A Scalable Audio Coder for High-quality Speech and Audio Services

이길호,이영한,김홍국,김도영,이미숙,Lee, Gil-Ho,Lee, Young-Han,Kim, Hong-Kook,Kim, Do-Young,Lee, Mi-Suk The Korean Society Of Phonetic Sciences And Speech 2007 말소리 Vol.61 No.-

In this paper, we propose a scalable audio coder, which has a variable bandwidth from the narrowband speech bandwidth to the audio bandwidth and also has a bit-rate from 8 to 320 kbits/s, in order to cope with the quality of service(QoS) according to the network load. First of all, the proposed scalable coder splits bandwidth of the input audio into narrowband up to around 4 kHz and above. Next, the narrowband signals are compressed by a speech coding method compatible to an existing standard speech coder such as G.729, and the other signals whose bandwidth is above the narrowband are compressed on the basis of a psychoacoustic model. It is shown from the objective quality tests using the signal-to-noise ratio(SNR) and the perceptual evaluation of audio quality(PEAQ) that the proposed scalable audio coder provides a comparable quality to the MPEG-1 Layer III (MP3) audio coder.

국제표준활동-ISO/TC38/SC24(섬유직물의 환경조건과 물리시험)

이길호,Lee, Gil-Ho 기술표준원 2002 기술표준 Vol.6 No.-

주요 KS 제.개정 해설-KS K ISO 7211-3(섬유제품-직물-구조-분석방법 : 제3부 직물의 실크림프율 측정방법) 제정 해설

이길호,Lee, Gil-Ho 기술표준원 2003 기술표준 Vol.22 No.-

네트워크 환경에서 서버용 음성 인식을 위한 MFCC 기반 음성 부호화기 설계

이길호,윤재삼,오유리,김홍국,Lee, Gil-Ho,Yoon, Jae-Sam,Oh, Yoo-Rhee,Kim, Hong-Kook 대한음성학회 2005 말소리 Vol.54 No.-

Existing standard speech coders can provide speech communication of high quality while they degrade the performance of speech recognition systems that use the reconstructed speech by the coders. The main cause of the degradation is that the spectral envelope parameters in speech coding are optimized to speech quality rather than to the performance of speech recognition. For example, mel-frequency cepstral coefficient (MFCC) is generally known to provide better speech recognition performance than linear prediction coefficient (LPC) that is a typical parameter set in speech coding. In this paper, we propose a speech coder using MFCC instead of LPC to improve the performance of a server-based speech recognition system in network environments. However, the main drawback of using MFCC is to develop the efficient MFCC quantization with a low-bit rate. First, we explore the interframe correlation of MFCCs, which results in the predictive quantization of MFCC. Second, a safety-net scheme is proposed to make the MFCC-based speech coder robust to channel error. As a result, we propose a 8.7 kbps MFCC-based CELP coder. It is shown from a PESQ test that the proposed speech coder has a comparable speech quality to 8 kbps G.729 while it is shown that the performance of speech recognition using the proposed speech coder is better than that using G.729.

패션브랜드의 모바일 쿠폰이용에 관한 연구

이길호(Lee, Gil Ho),이승민(Lee, Gil Ho),이진(Lee, Jin),김상화(Kim, Sang Hwa),나원규(Na, Won Kyu),김은영(Kim, Eun Young) 충북대학교 생활과학연구소 2017 생활과학연구논총 Vol.21 No.2

This study was to predict the effects of mobile coupons on consumer engagement, impulse buying, and purchasing behaviors for fashion brands. A self-administered questionnaire was developed for data collection and included attributes of mobile coupons, consumer engagement, impulse buying, and consumer behavior (brand loyalty, brand switching, and intention to use a mobile coupon). A total of 142 usable responses were obtained from university students who had redeemed a mobile coupon for the purchase of fashion brands. The sample represented a greater number of females than males. The findings demonstrated that the attributes of mobile coupons consisted of three factors: enjoyment, ease of use, and usefulness. Of these factors, enjoyment significantly influenced consumer engagement with the mobile coupon, which led to impulse buying behavior. Brand loyalty and brand switching were also significantly influenced by consumer engagement with fashion brands’ mobile coupons. Finally, this study discussed fashion marketers’ managerial implications for developing and effectively managing mobile promotional strategies through mobile devices in the fashion retail market.

