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The Excitation of Waves Associated with a Collapsing Granule in the Photosphere and Chromosphere

  • Kwak, Hannah;Chae, Jongchul
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.42.1-42.1
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    • 2019
  • We investigate a collapsing granule event and the associated excitation of waves in the photosphere and chromosphere. Our observations were carried out by using the Fast Imaging Solar Spectrograph and the TiO 7057Å Broadband Filter Imager of the 1.6 meter Goode Solar Telescope of Big Bear Solar Observatory. During our observations, we found a granule which became significantly darker than neighboring granules. The edge of the granule collapsed within several minutes. After the collapse, transient oscillations occurred in the photospheric and chromospheric layers. The dominant period of the oscillations is close to 4.5 minutes in the photosphere and 4 minutes in the chromosphere. Moreover, in the Ca II-0.5Å raster image, we observed brightenings which are considered as the manifestation of shock waves. Based on our results, we suggest that the impulsive collapse of a granule can generate upward-propagating acoustic waves in the solar quiet region that ultimately develop into shocks.

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A Study on International Business Competitiveness in Ship Industry

  • Lee, Jae-Sung
    • The Journal of Economics, Marketing and Management
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    • v.5 no.3
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    • pp.30-38
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    • 2017
  • The main target to do this analysis is to find out the competitiveness between 2 countries(Korea and USA) in the ship business industry. Ever since free from Japanese empire domination of modern history in Korean peninsular, Korea has been strong relationship with USA almost every fields. The purpose of this research is to realize which country is more competitive between 2 country's trade structure. This research conducted for period from 2000 to 2016. Expecting effect is to learn how to improve ship industry for 2 countries. Research method is used by comparative advantage trade theory. Even though Koran government has been accomplishing trade stimulus environment against USA ship industry, it is research limitation that overseas productions both Korean & USA are not available due to company business strategy. From early 50's, every USA industries hold a dominant position so far. Now, Korea is comparative advantage against that of USA in the field of ship industry. Sound competition relationship is good for both 2 countries for mutual benefits. The future prospect is Korea needs export market diversification to enlarge economic growth in the long run.

Solar North-South Asymmetry and Hilbert Transform Analysis

  • Heon-Young Chang
    • Journal of The Korean Astronomical Society
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    • v.56 no.1
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    • pp.125-135
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    • 2023
  • Here, we investigated the observed sunspot areas with respect to latitudes using the Hilbert transform technique. Conventional study of the cyclic patterns of sunspots is based on the Lomb-Scargle periodogram, which only obtains the amplitude information. In comparison, our approach characterizes the amplitude as well as the phase of solar activity. We demonstrated the solar North-South asymmetry in the instantaneous amplitude by analyzing daily sunspot data set spanning from the solar cycles 11 to 24. Our findings confirm that the northern hemisphere is dominant in the solar cycles 14, 15, 16, 18, and 20. Unlike the amplitude, the North-South asymmetry in the period of solar activity could not be established. We have also found that the standard deviation as a measure of fluctuation in the phase derivative is minimum in the latitude band 10° < l < 20°, and the fluctuations obtained for latitudes above 30° are considerable.

The Multidimensional Masculinity in Nguyễn Huy Thiệp's Short Stories

  • Van Thuan Nguyen;Anh Dan Nguyen;Van Luan Nguyen
    • SUVANNABHUMI
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    • v.16 no.1
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    • pp.147-173
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    • 2024
  • Nguyễn Huy Thiệp is a pillar in Vietnamese cultural life after the Second Indochina War, and the fates of men and women at the beginning of Đổi mới (Renovation) is one of the prominent themes in his short stories. To show off sexual power, seek glory, and maintain his dominant position, Thiệp's heroes engage in a game of oppressing the weak, hunting animals, and harassing women. However, due to the complex changes in social life, moral values, and gender inequality, men in the postwar period quickly experienced the feeling of humiliation, impotence, and failure. In turn, the sophisticated aspects of masculinity demonstrate the cultural and ethical concerns of contemporary Vietnamese society. By exploring the multidimensional nature of masculinity expressed in Thiệp's stories, this study aims to resolve misconceptions about gender and the relationship between men and women in his work.

