• Progress in Superconductivity
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• 제5권2호
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• pp.124-127
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• 2004

Many of research efforts have been focused on the improvement of critical current density (Jc) of silver-sheathed Bi-2223 tapes far practical applications. In this study, the transformation of Bi-2212 phase was investigated, which was transformed to orthorhombic from tetragonal through pre-annealing during powder packing and drawing process. The relationship between hardness of Bi-2212 orthorhombic phase and workability of Bi-2223/Ag tape was investigated. Bi-2223 superconducting wires with 55 filaments were fabricated by stacking and drawing process with different heat-treatment histories. Before rolling process, round wires were pre-annealing at 76$0^{\circ}C$ and in a low oxygen partial pressure. We confirmed that pre-annealing step was to transform to Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases. However the breakages were created at Ag-alloy clad during rolling for pre-annealed Bi-22231Ag tapes. Several pre-annealing scenarios were introduced to reduce the breakages during rolling process. Microstructure and critical current density of pre-annealed Bi-2223 superconducting tapes were investigated. We could achieve proper pre-annealing conditions for Ag-alloy clad Bi-2223 superconducting tapes.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2353-2358
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• 2017

A femtosecond laser pre-annealing process based on indium zinc oxide (IZO) thin-film transistors (TFTs) is fabricated. We demonstrate a stable pre-annealing process to analyze surface structure change of thin films, and we maintain electrical stability and improve electrical performance. Furthermore, dynamic electrical characteristics of the IZO TFTs were investigated. Femtosecond laser pre-annealing process-based IZO TFTs exhibit a field-effect mobility of $3.75cm^2/Vs$, an $I_{on}/I_{off}$ ratio of $1.77{\times}10^5$, a threshold voltage of 1.13 V, and a subthreshold swing of 1.21 V/dec. And the IZO-based inverter shows a fast switching behavior response. From this study, IZO TFTs from using the femtosecond laser annealing technique were found to strongly affect the electrical performance and charge transport dynamics in electronic devices.

• 한국분말재료학회지
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• 제21권2호
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• pp.142-146
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• 2014

Fundamental experiences have been studied for development of pre-treatment process of Sn by-products such as solders. Dry and wet separation/recovery processes were considered by the differences of physical properties. The by-products, which are analyzed by solder metal and oxides. The metal and oxide were simply separated by dry ball-milling process for 12 hours, after that recovery metal powder might be reusable as lead or lead-free solders. In terms of wet separation process, samples were dissolved in $HNO_3+H_2O_2$ and the precipitation were analyzed by $SnO_2$. Overall efficiency of recovery might be increasing via developing simple pre-treatment process.

• 품질경영학회지
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• 제44권3호
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• pp.587-600
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• 2016

Purpose: This paper evaluates the performance of the pre-control(PC), an alternative to statistical process control techniques and compares with a control chart considering the tolerance of process. Methods: The previous studies for PC have drawbacks that PC with two linked stages, qualification and running, are discussed separately and independently. Hence this paper analyzes the performance of PC by integrating two stages. Results: Average outgoing quality limits to grasp the outcome of PC are provided by computational results for two process capability indexes, $C_p$ and $C_{pk}$ and the usefulness of PC from comparative experiments with modified control charts is commented. Conclusion: Helpful guidelines for quality managers to apply PC in practice and areas of process for PC to be more benefit are presented.

• 한국축산식품학회지
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• 제38권1호
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• pp.162-171
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• 2018

The purpose of this study was to investigate the quality of duck ham formulated with duck skin through the pre-emulsification process. The experiments to investigate the quality characteristics of duck ham were carried out to measure proximate composition, cooking loss, emulsion stability, pH, color, texture profile analysis, apparent viscosity, and sensory characteristics. Duck ham was prepared with various ratios of duck skin in pre-emulsion as follows: Control (duct skin 30%), T1 (duck skin 20% + pre-emulsified duck skin 10%), T2 (duck skin 15% + pre-emulsified duck skin 15%), T3 (duck skin 10% + pre-emulsified duck skin 20%), and T4 (pre-emulsified duck skin 30%). As the ratio of duck skin to pre-emulsified skin changed, the quality of duck ham in terms of moisture content, fat content, cooking loss, emulsion stability, lightness, textural analysis, apparent viscosity, and overall acceptability changed. The moisture content of T2 was the highest (p<0.05) and that of the control and T4 was the lowest (p<0.05). The fat content of control was higher than all treatments (p<0.05). T2 had the lowest values in cooking loss, total expressible fluid, fat separation, hardness, springiness, and gumminess (p<0.05). The score of overall acceptability of all treatments with pre-emulsified skin was higher than control (p<0.05). Therefore, the pre-emulsification process can improve the quality characteristics of duck ham and 1:1 ratio of duck skin and pre-emulsified skin was the proper ratio to improve the quality characteristics of duck ham.

