• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.535-538
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• 2007

System manager needs monitoring tool(S/W) to manage cluster system. But, it is difficult to decide suitable monitoring tool for small SMP cluster system. This document described design of monitoring tool(mon) and development. Mon is monitoring tool for small SMP cluster system using InfiniBand network switch. Function of this tool is monitoring such as computing node(7 node), Infiniband network switch and monitoring of PBS job.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.4
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• pp.23-31
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• 1999

본 논문에서는 Ka 밴드 위성시스템에서 가장 큰 신호감쇠 요인으로 작용하는 강우효과를 분석하고 그 보상 방안으로서 계층형 8-PSK 변조방식을 제안하였다. 동기복조를 가정한 이론적인 BER 성능과 국내 강우 데이터에 근거한 예상되는 수신신호 품질을 분석하고 기존의 계층형 16-QAM 변조방식과 제안한 계층형 8-PSK 변조방식간의 성능을 비교하였다. 강우강도 및 강우감쇠는 대수정규 분포함수를 이용하여 추정하고 수신신호 품질은 서비스 중단 확률, 평균 수신 SNR에 대해 분석하였다. 결론적으로 제안한 계층형 8-PSK 변조방식은 기존의 계층형 16-QAM 변조방식과 비교해서 전반적으로 매우 우수한 성능을 가짐을 확인하였다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.82-85
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• 2001

본 논문에서는 S밴드(2-4 GHz)와 C밴드(4-8 GHz)에서 사용가능한 비동심원 복사구조와 저임피던스 급전구조를 갖는 광대역 원형 링슬롯 안테나를 제안하였다. 본 안테나는 유전율 4.3, 두께 1mm의 기판을 대상으로 해석되었다. 재안된 안테나의 계산된 임피던스 대역폭은 122%(S$_{11}$$\leq$-10 dB)이므로 기존의 원형 링슬롯 안테나보다 훨씬 광대역이다. 또한 주요 설계변수들을 변화시켰을 때 변경되는 안테나의 특성을 연구함으로써 최적화설계에 도움이 되도록 하였다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.329-336
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• 2016

Deaf people using sign language are experiencing social inequalities and financial losses due to communication restrictions. In this paper, real-time pattern recognition algorithm was applied to distinguish American Sign Language using an armband sensor(8-channel EMG sensors and one IMU) to enable communication between the deaf and the hearing people. The validation test was carried out with 11 people. Learning pattern classifier was established by gradually increasing the number of training database. Results showed that the recognition accuracy was over 97% with 20 training samples and over 99% with 30 training samples. The present study shows that sign language recognition using armband sensor is more convenient and well-performed.

• The Journal of the Acoustical Society of Korea
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• v.21 no.1
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• pp.37-41
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• 2002

In this paper, we made shorter EDT(early decay time) of room reverberation curve using multiple-channel. The speech signal was processed inverse filtering with full-band and sub-band in the basis MINT, and then the multiple-channel adaptive filters were used LMS (Least Mean Square) and NLMS (Normalized Least Mean Square) algorithm. Experimental results, we could get 1/3 of time reduction at 20dB level in the reverberation curve using full-band NLMS when two microphones were used. Also, it is shown that the speech articulation was improved 80% from the test listeners with the speech, which was to shorten EDT by MINT in the subjective assessments using real room impulse response.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.261-269
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• 2004

In this paper, an efficient algorithm for computing in the MPEG/audio Layer Ⅲ (MP3) encoder is proposed. The proposed algerian performs a full-band 1024-point FFT by computing 32-point FFT's of 32 subband outputs. To reduce the aliasing caused by the analysis filter bank, an aliasing cancellation butterfly is developed. A major benefit of the proposed algorithm is the computational saving. By using the proposed algorithm, it is possible to save 40~50% of computations for FFT, which results in about 20% reduction of the PAM-2 complexity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1067-1074
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• 2005

Studied antenna's basic structure was circular micro-strip patch antenna. Bandwidth was broaden and back-radiation pattern was decreased because studied antenna had PBG on a ground for improvement in its defect which is skin-effects. And character of antenna according to different shape of PBG was observed. Finally, air-gap whose dielectric constant is lower than substrates was added between substrates sc respond frequency was higher despite small size antenna.

• The Journal of the Korea Contents Association
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• v.2 no.4
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• pp.23-29
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• 2002

This paper suggest the image compression that is needed to process PACS in medical information system. The image decoding method is used Linear-predictor and Lloyd-Max quantizer(quantization) in the Wavelet transform domain. Wavelet Transform Method is processed the multi-resolution by dividing image into 10 sub-bands of 3 levels. Low frequency domain that is sensitive to human visual characteristic is encoded by DPCM which is lossless encoding methods, and Lloyed-Max quantizer, the optimal quantizer for reducing ringing and aliasing in the image of inter sub-band, is used in the remaining high frequency domain of sub-band. The examination verifies that decompressed images are superior by the result that PSNR is 28.53dB on the input image, 512$\times$152 abdominal CT image and Chest image.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.354-354
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• 2011

ZnO 나노와이어는 밴드 갭이 3.37 ev로 큰 밴드 갭을 갖는 물질이며 엑시톤 결합에너지가 60 meV로 GaN(25 meV)같은 다른 반도체보다 매우 크다. 또한 밴드갭 에너지가 큰 GaN, SiC와 같은 반도체에 비해서 화학적, 열적 안정성이 크며 낮은 온도에서 성장이 가능하다는 장점이 있다. 본 연구에서는 pre-heating process를 이용하여 1차원 구조인 ZnO nanowire를 수열합성법으로 합성하였다. 실험방법으로는 E2K glass 기판위에 AZO40 nm를 증착후, 시드층으로 이용하여 ZnO nanowire를 성장하였다. precusor 전구체에는 ZN(NO3)2 ${\cdot}$ 6H2O와 Capping agent으로의 역할을 위해 PEI와 OH-source 공급을 위한 Ammonium chloride를 첨가하여 합성하였고, 그에 따른 ZnO nanowire의 morphology 및 aspect ratio를 조절하고자 하였다. 마지막으로 ZnO 나노와이어의 구조적, 광학적 특성 평가를 하기위해 XRD, FE-SEM, PL 등을 이용하여 측정 하였고, 향후 나노발전기, 태양전지 등 여러 광학기기 등에 전극재료로서 응용 가능성에 대해 알아보고자 하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.1
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• pp.105-116
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• 2017

In this Paper, We Empirically Investigated what kind of Risks Exist that Drive high Failure rate of cloud Services, and whether Perception of such risks leads to the Adoption of the Abandonment Option of cloud Services. Such risk Perception is the Individual-level Factor, and we Empirically Tested whether Organizational Contexts such as CEO's Innovativeness and Dandwagon Effect can Moderate the Positive Effects of such Individual-level Risk Perception on the Adoption of Abandonment option. We Collected Survey data from IT Professionals Working for the Small and Medium-sized Companies near Seoul and found that the Perceived Technical Risk and Economic Risk Influence the Adoption of Abandonment Option. Out of two Organizational Contexts, only CEO's Innovativeness Moderates the Positive Influence of Technical Risk on the Adoption of Abandonment Option. Organizational Factors Demonstrated very Limited Moderation Effect on the Influence of Individual-level Perception of Cloud Service Risk on the Adoption of Abandonment Option.