• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.212-216
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• 2005

Benzotriazole which is used as a corrosion inhibitor for the zinc coated steel was intercalated into Na-MMT. X-ray diffraction experiments on intercalant/silicate composite samples demonstrated that the intercalation of intercalant leads to an increase in the spacing between silicate layers. Water soluble poly(ethylene-co-acrylic acid) (PEA) nanocomposites, to use as a coating agent, were prepared with these modified MMT. We found that mono-layered silicates were dispersed in PEA matrix and those resultants were exfoliated nanocomposites. From the result of salt spray test, we found that this coating agent prepared with water soluble poly(ethylene-co-acrylic acid) (PEA) nanocomposite provided good corrosion protection. These results were caused by decreasing the rate of oxygen permeation from silicate layers dispersed homogeneously in PEA matrix and the effect of corrosion inhibitor from benzotriazole.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.318-325
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• 2010

In this study, the wrapper database description language and model is suggested to collect product reviews from Korean shopping malls with multi-layer structures and are built in a variety of web languages. Above all, the wrapper based web crawlers have the website structure information to bring the exact desired data. The previously suggested wrapper based web crawler can collect HTML documents and the hierarchical structure of the target documents were only 2-3 layers. However, the Korean shopping malls in the study consist of not only HTML documents but also of various web language (JavaScript, Flash, and AJAX), and have a 5-layer hierarchical structure. A web crawler should have information about the review pages in order to visit the pages without visiting any non-review pages. The proposed wrapper contains the location information of review pages. We also propose a language grammar used in describing the location information.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.347-353
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• 2022

In the restaurant industry, start-ups are active due to high demand from consumers and low entry barriers. However, the restaurant industry has a high closure rate, and in the case of franchises, there is a large deviation in sales within the same brand. Thus, research is needed to prevent the closure of food franchises. Therefore, this study examines the factors affecting franchise sales and uses machine learning techniques to predict the success and failure of franchises. Various factors that affect franchise sales are extracted by using Point of Sale (PoS) data of food franchise and public data in Gangnam-gu, Seoul. And for more valid variable selection, multicollinearity is removed by using Variance Inflation Factor (VIF). Finally, classification models are used to predict the success and failure of food franchise stores. Through this method, we propose success and failure prediction model for food franchise stores with the accuracy of 0.92.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.531-536
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• 2024

Control drones, which are recently classified as smart agricultural machines in the agricultural field, are striving to build smart control and automatic control systems by combining hardware and software in order to shorten working hours and increase the effectiveness of control in the aging era of rural areas. In this paper, the characteristics of the nozzle dedicated to the control drone were analyzed as a basic study for the establishment of management control and automatic control systems. In order to consider various variables such as the type of various drone models, controller, wind, flight speed, flight altitude, weather conditions, and UAV pesticide types, related studies are needed to be able to present the drug spraying criteria in consideration of the characteristics and versatility of the nozzle. Therefore, to enable the consideration of various variables, flow analysis (CFD) simulation was conducted based on the self-designed nozzle, and the theoretical and experimental values of the droplet distribution were compared and analyzed through water reduction experiments. In the future, we intend to calculate accurate scattering in consideration of various variables according to drone operation and use it in management control and automatic control systems.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.541-548
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• 2002

This study, consisting of two experiments, was conducted to determine the effects of feeding heat treated protein and mineral complex (HPM) on milk production and composition, and ruminal fermentation of Holstein dairy cows. In in vitro experiment, HPM levels were 0, 0.2, 1 and 2%, and Timothy hay, which was substrate, was milled as 1 mm size, and the effects of HPM on pH, ammonia and VFA were analyzed after incubation times of 0, 6, 12, 24 and 48 h, respectively. The pH and ammonia production were not significantly different between treatments during the incubation. In addition, generally, total VFA and individual VFA were not affected by HPM on 0, 6 and 24 h. While, total VFA and individual VFA were increased in 0.2% and 1% of HPM supplemented treatments, but decreased in 2% of HPM treatment compared with control on 12 h. On 48 h, total VFA and individual VFA were increased in HPM treatments compared to control (P<0.05). However, A/P ratio was not affected by HPM supplementation. Gas production was higher in HPM treatment compared to control on 24 h (P<0.05) and 48 h (P<0.05). In lactating experiment, fourteen lactating Holstein cows were used for 4 months in a cross over experimental design. There were two treatments; no added HPM as a control and 0.2% of HPM added as a test treatment. Daily milk yield (P<0.001), 4% FCM (P<0.001), milk protein (P<0.05) and SNF (solid not fat; P<0.05) were increased in HPM treatment compared to control. While, milk fat, MUN (milk urea nitrogen) and SCC (somatic cell count) were not significantly different between treatments.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.87-93
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• 2002