Species composition and abundances of ichthyolplankton in Yeongsan River Estuary in Spring and Summer (영산강 하구역의 춘계와 하계에 출현하는 어류플랑크톤의 종조성과 개체수)

  • Byung Sun CHIN
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.1
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    • pp.37-46
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    • 2024
  • This study was conducted to provide the basic information on environment effects on appearance of ichthyoplankton in the Yeongsan River Estuary in Spring and Summer from 2018 to 2020. Data were obtain from the database of 'Coastal Ecosystem' in "National Survey of Marine Ecosystem." Among the abundance ichthyoplankton species, the Gobiidae spp. dominated, accounting for 85% of the total abundances with the secondary dominant species being the Parablennius yatabei, representing 3% of the abundances. Cluster analysis results revealed a composition differentiated between spring and summer. The Yeongsan River Estuary is known to be significantly influenced by the opening and closing of estuarine gates. In this study, the fluctuation in the number of occurrence groups and abundance among the years and season is attributed to the phenomenon of high water temperature period and the freshwater discharge.

A Literature Study on the Functional Change of 'Jeong(亭)' in Korea and China (한국과 중국에서 '정(亭)' 건축 기능의 변화에 대한 문헌적 고찰)

  • Lee, Joung-Ah
    • Journal of architectural history
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    • v.33 no.1
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    • pp.33-43
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    • 2024
  • In Korea, the function of Jeong(亭), Jeongja(亭子), and Nujeong(樓亭) architecture is essentially rest. However, in China, where the name Jeong was first coined and used, Jeong was not only used as a place of rest, but also for a variety of functions depending on the time and region, such as building units for guard posts, policing, and mail delivery. But why is it that in Korea, Jeong is primarily perceived and used as place of rest? Starting from this question, this article examines the historical process of the emergence of Jeong and its changing functions, focusing on the official history of China, and then examines the perception of Jeong in Korea through its connection to the dominant function of Jeong in China during the period of Jeong's emergence in Korean literature. This will help us to fundamentally understand the differences between Jeong architecture in Korea and Jeong architecture in China, and to further clarify the historical significance of the types of Jeongja and Nujeong architecture in Korea.

The Transformation of Korean Drama Discourse in Malaysia in the OTT Era

  • Kihyung Bae;Hong Sungah;Lee Sungmin
    • Asian Journal for Public Opinion Research
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    • v.12 no.3
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    • pp.142-165
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    • 2024
  • This article examines the shifts in discourse surrounding Korean dramas in Malaysia, a core market for the Korean Wave (Hallyu), to understand the evolving perceptions and reception of Hallyu as a role model. Employing a discourse analysis of 14 Malaysian newspapers available online from 2016 to 2022, a period marked by the rise of over-the-top (OTT) media, the study reveals a significant transition in the prevailing narrative. From 2016 to 2019, the dominant discourse was characterized by conservatism and "cultural protectionism," reflecting a tension in attitudes towards the Korean Wave. However, from 2020 onwards, there was a gradual change in perceptions and attitudes, with an increasing emphasis on the economic and cultural value of Hallyu. This shift towards an "economic discourse" illustrates a growing perception of Korean dramas as an opportunity and catalyst for regional economic development in the Malaysian context, rather than a crisis. The study highlights the dynamic nature of the Korean Wave discourse in Malaysia and its evolution in response to the changing media landscape and socio-economic factors.

Studies on the Distribution of the Microalgae in the Tidal Flats of Gamami Beach, Young-Gwang, Korea (가마미 해수욕장(전남 영광) 갯벌의 미세조류의 분포에 관한 연구)

