• Restorative Dentistry and Endodontics
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• v.33 no.3
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• pp.184-197
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• 2008

This study was to investigate the influence of combining composite resins with different elastic modulus, and occlusal loading condition on the stress distribution of restored notch-shaped non-carious cervical lesion using 3D finite element (FE) analysis. The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. A notch-shaped cavity was modeled and filled with hybrid, flowable resin or a combination of both. After restoration, a static load of 500N was applied in a point-load condition at buccal cusp and palatal cusp. The stress data were analyzed using analysis of principal stress. Results showed that combining method such that apex was restored by material with high elastic modulus and the occlusal and cervical cavosurface margin by small amount of material with low elastic modulus was the most profitable method in the view of tensile stress that was considered as the dominant factor jeopardizing the restoration durability and promoting the lesion progression.

• Journal of Korean Society of Forest Science
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• v.78 no.3
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• pp.323-330
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• 1989

Pinass densiflora natural forests of four local forms in Korea were studies to investigate effective biomass estimation method. Dimension analysis was used and three allometric regression models, such as logWt=A+BlogD, logWt=$A+B1ogD^2H$ and 1ogWt=A+BlogD+ClogH were applied to estimate biomass, The most accurate estimation was made by the regression model of logWt=A+BlogD+ClogH where Wt is dry weight, D is diameter at breast height, and H is tree height. However, dry weights of cones and dead branches were remotely related to tree size factor, such as D and H. In the interest of practical use. generalized allometric regressions for all samples trees of four stands were computed and analysis of covariance was used to compare the allometric regressions among the four stands. Based on the test criteria applied in this study, significant differences were found in terms of error variance and regression intercept, not in terms of regression slope. These trends suggest a generalized biomass regression is not valid for accurate estimation over a range of four local form stands.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.116-124
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• 2015

Background: Ginseng, the root of Panax ginseng (PG), is used widely as a herbal medicine to prevent and treat various diseases. Panax ginseng has pharmacological effects on neurodegenerative diseases such as Alzheimer's disease (AD). The present study evaluated the neuroprotective effects of PG and its possible neuroprotective mechanisms in advanced glycation end product (AGE)-induced AD in a rat model. Methods: Advanced glycation end products were injected bilaterally into the CA3 region of the rats' brains. The Morris water maze test and step-down type passive avoidance test were performed to evaluate their memory and cognitive abilities. The oxidation indexes in the hippocampus were detected. Immunohistochemistry was conducted to visualize the receptors for advanced glycation end products (RAGEs) and nuclear factor-kappa-light-chain-enhancer of activated B cell (NF-${\kappa}B$). Results: Behavioral results showed that PG (1 g/kg, 0.5 g/kg, and 0.25 g/kg) significantly shortened the escape latency, remarkably increased the number of crossing times, significantly decreased the number of errors, and prolonged the latency in rats with AGE-induced AD. Panax ginseng also significantly reduced the malondialdehyde level, increased the glutathione content, and increased superoxide dismutase activity in the hippocampus. Panax ginseng significantly decreased the expression of RAGE and NF-${\kappa}B$. The blockade of anti-RAGE antibody could significantly reduce AGE-induced impairments and regulate these expressions. Conclusion: Our results demonstrated that PG significantly inhibits AGE-induced memory impairment and attenuates Alzheimer-like pathophysiological changes. These neuroprotective effects of PG may be associated with the RAGE/NF-${\kappa}B$ pathway. Our results provided the experimental basis for applying PG in preventing and treating AD.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.159-169
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• 2014

The purpose of PMO (Project Management Office) systems implementation in public sectors is to prevent the potential risks of IT projects with the project management for the electronic government, and to improve the quality of the project. As a leading country in software areas, PMO systems will play an important role to lead the best smart electronic government in the global world. This study suggested an operating model of PMO systems in public sectors in advance to use the PMO systems in public sectors by conducting a research investigating the key organizational role as the major factor which affects the behavioral intention of PMO systems implementation. We tested a hypothesis that Effort Expectancy factors and Facilitating Condition among the interested party groups will influence the Behavioral Intention of PMO systems implementation, and the result have given no difference to the Control Effect among the interested party groups. This study have shown that the interested party groups have common recognition about the Behavioral Intention of PMO systems implementation in the public sectors.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.517-529
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• 2017

The purpose of this study is to develop and evaluate the scale for university students' health behaviors. This research is based on Roger's(1975) Protection Motivation Theory and Weinstein(1988)'s Precaution Adoption Process Model as theoretical frameworks. The contents of the scale were first abstracted from personal depth interviews of qualitative study on university students' health behavior experiences and review of its related literature. The initial items consisted of 76 behavior questions and 34 perception questions. After conducting the preliminary test, 33 behavior questions and 24 perception questions were selected for the final test by revisions on the basis of the result of the content validity test and the item understanding test. The questionnaires for the final test were distributed to 400 students enrolled in three universities. The questionnaires collected from 373 participants were analyzed by the SPSS program. From the examination of construct validity, item correlation, and factor relation turned out to be relevant. Five factors were determined from 27 items with a cumulative explained variance of 54.498 %. After examining reliability and validity of the collected dat, 27 items were finalized as the scale for university students' health behaviors.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.129-135
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• 2020

