횡구속강관으로 보강된 교각의 해석적 연구

박종현,최익창,박홍용 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - Recently the occurrence of earthquakes has been increasing all over the world. Even in Korea the number of the occurrence has been rising. A bridge built before induction of an aseismatic design would damage human's lives and property if there were an earthquakes. Therefore, urgently, aseimatic retrofit should be executed to improve aseismatic capacity of existing piers. The purpose of this project is to suggest the most suitable design condition, which is through Finite Element Method and that is established by evaluation of strength and ductility of a restraining steel pipe whose height, thickness, and expansive pressure are very important variable factors when applying Expansive Concrete -Filled Cross-Restraining Steel Pipe Reinforce Method to real structure.

원자력발전소 PSI/ISI 데이터 관리를 위한 지능형 데이터베이스 프로그램 개발(제2보)

박은수,박익근,엄병국,이종포,한치현 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.3

제 1보에서 Windows 환경 하에서 PSI/ISI 데이터의 효율적 관리 및 다원적평가와 분석이 가능한 고리 원전 PSI/ISI 데이터베이스 구축과 프로그램 개발(IDPIN)에 대해 소개하였다. 제 2보에서는 월성 원자력발전소 PSI/ISI 자료 관리를 위한 지능형 데이터베이스 프로그램(WS-IDPIN)을 개발하였다. 이 프로그램에는 월성 원전 PSI/ISI 관련 자료 분석 기능, PSI/ISI UT 검사 보고서 양식의 표준화와 전산 시스템화, PSI/ISI 비파괴검사 결과의 통계적 신뢰도 평가 프로그램(depth and length sizing performance 등) 등을 개발하여 원전 PSI/ISI 데이터 관리 전문가시스템(expert system)화에 한 단계 접근하였다. In a previous paper, we have discussed the intelligent Windows 95-based data management program(IDPIN) which was developed for (effective) and efficient management of large amounts of pre-/in-service inspection(PSI/ISI) data of Kori nuclear power plants. The IDPIN program enables the prompt extraction of previously conducted PSI/ISI conditions and results so that the time-consuming data management, painstaking data processing and analysis of the past are avoided. In this study, the intelligent Windows based data management program(WS-IDPIN) has been developed as an effective data management of PSI/ISI data for the Wolsong nuclear power plants. The WS-IDPIN program includes the modules of comprehensive management and analysis of PSI/ISI results, statistical reliability assessment program of PSI/ISI results(depth and length sizing performance etc), standardization of UT report form and computerization of UT results. In addition, the program can be further developed as a unique PSI/ISI data management expert system which can be part of the PSI/ISI total support system for Korean nuclear power plants.