The tree of heaven naturalized plant grows in the various habitats of the city. The principal reason is that it is reproduced not only through sexual reproduction but through asexual reproduction. By the spreading of sucker and a bud appearance of the seed it forms a group easily inside the city habitat. The distribution of seed and spreading of the seedlings of the tree of heaven were investigated like the followings. As the result of the sexual reproduction by the seed and hangs in cluster farm, 350 individuals are germinated at the Namsan the best environment, and 50 individuals at Toegyewon Rotary These seeds are dispersed by the effect of wind and geographical factor. Because the northwest wind is blowing mainly from late autumn to early spring, it is dispersed in the south. In Toegyewon Rotary, a slant site, is dispersed mainly by down the site. Compared with width of crown, the seedling of a seed germination are distributed outside more than inside the crown and the seed is spreaded until the maximum 7.5 times of crown width at the investigated area. 1 year seedlings appeared as a group at the place of 2-4 times of the crown (in 20m from the crown, 75% distribution). Considering the distribution by the seed scattering of the tree of heaven, there is a possibility of sudden individual increase even in the deteriorated city environment. So this possibility shows that we need to consider the protection of the city soil, and the species variety decrease resulted from the successful competition to the other species.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.1
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• pp.70-81
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• 2015

Helicases are known to be a proteins that use the chemical energy of NTP binding and hydrolyze to separate the complementary strands of double-stranded nucleic acids to single-stranded nucleic acids. They participate in various cellular metabolism in many organisms. DEAD-box proteins are ATP-dependent RNA helicase that participate in all biochemical steps involving RNA. DEAD-box3 (DDX3) gene is belonging to the DEAD-box family and plays an important role in germ cell development in many organisms including not only vertebrate, but also invertebrate during asexual and sexual reproduction and participates in stem cell differentiation during regeneration. In this study, in order to identify and characterize DDX3 gene in the earthworm, Perionyx excavatus having a powerful regeneration capacity, total RNA was isolated from adult head containing clitellum. Full length of DDX3 gene from P. excavatus, Pe-DDX3, was identified by RT-PCR using the total RNA from head as a template. Pe-DDX3 encoded a putative protein of 607 amino acids and it also has the nine conserved motifs of DEAD-box family, which is characteristic of DEAD-box protein family. It was confirmed that Pe-DDX3 has the nine conserved motifs by the comparison of entire amino acids sequence of Pe-DDX3 with other species of different taxa. Phylogenetic analysis revealed that Pe-DDX3 belongs to a DDX3 (PL10) subgroup of DEAD-box protein family. And it displayed a high homology with PL10a, b from P. dumerilii.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.233-238
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• 2020

Although the interest in NBR has been increasing due to the recent developments of the aerospace sector, there are few reports on HNBR's aeronautical oil, particularly evaluations of the accelerated life of harsh factors. In this study, the tensile strength was adopted as a performance evaluation factor to evaluate the accelerated life of HNBR used in the aviation field. The accelerated stress factor affecting the performance-aging characteristics was defined as temperature. The acceleration stress factor was determined to be temperature, and the result of measuring the tensile strength change over time. The sample for the acceleration condition was taken out of the oven for a certain period and left at room temperature for 24 hours. The dumbbell type 3 specimens were manufactured according to the standard specified in KS M 6518 and were measured the tensile strength, a factor in accelerated life evaluations. The activation energy was 0.895, and the shape parameter was 1.152 using the Arrhenius model. The characteristic life obtained from the tensile strength of the HNBR specimen immersed in aviation oil at 20℃ was 272,256 hours; the average life was 258,965 hours, and the B10 life was 38,624 hours.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.276-284
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• 2020

The purpose of this study was to provide basic data on hand washing of physical therapists by examining their awareness and practice of hand washing according to proper clinical practice. A total of 536 questionnaires were collected from physical therapy students in Gwangju metropolitan city. The general characteristics of the subjects were calculated by frequency analysis, and the awareness and practice of hand washing with and without clinical practice were analyzed by independent t-tests. As a result of analyzing hand washing awareness according to the clinical practice, there was a significant difference in hand washing up to the wrist (p<0.05), and a significant difference in 6 stages of proper hand washing (p<0.01). As a result of analyzing hand washing practice according to clinical practice, there was a significant difference in hand washing before eating and starting clinical practice (p<0.05), a significant difference in washing hands after contacting clinical practice equipment and washing your fingers from your thumb down (p<0.01). As a result of analyzing the correlation between awareness and practice, most showed positive correlation. This means it is important to raise the awareness of proper washing hands. Therefore, it is believed that the training school should repeatedly conduct its own hand washing training within the school and in clinical practice to increase awareness and improve handwashing in clinical practice.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.317-323
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• 1988

This survey was conducted to know characterization of weed occurrence under protected culture conditions at Yousong in 1985. Chenopodium album, Polygonum hydropiper, Portulaca oleracea and Digitaria sanguinalis were dominated in outdoor, whereas Capsella bursa-pastoris, C. album, D. sanguinalis and P. oleracea were dominant in polyethylene house. More weeds emerged in mulching plots and dry weight of weeds was greater in non-mulching plots. Summer broadleaf weeds and summer grasses were abundant in outdoor, whereas non-mulching plots in polyethylene house was dominated by winter broadleaf weeds, and mulching plots in polyethylene house were dominated by winter grasses and winter broadleaf weeds in early stage and summer grasses and summer broadleaf weeds in late stage. Simpson index was high in polyethylene house and Shannon's diversity index, maximum diversity for the Shannon diversity index were lower than eveness using the Shannon diversity index and this trend was more remarkable in mulching and mulching in tunnel than in non-mulching under polyethylene house condition. Shannon diversity index, maximum diversity for the Shannon diversity index were high in mulching or tunnel, and Simpson index was high in non-mulching in outdoor condition. Interspecific competition was more severe than intraspecific competition in both conditions.