http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
백서의 좌골신경 절단 후 비복근의 자기공명영상 신호강도 변화와 근전도 소견의 관계
이주환,이장철,김동원,박기영,이성문,Lee, Joo Hwan,Lee, Jang Chul,Kim, Dong Won,Park, Ki Young,Lee, Sung Moon 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.1
Objectives : The evaluation of peripheral nerve injuries has traditionally relied on a clinical history, physical examination, and electrodiagnostic studies. The purpose of the present study was to examine serial magnetic resonance image(MRI) changes following acute muscle denervation under experimental conditions and to identify potential advantages and disadvantages of this use of MRI. Methods : An experimental transection of right sciatic nerve on Spargue-Dawley rats was performed. MRI was performed with T1-weighted spin-echo and STIR sequences. The imaging findings were compared with EMG in order to determine its sensitivity relative to this standard procedure. A simultaneous histopathological study provided information about the morphological basis of the imaging findings. Signal intensities were expressed as a ratio of abnormal to normal. Results : The signal intensity ratio of muscles with the STIR sequence was increased significantly at 2 weeks after sciatic nerve transection(p<0.05), although definite signal change was seen as early as 4 days postdenervation in one. EMG revealed significant denervation potential from 3 days after nerve transection. Diffuse cell atrophy was revealed hostologically at 2 weeks after transection, which was at the same time of significant signal change in MRI. Conclusion : MRI signal changes in denervated muscles secondary to nerve injury correlate with the degree of muscle atrophy on histologic examination. In addition to EMG, MRI can document the course of muscle atrophy and mesenchymal abnormalities in denervation. These results indicate that MRI can play a complementary role in the evaluation of patients with denervation.
고주파수대(10GHz 이상) 무선 전송 링크 이용 기술 표준화 동향
이주환,심동욱,정영준,Lee, J.H.,Sim, D.W.,Chong, Y.J. 한국전자통신연구원 2012 전자통신동향분석 Vol.27 No.6
2012년 6월 30일자로 방송통신위원회에서는 10~60GHz 대역의 고정업무용 주파수 지정에 관한 입안 예고를 공고한 바 있다. 본고에서는 이 입안 예고의 배경이 되는 고정업무에 관한 국제 표준화 기구인 ITU-R(International Telecommunication Union-Radio Sector) 연구반의 표준화 동향에 대해 소개하고, 고주파 대역, 고정업무 시스템의 국내외 기술개발 동향을 소개한다. 또한, 국내외 고주파 대역 이용 현황을 국내 현황과 비교하고, 이를 통해 입안 예고된 고정업무용 주파수 지정의 개정 방안에 대해 간략히 소개하여, 향후 국내 전파통신망의 미래상을 전망할 수 있도록 한다.
대퇴 근위부의 골소주 패턴에 대한 복합적인 분석을 통한 골다공증 예측 연구
이주환,박성윤,정재훈,김성민,Lee, Ju-Hwan,Park, Sung-Yun,Jeong, Jae-Hoon,Kim, Sung-Min 한국정보처리학회 2012 정보처리학회논문지B Vol.19 No.2
본 연구에서는 각기 다른 측정 부위에서 도출된 골밀도와 골소주 패턴 간의 상관관계를 복합적으로 분석하여 측정부위에 따른 평가변수의 골다공증 예측 가능성을 평가하고자 하였다. 실험대상은 40대 이상의 폐경기 이후 여성 40명을 선정하였고, T-Score 분류법에 따라 각각 20명의 정상군 및 골다공증군으로 분류하였다. 실험대상의 골밀도는 이중 에너지 X선 흡수 계측법을 통해 대퇴경부(Femoral Neck), 전자부(Trochanter) 및 워드 삼각부(Ward's Triangle)에서 측정하였다. 또한 각 측정부위에 $50{\times}50$ 픽셀 크기의 관심영역을 지정하고, 기존 연구에서 제안된 영상처리기법을 적용하여 각 영역의 골소주 패턴을 추출하였다. 골다공증을 예측하기 위한 평가변수는 구조적 변수(평균 회색조, 골면적, 골둘레, 골두께, 말단거리), 골격화 변수(골개수, 골길이) 및 프랙탈 차원(fractal dimension)으로 구분되는 총 8가지를 선정하였다. 실험결과, 골면적, 골둘레, 골두께, 말단거리, 골개수, 골길이 및 프랙탈 차원이 골밀도를 유의하게 반영하였고(p<0.003), 평가변수의 분석을 통한 골다공증의 높은 예측 가능성을 확인하였다. The purpose of this study was to determine the evaluation parameters' osteoporosis predictability in accordance with measuring regions by analyzing the correlations between bone mineral density and trabecular patterns derived from different measuring regions. Experimental subjects were a total of 40 female patients after menopause aged over 40 years, and were classified into 20 control and 20 osteoporotic groups according to the T-score. Bone mineral density was measured on femoral neck, trochanter and ward's triangle by DEXA(Dual Energy X-ray Absorptiometry). We designated ROI(Region of Interest) with $50{\times}50$ pixel size on each measuring regions, and extracted trabecular patterns by using existing image processing method. We also selected a total of eight evaluation parameters that are categorized into structural(mean gray level, area, perimeter, thickness and terminal distance), skeletonized parameters(number, length) and fractal dimension. As a result, it was observed that area, perimeter, thickness, terminal distance, number, length and fractal dimension reflected the bone mineral density with high statistical validity(p<0.003). We also confirmed that the evaluation parameters could predict the osteoporosis more efficiently.
