• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.559-568
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• 2017

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.

• Journal of Korean Academy of Nursing
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• v.45 no.1
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• pp.64-75
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• 2015

Purpose: This study was designed to construct and test structural equation modeling on healthy menopausal transition in middle-aged women in order to identify variables affecting healthy menopausal transition. Methods: Participants, 276 women, 45 to 60 years of age, with menopausal symptom score higher than 5 on the Korean version of Menopause Rating Scale, were recruited in three cities and one county of Gyeongnam Province. Research data were collected via questionnaires and analysed using SPSS version 18.0 and AMOS version 20.0. Results: After confirmatory factor analysis, one of the observed variables was excluded due to relatively low factor loading. The model fit indices for the hypothetical model were suitable for the recommended level: GFI=.93, CFI=.92, RMSEA=.05. Self-efficacy, self-differentiation, and menopausal symptoms explained 67.7% of variance in menopausal transition, and self-differentiation was the most influential factor for menopausal transition. Self efficacy and menopausal symptoms explained 9.6% of variance in menopausal management, although "menopausal symptoms" was not significant. Conclusion: These results suggest that nursing interventions to improve self-differentiation, self efficacy, menopausal management and decrease menopausal symptoms are critical for healthy menopausal transition in middle-aged women. Continued development of a variety of community-based nursing interventions to facilitate healthy menopausal transition is suggested.

• Journal of Korean Academy of Nursing
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• v.48 no.4
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• pp.419-431
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• 2018

Purpose: The purpose of this study was to develop and establish the psychometric properties of a clinical nursing competency evaluation tool to be utilized by clinical preceptors. Methods: The initial items were identified through in-depth literature review and field interviews based on a hybrid model. Content validation of the items was evaluated through three rounds of content validity testing. Participants were 34 clinical preceptors and 443 nursing students participating in clinical practice. Data were analyzed using exploratory and confirmatory factor analysis, convergence and discriminant validity, internal consistency and inter-rater reliability. Results: The final scale consisted of 23 items and four factors, fundamental nursing skills performance, critical thinking skills based on the nursing process, basic nursing knowledge, and professional attitude; these factor explained 69.7% of the total variance. The analysis with multi-trait/multi-item matrix correlation coefficients yielded 100.0% and 95.7 % convergence and discriminant validity, respectively. Cronbach's alpha for the total items was .95. The four subscale model tested by confirmatory factor analysis was satisfactory. Inter-rater reliability ranged from .912 to .967. Conclusion: This scale was found to be a reliable and valid instrument that clinical preceptors can apply for evaluating the clinical nursing competency of nursing students in clinical settings.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.6
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• pp.823-832
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• 2002

A modified $textsc{k}$-$\varepsilon$model is proposed for calculation of transitional boundary-layer flows with changing pressure gradient. In order to develop the model for this problem, the flow is divided into three regions; pre-transition region, transition region and fully turbulent region. The effect of pressure gradient is taken into account in stream-wise intermittency factor, which bridges the eddy-viscosity models in the pre-transition region and the fully turbulent region. From intermittency data in various flows, Narashima＇s intermittency function, F(${\gamma}$), has been found to be proportional to $\chi$$^{n}$ according to the extent of pressure gradient. Three empirical correlations of intermittency factor being analyzed, the best one was chosen to calculate three benchmark cases of bypass transition flows with different free-stream turbulence intensity under arbitrary pressure gradient. It was found that the variations of skin friction and shape factor as well as the profiles of mean velocity in the transition region were very satisfactorily predicted.

• The Korean Journal of Community Living Science
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• v.17 no.3
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• pp.29-41
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• 2006

The purpose of this research is to study the causal model among mother related variables, child abuse, and children's emotional maladjustment behaviors. The sample subjects were 542 pairs of fifth and sixth grade elementary school students and first as well as eighth grade middle school students, and their mothers. The major findings of the research are as follows: First, the result of multiple regression analysis on the effects of the maternal parenting stress and marital satisfaction to the children's abuse indicates that stress related to learning expectation and stress related to relationship with child are the significant contributing factor to physical abuse and verbal abuse. Second, the result of multiple regression analysis on the effects of the maternal parenting stress and child abuse to the children's emotional maladjustment behaviors indicate that verbal abuse is the significant contributing factor. Third, looking at causal relations of the maternal variables (maternal parenting stress, marital satisfaction) and child abuse (physical abuse, verbal abuse, neglect) to the children's emotional maladjustment behaviors, maternal variables impact indirectly through the child abuse factor.

