• 분석과학
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• 제30권4호
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• pp.182-193
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• 2017

In order to examine the variation characteristics of chemical compositions in relation to the inflow pathways of Asian dust, $PM_{10}$ and $PM_{2.5}$ aerosols were collected at Gosan site of Jeju Island during the Asian dust days between 2010 and 2015, and their chemical compositions were analyzed. The mean mass concentrations of $PM_{10}$ and $PM_{2.5}$ during Asian dust days were $130.0{\pm}90.2$ and $38.2{\pm}24.7{\mu}g/m^3$, respectively. The composition ratios of major secondary pollutants ($nss-SO_4{^{2-}}$, $NH_4{^+}$, $NO_3{^-}$) were high as 53.7 % for $PM_{10-2.5}$ and 90.6 % for $PM_{2.5}$. When the Asian dusts had been transported to the Korean Peninsula via Loess Plateau of central China, the concentrations of $nss-Ca^{2+}$, $NH_4{^+}$, $nss-SO_4{^{2-}}$, and $NO_3{^-}$ increased more noticeably. Whereas in case when the inflow pathways of Asian dust had been through the Bohai bay, the concentrations of the crustal species such as Al, Fe, and Ca were relatively high in coarse particles. The atmospheric aerosols were acidified largely by sulfuric and nitric acids. They were neutralized mainly by calcium carbonate in coarse particle mode passed through Manchuria area, but by ammonia in fine particle mode passed through Loess plateau and Bohai bay. Ammonium salts are assumed to exist as ammonium sulfate and ammonium nitrate in coarse particles, but mostly as ammonium sulfate in fine particles.

• 한국대기환경학회지
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• 제28권3호
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• pp.282-293
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• 2012

This study aimed to show the chemical characteristics of $PM_{10}$ and $PM_{2.5}$ during Asian dust (AD) events and high PM episodes observed in Seoul. Time-resolved chemical composition of $PM_{10}$ or $PM_{2.5}$ was monitored in 1 hour interval using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF spectrometer at Seoul intensive monitoring site in 2009. Considering that AD events were classified into three different cases according to the source area and pathway, the concentrations of ammonium-sulfate and trace metal components were relatively high when the AD were occurred in Gobi and inner-mongolia and transported across the Bohai bay. In addition, the influence of alkaline dust, which carried from saline land located in the northeastern China, was observed when the AD was originated from Gobi, inner-mongolia, and Manchuria. Except AD events, the high PM episodes observed in Seoul were impacted by various anthropogenic sources such as biomass burning, motor vehicle, oil combustion and road dust.

• 대기
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• 제20권4호
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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.

• 대기
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• 제20권4호
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• pp.415-426
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• 2010

A Land cover map over East Asian region (Kongju national university Land Cover map: KLC) is classified by using support vector machine (SVM) and evaluated with ground truth data. The basic input data are the recent three years (2006-2008) of MODIS (MODerate Imaging Spectriradiometer) NDVI (normalized difference vegetation index) data. The spatial resolution and temporal frequency of MODIS NDVI are 1km and 16 days, respectively. To minimize the number of cloud contaminated pixels in the MODIS NDVI data, the maximum value composite is applied to the 16 days data. And correction of cloud contaminated pixels based on the spatiotemporal continuity assumption are applied to the monthly NDVI data. To reduce the dataset and improve the classification quality, 9 phenological data, such as, NDVI maximum, amplitude, average, and others, derived from the corrected monthly NDVI data. The 3 types of land cover maps (International Geosphere Biosphere Programme: IGBP, University of Maryland: UMd, and MODIS) were used to build up a "quasi" ground truth data set, which were composed of pixels where the three land cover maps classified as the same land cover type. The classification results show that the fractions of broadleaf trees and grasslands are greater, but those of the croplands and needleleaf trees are smaller compared to those of the IGBP or UMd. The validation results using in-situ observation database show that the percentages of pixels in agreement with the observations are 80%, 77%, 63%, 57% in MODIS, KLC, IGBP, UMd land cover data, respectively. The significant differences in land cover types among the MODIS, IGBP, UMd and KLC are mainly occurred at the southern China and Manchuria, where most of pixels are contaminated by cloud and snow during summer and winter, respectively. It shows that the quality of raw data is one of the most important factors in land cover classification.

