• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.343-356
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• 2022

As a part of round robin analysis to develop a finite element elastic-plastic seismic analysis procedure for nuclear safety class 1 components, a series of parametric analyses was carried out on the simulated pressurizer surge line system model to investigate sensitivity of the analysis results to finite element analysis variables. The analysis on the surge line system model considered dynamic effect due to the seismic load corresponding to PGA 0.6 g and elastic-plastic material behavior based on the Chaboche combined hardening model. From the parametric analysis results, it was found that strains such as accumulated equivalent plastic strain and equivalent plastic strain are more sensitive to the analysis variables than von Mises effect stress. The parametric analysis results also identified that finite element density and ovalization option in the elbow elements have more significant effect on the analysis results than the other variables.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.15-24
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• 2005

We investigated the changes of volatile flavor components from Codonopsis lanceolata, which were packed in woven polypropylene(WP) film or low density polyethylene(LDPE) film and stored for 15 and 30 days at refrigerated($2{\∼}4^{\circ}C$ ) or room($18{\∼}20^{\circ}C$) temperature. A hundred and sixty seven volatile flavor components in the fresh C. lanceolata were identified by GC/MS analysis. When determining the flavor components from C. lanceolata cultivated on a wild hill and stored at 4 conditions for 30days, six volatile components such as 1-hexadecene, 2,6-dimethyl-2-octanol, 2-methyl-2-dodecanol, $\alpha$-guaiene, $\delta$-cadinene and trans-2-hexen-1-ol were detected as common components of all stored samples, and The types of common flavor components of C. lanceolata were different according to storage conditions. The numbers were 16 from refrigerated, 7 from room temperature stored, and 10 components from WP or LDPE packed conditions, respectively. The total peak area ratio of the major 10 compounds were $52.0{\∼}86.8\%$, and the percentage of trans-2-hexen-1-ol, which was the only common compound among the major 10 components, was the highest as $26.4{\∼}68.1\%$ The major flavor profile, describe by highly trained panel, were green, aldehydic, earthy and camphoreous. As the result from sensory evaluation, the freshness of C. lanceolata was maintained better by controlling storage temperature rather than selection of package materials. The best condition for characteristic flavor of C. lanceolata was packing with LDPE and chilling.

• Journal of Ginseng Research
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• v.15 no.2
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• pp.117-119
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• 1991

In continuation of previous isolation of two lignan components, Gomisin A and -N, from Korean Red Ginseng the presence of the two lignans was identified in the hexane extract of Korean White Ginseng by gas chromatographic analysis.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.148-158
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• 2003

The purpose of this study is to investigate the impact of IT components of e-CRM on customer response performances in e-CRM. To this end, we classified IT components of e-CRM into the ones for customer management and the ones for customer analysis on the basis of previous studies. Also, we identified variables for customer response performances and conducted empirical analysis. The main results of this study are as following. First, this study derives the IT components of e-CRM for customer management and customer analysis respectively by reviewing the previous studies. Furthermore, this study defines business performance variables as customer response performances. Secondly, the hypotheses concerning the correlations between the use of the IT components of e-CRM for customer management and customer analysis and customer response performance are partly accepted, which shows that the use of particular IT components has significant influence on customer response performance. The findings of this study can contribute to expanding the theoretical background in the area of e-CRM adoption and development and be helpful to practical implementation of e-CRM systems in business organizations.

• Elastomers and Composites
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• v.47 no.3
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• pp.194-200
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• 2012

Rubber components have been widely used in automotive industry as anti-vibration components for many years. These subjected to fluctuating loads, often fail due to the nucleation and growth of defects or cracks. To prevent such failures, it is necessary to understand the fatigue failure mechanism for rubber materials and to evaluate the fatigue life for rubber components. The objective of this study is to develop the durability analysis process for vulcanized rubber components, which is applicable to predict fatigue life at initial product design step. The determination method of nonlinear material constants for FE analysis was proposed. In order to investigate the applicability of the commonly used damage parameters, fatigue tests and corresponding finite element analyses were carried out and strain energy density was proposed as the fatigue damage parameter for rubber components. The fatigue analysis for automotive rubber components was performed and the durability analysis process was reviewed.

• Elastomers and Composites
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• v.55 no.2
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• pp.81-87
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• 2020

Service life prediction and evaluation of rubber components is the foundational technology necessary for securing the safety and reliability of the product and to ensure an optimum design. Even though the domestic industry has recognized the importance thereof, technology for a systematic design and analysis of the same has not yet been established. In order to develop this technology, identifying the fatigue damage parameters that affect service life is imperative. Most anti-vibration rubber components had been damaged by repeated load and aging. Hence, the evaluation of the fatigue characteristics is indispensable. Therefore, in this paper, we propose a method that can predict the service life of rubber components relatively accurately in a short period of time. This method works even in the initial designing stage. We followed the service life prediction procedure of the proposed rubber components. The weak part of the rubber and the maximum strain were analyzed using finite element analysis of the rubber bushing for the tracked vehicles. In order to predict the service life of the rubber components that were in storage for a certain period of time, the fatigue test was performed on the three-dimensional dumbbell specimen, based on the results obtained by the rubber material acceleration test. The service life formula of the rubber bushing for tracked vehicles was derived using both finite element analysis and the fatigue test. The service life of the rubber bushing for tracked vehicles was estimated to be about 1.7 million cycles at room temperature (initial stage) and about 400,000 cycles when kept in storage for 3 years. Through this paper, the service life for various rubber parts is expected be predicted and evaluated. This will contribute to improving the durability and reliability of rubber components.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.3
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• pp.1-14
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• 2018

