• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.663-669
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• 2004

A nuclear power plant is composed of a number of primary components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to maintain the integrity of these primary components, a complicated procedure is required including regular in-service inspection, failure assessment, fracture mechanics analysis, etc. Also, experts in different fields have to co-operate to resolve the integrity issues on the basis of inspection results. This integrity evaluation process usually takes long, and thus, is detrimental for the plant productivity. Therefore, an effective safety evaluation system is essential to manage the integrity issues on a nuclear power plant. In this paper, a web-based fatigue life evaluation system for primary components in nuclear power plant is proposed. This system provides engineering knowledge-based information and concurrent and collaborative working environment through internet, and thus, is expected to raise the efficiency of integrity evaluation procedures on primary components of a nuclear power plant.

• The Korean Journal of Food And Nutrition
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• v.35 no.3
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• pp.185-192
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• 2022

This study investigated the volatile flavor components of the essential oil from Chrysanthemum coronarium var. spatiosumBailey. The essential oil obtained from the aerial parts of the plant by the hydrodistillation extraction method was analyzed by gas chromatography and gas chromatography-mass spectrometry. One hundred and one (99.11%) volatile flavor components were identified in the essential oil from the Chrysanthemum coronarium var. spatiosum Bailey. The major compounds were hexanedioic acid, bis(2-ethylhexyl) ester (12.45%), 6.10.14-trimethyl-2-pentadecanone (7.94%), 1-(phenylethynyl)-1-cyclohexanol (6.34%), α-farnesene (5.55%), phytol (4.99%), and α-caryophyllene (4.39%). When the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey were classified by functional group, the content was high in the order of hydrocarbons, alcohols, esters, ketones, aldehydes, and phthalides. Sesquiterpene hydrocarbons were the most common hydrocarbons, mainly due to α-farnesene and α-caryophyllene. Among the alcohols, the content of aliphatic alcohols was significantly higher, mainly due to 1-(phenylethnyl)-1-cyclohexanol (6.34%) and phytol (4.99%). The analysis of the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey in this study will provide useful information to consumers when purchasing food and to industries using fragrance ingredients.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.279-284
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• 2003

A nuclear power plant is composed of a number of primary components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to maintain the integrity of these primary components, a complicated procedure is required including regular in-service inspection, failure assessment, fracture mechanics analysis, etc. Also, experts in different fields have to co-operate to resolve the integrity issues on the basis of inspection results. This integrity evaluation process usually takes long, and thus, is detrimental for the plant productivity. Therefore, an effective safety evaluation system is essential to manage the integrity issues on a nuclear power plant. In this paper, a web-based fatigue life evaluation system for primary components in nuclear power plant is proposed. This system provides engineering knowledge-based information and concurrent and collaborative working environment through internet, and thus, is expected to raise the efficiency of integrity evaluation procedures on primary components of a nuclear power plant.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.99-107
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• 2007

In general, the reliabilities of the fuzzy system are represented and analyzed by real numbers between zero and one, fuzzy numbers, intervals of confidence, interval-valued fuzzy sets, vague sets, etc. This paper addresses the method to analyze the reliability of the fuzzy system for the weighted components with the weights reflected on the importance of weighted components in an system. The reliabilities and the weights of the weighted components in a fuzzy numbers and considers the weights of the weighted components in a fuzzy system, therefore, its execution is faster and more flexible than the conventional methods.

• Korean Journal of Remote Sensing
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• v.21 no.3
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• pp.213-219
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• 2005

In the Korean seas, Sea Surface Temperature (SST) and Thermal ronts (TF) were analyzed temporally and spatially during 8 years from 1993 to 2000 using NOAA/AVHRR MCSST. In the application of EOF analysis for SST, the variance of the 1st mode was 97.6%. Temporal components showed annual variations, and spatial components showed that where it is closer to continents, the SST variations are higher. Temporal components of the 2nd mode presented higher values of 1993, 94 and 95 than those of other years. Although these phenomena were not remarkable, they could be considered ELNI . NO effects to the Korean seas as the time was when ELNI . NO occurred. The Sobel Edge Detection Method (SEDM) delineated four fronts: the Subpolar Front (SPF) separating the northern and southern parts of the East Sea; the Kuroshio Front (KF) in the East China Sea, the South Sea Coastal Front (SSCF) in the South Sea, and the Tidal Front (TDF) in the West Sea. TF generally occurred over steep bathymetry slopes, and spatial components of the 1st mode in SST were bounded within these frontal areas. EOF analysis of SST gradient values revealed the temporal and spatial variations of the TF. The SPF and SSCF were most intense in March and October; the KF was most significant in March and May.

