담세관주위 Golgi장치의 유형 분류에 관한 전자현미경적 연구

정민화,신영철,Chung, Min-Hwa,Shin, Young-Chul 한국현미경학회 1992 Applied microscopy Vol.22 No.2

In this study, we have made morphological and cytochemical observations to investigate the type of Golgi apparatus around the bile canaliculus. The animal (Wister, $220{\sim}250gm$) were divided into 4 groups; normal, hydrochol, colchicine and hydrochol-colchicine. The Golgi apparatus is classified into 16 different types from 4 different groups. In the normal group, we could observe 12 different types of the sixteen. Type I which showed convexed cisterns facing the bile canaliculi was most abundant of the types. In the hydrochol group, 14 types were observed. Type VII and type I showed convexed cisterns facing the bile canaliculus and were abundant. In the colchicine group, 11 different types were viewed and type XIV which showed intensely dilated cisterns without the polarity was predominant. In the hydrochol-colchicine group, we observed 3 different types. Type XIV clearly showed the highest percentage, although that type was less numerous in this group than in the colchicine group. In the hydrochol group, the Golgi apparatus showed a tendency to increase in numbers, while in the hydrochol-colchicine group the Golgi apparatus showed a tendency to decrease in numbers. The reactive products of thiamine pyrophosphatase and acid phosphatase were apparent over the distal Golgi cistern in the normal and hydrochol groups, but were decreased or not observed in the colchicine and hydrochol-colchicine groups. From the results, it is assumed that with the presence of the microtubule, Golgi cisterns are dilated with polarity after stimulation of secretion. Without the microtubule, the cistern becomes more intensely dilated and none polaric. Also the enzymes within the cisternal membrane become decreaed or absent and the Golgi apparatus decreases in numbers after activation of secretion.

초음파 주파수분석법에 의한 발전소 고온배관재료의 크리프손상 평가

정민화(Min-Hwa Chung),이상국(Sang-Guk Lee) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.2

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions like high temperature and high pressure for an extended period time. Such material degradation lead to various component failures causing serious accidents at the plant. Conventional measurement techniques such as replica method, electric resistance method, and hardness test method have such disadvantages as complex preparation and measurement procedures, too many control parameters, and therefore, low practicality and they were applied only to component surfaces with good accessibility.<br/> In this study, both artificial creep degradation test using life prediction formula and frequency analysis by ultrasonic tests for their preparing creep degraded specimens have been carried out for the purpose of nondestructive evaluation for creep damage which can occur in high-temperature pipeline of fossil power plant. As a result of ultrasonic tests for crept specimens, we confirmed that the high frequency side spectra decrease and central frequency components shift to low frequency band, and bandwiths decrease as increasing creep damage in backwall echoes.

음향 방출을 이용한 저어널 베어링의 조기 파손 감지(Ⅲ)

정민화(Min-Hwa Chung),조용상(Yong-Sang Cho),윤동진(Dong-Jin Yoon),권오양(Oh-Yang Kwon) 한국비파괴검사학회 1996 한국비파괴검사학회지 Vol.16 No.3

체계적인 흉부호흡요법이 수술후 폐합병증에 미치는 영향

정민화(Min Hwa Chong),홍순찬(Soon Chan Hong),하우송(Woo Song Ha),박순태(Soon Tae Park),한호성(Ho Seong Han),이청기(Chung Kee Lee),김종철(Jong Cheol Kim) 대한외과학회 1992 Annals of Surgical Treatment and Research(ASRT) Vol.43 No.3

음소변동규칙의 발견빈도에 기반한 음성인식 발음사전 구성

나민수,정민화,Na, Min-Soo,Chung, Min-Hwa 대한음성학회 2007 말소리 Vol.64 No.-

The pronunciation lexicon of a continuous speech recognition system should contain enough pronunciation variations to be used for building a search space large enough to contain a correct path, whereas the size of the pronunciation lexicon needs to be constrained for effective decoding and lower perplexities. This paper describes a procedure for selecting pronunciation variations to be included in the lexicon based on the frequencies of the corresponding phonetic rules observed in the training corpus. Likelihood of a phonetic rule's application is estimated using the observation frequency of the rule and is used to control the construction of a pronunciation lexicon. Experiments with various pronunciation lexica show that the proposed method is helpful to improve the speech recognition performance.

코퍼스기반 음성합성기의 데이터베이스 감축방안

장경애,정민화,김재인,구명완,Jang Kyung-Ae,Chung Min-Hwa,Kim Jae-In,Koo Myoung-Wan 대한음성학회 2002 말소리 Vol.44 No.-

This paper describes the reduction of DB without degradation of speech quality in Corpus-based Speech synthesizer of the Korean language. In this paper, it is proposed that the frequency of every unit in reduced DB reflect the frequency of units in the Korean language. So, the target population of every unit is set to be proportional to its frequency in Korean large corpus (780k sentences, 45Mega phones). Secondly, the frequent instances during synthesis should be also maintained in reduced DB. To the last, it is proposed that frequency of every instance be reflected in clustering criteria and used as another important criterion for selection of representative instances. The evaluation result with proposed methods reveals better quality than that using conventional methods.

