• Animal cells and systems
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• v.15 no.2
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• pp.169-177
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• 2011

In August 2002, a heavy rainfall (445 mm in total for 5 consecutive days) resulted in a catastrophic flood, and it completely washed away the benthic fauna from the mainstream channel of the Gapyeong stream, a typical mid-sized stream in the central Korean peninsula. This study was to investigate the recovery patterns of aquatic insect communities that were damaged by the flood. Aquatic insects were sampled quantitatively using a Surber sampler ($50{\times}50$ cm, 1 riffle and 1 pool/run habitats per site) from three sites (4th-6th order) of the Gapyeong stream prior to 2000 and seasonally after the flood event from 2003 to 2006. Before the flood in the reference year (2000), a total of 77 species of aquatic insects were collected, whereas after the flood 47 species (2003), 51 species (2004), 64 species (2005) and 55 species (2006) were collected from the whole sampling sites. The aquatic insect density decreased to 26.85% (2003), 90.25% (2004), 52.53% (2005) and 54.95% (2006) of that recorded in the reference year. Although approximately 70% of the aquatic insect fauna has recovered since the flood event, the species composition in the most recent year differed substantially (similarity ca. 50%). On the other hand, the compositions of functional groups have not significantly changed. Aquatic insect communities at the riffle sites were affected more profoundly than those at the pool/run sites. The aquatic insect communities at the upstream site recovered more rapidly than those at the downstream sites.

• Advances in aircraft and spacecraft science
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• v.9 no.6
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• pp.525-536
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• 2022

The current state of telecommunications infrastructure in the Arctic does not allow providing a wide range of required services for people, businesses and other categories, which necessitates the use of non-traditional approaches to its organization. The paper proposes an innovative approach to building a combined communication network based on tethered high-altitude platform station (HAPS) located at an altitude of 1-7 km and connected via radio channels with terrestrial and satellite communication networks. Network configuration and composition of telecommunication equipment placed on HAPS and located on the terrestrial and satellite segment of the network was justified. The availability of modern equipment and the distributed structure of such an integrated network will allow, unlike existing networks (Iridium, Gonets, etc.), to organize personal mobile communications, data transmission and broadband Internet up to 100 Mbps access for mobile and fixed subscribers, rapid transmission of information from Internet of Things (IoT) sensors and unmanned aerial vehicles (UAV). A substantiation of the possibility of achieving high network capacity in various paths is presented: inter-platform radio links, subscriber radio links, HAPS feeder lines - terrestrial network gateway, HAPS radio links - satellite retransmitter (SR), etc. The economic efficiency of the proposed solution is assessed.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.640-647
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• 2023

Material corrosion in nuclear power plant (NPP) is not controlled only by amine injection but also by ion exchange (IX) which is the best option to remove trace Na⁺. This study was conducted to understand the Na⁺ leakage characteristics of IX beds packed with ethanolamine-form (ETAH-form) and hydrogen-form (H-form) resins in the simulated water-steam cycle in terms of intrinsic behaviors of four kinds of cation-exchange resins through ASTM test and Vanselow mass action modeling. Na⁺ was inappreciably escaped throughout the channel created in resin layer. Na⁺ leakage from IX bed was non-linearly raised because of its decreasing selectivity with increasing Na⁺ capture and with increasing the fraction of ETAH-form resin. Na⁺ did not reach the breakthrough earlier than ETAH⁺ and NH₄⁺ due to the increased selectivity of Na⁺ to the cation-exchange resin (H⁺ < ETAH⁺ < NH₄⁺ ≪ Na⁺) at the feed composition. Na⁺ leakage from the resin bed filled with small particles was decreased due to the enhanced dynamic IX processes, regardless of its low selectivity. Thus, the particle size is a predominant factor among intrinsic properties of IX resin to reduce Na⁺ leakage from the condensate polishing plant (CPP) in NPPs.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.118-141
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• 2024

