• Advances in concrete construction
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• v.6 no.6
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• pp.645-658
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• 2018

Despite being one of the most abundantly used construction materials because of its exceptional properties, concrete is susceptible to deterioration and damage due to various factors particularly corrosion, improper loading, poor workmanship and design discrepancies, and as a result concrete structures require retrofitting and strengthening. In recent times, Fiber Reinforced Polymer (FRP) composites have substituted the conventional techniques of retrofitting and strengthening of damaged concrete. Most of the research studies related to concrete strengthening using FRP have been performed on undamaged test specimens. This contribution presents the results of an experimental study in which concrete specimens were damaged by mechanical loading and elevated temperature in laboratory prior to application of Carbon Fiber Reinforced Polymer (CFRP) sheets for strengthening. The test specimens prepared using concrete of target compressive strength of 28 MPa at 28 days were subjected to compressive and splitting tensile testing up to failure and the intact pieces of the failed specimens were collected for the purpose of repair. In order to induce damage as a result of elevated temperature, the concrete cylinders were subjected to $400^{\circ}C$ and $800^{\circ}C$ temperature for two hours duration. Concrete cylinders damaged under compressive and split tensile loads were re-cast using concrete and rich cement-sand mortar, respectively and then strengthened using CFRP wrap. Concrete cylinders damaged due to elevated temperature were also strengthened using CFRP wrap. Re-cast and strengthened concrete cylinders were tested in compression and splitting tension. The obtained results revealed that re-casting of specimens damaged by mechanical loadings using concrete & mortar, and then strengthened by single layer CFRP wrap exhibited strength even higher than their original values. In case of specimens damaged by elevated temperature, the results indicated that concrete strength is significantly dropped and strengthening using CFRP wrap made it possible to not only recover the lost strength but also resulted in concrete strength greater than the original value.

• Journal of IKEEE
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• v.23 no.3
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• pp.1092-1095
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• 2019

In this paper, we propose the development of an embedded board for construction of smart factory. The proposed embedded board for construction of smart factory consists of main module, ADC module, I/O module. Main module is a main calculating device which includes communication pard that allows interface with external device with using industrial protocol and is ported operating system makes board operating into. ADC module takes part in transferring digital signal has converted from electrical signal to the main module from the external sensor which is installed on the field. I/O module is an input and output module which transfers to the main module about a status, alarm, command signal of field device and it has a function that blocks external noises from field device with isolation circuit into it. In order to evaluate the performance of the proposed embedded board for construction of smart factory, it has been tested by an authorized testing institute. As a result, quantity of interacting protocol was 5, speed of hardware clock synchronization was under 10us and operating time of battery without source power was over 8 hours. It produced the same result as the world's highest level.

• Journal of Apiculture
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• v.33 no.4
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• pp.283-295
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• 2018

As Sacbrood virus (SBV), a causative agent of larval death and colony collapse in Apis cerana honey bee, is prevalent and poses one of the most significant threats to the Korean apiculture, development of methods to counter this viral disease is urgently needed. In this study we tested some SBV controlling methods, such as requeen, shook swam, adding Apis mellifera and spraying yogurt to SBV inoculated colony. Colony size measured by number of sealed brood and adult were evaluated every 15 days until two months while instances of recurrence were recorded up to five months after applying treatment methods. We also test the effects of yogurt on healthy and SBV-infected larvae at both in vitro reared larvae and colony level. Our result showed that all SBV controlling methods had similar success rates with respect to elimination of SBV clinical symptom up to 30 days post treatment. Mix-species and spraying yogurt method had similar pattern of sealed brood and adult number and higher than that of other SBV controlling methods up to 45 days post treatment. These two groups also showed the lower percentage of SBV recurrence (50% and 66.7%) at 120 days post treatment than other group that mostly colony had clinical symptom. Result on in vitro reared larvae challenged with yogurt showed that yogurt have neither harmless on healthy larvae nor remedial effect on SBV infected larvae. However, at colony level, colony in group received yogurt treatment removed significantly more SBV-infected larvae, SBV-killed larvae, and even healthy larvae in comparison to the control, suggested that yogurt could trigger the hygienic behavior of nurse bee. Our results recommended that it is practical in beekeeping by adding A. mellifera and spraying yogurt to control SBV in A. cerana colony.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.556-567
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• 2021

