• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.160.1-160.1
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• 2011

In this study, the influence of methodology of assessing water levels on the discharge coefficient of sluice for tidal power generation was investigated. A physical experiment was performed in a planar open channel by installing 1/70 scale model of the sluice caisson in the planar open channel. In front of and behind the sluice model, sloping bathymetry was made to reproduce corresponding field condition. By analyzing the experimental results, it was found that the location of measuring water levels significantly affects the estimates of the discharge coefficient, due to the variability of the parameter according to the head difference between the measuring locations. Therefore, it is necessary to be careful in estimating and utilizing the discharge coefficient in the relevant study of a tidal power generation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.197-198
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• 2023

Construction waste takes about 50% of total industrial waste. Researchers focuses to decrease the amount of construction waste by recycling the waste during the construction site. However, research about recycling the gelatin-sand composite is not yet been studied. This research is an experimental research on recycling the total specimen of gelatin-sand composite. Two methods were held when making the 2^nd generation of the gelatin-sand specimen. As a result, there was no difference in flexural strenght between two different method of 2^nd generation of specimen. However, the second method of 2^nd generation showed about 20% higher compressive strength than the first method.

• 기술혁신학회지
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• 제9권3호
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• pp.451-470
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• 2006

본 연구는 사원 개인을 분석단위로 사원제안제도의 활용에 영향을 미치는 요인을 살펴보았다. 또한 사원제안제도가 지금까지 제조업 중심으로 이루어져 왔지만 최근 서비스업을 중심으로 비제조업에도 사원제안제도가 확산됨에 따라 업종별 차이도 분석하였다. 연구 가설은 Unsworth(2001)의 개인 창의성 분류와 Frese et al.(1999)의 사원제안제도 일반 모형에서 도출하였다. 자동차 조립업체와 은행을 대상으로 자료를 수집하였고 PLS로 통계분석을 실시하였다. 연구결과를 보면 Frese et al.(1999)의 일반모형은 대체로 지지되었으며 업종간 유의한 차이를 발견하지는 못하였다. 그러나 모형 내부 변수들의 상관관계의 정도는 유의한 통계적 차이를 보였다. 이를 바탕으로 비제조업의 사원제안제도 활용에 대한 제언을 제시하였다.

• 한국해안·해양공학회논문집
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• 제31권6호
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• pp.379-385
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• 2019

조력발전의 한 종류인 동적 조력 발전은 조석의 회절효과에 의한 위상차를 이용하여 발전하기 때문에 거대한 구조물이 요구된다. 실용화를 위해서는 경제성이 가장 요구되며, 이를 위해 다양한 연구들이 수행되고 있다. 본 연구에서는 기존 방식과 달리 여러 개의 구조물을 설치하여 발전량의 증가를 통한 경제성 향상을 도모하였다. 다수의 구조물 주변 해역의 흐름 변화를 연구하였으며, 효율적인 발전량 증가를 위해 구조물 사이에 적절한 간격이 필요함을 알 수 있었다.

• Transactions on Electrical and Electronic Materials
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• 제17권1호
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• pp.21-24
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• 2016

A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

• 대한음성학회지:말소리
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• 제57호
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• pp.15-30
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• 2006

This paper investigates differences between generations in the vowel system of the Daegu dialect in terms of F1 and F2 of the monophthongs. Three different groups of subjects participated in the present study: 20 female native speakers of the Daegu dialect(10 in their 20's and 10 in their 40's), and 10 female native speakers of the Seoul dialect as a control group. It has been assumed that the Daegu dialect has six vowels. However, younger generation appears to have 7 vowels different from older generation. The result of the present study showed that the Daegu dialect has different vowel systems between generations: for 40's have six vowels and 20's have seven vowels. These differences seems to be attributed to the influence of the Seoul dialect.

