• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.49-60
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• 2008

This study were predicted the corrosion threshold reached at steel reinforcement in latex modified concrete(LMC) which were applied the agricultural hydraulic concrete structures. Accelerated testing was accomplished to the evaluate the diffusion coefficient of LMC mix, and the time dependent constants of diffusion. Also, the average chloride diffusion coefficient was estimated. From the average chloride ion diffusion coefficient, the time which critical chloride contents at depth of reinforcement steel was estimated. Test results indicated that the corrosion threshold reached at reinforcement in LMC were effected on the mix proportion factor including cement contents, latex content, and water-cement ratio. Especially, the average chloride diffusion coefficient, the corrosion threshold reached at reinforcement in LMC were affected by the all mix proportion factor.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.281-286
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• 1997

Recent construction activities and maintenance of marine facilities have been accelerating to keep up with rapid economic growth in Korea. Marine concrete structures are exposed to salts an chloride from ocean environments. The corrosion of reinforcement steel caused by chloride-penetration into concrete may severely effect the durability of concrete structures. The objective of this research is to develop a durable concrete by investigating the corrosion resistance of various corrosion protection systems utilizing different water/cement ratio, silica fumes, corrosion inhibitors and etc. A tow-year verification test on various corrosion protection systems has been doing in the laboratory and at the seaside. Corrosion investigations on reinforcement steel are now under progress for more than 180 concrete specimen. Corrosion-related measurements include macrocell corrosion current, instant-off voltage between corroding and noncorroding reinforcement, chloride contents, the corroded surface areas on the reinforcement steel, and etc. A low level of corrosion is investigated on reinforcement steels in concrete specimen made with corrosion inhibitors or applied aqueous impregnating corrosion inhibitors into their surface, even though high chloride contents of concrete specimen.

• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.67-75
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• 2011

The effect of steel-fiber contents on the compressive behavior of ultra high performance cementitious composites (UHPCC) was studied to propose a compressive behavior model for UHPCC. The experiments considered fiber contents of 0~5 vol.% and the results indicated that compressive strength and corresponding strain as well as elastic modulus were improved as the fiber contents increased. Compared to the previous study results obtained from concrete with compressive strength of 100MPa or less, the reinforcement effect on strength showed similar tendency, while the effect on the strain and elastic modulus were much less. Strength, strain, and elastic modulus according to the fiber contents were presented as a linear function of fiber reinforcement index (RI). Fiber reinforcement in UHPCC had no influence on the shape of compressive behavioral curve. Considering its effect on compressive strength, strain, and elastic modulus, a compressive stress-strain relation for UHPCC was proposed.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.423-434
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• 2014

This study examined the relative effects of positive and negative reinforcement on customer service behaviors. In addition, we examined whether the intervention would lead to response generalization on non-target behaviors. Five employees at three different convenient stores participated and ABC/ACB within-subject design was adopted. For the three participants, followed by the baseline(A), the positive reinforcement was first introduced(B) and the negative reinforcement(C) was introduced for the next phase. For the remaining two participants, the negative reinforcement(C) was first introduced after baseline(A) and the positive reinforcement (B) was introduced. Results showed a greater improvement in target behaviors under the positive reinforcement condition than that of the negative reinforcement condition. In addition, both reinforcement condition cause response generalization on non-targeted service behaviors, however, the comparable effects was found between two reinforcement conditions. Post-interview indicated that participants experienced positive emotions under positive reinforcement condition and negative emotions under negative reinforcement condition. These results suggest that the he techniques using positive reinforcement can be more effective and efficient to improve the work performance.

