• Animal Bioscience
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• v.35 no.12
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• pp.1967-1976
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• 2022

Objective: The aim of this study was to characterize the fecal microbiota of broiler chickens reared in the presence of different shades of light-emitting diode (LED) lights, correlating this information with biochemical and molecular evidence that allowed drawing conclusions on the state of health of the animals. Methods: Overall, the metagenomic approach on fecal samples was associated with evaluations on enzymes involved in the cellular response to oxidative stress: glutathione peroxidase (GPX), superoxide dismutase and catalase; while the inflammatory aspect was studied through the dosage of a proinflammatory cytokine, the interleukin 6 (IL-6), and the evaluation of the matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9). Specifically, analysis was performed on distinct groups of chickens respectively raised in the presence of neutral (K = 3,300 to 3,700), cool (K = 5,500 to 6,000), and warm (K = 3,000 to 2,500) LED lightings, and a direct comparison was performed with animals reared with traditional neon lights. Results: The metagenomic analysis highlighted the presence of two most abundant bacterial phyla, the Firmicutes and the Bacteroidetes, with the latter characterized by a greater relative abundance (p<0.05) in the group of animals reared with Neutral LED light. The analysis on the enzymes involved in the antioxidant response showed an effect of the LED light, regardless of the applied shade, of reducing the expression of GPX (p<0.01), although this parameter is not correlated to an effective reduction in the tissue amount of the enzyme. Regarding the inflammatory state, no differences associated with IL-6 and MMP-9 were found; however, is noteworthy the significant reduction of MMP-2 activity in tissue samples obtained from animals subjected to illumination with neutral LED light. Conclusion: This evidence, combined with the metagenomic findings, supports a potential positive effect of neutral LED lighting on animal welfare, although these considerations must be reflected in more targeted biochemical evaluations.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.299-307
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• 2002

In this proposed study, a new emerging shape forming technique Direct Coagulation Casting(DCC) which enables to fabricate complex-shaped ceramic parts has been investigated using colloid surface chemistry. Various process variables affected by dispersant, coagulation agent and sintering additives, have been evaluated in order to achieve highly concentrated stabilized silicon nitride suspensions. A high solid loading of 51 vol% in the dispersed silicon nitride suspension was prepared with 1.0wt% Tetraethylammonium Hydroxide (TEAH), which obtained a stable silicon nitride suspension with sintering additives $(Al_2O_3\;and\;Y_2O_3)$ in alkaline regions. The addition of hydroxyaluminium diacetate into the suspension, which decomposed at elevated temperatures, led to coagulate of a silicon nitride suspension. In a basic medium, aluminum ions precipitated to aluminum hydroxide $(Al(OH)_3)$, leading to decreased $OH^-$ concentration and, thus, coagulated suspension.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.45-51
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• 2015

In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.121-129
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• 2022

This study explored effective teaching-learning activities under the hybrid teaching model combining flipped learning, direct instruction, cooperative learning and distance learning. Subjects were 99 college students enrolled in 2 teacher preparation courses. Students evaluated effectiveness of 22 teaching-learning activities according to Likert scale at the end of the semester. As a result, all 22 teaching learning activities were considered effective more or less. They facilitated motivation, comprehension, participation, thinking, and led to mastery of the task. ② Activities scored low were 'questioning and answering at the beginning of online class', 'open book test'. ③ Hybrid teaching model was favored over traditional instruction. Open ended responses were consistent with the ones in the questionnaire. This research supports the notion that key teaching models to be combined for successful flipped learning in college setting are direct instruction and cooperative learning. Furthermore, effective and ineffective teaching strategies for flipped learning were found.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.207-207
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• 2010

