• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.187-190
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• 2001

The poly(vinyl alcohol) (PVA) fiber is recognized as the best candidate because of its good machanical properties together with excellent resistance to alkalis[1-5]. PVA cannot be prepared by the direct polymerization due to tautomerism of vinyl alcohol monomer. Thus PVA is obtained by the saponification of poly(vinyl ester) like poly(vinyl acetate) (PVAc). (omitted)

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.172-175
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• 2004

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1193-1197
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• 2006

The novel oligomers were synthesized by Grignard reaction, the suzuki coupling reaction, etc. The oligomers were characterized by Infrared (IR), Mass spectrometer (MS). Their thermal properties were investigated by differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). The new oligomers showed high thermal stability above $300^{\circ}C$.

• Applied Microscopy
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• v.45 no.2
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• pp.89-94
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• 2015

This article briefly reviews the results of recently reported research on high-temperature Pb-free solder alloys and the research trend for characterization of the interfacial reaction layer. To improve the product reliability of high-temperature Pb-free solder alloys, thorough research is necessary not only to enhance the alloy properties but also to characterize and understand the interfacial reaction occurring during and after the bonding process. Transmission electron microscopy analysis is expected to play an important role in the development of high-temperature solders by providing accurate and reliable data with a high spatial resolution and facilitating understanding of the interfacial reaction at the solder joint.

• Journal of Engineering Education Research
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• v.13 no.5
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• pp.15-19
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• 2010

Upon request from the Tokushima Prefectural Senior High School of Science and Technology, two faculty staff members and eight students of The University of Tokushima visited the high school and set up a chemistry laboratory class for 59 students. Since the participating senior high school students were freshmen, four simple, safe and visual experiments were selected: 1) Water purification, 2) Surface modification, 3) Briggs-Rauscher reaction, and 4) Polymer synthesis and characterization. All experiments received a favorable reception as a follow-up questionnaire verified. Since the high school students enjoyed the experiments it is hoped that the results will strengthen the students' interest in chemistry. It was good opportunity for the observers; they recognized the difficulty of teaching students.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.2
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• pp.221-233
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• 2011

The purpose of this research was made to suggest the improvement for problems of indication subject of Fisheries & Maritime High School teacher's certificate issued by the operation of the 7th national curriculum in 2000. After analyzing the integrated indication subjects related with fisheries & Maritime high school, among the middle school teacher's 24 subjects of industrial world, the problems and improvements can be arranged as followed. Firstly, the subjects of fisheries & Maritime high school teacher's certificates are fishing industry, aquiculture, sailing, engine and freezing and new subjects are ocean shipping and ocean logistics. Because the teacher's certificate was changed to integrated indication subjects, there were problems of teacher cultivation, teacher hiring, etc. So, in the actual field of school, teacher cultivating university and related department are necessary to strengthen high-quality majoring education/subjects and practical education as well as need to establish teacher cultivating system by teacher cultivating organization's evaluation system and teacher cultivating education program related by differentiation and easiness of majoring characterization. Secondly, teacher cultivating for new departments and new subjects can apply related major system, free major system, etc. Thirdly, if professional high schools find majoring areas whose content is same one another and introduce common indication subject system, it will be helpful to improve the quality of teachers, teacher certification examination, etc. of professional area.

• Applied Microscopy
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• v.51
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• pp.7.1-7.9
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• 2021

Neuromorphic systems require integrated structures with high-density memory and selector devices to avoid interference and recognition errors between neighboring memory cells. To improve the performance of a selector device, it is important to understand the characteristics of the switching process. As changes by switching cycle occur at local nanoscale areas, a high-resolution analysis method is needed to investigate this phenomenon. Atomic force microscopy (AFM) is used to analyze the local changes because it offers nanoscale detection with high-resolution capabilities. This review introduces various types of AFM such as conductive AFM (C-AFM), electrostatic force microscopy (EFM), and Kelvin probe force microscopy (KPFM) to study switching behaviors.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1210-1213
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• 2006

The effect of surface treatment on CNT cathodes used in field emission displays was investigated. A liquid method using a polymer-based organic solution and a mechanical method were applied. The liquid method, using PVA(polyvinyl alcohol) showed high potential compared to the mechanical adhesive taping and rolling method used in the fabrication of CNT cathodes for large-sized field emission displays with high emission uniformity and a low cost.

• ETRI Journal
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• v.37 no.2
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• pp.317-327
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• 2015

A reliable analysis of consumer preference from a large amount of purchase data acquired in real time and an accurate customer characterization technique are essential for successful direct marketing campaigns. In this study, an optimal segmentation of post office customers in Korea is performed using a subspace projection-based clustering method to generate an accurate customer characterization from a high-dimensional census dataset. Moreover, a traditional temporal mining method is extended to an algorithm using the MapReduce framework for a consumer preference analysis. The experimental results show that it is possible to use parallel mining through a MapReduce-based algorithm and that the execution time of the algorithm is faster than that of a traditional method.

• Bulletin of the Korean Mathematical Society
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• v.45 no.2
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• pp.221-230
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• 2008

In the study of normal (complex analytic) surface singularities, it is interesting to investigate the invariants. The purpose of this paper is to give a characterization of the vanishing of ${\delta}_2$. In [11], we gave characterizations of minimally elliptic singularities and rational triple points in terms of th.. second plurigenera ${\delta}_2$ and ${\gamma}_2$. In this paper, we also give a characterization of rational triple points in terms of a certain computation sequence. To prove our main theorems, we give two formulae for ${\delta}_2$ and ${\gamma}_2$ of rational surface singularities.