• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.578-581
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• 2011

H.264/AVC에서는 율-왜곡 최적화 기법을 사용하여 부호화 성능을 이전 보다 대폭 향상시켰다. 율-왜곡 최적화 기법은 선택할 수 있는 모든 코딩 모드들의 비용을 계산한 후, 최소의 비용을 가진 모드를 선택하여 부호화를 한다. 따라서 코딩 모드들이 많아질수록 복잡도 역시 증가하며, 기존 표준보다 다양한 코딩모드를 지원하는 H.264에서는 복잡도가 더 많이 증가한다. 본 논문에서는 SAHTD(Sum of Absolute Hadamard Transform Difference)를 이용하여 화면 내 모드 결정부에서 빠른 화면내 모드 결정을 하면서도 압축 손실이 적게 발생하는 방법을 제시하였다. 휘도 신호 $16{\times}16$블록, 휘도 신호 $4{\times}4$블록, 색차 신호 $8{\times}8$블록 모두 SAHTD를 기준으로 최적의 모드가 결정된다. 휘도 신호 $16{\times}16$블록에서 SAHTD값에 따라 $4{\times}4$블록 부호화 과정을 조기 종결이 가능하게 하는 것과, 휘도 신호 $4{\times}4$에서는 SAHTD 값이 가장 낮은 3개의 모드와 MPM(Most Probable Mode)을 후보 모드로 선택하여 율-왜곡 최적화를 수행하는 방식이 사용되었다. MPM이 SAHTD값이 가장 낮을 경우 MPM이 휘도신호 $4{\times}4$블록의 최적의 모드로 선택되고 종료된다. JM 참조 소프트웨어를 통한 실험결과 제안된 기법은 기존 JM의 방식에 비해 화면 내 프레임의 부호화 시간의 84.7% 감소와 0.049dB의 PSNR 감소율, 0.595%의 비트 증가율을 보여주었다.

• Journal of Korea Multimedia Society
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• v.7 no.7
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• pp.896-904
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• 2004

In this paper, We present an efficient variable rate speech coder for spectral efficiency and packet processing technique for packet loss compensation of a voice codec with 10msec frame in VoIP service. Through disconnecting the users from the spectral resource during silence interval of about 60% period, a variable rate voice coder based on a voice activity detection(VAD) can increase spectral gain by two times. The performance of the method was analyzed by variation of detected voice activity factor and degraded speech frame ratio under various background noise level, and compared those of G.729B of ITU-T 8kbps standard speech codec. A method to compensate lost packets utilized addition of recovery data to a main stream and error concealment scheme for speech quality enhancement, the performance is verified by reconstructed speech quality. The proposed scheme can achieve spectral gain by two times or enhance speech quality by 3dB through reserved bandwidth of VAD. Therefore, the proposed method can enhance a spectral efficiency or speech quality of VoIP.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.5 no.2
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• pp.59-88
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• 2010

The National Research and Development(R&D) has put a greater emphasis on development of a market- and customer-oriented technology and its commercialization in the market. To promote commercialization of technologies invented through the national R&D, many governmental and public organizations have been offering various assistance programs. In spite of these assistance programs, the commercialization rate of the Korean national R&D outcomes is relatively lower than other advanced countries including the United States and European countries. Thus, this paper analyzed 24 R&D commercialization assistance programs which are provided by several institutions in the four different nations. As a result of analysis, we recommended the areas for improvement in the Korean R&D commercialization assistance programs. Also we suggested a framework driving an effective collaboration among the institutions assisting commercialization, the institutions funding and managing R&D, and the people performing R&D.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.893-900
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• 2004

This paper is to define the method that develops the software In proper to application areas of Geographic Information Systems and design patterns according to functions and roles that implement the system for safety evaluation of the groundwater well based on an object oriented spatial model. In order to design the user interface of the groundwater well, this paper proposes the framework that should classify only requisite components adaptable to various application areas. By specifying De pattern appropriate to the application domain and designing the analysis pattern using the UML based on the object oriented methodology. this paper shah contribute to enhance the reuse of components that can develop and distribute a .large scale open system.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.511-515
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• 1999

