• Journal of Applied Reliability
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• v.6 no.1
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• pp.27-36
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• 2006

It is increasingly important to ensure that a given vibration test specification of a particular machinery component is appropriately established by considering its real environmental conditions. Vibration test standards for electrical components are well documented, for example in an IEC 60068 series, while standards for machinery components are rarely found except a few military standards. Thus many vibration tests are performed based on the military standards. However, a test based on these military standards often results in over-testing, and under-testing in some cases due to the different environmental conditions. Also, these standards require an appropriate tailoring that may not be easily accomplished. In this paper, various international and military standards are compared and investigated to obtain test specifications relevant for machinery components. Also appropriate tailoring methods are demonstrated through a case study.

• Journal of Pharmacopuncture
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• v.18 no.1
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• pp.44-55
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• 2015

Objectives: Scolopendra subspinipes mutilans (S. subspinipes mutilans) is known as a traditional medicine and includes various amino acids, peptides and proteins. The amino acids in the pharmacopuncture extracted from S. subspinipes mutilans by using derivatization methods were analyzed quantitatively and qualitatively by using high performance liquid chromatography (HPLC) over a 12 month period to confirm its stability. Methods: Amino acids of pharmacopuncture extracted from S. subspinipes mutilans were derived by using O-phthaldialdehyde (OPA) & 9-fluorenyl methoxy carbonyl chloride (FMOC) reagent and were analyzed using HPLC. The amino acids were detected by using a diode array detector (DAD) and a fluorescence detector (FLD) to compare a mixed amino acid standard (STD) to the pharmacopuncture from centipedes. The stability tests on the pharmacopuncture from centipedes were done using HPLC for three conditions: a room temperature test chamber, an acceleration test chamber, and a cold test chamber. Results: The pharmacopuncture from centipedes was prepared by using the method of the Korean Pharmacopuncture Institute (KPI) and through quantitative analyses was shown to contain 9 amino acids of the 16 amino acids in the mixed amino acid STD. The amounts of the amino acids in the pharmacopuncture from centipedes were 34.37 ppm of aspartate, 123.72 ppm of arginine, 170.63 ppm of alanine, 59.55 ppm of leucine and 57 ppm of lysine. The relative standard deviation (RSD %) results for the pharmacopuncture from centipedes had a maximum value of 14.95% and minimum value of 1.795% on the room temperature test chamber, the acceleration test chamber and the cold test chamber stability tests. Conclusion: Stability tests on and quantitative and qualitative analyses of the amino acids in the pharmacopuncture extracted from centipedes by using derivatization methods were performed by using HPLC. Through research, we hope to determine the relationship between time and the concentrations of the amino acids in the pharmacopuncture extracted from centipedes.

• Toxicological Research
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• v.30 no.3
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• pp.185-191
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• 2014

Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.656-665
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• 2010

Shear modulus has been recognized as one of the important soil properties in dynamic analysis of ground and can be calculated from in situ measurement of shear wave velocity. Field seismic tests are the most accurate but expensive methods to investigate dynamic ground characteristics. Due to that reason, empirical equations for estimating the shear wave velocity are widely used rather than conducting in-situ tests. The most common equations are based on the N value obtained in conjuctions with a standard penetration test. In this paper, the field datas of standard penetration test and suspension PS logging measured in 126 sites of Korea were summarized and the correlation equations between N value and shear wave velocity are suggested.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.253-256
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• 2002

Generally, the owners of the facilities adopt CP(Cathodic Protection) Systems to protect the corrosion accidents previously. The developed countries have secured the standard of CP systems through the various researches and consolidation of the rules. So in the first stage. I had been studied the international standards; JSCE, NACE Standard, ASTM, DNV, Australian Standard etc. and standardized the CP systems about items performance. specifications and so on. In this thesis, I have been studying the results of standardization of performance test methods of CP rectifier to apply in Korea.

• Journal of Technologic Dentistry
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• v.42 no.2
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• pp.73-79
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• 2020

Purpose: The aim of this study was to investigate the influence of short and long duration sintering on microstructure and flexural strength of zirconia. Methods: To conduct three-point bending test, Zirconia specimens are milled according to ISO 6872 guidelines(N=18, n=9 per group). Two specimens group(n=8) is sintered for 10 hours(Standard schedule) and 3 hours(Speed schedule) at the peak temperature of 1550℃ with silicon carbide sintering furnace. Flexural strength of specimens are measured by instron. After coating each specimen(n=1), microstructure of specimens is observed using Scanning Electron Microscope(SEM). T-test was utilized to statistically assess the data. Results: The mean and standard deviation value of the flexural strength for standard schedule group are 578.15±57.48Mpa, that of speed schedule are 465.9±62.34Mpa. T-test showed significant differences in flexural strength between two zirconia specimen group which applied standard schedule and speed schedule respectively(p<0.05). Conclusion: The result of this study showed that the increase in sintering time led to increased grain size, and also to a positive effect on the flexural strength.

• Geomechanics and Engineering
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• v.5 no.6
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• pp.541-564
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• 2013

In this study, artificial neural networks (ANNs) were used to predict the settlement of pad footings on cohesionless soils based on standard penetration test. To achieve this, a computer programme was developed to calculate the settlement of pad footings from five traditional methods. The footing geometry (length and width), the footing embedment depth, $D_f$, the bulk unit weight, ${\gamma}$, of the cohesionless soil, the footing applied pressure, Q, and corrected standard penetration test, $N_{cor}$, varied during the settlement analyses and the settlement value of each footing was calculated for each method. Then, an ANN model was developed for each traditional method to predict the settlement by using the results of the analyses. The settlement values predicted from the ANN model were compared with the settlement values calculated from the traditional method for each method. The predicted values were found to be quite close to the calculated values. It has been demonstrated that the ANN models developed can be used as an accurate and quick tool at the preliminary designing stage of pad footings on cohesionless soils without a need to perform any manual work such as using tables or charts. Sensitivity analyses were also performed to examine the relative importance of the factors affecting settlement prediction. According to the analyses, for each traditional method, $N_{cor}$ is found to be the most important parameter while ${\gamma}$ is found to be the least important parameter.

• Communications for Statistical Applications and Methods
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• v.14 no.3
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• pp.609-621
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• 2007

Diagnostic test results, which are approximately normal with a few number of outliers, but non-normal probability distribution, are frequently observed in practice. In the evaluation of two diagnostic tests, Greenhouse and Mantel (1950) proposed a parametric test under the assumption of normality but this test is inappropriate for the above non-normal case. In this paper, we propose a computationally simple nonparametric test that is based on quantile estimators of mean and standard deviation, instead of the moment-based mean and standard deviation as in some parametric tests. Parametric and nonparametric tests are compared with simulations under the assumption of, respectively, normality and non-normality, and under various combinations of the probability distributions for the normal and diseased groups.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.956-960
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• 2002

Offices and other multipurpose buildings commonly have suspended ceilings installed over room dividing wall. But Korean Standards don't include any code on test methods and test facility of the suspended ceiling system. Therefore, test methods and test facility from ISO and ASTM have been used for evaluating sound performance in domestic so fu. In this study, Korean Standards draft on test methods and test facility of suspended ceiling system and materials is proposed on the basis of ISO and ASTM.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.27-30
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• 2009

In this paper, we introduce the status of certificate test on crystalline silicon photovoltaic module in Korea. Up to 3. 2009, about 149 models have passed certificate test under KS C IEC61215 standard. Most products are from Korea, Japan, China. And some are from USA, German and Taiwan. A few environmental test items' results and standard test methods will be discussed. The detail discussion will be shown in the following paper.