• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.267-268
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• 1998

In this paper, we analysis 3 types of magnetic resonance image for determining whether brain infarction period is hyperacute or not. If its peirod is hyperacute, we can predict brain infarction transition direction. We use EPI(Echo Planar Image) for prediction of brain infarction transition direction. EPI is a good image for detecting brain infarction because EPI can detect the moving of water in brain which play an important role in deciding method of medical treatment. We utilize characteristics of 3 type of MRI and their relation in brain infarction patient for determining brain infarction period. By this method, we obtain each period characteristics and predict brain infarction transition direction more accurately comparing past method.

• Korean Journal of Materials Research
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• v.25 no.8
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• pp.417-422
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• 2015

In this study, low-carbon hypoeutectoid steels with different ferrite-pearlite microstructures were fabricated by varying transformation temperature. The microstructural factors such as pearlite fraction and interlamellar spacing, and cementite thickness were quantitatively measured and then Charpy impact tests conducted on the specimens in order to investigate the correlation of the microstructural factors with impact toughness and ductile-brittle transition temperature. The microstructural analysis results showed that the pearlite interlamellar spacing and cementite thickness decreases while the pearlite fraction increases as the transformation temperature decreases. Although the specimens with higher pearlite fractions have low absorbed energy, on the other hand, the absorbed energy is higher in room temperature than in low temperature. The upper-shelf energy slightly increases with decreasing the pearlite interlamellar spacing. However, the ductile-brittle transition temperature is hardly affected by the pearlite interlamellar spacing because there is an optimum interlamellar spacing dependent on lamellar ferrite and cementite thickness and because the increase in pearlite fraction and the decrease in interlamellar spacing with decreasing transformation temperature have a contradictory role on absorbed energy.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.4
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• pp.69-81
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• 2020

Since airline safety depends significantly on the role of pilot, the importance of airlines' training qualified pilots and investing in the training program grows. This study aims to analyze the determinants of the commercial airline pilot competencies during the transition course. To this purpose, one-year training evaluation results of 215 new airline pilots in the JET transition course of Company K in 2019 are studied with correlation coefficient analysis, factor analysis, ANOVA, and regression analysis. Undergraduate major and Uljin-trained pilots show higher final-stage scores in PROC, AUTO, and CRM. Due to Uljin-trained pilots' higher first-stage scores, their score increase during the course is limited. Uljin-trained pilots' MANUAL scores in the final stage are lower than those of undergraduate major and overseas-trained pilots. Influence of trained location is found greater than English competency, undergraduate GPA, and ground school scores on commercial airline pilot competency evaluation scores during the program. The results will be useful in establishing scenario-based training focusing on different background to apply competency-based training and assessment.

• Current Optics and Photonics
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• v.5 no.3
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• pp.243-249
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• 2021

In this paper, the sensing characteristics of a double cladding fiber (DCF) long-period fiber grating (LPFG) to the surrounding refractive index (SRI) are studied. The outer cladding of the DCF plays the role of the overlay, thus, the mode transition (MT) phenomenon of DCF can be induced by etching the outer cladding radius instead of coating overlays. The response characteristics of the effective refractive index (ERI) of the cladding mode to the outer cladding radius are analyzed. It is found that in the MT range, the change rate of ERIs of cladding modes is relatively larger than that for other ranges. Further, based on the features of the mode transition region (MTR), the phase-matching curve of the 11^th cladding mode is investigated, and the response of the DCF-LPFG to the SRI is characterized by the change of wavelength intervals between the dual peaks under different outer cladding radii. The numerical simulation results show that the SRI sensitivity is greatly improved, which is available to 3484.0 nm/RIU with the fitting degree 0.998 in the SRI range of 1.33-1.37. The proposed DCF-LPFG can provide new theoretical support for designing the DCF-LPFG refractive index sensor with excellent performances of sensitivity, linearity and structure.

• Korean Journal of Childcare and Education
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• v.17 no.4
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• pp.49-71
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• 2021

Objective: This study aims to explore the experiences of women who take a career break while working in daycare center as a teacher assistant. Methods: Seven assistant teachers and two child care teachers who took more than two years of career break were selected and given in-depth interviews over 17 weeks from August to December in 2020. Results: The results of this study are as follows. First, the women experienced the need for a career transition as an assistant teacher because it was time to for a change. Second, while working as a teacher assistant, they had various experiences and meanings in the process of career transition while playing the role as a teacher in daycare centers. Third, they also had some difficulties in conflict and some needs to build their professional expertise as a teacher. Conclusion/Implications: The study is expected to give insights to understand the difficulties of teachers who had experienced the need for a career transition as teacher assistant and to provide important data to develop teacher professional development.

