STS316L 용접부의 피로거동 및 초음파시럼에 의한 열화특성 평가

남기우,박소순,안석환,도재윤,박인덕 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.2

STS316L은 인성, 연성, 부식저항성 등 우수한 기계적 성질 때문에 에너지환경설비 등 구조물에 널리 이용되고 있다. 그러나, 용접구조물은 가혹한 환경하에서 경년열화가 심각하다. 지금까지의 연구들은 주로 용접부의 피로균열진전거동에 관하여 수행되었고, 피로균열진전속도식의 재료상수와 비파괴적 평가의 상관성에 관한 연구는 거의 없었다. 본 연구는 STS316L 용접부의 피로균열진전 거동을 조사하고, 초음파 파라미터로 열화특성을 평가하고 시간-주파수 분석으로 해석을 하였다. 본 연구 결과는 용접구조물의 사용기간 중 피로수명 등을 예측하기 위한 기초 데이터로서 사용될 수 있다. STS316L had been used as the structural material for energy environmental facilities, because austenite stainless steels like 316L have superior mechanical properties of which toughness, ductility, corrosion resistant and etc. However, those welded structures are receiving severe damage due to increasing of the aged degradation. Most studies until now have been carried out against fatigue bahaviors of weldments, and were not well studied on nondestructive evaluation methods. In this study, the fatigue crack propagation behavior of STS316L weldment usually used for vessels of the nuclear power plant was investigated. Also, the degradation characterstics of 316L stainless steel weldments were evaluated by the ultrasonic parameter such as ultrasonic velocity, attenuation factor and time-frequency analysis. The results of this study can be used as a basic data for the prediction of the fatigue crack life of weldments structures without disjointing or stopping service of structures in service.

전자상거래를 위한 인터넷 마케팅 분석시스템의 설계 및 구현

남철기,남중헌,배재학 울산대학교 1999 공학연구논문집 Vol.30 No.1

인터넷의 급속한 성장과 더불어 전자 상거래의 규모가 커져가고 있다.사이버마켓에서 비지니스를 하려는 기업의 입장에서는 고객의 행태가 달라졌으므로 새로운 마케팅 패러다임의 도입이 불가피하다. 고객별로 개별화된 마케팅, 즉 1 대 1 마케팅(one-to-one marketing)이, 그 중 한 가지이다. 이것은 사이버마켓이라는 새로운 환경의 장점을 살리면서 기업의 경쟁력을 극대화할 수 있는 마케팅 방법으로 간주되고 있다. 이에 본 논문에서는 쇼핑몰 운영을 통해 축적된 데이터를 데이터 웨어하우스로 구축한 뒤, ROLAP도구를 통해서 1 대 1 마케팅에 필요한 정보를 분석해내고자 하였다. 이와 더불어, 고객의 특성을 정확히 파악하여 그들의 요구와 흥미에 부합하는 개인화된 정보나 상품, 그리고 서비스를 제공할 수 있는 인터넷 마케팅 분석 시스템 구현 모델을 제시하고자 한다. The scale of electronic commerce is getting larger with the rapid development of the Internet. As the behavior of customers in the cybermarket is different from the one that is in the conventional market, it is necessary for companies to adopt a new marketing paradigm. The individually customized marketing - one-to -one marketing- is known as the way to maximize the core competence of the companies which are to take advantage of the new market environment - the cybermarket. In this paper, the followings are introduced : (1) building a data warehouse of the accumulated data from a cyber shopping mall in use, (2) the analysis of this using a ROLAP tool, and (3) the implementation model of an Internet marketing analysis system to provide the customer-specific individualized marketing information about customers' informational need, products, and services corresponding to their demand and interest.

중학교 남자 테니스 선수의 운동기능수준별 시합 전 경쟁상태불안

남인수,최인태,전중기,윤재만,고성경,이종삼,임승현 대구대학교 인문과학연구소 2008 人文科學硏究 Vol.31 No.-

The purpose of this study was to investigate if there is any difference in the level of competitive state anxiety according to the level of motor skill before the game and to provide the players with basic data for the mental practice. The subjects of this study consist of 20 men's a middle school tennis players. The experimental group was divided into superior players group and inferior players group. And then by using a CSAI-2 questionnaire, three subfactors of competitive state anxiety, or cognitive state anxiety, somatic state anxiety and state self-confidence were measured. The method of measurement was carried out three times, or one week, one day and two hours before the game. The results of this study were as follows. First, About both cognitive state anxiety and somatic state anxiety, inferior players were significantly higher than superior players. Second, About state self-confidence, superior players were significantly higher than inferior players. Third, As the game was around, both cognitive state anxiety and somatic state anxiety which all the players including superior and inferior players had increased. But the state self-confidence of all players decreased.

