• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1475-1477
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• 2003

The satellite remote sensing data is good in order to grasp the wide natural environment. The purpose of study is that it examines spectral reflection characteristic and vegetation index by the utilization of the plant energy ( chlorophyll ) for examining the reliability of satellite data and grasps the transition of the natural environment using the result. According to result of analysis, there were NDVI and mutual relationship on chlorophyll, and luminance compensation of NDVI was effective for all area. In vegetation transition, there were no luminance compensation and relation, and there was a decrease of vegetation in area in south and north. The reason was a result by the artificial and natural effect. This analysis is an effective method in order to confirm the change of specific vegetation.

• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.3
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• pp.11-25
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• 2013

This study aims on finding a direction of desirable space organization of future elementary school in Korea by analyzing current status of space organization of elementary school in Japan. In this study comparison and analysis of curriculum of Korea and Japan, facility standards on national level and standards of national subsidy, current status of number of schools and students, transition of changes in facility area of elementary school for last 10 years are included. In Korea and Japan each 7 elementary schools which were constructed after 2007 and are good in space organization and school planning are selected. The comparison and analysis of satisfaction level on physical educational conditions and facilities such as current status of space organization and how to use them are conducted in this study. The contents of analyzing space organization are 'entry and placement, outdoor space', 'space program' and 'phase structure and organization of unit space'.

• Korean Journal of Materials Research
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• v.33 no.8
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• pp.344-351
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• 2023

Cesium lead iodide (CsPbI₃) with a bandgap of ~1.7 eV is an attractive material for use as a wide-gap perovskite in tandem perovskite solar cells due to its single halide component, which is capable of inhibiting halide segregation. However, phase transition into a photo inactive δ-CsPbI₃ at room temperature significantly hinders performance and stability. Thus, maintaining the photo-active phase is a key challenge because it determines the reliability of the tandem device. The dimethylammonium (DMA)-facilitated CsPbI₃, widely used to fabricate CsPbI₃, exhibits different phase transition behaviors than pure CsPbI₃. Here, we experimentally investigated the phase behavior of DMA-facilitated CsPbI₃ when exposed to external factors, such as heat and moisture. In DMA-facilitated CsPbI₃ films, the phase transition involving degradation was observed to begin at a temperature of 150 ℃ and a relative humidity of 65 %, which is presumed to be related to the sublimation of DMA. Forming a closed system to inhibit the sublimation of DMA significantly improved the phase transition under the same conditions. These results indicate that management of DMA is a crucial factor in maintaining the photo-active phase and implies that when employing DMA designs are necessary to ensure phase stability in DMA-facilitated CsPbI₃ devices.

• Korean Journal of Childcare and Education
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• v.15 no.6
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• pp.21-40
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• 2019

Objective: The purpose of this study is to find the tendencies and differences of mother's child-rearing anxiety before and after their children enter into elementary school, to analyze the factors influencing child-rearing anxiety at each time, and thereby to seek a support plan at the time of transition. Methods: The subjects of this study were 181 mothers who participated in two surveys which were conducted before and after their child entered into elementary school. Results: Firstly, mother's child-rearing anxiety before and after their children's entrance into elementary school was at a middle level, but increased significantly when they experienced their children's transition to elementary school. Secondly, mother's child-rearing anxiety, before their children's entrance into elementary school, was influenced by private education, the collection of educational information, cognitive ability, whether or not to develop a work status change plan, and birth order sequentially. Thirdly, child-rearing anxiety after their children's entrance into elementary school was significantly influenced by child-rearing anxiety before their children's entrance into elementary school and the mother's employment. Conclusion/Implications: This study is meaningful in the point that it suggested the necessity for the cooperation between multiple systems, such as systematic and stepwise parenting education, the importance of offering information to educational institutions and local governments, and for work- family support policy to prioritize children in order to support children's successful transition into elementary school.