• 대기
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• 제21권4호
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• pp.447-454
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• 2011

As dust storms originated in Neimongu Plateau and Manchuria became more frequent in Korea, there was a growing need for Asian Dust (Hwangsa) monitoring stations in North Korea, which is a pathway of Asian Dust to South Korea. The South Korean and the North Korean Governments agreed to build the Automatic Weather System and the PM10 measurement instruments in the Gaeseong Industrial Zone and the Keumgangsan Tourist Region, North Korea in 2007. PM10 mass concentration data in the Keumgangsan Tourist Region could be collected only during the period from September 2007 to May 2008. In this study, daily, monthly and diurnal variations of PM10 mass concentration of the Keumgangsan are analyzed and compared with those of Sokcho and Gwangdeoksan. Three sites show similar variations in daily and monthly means. Correlation coefficients (r) between Sokcho and Keumgangsan, and between Gwangdeoksan and Keumgangsan are 0.89 and 0.67, respectively. But diurnal variation at Keumgangsan has a distinct feature compared to the other sites. Diurnal PM10 variation shows two peaks around 8 AM and 4-5 PM and very low at night. The difference between the daily maximum and minimum is $20{\sim}60{\mu}g\;m^{-3}$ during September to November 2007. Temperature, relative humidity and wind speed from the Keumgangsan AWS data were compared with those from the Changjon station, and showed good correlation each other except wind speed.

• 미술이론과 현장
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• 제4호
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• pp.105-121
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• 2006

The term 'modern', in broader sense, refers to the concepts like modernity, modernization, modernism and the like, which came from Westernization impling the recognition of indigenous culture as being inferior to Western culture by comparison along with the expanded influences of the Empire of Japan. These concepts, however, rather than evolving from Western standards, came into being as a form of civilization led by Japan which had already tasted the fruits of modernization by 1920s. Since 1920s, the policy of, so-called, reconstructing Asian countries by Japan came to create eastern way of modernism, as a new East Asian trend mainly revealed in China which was against colonization after Japan's invasion and conquest of Manchuria. Therefore, Eastern' modern' unlike Western one could be understood in the widespread terminology, 'Modern(摩登)' in Shanghai, reflecting consciousness like 'Fashion' or 'Trend' in female images on a variety of visual media. By 1930s it was the most notable that 'modern' was accepted as something similar with 'Fashion', or 'Trend' in sociocultural contexts. These atmosphere had led commercial arts to enable to communicate with the public in a great deal of supports and success in Shanghai which was widely regarded as the citadel for the inflow of Western culture, among which transformations in female images were remarkable as a representative form of culture. It is also remarkable that 'historical modernity' transforming from the feudal age to modern society was considered a synchronic modernity, and nationalism was regarded as a sort of being modern, while involved in the newly-changed female images as a fashion mode. Changes in fashion including hair style in Shanghai by 1930s, as a way of expressions showing what was modern through commercial artistic productions, were easily noticed in visual media as an outlet of modern women's inner desire revealing their pursuit for new mode of life in metropolitan cities. As a characteristic of the time creating a new code of visual female images, it is notable that there existed another form of 'modern' satisfying socio-cultural needs of the general public seeking for being 'modern'.

• 한국지구과학회지
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• 제32권1호
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• pp.152-157
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• 2011

일본, 중국 등 인접 지진다발 국가에서 큰 지진동이 전파되어 오는 경우, Lg파가 최대 진폭을 갖게 되어 Lg파의 감쇠상수($Q^{-1}$)는 매우 중요한 의미를 갖게 된다. 지진연구협의회(IRIS)의 자료를 바탕으로 관측점간 경로거리가 긴 자료에 대하여 두관측점법을 이용하여 Lg파의 감쇠상수 값을 도출한 결과, 지진활동도에 상응하는 감쇠값을 얻었다. 일본지역을 잇는, 해양지각을 통과하는 경로는 높은 감쇠값을 보여서 지진활동도 및 지각의 감쇠특성을 잘 나타내고 있으며, 또한 큰 지진이 많았던 중국 상해지역을 잇는 경로도 일본지역 다음으로 높은 감쇠값을 보인다. 반면, 한반도 및 만주지역을 잇는 경로는 지진활동상황과 상응하는 매우 낮은 값을 보였다.