Both ZnO and GaN have excellent physical properties in optoelectronic devices such as blue light emitting diode (LED), blue laser diode (LD), and ultra-violet (UV) detector. The ZnO/GaN heterostructure, which has a potential to achieve the cost efficient LED technology, has been fabricated by using radio frequency (RF) sputtering, pyrolysis, metal organic chemical vapor deposition (MOCVD), direct current (DC) arc plasmatron, and pulsed laser deposition (PLD) methods. Among them, the PLD system has a benefit to control the composition ratio of the grown film from the mixture target. A 500-nm-thick ZnO film was grown by PLD technique on c-plane GaN/sapphire substrates. The post annealing process was executed at some varied temperature between from $300^{\circ}C$ to $900^{\circ}C$. The morphology and crystal structural properties obtained by using atomic force microscope (AFM) and x-ray diffraction (XRD) showed that the crystal quality of ZnO thin films can be improved as increasing the annealing temperature. We will discuss the post-treatment effect on film quality (uniformity and reliability) of ZnO/GaN heterostructures.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1036-1047
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• 2003

This study was carried out in the purpose of proposing internet marketing strategy which can make conversion rate higher through analysis of internet shopping behavior types. This study was executed in two stages; qualitative study, quantitative study. In the qualitative study, internet shopping behavior types were investigated through the In-depth interview and direct observation, and then in the quantitative study, differences of internet shopping behavior types according to consumer characteristics, product properties and shopping-mall types were examined. For qualitative study, 30 samples by focus sampling were inquired and for quantitative study, 334 data were collected through web survey. The results of this study are as follows: First, 7 Internet shopping behavior types of apparel were found through the qualitative study: cautious purchase by price comparison, searching purchase, special low price purchase, impulse purchase, prepurchase deliberation, information accumulation, recreation-oriented. Second, in relation to consumer characteristics, consumers that have many internet purchase experiences showed goal-directed behavior more and female did more special low price purchase behavior and impulse purchase behavior than male. Third, according to product properties, high price product led more cautious purchase by price comparison & prepurchase deliberation behavior and fashionable product led more information-searching behavior. In the case of low price and fashionable products, impulse purchase behaviors were showed more. Forth, according to Internet shopping mall types, category killer shopping mall visitors showed information search behavior, recreation-oriented behavior more.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1595-1600
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• 2011

We analyzed the noise effect from artificial light and sunlight on the signal performance in visible light communication systems based on Intensity Modulation/Direct Detection(IM/DD). System performance was experimentally demonstrated by transmitting 50ksysmbol/s QPSK signals at 2MHz sub-carrier. And received signals were analyzed using EVM and RF spectrum. Finally, the system performance was improved by utilizing a visor and we confirm that the outdoor visible light communication was possible using IM/DD method.

• Journal of Fashion Business
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• v.11 no.4
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• pp.135-151
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• 2007

This study is human body measurement of 200 adult males in their 20s by both direct and indirect methods in order to reveal the representative male upper body types. Composition factors of body types were classified while the combination of direct-indirect measurement values was chosen. The following are the findings: 1) The analysis of direct-indirect measurement statistics showed the following results: 173.80cm (height), 69.87kg (weight), 95.58cm (chest girth), $24.67^{\circ}$ (right shoulder angle), and $9.34^{\circ}$ (shoulder width angle). 2) The factor analysis of the body types by direct measurement produced 5 factors: 1 (front length of upper body), 2 (front length of upper body), 3 (back length of upper body), 4 (circumference of upper body), and 5 (shoulders length). These factors accounted for 90.08%. Also, the cluster analysis of factor scores led to 3 types: 1 (33%, short, comparatively wide shoulders and full in the hips), 2 (25.1%, well-developed upper body in tall, inversed triangle), 3 (41%, average height, short upper body). 3) The body-type factor analysis by indirect measurement resulted in 6 factors with the explanation of 83.24%: 1 (rear upper bady thickness), 2 (front upper body width), 3 (front chest thickness), 4 (left-right shoulder angle), 5 (front width of protrusion distance in chest and shoulders), and 6 (neck's front-rear side angle).In addition, the cluster analysis of factor scores brought about 4 types: 1 (15%, well-developed front chest, beardless waist), 2 (23.5%, flat chest, with shoulder, drooping shoulders, strait neck), 3 (39%, with shoulder, curved back), and 4 (22.5%, narrow and thin, curved waist). 4) Among the 118 subjects (75%), 58 subjects commonly appearing in indirect measurement values group and direct measurement values group were chosen the representative body type group according to asterisk indexes. They had the highest frequency in direct type 3 and indirect type 3, whose combination represented the physical characteristics of the representative body types.