• Human Ecology Research
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• v.52 no.5
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• pp.519-528
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• 2014

This study explores how the main variables of youth going through a transition period (parents' nurturing behavior, the youth's self-esteem and ego resilience, the peer group relationships) affect the youth's school adjustment. It also analyzes the effects of theses variables on the youth's dependence on cell phones, which are considered a necessity in modern society. This research is verified by using a structure model verification method based on data from the Korean Children Youth Panel Study. According to the research, first, 1st-year students in middle school show better adjustment to their school life and less dependence on cell phones when they have a stronger sense of self-esteem and ego resilience; further, it is revealed that cell phone dependence has an indirect influence on the school life of these children. Second, they tend to show better adjustment to their school life and less dependence on cell phones when their parents' nurturing behaviors are more positive. Third, these children tend to depend more on cell phones when they have a positive peer group relationship, Moreover, cell phone dependence has an indirect influence on their school life. When considering the impact of cell phone to youth in modern society, need to prepare proper training program for correct uses and preventing from addiction.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.230-235
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• 2007

In the early neonatal period, the neonate is challenged by the loss of the placental calcium transport and manifests a quick transition, from an environment in which PTHrP plays an important role to a PTH- and 1,25-dihydroxyvitamin D-controlled neonatal milieu. Disturbances in mineral homeostasis are common in the neonatal period, especially in premature infants and infants who are hospitalized in an intensive care unit. In many cases these disturbances are thought to be exaggerated responses to the normal physiological transition from the intrauterine environment to neonatal independence. Some disturbances in calcium and phosphate homeostasis are the result of genetic defects, which in many instances can now be identified at the molecular level. Although fetus develop remarkably normally in the presence of maternal calcium, PTH and vitamin D deficiency, the neonates demonstrate abnormalities that are consequences of the prior abnormal maternal calcium homeostasis. Evaluation and management of hypocalcemia and hypercalcemia in neonate requires specific knowledge of perinatal mineral physiology and the unique clinical and biochemical features of newborn mineral metabolism.

• Ocean Systems Engineering
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• v.6 no.2
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• pp.191-201
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• 2016

Stern bearing is a key component of marine propulsion plant. Its environment is diverse, working condition changeable, and condition severe, so that stern bearing load is of strong time variability, which directly affects the safety and reliability of the system and the normal navigation of ships. In this paper, three affecting factors of the stern bearing load such as hull deformation, propeller hydrodynamic vertical force and bearing wear are calculated and characterized by random theory. The uncertainty mathematical model of stern bearing load is established to research the relationships between factors and uncertainty load of stern bearing. The validity of calculation mathematical model and results is verified by examples and experiment yet. Therefore, the research on the uncertainty load of stern bearing has important theoretical significance and engineering practical value.

• Tribology and Lubricants
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• v.20 no.2
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• pp.91-96
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• 2004

Wear behavior of self-mated stainless steels in NaCl solution has been investigated. The experiment was done in the corrosive liquid of which NaCl concentration of $0\~3\%$ and temperature of $15\~90^{\circ}C$. Two kinds of wear type were observed: one is 'severe wear' type which shows gradually increasing wear volume with increasing sliding distances, the other is 'mild wear' type which shows change of wear rate from high value to low at transition distance. The specific wear rate in severe wear type was not sensitive to the liquid temperature and concentration of NaCl but stable at value of $1\times10^{-3}\;mm^3$ approximately.

• Current Photovoltaic Research
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• v.3 no.2
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• pp.61-64
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• 2015

In solar industry, numerous researchers reported about cold spray method among various electrode formation technic, but there are no known a bonding mechanism of metal powder. In this study, a cross-section of copper electrode formed by cold spray method was observed and heterogeneous phase between silicon substrate and copper electrode was analyzed using morphology observation technic. SEM and TEM analysis were performed to analyze a crystallinity and distribution shape of heterogeneous copper phase. Molecular dynamics simulation was performed to calculate glass transition temperature of copper metal. In the result, amorphous copper phase was observed near interface between silicon substrate and metal electrode. The results of the molecular dynamics simulation show that an amorphous copper phase could be formed at a temperature below the melting point of copper because cold spraying resulted in a lower glass transition temperature.

• 한국전기화학회:학술대회논문집
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• 2003.11a
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• pp.141-151
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• 2003

The electrochemical activity of the olivine type $LiMPO_4$ (M=transition metals) cathodes strongly depends on various factors, e.g., the transition metal element M, perturbative doping of the supervalent cations into Li site, composite formation with conductive additives, state of charge/discharge, and particle size and its geometries, etc. This is, therefore, an important issue of interdisciplinary between electrochemistry and solid state science towards practical applications. In order to shed light on this interesting but complicated issue with the transport properties and crystallographic aspects, systematic discussion will be made with the review of our recent publications; (1) first principle derivation of the electronic structures, (2) crystallographic mapping of the selected solid solutions, (3) quantitative elucidation of the electron-lattice interaction, (4) spectroscopic detection of the local environment with Mossbauer and EXAFS, (5) synthetic optimization of the electrode composite, and (6) electrochemical evaluation of the reaction kinetics, particularly on M = Fe, Mn.