• 천문학회지
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• 제50권6호
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• pp.191-200
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• 2017

We analyze the time data recorded in Korean astronomical almanacs for the years from 1913 to 1945, which belong to the period in which Japan occupied Korea (1910-1945). These almanacs, published by Japanese scholars, differ from previous almanacs in terms of organization, content, and calendrical methods. In this study, we first extract twelve kinds of time data from the almanacs at the following times: solar terms, rising and setting of the Sun and Moon, transit of the Sun, phases of the Moon (i.e., new Moon, first quarter Moon, full Moon, and last quarter Moon), and eclipses of the Sun and Moon. Then, we compare the time data with that obtained from modern calculations. Even though all time data in the almanacs are tabulated in units of minutes, we calculate the data in units of seconds and determine the root mean square (RMS) deviation values for each kind of time data to estimate the accuracy of the data. Our findings are as follows: First, the kind and tabulation method of time data changes several times. For instance, solar transit time is listed only for six years from 1937 to 1942. Second, the times of two equinoxes and those of a new Moon are considerably close to midnight. Third, there are some typographical errors in the almanacs, particularly in the times of moonrise and moonset. Fourth, the contact times for lunar eclipses represent the times of the umbra and not of the penumbra, which is different from the times for solar eclipses. Finally, the RMS deviation values are approximately 0.5 min on average in all kinds of time data, even though they show slightly large differences in the times related to the Moon. In conclusion, we believe that this study is useful for investigating the time data in the almanacs of other East Asian countries that were published during the same period, such as China, Japan, and Manchuria.

• 대한치과의사협회지
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• 제48권12호
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• pp.893-918
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• 2010

This article is purposed of reviewing the development history of Japanese dental devices and instrument, and their related advertisement activities during the Japanese colonized period in Korea in early 20th century. Japanese dental devices and instrument were redesigned to accommodate their ergonomic shape above the simple imitation, and it implies the excessive desires brought them frustrations. The tragic earthquake on Sep. l, 1923, medical insurance law enforcement on Jan. 1, 1927, celebration of "Cavity prevention Day" started on Jun. 4, 1928, and the attack of Manchuria and China by Japan after 1931, all of these historical incidents become the preliminary requirement for the development of dental devices. On Nov. 1, 1937, Japanese government started to control dental materials, driving the campaigns for excluding foreign products and encourging the use of local products. In 1939, Nakajima dental manufacturers used this political and social atmosphere on their advertisement as saying "Our Nakajima's products have no compromise with the short raw materials, but only commitment to our quality". Since after 1940, the price and supply have been strongly under control, and the control group was appeared to manage all of supply and distribution of raw materials, regular price system, and specifications. At last, the Japanese national power were devastated in its production and distribution capacities, and get to the frustrated period. The main advertised dental devices and instruments in Korea during the Japanese colonized period were 1) dental chair, unit and cabinet, 2) dental x-ray, 3) compressors, 4) dental needles, 5) small instrument and carryon medical(emergency) kit, 6) oral hygiene and pyorrhea alveolaris, infrared rays, sunlight lamp, ultrashort wave treatment devices, 7)crown former, electric furnace, casting machine, articulator, electric lathe, and laboratory equipments, etc.

• Animal Systematics, Evolution and Diversity
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• 제7권2호
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• pp.179-188
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• 1991

한국의 제주도에 서식하고 있는 등줄쥐의 한 아종인 Apodemus agrarius chejuensis의 분류학적 위치의 파악을 위하여, 아시아에 서식하는 등줄쥐중에 터키,중국,대만,만주 및 한국에서 채칩된 8아종(agrarius, ningpoensis, pallidior, chevrieri, insulaemus, manchuricus, coreae 및 chejuensis), 311마리의 표본들을 사용하였다. 4개 외부형질과 27개 두골형질들을 측정하였고 cluster, principal components 및 discriminant 분석등의 다변량분석을 수행하였다. 4개형(form)으로 나뉘어졌는데, chejuensis는 가장 큰 형이었고, 큰 형인 chevrieri는 Wang(1985)에 의하여 종으로도 기술된 바가 있다. 중간 크기의 형과 작은 크기의 형은 각각 coreae와 나머지 5개 아종(agrarius, ningpoensis, pallidior, in-sulaemus 및 manchuricus)이었으며, 연속적 변이를 나타냈다. 제주도의 chejuensis(가장 큰 형)는 등줄쥐의 다른 6개 아종(중간과 작은 크기의 형들)과 형태적 형질에 있어서 불연속적 차이를 보였으므로 신종으로 판단되지만, 신종으로서의 기재를 위해서는 연구가 더 필요하다고 결론지었다.