• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.564-569
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• 2021

In this paper, for the typical LED and the tilted LED, when there is no electrode, when 20% absorption (80% reflection) occurs at the electrode, and when 60% absorption (40% reflection) occurs at the electrode, the effect of the absorption at the electrode and the height of the active region on the photon extraction efficiency and the mean photon path length was investigated, and an appropriate height of the active region was proposed. In a typical LED, as the absorption of the electrode increases, the photon extraction efficiency decreases from 18% to 15% and 13%, and the photon extraction efficiency is highest when the height of the active area is located in the center between the two electrodes. In the tilted LED, as the absorption of the electrode increases, the photon extraction efficiency decreases from 38% to 33% and 25%, and the photon extraction efficiency is highest when the height of the active area is located in the center between the two electrodes. The tilted LED can increase the photon extraction efficiency more than twice than that of a typical LED, where photons are trapped inside the chip due to total reflection.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.42-47
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• 2007

In this paper, influence of lossy ground and gap variation between lossy ground and UWB antenna on impulse propagation in time domain for impulse ground penetrating radar (GPR) is numerically and experimentally investigated. For this study, a novel planar UWB fat dipole antenna is developed. First, influence of lossy ground and gap variation between lossy ground and UWB antenna is simulated. For verification, a test field of sand and wet clay soil is built and using the developed dipole antenna, transmission behavior is investigated at the test field. With an aid of IDFT (inverse discrete Fourier transform), time domain impulse response for transmission coefficient measured and simulated in frequency domain is obtained. Measurement and simulation show that the frequency of maximum transmission coefficient and transmission coefficient are increased with higher dielectric constant and larger gap distance. In time domain, it is shown that for higher dielectric constant, the amplitude of the received signal in time domain is higher and reflected signals are seriously modified. Also, it is found that variation of gap between antenna and ground surface makes timing of peak value changed.

• Journal of Gifted/Talented Education
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• v.19 no.3
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• pp.585-602
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• 2009

The purpose of this study was to compare the 5 OEs of Korean gifted elementary students and non-gifted and to find out the gender difference in gifted and non-gifted to clarify the best predictor of giftedness in gender group. The total subjects of this study were 372 Korean third, fourth, and fifth grade elementary school children. One hundred sixty six children of them belonged to a gifted group, and 206 were non-gifted group. Two hundreds one out of 372 subjects were boys and 171 were girls. The Overexcitability Questionnaire II(OEQII) used in this study was developed by Falk, Lind, Miller, Piechowski, & Silverman in 1999. The OEQ II is consisted of 50 Likert-type items, classified into five subscale: psychomotor, sensual, imaginational, intellectual, and emotional. And it was translated into Korean. It was administered in group sessions during the winter of 2008. Data were analyzed with SPSSWin 12.0. MANOVA was conducted to determine statistical differences by giftedness and by gender. The results revealed that the level of 5 OEs of gifted elementary children was higher than non-gifted(normal) children. The intellectual OE showed the most powerful explanation among the 5 forms of OEs. This study also found the gender difference within the gifted group as well as with the whole subjects. The mean scores of sensual, imaginational and emotional OEs were higher in girls than in boys. Based on the gender difference within the gifted group and the whole group, it is assumed that imaginational OE may be the best predictor of gifted girls among school-age children.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.151-154
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• 2012

본 논문에서는 화상통신의 현실감을 증진시킬 수 있는 화자 간 시선 맞춤 시스템을 제안한다. 제안하는 방법은 Kinect 거리 카메라로부터 입력된 영상에서 화자의 얼굴 영역을 획득하여 화자의 시선이 카메라를 응시하도록 획득한 영역을 변환한 후에 원본 영상과 합성한다. Kinect 거리 카메라에서 획득한 얼굴 영역에는 다양한 형태의 잡음이 많아 미디언 필터와 모폴로지 연산을 통해 얼굴 영역의 잡음을 제거한다. 화자의 위치에 상관 없이 화자가 카메라를 응시하는 영상을 생성하기 위해서 Kinect 가 제공하는 거리 정보를 이용하여 시선 보정 각도와 회전 축을 획득한다. 시선이 보정된 얼굴 영역은 원본 영상에서 존재하지 않는 영역을 포함하고 있기 때문에, 원본 영상의 각 화소를 삼각형 메쉬로 구성한 후 해당 영역을 보간하여 최종적으로 시선이 보정된 영상을 생성한다. 제안하는 방법은 시선 맞춤 영상을 생성하는 데 필수적인 눈과 주변 얼굴 영역만 선택해서 변환하므로 영상의 왜곡이 적고 실시간 처리가 가능하다는 장점이 있다. 또한 카메라와 화자 사이의 거리 정보를 이용해 화자의 위치에 적응적인 시선 맞춤 영상을 생성할 수 있다. 실험을 통해 Intel i5 CPU 를 장착한 PC에서 $320{\times}240$ 크기의 영상을 사용할 경우 초당 약 35 프레임의 보정된 영상을 생성하여 제안하는 방법이 실시간 처리가 가능하다는 것을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.1-15
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• 2009

