• Korean Journal of Microbiology
• /
• v.52 no.2
• /
• pp.157-165
• /
• 2016

Under flooded rice fields, methanogens produce methane which comes out through rice stalks, thus rice fields are known as one of the anthropogenic sources of atmospheric methane. Studies have shown that use of manure increases amount of methane emission from rice. To investigate mechanisms by which manure boosts methane emission, comparative soil metagenomics between inorganically (NPK) and pig manure fertilized paddy soils (PIG) were conducted. Results from taxonomy analysis showed that more abundant methanogens, methanotrophs, methylotrophs, and acetogens were found in PIG than in NPK. In addition, BLAST results indicated more abundant carbohydrate mabolisetm functional genes in PIG. Among the methane metabolism related genes, PIG sample showed higher abundance of methyl-coenzyme M reductase (mcrB/mcrD/mcrG) and trimethylamine-corrinoid protein Co-methyltransferase (mttB) genes. In contrast, genes that down regulate methane emission, such as trimethylamine monooxygenase (tmm) and phosphoserine/homoserine phosphotransferase (thrH), were observed more in NPK sample. In addition, more methanotrophic genes (pmoB/amoB/mxaJ), were found more abundant in PIG sample. Identifying key genes related to methane emission and methane oxidation may provide fundamental information regarding to mechanisms by which use of manure boosts methane emission from rice. The study presented here characterized molecular variation in rice paddy, introduced by the use of pig manure.

• Restorative Dentistry and Endodontics
• /
• v.28 no.5
• /
• pp.378-384
• /
• 2003

This study evaluated the influence of a desensitizer(MS coat) on microtensile bond strength of different adhesives:a three-step adhesive(All-Bond 2), a two-step adhesive(Single Bond), a one-step adhesive(One-up Bond F). Non-caries extracted human molars were used. Dentin surface was obtained by horizontal section on mid-portion of crown using a water-cooled low speed diamond saw. Teeth were randomly divided into 6 group. AMO(MS coat + All Bond), SMO(MS coat + Single Bond)- and OMO(MS coat + One-up Bond F)-dentin surface were treated with 17% EDTA before bonded adhesive. AMX-, SMX- and OMX-dentin surface were bonded with All-Bond 2, Single Bond and One-up Bond F, respectively. with no previous treatment with MS coat and 17% EDTA. About 1cm high resin composite($Z-250^{TM}$) were incrementally build-up on the treated surface. The specimens for the microtensile test were serially sectioned perpendicular to the adhesive layer to obtain $0.7{\times}0.7mm$ sticks. 30 sticks were prepared from each group. After that. tensile bond strength for each stick was measured with Microtensile Tester at a 1mm/min crosshead speed. Fractured dentin surfaces were observed under the SEM. The results were statistically analysed by using a One-way ANOVA and Tukey's test(p<0.05). Value in MPa were: $AMO-44.35{\pm}13.21;{\;}SMO-39.35{\pm}13.32;{\;}OMO-31.07{\pm}10.25;{\;}AMX-49.22{\pm}16.38;{\;}SMX-56.02{\pm}13.35;{\;}OMX-72.93{\pm}16.19$. Application of MS coat reduced microtensile bond strengths of both Single Bond and One-up Bond F, whereas microtensile bond strengths of All-Bond 2 were not affected significantly.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.1
• /
• pp.165-174
• /
• 2019

As a nonstationarity is observed in hydrological data, various studies on nonstationary frequency analysis for hydraulic structure design have been actively conducted. Although the inherent diversity in the atmosphere-ocean system is known to be related to the nonstationary phenomena, a nonstationary frequency analysis is generally performed based on the linear trend. In this study, a nonstationary frequency analysis was performed using climate indices as covariates to consider the climate variability and the long-term trend of the extreme rainfall. For 11 weather stations where the trend was detected, the long-term trend within the annual maximum rainfall data was extracted using the ensemble empirical mode decomposition. Then the correlation between the extracted data and various climate indices was analyzed. As a result, autumn-averaged AMM, autumn-averaged AMO, and summer-averaged NINO4 in the previous year significantly influenced the long-term trend of the annual maximum rainfall data at almost all stations. The selected seasonal climate indices were applied to the generalized extreme value (GEV) model and the best model was selected using the AIC. Using the model diagnosis for the selected model and the nonstationary GEV model with the linear trend, we identified that the selected model could compensate the underestimation of the rainfall quantiles.