음악신호와 뇌파 특징의 회귀 모델 기반 감정 인식을 통한 음악 분류 시스템
이주환,김진영,정동기,김형국,Lee, Ju-Hwan,Kim, Jin-Young,Jeong, Dong-Ki,Kim, Hyoung-Gook 한국음향학회 2022 韓國音響學會誌 Vol.41 No.2
본 논문에서는 음악 청취 시에 나타나는 뇌파 특징을 이용하여 사용자 감정에 따른 음악 분류 시스템을 제안한다. 제안된 시스템에서는 뇌파 신호로부터 추출한 감정별 뇌파 특징과 음악신호에서 추출한 청각적 특징 간의 관계를 회귀 심층신경망을 통해 학습한다. 실제 적용 시에는 이러한 회귀모델을 기반으로 제안된 시스템은 입력되는 음악의 청각 특성에 매핑된 뇌파 신호 특징을 자동으로 생성하고, 이 특징을 주의집중 기반의 심층신경망에 적용함으로써 음악을 자동으로 분류한다. 실험결과는 제안된 자동 음악분류 프레임 워크의 음악 분류 정확도를 제시한다.
이주환,이철,김인기,윤명환,Lee, Joo-Hwan,Lee, Cheol,Kim, In-Ki,Yun, Myung-Hwan 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.1
KTX (Korea Train eXpress) is launched as the $5^{th}$ develop a ride-comfort model for high-speed rail pasengers using structural equation model (SEM). Both qualitative and quantitative factors affecting ride-comfort were investigated, and employed to construct a comprehensive ride-comfort model. The SEM model was built with twenty measurement variables and seven latent variables for the evaluation of ride-comfort of high-speed train passenger. A total of six hundreds thirty two subjects participated in the evaluation using face-to-face survey method. As a result, the proposed SEM model model fitnes (GFI=0.93). According to the results, overall ride-comfort was significantly affected by the seat-, fatigue-, interior-related, and customer satisfaction variables such as fare. Among the engineering design variables of high-speed train, seat-related variables were identified as critical factors of the ride-comfort. It is expected that the result of this study could be useful for the enhancement of ride comfort in next generation KTX.
이주환,노홍섭,Lee, Ju Whoan,Ro, Hong Sup 대한악안면성형재건외과학회 1992 Maxillofacial Plastic Reconstructive Surgery Vol.14 No.1
The purpose of this study was to investigate the fractures of facial skeleton ; mandible, maxilla, zygoma Clinically, we observed 413 patients with facial bone fractures treated at the department of dentistry, Koryo General Hospital from Jan. l989 to Dec. I991. This results ere as follows : 1. The most common fracture was occured in the mandible (63.7%) and the symphysis was occured most freguently(30.4%) 2. The most prevalent age was twenties(37.5%) 3. Main causes was traffic accident(21.7% ) 4. The ratio of male to female was about 9.3 : 1 5. Most combined injuries was head injuries. (54.6%) 6. The most frequent job was a company employee. 7. There were the highest frequency in March, and the lowest frequency in February.