An Analysis of the English l Sound Produced by Korean Students

Yang, Byung-Gon Korean Society of Speech Sciences 2008 음성과학 Vol.15 No.1

The purpose of this study was to examine the English l sound in an English short story produced by 16 Korean students in order to determine various allophones of the sound using acoustic visual displays and perceptual judgments. The subjects read the story in a quiet office at normal speed. Each word included the lateral sound in onset or coda positions and before a vowel of the following word. Results showed as follows: Firstly, there was a durational difference between the two major groups. Also the majority of the subjects produced the clear l regardless of the contexts. Some students produced the sound as the Korean flap or the English glide [r]. A few missing cases were also seen. The dark l was mostly produced by the subjects of English majors in coda position with a few cases before a vowel in a phrase. Visual displays using the computer analysis were very helpful in distinguishing lateral variants but sometimes perceptual process would be necessary to judge them in fast and weak production of the target word. Further studies would be desirable to test the discrepancies between the acoustical and perceptual decisions.

Discrimination of Synthesized English Vowels by American and Korean Listeners

Yang, Byung-Gon Korean Society of Speech Sciences 2006 음성과학 Vol.13 No.1

This study explored the discrimination of synthesized English vowel pairs by twenty-seven American and Korean, male and female listeners. The average formant values of nine monophthongs produced by ten American English male speakers were employed to synthesize the vowels. Then, subjects were instructed explicitly to respond to AX discrimination tasks in which the standard vowel was followed by another one with the increment or decrement of the original formant values. The highest and lowest formant values of the same vowel quality were collected and compared to examine patterns of vowel discrimination. Results showed that the American and Korean groups discriminated the vowel pairs almost identically and their center formant frequency values of the high and low boundary fell almost exactly on those of the standards. In addition, the acceptable range of the same vowel quality was similar among the language and gender groups. The acceptable thresholds of each vowel formed oval to maintain perceptual contrast from adjacent vowels. The results suggested that nonnative speakers with high English proficiency could match native speakers' performance in discriminating vowel pairs with a shorter inter-stimulus interval. Pedagogical implications of those findings are discussed.

An Acoustical Study on the Syllable Structures of Korean Numeric Sounds

Yang, Byung-Gon Korean Society of Speech Sciences 2007 음성과학 Vol.14 No.1

The purpose of this study was to examine the syllable structures of ten Korean numeric sounds produced by ten students. Each sound was normalized by its maximum intensity value and divided into onset, vowel, and coda sections after finding abrupt or visible changes in energy values or cumulative values of lower spectral energy at each pulse point using four Praat scripts. Then, segmental durations and cumulative intensity values of each syllable were obtained to find a statistical summary of the syllable structure. Intensity values at 100 proportional time points were also collected to compare the ten sounds. Results showed as follows: Firstly, there was not much deviation from the grand average duration and intensity for the majority of the sounds except the two diphthongal sounds on which their boundary points varied among the speakers. Secondly, the onset point for the CV or CVC category sounds and the boundary between the vowel and the nasal or lateral sound were easy to identify, which may be automatically traced later. Thirdly, there seems some tradeoff among the sections maintaining the same total duration per each syllable. Further studies on syllables with various onsets or codas would be desirable to make a general statement on the Korean syllable structure.

A Comparative Study of Glottal Data from Normal Adults Using Two Laryngographs

Yang, Byung Gon,Wang, Soo Geun,Kwon, Soon Bok 한국음성과학회 2003 음성과학 Vol.10 No.1

A laryngograph was developed to meassssure the open and closed movements of vocal folds in our laboratory. This study attempted to evaluate its performance by comparing its glottal data with that of the orginal laryngograph. Ten normal Korean adults participated in the experiment. Each subject produced a sustained vowel /a/ for about five seconds. This study compared f0 values, contact quotients of the duration of closed vocal folds over one glottal pulse, and area quotients of the closed over open vocal folds derived from glottal waves using both the original and new laryngographs. Results showed that the mean and standard deviation of the two laryngographs were almost comparable with a correlation coefficient 0.662 but minor systematic shift below those fo the original laryngograph was observed. The absolute mean difference converged into 1㎐, which indicates a plssibility of adopting some threshold of rejecting inappropriate pitch values beyond a threshold value. The contact quotient of the normal subjects came out slightly over the 50% in a citation speech. Finally, the area quotient converged into 1. We will pursue further studies on the abnormal patients in the future.

