• Strategy21
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• s.46
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• pp.159-204
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• 2020

This study is written to bring the proposal forward for the direction of south korean naval force. The political situation and the circumstance of the world, especially in the area of Pacific Ocean, are changing very rapidly. North Korea has been always the conventional existing intimidator for South Korea since the 6·25-War. Additionally, the strengthening movements of the national defense, which is easily noticed from China and Russia, is also an other part of intimidating countries against South Korea. Those three mentioned countries are continually developing the asymmetrical warfare systems, for example a strategic nuclear weapon. Since the Obama Administration, the Asia-Pacific Rebalancing-Strategy has been changed as an East Asian foreign policy. Nowadays, Trump Administration renamed the 'United States Pacific-Command' to 'United States Indo-Pacific Command'. The purpose of this is not only letting India to participate in american alliance, but also reducing an economic burden, which is often mentioned in USA. West Germany was located in the very similar geopolitical position during the Cold War just like South Korea these days. And that's why the strategy of West German Navy is worthy of notice for south korean naval force to decide its suitable strategy. Most of all, the two most important things to refer to this study are the plan to expand naval air force and the realistic political stand for us to take it. In conclusion, I laid an emphasis on maintenance of 'green-water-navy'. instead of selecting the strategy as a 'blue-water-navy'. The reason I would like to say, is that south korean navy is not available to hold the unnecessary war potential, just like Aircraft-Carrier. However, this is not meaning to let the expansion of naval force carelessly. We must search the best solution in order to maintain the firm peace within the situation. To fulfill this concept, it is mostly very important to maintain the stream of laying down a keel of destroyers, submarines and air-defense-missile, as well as the hight-tech software system, taking a survey of 4th industrial revolution. Research and development for the best solution of future aircraft by south korean navy is likewise necessary. Besides, we must also set the international diplomatic flexibly. As well as maintaining the relationship with US Forces, it is also very important to improve the relationship with other potential allied nation.

• Food Science and Preservation
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• v.22 no.6
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• pp.878-885
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• 2015

The purpose of this study was to evaluate the antioxidant activity of Metaplexis japonica by using hot-water and ethanol extracts of its leaf and stem. Yields of hot-water and ethanol extracts of M. japonica leaf were high at 6.89 and 6.23%, respectively. The polyphenol and flavonoid contents in ethanol extracts of M. japonica leaf (ALEE) were high (86.96 and 60.73 mg/g, respectively). The electron-donating ability of all M. japonica extracts increased with an increase in extract concentration, with the highest electron-donating ability of 36.20~68.19% shown by hot-water extracts of M. japonica leaf (ALWE). The superoxide dismutase (SOD)-like activities of ALWE and ALEE increased with an increase in extract concentration. The nitrite-scavenging ability of the extracts was the highest at pH 1.2 and that of ALWE was higher than that of ALEE. The reducing power of $62.5{\mu}g/mL$ ALEE was 0.09 and that of $1,000{\mu}g/mL$ was 0.44. The inhibitory effect of an ethanol extract of M. japonica stem (ASEE) on tyrosinase was 13.81% at a concentration of $62.5{\mu}g/mL$ and that of $1,000{\mu}g/mL$ ALEE was 57.04%.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.154-159
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• 2012

The efficacy of water soluble formulation of diclazuril (Coccimuel-S 0.5%) was tested against $Eimeria$ spp. infection broiler chickens. The experiment was performed both experimentally infection and in the field test. Coccimuel-S composed with diclazuril induced a marked inhibitory effect on the different stages of $Eimeria$ life cycle in experimentally infected broiler chickens treated with the drug. The tested dosage levels of Coccimuel-S (0.5 ml/L, equivalent to diclazuril 2.5 ppm) in drinking water showed the significant effect compared with the control group in controlling coccidial infection and reducing the total oocyst numbers, lesion and fecal scores ($p$ < 0.001). In addition, testing of Coccimuel-S (0.25 and 0.5 ml/L) in naturally infected poultry farms (1,200 broiler chickens), showed the significant anticoccidial effect compared to control ($p$ < 0.001). In conclusion, addition of Coccimuel-S at the dose of 0.25 and 0.5 ml/L in the drinking water, induced efficacious effect for the treatment of coccidiosis in naturally coccidia infected broiler chickens.

