신경회로망을 이용한 터빈로타 디스크 키웨이의 결함 검출

이병우,이종오,윤운하,이병우,서원찬,이종규 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.1

최근 터빈 로타 디스크 키웨이에서 많은 응력부식균열이 발견되었으며, 터빈설비의 중대한 파손을 예방하기 위해 이러한 균열은 조기에 검출 및 평가되어야 한다. 본 연구에서는 초음파탐상의 RF(radio frequency) 신호를 역전파 알고리즘에 근거한 신경회로망에 적용하여 키웨이 주변의 균열에 대한 위치, 크기 및 방향성을 평가하였다. 각 반사영역에서 수신된 여러개의 피크로 나타나는 RF 신호를 각 반사영역에 대해 하나의 최대 피크를 가지도록 처리한 후, 트랜스듀서의 위치 정보와 각 반사파의 도달시간이 들어있는 주사 데이터를 작성하였다. 이 주사 데이터로부터 각 반사영역 사이의 시간차이와 트랜스듀서의 위치 정보를 신경회로망에 적용한 결과 키웨이에서 시작된 균열의 위치, 크기 및 방향성을 평가하는데 유용함을 알 수 있었다. A number of stress corrosion cracks in turbine rotor disk keyway in power plants have been found and the necessity has been raised to detect and evaluate the cracks prior to the catastrophic failure of turbine disk. By ultrasonic RF signal analysis and using a neural network based on back-propagation algorithm, we tried to evaluate the location, size and orientation of cracks around keyway. Because RF signals received from each reflector have a number of peaks, they were processed to have a single peak for each reflector. Using the processed RF signals, scan data that contain the information on the position of transducer and the arrival time of reflected waves from each reflector were obtained. The time difference between each reflector and the position of transducer extracted from the scan data were then applied to the back-propagation neural network. As a result, the neural network was found useful to evaluate the location, size and orientation of cracks initiated from keyway.

작은 피질하 병변에 대한 정위적 개두술 및 경-구 접근법

손병철,김문찬,이관성,박춘근,홍용길,강준기 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.12

마산만의 해수오염 추이 및 대책

이찬원,민병윤,손성원 경남대학교 환경문제연구소 1989 환경연구 Vol.11 No.-

Over the past two decays, coastal waters of Masan Bay have been extensively used by coastal communities and industries for the disposal of various wastes. The average COD had increased from 3.9㎎/1 in 1984 to 5.7㎎/1 in 1988. Both nitrogen and phosphorous as main sources of eutrophication had rapidly increased in 1985 and maintained above 1.0㎎/1 as T-N(total nitrogen) and 0.03㎎/1 as PO₄,-P. This data shows that the Masan bay is now the most polluted bay in Korea. To monitor the water quality of Masan Bay, some chemical parameters were determined. The results indicate deficiences in dissolved oxygen(DO) content of bottom waters(depth 6-18m) of all the sites examined. Concentrations of PO₄-P in bottom waters were higher than those in surface waters of all the sampling sites. These resultes of this study reflect that sediments in all areas of Masan Bay are contaminated with organics and these pollutants are extracted into water columns. Considering the values of temperature, pH, concentration of DO, PO₄-P, and T-N(total nitrogen), the waters do not appear to be mixed both vertically and horizontally. The coastal waters in all areas of Masan Bay were also polluted with dissolved heavy metals. The concentration ranges of dissolved Zn, Mn, Cr, Cu, Pb, and Hg wpre 1.17-11.07, 0.09-0.94, 0.04-0.40, 0.03-0.13, 0.02-0.12 and 0.02-0.09 g/ repectively. The extend of current pollution is severe enough with high levels of organic chemicals. metals, nutrients and low oxygen levels(especially in water columns overlayed sediments). Fortunately, a municipal sewage treatment plant will have been built in Masan area by 1990. But the master plan only includes pretreatments such as screening and grit removal, primary treatment, sludge handling system, and chlorinating chamber. Aeration basin and secondary clarifier for secondary treatment will be accomplished by 2001. Construction of upgrading of municipal treatment plant including secondary and advanced treatment in very near future is now recommended.