In this paper, we have proposed an automated system that accurately measures the thickness and unbalanced wear of brake shoes, and the distance between brake shoes and wheels for travelling rolling stock. The images of brake shoes are captured automatically while rolling stock is passing by an inspection station. And in order to measure the thickness, etc. the locations of brake shoes are first determined because the locations are not the same in the captured image. Toward this goal, shadow regions between the brake shoes and wheels are utilized that are common in all captured images. The boundary of the shadow regions is modeled by an second order polynomial, and constrained curve fitting method is adopted to detect a curve (the initial curve) that passes through the regions. Then, three curves that correspond to the front, back of brake shoes and wheels, and a line that passes through the vertical surface of brake shoes are detected using the initial curve and intensity change information. Finally, the thickness, etc. are calculated using the detected curves and line, and experimental results showed that the brake shoe thickness was measured with an accuracy of 0.654mm.

• The Journal of the Acoustical Society of Korea
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• v.25 no.4
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• pp.151-158
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• 2006

In this paper, we proposed a new audio fingerprint extraction method, based on Philips' music retrieval algorithm, which uses the energy difference of neighboring filter-bank and probabilistic characteristics of music. Since Philips method uses too many filter-banks in limited frequency band, it may cause audio fingerprints to be highly sensitive to additive noises and to have too high correlation between neighboring bands. The proposed method improves robustness to noises by reducing the number of filter-banks while it maintains the discriminative power by representing the energy difference of bands with 2 bits where the quantization levels are determined by probabilistic characteristics. The correlation which exists among 4 different levels in 2 bits is not only utilized in similarity measurement. but also in efficient reduction of searching area. Experiments show that the proposed method is not only more robust to various environmental noises (street, department, car, office, and restaurant), but also takes less time for database search than Philips in the case where music is highly degraded.

• 한국IT서비스학회:학술대회논문집
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• 2007.11a
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• pp.685-690
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• 2007

서비스산업의 비중이 전체 경제에서 70% 이상의 비중을 차지하면서 서비스산업의 중요성은 날로 높아지고 있다. 이러한 시기에 IBM에서는 경영과 과학의 접목을 통한 접근법을 제안하며 서비스 사이언스라는 키워드를 학계에 제시했다. 그러나 초기 단계인 서비스 사이언스는 아직 학문으로 정립되지 않은 분야이지만 앞으로의 기업경영활동에 양적, 질적 경쟁력 확보에 큰 역할을 하리라 예상된다. 본 연구에서는 기존 비즈니스 모델의 선행연구를 통하여 비즈니스모델의 구성요인을 서비스 사이언스 구성요소에 맞추어 재배치 시켜봄으로써 서비스 사이언스가 전혀 새로운 개별의 용어가 아니라 기존 비즈니스 모델의 확장된 영역임을 확인하고 이를 통하며 복합적인 학문의 범위를 어느 정도 가시화 시켜보고자 하는데 연구의 목적이 있다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.831-834
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• 2004

본 연구에서는 무제약으로 쓰여진 필기체 한글단어를 글자단위로 분할하는 새로운 방법을 제안한다. 이 방법은 글자와 글자사이 흑은 자소사이에 존재하는 배경(Background)정보를 세선화(Thinning) 처리하여 얻은 패스(Path)를 이용하여 글자와 글자사이를 지나는 패스를 결정하는 방법이다. 특히, 이 방법은 분할에 대한 판단을 인식기로 넘기지 않는 외적분할 방법으로 빠른 처리시간을 얻을 수 있고 외적분할 방법의 단정인 정확도를 다른 외적분할 방법에 비해서 높일 수 있었다. 제안한 방법은 필기체 한글에서 많이 발생할 수 있는 중첩(Over lap)글자와 연결(Touched)글자를 분할하는데 효과적인 성능을 보였다. 중첩글자의 경우, 세선화에 의해 생성된 패스가 자연스럽게 중첩된 부분의 사이를 지나가면서 생성되기 때문에 매우 정확한 패스를 얻을 수 있었고, 연결 글자의 경우는 연결된 부분을 판단하고, 후보영역을 선정하여 연결된 부분을 분리해내는 방법을 사용하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.426-428
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• 2021

반도체 디스플레이 기술과 정보통신 기술의 발전으로 디지털 사이니지는 기존의 단순 옥외 광고매체에서 탈피하여 이용자 맞춤 광고나 정보를 제공 및 스마트폰과 연동하여 콘텐츠 제공 가능한 시스템으로 발전하고 있다. 본 연구에서 디지털 사이니지의 작동오류의 위험성을 낮추며 비용절감을 할 수 있도록 제어 서버의 역할을 축소시키고 엣지 영역으로 서버의 역할을 최대한 분담하는 서버리스 기반 디지털 사이니지 시스템 구축 가능성에 대해 연구한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.600-601
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• 2021

The cyberspace, which is the fifth battle field, should be utilized for multi-domain maneuvering between the cyberspace and the physical space using an electromagnetic spectrum. This becomes a major concept of cyber electronic warfare that combines the characteristics of cyber warfare and electronic warfare. In this study, the concept of cyber electronic warfare is analyzed by using the OSI reference model and examining the threats of the two-layer data link layer.