• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.74-80
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• 2021

Korea Atomic Energy Research Institute (KAERI) has been operating an integral effects test facility, the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS), according to APR1400 for transient experimental and design basis accident simulation. Moreover, based on the experimental data, the domestic standard problem (DSP) program has been conducted in Korea to validate system codes. Recently, through DSP-05, the performance of the passive auxiliary feedwater system (PAFS) in the event of multiple steam generator tube rupture (MSGTR) has been analyzed. However, some errors exist in the reference input model distributed for DSP-05. Furthermore, the calculation results of the heat loss correlation for the secondary system presented in the technical report of the reference indicate that a large difference is present in heat loss from the target value. Thus, in this study, the reference model is corrected using the geometric information from the design report and drawings of ATLAS. Additionally, a new heat loss correlation is suggested by fitting the results of the heat loss tests. Herein, MSGTR-PAFS accident analysis is performed using MARS-KS 1.5 with the improved model. The steady-state calculation results do not significantly differ from the experimental values, and the overall physical behavior of the transient state is properly predicted. Particularly, the predicted operating time of PAFS is similar to the experimental results obtained by the modified model. Furthermore, the operating time of PAFS varies according to the heat loss of the secondary system, and the sensitivity analysis results for the heat loss of the secondary system are presented.

• Journal of Wind Energy
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• v.13 no.3
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• pp.13-21
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• 2022

When a wind turbine is designed, the dynamic stability of the system as well as the dynamic characteristics of the main components such as blades, hub, main shaft and tower must be evaluated. In particular, the natural frequencies of a blade, as a main load-generating component, need to be measured and assessed by component level testing. In conventional practice, the natural frequencies of a blade are determined as the measured frequencies near the reference frequencies provided by FE analysis results. But the reference frequencies are also uncertain since designers have difficulty distinguishing the torsional mode shape among the analysis results due to the complexity of its mode shape. So, in conventional practice, the determination of a measured torsional frequency inevitably contains uncertainty. Therefore, a novel method to definitely determine the torsional frequencies from the experimental data itself is necessary. In this paper, a new methodology to measure the torsional frequency of a blade was studied from the perspective of a modal test procedure, data processing method and mode determination logic. Finally, the validity of the method that can measure torsional frequency without reference FE analysis results was verified by applying it to an actual large wind turbine blade

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.80-91
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• 2023

Objective: The purpose of this study is to identify factors that affect the incidence of hypertension using logistic regression and decision tree analysis, and to build and compare predictive models. Design: Secondary data analysis study Methods: We analyzed 9,859 subjects from the Korean health panel annual 2019 data provided by the Korea Institute for Health and Social Affairs and National Health Insurance Service. Frequency analysis, chi-square test, binary logistic regression, and decision tree analysis were performed on the data. Results: In logistic regression analysis, those who were 60 years of age or older (Odds ratio, OR=68.801, p<0.001), those who were divorced/widowhood/separated (OR=1.377, p<0.001), those who graduated from middle school or younger (OR=1, reference), those who did not walk at all (OR=1, reference), those who were obese (OR=5.109, p<0.001), and those who had poor subjective health status (OR=2.163, p<0.001) were more likely to develop hypertension. In the decision tree, those over 60 years of age, overweight or obese, and those who graduated from middle school or younger had the highest probability of developing hypertension at 83.3%. Logistic regression analysis showed a specificity of 85.3% and sensitivity of 47.9%; while decision tree analysis showed a specificity of 81.9% and sensitivity of 52.9%. In classification accuracy, logistic regression and decision tree analysis showed 73.6% and 72.6% prediction, respectively. Conclusions: Both logistic regression and decision tree analysis were adequate to explain the predictive model. It is thought that both analysis methods can be used as useful data for constructing a predictive model for hypertension.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.1
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• pp.39-42
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• 2005

Though full 3D analysis is the proper method to analyze the hybrid stepping motor (HSM), it has weak points in the areas of computation time and complexity. This paper introduces 2D FEA using a virtual magnetic barrier for the axial cross section to save computation time. For the purpose of 2D FEA, the virtual magnetic barrier and equivalent permanent magnet model of HSM are proposed. This result is compared with that of experimental and 3D analysis, considered as a reference result.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.376-378
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• 1992

A chemical tool was developed for the analysis of complex mixtures such as crude drugs by the method of pattern recognition. Pattern recognition was accomplished by a multiple reference peak identification method and three kinds of outlier statistics. This tool was tested on the analysis of synthetic mixtures.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.76-79
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• 2013