Purpose: In this study, various methods of deep learning-based automatic damage analysis technology were reviewed based on images taken through Unmanned Aerial Vehicle to more efficiently and reliably inspect the exterior inspection and inspection of railway bridges using Unmanned Aerial Vehicle. Method: A deep learning analysis model was created by defining damage items based on the acquired images and extracting deep learning data. In addition, the model that learned the damage images for cracks, concrete and paint scaling·spalling, leakage, and Reinforcement exposure among damage of railway bridges was applied and tested with the results of automatic damage analysis. Result: As a result of the analysis, a method with an average detection recall of 95% or more was confirmed. This analysis technology enables more objective and accurate damage detection compared to the existing visual inspection results. Conclusion: through the developed technology in this study, it is expected that it will be possible to analysis more accurate results, shorter time and reduce costs by using the automatic damage analysis technology using Unmanned Aerial Vehicle in railway maintenance.

• The Korean Journal of Franchise Management
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• v.11 no.2
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• pp.23-39
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• 2020

Purpose: Social Network Sites(SNS) have been grown up as a public communication channel consumer frequently participate in. Most of food service brands are utilizing social media for advertising recently. As a result of SNS marketing, food service brands anticipate positive outputs from SNS engagement and consumer brand engagement so that we need to verify structural relationship among SNS characteristics, SNS engagement and consumer brand engagement. Research design, data, and methodology: This study identifies that SNS characteristics have effects on SNS engagement and examines relationship between SNS engagement and behavioral engagement. We conceptualize SNS characteristics as information quality, hedonic level and interaction. Furthermore, SNS engagement is composed of SNS participation, positive word of mouth(WOM). In order to verify the purposes of this research, research model and hypotheses were developed. All constructs were measured with multiple items developed and tested in the previous studies. Sample data were collected from 433 online survey panels and analyzed by using SmartPLS 3.2.9. Result: The findings of this research are as follows. First, information quality is positively related with SNS participation. Hedonic level and interaction have impacts on SNS participation and positive WOM respectively. Second, SNS participation has positive effects on positive WOM. Third, both SNS participation and WOM influence behavioral engagement respectively. Conclusions: The implications demonstrate that SNS characteristics such as information quality and hedonic level and interaction exert effects for consumer to participate in SNS brand page. Meanwhile, hedonic level and interaction influence on positive WOM but information quality doesn't. SNS participation and positive WOM affect consumer to engage in specific brand behaviorally as well. Therefore, food service brand marketer is required to manage SNS information quality and hedonic level and interaction among members to encourage SNS participation and positive WOM. As SNS participation and positive WOM increases behavioral engagement of consumer, marketer needs to incentivize SNS participation and look after situation of positive WOM and respond swiftly.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1773-1778
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• 2020

This study evaluated the skin improvement effect and feeling of use of a temperaturesensitive hydrogel mask pack containing an hyaluronic acid. Ten women in their 30s to 40s who met the selection criteria were tested. The hydrogel mask pack was applied 3 times a week for 4 weeks, and moisture, oil, and skin tone were measured. As a result, skin moisture content increased by 11.3% after one application and 58.36% after 4 weeks of use, showing a very high rate of moisture increase. The oil content increased by 67% after one use, and after that, an appropriate amount of oil was maintained. Did not increase any more. Skin tone increased after 4 weeks. After 4 weeks, evaluation of application feeling and sensory efficacy obtained 87.6% of positive results. As a result of the above, the temperature-sensitive hydrogel mask pack helps to improve the skin and has an excellent feeling of use.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.79-84
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• 2021

The objective of this paper is to find out the factors for the performance of the Hospital Customer Relationship Management (HCRM) system. Furthermore, the relationships between these factors have been analyzed. In order to analyze the performance of the HCRM system, factor analysis with several Key Performance Indicators (KPIs) was conducted. And also multiple regression analysis and Chi-square test were executed. In this study, several hypotheses were derived to analyze the relationships between factors of performance of HCRM system. These hypotheses were tested by using the Structural Equation Model (SEM). As the result of this study, we discovered the HCRM-Infrastructure has positive effects on the HCRM-Performance. And the HCRM-Performance has also positive influences on the hospital management performance. On the basis of the research result, we proposed some suggestions and guidelines for the successful implementation and improvement of HCRM system.

