• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.48-53
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• 2000

To analyze a room reverberation, many objective parameters have been suggested as measures of subjective perception in concert hall acoustics. However, it is difficult to understand the relationship among the individual parameters and to have a whole image of them. In this paper five primary objective parameters were selected and a reverberation model based on them was established by the reverberation decay curve. The proposed model was interpreted geometrically in terms of subjective characteristics. And finally we discuss the usefulness and the limitation of the model when it is applied to the analysis and.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.256-260
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• 2001

본 논문에서는 디지털 이동전화(CDMA) 채널환경을 통과한 왜곡된 전화음성에 대해 객관적 음질평가 척도의 개발을 위한 기초 연구로서 기존의 CD(Cepstral Distance), MSD(Mel Spectral Distance), BSD(Bark Spectral Distance), Modified BSD, PSQM(Perceptual Speech Quality Measure)를 대상으로 객관척도 알고리즘을 성능평가 하였다. 이 척도들은 실제 이동전화 환경에서 수집된 PCS 음성데이터에 대해서 적용하였으며 이 결과치를 주관적 음질평가 방법인 MU와 상관성을 비교 조사하였다. 실험 결과, BSD와 MBSD, 그리고 PSQM 척도의 상관성이 각각 0.80, 0.85, 0.84로 나타났으며 CD, MSD 보다 성능이 상대적으로 더 우수함을 보였다.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.87-95
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• 2012

We propose that a subjective image quality assessment based on objective image quality factors in order to evaluate objectively preference of consumers. In other words, we define objective image quality factors which are easy to accept by manufacturers and they are composed of subjective image quality assessment questionnaires. Also, portrait image is selected by stimulus in order to persue easiness of evaluation for the general subjects. Throughout a subjective image quality assessment model, we evaluate recognition of image quality by consumers and analyze the effectiveness of correlation in terms of the final image quality preference. Analyzing the relationship between image quality factors, we can figure out the preferable image quality and confirm the positive effects on consumers' recognition of image quality. In the results, there are strong relationship between preference and color reproduction, dynamic range, noise, and resolution respectively. especially, the characteristic of portrait, there is high correlation between color reproduction and preference.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4A
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• pp.310-315
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• 2002

The Bark Coherence Function (BCF) defies a coherence function within perceptual domain as a new cognition module, robust to linear distortions due to the analog interface of digital mobile system. Our previous experiments have shown the superiority of BCF over current measures. In this paper, a new BCF suitable for VoIP is developed. The unproved BCF is based on the wavelet series expansion that provides good frequency resolution while keeping good time locality. The proposed Wavelet based Bark Coherence function (WBCF) is robust to variable delay often observed in packet-based telephony such as Voice over Internet Protocol (VoIP). We also show that the refinement of time synchronization after signal decomposition can improve the performance of the WBCF. The regression analysis was performed with VoIP speech data. The correlation coefficients and the standard error of estimates computed using the WBCF showed noticeable improvement over the Perceptual Speech Quality Measure (PSQM) that is recommended by ITU-T.

• Science of Emotion and Sensibility
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• v.19 no.2
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• pp.67-78
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• 2016

The purpose of this study was to investigate relationships among the older drivers' subjective evaluation and objective performances for driving ability, mobility and subjective well-being. Scores for mobility and subjective well-being were obtained using questionnaires. Diagram-based driving scenarios and driving simulation were used to measure subjective and objective driving abilities, respectively. The results can be summarized as followings. First, subjective evaluation scores of driving ability but not objective driving performance significantly correlated with mobility. Second, the higher level of mobility predicted higher life satisfaction, higher positive affectivity, and lower negative affectivity. Third, the older driver's higher scores of subjective driving ability induced higher level of mobility, which, in turn, increased life satisfaction and positive affectivity but lower negative affectivity. The results suggested that subjective rather than objective ability for driving is more important in determining the level of old driver's subjective well-being.

• The Journal of Information Technology
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• v.3 no.3
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• pp.27-37
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• 2000

Although an insurance criterion for reliance is unified, the difference in evaluation mechanism in every country is already ambiguity. In other words, the aspect of objectivity would be a little because it is true that the vulnerability evaluation include evaluator, scenario and tools (TSVES) applying in test, depth and scope of evaluation. But evaluation results can be difference in accordance with each evaluation elements. By using TSVES to evaluating network security vulnerability, first, we expected the evaluation results is impartiality, objectivity, repeatability, reproducibility, appropriateness and soundness of results. Second, it could be transferred manual ways into automation ways, and then expected easiness and safety of extension and modification in a quality of products as well as a dramatical reduction of waste of time and energy.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.207-216
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• 2003

An instructor in education generally takes the objective-type evaluation for grading. The subjective-type evaluation has the merit that it can estimate the high-recognition ability, but the problem of the objectivity and reliability of the evaluation. This paper proposes the model which grades for the subjective-type evaluation. and designs and implements the evaluation system using the synonym thesaurus. This system can process the diverse and wide subjective-type questions and provide the easy usage for a beginner. It also can reduce the time and endeavor for evaluation and provide the objectivity of the evaluation. The system results the 73% success rate. We expect that this system will become a basis of the research on the subjective-type evaluation.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.545-548
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• 2002

Inharmonicity가 피아노의 음색에 미치는 영향을 가능한 한 객관적으로 평가하기 위해 본 연구 에서는 inharmonicity는 다르면서 음색에 영향을 미치는 다른 모든 요소들은 같게 합성된 여러 샘플들을 이용해 청취평가를 시행하는 방법을 사용한다. 합성된 피아노 음의 부분음들이 가지는 시간 영역 엔벌로프는 실제 녹음된 피아노 음에서 추출되었으며 인위적으로 조절되는 inharmonicity 의 크기 역시 실제 녹음된 피아노 음에서 얻은 데이터에 근거하였다. 청취평가는 피아노의 음색을 표현한다고 생각되는 적절한 형용사들의 쌍으로 만들어진 질문들로 이루어졌으며 평가를 반복해가며 보다 객관성을 높이기 위한 방법들을 시도하였다. 이러한 과정에서 얻은 결과들을 통해 그 동안 막연히 이해되어오던 inharmonicity와 음색의 관계를 보다 세밀하고 객관적으로 분석할 수 있다.

• Information and Communications Magazine
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• v.11 no.9
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• pp.79-92
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• 1994

음성인식 및 합성 시스템으로 대표되는 음성입출력장치의 개발 및 실용화에 따라 이들의 성능을 객관적으로 평가할 수 있는 방법이 중요하게 되었다. 그러나 국내에서의 이분야에 대한 체계적인 연구는 맞지 않다. 본고에서는 이와 관련한 지금까지의 국내외 연구예들을 검토하고 우리 실정에 맞는 평가법 작성을 위한 방법을 모색하고자 한다. 음성입출력장치의 객관적인 평가방법이 확립되면 연구 개발자는 여러방식의 우열을 객관적으로 파악할 수 있고 신뢰성있는 시스템을 효율적으로 개발할 수 있으며 관련제품의 사용자입장에서는 제품간의 성능비교가 가능하게 될 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1331-1332
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• 2011

가상사설망(VPN)시스템은 기존 사설망의 고비용과 비효율적인 관리를 해결하기 위해 인터넷망을 마치 전용선으로 사설망을 구출한 것처럼 개발한다. 본 연구에서는 ISO/IEC 9126과 ISO/IEC 25000를 기반을 둔 객관성 있는 품질평가 방법을 구축하고 가상사설망시스템 제품 고유의 보안특성을 접목한 품질평가 체계를 구축함으로써 객관성과 타당성을 갖춘 평가모델을 개발하였다.