• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.359-367
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• 1999

For investigating the activities of algicidal bacteria, the variations of algicidal bacterial population and chlorophyll-a were checked weekly in Chindong Bay, Korea from May to July, 1998. For identifying their killing characteristics, three strains were selected from the isolated algicidal bacteria. The density of algicidal bacteria kept changing in the range of $6.0\times10^1$ to $6.4\times10^5$ cell $\ell^{-1}$. The density flux of algicidal bacteria coincided with that of chlorophyll-a by a week of lag time. Three algicidal bacteria isolated from field strains, H519S5-4, H605S5-15 and H605S5-22, were investigated in nine microalgal species, Heterosigma akashiwo, Chattonella sp. (Raphidlphyceae), Gymnodinium catenatum, Gyrodinium impudicum, Cochlodinium polyklikoides (Dinophyceae), Chaetoceros sp., Coscinodiscus granii, Ditylum brightwellii, Thalassiosira rotula (Bacillariophyceae). Strain H605S5-22 showed a wide algicidal activities over nine microlgae, strain H605S5-15 over H. akashiwo, G. catenatum, T. rotula, Chattonella sp. and strain H519S5-4 over H. akashiwo, Chattonella sp., Chaetoceros sp., G. catenatum. The activities of the three strains were detected by the secretion of algicidal substances. Therefore, it is suggested that the activities of algicidal bacteria have a significant influence over the population dynamics of phytoplankton and get involved with the sharp decrease in red tides in the coastal area.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.155-160
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• 1984

This study was conducted to find out the effects of soil physical properties on workability of farm machines in the paddy fields. Various soil physical properties, workability of cultivator and tractor were investigated at three different textured soils and three levels of soil moisture conditions. The results are summarized as follows: 1. Soil strength, shear and friction resistance, plate sinkage, wheel and footprint sinkage, and slippage were greatly affected by the soil texture and moisture conditions, and the workabilities were changed by the soil physical properties. 2. Cultivator workability were high values at the range of soil shear resistance $200-450g/cm^2$, and cultivator or tractor working was difficult at below $200g/cm^2$ of the shear resistance. 3. The favorable range of soil strength for tractor working was $8-12kg/cm^2$, and $6-10kg/cm^2$ for cultivator. 4. Footprint sinkage was closely related to the values obtained by testers. It's optimum range for cultivator was 1-2cm, and tractor workability was increased by decreasing the footprint sinkage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.721-730
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• 2021

Maritime air pollutants around port cities have gained a great deal of attention due to their direct impacts on regional air quality. This study aims to determine the geographical properties of sea/land breezes in different areas to discover overall ranges of maritime emission dispersion. The HOTMAC-RAPTAD modeling program was used to simulate regional-scale air dispersion considering non-linear and unsteady states during the general summer period for the target areas of the Yellow Sea (Incheon Port and Pyeongtaek·Dangjin Ports), archipelago region (Mokpo Port), South and East Sea (Busan and Masan Ports) and East Sea with mountainous area (Donghae·Mukho Ports). The resulting dispersion lengths of vessel emissions into the onshore regions around the target ports shed light on portal air quality management, because vessel emissions from the Incheon, Mokpo, Busan, and Donghae·Mukho ports were transported 27-31km (Western Seoul), 21-24km (Southern Muan), 20-26km (Gimhae and Yangsan), and 22-25km (Taebeak Mountains), respectively. Therefore, the results of this study provide useful data for regional air quality management and marine air pollution mitigation to improve the sustainability of port cities.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.314-320
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• 2017

This study was carried out to investigate and evaluate total sugar and artificial sweetener contents in health functional foods. In this study, HPLC with evaporative light scattering detector (ELSD) and HPLC-UV were used to determine the contents of total sugar and artificial sweetener in health functional foods. Sixty-six chewable products and sixty red ginseng products were collected from markets in Seoul. The average content of 126 samples per daily intake portion was 1.96 g ranging from not-detected (N.D.) to 12.61 g. The mean total sugar content per serving of chewable product was 1.26 g and N.D. to 10.39 g. The average amount of total sugar per daily intake of ginseng and red ginseng was 2.70 g and N.D. to 12.61 g. The average amount of sugar per daily intake of chewable products was 2.10 g for children, 1.43 g for nutrients, and 0.35 g for functional raw material. For children's products, the content of sugar per serving was ranged from 1.03 g to 5.33 g, from N.D. to 10.39 g for nutrients and from N.D. to 2.61 g for functional raw materials. The average content of sugar per daily intake of ginseng and red ginseng product was 4.25 g in liquid product, 1.51 g in concentrate product and 1.49 g in powder product. The contents of sugar per the daily intake of the liquid product ranged from N.D. to 10.80 g, from 0.01 g to 12.61 g for the concentrated product, and from 0.06 g to 5.64 g for the powdered product. Analysis of artificial sweeteners showed that artificial sweeteners were detected in three cases. No artificial sweeteners were detected in ginseng and red ginseng products. Two of the chewable products and one of the functional raw materials were detected. The detected artificial sweeteners were aspartame, 3.09 g/kg in nutrients and 1.09 g/kg in functional raw material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.7-14
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• 2006

