• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.25-26
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• 2007

At the time when nanostructured materials (NSMs) are becoming a major focus of materials research, the attention of researchers is turning more to their mechanical performance. In contrast with conventional coarse grained materials, which are either strong or ductile, but rarely both at the same time, it is expected that with NSMs both high strength and ductility can be achieved and confirmed by several experimental studies. In spite of the significant interest and efforts in the mechanical properties of NSMs, deformation mechanisms during plastic deformation as well as elastic deformation are not well established yet. In this talk, the deformation mechanisms of NSMs under various grain sizes, temperatures and strain rates were investigated. It is based on recent modelling that appears to provide a conclusive description of the phenomenology and the mechanisms underlying the mechanical properties of NSMs. Based on the theoretical model that provides an adequate description of the grain size dependence of elasticity and plasticity covering all grain size range from coarse down to the nanoscale, the tensile deformation response of NSMs, especially focusing on the deformation mechanisms was investigated.

• 한국농공학회지
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• 제39권3호
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• pp.128-137
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• 1997

In this study, examined influence of consolidation effect that had affected by location of pump inlet that was set collection well for drainage of pore water discharged by embankment on soft ground through the field test. The results of this study are summarized as follows; 1 Initial consolidation curve value were larger than theoritic value, the cause of these phenomena were thought influence of secondary consolidation and three dimensional strain of soft clay. 2. The settlement value of Hosino method was larger than that of Hyperbolic method, but settlement value of Hyperbolic method was accurate more than that of Hosino method in the prediction of settlement. 3. When pump inlet in collection well came down from GL+O.3m to GL-1.5m, settlement value increased about 10cm and when the ground water level was made insitu after pumping had completed , settlement was expanded about 7~8cm. So it is found that location change of pump inlet bad an influence on settlement remarkably. 4. If location of pump inlet in collection well for large scale estate or wide road site is lowered than original ground level, the settlement will be accelerated effectively, and at this stage automatic pump must be used in pumping.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.479-489
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• 2020

The purpose of this paper is to uncover whether and how contextual factors (information exchange, participation, trust in management, and training), relate to resistance to change. It also explores the mediating effect of perceived impact of change on the relations between contextual factors and resistance to change. This study is conducted in several manufacturing plants in food processing industry in Vietnam, which is implementing a top-down large-scale change - Lean transformation, adopting Total Productive Maintenance (TPM) program, to be specific. The findings suggest that all four contextual factors are negatively associated with resistance to change, in which training had the strongest impact. Also, the perceived change impact partially mediates the relationships between the four contextual factors and resistance to change. The practical implications of this paper are that employees who receive adequate, timely and useful information relating to change are less likely to show opposing behaviors towards change. Fostering trust in management among employees, and employee involvement in decision-making, also have a significant influence when addressing employee resistance to change. Employees who are well-trained, well-equipped with tools and knowledge about the change, are less likely to resist as they view the benefits of changes more significant than the risks.

• 건축역사연구
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• 제1권1호
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• pp.49-67
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• 1992

This study is an architectural investigation paper which has been investigated for 5 years from 1986 about commoner's traditional houses and village in southwestern island area of Korea. Man has lived in this area form the prehistoric age. But from 13C to 14C and in 16C most of people had left this islands by external invasion (Japan) and from 17C many people have lived in real earnest. This area did not have cultural interchange easily than inland area because of geographical conditions, Therefore, so far, many traditional factors have been handed down and especially, a good many commoner's traditional houses exist. The time of builging of these houses is mainly 19C and building shape of those days remains nearly as it is. About 450 houses have been investigated for 5 years. The composition of the houses is composed of Anchae (a centeral house), Sarangchae (an attached house of anchae) and Chukganchae (It has rest room and stores barnyard manure). Somtimes, Sarangchae was ommitted according to the circumstance of the house. Generally, the form of arrangement of house is divided into two shapes; One is 'ㅡ'shape which has only Anchae and the other is 'ㄱ' shape which has Anchae and Sarangchae. In the scale of the house, Anchae averages $41m^2$ and Sarangchae averages $27m^2$.

• 한국전자파학회논문지
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• 제27권2호
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• pp.131-137
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• 2016

본 논문에서는 지하에 매설된 관 주변에 발생한 지하 공동의 탐지를 위해 지하 탐사 레이다의 가능성을 모의실험으로 조사하였다. 실험 장치는 임펄스형 지하 탐사 레이다 시스템, xy 직교 좌표 로봇, 지하 매질을 채운 탱크, 금속관, 모의실험용 공동 모델로 구현하였다. 특히, 모의실험용 공동 모델은 공기로 채워진 지하 공동의 전기적 특성과 유사하면서 견고한 형상을 유지할 수 있는 스티로폼 ?과 볼을 포장해서 구성하였다. 대표적인 3가지 실험을 통해서 지하 탐사 레이다의 B-scan 자료를 획득하여 2차원 그레이 스케일 영상으로 가시화하였다. B-scan 영상들의 비교를 통해 지하에 매설된 관 주변에 존재하는 지하 공동을 지하 탐사 레이다로 탐지할 수 있음을 보였다.

