• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.7-17
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• 1982

In order to predict substituent and Lewis acid effects on the regiospecificity of the Diels-Alder reaction, and to investigate the competition for the complexation of Lewis acid between diene and dienophile, frontier orbital theory has been applied to thermal and catalyzed Diels-Alder reaction by means of CNDO/2 MO method. It has been found that: (1) Lewis acid coordinated preferentially with diene rather than dienophile when carbonyl oxygen of acetoxy substituted diene had larger negative atomic charges than that of dienophile. (2) Most of the reaction were neutral electron demand type, and hence 4-C, 2-C and quantitative secondary orbital interacion methods were generally in good accord with experiments. (3) Sulfur activated the adjacent terminal carbon atom greatly to increase diene LUMO-dienophile HOMO interaction through vacant-d-orbital participation, and played an important role in controlling regioselectivity of neutral electron demand reaction type.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1223-1230
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• 2020

Due to the aging of the population, the number of the elderly is increasing, and the nuclear family is rapidly progressing. Today's AI speakers respond to user's commands rather than conversations that occur on a daily basis. If the elderly living alone do not talk first, the usability of the AI speaker will decrease. In this paper, it describes the development of AI speakers for active interaction tailored to the aged. This speaker can identify the movements of the elderly who live alone and their surroundings, actively speak to them, and display emotional expressions appropriate to the content of the conversation. Through this, users will be able to anthropomorphize AI speakers, so they can feel familiarity and emotional conversation is expected to play a positive role in easing their loneliness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.481-488
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• 2006

This paper suggests a novel approach of integrating the quasi-distributed watershed model SWAT with the fully-distributed groundwater model MODFLOW. Since the SWAT model has semi distributed features, its groundwater components hardly considers distributed parameters such as hydraulic conductivity and storage coefficient. Generating a detailed representation of groundwater recharge, head distribution and pumping rate is equally difficult. To solve these problems, the method of exchanging the characteristics of the hydrologic response units (HRUs) in SWAT with cells in MODFLOW by fully combined manner is proposed. The linkage is completed by considering the interaction between the stream network and the aquifer to reflect boundary flow. This approach is provisionally applied to Gyungancheon basin in Korea. The application demonstrates a combined model which enables an interaction between saturated zones and channel reaches. This interaction plays an essential role in the runoff generation in the Gyungancheon basin. The comprehensive results show a wide applicability of the model which represents the temporal-spatial groundwater head distribution and recharge.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.3
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• pp.75-82
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• 2008

Two UASB reactors were operated to investigate the effect of high concentration of sulfate on anaerobic digestion of propionate using an upflow anaerobic sludge blanket (UASB) reactor. An organic loading rate of $1.2kg\;COD/m^3{\cdot}d$ and a hydraulic retention time of 1.6 d were maintained during this study. In the absence of sulfate, the UASB reactor achieved about 95% removal of chemical oxygen demand whereas in the presence of $2,000\;SO_4^{2-}mg/L$, the COD removal rate decreased to 83% due probably to the inhibition of dissolved sulfide inhibition. Interactions between the methane producing bacteria (MPB) and sulfate reducing bacteria (SRB) were measured to investigate the competition between MPB and SRB. The MPB consumed average 58% of the available electron donors at $COD/SO_4^{2-}$ ratio of 1. Propionate was consumed mainly by SRB, converting sulfate into sulfide and suppressing the methane production. The specific methanogenic activity (SMA) using acetate and propionate increased as microorganism acclimated to the substrate.

• KSBB Journal
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• v.9 no.3
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• pp.325-331
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• 1994

PGA is formed in a route of CO2 fixation of RuBP catalyzed by RuBPCase, followed by reduction of the PGA by NADH to GAP This reduction is enhanced in an anionic micellar solution(SDS), in which NADH is distributed in the aqueous and the micellar pseudophases in a given ratio. This micellar bounded NADH reacts to PGA, and in higher micellar concentration than $1.25{\times}10^{-2}M$, most of NADH is oxidized to NAD+ by PGA. On the other hand, in the solutions of the positive ionic(CTABr), zwitter ionic(Chaps) and nonionic (Brij and Triton X-100) micelles, the reactions are also enhanced and the concentrations of NADH reach minima with micellar concentrations. Such minima are typical of micellar catalyzed bimolecular reactions, and the fall in concentrations of the reductant followed by a gradual increase is charataristic of reactions of hydrophobic substrates: that is, the reductions of PGA by NADH are sharply enhanced in a range of the lower micellar concentrations, and NADH amounts in ca. $1.25-2.50{\times}10^{-3}M$ micellar solutions are reached to minima, followed by gradual increases of the reductant concentration.

