• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.30-39
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• 2022

Maintaining structural integrity of major apparatuses in a nuclear power plant, including piping system, is recognized as a critical safety issue. The integrity of piping system is also a critical matter related to the safety of a nuclear power plant. The actual failure mode of a piping system due to a seismic load is the leakage due to a fatigue crack, and the structural damage mechanism is the low-cycle fatigue due to large relative displacement that may cause plastic deformation. In this study, in-plane cyclic loading tests were conducted under various constant amplitudes using specimens composed of steel straight pipes and a steel pipe tee in the piping system of a nuclear power plant. The loading amplitude was increased to consider the relative displacement generated in the piping system under seismic loads, and the test was conducted until leakage, which is the limit state of the steel pipe tee, occurred due to fatigue cracks. The limit state of the steel pipe tee was expressed using a damage model based on the damage index that used the force-displacement relationship. As a result, it was confirmed that the limit state of the steel pipe tee can be quantitatively expressed using the damage index.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.1
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• pp.59-64
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• 2017

Scutellaria baicalensis Georgi is one of major herbs used to treat patients with skin diseases diagnosed by wind-heat syndrome. This study was designed to investigate the effects of Scutellaria baicalensis Extract (SBE) on skin lesion of Contact dermatitis (CD) in mice. We investigated the effects of SBE on skin thickness, skin lesions, erythema index and melanin index in vivo. The effects on body weights and spleen/body weight ratio were also investigated in mice with CD induced by topical application of 1-Fluoro-2,4-dinitrofluorobenzene (DNFB). In our results, topical application of SBE lowered skin thickness significantly. In addition, SBE ameliorated skin lesions such as erythema, exudate and petechia in mice with CD. SBE also inhibited erythema index elevated by DNFB significantly. finally, SBE did not affect body weight and spleen/body weight ratio. In conclusion, these data imply that SBE can ameliorate skin lesion of CD such as erythema, exudate and petechia, and be used to treat CD patients with relative safety.

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.15-25
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• 2018

Purposes: The objectives of this study present the direction of the criteria for the separately reimbursement of therapeutic medical device. Methodology: We summarized experts' opinion using Delphi survey and Analytic Hierarchy Process(AHP). 48 experts were gathered from Medical Insurance Review Nurses Association, medical device industry, academy and association, Medical Device Expert Evaluation Committee. Descriptive statistics, consistency index, content validity ratio were analyzed. Findings: Clinical utility, patient safety, infection control, cost-homogeneity, cost-effectiveness showed high feasibility and importance, but market contribution and functional utility showed low feasibility and importance in a relative sense. The results of functional utility differed between clinical and non-clinical experts. Measurability was low across the whole area. Among the criteria for the separately reimbursement of therapeutic medical device. Patient safety/infection control and clinical utility showed the highest relative importance values, analyzed using AHP. Practical Implications: Patient safety and infection control are needed to be considered as one of Value Assessment Criteria. It is important to find out how to improve the measurability of therapeutic medical device.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.379-392
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• 2005

The size of state in Korea is like Israel, this country's venture capital is ruled by government. This venture capital's character is below: the concentration on research of venturer affect positively at quality of products. This paper lies with venture capital's risk character & performance. The results show that Korean venture capitals have lager unsystematic risk than systematic risk, which implies they specialize in specific business and/or regional areas instead of diversification. The Sharpe & Jensen measures reveal that the performances of Korean venture capitals are very low relative to even the market portfolio(Kospi) and Kosdaq Venture Index. Contrary to this, Venture firm's performance according to Entrepreneurship will cause to push up stock price.

• Journal of Auto-vehicle Safety Association
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• v.5 no.2
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• pp.17-23
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• 2013

This paper describes an algorithm for Advanced Emergency Braking(AEB) with tire-road friction coefficient estimation. The AEB is a system to avoid a collision or mitigate a collision impact by decelerating the car automatically when forward collision is imminent. Typical AEB system is operated by Time-to-collision(TTC), which considers only relative velocity and clearance from control vehicle to preceding vehicle. AEB operation by TTC has a limit that tire-road friction coefficient is not considered. In this paper, Tire-road friction coefficient is also considered to achieve more safe operation of AEB. Interacting Multiple Model method(IMM) is used for Tire-road friction coefficient estimation. The AEB algorithm consists of friction coefficient estimator and upper level controller and lower level controller. The numerical simulation has been conducted to demonstrate the control performance of the proposed AEB algorithm. The simulation study has been conducted with a closed-loop driver-controller-vehicle system using using MATLAB-Simulink software and CarSim Vehicle model.

• Safety and Health at Work
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• v.12 no.3
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• pp.324-338
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• 2021

Background: We hypothesized that the growing demand of Korean workers for work-life balance would change the factors influencing job satisfaction. We sought to verify our hypothesis by conducting a conjoint analysis based on the Korean Working Conditions Survey (KWCS). Methods: We analyzed the raw data of the KWCS, conducted by the Occupational Safety and Health Research Institute from 2006 to 2017. To complete the analysis, we counted on a conjoint model of analysis, typically used in the analysis of customer satisfaction. The dependent variable was the satisfaction of workers with their working conditions, and the independent variables were the job quality indicators identified by Eurofound. Results: The factors that have the greatest impact on working conditions satisfaction are summarized as follows: "physical environment" for the first wave, "adverse social behavior" for the second wave, "occupational status" for the third and fourth waves, and "management quality" for the fifth wave. "Earnings" were not a major factor in determining employee job satisfaction, and the relative importance index is decreasing. Conclusion: According to the results of the analysis of the tendencies of Korean workers, the factors that affect the satisfaction with the working conditions have changed over time. It is crucial to identify factors that affect working conditions to assure the health and productivity of workers. The results of this study demonstrate that policymakers and employers are required to attentively consider human relations and social environment at work to improve working conditions in the future.

