• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.5
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• pp.660-666
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• 2009

Thermoplastic polyurethane elastomer(PU-TPE) and energetic thermoplastic polyurethane Elastomer(E-PU-TPE) were prepared from Hexamethylene diisocyanate(HDI), 1,4-BD/AA ester polyol and glycidyl azide polymer(GAP-2400) as an energetic material by the addition polymerization. The PU-TPE and E-PU-TPE were characterized by FT-IR and GPC. Viscometer, DSC and UTM were used to investigate the viscose behavior with a various solvent, thermal properties and mechanical properties of PU-TPE and E-PU-TPE, which are of potential interest for the development of high performance binder of energetic solid propellants. It was found that $M_w$ of PU-TPE and E-PU-TPEs are over 100,000 and decreased with increase of GAP-2400 contents. $T_m$ and ${\Delta}H$ as thermal properties decreased and also tensile strength and elongation at break as mechanical properties decreased with increase of GAP-2400 contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.605-608
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• 2001

With the intention of investigating the breakdown properties of oil-immersed transformer oils in temperature range of $20\sim100[^{\circ}C]$, we are made researches AC breakdown in the gap of $500\sim2500[{\mu}m]$. The classification for the physical properties of oil for oil-immersed transformer by FTIR and H-NMR experiments was confirmed to type of mineral oils. As the dependance of breakdown properties due to electrode gap length variation, breakdown voltage was found increasing according to the increase of gap, while dielectric strength was decreasing. As a result the characteristics for AC breakdown, It goes to prove that the breakdown voltage was increased to $90[^{\circ}C]$ but decreased over $90[^{\circ}C]$ in the temperature range. Also, breakdown voltage was found increasing in the increase of gap and the rising of temperature according to Weibull distribution.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.88-93
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• 2002

$Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}$ and $Zn_{0.5}Cd_{0.5}Al_{2}Se_{4}:Co^{2+}$ + single crystals were grown by CTR method. The grown single crystals have defect chalcopyrite structure with lattice constant a= 5.5966A. c= 10.8042${{\AA}}$ for the pure. a= 5.6543${{\AA}}$. c= 10.8205${{\AA}}$ for the Co-doped single crystal. respectively. The optical energy band gap was given as indirect band gap. The optical energy band gap was decreased according to add of Co-impurity. Temperature dependence of optical energy band gap was fitted well to the Varshni equation. From this relation. we can deduced the entropy. enthalpy and heat capacity. Also. we can observed the Co-impurity optical absorption peaks assigned to the $Co^{2+}$ ion sited at the $T_d$ symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.

• Korean Journal of Community Nutrition
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• v.4 no.3
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• pp.466-478
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• 1999

A significant gap can exist between what customers expect in foodservice and what service providers deliver to customers. Reducing the gap and enhancing service quality plays a key role in increasing customer satisfaction and repurchase intentions. The purpose of this study was to investigate the personal and operational characteristics that affect the customer perceptions of service quality, to analyze the overall satisfaction and repurchase intention of customers, and to study the service quality gap between customer and foodservice provides. 427 customers and 278 foodservice providers in 82 fast food and family restaurants were surveyed. T-test, ANOVA, Correlation Analysis, and Multiple Regression were used for statistical analysis, The results of this study were as follows: 1) Among the personal characteristics of customers, sex affected the preception of 'General Management' and 'Reputation', and the expense per person showed a correlation with service quality. 2) Among the operational characteristics, the type of restaurant, months since opening, and the number of seats had a significant impact on service quality, while the seat turnover rate showed a negative correlation with service quality. 3) Among the human resource characteristics, the proportion of part-time employees had a negative correlation with service quality, and in general, the training program for full-time employees led to a higher degree of customer perception of service quality. 4) Six dimensions of service quality accounted for 38.39% of customer satisfaction in Multiple Regression. 5) The overall satisfaction of customers willing to repurchase was significantly higher than that of the non-repurchase customers. 6) The operational characteristics explained over 35% for the service quality gap among the customers and the service providers in Multiple Regression.

