AISI 316 스테인리스강의 크리프-피로 상호작용시 수명예측에 관한 연구

권영일,김범준,임병수 成均館大學校 科學技術硏究所 2000 論文集 Vol.51 No.2

The effect of tensile hold time on the creep-fatigue interaction in AISI 316 stainless steel was investigated. To study the fatigue characteristics of the material, strain controlled low cycle fatigue(LCF) tests were carried out under the continuous triangular waveshape with three different total strain ranges of 1.0%, 1.5%, and 2.0%. To study the creep-fatigue interaction, 5 min., 10 min., and 30 min. of tensile hold times were applied to the continuous triangular waveshape with the same three total strain ranges. The creep-fatigue life was found to be the longest when the 5 min. tensile hold time was applied and was the shortest when the 30 min. tensile hold time was applied. The cause for the shortest creep-fatigue life under the 30 min. tensile hold time is believed to be the effect of the increased creep damage per cycle as the hold time increases. Under the total strain range of 1%, significant reduction in life was observed as the tensile hold time was increased compared to the result of 2% total strain range. The theoretical prediction obtained by the Modified Coffin-Manson method and the experimental results of creep-fatigue life were found to be in resonable agreement with each other.

유지시간 변화에 따른 크리프-피로 수명예측 방법에 관한 연구

권영일,김범준,임병수 成均館大學校 科學技術硏究所 2001 論文集 Vol.52 No.2

In this study, creep-fatigue tests were carried out under the various test conditions using AISI 316 stainless steel. Life prediction was made by three different methods which are the modified Coffin-Manson method, the modified Ostergen method and the artificial neural network method with the adaptive learning rate. The predicted lives were compared with the experimental results and following conclusions were obtained within the scope of this study. Creep-fatigue life prediction by the modified Coffin-Manson method and the modified Ostegren method had the average error of 47.3% and 50.8% respectively whereas the artificial neural network method had only 28.8% for compressive and tensile+compressive hold time. From the obtained results, the artificial neural network method with the adaptive learning rate was proved to be more accurate and effective than the other two methods. The validity of artificial neural network method for life prediction checked with 3 verification data points proved also to be very satisfactory.

인후두부 이물감을 호소하는 환자에서의 기질적 요인 및 심인성 요인의 중요성

손영익,권중근,이풍렬,이화영,유범희,김지혜 대한이비인후과학회 1998 대한이비인후과학회지 두경부외과학 Vol.41 No.3

실내사무환경의 환경성담배연기(ETS)의 지표물질에 관한 연구

하권철,백남원,박동욱,윤충식,김원,최상준,박지영,최인자,김신범,강태선 한국산업위생학회 2003 한국산업보건학회지 Vol.13 No.2

The purpose of this research is to evaluate indoor office environment using the concentrations of nicotine, 3-enthenyl-pyridine(3-EP), and respirable suspended particulate(RSP), which are indicators for environmental tobacco smoke(ETS) and the correlations between indicators and environmental conditions(smoking density, smoking index). The mean air charge per hour (ACH) in smoking rooms was 10.4 and most of the smoking rooms showed non-compliance withe ASHRAE standard value except only one smoking rooms. The concentrations of RSP, 3-EP, nicotine showed log=normal distributions, and became different statistically depending on smoking condition(p〈0.01). The geometric mean concentration of RSP in smoking room was 441.7 ug/㎡ that is far exceeded environmental standard(150 ug/㎡). This implies that fine particulate in smoking room should be carefully controlled considering smoking density and ventilation fate. The mean concentrations of nicotine and 3-EP were 93.4 ug/㎥, respectively. The correlation coefficients between RSP and SI, 3-EP and SI, and Nicotine and SI were 0.67, 0.84 and 0.74, respectively. The correlation coefficient between nicotine and 3-EP, nicotine and RSP, and RSP and 3-EP were 0.76,0.78 and 0.57 respectively.

일부 세탁소의 유기용제 관리실태 및 공기중 노출농도에 관한 조사

노영만,권기범,박승현,정지연 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.1

This study was conducted to identify the current status of occupational safety and health by checklist and to evaluate the airborne exposure to chemicals and to provide the appropriate recommendation for safety and health of laundries. A total of 20 laundries located in the Gyungi district area were surveyed from July 20 to September 15, 2000. The prevalence of laundries having a stove and gas range were found to be 25 % and 55 %, respectively. Smoking is not allowed in 60 % of the laundries. Only 10 % of dry-cleaners were isolated. Ventilation system in laundries had not been annually inspected. Most of the workers didn't put on respirators, MSDS were not available, and storage bottles did not contain warning labels. The bulk samples of dry cleaning agent include many chemicals that are not controlled by the MOL in Korea. The detected airborne organic solvents in the laundries were benzene, toluene, p-xylene, m-xylene, o-xylene, perchloroethylene, and 2-butoxy ethanol. The airborne concentrations of organic solvents were much less than the occupational exposure limits proposed by the Ministry of Labor(MOL) in Korea. But the concentrations of benzene exceeded the TLV of ACGIH. This study showed that the current status of occupational safety and health was not appropriate for workers in laundries. It is recommended that laundry workers should be educated for the treatment and storage of hazardous organic solvents to improve the occupational safety and health of the working environment as well as MSDS usage. Also, extended research and survey for the organic solvents that are not controlled by the MOL has to be conducted.

