언어 교육을 위한 음성 코퍼스의 설계 및 구축

최대림,김봉완,정은순,고락환,이용주 한국어정보학회 2007 한국어정보학 Vol.9 No.2

As language learning that utilizes speech and information processing technology is getting popular. Speech Information Technology & Promotion Center(SiTEC) has created and is distributing speech corpora for STiLL in order to support basic research and development of products. We will introduce the corpus for Korean and those for English which we have created and are distributing.

PVDHMM을 이용한 음소열 기반의 SDR 응용

최대림,김봉완,김종교,이용주,Choi, Dae-Lim,Kim, Bong-Wan,Kim, Chong-Kyo,Lee, Yong-Ju 대한음성학회 2007 말소리 Vol.62 No.-

In this paper, we introduce a phone vector discrete HMM(PVDHMM) that decodes a phone sequence string, and demonstrates the applicability to spoken document retrieval. The PVDHMM treats a phone recognizer or large vocabulary continuous speech recognizer (LVCSR) as a vector quantizer whose codebook size is equal to the size of its phone set. We apply the PVDHMM to decode the phone sequence strings and compare the outputs with those of a continuous speech recognizer(CSR). Also we carry out spoken document retrieval experiment through PVDHMM word spotter on the phone sequence strings which are generated by phone recognizer or LVCSR and compare its results with those of retrieval through the phone-based vector space model.

QoLT 소프트웨어 기술 개발을 위한 장애인용 음성 DB의 설계 및 구축

최대림(Dae-Lim Choi),김봉완(Bong-Wan Kim),정민화(Minhwa Chung),이용주(Yong-Ju Lee) 한국HCI학회 2012 한국HCI학회 학술대회 Vol.2012 No.1

In this paper we will introduce the work of creating a speech database to develop QoLT speech technology for disabled persons, which has been done as part of a national program to help better life for people. Speech recognition technology is indispensible to help the disabled communicate easily with others, and the distribution of a speech database which is created with the disabled in real environments is essential to develop this technology. Speech databases for development of QoLT software technology are composed of dysarthric speech database which is needed to develop an embedded key-word spotting speech recognition system tailored for the persons disabled in articulation and speech database for voice-controlled PC and word processors. At present a dysarthric speech database of a total of 160 speakers has been completed, and we are continuing to record new speakers with cerebral paralysis of mild and moderate severity. Speech database for voice-controlled PC and word processors of a total of 300 speakers will be collected this year. The created database is being used by the technology development team for QoLT speech recognition system. 본 논문에서는 지경부의 국민편익증진사업(QoLT)중 산업기술 기반 구축 사업의 일환으로 수행되고 있는 QoLT 소프트웨어 기술 개발을 위한 장애인용 음성 DB 구축 과제를 소개한다. 음성인식 기술을 활용한 QoLT 소프트웨어 기술은 장애인의 원활한 의사소통을 지원할 수 있는 필수적 기술이며, 발성 장애인을 위한 개인 맞춤형 내장형 명령어 인식기 개발과 지체장애인을 위한 음성워드프로세서 및 음성컴퓨터 소프트웨어 개발 분야에서 필요한 음성DB의 구축 및 보급이 반드시 선행되어야 한다. 현재 160명분의 경도 및 중도 마비 말장애인 음성 인식용 DB가 구축되었으며 올해 240명 규모로 확대할 계획이다. 이와 더불어 음성워드프로세서용 낭독체 연속어 음성DB가 300명 규모로 당해에 수집될 예정이다. 구축된 DB는 국민편익증진사업을 위한 기술 개발팀에게 보급하여 장애 유형에 따른 장애 음성 특성 분석 및 발성 장애인 개인 맞춤형 음성인식 소프트웨어 프로토타입 설계 및 구현, 지체장애인을 위한 음성워드프로세서 및 음성 컴퓨터 소프트웨어 개발 등의 연구에 공동 활용 중이다.

오디오 신호에 기반한 음란 동영상 판별

김봉완,최대림,이용주,Kim, Bong-Wan,Choi, Dae-Lim,Lee, Yong-Ju 대한음성학회 2007 말소리 Vol.63 No.-

As the Internet becomes prevalent in our lives, harmful contents, such as phornographic videos, have been increasing on the Internet, which has become a very serious problem. To prevent such an event, there are many filtering systems mainly based on the keyword-or image-based methods. The main purpose of this paper is to devise a system that classifies pornographic videos based on the audio information. We use the mel-cepstrum modulation energy (MCME) which is a modulation energy calculated on the time trajectory of the mel-frequency cepstral coefficients (MFCC) as well as the MFCC as the feature vector. For the classifier, we use the well-known Gaussian mixture model (GMM). The experimental results showed that the proposed system effectively classified 98.3% of pornographic data and 99.8% of non-pornographic data. We expect the proposed method can be applied to the more accurate classification system which uses both video and audio information.