• The Korea Journal of Herbology
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• v.28 no.3
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• pp.107-113
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• 2013

Objective : The purpose of this study was to investigate the effect of fermented Artemisiae Argyi Folium(AAF) on some activities of human hepatoma cell, HepG2. Method : To investigate the effect of fermented Artemisiae Argyi Folium(AAF) activity on the human hepatoma cells, AAF extracts was fermented by Lactobacillus pentosus K34(AFL) and Sacchromyces cerevisiae STV89(AFS). And the effects of AFL or AFS on the activities of HepG2 cell, such as cell viability, nitric oxide(NO) production and reactive oxygen species(ROS) production, were tested. Result : Human Hepatoma Cells were incubated each for 3 hours and 24 hours. Human Hepatoma Cells treated with the extract was measured with MTT assay. Then AFL was found to be non-toxic at concentrations of 10 ug/mL(3h), 100 ug/mL(24h) or more. AFS was the same result at concentrations of more than 10 ug/mL. The extract increased ROS generation in Human Hepatoma Cells. AFL increased at concentrations of 100 ug/mL more (3h, also 10 ug/mL more) and 50 ug/mL(24h) and AFS increased both 50 ug/mL. In point of NO generation, AFL inhibited at concentrations of 10 ug/mL(3h) and 100 ug/mL(24h) more (3h, also 10 ug/mL more) and AFS also inhibited 50 ug/mL or more. Conclusion : AFL and AFS, obtained from Artemisiae Argyi Folium extracts by fermentation, reduced the NO production and increased ROS production in HepG2 cell, without cytotoxicity on HepG2 cell. The results suggested that AFL and AFS increased the immunological effects of Artemisiae Argyi Folium extracts.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.31-47
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• 2022

The purpose of this study is to develop a reliable tool that can classify and measure detailed indicators related to the performance of ESG implementation in the country and verify their applicability. Based on World Bank's data as input data, 67 types of ESG-related detailed indicators measured in a total of 239 countries were tested to derive an optimal model that could group detailed indicators into three categories: environment, society, and governance. As a result of the analysis, it was confirmed that a total of 10 detailed indicators had a statistically significant relationship with the country's ESG performance. In addition, the detailed indicators showed a positive correlation with the primary latent variables E, S, and G, and showed a high overall index in the suitability of the model to secure the validity and reliability of variable input. As a result, this study confirmed that several detailed performance indicators constituting ESG can be classified as latent variables, and it can be said that clear criteria for the selection method and input validity of variables were presented.

• Journal of the Korean Geotechnical Society
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• v.24 no.11
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• pp.133-141
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• 2008

In this study, a new method for estimating the undrained shear strength $s_u$ of saturated clays using piezocone penetration test (CPTu) result is proposed. This is to develop more effective CPTu-based $s_u$ estimation method at lower cost with less uncertainty. For this purpose, a marine clay deposit is selected and tested through extensive experimental testing program including both in-situ and fundamental laboratory tests. The proposed method is based on a correlation between the undrained shear strength $s_u$ and the cone resistance $q_t$, without introduction of the total overburden stress into the $s_u-q_t$ correlation. As a result, no additional testing procedure for collecting undisturbed soils samples is required, which can reduce overall testing cost. To verify the proposed method, 4 test sites, which consist of a variety of soil conditions, are selected and used for comparison between measured and predicted undrained shear strength. From comparison, it is seen that predicted values of $s_u$ using the proposed method match well those from measured results.