韓國의 看護現狀에 대한 고찰

김병찬,손영주 제주한라대학 1998 論文集 Vol.22 No.-

The purpose of this study is to research the present situation of nursing in Korea in accordance with many different areas. Modern nursing in Korea started in 1903 with the foreign nurses visiting Korea for missionary work and has developed a lot recently. The title of nurses has changed 3 times and nursing educational system has been institutionalized into three or four year college education. In the past, the career of nurses was limited largely in the medical institutions as a medical assistant, but these days their speciality field has been expanded into various areas such as schools, industrial organizations, social welfare facilities, and many different institutions practicing inclusive health and medical enterprises. As of 1998, to be a nurse in Korea, they have to complete 3 or 4 years nursing college course as a basic curriculum and get a nurse license after passing state examination. After that, they work in the clinical field or community nursing field. If they want to be scholars or researchers, they go to graduate school. At the present there are 37 universities which offer the master's coures, and 12 universities which offer the doctor's course. Nursing in Cheju began with opining JA-HYE clinic, the predecessor of Cheju Medical Center, but because licensed nurses were very few, unqualified nurses had been working as a nurse assistant. However, in 1969, Cheju Nursing School, the predecessor of Cheju Halla College, opened as a three-year college course and has produced qualified nurses who have had regular nursing education. At the present Cheju Halla College turns out about 200 nurses yearly, and there are 824 nurses who are working in Cheju community. In the nursing curriculum of college, 4-year nursing colleges give more weight on cultural subjects than 3-year nursing college. But the students of both the colleges have to pass state examination, they have to complete the same level of major subjects. The core subjects are as follows : Adult Nursing, Pediatry Nursing, Obstetrics and Gynecology Nursing Psychiatric Nursing, Community Nursing, Nursing Management, and Basic Nursing. Nurse's employment range and its present situation is divided by a clinical field and community field. A clinic field includes medical institutions prescribed by the Medical Services Law such as general hospital, hospital, dental hospital, Chinese medicine hospital, nursing home, private dental clinic, and so on. Community field includes public health center, primary, middle and high schools where nurses are working as school nurses, medical rooms in the industrial organizations, social welfare facilities, administrational institutions, research institutions, and colleges. As of the end of 1996, the employment rate of nurses available came up to 60.1%. But because of recent IMF economic crisis in Korea, each medical institution is having difficulties in managing, therefore, nurses and staff have been dismissed by way of structural reform. Even though it is a passing phenomenon, the employment rate of nurses has been declined as of May in 1998. The future perspective of Korean Nursing is predicted that by the improvement of educational level, 3-year nursing colleges will offer intensive courses and expand the opportunities of nurses' reeducation, while it is likely that nursing education will be unitary with 4-year course. Besides, nursing specialist system is predicated to be more activated on account of the improvement of public health and medical level, and the development of Medical science and Nursing.

白金의 比色定量에 關한 硏究

朴茂淳,孫炳贊,金演斗 순천향의과대학 1978 Journal of Soonchunhyang Medical Science Vol.1 No.1

It has been observed that Pt(IV) in Hydrochloric acid solution, when treated with Tin(II) chloride give a orange color and the color that is due to chloroplatin-ous acid, is stable reproducible and quantitative. Thus it is possible to determine platinum by use of spectrophotometer. This method saves time in determination of Pt and is applied to estimation of small amounts of Pt in its ores and alloys.

W-Thiocyanate Complex의 抽出에 있어서 Amberlite LA₁의 利用

朴茂淳,孫炳贊 순천향의과대학 1979 Journal of Soonchunhyang Medical Science Vol.2 No.1

Comparision studies onthe extraction of Tungsten thiocyanate complex have been carried out using several pure organic solvents and 0.1% Amberlite LA₁solvents diluted with each solvent. The latter solvents show more advantages not only on extractability but also on linearity for the spectrophotometric determination of the complex than the former cases.

