• Journal of Labour Economics
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• v.30 no.1
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• pp.85-108
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• 2007

This article analyzes the formative factors of the basic job skills(also the ability of computer using) and the economic effects of the basic job skills in Korea. This article uses the ALL(Adult Literacy and Life Skills) 2005 data in Korea. The factors which form the basic job skills are school years, father's education. Women are under men in the ability of computer using. The older a man grow, the more basic job skills he has, but the less ability of computer using he has. The employees in office worker or new service industry have more using computer ability than them in sales worker or manufacture industry. The wage effects of the basic job skills are insignificant, and the economic effects of basic job skills appear apparently in the entry into the good jobs. As the basic job skills can play a important role to enter into the good jobs, the policy agenda should make deal with the methods and programs through which the people without basic job skills must have the opportunities to get a lifelong learning for the basic job skills.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.185-190
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• 2017

Antioxidative ability of 50% ethanol extract from leaves of Leucaena leucocephala (Lam.) de Wit was investigated. The extraction yield, total polyphenols and total flavonoids of the ethanol extract were $18.3{\pm}0.40%$, $121.3{\pm}11.04{\mu}g$ gallic acid equivalents/mg and $105.2{\pm}2.77{\mu}g$ quercetin equivalents/mg, respectively. The ethanol extract possessed the antioxidative activities such as free radical, cation radical, and nitrite scavenging activities as well as reducing power and lipid peroxidation inhibitory activity. These antioxidative activities of the ethanol extract increased in proportion to the extract concentration. $EC_{50}$ values for free radical scavenging, cation radical scavenging nitrite scavenging, and reducing power were $133.51{\mu}g/mL$, $667.22{\mu}g/mL$, 2.58 mg/mL, and $250.00{\mu}g/mL$, respectively. Polyphenols and flavonoids are suggested to be the key contributors for the antioxidative ability of the ethanol extract from Leucaena leucocephala leaves.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.2
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• pp.315-335
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• 2010

The goal of this research was to study the effects of the Mathematical Problem Generating Program on problem solving ability and learning attitude. The experiment was carried out between two classes. One class was applied with the experimental program (treatment group), and the other continued with normal teaching and learning methods (comparative group). In this study, two 5th grade elementary classes participated in Seoul city. In this study, the students were tested their problem solving abilities by the IPSP test and learning attitude by the Korean Education Development Institute (KEDI) before and after use of the program. The collected results were t-tested to find any meaningful changes. The results showed the followings. First, use of the mathematical generating program showed meaningful progressive results in problem solving ability. Second, the students that used the program showed positive results in learning attitude. In conclusion, learning mathematics using the problem generating method helps students deeper understand and solve complex problems. In addition, problem solving abilities can be improved and the attitude towards mathematics can be changed while students are using an active and positive approach in problem solving processes.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1582-1585
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• 2004

The antioxidative ability on the basis of reduced glutathione sulphydryl level, the inhibition activities of linoleic acid peroxidation of cell free extract of Lactobacillus spp. and the effects of types of media and growth phase of the cells on the cellular GSH level have been determined. Correlation between reduced glutathione sulphydryl level and antioxidative ability of Lactobacillus spp. was analyzed: Lactobacillus casei HY 2782 contained 25.15 $\mu$mole/g of GSH, the cellular GSH level of L. casei HY 2782 reached maximum after 24 h of cultivation and tended to decrease on further cultivation up to 72 h. There was a significantly higher level of cellular GSH when grown in de Man Rogosa and Sharpe (MRS) broth than in tryptone phytone yeast extract (TPY) broth or bromcresol pruple dextrose (BCP) broth (p<0.05). The antioxidant activity of cell free extract of Lactobacillus spp. have been shown to be significantly different among strains in the inhibition of linoleic acid peroxidation by thiobarbituric acid (TBA) test (p<0.01). L. casei HY 2782 and L. acidophilus ATCC 4356 revealed a high degree of antioxidative effect in linoleic acid oxidation system. Spearmans' rank correlation coefficient between inhibitory activity on linoleic acid peroxidation and cellular GSH levels of Lactobacillus spp. was 0.65, which means a significant positive correlation.