연구논문 : 사이버스페이스에서 증여의 논리

이길호 ( Gil Ho Lee ) 한국문화인류학회 2011 韓國文化人類學 Vol.44 No.1

``디시인사이드``라는 사이버스페이스 상의 어느 장소에서 사람들은 일상적으로 증여를 수행한다. 이곳에서 증여는 곧 ``존재``의 문제에 직접 닿아 있다. 사람들은 자신들의 말과 행동과 그리고 ``생산물``로서 특정 장소들( ``갤러리``)에 출현한다. 갤러리에서 그 이외의 존재의 방법이란 없으며, 언제나 비가시적인 것들은 자신의 존재를 주장하기 위해 가시화되어야 한다. ``말과 사물``은 그의 ``이름``으로서 상황 안에 출현하며, 이제 갤러리 내에는 이름들이 있다. 그 이름들은 저마다 자신의 존재를 집단의 몸체 위에 각인시키기 위해 함성을 지른다. 그 치열한 존재의 함성은 그 자체로 일방적인 증여의 행위이다. 따라서 이곳에서 ``증여``란 곧 존재의 방식이며, 또한 각각의 개별적 증여의 행위는 특정``개인``을 향하고 있다기보다는 집단 전체를 향해 있다. 본 논문은 일련의 증여의 양상과 물건의 이동 및 그것이 유발하는 후(後)사건적 효과에 대해서 이야기하는데, 결과적으로 이는 사이버스페이스에서 어떤 ``증여의 논리``에 대한 인식으로 이어진다. People carry out constant gift-giving in certain places of DCINSIDE, a virtual community in cyberspace. In these places, gift-giving is concerned with the problem of being. People present themselves as their words, actions and ``products`` (jjalbang) in their living places(galleries) of DCINSIDE. There is no other way of their being in these galleries, and the invisible always must be made visible in order to claim its being. The words and things produced by someone of each gallery are presented with his ``name`` within the situation, and thus there are a multitude of names inside the galleries. Every name raises the clamor to inscribe itself on the social bodies. Its fierce clamor of being is itself a unilateral act of donation. The gift-giving or presentation, therefore, is the only way of being here, and each presentation is for the group as a whole, and not for a particular individual. This article investigates some specific aspects of gift-giving, and the post-evental effect which individual acts of gift-giving cause, before turning, in the conclusion, to the recognition of a certain ``logic of gift`` in cyberspace, as distinguished from gift exchange and reciprocity theory.

‘일베’를 어떻게 인지할 것인가

이길호(Gil-Ho Lee) 참여연대 참여사회연구소 2014 시민과세계 Vol.- No.25

Openflow기반 오케스트레이션 프로토콜 설계 및 구현

이길호(Gil-ho Lee),권원식(Won-sic Kwon),천세준(Se-joon Chun),최진식(Jin-seek Choi) 한국통신학회 2020 韓國通信學會論文誌 Vol.45 No.9

DEA를 이용한 국립대학도서관 경영효율성 분석

조성한,박동진,이길호,윤동원,Jo, Sung-Han,Park, Tong-Jin,Lee, Gil-Ho,Yoon, Dong-Won 한국도서관정보학회 2009 한국도서관정보학회지 Vol.40 No.1

