• Journal of Gifted/Talented Education
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• v.26 no.3
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• pp.541-559
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• 2016

This study investigated a relationship among facilitating discourse, students' perceived challenge, and learning outcomes(persistent intention and learning achievement) in an online science gifted education program. Two hundreds and forty-two middle school students participated in the study. A survey questionnaire which was consisted of 6 items of facilitating discourse from teaching presence questionnaire(Shea, Swan, & Pickett, 2005) and 5 items of challenge from Student Perceptions of Classroom Quality(Gentry & Owen, 2004) was administered. First, the findings of this study showed that students' perceived facilitating discourse as a part of teaching presence was positively related to students' perceived challenge in an online course. Second, students' perceived facilitating discourse were positively related to persistent intention, but were negatively related to students' achievement. Third, students' perceived challenge was positively related to persistent intention and achievement. Finally, challenge mediated the relationship between students' perceived facilitating discourse and persistent intention, and the relationship between students' perceived facilitating discourse and students' achievement as well. This results suggested that online program should be designed to increase the levels of facilitating discourse.

• Journal of Internet Computing and Services
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• v.21 no.6
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• pp.123-132
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• 2020

The EDucation-research Integration through Simulation On the Net (EDISON) platform, which is a web-based platform that provides computational science and engineering simulation execution environments, can offer various analysis environments to students, general users, as well as computational science and engineering researchers. To expand the user base of the simulation environment services, the EDISON platform holds a challenge every year and attempts to increase the competitiveness and excellence of the platform by analyzing the user requirements of the various simulation environment offered. The challenge platform system in the field of computational science and engineering is provided to users in relation to the simulation service used in the existing EDISON platform. Previously, EDISON challenge servicesoperated independently from simulation services, and hence, services such as end-user review and intermediate simulation results could not be linked. To meet these user requirements, the currently in-service challenge platform for computational science and engineering is linked to the existing computational science and engineering service. In addition, it was possible to increase the efficiency of service resources by providing limited services through various analyses of all users participating in the challenge. In this study, by analyzing the simulation and usage environments of users, we provide an improved challenge platform; we also analyze ways to improve the simulation execution environment.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.605-613
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• 2020

This study was conducted to evaluate the effects of dietary supplementation of plant flavonoid (quercetin) on immune parameters, growth performance, and nutrient digestibility in growing pigs challenged with Escherichia coli lipopolysaccharide (LPS). A total of 40 crossbred ([Landrace × Yorkshire] × Duroc) growing pigs; initial body weight (BW) of 26.95 ± 1.26 kg were used in a six-week experimental trial. Pigs were randomly allocated into one of four treatment groups in a 2 × 2 factorial arrangement with the following factors; without LPS challenge and with LPS challenge (day 21) supplemented with or without 0.1% flavonoid according to BW (2 replicate pens per treatment with 2 gilts and 3 barrows per pen). The single-dose LPS (100 ug / kg BW) injection showed trends tended to be increased in interleukin-6 (IL-6) after 2 h and 6 h of challenge compared with unchallenged pigs. However, other measured immune indices (white blood cell, immunoglobulin G, lymphocyte, and tumor necrosis factor), growth performance, and nutrient digestibility were not significantly different between challenged and non-challenged animals. The supplementation of flavonoid significantly increased (p < 0.05) average daily gain (ADG) during day 0-21, tended to increase dry matter and nitrogen digestibility, significantly reduced IL-6, increased Ig-G and WBC concentrations and increased lymphocytes percentage regardless of LPS challenge.

• Journal of Arbitration Studies
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• v.21 no.3
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• pp.3-20
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• 2011

An arbitrator is an impartial person chosen to decide the issue between parties engaged in a dispute. But the arbitrator appointed by a party or arbitration institution shall be impartial or independent and should disclose to the administrator any circumstances likely to give rise to justifiable doubts as to his impartiality or independence. If, at any stage during the arbitration, new circumstances arise that may give rise to such doubts, the arbitrator shall promptly disclose such circumstances to the parties and to the administrator. Upon receipt of such information from an arbitrator or a party, an party must challenge any arbitrator whenever circumstances exist that give rise to justifiable doubts as to arbitrator's impartiality or independence. Under these circumstance, there were two cases declared by the Korean Supreme Court in relation to the cancellation of the arbitration award. One arbitral case was cancelled for the reason of the having been arbitral procedure without disclosure arbitrator's impartiality, and the other case was refused to cancel the ward for the reason of the having been arbitral procedure without challenge an arbitrator. There are not, however, the standard to decide what is definitely the arbitrator's impartiality or independence and the difference on qualification between arbitrator chosen by an party and neutral arbitrator in korean arbitration law and rules. Nevertheless, korean court require arbitrator to be impartial and independent and the arbitration parties to challenge arbitrator' impartiality or independence.

