• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.567-573
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• 2005

This study aims to evaluate the antioxidative activities of cow-milk kefir and goat-milk kefir. Antioxidative mechanisms, including radical-scavenging effects, ferrous-ion chelating ability, reducing power and antioxidant activity, were investigated herein. Kefirs demonstrated significantly greater scavenging effects upon 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals, an inhibition effect upon linoleic-acid peroxidation, and more substantial reducing power, but reduced glutathione peroxidase (GSH-Px) activity than was the case for milks. There was no significant difference between milks and kefirs as regards ferrous-ion chelating ability and superoxide dismutase (SOD) activity. These findings have demonstrated that kefirs possess antioxidant activity, thereby suggesting that kefirs are potential candidates for the role of useful natural antioxidant supplements for the human diet.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.912-924
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• 2002

Disease susceptibility is linked to nutritional status for a wide range of human and animal diseases. Nutritional status can influence both resistance (ability to resist the pathogen) and resilience (ability to tolerate or ameliorate the effects of the pathogen). This review focuses on the nutritional modulation of gastro-intestinal nematode infection in domestic ruminants, primarily sheep. It highlights the duality of the adverse consequences of infection on host nutritional status and the adverse consequences of poor host nutritional status on resistance to infection. Central to both phenomena is the complex, gut-based immune response to gastrointestinal nematode infection. The potential for strategic nutritional supplementation to enhance host resistance and resilience is reviewed together with recent findings on responses to increased ME supply, and long term effects on host immunity of short term protein supplementation.

• Journal of Surface Science and Engineering
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• v.36 no.5
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• pp.398-405
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• 2003

The stainless steel wire requires good corrosion resistance and mechanical properties, such as drawing ability, combined with a high resistance to corrosion. For increasing drawing ability of stainless steel, Ni coating methods have been used in this study. However, there is no information on the electrochemical corrosion behavior of drawed wires after Ni coating. To investigate corrosion resistance and mechanical property of drawed wire, the characteristics of Ni coated wires have been determined by tensile strength tester, hardness tester, field emission scanning microscope, energy dispersive x-ray analysis and potentiodynamic method in 0.1 M HCl. The drawed stainless steel wires showed the strain-induced martensitic structure, whereas non-drawed stainless steel wire showed annealing twin in the matrix of austenitic structure. The hardness and tensile strength of drawed stainless steel wire were higer than that of non-drawed stainless steel wire. Electrochemical measurements showed that, in the case of drawed stainless steel o ire after Ni coating, the corrosion resistance and pitting potential increased compared with non-coated and drawed stainless steel wire due to decrease in the surface roughness.

• Mycobiology
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• v.31 no.4
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• pp.209-213
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• 2003

Aspergillus flavus K-03 isolated from poultry forming soil in Korea was studied for its ability to produce extracellular proteases on basal medium containing 2%(w/v) chicken feathers. The fungus was observed to be a potent producer of such enzymes. Keratinolytic enzyme secretion was the best at 15 days of incubation period at pH 9 and temperature $40^{\circ}C$. No relationship existed between the enzyme yield and increase of biomass. Enzyme production was suppressed by exogenous sugars in descending order arabinose>maltose>mannose>fructose. But glucose did not influence the enzyme activity. The keratinolytic enzyme released by the fungus demonstrated the ability to decompose keratin substrates as chicken feather when exogenous glucose was present. The keratinolytic activity was inhibited by $HgCl_2$ and serine-protease inhibitors such as phenymethylsulfonyl fluoride(100%), chymostain(88%), crystalline soybean trypsin inhibtor(80%), antipain(45%) and aprotinin(40%), and was not by cystein-protease and aspartyl-protease inhibitors. The enzyme activity is only partially inhibited by metallo-protease inhibitor. Thus, the enzyme secreted by A. flavus K-03 belongs to the alkaline serine-type protease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.333-337
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• 1998

This study was carried out to get infomation on the nitric oxide production ability and its formation mechanisms of polysaccharides extracted from Ganoderma lucidum(PSG) by using murine macrophage cell line. The cultured mycelial cells of Ganoderma lucidum were extracted by alkali, and than neutralized by acid. The extract were passed through the column of DEAE cellulose for more purification. The neutral fraction was concentrated and precipitated with 95% ethanol. The precipitate was lyophilized and PSG was obtained. The immunomodulating effects of PSG on macrophage were performed by using murine macrophage cell line ATCC TIB 71 cells with PSG 0.5mg. PSG alone could not induce the production of nitrite, but it had a significant potential effect on nitrite secretion when the cells were primed and triggered with BCG and Interferon(IFN)-${\gamma}$. Also it was prominent by using calcium channel blocker(verapamil) and adenylate cyclase activator(forskolin).

