• Journal of the Korean earth science society
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• v.31 no.6
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• pp.600-607
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• 2010

In 2008, multiple episodes of large-scale transport of natural airborne particles and anthropogenically affected particles from different sources in the East Asian continent were identified in the National Oceanic and Atmospheric Administration (NOAA) satellite RGB-composite images and the mass concentrations of ground level particulate matters. To analyze the aerosol size distribution during the large-scale transport of atmospheric aerosols, both aerosol optical depth (AOD; proportional to the aerosol total loading in the vertical column) and fine aerosol weighting (FW; fractional contribution of fine aerosol to the total AOD) of Moderate resolution Imaging Spectroradiometer (MODIS) aerosol products were used over the East Asian region. The six episodes of massive natural airborne particles were observed at Cheongwon, originating from sandstorms in northern China, Mongolia and the loess plateau of China. The $PM_{10}$ and $PM_{2.5}$ stood at 70% and 16% of the total mass concentration of TSP, respectively. However, the mass concentration of $PM_{2.5}$ among TSP increased as high as 23% in the episode in which they were flowing in by way f the industrial area in east China. In the other five episodes of anthropogenically affected particles that flowed into the Korean Peninsula from east China, the mass concentrations of $PM_{10}$ and $PM_{2.5}$ among TSP reached 82% and 65%, respectively. The average AOD for the large-scale transport of anthropogenically affected particle episodes in the East Asian region was measured at $0.42{\pm}0.17$ compared with AOD ($0.36{\pm}0.13$) for the natural airborne particle episodes. Particularly, the regions covering east China, the Yellow Sea, the Korean Peninsula, and the east Korean sea were characterized by high levels of AOD. The average FW values observed during the event of anthropogenically affected aerosols ($0.63{\pm}0.16$) were moderately higher than those of natural airborne particles ($0.52{\pm}0.13$). This observation suggests that anthropogenically affected particles contribute greatly to the atmospheric aerosols in East Asia.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.2
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• pp.63-78
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• 2017

The purposes of this study was to study Turkic clothing traditions as a way to shed light on cultural development via the interactions among different tribes along the Silk Road, the close correlations between the surroundings of the Turks and their costumes, and the root of Turkic culture through literature studies and empirical studies. The study results are as follows. First, the Turks were nomadic equestrian tribes in the north that dominated the cold dry steppes from the $6^{th}$ to $8^{th}$ century A.D., when they expanded their influence to Dongbei, China to the east, and Turkistan (Central Asia) to the west. The Turks formed a nomadic lifestyle and culture suited to a cold dry climate, and interacted with various other tribes via the Silk Road, while exchanging and sharing different cultural aspects. Second, given that the Turkic garments constitute a two-piece style, which is a category of the basic nomadic costume of northern tribes, and that the artifact materials manifest jackets, overcoats, pants and skirts, the garments are categorized into tops and bottoms. The tops are sub-categorized into jackets and overcoats. The bottoms are sub-categorized into pants and skirts. In light of the necklines of tops, jackets have round necklines, while overcoats have V-necklines, round necklines and lapel collars. The bottoms include narrow-legged pants, wide-legged pants and closed-hem pants. Drapery skirts are worn at the waist. Third, the Turkic V-neckline overcoat is comparable to the Huns' silk overcoat, which illustrates the ethnic link between the two tribes. Also, the Turkic narrow- and wide-legged pants are consistent with the Huns' silk pants discovered in Noin Ula. The Turkic costumes are mostly tight fitting, suitable for the nomadic lifestyle in a cold, dry climate. Also, additional patches must be attached to the crotch points of pants due to the equestrian lifestyle.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.187-193
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• 2015

The purpose of the present study is to trace the provenance of lead raw materials using the lead isotope ratio of 9 lead glasses excavated from the Sarira hole of Mireuksaji stone pagoda and to determine correlation between them and other lead glasses excavated from the Wanggungri site. The results of chemical analysis of the 9 lead glasses show that they are common lead glass system($PbO-SiO_2$) with respect to the contents of PbO (70 wt.%) and $SiO_2$ (30 wt.%). The lead isotope ratios of them plot to northern Korean peninsula when applied to the distribution map of lead isotopes of East Asia. On the other hand, southern Korean peninsula is verified as the main deposits of the lead ore in the distribution map of lead isotopes of South Korea. With respect to the results, it is notable that the provenance of the 9 lead glasses can be very different depending on the distribution map. In addition, a comparative study between them and the lead glasses excavated from the Wanggungri which was built in the same region and period shows that their lead isotopes are highly correlated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1548-1554
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• 2005