• Journal of fish pathology
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• v.24 no.3
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• pp.269-278
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• 2011

Gene expression of two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) paralogs was examined during Edwardsiella tarda challenge and heavy metal exposures in mud loach (Misgurnus mizolepis; Cypriniformes) kidney and spleen. Transcription of the two mud loach GAPDH paralogs (mlGAPDH-1 and mlGAPDH-2) was significantly modulated by these stimulatory challenges in an isoform-dependent manner. Based on the real-time RT-PCR analysis, the mlGAPDH-2 transcripts were more preferentially induced by E. tarda challenge, whereas the mlGAPDH-1 transcripts were proven to show more inducibility in response to heavy metal exposure using Cd, Cu, Mn and Zn at $5{\mu}M$. Their isoform-specific response patterns were closely in accordance with the TF binding profiles in promoter and intron-1 of the two mlGAPDH isoforms, in which the mlGAPDH-2 has more binding sites for immune-related transcription factors than mlGAPDH-1 while the mlGAPDH-1 possesses exclusively metal responsive elements in its intron. Collectively, the mlGAPDHs are potentially involved in cellular pathways independent of glycolysis and the two GAPDH paralogs might undergo functional diversification or subfunctionalization at least at the transcription level.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.209-216
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• 2010

The purpose of this paper is to examine a user's flow experience of digital contents. In the paper, the flow experience of digital contents was applied to the case of online games and it was experimentally investigated whether challenge and skill affect the user's flow experience. The results of the paper indicate that there are differences in the flow experience according to the level (low, medium, high) of challenge and skill in the context of online games. Furthermore, there is no interaction effect between challenge and skill affecting flow experience. The findings provide useful implications for IT firms that will plan to develop and design digital contents.

• Journal of the military operations research society of Korea
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• v.22 no.2
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• pp.49-72
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• 1996

This study examined the antecedents and outcomes of leader-member exchange (LMX) quality in the Korean Army platoons. Although a number of studies have devoted substantial attention to the application of the LMX theory in various organizational settings, there has been no effort to verify or to apply the model to a military situation. In this paper, we tried to build an integrative LMX model to apply to the Korean army. We developed, on the basis of literature review, an integrative framework describing the factors affecting the LMX quality, LMX quality outcomes and the moderators of LMX quality-outcomes. Then we collected data from the 404 lieutenant-soldier dyads. The analysis of the data showed that 1) interpersonal variables (perceived similarity and liking of soldier) and LMX quality were significantly related, 2) LMX quality and outcome variables(soldier's performance, job satisfaction, and morale) were significantly related, and 3) the relationship between LMX quality and soldier's performance were strongly significant when task challenge is high but nonsignificant when task challenge is low, while there were nonsignificant or weekly significant relationships between LMX quality and soldier's performance when task challenge is moderate. The results are basically coinciding with the previous research, except that, with the low challenge tasks, the LMX quality did not affect soldier's performance, which seems to be due to the directive leadership style of the lieutenants. The theoretical and practical implications and future research directions are discussed.

• Journal of Microbiology
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• v.40 no.3
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• pp.205-210
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• 2002

To study interactions between $C_{4}$-dicarboxylic acid transport protein D and E$\sigma$$^{54}$ in the dctA promoter regulatory region, we used the challenge phage system. An ant＇-｀lac fusion was recombined onto the challenge phage, and this ant＇-｀lac fusion along with Pant and the R. meliloti dctA promoter regulatory region were cloned onto a plasmid. The plasmid bearing the ant＇-｀lac fusion was used as a reporter plasmid in a coupled transcription-translation system. Addition of purified $\sigma$$^{54}$ to the coupled system specifically repressed transcription of the plasmid-borne ant＇-｀lac fusion. When DCTD was added along with $\sigma$$^{54}$ to the coupled system, transcription of the ant＇-｀lac fusion was even further repressed, suggesting that DCTD may stabilize closed complexes between E$\sigma$$^{54}$ and the dctA promoter.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.19-31
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• 1999

Most breakthrough tests are conducted at higher concentration levels compared to those in the field of air-purifying respirator applications. For example, typical challenge concentrations for breakthrough tests agains tcarbon tetrachloride are ranged between 250-1000 ppm although applicable concentrations range for air-purifying cartridge is 5-50 ppm for carbon tetrachloride. However, no guarantee has been made that isotherms derived from the experiment at high challenge concentrations could estimate adsorption capacity at the lower concentration range where workers wear usually air-purifying respirators. Three models of adsorption isotherms (Freundlich, Langmuir and Dubinin/Radushkevich(D/R) isotherms) that have been commonly applied for respirator cartridge testing were evaluated. Adsorption capacity at each challenge concentration was calculated from the Reaction Kinetic equation fitted for the breakthrough data. These data were used for derivation of three isotherms. In general, the D/R isotherm has given the best agreement between estimated adsorption capacities and experimentally measured. If the challenge concentration of 100 ppm is included for derivation of models, Freundlich and D/R models could succes sfully produced good estimations for adsorption capacities at 50 ppm level. Estimated adsorption capacities by both models ranged in 94 - 109 % of the experimentally measured. However, Langmuir model gives underes timation in all cases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1149-1154
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• 2006

Repeated administration of all addictive drugs, including nicotine, can produce sensitization of extracellular dopamine levels in the nucleus accumbens and behavioral sensitization in rat, as evidenced by an enhanced locomotor response and increased dopamine release in brain to a subsequent injection of the drug. In order to investigate the effect of Zizyphus jujuba extract on repeated nicotin-induced sensitization, rats were given repeated injection of saline or nicotine (0.4 mg/kg s.c., twice a day for 7 d), followed by one challenge injection on the 4th day after the last daily injection. Systemic challenge with nicotine (0.4 mg/kg s.c.) and a direct local challenge of 3 mM a larger increase in locomotor activity and extracellular dopamine release in the nucleus accumbens in nicotine-pretreated rats than in saline-pretreated rats, respectively. Zizyphus jujuba extract significantly decreases locomotor activitiy and dopamine release in the nucleus accumbens induced by a nicotine challenge. These results suggest that Zizyphus jujuba extract may attenuate nicotine-induced neurochemical and behavioral sensitization and may be effective in suppressing compulsive nicotine-seeking behavior.