롬바드 음성을 이용한 음성인식기의 성능 평가

정성윤,정현열,김경태,Jung, Sung-Yun,Chung, Hyun-Yeol,Kim, Kyung-Tae 한국음향학회 1994 韓國音響學會誌 Vol.13 No.5

한국어 음성인식기의 성능평가를 위한 기초 연구로서 인식기의 성능에 영향을 끼치는 여러 요인 중 잡음환경 하에서의 롬바드 영향을 입은 음성을 인식하는 경우 인식기의 성능평가와 분석에 관해 논하였다. 성능평가에 있어서는 표준 음성데이타를 잡음환경에서 발성한 것에 가깝게 조작해서 롬바드 영향을 고려한 경우와 그렇지 않은 경우에 대해 평가항목 (잡음의 종류, 신호대 잡음비) 에 따라 인식실험을 행한 결과, 잡음의 종류는 인식성능에 영향을 미치지 않음을 알 수 있었고, 인식률 90%를 한계치로 했을 경우 롬바드 영향을 고려하지 않았을 때는 신호대 잡음비가 10dB 정도에서, 롬바드 영향을 고려한 경우에는 30dB정도에서 동일한 인식률을 나타내어 롬바드 영향을 고려한 경우가 20dB 정도의 인식률 저하를 가져와 실제 평가시 롬바드 영향을 고려해야 함을 알 수 있었다. 분산분석의 결과로부터는 여러 종류의 인식기를 다양한 평가항목에 대해 평가할 때, 각 평가 항목이 인식성능에 미치는 영향을 정량화할 수 있음을 알 수 있었다. This paper describes the performance assessment test and analysis of test results on a Korean speech recognizer which recognizes Lombard effect received speech in noisy environment, as a basic performance assessment research. In the assessement test, standard speech data were first manipulated close to speech uttered in a noisy environment, and then performance assessment tests were carried out along with the assessment items (the type of noise, SNR) in two ways-one with Lombard effect received speech(LES), the other with not received(NLES). As a result, when 90% of recognition rate is set to be a recognition limit, it was achieved at 10dB SNR point with LES, while at 30dB with NLES. This 20dB of SNR difference indicates Lombard effect should be considered in real world assessment test. The type of noises didn't affect performance of recognizers in out tests. ANOVA analysis, in evaluating several kinds of recognizers, showed every assessment item affecting the recognition performance could be quantified.

한국 동해연안의 종관주기 해수면 변동 특성과 발생원인

정성윤,윤재열,박태욱,임세한,오임상,Jung, Sung-Yun,Yun, Jae-Yul,Park, Tae-Wook,Lim, Se-Han,Oh, Im-Sang 한국해양학회 2008 바다 Vol.13 No.2