e-Trade could improve marine logistic industry of our country to be convenient and efficient. However, in view of management, technical problems of networks have been revealed due to rapid increase of communications including electronic data. So, in order for Korea to be a leading country in east-northern Asia and a center for marine logistic information, control methods of networks should be employed effectively among information technology needed for e-Trade. Our objective to this research is focused as follows; Firstly, we investigate each part of e-Trade network and technical problems of communication networks. Secondly, we present an efficient control method of e-Trade network handling a large amount of network traffic. In this research, we try to provide an analytic foundation to practitioners rather than to present a direction to develop a new technology of communication networks.

• Journal of Korean Library and Information Science Society
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• v.49 no.2
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• pp.25-58
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• 2018

This study analyzed the agriculutral book Gyemi Metal Type Sasichanyo which was produced in Jujaso(鑄字所), by early Joseon dynasty's king Taejo(太宗). It is the most advanced edition of Sasichanyo("四時纂要") among whole east-northern Asia, which contains miscellanies about monthly agricultural plan(月令式 農家雜錄) and the themes are; agriculture, production spin-off processing, sanitation and medicine, tool fixing and conservation, business management. This research divided all letters appeared in Gyemi metal type Sasichanyo("四時纂要") by three categories; small letters, smaller letters, smallest letters to define its' function and characteristics and estimated the value of Sasichanyo("四時纂要"). Also in the aspect of typeface of letters and typesettings, this study compared all editions of Sasichanyo("四時纂要") with Gyemi metal type Sasichanyo("四時纂要").

• Communications of Mathematical Education
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• v.23 no.4
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• pp.1093-1130
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• 2009

The purpose of this study is to examine obstacles to progress for 20th century Korean mathematics. In 1945, shortly after Korea was liberated from Japan, there were no Korean mathematics Ph.D. holders, less than ten bachelor degree holders, and only one person with a master's degree in mathematics. We investigate the reasons for this. Korea has to overcome such an unforgiving condition and rebuild quality education programs in higher mathematics over the last several decades. These debilitating circumstances in higher mathematics were considerable obstacles in developing a higher level of mathematical research for the mainstream of 20th century world mathematics. We study policy and curriculums of Korean school mathematics in the late 19th and early 20th century, with some educational and socio-political background.

• Journal of the Korean earth science society
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• v.40 no.4
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• pp.414-427
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• 2019

In East Asia, the long-range transport of dust storms originating from Mongolia and northern China affects airborne dust loadings over downwind areas in the southern Korean Peninsula. Since 1997, dust loading cases caused by dust storms have been observed using the thresholds of total suspended particles (TSP, ${\geq}250{\mu}g\;m^{-3}\;hr^{-1}$) and particulate matter less than $10{\mu}g$ ($PM_{10}$, ${\geq}190{\mu}g\;m^{-3}\;hr^{-1}$) in the central-southern Korean Peninsula. There were two dust loading cases that exceeded these thresholds in 2016 and three in 2017, which reflects the downward trend of the last twenty-one years in the central-southern Korean Peninsula. Furthermore, five other dust loading cases with mass concentrations lower than the thresholds were observed from 2016 to 2017. In the moderate dust loading cases exceeding the thresholds, a descending motion of cut-off lows below $45^{\circ}N$ and a southward trough at 500 hPa gpm isopleths intensified at the western ridge, and largely extended the surface high-pressure system over southeast China. Airborne dust loadings following pronounced north-westerlies in the forward side of the high-pressure system were transported to the surface of the central-southern Korean Peninsula. However, in slight dust loading cases lower than the thresholds, the restricted descending motion of cut-off lows over $45^{\circ}N$ and the southwestward trough at 500 hPa gpm isopleths intensified the zonal flow over the Korean Peninsula. Surface high- and low-pressure systems moved eastward from the source compared to moderate dust loading cases. Due to the zonal movement of dust storms traversing eastern China, slight dust loading cases were observed with relatively higher ratios of $PM_{2.5}/TSP$ and carbon monoxide (CO) in the central-southern Korean Peninsula.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.278-295
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• 2021

