• 한국유체기계학회 논문집
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• 제1권1호
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• pp.41-48
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• 1998

This study was carried out to investigate the effect of design parameters on the volume flow-rate and the noise level and to finally find the optimal design variables. Eighteen cross-flow fans were designed by the method of orthogonal array, and the flow-rate and the noise level were measured. These data were analyzed by the neural network system. The effects of eight design variables(scroll exit angle, scroll arc length et al.) on the fan performance and the noise level were valuated and discussed. This experiment shows that the design solutions suggested by neural network system may increase its volume flow-rate and reduce noise simultaneously.

• 디지털융복합연구
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• 제18권8호
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• pp.29-35
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• 2020

본 연구는 증강현실 광고가 프레즌스 유형과 플로우(flow) 수준에 따른 광고태도와 기억 효과에 미치는 효과를 규명하였다. 증강현실(AR) 광고의 프레즌스(인지, 감성, 미디어)와 플로우 수준(고 vs. 저)을 독립변인으로 Two-Way MANOVA 분석을 하였다. 연구결과, 첫째, 증강현실 광고태도는 감성적 프레즌스와 플로우 수준이 높은 경우 긍정적이었다. 둘째, 인지적 프레즌스는 플로우 수준이 높으면 제품 속성정보와 같은 ARM이 증가하나 플로우 수준이 낮으면 평가 위주의 GRM이 증가하였다. 셋째, 감성적 프레즌스는 플로우 수준이 높으면 GRM이 증가하나 플로우 수준이 낮으면 ARM이 증가하였다. 넷째, 미디어 프레즌스는 플로우 수준과 상관없이 기억 효과는 낮았다. 본 연구는 프레즌스를 세 가지 차원으로 유형화하여 실험을 통해 실증적으로 규명하였다는 점에서 일반화 가능성이 높다.

• 기독교교육논총
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• 제72권
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• pp.165-182
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• 2022

연구 목적 : 본 연구의 목적은 학업성취에 가장 중요한 영향을 미치는 요인 중에서 흥미수준에 따라서 인지적 실재감이 몰입에 미치는 영향을 탐색하기 위한 것이다. 연구 내용 및 방법 : 본 연구는 B대학의 사범학부에서 교직교과목을 수강한 162명을 대상으로 했다. 연구를 위해 흥미수준, 인지적 실재감, 몰입을 설문을 통해 자료를 수집했다. 수집된 자료는 흥미 수준에 따라 인지적 실재감이 몰입에 어떠한 영향을 주는지 검증하기 위해, 흥미 수준의 평균을 기준으로 저집단과 고집단으로 구분하여 다중 회귀 분석을 수행하였다. 그 결과 흥미수준 고집단에서 인지적 실재감의 하위요인 학습 관리 정도가 .071이며, 흥미수준 저집단에서 인지적 실재감의 하위요인 학습 관리 정도가 .143 수준으로 정적인 영향이 있었다. 결론 및 제언 : 이와 같은 결과로, 흥미수준에 따라서 인지적 실재감의 학습 관리 정도가 몰입에 미치는 영향이 확인되었다. 본 연구 결과를 통해 몰입에 있어서 인지적 실재감 지원을 통해 흥미수준을 향상할 수 있는 수업설계 전략을 제언하였다.

• 대한지구과학교육학회지
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• 제5권3호
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• pp.225-234
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• 2012

The Purpose of this study is searching the effect of the flow level increasing by using flow learning on scientific achievement and attitude toward science in 4rd grade elementary school student's scientific learning factors, and the better way to approach scientific institude than now in used. Participants included 52 elementary school students. For this study, two classes were divided into experimental class and control class. The control class takes a regular instructions and the experimental class takes a flow learning instructions. Two chapter were selected, 'Plant's World' and 'Fossil and Rock', for this study. Students were treated for 18 hours. The results were as follows: First, flow learning related program about plant's world, fossil and rock is increasing 4rd grade elementary school students' flow level in science class. Second, students are not increasing their scientific achievement according to increasing their flow level. Third, students are not increasing their attitude toward science according to increasing their flow level. But in attitude toward scientific inquiry, adoption of attitude toward science and preference of job related science subordinated, students are increasing subordinate factors of attitude toward science.

• Journal of information and communication convergence engineering
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• 제9권3호
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• pp.319-324
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• 2011

In computing the optical flow. Horn and Schunck's method which is a representative algorithm is based on differentiation. But it is difficult to estimate the velocity for a large displacement by this algorithm. To cope with this problem multigrid method has been proposed. In this paper, we have proposed a scaled multigrid algorithm which the initial flow for a level is calculated by the summation of the optimally scaled flow and error flow. The optimally scaled flow is the scaled expanded flow of the previous level, which can generate an estimated second image having the least RMS error with respect to the original second image, and the error flow is the flow between the estimated second image (generated by the optimally scaled flow) and the original second image. The flow for this level is then estimated using the original first and second images and the initial flow for that level. From among the various coarsest starting levels of the multigrid algorithm, we select the one that finally gives the best estimated flow. Better results were achieved using our proposed method compared with Horn and Schunck's method and a conventional multigrid algorithm.

