• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.278-281
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• 2005

본 논문에서는 백색 잡음이 첨가된 오디오 신호로부터 잡음을 추정하고 이에 따른 지각 필터 보정을 통한 적응적 지각 필터의 속도 개선 알고리즘을 제안한다. 제안된 잡음 추정 알고리즘은 고주파 구간에서 획득한 잡음 에너지를 사용하여 지각필터를 구성하고 일정 대역에서 추정된 기울기를 고주파 영역에 적용함으로써 전 대역의 잡음 에너지를 효과적으로 제거할 수 있게 되며 필터의 속도 향상에도 크게 기여하게 된다. 이는 기존의 적응지각필터와의 비교를 위하여 수행속도 및 SSNR, NMR 비교를 수행하였고 그 결과를 통하여 성능 개선을 확인할 수 있었다.

• Current Photovoltaic Research
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• v.4 no.3
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• pp.119-123
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• 2016

We discussed various cover glass substrates available for photovoltaic (PV) modules, and investigated the fabrication methods of light trapping structures for the efficiency enhancement of PV modules: wet and dry etching or laser and direct patternings. We also introduced the analysis of haze at etched glass surfaces as a function of wavelength and also presented a anti-reflection coating technology for PV module.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.1
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• pp.31-39
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• 2010

An exergy analysis is carried out for the regenerative gas turbine cycle which has a potential of enhanced thermal efficiency and specific power owing to the more possible water injection than that of inlet fogging under the ambient conditions. Using the analysis model in the view of the second law of thermodynamics, the effects of pressure ratio, water injection ratio and ambient temperature are investigated on the performance of the system such as exergetic efficiency, heat recovery ratio of recuperator, exergy destruction or loss ratios, and on the optimal conditions for maximum exergy efficiency. The results of computation for the typical cases show that the regenerative gas turbine system with afterfogging can make a notable enhancement of exergy efficiency.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.2
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• pp.71-78
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• 2018

In this paper, we propose the performance enhancement of solar individual string power generation system using booster power control for voltage compensation. The proposed control method determines the variable voltage for the compensator using direct power control (DPC) modeling applied to motion factor estimation. This method also maintains excellent dynamic response to the characteristics of direct power control (DPC) by calculating the mismatch ratio of the arrestered PV modules. The validity of the proposed algorithm is verified through simulation and experiments.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.5
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• pp.14-23
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• 1995

A new dual-mode algorithm for blind equalization of quadrature amplitude modulation (QAM) signals is proposed. To solve the problem that the constant modulus algorithm (CMA) converges to the constellation with the arbitrary phase rotation, with the modification of the CMA, the proposed algorithm accomplishes blind equalization and carrier phase recovery simultaneously. In addition, the dual-mode algorithm combining the modified constant modulus algorithm (MCMA) with decision-directed (DD) algorithm achieves the performance enhancement of blind convergence speed and steady-state residual ISI. So we can refer the proposed algorithm to as a scheme for joint blind equalization and carrier phase recovery. Simulation results for i.i.d. input signals confirm that the dual-mode algorithm results in faster convergence speed, samller residual ISI, and better carrier phase recovery than those of the CMA and DD algorithm without any significant increase in computational complexity.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.3
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• pp.65-69
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• 2012

Since 2010, enhancement of the building energy efficiency and certification system and public office building should have been acquiring the first grade of Building Energy Efficiency. The Building Energy Efficiency Rating evaluation tool and Dynamic Analysis Energy simulation program for Building Energy Efficiency are widely used. The suitability to those programs have been discussed as a variety of programs have been used accordingly. In this study, evaluated the characteristic of Building Energy Efficiency Rating tool(ECO2) of the business building. At a result, the variables on the Weather Data, building Profile and building Load property in hourly between those Building Energy Efficiency evaluation tools have different.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.1
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• pp.115-120
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• 2004

An indoor air cleaner consisting of a dielectric barrier discharge system and an electrostatic precipitator (ESP) was experimentally investigated. The function of the dielectric barrier discharge is to precharge particles by producing nonthermal plasma before indoor air enters ESP, leading to an enhancement in dust collection efficiency. The dependence of particle size distribution on the plasma discharge was examined to understand the mechanism of the particle precharging. The plasma discharge was found to increase the electrical force of the particles, rather than agglomerate them. Coarse particles in the range of 0.5 to $5.0{\mu}m$ were observed to be easily collected by this indoor air cleaner, and the present study laid emphasis on the removal of fine particles of $0.3{\mu}m$. The collection efficiency of the fine particles was largely enhanced by the plasma discharge.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.63-66
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• 2006

음성인식시스템은 사람이 별도의 장비 없이 음성만으로 시스템의 사용이 가능한 편리한 장점을 지니고 있으나 여러 가지 기술적인 어려움과 실제 환경의 낮은 인식률로 폭넓게 사용되지 못한 상황이다. 그 중 배경잡음은 음성인식의 인식률을 저하시키는 원인으로 지적 받고 있다. 이러한 잡음환경에 있는 ASR(Automatic Speech Recognition)의 성능 향상을 위해 외측억제 기능 이 추가된 파라미터를 제안한다. ASR 에서 널리 사용되는 파라미터인 MFCC을 본 논문에서 제안한 파라미터와 HMM를 이용하여 인식률을 비교하여 성능을 비교하였다. 실험결과를 통해 제안된 파라미터의 사용을 통해 잡음환경에 있는 ASR의 성능 향상을 확인할 수 있었다.

• ETRI Journal
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• v.33 no.4
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• pp.645-647
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• 2011

In this study, a microcapillary pumped loop (MCPL) that can be used as a cooling device for small electronic and telecommunications equipment has been developed. For thin devices such as an MCPL, securing a vapor flow space is a critical issue for enhancing the thermal performance. In this letter, such enhancement in thermal performance was accomplished by eliminating condensed droplets from the vapor line. By fabricating the grooves in the vapor line to eliminate droplets, a decrease in thermal resistance of about 63.7% was achieved.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.12a
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• pp.109-112
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• 2000

고역의 주파수 성분이 감쇠되어 선명도가 저하된 이미지나 선형 보간법에 의해 확대된 이미지의 계단모양 왜곡을 감소시킴으로써 경계선의 선명도가 저하된 이미지들을 위해 형태학적 처리(morphological processing)에 의한 이미지 윤곽선의 선명도를 향상시키는 방법을 제안하였다. 본 논문에서는 블러링(blurring)된 이미지를 화소의 명암에 따라 다수개의 평판 이미지(slice image)로 나누고 각 평판 이미지에 대해 반복적인 최대/최소값 필터(min/max filter)의 적용으로 얻어진 윤곽선의 중심을 기준으로 하여 팽창(dilation)과 침식(erosion)을 수행함으로 이미지의 윤곽선에서의 명암 변화에 대한 경사도를 크게 만들고 이로써 이미지 윤곽선의 선명도를 향상시키는 방법을 사용하였으며 모의 시험결과를 통하여 고역 주파수 강조에 의한 방법에 비하여 인위적인 잡음(artifact)없이 효과적으로 선명도를 향상시킬 수 있음을 보였다.