• Nuclear Engineering and Technology
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• 제40권4호
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• pp.299-304
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• 2008

A detection system was set up to measure the neutron generation rate of a recently developed D-D neutron generator. The system is composed of a Si detector, He-3 detector, and electronics for pulse height analysis. The neutron generation rate was measured by counting protons using the Si detector, and the data was crosschecked by counting neutrons with the He-3 detector. The efficiencies of the Si and He-3 detectors were calibrated independently by using a standard alpha particle source $^{241}Am$ and a bare isotopic neutron source $^{252}Cf$, respectively. The effect of the cross-sectional difference between the D(d,p)T and $D(d,n)^3He$ reactions was evaluated for the case of a thick target. The neutron generation rate was theoretically corrected for the anisotropic emission of protons and neutrons in the D-D reactions. The attenuations of neutron on the path to the He-3 detector by the target assembly and vacuum flange of the neutron generator were considered by the Monte Carlo method using the MCNP 4C2 code. As a result, the neutron generation rate based on the Si detector measurement was determined with a relative uncertainty of ${\pm}5%$, and the two rates measured by both detectors corroborated within 20%.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.156-157
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• 2003

The wavelength converter is considered to be a key element of future dense WDM optical networks. It enables wavelength reuse and resolves contention problem. Moreover, the tunability of the wavelength converter enhance the flexibility of network systems by facilitating reconfigurable dynamic wavelength routing. In order to achieve optically tunable wavelength conversion, we recently proposed and experimentally demonstrated wavelength conversion and tuning based on cascaded sum and difference frequency generation in a Ti：PPLN channel waveguide. (omitted)

• Journal of Welding and Joining
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• 제21권1호
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• pp.48-53
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• 2003

The object of this study is to examine the effect of short circuit time ratio (SCTR) and current rise delay time (Td) on the spatter generation at low and medium current range in $CO_2$ welding. The spatter was evaluated by the weight generated in the welding of bead-on-plate for 30 seconds (3 times). Td was varied by order of 0, 0.4, 0.8 and 1.2 msec. At each Td, the short circuit time ratio was varied by the output voltage of the welding power source. In the low current range, it was found that the optimum SCTR was 20~25%, and the minimum spatter generation weight was obtained in the case of Td=0.4msec and SCTR=22% even though the remarkable difference was not showed by the application of Td. In the medium current range, it was confirmed that the arc was stable though the SCTR was increased from 20% to 40% by the control of current wave. Spatter generation weight depended on the variation of Td, and the lowest value of spatter generation weight occurred at Td=0.8~1.2msec.

• 한국콘텐츠학회논문지
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• 제21권4호
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• pp.591-602
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• 2021

본 연구는 베이비붐세대와 노인세대의 행복영향요인을 비교분석하여, 노년기 행복감의 영향요인의 차이를 밝히는 것을 목적으로 한다. 이에 '2019 서울서베이 도시정책지표조사'자료를 사용하여 베이비붐세대(1955~1963년 출생자) 7,831명과 노인세대(1954년이전 출생자) 7,620명 등 총 15,451명을 표본으로, 주관적 행복감의 정도와 행복감에 영향미치는 요인들에 대해 회귀분석을 실시였다. 분석결과, 베이비붐세대의 행복감의 정도가 노인세대에 비해 유의미하게 높았으며, 행복영향요인으로 연령, 건강, 배우자유무, 종교유무, 경제수준, 직업유무, 여가활동, 문화생활참여, 가족관계, 경제적지지, 심리적지지, SNS참여, SNS이용만족도, 스트레스정도, 근린환경만족도, 녹지환경만족도 등이 유의미하게 나타났으나 두 집단에서 영향요인간에 차이를 보여주었다. 두 집단모두 가족관계가 행복감의 가장 큰 영향요인이었으나 다음으로 베이비붐세대에게는 여가활동참여를 통한 만족도가, 노인세대에게는 경제적지지유무, 즉 필요할 때 경제적 도움을 줄 수 있는 사람의 유무가 행복감에 큰 영향력을 갖고 있었다. 또한 베이비붐세대에는 영향이 없는 SNS참여정도가 노인세대에게는 유의미한 행복영향요인으로 나타나 디지털환경에의 참여가 노인세대에게 중요한 의미임을 보여주었다. 본 연구결과에서 베이비붐세대와 노인세대는 집단적 특징면에서 유의미하게 다르며, 따라서 이들의 노년기 행복추구를 위한 사회복지적 대응은 차별적으로 접근되어야 함을 제안하였다.