• 음성과학
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• 제8권1호
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• pp.53-66
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• 2001

This paper aims to investigate the acoustic characteristics of the vowels attested in Korean and French and to seek a way of understanding them from a phonological point of view. We first compare the two vowel systems by measuring the actual frequencies of the formants using CSL. It is shown that the first and second formants vary in wider range in French compared to Korean. In order to understand the two vowel systems from a phonological point of view, we apply the theory of Licensing Constraints, proposed and developed by Kaye (1994), and Charette and Kaye (1994). We propose the licensing constraints placed upon the vowels both in Korean and French. For Korean, we propose the licensing constraints such that both elements I and U must be heads. For French, we claim the following licensing constraints: U in a headed expression must be head, A cannot be head, and Nothing can only license an expression A in it.

• Industrial Engineering and Management Systems
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• 제11권1호
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• pp.87-93
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• 2012

This paper discusses a new weighting method for text analyzing from the view point of supervised learning. The term frequency and inverse term frequency measure (tf-idf measure) is famous weighting method for information retrieval, and this method can be used for text analyzing either. However, it is an experimental weighting method for information retrieval whose effectiveness is not clarified from the theoretical viewpoints. Therefore, other effective weighting measure may be obtained for document classification problems. In this study, we propose the optimal weighting method for document classification problems from the view point of supervised learning. The proposed measure is more suitable for the text classification problem as used training data than the tf-idf measure. The effectiveness of our proposal is clarified by simulation experiments for the text classification problems of newspaper article and the customer review which is posted on the web site.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.957-960
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• 2004

From a water-environmental point of view, with a change of understanding and concern about vegetation, it changes that vegetation acts as stability of channel and bed, providing habitats and feed for fauna, and means improving those with appreciation of the beautiful but resistant factor to the flow So, it becomes important concern and study subjects that turbulent structure by vegetation, shear stress and transport as well as roughness and average velocity by vegetation. But from a hydraulic point of view, vegetation causes resistance to the flow and can increase the risk of flooding, Therefore, this thesis concern the flow characteristics in vegetated open channels. According to the experimental results, $z_0$ was on an average $0.4h_p$ in a vegetated open channel. So, the elevation corresponding to zero velocity in a vegetated channel was the middle of roughness element. The limit for logarithmically distributed profile over the roughness element was from $z_0$ to $0.80h_{over}$ for a vegetated channel. Among the existing theory, the method of Kouwen et al.(1969), Haber(1982), and El-Hakim and Salama(1992) except Stephan(2001) gave a very good value compared to the measured velocity profile.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.430-437
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• 1998

The existing design expressions for shear strength of reinforced concrete columns are lacking in consistent seismic design philosophy and very conservative. However, relatively not so many experiments have been conducted to verify the shear resisting mechanisms of columns. The previous researches concentrated on deriving an experimental model from their test results. So, there is a need to approach this problem from the analytical point of view to be balanced with the experimental effort. This paper presents a method of modeling reinforced concrete columns under seismic shear loading. Lower bound solutions are obtained by using an analogous truss model and concrete arch actions. This model agrees with the precedented test results by some margins.

• 한국인터넷방송통신학회논문지
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• 제14권4호
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• pp.29-37
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• 2014

다시점 비디오는 카메라 수만큼의 컬러영상들과 깊이 영상들이 존재하므로 막대한 양의 데이터를 갖게 되어서, 그 양을 줄이는 새로운 압축 기술 개발이 필수적이다. 최근 계층적 깊이 영상(Layered Depth Image : LDI)의 개념을 이용하여 깊이 정보를 포함하는 다시점 비디오를 효과적으로 압축 부호화하는 기술이 주목 받고 있다. 이 방법은 여러 시점의 깊이 정보와 워핑(warping) 함수를 사용하여 다시점의 컬러와 깊이 영상을 합성하여 하나의 데이터 구조를 만드는 방법이다. 본 논문에서는 계층적 깊이 영상에서 실제 거리를 이용하고 오버랩(overlap) 문제를 해결하고 그리고 컬러 변환을 기반으로 복원을 위해서 추가되는 데이터의 양을 감소시켜 압축 성능을 향상시키는 방법을 제안하였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권3호
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• pp.271-275
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• 2008