• Human Ecology Research
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• v.54 no.5
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• pp.487-498
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• 2016

The study was examined the multiple mediated effects of maternal self-efficacy and depression between perception gap about paternal involvement and marital conflict for dual-income parents. The data used were the fifth year data of the Panel Study on Korean Children from Korea Institute of Child Care and Education in 2012. The subjects consisted of 449 dual-income parents with more than one child. Data were analyzed using descriptive statistics, one-way analysis of variance, paired t -test, and correlation. SPSS macro and bootstrapping methods also assessed the mediation effects of maternal self-efficacy and depression between the perception gap about paternal involvement and marital conflict in dual-income parents. The results of this study were as follows. Significant positive correlations were observed for marital conflict, perception gap of dual-income parents about paternal involvement and maternal depression. Perception gaps by parents and self-efficacy were negatively correlated. Perception gaps by parents showed a direct effect on marital conflict. The results of indirect effects of all mediators showed the mediated effect of maternal self-efficacy and depression. The study revealed that the perceptive gap about paternal involvement has a significant impact on maternal self-efficacy and depression, as well as marital conflict. The perceptive gap of dual-income parents about paternal involvement has critical effects on marital conflict as much as the quantity of paternal involvement.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.79-89
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• 2021

This study attempted to identify the information gap about Internet of Things (IoT) devices and services in the era of digital transformation. To this end, we analyzed differences in perception of predicting future issues about IoT devices and services, and analyzed differences in the need for digital technology and help in life according to perceptions and experience of using IoT devices and services. Also, the level of education and demand for education were analyzed. A survey was conducted from February 15th to March 7th, 2021 for residents in Gwangju Metropolitan City and Jeollanam-do, and 232 respondents responded. Analysis was performed using SPSS 21.0, and all statistical values were presented as average values. The results of the study are as follows. First, the future issues of the intelligent information society according to the recognition of the intelligent information society, the help of life provided by artificial intelligence devices and services, and the need for intelligent information technology were presented. Second, the difference in Life help provided by artificial intelligence according to the recognition and use experience of artificial intelligence devices was presented. Third, the difference in life help provided by artificial intelligence according to the recognition and use experience of artificial intelligence service was presented. Fourth, the difference in necessity according to artificial intelligence technology recognition and use experience was presented. Fifth, the educational level and educational demand of the intelligent information society were investigated and presented. Through the results of this study, a suggestion for resolving the information gap in the era of digital transformation was suggested.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.455-459
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• 2003

Tunneling spectra of B $i_2$S $r_2$Ca(C $u_{1-x}$ N $i_{x}$ )$_2$ $O_{8+}$$\delta$/ film by LPE method have been measured using break junctions. The energy gap 2$\Delta$ and 2$\Delta$/ $k_{B}$ $T_{c}$ $^{zero}$ increased with increase of ft. We obtained the energy gap Parameter 2$\Delta$(4.2 K) = 54.4~64 meV, and corresponding1y $\Delta$/ $k_{B}$ $T_{c}$ $^{zero}$=7.36~10.14, larger than the BCS value. The lattice constant c and critical temperature $T_{c}$ $^{zero}$ decrease with increase of $\chi$$_{L}$.

• Hwankyungkyoyuk
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• v.20 no.3
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• pp.1-17
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• 2007

The purpose of this study was to establish objectives for ninth grade studies of heredity and evolution in middle school in an attempt to foster students' consciousness of bioethics, and it's additionally intended to develop and apply lesson plans handling different points at issue and to determine the effects of the lesson plans on the bioethics of middle school students. The subjects in this study were 152 ninth graders in a middle school, whose science scores were similar. An experimental group and a control group were made up of 76 students respectively, and a pretest was conducted with test paper developed by this researcher to assess their awareness of bioethics. The experimental group took lessons by using the teaching plans prepared in this study, and the control group received typical education according to the curriculum. And then a posttest was implemented with test paper developed in this study to compare the two groups. In addition their science grades were compared as well. The findings of the study were as follows: First, seven learning objectives were selected from three units related to bioethics in the third-year 8th category of heredity and evolution of middle school. Second, in order to attain the selected learning objectives, four session lesson plans were prepared. Third, the experimental group that studied using by the lesson plans made better progress in bioethics awareness and the gap between the two was statistically significant(t=6.61, p<.001). The former were ahead of the latter in consciousness about species equity(t=7.71, p<.001), the dignity of life (t=3.78, p<.001), human rights(t=2.99, p<.01) and equity among generations(t=2.66, p<.01), but not in awareness of the diversity of species. Fourth, there was no significant gap in science scores between the students studied according to the curriculum and those who received instructions by using the lesson plans developed in the study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.277-278
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• 2006

• Journal of Magnetics
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• v.1 no.1
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• pp.1-3
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• 1996

The $YBa_2Cu_3O_{7-x}$ structure has been fluorinated by a gas phase exchange technique. The ${^19}F$NMR (nuclear magnetic resonance) spin-lattice relaxation rate (1/T1) measurements on a fluorinated sample gave superconducting energy gap of $2\Delta=4.6kT_c$.