An Acoustical Study of English Word Stress Produced by Americans and Koreans

Yang, Byung Gon 한국음성과학회 2002 음성과학 Vol.9 No.1

Acoustical correlates of stress can be classified asduration, intensity and fundamental frequency. This study examined the acoustical differences in the first two syllables of stressed english words produced by ten American and Korean speakers. The Korean subjects scored very high on the TOEFL. They read at a normal speed a fable from which theacoustical parameters of eight words were analyzed. In order to make the data comparison meaningful, each paramenter was collected at 100 dynamic time points proportional to the total duration of the two syllables. Then the ratio of the parameter sum of the firstrime to that of the second rime was calculated to determine the relative prominence of the syllables. Resultsshowed that the durations of the first two syllables were almost comparable between the Americans and Koreans. However, statistically significant differences showed up in the diphthong pronunciatious and in the words with the second syllable stressed. Also, remarkably high r-squared values were found between pairs of thethree acoustical parameters, which suggests that either one or a combination of two or more parameters mayaccount for the prominence of a syllable within a word.

반폐쇄 순환여과식 넙치양식장의 수질제어에 관한 연구

양병수(Byung-Soo YANG),이헌모(Heon-Mo LEE),정병곤(Byung-Gon JEONG) 군산대학교 수산과학연구소 1994 군산대학교 수산과학연구소 연구논문집 Vol.2 No.-

넙치양식장의 수질관리 및 제어 방안을 검토하기 위하여 같은 조건에서 양식되고 있는 유수식 및 순환여과식 양식장을 선택하여 상호수질의 비교 평가를 행하였다. 두양식장 공히 COD, PO₄-P 및 SS의 최대농도느,ㄴ 급이와 동시에 나타났고 2시간 이내에 평상농도로 회복되어 일정한 농도로 거의 유지되었다. NH₄-N의 경우 유수식에는 금이후 시간 경과에 따라 농도차이가 별로 없으나 순환식의 경우는 금이후 2시간 이후에 다소 증가하는 경향을 보였다. NH₄-N을 제외한 COD, PO₄-P, SS 및 TIN의 농도는 순환여과식에서 다소 높은 경향을 보였다. 이는 처리 시스템내에 축적된 유기부유물이 무기화에 기인된 것을 평가되었으며, 이것이 질산화율을 떨어뜨리는 결과를 초래한 것으로 사려되었다. 유수식 및 순환여과식의 수질에 직접적인 영향을 주는 해수 교환율이 양식장마다 크게 다르게 나타나 이에 대한 최적화가 시급한 것으로 나타났다. A comparative evaluation of water quality in the existing semiclosed fish culture system was made to improve the system management. From the comparison of water quality quality between the flow-through mode and the recycle mode of the semiclosed system, the malfunctioning of the settling channel deteriorated water Quality and reduce the nitrification rate in the recycle mode. The peak concentrations of COD, PO₄-P and SS in the fish tanks appeared just after feeding, and then decreased to normal levels within two hours. However, the NH₄-N concentration increased slightly after two hours of feeding in the recycle mode. The water exchange rate was directly related to the water quality in the semiclosed fish culture system.

수소기질 결핍 환경하에서 수소분압이 슬러지 입상화에 미치는 영향

정병곤(Byung Gon Jeong),정형숙(Hyung Sook Chung),양병수(Byung Soo Yang) 大韓環境工學會 1996 대한환경공학회지 Vol.18 No.7

남성의 숫자음 발성에 나타난 화자변이

양병곤 한국음성과학회 2001 음성과학 Vol.8 No.3

The author analyzed acoustic parameters of ten Korean numbers produced by ten male students using Praat. Variations of f0, F1, F2 and F3 within and between speakers were examined by determining an average and standard deviation of the parameters of each number and by comparing the acoustic values with one another. Results showed that each subject produced the numbers within a certain range of variation across time. Thus, speaker identification can be more certain using dynamic information of the acoustic parameters within each vocalic segment. Also, percent difference of within-subjects' variation to that of between-subjects can be utilized to determine which sounds would be better stimuli for speaker identification. According to the criteria, the number '2' proved the best stimulus while the number '7' was the worst. Future studies will be necessary to explore robust methods of speaker identification under noisy conditions.