This study investigates and analyzes ancient literature records and iconographic materials to examine the Willow Tree Fence(樹柵) built on Gasan(假山) Cheonggyecheon(淸溪川) within the Hanyangdoseong, which was deliberately created to prevent flood damage during the Joseon Dynasty. Although there have been research cases related to the willow tree, it is difficult to find research conducted with the purpose of identifying its archetypal value by investigating and analyzing specific use cases of the willow tree and its historical background. Accordingly, this study aims to identify examples of the Willow Tree Fence(樹柵) created in Cheonggyecheon(淸溪川) during the Joseon Dynasty and reinterpret their value by illuminating the background of construction and regional characteristics. The main contents of this study are as follows. It is presumed that floods during the Joseon Dynasty were a great hazard. Between the 16th and 18th centuries, Joseon suffered severe damage from floods. By the time of King Yeongjo, all Four Mountains(四山) of the capital had become bare mountains, which was the cause of frequent floods. In the year of Gyeongjin(庚辰, the 26th year of King Yeongjo's reign, 1760), King Yeongjo dredged the channel bottom of Cheonggyecheon(淸溪川), which overflowed every rainy season, with the Juncheon Project(Channel-Dredging, 濬川事業) and planted willow trees on the mountain on both sides of the Ogan Water Gate(五間水門), as measures to prevent flood damage and soil loss. was implemented. In the <Doseongdo(都城圖)> in 《 Gwangyeodo(廣輿圖)》 produced in the mid-18th century during the reign of King Yeongjo, Gasan(假山), built in front of the Ogan Water Gate(五間水門) is visible, and in the record 『Sinjeung Donggukyeoji Seungnam(新增東國輿地勝)』 In the record, it appears that willows were planted on both sides of the mountain in the year of Gyeongjin(1760). With <Hanyangdoseong Map(漢陽都城圖)> produced in the 46th year of King Yeongjo's reign(1770), it is confirmed that willow trees formed a thick forest on Gasan Mountain near the Ogan Water Gate(五間水門) in the late 18th century. In addition, the Juncheon Project(Channel-Dredging, 濬川事業) and the creation of the Willow Tree Fence(樹柵) continued from the 15th century, the early Joseon Dynasty(朝鮮前期), to the end of the 19th century, the late Joseon Dynasty(朝鮮後期), through the records of ancient literature such as 『Annals of the Joseon Dynasty(朝鮮王朝實錄)』, 『Seungjeongwon Diary(承政院日記)』, and 『Records of Daily Reflections(日省錄)』. This study is meaningful in informing that the willow tree was a unique cultural heritage and traditional landscape resource by investigating the composition and use of the Willow Tree Fence in the Joseon Dynasty, which was a great basis for preventing floods and flood damage, as well as forming a beautiful landscape.

• Journal of Distribution Science
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• v.17 no.10
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• pp.83-91
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• 2019

Purpose - Media is a significant distributional channel in sport. In terms of determining the influencer in building sport media contents, recent sport media studies have employed agenda-setting theory, assuming media itself as the agenda provider. In a real-world situation, however, sports stars have been deemed key factor determining distribution contents in sport. The starting point of this study is the "tacit premise" of agenda-setting theory. Given the agenda-setting theory, the current study attempted to explore the function of sport stars as an agenda provider, which is a key determinant of sport distribution. Research design, data, and methodology - This study has reviewed articles of Yuna Kim, Sang-hwa Lee, and Hyun-jin Ryu from daily newspapers including as dong-a ilbo and joongang ilbo (2013 to 2017). The study collected data, portable document format (PDF), from the online archive of dong-a ilbo and joongang ilbo. We coded the length of the article, the frequency, the size of the picture, and the structural form of the article. Inter-coder reliability was compared with data previously investigated by the researcher. Inter-coder reliabilities for study 1 and 2 was .89 and .85. To examine hypotheses, descriptive analysis, correlations, and cross-tap analysis were performed. Results - The results partially supported the hypotheses proposing the significant role of sports stars as the agenda setters in distributing sport media contents. In specific, the study found that the number of articles about sports stars prevailed the number of articles about regular athletes. Besides, studies found that the use of photos was more frequent in articles of sports starts than that of regular athletes. In sports newspaper articles, featured story articles were used more than straight-articles for news relating to sports stars. Also, sports newspaper of sports stars contained more information associated within an event rather than outside of an event. Conclusions - In sports journalism, this study challenges the current theory that the media affects the composition and the content of sports coverages. As the principle of the agenda-setting of sports media, the influence of sports stars must be continuously studied along with a follow-up study.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.1
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• pp.29-35
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• 2010

We have shown that myosin light chain kinase (MLCK) was required for the off-contraction in response to the electrical field stimulation (EFS) of feline esophageal smooth muscle. In this study, we investigated whether protein kinase C (PKC) may require the on-contraction in response to EFS using feline esophageal smooth muscle. The contractions were recorded using an isometric force transducer. On-contraction occurred in the presence of $N^G$-nitro-L-arginine methyl ester (L-NAME), suggesting that nitric oxide acts as an inhibitory mediator in smooth muscle. The excitatory composition of both contractions was cholinergic dependent which was blocked by tetrodotoxin or atropine. The on-contraction was abolished in $Ca^{2+}$-free buffer but reappeared in normal $Ca^{2+}$-containing buffer indicating that the contraction was $Ca^{2+}$ dependent. 4-aminopyridine (4-AP), voltage-dependent $K^+$ channel blocker, significantly enhanced on-contraction. Aluminum fluoride (a G-protein activator) increased on-contraction. Pertussis toxin (a $G_i$ inactivator) and C3 exoenzyme (a rhoA inactivator) significantly decreased on-contraction suggesting that Gi or rhoA protein may be related with $Ca^{2+}$ and $K^+$ channel. ML-9, a MLCK inhibitor, significantly inhibited on-contraction, and chelerythrine (PKC inhibitor) affected on the contraction. These results suggest that endogenous cholinergic contractions activated directly by low-frequency EFS may be mediated by $Ca^{2+}$, and G proteins, such as Gi and rhoA, which resulted in the activation of MLCK, and PKC to produce the contraction in feline distal esophageal smooth muscle.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.4
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• pp.85-95
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• 2014