2.25Cr-1Mo 강 인공 열화재의 고주파수 초음파 감쇠특성에 관한 연구

박익근,박은수,김정석,김현묵,권숙인,변재원 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.4

재료나 설비의 고온 장시간 사용으로 인하여 발생되는 재질열화 평가에는 파괴적인 방법이 널리 사용되고 있으며, 신뢰도가 높다. 그러나, 시험편의 채취가 어렵고 많은 경비와 시간이 소요된다. 전기저항법, 레프리카법, 바크하우젠 노이즈법, 전기화학적방법, 초음파법 등과 같은 비파괴적인 열화손상 평가 방법이 주목을 받고 있다. 본 연구에서는 2.25Cr-1Mo 강을 630℃에서 장시간 등온열처리로 모의 열화시험편을 제작하고, 고온설비부재에서 발생되는 미세조직의 변화와 고주파 초음파의 전파특성(감쇠계수)과의 일대일 상관관계를 규명하여 초음파 비파괴평가에 의한 열화도 평가의 유용성 유무를 실험적으로 검증하였다. 그 결과 2.25Cr-1Mo 인공열화재의 경우 열화가 진행됨에 따라 탄화물의 석출 및 조대화가 일어나며 초음파 감쇠계수는 증가하는 경향을 나타내었으며, 그 정도는 침상의 탄화물이 거의 소멸되는 1,000 시간 이후에 초음파 감쇠계수가 급격히 증가하는 매우 좋은 상관성을 나타내었다. The destructive method is reliable and widely used for the estimation of material degradation but, it have time-consuming and a great difficulty in preparing specimens from in-service industrial facilities. Therefore, the estimation of degraded structural materials used at high temperature by nondestructive evaluation such as electric resistance method, replica method, Barkhausen noise method, electro-chemical method and ultrasonic method are strongly desired. Ultrasonic nondestructive evaluation technique has been reported good to attain efficiency of measurement, high sensitivity of measurement, and rapidity and reliability of result interpretation. In this study, it was verified experimentally the feasibility of the evaluation of degraded 2.25Cr-1Mo steel specimens which were prepared by the isothermal aging heat treatment at 630℃ by high frequency longitudinal wave method investigating the change of attenuation coefficient by FFT analysis and wavelet transform. Because of carbide precipitation increase and spheroidization near grain boundary of microstructure to aging degradation, attenuation coefficient had a tendency to increase as degradation proceeded. It was identified possibly to evaluate degradation using the characteristics of high-frequency ultrasonics. Frequency dependence of ultrasonic attenuation coefficient to aging degradation appeared large, which made sure that attenuation coefficient is an important parameter for evaluation of aging degradation.

한국의 정신분열병 외래 환자의 직ㆍ간접비용

박종익,송선희,서동우,장현종,이종국,장안기,김윤,이철,홍진표 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.3

연구목적 : 정신분열병 외래 환자의 직접 비용과 간접 비용을 추산해 보고, 의료 자원의 적절한 운용과 효과적인 배분을 위한 보건 정책의 기초자료로 사용하고자 한다. 방 법 : 정신분열병 진단을 받은 289명의 환자를 대상으로 6개월간 외래를 방문하면서 사용한 의료비와 시간을 조사하여 직접 비용을 추산하였고, 이 기간 동안 소실된 생산성을 간접 비용으로 환산하였다. 만성질환인 관상동맥 질환을 앓고 있는 환자 82명을 대조군으로 하여 비용을 비교하였다. 결 과 : 정신분열병 환자의 실업률은 72.1%였으며, 직장을 가지고 있는 경우에도 단순노무직의 비율이 64.5%로 매우 높았다. 정신분열병의 직접 비용은 평균 81.5만원으로 관상동맥 질환의 평균 71.5 만원보다 상대적으로 많이 추산되었으나 유의하지는 않았다. 간접 비용은 평균 645.6만원, 258.9 만원으로 정신분열병군이 2.5배 정도 높았다. 결 론 : 정신분열병은 다른 만성질환에 비하여 상대적으로 매우 고비용이 요구되는 질환이며, 보다 체계적인 비용의 추산을 통하여 양질의 정신 보건 서비스를 제공할 수 있는 토대가 마련되어야 할 것이다. Objectives : We have aimed to estimate the direct and indirect costs of treating out-patients with schizophrenia in Korea, to use this fundamental data for the effective management and proper distribution of the medical resource. Method : To estimate the direct cost, we surveyed the medical cost and time of two hundred and eighty-nine out-patients with schizophrenia for six months. And the lost productivity as many months was converted into the indirect cost. Those of eighty-two coronary heart disease patients were also estimated as a comparison group. Results : An unemployement rate of schizophrenic patients was 72.1 percent. Moreover the ratio of the laborer in the sample was, even if employed, 64.5 percent. The mean direct cost of schizophrenic patients was, about 815,000 won, higher than that of coronary heart disease, 715,000 won however it was not statistically significant. The former was also estimated 2.5 times more than the latter for the indirect cost, or 6,456,000 won versus 2,589,000 won. Conclusion : Schizophrenia is a relatively costly illness compared to other chronic illness, so the systematic estimation of the cost is necessary to provide mental health service of high quality.