일반화된 에너지 거리를 이용한 음성 향상

손병찬(Byung-Chan Son),조원익(Won-Ik Choi),천성준(Sung-Jun Cheon),최병진(Byoung-Jin Choi),한민현(Min-Hyun Han),김남수(Nam-Soo Kim) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

브레이드 外形이 風力 터어빈의 空力性能에 미치는 영향

손병찬(Son Byung Chan) 한국태양에너지학회 1986 한국태양에너지학회 논문집 Vol.6 No.2

本 硏究는 비틀림이 없는 테이퍼 날개를 갖는 수평축 風力 터어빈의 空力性能 변화에 관한 것이다. 風力 터어빈을 構成하고 있는 날개의 形態, 즉 테이퍼比가 터어빈의 空力性能에 미치는 영향을 알아보기 위해 回轉面積比와 터어빈의 반경을 일정하게 유지시키고 테이퍼比를 0.1에서 1까지, 날개의 붙임각을 2°에서 4°까지 차례로 변화시켜가면서 風力터어빈의 最大動力係數와 날개끝 손실의 변화를 比較하였다. 또한 날개의 外形을 간단화하기 위하여 날개의 비틀림 율을 0으로 하였으며, 날개단면은 NACA 4415를 선택하였다.<br/> 그 결과, 테이퍼比가 0.5인 날개를 갖는 風力터이빈의 空力特性이 가장 우수한 것으로 나타났다. 또한 테이퍼比가 0.2이하인 날개를 갖는 風力터어빈의 最大動力係數는 구형날개의 最大動力係數보다 낮은 값을 가지므로 空力性能面에서 뒤떨어짐을 알 수 있다. 날개끝 손실은 구형날개일 경우 가장 크게 나타나며, 테이퍼比가 작아질수록 서서히 감소하였다. This paper presents the aerodynamic performances of horizontal axis wind turbines with non-twisted but taperd blades. Five configurations of blades, namely, one straight blade and four tapered blades with taper ratio of ranging from 0.1 to 0.7 have been simulated. The aerodynamic performances of the wind turbines have been determined over blade incidence angle of ranging from 2° to 6° and keeping same solidity and radius of them.<br/> The results are presented comparing straight blade from four tapered blades for maximum power coefficient and tip looses against variation of taper ratio. It also shows that the wind turbine with taper ratio of 0.5 has the highest maximum power coefficient than others. And wind turbines with taper ratio below 0.2 have lower values of maximum power coefficients than straight one. The tip loss of straight blade is the largest and reduces slightly with the decrementation of taper ratio.

유방암 수술 2,000예의 임상적 분석

손병호(Byung Ho Son),윤호성(Ho Sung Yoon),곽희숙(Hi Suk Kwak),이병찬(Pyung Chan Lee),고병균(Byung Kyun Ko),김지수(Ji Su Kim),안세현(Sei Hyun Ahn) 대한외과학회 2001 Annals of Surgical Treatment and Research Vol.60 No.5

ATM 망에서 동적인 임계치를 이용한 Early Packet Discard 방식에 대한 성능 분석

손병찬(Byung-Chan Son),조유제(You-Ze Cho),이명용(Myong-Yong Lee) 한국정보과학회 1996 한국정보과학회 학술발표논문집 Vol.23 No.2B

ATM 망을 통해 데이타 서비스를 제공할 때, 폭주에 의한 버퍼 범람이 발생하면 ATM 계층에서는 셀 폐기를 시작한다. 이때 TCP와 같은 패킷 기반 프로토콜이 상위 계층에 사용되고, 폐기된 셀들이 개별적인 패킷에 속한다면 손실된 셀을 포함한 패킷들은 모두 재전송되어야 한다. 따라서 셀이 폐기되는 경우에는 패킷 단위의 셀 폐기가 바람직하다. 패킷 단위의 셀 폐기 방식으로 제안된 EPD (Early Packet Discard) 방식에서는 버퍼 범람이 일어나기 전에 임계치를 넘은 셀에 대해 패킷 단위의 셀 폐기를 하여 손상된 패킷이 전송되지 않도록 한다. 따라서 EPD에서는 임계치를 정하는 것이 중요하다. 본 논문에서는 기존의 고정적으로 임계치를 설정하는 방법과 달리 pending_vc를 고려하여 동적으로 임계치를 설정하는 방법을 제안한다. 그리고 TCP 계층에서 goodput을 분석한 결과 제안된 동적인 임계치 설정 방법이 기존의 고정적인 임계치 설정 방법에 비해서 성능이 우수함을 보였다.