공여자의 종류에 따른 간이식 후 감염성 합병증의 비교 : Comparison between Orthotopic and Living Donor Transplantation

기현균,손준성,오원섭,백경란,이남용,김성주,조재원,이석구,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.3

목적 : 최근 간이식 수요가 증가함에 따라 이에 대한 하나의 대안으로 생체 부분 간이식(LDLT) 시행례가 증가하고 있다. 이에 뇌사자 사체 간이식(OLT)과의 감염 양상을 비교하기 위하여 본 연구를 시행하였다. 방법 : 1996년 5월부터 2003년 8월까지 삼성서울병원에서 간이식을 시행 받은 284명의 환자들을 대상으로 후향적으로 분석하였다. 결과 : 188명은 LDLT를, 96명은 OLT를 시행 받았다. 간이식 후 감염증은 총 191명에서 발생하였고(67.0%) OLT 환자군과 LDLT 환자군 사이에 감염증의 발생 빈도와 원인 병원체의 빈도는 유의한 차이를 보이지 않았다. 병원체 별로는 Enterococcus 균정(16.2%) S. aureus(15.1%), coagulase negative staphylococci (13.4%)의 순서였다. 감염증의 종류는 복강 내 감염이 총 83례로 가장 많았는데, LDLT에서 OLT에 비하여 유의하게 높게 발생하였다(34.0% vs 19.8%, P=0.012). 요로 감염증(11.5% vs 4.3%, P=0.022)과 침습성 아스페르길루스증(7.3% vs 1.6%, P=0.034)은 OLT을 시행한 경우에 많았다. 기타 감염증은 통계적으로 유의한 차이가 없었다. 결론 : 간이식 환자에서 공여자의 종류에 따른 감염의 발생빈도는 차이가 없었으나 감염증 중 복강 내 감염은 LDLT에서 더 많이 발생하였다. 장구균 감염, 특히 반코마이신 내성 장구균이 간이식 후 발생하는 감염증의 중요한 원인 병원체임을 확인하였다. Background : Living donor liver transplantation (LDLT) has been performed more frequently to circumvent the shortage of donor organs. However, infectious complications after LDLT compared with orthotopic liver transplantation (OLT) have not been well investigated to date. Methods : We have retrospectively reviewed the medical records of all consecutive cases of liver transplantation, which had been performed at the Samsung Medical Center, Seoul, Korea, from May 1996 to August 2003. Results : Of the 284 patients enrolled, 188 (66.2%) underwent LDLT. Overall incidence of infectious complications after liver transplantation was 67.0% (191/284). Incidence of infections was not different between OLT group (67.7%) and LDLT group (67.0%) (P=0.9). Bacterial infections were the most common infectious complications (146 cases) followed by viral infections (32 cases), fungal infections (26 cases), and tuberculosis (4 cases). Enterococcus spp. (16.2%) were the leading pathogens followed by Staphylococcus aureus (15.1 %) and coagulase-negative staphylococci (13.4%). However, the distribution of etiologic agents was not different between OLT and LDLT group. Intra-abdominal infections (83 cases) were the most common type of infectious complications, which were more frequent in LDLT group (34.0%) than in OLT group (19.8%) (P=O.Ol). Conclusion : LDLT resulted in intra-abdominal infections more frequently than OLT. Enterococcus spp., especially vancomycin-resistant enterococci, are emerging pathogens in patients with liver transplantation.

토사 절토사면 안정성 영향인자의 민감도 분석

유남재,박병수,전상현,조한기 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

A sensitivity analysis about effects of influencing factors on the stability of Soil cut slope was performed. Slope stability analyses were carried out under dry, rainy and seismic conditions. Dominant factors controlling the slope stability were chosen such as cohesion and internal friction angle, unit weight of soil, water table and seismic horizontal coefficient used for the slope stability during eurthquake. Parametric stability analysis with those factors was performed for sensitivity analysis. As results of analyzing the sensitivity of factors under dry and rainy conditions, effects of cohesion, internal friction angle and unit weight of soil on the stability of slope are more critical in the dry condition than in the rainy condition. Cohesion and internal friction angle are more dominant factors influencing the slope stability irrespective of dry or rainy conditions than unit weight of soil and the horizontal seismic coefficient. The unit weight and the horizontal seismic coefficient affects crucially the stability according to conditions of slope formation and dry or rainy seasons. For the effect of horizontal seismic coefficient on stability of slope, safety factor of slope is not affected significantly by dry or rainy conditions, However, increase of the horizontal seismic coefficient under the rainy condition does reduce the safety factor significantly rather than the dry condition. Therefore, it is needed that the location of the water table is assigned appropriately to satisfy the required safety factor of stability in the case of checking slope stability for the rainy and seismic conditions.