  • 이학영
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.715-724
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    • 2003
  • Distributional patterns of microalgae were studied in the tidal flats of Gamami Beach(Young-Gwang, Korea) from November 1999 to 2000 July. The tidal flats of Gamami Beach was composed mainly of sandy sediment. The concentrations of nutrients were low compared with other tidal flats. In the present study, 68 species of microalgal flora were identified. These were comprised of 25 species of benthic microalgae and 59 species of planktonic microalgae. Diatoms predominated the benthic microalgae with 96.0% of total species occurred. Dominant species were Amphora sp., Cocconeis sp., Coscinodiscus asteromphalus, Coscinodiscus sp., Nitzschia sigma var. intermedia, Nitzschia distans, Navicula spp., Paralia sulcata, Pleurosigma sp. Skeletonema coastatum, and Surirella sp. Among them, Amphora sp., Paralia sulcata, and species of Pleurosigma and Nitzschia were observed throughout the studied period. Planktonic microalgae of Gamami Beach was also predominated by diatoms. They occupied 88.1% of total planktonic microalgae. The density of microalgal population was higher in silty sediment than in sandy sediment. The population density of microalgae was higher in high tide zone than that in low tide zone. The density of the benthic microalgae in the surface layer of tidal flats showed increasing tendency for 2 hours after the beginning of ebb tide. On the contrary, benthic microalgal density of subsurface layer was decreased during the period. Concentrations of chlorophyll ${\alpha}$ from sediment and water were not synchronized during the study period. Therefore, the distributional patterns of the benthic microalgae and planktonic algae seemed not to be related. Chlorophyll ${\alpha}$ of water was highly related with the concentration of NH$_4$-N, whereas, chlorophyll ${\alpha}$ of sediment uas related with NO$_3$-N concentration.

The Effect of Enhanced Nitrate Input on the Temporal Variation of the Plankton Community in a Mesocosm (질산염 첨가에 따른 중형폐쇄생태계 내 플랑크톤 군집의 변화)

  • Kang, Jung-Hoon;Kim, Woong-Seo;Shin, Kyoung-Soon;Chang, Man;Hwang, Keun-Choon
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.341-349
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    • 2005
  • Temporal variation of the natural planktonic community in the Southern Sea of Korea was investigated by using low floating enclosed bags (3.2m deep and 2,500 liter) in order to understand the effect of enriched nitrate on the planktonic community in the spring (March-April) of 2002. Prior to beginning the incubation, the bags were placed in two different concentrations of nitrate, which consisted of control (ambient water) and experimental mesocosms (final concentration of $12{\mu}M$). The nitrate concentration in the experimental mesocosms remained significantly higher than those in control mesocosms throughout the study period (ANOYA, p<0.001). Following the addition of nitrate, abundance and chi-a concentration of phytoplankton peaked on Day 1, when diatoms established the peak in the experimental mesocosms. Diatoms consisted mainly of Thalasxiosira decipiens, Pseudo-nitzschia pungem, Leptocylindrus danicu, Thalassionema nitzschioides, Chaetoceros pseudocrinitus and Actinoptychus senariu. However, the peak did not lead to the difference in abundance and composition of phytoplankton between control and experimental mesocosms during the study period. The dinoflagellates began to increase soon after the diatoms decreased in all mesocosms. Copepods, as a dominant group in the rnosozooplankton community, showed no immediate peak in relation to the nitrate addition, but only their own developmental process from the eggs to adult stage during the study period. The bottom-up control from enriched nitrate via phytoplankton to adult copepods was not distinguished in terms of the abundance of the planktonic community. This might stem from the relatively low nitrate availability of phytoplankton at no N-limited seawater and the weak coupling between rapidly sunken diatoms and copepods through the water column.

A Methodology of Estimating Design Waves for the Operable Harbor Condition Using Long-term Wave Data (장기 파랑측정자료를 이용한 평상파 산정 방법론)

  • Ahn Kyungmo;Chun Je Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.16 no.3
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    • pp.178-189
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    • 2004
  • For designing a reliable harbor, a methodology for estimating design waves of 97.5% operable harbor condition is suggested using long-term wave data. For a practical application of the methodology, a marine police harbor was selected as a site. Wave data used were collected from February 1993 to December 2003 at Jodo wave gage station in front of Pusan harbor. Joint distributions of significant wave height and significant wave period for specified wave directions were obtained and used to feed as input waves for parabolic mild-slope wave model. Results showed that input waves with significant wave height of 1.75 m, significant wave period off sec and wave direction E yield design waves height of 1.06 m at the site of interests, which is a 97.5% operable harbor condition. Wind waves generated inside harbor showed to be no effect on the design wave condition. Swells propagated from deep water into harbor are shown to be dominant effects on the design waves of operable harbor condition.