The main factor decreasing speech recognition rate is the surrounding noise. To lower the noise effect, we generally used the filter bank at preprocessing stage. But, in this paper, we tried to recognize the 10 numeral numbers using 2-D LPC to extract image feature. At first, we obtained the result of speech-only recognition using 13th-order LPC coefficients and then, for distorted speech recognition results of ‘0’, ‘4’, ‘5’, ‘6’ and 9’, we added image parameters such as 12th-order 2-D LPC coefficients. At each frame, we extracted the 2-D LPC coefficients, and simulated recognizer with two parameters such as speech and image. Finally, for the numbers, such as ‘4’and ‘9’, the better results were obtained.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.523-530
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• 2008

There are many defects that cause the process improvement of lifecycle problems during software development. This paper propose the management method of risk items that removes and manages the lifecycle problems as well. For the similar projects, we can estimate defects and prepare to solve them by using domain expert knowledge and the state analysis of defect items, which can greatly improve the software process. This research provides solution of management of risk items problem and detection of defect transition and its prevention and causes that happen on software development. Also, In this paper propose to making quantity of degree and transition phase.

• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.310-315
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• 2015

A single channel VAD (Voice Activity Detection) algorithm for nonstationary noise environment is proposed in this paper. Threshold values of the feature parameter for VAD decision are updated adaptively based on estimates of means and standard deviations of past non-speech frames. The feature parameter, SPD-TE (Spectral Power Difference-Teager Energy), is obtained by applying the Teager energy to the WPD (Wavelet Packet Decomposition) coefficients. It was reported previously that the SPD-TE is robust to noise as a feature for VAD. Experimental results by using TIMIT speech and NOISEX-92 noise databases show that decision accuracy of the proposed algorithm is comparable to several typical VAD algorithms including standards for SNR values ranging from 10 to -10 dB.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.415-417
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• 2020

무형문화유산의 전수 방식은 장인과 이수자의 직접적인 교육으로만 이루어져 왔으며 또한 전수는 긴 시간 동안 이루어지고 전수 방식을 따로 기록하는 경우가 드물며 동작이나 구전으로만 전해지기 때문에 표준화된 전수는 이루어질 수 없었다. 현재 국제 유네스코와 국내문화재청에서는 유무형문화재에 대한 전수와 기록의 중요성을 알고 다양한 디지털 기록을 진행하고 있다. 하지만 4차 산업혁명 시대에 무형유산 기록화 기술은 보유자의 기 예능 장인 공법을 기록하는 부분으로 영상기록 및 사진기록 도서 음원 등 아직까지 기존 아날로그 기술 방법으로 기록이 이루어지고 있으며 최근 5G 상용화와 함께 디지털 4차 산업 혁명시대와 발맞춰 무형유산 정보관리 기관에서도 무형유산 ICT 기반 기술 지원을 활성화되고 있는 시점에서 본 연구는 오랜 시간 동안 숙련도 높은 기술공법으로 한국 전통문화의 맥을 이어가고 있는 무형문화재 장인들의 기술 중에서 손을 사용하는 바느질 중심으로 자이로센서 기반으로 정확한 손동작 정보를 획득하고 기록할 수 있는 시스템 설계 및 연구개발을 통하여 ICT 기반 장인 공법 4D 기록화 기술을 제시하고자 한다. 이와 같은 기술로 무형문화유산의 새로운 4D 기록 방법으로 정확하게 기록하고 보존하여 무형문화유산 전승과 교육을 할 수 있고 문화유산의 유형에 맞는 교육·산업·홍보 등 다양한 사용 목적에 맞는 형태로 폭넓게 사용될 수 있다.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.38-47
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• 2000

Recently, finite element method has been used as an effective tool in the design process of sheet metal forming. In the present study, an implicit method and an explicit method have been developed for 2D analysis and 3D analysis, respectively, and applied to several processes including plane strain draw bending and TWB sqaure cup drawing. Also, commercial codes are used for geometrically complex problems, such as tube hydroforming, "L" cup deep drawing and side frame forming. In this paper, basic formulations used in the methods are introduced and results obtained from the applications are discussed.discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.674-681
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• 2008

The main noise source of the BLDC rotary compressor for air conditioner was analyzed by using the measurement of noise and vibration, noise contour, and experimental modal analysis. The source is presumed to the mechanical resonance excited by the electromagnetic attractive force of the BLDC motor. To reduce the excessive noise of the BLDC rotary compressor due to the mechanical resonance, air-gap was enlarged. Its validation was conducted by the analysis of the electromagnetic attractive force which is generated by the BLDC motor. By enlarging the length of air-gap, the noise in the compressor and air conditioner was significantly improved by 2.5dB(A) and 4.5dB(A), respectively.