• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.393-397
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• 2012

We report a new route to synthesize high quality zinc blende CdS and ZnS nanocrystals in noncoordinating solvent 1-octadecene, using dodecanethiol (DDT) molecules as both the sulfur source and surface capping ligands. Different reaction temperatures and Cd(Zn)/DDT molar ratios were tested to optimize the synthesis conditions. Absorption photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) pattern, and transmission electron microscopy (TEM) were used to characterize assynthesized nanocrystals. The narrow half width at the half-maximum on the long wavelength side of the firstexcitonic absorption peak and TEM images demonstrated nearly monodisperse size distributions of asprepared CdS, ZnS, and CdS/ZnS core/shell nanocrystals. Only trap emissions of the nanocrystals were detected when the amount of DDT was excessive, this came from the strong quenching effect of thiol groups on the nanocrystal surfaces. After overcoating with ZnS shells, band-gap emissions of CdS nanocrystals were partially recovered.

• Macromolecular Research
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• v.14 no.5
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• pp.524-529
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• 2006

New, thermally robust, arylenevinylene conjugated polymers, including poly(9,9-dioctylfluorenyl-2,7-vinylene) [poly(FV)] and poly[2-(3'-dimethyldodecylsilylphenyl)-1,4-phenylenevinylene] [poly(m-SiPhPV)], were synthesized and used for the fabrication of efficient photovoltaic cells. Bulk heterojunction photovoltaic cells fabricated by blending one of the polymers, [poly(FV)], [poly(m-SiPhPV)], and poly(FV-co-m-SiPhPV), with the fullerene derivative [6,6]-phenyl-$C_{61}$-butyric acid methyl ester (PCBM) were found to have a power conversion efficiency of up to 0.038%..

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.793-800
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• 2014

The purpose of this study is to analyze the perception and need of the early childhood education field on authentication of teaching materials and implements for young children. To achieve this, a survey was carried out on 350 teachers and directors in Daejeon-based kindergartens and child-care centers from September 21 to September 30, 2013. The results of the analysis are as follows. First, 59.4% of them thought that it needed the evaluation authentication of teaching materials and implements for young children. 32.9% of them had a high perception of the early childhood education field. 39.4% of them had high need of the early childhood education field. And 45.1% of them expected a high effect of introducing the evaluation authentication system of teaching materials and implements for young children. Second, most of them had the highest need of the evaluation authentication of teaching materials and implements for young children in terms of education, followed by function and field. And most of them placed the highest emphasis on social development, safety and language in terms of education, function and field, respectively. Consequently, the use of teaching materials and implements, which the social development and safety in terms of education and function are respectively evaluated and authenticated by the diversity of teaching materials and implements for young children, has need of the high evaluation and authentication of teaching materials and implements that can guarantee the quality when young children use a lot of experiment and observation implements such as block play, reading materials, manipulating materials, making implements.

• Smart Media Journal
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• v.5 no.2
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• pp.24-32
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• 2016

Recently, the development of electronic teaching materials and the demand of digital learners have led the needs on the education contents that replace learning from character information and the change of an information design method for this. Chinese character education in the traditional schooling mainly focuses on writing and memorization (semantic memory). This way that the stories do not exist has brought the learners' recognition that Chinese character is difficult to learn. Meanwhile, for a language study such as English, cross-media development between printed materials and audio-visual materials has been actively introduced. The method that extends episode memories along with memorization through a story is widely used. Therefore, this content suggests a prototype, which is broken away from an existing way of learning Chinese character that mainly focuses on writing, one sided instruction and information cramming. This makes learners learn through a story from printed materials and animation. Furthermore, it suggests a method that extends episode memories through Chinese education contents based on IoT explaining the principle of Chinese character by combining IT technology (information and communications, IoT) and education contents on block toys.

• Journal of Korean Home Economics Education Association
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• v.26 no.1
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• pp.55-68
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• 2014

The study aims to develop teaching and learning media to raise up learners' interests and understanding during clothing class by providing a clothing swatch materials and its guide for applying to the unit of clothing in technology and home economics subject in middle school. To do so, clothing swatch materials, study sheet and guide were developed, applied and then analyzed for their effects. In this study, in order to figure out effects of class using clothing swatch materials on learning interest, learning necessity, learning understanding and academic achievements, the experiment was conducted for comparing and analyzing the learning interest, learning acceptance attitude and academic achievement between experiment group with using clothing swatch materials and control group without using the materials. The results of the study are as follows: First, the experiment group using clothing swatch materials shows higher learning interest than the control group without materials. Second, the experiment group showed higher learning acceptance attitude than the control group. Third, the experiment group achieved higher academic accomplishments than the control group.