초음파탐상 PD-RR Test의 통계적 신뢰도 평가 (Ⅲ) : a Round Robin Test Reesult (Part Ⅲ)

박익근,박은수,김현묵,박윤원,강석철,최영환,이진호 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

국내 원전의 건전성 및 안전성 확보에 직결되는 자동 초음파검사의 신뢰도 및 검사시스템의 기량을 평가하기 위해 자동UT-PD RRT를 수행하였다. 수행된 RRT의 조건은 2001년 수동 PD-RRT에 적용된 설계변수와 동일하다. 본 연구에서는 자동 UT의 결함검출확률 및 오판확률과 결함크기측정에 대한 불확도 분석을 이용하여 자동 초음파검사의 통계적인 신뢰도를 평가하고 수동 UT PD-RRT의 결과와 비교하여 기량을 검증하고자 한다. 이러한 연구결과를 토대로 향후 각종 비파괴검사에 대한 RRT를 수행하여 기술수준을 파악하고 비파괴검사기술의 발전을 도모할 수 있을 것으로 판단된다.

유도초음파를 이용한 2.25Cr-1Mo재의 열화도 평가

박익근,박은수,이상용,권숙인,조윤호,윤승현 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.4

고온에서 장시간 사용으로 인하여 발생되는 경년열화 평가에는 파괴적인 방법이 신뢰성이 높지만 시험편 채취의 어려움이 있다. 그러므로 비파괴적인 방법에 의한 열화도 평가가 바람직하다. 본 연구에서는 2.25Cr-1Mo강에 대하여 장시간 등온열처리로 모의 열화시험편을 제작하여 고온설비부재에서 발생되는 탄화물의 석출 및 조대화, 불순물의 입계편석 등 금속학적 미세조직을 관찰하고, 미세조직의 변화와 유도 초음파의 전파특성과의 상관관계를 규명하고, 파괴시험치와 그 결과를 비교하여 초음파 비파괴평가에 의한 고온부재의 열화도 평가의 가능성을 실험적으로 검증하고자 한다. The destructive method is reliable and widely used for the estimation of material degradation but, it have time-consuming and a great difficulty in preparing specimens from in-service industrial facilities. Therefore, the etimation of degraded structural materials by nondestructive evaluation is strongly desired. In this paper, the use of guided wave was suggested for the evaluation of thermally damaged 2.25Cr-1Mo steel as an alternative way to compensate for limitations of fracture tests. The observation of microstructure variations of the material including carbide precipitation increase and spheroidization near gain boundary was conducted and the correlation with the guided wave features such as energy loss ratio and group velocity changes was investigated. Through this study the feasibility of ultrasonic guided wave evaluation for thermally damaged materials was explored.

Air-coupled 트랜스듀서를 이용한 발전설비 배관에서의 유도초음파 모드 규명

박익근,김현묵,김용권,송원준,조용상,장경영,조윤호 한국비파괴검사학회 2004 한국비파괴검사학회지 Vol.24 No.4

발전설비의 중요한 요소인 배관의 효율적인 비파괴검사를 위해, 배관내에 유도초음파를 comb 트랜스듀서를 이용하여 발생시켰으며, 유도초음파를 비접촉 방식으로 수신하기 위해 ACT(air-coupled transducer)를 적용하였다. comb 트랜스듀서의 요소간격과 이론적인 분산선도로부터 발생가능 한 유도초음파 모드가 예측되었다. 또한 예측된 모드를 수신하기 위해 각 모드의 이론적인 위상속도를 이용하여 ACT의 수신 각도를 결정하였다. 수신모드의 특성을 규명하기 위해 웨이블릿 변환과 2D-FFT를 이용한 시간-주파수해석을 수행하여 이론적인 분산선도와 비교한 결과, 수신된 모드는 이론적으로 예측된 모드와 일치하는 것으로 나타났다. In order to inspect the piping effectively, one of the important components in the facility of power plants, the ultrasonic guided wave was generated by a comb transducer and was received in a non-contact fashion by using an air-coupled transducer. The guided wave modes that can be generated by the comb transducer in piping are predicted from the theoretical dispersion curves and the element spacing of a comb transducer. Moreover, to receive the specific modes, the receiving angle of the air-coupled transducer is calculated from Snell's law between the phase velocities of guided waves and the sound velocity of air. The guided wave modes obtained in experiments are identified from the result of time-frequency analysis such as wavelet transform and two-dimensional fast Fourier transform.

