• Title/Summary/Keyword: experimental methods

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Experimental validation of ASME strain-based seismic assessment methods using piping elbow test data

  • Jong-Min Lee ;Jae-Yoon Kim;Hyun-Seok Song ;Yun-Jae Kim ;Jin-Weon Kim
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1616-1629
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    • 2023
  • To quantify the conservatism of existing ASME strain-based evaluation methods for seismic loading, this paper presents very low cycle fatigue test data of elbows under various cyclic loading conditions and comparison of evaluation results with experimental failure cycles. For strain-based evaluation methods, the method presented in ASME BPVC CC N-900 and Sec. VIII are used. Predicted failure cycles are compared with experimental failure cycle to quantify the conservatism of evaluation methods. All methods give very conservative failure cycles. The CC N-900 method is the most conservative and prediction results are only ~0.5% of experimental data. For Sec. VIII method, the use of the option using code tensile properties gives ~3% of experimental data, and the use of the material-specific reduction of area can reduce conservatism but still gives ~15% of experimental data.

Outcomes of active learning methods in an electrocardiography course; identifying the effects of flipped, case-based, and team-based learning (액티브 러닝 학습방법을 활용한 심전도 개론 및 실습 교과과정의 학습효과와 만족도 조사)

  • Kim, Chul-Tae;Kim, Jung Sun
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.2
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    • pp.61-73
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    • 2019
  • Purpose: This study aimed to introduce active learning methods, including flipped, case-based, and team-based learning in an electrocardiography (ECG) course and to investigate outcomes and satisfaction with these methods. Methods: To identify the learning effect of active learning, pre-and post-academic self-efficacy was compared between the experimental and control groups. In the experimental group, pre-and post-knowledge and clinical performance regarding ECG were also assessed. In addition, class satisfaction was investigated after application of active learning methods in the experimental group. Data were collected from 84 paramedic students and analyzed using SPSS 22.0 (IBM, Armonk, NY, USA). Results: The experimental group showed significant improvement in post-academic self-efficacy and knowledge. The experimental group also showed high clinical performance (9.83 out of 10 in ECG checking ability and 9.63 out of 10 in ECG reading ability). The mean satisfaction score was 4.23 out of 5 (responses based on a Likert scale) in the experimental group. Conclusion: Active learning in an ECG course was found to be highly effective and satisfactory. Furthermore, paramedic students can enhance their accountability and judgement with team-based learning through free engagement in discussion.

Ab Initio Studies of Hydrogen Bihalide Anions: Anharmonic Frequencies and Hydrogen-Bond Energies

  • Cheong, Byeong-Seo
    • Journal of the Korean Chemical Society
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    • v.63 no.4
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    • pp.237-245
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    • 2019
  • Hydrogen bihalide anions, $XHX^-$ (X = F, Cl, and Br) have been studied by high level ab initio methods to determine the molecular structure, vibrational frequencies, and energetics of the anions. All bihalide anions are found to be of linear and symmetric structures, and the calculated bond lengths are consistent with experimental data. The harmonic frequencies exhibit large deviations from the experimental frequencies, suggesting the vibrations of these anions are very anharmonic. Two different approaches, the VSCF and VPT2 methods, are employed to calculate the anharmonic frequencies, and the results are compared with the experimental frequencies. While the ${\nu}_1$ and ${\nu}_2$ frequencies are in reasonable agreement with the experimental values, the ${\nu}_3$ and ${\nu}_1+{\nu}_3$ frequencies still exhibit large deviations. The hydrogen-bond energies and enthalpies are calculated at various levels including the W1BD and G4 composite methods. The hydrogen-bond enthalpies calculated are in good agreement with the experimental values.