한국 동해 연안에서의 종관주기 해수면 변동 특성과 그 원인을 규명하기 위해 동해 연안 4개 정점에 대하여 1999-2005년까지 7년 동안의 해수면과 대기압 자료를 분석하였다. 해수면의 wavelet 스펙트럼 분석 결과 모든 연도에 걸쳐 약 3-17일에 이르는 종관주기에서 95% 신뢰수준의 유의한 해수면 변동성이 식별되었고, 그러한 변동성은 봄에서 초여름에 이르는 기간에 비교적 강하게 나타났다. 이러한 변동성의 원인을 찾기 위해 해수면과 대기압 간 교차 스펙트럼 분석을 한 결과, 종관주기에서 높은 상관성을 보여 종관주기 해수면 변동의 생성에 있어 역기압 효과(inverted barometric effect)가 중요하게 작용함을 알 수 있었다. 또한, 동해 연안의 인접 해수면 관측소간 교차 스펙트럼 분석결과 북에서 남으로 위상지연이 생기는 경우와 그렇지 않은 경우로 나뉘었다. 즉 1999, 2003, 2005년은 인접 해수면 관측소간 남쪽으로 점진적인 위상지연이 발생하였고 2000-2002, 2004년은 점진적인 위상지연이 발생하지 않았다. 위상지연이 발생하는 경우의 위상속도는 약 12-15m/s로 연안 켈빈파의 위상속도와 유사한 형태로 볼 수 있다. 이러한 점진적인 위상지연의 발생원인은 봄에서 초여름 기간에 동아시아 대륙에서 발달한 저기압이 동해 북부해역을 통과하여 동진할 때 발생하는 것으로 사료된다. 인접 관측소간 점진적인 위상지연이 발생하지 않은 경우는 동아시아 대륙에서 발달한 저기압이 종관주기를 가지고 동해 연안을 중부나 남부 구역을 통해 지날 때 나타남을 알 수 있었다. 이처럼 우리나라 동해안에서 점진적인 위상지연이 발생하지 않는 경우에는 일본 남서해안에서 북동쪽으로 연안을 따라 $5{\sim}8\;m/s$의 전파속도를 가지고 점진적인 위상지연이 발생함을 알 수 있었다. Sea level and atmospheric pressure data of 1999-2005 from four stations along the Korean east coast were analyzed to understand the sea level variability and its causal mechanism. The results of the wavelet and the auto-spectrum analyses indicate that the sea level fluctuations of 3-17 day period are statistically significant at the 95% confidence level, especially in spring to early summer. In this period, the coherency between the sea levels and the atmospheric pressures in a cross-spectrum is high, implying the importance of an inverted barometric effect in generation of the sea level fluctuations. To learn about the sea level variability, the cross-spectrum analyses were applied between the sea levels of the adjacent stations. The results show a case of southward phase propagations along the coast, as in 1999, 2003 and 2005, and an another case of no progressive phase lags between the stations, as in 2000-2002, and 2004. The phase speed in the former case is 12-15 m/s, which is a commonly observed phase speed of coastal Kelvin waves. Generation of such fluctuations seems to be related to low pressure cells developed in the Asian continent in spring and summer and moving eastward over the coastal region north of the stations. The latter case of no progressive phase lag, however, occurs when the low pressure cells developed in the continent move along the region south of the stations. In this case, the northeastward phase propagation with a speed of 5-8 m/s is observed along the southwestern coast of Japan.

생체모방형 건구동식 의수의 설계

정성윤,강성균,배주환,문인혁,Jung, Sung-Yoon,Kang, Sung-Kyun,Bae, Ju-Hwan,Moon, In-Hyuk 대한의용생체공학회 2009 의공학회지 Vol.30 No.3

This paper proposes a biomimetic hand prosthesis with tendon-driven five fingers. Each finger is composed of a distal-middle phalange, a proximal phalange and a metacarpal bone, which are connected to a link mechanism. The finger flexion is a resultant motion by pulling a wire to serve as a tendon, but the finger extension is performed by an elastic mechanism composed of a restoration spring. The designed hand prosthesis with tendon-driven five fingers has totally six degrees of freedom. But its weight is merely 400.73g. The hand can perform various hand functions such as the grasping and the hand postures. From experimental results, we show that the proposed hand prosthesis is useful to amputees as a prosthetic hand.

족관절 삼과 골절에서 전후방 유관나사 후과 고정술의 2년 추시 결과

정성윤,이명진,정영훈,Jung, Sung Yoon,Lee, Myoung Jin,Jung, Young Hun 대한족부족관절학회 2016 대한족부족관절학회지 Vol.20 No.2

Purpose: The purpose of this study was to assess the 2-year follow-up results of patients with a trimalleolar fracture, who had undergone an anterior incision cannulated screw fixation of the posterior malleolar fragment, which had more than 25% of articular involvement or had no cortical continuity with the distal tibia. Materials and Methods: Among 28 patients with a trimalleolar fracture who had undergone fixation of the posterior malleolar fragment between February 2005 and February 2010, 14 patients, who underwent an anterior incision cannulated screw fixation of posterior malleolar fragment and were followed-up for more than 2 years, were selected. The postoperative clinical and radiological findings immediately and at the 1- and 2-year follow-up were compared. The clinical findings were evaluated as American Orthopaedic Foot and Ankle Society (AOFAS) score. The radiological assessment was evaluated as the maintenance of reduction, period to bone union, and the presence of nonunion, malunion, and complications. Results: The clinical outcome by mean AOFAS score revealed 83.0 points in the group with preoperative displacement below 2 mm and 80.7 points in the group with preoperative displacement above 2 mm postoperatively. The mean AOFAS score was 91.7 and 93.1 points in the group with preoperative displacement below 2 mm on 1- and 2-year follow-up, respectively, and 89.8 and 91.7 points in group with the preoperative displacement above 2 mm on 1- and 2-year follow-up, respectively. After a 2-year follow-up among 14 cases selected for this study, 13 cases showed an excellent reduction state and only 1 case (7.1%) showed a displacement of more than 2 mm. No complication were encountered in the group with preoperative displacement below 2 mm. On the other hand, among 8 patients in the group with preoperative displacement above 2 mm, there were 3 with limitations of the range of motion of the ankle joint (37.5%) and 1 post-traumatic arthritis (12.5%) at the 2-year follow-up. Conclusion: Anterior incision cannulated screw fixation of the posterior malleolar fragment could be a valuable method for the treatment of trimalleolar fractures that provides satisfactory results.

