• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.33-46
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• 2024

As YouTube is rapidly growing as an information platform, we investigated practical impacts of YouTube knowledge content and creator characteristics on viewer satisfaction and purchase intention. In so doing, an empirical survey was conducted among the viewers of <Chekgrim>, one of representative book YouTube channels in Korea. A total of 641 valid samples were analyzed. This study aims to understand the impact of knowledge contents on YouTube, and creator characteristics on viewer satisfaction and purchase intention. Specifically, for the study, content characteristics were divided into three sub-factors: entertainment, information, and interactivity, and the creator characteristics were divided into two sub-factors: intimacy and professionalism. Viewing satisfaction and purchase intention were set as dependent variables. The results of various analyses confirm that creator characteristics have direct and indirect effects on viewers' purchase intentions, and in particular, intimacy has the greatest influence on purchase intentions. This is expected to be a meaningful empirical analysis for future influencer marketing strategies and effective communications between content creators and consumers.

• The Korean Journal of Ecology
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• v.15 no.4
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• pp.365-375
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• 1992

The environmental gradient analyses were applied for the distribution patterns of species populations in mt. moak provincial park in korea. The species populations were sequentially ordered along the environmental gradients such as soil moisture, soil ph, soil organic matter content and elevation and were grouped into seven ecological groups by the two-dimensional analyses of temperature-moisture gradient : zelkova serrata group on mesic-lower parts near the streames and well drained stony slopes, carpinus tschonoskii group on mesic-middle parts, quercus acutissima group on lower parts destroyed by human activities, quercus variabilis group on xeric-middle parts, quercus serrata group on xeric-upper middle parts, quercus mongolica group on xeric-upper parts and pinus densiflora group on xeric-rock ridge lines, hillocks and lower parts interfered by human. Four forest vegetation types, zelkova forest dominated by the c. tschonoskii group on mesic-middle parts, oak forest dominated by the groups of q. acutissima, q. variabilis, q. serrata and q. mongolica on xeric sites and pine forest dominated by the p. densiflora group on dry and poor sites, were separated in mosaic chart by the two-dimensional analysis.

• Journal of Information Technology Services
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• v.7 no.3
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• pp.175-198
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• 2008

The wide spread of the Internet has become a momentum to promote informatization, and thus individuals, organizations, and government bodies are competitively participating in this kind of new wave. Informatization enables us not only to circulate and utilize information without any limitation but also to maximize users' benefits and convenience. On the other hand, it brings about negative effects-security incidents such as cyber terror, Internet fraud and technology leakage, etc. Evaluation on security level should precede over all the others in order to minimize damage by security incidents since it diagnoses current status on security as it is and can be used as a guideline for appropriate security management. In this study, evaluation domains, items and indicators of information security to evaluate information security are theoretically developed on the basis of critically reviewing the major existing research. And then the coincidence level(content validity, ease and reliability of evaluation) of each evaluation indicators are empirically analyzed through performing the field study of 83 information security experts.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.314-314
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• 2009

The effects of mixtures of each of rice hull charcoal and wood charcoal with pyroligneous acid on the cultivation and antioxidant activities of rice were investigated. Results of the total phenolic compounds, DPPH radical electron-donating ability and xanthine oxidase stress activity analyses revealed that the environment-friendly materials increased the total antioxidant capacity in rice. In the case of palatability of rice, total amylose blue value and starch-I2color reaction analyses, data showed that environment-friendly materials generally decreased the amylose content of rice. Also, the environment-friendly materials improved the rice endosperm quality.

• Journal of Powder Materials
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• v.6 no.2
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• pp.171-177
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• 1999

Ti-45.2at.%Ni-5at.%Cu and Ti-40.2at.%Ni-10atat.%Cu alloy powders were fabricated by gas atomization process. The microstructures, Shape, hardness and phase transformation behaviors of the powders were investigated by means of optical microscopy, scanning electron microscopy, micro-hardness measurement, x-ray diffraction analyses and differential scanning calorimetry. The hardness of the Ti-Ni-XCu alloy powders decreased as Cu-content increased. The x-ray diffraction analyses were carried out for powders without heat treatment, and those that treated at 85$0^{\circ}C$ for an hour in a vaccum state($10^5$ torr) and then quenched into ice water. The intensity of B$19^t$ phase increased with heat treating. The monoclinic B$19^t$ martensite was formed in the Ti-Ni-XCu alloy powders during cooling.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1573-1574
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• 2009