生産技術革新이 會計시스템에 미치 影響

朴武鉉,許益九 진주산업대학교 1996 論文集 Vol.35 No.-

The purpose of this study is to investigate the effects of manufacturing technology changes on accounting system focused on cost accounting problems caused by the adoption of Flexible Manufacturing System(FMS). Increased national and international competition in manufacturing has stimulated the adoption of new technologies such as FMS. Those companies that fail to focus on the demands and opportunities presented by technological improvement are risking their continued profitability and long-term survival. Many challenges facing Korean manufacturers today indicate that technology management is a critical strategic issue. Successful design and implementation of new technology requires the close integration and coordination of variables ranging from technical issues to human and managerial ones. On the other hand, adoption of new manufacturing technologies such as FMS has caused many unexpected accounting problems. In this paper we investigated cost accounting problems resulted by the application of FMS. We discussed the problems and proposed appropriate solutions as the following four categories: ⑴ Acquisition of FMS facilities ⑵ Cost control ⑶ Calculation of product cost ⑷ Performance evaluation. Being expected that the future main stream of manufacturing system will be FMS in the future, we need to seek solutions toward problems induced by the changes in manufacturing technology.

뇌졸중 후 중추성 통증 환자에 대한 동서협진이 진통과 재활에 미치는 영향

이현종,김수영,이상훈,서동민,이두익,김건식,이재동,이윤호,양형인,박재경,최도영 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2003 東西醫學硏究所 論文集 Vol.2003 No.-

Purpose : In order to study the effectiveness of East-West pain treatment on central poststroke pain(CPSP), we evaluated its effect on alleviation of pain and rehabilitation of CPSP Patients who were treated with electroacupuncture and west pain treatment for four weeks. Methods : Twenty four patients diagnosed by their pain characteristics of central pain from stroke were treated with sympathetic nerve block, gabapentin, amitriptyline, and electroacupuncture for four weeks. Pain intensity through the visual analogue scale(VAS), and improvements of mobility and rehabilitation through the modified Barthel index(MBI) and Rankin scale(RS), respectively, before and after pain treatment were also assessed. Results : VAS pain scores were significantly improved from 7.7±1.7 to 4.4±2.0 with pain treatment(p<0.05). In accordance with improvement of pain scores, RS and MBI scores were also improved from 2.88±0.95 to 2.13± 1.01 and from 83.0± 16.9 to 94.7±9.5(p<0.05), respectively, with pain treatment(p<0.05). Conclusions : It was suggested that the active pain treatment was contributed to the rehabilitation of CPSP patients, resulting in improvement of quality of life of CPSP patients. Futhermore, East pain treatment in combination with West pain treatment may be useful modality to alleviate CPSP.

CdS:In 單結晶의 基本特性과 photosensor로의 應用

강현식,박병채,장성우,이해익,최용대 全北大學校 敎育大學院 1986 敎育論叢 Vol.6 No.-

The opto-electrical properties of the CdS : In single crystals were studied by these means of the scanning electron microscope, X-ray diffraction, optical transmission & photoconductivity, resitivity variation v.s. impurites, and resitivity v.s. photon flux change. By X-ray diffraction measurement, the structure was found to be hexagonal and the lattice constant was calculated to be a_o=4.13Å and c_o=6.75Å The band gap was estimated to be about 2,419eV (300K). By the transmission measure ments a donor impurity level of In or Al was 0.024eV below the conduction level edge. For the application on the photosensor, the resistivity(ρ) variation of the CdS : In was measured with respect to photon flux(P_o) change and to wavelength, the resistivity was found to be ρ=8.75×10^6P_o^-125 (Ω―㎝/Lux) and the photoconductivity showed its highest response peak between 5,000Å and 5,400Å ranges.