• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.4
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• pp.277-286
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• 2012

In the numerical simulation of wave fields using a multi-phase flow model that considers simultaneous flows of materials with different states such as gas, liquid and solid, there is need of an accurate representation of the interface separating the fluids. We adopted an algebraic interface capturing method called tangent of hyperbola for interface-capturing(THINC) method for the capture of the free-surface in computations of multi-phase flow simulations instead of geometrical-type methods such a volume of fluid(VOF) method. The THINC method uses a hyperbolic tangent functions to represent the surface, and compute the numerical flux for the fluid fraction functions. One of the remarkable advantages of THINC method is its easy applicability to incorporate various numerical codes based on Navier-Stokes solver because it does not require the extra geometric reconstruction needed in most of VOF-type methods. Several tests were carried out in order to investigate the advection of interfaces and to verify the applicability of the THINC method to wave fields based on the one-field model for immiscible two-phase flows (TWOPM). The numerical results revealed that the THINC method is able to track the interface between air and water separating the fluids although its algorithm is fairly simple.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.289-296
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• 2011

Swine industry in Korea plays an important role in providing the meat for domestic consumption, and the number of pigs in Korea was about 9.72 million heads as of June, 2010. Meat quality is used to describe any traits which impact the consumer acceptability of fresh meat products. Meat color, firmness, water holding capacity, ultimate muscle $pH_{24h}$ (measured 24 hours post-mortem), shear force, and intramuscular fat percentage (IMF) are generally accepted as important indicators of meat quality and ultimately, consumer acceptance of fresh pork. The objective of this study was to estimate genetic parameters for meat quality traits in Berkshire pigs. The heritability estimates for muscle $pH_{24h}$, lightness (CIE $L^*$), NPPC marbling were 0.61, 0.56 and 0.57, respectively, The heritability estimates for drip loss, cooking loss, shear force were 0.51, 0.66 and 0.56, respectively. The phenotypic correlations between $pH_{24h}$ and lightness (CIE $L^*$), drip loss, cooking loss were negative, ranging from -.45 ~ -.13. The genetic correlations between muscle $pH_{24h}$ and lightness (CIE $L^*$), drip loss were negative, ranging from -.35 ~ -.32. Genetic parameters obtained herein indicate that genetic improvement of muscle $pH_{24h}$ is not related to the NPPC marbling of meat, but rather to improved lightness(CIE $L^*$) and drip loss. Genetic trends of meat quality traits showed increased muscle $pH_{24h}$ and decreased cooking loss and drip loss.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.92-99
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• 2017

In Korea, the zero energy building was designated as the 7 new industries in the Ministry of Land and the 8 new industries in the Ministry of Industry. In order to maximize the insulation performance of the building envelope, improve the efficiency of building equipment, We are aiming. It is necessary to analyze the energy requirements of the buildings (cooling, heating, hot water supply, lighting, ventilation) of buildings with energy efficiency level of 1++ which is equivalent to the zero energy building certification system in Korea, It is aimed to be used as basic data for the advancement of energy building certification system. Zero Energy Building certification is estimated to be 61 buildings by 2017, and the approximate reference value and the first energy requirement for each of the five loads are calculated considering passive and active aspects. It is difficult to say that it is a clear standard because there is a small sample of data for calculating the load standard. However, it is necessary to interpret various methods in order to upgrade the Zero Energy Building certification standard in the future.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.299-303
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• 2016

Salmonella spp. and Brucella spp. can cause considerable diseases on both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a disinfectant spray, composed to grapefruit seed extract, citric acid, malic acid and benzalkonium chloride, was evaluated against S. Typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant spray against S. Typhimurium and B. ovis was 5 and 4 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant spray was 2 and 1 fold dilutions against S. Typhimurium and B. ovis, respectively. As the disinfectant spray possesses bactericidal efficacy against foodborne pathogens such as S. Typhimurium and B. ovis, the disinfectant spray can be used to control the spread of bacterial diseases.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.380-385
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• 2014

Spherical atomizing reduction steel slag was prepared by atomizing technology using reduction steel slag (ladle furnace slag, LFS) generated from steel industry. In order to develop the mass-recycling technology of atomizing reduction steel slag, polymer concrete composite was prepared using spherical atomizing reduction steel slag instead of fine aggregate (river sand) and coarse aggregate (crushed aggregate), depending on the grain size. Different polymer concrete specimens were prepared with the various proportions of polymer binder and replacement ratios of atomizing reduction steel slag in order to investigate the characteristics of polymer concrete composite. Results showed that compressive strengths of polymer concrete specimens decreased with the increase of replacement ratios of atomizing reduction steel slag, but flexural strengths of the specimens showed a maximum strength at the 50% of replacement ratios of atomizing reduction steel slag. It was concluded that addition ratio of polymer binder, which affect greatly on the prime cost of production of polymer concrete, could be reduced by maximum 18.2 vol% because the workability of the polymer concrete was remarkably improved by using the atomizing reduction steel slag. However, further study is required because the mechanical strength of the specimen using atomizing reduction steel slag was greatly reduced in hot water resistance test.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.86-91
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• 1995

In order to expand the utility of alginic acid in the food industry, we have investigated to prepare low viscous alginic acid using a method for degradation of alginic acid with the enzyme system of Vibrio sp. AL-145. The enzyme showed maximum activity at pH 8.0 and $37^{\circ}C$, and was stable in the pH range 7.5 to 8.5 and at temperature up to $30^{\circ}C$, and 0.5M NaCl needed for the enzyme activity. The viscosity of alginic acid decreased with the reaction time courses regardless of alginic acid and enzyme concentration, and 90% of viscosity decreased with 60 min of reaction time, but the changes of reducing sugar not exhibited. The soluble concentration of partially degradated alginic acid(PDA) in water was about 10%(w/v), and adsorption capacity of $Ca^{2+}$ ion increased with increasing the concentration of PDA. The alcohol concentration on precipitation of PDA was higher than Na-alginic acid.

• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.113-132
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• 2014

With the global warming phenomenon, the deep sea water area that fishing vessels can enter and operate is ever widening. For example, the Arctic Ocean recently has overall competitive advantages due to having many deep-sea fish stocks. The North Pacific region is a strategic coastal district, the closest access point of Arctic Ocean. For Korean fishing vessels which now operate in North Pacific region, and want to entry the Arctic Ocean, the analysis of technical efficiency is needed for preparing the better industry's future. This paper aims to analyze the relative efficiency, and select the low effective deep-sea fishing vessels in the North Pacific, and to suggest their desirables strategies. As a research methodology, Data Envelopment Analysis (DEA) and Malmquist Index are applied to 16 fishing vessels for the periods(2009 to 2013). To draw out the efficiency of targeted deep-sea fishing vessels, gross tons, horsepowers, and operating days are used as input variables while total catch stands for an output variable. As a result, CCR efficiency, BCC efficiency and scalability efficiency are measured to be 0.8405, 0.9484 and 0.8858 respectively for 5 years (2009 to 2013). In conclusion, 38% of total tons, 36% of horsepowers and 29% of operating days each fishing vessel should be reduced to keep their competitive powers.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.22-28
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• 2008

This study was performed to aid promotion of fish paste containing Lycii fructus powder as a food. The tested concentrations of Lycii fructus powder were 0, 1, 3, 5, and 7%. All the fish paste samples had 37% water content. The L values of the samples decreased as the concentration of Lycii fructus powder increased(p<0.001), and the a- and b-value increased(p<0.001). All samples with 3 mm of thickness had good flexibility and did not break even after four times of folding. In texture meter tests, the cohesiveness increased, but gumminess and brittleness decreased according to increasing concentration of Lycii fructus' powder. In the sensory evaluation, scores for color, flavor, pleasant taste, hardness and adhesiveness increased with increasing powder concentration; however oily taste was decreased. The 3% Lycii fructus powder sample had the highest acceptance scores in terms of appearance, flavor, taste, texture and overall acceptability. The results suggest that Lycii fructus powder can be applied to fish paste for both quality and functionality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.325-330
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• 2000

Alginate obtained from brown algae had various physicochemical and rheological properties and could used as a dietary fiber, However, alginate has not been widely applied to the food industry, since it had high viscosity, high gelling effect conjugated with some mineral, and low solubility. To improve functionality of alginate, partially develymerized alginates, which was water-soluble dietary fiber were obtained by hydrolysis of alginate from the sea tangle, Laminaria japonicus, heated at $121^{\circ}C$. Effects of depolymerization of alginate on the changes of viscosity and average molecular weight, block composition ratio of mannuronate to guluronate (M/G ratio), chemical properties using $PT-IR, ^1H-NMR, and ^(13)C-NMR$ spectrum were investigated. The average molecular weight and viscosity of the alginate were rapidly decreased with the thermal decomposition, and estimated to be 1,307,415 dalton and 284,000 cps, before heating, 728,106 and 3,940.29 cps after 30 min heating, 102,635 and 22.22 cps after 2.5 hrs heating, 51,205 and 12.05 cps after 3 hrs, and 10,049 and 4.28 cps after 6.5 hrs, respectively. The M/G ratio was increased with the heating time, while MM-block did not show any changes and GG-block diminished. The results of $FT-IR, ^1H-NMR and ^(13)C-NMR$ spectrum suggested that changes of molecular structure did not occur by the thermal decomposition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.5
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• pp.287-296
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• 2020

The wave-impact load on offshore structures can be divided into green-water and wave-slamming impact loads. These wave impact loads are known to have strong nonlinear characteristics. Although the wave impact loads are dealt with in the current classification rules in the shipping industry, their strong nonlinear characteristics are not considered in detail. Therefore, to investigate these characteristics, wave-impact loads induced by a breaking wave on a circular cylinder were analyzed. A model test was carried out to measure the wave-impact loads due to breaking waves in a two-dimensional (2D) wave tank. To generate a breaking wave, the focusing wave method was applied. A series of 2D tank tests under a horizontal wave impact was carried out to investigate the structural responses of the cylindrical structure, which were obtained from the measured model test data. According to the results, we proposed a structural damage-estimation procedure of an offshore tubular member due to a wave impact load. Furthermore, a recommended wave-impact load is suggested that considers the minimum required thickness of each member. From the experimental results, we found that the required minimum thickness is dependent on the impact pressure located in a three-dimensional space on the surface of a tubular member.