• Geomechanics and Engineering
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• v.18 no.4
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• pp.353-362
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• 2019

Soil-rock mixture (S-RM) is an inhomogeneous geomaterial that is widely encountered in nature. The mechanical and physical properties of S-RM are important factors contributing towards different deformation characteristics and unstable modes of the talus slope. In this paper, the equivalent substitution method was employed for the preparation of S-RM test samples, and large-scale triaxial laboratory tests were conducted to investigate their mechanical parameters by varying the water content and confining pressure. Additionally, a simplified geological model based on the finite element method was established to compare the stability of talus slopes with different strength parameters and in different excavation and support processes. The results showed that the S-RM samples exhibit slight strain softening and strain hardening under low and high water content, respectively. The water content of S-RM also had an effect on decreasing strength parameters, with the decrease in magnitude of the cohesive force and internal friction angle being mainly influenced by the low and high water content, respectively. The stability of talus slope decreased with a decrease in the cohesion force and internal friction angle, thereby creating a new shallow slip surface. Since the excavation of toe of the slope for road construction can easily cause a landslide, anti-slide piles can be used to effectively improve the slope stability, especially for shallow excavations. But the efficacy of anti-slide piles gradually decreases with increasing water content. This paper can act as a reference for the selection of strength parameters of S-RM and provide an analysis of the instability of the talus slope.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.1-28
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• 2018

With the growing number of emerging carmakers, automotive parts manufacturers have to penetrate into emerging markets. They can provide large existing carmakers with fully customized parts because of economies scale, but cannot do this for small emerging carmakers due to their small and highly volatile volume order. Once the order by an emerging carmaker is placed, a part manufacturer is exposed to high risks both of decrease in profit margin and high opportunity cost. The platform-based mass customization can be a solution for cost reduction, but the risks of volatility in volume hard to manage. Tackling this issue, we presents a method of optimizing the product portfolio to maximize profits while managing volatility of volume order by emerging carmakers at an affordable level. It is the first robust product portfolio method to keep the scaled deviation of profits at a fixed level under volume order uncertainty. Also, the effect of on the platform-based mass customization on cost is considered. This model can be a building block of conservative market penetration as well as product development strategy while minimizing the financial risks. We conducted an empirical study of a part manufacturer targeting on eighteen automobile manufacturers in North America, Europe and Asia with it powered lift gate.

• Korean Journal of Clinical Pharmacy
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• v.29 no.3
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• pp.173-185
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• 2019

Objective: To gather inputs from clinical experts on selecting and prioritizing research topics, to address unmet vaccine safety needs. Methods: A questionnaire containing 15 vaccine safety assessment research proposals was sent to 28 vaccine experts chosen from various domestic medical association boards, and the rationale for each of the proposals was provided by presenting the following information: 1) a brief summary of the clinical safety studies on the vaccine, conducted by the Clinical Immunization Safety Assessment (CISA) project group, supervised by the United States Center for Disease Control (U.S. CDC), and 2) a summary of recently published studies that address vaccine safety issues. The experts were instructed to select and rank 5 topics in the order of preference, and the preference score for each proposed topic was calculated by assigning points on a scale of 1 to 5. Results: All 28 experts responded to the questionnaire, and the following topics were selected according to their calculated preference scores: 1) Human papillomavirus vaccine safety profile in the Korean female adolescents; 2) A signal detection of adverse events following Influenza vaccination: comparison between the US and South Korea; 3) Incidence of anaphylaxis following National Immunization Program vaccines between 2008 and 2017; 4) Safety of quadrivalent influenza vaccines compared to trivalent influenza vaccines; and 5) Pneumococcal vaccine safety profile in the general population. Conclusion: Five research topics addressing vaccine safety were selected, for which well-constructed research protocols need to be promptly developed to address current unmet vaccine safety needs in South Korea.