• Computers and Concrete
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• v.13 no.1
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• pp.135-147
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• 2014

Strut-and-tie model (STM) has been recommended by many codes and standards as a rational model for discontinuity regions in structural members. STM has been adopted in ACI building code for analysis of reinforced concrete (RC) deep beams since 2002. However, STM recommended by ACI 318-11 is only applicable for analysis of ordinary RC deep beams. This paper aims to develop the STM for CFRP strengthened RC deep beams through the strut effectiveness factor recommended by ACI 318-11. Two sets of RC deep beams were cast and tested in this research. Each set consisted of six simply-supported specimens loaded in four-point bending. The first set had no CFRP strengthening while the second was strengthened by means of CFRP sheets using two-side wet lay-up system. Each set consisted of six RC deep beams with shear span to effective depth ratio of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00.The value of strut effectiveness factor recommended by ACI 318-11 is modified using a proposed empirical relationship in this research. The empirical relationship is established based on shear span to effective depth ratio.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.127-134
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• 2018

Myofibrillogenesis regulator-1 (MR-1) is a novel protein involved in cellular proliferation, migration, inflammatory reaction and signal transduction. However, little information is available on the relationship between MR-1 expression and the progression of atherosclerosis. Here we report atheroprotective effects of silencing MR-1 in a model of Ang II-accelerated atherosclerosis, characterized by suppression focal adhesion kinase (FAK) and nuclear factor kappaB ($NF-{\kappa}B$) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the siRNA-MR-1 substantially attenuated Ang II-accelerated atherosclerosis with stabilization of atherosclerotic plaques and inhibited FAK, Akt, mammalian target of rapamycin (mTOR) and NF-kB activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in Ang II-treated vascular smooth muscle cells (VSMCs) and macrophages: siRNA-MR-1 inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of Ang II and highlight actions of silencing MR-1 to inhibit Ang II signaling, which is atheroprotective.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.4
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• pp.549-559
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• 1999

An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.

• Journal of Korean Academy of Nursing Administration
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• v.22 no.1
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• pp.11-21
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• 2016

Purpose: The purpose of this study was to develop and test the validity and reliability of the Korean version of nurses' attitudes toward delegation and preparedness to delegate (APD). Methods: The Korean version of APD was developed through forward-backward translation methods. Internal consistency reliability, criterion validity, and construct validity using exploratory and confirmatory factor analysis were conducted using IBM SPSS Statistics 19 and AMOS 20.0. Survey data were collected from 161 nurses working in 2 general hospitals. Results: The Korean version of APD showed Cronbach's alphas of .68 and .85. Factor loadings of the 8 attitude items on the 3 subscales ranged from .60 to .86 and the 15 preparedness items on the 4 subscales ranged from .47 to .90. The model of 3 subscales for the Korean nurses' attitude toward delegation and the model of 4 subscales for the Korean nurses' preparedness to delegate were both validated by confirmatory factor analysis(NC<3, CFI>.90, RMSEA<.10). Criterion validity compared to job satisfaction showed significant correlation. Conclusion: The findings of this study demonstrate that this modified Korean version of APD is applicable for measuring Korean nurses' attitude toward delegation and preparedness to delegate.

• The Korean Journal of Ecology
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• v.4 no.1_2
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• pp.38-51
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• 1981

The present investigation was estimated the effect of temperature, precipitatiion, and time on the decomposition of litters with litter bags of Pinus densiffora and Quercus mongolica at Gure where elevation in 50m, and at Nogodan where elevation in 1300m on Mt. Jiri. As the above results, decomposition model was proposed to relation of the environmental conditions. And was investigated the production and decomposition of litters from the stands of various forest communities in Kwangneung, Mt. Jiri and Mt. Halla. The results are as follows; The models for the decay of organic carbon (C) was as follows: $C=Coe^{-Kt}$ (limiting factor;time) $C=Coe^{-K'te}$ (limiting factor;tempedrature) $C=Coe^{-KnP}$ (limiting factor:precipitation) As observed in litter bag method, the decomposition rate of litter in Pinus densiflora was slower than that of Quercus mongolica. The higher elevation, the slower decomposition rate. The decomposition of litters at Gure where elevation in 50m was equally influenced by temperature and precipitation. But at Nogodan where elevation in 1300m was much inflenced by precipitation. The decay constant of litters was larger in hardwood forest than in coniferous forest. In the same species, the more elevatiion, the less decomposition constant. The time required for the decay of 50%, 95^, 99% of the accumulated litters in the forest floor were faster in hardwood forest than in coniferous forest. In the same species, the higher elevatiion, the longer time required.