효율성은 산출물의 가치와 그 산출물의 생산과정에서 소요되는 투입물가치의 비율로 나타낸다. DEA모형은 효율성을 여러 가지 투입물의 가중평균에 대한 산출물 가중평균의 비율로 표시하며, 특정 의성결정단위의 효율성을 유사한 투입 산출구조를 가지는 준거집단과 비교함으로써 상대적인 측면에서 측정하는 방법이다. 본 연구는 DEA모형을 이용하여 국립대학도서관의 효율성과 효율성 개선에 관한 분석을 시도하였다. 투입변수로는 직원수, 시설면적, 예산, 장서량을 사용하였고, 산출변수로는 자료실이용자수, 대출책수, 상호대차이용건수를 사용하였다. 그 결과 전국 26개의 국립대학도서관 중 효율적인 도서관은 2007년, 2006년, 2005년에 각각 10개, 9개, 9개로 나타났다. 또한 비효율적인 국립대학도서관의 경우 투입물을 줄이고, 산출물을 늘여야 할 정보들을 제시하였다. Data Envelopment Analysis(DEA) model is a linear programing based technique for measuring the relative performance of organizational units where the presence of multiple inputs and outputs makes comparison difficult. DEA model allows each unit to adopt a set of weight that shows it in the most favorable light in comparison to the other units. The purpose of this study was to evaluate the performance of the libraries of national university in terms of relative efficiency, measured by the method of DEA. Twenty six libraries of national universities in Korea were used to analyze. The number of employees, size of library, budget, and number of books were used for input data, and the number of visitors, number of loan books, and number of books for lending and borrowing were used for output data. We found out that number of libraries with 100% relative efficiency among 26 libraries from 2005 to 2007 were only 9, 9 and 10, respectively. Moreover most of the libraries need to increase outputs and decrease inputs in order to improve efficiency.

연직 매트로 보강된 연약지반의 지지력 특성

신은철(Eun-Chul Shin),이길호(Gil-Ho Lee) 한국지반환경공학회 2012 한국지반환경공학회논문집 Vol.13 No.6

일반적으로 심층혼합공법에 의한 점토지반의 개량효과는 물리적 개량효과에 비해서 훨씬 크며 조기에 큰 개량 강도를 얻을 수 있으나, 국내 시공실적이 부족하고 시멘트-점토의 혼합방법에 따른 품질관리에 문제점이 있는 것으로 알려져 있다. 본 연구에서는 시멘트, 모래, 점토의 배합비에 따른 강도특성과 연직MAT의 형태에 따른 연약지반의 개량특성을 파악하기 위해 해성점토를 이용하여 일축압축 강도시험과 모형토조시험을 수행하였다. 일축압축강도 시험을 위한 공시체는 시멘트와 물의 중량비를 기준으로하여 모래를 일정 비율로 혼합하였고, 시멘트는 점토중량대비 각각 10%, 20%, 30%, 40%를 혼합하였고 대상지반토의 함수비는 40%, 60%, 80%로 조정하여 제작하였다. 공시체는 습윤방법을 이용하여 7일, 14일, 28일간 양생하여 양생기간에 따른 일축압축강도 시험을 수행하였다. 지지력시험은 모형토조를 제작하고 Mat식으로 개량한 지반을 형성한 다음 개량률에 따른 지지력을 비교하고 연직MAT 장벽 상호간의 간섭효과를 분석하였다. Generally, the effect of the cement deep mixing method on the improvement of clay ground is far greater than the effect of physical improvement. Although it leads to great improvement strength in the initial stage, there are not many constructional precedents in Korea and it is hard to manage quality according to the cement-clay mixing method. In order to figure out the strength characteristics according to the mixing ratio of cement, sand, and clay and the improvement characteristics of weak ground according to the forms of the specimens to be improved, marine clay was used in this study to conduct the uniaxial compression test and soil bin model test. The test piece specimens for the uniaxial compression test were mixed with sand in a fixed ratio with the criterion of the water cement ratio. The cement was mixed with clay in the ratios of 10%, 20%, 30%, and 40% to the clay weight. The moisture content of the soil ground was made in the ratios of 40%, 60%, and 80%. The test piece specimens went through curing by moistening for 7, 14, and 28 days and underwent the uniaxial compression test according to the curing period. For the bearing test, the soil bin models were made and the ground improved in the Mat type was formed. After that, the bearing strength was compared in this study according to the improvement ratio and analyzed the intervening effect between the walls of the improved specimens.