• Journal of Practical Engineering Education
• /
• v.12 no.1
• /
• pp.73-83
• /
• 2020

Recently, the importance of self-directed learning has emerged in the fields of public education, private education, lifelong education, and vocational training education, in which learners can actively cope with knowledge in an infusion-oriented way. However, there are various theoretical knowledge such as concepts and strategies for self-directed learning, but the situation is insufficient for a system where learners can easily receive content in the academic field they want, depending on the actual self-directed learning operation plan or learning area. Therefore, since it is important to provide various learning content in this paper, we utilize text mining techniques to obtain appropriate information and refine and categorize the meaning. On-line, they want to study a system that provides a variety of content in the academic field that learners are trying to acquire.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.05a
• /
• pp.120-129
• /
• 2002

New method and device for the on-line measurement of soot concentration in a diesel engine oil are proposed, where the measurement principle is based mainly on attenuated internal total reflection. Various laboratory tests of the detector were performed mainly with carbon black particles of different contamination levels. It was found that the proposed detector could be well used to monitor oil deterioration due to soot contamination. Operational range of the detector was found from 0 to 5 mass percentage of soot content. Test results with water and fuel dilution showed that these effects were not remarkable. However, adsorption of carbon black particles to a measurement surface was considered to be a critical problem in the new detector. Effects of particle deposition onto the interface was experimentally evaluated with the oil temperature and turbulence and discussed throughout this work.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.3
• /
• pp.61-69
• /
• 2003

This study investigated the effect of moisture content and loading direction on dowel bearing strength of two types of SCL. Dowel bearing tests of LVL and PSL were conducted with two different MC level, 7.5% and 19%, and two different oriention, L-direction(loading parallel to grain) and X-direction(loading perpendicular to grain). Most of specimens showed typical load-deformation curves and intersected 5% offset line. Failure modes were classified into two categories; spliting(for L-direction specimens) and peeling(for X-direction specimens). Dowel bearing strength generally decreased with increasing MC. The decreasing rate was more significant in X-directon. ESG also decreased with increasing MC, and the ratio of ESG of 7.5% versus 19% was about 1.47. Dowel bearing strength of LVL and PSL in L-direction was higher than that of X-direction. This results indicated that MC and loading orientation had a significant effect on dowel bearing strength of SCL. The average dowel bearing strength of LVL were higher than that of PSL in each loading direction. Two types of probability distribution model were chosen to quantify strength distribution, normal and 2-parameter weibull distribution. The two models showed good agreement with the data, especially in lower tail of the cumulative distribution. Normal and 2-parameter weibull distribution seemed to proper model of the dowel bearing strength for each MC levels.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.3
• /
• pp.9-16
• /
• 2003

In support of remote sensing applications for monitoring processes of the Earth system, research was conducted to analyze the basic spectral response related to background soil and vegetation cover characteristics in the visible and reflective infrared wavelengths. Surface samples of seven stations were examined. Five soils were from land-field and two soils from tideland areas. The vegetation cover experiment was conducted on seven soil samples with known natural moisture content (%) by weight. To study the effect of vegetation cover, spectral measurements were taken on five or six vegetation cover treatments of the seven soils with 3 replications in air dry conditions. For collecting RS base data, used spectro-radiometer that measures reflection characteristics between 300~1,100nm was used and measured the reflection of vegetation from bean leaves. The relationships were evaluated for both a general soil line and for the individual lines of five soils, under air-dried condition as well as different vegetation cover ratio, through the determination of the line parameters. As vegetation cover ratio in bean leaves increases, features of soil reflectance decrease and those of plant reflectance become more and more apparent. In proportion to vegetation cover rate, near-infrared reflectance increased and visible reflectance decreased. Analysis results are compared to commonly used vegetation indices(RVI and NDVI ).

• Natural Product Sciences
• /
• v.10 no.6
• /
• pp.296-301
• /
• 2004

Previously, a flavonoid fraction, which consisted mainly of protocatechuic acid, fustin, fisetin, sulfuretin, and butein, here named RCMF $({\underline{R}}VS\;{\underline{c}}hloroform-{\underline{m}}ethanol\;{\underline{f}}raction)$, was prepared from a crude acetone extract of Rhus verniciflua Stokes (RVS) which is traditionally used as a food additive and as an herbal medicine. In this study, we evaluated the effects of RCMF on the antioxidant defense system using embryonic normal hepatic cell line (BNL CL.2) and its SV40-mediated transformed cell line (BNL SV A.8). This study demonstrates that RCMF selectively stimulated the antioxidant defense system of normal cells, as BNL CL.2 cells proved to be more sensitive to RCMF-mediated increases of superoxide dismutase, catalase, glutathione, and glutathione reductase than BNL SV A.8 cells. In particular, RCMF caused a significant increase in the malonaldehyde content of BNL SV A.8 cells, which is believed to be closely associated with cytotoxicity of RCMF and RCMF-mediated growth inhibition. Collectively, our findings suggest that the flavonoid fraction, RCMF, selectively stimulates the antioxidant defense system in normal rather than hepatic tumor cells.

