• Communications of the Korean Mathematical Society
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• v.31 no.4
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• pp.869-878
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• 2016

This paper presents an ecient fractional shifted Legendre polynomial method to solve the fractional Volterra's model for population growth model. The fractional derivatives are described based on the Caputo sense by using Riemann-Liouville fractional integral operator. The theoretical analysis, such as convergence analysis and error bound for the proposed technique has been demonstrated. In applications, the reliability of the technique is demonstrated by the error function based on the accuracy of the approximate solution. The numerical applications have provided the eciency of the method with dierent coecients of the population growth model. Finally, the obtained results reveal that the proposed technique is very convenient and quite accurate to such considered problems.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.1
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• pp.35-42
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• 1984

In the present study, rotating bending fatigue tests have been carried out in three kinds of carbon steel specimens; an annealed low carbon steel, an annealed high carbon steel and quenched-tempered high carbon steel; with a small artificial surface defect that might exist in real structures. Fatigue crack lengths have been observed by a method of replication in order to investigate the growth characteristic of fatigue crack in the viewpoints of strength of materials and fracture mechanics. The main results obtained are as follows: 1) The effect of a small surface defect upon the reduction of fatigue limit is considerably large, and the rate of fatigue limit reduction grows in the following order; annealed low carbon steel(mild steel), annealed high carbon steel, quenched-tempered high carbon steel. 2) When the growth rate of surface crack length(2a) was investigated in the viewpoints of fracture mechanics based upon $ ${\Delta}K_{\varepsilon}$, the dependence of stress level and of surface defect size disappear, and there exists a linear relationships between d(2a)/dN and ${\Delta}K_{{\varepsilon}t},\;\Delta_{{\varepsilon}t}\sqrt{{\pi}a}$, on log. plot, i.e, $d(2a)/dN={C{\cdot}{\Delta}K_{\varepsilon}}^3_t$, where ${\Delta}_{{\varepsilon}t}\sqrt{{\pi}a}$ a is the cyclic total strain intensity factor range.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.439-443
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• 2018

The outstanding characteristics of high quality GaN single crystal substrates make it possible to apply the manufacture of high brightness light emitting diodes and power devices. However, it is very difficult to obtain high quality GaN substrate because the process conditions are hard to control. In order to effectively control the formation of GaN polycrystals during the bulk GaN single crystal growth by the HVPE (hydride vapor phase epitaxy) method, a quartz ring was introduced in the edge of substrate. A variety of evaluating method such as high resolution X-ray diffraction, Raman spectroscopy and photoluminescence was used in order to measure the effectiveness of the quartz ring. A secondary ion mass spectroscopy was also used for evaluating the variations of impurity concentration in the resulting GaN single crystal. Through the detailed investigations, we could confirm that the introduction of a quartz ring during the GaN single crystal growth process using HVPE is a very effective strategy to obtain a high quality GaN single crystal.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.459-466
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• 2007

The Korean Musk deer (Moschus Moschiferus) is endangered due to heavy hunting and Massive destructions of natural habitat. They are included in CITES appendix II. In addition they are designated as a precious natural product in 1968 and listed as endangered species by the Government and Cultural Heritage Administration. At present, the number of musk deer in Korea is smaller than minimum viable population. Without increment of the population size, natural restoration is impossible. It is necessary to develop the artificial growth and re-enforcement methods in order to conservation Korean musk deer. Furthermore, It is necessary to ensure that we have an adequate individual group for artificial growth and re-enforcement. To ensure that we have an adequate individual group, it is necessary to know ecology of musk deer. This study is conducted to confirm and investigate of habitat of musk deer in order to capture individual musk deer. we investigated, confirmed habitats, found traces and captured using trap and decoy. Captured musk deer is male and 5.5 kg, this have canine tooth of 1.5cm, is estimated 15 months old. After capture, we measured each parts of body and tested to research of parasite infection. Strongyloides papillous was founded in the feces. It is essential to get healthy individual and establish of artificial growth technique.

• KSBB Journal
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• v.17 no.3
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• pp.307-310
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• 2002

In order to obtain high density seed cells for biofiltration, we studied batch and fed-batch culture of P. putida. Studies were carried out to find optimum fermentation conditions such as pH, concentration of glucose and agitation speed. Specific growth rate of P. putida was dependent on agitation speed and a high rpm of 300 was necessary to carry out the efficient aerobic growth of P. putida. Specific growth rate was highest at pH 7. Feeding glucose and yeast extract continuously at the initial growth phase was the most effective way to get high cell density of P. putida.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.138-147
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• 1996

DWP401, a recombinant human epidermal growth factor, was subcutaneously administered to ICR mice at the dose levels of 0, 0.04, 0.2 and 1.0 mg/kg/day (15rats/sex/group) in order to evaluate the subchronic toxicity. General observations, examinations for food and water consumption, ophthalmoscopy and urinalysis were carried out during the study. For the complete gross and microscopic examinations, 10 mice/ sex/group were sacrificed at the ends of the dosing period, and the remaining animals were sacrificed with a 5 week recovery period. Examinations for hematology and blood biochemistry were also carried out at the time of recovery period. Based on the results, it was thought that the target tissue or organs were mesothelial cell, injection site, spleen, adrenal gland, ovary and transitional epithelial cell of urinary tract, and no observed toxic level of DWP401 was 0.04 mg/kg while definite toxic dose level might be 0.2 mg/kg.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.6
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• pp.49-53
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• 2004

