• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.763-770
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• 1998

This paper deals with evaluation of bending fatigue strength in SCM415 carburized spur gears. The constant stress amplitude fatigue test is performed by using an electrohydraulic servo-controlled pulsating tester. The S-N curves are obtained and the enhanvement of fatigue strength due to carburized treatment is clarified. In this study the improvement of fatigue strength is assumed to be caused by an increase of both hardness and residual stress and experimental formula has been proposed for the estimation of bending fatigue strength of carburized gears. The effect of surface conditions on the fatigue strength is evaluated quantitatively and it is close to the relative surface condition factor used in the ISO strength rating formula.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2174-2183
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• 2000

In this paper, the evaluation method of interfacial fracture toughness to apply the fracture toughness was investigated in adhesively bonded joints of AI/Ced./A1. Four types of adhesively bonded double-cantilever beam(DCB) joints with the interface crack were prepared for the test of interfacial fracture toughness. The experiments to measure the interfacial fracture toughness were performed under the various mixed-mode conditions. The critical energy release rate, Gc, was obtained by the experimental measurement of compliances. From the experimental results, the interfacial fracture toughness for the mixed-mode specimens is well characterized by the energy release rate, and the method of strength evaluation by the interfacial fracture toughness was discussed in adhesively bonded joints.

• 연구논문집
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• 통권33호
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• pp.67-79
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• 2003

The life of oilless bearing affects the durability of scroll compressor. The main shaft of the scroll compressor is supported by oiiless bearing. Some of the major parameters which influence the life of oilless bearing are rotational speed, normal load, environment of refrigerant and oil film thickness. The reliability evaluation of oiiless bearing is performed through the acceleration life test for reduction of experimental time and costs. In this study, the experimental and computational investigations were performed to verify the effects of various parameters on the life of oilless bearing. The acceleration factor was achieved with the lubrication analysis between the scroll compressor and the developed reliability tester. the expected life of oilless bearing was guaranteed by reliability evaluation accompanied with the acceleration life test.

• 대한후두음성언어의학회지
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• 제3권1호
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• pp.6-12
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• 1989

Methods of voice rehabilitation in laryngectomees include training of esophageal speech, use of electrolarynx and pneumatic speech aid and surgical methods, etc. In this paper, we introduce the experimental model of obturator-type electrolarynx which has several advantages for use such as ease of learning, no disagreeable appearance, and both hands not being occupied. We compared it to normal voice and other voice rehabilitation methods such as esophageal voice, japanese pneumatic speech aid and cervical electrolarynx in intelligibility and sonagraphic evaluation. The results are as follows; 1) Obturator-type electrolarynx exhibited the lowest intelligibility. 2) In sonagraphic evaluation, the spectrogram produced by the obturator-type electrolarynx was the most different from those of normal voice.

• Geomechanics and Engineering
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• 제29권3호
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• pp.349-357
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• 2022

Abnormal climate events are occurring frequently around the world. In particular, cold waves and heavy snow lead to damage and deterioration of facilities, which can cause loss of life or property damage, such as shortening the lifespan of facilities. Therefore, it is very important to prepare an appropriate maintenance system and to establish a strategy to cope with abnormal weather conditions. In this study, laboratory freezing experiments were performed to analyze the freeze-thaw characteristics affecting the tunnel concrete lining, and heat flow analysis was carried out based on the test results. Based on these experimental and theoretical analysis results, quantitative freeze-thaw evaluation criteria for tunnel concrete linings were proposed.

• 한국초등과학교육학회지:초등과학교육
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• 제26권2호
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• pp.161-170
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• 2007

This study aims at helping us improve the methods used to teach elementary school students how to handle experimental apparatus by examining their manual skills and their understanding of the alcohol lamp, spuit and thermometer. To evaluate their ability to handle each experimental apparatus, a practical skills test and knowledge evaluation sheets were developed. The evaluation was carried out with 270 students from 2 classes each in the 3rd, 4th, 5th and 6th grade of D Elementary School located in Daejeon City. For their handling ability of the alcohol lamp, the results for the practical skills test showed that the students had a very low ability in placing objects in the center of the apparatus for safe use and also in adjusting the height of the trivet to place objects so that they contact the outer flames correctly. For the spuit, the pass rate of the skills test was generally low in regards to how students should grasp a spuit and the timing and method of depressing the rubber part before dipping it into liquid. For the thermometer, on the other hand, the pass rate was relatively high in every respect. The knowledge evaluation results for the use of experimental apparatus showed a very high rate of correct answers for alcohol lamps and thermometers. The test results for spoils also produced a relatively high rate of correct answers, with the exception of the test item regarding the way that students should grasp them.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 추계학술대회
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• pp.557-563
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• 2009

The research develops measurement processes for estimating and evaluating the gauge R&R(Reproducibility & Repeatability) using ANOVA(Analysis of Variance) of experimental design tools. The ten-step processes developed include experimental goal setting, the selection of characteristics(factors, levels), data model, ANOVA, EMS(Expected Mean Square), estimation of gauge precisions, and evaluation indexes. The three-factor combined measurement models are presented to show the processes developed in this paper.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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• pp.243-250
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• 2004

This paper reports on the evaluation of the initial stiffness of steel joints using component method as well as experimental tests. The so-called component method corresponds precisely to a simplified mechanical model composed of extensional springs and rigid links, whereby the joint is simulated by an appropriate choice of rigid and flexible components. An application to a cantilever beam-to-column steel joint is presented and compared to the experimental results obtained under cyclic loading condition. Comparison between numerical and experimental results allows to conclude that the numerical model is able to simulate, with a good level of accuracy for initial stiffness, the behaviour of beam-to-column joints.

• 한국통신학회논문지
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• 제42권1호
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• pp.42-45
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• 2017

본 논문에서는 "축구 동영상" 분석을 위한 "최적의" 배경 분리 알고리즘을 결정하기 위하여 정량적인 비교 평가 연구를 수행하였다. 이를 위해 본 논문에서는 다섯 가지 서로 다른 배경 분리 알고리즘을 동일한 실험 환경에서 비교 평가하였다. 정량적인 비교 평가를 위해 Precision, Recall 및 F-measure를 이용하였다. 본 논문에서 제시된 정량적 비교 평가 결과는 지능형 축구 동영상 분석 시스템 개발을 위해 배경 분리 기술을 이용하거나 축구 동영상에 특화된 배경 분리 기술을 연구하고자 하는 연구자 및 개발자들에게 실질적인 도움이 될 것으로 예상된다.

• Nuclear Engineering and Technology
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• 제34권6호
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• pp.533-544
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• 2002

The neutron induced nuclear data for Mo-95, Tc-99, Ru-101 and Rh-103 was calculated and evaluated in the fast energy region. The energy dependent optical model potential parameters were extracted based on the recent experimental data and applied up to 20 MeV. The s-wave strength function was calculated from the parameters. Spherical optical model, statistical model in equilibrium energy, multistep direct and multistep compound model in pre-equilibrium energy and direct capture model were used in the calculation. The theoretically calculated cross sections were compared with the experimental data and the evaluated files The model- calculated total and capture cross sections were in good agreement with the reference experimental data. The direct capture contribution improved the capture cross sections in pre- equilibrium region. The evaluated cross section results were compiled to ENDF-6 format and will improve the ENDF/B-Vl.