• 열처리공학회지
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• 제7권1호
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• pp.44-52
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• 1994

In order to investigate the effect of tempring treatment on the mechanical properties of ausformed martensite in Fe-30%Ni-0.35%C alloy, the hardness, yield strength and elongation were examined by tensile test. 1. The strength of deformed austenite in Fe-30%Ni-0.35%C alloy was increased due to the work hardening induced from the dislocation density increased during deformation. The strength of ausformed martensite was increased because of defects inherited from deformed austenite by martensitic transformation. 2. The ductility of ausformed martensite was shown a nearly constant values independent of deformation degrees because of the interaction of multiple factors such as increased retained austenite, formation of void and decrement of twin in ausformed martensite. 3. The strength of ausformed martensite by tempering treatment was shown a little decrement up to $340^{\circ}C$, especially showed remarkable softening resistance in higher deformation degrees. 4. Virgin martensite and ausformed martensite were shown a maximum yield strength by clustering in tempering at $100^{\circ}C$ and above $100^{\circ}C$, yield strength was very small decreased due to the decrement of solute carbon by the destruction of clustering. 5. The decomposition of retained austenite was not shown up to $450^{\circ}C$ in ausformed martensite with tempering treatment, and the matrix was rapidly softening because of the decomposition of martensite and the formation of reversed austenite with tempering above $400^{\circ}C$.

• 한국CDE학회논문집
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• 제10권6호
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• pp.444-454
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• 2005

Recently, the requirements of multi-resolution models of a solid model, which represent an object at multiple levels of feature detail, are increasing for engineering tasks such as analysis, network-based collaborative design, and virtual prototyping and manufacturing. The research on this area has focused on several topics: topological frameworks for representing multi-resolution solid models, criteria for the level of detail (LOD), and generation of valid models after rearrangement of features. As a solution to the feature rearrangement problem, the new concept of the effective zone of a feature is introduced in the former part of the paper. In this paper, we propose a feature-based non-manifold modeling system to provide multi-resolution models of a feature-based solid or non-manifold model on the basis of the effective feature zones. To facilitate the implementation, we introduce the class of the multi-resolution feature whose attributes contain all necessary information to build a multi-resolution solid model and extract LOD models from it. In addition, two methods are introduced to accelerate the extraction of LOD models from the multi-resolution modeling database: the one is using an NMT model, known as a merged set, to represent multi-resolution models, and the other is storing differences between adjacent LOD models to accelerate the transition to the other LOD. We also suggest the volume of the feature, regardless of feature type, as a criterion for the LOD. This criterion can be used in a wide range of applications, since there is no distinction between additive and subtractive features unlike the previous method.

• 한국지구과학회지
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• 제39권5호
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• pp.403-418
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• 2018

This study conducted synoptic and mesoscale analyses to understand the cause of Japan Tsukuba tornado development, which occurred at 0340 UTC 6 May 2012. Prior to the tornado occurrence, there was a circular jet stream over Japan, and the surface was moist due to overnight precipitation. The circular jet stream brought cold and dry air to the upper-level atmosphere which let strong solar radiation heat the ground with clearing of sky cover. A tornadic supercell developed in the area of potentially unstable atmosphere. Sounding data at Tateno showed a capping inversion at 900 hPa at 0000 UTC 6 May. Strong insolation in early morning hours and removal of the inversion instigated vigorous updraft with rotation due to vertical shear in the upper-level atmosphere. This caused multiple tornadoes to occur from 0220 to 0340 UTC 6 May 2012. When comparing Tateno's climatological temperature and dew-point temperature profile on the day of event, the mid-level atmosphere was moister than typical sounding in the region. This study showed that tornado development in Tsukuba was caused by a combination of (a) topography and potential vorticity anomaly, which increased vorticity over the Kanto Plain; (b) vertical shear, which produced horizontal vortex line; and c) thermal instability, which triggered supercell and tilted the vortex line in the vertical.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.866-874
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• 2014