• The Journal of the Korea Contents Association
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• v.16 no.9
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• pp.117-126
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• 2016

This study examined the relative effects of different feedback delivery method (face-to-face vs. e-mail) and reinforcement history on work performance. Participants were asked to work on a simulated mobile phone assembly task. They performed for 30 minutes per session and attended 4 sessions. The dependents variable was the percentage of correctly completed work tasks. Of 100 participants recruited, 50 had a reinforcement history and another 50 had no reinforcement history with the feedback provider in this study. The participants in each group were randomly assigned into two experimental conditions: face-to-face feedback and e-mail feedback. The results showed that for the participants who had reinforcement history, the two feedback delivery methods did not produce a significant difference in the percentage of correctly completed work tasks. However, for those who had no reinforcement history, the two feedback methods did produce a significant difference.

• Journal of Korean Home Economics Education Association
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• v.22 no.3
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• pp.95-116
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• 2010

The purpose of this study is to explore the role of Home Economics Education for low fertility Aged Society. Hence home economics educational contents for low fertility Aged Society was estsblished extracting the contents from both Revised 2007 Home Economics Curriculum and government. policy for low fertility Aged Society. Also home economics educational contents for low fertility Aged Society("Home Economics Class for both parents and Children") implemented in Healthy Family Support Center. The main results of the study are as follows. Firstly, Home Economics Education for low fertility Aged Society should be emphasized with the contents such as marriage of one's choice, family life reinforcement, healthy family culture and neighborhood living together. Secondly, the goal of home economics education is very similar to the action plans of Saeromaji Project 2010 which are 'social responsibility reinforcement for marriage, birth and child rearing', 'balancing family and work', 'family-friendly culture' and 'security for the aged with health and care'. It has also much in common with the project plans by Seoul Metropolitan Office of Education 'family-friendly culture and filial duty education reinforcement', 'school education reinforcement regarding Low Fertility-Aged Society' and 'values education reinforcement for gender equality society'. Thirdly, "Home Economics Class for both parents and Children" applied in Healthy Family Support Center in Jung-gu, Seoul. This ensures home economic education can play a leading role in the social education filed.

• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.351-352
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• 2014

• Journal of Korea Game Society
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• v.21 no.5
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• pp.17-28
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• 2021

Reinforcement learning, in which artificial intelligence develops itself to find the best solution to problems, is a technology that is highly valuable in many fields. In particular, the game field has the advantage of providing a virtual environment for problem-solving to reinforcement learning artificial intelligence, and reinforcement learning agents solve problems about their environment by identifying information about their situation and environment using observations. In this experiment, the instant dungeon environment of the RPG game was simplified and produced and various observation variables related to the field of view were set to the agent. As a result of the experiment, it was possible to figure out how much each set variable affects the learning speed, and these results can be referred to in the study of game RPG reinforcement learning.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.51-58
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• 2009

Reinforcement learning is a sub area of machine learning concerned with how an agent ought to take actions in an environment so as to maximize some notion of long-term reward. In the case of multi-agent, especially, which state space and action space gets very enormous in compared to single agent, so it needs to take most effective measure available select the action strategy for effective reinforcement learning. This paper proposes a multi-agent reinforcement learning model based on fuzzy inference system in order to improve learning collect speed and select an effective action in multi-agent. This paper verifies an effective action select strategy through evaluation tests based on Robocup Keepaway which is one of useful test-beds for multi-agent. Our proposed model can apply to evaluate efficiency of the various intelligent multi-agents and also can apply to strategy and tactics of robot soccer system.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.1-9
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• 2005

In this paper, we suggest multi colony interaction ant reinforcement learning model. This method is a hybrid of multi colony interaction by elite strategy and reinforcement teaming applying Temporal Difference(TD) learning to Ant-Q loaming. Proposed model is consisted of some independent AS colonies, and interaction achieves search according to elite strategy(Intensification, Diversification strategy) between the colonies. Intensification strategy enables to select of good path to use heuristic information of other agent colony. This makes to select the high frequency of the visit of a edge by agents through positive interaction of between the colonies. Diversification strategy makes to escape selection of the high frequency of the visit of a edge by agents achieve negative interaction by search information of other agent colony. Through this strategies, we could know that proposed reinforcement loaming method converges faster to optimal solution than original ACS and Ant-Q.