• 한국언어정보학회지:언어와정보
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• 제19권1호
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• pp.1-18
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• 2015

Korean marks case for subjects and objects, but it is well known that case-markers can be dropped in certain contexts. Kwon and Zribi-Hertz (2008) establishes the phenomenon of Korean case drop on a single factor of f(ocus)-structure visibility and claims that both subject and object case drop can fall under a single linguistic generalization of information structure. However, the supporting data is not empirically substantiated and the tenability of the f-structure analysis is still under question. In this paper, an experiment was conducted to show that the specific claims of Kwon and Zribi-Hertz's analysis that places exclusive importance on information structure cannot be adequately supported by empirical evidence. In addition, the present study examines H. Lee's (2006a, 2006c) multi-factor analysis of object case drop and investigates whether this approach can subsume both subject and object case drop under a unified analysis. The present findings indicate that the multi-factor analysis that involves the interaction of independent factors (Focus, Animacy, and Definiteness) is also compatible with subject case drop, and that judgments on case drop are not categorical but form gradient statistical preferences.

• 음성과학
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• 제7권3호
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• pp.35-51
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• 2000

The goal of this paper is to examine how Case Drop (the drop of the case markers) correlates with the prosodic structure in Korean. On the assumption that intervocalic Lenis Stop Voicing (LSV) applies within the domain of the Accentual Phrase (AP), voicing analyses are performed on intervocalic lenis stop consonants before and after Case Drop. A statistical analysis reveals that the drop of the nominative and accusative case markers significantly alter the AP structure. Pitch values will then be extracted to verify that such changes in the AP structure conform to the pitch properties proposed for the AP (Jun 1993, 1998). The results show that the AP structure suggested by LSV does not always coincide with that imposed by the pitch properties.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.8-14
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• 2019

대표적인 하천횡단구조물 중 하나인 낙차공은 하천하상의 안정을 목적으로 설치되지만 이는 하천환경의 연속성을 차단하고, 수생태환경의 파괴를 야기하는 것으로 알려져 있다. 따라서 본 연구에서는 생태통로로서의 기능을 갖는 저낙차 자연형 낙차공을 모형으로 제작하여 실험실 실험을 수행하고, 적절한 지배인자 사이의 관계를 도출하여 국부세굴공 규모의 예측식을 제안하였다. 직선형과 6가지 상향 V 자형의 낙차공 모형에 대하여 각각 실험유량은 4가지로 총 28개의 조건에 대해서 실험을 수행하였다. 각각의 실험조건별 세굴실험 결과를 바탕으로 기존에 제안된 세굴심 추정식을 적용한 결과보다 최대세굴심이 다소 크게 발생함을 확인하였다. 따라서 낙차공 직하류부에서 발생하는 세굴공 발생 주요인자들 사이의 상관관계를 분석한 결과, 낙차공으로의 유입흐름 특성과 낙차공의 높이, 낙차공의 총횡단길이와의 상관관계가 높게 나타남을 확인하였다. 또한 이를 토대로 각 실험조건별 세굴심과 세굴길이에 상관관계가 높다고 판단되는 변수들을 무차원화하여 최대세굴공의 깊이와 길이 산정식을 각각 제안하였다. 향후 추가적으로 다양한 하상토 재료와 수심변화를 고려한 실험적 연구 및 수치해석 연구를 병행하여 보다 정확한 세굴심 산정식을 도출할 수 있다.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2491-2498
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• 2020

The paper concentrates on an experimental study of the pressure drop in double-layered packed beds formed by glass spheres, having the configuration of horizontal and vertical stratification. Both single-phase and two-phase flow tests are performed. The pressure drop during the test is recorded and the measured data are compared with those of homogeneous beds consisting of mono-size particles. The results show that for the horizontally stratified bed with fine particles atop coarse particles, the pressure drop in top layer is found higher than those of homogenous bed consisting of the same smaller size particles, while the measured pressure drop of bottom part is similar with those of similar homogenous bed. But for the homologous bed with upside-down structure, the stratification has little or no effect on the pressure drop of the horizontally stratified bed, and the pressure drop of each layer is almost same as that of homogeneous bed packed with corresponding spheres. Additionally, in vertically stratified bed, the pressure drops on the left and right side is almost equal and between those in homogeneous beds. It is speculated that vertically stratified structure may lead to lateral flow which redistributes the flow rate in different parts of packed bed.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.609-613
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• 2023

In this paper, a 1,200 V Si-based IGBT used in electric vehicles and new energy industries was designed. A field stop IGBT with a separate gate structure, which is the proposed structure, was designed to change trench depth and split gate width variables. Then, the general trench structure and electrical characteristics were compared and analyzed. As a result of conducting the trench depth experiment, it was confirmed that the breakdown voltage was the highest at 6 ㎛, and the on-state voltage drop was the lowest at 3.5 ㎛. In the separate gate width experiment, it was confirmed that the breakdown voltage decreased as the variable increased, and the on-state voltage drop increased. Therefore, it may be seen that it is preferable not to change the width of the separate gate. In addition, experiments show that there is no difference in on-state voltage drop compared to a structure in which a general field stop structure has a separate gate structure. In other words, it is determined that adding a dummy gate with a separate gate structure to the active cell will significantly improve the on-voltage drop characteristics, while confirming that the on-voltage drop does not change, and while having excellent characteristics in terms of breakdown voltage.

