• Journal of the Korean Home Economics Association
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• v.46 no.10
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• pp.23-36
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• 2008

The purpose of this study is to analyze the research trends about the child care center accreditation system in Korea which has been practiced relatively recently. To solve the research problems, 68 pieces of master's theses, doctoral dissertations, and journal articles were analyzed. The results of this study are as follows: First, since 2005 when the research about the child care center accreditation system was first applied, the number of research has increased dramatically over the year 2006 and 2007. Also, majority of the research was done mostly in the region of Seoul and Gyeonggi-do compared to other regions. Second, the child care center accreditation system administration was the most frequently researched topic, followed by the evaluation on the child care center accreditation system, and the general understanding and recognition of the child care center accreditation system. Third, quantitative method was used most frequently to research the child care center accreditation system, and literature review and qualitative method were used relatively less. Most of the research subjects were the child care center directors and teachers. The sample size of the research was relatively big, and most of the survey were either made by the researcher or were modified and adjusted from the previously used survey questions according to the present research. Most of the data analysis of quantitative study were done with descriptive statistics, and with t-test, chi-square, and ANOVA and there was only one done with correlation analysis.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.2
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• pp.70-78
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• 2013

Plants which are having conditions of high temperature and pressure always are exposed to danger. In order to prevent unexpected accidents, safety management that can effectively and appropriately examine facilities is required in plant operation. RBI(Risk-Based Inspection) technology in API 581 is one of standard management technique for evaluating risk on petroleum plants. There are qualitative and quantitative assessments in RBI methodology. Quantitative evaluation step is complex and required much information, so high-risk facilities in plant are selected firstly by qualitative method. Qualitative RBI is performed by choosing the answer in prepared questionnaire. However, it is difficult to believe thoroughly results from survey including ambiguous information. In this study, the procedure of qualitative RBI analysis with considering probability distribution concept were proposed by using Monte Carlo simulation method in order to increase reliability in spite of uncertain factors. In addition, qualitative risk of cooling system for LNG plant was evaluated using proposed procedure. Although 20 items of total 39 assessment items are applied to uncertain factors, risk section of high probability(89%) were verified. The detailed results were described in manuscript.

• 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.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.321-327
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• 2021

Wrist PA-grip view is used to diagnose triangular fibrocartilage complex (TFCC) tear because it can easily diagnose damage to the surrounding wrist ligaments. However, despite advances in radiology equipment, distortion of images due to geometric elements still has many limitations. In this paper, we propose a method that can minimize the distortions of images by analyzing the distortions occurring in the wrist PA-grip view. A source of image distance (SID) were set at 130 cm and 150 cm for comparison with 110 cm. Depending on the SID, the phantom of wrist was moved at 0, 2, 4, 6, 8, and 10 cm in the X-axis and Y-axis directions, respectively. For quantitative evaluation, the difference of distance between the radius and ulna was measured in picture archiving and communication system (PACS) system. As a qualitative evaluation, survey was conducted among 20 radiologic technologists who examined the Wrist PA-grip view. The Kruskal Wallis test was performed to compare the distortion according to the phantom movement in the X-axis and Y-axis directions based on the SID, and the Tukey test was performed as a post-test. In the quantitative evaluation results, the measured values obtained in the X-axis was not significantly different in all groups (p>0.05). The measured values obtained in the Y-axis was significantly different in the most groups (p<0.05). Therefore, to reduce distortion while maintaining image quality, we recommend what examine the SID at 150 cm than 110 cm.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.87-92
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• 2007

KTX (Korea Train eXpress) is launched as the $5^{th}$ develop a ride-comfort model for high-speed rail pasengers using structural equation model (SEM). Both qualitative and quantitative factors affecting ride-comfort were investigated, and employed to construct a comprehensive ride-comfort model. The SEM model was built with twenty measurement variables and seven latent variables for the evaluation of ride-comfort of high-speed train passenger. A total of six hundreds thirty two subjects participated in the evaluation using face-to-face survey method. As a result, the proposed SEM model model fitnes (GFI=0.93). According to the results, overall ride-comfort was significantly affected by the seat-, fatigue-, interior-related, and customer satisfaction variables such as fare. Among the engineering design variables of high-speed train, seat-related variables were identified as critical factors of the ride-comfort. It is expected that the result of this study could be useful for the enhancement of ride comfort in next generation KTX.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3059-3064
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• 2011

