• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.244-249
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• 2011

The potential hazards resulting from a low-velocity impact (bird-strike, tool drop, runway debris, etc.) on aircraft structures, such as engine nacelle or a leading edges, has been a long-term concern to the aircraft industry. Certification authorities require that exposed aircraft components must be tested to prove their capability to withstand low-velocity impact without suffering critical damage. In most of the past research studies unloaded specimens have been used for impact tests, however, in reality it is much more likely that a composite structure is exposed to a certain stress state when it is being impacted, which can have a significant effect on the impact performance. And the radiated impact sound induced by impact is analyzed for the damage detection evaluation. In this study, an investigation was undertaken to evaluate the effect in-plane loading on the impact force and sound of composite laminates numerically.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.675-682
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• 2005

This is the evaluation report of clinical competence of undergraduate medical students in Plastic Surgery field using OSCE(Objective Structured Clinical Examination) executed in three years. OSCE comprises of assessment of subject, choice of clinical stations sampling, identification of components of clinical competence to be evaluated, the level of performance required, development of specification table, editing of OSCE presentation page and assessment of practicability and results exploitation. About fifty students were examined annually. Seven station stimuli with simulated patient participation were carried out. The mean OSCE score was $82.3{\pm}6.19$. The reliability of the total station was 0.72. The examination shows a positive response to the OSCE. Our experience shows OSCE's feasibility for Plastic Surgery during the initial course of education. Referring to our experiences, the Korean Society of Plastic and Reconstructive Surgeons (KPRS) applied the OSCE test for Korean Plastic Surgery Board Certification

• 품질경영학회지
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• 제19권2호
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• pp.63-77
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• 1991

Currently the problem of air pollution caused by the motor vehicle emission is one of the most serious problems to be solved. Thus we needed the inspection method and technical innovation constraining the motor vehicle emission. In order to establish the more reasonable certified test, the multivariate sequential rectifying inspection plan designed in this paper has been applied to the domestic vehicles by analyzing the statistic characteristics of the emission distribution. This inspection method is designed to satisfy the evaluation measure constraining domestic vehicle emission, and it serves the defect rectifying system and performance certification of catalytic converts. As the prior parameter for the domestic vehicles, we used the data for the catalytic converts which passed the certified test excuted by the EPK. For the case of engine test, we used those data which passed the certified test of domestic vehicles. The multivariate sequential rectifying inspection plan of the vector parameter is able to minimize the average sample number and increase the pass probability of operating characteristic curve.

• 비파괴검사학회지
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• 제30권1호
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• pp.54-59
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• 2010

After the advent of B787(Boeing Co.), a civil aircraft using composite materials more than 50% of it total structural weight for weight savings，best performances and efficiencies, various endeavors to develop and apply the state of art of structural health monitoring(SHM) technologies for composite aircraft have been made for many years. Despite their plentiful advantages composite aircraft structures are susceptible to the hidden or barely visible impact damages(BVID) and excessive loads that if unchecked may lead to lower structural integrity, loss of operational performance and finally a sudden catastrophic failure of the aircraft structure. In this paper background of SHM technology and relevant technologies for application of SHM technology to the composite aircraft in the near future and requirements for certification of SHM system are shortly presented.

• 인터넷정보학회논문지
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• 제9권4호
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• pp.69-77
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• 2008

X.509 인증서 확장영역에 사용자 MAC 주소를 추가함으로써 더 신뢰성 있는 사용자 인증을 제공한다. 사용자 MAC 주소를 인증서에 첨가해도 통신 퍼포먼스에 영향을 미치지 않는 것을 시연하였으며, 간단한 MAC 주소 첨가로 인해 향상된 사용자 인증을 기대한다.

• 공학교육연구
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• 제11권4호
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• pp.58-63
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• 2008

본 논문은 중소도시의 전기 설비 및 전기공사 업체의 인력 수요와 채용과정 및 훈련기관의 교육 내용을 조사하였다. 그리고 학생의 취업 향상과 교육훈련과정개발을 위한 정보를 제공함에 목적이 있다. 인력수요 및 교육수요와 현장 실습생 수요에 대해 분석하였다. 표본추출은 업종별, 규모별 할당표본 추출방법(quota Sampling)을 사용하였다. 조사방법은 전화 및 방문하여 조사하였으며, 자료분석은 엑셀을 이용한 통계 분석을 하였다.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권5호
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• pp.177-181
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• 2003

Partial discharge pulse shapes from variable PD (partial discharge) sources sustain many characteristics such as types of PD. Ultra high frequency antennas have wide bandwidth from 30KHz to 2㎓. Therefore, signals taken from a UHF antenna have important attributes (rising time, falling time, shape factor, etc.) for electromagnetic sources, such as PD sources. We investigated PD pulse shapes from several PD sources using a UHF antenna and the results were used for classification of PD sources. Features for discrimination are extracted from frequency distribution and LPC (Linear Prediction Coefficient) of time signal. RBFN are used for investigating the possibility of classification of multi-PD sources.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1419-1427
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• 2008

This paper shows the kernel Poisson regression which can be applied in the claims reserving, where the row effect is assumed to be a nonlinear function of the row index. The paper concentrates on the chain-ladder technique, within the framework of the chain-ladder linear model. It is shown that the proposed method can provide better reserve estimates than the Poisson model. The cross validation function is introduced to choose optimal hyper-parameters in the procedure. Experimental results are then presented which indicate the performance of the proposed model.

• 한국컴퓨터정보학회논문지
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• 제21권9호
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• pp.149-156
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• 2016

This paper is concerned with education courses operating practices for basic computer literacy training. In this study, we propose an example for students to effectively measure and evaluate the achievement of defined ability in the performance measurement and analysis, learning objectives and learning outcomes set in operation throughout the course. Through research and development use case presents the tools for teaching method and effective and objective measurement of the related subjects. And based on the results, we propose the possibility of utilizing NCS-based course operation and education certification. In this study, the measurement process is based on the association with the objective of the development and operation, and measurement tools, measuring tools for measuring learning outcomes associated with the curriculum design methods for the measurement and evaluation of the case of the operation of the course units of learning outcomes and the method proposed.

• 자동차안전학회지
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• 제7권3호
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• pp.19-24
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• 2015

Brake pads are a component of disc brake system of automobile and consist of steel backing plates and friction material facing the disk brake rotor. Due to the repeated sliding forces and torque in vehicle braking, friction performance of brake pads are ensured. Futhermore, the brake pad is one of major tuning components in aftermarket, mechanical characteristics of the brake pad are necessary to evaluate for establishing the certification standards of tuning components. This study had performed the five specimen tests for friction coefficients and wear loss rates according to the SAE test specification. Using the instrumented indentation method, yield strength and tensile strength were measured. Friction coefficients, 0.386 - 0.489, and wear loss rates, 1.0% - 3.7% are obtained. The range of yield strength and tensile strength are 21.4 MPa - 105.3 MPa and 39.5 MPa - 176.4 MPa respectively.