpret the characteristics of sensitivity structures from the viewpoint of dynamics and predictability. To investigate the forecast sensitivities to the initial condition, adjoint sensitivities that calculate gradient of the forecast aspect (i.e., response function) with respect to the initial condition are used. The forecast aspects relevant to Asian dust transports are dry energy forecast error and lower tropospheric pressure forecast error. The results show that the sensitive regions for the dry energy forecast error and the lower tropospheric pressure forecast error are initially located in the vicinity of the trough and then propagate eastward as the surface low system moves eastward. The vertical structures of the adjoint sensitivities for the dry energy forecast error are upshear tilted structures, which are typical adjoint sensitivity structures for extratropical cyclones. Energy distribution of singular vectors also show very similar structures with the adjoint sensitivities for the dry energy forecast error. The adjoint sensitivities of the lower tropospheric pressure forecast error with respect to the relative vorticity show that the accurate forecast of the trough (or relative vorticity) location and intensity is essential to have better forecasts of the Asian dust event. Forecast error for the atmospheric circulation during the dust event is reduced 62.8% by extracting properly weighted adjoint sensitivity perturbations from the initial state. Linearity assumption holds generally well for this case. Dynamics of the Asian dust transport is closely associated with predictability of it, and the improvement in the overall forecast by the adjoint sensitivity perturbations implies that adjoint sensitivities would be beneficial in improving the forecast of Asian dust events.

Detection and Classification of Major Aerosol Type Using the Himawari-8/AHI Observation Data (Himawari-8/AHI 관측자료를 이용한 주요 대기 에어로솔 탐지 및 분류 방법)

  • Lee, Kwon-Ho;Lee, Kyu-Tae
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.3
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    • pp.493-507
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    • 2018
  • Due to high spatio-temporal variability of amount and optical/microphysical properties of atmospheric aerosols, satellite-based observations have been demanded for spatiotemporal monitoring the major aerosols. Observations of the heavy aerosol episodes and determination on the dominant aerosol types from a geostationary satellite can provide a chance to prepare in advance for harmful aerosol episodes as it can repeatedly monitor the temporal evolution. A new geostationary observation sensor, namely the Advanced Himawari Imager (AHI), onboard the Himawari-8 platform, has been observing high spatial and temporal images at sixteen wavelengths from 2016. Using observed spectral visible reflectance and infrared brightness temperature (BT), the algorithm to find major aerosol type such as volcanic ash (VA), desert dust (DD), polluted aerosol (PA), and clean aerosol (CA), was developed. RGB color composite image shows dusty, hazy, and cloudy area then it can be applied for comparing aerosol detection product (ADP). The CALIPSO level 2 vertical feature mask (VFM) data and MODIS level 2 aerosol product are used to be compared with the Himawari-8/AHI ADP. The VFM products can deliver nearly coincident dataset, but not many match-ups can be returned due to presence of clouds and very narrow swath. From the case study, the percent correct (PC) values acquired from this comparisons are 0.76 for DD, 0.99 for PA, 0.87 for CA, respectively. The MODIS L2 Aerosol products can deliver nearly coincident dataset with many collocated locations over ocean and land. Increased accuracy values were acquired in Asian region as POD=0.96 over land and 0.69 over ocean, which were comparable to full disc region as POD=0.93 over land and 0.48 over ocean. The Himawari-8/AHI ADP algorithm is going to be improved continuously as well as the validation efforts will be processed by comparing the larger number of collocation data with another satellite or ground based observation data.

Analysis on Characteristics of Agricultural Heritage in GIAHS sites (세계중요농업유산(GIAHS) 등재지역 농업유산의 특성 분석)

  • Jeong, Myeong-Cheol;Mun, Hyo-Yun;Yoon, Soon-Duck;Kim, Sang-Bum
    • Journal of Korean Society of Rural Planning
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    • v.22 no.4
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    • pp.171-182
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    • 2016
  • Since FAO introduced the Globally Important Agricultural Heritage Systems(GIAHS) in 2002, 36 sites of 15 countries so far have been listed on GIAHS. This study aims to find the important agricultural heritages of Korea and to prepare the methods for them to be selected as GIAHS. We have analyzed the proposals of the 36 GIAHS listed in order to study the characteristics of their components of the agricultural heritage which worked for being selected. To analyze the components of the agricultural heritage first, agricultural heritage was classified into 13 types and 42 components in light of GIAHS criteria. Then central themes were set to analyze the relevant contents in the proposals. They were, the type of GIAHS Site, significant agricultural landscape, the agriculture-forestry-fisheries-livestock linkage systems, the multi-layered, inter-cropping, circulation cultivation systems, the soil and water management systems, the conservation of agrobiological diversity and genetic resources, the history of the agricultural heritage, the succession of traditional farming techniques, the cultural diversity and so on. Most GIAHS are located in mountains, grasslands, rivers and coasts, desert than in plains, through which GIAHS assure us that it is the heritage of human challenge to overcome the harsh geographic environment and maintain a livelihood. In these sites the traditional farming techniques are carried on, such as mountain clearings, terraced rice paddies, and burn fields, and the unique irrigation systems and agricultural landscapes are well maintained, and the eco-friendly traditional farming techniques utilizing abundant forest resources and agriculture are well handed down. The origin or home of crop growing, a variety of genetic crop storage, the world's largest crop producer and preserving cultural diversity are also important factors for the selection.