한국어 음성인식을 위한 음성학 기반의 유사음소단위 집합 설계

홍혜진,김선희,정민화,Hong, Hye-Jin,Kim, Sun-Hee,Chung, Min-Hwa 대한음성학회 2008 말소리 Vol.65 No.-

This paper presents the effects of different phone-like-unit (PLU) sets in order to propose an optimal PLU set for the performance improvement of Korean automatic speech recognition (ASR) systems. The examination of 9 currently used PLU sets indicates that most of them include a selection of allophones without any sufficient phonetic base. In this paper, a total of 34 PLU sets are designed based on Korean phonetic characteristics arid the effects of each PLU set are evaluated through experiments. The results show that the accuracy rate of each phone is influenced by different phonetic constraint(s) which determine(s) the PLU sets, and that an optimal PLU set can be anticipated through the phonetic analysis of the given speech data.

한국어 연속음성인식을 위한 발음사전 구축

이경님(Kyong-Nim Lee),정민화(Min-Hwa Chung) 한국정보과학회 2000 한국정보과학회 학술발표논문집 Vol.27 No.2Ⅱ

연속음성인식을 수행하기 위해서는 발음사전과 언어모델이 필요하다. 이 둘 사이에는 디코딩 단위가 일치하여야 하므로 발음사전 구축시 디코딩 단위로 표제어 단위를 선정하며 표제어 사이의 음운변화 현상을 반영한 발음사전을 구축하여야 한다. 한국어에 부합하는 음운변화현상을 분석하여 학습용 자동 발음열을 생성하고, 이를 통하여 발음사전을 구축한다. 전처리 단계로 기호, 단위, 숫자 등 전처리 과정 및 형태소 분석 과정을 수행하며, 디코딩 단위인 의사 형태소 단위를 생성하기 위해 규칙을 이용한 태깅 과정을 거친다. 이를 통해 나온 결과를 발음열 생성기 입력으로 하며, 결과는 학습용 발음열 또는 발음사전 구성을 위한 형태로 출력한다. 표제어간 음운변화 현상이 반영된 상태의 표제어 단위이므로 실제 음운변화가 반영되지 않은 상태의 표제어와는 그 형태가 상이하다. 이는 연속 발음시 생기는 현상으로 실제 인식에는 이 음운변화 현상이 반영된 사전이 필요하게 된다. 생성된 발음사전의 효용성을 확인하기 위해 다음과 같은 실험을 통해 성능을 평가하였다. 음향학습을 위하여 PBS(Phonetically Balanced Sentence) 낭독체 17200문장을 녹음하고 그 전사파일을 사용하여 학습을 수행하였고, 발음사전의 평가를 위하여 이 중 각각 3100문장을 사용하여 다음과 같은 실험을 수행하였다. 형태소 태그정보를 이용하여 표제어간 음운변화 현상을 반영한 최적의 발음사전과 다중 발음사전, 언어학적 기준에 의한 수작업으로 생성한 표준 발음사전, 그리고 표제어간의 음운변화 현상을 고려하지 않고 독립된 단어로 생성한 발음사전과의 비교 실험을 수행하였다. 실험결과 표제어간 음운변화 현상을 반영하지 않은 경우 단어 인식률이 43.21% 인 반면 표제어간 음운변화 현상을 반영한 1-Best 사전의 경우 48.99%, Multi 사전의 경우 50.19% 로 인식률이 5~6% 정도 향상되었음을 볼 수 있었고, 수작업에 의한 표준발음사전의 단어 인식률 45.90% 보다도 약 3~4% 좋은 성능을 보였다.

고 Prolactin 혈증에 관한 임상적 고찰

민헌기 ( Hun Ki Min ),이홍규 ( Hong Kyu Lee ),이기업 ( Ki Up Lee ),김성연 ( Sung Yun Kim ),정민화 ( Min Hwa Chung ),최문기 ( Moon Gi Choi ),민용기 ( Yong Ki Minn ) 대한내과학회 1985 대한내과학회지 Vol.29 No.6

초음파법에 의한 발전소 고온배관재료의 크리프손상 평가

이상국(Sang Guk Lee),정민화(Min Hwa Chung) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.2

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions which are high are temperature and high pressure for an extended period time. Such material degradation leads to various component failures causing serious accidents at the plants. Conventional measurement techniques such as replica method, electric resistance method, and hardness test method have such disadvantages as complex preparation and measurement procedures, too many control parameters, and therefore, low practicality and they were applied only to component surfaces with good accessibility.<br/> In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens have been carried out for the purpose of evaluation for creep damage which can occur in high-temperature pipeline of fossil power plant Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradation tests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens, we confirmed that the sound velocity decreased and the attenuation coefficient linearly increased in proportion to the increase of creep fraction(Øc).