• Composites Research
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• v.13 no.2
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• pp.30-39
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• 2000

It is difficult for civil engineer to apply composite materials of laminated type to structure for civil construction because of complicated theory although those have much merit. A simple method by which one can predict "exact" values of the natural frequency of vibration of laminated plates is presented. Many laminates with particular orientations have negligible values of $B_{16}$ and $B_{26}$ as the number of plies increases. Such laminates, with $D_{16}$ = $D_{26}$ ->0 can be solved by the same equation as for the special orthotropic laminates(1991,1995). If the quasi-isotrpic constants are used, It is possible to simplify analysis procedure since the equations for isotropic plates can be used. Use of some coefficients can produce "exact" values for laminates with such configuration. This coefficient, in fact, represents the effect of the anisotropy of the laminate. D. H. Kim proposed to use a correction factor, he developed, to produce "exact" solution out of the approximate solution obtained by using the quasi-isotropic constants(1995). In this paper, the fiber orienation studied is [$\alpha$/$\beta$/$\beta$/$\gamma$/$\alpha$/$\alpha$/$\beta$]r, with $\alpha$=-$\beta$, and $\gamma$${\gamma}$=$0^{\circ}$ or $90^{\circ}$ and the above-mentioned method is used to obtain the natural frequencies of plates with such orientations, and detailed result is presented for the use of engineers.nted for the use of engineers.

• Progress in Medical Physics
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• v.20 no.2
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• pp.62-71
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• 2009

Recently, optical coherence tomography (OCT) has demonstrated considerable promise for the noninvasive assessment of biological tissues. However, OCT images difficult to analyze due to speckle noise. In this paper, we tested various image processing techniques for speckle removal of human and rabbit cartilage OCT images. Also, we distinguished the images which get with methods of image segmentation for OCT images, and found the most suitable method for segmenting an image. And, we selected image segmentation suitable for OCT before image reconstruction. OCT was a weak point to system design and image processing. It was a limit owing to measure small a distance and depth size. So, good edge matching algorithms are important for image reconstruction. This paper presents such an algorithm, the chamfer matching algorithm. It is made of background for 3D image reconstruction. The purpose of this paper is to describe good image processing techniques for speckle removal, image segmentation, and the 3D reconstruction of cartilage OCT images.

• Journal of Korean Society of Steel Construction
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• v.25 no.3
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• pp.307-320
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• 2013

This paper proposes a new hybrid support structure by the driven piles which removes disadvantages of the existing type of support structure for offshore wind turbines. The hybrid type of support structure is combined with concrete cone and steel shaft, and is supported not only by gravity type foundations but also by driven piles. For three dimensional analysis of the huge and thick concrete structure, a solid-shell element that is capable of exact modeling and node interpolations of stresses is developed. By applying wave theory of stream function and solid-shell element in XSEA simulation software for fixed offshore wind turbines, a quasi-static analysis and natural frequency analysis of proposed support structure are performed with the environmental condition on Southwest Coast in Korea. In the result, lateral displacement is not exceed allowable displacement and a superiority of dynamic behavior of new hybrid support structure is validated by natural frequency analysis. Consequently, the hybrid support structure presented in this study has a structural stability enough to be applied on real-site condition in Korea. The optimized structures based on the preliminary design concept resulted in an efficient structure, which reasonably reduces fabrication costs.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.96-108
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• 2015

A passive containment cooling system has been designed to remove the heat inside a containment during accidents without external power supply. In this work, the PCCS was introduced in the APR1400 plant to replace the containment spray system and, then, the thermal-hydraulic performance of the PCCS was analyzed using the system thermal-hydraulic computer code, MARS. A double-ended cold-leg break accident, which is known to induce the maximum pressure in the containment, is simulated, where the thermal hydraulics of the PCCS, the reactor coolant system, and the containment are simultaneously simulated. The results of the calculations showed that the PCCS can replace the existing spray system and that the containment building and its internal structure also play a very important role for the heat removal during the accident. Some sensitivity calculations were carried out to evaluate the model uncertainty and the effects of design parameters. The limitations of the PCCS are also discussed.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.315-326
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• 2020

Corporate efforts to build strong brands have made consumers interested in brand love. In the field of brand love, however, there is a lack of systematic research on the multidimensionality of the concept of brand love and on the scale development to measure it. Thus, based on the methodological research design of Churchill(1979) and DeVellis(1991), this study explored properties of brand love and classified them into two levels - 'emotion' and 'relationship' - and generated corresponding measurement items. To do this, the research was conducted in a total of eight stages, including preliminary studies such as literature review, open surveys, and in-depth interviews, as well as the main study process in which the factors were analyzed step by step. As a result, the level of emotion appeared to have five subcomponents (self-esteem, warmth, interest, responsibility, pleasure) with 19 items, and the level of relationship - three subcomponents (unchanging, sharing/supporting, understanding) with 11 items, adding up to a total of 30 measurement items for brand love with reliability, convergent and discriminant validity, and nomological validity. Additionally, we intended to expand the scope of research related to brand love by presenting the result model of organic interaction between the concepts that constitute brand love and proposing '4 categories of brand love strength' based on it.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.83-89
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• 2003

2,4-Dichlorophenoxyacetic acid (2,4-D) as a widely used herbicide has caused serious environmental problems because of its difficult decomposition in nature. We isolated the strain capable of metabolizing 2,4-D as sole carbon and energy source by an enrichment culture technique from the 2,4-D contaminated soil collected at orchard in Gwangju, Korea. This strain was identified tentatively as Aeromonas sp. NOH2. With this strain, we established the response surface methodology (Box-Behnken Design) to optimize the principle parameters for maximizing biodegradation of 2,4-D such as culture pH, temperature, and nutrient concentration in liquid batch culture. The ranges of parameters were obtained from preliminary works done at our laboratory and chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 5, 20, and 35 g/1 nutrient concentration. Initial concentration of 2,4-D was 500 ppm and nutrient source was tryptic soy broth. The experimental data were significantly fitted to a second order polynomial equation using multiple regression. The most important parameter influencing 2,4-D degradation and biomass production was nutrient concentration. For 2,4-D degradation, the optimum values of pH and temperature, and nutrient concentration were obtained at pH (6.5), temperature (31.8 to $32.1^{\circ}C$), and nutrient concentration (29.6 to 30.1.0 g/1).