Fullerene/polystyrene nanoparticles having the average size of 300 nm ~ 1 ${\mu}m$ were prepared by emulsion polymerization in aqueous medium. Poly(vinyl pyrrolidone) and potassium persulfate were used as a dispersant and an initiator, respectively. The contents of fullerene in the nanoparticle were controlled to be from 10 to 57 wt% by varying the feed ratio, which was confirmed by IR-spectroscopy, thermogravimetric analyses, and elemental analyses. Dynamic light scattering experiments revealed the particles have a broad size distribution. Further characterizations of the nanoparticles were performed by using SEM and TEM observation. The high content of fullerene in the particles will find applications in photovoltaic and organic semiconducting area.

• Elastomers and Composites
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• v.56 no.4
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• pp.254-263
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• 2021

In this study, chitosan obtained after varying extents of deacetylation (i.e., 10%, 30%, and 47%) was employed to introduce antibacterial properties to chitin. The deacetylation reaction completion, wherein the amino group content of chitin was reduced, was ascertained from the FT-IR and NMR analyses. The 47%-deacetylated chitosan exhibited superior antibacterial properties against Bacillus in a disk diffusion test. To further improve these properties, chitosan derivatives were grafted by acrylic acid and acrylamide. The varying concentrations of carboxyl groups, primary amines, and -CH₂-CH₂- with increasing acrylic acid and acrylamide contents were determined by FT-IR and NMR analyses. The enhanced antibacterial properties of the chitosan derivatives, owing to the increased acrylic acid and acrylamide contents, were revealed by the disk diffusion test. In particular, the derivatives with 1.3% acrylic acid and acrylamide showed the highest antibacterial activity, the bacterial reduction rate against Staphylococcus aureus and Escherichia coli being 99.9%, as observed through the ASTM E2149 standard test.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.227-236
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• 2019

Antioxidant activity in water and ethanol extracts of dried Lycium chinense fruit, as a result of the total phenolic and tannin content, was measured using a number of chemical and biochemical assays for radical scavenging and inhibition of lipid peroxidation, with the analysis being extended by applying a bootstrapping statistical method. Previous statistical analyses mostly provided linear correlation and regression analyses between antioxidant activity and increasing concentrations of phenolics and tannins in a concentration-dependent mode. The present study showed that multiple component or multivariate analysis by applying multiple regression analysis or regression planes proved more informative than linear regression analysis of the relationship between the concentration of individual components and antioxidant activity. In this paper, we represented the multivariate analysis of antioxidant activities of both phenolic and tannin contents combined in the water and ethanol extracts, which revealed the hidden observations that were not evident from linear statistical analysis.

• Earthquakes and Structures
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• v.22 no.2
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• pp.147-155
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• 2022

Regarding the importance of seismic pounding, the available standards and guidelines specify minimum separation distance between adjacent buildings. However, the rules in this field are generally based on some simple assumptions, and the level of confidence is uncertain. This is attributed to the fact that the relative response of adjacent structures is strongly dependent on the frequency content of the applied records and the Eigen frequencies of the adjacent structures as well. Therefore, this research aims at investigating the separation distance of the buildings through a probabilistic-based algorithm. In order to empower the algorithm, the record-to-record uncertainties, are considered by probabilistic approaches; besides, a wide extent of material nonlinear behaviors can be introduced into the structural model by the implementation of the hysteresis Bouc-Wen model. The algorithm is then simplified by the application of the linearization concept and using the response acceleration spectrum. By implementing the proposed algorithm, the separation distance in a specific probability level can be evaluated without the essential need of performing time-consuming dynamic analyses. Accuracy of the proposed method is evaluated using nonlinear dynamic analyses of adjacent structures.

• Journal of Environmental Science International
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• v.31 no.3
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• pp.255-263
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• 2022

The relationship between environmental growth conditions of savory(Satureja hortensis) and Zn and vitamin B3 has been previously reported. Based on these results, HPLC and GC-MS were used to investigate the levels of phenolic compounds and perform metabolite analysis, respectively, in plants collected from different areas. Differences were observed in the levels of polyphenols and flavonoids depending on sampled areas and natural conditions. Next, HPLC and metabolite analyses confirmed the presence of bioactive substances. The results also showed that the longer the storage time, the higher was the content of carvacrol and of rosmarinic acid. Finally, the difference in the active ingredients was minimal when plants were cultivated under growth conditions similar to those in the place of origin.