This study examined the consumer response of the current O2O service between service types. Previous studies mainly focused on the quality factor of O2O service or Technology Acceptance Model or extended TAM, This study is different from the fact that there are differences in factors that consumers consider important and consumer reactions by service type. It is also significant that we compared between representative food delivery services and car sharing services that are actively used among O2O services. As O2O service is closely related to consumer's life, this study chose three factors that the issue of personal information security and trust of intermediary platform companies, and finally subjective norm based on individuals and groups who are aware of new O2O service. To test hypotheses, data were collected and analyzed for 301 samples, focusing on delivery and car sharing service, As a result, the delivery service among the O2O services was more positive to attitude toward service in the consumer group with lower personal information security, trust in platform, and subjective norm than car sharing service. Based on these results, implications and future research directions were presented.

• Korean journal of communication and information
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• v.46
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• pp.75-107
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• 2009

Nevertheless reported the same events, news audience have diverse sense of sights and opinions about the events because of the different news frames. This notion was repeatedly evi nnced by several framing studies. This pa wa tried to analyse an interacting relationship between viewer’s level of elaboration likelihood and the effects of the news frames. This pa wa sfrrted with a discussion about the framing effects, then compared them with Elaboration Likelihood Ms notraming effely. And this study conducted an ex waiment selecting indivi ual dispngitions (involvement and cognitive complexity) and message characteristics(number of cues and arguments) as intermediating variables on the message framing effects. This study found out that, the more involvement about the issues the viewers had, the more their thoughts coincided with the issue's frame. On the other hand, when the viewers had low involvement about the issues and cognitive complexity, the framing effects were not found because they processed the messages through the peripheral route. Although the viewers' cognitive complexity was a factor in choosing the central route, but it was not directly connected to the framing effect. Both the number of cues and argument diversity in the messages had positive relationships with the framing effects.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.425-438
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• 2018

Existing studies that analyze the causes and effects of water circulation use mostly rainfall - runoff models, which requires much effort in model development, calibration and verification. In this study, hydrological sensitivity analysis which can separate quantitatively the impacts by natural factors and anthropogenic factor was applied to the Hwacheon dam upper basin from 1967 to 2017. As a result of using various variable change point detection methods, 1999 was detected as a statistically significant change point. Especially, based on the hydrological sensitivity analysis using 5 Budyko based functions, it was estimated that the average inflow reduction amount by Imnam dam construction was $1.890\;billion\;m^3/year$. This results in this study was slightly larger than the those by existing researchers due to increase of rainfall and decrease of Hwacheon dam inflow. In future, it was suggested that effective water management measures were needed to resolve theses problems. Especially, it can be suggested that the monthly or seasonal analysis should be performed and also the prediction of discharge for future climate change should be considered to establish resonable measures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5D
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• pp.483-492
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• 2012

The early setting time of concrete is an important factor determining the slip up velocity of the slip-form system. Accordingly, need is for a technique evaluating the early setting time in order to secure the safety of the slip-form system and the construction quality of concrete. This paper intends to estimate the early setting time by evaluating the setting degree of concrete using surface wave velocity so as to determine the slip up time of the slip-form system. Penetration resistance test and compressive strength test are performed first to clarify the relationship between the early setting time of concrete and the compressive strength. Then, compressive strength test and ultrasonic wave test are conducted to examine the relation between the compressive strength and the surface wave velocity. Continuous wavelet transform is adopted to measure the surface wave velocity. Numerical analysis is carried out to demonstrate the appropriateness of the application of continuous wavelet transform. Based on these results, the propagation velocity of the surface wave required for the slip up of slip-form system is suggested. Finally, a reduced model test of the slip-form system is conducted to verify the feasibility of the proposed surface wave velocity for the determination of th slip up velocity.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.153-184
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• 2018

This study aims to investigate the effects of emotional labor level on the level of job satisfaction and library information service provision in public libraries. The research model used emotional labor levels as an independent variable; job satisfaction and level of library information service provision as a dependent variable; and organizational culture as a control factor. The data were collected randomly from 220 librarians of public libraries in Seoul by distributing and collecting internet surveys. Reliability analysis, correlation coefficient analysis, multiple regression analysis, and regression analysis were performed using the SPSS 18.0 program. The statistic hypothesis test results of this study can be summarized as follows. First, public library librarians did not like to express their emotions to users, trying to express their emotions more positively than what they were actually feeling. Second, although librarians experience emotional labors, they feel a sense of achievement when undertaking their tasks and develop pride and happiness in their work. As librarians perceive their work professional, they overcome emotional labors, and have pride in their work. Third, although librarians experience emotional labors, a reasonable job evaluation with goals, and their relationships with colleagues would lead to accomplishment in their work. In addition, although the evaluation of employees is focused on performance, librarians improve their service if library users are satisfied with their service and the services are provided adequately.