• 비파괴검사학회지
• /
• 제24권3호
• /
• pp.246-252
• /
• 2004

복합재료는 이방성의 특징으로 매우 복잡한 역학거동을 하며, 해석 및 신뢰성 검사에 많은 어려움이 있다. 특히, 기존의 비파괴검사기법으로 내부손상을 검출하는 것은 매우 어려운 실정이다. 이에 본 연구에서는 복합재구조물의 가장 취약한 분야인 충격에 의한 손상이 발생할 경우 효과적인 검출기법을 개발하고, 충격에 따른 내부결함의 정량평가에 ESPI를 활용하였다. 인공결함을 이용하여 ESPI기법의 신뢰성을 확보하고 실제 충격손상 시험편에 대해 적용하여 5%이내의 오차율로 결함을 정량평가하였다.

• 컴퓨터교육학회논문지
• /
• 제9권2호
• /
• pp.69-78
• /
• 2006

교육평가란 학습자들을 서열별로 등급화 하는 과정이 아니라 적절한 평가를 통해 학습자의 문제를 해결하고 교육 과정을 개선하여 교육적 효과를 높이는 과정이다. 기존의 웹 기반 평가 시스템은 학습자의 인지 수준을 정 오답 이분 변수로만 측정하였다. 또한 수준별 평가를 지원하나 평가 시 학습동기 부여와 흥미를 이끌어 내는데 미흡하였으며, 평가 후 틀린 문제에 대한 피드백만을 제공하여 추후 학습 방향 설정과 재학습이 효율적으로 이루어지지 못한 문제점이 있다. 본 논문에서는 문제의 답지에 따라 학습자의 인지 능력을 좀 더 세밀하게 추정하고자 부분점수를 고려하여 문제를 출제하고 학습자의 수준을 평가하였으며 평가가 끝나면 학습 진단을 제공하여 피드백 학습이 효과적으로 이루어질 수 있도록 하였다.

• 비파괴검사학회지
• /
• 제8권1호
• /
• pp.30-37
• /
• 1988

Interfaces, both grain boundaries and phase boundaries, play a very important role in the mechanical behavior of structural materials. The problemis particularly intense in composite materials where interfaces play a primary role in the meehanical response of the composites. This paper will concentrate on the approaches to perform nondestructive evaluation of the interfaces in a man nor in which some measure of the mechanical behavior of the interface can be established. Some of the possible approaches that may have potential for the nondestructive evaluation of interfaces are optical, electronic/ electrical, and acoustic approaches.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1608-1609
• /
• 2011

In this study, in order to develop the evaluation method for XLPE materials for HVDC cables, DC/Impulse superposition testing system was builded up. Throughout the P-spice simulation, optimal values of the protection resistor for the DC generation system and the blocking capacitor for the Impulse generator were calculated. DC/Impulse superposition system showed good result maintaining their proper wave shapes and amplitudes. This system would be planned to apply to the evaluation of XLPE materials for HVDC cables.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 학술대회 논문집
• /
• pp.315-319
• /
• 2004

This paper presents the integrity evaluation method of the windings in cast resin transformers using vertical thermal distribution analysis. The method is to compare the temperature distribution in a sound condition specimen with that in the failure condition specimen layer-shorted by accelerated testing. The temperature distribution was acquisited by a infrared thermography system, and the Arrhenius equation was adopted to the accelerated testing. The proposed method may be available to detect the failures in cast resin transformers.

• Journal of applied mathematics & informatics
• /
• 제6권2호
• /
• pp.631-638
• /
• 1999

Sensitive testing has been widely employed for many years in connection with the development and evaluation explosives detonation devices and propellants. Perhaps its earliest and possibly most important implementation was in biological studies of dosage mortality and response to drugs. Recently sensitivity experiments has been employed in the evaluation of new materials subject to stress in various environments and in delineanation of unstable combustion regions in chemical propulsion systems. This paper discussed a sta-tistical development of sensitivity testing.

• 비파괴검사학회지
• /
• 제7권1호
• /
• pp.18-31
• /
• 1987

For the purpose of domestic production of ultrasonic transducer, experiments on material selection for backing and matching layer, and electrical impedance matching between transducer and equipment were performed. The characteristics of manufactured transducers with experimental results were analyzed and compared with foreign products. Through the evaluation of the transducers manufactured and the comparision with foreign products, it is confirmed that the transducers manufactured show the good performance characteristics and efficiency.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 C
• /
• pp.1629-1630
• /
• 2001

The high voltage measuring systems used in the testing systems shall be required to maintain the traceability to the national or international standards by the IEC 60060-2. Also all testing laboratories should prepare the documents evaluating the measurement uncertainty of the tests. By the way, this paper introduces the principal of IEC about the maintenance of traceability and evaluation methode of uncertainty.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
• /
• pp.60-61
• /
• 2018

Finishing materials are very important to restrain fire spread from a compartment to another in a fire situation. Therefore, the evaluation of combustible properties for the combustible material is essential to apply finishing materials into a generic buillding or s special occupancy structure. In this study, the testing methods for evaluation of combustible performance of finishing materials of domestic were surveyed in order to prepare the guideline of application of finishing materials in nulear power plant.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 추계학술대회 논문집
• /
• pp.332-337
• /
• 2005

In order to investigate performance changes, the acceleration, vibration, and braking performance tests were carried out on the electric multiple units (EMUs) with over 20 years operation. According to the testing results, in vibration and braking performance, the similar performance results were obtained as compared with newly manufactured EMUs. However, in terms of acceleration performance, below reference value (3.0 km/h/s) has been obtained. This is mainly due to performance deterioration including traction motor. The precision diagnosis evaluation of deteriorated EMUs will be provided through the overall evaluation of corrosion testing and structural performance of car body.