• Journal of the Korean Society of Safety
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• v.28 no.5
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• pp.41-48
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• 2013

This paper is intended to provide the background information and justification for Korean highway bridge design code(limit state design)(2012). Limit state design method calculates reliability index and probability of failure through the analysis of the reliability of the experimental database. It has become possible to perform the economical and consistent design by evaluating the safety of a structure quantitatively. In this paper, we used the design specifications of RC slab bridge of superstructure form of Road Design Manual in Part 5 bridge built in highway bridge. This study conducted structural analysis using the method of frame structure theory, design and analysis of bridge by limit state design method, the design code including various standards and Load model applied Korean highway bridge design code limit state design(KHBDC;2012). As a result, it analyzed the effect of safety through comparison. Showing effect of improvement the safety factor and comparing the value of the result, it is determined to be capable of economical design and safety. Furthermore, limit state design method was able to determine many redundant force of cross-section compared with existing design method. It is determined that it can reduce the overall amount because of the reduction of the cross-section and girder depth.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.49-60
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• 2011

This study was performed to develop a children's dietary life safety index required by the Special Act on Safety Management of Children's Dietary Life enacted in 2009. An analytical hierarchy process was used to obtain initial weights of dietary life safety evaluation indicators. The Delphi method was applied to develop the weights along with 98 food and nutrition professionals. Three representative policy indicators, nine strategy indicators, 11 main evaluation indicators, and 20 detailed evaluation indicators were selected for the children's dietary life safety assessment. Three policy indicators and nine strategy indicators were the following: children's food safety indicator (support level of children' safety, safety management level of children's favorite foods, and safety management level of institutional food service), children's nutrition safety indicator (management level of missing meals and obesity, nutrition management level of children's favorite foods, and nutrition management level of institutional food service), and children's perception and practice level indicator ("Dietary Life Law" perception level, perception, and practice level for dietary life safety management, perception, and practice level for nutrition management). Weights of 40%, 40%, and 20% were given for the three representative policy indicators. The relative importance of nine strategic indicators, which were determined by the Delphi method is as follows: For children’s food safety, support level of children's safety, safety management level of children's favorite foods, and safety management level of institutional food service were given weights of 12%, 9%, and 19%, respectively. For children's nutrition safety, the missing meals and obesity management level, nutrition management level of children's favorite foods, and the nutrition management level of institutional food service were given weights of 13%, 11%, and 16%, respectively. The "Dietary Life Law" perception level, perception and practice level of dietary life safety management, and perception and practice level of nutrition management were given weights of 4%, 7%, and 9%, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.483-492
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• 2020

In this study, we compared and analyzed the Revealed Comparative Advantage (RCA) and Trade Specialization Index (TSI) based on ballast water management systems (BWMS) trade data, which are related to the International Maritime Organization (IMO) Ballast Water Management Convention to suggest the current status of Korea's industrial competitiveness and suggest future development directions for the BWMS industry. As international interest in eco-friendly vessels is expanding, the IMO is engaged in dramatic discussions and agreement-making related to marine emissions of pollutants from ships. IMO member states that must implement this convention are striving to develop technology and secure industrial competitiveness as major industries in the eco-friendly shipping sector, with the BWMS industry experiencing a high market entry barrier and the possibility of the leading market entrants gaining leadership. The Republic of Korea accounts for 17 (approximately 38 %) of the 45 BWMS that received final approval as of October 2019. Based on trade data relating to product codes HS842219, HS84212, and HS89, the RCA index and TSI were calculated and compared. The findings revealed that the Republic of Korea has relative inferiority compared to countries such as Germany and Denmark. Despite this, Korea's favorable industrial environment, which includes several IMO-approved BWMS technologies and the possession of domestic certification institutions, is likely to strengthen its competitiveness in the BWMS market.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.107-120
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• 2020

In a performance-based evaluation of structures in use, the current performance is assessed by summing up the weighting of the evaluation indices for each performance. In this study, to suggest a performance-based evaluation technique for NATM tunnels in use, the performance evaluation indices were derived by examining the characteristics and similarities of each index developed from previous study. The weighting of the evaluation indices was derived by calculating the relative importance of each evaluation indices from the AHP analysis. In order to develop a quantitative evaluation model, grading criteria for each performance index was derived through literature review, and performance evaluation tables for road and railway tunnels were presented. In order to verify the significance of the proposed performance evaluation model, the correlation analysis was performed between each evaluation index and the final evaluation result. In the correlation analysis, the survey data measured through precision safety diagnosis in the tunnel in use was applied. It may be said that the proposed evaluation indices, weighting, criteria and evaluation models for tunnels in use can be applied to the performance-based maintenance system of tunnels.