압력 및 용존산소 농도가 활성슬러지에 미치는 영향

양병수,신현무,정형숙,류동춘,윤종호,정병곤 한국환경과학회 1995 한국환경과학회지 Vol.4 No.3

This study was conducted to evaluate the effects of pressure and dissolved oxygen concentration on the activated sludge and to determine the optimum depth of deep shaft process. Some results from this study were summarized as follows. 1. It is considered that low sludge product in the activated sludge system maintaining high dissolved oxygen concentration is attributed to the increase of endogeneous respiration rate caused by the increase of aerobic zone in the sludge floc. 2. The increase of dissolved oxygen concentration does not affect to the increase of organic removal efficiency greatly and therefore the limiting factor is the substrate transfer into the inner part of floc. 3. The yield coefficient, Y is decreased in proportion to the increase of oxygen concentration. In this study, Y values arre ranged from 0.70 to 0.41 according to the variation of dissolved oxygen concentration from 18.0㎎/ℓ to 258 ㎎/ℓ. 4. The optimum depth of deep shaft process should be determined within the limits of non-toxicity to the microorganism and it is about 100m in this study.

반폐쇄 순환여과식 넙치양식장의 수질제어에 관한 연구

양병수,정병곤,이헌모 한국수산학회 1992 한국수산과학회지 Vol.25 No.3

넙치양식장의 수질관리 및 제어 방안을 검토하기 위하여 같은 조건에서 양식되고 있는 유수식 및 순환여과식 양식장을 선택하여 상호수질의 비교 평가를 행하였다. 두양식장 공히 COD, PO₄-P 및 SS의 최대농도는 급이와 동시에 나타났고 2시간 이내에 평상농도로 회복되어 일정한 농도로 거의 유지되었다. NH₄-N의 경우 유수식에는 급이후 시간 경과에 따라 농도차이가 별로 없으나 순환식의 경우는 급이후 2시간 이후에 다소 증가하는 경향을 보였다. NH₄-N을 제외한 COD, PO₄-P, SS 및 TIN의 농도는 순환여과식에서 다소 높은 경향을 보였다. 이는 처리 시스템내에 축적된 유기부유물이 무기화에 기인된 것을 평가되었으며, 이것이 질산화율을 떨어뜨리는 결과를 초래한 것으로 사려되었다. 유수식 및 순환여과식의 수질에 직접적인 영향을 주는 해수 교환율이 양식장마다 크게 다르게 나타나 이에 대한 최적화가 시급한 것으로 나타났다. A comparative evaluation of water quality in the existing semiclosed fish culture system was made to improve the system management. From the comparison of water quality between the flow-through mode and the recycle mode of the semiclosed system, the malfunctioning of the settling channel deteriorated water quality and reduce the nitrification rate in the recycle mode. The peak concentrations of COD, PO₄-P and SS in the fish tanks appeared just after feeding, and then decreased to normal levels within two hours. However, the NH₄-N concentration increased slightly after two hours of feeding in the recycle mode. The water exchange rate was directly related to the water quality in the semiclosed fish culture system. Water quality in a semiclosed system of flounder culture in Korea was evaluated to improve the fish culture system management skill with particular emphasis on enhancement of water quality. From the comparison of water quality between the flowthrough mode and the recycle mode of the existing semiclosed system, the followings were found. The peak concentrations of COD, PO₄-P and SS appeared just after feeding, and decreased gradually to normal levels within two hours. However, the ammonia nitrogen concentration in the recycle mode tended to increase after two hours of feeding. Concentrations of all the water quality parameters except ammonia in the recycle mode were slightly higher than those in the flow-through mode. These were attributed to the mineralization of organic debris accumulated in the RBC and the submerged filter unit due to the poor functioning of the settling channel. Consequently, the average nitrification efficiency of the recycle mode was 22% that was not effective than might be expected. The water exchange rate was directly related to water quality in the semiclosed fish culture system. The rate should be optimized based on water quality to reduce the running cost of the fish culture system.