• Food Science and Biotechnology
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• v.18 no.3
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• pp.655-660
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• 2009

Biotechnological phytase preparations are commercially available and are currently used in animal feeding. However, thermostability constraints, low yields, and the high cost of the enzyme have limited its use. This study represents a new perspective for the food enzyme market. The research screened thermostable yeast strains for their ability to produce phytase. The screening was carried out with a gradual increase in temperature ($30-48^{\circ}C$). Sixteen strains (1 strain identified as Saccharomyces cerevisiae) maintained the ability to produce phytase at $48^{\circ}C$ and their phytase activity was confirmed using 2 phytase assay methodologies. The yeast strains tested in this study seem to be potential efficient producers of phytase, indicating a possible new source of thermostable phytase of commercial interest, particularly that from S. cerevisiae.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.188-191
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• 2011

Path finding and path planning is crucial in today's world where time is an extremely valuable element. It is easy to plan the optimum path to a destination if provided a map but the same cannot be said for an unknown and unexplored environment. It will surely be exhaustive to search and explore for paths to reach the destination, not to mention planning for the optimum path. This is very much similar to finding for an exit of a maze. A very popular competition designed to tackle the maze solving ability of autonomous called Micromouse will be used as a guideline for us to design our maze. There are numerous ways one can think of to solve a maze such as Dijkstra's algorithm, flood fill algorithm, modified flood fill algorithm, partition-central algorithm [1], and potential maze solving algorithm [2]. We will analyze these algorithms from various aspects such as maze solving ability, computational complexity, and also feasibility to be implemented.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.2
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• pp.80-85
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• 2016

This study suggests a process design using cognitive processes. Job characteristic model for job design and recent cognitive engineering studies for process design are reviewed briefly. By using these concepts, the lean production system is re-interpreted in terms of cognitive engineering and the latent dimensions of the lean production system are revealed as the application of cognitive engineering principles. An integrated process design framework for cognitive manufacturing system using job characteristic model is suggested for the effective design of manufacturing system. Propositions for empirical analysis of this model are also analyzed through a questionnaire survey. Propositions are (1) experiential cognition and motivation potential affect the ability, role perception, and need for achievement of the operator in the manufacturing system, (2) the ability, role perception, and need for achievement of the operator affect the job performance. Both propositions are supported by correlation analysis and path analysis.

• Communications for Statistical Applications and Methods
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• v.27 no.4
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• pp.459-468
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• 2020

We examine the rate of substitution of jobs by artificial intelligence using a score called the "weighted ability rate of substitution (WARS)." WARS is a indicator that represents each job's potential for substitution by automation and digitalization. Since the conventional WARS is sensitive to the particular responses from the employees, we consider a robust version of the indicator. In this paper, we propose the individualized WARS, which is a modification of the conventional WARS, and compute robust averages and confidence intervals for inference. In addition, we use the clustering method to statistically classify jobs according to the proposed individualized WARS. The proposed method is applied to Korean job data, and proposed WARS are computed for five future years. Also, we observe that 747 jobs are well-clustered according to the substitution levels.

• Journal of Yeungnam Medical Science
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• v.26 no.1
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• pp.1-14
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• 2009

Human bone marrow-derived mesenchymal stem cells (MSCs) are a rare population of undifferentiated cells that have the capacity of self renewal and the ability to differentiate into mesodermal phenotypes, including osteocytes, chondrocytes, and adipocytes in vitro. Recently, MSCs have been shown to reside within the connective tissue of most organs, and their surface phenotype has been well analyzed. Many reports showed that transplanted MSCs enhanced regeneration as well as functional improvement of damaged organs and tissues. The wide differentiation plasticity of MSCs was expected to contribute to their demonstrated efficacy in a wide variety of experimental animal models and in human clinical trials. However, new findings suggest that the ability of MSCs to alter the tissue microenvironment via secretion of soluble factors may contribute more significantly than their capacity for differentiation in tissue repair. This review describes what is known about the cellular characteristics and differentiation potential of MSCs, which represent a promising stem cell population for further applications in regenerative medicine.