• Journal of Internet Computing and Services
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• v.18 no.1
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• pp.89-103
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• 2017

This paper analyzed the influence of government-owned social media's environmental characteristics on the level of users' active participation and types of message diffusion during government's crisis. The social media environment was categorized based on human interactivity and media interactivity. Users' active participation was measured based on amount of like/dislike and number of comments. User's comments were categorized through network analysis. This study found that the level of user's active participation was high on the information-provider participation type and the relationship-oriented participation type. The level of user's active participation was low on the information-provider type and the limited platform. The analysis of message diffusion type showed that a restrictive rational opinion type was found for the limited platform and diffusive or restrictive emotional opinion types were found for other types of social media environment. This study found that during MERS crisis, the government did not provide messages suitable for the social media environment, and the media environment influenced users' participation and comments. The government should provide user friendly social media environment by increasing interaction with users and should make efforts to communicate with users in crisis situation.

• Journal of Science Education
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• v.33 no.1
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• pp.122-132
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• 2009

This study aimed at designing an effective earth science instruction which would help to improve students' scientific creativity using the questioning strategies. The developed questioning strategies were applied to 153 students of $10^{th}{\sim}11^{th}$ grades from March, 2004 to February, 2006. The Reaction Evaluation of Educational Program was used for students' reponses on these questioning strategies. And the Creativity Test developed by the Korea Institute for Aptitude Test was used for the changes of students' scientific creativity. The students responded that these questioning strategies improved students' scientific creativity, and those did not promoted interaction between the teacher and the students. After implementing these questioning strategies, students' analogical ability of language was evaluated the largest score among the 6 categories of scientific creativity. The survey about students' scientific creativity showed that there are meaningful differences between before and after implementing these questioning strategies : analogical ability of figure, analogical ability of language, reading comprehension ability.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.186-198
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• 2020

The current study examines how product type and attitudes toward the webtoon - a digital comic that originated in Korea - affect consumer responses to webtoon product placement (PPL). Specifically, it examines the following responses: the perception of PPL intrusiveness, attitudes toward the PPL, attitudes toward the brand, word-of-mouth intention, and purchase intention. It further investigates how PPL type interacts with product type and attitudes toward the webtoon on consumer responses to the PPL. The findings from a 2 (product type: functional vs. hedonic) × 2 (attitudes toward the webtoon: negative vs. positive) × 2 (PPL type: creative placement vs. on-set placement) between-subject experimental study suggest the following: consumer responses to PPL in webtoon is more positive when the product is hedonic (vs. functional) and when attitudes toward the webtoon are positive (vs. negative). This study further suggests when subjects felt favorably toward the webtoon, the creative placement produced weaker perceptions of PPL intrusiveness and more favorable attitudes toward the PPL than the on-set placement. On the other hand, when subjects felt negatively toward the webtoon, the on-set placement evoked weaker perceptions of intrusiveness and more favorable attitudes toward the PPL than did the creative placement.

• Journal of Gifted/Talented Education
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• v.13 no.3
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• pp.1-17
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• 2003

Development and evaluation of distance learning for the gifted students in science and mathematics In this study, we developed and administrated the distance learning for the gifted students in science and mathematics, and analysed their responses. To do this, four types of teaching programs - lectures using program for distance learning, practice activities using simulation program, tasks solving programs based on discussions, and problem solving activities - were developed and students responses were analysed in eight area - stimulus, difficulties, structure, learning circumstances, involvement, interaction, learning outcomes, comparison with other learning -. As results, it was found that many students responded positively and thought programs helped their creativity, logical thinking, intelligent ability, and information searching ability. Students preferred practice activities based on appropriate guidances to lectures providing detailed explanations. And interaction could be stimulated by inducing discussion.

• Exercise Science
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• v.21 no.1
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• pp.111-120
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• 2012

The purpose of the study was to assess the effects of different cardiorespiratory fitness response to exercise training on cardiovascular disease and adipocytokine release and gene expression in abdominal obesity women. forty eight middle-age women were divided to a exercise-responder (n=34) group (ERG) and a exercise-nonresponder (n=14) group (ENRG) based on cardiorespiratory fitness after exercise training (12weeks, 1200 kcal/week, moderate-vigorous intensity, walking and jogging). Cardiorespiratory fitness was measured using maximal oxygen uptake with metabolic gas analysis and body composition was determined by bioelectrical impedance. We measured lipid and glucose profiles, blood adipocytokines and adipocytokine genes expression in adipose tissue. Waist girth (p=0.040), and %body fat (p=0.031) were significantly decreased in ERG than ENRG. Triglyceride (p=0.023) and systolic blood pressure (0.046) were significantly decreased in ERG than ENRG. Blood leptin (p=0.022) was significantly decrease in ERG than ENRG but leptin gene expression was decreased both groups (p<0.001). These results show that exercise-responder group improved cardiovascular disease risk factors and adipocytokine more than exercise-nonresponder group after exercise training. Moreover, exercise-nonresponders group show that obese indices and blood leptin and leptin gene expression in adipose tissue were decreased despite the failure to improve fitness. Therefore, regular exercise training seems to give health benefits although the failure to improve fitness.