• Journal of Family Resource Management and Policy Review
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• v.22 no.4
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• pp.17-32
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• 2018

The purpose of this study was to explore the effects of family life stress and family values on marital stability among middle-aged couples. The subjects included a total of 302 men and women aged 45-64 who had been married for more than 20 years and were living in Seoul. The collected data were statistically analyzed with the SPSS 21.0 Package. First, Cronbach's alpha was calculated to measure the reliability of the scale that assessed the variables of the research model. Then, mean and standard deviation were calculated to determine the degrees of family life stress, family values, and marital stability among the subjects. Finally, a hierarchical multiple regression analysis was performed to identify factors that affected the subjects' marital stability. The results revealed that the level of family life stress in middle-aged married men and women was slightly higher than the mean value. Of all the sub-scales of family life stress, the subjects were found to experience the most stress from factors related to financial pressure, followed by family relationships, a sense of loss within a family, and work-family compatibility. Therefore, financial problems were one of the critical stressors for middle-aged married couples. Also, for this demographic, the levels of family values and marital stability were higher than the medians. The factors affecting marital stability in middle-aged couples were identified to be family relationship stress, financial stress, subjective economic status, family values, stress related to work-familycompatibility,religion,andage.Thedegreeofmaritalstabilitywashigherinmiddle-agedcouplesa stheirstresslevelsfromfamilyrelationshipsandfinancialproblemswerelower.Moreover,thehigherthes ubjectiveeconomicstatusandthemoretraditionalthefamilyvalues,thehigherthedegreeofmaritalstabili ty.Finally,marriedcoupleswhowerereligioushadalowerlevelofstressfromwork-family compatibility, and the younger the couples, the higher the degree of marital stability.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.55-65
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• 2019

Although crack on concrete exists from its early formation, crack requires attention as it affects stiffness of structure and can lead demolition of structure as it grows. Detecting cracks on concrete is needed to take action prior to performance degradation of structure, and deep learning can be utilized for it. In this study, transfer learning, one of the deep learning techniques, was used to detect the crack, as the amount of crack's image data was limited. Pre-trained Inception-v3 was applied as a base model for the transfer learning. Web scrapping was utilized to fetch images of concrete wall with or without crack from web. In the recognition of crack, image post-process including changing size or removing color were applied. In the visualization of crack, source images divided into 30px, 50px or 100px size were used as input data, and different numbers of input data per category were applied for each case. With the results of visualized crack image, false positive and false negative errors were examined. Highest accuracy for the recognizing crack was achieved when the source images were adjusted into 224px size under gray-scale. In visualization, the result using 50 data per category under 100px interval size showed the smallest error. With regard to the false positive error, the best result was obtained using 400 data per category, and regarding to the false negative error, the case using 50 data per category showed the best result.

• Korea Journal of Hospital Management
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• v.24 no.1
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• pp.57-76
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• 2019

The purpose of this study was to investigate the effect of characteristics of hospital choice and hospital service quality on service value, customer satisfaction and hospital revisiting intent and a survey involving patients and their caregivers who used the hospital before was conducted for empirical analysis. Thus, the theory and factors concerning the characteristics of hospital choice, hospital service quality, service value, customer satisfaction and hospital revisiting intent and relevant preceding research were explored after examining the preceding research, the research model was developed accordingly. A total of 459 collected questionnaires were analyze after carrying out the survey on a national scale. The findings of this study have significance since it identified the motivation that affect the choice of hospital and provide information. Also, this study could be utilized as reference data for hospitals to survive in the fierce competition, as it carried out factual survey on considerations when making choice of hospital. Furthermore, due to the low expectation of patients and caregivers for hospital administration, the study indicated that it's linked to a significantly low chance of customer satisfaction and provide the cause. This study was differentiated with other research on hospital choice since it selected security as a factor of hospital choice, though it's not discussed in the preceding research and moreover, conducted the empirical analysis. And the results of empirical analysis revealed that customers felt that service value was improved when the information security was strengthened. In other words, the strengthening of hospital information security could be hospital choice motivation, which means this study provided practical implication.

