• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.2
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• pp.96-105
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• 1992

The objective of this paper is to study experimentally on the noise characteristics of supersonic jet from multihole orifice in the range of jet pressure from $at_g$ to $at_g$ in the reverberation room. At first, the single orifice jets are investigated for various hole diameter from 3.8mm to 10mm. Through the noise spectrum, the turbulent mixing noise and the shock associated noise is analyzed. The noise for confined jets into a tube of diameter 30mm or 90mm with length 2m is investigated in comparision with that for the free jets. The sound power level is measured and compared with thoretical models for free jet. At second, multihole orifice jets are investigated to study the effect of multijet on noise reduction. The spectrum and power level of multijets are measured and compared with single jets. The multi-jets in a confined pipe are also investigated. It is found that the noise spectrum is significantly altered by increasing the number of jet with decrease in jet diameter and also by confining the jet into tube.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.53-57
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• 2009

The dividing flow in an open channel has a number of distinctive characteristics. One of these is that the separation zone interacts with a secondary motion along the inner wall of a branch channel, generating sediment accumulation. To investigate this phenomenon, a two-dimensional numerical model based on the shallow-water equations, RMA2, which calculates water surface elevations and horizontal-velocity components, was used to analyze the dividing flow. The obtained numerical results fully coincide with the laboratory measurements reported by Hsu et al.(2002). For the analysis of the numerical results, a separation zone-discharge rate relationship was proposed. To reduce the size of a separation zone, the topographies of diagonal and curved edges were proposed, smoothly connecting the upstream corner to branch channel.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.6
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• pp.617-624
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• 2011

The two-dimensional sloshing problem in a rigid rectangular tank with a free surface is considered. The flow is generated by a container in harmonic motion in time along the horizontal axis, i.e., a container excited by u=Asin($2{\pi}ft$) where u denotes the container velocity imposed externally, A is the amplitude of the oscillation velocity, and f is the frequency of oscillation. Experimental apparatus is arranged to investigate the large-amplitude sloshing flows in off-resonant conditions, where the large amplitude means that A~O(1), and the distance, S, is comparable to the breadth, L, of the container, i.e., L/S~O(1). Comprehensive particle image velocimetry (PIV) data are obtained, which show that the flow physics of the nonlinear off-resonant sloshing problem can be characterized into three peculiar free surface motions: standing-wave motions similar to those of linear sloshing, a run-up phenomenon along the vertical sidewall at the moment of turn-over of the container, and gradually propagating bore motion from the sidewall to the interior fluid region, like a hydraulic jump.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.187-195
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• 2015

This paper purposes to identify who is/are in charge of KBS broadcasting programming in view of freedom of broadcasting and interest of audience under the circumstance that Blue House put pressure on KBS to refrain from reporting Sewol Ferry disaster. For this purpose this study has reviewed prior theses, books, journals, laws, and cases, etc. It is analyzed that principal agents in charge of freedom of broadcasting journalism and programming are KBS employees in charge of producing broadcasting programs and KBS chief programming officer, who is appointed by KBS CEO. KBS CEO, who can easily be influenced by governmental pressure in terms of KBS structure, should avoid interfering with programming and producing directly or indirectly for freedom of the press and public interests.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.3 s.18
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• pp.11-21
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• 2005

This study is performed to understand complex behavior and to investigate the rational analysis methods for seismic design of the curved bridges. To analyze the curved bridges for the seismic loadings, it is used that the finite element analysis program has the 7-dof curved beam and straight beam element. The free vibration characteristics of the curved bridges are compared with the straight bridges that have span length same as the average arc length of inside and outside girder of those. For the same case, the dynamic behavior is compared under seismic loadings. It is found that regular bridges classified by AASHTO are analyzed as if those were straight. To investigate the dynamic behavior of general curved bridges under seismic loading, the seismic loading directions and the subtended angle of curved bridges are varied.