본 논문은 사례연구로서 '시장 프로젝트' 수업분석을 통하여 유아교육 현장의 기존 교육과정을 재구성함으로써 지속가능발전교육으로 전환이 가능한 지 알아보기 위하여 실시되었다. 이를 위해 유아교육기관에서 일반적으로 수행하는 시장놀이 행사를 시장 프로젝트로 전환하여 수업을 실시하였다. 본 연구는 충남 K시 H 유치원 만 5세 2학급에서 이루어졌다. 교사의 수업일지 및 교사와의 면담을 통해 자료를 수집하고, 프로젝트 과정을 분석하였다. 본 연구는 기존의 유아교육과정 재구성을 통해 지속가능발전교육이 이루어질 수 있음을 나타내주었다. 프로젝트 진행 과정에서 지속가능발전교육의 기능발달이 이루어졌고, 사회적 환경적 경제적 영역의 핵심내용을 반영하였다. 또한 간학문적 통합교육이 이루어졌으며, 학습자 참여 의사결정이 이루어졌다. 이야기나누기, 토의, 견학, 역할놀이 등 다양한 교육방법이 수업에 활용되었다. 이에 따라 지속가능발전교육을 위한 교육방법으로 프로젝트 수업이 적절함을 확인하였다.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.753-759
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• 2014

본 논문은 전문대학 비서 관련학과의 융합 형 인재 개발을 위한 표준화 역량기반과 이원적 전공기반의 다중 기반에 근거한 교과과정체계 수립을 목적으로 한다. 이를 위하여 수도권 비서관련 학과 분석을 통해 요소능력을 추출, 역량계열화 및 그룹핑을 토대로 도출한 역량군과 NCS에서 제시하고 있는 표준화 역량을 기저로 현행 교과의 역량 표준화 기반을 시안적으로 제안하고 이를 현행 H여대 비서 인재과의 이원적 교과과정과 교직시킴으로써 다중기반 교과과정 체계를 수립하고자 하였다. 이는 비서 분야와 경영, 회계, 행정 기타 분야가 서로 융합하여 이원적으로 이루어진 여타 비서관련 학과의 교과과정 수립에 시사점을 줌으로써 역량기반 융합 형 인재개발의 프레임웍을 이룰 수 있는 하나의 제언이 될 것이라 생각한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.93-93
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• 2010

Semiconductor nanocrystal quantum dots (NQDs) have recently attracted considerable interest for use in photovoltaics. Band gaps of NQDs can be tuned over a considerable range by varying the particle size thereby allowing enhance absorption of solar spectrum. NQDs, synthesized using colloidal routes, are solution processable and promise for a large-area fabrication. Recent advancements in multiple-exciton generation in NQD solutions have afforded possible efficiency improvements. Various architectures have attempted to utilize the NQDs in photovoltaics, such as NQD-sensitized solar cell, NQD-bulk-heterojuction solar cell and etc. Here we have fabricated CdSe NQDs with the band gap of 1.8 eV to 2.1 eV on thin-layers of p-type organic crystallites (1.61 eV) to realize a donor-acceptor type heterojuction solar cell. Simple structure as it was, we could control the interface of electrode-p-layer, and n-p-layer and monitor the following efficiency changes. Specifically, surface molecules adsorbed on the NQDs were critical to enhance the carrier transfer among the n-layer where we could verify by measuring the photo-response from the NQD layers only. Further modifying the annealing temperature after the deposition of NQDs on p-layers allowed higher conversion efficiencies in the device.

• 대한교통학회지
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• 제17권1호
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• pp.187-196
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• 1999

본 연구의 목적은 국내에 설치가 확대되고 있는 자동과속단속시스템의 교통안전 개선 메커니즘을 밝히자는 것이다. 이를 위해서 첫째, 시스템 운영이 교통류 특성에 미치는 영향을 분석하고, 둘째, 교통류 특성 변수와 안전도와의 모형을 설정하였다. 1997년부터 운영된 32대 시스템의 1년간 운영효과를 분석한 결과 교통사고 28%, 사망자수 60%가 감소한 것으로 나타났다. 시스템 설치지점의 교통류 특성변화를 분석한 결과 평균속도, 속도분산, 짧은 차두시간 비율 등의 변수가 현저하게 감소하였다. 교통사고빈도와 교통류 특성 변수간의 회귀모형을 설정한 결과 평균속도, 속도분산, 과속교통량이 유의한 설명변수로 나타났다. 따라서 자동과속단속시스템의 교통안전도의 개선 메커니즘은 (1)단속시스템 도입 $\longrightarrow$(2)교통류 특성 개선 $\longrightarrow$ (3)안전도개선이란 과정에 의하여 달성된다는 가설을 입증하였다. 본 연구는 ITS의 도입이 교통안전에 미치는 효과를 계량적으로 평가할 수 있는 토대가 될 것이며 동적 교통안전(operational traffic safety)이란 측면에서 교통안전 연구에 대한 새로운 시각을 제공하는데 의의가 있다고 하겠다.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.127-134
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• 2021