Objectives: The purpose of this study was to investigate the prevalence of metabolic syndrome and to find related factors according to the number of metabolic syndrome diagnostic components in Korean adolescents. Methods: The subjects of this study were 469 Korean adolescents aged from 12 to 18 enrolled in the 2016 Korea National Health and Nutrition Examination Survey. Statistical package R 3.4.2 was used for programming to apply diagnostic criterion of adolescent metabolic syndrome and for the analysis of the data such as weighted frequent analysis, weighted mean analysis and complex sampling design logistic regression analysis. Results: For adolescents 12 to 18 years of age, 2.55% had more than 2(${\geq_-}3$), 9.88% had more than 1(${\geq_-}2$) and 33.17% had more than 0(${\geq_-}1$) metabolic syndrome diagnostic components. It has been found that risk factors for no less than 2 metabolic syndrome diagnostic components were higher body mass index and higher stress, and risk factors for no less than 1 were higher body mass index, younger teenager and female. Conclusion: Obesity is the primary risk factor for the development of adolescent metabolic syndrome. Female or younger teenager are more likely to have one or more metabolic syndrome diagnostic components, and higher stress develop to the risk level of having two or more metabolic syndrome diagnostic components. Therefore, it is important to focus on obesity and stress management for the prevention and control of Korean adolescent metabolic syndrome.

• Journal of Korean Elementary Science Education
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• v.40 no.2
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• pp.145-161
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• 2021

This study analyzes the characteristic of elementary science-gifted education winner programs in Gifted Education Database (GED) focusing on scientific creativity. For this purpose, an analysis framework to analyze the programs was developed and a total of 840 inquiry activities from 55 winner programs were analyzed according to the analysis framework. The analysis of the results reveal that 'scientific inquiry skill' of the five scientific creativity components was most frequently included in the activities. 'Scientific knowledge content' and 'creative thinking' were also frequently included. However, 'problem solving ability' and 'common factor' were a little included. In the aspects of integration, the integrations between two or three components with five or eight types were frequently found. No integrations were also frequently included although less than the previous categories. The integrations among four with four types or five components were also slightly found. 'Scientific knowledge content', 'scientific inquiry skills', and 'creative thinking' with other components were more frequently found. However, the integrations of 'common factor' or 'problem solving ability' with the other components were less frequently found. Educational implications of these findings are discussed.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.615-621
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• 2009

In order to optimize the supercritical fluid extraction (SFE) conditions of volatile components from the strawberry, we conducted an evaluation of the sample preparation and SFE operating conditions. The analysis of the volatile components extracted by a variety of sample preparation protocols led to the identification of 30, 26, 30, and 34 volatile components in fresh, freeze-dried, 30% celite and 70% celite treatments, respectively. The 70% celite treatment was the most effective in extracting the volatile components from strawberry via SFE. Analysis of the volatile components extracted by a variety of SFE operating conditions yielded identifications of 34, 35, 34, and 35 volatile components at 3,000 psi (40, $50^{\circ}C$) and 6,000 psi (40, $50^{\circ}C$), respectively. The extraction yield of alcohols and acids, and the total volatile component contents, were highest under conditions of 3,000 psi and $55^{\circ}C$. Volatile components from the strawberry were extracted via SFE, simultaneous steam distillation and extraction (SDE), and solvent extraction (SE). The analysis of the volatile components extracted via different extraction methods resulted in the identification of 56, 34, and 32 volatile components in the SDE, SFE, and SE extracts, respectively. The total volatile component contents identified in the SDE, SFE, and SE extracts were $20.268{\pm}1.144$, $21.627{\pm}1.215$ and $2.476{\pm}0.177\;mg/kg$, respectively. The SFE extract evidenced higher contents of sweet flavors such as 2-methylbutanoic acid, 2-methylpropanoic acid, and hexanoic acid than the SDE and SE extracts. SFE proved to be the most appropriate method for the extraction of fresh volatile components from the strawberry.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.682-688
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• 2017

Fresh japanese anise (Illicium anisatum L.) tree leaves were collected and ground after drying. The essential oils of the leaves were analyzed by gas chromatography-mass spectrometry (GC-MS) using headspace (HS) and solid phase-microextra (SPME) methods. Volatile components of the leaves were identified 21 and 65 components in HS and SPME, respectively. The main components of the essential oils obtained by HS method were eucalyptol (36.7%), (+)-sabinene (15.61%), ${\delta}$-3-carene (6.87%), ${\alpha}$-pinene (6.07%), ${\gamma}$-terpinen (5.72%), ${\alpha}$-limonene (5.26%), ${\beta}$-myrcene (4.13%), ${\alpha}$-terpinene (4.04%) and ${\beta}$-pinene (3.73%). The other components were less than 3.5%. SPME method also showed that eucalyptol (17.88%) was main. The other were 5-allyl-1-methoxy-2 (13.29%), caryophyllene (6.09%), (+)-sabinene (5.60%), ${\alpha}$-ocimene (4.89%) and ${\beta}$-myrcene (3.73%), and the rest were less amounts than 3.5%. This work indicated that many more volatile components were isolated, comparing to the previous literature data and that SPME method was much more effective than HS method in the analysis of the volatile components.