打擊速度 및 溫度變化가 豫크랙을 가진 衝擊試驗片의 動的破壞靭性에 미치는 影響

兪在煥,李敬奉,金重吉,李致雨,吳世旭 慶南大學校 附設 工業技術硏究所 1989 硏究論文集 Vol.7 No.-

計裝化衝擊試驗에서 打擊速度와 溫度의 變化가 豫크랙을 揷入한 衝擊試驗片의 動的破壞靭性에 미치는 影響을 考察한 結果 다음을 알 수 있었다. 豫크랙을 揷入한 試驗片이 V-노치 試驗片에 比하여 實驗値의 分散度가 적으며 0℃以下의 溫度領域에서 動的破壞靭性의 有效性이 있었다. 또한 打擊速度와 實驗溫度의 影響은 溫度가 速度보다 훨씬 上廻하는 傾向이었다. The effect of various impact velocity and temperature on dynamic fracture toughness is tested with precracked Charpy specimen, and conclude following results. Precracked specimen has less dispersion of test results than V-notched specimen, unstable crack initiation load didn't agreed to maximum load at room temperature but at 0℃ below, thus, the availability of dynamic fracture toughness is relatively high. Comparing V-notched specimen, the precracked Charpy specimen represented lower shelf of temperature different. But, at this time, the absorbed energy is estimated equivalently. With the decrease of temperature, the reduction of fracture toughness was obvious, but the effect of impact velocity didn't appear.

머리-목 회전이 편부전마비 환자의 팔꿈치 신전근력에 미치는 영향

유욱재,이상은,이정원 한국전문물리치료학회 1997 한국전문물리치료학회지 Vol.4 No.1

최근 5년간 급성 A형 간염으로 입원한 환자들에 대한 입원 내용 분석

장재영,유병욱,조용진,오정은,홍성호,조주연 순천향대학교 의학연구소 2009 Journal of Soonchunhyang Medical Science Vol.15 No.1

Abstract Background : Due to improvements in Korea's sanitary conditions, antibody rates to the hepatitis A virus is decreasing rapidly and admission due to the disease is increasing, Patients who were admitted for hepatitis A during the last 5 years were selected and yearly differences in admission, clinical picture, medical fees, and differences according to age and gender were analyzed. Methods : Patients who were admitted to the Seoul Soonchunhyang University Hospital during the 5 year period between May of 2003 and April of 2008 and tested positive for IgM anti-HAV were selected and their medical records retrospectively analyzed. Results : 156 subjects [91 male (58%), 65 female (42%) were selected. The average age was 29.2 years (range; 21.4-37), average admission period 12.6 days (range; 12.5-1 7.7) days, and average medical fees 2,295,151 (range; 932,097-3,658,205) KRW(Korean Won), Yearly incidence rates were as follows : 10 for May, 2003 to April, 2004, 14 for May, 2004 to April, 2005, 23 for May, 2005 to April, 2006, 69 for May, 2006 to April, 2007, and 41 for May, 2007 to April, 2008, The maximum value median of AST, ALT, and bilirubin during admission was 989 IU/L, 1999 IU/L, and 5.6 mg/dL each, Each factors were all positively correlated with the patient's age. Conclusions : Recent decrease in antibody positivity of the hepatitis A virus and subsequent surge of acute hepatitis A is a cause of rising socioeconomic costs. A large scale epidemiologic research on whether HAV vaccination should be made mandatory and health insurance applied seems to be needed. Key words : Hepatitis A, Age, Medical fees, Vaccination

담낭질환의 Neuron Specific Enolase 반응세포 출현에 관한 면역조직화학적 연구

박용욱,박언섭,유재형 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.1

A total 50 patients who had undergone cholecystectomy for cholecystopathy were included in the study to observe the staining pattern of the cells and distribution of antihuman Neuron Spectific Enolase (NSE) antibody by avidin-biotin immunoperoxidase method. The studies consisted of 31 cased of chronic cholecystitis with lithiasis, 9 cases of adenoma and 10 cases of carcinoma including 6 cases of moderately differentiated adenocarcinoma, 3 cased of poorly differentiated adenocarcinoma, and 1 case of small cell carcinoma of combined type. The results were as follows : 1. In the chronic cholecystitis with lithiasis, nine of 31 cases (29%) with the NSE immunoreactive cells, arranged in single of grouped fashion, are focally observed in the covering surface epithelium. 2. The NSE immunoreactivities of carcinoma is more stronger than that of chronic cholecystitis and adenoma. 3. The coarse granular intracytoplasmic strong positive reaction of small cell carcinoma is diffusely observed in noeplastic small cell and glandular epithelium. Therfore, authors suggested that two elements arise from a common primitive cells of endodermal derivation capapble of differentiation along two cell-endocrine ans epithelial.