수신부인방지를 제공하는 E-mail기반의 인터넷 EDI 보안 메커니즘

김준범,권혁인,김영찬 중앙대학교 정보통신연구소 1999 정보통신연구소논문집 Vol.1 No.1

개방형 특성을 가지는 인터넷을 사용함으로써 누구나 자유롭게 인터넷 EDI 시스템을 사용할 수 있게된 반면 이러한 개방성은 보안의 측면에서 중요한 정보 전달 시에 정보가 누출될 수 있다는 문제점을 가진다. 이러한 정보 노출은 전송하려는 정보를 암호화하여 송 ·수신함으로써 방지할 수 있다. 이메일 기반의 IEDI 시스템을 위한 보안 해결책은 S/MIME 프로토콜과 PGP 보안 메커니즘이 있다. 본 논문에서는 S/MIME과 PGP를 분석하여 이메일 기반의 안전한 문서 전송을 위해 기밀성, 무결성, 인증, 송 ·수신 부인 방지의 기능을 제공할 수 있는 보안 메커니즘을 설계 및 구현하였다. The openness of Internet has not only the property that everybody use the IEDI systems freely but also security problem that informations are leaked in transferring. The leakage of information is protected by encryption of data. Security solutions for e-mail based IEDI system are S/MIME protocol and PGP security mechanism. In this paper, security mechanism that providing confidentiality, authentication, integrity, sender/receiver non-repudiation for secure transferring of IEDI documents are designed and implemented

업무적응능력 관점에서 본 우리나라 대학회계교육의 개선방안 : Competence Perspective

김학범,권영도 慶南大學校 産業經營硏究所 2001 産業經營 Vol.29 No.-

독립콜리메타 사용 시 축외 조사면에서의 쐐기필터투과계수에 대한 고찰

김유현,권영호,김영범 高麗大學校 倂設 保健大學 保健科學硏究所 2002 保健科學論集 Vol.28 No.1

The transmission factor of wedge filter is usually measured on field center at a fixed depth, preferably that of maximum buildup or d_(max). But dose profiles produced at field center may be difference from that of off axis. The implementation of wedge with independent collimator is desired in a number of clinical situations. We have attempted to measure dependence of the wedge transmission upon off axis in case of using wedge with independent collimator. And those redefined relative to a transmission at field center. The discrepancies in wedge factor between off axis and center shapes up from 2.4% to 17.2%.

기능성척추측만증에 근막이완요법 및 전침치료 증례

김성욱,강영화,이상훈,권혜연,조태성,송춘호,안창범 동의대학교 한의학연구소 2001 동의한의연구 Vol.5 No.-

목적 : 우리는 신체를 근막의 통합된 전체로 보는 근막이완요법과 TrP를 파괴하는 전침요법을 기능성 척추측만증에 적용시킬수 있는지 알아보았다. 방법 : 22세의 기능성 척추측만증을 가진 남성에게 다양한 형태의 근막이완요법을 적용하였고, 중둔근, 요방형근, 슬괵근에 전침요법을 적용하였다. 결과 : 3주시술후 다리길이차이, 근막구축, Cobb's 각과 척추회전변위가 감소되었고 흉부압박감 같은 전신적증상이 호전되었다. 결론 : 근막이완요법과 전침병행치료가 신체를 근막의 일체로 보는 관점으로 인체의 구조적불균형을 바로 잡아줄수 있는 새로운 치료법의 기능성을 찾았다. Objective: We investigated this study in order to see the adaptation capability of myofascial release that translating the body being integrated fascial totality and electroacupuncture treatment that breaking trigger points in functional scoliosis. Methods: We applied myofascial relase by three patterns and electroacupuncture in TrPs of gluteus medius, Quadratus lumborum and Hamstring muscle to 22 year-old who have had functional scoliosis. Results: After 3 weeks, The leg length, fascial restriction. Cobb's angle and rotation scoliosis are decreased. Systemic symptoms, for example; chest discomfort are improved. conclusion: Myofascial release and electroacupuncture treatment is new methods that treating the sturctural unbalance in view of body's fascial network.

창의성 및 정보과학적 특성을 기반으로 한 정보영재 판별도구 개발연구

신승용,신수범,배영권,이태욱 한국컴퓨터교육학회 2004 컴퓨터교육학회 논문지 Vol.7 No.4

오늘날 정보화가 빠르게 진행되면서 정보과학의 중요성이 수학, 과학의 중요성 못지않게 대두되고 있기 때문에 이 분야의 영재 역시 조기에 판별하여 교육시켜야 한다는 필요성이 강조되고 있다. 하지만 이에 대한 연구는 초보적인 단계에 머물고 있다. 이에, 본 연구에서는 영재의 판별에 대한 이론적 고찰을 통해서 영재의 특성, 정의 및 판별방법과 도구의 제작과정을 살펴보고 영재의 올바른 판별과정을 조사, 분석하였다. 또한 이를 바탕으로 정보과학의 기반이 되는 이산수학의 특성을 규정하여 이를 바탕으로 정보영재의 특성 및 정의를 내렸으며 이를 근거로 정보영재를 판별할 수 있는 도구를 제작하였다. 판별도구를 이용하여 적용한 결과 판별도구는 신뢰성이 있는 것으로 분석되었으며 향후 정보영재의 의미 있는 판별도구로 활용될 수 있을 수 것이다. Since the science of information is appearing no less important than mathematics and natural science as our society is rapidly becoming information-oriented, the necessity to distinguish prodigies of this field and to educate them as early as possible is also being emphasized. Unfortunately, however, the pertinent study is still in its beginning stage. In this study, I have reviewed the character, definition and method to distinguish prodigies and the procedure of developing a test, as well as researching and analyzing the proper process of distinguishing prodigies, through theoretical contemplation on the method of distinguishing the gifted children. Also, I have characterized and defined the information prodigies after clarifying the character of 'Discrete Mathematics' which becomes the basis of the science of information, paving the way to make a test method that can distinguish those information prodigies. As a result of our applying the system by using the distinction test, it turned out that the distinction test was pretty reliable. Accordingly, it can be utilized as a significant distinction test for information prodigies in the forthcoming future.