SiTEC의 공동 이용을 위한 음성 코퍼스 구축 현황 및 계획

김봉완,최대림,김영일,이광현,이용주,Kim Bong-Wan,Choi Dae-Lim,Kim Young-Il,Lee Kwang-Hyun,Lee Yong-Ju 대한음성학회 2003 말소리 Vol.46 No.-

To support speech information technology industry it is vital to create and distribute standardized speech corpora to be used for the development of products and technologies. In this article we introduce speech corpora created by Speech Information Technology & Industry Promotion Center(SiTEC) during its 1st and 2nd fiscal years (2001/5/1-2003/4/30) and plans for those corpora which is being created currently or will be created in near future. We introduce the corpus for car application to expand speech information technology to the field of traditional industry, the corpora for foreign languages to support exportation, the corpus for basic research for the sake of application in the industry, the corpora for common use, and others.

자동차 주행 환경에서의 음성 전달 명료도와 음성 인식 성능 비교

이광현,최대림,김영일,김봉완,이용주,Lee Kwang-Hyun,Choi Dae-Lim,Kim Young-Il,Kim Bong-Wan,Lee Yong-Ju 대한음성학회 2004 말소리 Vol.50 No.-

The normal transmission characteristics of sound are hardly obtained due to the various noises and structural factors in a running car environment. It is due to the channel distortion of the original source sound recorded by microphones, and it seriously degrades the performance of the speech recognition in real driving environments. In this paper we analyze the degree of intelligibility under the various sound distortion environments by channels according to driving speed with respect to speech transmission index(STI) and compare the STI with rates of speech recognition. We examine the correlation between measures of intelligibility depending on sound pick-up patterns and performance in speech recognition. Thereby we consider the optimal location of a microphone in single channel environment. In experimentation we find that high correlation is obtained between STI and rates of speech recognition.

멜 켑스트럼 모듈레이션 에너지를 이용한 음성/음악 판별

김봉완,최대림,이용주,Kim, Bong-Wan,Choi, Dea-Lim,Lee, Yong-Ju 대한음성학회 2007 말소리 Vol.64 No.-

In this paper, we introduce mel-cepstrum modulation energy (MCME) for a feature to discriminate speech and music data. MCME is a mel-cepstrum domain extension of modulation energy (ME). MCME is extracted on the time trajectory of Mel-frequency cepstral coefficients, while ME is based on the spectrum. As cepstral coefficients are mutually uncorrelated, we expect the MCME to perform better than the ME. To find out the best modulation frequency for MCME, we perform experiments with 4 Hz to 20 Hz modulation frequency. To show effectiveness of the proposed feature, MCME, we compare the discrimination accuracy with the results obtained from the ME and the cepstral flux.

한국의 공동이용을 위한 음성언어자원의 구축 및 보급현황

이용주,김봉완,김영일,최대림,박지영 한국어정보학회 2008 한국어정보학 Vol.10 No.1

한국의 음성 정보 기술을 세계적 수준으로 향상시키기 위하여 음성정보기술산업 지원센터(SITEC)에서는 다양한 언어 자원을 구축하여 배포하고 있으며, 또한 다른 기관에서 구축된 자원들도 배포하고 있다. 본 논문에서는 관련 연구자들의 참고를 위하여 5년 동안의 정부 지원 기간에 SITEC에서 수행된 관련 활동과 언어 자원 관련 기관인 한국전자통신 연구원(ETRI), 언어자원은행 (BOLA) 및 국립국어원의 활동에 대해서도 요약하여 기술하고자 한다.

주파수 대역 제한에 의한 한국어 모음의 지각 특성 분석

김연화(Kim, YeonWhoa),최대림(Choi, DaeLim),이숙향(Lee, Sook-hyang),이용주(Lee, YongJu) 한국음성학회 2014 말소리와 음성과학 Vol.6 No.1

This paper investigated the effects of frequency band limitation on perceptual characteristics of Korean vowels. Monosyllabic speech (144 syllables of CV type, 56 syllables of VC type, 8 syllables of V type) produced by two announcers were low- and high-pass filtered with cutoff frequencies ranging from 300 to 5000 Hz. Six listeners with normal hearing performed perception tests by types of filter and cutoff frequencies. We reported phoneme recognition rates and types of perception error of band-limited Korean vowels to examine how frequency distortion in the process of speech transmission affect listener’s perception.

주파수 대역 제한에 의한 한국어 자음의 지각 특성 분석

김연화(Kim, YeonWhoa),최대림(Choi, DaeLim),이숙향(Lee, Sook-hyang),이용주(Lee, YongJu) 한국음성학회 2014 말소리와 음성과학 Vol.6 No.1

This paper investigated the effects of frequency band limitation on perceptual characteristics of Korean consonants. Monosyllabic speech (144 syllables of CV type, 56 syllables of VC type, 8 syllables of V type) produced by two announcers were low- and high-pass filtered with cutoff frequencies ranging from 300 to 5000 Hz. Six listeners with normal hearing performed perception test by types of filter and cutoff frequencies. We reported phoneme recognition rates and types of perception error of band-limited Korean consonants to examine how frequency distortion in the process of speech transmission affect listener’s perception. The results showed that recognition rates varied with the following factors: position in a syllable, manner of articulation, place of articulation, and phonation types. Consonants in the final position were stronger to the frequency band limitation than those in the initial position. Fricatives and Affricates are stronger than stops. Fortis consonants were less stronger than their lenis or aspirated counterparts. Types of perception error also varied depending on such factors as consonant’s place of articulation: In case of bilabial stops, they were perceived as alveolar stops with while in cases of alveolar and velar stops, there were changes in phonation types without any change in the place of articulation.