• International Journal of Aerospace System Engineering
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• 제5권1호
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• pp.9-18
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• 2018

The longitudinal flight parameters of a light airplane are estimated from flight test data by use of the output error method. The reliability of the flight test measurement is examined in engineering judgment, scatter and Cramer-Rao bound, which turns out to be satisfactory with minor defects. Estimated parameter values are validated by comparing the simulated responses with the ones from actual flight tests. The FTD(Flight Training Device) of a light airplane turns out to satisfy the qualification of FAA Level 5 FTD in longitudinal motion. All the necessary practices for generation of high-fidelity data in longitudinal motion of a light aircraft are successfully performed in this study.

• 비파괴검사학회지
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• 제35권5호
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• pp.358-366
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• 2015

본 논문에서는 자주포, 전차 및 장갑차 등 지상궤도전투장비에 적용되는 비파괴검사 방안 검토 및 설계방안에 대해서 연구하였다. 비파괴검사 방안 중에서 지상궤도전투장비 비파괴검사자의 기량검증 요건은 미군규격에서 최초로 언급 되었으며, 이후 국내 지상궤도전투장비 무기 개발시 국방규격에도 적용되었다. 그러나 민 군 규격통일화사업을 통해 방산용 비파괴검사자의 자격은 기존 항공분야에서 적용중이던 NAS410이 항공/방산 공용규격으로 통합화 되었다. 본 연구에 대한 설계방안의 검증은 자주포에 사용되는 Al 단조품에 대해 최적설계된 액체침투탐상검사 방법을 적용하여 제품의 신뢰성 및 건전성을 확인하였다.

• 한국전자통신학회논문지
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• 제9권6호
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• pp.681-687
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• 2014

원자력 산업계는 최근 원전 계측제어계통 설비의 단종과 같은 예상치 못한 환경에 직면해오고 있으며, 이러한 문제를 근본적으로 해결하고자 노력하고 있다. IAEA, IEC, 등의 연구결과에 따르면, FPGA는 단종이 예상되는 제어계통에의 대체수단으로 주목받고 있다. FPGA가 원자력 플랜트의 PLC(Programmable Logic Controller)를 대체하기 위해서는 높은 건정성과 신뢰성을 가져야 한다. 따라서, FPGA 기반 제어기의 건전성과 신뢰성을 향상시키기 위하여 HDL 개발수명주기를 적용하여 개발하였다. 또한, 원전 계측제어계통에 적용하기 위하여 번인시험과 환경시험의 기기검증이 수행되었다. 시험수행결과, 352시간의 번인시험과 92시간의 환경시험 중에 정상적인 기능 및 성능을 수행함을 확인할 수 있었다.

• 근관절건강학회지
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• 제21권3호
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• pp.224-235
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• 2014

Purpose: The purpose of this study was to test the reliability and the validity of the Practice Environment Scale of Nursing Work Index (PES-NWI) scale when applied to Korean psychiatric nurses working in the psychiatric hospital in Korea. Methods: Data from 224 psychiatric nurses working in the 6 psychiatric hospitals in Korea were analyzed using Cronbach's ${\alpha}$, item total correlation, and exploratory factor analysis. Results: The Cronbach's ${\alpha}$ for the 27 items from the PES-NWI were .93, and the item total correlation coefficients ranged from .38 to .64. Six factors which explained 61.2 of variance in the perception of practice environment, emerged; nurse professional role and development, nurse manager ability, leadership, and support of nurses, staffing and resource adequacy, nursing foundation for quality of care, collegial nurse-physician relations, co-worker's ability and qualification. Five derived factors reconstructed, and two factors were renamed. Conclusion: Findings demonstrate that not all but 27 items from PES-NWI is a reliable and valid scale when applied to Korean psychiatric nurses working in Korea. Also findings indicate that Korean psychiatric nurses perceive practice environment differently than American nurses but have some point of similarities with Asian nurses working in the United States.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.433-433
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• 2012

As the requirement in patterning geometry continuously shrinks down, the termination of etch process at the exact time became crucial for the success in nano patterning technology. By virtue of real-time optical emission spectroscopy (OES), etch end point detection (EPD) technique continuously develops; however, it also faced with difficulty in low open ratio etching, typically in self aligned contact (SAC) and one cylinder contact (OCS), because of very small amount of optical emission from by-product gas species in the bulk plasma glow discharge. In developing etching process, one may observe that coupon test is being performed. It consumes costs and time for preparing the patterned sample wafers every test in priority, so the coupon wafer test instead of the whole patterned wafer is beneficial for testing and developing etch process condition. We also can observe that etch open area is varied with the number of coupons on a dummy wafer. However, this can be a misleading in OES study. If the coupon wafer test are monitored using OES, we can conjecture the endpoint by experienced method, but considering by data, the materials for residual area by being etched open area are needed to consider. In this research, we compare and analysis the OES data for coupon wafer test results for monitoring about the conditions that the areas except the patterns on the coupon wafers for real-time process monitoring. In this research, we compared two cases, first one is etching the coupon wafers attached on the carrier wafer that is covered by the photoresist, and other case is etching the coupon wafers on the chuck. For comparing the emission intensity, we chose the four chemical species (SiF2, N2, CO, CN), and for comparing the etched profile, measured by scanning electron microscope (SEM). In addition, we adopted the Dynamic Time Warping (DTW) algorithm for analyzing the chose OES data patterns, and analysis the covariance and coefficient for statistical method. After the result, coupon wafers are over-etched for without carrier wafer groups, while with carrier wafer groups are under-etched. And the CN emission intensity has significant difference compare with OES raw data. Based on these results, it necessary to reasonable analysis of the OES data to adopt the pre-data processing and algorithms, and the result will influence the reliability for relation of coupon wafer test and whole wafer test.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.43-46
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• 2010