상사성을 고려한 배수재 설치 연약점토 지반의 원심모델링

유남재,홍영길,정길수,조한기 강원대학교 산업기술연구소 2007 産業技術硏究 Vol.27 No.A

This paper is results of experimental research on the effect of application of similarity related to permeability of soil on the consolidation behavior as centrifuge modeling of consolidation is performed with the centrifuge model facility. In this research, the permeability of soil was controlled by changing the viscosity of porewater as the mixed water with glycerin was used during the centrifuge model experiments. The effect of drainage path on consolidation was investigated by installing the vertical drains. A serise of centrifuge model tests with conditions of single vertical and radial horizontal drainage were carried out. Kaolinite and Jumunjin standard sand were used as soft clay and surcharges respectively during tests. For testing condition of single vertical drainage considering similarity of permeability, it was found that consolidation with mixed porewater with glycerin was delayed in comparisons with test results with water only. For conditions of horizontal drainage with vertical drains, a low permeability by changing the viscosity of pore water resulted in delayed degree of consolidation at an initial stage of consolidation. But, it predicted not much differences in settlement as long as the consolidation time was sufficiently long enough to finish consolidation. Consequently, it was found that similarity in permeability should be considered to be critical for the case of centrifuge model experiments related to consolidation with long drainage path.

만성 화농성 중이염의 세균학적 고찰

조남순,이영훈,강기훈,최제환,송태현,이병돈,장혁순,강주원,김연준 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

Background and Objectives : Chronic suppurative otitis media is one of the frequent diseases in otolaryngologic field. It is important to choose of antibiotics in the management of infectious disease. But the organisms in infections have been changed and resistance to antibiotics has been grown as the development of antibiotics has been achieved. And so it has been necessary to recognize the changes of organisms and resistance in antibiotics. Our study was performed to identify the pathogens isolated from discharges in chronic otitis media and evaluate the antibiotic agents, to recognize the change of to resistance to·antibiotic agents and to use the appropriate anitiotics. Materials and Methods : Retrospectively, authors reviewed the backeriologic study of 114 cases of chronic suppurative otitis media who visited the Department of Otolaryngology, Soonchunhyang University in Seoul from Nov. 1996 to Oct. 1999 and analyzed 101 strains and its sensitivity test to various antibiotics. Result : In 93 cases in which pathogenic organism was isolated, single infection was 85 cases(91.4%) and mixed infection was 8 cases(8.6%). The most frequent pathogenic organism was Staphylococcus aureus(59.4%), Pseudomonas aeruginosa(13.9%), Providencia(4.8%), Alcaligenes(3.0%) and Streptococcus pneumoniae(2.9%) were the next. Methicilline-Resistance Staphylococcus aureus was 34 cases(57.6%) of Staphylococcus aureus. Staphylococcus aureus was sensitive to Vancomycin(96.7%), Trimethoprim-Sulfamethoxazole (57.6%), Cefuroxime(42.4%) and Ciprofloxacin(40.7%) but resistant to Penicillin(94.9%). Pseudomonas aeruginosa was sentitive Amikacin(100%), Ciprofloxacin(100%) and Gentamicin(67%). Conclusion : As MRSA recently was wide spread in community accquired infection as well as nosocomial infection, we must consider strict control of MRSA.

경피적 겸자 정복 및 골수강내 금속핀 고정을 이용한 쇄골 골절의 치료

홍기도,하성식,정남식,심재천,김경호 대한골절학회 2004 대한골절학회지 Vol.17 No.4

목적 : 경피적 겸자 정복 및 골수강내 금속판 고정술을 이용한 쇄골 간부 골절의 치료에 대해 유용성을 규명해 보고자 하였다. 대상 및 방법 : 2002년 1월부터 2003년 7월까지 본원에서 쇄골 간부 골절 환자 중 신경 및 혈관 손상이 없었고, 골절의 분쇄상이 비교적 적었던 총 16례를 대상으로 겸자를 이용한 경피적 정복 후에 골수강에 금속판을 삽입하여 고정하였다. 술 후 유합 정도 및 결과를 임상적, 방사선학적으로 분석하였다. 결과 : 방사선학적으로 골유합을 보인 경우가 총 15례였으며, 술 후 평균 9.1주에 유합 소견을 관찰하였다, 임상적으로 강 등의 기준에 따라 구분한 결과, 우수 이상이 14례로 나타났다. 1례에서 1주 만에 K-강선의 내측전위로 골절부위가 재전위되어 관혈적 정복 및 금속판 내 고정을 시행한 이외에 다른 주요 합병증은 없었다. 결론 : 저자들의 방법은 수술시간이 짧고 간단하며, 연부조직의 추가적 손상이 적어 골유합율이 높고, 수술 반흔을 남기지 않아 수술적 적응을 신중히 고려한다면 쇄골 간부 골절의 치료법의 하나로 유용할 것으로 사료된다. Purpose: To investigate the utility of surgical treatment of clavicle shan fracture using a percutaneous towel clip reduction and intramedullary fixation. Materials and Methods : This study was conducted for total 16 case of patients who had no neurovascular injury and a few comminuted bone fragment among patients with clavicle shaft fracture from January 2002 to July 2003. The method of operation was percutaneous towel clip reduction and intramedullary fixation. The clinical and radiological results were evaluated. Results : Radiologically, 15 cases showed bone unions and the avenge time was 9.1 weeks. According to Kang's criteria clinically, there were 14 cases which were more than an excellence. One case substituted open reduction and nailing fixation due to a medial migration of K-wire and re-displacement of fracture even in 1 week. However, there wasn't any other major complication. Conclusion : Due to its having no additional injury to soft tissues, no scar formations, and its short operation time, percutaneous towel clip reduction and intramedullary fixation will be very useful as one of the treatments of clavicular shaft fracture if it follows correct surgical indications.