A Trolley line is a very important equipment among electric railway equipments since it contacts directly with pantograph and supplies electricity on the electromotive. Such it was thought that a trolley line need not to consider fatigue since the replace cycle by wear is shorter than the replace cycle by fatigue breakage. But, the bending fatigue breakage accidents occurred several times at the Shinkansen trolley line in East Japan Railway Company. Therefore, in case of a new developed trolley line, the evaluation for bending fatigue life became more important, But, since there are not an authorized fatigue test method and a testing device for the trolley line, the quantitative evaluation is difficult. In this study, we analyzed the load and environment condition of trolley line used in the actual spot and the developed testing device that can evaluate bending fatigue properties of the trolley line as simulating the real condition. The bending fatigue test of the trolley line was achieved using the developed testing device and estimated the fatigue life of trolley line and also, established the fatigue test process.

• Earthquakes and Structures
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• v.1 no.1
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• pp.93-108
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• 2010

This paper investigates the seismic performance of existing reinforced concrete frames with wide beams mainly designed for gravity loads, as typically found in the seismic-prone Mediterranean area before the introduction of modern codes. The seismic capacity is evaluated in terms of the overall amount of input energy that the frame can dissipate/absorb up to collapse. This approach provides a quantitative evaluation that can be useful for selecting and designing an appropriate retrofit strategy. Six prototype frames representative of past construction practices in the southern part of Spain are designed, and the corresponding non-linear numerical models are developed and calibrated with purposely conducted tests on wide beam-column subassemblages. The models are subjected to sixteen earthquake records until collapse by applying the incremental dynamic analysis method. It is found that the ultimate energy dissipation capacity at the story level is markedly low (about 1.36 times the product of the lateral yield strength and yield displacement of the story), giving values for the maximum amount of energy that the frame can dissipate which are from one fourth to half of that required in moderate-seismicity regions.

• Earthquakes and Structures
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• v.12 no.6
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• pp.653-663
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• 2017

A seismic margin assessment evaluates how much margin exists for the system under beyond design basis earthquake events. Specifically, the seismic margin for the entire system is evaluated by utilizing a systems analysis based on the sub-system and component seismic fragility data. Each seismic fragility curve is obtained by using empirical, experimental, and/or numerical simulation data. The systems analysis is generally performed by employing a fault tree analysis. However, the current practice has clear limitations in that it cannot deal with the uncertainties of basic components and accommodate the newly observed data. Therefore, in this paper, we present a Bayesian-based seismic margin assessment that is conducted using seismic fragility data and fault tree analysis including Bayesian inference. This proposed approach is first applied to the pooltype nuclear research reactor system for the quantitative evaluation of the seismic margin. The results show that the applied approach can allow updating by considering the newly available data/information at any level of the fault tree, and can identify critical scenarios modified due to new information. Also, given the seismic hazard information, this approach is further extended to the real-time risk evaluation. Thus, the proposed approach can finally be expected to solve the fundamental restrictions of the current method.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.497-504
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• 2015

Apart from hydrates, asphaltenes, and inorganic minerals, paraffinic waxes are also very important in flow assurance area. Evaluation of wax gel behavior has been important as off-shore oil recovery becomes more popular in oil production. Restart after either planned or emergency shutdown requires pump operation in high pressure since a waxy oil forms troublesome gel. In this paper, vane method is introduced to determine wax gel strength by determining yield stress. Prediction of gel strength are discussed in qualitative and quantitative manners.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.1 s.12
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• pp.57-64
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• 2004

Recent abnormal weather condition and accompanying increase in forest fire require more study on the effect of forest fire on the stability of mountain slopes. The aims of this paper are to investigate how destroy of trees caused by forest fire influences the stability of mountain slopes and to propose a safety evaluation method for mountain slopes considering the effect of forest fire, in order to minimize the expected damage due to forest fire. To accomplish this aim, the effects of forest fire on the stability of mountain slopes are analyzed in quantitative way, and a slope stability chart is proposed as a result.