As the nuclear power plant has been constructed continuously for several decades in Korea, the welding technology for components manufacturing and installation has been improved largely. Standardization for weld test and qualification was also established systematically according to the concerned code. The welding for the main components requires the high reliability to keep the constant quality level, which means the repeatability of weld quality. Therefore the weld process qualified by thorough test and evaluation is able to be applied for manufacturing. Narrow gap SAW and GTAW process are usually applied for girth seam welding of pressure vessel like Reactor vessel, steam generator, and etc. For the surface cladding with stainless steel and Inconel material, strip welding process is mainly used. Inside cladding of nozzles is additionally applied with Hot wire GTAW and semi-auto welding process. Especially the weld joint having elliptical weld line on curved surface needs a specialized weld system which is automatically rotating with adjusting position of the head torch. The small sized pipe, tube, and internal parts of reactor vessel requests precise weld processes like an automatic GTAW and electron beam welding. Welding of dissimilar materials including Inconel690 material has high possibility of weld defects like a lack of fusion, various types of crack. To avoid these kinds of problem, optimum weld parameters and sequence should be set up through the many tests. As the life extension of nuclear power plant is general trend, weld technologies having higher reliability is required gradually. More development of specialized welding systems, weld part analysis and evaluation, and life prediction for main components should be taken into a consideration extensively.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.384-388
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• 2016

Background: For a verification of newly-developed neutron absorbers, one of guidelines on the qualification and acceptance of neutron absorbers is the neutron attenuation test. However, this approach can cause a problem for the qualifications that it cannot distinguish how the neutron attenuates from materials. Materials and Methods: In this study, an estimation method of neutron absorption performances for materials is proposed to detect both direct penetration and back-scattering neutrons. For the verification of the proposed method, MCNP simulations with the experimental system designed in this study were pursued using the polyethylene, iron, normal glass and the vitrified form. Results and Discussion: The results show that it can easily test neutron absorption ability using single absorber model. Also, from simulation results of single absorber and double absorbers model, it is verified that the proposed method can evaluate not only the direct thermal neutrons passing through materials, but also the scattered neutrons reflected to the materials. Therefore, the neutron absorption performances can be accurately estimated using the proposed method comparing with the conventional neutron attenuation test. Conclusion: It is expected that the proposed method can contribute to increase the reliability of the performance of neutron absorbers.

• 보건교육건강증진학회지
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• 제31권1호
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• pp.1-11
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• 2014

Objectives: In this study, the most executed social norm and advertisement about health consequences status were examined. The direction of effective anti-smoking advertisement is suggested in this study by figuring out the primary factors which affect smoking attitudes. Methods: The survey period of this study was from Nov $5^{th}$ to Nov $16^{th}$, 2012. 423 complete questionnaires were used for final analysis. The collected data were analyzed by SPSS Ver. 14.0, and reliability analysis, factor analysis, frequency analysis, F/t qualification, t-test, and multiple regression analysis, were performed. Results: This study is worth as a diagnosis of current status by using advertisement about social norm(51.4%) and health result(34.3%), which covers total of 85% in appeal types of anti-smoking advertisement that has been practically used in Korea. As a result, the health result type showed better result on belief and attitude. Conclusions: When establishing message strategy for anti-smoking advertisement, this study can help future direction for effective anti-smoking advertisement by figuring out effect of factors on smoking attitude.

• 한국항해학회지
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• 제20권4호
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• pp.7-44
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• 1996

The purpose of this study is to develop the training programme for VTS operators in Korea. The methodology used are literature and questionnaire survey. The literature, proceedings of international symposia and letters from Canada, USA, Japan and other countries were properly used and analyzed in order to compare their contents. Through the results of this study, I proposed the basic training programme for VTS operators in Korea as followings. First, the number and level of Korean VTS should be properly decided. Second, the training organization and staff should be built and appointed. Third, the VTS trainee should selected, and the training level & period should be established according to their qualification and experience. Fourth, the training should be acted by the VTS training curriculum. Fifth, The VTS operator certificate should be issued through proper test. This paper concluded as followings through the analysis of the questionnaire regarding to VTS training programme in Korea. First, the proposed curriculum were properly constructed and the independence among them was existed through the reliability and correlation analysis. Second, the difference of the curriculum importance among the questionnaire group was nearly not found through the Analysis of Variance(ANOVA). Third, the required days per each curriculum was limited to maximum 5days.

• 한국항공우주학회지
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• 제46권10호
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• pp.876-882
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• 2018

이 연구의 목적은 상업적으로 가장 많이 쓰이는 패키징의 하나인 PBGA 구조가 발사중 인공위성에서 발생하는 강력한 임의 진동하에서 구조적 신뢰성을 유지하는가에 대한 검증에 있다. 실험시편을 만들기 위해 데이지 체인이 형성된 회로기판에 두 가지 큰 사이즈의 PBGA칩들을 실장시킨 후, 인공위성의 전자장비 채결에 사용되는 일반적인 알루미늄 프레임에 고정하여 실험에 필요한 샘플을 제작하였다. 이 샘플을 진동 시험기에 고정시키고 22.7 Grms의 수락수준 및 32.1 Grms의 인증수준 등 두 단계로 구성된 임의진동을 사용하여 주어진 시간에 따라 실험을 실시하였다. 실험 결과 모든 샘플에서 솔더의 균열이 발생되지 않았으며, 차후 항공 및 우주용 전자장비를 대치할 수 있는 효과적인 패키징 구조의 가능성을 보여 줬다. 또한 유한요소법을 이용하여 솔더의 응력을 계산하고 그 발생 메커니즘을 해석하였다.