Time Frequency Domain Reflectometry 기법을 이용한 Coaxial Cable에서의 결함 감지 및 추정

송은석,신용준,최덕선,육종관,박진배,Powers, Edward J. 한국항행학회 2003 韓國航行學會論文誌 Vol.7 No.1

본 논문에서는 도선사에서 발생하는 결함 위치와 이상 유무를 감지하는 새로운 고분해능 반사측정법인 시간-주파수 영역반사측정법 (TFDR, Time-Frequency Domain Reflectometry)을 제안하였다. 고전적인 반사측정법들은 단지 시간 또는 주파수의 한 영역에서 분석되어져 왔으나, 본 논문에서 제시한 TFDR은 도선의 결함 위치와 이상 유무를 발견하기 위해 과도신호의 시간과 주파수 영역의 정보를 동시에 이용할 수 있는 시간-주파수 분석기법으로 특성화하였다. TFDR의 기준신호 설계는 측정 케이블의 물리적 성질들을 고려하여 주파수 밴드를 결정하며, 도선의 결함감지와 추정은 시간-주파수 상호상관관계 함수에 의해 이루어진다. TFDR 시스템을 이용하여 여러 결함 상태를 가진 실제 coaxial cable (RG-142, RG-400)에 대해 실험하였고 정확성을 입증하기 위해 TDR (Time Domain Reflectometry) 장비와 성능은 비교하였다. 본 논문에서는 TFDR이 TDR보다 작은 오차로 결함을 찾아냄을 나타내고 있으며, 측정된 정확도는 TFDR의 오차율이 0.5%이하로 TDR (54750A/54754A) 장비보다 성능이 월등히 우수하다는 것을 알 수 있다. In this paper, a new high resolution reflectometry scheme, time-frequency domain reflectometry (TFDR), is proposed to detect and locate fault in wiring. Traditional reflectometry methods have been achieved in either the time domain or frequency domain only. However, time-frequency domain reflectometry utilizes time and frequency information of a transient signal to detect and locate the fault. The time-frequency domain reflectometry approach described in this paper is characterized by time-frequency reference signal design and post-processing of the reference and reflected signals to detect and locate the fault. Design of the reference signal in time-frequency domain reflectometry is based on the determination of the frequency bandwidth of the physical properties of cable under test. The detection and estimation of the fault on the time-frequency domain reflectometry relies on the time-frequency domain reflectometry is compared with commercial time domain reflectometry (TDR) instrument. In these experiments provided in this paper, TFDR locates the fault with smaller error than TDR. Knowledge of time and frequency localized information for the reference and reflected signal gained via time-frequency analysis, allows one to detect the fault and estimate the location accurately.

중증 두부 손상 환자의 예후 인자에 대한 임상 분석 : Clinical Prognostic Factors

송준석,하은주,이종수,이승재,박효일 대한신경외과학회 1993 Journal of Korean neurosurgical society Vol.22 No.2

A clinical analysis was carried out retrospectively with 54 cases of severe head injured patients(Glasgow Coma Scale score 3 to 8) in identify prognostic factors. Unawareness for over 1 month, abnormal pupillary reaction, abnormal motor response pattern, and diffuse head injury with basal cisternal compression prove to be the most reliable predictors. Individual predictions of outcome provide a powerful tool for assessing the relative efficacy of alternative treatments.

TWO-PARAMETER 탄성지반위에 놓인 고차전단변형 직교이방성 적층판의 정적 및 동적해석

송석은,이원홍 진주산업대학교 2000 산업과학기술연구소보 Vol.- No.7

Static and Transient results for a Orthgtropic laminated plate on two-parameter elastic foundations base on a higher-order shear deformation theory are presented. The effects on central deflection by plate thickness ratio, material modulus ratio, ply lamination geometry, shear and winkler modulus of elastic foundations are investigated. To validate the derived equations, the obtained deflections of simply supported isotropic plates are compared with those of Timoshenko. The information presented should be useful to composite-structure designers, to researchers seeking to obtain better correlation between theory and experiment and to numerical analysts in checking out their programs.

전신성 홍반성 루푸스 환자에서 병발된 Coxsackievirus B3 심근염 1예

송봉근,임병관,김민형,신성철,정재홍,김동희,김정환,박건우,고은미,전은석 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.12

뇌 경막하 축농

송준석,하은주,이종수,이승재,박효일 대한신경외과학회 1992 Journal of Korean neurosurgical society Vol.21 No.12

Subdural empyema is relatively uncommon condition. characterized by purulent collection in the subdural space. Having presented a fulminating clinical course with very high morbidity and mortality. it is conconsidered as a neurosurgical emergency. In recent years, the mortality of subdural empyema has significantly diminished due to rapid diagnosis, aggressive antibiotic therapy and timely surgical intervention. The condition remains a diagnostic challenge ; CT scanning cannot be relied upon although the use of intravenous contrast and more modem scanner has improved the diagnostic yield. MRI offers earlier and more accurate diagnosis of computed tomographically suspected lesion. We report cases of subdural empyemas. which were diagnosed with MR and operaton. We treated one case successfully and the other postoperative case unsuccessfully owing to a delayed diagnosis.