• The Journal of Korean Association of Computer Education
• /
• v.17 no.5
• /
• pp.35-42
• /
• 2014

This study utilized an analysis of teachers' use of smart devices in the class, which highlighted the impact factors, and elucidated the relationship between in fluencing factors. The Unified theory of Acceptance and Use of Technology (UTAUT) model is based on the study of extension and modification of the model proposed. For the study, a survey of 1,016 elementary school teachers in the Gangwon and Metropolitan(Seoul, Gyeonggi, Incheon) area was conducted. Was applied using the AMOS structural equation modeling analysis. The analysis examines the utilization of smart devices in class as factors affecting performance expectancy, effort expectancy of the main variables showed, Instant connectivity and Openness that has a direct impact on the performance expectations and effort expectancy.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.3
• /
• pp.360-365
• /
• 2000

The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. fixed full-arch cert amo-metal restorations can be a predictable implant treatment modality for the edentulous patient. Implant-supported fixed prosthesis has several advantages: predictability, fixedness, retrievability, improved function, lower maintenance of prosthesis, long-term published success. Edentulous patients with a severely resorbed mandible often experience problems with their dentures. Treatment concepts involving two to four implants for the support of an overdenture have been proposed. There seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion. Using short endosseous implants and an overdenture in the extremely resorbed mandible is a justified treatment option because of the relative simplicity and low morbidity of this treatment strategy. Implant-supported overdenture has several advantages: Cost, retrievability, hygiene access, profile and contour control, increased retention and stability, implant installed in a predicted region(ant. mandible).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.131-134
• /
• 2018

Structural equation modeling is pointing to statistical procedures that simultaneously perform path analysis and confirmatory factor analysis. Today, this statistical procedure is an essential tool for researchers in the social sciences. There are as (AMOS, LISREL and PLS) representative tools that can perform structural equation modeling analysis. AMOS provides a convenient graphical user interface for beginners to use. PLS has the advantage of not having a constraint on normal distribution as well as a graphical user interface. Therefore, we compared and analyzed the three most commonly used tools in social sciences. This study suggests practical and theoretical implications based on the results.

• Journal of the Korea Convergence Society
• /
• v.11 no.7
• /
• pp.145-150
• /
• 2020

It needs to explain the relationship between influencers and consequences to use continuity of social media. To address this question, we have developed an framework and made hypotheses to explicate and analyze influencers(social presence, perceived privacy risk, perceived enjoyment, commitment, and community identification) to the attitude and continuity of social media. To test empirically, data collected from on and line survey and resolved by structural equation model. We found that social presence, perceived enjoyment and commitment influence to the attitude and continuity of social media. Finally, the theoretical and practical implications of theses results are discussed also research limitation and future research directions.

• Proceedings of the KIEE Conference
• /
• 1996.07c
• /
• pp.1421-1423
• /
• 1996

In this study, the effect of solar cell cover glass on the solar cell performance is evaluated. Silicon solar cell (active area:4*6cm, efficiency:12.6% at AMO condition) is used for this study. ITO(Indium tin Oxide) film thickness of the ITO/AR/substrate glass/solar cell structure samples are $40{\AA}$, $60{\AA}$, $160{\AA}$, $240{\AA}$ respectively. The solar cell maximum output power on the stacking structure variations showed 465mW in the AR/ITO/substrate glass/solar cell, and minimum output power showed 403mW in the AR/substrate glass/solar cell. The maximum output power of the solar cell on the ITO thickness variations of the ITO/AR/substrate glass/solar cell showed 460mW at $40{\AA}$ then decrease output power as ITO thickness increase. For environment tests, all samples are exposed UV light in the vacuum chanber. The output power degradation of AR(UVR)/substrate glass/solar cell stacking structure is small compared with ITO/AR(UVR)/substrate glass/solar cell stacking structure.

• The Journal of the Korea Contents Association
• /
• v.11 no.8
• /
• pp.321-330
• /
• 2011

This study focuses on the moderating effect of sex role on the relationship between perceived values on the reward program of tele-communication firms and customer satisfaction. To test moderating effect, Difference test for distinct parameters in Amos 18.0 program was used. Results show that both kind of perceived values(utilitarian value and hedonic value) have a significant effect on customer satisfaction. And the moderating effect of sex variable was verified. For male, hedonic value has influenced on the customer satisfaction more than utilitarian value. And for female, reversely, utilitarian value has influenced on the customer satisfaction more than female value.

• Journal of Korean Library and Information Science Society
• /
• v.46 no.2
• /
• pp.113-129
• /
• 2015

The aim of this study is to analyse the relationships between the usefulness of information literacy education and life satisfaction on the older adults in Korea. How the information literacy education impact on the information activities is an additional research question. To achieve these objectives, data were collected through the 227 respondents of over 50-years-old adults in Korea and analysed using AMOS for the structural equation modeling. In this study, information literacy education was measured by it's usefulness aspects, and information activities were measured by it's convenience aspects. The results showed that the information literacy education influences positively both in life satisfaction and in information activities.