훈련데이터 기반의 temporal filter를 적용한 4연숫자 전화음성 인식

정성윤,배건성,Jung, Sung-Yun,Bae, Keun-Sung 대한음성학회 2005 말소리 Vol.53 No.-

The performance of a speech recognition system is generally degraded in telephone environment because of distortions caused by background noise and various channel characteristics. In this paper, data-driven temporal filters are investigated to improve the performance of a specific recognition task such as telephone speech. Three different temporal filtering methods are presented with recognition results for Korean connected-digit telephone speech. Filter coefficients are derived from the cepstral domain feature vectors using the principal component analysis. According to experimental results, the proposed temporal filtering method has shown slightly better performance than the previous ones.

Implementation of HMM Based Speech Recognizer with Medium Vocabulary Size Using TMS320C6201 DSP

정성윤,손종목,배건성,Jung, Sung-Yun,Son, Jong-Mok,Bae, Keun-Sung The Acoustical Society of Korea 2006 韓國音響學會誌 Vol.25 No.e1

In this paper, we focused on the real time implementation of a speech recognition system with medium size of vocabulary considering its application to a mobile phone. First, we developed the PC based variable vocabulary word recognizer having the size of program memory and total acoustic models as small as possible. To reduce the memory size of acoustic models, linear discriminant analysis and phonetic tied mixture were applied in the feature selection process and training HMMs, respectively. In addition, state based Gaussian selection method with the real time cepstral normalization was used for reduction of computational load and robust recognition. Then, we verified the real-time operation of the implemented recognition system on the TMS320C6201 EVM board. The implemented recognition system uses memory size of about 610 kbytes including both program memory and data memory. The recognition rate was 95.86% for ETRI 445DB, and 96.4%, 97.92%, 87.04% for three kinds of name databases collected through the mobile phones.

The Current Status of Bacterial Identification by Wound Culture for Diabetic Foot Lesions in a Single Tertiary Hospital in South Korea

정성윤,이명진,이승엽,이상윤,Jung, Sung Yoon,Lee, Myoung Jin,Lee, Seung Yup,Lee, Sang Yoon Korean FootAnkle Society 2021 대한족부족관절학회지 Vol.25 No.2

Purpose: The present study aimed to develop guidelines regarding initial choice of antibiotics for diabetic foot ulcers (DFU) by investigating bacterial isolates. Materials and Methods: This study included 223 DFU patients that visited a single tertiary hospital and underwent bacterial culture between January 2016 and February 2020. The study was conducted in two parts: 1) to compare bacterial isolates and wound healing according to comorbidities such as chronic kidney disease (CKD) and peripheral artery disease (PAD), and 2) to compare bacterial isolates according to wound depth using the Wagner classification. Results: Of the 223 patients, 43 had CKD (group A), 56 had PAD (group B), 30 had CKD and PAD (group C), and 94 had none of these comorbidities (group D). The isolation rate for multidrug-resistant gram-negative bacteria (MRGNB) and gram-negative to gram-positive bacteria ratio were highest in group C (p=0.018, p=0.038), and the proportion that achieved wound healing was lowest in group C (p<0.001). In the second part of the study, subjects were classified into 5 grades by wound depth using the Wagner classification; 13 grade I, 62 grade II, 60 grade III, 70 grade IV, and 17 grade V. No significant difference was observed between these grades in terms of isolation rates or gram-negative to gram-positive bacteria ratios. Conclusion: This study suggests antibiotics that cover gram-negative bacteria including MRGNB produces better results in the presence of CKD and PAD and that initial antibiotic choice should be based on the presence of CKD and PAD rather than wound depth.