근래의 지속적인 멀티미디어 기술의 발전과 컨덴츠를 이용하는 사용자의 향상된 욕구가 부합하여 새로운 실감 미디어 기술이 창출되고 있다. 그 중에서 다시점 비디오는 3차원 TV, 자유 시점 비디오 등의 기반 기술로써 활발하게 연구되고 있다. 하지만 시점 수의 증가에 따른 부호화 시간 증가, 비트율 증가 등이 문제점으로 작용한다. 본 논문에서는 다시점 비디오의 부호화 효율을 높이기 위해 향상된 GoGOP 구조를 제안한다. 즉, Key 프레임 위치 조절, 동적인 I 프레임 수 그리고 동적인 B 프레임 수를 이용하는 방법을 적용하여 향상된 GoGOP 구조를 제안하였다. 실험 결과, 본 논문에서 제안한 기법이 Anchor 구조와 비교하여 유사한 PSNR 값을 가지면서, 비트율이 상당히 감소하였다.

• 천문학회보
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• 제38권1호
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• pp.64.1-64.1
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• 2013

The point spread function (PSF) of an optical system is in general defined as a two-dimensional intensity distribution which results from a single point source at infinity. It is an important key for the evaluation of the optical performance of an astronomical telescope. The PSFs of the soft X-ray telescope (SXT) aboard Yohkoh were measured in a wide range of the field-of-view under the in-flight configuration at White Sands Missile Range prior to launching the satellite. It has been known that the SXT PSF has a sharp peak at the core and the intensity drops very fast as it goes distant from the center. Due to the combination of this sharp peak at the PSF core and the effect of undersampling by a large pixel size, a carefully designed method is requested in the examination of the PSF data. The pattern of the SXT PSF is determined by the fitting of a mathematical functional form to the pre-launch experimental data. The elliptical Moffat function has been adopted for the evaluation of the SXT PSF. It is revealed from our study that the SXT PSF shows a peculiar characteristics, and thus a careful consideration on the undersampling effect and also a proper choice of statistics are necessary for the determination of the best fit function of the PSF. Details on the on- and off-axis SXT PSF in the field-of-view will be introduced and discussed in our presentation.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.220-223
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• 2008

Large curved plate blocks are widely used to construct hull structure in shipbuilding industry. Most curved plates are manufactured by using manual method called as line heating that use deformation caused by residual stress after local heating along a line which is perpendicular to the curvature direction. However, its working environment is poor and its formability is totally dependent on an experienced technician. In view of that, multi-point dieless forming (MDF) technology that use reconfigurable punch arrays instead of one piece die is proposed in this study. The MDF process is based on a concept of equivalent die surface made by numbers of punches which has round tip at the end of it. In this study, numerical simulation for common curvature type such as saddle shape was carried out. In addition, experiments in the plate forming process were also conducted to compare with the numerical results in view of final configuration. Consequently, it was noted that the proposed dieless forming method has considerable feasibility to substitute the new process for conventional manual method.

• 공학교육연구
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• 제20권4호
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• pp.61-66
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• 2017

Automatic flow control system composed by hardware and software was designed and fabricated to be used as teaching tool of feedback control theory in university experimental class. This system includes hardwares like data acquisition board, flow measuring device, transmitters, and the pneumatic valve, and software like LabView program for the monitoring and control of flow rates. The system was designed as the student can see the control effect of not only set point but also disturbance changes. Also the LabView program was composed for the calculation of controller parameters of both Ziegler-Nichols and Cohen-Coon tuning. The students can apply both tuning constants and compare the control performances. This system will provide the easy way for the students to understand the function and specification of control hardwares, and to raise the programing ability of control software.

• 한국안전학회지
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• 제20권2호
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• pp.73-78
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• 2005

A fire is occurring increasingly every you and the damage is bigger in proportion to the number. Therefore a fire is classified as a serious calamity. It is important to evacuate and fight a fire by early Perception. However, if the alarming sound is not perceived when a fire breaks out the damage could be expanded. From this point of view, this study aims to analyse the correlation between alarming sound sources and sound quality parameters through psycho-acoustic experiment using Korean vocabularies extracted by existing study. The sound sources more dangerous, tense and urgent were chosen. The results from this study are as follows: 1. airraid, klaxon2 and S.O.S got a point more than conventional alarming sound.2. correlation coefficient between Loudness(L) and Unbiased Annoyance(UA) was highest with 0.63 md Sharpness(S) and Roughness(R) was -0.40 and Fluctuation Strength(FL) and Tonality(T).