공동이용을 위한 음성DB의 설계 및 구축에 관한 연구

김봉완,김종진,김선태,이용주,Kim, Bong-Wan,Kim, Jong-Jin,Kim, Sun-Tae,Lee, Yong-Ju 한국음향학회 1997 韓國音響學會誌 Vol.16 No.4

공동이용 가능한 각종 대량의 음성 데이터를 수록, 보관, 공개하는 것은 연구 개발 과정에서의 이용 및 음성 정보 처리 시스템의 성능평가 양면에서 필요하다. 이러한 공동 음성 데이타 베이스의 구축을 위해서는 발생 가능한 모든 음운환경을 포함하며, 특정 테스크에 집중되지 않는 발성 대상 단어나 문장의 설계가 필요하다. 본 논문에서는 이와같은 목적으로 신문, 소설, 기타 구어자료로부터 수집된 120만여 어절의 텍스트 코퍼스에서 PBW(Phonetically Balanced Word)를 추출하고 이를 발성목록으로 음성DB를 구축한 결과와 구축된 음성DB의 특성을 제시한다. Speech database is an indispensable part of speech research. Speech database is necessary to use in speech research and development processes, and to evaluate performances of various speech-processing systems. To use speech database for common purpose, it is necessary to design utterance list that has all the possible phonetical events in minimal number of words, and is independent of tasks. To meet those restrictions this paper extracts PBW set from large text corpus. Speech database that was constructed using PBW set for utterance list and its properties are described in this paper.

장기LPG 수급안정화를 위한 추진과제 및 대책

김봉완,Kim, Bong-Wan 대한석유협회 1989 석유와 에너지 Vol.1989 No.9

이 자료는 지난 8월 17일 전경련회관에서 한국가스연맹 주최로 열린 가스정책세미나에서 김봉완고문이 발표한 주제내용을 옮긴 것이다. <편집자 주>

공동이용을 위한 음성DB의 구축 및 음성 자료 수집을 위한 Workbench의 구현

김봉완,이용주,Kim Bong-wan,Lee Yong-Ju 대한음성학회 1998 말소리 Vol.35 No.-

This study discusses Korean speech database that has been designed and constructed for common use, especially focusing on designing a list of words or sentences that covers various phonological environments. As the results, PBW(Phonetically Balanced words) and PBS(Phonetically Balanced Sentences) was selected from balanced text corpus using maximum entropy method. And, implemented workbench for spoken language data acquisition is presented in this paper. The workbench consists of grapheme to phoneme converter, utterance list selection module, speech data editing module, multi-layer labelling module, and phoneme context search module.

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.

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.

고 Mole 비 규산소다를 사용한 CO2 주형의 (鑄型) 잔류강도와 (殘留强度) 반응생성물의 성상에 (性狀) 관한 연구

김봉완,남태운,이계완 ( Bong Wan Kim,Tae Woon Nam,Kye Wan Lee ) 한국주조공학회 1988 한국주조공학회지 Vol.8 No.2

N/A The study was carried out to investigate the changes of retained strength and reaction products in the CO₂ sands obtained are as follows. 1) Higher mole-ratio sodium silicates have the lower retained compression strength. 2) Organic liquid additives make a notable decrease in the retained strength and, in case of when use the 2.7 mole-ratio sodium sillicate, the effect is remarkable at the range of temperature to 600℃. 3) Sodium silicate binder forms silica gel with very high bonding force, accompaning an exothemic reaction at the temperatures of around 200℃, and dehydrated brittle silica gel and hydrated sodium silicate glass with sands transformed at the temperature of ahout 600℃. 4) It forms dehydrated glass with sintering of the sand gain surfaces, at the temperatures of around 800℃ and has a value of high retatined strength. 5) The decreases in the retaired strength of CO₂sands are accelerated with the lots of defects resulted from the porosity and cracks in sodium silicate bond films which are caused by the evaporation or combustion of the organic additives.

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.

효율적 한국어 음성 인식을 위한 PTM 음절 모델

김봉완,이용주,Kim Bong-Wan,Lee Yong-Jn 대한음성학회 2004 말소리 Vol.50 No.-

A Phonetic Tied-Mixture (PTM) model has been proposed as a way of efficient decoding in large vocabulary continuous speech recognition systems (LVCSR). It has been reported that PTM model shows better performance in decoding than triphones by sharing a set of mixture components among states of the same topological location[5]. In this paper we propose a Phonetic Tied-Mixture Syllable (PTMS) model which extends PTM technique up to syllables. The proposed PTMS model shows 13% enhancement in decoding speed than PTM. In spite of difference in context dependent modeling (PTM : cross-word context dependent modeling, PTMS : word-internal left-phone dependent modeling), the proposed model shows just less than 1% degradation in word accuracy than PTM with the same beam width. With a different beam width, it shows better word accuracy than in PTM at the same or higher speed.