알코올 의존 환자의 적혈구막 지질과산화 정도와 적혈구 평균 용적 및 간 효소 지표와의 관련성

정성윤,최인근,서국희,강희정,Jeong, Seong Yun,Choi, Ihn-Geun,Suh, Guk-Hee,Kang, Hee Jung 대한생물정신의학회 1998 생물정신의학 Vol.5 No.2

Objectives : Alcohol-induced oxidative stress has been known to injure various tissues or organs. This stress is related with free radicals which are produced as the result of long-term alcohol consumption. Malonyldialdehyde(MDA) is produced by the interaction of free radicals and cell membrane lipids, and indicates the degree of lipid peroxidation indirectly. The purpose of this study was to investigate the relationship between red blood cell(RBC) membrane lipid peroxidation by free radicals, and associated hepatic injuries and hematologic changes. Methods : Thirty-three subjects diagnosed as alcohol dependence according to DSM-IV diagnostic criteria were evaluated within 72 hours after discontinuing alcohol drinking. Clinical characteristics were evaluated by CAGE questionnaire and Korean Michigan Alcoholism Screening Test(MAST). RBC membrane MDA level was measured as the marker of RBC membrane lipid peroxidation. Aspartate aminotransferase(AST), alanine aminotransferase(ALT) and gamma-glutamyltransferase(GGT) were used as the biochemical markers of liver damage due to alcohol ingestion. The alcohol-induced hematologic change was assessed by mean corpuscular volume(MCV). Results : The results were as follows. Clinical characteristics were not different between two groups having normal and abnormal levels of AST, ALT, GGT or MCV. The levels of MDA were not correlated with the clinical characteristics and serum levels of AST, ALT and GGT. However, there was a significant correlation between the levels of MDA and the value of MCV(p=0.017). Conclusions : These findings suggest that oxidative stress in alcohol dependence may not be reflected in liver enzyme markers such as AST, ALT and GGT, but may be reflected in MCV.

한국어 숫자음 전화음성의 채널왜곡에 따른 특징파라미터의 변이 분석 및 인식실험

정성윤,손종목,김민성,배건성,Jung Sung-Yun,Son Jong-Mok,Kim Min-Sung,Bae Keun-Sung 대한음성학회 2002 말소리 Vol.43 No.-

Improving the recognition performance of connected digit telephone speech still remains a problem to be solved. As a basic study for it, this paper analyzes the variation of feature parameters of Korean digit telephone speech according to channel distortion. As a feature parameter for analysis and recognition MFCC is used. To analyze the effect of telephone channel distortion depending on each call, MFCCs are first obtained from the connected digit telephone speech for each phoneme included in the Korean digit. Then CMN, RTCN, and RASTA are applied to the MFCC as channel compensation techniques. Using the feature parameters of MFCC, MFCC+CMN, MFCC+RTCN, and MFCC+RASTA, variances of phonemes are analyzed and recognition experiments are done for each case. Experimental results are discussed with our findings and discussions

경량 의수용 SMA 구동식 생체모방 손가락 모듈

정성윤(Sungyoon Jung),문인혁(Inhyuk Moon) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.2

This paper proposes a biomimetic finger module to be used in a lightweight hand prosthesis. The finger module consists of finger skeleton and an actuator module driven by SMA (Shape Memory Alloy). The prototype finger module can perform flexion and extension motions; finger flexion is driven by a contraction force of SMA, but it is extended by an elastic force of an extension spring inserted into the finger skeleton. The finger motions are controlled by feedback of electric resistance of SMA because the finger module has no sensors to measure length and angle. Total weight of a prototype finger module is 30g. In experiments the finger motions and finger grip force are tested and compared with simulation results when a constant contraction force of SMA is given. The experimental results show that the proposed SMA-driven finger module is feasible to the lightweight hand prosthesis.