• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.103-112
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• 2009

The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No.3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtensteih) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8): R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

• Restorative Dentistry and Endodontics
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• v.33 no.5
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• pp.443-451
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• 2008

The purpose of this study was to evaluate the effect of additional etching procedure prior to Maxcem resin cement application in indirect restoration cementation using push-out bonding strength. One hundred and two extracted human molars were used to make indirect resin restorations of gold inlay and Synfony. These restorations were cemented using Maxcem and Variolink II. Additional etching procedures were done for one group with Maxcem. Three groups have 17 specimens in both restoration types. Push-out bond strength was measured using multi-purpose tester and calculated for bonding strength per sqaure-millimeter area. The mean bonding strength values were compared using SPSS 12.0K program for one-way ANOVA and Scheffe's Test with 95% significance. Under the condition of this study, the additional etching procedure prior to usage of Maxcem resulted in reduced bond strength for both of restoration types.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.109-121
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• 2006

The road should be designed in the consistent alignment which the driver can drive safely. Also, proper highway environments in order to maintain optimal operational speeds on highway sections should be provided In design stage, for highway environments, it is essential for an operational speed estimation model to different highway environments. If a method which could evaluate the status of the road safety is developed through this operational speed estimation model, it is possible to provide safe and more comfortable highways to road users. In the study factors to effect on operational speeds are classified into three groups horizontal & vertical alignments and traffic operation characteristic factors. Factors are chosen to effect on operational speeds by using collation analysis as classifications of tangent sections, horizontal curve sections and vertical curve sections. In order to develop operational speed estimation models in express highways, multi-regression analysis has been used in this study using the selected factors. This study has meaning that the developed estimation models for operational speeds and evaluation of degree of safety to horizontal and vortical alignments simultaneous. In order to represent whole area of the country with the developed models, the models should be re-analyzed with vast data related with road alignment factors in the near future.

• Journal of the Korean Vacuum Society
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• v.19 no.6
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• pp.495-500
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• 2010

In this study, $Al_2O_3$ and $TiO_2$ films was deposited on to PES (poly(ethersulfon) substrate by using atomic layer deposition as functions of deposition temperature and plasma power. The density and carbon contents of $Al_2O_3$ and $TiO_2$ films was changed by varying process conditions. High density thin films was achieved through optimizing the process conditions. Buffer layer was deposited prior to the processing of upper thin films to avoid PES surface destruction during the high power plasma process and to enhances the tortuous path for water vapor permeation for the defect decoupling effect. The water vapor transmission rate by using MOCON test was investigated to analyze the effect. Water vaper permeation properties was improved by using the inorganic multi-layer passivation layer and activation energy of the water vapor permeation was increased.

• Korean Journal of Remote Sensing
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• v.24 no.4
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• pp.273-287
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• 2008

Characteristics of skin-bulk sea surface temperature (SST) differences in the Northeast Asia seas were analyzed by utilizing 845 collocated matchup data between NOAA/AVHRR data and oceanic in-situ temperature measurements for selected months from 1994 to 2003. In order to understand diurnal variation of SST within a few meters of the upper ocean, the matchup database were classified into four categories according to day-night and drifter-shipboard measurements. Temperature measurements from daytime drifters showed a good agreement with satellite MCSST (Multi-Channel Sea Surface Temperature) with an RMS error of about $0.56^{\circ}C$. Poor accuracy of SST with an rrns error of $1.12^{\circ}C$ was found in the case of daytime shipboard CTD (Conductivity, Temperature, Depth) measurements. SST differences between MCSST and in-situ measurements are caused by various errors coming from atmospheric moist effect, coastal effect, and others. Most of the remarkable errors were resulted from the diurnal variation of vertical temperature structure within a few meters as well as in-situ oceanic temperatures at different depth, about 20 cm for a satellite-tracked drifting buoy and a few meters for shipboard CTD or moored buoy. This study suggests that satellite-derived SST shows significant errors of about ${\pm}3^{\circ}C$ in some cases and therefore it should be carefully used for one's purpose on the base of in-depth understanding of skin-bulk SST difference and vertical temperature structure in regional sea.

• Journal of the Korean Society of Child Welfare
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• no.56
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• pp.195-220
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• 2016

The purpose of this study was to compare between two-parent and single-parent families the relationship between perceived parental monitoring/affection and adolescent offline/online delinquency. we analyzed 1,812 cases of high school students (1,628 cases of two-parent families and 184 cases of single-parent families) using the $4^{th}$-and $5^{th}$-year data from the 'Korean Children and Youth Panel Survey'. We used structural equation modeling to understand the correlation between variables, and conducted multi-group analysis to confirm the distinction between family structures. The results of the study were as follows. First, perceived parental monitoring influenced offline adolescent delinquency only among two parent families, while perceived parental affection did not influence either family type. Second, perceived parental affection influenced online adolescent delinquency only among single-parent families, and the path also had a greater negative effect than two-parent families. In the case of perceived parental monitoring, it did not influence online adolescent delinquency regardless of family type, but the path had a greater negative effect on two-parent families than single-parent families. Based on these results-, more concrete social-welfare practical and political implications about adolescent delinquency proposed.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1035-1041
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• 2011