China's shutdown due to COVID-19 in 2020 reduced air pollutant emissions, which is located on the windward side of South Korea. The positive temperature anomaly and negative zonal wind anomaly from northern Mongolia to South Korea through eastern China presented warm and stationary air masses during January and February 2020. Decreased concentrations of PM10, NO₂, and O₃ were measured at Seokmo-ri and Pado-ri, located in the central-western region of South Korea, due to decreased emissions in China from January to March 2020. After China's shutdown from January to March 2020, in Pado-ri, the ratio of monthly average concentrations in that period with those of PM10 and O₃ in the last four years decreased by approximately 0.7-4.7% and 9.2-22.8%, respectively. In January 2020, during the Lunar New Year holidays in China, concentrations of PM10, NO₂, and O₃ at Seokmo-ri and Pado-ri decreased just as much as it did during the same period in the last four years. However, average concentrations in January 2020 decreased before and after the Lunar New Year holidays in China when compared with those in January of the last four years. In Seokmori, ratios of actual and predicted values (${\bar{O}_s$/M) for PM10, NO₂, and O₃ concentrations were calculated as 70.8 to 89.7%, 70.5 to 87.1%, and 72.5 to 97.1%, respectively, during January and March 2020. Moreover, those of Pado-ri were 79.6 to 93.5%, 67.7 to 84.9%, and 83.7 to 94.6%, respectively. In January 2020, the aerosol optical depth (AOD) data showed a higher distribution than that of the last four years due to photochemical reactions in regions from northern Mongolia to eastern China and the Korean Peninsula. However, the decrease in AOD values compared with those of the last four years was attributed to the decrease in emissions of precursors that generate secondary aerosols in China during March 2020.

• Journal of Climate Change Research
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• v.1 no.2
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• pp.133-145
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• 2010

This study examined the characteristics of tropical cyclone(TC) activity over the western North Pacific(WNP) in 2009. Twenty-two TCs formed in 2009, which is slightly below normal(1979~2009 average: 25.8) and most of these occurred during the months of July to October. Most TCs in 2009 was formed over the northern Philippines and the eastern part of the WNP and they moved towards the South China Sea and the east of Japan, resulting in less TC affecting the East China Sea and Korea. The TC activity in 2009 is modulated by the large-scale circulations induced by the El $Ni{\tilde{n}}o$ and vigorous convection activity over the WNP. As the general characteristics of El $Ni{\tilde{n}}o$ year, the difference in sea surface temperature between the central Pacific and the eastern Pacific causes an anomalous westerly winds, expanding the WNP monsoon trough farther eastward. Accordingly, TC formation has relatively increased in the east part of the WNP. Active convection activities over the subtropical western Pacific excite a Rossby wave propagating from the South China Sea to mid-latitudes, resulting in an anomalous easterly steering flow in the South China, anomalous northwesterly over the East China Sea and Korea, and anomalous southwesterly over the east of Japan. Summing up, the TCs cannot enter the East China Sea and Korean region and instead they move towards the South China Sea or south-east of Japan. There were no effects of TCs in Korea in 2009. It is anticipated that this study which analyzed unusual TC activity and large-scale circulations in 2009 would help the predictability of TC effects to increase according to climate change in the East Asia.

• Journal of Korea Water Resources Association
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• v.53 no.6
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• pp.409-416
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• 2020

An extreme climate monitoring is essential to the reduction of socioeconomic damages from extreme events. The objective of this study was to produce the near-realtime weekly root-zone Soil Moisture Index (SMI) on the basis of soil moisture using the Noah 3.3 Land Surface Model (LSM) for potentially monitoring extreme drought events. The Yangtze basin was selected to evaluate the Noah LSM performance for the East Asia region (15-60°N, 70-150°E) and the evapotranspiration (ET) and sensible heat flux (SH) were compared with ET and SH from FluxNet and with ET from FluxCom, Global Land Evaporation Amsterdam Model (GLEAM), ERA-5, and Generalized Complementary Relationship (GCR). For the ET, the coefficients of determination (R²) were higher than 0.96, while the R² value for the SH was 0.71 with slightly lower than those. A time series of the weekly root-zone SMI revealed that the regions with Extreme drought had been expanded from the northern part of East China to the entire East China between July to October 2019. The trend analysis of the number of extreme drought events showed that extreme drought events in spring had reduced in South Korea over the past 20 years, while those in fall had a tendency to increase. It is concluded that this study can be useful to reduce the socioeconomic damages resulted from climate extremes by comprehensively characterizing extreme drought events.