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.518-528
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• 2014

The purpose of this study is to observe the effects of road facilities that have adopted digital media such as total road facility called L.E.D media pole installed on U-street, Gangnam-gu on the pedestrians' satisfaction. Through the study, we would like to improve the brand competitiveness, increase the revisiting decision factors and suggest the fundamental development direction for the digital media road facilities on the typical pedestrian road, Gangnam street. The three factors from the studies came out to be spatial component, design component, and functional component. In order to analyze the factors, the pedestrians' behaviors were observed through a direct survey which provided 35 reserved factors. Also, the preliminary factors derived through survey questionnaires were revised by experts which compressed the result into 20 factors. The result of the regression analisis states that the 'Factor of the spatial component' is the statistically significant factor among the five elicited factors of the effect of the media pole on the pedestrian satisfaction. U-street's media pole provides the comfortable and various contents and application methods and will provide the new perspective on the purpose of pedestrians by new experience that is based on digital technology.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.87-94
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• 1991

An approximate analytical method to predict performance characteristics of the stirling engines in a preliminary design stage was investigated. In basic equations proposed by walker, typical temperatures of working fluids in expansion and compression spaces were treated the same as those of working fluids in heater and cooler respectively. While the temperature of working fluids in the expansion space was actually lower than that of working fluids in the heater, the temperature of working fluids in the compression space was higher than that of working fluids in the cooler. The aim of this study divided typical temperatures of working fluids in expansion and compression spaces into serval grades, and than evaluated the experimental engine. As the result, the case which working fluids temperature of expansion space was treated as lower than the heater temperature and which that of compression space was treated as higher than the cooler temperature, was much closer to the experimental value.

• The Journal of Industrial Distribution & Business
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• v.10 no.3
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• pp.45-58
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• 2019

Purpose - The purpose of this study was to investigate the effects of the chatbot's characteristics (ease of use, social presence, playfulness, usefulness) on service value, customer satisfaction and reuse intention when consumers purchased fashion products in the mobile shopping environments. Research design, data, and methodology - Data were collected from Korean consumers from ages 20 to 59 who have experienced using chatbot in a mobile shopping for fashion products. After a pilot survey to 53 customers, the preliminary questionnaire was revised for the final test, and the final questionnaire was administered to 1500 customers. Out of these, 300 were collected. After deleting 48 incomplete ones, 252 questionnaires were used in the statistical analysis. Frequency analysis and exploratory factor analysis using SPSS 23.0 and confirmatory factor analysis and structure equation analysis using AMOS 18.0 were employed for data analyses. Results - First, four factors were extracted for the chatbot's characteristics: ease of use, social presence, playfulness and usefulness. Second, regarding the effect of chatbot's characteristics on service value when purchasing fashion products in the mobile shopping environment, ease of use, playfulness and usefulness of chatbot significantly affected service value. Social presence did not have significant effects on service value. Third, in terms of the effect of the chatbot's characteristics on customer satisfaction when purchasing fashion products in the mobile shopping environment, social presence, playfulness and usefulness of chatbot significantly had an effect on customer satisfaction. Ease of use did not have a significant effect on customer satisfaction. Fourth, service value of chatbot when purchasing fashion products in mobile shopping environment was found to have an effect on customer satisfaction with chatbot. Fifth, service value of chatbot on reuse intention when purchasing fashion products in the mobile shopping environment was found to have an effect on reuse intention of chatbot. Sixth, customer satisfaction with chatbot had a significant impact on the reuse intention of the chatbot when purchasing fashion products in the mobile shopping environment. Conclusions - The present study provide dimensions on the chatbot's characteristics and these may provide helpful data for further studies in this area and for marketers as well.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.10-27
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• 2014

HAZUS-MH is a GIS-based computer program that estimates potential losses from multi-hazard phenomena: earthquakes, floods and hurricanes. With respect to seismic disaster, characteristics of a hypothetical or actual earthquake are entered into HAZUS. Then HAZUS estimates the intensity of ground shaking and calculates the correspondent losses. In this study, HAZUS was used as a part of the preparations of the future seismic events at a coastal plant facility area. To reliably characterize the target facility area, many geotechnical characteristics data were synthesized from the existing site investigation reports. And the buildings and facilities were sorted by analyzing their material and structural characteristics. In particular, the study area was divided into 17 blocks taking into account the situation of both land development and facility distribution. The ground conditions of blocks were categorized according to the site classification scheme for earthquake-resistant design. Moreover, seismic fragility curves of a main facilities were derived based on the numerical modeling and were incorporated into the database in HAZUS. The results estimated in the study area using HAZUS showed various seismic damage and loss potentials depending on site conditions and structural categories. This case study verified the usefulness of the HAZUS for estimating earthquake losses in coastal facility areas.