Salinity of soil under the plastic film houses in Korea is known as a significant factor to lower the crop production and to hamper the sustainable agricultural land management. In this study we propose a field monitoring technique to examine the methods applied to minimize the adverse effect of salts in soil based on the relationship between soil electrical characteristics and soil properties. Field experiments for 4 different treatments (water only, fertilizer only, DTPA only, and DTPA and fertilizer together) were conducted on soils at the plastic film house built for cultivating a cucumber plant located at Chunan-si, Chungchungnam-do in Korea. The electrical resistivity was measured by both a dipole-dipole and wenner multi-electrodes array method. After the electrical resistivity measurement we also measured the soil water content, temperature, and electrical conductivity on surface soil. The resulted image of the interpreted resistivity by the inversion technique presented a unique spatial distribution depending on the treatment, implying the effect of the different chemical components. It was also highly suspected that resistivity response changed with the nutrients level, suggesting that our proposed technique could be the effective tool for the monitoring soil water as well as nutrient during the cropping period. Especially, subsoils under DTPA treatment at 40 to 60 cm depth typically presented lower soil water accumulation comparing to subsoils under non-DTPA treatment. It is considered that DTPA resulted in increase of a root water uptake. However, our demonstrated results were mainly based on qualitative comparison. Further experiments need to be conducted to monitor temporal changes of electrical resistivity using time lapse analysis, providing that a plant root activity difference based on changes of soil water and nutrients level in time.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.5
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• pp.423-431
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• 2021

Purpose: To assess the effect of combination probiotic Saccharomyces boulardii CNCM-I 3799 and Bacillus subtilis CU-1 in outpatient management of acute watery diarrhea in children. Methods: A randomized double-blind placebo-controlled study was conducted in 180 participants aged six months to five years with acute mild to moderate diarrhea. All were enrolled from six centers across India and centrally randomized to receive S. boulardii CNCM-I 3799 and B. subtilis CU-1 or a placebo along with oral rehydration salts and zinc supplementation. Each participant was followed up for three months to assess recurrence of diarrhea. Results: The mean duration of diarrhea in the probiotic and placebo groups were 54.16 hours and 59.48 hours, respectively. The difference in the duration of diarrhea in those administered with probiotic or placebo within 24 hours of diarrhea onset was 25.21 hours. Furthermore, the difference in duration of diarrhea was 13.84 hours (p<0.05) for participants who were administered with probiotics within 48 hours. There were no significant differences in the stool frequencies between the two arms. After three months, 15% in the probiotic group and 18.5% in the placebo group reported episodes of diarrhea. The mean duration of diarrhea was considerably lower in the probiotic group, 31.02 hours versus 48 hours in placebo (p=0.017). Conclusion: S. boulardii CNCM-I 3799 and B. subtilis CU-1 combination was effective in reducing the duration of diarrhea when administered within 48 hours of diarrhea onset. Similarly, it reduced recurrence of diarrhea and its intensity in the subsequent three months.

• Industry Promotion Research
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• v.6 no.4
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• pp.47-58
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• 2021

The purpose of this study is to analyze the effect of reminiscence-based collective art therapy on the depression, interpersonal relationships, and the subjective sense of happiness among the elderly with dementia. The study was conducted on 30 volunteers with dementia aged 65 or older attending the S Weekly Care Center located in S-gun as subjects during the period between November 7, 2020 and January 2, 2021 with one session week for a total of 12 sessions. The SPSS 24.0 statistics program has been used for various data analyses, including confidence verification, cross tabulation analysis, independent sample T-test, 3×2 multi-variant analysis. The study findings are as follows. First, the collective art therapy based on reminiscence therapy is effective in reducing the depression among the elderly with dementia. Second, the collective art therapy based on reminiscence therapy is effective in promoting interpersonal relationships among the elderly with dementia. Third, the collective art therapy based on reminiscence therapy is effective in improving the subjective sense of happiness among the elderly with dementia. Therefore, the reminiscence-based collective art therapy is found to serve as an effective means to relieve depression, improve interpersonal relationships and to promote a subjective sense of happiness among elderly people witn dementia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.701-710
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• 2018

This study aims to verify the mediating effect of perceived risk of internet shopping mall users' innovativeness on product purchase intention. Research subjects included consumers with prior experience of using internet shopping malls, and 405 respondents were used for final analysis. The major findings of the study are as follows: First, as a result of the investigation on the relationships among users' innovativeness, perceived risk, and product purchase intention, all correlation coefficients were positive. Second, consumer innovativeness was found to significantly influence perceived risk and purchase intention, and perceived risk mediated the relationship between consumer innovativeness and purchase intention. Third, when we performed sub-group analysis on the research model by dividing products into hedonic and utilitarian products, it was found that hedonic products revealed path coefficients which are statistically more significant compared with those for utilitarian products. We can draw the conclusion that in terms of internet shopping mall purchases, hedonic products exert a greater influence on the effect of consumer innovativeness on purchase intention compared to utilitarian products.