http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
중간부 담도암 환자에서 담도분절절제와 췌두십이지장절제에 따른 예후 비교
서석인(Seok-In Seo),황신(Shin Hwang),이영주(Young-Joo Lee),김기훈(Ki-Hun Kim),안철수(Chul-Soo Ahn),문덕복(Deok-Bog Moon),하태용(Tae-Yong Ha),송기원(Gi-Won Song),정동환(Dong-Hwan Jung),박광민(Kwang-Min Park),황대욱(Dae-Wook Hwang),이승 한국간담췌외과학회 2011 한국간담췌외과학회지 Vol.15 No.1
Purpose: This study was designed to analyze the prognosis following segmental bile duct resection (BDR) versus pancreatoduodenectomy (PD) for mid bile duct (mBD) cancer. Methods: During the 4 years between 2003 and 2006, 55 patients underwent surgical resection for mBD cancer in our institution. Medical records were reviewed retrospectively. They were divided into two groups, a BDR group (n=24) and a PD group (n=31) according to the extent of resection. Results: Median follow-up was 43 months. Overall 3- and 5-year survival rates were 56.0% and 33.8%, respectively. The BDR group had lower tumor stages than the PD group (p=0.011). R0 resection was achieved in 17 (70.8%) of the BDR group and 30 (96.8%) of the PD group. Median survival periods were 43 and 34 months after R0 and R1 resections, respectively (p=0.715). Recurrence occurred in 41 patients after a mean period of 18 months. Three- and 5-year survival rates were 62.5% and 27.2% after BDR, respectively, and 51.5% and 34% after PD, respectively (p=0.715). No significant risk factors for shorter patient survival times was identified. Aggressive treatment of recurrence did not appear to prolong patient survival. Conclusion: The extent of resection for mBD cancer did not affect the survival outcome when R0 resection was achieved. Considering the operative risk in patients with older ages or co-morbidities, PD should be considered only after obtainment of simultaneous tumor-free radial and proximal longitudinal resection margins.
유체유동에 의한 외력을 고려한 회전 블레이드의 동역학적 거동해석
서석,유홍희,윤준용,Seo, Seok,Yu, Hong-Hui,Yun, Jun-Yong 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.9
A dynamic modeling of a rotating pretwist blade which interacts with the fluid is proposed in this study. The hybrid deformation variable modeling method is employed to derive the equations of motion. The external force and moment induced by the fluid (with fixed configurations of the blade) are obtained by fluid flow analysis and tabulated in a database. This database is efficiently utilized to save the computational effort to calculate the dynamic response of the blade. The numerical results show that the fluid affects the transient response as well as frequency characteristics of the system.
해양 음향 토모그래피에서 M-시퀀스를 이용한 해양 음향 채널 분석
서석,이찬길,Seo, Seok,Lee, Chan-Kil 한국음향학회 2004 韓國音響學會誌 Vol.23 No.1
In ocean acoustic tomography (OAT), the pulse compression techniques using M-sequences are employed in the many studies for investigating the ocean structures. M-sequences can provide the good time and Doppler resolution in the process of demodulation using matched-filter. The signal-to-noise (SNR) performance at the output of receiver may be improved by manipulating received signal, i. e. coherently averaging. The processing time can be significantly reduced by using fast hadarmard transform (FHT) or fast Fourier transform (FFT). In this paper, we estimate the multipath arrival structures and delay times using the East Korean Sea experiment data and explore the compensation method for the detrimental effects on performance due to sampling rate error. We also analyze the characteristics of the ocean acoustic channels through scattering function, delay power profile, and time dispersions. 최근에 OAT(Ocean Acoustic Tomography) 분야에서 M-시퀀스를 이용한 펄스압축 (pulse compression) 기법을 이용하여 해양 구조를 분석하는 많은 연구가 이뤄지고 있다. M-시퀀스는 정합필터 (matched-filter)을 사용한 복조를 통해. 훌륭한 시간 분해능 (resolution) 및 도플러 분해능을 제공할 수 있다. 또한 수신 신호를 적절하게 처리함으로써 수신기 출력의 신호대잡음비 성능을 개선할 수 있으며, 수신 신호를 동기적으로 평균하는 것은 그것에 대한 좋은 예라고 할 수 있다. 그리고 데이터를 빠르고 효율적으로 처리할 수 있는 FHT (Fast Hadamard Transform) 또는 FFT (Fast Fourier Transform) 기법을 사용함으로써 처리 속도를 효율적으로 개선할 수 있다. 본 논문에서는 동해 연안에서 수집된 데이터를 이용하여 수중 음파의 다중경로 성분과 지연 시간을 분석하며, 송수신기간의 샘플링 속도 오차에서 비롯된 현상을 설명하고 오차를 보상하는 방법을 제시한다. 그리고 채널의 scattering 함수, 지연 전력 프로파일 (delay power profile), 시간 확산 특성 등을 통하여 해양 음향 채널의 특성을 분석하도록 한다.