• Journal of Korean Society on Water Environment
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• v.35 no.1
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• pp.35-42
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• 2019

Urbanization has led to extreme changes in land use on urban watersheds. Most cities are becoming residential, commercial and industrial areas, making infiltration and storage of rainfall less favorable. The demand for LID (Low Impact Development) technology is increasing in order to mitigate this water cycle distortion and return to existing hydrological conditions. The LID technique is effective in reducing runoff by permeating the urban impervious area. However, considering the limit of the installation area and the financial requirement of the installation, there is not much research on the linkage of each LID component technology for optimum efficiency according to the appropriate scale. In this study, the effects of the LID facilities applied to the target site were simulated using the SWMM model, suggesting the optimal linkage method considering interconnectivity, and applying the effects as an existing installation of individual facilities. The water balance at the time of application of the LID technology, short-term and long-term rainfall event were compared. Also, the individual application and the linkage application were compared with each other. If each component technology has sufficient processing size, then linkage application is more effective than individual application.

• Journal of Coastal Disaster Prevention
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• v.4 no.3
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• pp.119-131
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• 2017

Global warming under the influence of climate change and its direct impact on glacial and sea level are known issue. However, there is a lack of research on an indirect impact of climate change such as coastal structure design which is mainly based on a frequency analysis of water level under the stationary assumption, meaning that maximum sea level will not vary significantly over time. In general, stationary assumption does not hold and may not be valid under a changing climate. Therefore, this study aims to develop a novel approach to explore possible distributional changes in annual maximum sea levels (AMSLs) and provide the estimate of design water level for coastal structures using a multiple non-crossing quantile regression based nonstationary frequency analysis within a Bayesian framework. In this study, 20 tide gauge stations, where more than 30 years of hourly records are available, are considered. First, the possible distributional changes in the AMSLs are explored, focusing on the change in the scale and location parameter of the probability distributions. The most of the AMSLs are found to be upward-convergent/divergent pattern in the distribution, and the significance test on distributional changes is then performed. In this study, we confirm that a stationary assumption under the current climate characteristic may lead to underestimation of the design sea level, which results in increase in the failure risk in coastal structures. A detailed discussion on the role of the distribution changes for design water level is provided.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.735-742
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• 2021

Recently, renewable energy-related power generation facilities have been surging due to the government's "Renewable Energy 3020", "Green New Deal", "2050 Carbon Neutrality" and "K-RE100" policies. Most renewable energy facilities are small and distributed, making it difficult to manage efficiently, and small distributed resources less than 1MW are having a hard time with participating in the market due to the limited sales and avoidance of trading. In particular, the intermittency of renewable energy has a significant impact on the stability of the power grid. The government is seeking to address volatility and intermittency issues through 'small distributed resource brokerage trading, and to expand the systematic resourceization and acceptability of heterogeneous large and small distributed resources. In this work, we intend to apply an AI-based power generation prediction model to a distributed resource brokerage trading system so that it can be utilized as a foundation platform for pioneering new energy business markets.

• Journal of Engineering Education Research
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• v.24 no.4
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• pp.21-29
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• 2021

The objective of this research is to devise a BARS evaluation system as a performance evaluation plan for non-face-to-face capstone design and to verify the validity through the expert FGI as the remote education is highlighted as a new normal standard in the post corona epoch. The conclusion of this research is as follows. First, the non-face-to-face capstone design is a competency centered subject that allows you to develop the engineering and majoring knowledge and its function and attitude, and the achievement of program outcome is the objective competency, and the researcher proposes the BARS method evaluation, one of competency evaluation method, as a new performance evaluation plan. Second, for the evaluation of PO achievement of non-face-to-face capstone design, the researcher deduced 20 behavior identification standard(anchor) of BARS evaluation system, and developed the achievement standard per 4 levels. Third, as the evaluation tool of non-face-to-face capstone design, the presentation data(PPT), presentation video, product such as trial product(model), non-face-to-face class participation video, discussion participating video, team activity report, and result report for the evidential data of BARS evaluation were appeared as proper. Finally, the BARS evaluation plan of non-face-to-face capstone design would be efficiently made through the establishment of evaluation plan, the establishment of grading standard of BARS evaluation scale, the determination of evaluation subject and online BARS evaluation site.