• Microbiology and Biotechnology Letters
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• v.35 no.2
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• pp.142-149
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• 2007

In this study, we investigated the biological activity of antioxidant and antibacterial activity of citrus by-product ferment. Hot water extracts and 80% methanol extracts from citrus byproduct of ferment were screened for antibacterial activity pathogenic bacteria by paper disc method. Among the various hot water extracts and 80% methanol extracts the Bacillus subtilis showed relatively strong antibacterial activities in the order. The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical and ${\cdot}OH$ radical scavenging potential were sequentially screened, in search for antioxidant activities of citrus by-product ferment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1229-1234
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• 2007

Antioxidant activities of extracts from anglerfish (Lophiiu Zitulon) were evaluated. Each part of fresh (skin, flesh, stomach, and liver) or dried (skin and flesh) anglerfish was extracted by four different solvents (methanol, ethanol, acetone, and distilled water). Antioxidant activities of the extracts were determined by radical scavenging activity (RSA) and reducing power (RP). Relatively higher RSA and RP were found in methanol and water extract of fresh anglerfish liver. Antigenotoxic effect of the extracts, which was measured by Comet assay, was shown in most of the extracts except methanol, acetone and distilled water extracts of fresh stomach sample. These results indicated that antioxidant and antigenotoxic properties of extracts from angler fish were variable depending on parts, solvent, and/or physicochemical state. The appropriate extraction process could provide some valuable bioactive materials from anglerfish.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.103-110
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• 2011

This study is to comparatively analyze the characteristics of pH decrease in recycled fine aggregates for embankment and landfill produced from waste concrete by using natural process and artificial process. The result was as follows In case of recycled fine aggregates left outdoor, it was found that pH level was decreased if the thickness of embankment becomes thinner, or the materials left outdoors owing to high concentration of $CO_2$ in atmosphere caused by respirations of people. When the air was permeated, pH level was decreased more effectively. It was analyzed that this phenomenon was caused by efficient supply of $CO_2$ in the recycled fine aggregates owing to high-pressure ventilators. In case of water spraying treatment, sprayed water facilitated hydration of unhydrated cement to dissolve calcium hydroxides which neutralized $CO_2$ in the atmosphere during desiccation process and decrease pH level by a considerable margin. In case of Immersed treatment, decrease of pH was not sufficient. When facilitating the supply of $CO_2$, pH level of the recycled fine aggregates was decreased by the largest margin. It was analyzed that this phenomenon was caused by efficient supply of $CO_2$. From the above results, it was analyzed that the most effective method of reducing pH level of the recycled fine aggregates from the aspects of pH reduction performance, economic efficiency and workability was repeated wet-dry cycles of spraying water to the aggregates in the proportion of 1:0.5 by weight and then treating by forcefully blowing $CO_2$ gas into the aggregates.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.74-79
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• 2014

The purpose of this study was to determine the efficacy of Aster koraiensis Nakai as a natural health food source. To accomplish this, the general and antioxidative contents of A. koraiensis were measured. Total contents of carbohydrates, crude protein, crude lipid, and ash were 72.15%, 13.49%, 5.09%, and 9.27%, respectively. Caloric content of A. koraiensis was 349.70 kcal, while total dietary fiber was 49.79%. Total proteins consisted of 18 different kinds of amino acids. Contents of essential and non-essential amino acids were 4.6 and 5.5 g/100 g, respectively. Regarding mineral contents, P was the most abundant mineral, followed by K, Ca, and Na. Therefore, A. koraiensis is an alkali material. Total phenol contents of the hot water and 80% ethanolic extracts of A. koraiensis were $87.7{\pm}5.01$ and $112.4{\pm}3.41$ mg GAE/g, respectively. Total flavonoid contents of the hot water and 80% ethanolic extracts were $86.6{\pm}3.71$ and $95.1{\pm}8.00$ mg RE/g, respectively. The DPPH radical-scavenging activity and reducing power of the 80% ethanolic extract of A. koraiensis were higher than those of the water extract. Therefore, the general nutrients and antioxidant bioactive materials in A. koraiensis are potential materials for health foods.