• KSBB Journal
• /
• v.24 no.2
• /
• pp.189-194
• /
• 2009

In this work, antioxidant substance homoorientin from Pseudosasa japonica and Phyllostachys bambusoides leaves wereextracted using ultrasonic system, and analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) on-line ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant screening method. Also, the various experimental variables were the frequency and time of ultrasonic system. From the results, homoorientin was high extracted at the experimental condition of low frequency 35 kHz and time 60 min. And the content of homoorientin in Phyllostachys bambusoides was remarkably higher than that in the Pseudosasa japonica extract.

• Journal of Fashion Business
• /
• v.25 no.4
• /
• pp.14-35
• /
• 2021

This study compares and analyzes the designs of Burberry creative directors, Christopher Bailey and Riccardo Tisci. For this purpose, 322 photographs (176 Christopher Bailey and 146 Riccardo Tisci) were collected and the data analysis criteria were classified into color, shape, material, decoration, item, and fashion style. With respect to the data analysis method, statistical analysis and content analysis were combined. First, the design characteristics of Christopher Bailey top and bottom combined bright tone, tone-in-tone color scheme, H-line, heterogeneous material combination, and smart casual appeared very frequently. Second, the design characteristics of Riccardo Tisci top and bottom combined were monotone, tone-on-tone color scheme, H-line, heterogeneous material combinations, and street culture. Third, the design differences between creative directors were significantly different in color, tone, color arrangement, pattern, material type, material combination, detail, top and bottom items, and fashion style. Burberry men's wear maintains Burberry's traditional design identity with achromatic colors, beige-based colors, and beige checks. Christopher Bailey's design direction is characterized by modernity in a casual mood that emphasizes practicality. The design direction of Riccardo Tisci is characterized by a wide gap between images in a semi-formal style that emphasizes Burberry's tradition and a free-spirited casual style.

• Corrosion Science and Technology
• /
• v.23 no.2
• /
• pp.83-92
• /
• 2024

A hot-dip simulator was utilized to replicate abnormal coating buildup observed during line stops at galvanize lines, assessing the influence of processing conditions on buildup (up to 14 mm/side). Steel samples from 19 coils (comprising IF, BH, LCAK, HSLA, DP600-DP1180, Si: 0.006 - 0.8 wt%, P: 0.009 - 0.045 wt%) were examined to explore the phenomenon of heavy coating growth. It was discovered that heavy coating buildup (~3 mm/h) and rapid strip dissolution (~0.17 mm/h) in a GA or GI pot can manifest with specific combinations of steel chemistry and processing conditions. The results reveal the formation of a unique coating microstructure, characterized by a blend of bulky Zeta crystals and free Zn pockets/networks due to the "Sandlin" growth mechanism. Key variables contributing to abnormal coating growth include steel Si content, anneal temperature, dew point in heating and soaking furnaces, Zn pot temperature, Zn bath Al%, and cold-rolling reduction%. At ArcelorMittal Dofasco galvanize lines, an automatic online warning system for operators and special scheduling for incoming Si-bearing steels have been implemented, effectively preventing further heavy buildup occurrences.

• Journal of Bio-Environment Control
• /
• v.20 no.3
• /
• pp.204-210
• /
• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.

• Corrosion Science and Technology
• /
• v.8 no.4
• /
• pp.143-147
• /
• 2009

In biomedical implants and dental fields, titanium has been widely utilized for excellent corrosion resistance and biocompatibility. However, Ti and its alloys are nonbioactive after being implanted in bone. In this study, for the purpose of improvement in biocompatibility the anodic $TiO_2$ layer on Ti-xNb alloys were fabricated by electrochemical method in phosphate solution, and the effect of Nb content on the pore size, the morphology and crystallinity of Ti oxide layer formed by the anodic oxidation method was investigated. The Ti containing Nb up to 3 wt%, 20 wt% and 40 wt% were melted by using a vacuum furnace. The sample were cut, polished, and homogenized for 24 hr at $1050^{\circ}C$ for surface roughness test and anodizing. Titanium anodic layer was formed on the specimen surface in an electrolytic solution of 1 M phosphoric acid at constant current densities ($30mA/cm^2$) by anodizing method. Microstructural morphology, crystallinity, composition, and surface roughness of oxide layer were observed by FE-SEM, XRD, EDS, and roughness tester, respectively. The structure of alloy was changed from $\alpha$-phase to $\beta$-phase with increase of Nb content. From XRD results, the structure of $TiO_2$ formed on the Ti-xNb surface was anatase, and no peaks of $Nb_2O_5$ or other Nb oxide were detected suggesting that Nb atoms are dispersed in $TiO_2$-based solid solution. Surface roughness test and SEM results, pore size formed on surface and surface roughness decreased as Nb content increased. From the line analysis results, intensity of Ti peak was high in the center of pore, whereas, intensity of O peak was high in the outside of pore center.