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.3-12
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• 1995

In this research, we investigated the effect of three visual feedback conditions (direct viewing, one-monitor viewing, and tow-monitors viewing) on the task performance of human operator in teloperation task. The three different level of task difficulties under each concitions were performed by thirty-six subjects. The result of the experiments was analysed by the task difficulties, and the measurements of performance are the task completion time and the frequency of task errors. In a teleoperator, the participation of a human operator is always required, and the man-machine interface and the operator's abilities is an important issue. Recently, the different types of sensory feedback conditions(force, vision, sound, tactile, etc) for teleoperation is a very active research area in ergonomics. Among them, visual feedback conditon is an important sense that can provide the information of task environment. Therefore, the sufficient understandings and investigation for human ability under various visual feedback conditions is required to establish the efficient man-machine interface of teleoperation. The result showed that the visual feecback conditions and the level of task difficulties have a significant effect on the task performance. For three level of task difficulties, the task completion time was the shortest under the condition of direct viewing. The number of task errors under the conditions of direct viewing and two-monitors viewing were reduced by more than half compare to that of one-monitor viewing.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1204-1207
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• 2007

Structural analyses have shown that nucleotides at the positions 770 and 771 of Escherichia coli 16S rRNA are implicated in forming one of highly conserved intersubunit bridges of the ribosome, B2c. To examine a functional role of these residues, base substitutions were introduced at these positions and mutant ribosomes were analyzed for their protein synthesis ability using a specialized ribosome system. The results showed requirement of a pyrimidine at the position 770 for ribosome function regardless of the nucleotide identity at the position 771. Sucrose gradient profiles of ribosomes revealed that the loss of protein-synthesis ability of mutant ribosome bearing a base substitution from C to G at the position 770 stems from its inability to form 70S ribosomes. These findings indicate involvement of nucleotide at the position 770, not 771, in ribosomal subunit association and provide a useful rRNA mutation that can be used as a target to investigate the physical interaction between 16S and 23S rRNA.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.5
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• pp.404-413
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• 2011

It is important to assess and improve the warship survivability for the weapon threats which have a critical effect on warship. The survivability of the warship is defined as the capability of a warship to avoid or withstand a man-made hostile environment. The survivability of the warship consists of three categories (Susceptibility, Vulnerability and Recoverability). Firstly, the susceptibility is defined as the inability of a warship to avoid radars, guns, missiles and etc. Secondly, the vulnerability is defined as the inability of a warship to withstand the man-made hostile environment. Finally, the recoverability is defined as the ability of a warship to recover the damaged components and systems. Among them, this paper has described the vulnerability assessment for the hypothetical system which is composed of critical components. Also, the procedure which is suggested to calculate the vulnerable probability of the damaged warship is based on the Vulnerable Area Method.

• Journal of Mechanical Science and Technology
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• v.20 no.6
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• pp.864-873
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• 2006

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.27-30
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• 2007

Recently, use of light-weight panel is increasing in building. Styrofoam sandwich panel is inexpensive and it is excellent in insulation ability and constructability. But styrofoam of panel inside is low ignition point. Consequently, when panel is fired, it is occur in poisonous gas. On the other hand, light-weight foamed concrete is excellent in insulation ability, fire resistance due to inner pore. Properties of light-weight concrete is influenced by foaming agent type. Accordingly, this study investigate in insulation property of according to foaming agent type in order to using light-weight foamed concrete instead of styrofoam. As a results, Non-heating zone temperature of light-weight foamed concrete of using AP, FP are lower than light-weight foamed concrete of using AES. Light-weight foamed concrete of using AES, FP are satisfied with fire performance of two hours at foam ratio 50, 100. Light-weight foamed concrete of using AP is satisfied with fire performance of two hours at AP ratio 0.1, 0.15. Insulation property is better closed pore by made AP, FP than open pore by made AES.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.189-194
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• 2012

It is well-known fact that woodworking activity could contribute in enhancing creativity, scientific problem-solving ability, spatial perception ability and prosocial behavior of children. However, there is little chance that children experience woodworking at home or in kindergarten. This study was conducted to know how much children and adults have done woodworking in there daily life and how they perceived children's woodworking activity. Woodworking activities for children (N=207, 5 and 6 year old kids) with adults (N=271, only fathers) were carried out in 10 kindergartens of Cheongju. Actually, the survey result shows that very few children and adults experienced woodworking in their daily life. 62.8% of children and 34.3% of adults surveyed responded that they had never done woodworking. However, the greater part of children and adults evaluated the woodworking activity positively. Over 95% of children surveyed responded that their woodworking activity was fun and they want to play woodworking again. Over 73% of adults surveyed responded that children's woodworking activity was safe, and over 99% of adults surveyed responded that they can recommend children's woodworking activity to others. In conclusion, the development of safe tools and programs for children's woodworking activity helps its spread and activation.