複合組織鋼이 腐蝕疲勞크랙傳播特性에 미치는 食鹽水 濃度의 影響

吳世旭,姜鎬珉,兪在煥 東亞大學校 海洋資源硏究所 1989 硏究論文集 Vol.2 No.1

The corrosion fatigue test was performed under rotated bending in salt solution having a concentration from 0.01 wt percent to 3.5 wt percent to investigate the corrosion fatigue crack propagation characteristics for dual phase steel. Corrosion pits were occurred in martensite, and microcracks occurred at corrosion pits were selectively propagated towared martensite because slip bands were not found in ferrite which were encapsulated by martensite. The number of corrosion pits, the diameter of corrosion pits and the length of corrosion cracks for M.E.F. and raw material(R.M)were increased with the concentration of salt solution and the number of cycles. The initiation of crack was almost same regardless of the concentration of salt solution; approximately N??/N??=20% in case of M.E.F. and N??/N??=14% in case of raw material (R.M.) The difference of corrosion fatigue crack propagation was increased with an increase in concentration of salt solution. The corrosion resistance effect of dual phase steel was smaller than that of raw material (R.M.) in corrosion fatigue crack propagation rate.

複合組織鋼의 摩擦 熔接部의 疲勞破壞特性에 관한 硏究

吳世旭,姜鎬珉,兪在煥,林東哲 東亞大學校 1988 東亞論叢 Vol.25 No.1

This study has been carried out to investigate the characteristics of fatigue crack of welded zone and heat affected zone of friction welded dual phase steel. The results obtained from the experiments are summarized as follows. Microstructure of welded zone is changed to ferrite and pearlite from ferrite and martensite by wel-ding heat. Micro-vickers hardness of welded zone is higher than that of base metal zone and heat affec-ted zone. Micro-vickers hardness of heat affected zone is lower than that of welded zone and microstructure of heat affected zone is changed to fine martensite and ferrite by heating cycle of welding. Fatigue limits of heat affected zone is a little higher than that of welded zone and base metal zone. There are no difference of fatigue limit of base metal zone and welded zone. Fatigue strength of welded zone is similar to that of base metal zone. At high △K region(△K>19MPa·??), fatigue crack propagation velocity of heat affected zone is slower than that of welded zone and base metal zone, and the difference of fatigue crack propagation velocity is smaller than that of high △K region. The crack occurs to the notch in heat affected zone first, but the final fracture surface is the surface of welded zone. It is abvious that heat affected zone of friction welded dual phase steel superior to welded zone and base metal zone in fatigue strength and resistance of fatigue crack propagation. The above mentioned facts are contrary to theory that heat affected zone of general metals is weaker than welded zone and base metal zone.

계장화충격시험에 의한 복합조직강의 파괴인성에 관한 연구

오세욱,유재환,박원조,이경봉 동아대학교 공과대학 부설 한국자원개발연구소 1989 硏究報告 Vol.13 No.1

The dynamic fracture toughness (K_(Id)) is measured using the precracked standard Charpy specimen with an instrumented impact machine. The value of K_(Id) is determined as a function of yield strength and microstructure, and correlations are established between K_(Id) and both energy of initial fracture and total energy of fracture. Since the K_(Id) values of the precracted impact specimens are in accordance with their theoretical ones, this test method is sufficiently practical.

Risk Based Inspection 기법을 이용한 화학공장의 안전성 향상에 관한 연구

노용해,유진환,서재민,임차순,고재욱 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3

The RBI technique proposed by API is composed of three steps. The qualitative RBI method can be used for the purpose of screening the components with high risk. And, the quantitative RBI method employs complex risk evaluation model for predicting component risk in a quantitative manner. The inspection program can be optimized based on the results obtained by these RBI technique. The forementioned RBI technique has been applied to a common hydrodesulfurizer unit and the technique is critically evaluated for studying its benefits and limitations, which is the main issue of this thesis. It's conducted that the RBI method can provide a method for defining and measuring the component risk, and also provide a powerful tool for managing many of the important elements of a process plant.

월경주기 증상의 요인 분석

이수일,유태혁,강종선,안석철,이병욱,김헌,석재호 大韓神經精神醫學會 1986 신경정신의학 Vol.25 No.1

404 nurses and nurse-aids rated their experiences of 45 symptoms(Moos' Menstrual Distress Questionnaire) of the menstrual, premenstrual and intermenstrual phase on a 4 point scale separately. The 45 symptoms were inter-related and factor analyzed separately for each phase. six common clusters of symptoms emerged from 3 phases, which were labeled concentration, motor tension, pain, pleasurable affect, autonomic reactions and water retention. Four clusters of symptoms emerged from premenstrual phase. These clusters were labeled instabillity, withdrwal reactions, depression and headache. The factor named unpleasurable affect emerged from intermenstrual and menstrual phase. Above findings were differed from the results of Moos' study in which eight basically replicated clusters of symptoms emerged from three phases. Through discussion of validity of this scale, and differences between results of Moos' and this study, we came to the conclusion that sampling of subjects, prospective longitudinal symptoms reporting, amount of variance in a symptom over the course of menstrual cycle and proper choice of factor analysis method would be salient variables to construct valid scale for measuring menstrual cycle symptoms.

방사성 페기물 처리장의 지하수 온도 측정을 위한 광섬유 센서의 제작 및 특성 분석

서정기,유욱재,장경원,조동현,신상훈,이봉수 제주대학교 방사선응용과학연구소 2008 방사선응용과학연구소논문집 Vol.22 No.-

Fiber-optic temperature sensing technology can alternative to classical measurement techniques in nuclear environment, Its advantages allow low cost, a long distance measurement and real-time, In this study, we have measured the optical power of power meter and the output voltage of photodiode according to change temperature of water.