• 한국초등과학교육학회지:초등과학교육
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• 제26권5호
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• pp.489-498
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• 2007

This study focuses on surveying and examining the beliefs of elementary pre-service and in-service teachers about science and science education. The instrument consisted of 21 items about science and science education on a 5-Likert scale(score range from 1 to 5). The one contained science knowledge and scientific invention, and the other contained science teacher, learning science and science learning and teaching. Data were collected from 76 pre-service and 96 in-service elementary teachers(24 male and 148 female). The elementary pre-service and in-service teachers had higher level belief about that science knowledge should be acquired by sequential scientific process, the beliefs of in-service teachers was more explicit than those of pre-service teachers. They had beliefs to educate learners by providing scientific joyfulness and sequential scientific process. But, in-service teachers had difficulties to perform scientific process-based activities. It is necessary to provide scientific experiences to understand the nature of science in pre-service and in-service programs.

• 대한가정학회지
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• 제36권5호
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• pp.167-185
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• 1998

The propose of this study was to develop the new pre-parent education program for couples in i=transition to parenthood. This program was consisted three process, total eight sessions. The first process(the basic process) has two sessions. This process was designed to understand the whole parenthood, and to cope the role strain in early parenting period. The second process has three sessions, designed to enrich the marital relationship before the baby was born. And the Third process(parent-child process) has three sessions, too. Especially in last sessions, parent can exercise infant caring, and adapt fetus to their family member.

• 시스템엔지니어링워크숍
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• 통권6호
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• pp.81-85
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• 2005

• Environmental Engineering Research
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• 제19권1호
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• pp.59-66
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• 2014

The aim of this study was to assess the effect of pre-aeration on sludge solubilization and the behaviors of nitrogen, dissolved sulfide, sulfate, and siloxane. The results of this study showed that soluble chemical oxygen demand in sewage sludge could be increased through pre-aeration. The pre-aeration process resulted in a higher methane yield compared to the anaerobic condition (blank). The pre-aeration of sewage sludge, therefore, was shown to be an effective method for enhancing the digestibility of the sewage sludge. In addition, this result confirms that the pre-aeration of sewage sludge prior to its anaerobic digestion accelerates the growth of methanogenic bacteria. Removal rates for $NH_3$-N and T-N increased simultaneously during pre-aeration, indicating simultaneous nitrification and denitrification. The siloxane concentration in sewage sludge decreased by 40% after 96 hr of pre-aeration; in contrast, the sulfide concentration in sewage sludge did not change. Therefore, pre-aeration can be employed as an efficient treatment option to achieve higher methane yield and lower siloxane concentration in sewage sludge. In addition, reduction of nitrogen loading by pre-aeration can reduce operating costs to achieve better effluent water quality in wastewater treatment plant and benefit the anaerobic process by minimizing the toxic effect of ammonia.

• 문화기술의 융합
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• 제9권5호
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• pp.319-327
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• 2023

국가수준 교육과정의 기본적 접근방법이 내용중심에서 역량중심으로 전환됨에 따라 과정중심 평가의 중요성이 강조되고 있다. 이에 따라 교사의 평가자로서의 역할 역시 과정중심 평가에 초점이 맞추어지고 있으며, 임용을 앞둔 예비교사들에게도 과정중심 평가의 역량을 개발하는 것은 중시되고 있다. 본 연구는 예비교사의 과정중심 평가 역량개발을 지원하기 위하여 교원양성대학 교과목을 개선하여 운영하고 그 효과를 탐색하는 것을 목적으로 한다. 연구 목적을 달성하기 위하여 C 교육대학교에서 운영되는 한 교과목을 PBL 중심으로 재구성하여 운영하고 과정중심 평가의 관점에서 예비 초등교사에게 미치는 효과를 분석하였다. 수강생들의 프로젝트 결과물, 관찰노트, 수강생 반응 등의 자료 분석을 통해 PBL 활동 경험이 예비 초등교사들의 과정중심 평가에 대한 인식과 이해에 긍정적인 영향을 미친다는 점을 확인할 수 있었다. 이는 PBL과 같이 과정중심 평가관이 반영된 학습 경험을 제공하는 것이 예비교사의 과정중심 평가 역량 개발에 중요한 역할을 할 수 있다는 점을 시사해준다. 본 연구의 결과는 예비교사의 과정중심 평가역량 개발을 위한 교원양성대학의 교육과정과 수업의 혁신을 위한 구체적 방법을 제시해줄 수 있을 것이다.