• The Journal of Industrial Distribution & Business
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• v.14 no.12
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• pp.11-21
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• 2023

Purpose: This study aims to investigate the impact of mobile shopping app components on shopping flow and the continuous usage intention of the shopping apps in the rapidly growing mobile market facilitated by advancements in the mobile environment. Research Methodology: A survey was conducted, targeting users aged 20 and older with experience in using mobile shopping apps. The responses of 456 participants were analyzed through frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, and structural equation modeling. Results: The study found that within the components of mobile shopping apps, enjoyment significantly impacted both shopping flow and the continuous usage intention of shopping apps. The diversity of product assortment had a significant effect only on shopping flow. The usefulness and ease of use influenced on the intention to continue using shopping apps. Conclusions: Based on the findings, it is recommended that shopping app operators try to identify essential components for stimulating user interest and engagement when developing or modifying apps. Additionally, a diverse range of products enhances the shopping experience and drives spontaneous purchases. Furthermore, providing an easy interface and minimizing the effort required, this experience can enhance user perception of its value and sustain consumers' continuous usage intention of the shopping app.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.213-219
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• 2018

Mechanical components are to be produced with accurate dimensions in order to function properly in assemblies of a machine. Once designs of mechanical components are created, designers examine the designs by adopting many known experimental methods. A primary test method includes stress and strain evaluation of structural parts. In addition, fatigue test and vibration analysis are an important test method for mechanical components. Real experiments at a laboratory are established when products are manufactured. Since design changes should be done before producing the designs in factories, rapid modifications for new designs are required in production industries. FEM simulation is a proper choice for a design evaluation with speed at a detail stage in design process. This research focuses modeling and mechanical simulation of a mechanical component in order to ensure structural safety. In this paper, a universal joint, being used in driving axels of vehicles, is studied as a target component. A design model is created and tested in some ways by using commercial software of FEM. The designed component is being twisted to transmit heavy power and thus, torsional stress should be under strengths of the component's material. The next is fatigue analysis to convince fatigue cycles to be within the endurance limit of the material. Another test is a vibration analysis for rotational components. This research draws final conclusions from these test analyses and recommends whether the designed model is under safety condition in terms of mechanical structure.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.53-59
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• 2010

A fatigue damage caused by cyclic load is considered as one of the important failure mechanisms that threaten the integrity of structures and components in a nuclear power plant. In ASME code section III NB, the fatigue analysis procedure and standard S-N curves for the class 1 components are described and these criteria should be met at the design step of components. As the current ASME S-N curves are based on the very conservative assumptions such as a local stress concentration effect, immoderate transient frequencies and a constant Young's modulus, however, they can not precisely address the fatigue behavior of components. In order to find out the technical solution for these problems, a number of researches and discussion have been carried out continuously at home and abroad over the decades. In this study, detailed fatigue analyses for DVI nozzle with various mesh density of finite elements were performed to evaluate effect of stress concentration factors on the fatigue analysis procedure and the excessive conservatism of stress concentration factors are confirmed through the analysis results.

• Korean Journal of Remote Sensing
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• v.4 no.1
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• pp.49-60
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• 1988

Principal Component Analysis (PCA) was applied for regional geological mapping to a multivariate data set of the Landsat TM data in the heavily vegetated and topographically rugged Chungju area. The multivariate data set selection was made by statistical analysis based on the magnitude of regression of squares in multiple regression, and it includes R1/2/R3/4, R2/3, R5/7/R4/3, R1/2, R3/4. R4/3. AND R4/5. As a result of application of PCA, some of later principal components (in this study PC 3 and PC 5) are geologically more significant than earlier major components, PC 1 and PC 2 herein. The earlier two major components which comprise 96% of the total information of the data set, mainly represent reflectance of vegetation and topographic effects, while though the rest represent 3% of the total information which statistically indicates the information unstable, geological significance of PC3 and PC5 in the study implies that application of the technique in more favorable areas should lead to much better results.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.511-513
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• 2008

Since conventional analysis of LLC resonant converter has a limit to explain a practical operation of LLC Resonant Converter, LLC resonant converter designed by conventional analysis can not regulate output voltage in several conditions. To solve this problem, analysis and design of LLC resonant converter including parasitic components is proposed. Experimental results are shown to confirm the feasibility of the proposed method.