• Hwankyungkyoyuk
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• v.16 no.2
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• pp.65-73
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• 2003

This study has an aim to construct a reference frame to analyze the appropriateness of environmental education(EE) materials of elementary schools, and to search the basic direction of the scheme for analysis. In addition, this study has an aim to induce what the results of this analysis suggests for the development and reconstruction of EE materials. It was analyzed how truly EE materials reflected contents selected as an analysis scheme, after grasping practical use and features of textbooks, audio-visual materials, and a web-site that are typical materials in EE of elementary schools. The results in textbook analysis were that there were a human-centered environmentalism in the EE unit ("Environmentally Sound National Development", 5th Grade) of Social Studies. The result in analysis of audio-visual materials "Environmental Warrior, Zentaforce" of EBS, were that there are unhealthy environmentalism in that material. In other words, technology itself is considered as a almighty means to solve environmental problems. Finally, the result in web-site analysis were that the "Environmental Class" of Ministry of Environment did not have sound environmentalism. The above result of study shows us that the most important thing in developing and using the environmental education materials is to have sound environmental values and EE perspective, to evaluate EE material with various point of view, to judge its result, and to use it.

• Nuclear Engineering and Technology
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• v.52 no.1
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• pp.148-154
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• 2020

The radiation induced segregation of Cr at grain boundaries (GBs) in Ferritic/Martensitic steels was modeled assuming vacancy and interstitialcy diffusion mechanisms. In particular, the dependence of segregation on temperature and grain boundary misorientation angle was analyzed. It is found that Cr enriches at grain boundaries at low temperatures primarily through the interstitialcy mechanism while depletes at high temperatures predominantly through the vacancy mechanism. There is a crossover from Cr enrichment to depletion at an intermediate temperature where the Cr:Fe vacancy and interstitialcy diffusion coefficient ratios intersect. The bell-shape Cr enrichment response is attributed to the decreasing void sinks inside the grains as temperature rises. It is also shown that low angle grain boundaries (LAGBs) and special Σ coincidence-site lattice (CSL) grain boundaries exhibit suppressed radiation induced segregation (RIS) response while high angle grain boundaries (HAGBs) have high RIS segregation. This different behavior is attributed to the variations in dislocation density at different grain boundaries.

• BMB Reports
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• v.46 no.5
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• pp.244-251
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• 2013

Lignocellulosic materials are commonly used in bio-$H_2$ production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-$H_2$ production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to $H_2$ by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-$H_2$ production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized.

• Journal of the Korean Society of Food Culture
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• v.27 no.5
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• pp.434-444
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• 2012

The purpose of this study was to develop children-friendly education materials based on food replicas for the dietary education of lower grade elementary students. Through a literature review on current dietary problems and dietary education for children, five education themes were chosen: balanced diet, seasonal food, traditional food, noodle culture, and making instant noodles. A total of 304 key food items for food replicas were selected based on the themes: six basic food groups (113 items), balanced meals (37 items), dietary habits (74 items), spring foods (13 items), summer foods (17 items), autumn foods (16 items), winter foods (11 items), Korean traditional foods (52 items), Korean native noodles (18 items), noodles from foreign countries (19 items), and making instant noodles (46 items). Next, a food replica database was developed consisting of name of the food, picture, size, ingredient, recipe, reference, and attached code. Powerpoint slides and teaching plans for all education themes were developed utilizing the food replicas in order to raise interest and understanding of serving size and intake amount. This research provides a basis for the development of food replicas as effective dietary education materials for elementary students and their use in extra-curricular activities, after school programs, community health centers, or food companies.

• Journal of Korean language education
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• v.28 no.4
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• pp.221-244
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• 2017

The purpose of this study is to prepare educational contents and criteria for selecting advertisement materials by exploring the necessity of value system education in Korean culture education. Furthermore, the study aims to suggest advertisements that contain meaningful materials through the criteria among the public and commercial advertisements as of 2017. Advertisements have advantages in three aspects as they focus on current culture, cultural implications and the ease of teaching and learning. These advantages indicate the usefulness of advertisements in value education. Also, the research of Hofstede (2010), Kang (2007), and Kim et al. (2011) provide discussion regarding educational contents. Subsequently, the criteria for selecting advertisements are further developed as the main purpose of this study. The criterion are to consider the objectives of culture education, to take into account the learning situation, to find relevance between the contents of the advertisement and the contents for the value system education, and consider expressive methods of advertisements and extensibility to the activities. Next, advertisements were selected for core educational items and the list of 22 is presented according to the value system, educational contents and the criterion of the advertisements discussed in the above.