복식 전자궁적출술후 절단부에 발생한 난관탈출증 1예

송은석,이해혁,김태희,김정식,남계현,이권해,고은석 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Prolapse of the fallopian tube into the vaginal vault after hysterectomy is a rare complication. Since most of cases may resolve before detection or remain undiagnosed, the exact incidence is still unknown. Though most common sign of tubal prolapse is tender friable tissue in vaginal cuff, with the simptoms of lower abdominal pain, dysparenunia, vaginal discharge, or postcoital spotting. The definitive diagnosis should be confirmed histologically Recently, we experienced a case of fallopian tube prolapse after abdominal hysterectomy in a 41-year-old woman and report with a brief review of the literature.

開墾地의 耕耘整地및 丞水路作業에 關한 硏究

宋錫銀,洪鐘浩 진주산업대학교 1979 論文集 Vol.17 No.-

It is necessary to develop and supply special equipment suitable for reclaimed area agriculture in accordance with the progress of agricultural mechanization. But it is more worth while to consider how to effectively use the machinery such as tractors and power tillers which have already been supplied for reclaimed area agriculture. Thus we have carried out an experiment to study the working rate slope and safety of the machine frame when this machinery is used in the area. 1. Plowing working rate of bottom plough was 35.8 minute per 10 ares on the 6 slope and 47.6 minutes on the 10 slope. These working rates were lower. than those of flat land by 44% and 33% respectively. Working rates of disc harrow on the 6 and 10 slopes were 55-76% of the working rates at the flat land. In case of power tiller, working rates on slopes were about 35-58% of those an float land. 2. Harrowing working rates on the Rotavator was 18.5 minutes per 10 ares on the 6 slope and 22.01 minutes on the 10 slope. 3. The working rate of making catch canals was 18.8 minutes per 50m of catch canal when a disc harrow was used on the 6 slope. 4. The real slope of the tractor body in the plowing operation in accordence with the different land slope is almost the same when plowing by bottom plough or plowing by disc plow. However, considering the overturn of tractor on the steep slope and the proliferation of roots it is better to plow by disc plough than by bottom plough. 5. During ploughing operation in the sloping area, the inclination of the tractor with bottom plough was more than that of the tractor equipped with disc harrow and for power tiller it was more with rubber tire than with cage wheel. 6. It was found that the steeper the slope is, the more was the slip of the tractor, or power tiller and the slip to the contour direction was more in conparition to the slip occured to the direction of the slope.

음절 모델을 이용한 단어인식

송은석,김창석 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-

This paper is proposed word recognition use connected syllable. This proposed method is able to large-scale word recognition using a few syllables model. Syllable model is made by HMM Word model is made by null transition using concatenation syllable model and syllable model. Feature extraction of speech signal is LPC coefficients. LPC coefficients are obtained by FRLS algorithm Differenced LPC cepstrum coefficients are converted LPC coefficients. Speech recognition parameters are using differenced LPC cepstrum coefficients because these coefficients are separate speech source and vocal tract spectrum. The vector quantization codebook is made by using the LBG algorithm. The training procedure of the HMM uses Viterbi and Baum-We1ch algorithms, and the recognizing procedure use forward algorithm. Experiment recognition results of the proposed method is able to large-scale word recognition using a few syllables model with null transition.

당뇨병 및 간경변증 환자에서 발생한 Fusarium verticillioides에 의한 피부 감염 1예

이석종,전영민,원지연,송은섭,최용우,김한욱 대한의진균학회 1997 대한의진균학회지 Vol.2 No.1

Fusarum species, which are common soil saprophytes, have been implicated as a pathogen causing a variety of opportunistic infections such as keratitis, onychomycosis, burn wound infection or disseminated systemic infections in immunocompromised hosts. We report a case of cutaneous infection caused by F. verticillioides in a 59-year-old man, with a long history of diabetes mellitus and alcoholic liver cirrhosis. He presented with a few papules and fluctuant cutaneous nodules on both forearms traumatized by woodstick 4 months ago. The diagnosis of F. verticillioides infection was established by histopathologic examination and findings of tissue cultures.

상부 조기 위암 환자의 복강경하 상부 위절제술 3례 경험

조규석,김형철,박경규,이문수,송옥평,임철완,신웅진,주종우,유기원 순천향의학연구소;Soonchunhyang Medical Research Institute 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Background : The reported incidence of early gastric cancer located in the upper portion of the stomach has been increasing with the recent advances in its diagnosis and screening. Recently, we have successfully performed laparoscopic assisted proximal gastrectomy and gastric tube reconstruction without pyloroplasty on three patients with early gastric carcinoma localized to the upper third of the stomach. We describe our modification of this procedure in this report. Method : After creating an surgical pneumoperitoneum, the stomach was mobilized using laparoscopic coagulating shears. Upper half of the greater curvature and three-quarters of the lesser curvature were then dissected along with regoinal D2 lymphadenectomy. This was followed by a 5 cm, longitudinal mini-laparotomy in the upper abdomen, and the construction of the exteriorized stomach with a gastric tube measuring 20 cm long and 4 cm wide. Reconstruction with an esophagogastrostomy was performed using a circular stapler. Result : No post-operative morbidity or mortality was observed in this small series of patients. The average operative time was 250 minutes (range 220-300 minutes), and the average blood loss was 150 ml (range 90-180 ml). The mean number of lymph nodes harvested during these laparoscopic proximal gastrectomies was 24 nodes (range 22-25 lymph nodes). The average postoperative hospital stays was 7.5 days (range 7-8 days). Conclusion : Our technique of laparoscopic assisted proximal gastrectomy and gastric tube reconstruction without phloroplasty offers a minimally invasive technique with the potential of impoving the post-operative quality of life patients with an early-stage proximal gastric cancer.