• International Area Studies Review
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• v.16 no.1
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• pp.327-349
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• 2012

This paper examined the strategic inward foreign direct investment and business performance in free economic zone. attractive of segment and country's competitive advantage were as proxy for the matrix of appropriateness. The marketing differentiation, inducement promotion, incentive, and business support were as proxy for the business performance. Based on the analysis of one hundred twenty cases, the following results were found. First, based on the attractive of segment and country's competitive advantage, the types of four segments was drawn. Second, the segment 4 have a significantly difference on their business performance. Third, strategic foreign direct investment have a significantly high difference on their marketing differentiation but a significantly low difference on their business support. Finally, the business performance, in order of performance, have a significantly difference on their marketing differentiation, inducement promotion, incentive, and business support. Limitation and suggestions for further are also highlighted.

• Journal of the Korean Magnetics Society
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• v.14 no.6
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• pp.236-239
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• 2004

We studied the specular spin valve (SSV) having the spin filter layer (SFL) in contact with the ultrathin free layer composed of Ta3/NiFe2/IrMn7/CoFel/(NOLl)/CoFe2/Cu1.8/CoFe( $t_{F}$)/Cu( $t_{SF}$ )/(NOL2)/Ta3.5 (in nm) by the magnetron sputtering system. For this antiferromagnetic I $r_{22}$M $n_{78}$-pinned spin filter specular spin valve (SFSSV) films, an optimal magnetoresistance (MR) ratio of 11.9% was obtained when both the free layer thickness ( $t_{F}$) and the SFL thickness ( $t_{SF}$ ) were 1.5 nm, and the MR ratio higher than 11% was maintained even when the $t_{F}$ was reduced to 1.0 nm. It was due to increase of specular electron by the nano-oxide layer (NOL) and of current shunting through the SFL. Moreover, the interlayer coupling field ( $H_{int}$) between free layer and pinned layer could be explained by considering the RKKY and magnetostatic coupling. The coercivity of the free layer ( $H_{cf}$ ) was significantly reduced as compared to the traditional spin valve (TSV), and was remained as low as 4 Oe when the $t_{F}$ varied from 1 nm to 4 urn. It was found that the SFL made it possible to reduce the free layer thickness and enhance the MR ratio without degrading the soft magnetic property of the free layer.

• Journal of KIISE:Software and Applications
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• v.35 no.11
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• pp.681-691
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• 2008

In this paper, we have evaluated and compared each feature and feature combinations necessary for statistical Korean dialogue act classification. We have implemented a Korean dialogue act classification system by using the Support Vector Machine method. The experimental results show that the POS bigram does not work well and the morpheme-POS pair and other features can be complementary to each other. In addition, a small number of features, which are selected by a feature selection technique such as chi-square, are enough to show steady performance of dialogue act classification. We also found that the last eojeol plays an important role in classifying an entire sentence, and that Korean characteristics such as free order and frequent subject ellipsis can affect the performance of dialogue act classification.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.489-491
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• 2012

본 논문은 교육용 서비스로 이용 가능한 카드 인식 시스템을 제안한다. 사용자는 자유자재로 카드 등록 및 삭제가 가능하며 카드의 회전 및 크기 변화에도 강건한 인식을 보인다. 본 논문에서는 카드 템플릿의 형태 정보와 Histogram of Oriented Gradients를 특징점으로 이용한다. 또한 최종 분류기에서 계층적인 구조를 적용하여 보다 정확한 카드 검출 및 인식을 제안한다.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.193-194
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• 2017

본 연구에서 다루고자 하는 마스크 디자인은 개인의 감정과 사고를 적극적으로 표현하기에 적합한 예술 영역에 해당한다. 따라서 마스크에 디자인된 조형미를 살펴보기 위해 디자인 된 마스크의 유형을 분류하고자 한다. 자유주제로 완성된 마스크디자인 작품을 그룹핑 하였으며, 최종적으로 데카탕스(Decadence), 판타지(Fantasy), 인사이트(Insight), 러블리(Lovely), 키치(Kitsch), 하이퍼 테크노(Hyper Techno)의 6가지 유형으로 도출하게 되었다. 이와 같은 유형 연구는 창의적인 마스크 디자인에 대한 정체성을 파악하는 데에도 매우 중요한 역할을 할 것이며, 관련 연구의 기초적인 토대를 마련하는 계기가 될 것으로 기대한다.