Effect of Chuna on Nervous System - Based on Experimental Chuna Science - (추나의 신경계에 미치는 영향에 대한 고찰 - 실험추나학을 중심으로-)

  • Ahn, Min-Youn;Song, Yun-Kyung;Lim, Hyoung-Ho
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.8 no.2
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    • pp.47-56
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    • 2013
  • Objectives : Many studies are being done in the method of experimental chuna science in China. The aim of this review is to understand and study the methods of experimental chuna science, focusing on the effects of chuna on nervous system. Methods : We reviewed "實驗推拿學"(experimental tuina science) and Chinese journals were searched using China National Knowledge Infrastructure(CNKI). Korean journals were searched using 3 Korean web databases(OASIS, NDSL, RISS). Results : By experimental chuna science, analgesic effect of chuna, therapeutic action of chuna on stroke, therapeutic action on polio, effect of modulating autonomic nerves of chuna and effect of modulating thermoregulatory centers of chuna were proved. Conclusions : Experimental chuna science is necessary for development of chuna to a higher level. In Korea, not a lot experimental studies are being done, especially in chuna. For this reason we need to learn and adapt the methods of experimental chuna science of China.

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The Experimental Bias in Person Perception as Results of the Method of Developments Stimulus (자극물의 표현방법에 따른 대인지각에서의 편파)

  • 김재숙;김희숙
    • The Research Journal of the Costume Culture
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    • v.12 no.1
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    • pp.28-40
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    • 2004
  • The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of development methods (2) to find out the most desirable method in developments of stimulus. The research was a quasi experiment and the subjects were 358 male and female undergraduate students by convenient sampling. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7-point bi-polar adjectives. The collected data were analyzed by Principle Component Analysis, ANOVA(analysis of variance), Scheffe's multiple range test. The independent variables were developing methods of stimulus(live person, photography of real person, 2 kinds of black and white line drawing, 2 kinds of color drawing). The results were as follows. First, five factors which were potency, sociality, appearance, evaluation, activity impressional dimensions emerged to account for the methods of development of stimulus. Second, the methods of development of stimulus had significant effects on potency, sociality, appearance, activity factors. In sociality factors, the impression of photographic stimulus was the closest to the live person's impression. However in the appearance and activity impressions, significant difference existed between live person and other developing stimulus. In the potency impression, black and white line-drawing gave the highest impressional bias. In the sociability and appearance impressions, color-drawing stimulus gave the highest impressional bias. Result: On conclusion the developments of stimulus can effect on stimulus person's impressions and these effects can produce experimental biases, the photographic stimulus gave the least impressional bias. The study shows that photography of real person will produce minimize measurement error.

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Determination of Optimum Micro Drilling Conditions Using Experimental Design Methods (실험계획법에 의한 마이크로 드릴링 공정의 최적 절삭조건 결정)

  • 김동우;조명우;이응숙;서태일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.993-998
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    • 2002
  • watches, air bearings and printed circuit hoards (PCB). However, it is not easy to determine optimum cutting conditions since the micro drilling process is very sensitive to various disturbances. Also, undesirable characteristics to optimize the micro drilling are small signal-to-noise ratios, drill wandering motions and high aspect ratios. Thus, in this study, experimental design methods are applied to determine optimum cutting conditions. Suing the methods, three cutting parameters, fred, step and curving speed are optimized to minimize thrust forces. Obtained conditions are verified through required experimental works. As the results, it is shown that the experimental methods can be applied to micro drilling processes to determine Optimum Cutting Conditions.

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Experimental Methods for the Measurement of Damping Loss Factors (내부손실계수 측정을 위한 실험 방법)

  • 김관주;최승권
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1187-1192
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    • 1999
  • The purpose of this study is to determine the most appropriate experimental method of the measurement of "damping loss factors" (DLF) for the statistical energy analysis(SEA) calculation. The successful prediction of vibration levels from the structure is critically dependent on the accurate estimation of DLF's not only in conventional vibration analysis but especially in SEA. Unforunately, calculation of accurate DLF is not an easy matter. So experimental methods are made use of for the DLF values. Three kinds of experimental methods for estimating DLF, i.e. decay rate method, half-power bandwidth method and power balance method, are presented and tests are carried out for the plate and the cylindrical shell examples. Pro and con of each methods is reviewed. Finally, calculated DLF values are used for vibration level estimation using commercial SEA software and compared with measured vibration data.tion data.

