• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.607-616
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• 2019

Free body diagram analysis is done for key parts of pilot stage of LLV (Load Limit Valve) which is used to protect overload for static structural test of aerospace flight vehicle. It is shown through the analysis that diameter ratio($D_2)^{ten}/D_2)^{comp}$) of two poppets in a pilot stage must be equal to piston area ratio($A_{comp}/A_{ten}$) of a hydraulic actuator for making a poppet open consistently at constant force applied by an actuator. The result of the analysis is verified by measuring geometries of the poppets in the four different LLVs which are corresponding to four actuators with different capacity and have been used after being imported in this laboratory. Results of "Adjuster resolution tests" with two different pilot stages show the max. deviation of Fi(actuator force in instant of opening poppet) from average Fi obtained for each turn of adjuster is 0.3KN and max. deviation of the Fi normalized by average Fi of each turn of adjuster is 3.7%. From the results, it is verified that the two pilot stages with same poppet diameter ratio make a poppet consistently open at Fis within ${\pm}3.7%$ deviation from the average Fi. The deviation is shown to be caused from frictional force of O-ring in the poppet. Additionally, design factors for poppet spring and adjuster, which are also key parts of the pilot stage, are distinguished and procedure for deciding the factors are also shown in this study.

• Journal of the Korean Society for information Management
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• v.38 no.1
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• pp.25-51
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• 2021

In this study, we tried to provide basic materials necessary for introduction of smart libraries by analyzing present conditions of its operation based on the actual conditions of digital materials. For this study, a survey of actual use of digital materials is conducted for digital material rooms of public libraries in nationwide and 213 persons in charge of digital materials. As a result of this study, the followings are found: first, 80.8% of those public libraries responding to the survey operate digital material rooms and average 1.75 person is in charge of managing digital materials and open type Wi-Fis are installed in those public libraties but only 11.3% of those libraries provide 5G services; second, it is found that the digital data which are owned by those public libraries most are video contents (63.8%), e-books (53.5%) and audio books (53.5%) in order. In addition average number of types of audio books 781, video contents 4,985, nonbook contents except for video 3,616 and other digital data 626. This study is a basic research for introduction of smart library and it is necessary to conduct another study of a plan for future revitalization of digital materials and librarians' awareness on introduction of smart library.

• Industry Promotion Research
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• v.8 no.1
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• pp.103-110
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• 2023

This study targeted KakaoTalk app users, mainly in Seoul and the metropolitan area, and verified the factors that had a significant impact on the intention to continuously use the app through KakaoTalk contents. Among various content characteristics, five variables were used to verify the variables that had the greatest influence on the intention to continue using, and the ones that did not. As a result of testing the five hypotheses, it was found that convenience, enjoyment, informativeness, and perceived usefulness had a significant positive(+) effect on the intention to continue using, but intimacy did not. From this, it can be determined that the majority of users use the app content because it is useful and informative, rather than because they have a sense of familiarity. In this way, the purpose of this study is to provide empirical help to factors closely related to the intention of continuous use in deriving priorities to be considered in the service planning stage as well as in terms of technical design of contents when developing mobile apps in the mobile app industry as a whole and in the field in the future. I want to provide it, but there is a meaning.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.42-51
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• 2012

This study investigated the characteristics of natural organic matter (NOM) with general water characteristics (pH, DO, electrical conductivity, BOD, COD, TN, TP, Chl-$a$, DOC, $UV_{254}$, SUVA) and the 3D fluorescence excitation-emission matrix (FEEM) in the Yeongsan River basin. FEEM was used to classify protein-like and fulvic & humiclike substances with fluorescence intensity in the matrix of excitation and emission wavelength. The concentration of BOD, COD, TN, electrical conductivity and DOC in the region of Gwangju city (Gwangju sewage treatment plant: GJS, Gwangjucheon: GJC, Gwangju 2: GJ2) was relatively higher than the upper reaches and lower reaches of the Yeongsan River basin. SUVA in most sites was lower than 3 L $mg^{-1}\;m^{-1}$ as the hydrophilic substances, except Damyang (DY) in the upper reaches of Yeongsan river was higher than 3 L $mg^{-1}\;m^{-1}$ as the hydrophobic substances during winter and autumn. In the FEEM investigation the fulvic and humic substances were found in most sites, and in sites regarding Gwangju city (GJS, GJC, GJ2) during winter and GJC in summer, protein-like substances were found. The trend of fluorescence intensities from the upper reaches to the lower reaches in most sites corresponded to that regarding the concentration of water characteristics (BOD, COD, TN, DOC). That is why the region of Gwangju city (GJS, GJC, GJ2) was relatively higher. This results were an equivalent trend to those of fluorescence index (FI) in most sites, and the higher FIs in the sites of Gwangju city indicate more microbial-derived substances due to enormous effluent organic matters (EfOM) from huge Gwangju sewage treatment plants.

