• 한국산학기술학회논문지
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• 제13권7호
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• pp.3275-3284
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• 2012

본 논문은 국내 농업용저수지의 성층현상을 방지하고자 물순환장치를 설치하였을 때, 3차원 수리해석모델인 EFDC를 이용하여 부유물질 이송확산모의를 하였다. 이를 통해 물순환장치의 이송확산범위를 예측하고, 다양한 운전인자를 조절함으로써 최적의 운전인자를 도출하여 물순환으로 인한 내부변화의 영향을 최소화하고자 하였다. 3차원 이송확산모의 결과에 의하면, 30일 이후에 전 수층에 걸쳐 물순환이 시작되며, 100일 이후 저수지의 전체순환이 가능한 것으로 모의되었다. 또한, 연속운전보다 간헐운전이 저수지 전 구간에서 이송확산농도가 낮게 나타났으며, 안정적으로 전체순환이 일어났다. 물순환장치의 표층과 저층 혼합비율은 표층 혼합율이 높을수록 저수지 영향을 감소시킬 수 있으며, 3:1 동일조건일 경우, Case 8(50일운전:50일정지) 조건이 저수지의 내부영향을 최소화할 수 있을 것으로 나타났다.

• 한국조리학회지
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• 제22권3호
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• pp.79-91
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• 2016

본 연구는 2015년 5월 1일 경부터 5월 30일에 이르는 한 달간 조사기간을 두어 실시하였고, 자료 수집은 서울 시내 레스토랑 및 일반음식점 관리 책임자에게 연구목적과 설문내용을 충분히 설명한 후 레스토랑 및 일반음식점 관리 책임자의 책임하에서 방문하는 고객에게 자기기입식으로 응답하게 하였다. 첫째, 노스텔지어 성향으로 지각된 감정의 음식 때문에 레스토랑 및 일반음식점 재방문의도에 영향을 미치는지 규명하고자 한다. 노스텔지어 성향이 재구매의도에 미치는 영향 은 B=0.767(p<.001)로 재구매의도에 유의적인 정(+)의 영향력이 있었다. 모형의 적합성을 측정하는 결정계수는 모형의 적합성을 측정하는 결정계수는 0.589로 전제 변동의 58.9%를 설명하였고, 모형의 유의성을 검증하는 F=431.234(p<.001)로 모형은 유의적으로 나왔다. 둘째, 노스텔지어 성향과 사회적 유대감의 유의적인 부(-)의 영향력으로 강한 조절효과를 나타냈다. 이에 사회적 유대감이 낮을수록 노스텔지어 성향이 높아지는 것으로 나타났다.

• 대한조선학회논문집
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• 제50권6호
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• pp.390-398
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• 2013

In this paper, an experimental study on sloshing problems in an independent B-type tank of STX Offshore and Shipbuilding Co. is described. Recently STX Offshore and Shipbuilding Co. introduced a new design of an independent B-type tank in order to reduce sloshing impact loads on LNG CCS. This tank has many internal members, so that sloshing flow and the resultant hydrodynamic loads are very different from those in typical membrane tanks. In this study, a series of sloshing experiment have been carried out for 1/50 scale model, and the main characteristics of sloshing load on the independent tank are observed. The properly scaled internal members such as swash bulkhead, center bulkhead and stringers have been installed in the test tank model, but sloshing pressures are measured on the tank walls only. The forced excitation signals have been generated by using the predicted ship motion in irregular sea states. The characteristics of sloshing loads on this tank have been observed in different filling levels with various heading angles, and sea states. In this paper, some key findings from the model tests are discussed.

• 통상정보연구
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• 제16권4호
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• pp.3-34
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• 2014

글로벌 금융위기 이후 수출기업들은 무한경쟁시장에서 살아남기 위하여 기술을 혁신하고 제품경쟁력을 강화하고 있다. 이러한 글로벌 B2B 환경에서 수출 제조기업이 지속적인 생존과 성장을 위해서는 글로벌 구매업체와의 관계를 강화하는 것이 매우 중요하다. 관계강화를 통해서 마케팅 및 거래 비용을 절감하고 기업 활동의 안정성을 보장받을 수 있기 때문이다. 본 연구는 수출 제조기업의 구매업체와의 관계강화에 영향을 미치는 선행요인을 규명하는 연구로서, 관계강화의 핵심 요인으로 관계품질, 관계품질의 구성 요소로 관계만족, 신뢰, 관계몰입을 채택하였다. 또한, 관계만족의 선행요인으로 기술적 서비스 품질과 관계적 서비스역량을, 신뢰의 선행요인으로 소통과 정보교환, 관계정책, 기회주의적 행동을 살펴보았다. 수출제조기업 P의류업체와 거래관계를 가지고 있는 107개 업체 데이터를 바탕으로 실증분석을 수행하였으며, PLS를 활용하여 분석하였다. 연구결과, 수출 제조기업의 구매업체와의 관계몰입은 관계강화에 유의한 영향을 미쳤으며, 관계만족과 신뢰는 관계몰입을 매개로 하여 관계강화에 영향을 미쳤다. 또한, 기술적 서비스품질은 관계만족에 유의한 영향을 미쳤으나, 관계적 서비스역량은 유의한 영향을 미치지 못했다. 소통과 정보 교환, 관계정책은 긍정적으로 유의한 영향을 미친 반면, 기회주의적 행동은 부정적으로 유의한 영향을 미치는 것으로 나타났다. 본 연구는 글로벌 고객사와 win-win 전략 수립 시 자원투입을 어디에 집중해야 하는가를 판단하는 데 시사점을 제공할 수 있을 것으로 판단된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.826-829
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• 2008

In a field measurement, measurement errors are produced by measuring environments and systematic errors in the measurement procedure. Measurement errors can be expressed as a measurement uncertainty. In this study, the measurement uncertainty and various measuring factors are investigated in heavy-weight impact sounds. According to KS 2810-2, the model functions, which is the estimation of the maximum SPL measurement in each octave band frequency, are determined. From this estimation model, 3.53dB is shown in 63Hz. This level is caused by the sound field of the receiving room, which does not meet the diffusing field.