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Effect of Chuna on circulatory system - Based on Experimental Chuna Science - (추나의 순환계에 미치는 영향에 대한 고찰 - 실험추나학을 중심으로-)

  • Ahn, Min-Youn;Song, Yun-Kyung;Lim, Hyoung-Ho
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.9 no.2
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    • pp.1-9
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    • 2014
  • Objectives : Many studies are being done in the method of experimental chuna science in China. The aim of this review is to understand and study the methods of experimental chuna science, focusing on the effects of chuna on circulatory system. Methods : We reviewed "實驗推拿學" and Chinese journals were searched using China National Knowledge Infrastructure(CNKI). Korean journals were searched using 3 Korean web databases(OASIS, NDSL, RISS). Results : By experimental chuna science, effect of chuna on blood pressure, cardiovascular system, hemorheologic system, blood flow velocity, circulation and lymphatic system were proved. Conclusions : Experimental chuna science is necessary for improvement of chuna to a higher level. In Korea, not many experimental studies are being done, especially in chuna and it has very narrow target diseases. For this reason we need to learn and adapt the methods of experimental chuna science of China.

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A Benchmark study on ultimate strength formulations of the aluminium stiffened panels under axial compression (알루미늄합금 보강판의 압축 최종강도 설계식의 비교연구)

  • ;;;O.F., Hughes;P.E., Hess
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.110-117
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    • 2004
  • The aim of a benchmark study is carried out nine methods are employed for ULS analysis which implicitly predict the ultimate strength of aluminium stiffened panels under axial compression. For this purpose, DNV PULS, experimental and numerical data on the ultimate strength of panels were collected. Comparison of these experimental / numerical, DNV PULS / numerical, results with theoretical solutions by the candidate methods is performed. Also it's compared that ALPS/ULSAP program is based on closed-form formula for the ULS of plates and grillages under axial compression. It is considered that ALPS/ULSAP methodology provides quite accurate and reasonable ULS calculations by a comparison with more refined FEA. Comparison of these experimental data, numerical, computational software results with the simplified solutions obtained by the candidate methods is then performed. The model uncertainties associated with the candidate methods are studied in terms of mean bias and COV (i.e., coefficient of variation) against experiments and numerical solutions, and the relative performance of the various methods is discussed.

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A literature review on RSM-based robust parameter design (RPD): Experimental design, estimation modeling, and optimization methods (반응표면법기반 강건파라미터설계에 대한 문헌연구: 실험설계, 추정 모형, 최적화 방법)

  • Le, Tuan-Ho;Shin, Sangmun
    • Journal of Korean Society for Quality Management
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    • v.46 no.1
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    • pp.39-74
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    • 2018
  • Purpose: For more than 30 years, robust parameter design (RPD), which attempts to minimize the process bias (i.e., deviation between the mean and the target) and its variability simultaneously, has received consistent attention from researchers in academia and industry. Based on Taguchi's philosophy, a number of RPD methodologies have been developed to improve the quality of products and processes. The primary purpose of this paper is to review and discuss existing RPD methodologies in terms of the three sequential RPD procedures of experimental design, parameter estimation, and optimization. Methods: This literature study composes three review aspects including experimental design, estimation modeling, and optimization methods. Results: To analyze the benefits and weaknesses of conventional RPD methods and investigate the requirements of future research, we first analyze a variety of experimental formats associated with input control and noise factors, output responses and replication, and estimation approaches. Secondly, existing estimation methods are categorized according to their implementation of least-squares, maximum likelihood estimation, generalized linear models, Bayesian techniques, or the response surface methodology. Thirdly, optimization models for single and multiple responses problems are analyzed within their historical and functional framework. Conclusion: This study identifies the current RPD foundations and unresolved problems, including ample discussion of further directions of study.