• Cross-Cultural Studies
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• v.37
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• pp.211-231
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• 2014

Comment faciliter l'apprentissage du français pour rendre notre enseignement plus efficace? Beaucoup de recherches ont ${\acute{e}}t{\acute{e}}$ $men{\acute{e}}es$ sur cette question; en $r{\grave{e}}gle$ $g{\acute{e}}n{\acute{e}}rale$ l'enseignement de la langue d'une part et l'expression ${\acute{e}}crite$ et la $r{\acute{e}}flexion$ d'autre part ${\acute{e}}taient$ $men{\acute{e}}es$ $ind{\acute{e}}pendamment$. Notre intention dans ce $pr{\acute{e}}sent$ travail a ${\acute{e}}t{\acute{e}}$ d'introduire et $d^{\prime}e xp{\acute{e}}rimenter$ pendant $l^{\prime}ann{\acute{e}}e$ scolaire des cours associant le $d{\acute{e}}bat$ $d^{\prime}id{\acute{e}}e$ et la $r{\acute{e}}flexion$ $th{\acute{e}}matique$ avec l'apprentissage linguistique(grammaire, vocabulaire${\dots}$), afin de susciter $l^{\prime}i nt{\acute{e}}r{\hat{e}}t$ des apprenants, leur $curiosit{\acute{e}}$ et leur $vivacit{\acute{e}}$, au $del{\grave{a}}$ des $d{\acute{e}}fis$ $pos{\acute{e}}s$ par la langue française. Nous avons en particulier $utilis{\acute{e}}$ une $publicit{\acute{e}}$ comme support d'apprentissage des bases linguistiques et comme moteur $d^{\prime}{\acute{e}}veil$ ${\grave{a}}$ la civilisation française pour mobiliser leur attention et stimuler leur $activit{\acute{e}}$ cognitive par $l^{\prime}interdisciplinarit{\acute{e}}$. Nous avons donc $expos{\acute{e}}$ ici les exemples d'argumentation autour les deux $s{\acute{e}}quences$ publicitaires conduites avec les ${\acute{e}}tudiants$ et les arborescences $d{\acute{e}}gag{\acute{e}}es$ de ces analyses. Presque concomittamment ${\grave{a}}$ "voir" et "${\acute{e}}couter$", l'information est $trait{\acute{e}}e$ par $l^{\prime}activit{\acute{e}}$ "$d{\acute{e}}coder$". Nous approfondissons ensemble cette $interpr{\acute{e}}tation$ $s{\acute{e}}miotique$, et l'analyse de la façon dont la $publicit{\acute{e}}$ capte l'attention du spectateur nous $am{\grave{e}}ne$ ${\grave{a}}$ $d{\acute{e}}gager$ des faits de $soci{\acute{e}}t{\acute{e}}$ et ${\grave{a}}$ y $r{\acute{e}}fl{\acute{e}}chir$; comment, avec l'exemple de la $publicit{\acute{e}}$ jouant la musique $d{\acute{e}}licieuse$ de la gourmandise, nous entrevoyons la $r{\acute{e}}alit{\acute{e}}$ obscure de $l^{\prime}ob{\acute{e}}sit{\acute{e}}$ infantile. Ces approches interdisciplinaires ${\grave{a}}$ partir du multi-$m{\acute{e}}dia$ $r{\acute{e}}pondent$ ${\grave{a}}$ la $n{\acute{e}}cessit{\acute{e}}$ de distance critique que requiert la $soci{\acute{e}}t{\acute{e}}$ contemporaine. $L^{\prime}{\acute{e}}tude$ d'une $s{\acute{e}}quence$ publicitaire ne permet certes pas $d^{\prime}appr{\acute{e}}hender$ la $soci{\acute{e}}t{\acute{e}}$ française dans sa $globalit{\acute{e}}$, mais en $consid{\acute{e}}rant$ que notre travail consiste tout autant ${\grave{a}}$ stimuler la $facult{\acute{e}}$ critique $qu^{\prime}{\grave{a}}$ favoriser l'apprentissage linguistitique, notre $strat{\acute{e}}gie$ nous permet de $r{\acute{e}}aliser$ plusieurs objectifs autour d'un $m{\hat{e}}me$ axe d'enseignement.