In the e-commerce, the conversion into the multi-media is the important issue. According to the research by Nielsen Korea, the 83% of customers who purchase the products in the e-commerce utilize multi-channel to buy the products such as mobile and online [3]. Thus, to effectively implement online advertising, marketers should understand the customers' path [15] in the multi-channel. The study of the multi-site activities plays an important role to predict customers' purchase [28]. To explain the e-commerce site visit activities of customers, we have developed research model in terms of the online advertising. This research model is based on the study of Moe and Fader [23]. There are two types of composition in the research model. First, general site visit as an exploratory search have net effect on the shopping site visit because customers could acquire or develop information on the e-commerce site via online advertising. Secondly, the e-commerce site visit as a goal-directed search cause threshold of the e-commerce site visit because customers could achieve their goal. When the threshold is increased, the probability of a shopping site visit is decreased and vice versa. Thus, we have investigated the impact of customers' previous visit activities (general site visit and shopping site visit) on the next e-commerce site visit in terms of dynamic view. Research data was provided by Cheil World Wide. This panel data include mobile and online log data of panelists from Jan. 2013 to March 2013. As the results, the customers' e-commerce site visit on the online media would decrease the probability of e-commerce site visit because these visit activities increase the threshold of e-commerce site visit. This result is similar with the previous study [23]. Otherwise, since e-commerce site visit on the mobile media decrease the threshold, the customers' probability of e-commerce site visit would increase In summary, the site visit activities on the mobile could improve the probability of e-commerce site visits.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.635-648
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• 1995

Macrobenthic fauna were collected seasonally using the van Veen Grab $(0,1/m^2)$ to investigate the benthic faunal assemblages on the soft-bottoms around the Youngjong Island during October 1991 to July 1992. A total of 266 species was identified. Of these polychaetes comprised 111 species $(41.7\%)$; crustaceans $75(28.2\%)$ molluscs, $59 (22.2\%)$ and others including echinoderms, $27(7.9\%)$. Mean density and biomass were estimated to be 498 $ind./m^2$ and 54.8$g./m^2$, respectively. Polychaetes were the most dominant faunal group in terms of abundance $(332\;ind./m^2)$ and number of species as well, whereas echinoderms were predominant in biomass $(332\;g./m^2)$. The dominant species were Mediomastus sp., Heteromastus sp., Nipponomysella oblongata, and Nephts polyranchia; the abundance of these species showed seasonal variations. The study area was divided into three regions by cluster analysis based on the similarity of species composition. The first region consisted of intertidal flat (G-I); the second, shallow subtital region of muddy sand (G-II); the third, channel region of mud sediments (G-III). The intertidal flat showed the highest density, and the channel was the lowest density, but the Highest in species diversity. Distribution of macrobenthic faunal assemblages of the study area seemed to be controlled by sedimentary facies and duration of tidal exposure.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.66-75
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• 2021

The research is centered towards analyzing the usage status of YouTube platform and the nature of content supplied to YouTube by selecting Korean two Traffic Broadcastings Based on TBS(Traffic Broadcasting System) and TBN(Traffic Broadcasting Network). TBS operates 'Citizen's Broadcasting', which has 1.1 million subscribers among 13 YouTube channels, as its main channel. TBN has only 15,000 subscribers to its main 'TBN Tong', and YouTube channels in 12 local networks. TBS which has a dedicated YouTube manpower, is far ahead of TBN in terms of YouTube channel management and content composition. Both broadcasters are passive about creating new media content due to job stability. For the development of the YouTube platform for these two broadcasters, organizational changes within traffic broadcasting and changes in the perception of members are required, and live broadcasting and discovery of star creators are required. In the changing media environment two traffic broadcastings need a program distribution strategy that can be included in various media platforms.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.161-173
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• 2020

In-depth interview in the field of hospitality industry services was conducted in COVID- 19. Introduction of kiosks for non-face-to-face services using untact technology, reservation, pay systems, self-service, service improvement using room service should be carried out. It is also necessary to implement Instagram, Facebook, YouTube, P-blogs, online broadcasting and live commerce through the establishment of m-channel system through untact marketing sales channels in the hospitality industry now that the product composition to solve the pro -blem of untact marketing is drawing attention due to diversification of online sales channe -ls. Now, the recognition of important elements of service education and a establishment of differentiated system of untact marketing, expansion of untact sale channel, implementation of non-face-to-face counseling service and introduction of pre-booking, telecommuting were recognized as urgent parts. In particular, a service differentiation and importance of human services, which were recognized free of charge, have re-recognized as premium, and quality service aspect of the hospitality industry in untact and the direction to diversify marketing channels are presented.