Purpose: It is very important to establish the appropriate reference range in the laboratory for preventing mistakes like false positive or false negative. Because the reference range in the laboratory is standard of patient test results interpretation. Proinsulin is precursor hormone of insulin, and the importance is increasing for diagnosing diabetes or insulinoma. Proinsulin reagent used in our laboratory is produced in the USA, and the reference range provided by manufacturer was adapted to our reference range after the validation test. But, it is generally recommend for the every laboratory to establish the their own reference range. So, we decided to re-evaluate the reference range with our patients' test results. Materials and Methods: Among 737 patients who had been to health promotion center in our hospital between Dec. $8^{th}$ 2011 and Dec. $21^{st}$ 2011, 563 patients are chosen with exception of diabetics patients and patients showing abnormal test results in Fasting Glucose, HbA1c, Insulin, and C-peptide. The 563 test results (275 males and 288 females) were classified with three groups(entire, male, female), and analysis of normal distribution was performed with aid of SPSS(version 19.0). Because Each group didn't show normal distribution, the reference range was set from the lowest limit of 2.5% to the highest limit of 97.5% with Percentile method used in non-normal distribution. Results: When evaluation values are sorted in ascending order, the entire range is 4.5~52.0 pM and 5.3~51.9 pM for male and 4.5~52.0 pM for female. The calculated reference range with percentile method shows 6.7~26.5 pM for entire group, 6.8~26.5 pM for male and 6.7~26.5 pM for female, respectively. Conclusion: The reference range provided by reagent manufacturer is 6.4~9.4 pM and the one established in this study is 6.7~26.5 pM. This difference might be caused by racial characteristics between Western people and Koreans. So an ideal reference range can be gotten with normal population visiting to every hospital. Our hospital has been using the newly re-establishing reference range under consultation with the department of endocrinology since Aug. $1^{st}$ 2012.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.495-503
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• 1999

Airborne particulate matter $(PM_{10})$ collected using high volume air sampler and silica fiber filter were analyzed by Instrumental Neutron Activation Analysis(INAA), Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES) and Atomic Absorption Spectrometry(AAS), and the results were compared with each other. 30~40 trace elements in environmental standard reference materials(NIST SRM 1648 and NIES CRM No.8) were analyzed for the analytical quality control. The relative error for two-third of elements detected was less than 10%, and the standard deviation was less than 15%. During the sampling period for 24 hours, the mass concentration of total suspended particulate was 36.1$\mu\textrm{g}$/㎥ and the value is lower than the critical level in Korea. In the results of NAA, the elements of Al, As, Ba, Fe, La, Mg, Na, Sb, Zn were well agreed with those of other methods. In statistical estimation between different methods, the deviation of Al, Ba, Cr, Fe was less than 10% and quite reliable.

• Journal of the Korean Society for Library and Information Science
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• v.47 no.2
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• pp.143-159
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• 2013

A series of citation analyses are conducted to find out the characteristics of citation behavior in the field of military science and technology in Korea. The analyses are done against the references at the ends of articles in the Journal of the Korea Institute of Military Science and Technology published during the period 1998-2012. The sample includes 4,563 references from 537 articles. The analyses focused on types of materials, such as monographs, continuous materials, reports, etc., cited by the researchers by year. Lastly, the study aims to suggest the preferences of cited materials. The results of the analyses might provide a guide for a research library to establish an effective acquisition policy and a basis for tangible proof to secure continuous financial support from administration.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.65-78
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• 2011

The purpose of this study is to identify topic areas of academic library research using two informetric methods; word clustering and Pathfinder network. For the data analysis, 139 articles published in major library and information science journals from 2005 to 2009 were collected from the Korean Science Citation Index database. The keywords that represent research topics were gathered from two sections: an and titles in references. Results showed that reference titles usefully represent topics in detail, and combinings and reference titles can produce an expanded topic map.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.149-155
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• 2018

Quantitative analysis was performed to confirm that moire artifact was removed without loss of image when using grid suppression software in the diagnosis of micro lesions. we showed that grid suppression images can be morphologically different from original images as they are significantly lower than those of the optimized grid in the similarity analysis with reference images in mammographic phantom images. We were confirmed that images of microcalcification with smaller signal than noise were lost because the pixel values of all lesions increased significantly after the grid suppression, The change in contrast using the NORMI 13 X-ray test phantom was reduced to 30% of the reference image, This result was significantly lower than the 90% when using the optimized grid. In conclusion, the use of grid suppression software in clinical images should be carefully considered because of the possibility of misdiagnosis due to micro lesion loss and morphological changes.