This study aims to determine the role of innovative capabilities as a mediator in analyzing entrepreneurial marketing's effect on sustainable competitive advantage in food and beverage micro-, small-, and medium- enterprises (MSMEs). Data was obtained from a food and beverage store manager in Tangerang City, comprising 119 samples. Furthermore, the G⁎Power, a tool used to calculate statistical power analysis for various t-tests, F tests, χ2 tests, z tests, and several exact tests, was used to determine the number of research samples, the α error probability of 5%, and 3 variables. The data collection method used questionnaires with Likert Scale 1-5 to indicate strongly disagree to strongly agree. To analyze data, we used Path Analysis supported by SmartPLS statistics software. Path analysis is a form of multiple regression statistical analysis that is used to evaluate causal models by examining the relationships between a dependent variable and two or more independent variables. It aims to provide estimates of the magnitude and significance of hypothesized causal connections between sets of variables. The data processing process took place in two stages, namely the estimation model testing with validity and reliability, and the structural model testing to decide the impact or correlation between variables utilizing the t-test. The result showed a positive and significant effect of entrepreneurial marketing to innovative capability and competitive advantage through the innovative capability of MSMEs.

• 융합정보논문지
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• 제9권1호
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• pp.1-11
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• 2019

본 연구는 J지역, H대학교 치위생학과 학생 322명을 대상으로 문제해결능력과 비판적 사고 성향과의 관계를 규명하기 위해 2018년 7월 1일부터 8월 30일까지 조사하였다. 수집된 자료는 SPSS 18.0 프로그램을 사용하여 일원배치분산분석, 피어슨의 상관분석, 회귀분석을 하였다. 기술통계 분석에 따라 비판적 사고 성향은 평균 3.36점 이었고, 문제 해결 능력은 평균 3.41점이었다. 상관분석 결과 비판적 사고 성향과 대상자의 문제해결능력은 통계적로 유의한 차이를 나타내었다(p<0.001). 유의미한 변수들은 전공만족도, 학업성적, 비판적 사고 성향을 포함하였고, 모형의 설명력은 52.2%였다. 치위생학과 학생들의 전공만족도, 학업성적, 비판적 사고 성향과과 문제해결능력을 향상시키는데 있어서는 교수학습방법과 교육과정개발, 교육환경의 변화가 필요하다고 본다.

• Nutrition Research and Practice
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• 제13권4호
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• pp.323-332
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• 2019

BACKGROUND/OBJECTIVES: The aim of this study was to analyze specific foods influencing absolute nutrient intake and between-person variations of nutrient intake among Korean preschoolers. SUBJECTS/METHODS: This study included 2,766 participants aged 1-5 years in the 2009-2013 Korea National Health and Nutrition Examination Surveys. Dietary data were obtained from a 24-h dietary recall method. Major food sources of absolute nutrient intake were evaluated based on percent contribution of each food. To assess the contribution of specific foods to between-person variations in nutrient intake, stepwise multiple regressions were performed and cumulative $R^2$ was used. RESULTS: White rice and milk were main food sources of energy, protein, carbohydrate, phosphorus, iron, potassium, thiamin, riboflavin, and niacin. The percentage of fat contributed by milk was 21.3% which was the highest, followed by pork, soybean oil, and egg. White rice accounted for 25% and 40% of total variability in total energy and carbohydrate intakes, respectively. About 39% of variation in calcium intake was explained by milk while 40% of variation in phosphorous intake was explained by cheese. The top 10 foods contributing to between-person variations in nutrient intakes were similar with food items that mainly contributed to absolute nutrient intakes. The number of foods explaining 90% of absolute amounts of nutrient intakes varied from 28 for vitamin A to 80 for iron. CONCLUSIONS: This study identified specific foods that contributed to absolute nutrient intakes and between-person variations in nutrient intakes among Korean preschoolers. Our findings can be used to develop dietary assessment tools and establish food-based dietary guidelines for young children.