• Ecology and Resilient Infrastructure
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• 제3권1호
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• pp.14-21
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• 2016

본 연구에서는 2차원 수치모형을 이용하여 복단면 하도에서 낙차공을 고려하여 하도 변화와 사주의 거동 특성을 분석하였다. 교호사주에 의하여 흐름이 분리되며, 사주의 선단부에서 흐름이 집중되고 수충부가 형성되었다. 낙차공에 의하여 흐름은 하도 전체에 균등하게 분산되었으며, 낙차공 하류에서는 흐름이 집중되고 하상고가 낮아졌다. 그러나 사주의 형상은 낙차공 상류의 영향을 받아 교호사주의 형상을 유지되었다. 하폭 대 수심이 증가하면서 교호사주, 중앙사주, 복렬사주가 형성되었으며, 사주의 수가 증가하였다. 낙차공에 의하여 흐름이 집중되어 낙차공 상류에서 사주길이보다 낙차공 하류에서 사주길이가 더 짧게 나타났다.

• Water Engineering Research
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• 제5권4호
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• pp.195-206
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• 2004

This paper deals with oxygen transfer by air entrainment and energy dissipations by flow characteristics at the stepped drop structure. Nappe flow occurred at low flow rates and for relatively large step height. Dominant flow features included an air pocket, a free-falling nappe impact and a subsequent hydraulic jump on the downstream step. Most energy was dissipated by nappe impact and in the downstream hydraulic jump. Skimming flow occurred at larger flow rates with formation of recirculating vortices between the main flow and the step comers. Oxygen transfer was found to be proportional to the flow velocity, the flow discharge, and the Froude number. It was more related to the flow discharge than to the Froude number. Energy dissipations in both cases of nappe flow and skimming flow were proportional to the step height and were inversely proportional to the overflow depth, and were not proportional to the step slope. The stepped drop structure was found to be efficient for water treatment associated with substantial air entrainment and for energy dissipation.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2007년도 SMT/PCB 기술세미나
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• pp.37-47
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• 2007

Factor : Structure Metal pad & SMO size Board level TC test : - Large SMO size better Board level Drop test : - Large SMO size better Factor : Structure Substrate thickness Board level TC test : - Thick substrate better Board level Drop test : - Substrate thickness is not a significant factor for drop test Factor : Material Solder alloy Board level TC test : - Not so big differences over Pb-free solder and NiAu, OSP finish Board level Drop test : - Ni/Au+SAC105, CuOSP+LF35 are better Factor : Material Pad finish Board level TC test : - NiAu/NiAu is best Board livel Drop test : - CuOSP is best Factor : Material Underfill Board level TC test - Several underfills (reworkable) are passed TCG x500 cycles Board level Drop test : - Underfill lots have better performance than non-underfill lots Factor : Process Multiple reflow Board level TC test : - Multiple reflow is not a significant actor for TC test Board level Drop test : N/A Factor : Process Peak temp Board level TC test : - Higher peak temperature is worse than STD Board level Drop test : N/A Factor : Process Stack method Board level TC test : - No big difference between pre-stack and SMT stack Board level Drop test : - Flux dipping is better than paste dipping but failure rate is more faster

• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3450-3462
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• 2024

This paper presents a computational framework for drop time assessment of a control element assembly (CEA) under fuel assembly (FA) deformations. The proposed framework consists of three key components: 1) finite element modeling of CEA, 2) fluid-structure interaction to compute drag force, and 3) modeling of frictional contact between CEA and FA. Specially, to accommodate the large motion of CEA, beam elements based on absolute nodal coordinate formulation (ANCF) are adopted. The continuity equation is utilized to calculate the drag force, considering flow changes in the cross-sectional area during the CEA drop. Lastly, beam-inside-beam frictional contact model is employed to capture practical contact conditions between CEA and FA. The proposed framework is validated through experiments under two scenarios: free falls of CEA within FA, encompassing undeformed and deformed scenarios. The experimental validation of the framework demonstrated that the drop time of CEA can be accurately predicted under the complex coupling effects of fluid and frictional contact. The drop times of the S-shaped deformation case is longer than those of the C-shaped deformation case, affirming the time delay due to frictional force. The validation confirms the potential applicability to access the safety and reliability of nuclear power plants under extreme conditions.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.271-272
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• 2005