고 MOLE 비의 규산소다를 사용한 CO2 주형의 (鑄型) 강도개선에 관한 연구

김봉완,이계완 ( Bong Wan Kim,Kye Wan Lee ) 한국주조공학회 1987 한국주조공학회지 Vol.7 No.4

The influences of some factors on the variation of compression strength of CO₂process were investigated with an attention given to use of high SiO₂/Na₂O silicate, addition of organics and gassing operation. 1) Higher ratio binder offers faster rates of hardening with lower CO₂consumption requiring more concentration for a good strength development. A mixture containing 4 percent of 2.7 : 1 ratio silicate produces the strength above 8㎏/㎠ after 80 seconds gassing, but 5% and 6% respectively of 3.0 : 1 and3.3 : 1 ratio silicate are necessary to achieve equivalent levels of strength. 2) The correct water content in sand mixtures containing higher ratio silicates is necessary for the better strength properties to be obtained. The addition of 1% water to the sand mixtures bonded with 5%, 3 : 1 ratio and 6%, 3.3 : 1 ratio silicates maintains near-maximum strength on extended gassing. 3) When higher ratio silicates with 3 : 1 and 3.3 : 1 ratios are used,the addition of organic additives such as oil, sucrose and polyol results in considerable changes in strength. The presence of 1.0 to 1.5 percent of polyol produces a noticiable improvement 4) Gas diluted with air raises the efficiency of gas utilization. When gas contains 50 percent CO₂, the efficience is significantly increased with the best strength in the silicates having high ratios of 3 : 1 and 3.3 : 1. 5) The strength of molds is liable to change on storage with the reduction in water content. The magnitude of the strength change is determinded with the mole ratio. The presence of polyol in the mixture with 3.3 : 1 ratio silicate has a pronounced effect on maintaining the gassed strength.

고 Mole 비 규산소다를 이용한 CO2 주형의 (鑄型) 고온특성에 관한 연구

김봉완,이계완 ( Bong Wan Kim,Kye Wan Lee ) 한국주조공학회 1988 한국주조공학회지 Vol.8 No.1

In this study the elevated temperatures properties of CO₂sands bonded with high mole ratio sodium silcates were investigated and following results obtained. 1) The CO₂sand has peaks of the compression strength at the temperatures of 200℃ and 500℃ and its strength decreases to 2㎏/㎠ at 690℃. The higher mole ratio binder shows strength at the region of overall temperatures and the sodium silicate with 3.3 mole ratio appears very low strength of under 2.5㎏/㎠ at the peak point. 2) The dehydration reaction of sodium silicate continues up to 500℃ and at the temperatures higher than that, the dehydration does not take place. Near the temperature of 600℃, the silica sand diminishes in its grain sizes with the phase transformation occurred. 3) among organic additives, polyol increases Strength at the temperatures up to 400℃ and has the contrary influence at the temperature higher than hat. The bonding strength of sodium silicate at the temperature region of up to 400℃ is affected by the retained moisture and by the sponge structure changes of formed silica gel. And the addition of polyol has an affect of maintaining higher retained moisture within silica gel. 4) The bonding strength of high mole ratio sodium silicate increases with its content, and for the binder with 3.3 mole ratio, it is necessary to add 6% of sodium silicate for the enough strength. 5) The high temperature compression deformation of CO₂sand decreases gradually at the temperatures below 400℃ and has a linear increase at the temperatures up to 700℃. But the sand has a tendency of sligt increase in deformation at the temperatures above 700℃. With silicate bond softening by fusion, the silicate forms a viscous glass and the rise in compressiveness occurs. 6) The higher mole ratio silicate has a lower deformation. Organic addition produces a lower deformation, though depending upon its material. 7) The expansion of CO₂ sand forms a peak near the temperature of 600℃ with the phase transformation of silica and has the maximum value near 1,100℃. But the sand boned with 3.3 mole ratio sodium silicate decreases gradually its value and comes to a null value at 600℃. 8) when the mole ratio of the binder increases, the expansion of CO₂sand decreases on the contrary. And polyol additive has a considerable effect of absorbing the sand expansion. In conclusion, the addition of polyol to the CO₂sand bonded with high mole ratio sodium silicate causes a good effect of improving the mold strength, which is requested at the region of low temperature of up to 500℃ and of decreasing deformation and expansion.