• Molecular & Cellular Toxicology
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• v.2 no.4
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• pp.244-250
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• 2006

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, to regulate and to evaluate the chemical hazard will be important to environment and human health. The genotoxicity of 3 synthetic chemicals was evaluated in L5178Y $tk^{+/-}$ mouse lymphoma cells in vitro. 9H-carbazole (CAS No. 86-74-8) did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 1, 3-Dichloro-2-propanol (CAS No. 96-23-1) revealed a significant increase of mutation frequencies in the range of $625-373\;{\mu}g/mL$ in the absence of metabolic activation system and $157-79\;{\mu}g/mL$ in the presence of metabolic activation system. And also, fenpropathrin (CAS No. 64257-84-7) appeared the positive results only in the absence of metabolic activation system. Through the results of MLA tk assay with 3 synthetic chemicals in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these 3 chemicals.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• autumn
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• pp.103-106
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• 2004

• Journal of Information Processing Systems
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• v.16 no.5
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• pp.1074-1082
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• 2020

Recently, research has been actively conducted to create artificial intelligence agents that learn games through reinforcement learning. There are several factors that determine performance when the agent learns a game, but using any of the activation functions is also an important factor. This paper compares and evaluates which activation function gets the best results if the agent learns the game through reinforcement learning in the 2D racing game environment. We built the agent using a reinforcement learning algorithm and a neural network. We evaluated the activation functions in the network by switching them together. We measured the reward, the output of the advantage function, and the output of the loss function while training and testing. As a result of performance evaluation, we found out the best activation function for the agent to learn the game. The difference between the best and the worst was 35.4%.

• KIEAE Journal
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• v.14 no.2
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• pp.61-68
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• 2014

This study aims at proposing a sound and sustainable development direction of an residential environment by analyzing testimonies of residents who lived in Park Hill flats or their surround at Sheffield City in the United Kingdom. The results are obtained through the analysis on a residential environment of Park Hill flats, opinions of the residents on its refurbishment, and effects of the building on the residential environment. The block of Park Hill flats was a community with a strong unity and solidarity, but that became increasingly a slum by the decline of the physical and social environment since the 1980s. In particular, it was identified that the deterioration of the social environment than that of the physical environment was a major cause of the decline. Nevertheless, it was found that "streets in the sky", the concept applied in Park Hill, played a key role in activating the community in the apartment complex. However, that street system in the complex has caused noise, poor security, and invasion of privacy. If such problems are solved, the streets in the sky will be a meaningful alternative for community activation and then ensuring sustainability in Korean residential environments that lost the function of the community.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1996.11a
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• pp.15-18
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• 1996

A general description of sprinkler activation time in compartment-fire-generated smoke layers is made. For calculation of the time hot layer temperature is obtained from two-layer zonal model and time constant of sprinkler is measured. Upper-layer thickness at the instant of sprinkler activation is also presented with changes of opening area. The outputs of the present study provide inputs for the interaction modeling of sprinkler spray and compartment fire environment, which simulates fire suppression phenomena.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.54-61
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• 1993

Principles and advantages of neutron actiation analysis which is one of widely using nuclear techniques are introduced. The importance of neutron activation analysis in occupational health study is discussed. The indusrial hygienic study of the samples like human hair, blood, urine, organs, tissues and airborne contamination of the working environment can be enhanced by the technique. Statistical treatments of the acquired data are also emphasized.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.3
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• pp.43-48
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• 1991

Activation energies of alcohol fuels have been determined through droplet combustion and extinction experiments using droplet suspension technique in a low pressure environment to minimize the effect of buoyance. Results show that the activation energies determined are 41.4 kcal/mol for ethanol, 47.6 for 1-propanol, 48.4 for 1-butanol, 40.0 for 2-butanol, 48.0 for 1- pentanol, 50.8 for 1-hexanol and 51.7 for 1-decanol.

• Journal of Power System Engineering
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• v.20 no.4
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• pp.38-43
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• 2016

Safety-related equipments of Nuclear Power Plants(NPP) have to perform environmental qualification test in accordance with IEEE-323 standards. However, non-metallic materials replace new one regularly instead of the test because they are considered as consumable parts. In this study, the seven kinds of non-metallic materials are selected and their activation energy was experimentally evaluated with uncertainty analysis by using thermogravimetric analyzer(TGA). In order to obtain activation energy of non-metallic materials, mass difference, temperature raising rate and conversion rate on the specimen are analyzed. It is postulated that the three experiment conditions are important to get a reliable activation energy. This postulate was experimentally confirmed using Arrhenius equation and Flynn-Wall-Ozawa analysis.

• KIEAE Journal
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• v.8 no.4
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• pp.29-36
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• 2008

The rapid industrialization since the 1960s has caused considerable changes in the appearance of Korean cities. The huge demand and cityward tendency derived from the increase of population with such the expansion from 9 millions in 1960 to 43 millions in 2003, have resulted in number of problems such as the falling-off in the quality of life, amenity, and safety. And above all, the urban identities is not to be found obviously in the cities. With regard to these problems, the re-creation of cities should be emphasized to make environmental, economical, and social improvements and to restore human-oriented activities. In the course of making new improvements cities need to preserve the characteristics and maintain the concordance with their environments. In other words, the restoration of cities ought to be made in the aspect of continuity, which means the accession of genetic factors inherent in cities. In this background, concerning about the system on apartment house especially relating to environmentally sound restoration and comparing with that of Japan, this study proposes the direction needed in the development of urban space.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.569-576
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• 2003

Although the Free Trade Zone(FTZ) are actually competing with various strategies, the definition and structural understanding of activation strategies are not known very much Therefore this study has launched from this fact, and has the objective of obtaining the structural model for activation strategies in Gunsan FTZ, and understanding the components of activation in these region The process began by abstracting the components that composed the success factors in FTZ through recent research, and grouping it by the most core components. Also, by using the FSM(Fuzzy Structural Modeling) method to understand the structure of the grouped components, and the structural model for activation of FTZ was able to obtain as the result. When analyzing the obtained structural model, expansion of tax reduction, flexibility of law systems and good business environment came out to be the most important component groups, and especially flexibility of law systems and good business environment were the most effective component that effected all the other components overall.