Vibrio parahaemolyticus와 Vibrio vulnificus 중복 감염에 의한 급성 위장관염 1예

이남용,기창석,이 혁,송재훈 대한감염학회 1998 감염 Vol.30 No.5

비브리오속의 중복 감염은 대부분의 병원성 비브리오속이 해수에서 잘 증식하는 호염성 세균이며 30℃ 이하의 낮은 온도에서 잘 자랄 뿐만 아니라 생굴과 어패류에서 자주 분리되는 등 동일한 생태를 보이는데 반해 매우 드물다. 그러나, 비브리오속은 여러 가지 질병 양상을 보일 수 있으며 인체 침습성, 병원성 및 항균제 감수성이 다르기 때문에 중복 감염을 진단하는 것은 환자 치료에 매우 중요하다. 저자들은 밴댕이(Herklotsichthys zunasi)회를 먹은 후 점액성 설사와 복통 및 구토를 보인 환자에서 Vibiro parahaemolyticus와 Vibrio vulnificus를 동시에 분리하였기에 증례와 함께 보고한다. Acute gastroenteritis caused by more than one Vibrio species has been rarely reported although most pathogenic Vibrio species share the same natural habitats. Recognition of multiple Vibrio species in one or more infectious processes is crucial in the management of patients because invasiveness, virulence, and resistance to antimicrobials can vary from species to species. We report a case of acute gastroenteritis by Vibrio parahaemolyticus and Vibrio vulnificus. The patient was a previously healthy 47-year old man who presented with watery mucoid diarrhea, abdominal cramps, and vomiting. On the previous day, he had eaten raw fish and developed the above symptoms about 10 hours later. The patient received only supportive therapy and was discharged on the same day with improvement. V. parahaemolyticus and V. vulnificus were isolated from stool specimen. The patient was fully recovered and subsequent stool culture demonstrated no pathogenic microorganisms.

수송기계용 복합재 원형튜브의 에너지흡수특성

김영남,황재중,차천석,심재기,양인영 朝鮮大學校 機械技術硏究所 2002 機械技術硏究 Vol.5 No.1

본 연구에서는 일 방향 CFRP 복합재 튜브에서 나타나는 상이한 압궤특성의 일관성을 보이고자 하며, 또한 계면수가 에너지 흡수능력의 함수인지 아닌지를 결정하고자 한다. 계면수는 최외층각도 0?를 갖는 4가지 형태(계면수는 2, 3, 6, 7 개)이며, 각 튜브에 압궤하중이 가해졌을 때 그 응답은 압궤과정을 제어하는 상이한 메카니즘 사이에서의 상호작용에 의존하고 그것을 매우 복잡하다. 따라서 본 연구에서는 정적 및 충격압궤실험을 행하고, 그 결과 계면함수, g(k)에 대해 정의하였다. 또한 일반적으로 [0/90〕_(2s) 적층된 CFRP 튜브가 더 높은 에너지를 흡수하였으며, 이론적 및 실험적 데이터는 서로 일치하였다. The objective of this paper is to present a consistent description of the different collapse characteristics exhibited by uni-directional CFRP(Carbon Fiber Reinforced Plastics) composite tubes and determine whether the energy-absorption capability of these tubes is a function interlaminar number. Tube interlaminar number was 4 types (2, 3, 6 and 7) included ply orientation angle of outer was 0. When such tubes are subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that control the crushing process. In this study static and impact collapse test were performed and the results have been shown as a function interlaminar number(g(k)). In general, the stacking sequence [0/90〕_(2s) CFRP tubes absorbed more energy than other tubes, theoretical and experimental data were to be likely each other.