• 한국수자원학회논문집
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• 제55권1호
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• pp.33-42
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• 2022

본 연구에서는 3차원 상용 수치모형 Flow-3D를 활용하여 상류 수위(유입유량) 변동, 격벽의 간격(pool의 길이) 변화, 잠공 유무 등에 따른 아이스 하버 어도 내 흐름 양상을 분석하였다. 수치모의 결과의 적합성을 입증하기 위해 경안천 대곡교 하류에 설치된 실제 어도에서 3차원 초음파 유속계를 사용하여 어도 출구부 단면 유속과 유량을 관측하였다. Flow-3D 모형에는 난류 모듈로 4가지를 선택할 수 있는데, 관측 자료로 검증 결과 RNG 모형이 아이스하버 어도 내 흐름 특성을 가장 잘 재현하였다. 하천의 유량 전량이 어도로만 유입되어 흐른다는 조건에서 수위 변화에 따른 어도 내 유속구조를 모의해 보았다. 그 결과 최저수위에서는 잠입류와 표면류가 혼재하여 발생하였는데, 최저수위에서 약 10 cm 이상만 수위가 상승하여도 모든 pool에서 잠입류가 사라지고 오직 표면류만 발생하였다. 예상과 달리 수위가 조금 상승해도 흐름이 꽤 단순하게 표면류 위주로 발생하였다. 격벽간 간격을 늘려주면 수위가 상승하더라도 잠입류와 표면류가 혼재되어 나타나는 현상이 지속되었다. 그리고 격벽 하단에 잠공이 있는 경우가 없는 경우에 비해 잠입류가 여러 pool에서 생성되는 경향을 보였다. 보다 적극적인 어도 사후 관리로 잠공 폐색을 막아 어도 내 다양한 흐름이 생성될 수 있도록 유도하는 것이 필요해 보인다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.565-567
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• 2008

In the present study, a least square/level set based two-phase flow code has been developed using finite element discretization, which can be utilized for the analysis of a free surface flow problem in a complex geometry. Since the finite element method is employed for the spatial discretization of governing equations, an unstructured mesh can be naturally adopted for the level set simulation of a bubble-in-liquid flow without an additional load for the code development except that solution methods of the hyperbolic type redistancing and advection equations of the level set function should be devised in order to give a bounded solution on the unstructured mesh. For the discretization of hyperbolic type redistancing and advection equations, least square method is adopted. From the numerical experiments of the present study, it is shown that the proposed method is both robust and accurate.

• Asian Journal of Business Environment
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• 제9권1호
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• pp.21-28
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• 2019

Purpose - The purpose of this paper is to investigate the relationship between corporate social responsibility disclosure (CSRD) and investment-cash flow sensitivity, which is a surrogate for financing constraints. Research design, data, and methodology - Taking China's A-share listed companies between 2009 and 2016 as a sample, this paper empirically tests the relationship between CSRD and investment-cash flow sensitivity by Panel VAR model. By introducing the orthogonal impulse response function, this paper distinguishes the fundamental factors and financial ones that affect corporate investment behavior. Results - Findings indicate that: (1) investment-cash flow sensitivity of firms with low level of CSRD is significantly lower than that of firms with high level of CSRD; (2) the orthogonal impulse response of corporate investment to cash flow in firms with high level of CSRD is significantly different from zero, but it is not significant in firms with low level of CSRD; (3) for firms with low level of CSRD, 0.7% of corporate investment volatility can be explained by the change in cash flow, which is lower than that of firms with high level of CSRD (1.1%). Conclusions - Corporations disclosing more and higher quality CSRD are often those faced with financing constraints. Voluntary disclosure can help them alleviate information asymmetry and financing constraints.

• ETRI Journal
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• 제30권2호
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• pp.205-215
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• 2008

Many control schemes have been proposed for flow-level traffic control. However, flow-level traffic control is implemented only in limited areas such as traffic monitoring and traffic control at edge nodes. No clear solution for end-to-end architecture has been proposed. Scalability and the lack of a business model are major problems for deploying end-to-end flow-level control architecture. This paper introduces an end-to-end transport architecture and a scalable control mechanism to support the various flow-level QoS requests from applications.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1851-1859
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• 2022

Experimental research on flow characteristics of open natural circulation system was performed, to figure out the mechanism of the open natural circulation behaviors. The influence factors, such as the heating power, the inlet subcooled and the level of cooling tank on the flow characteristics of the system were examined. It was shown that within the scope of the experimental conditions, there are five flow types: single-phase stable flow, flash and geyser coexisting unstable flow, flash stable flow, flash unstable flow, and flash and boiling coexisting unstable flow. The geyser flow in flash and geyser coexisting unstable flow is different from classic geysers flow. The flow oscillation period and amplitude of the former are more regular, is a newly discovered flow pattern. By drawing the flow instability boundary diagram and sorting out the flow types, it is found that the two-phase unstable flow is mainly characterized by boiling and flash, which determine the behavior of open natural circulation respectively or jointly. Moreover, compared with full liquid level system, non-full liquid level system is more prone to boiling phenomenon, and the range of heat flux density and undercooling degree corresponding to unstable flow is larger.