• Journal of Digital Convergence
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• v.18 no.9
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• pp.229-237
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• 2020

The study was done to identify relations among moral sensitivity, self-leadership, fatigue and compliance with standard precautions and to identify the influencing factors on compliance with standard precautions for intensive care nurses. Data were collected from 153 intensive care nurses in March 2019 and were analyzed using Descriptive statistics, Pearson correlation coefficients, and Stepwise multiple regression with SPSS/WIN 24.0 version. The compliance with standard precautions has positive correlation with their self-leadership (r=.17, p=.042). The self-leadership (β=.17, p=.042) was a significant predictor of the compliance with standard precautions. It was statistically significant (R²=.03, F=4.21, p=.042). Based on the findings of this study, each institution needs to make efforts to strengthen the capacity of nurses for self-leadership.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.1
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• pp.78-87
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• 2014

Recently the offshore wind turbine development is requested to be installed off south-west coast and Jeju island in Korea. Reliable and robust support structures are required to meet the demand on the offshore wind turbine in harsh and rapidly varying environmental conditions. Monopile is the most preferred substructure in shallow water with long term experiences from the offshore gas and oil industries. This paper presents an optimum design of a monopile connection with grouted transition piece (TP) for the reliable and cost-effective design purposes. First, design loads are simulated for a 5 MW offshore wind turbine in site conditions off the southwest coast of Korea. Second, sensitivity analysis is performed to investigate the design sensitivity of geometry and material parameters of monopile connection based on the ultimate and fatigue capacities according to DNV standards. Next, optimization is conducted to minimize the total mass and resulted in 30% weight reduction and the optimum geometry and material properties of the monopile substructure of the fixed offshore wind turbine.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1821-1828
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• 2010

Laser shock peening(LSP) is an innovative surface treatment technique, and it has been successfully used to improve the fatigue performance of metallic components. It is widely known, that cracks caused by metal fatigue occur only at the location where the metal is subject to tension, and not at the location where the metal is subjected to compression. Therefore, LSP can be employed to improve fatigue life because it generates a high-magnitude compressive residual stress on the surface and interior of metallic components. In this study, we analyzed the applicability of the LSP method in improving fatigue performance and evaluated the various parameters that influence the compressive residual stress. Further, we analyzed the change in the mechanical properties such as surface dynamic stress and the compressive residual stress on the surface and interior of metallic components.

• Computational Structural Engineering
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• v.5 no.3
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• pp.97-103
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• 1992

Since many design problems in the railroad, aerospace and machine structures involve considerations of the effect of cyclic loading, manufacturing and quality control processes much fully account for fatigue of critical components. Due to the sensitivity of the Paris law, it is very important to calculate .DELTA.K numerically to minimize the error of predicted fatigue life in cycles. However, it is shown that the p-version of FEM based on LEFM analysis is far better suited for computing the stress intensity factors than the conventional h-version. To demonstrate the proficiency of the proposed scheme, the welded T-joint with crack problems of box car body bolster assembly and a crack problem emanating from a circular hole in finite strip have been solved.

• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.299-307
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• 2017

The design of the mooring line to maintain the position of an offshore structure in rough marine environments is recognized as a very important consideration. Conventional fatigue evaluation of a mooring line was performed by considering the tensile force acting on the mooring line, but the mooring line broke after 238 days in the girassol area even though the expected fatigue life was expected to be longer. The causes of this event are known to be due to OPB/IPB (out-of-plane bending/in-plane bending) caused by chain link friction due to the excessive tensile strength of the mooring line. In this study, three models with different boundary conditions were proposed for fatigue analysis of a mooring line considering OPB/IPB. Interlink stiffness was calculated by nonlinear structure analysis and a stress concentration factor was derived. In addition, the sensitivity of interlink stiffness according to the magnitude of tensile force, large deformation effect, and coefficient of friction was analyzed, and the effect of critical elastic slip and bending moment calculation position on interlink stiffness was confirmed.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.301-304
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• 2006

Tower shell design is very important because tower takes about 20% of overall wind turbine cost. This paper contains procedure of tower analysis and optimization content. Some of requirements like eigenfreauency and buckling evaluated by numerical method, strength, are derived by analytic method. But strength and fatigue can be derived by mathematical method simply.

• New & Renewable Energy
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• v.2 no.4 s.8
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• pp.19-26
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• 2006

Tower shell design is very important because tower takes about 20% of overall wind turbine cost. This paper contains procedure of tower analysis and tower shell thickness optimization concept. Some of requirements like eigenfrequency and buckling evaluated by numerical method. But strength and fatigue can be derived by mathematical method simply. Using this procedure, tower shell thickness can be designed without repetition of complicated calculation.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.103-115
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• 2011

Concrete slab curls and warps due to the uneven distribution of temperature and moisture and as the result, internal stress develops within the slab. Therefore, environmental loads must be considered in addition to the traffic loads to predict the lifespan of the concrete pavement more accurately. The strength of the concrete slab is gradually decreases to a certain level at which fatigue cracking is generated by the repetitive traffic and environmental loadings. In this study, a new fatigue regression model was developed based on the results from previously performed studies. To verify the model, another laboratory flexural fatigue test program which was not used in the model development, was conducted and compared with the predictions of other existing models. Each fatigue model was applied to analysis logic of cumulative fatigue damage of concrete pavement developed in the study. The sensitivity of cumulative fatigue damage calculated by each model was analyzed for the design factors such as slab thickness, joint spacing, complex modulus of subgrade reaction and the load transfer at joints. As the result, the model developed in this study could reflect environmental loading more reasonably by improving other existing models which consider R, minimum/maximum stress ratio.

• Journal of dental hygiene science
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• v.20 no.1
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• pp.51-58
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• 2020

Background: The present study aimed to provide basic data to establish a foundation for efficient operation of the organization by identifying the effects of factors related to moral sensitivity and psychological well-being on job engagement of clinical dental hygienists. Methods: This cross-sectional survey consisted of self-administration questionnaires. After the approval by the Institutional Review Board, a survey was conducted from September 2019 to November 2019, targeting dental hygienists with clinical experience of 1 year or more. A total of 189 questionnaires were analyzed using SPSS 18.0 for Windows. The data were analyzed using average standard deviation, t-test, one-way analysis of variance, Scheffe test, Pearson's correlation analysis, and multiple regression analysis. Results: According to job-related characteristics, higher job engagement was associated with more amount of clinical experience, less turnover intention, higher positions, and occasional job fatigue. Job engagement was improved by increasing moral sensitivity and psychological well-being of clinical dental hygienists. The factors affecting job engagement revealed that along with clinical career, the sub-areas of job engagement, namely turnover intention, moral sensitivity, and psychological well-being had statistically significant influence on job engagement and the explanatory power of the model was approximately 44.8%. Conclusion: Joy of working as a clinical dental hygienist, clinical career, turnover intention, moral sensitivity, and psychological well-being were confirmed as influencing factors that affected job engagement of clinical dental hygienists. It is necessary to establish an effective plan to improve job engagement by increasing moral sensitivity and psychological well-being of clinical dental hygienists.

• Applied Biological Chemistry
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• v.20 no.3
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• pp.270-278
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• 1977

In case of sensory evaluation with multi-samples and long-period, in spite of using method with good sensitivity, quality differences among samples could net be detected well because of panel's fatigue and tiredness. So new method to reduce panel's sense of psychological and physiological responsibility, "Trio Paired Comparison", is designed, and New Modified Scheffe's Method 2 as the statistical method for a test of "Trio Paired Comparison" is proposed. And also in this paper problems and countermeasures in applicating "Trio Paired Comparison" are considered.