• 전기학회논문지
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• 제59권2호
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• pp.355-358
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• 2010

As CMOS technology continues to scale down, signal processing is favorably done in the digital domain, which requires Analog-to-Digital (A/D) Converter to be integrated on-chip. This paper presents a design methodology of 12-bit 1-MS/s Rail-to-Rail fully differential SAR ADC using Deep N-well Switch based on binary search algorithm. Proposed A/D Converter has the following architecture and techniques. Firstly, chip size and power consumption is reduced due to split capacitor array architecture and charge recycling method. Secondly, fully differential architecture is used to reduce noise between the digital part and converters. Finally, to reduce the mismatch effect and noise error, the circuit is designed to be available for Rail-to-Rail input range using simple Deep N-well switch. The A/D Converter fabricated in a TSMC 0.18um 1P6M CMOS technology and has a Signal-to-Noise-and-Distortion-Ratio(SNDR) of 69 dB and Free-Dynamic-Range (SFDR) of 73 dB. The occupied active area is $0.6mm^2$.

• 전력전자학회논문지
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• 제25권5호
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• pp.333-342
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• 2020

Power exchanges between the grid and the battery through a bidirectional DC-DC converter are essential for DC microgrid systems. In general, the battery is charged when the grid is connected, and the system is powered by the battery when the grid is disconnected. In this mode transition, the saturation of the voltage controller slows down output response and produces large transient errors in DC link voltage. To solve this problem, a novel anti-windup design is proposed to improve anti-windup performance further. The proposed method stabilizes DC bus voltage through a wider range of battery voltage with faster transition compared with that of conventional methods. The proposed method is verified through an experimental setup composed of a 125 W laboratory-scale DC microgrid system.

• 수산경영론집
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• 제36권1호
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• pp.155-166
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• 2005

Since 1980's, fishery household population have been continuously in a down slope with a 5$\%$ annual decreasing rate in Korea. With a particular situation that the scale of over 60s population has been soaring compared with that of under 16 aged population plunging, some difficulties have been raised with the respect of labor supply into fishery communities. This study is aimed at analyzing the tendency of fisheries population with the change of economic development rates and prospect a future fisheries population with the consideration of present decreasing rate. Model results indicate that the tendency of future fishery household population would be decreased by 4.96$\%$ annually through a decade from 2000. Interestingly, it is predicted that the decreasing rate of male fishery household population would be faster than that of female. Consequently, women would hold a greater part in Fishery household population in 2010. In addition, the fishery household population of 40s and 50s would increase from 36$\%$ to 49$\%$, that of over 60s from 21$\%$ to 37$\%$. In conclusion, as a population over 40's encompass almost 90$\%$ in the total population, the fishing communities have a difficulty in shortage of the young workforce.

• 간호행정학회지
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• 제20권4호
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• pp.394-404
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• 2014

Purpose: The purpose of this study was to identify the conceptual structure of stressors experienced by nursing students during clinical practice. Methods: Ten men and 10 women nursing college students were interviewed. The results were 208 ideas. By synthesizing and editing these ideas, the final statement was trimmed down to 39 questions. The next step was to have the participants classify these 39 final questions. They were asked to rate stress scores using a five-point scale. Through multidimensional scaling analysis and hierarchical cluster analysis yielded dimensions and clusters. Results: Results of the study showed 2 dimensions which were classified as 'interpersonal relationship-practice system' and 'identity-practice environment'. It also yielded 8 clusters which were classified as 'role confusion', 'gender discrimination', 'attitudes of medical personnel and patients', 'comparison between fellow students', 'difference between theory and practice', 'disestablishing the role of practice guide', 'interference with training', and 'problems of the practice environment'. Further, stress factors and stress levels were differentiated depending on the gender of the student. Conclusion: The results of the study indicate that educators who are developing clinical practice programs and clinical practitioners should consider stressors during clinical practice and the educational implications to nursing students.

• 전기전자학회논문지
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• 제21권1호
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• pp.81-84
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• 2017

본 논문에서는 대형 풍력발전시스템에서 신뢰성 및 품질에 가장 큰 영향을 주는 기계적인 부품에 있어서 증속기어를 제거함으로서 잠재적인 고장 및 전력품질 저하의 문제점을 해결하고자 한다. 제안된 방식은 회전가능한 고정자와 슬립링을 적용하고, 고정자를 회전시킴으로써 기존의 증속기를 갖는 풍력발전시스템과 유사한 발전특성을 확보하고자 한다. 또한, 제안된 방식의 동작과 성능을 확인하기 위해 PSIM 시뮬레이션 패키지를 사용하여 시뮬레이션을 수행하여 성능을 검증하였다.