• 한국전산유체공학회지
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• 제12권4호
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• pp.61-67
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• 2007

Numerical simulation of laminar flow over two spheres in a side-by-side arrangement is carried out to investigate the effect of the inter-sphere spacing on the flow characteristics. The Reynolds numbers considered are 100, 250, and 300, covering the steady axisymmetric, steady planar-symmetric, and unsteady planar-symmetric flows in the case of a single sphere. Results show that the drag and lift coefficients and wake structures are significantly modified depending on both the Reynolds number and the spacing between the spheres. At Re=100, the flow is steady planar-symmetric irrespective of the spacing, but it shows some variation according to the spacing at Re=250 and 300. That is, the flow maintains planar symmetry of the single-sphere wake at large spacings, while it loses the symmetry at small spacings due to the generation of new asymmetric vortical structures. It is also shown that the drag and lift coefficients generally increase with decreasing inter-sphere spacing because the high pressure region is formed near the gap between the spheres.

• Steel and Composite Structures
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• 제32권4호
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• pp.549-557
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• 2019

The use of shear studs usually placed in the form of mechanical shear connectors makes it possible to adopt composite steel-concrete structures in various structures, and steel-concrete plate composite (SCP) is being seriously considered for the installation of storage tanks exposed to harsh environments. However, manufacturing of SCP must be based on the application of existing design guidelines which require very close arrangement of shear studs. This means that the direct application of current design guidelines usually produces very conservative results and close arrangement of shear studs precludes pouring concrete within exterior steel faceplates. In this light, an improved guideline to determine the stud spacing should be introduced, and this paper proposes an improved ratio of the stud spacing to the thickness of steel plate on the basis of numerous parametric studies to evaluate the relative influence of the stud spacing on the stability of the SCP.

• 천문학회지
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• 제25권2호
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• pp.105-109
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• 1992

We show that spacing patterns of planets and satellites in the solar system are formulatable in a single form. It is suggested that a possible explanation for the rule might be the orbital resonance effect, which has existed at an earlier epoch of the solar (planet) system. By extrapolating the formulated spacing patterns beyond the sun-Pluto distance, we find the sun-Planet X distance falls in a range ($46{\sim}79$) A. U..

• 인지과학
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• 제16권4호
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• pp.255-270
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• 2005

항목이 연달아 반복되는 경우(집중반복)보다 간격을 두고 반복되는 경우(간격반복) 기억 수행이 더 우수한 현상을 간격효과라 한다. 단서기억과제(재인과제)의 간격효과 및 성공적 부호화와 관련된 신경기전을 밝히기 위해 event-related fMRI연구를 수행하였는데, 부호화단계에서 단어의 반복제시 간격을 조작하고서 fMRI 영상을 구하였다. 그 결과, 재인 수행에서 전형적인 간격효과가 관찰되었고 집중반복조건에 비해 간격반복조건 뿐만 아니라 비반복조건에서 좌반구의 배외측 전두피질(DLFC), 복외측 전두피질(VLFC)의 높은 활성화가 관찰되었다. 이러한 결과는 간격효과 및 이와 관련된 성공적 부호화가 높은 수준의 주의통제와 의미적 처리에 기인한다는 것을 시사한다.

• 한국작물학회지
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• 제26권4호
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• pp.357-362
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• 1981

홍화증수를 위한 알맞는 재식밀도를 구명하고 그에 따를 수량 및 농업 형질의 변이를 조사하기 위하여 1980년 3월부터 10월30일까지 강원도 원주상지대학 실습포장에서 실험을 실시하여 얻은 결과를 요약하면 다음과 같다. 1. 초장은 휴폭과 주간이 좁을수록 커지는 것으로 나타났으며 이들 양자에 의해 영향을 받았다. 2. 주당 분지수는 휴폭과 주간이 좁아짐에 따라 감소하였으며 이를 양요인에 의해 영향을 받았다. 3. 지표면에서 제1분지까지의 높이는 주간에 의해 영향을 받으며, 좁을수록 그 위치가 높아졌다. 4. 초장은 휴폭과 부의 상관을 가지며, 초장과 제1분지까지의 높이는 휴폭x주간과 부상관을 갖는다. 또한 주당 분지수는 휴폭, 휴폭x주간과는 정상관, 초장과는 부상관을 보였다. 5. 수량은 주간, 휴폭x주간에 관하여 부상관을 가지며 제 1분지의 높이와는 정상관을 가졌다. 6. 수량은 주간에 의해 크게 영향을 받으며 다음은 주간xs휴폭이 영향하는 것으로 나타났다. 휴폭은 수량에 크게 영향하지 않으나 30cm 또는 40cm구가 가장 증수되었으며 주간은 5cm구가 가장 증수되어 30cm x 5cm구, 또는 40cm x 5cm구가 홍화의 증수를 위한 적철한 재식밀도인 것으로 나타났다.