• Biomedical Science Letters
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• v.24 no.4
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• pp.285-291
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• 2018

Gremlin-1 (GREM1) has been defined as an antagonist of bone morphogenetic proteins (BMPs), particularly during embryonic development and tissue differentiation. However, recent studies have shown that GREM1 has BMPs-dependent or -independent functions in diverse human diseases. GREM1 plays a key role in the process of organ fibrosis, including lungs, kidneys, and so on. The GREM1-induced fibrosis typically promotes the development of other diseases, such as pulmonary hypertension, renal inflammation, and diabetic nephropathy. More recently, considerable evidence has been reported showing that GREM1 is involved in the promotion and/or progression of tumors in vitro and in vivo. It also performs an oncogenic role in the maintenance of cancer stem cells. Although GREM1 is known to function in a variety of diseases, here we focus on the role of GREM1 in cancer, and suggest GREM1 as a potential therapeutic target in certain types of cancer.

• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.155-155
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• 2016

• Bulletin of the Korean Chemical Society
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• v.17 no.3
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• pp.285-288
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• 1996

The electrical conductivity of some phthalimide derivatives and their complexes with Co(II), Ni(II), Cu(II), or Zn(II) has been measured in the temperature range 290-435 K. Both the structure of phthalimide molecule and its complexes played an effective role in the conduction process. Conductometric titration and IR spectra were used to characterize the structure of studied samples.

• Women's Health Nursing
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• v.21 no.4
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• pp.308-320
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• 2015

Purpose: The aim of this study was to determine the predictive factors for maternal role development for mothers of premature infants. Methods: A descriptive correlational study was conducted. A total sample of 121 mothers of premature infants following discharge from the neonatal intensive care unit were recruited using two strategies; an internet-based survey and an in-person data collection in a tertiary university hospital in Korea. A self-report questionnaire was used to collect data regarding personal, birth variables, marital intimacy, maternal attachment, maternal identity and maternal role development. Results: A hierarchical multiple regression analysis indicated that parity, maternal attachment, marital intimacy and maternal identity were predictors for maternal role development for mothers of premature infants, accounting for 70% of the variance. Among these variables, maternal attachment is the most powerful predictor for maternal role development. Conclusion: Nursing interventions during hospitalization to post-discharge education that includes parents of premature babies with positive interaction between couples strengthening marital intimacy and promotes maternal attachment that leads to integrate maternal identity should be considered by priority. Community-based family services such as home visits should be focused on maximizing the predictive factors for maternal role development in transition to motherhood that can contribute to maternal health as well as optimal growth and development of premature infants.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.132-132
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• 2013

Colloidal synthesis of nanoparticles with well-controlled size, shape, and composition, together with development of in situ surface science characterization tools, such as ambient pressure X-ray photoelectron spectroscopy (APXPS), has brought new opportunities to unravel the surface structure of working catalysts. Recent studies suggest that surface oxides on transition metal nanoparticles play an important role in determining the catalytic activity of CO oxidation. In this talk, I will outline the recent studies on the influence of surface oxides on Rh, Pt, Ru and Co nanoparticles on the catalytic activity of CO oxidation [1-3]. Transition metal nanoparticle model catalysts were synthesized in the presence of poly(vinyl pyrrolidone) polymer capping agent and deposited onto a flat Si support as two-dimensional arrays using the Langmuir-Blodgett deposition technique. APXPS studies exhibited the reversible formation of surface oxides during oxidizing, reducing, and CO oxidation reaction [4]. General trend is that the smaller nanoparticles exhibit the thicker surface oxides, while the bigger ones have the thin oxide layers. Combined with the nature of surface oxides, this trend leads to the different size dependences of catalytic activity. Such in situ observations of metal nanoparticles are useful in identifying the active state of the catalysts during use and, hence, may allow for rational catalyst designs for practical applications. I will also show that the surface oxide can be engineered by using the simple surface treatment such as UV-ozone techniques, which results in changing the catalytic activity [5]. The results suggest an intriguing way to tune catalytic activity via engineering of the nanoscale surface oxide.