• Food Science and Preservation
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• v.24 no.6
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• pp.827-833
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• 2017

This study was investigated the effects of various commercial sanitizers on microbial characteristics in fresh-cut iceberg lettuce during storage. For screening sanitizer, lettuce was cut and dipped in chlorine water ($0.2ml{\cdot}L^{-1}$), solution of organic acids such as ascorbic acid, citric acid, acetic acid, mixture of ascorbic acid and acetic acid (1-6%), and solutions of commercial sanitizers such as Formula 4$^{TM}$ (1,3,4%), Fresh produce wash$^{TM}$ (1,3,4%), Cleancol$^{TM}$ (1%), Chitochol$^{TM}$ (1%) and Natural Ca$^{TM}$ (0.1%) for 3 min, respectively. Washing lettuce with selected sanitizers resulted in reduction of aerobic bacteria of more than 2 log CFU/g. Initial pH of lettuce was related with the pH of sanitizers. pH ranged from 4.7 to 6.1 in Formula 4 (4%, pH 1.7) and Natural Ca (0.1%, pH 12.0), respectively. Chlorine water showed consistent and significant inhibition effect in all of microorganisms except total coliform. Over 3% of Formula 4 and Fresh produce wash were found to have high bactericidal activity among sanitizers. The sanitizers of chlorine water, Fresh produce wash, Chitochol and Natural Ca were effective in reducing yeast and mould populations. As coliform and E. coli, Formula 4 (4%) showed the highest bactericidal activity. The bactericidal effect of commercial sanitizers during storage varied with the kinds and concentrations of tested sanitizers. Although inhibition effect was not showed during storage, these results suggest that commercial sanitizers could be an alternative to chlorine for washing fresh-cut produce.

• Journal of Life Science
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• v.24 no.6
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• pp.655-663
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• 2014

Woosul (Achyranthis radix), a widely used material in food and oriental medicinal industry, has different origins of plant species in Korea, Japan and China. In Korea, woosul is designated as the radix of Achyranthes japonica Nakai (AJN) and Achyranthes bidentata Blume (ABB) in the regulation of The Korean Pharmacopoeia. However, the comparative study of hot water (HW) extracts between AJN and ABB is still rudimentary. In this study, HW extracts and its subsequent organic solvent fractions of AJB and ABB were prepared, and their in-vitro antimicrobial, antioxidant and anti-diabetes activities were evaluated. The HW extract of ABB has higher sugars and polyphenol compounds, and higher lightness and lower yellowness compared than those of AJN. Analysis of biological activities showed that the ethylacetate (EA) fraction of AJN and n-hexane fraction of ABB have antibacterial activities, and the EA fractions of AJN and ABB has strong antioxidation activities determined by radical scavenging activity and reducing power. In anti-diabetes activity assay, the EA fractions of AJN and ABB showed ${\alpha}$-amylase inhibitory activities, while the butanol fractions of AJN and ABB showed ${\alpha}$-glucosidase inhibitory activities. Our results suggest that the HW extracts of AJB and ABB have different components and extraction yields, and their subsequent fractions have different biological activity. Therefore it was concluded that the EA fraction of AJN is appropriate to develop as natural medicine, and the HW extract of AJN is suitable to woosul-tea or woosul-sikhye production.

• KSBB Journal
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• v.23 no.6
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• pp.494-498
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• 2008

We investigated the bioethanol production using wood biomass hydrolysate which obtained from the supercritical water (SCW) treatment. SCW-treated hydrolysate was used C-source of culture medium in shaking flask culture for bioethanol production. When the concentrated SCW-treated hydrolysate (SCW3) was used, yeast cell growth was slower compared with those in other SCW-treated hydrolysate (SCW1, SCW2). In addition, the bioethanol productions were 0.51 to 0.56 (%,w/v) when SCW1, SCW2, and SCW3 were used. Therefore, we removed the toxic phenolic compound in SCW-treated hydrolysate by pretreatments of activated charcoal and calcium hydroxide. Activated charcoal reduced more efficiently the phenolic compounds in SCW3 by 94.6%. Finally, when we pretreated SCW3 by activated charcoal and this was used for bioethanol production, 0.96 (%,w/v) bioethanol was produced and the ethanol yield based on reducing sugar reached 0.5.