This study was aimed to promote evergreen ferns native to Korea as a material for interior landscape by investigate effects of light quality on the growth of Cyrtomium falcatum and Rumohra aristata, in an indoor environment that artificial light was used, especially. Result of experiments are as follows; 1. Wavelengths were measured as control(=570~580nm), red(=600~610nm), yellow(=550~580nm), green(=500~510nm) and blue(=430~440nm) between different color film. The order of photon flux density was red>yellow>control>green>blue decreased. 2. Although there was no difference in the growth of Cyrtomium falcatum depending on light quality, in case of fronds with sori and new fronds, there were highest under red film. Fresh weight was no significant in all treatments, but dry weight was increased with green>control>yellow>blue>red in order. 3. In case of Rumohra aristata, there was no difference in its growth, however, number of total fronds was highest under green film. Although fresh weight was increased with yellow film, dry weight was highest under green film.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.87-92
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• 2016

With the population growth and industrialization, the characteristics of discharged waste water and sewage have become more diverse. The removal of phosphorus (P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was performed in order to estimate the field application of the Bacillus sp. 3434 BRRJ. Bacillus sp. 3434 BRRJ was cultured in the raw wastewater and synthetic medium at the 5 L reactor. The best optimum conditions for P removal by Bacillus sp. 3434BRRJ in the synthetic medium at the 5 L reactor were as follows: temperature, $30^{\circ}C$; P concentration, 20 mg/L; carbon sources, glucose + acetate (1:1); oxygen concentration, alternatively anaerobic and aerobic conditions. P removal efficiency under the optimum condition was 89.4%. In case of wastewater, P removal efficiency was 95.5% under controlled at $30^{\circ}C$. Through this study we confirmed that P removal by Bacillus sp. 3434BRRJ in case of wastewater was as effective as the synthetic medium. It is considered that Bacillus sp. 3434 BRRJ can be applied to the treatment of wastewater in order to biologically remove P from the wastewater on a large scale.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.181-187
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• 1997

Lactobacillus acidophilus NCFM, Lactobacillus casei YIT 9018, Bifidobacterium longum 8001, and Bifidobacterium longum 8025 at the level of 106 cfu/$m\ell$ were cultured with 104 cfu/$m\ell$ of Escherichia coli O157:H7 KSC 109 or Salmonella typhimurium ATCC14028, in order to verify the effects of lactic acid bacteria and bifidobacteria on the growth of the pathogens. In the mixed culture of lactic acid bacteria with E. coli O157:H7 KSC 109, Growth inhibition and atypical microcolonies of E. coli O157:H7 KSC 109 were observed. The pathogens inoculated grew for 5 hors (pH 5.3), by the time L. acidophilus NCFM reached the exponential growth phase, and then the surviving pathogens were decreased to 101 cfu/$m\ell$ after 35 hours. When L. caseiYIT 9018 was grown with the pathogens, they grew for 10 hours (pH 4.6), by the time L. casei YIT 9018 reached the end of exponential growth phase, and then the surviving pathogens were decreased drastically. Up to the stationary growth phase of lactic acid bacteria, L. acidophilus NCFM exhibited stronger inhibition against the pathogens than L. casei YIT 9018 did, which might be attributed to its faster growth. Likewise bifidobacteria inhibited the growth of the pathogens tested, bifidobaceria was weaker in the inhibitory activity than lactic acid bacteria. When Bifidobacterium longum 8001 was cultured with the pathogens, E. coli O157:H7 KSC 109 was gradually ingibited at the stationary growth phase of bifidobacteria, atypical microcolonies were formed on Levine EMB medium after 48 hours, and Salmonella grew up to 106 dfu/$m\ell$, then was drastically ingibited at the exponential growth phage of Bifidobacterium longum 8001. But when Bifidobacteriuam longum 8025 was cultured with the pathogens, the pathogens grew to the same level of Bifidobacteriuam longum 8025 was cultured with the pathogens, the pathogens grew to the same lever of Bifidobacteriuam longum 8025 after 10 hours, then the surviving pathogens were decreased drastically.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.131-137
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• 2016

This study was conducted to investigate the effects of temperature and shade, which are basic environmental conditions, on growth, yield, inorganic components, and general components of Codonopsis lanceolata, in order to obtain basic data for improving yield capacity. In natural light, in the 15, 20, and $25^{\circ}C$ groups, the plant heights ranged between 218.9 cm and 223.9 cm, and there was no significant difference between groups. However, the leaf size was larger in shade, and the leaf area was significantly larger in the 15 and $30^{\circ}C$ groups. In natural light, root length and diameter were shorter and thinner when the temperature was higher, and growth was highly suppressed at $30^{\circ}C$. With regards to macroelements, the contents of Na, Mg, and P increased as temperature increased, regardless of the plant part; however, no constant tendency was observed in K and Ca according to temperature. The contents of Mg and Ca (from highest to lowest) were in the order leaf>stem>root, whereas the contents of Na, P, and K were in the order stem>leaf>root. Contents of general components varied according to temperature, and were highest at $30^{\circ}C$. While the plant height was increased under the constant $25^{\circ}C$+DIF (Difference between day and night temperature) condition, growth was suppressed in the -DIF group, in which the night temperature was higher than the day temperature, which suggests that a change in night temperature is one of the factors that affects the growth of C. lanceolata. As in the growth of the above-ground parts, fresh weight of the root was high in the constant $25^{\circ}C$ group and +DIF group. Notably, it was more than 2.5 times the fresh weights in the constant $15^{\circ}C$ group, constant $20^{\circ}C$ group, and -15 DIF group.