• 한국도로학회논문집
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• 제9권3호
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• pp.101-110
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• 2007

국내 줄눈콘크리트 포장의 줄눈간격은 6m로 획일적으로 설계 건설되어 왔으며 이에 대한 과학적 근거는 제시된 바 없었다. 현재 진행중인 한국형 포장설계법 개발에서는 국내 지역별 기후조건 등을 고려하여 줄눈간격 변화에 따른 줄눈콘크리트 포장의 장 단기 파손을 역학적-경험적 방법을 토대로 분석하여 줄눈간격을 지역별로 $6{\sim}8m$로 설계할 것을 제시한 바 있다. 본 연구는 한국형 포장설계법에서 제시한 줄눈간격 잠정안에 대한 타당성을 검증하기 위한 연구의 일환이다. 줄눈간격이 증가할 경우 시공초기에 하중전달률의 변화, 무작위균열 등의 발생가능성에 문제점이 없는지를 검증하기 위해서 한국형 포장설계법의 줄눈간격 잠정안에서 줄눈간격이 7m로 제시된 지역에 대해서 7m 줄눈간격으로 시험시공하고 초기거동을 모니터링 하였다. 하중전달률, 무작위균열, 줄눈폭변화 등 모니터 링 결과를 시공조건이 동일한 인접 6m 줄눈간격 비교구간의 초기거동과 비교분석하였다.

• 한국항해항만학회지
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• 제37권3호
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• pp.251-256
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• 2013

This paper is mainly concerned with the ship-bank interaction by model test. The experiments for the characteristics of hydrodynamic interaction forces and moments between vessel and bank with a mound were carried out in the seakeeping and maneuvering basin. A series of tests were carried out with ship model in parallel course along a vertical sidewall with a mound with varying lateral spacing between model ship and sidewall, length of sidewall and water depth. From the experimental results, it indicated that the hydrodynamic interaction effects increase as length of sidewall with a mound increases. Furthermore, for lateral spacing less than about 0.2L between vessel and bank, it can be concluded that the bank effects increase largely as the lateral spacing between vessel and bank decreases. However, for spacing between vessel and bank more than about 0.3L, the interaction effects increase slowly as lateral spacing decreases. Also, for the water depth to draft ratio(h/d) less than about 1.5, the hydrodynamic interaction effects increase dramatically as h/d decreases.

• 한국지진공학회논문집
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• 제28권4호
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• pp.171-181
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• 2024

For low-rise piloti-type buildings that suffered significant damage in the Pohang earthquake, the seismic performance of those designed by codes issued before and after the earthquake has been recently revised. This study started with the expectation that many of the requirements presented in the current codes may be excessive, and among them, the spacing of column stirrup could be relaxed. In particular, the recently revised design code of concrete structures for buildings, KDS 41 20 00, suggests that the column stirrup spacing is 1/2 of the minimum cross-sectional size or 200 mm, which is strengthened compared to KBC 2016, but relaxed than the current KDS, 41 17 00, which is 1/4 of the minimum size or 150 mm. As a result of the study, it was found that the target performance level was sufficiently satisfied by following the current standards and that it could be satisfied even if the relaxed spacing was followed. Therefore, the strict column stirrup spacing of KDS 41 17 00 could be relaxed if a wall other than core walls is recommended in the current guideline for the structural design of piloti-type buildings.

• 대한기계학회논문집B
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• 제21권1호
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• pp.185-194
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• 1997

An experimental study has been performed on the effect of baffle parameters on shell -side heat transfer in a conventional shell-and-tube heat exchanger. The baffle spacing distance and the number of baffle were varied to investigate the behavior of unequal baffle spacing correction factor which is appeared in the Bell Delaware method for prediction of the shell-side heat transfer coefficient. It was obvious that heat duties obtained from the experiment significantly deviated from those calculated by the conventional Bell-Delaware method. A new correlation of the unequal baffle spacing correction factor was developed. It was shown that the new correlation improves the accuracy of the Bell-Delaware method considerably. This result may induce the use of the Bell-Delaware method in developing a computer software for design of shell-and-tube heat exchangers.

• 대한인간공학회지
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• 제32권5호
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• pp.449-457
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• 2013

Objective: The aim of this study is to investigate the effect of Hangul font on reading speed when texts are displayed on the computer screen. Background: Reading performance is influenced by fonts. However, there are few studies of Hangul font from a cognitive perspective. Fonts could affect reading performance directly and indirectly, interacting with other visual-perceptual factors such as size, word spacing, and line spacing. Method: In experiment 1, two variables were manipulated; a frame condition(square frame non-square frame) and a stroke condition(serif sans-serif). According to each condition, one of the four fonts was applied to the texts. The height of the four fonts was controlled. The participants were asked to read aloud the presented texts. In experiment 2, the non-square frame fonts were adjusted to have approximately the same size, width, letter spacing, and word spacing as the square frame fonts. The experimental design and task used in experiment 2 were identical with experiment 1. Results: In general, reading speed was faster in the square frame fonts than in the non-square frame fonts. The reading speed was not significantly different across stroke conditions. Conclusion: The frame of Hangul font significantly influenced reading speed. These results suggest that the type of Hangul font is a factor to affect reading performance. Application: The frame of fonts should be considered in designing of new fonts. The square frame fonts should be the preferred choice to enhance legibility.