• 대한기계학회논문집B
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• 제27권8호
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• pp.1165-1173
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• 2003

The effects of (1) phonon dispersion on thermal conductivity model and (2) differentiation of group velocity and phase velocity are examined for germanium. The results show drastic change of thermal conductivity regardless of the same relaxation time model. Also the contribution of transverse acoustic (TA) phonon and longitudinal acoustic (LA) phonon on the thermal conductivity at high temperatures is reassessed by considering more rigorous dispersion model. Holland model, which is commonly used for modeling thermal conductivity, underestimates the scattering rate for TA phonon at high frequency. This leads the conclusion that TA is dominant heat transfer mode at high temperatures. But according to the rigorous consideration of phonon dispersion, the reduction of thermal conductivity is much larger than the estimation of Holland model, thus the TA at high frequency is expected to be no more dominant heat transfer mode. Another heat transfer mechanism may exist at high temperatures. Two possible explanations we the roles of (1) Umklapp scattering of LA phonon at high frequency and (2) optical phonon.

• 대한원격탐사학회지
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• 제24권1호
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• pp.25-33
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• 2008

To investigate the hydrologic impacts of climate changes on dam inflow for Soyanggangdam watershed $(2694.4km^2)$ of northeastern South Korea, SLURP (Semi-distributed Land Use-based Runoff Process) model and the climate change results of CCCma CGCM2 based on SRES A2 and B2 were adopted. By the CA-Markov technique, future land use changes were estimated using the three land cover maps (1985, 1990, 2000) classified by Landsat TM satellite images. NDVI values for 2050 and 2100 land uses were estimated from the relationship of NDVI-Temperature linear regression derived from the observed data (1998-2002). Before the assessment, the SLURP model was calibrated and verified using 4 years (1998-2001) dam inflow data with the Nash-Sutcliffe efficiencies of 0.61 to 0.77. In case of A2 scenario, the dam inflows of 2050 and 2100 decreased 49.7 % and 25.0 % comparing with the dam inflow of 2000, and in case of B2 scenario, the dam inflows of 2050 and 2100 decreased 45.3 % and 53.0 %, respectively. The results showed that the impact of land use change covered 2.3 % to 4.9 % for the dam inflow change.

• Structural Engineering and Mechanics
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• 제63권2호
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• pp.207-215
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• 2017

The paper presents the studies carried out on low velocity impact of Ultra high performance concrete (UHPC) panels of size $350{\times}350{\times}10mm^3$ and $350{\times}350{\times}15mm^3$. The panels are cast with 2 and 2.5% micro steel fibre and compared with UHPC without fiber. The panels are subjected to low velocity impact, by a drop-weight hemispherical impactor, at three different energy levels of 10, 15 and 20 J. The impact force obtained from the experiments are compared with numerically obtained results using finite element method, theoretically by energy balance approach and empirically by nonlinear multi-genetic programming. The predictions by these models are found to be in good coherence with the experimental results.

• 대한기계학회논문집B
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• 제28권9호
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• pp.1093-1100
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• 2004

Numerical analysis of the heat transfer associated with droplet impact on a hot solid surface is performed by solving the equations governing conservation of mass, momentum and energy in the liquid and gas phases. The deformed droplet shape is tracked by a level set method which is modified to achieve volume conservation and to include the effect of contact angle at the wall. The numerical method is validated through the calculations for the cases reported in the literature. Based on the numerical results, the heat transfer rate is found to depend strongly on the droplet spread radius. Decreased advancing/receding contact angles enlarge the splat radius and in turn enhance the wall heat flux. The effect of impact velocity on the droplet spread is reduced as the droplet size decreases. Also, droplet atomization is observed to significantly enhance the heat transfer rate and the effect is pronounced for a smaller size of droplet. An existing model equation to predict the maximum spread radius is improved for application to a micro droplet.

• 대한간호학회지
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• 제48권5호
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• pp.565-577
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• 2018

Purpose: The purpose of this study was to construct and test a hypothetical model about impact of parents' problem drinking on suicidal ideation of their children who are university students and the multiple mediating effects of childhood trauma, experiential avoidance, and depression based on stress-vulnerability model. Methods: A purposive sample of 400 university students was recruited from three universities in provincial areas and the data were collected between October and November 2016. The collected data were then analyzed using SPSS 20.0 and AMOS 20.0 programs. For data analysis, descriptive statistics, factor analysis, and structural equation modeling were performed. Multiple mediating effects analysis using phantom variable and bootstrapping were implemented to verify the mediating effect of the research model. Results: We found no significant direct effect on depression and suicidal ideation of parents' problem drinking, but multiple mediating effects of childhood trauma and experiential avoidance between parents' problem drinking and depression (B=.38, p=.001). The path from parents' problem drinking to suicidal ideation was significantly mediated by childhood trauma and depression (B=.02, p=.016) and by childhood trauma, experiential avoidance, and depression (B=.05, p=.011), but experiential avoidance did not have a significant direct effect on suicidal ideation (B=.02, p=.616). Conclusions: Based on the results of this study, it can be suggested that in order to decrease depression and prevent suicide of university students, considering of parents' problem drinking and childhood trauma, intervention methods that decreased chronic use of experiential avoidance and strengthen acceptance should be developed and made available to them.