• Structural Engineering and Mechanics
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• v.86 no.5
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• pp.607-619
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• 2023

This study, it was tried to evaluate the asphalt behavior under tensile loading conditions through indirect Brazilian and direct tensile tests, experimentally and numerically. This paper is important from two points of view. The first one, a new test method was developed for the determination of the direct tensile strength of asphalt and its difference was obtained from the indirect test method. The second one, the effects of particle size and loading rate have been cleared on the tensile fracture mechanism. The experimental direct tensile strength of the asphalt specimens was measured in the laboratory using the compression-to-tensile load converting (CTLC) device. Some special types of asphalt specimens were prepared in the form of slabs with a central hole. The CTLC device is then equipped with this specimen and placed in the universal testing machine. Then, the direct tensile strength of asphalt specimens with different sizes of ingredients can be measured at different loading rates in the laboratory. The particle flow code (PFC) was used to numerically simulate the direct tensile strength test of asphalt samples. This numerical modeling technique is based on the versatile discrete element method (DEM). Three different particle diameters were chosen and were tested under three different loading rates. The results show that when the loading rate was 0.016 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis till coalescence to the model boundary. When the loading rate was 0.032 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis. The branching occurs in these cracks. This shows that the crack propagation is under quasi-static conditions. When the loading rate was 0.064 mm/sec, mixed tensile and shear cracks were initiated below the loading walls and branching occurred in these cracks. This shows that the crack propagation is under dynamic conditions. The loading rate increases and the tensile strength increases. Because all defects mobilized under a low loading rate and this led to decreasing the tensile strength. The experimental results for the direct tensile strengths of asphalt specimens of different ingredients were in good accordance with their corresponding results approximated by DEM software.

• Analyses & Alternatives
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• v.1 no.1
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• pp.44-64
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• 2017

Russia's push in the Asia-Pacific region stems from its interests that have the national, regional and global dimensions. In their turn, the aims of this policy are civilizational, geopolitical, economic and prospective, with a long-term outlook. In the course of their achievement, cooperation with Northeast Asia's countries will play one of the key roles owing to the factors of geographic proximity, Northeast Asia's economic potential, risk hedging and a growing influence Northeast Asia exerts upon the global development. A new cooperation paradigm between Russia and the states of Northeast Asia should be based upon establishing and cementing self-reproducing ties. This is the central aim of Russian initiatives in relations, with Japan, the Republic of Korea, Democratic People's Republic of Korea, Mongolia and China. However, numerous obstacles ranging from Russia's absence in the regional free trade agreements and supply-production chains of value-added production to the permanent international instability generated by Pyongyang's missile-nuclear developments hamper the practical implementation of this task. Realizing the necessity to give an additional impetus to this new cooperative paradigm, Russia has to develop directions with an apparent consolidating effect. The most promising may be the establishment of a permanent security forum based upon Northeast Asia Peace and Security Mechanism chaired by the Russian Federation. The urgency of this measure and its expected support stem from the necessity to strengthen security in Northeast Asia, a task neither the US-led hub-and-spoke system nor ASE-AN-led multilateral dialogue venues have been able to resolve. The issues addressed at the security forum must include the unification of approaches to North Korean nuclear issue and producing a document specifying actions of the claimants on the disputed maritime territories in the "direct contact" situations. At the expert level, Russia has elaborated on the idea to establish such a forum outlining the spectrum of the key directions of cooperation. With the urgency in the establishment of this dialogue venue, its agenda has to be coordinated with the agendas of the existing security systems presented by the US alliances and the ASE-AN-led multilateral negotiations. The practical implementation of this initiative will strengthen security in Northeast Asia as its challenges will be resolved in the pre-emptive way based on coordinated approaches. Therefore, Russia as the Eurasian state will be one of the role players in the advent of the Asian century.