The antioxidative activity and the related parameters of hot water extracts obtained from 16 medicinal plants were tested. The extraction yield was the highest in Salvia miltiorrhiza Bunge $(36.49\%)$ pH range was $4.00\~5.92$ in all samples. Absorbance at 280 nm was examined to determine aromatic compounds content. The absorbance of $250{\mu}g/mL$ sample was the highest in Prunella vulgaris Linne var. lilacina Nakai (2.872) and below 0.5 in Cirsium maackii, Crataegus pinnatifida Bunge and Zizyphus jujuba Miller. Also, absorbance at 420 nm was high in order of Prunella vulgaris Linne vu. lilacina Nakai (1.312), Zea mays Linne (0.917) and Inula japonica Thunberg (0.725) Total phenolic compounds contents was the highest in Prunella vulgaris Linne var. lilacina Nakai $(5.07{\pm}0.05\;mg/100g)$ and flavonoids contents was 2-fold higher in Salvia miltiorrhiza Bunge $(4.82{\pm}1.16\;mg/100g)$ than the other samples. Electron donating abilities of Zizyphus jujuba Miller, Cornus officinalis Siebold et Zuccarini and Salvia miltiorrhiza Bunge were over $90\%$ at $1000{\mu}g/mL$. Reducing power had similar tendency to electron donating ability while reducing power was significantly lower in samples compared to BHT. Two samples (Prunella vulgaris Linne val. lilacina Nakai and Inula japonica Thunberg) were found to have more than $50\%$ nitrite scavenging effect at $500{\mu}g/mL$ while 8 kinds samples (Zizyphus jujuba Miller, Cornus officinalis Siebold 81 Zuccarini, Chrysanthemum indicum Linne, Prunella vulgaris Linne var. lilacina Nakai, Inula japonica Thunberg, Acanthopanax sessiliflorum Seeman, Salvia miltiorrhiza Bunge and Curcuma longa Linne) showed more than $50\%$ nitrite scavenging effect at $1000{\mu}g/mL$. Prunella vulgaris Linne var. lilacina Nakai showed significantly stronger nitrite scavenging effect than other samples, and its activity was $59.62{\pm}1.573\%$ and $80.58{\pm}0.300\%$ at concentrations of 250 and $1000{\mu}g/mL$, respectively.

• Journal of Life Science
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• v.17 no.12
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• pp.1675-1681
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• 2007

The seasoned porks loins manufactured using with seasoning sauce that were prepared with difference composites of medicinal plant extracts (T-0; medicinal plants extract not added, $T-1{\sim}3$ ; pork treated with mixture of 6 kinds medicinal plant, respectively). And the changes of lipids were investigated during storage at $4^{\circ}C$ for 15 days. Content of TBARS in raw pork was $0.15{\pm}0.03$ MA mg/kg at beginning storage stage, in seasoned pork group (T-1), TBARS content was $0.35{\pm}0.01$ MA mg/kg after storage for 15 days. But TBARS contents were ranged from 0.27 to 0.3MA mg/kg in seasoned pork groups (T-1, T-2 and T-3) and it significantly lower than T-0 group. Unsaturated fatty acid content tended to increase during storage, but decreased after storage 9 days. These tendency was equally appeared in the cholesterol content of $T-1{\sim}3$ groups. In conclusion, the addition of medicinal plant composites enhanced antioxidant activity of the seasoned pork.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.707-712
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• 2012

Very high cycle fatigue (VHCF) behavior of aerospace components has emerged much attention due to their long service life. In this study, a piezoelectric ultrasonic fatigue testing (UFT) system has been developed by Mbrosiatec Co., Ltd. to study the high cycle fatigue (HCF) strength of Ti-6Al-4V alloy. Hourglass-shaped specimens have been investigated in the range from $10^6$ to $10^9$ cycles at room temperature under completely reversed R = -1 loading conditions,. Scanning electron microscopy (SEM) analysis revealed that failures occurred in the entire range up to the gigacycle regime, and the fractures have beenfound to be initiated from the surface, unlike in steels. However, it was found from the SEM microgprahs that microcracks transformed into intergranular fractures. Thus, it can be concluded from according to the results that this test method can be applicable to commercialized automotive and railroad parts that require high cycle fatigue strength.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.325-329
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• 1984

This study was conducted to evaluate the performance of a miniaturized hydrometer of clay content determination in the field. The performance of the miniaturized hydrometer was compared to that of 152H hydrometer and pipette methods. Statistical analysis of the results showed the possibility of using the miniaturized hydrometer for clay content determination in the field.

• Polymer(Korea)
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• v.34 no.3
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• pp.226-236
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• 2010

UV irradiated acrylic pressure sensitive adhesives(PSAs) are prepared to be used for thermal pad in plasma display panel(PDP). The effect of the chemical structure of side-chain in comonomer and of crosslinking agent on wet-out property of acrylic PSAs in wide temperature range were investigated. The correlationship between viscoelastic behavior and adhesion properties, such as tack and peel strength, was also studied. The experimental results supported that wet-out and adhesion properties of acrylic PSAs were enhanced inversely proportional to side-chain length of comonomer in wide temperature range. The peel energy clearly increased in acrylic PSAs prepared by using di(ethylene glycol) dimethylacrylate (DEGDMA) for crosslinking agent. The results might be due to the difference in the glass transition temperature and viscoelastic behavior of acrylic PSAs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.259-273
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• 2016

After realizing through the three large-scale data leakage incidents that intentional or accidental insider jobs are more serious than external intrusions, financial companies in Korea have been taking measures to prevent data leakage from occuring again. But, the IT system architecture reflecting the domestic financial environment is highly complicated and thereby difficult to grasp. It is obvious that despite administrative, physical, and technical controls, insider threats are likely to cause personal data leakage. In this paper, we present a process that based on metadata defines and manages personally identifiable attribute data, and that through inter-table integration identifies personal information broadly and controls access. This process is to decrease the likelihood of violating compliance outlined by the financial supervisory authority, and to reinforce internal controls. We derive and verify a decision-making model that reflects the proposed process.