• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.174-180
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• 2017

Recently, the world faces the environmental problem such as air pollution due to harmful gas discharged from car and abnormal climate due to the green-house gases increased by the discharge of $CO_2$. Compressed Natural Gas (CNG), one of alternative for this problem, is less harmful, compared to the existing fossil fuel, as gaseous fuel, and less carbon in fuel ingredients and carbon dioxide generation rate relatively favorable more than the existing fuel. However, CNG fuel has the weakness of slow flame propagation speed and difficult fast burn. On the other hand, hydrogen does not include carbon in fuel ingredients, and does not discharge harmful gas such as CO and HC. Moreover, it has strength of quick burning velocity and ignition is possible with small ignition energy source and it's has wide Lean Flammability Limit. If using this hydrogen with CNG fuel, the characteristics of output and discharge gas is improved by the mixer's burning velocity improved, and, at the same time, is possible to have stable lean combustion with the reduction of $CO_2$ expected. Therefore, this research tries to identify the characteristics of engine and emission gas when mixing CNG fuel and hydrogen in each portion and burning them in spark igniting engine, and grasp the lean combustion limit and emission gas characteristics according and use it as the basic data of hydrogen-CNG premixed engine.

• Journal of Institute of Convergence Technology
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• v.5 no.1
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• pp.13-17
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• 2015

In wafer level molding progress, the thermal releasing failure phenomenon is shown up as the important problem. This phenomenon can cause the problem including the warpage, crack of the molded wafer. The thermal releasing failure is due to the insufficiency of adhesion strength degradation of the molding tape. To solve this problem, we studied experimental method increasing the release property of the molding tape through the plasma surface treatment on the wafer substrate. In this research, the vacuum plasma treatment system is used for release property improvement of the molding tape and controls the operating condition of the hydrophilic($O_2$, 100kW, 10min) and hydrophobic($C_2F_6$, 200kW, 10min). In order to perform the peeling test for measuring the releasing force precisely, we remodel the micro scale material property evaluation system developed by Korea institute of industrial technology. In case of hydrophilic surface treatment on the wafer substrate, we can figure out the releasing property of molding tape increase. In order to grasp the effect that it reaches to the release property increase when repeating the hydrophilic treatment, we make an experiment with twice treatment and get the result to increase about 12%. We find out the hydrophilic surface treatment method using plasma can improve releasing property of molding tape in the wafer level molding process.

• Korean Journal of Cognitive Science
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• v.1 no.2
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• pp.175-192
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• 1989

The main problems of artificial intelligence (AI)which are vividly being discussed today are not only scientific but also involve serious philosophical dimension.The purpose of this paper is to analyze the computer scientist's definitions of AI and by this method uncober and examine the controversial arguments and problems.The result is to clarify the meaning of AI-research program. It can be said that we can clssify the definitions of AI in various types according to the interest and purpose of AI-reasearchers or the strength of their arguments.But this leaves much to be considered.We have also to consider and analyze the following related problems: Understanding how we grasp human intelligence,what relations there are between intelligence and the brain,and what the logical structure of simulating and copying is with the computer. In this respect,the key problem in AI-research is not the matter of it's use and experience such as computer technonolgy,rather it is the philosophical problem of the a priori such as logic,analysis of the concept.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.227-237
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• 2009

The purpose of this study was to determine the relationships with physical activity and depression and body function in elderly. Methods: Total 79 elderly(over 65years old) were participated in this study. A Korean Form of Geriatric Depression Scale(KGDS), Mini-Mental State Examination(MMSE-K), Jebsen hand function test, dynamometer, five time sit-up test were used to measure the depression and cognition, body function(hand function, grasp power, lower extremity strength). Results: Physical activity participated group shows higher in the body function and lower in the depression than non participated group. Conclusion: The findings of this study indicate that the physical activity is helpful to indicate and manage the depression and body function in elderly.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.4
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• pp.357-364
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• 2016

Recently, the world faces the environmental problem such as air pollution due to harmful gas discharged from car and abnormal climate due to the green-house gases increased by the discharge of $CO_2$. Compressed Natural Gas (CNG), one of alternative for this problem, is less harmful, compared to the existing fossil fuel, as gaseous fuel, and less carbon in fuel ingredients and carbon dioxide generation rate relatively favorable more than the existing fuel. However, CNG fuel has the weakness of slow flame propagation speed and difficult fast burn. On the other hand, hydrogen does not include carbon in fuel ingredients, and does not discharge harmful gas such as CO and HC. Moreover, it has strength of quick burning velocity and ignition is possible with small ignition energy source and it's has wide Lean Flammability Limit. If using this hydrogen with CNG fuel, the characteristics of output and discharge gas is improved by the mixer's burning velocity improved, and, at the same time, is possible to have stable lean combustion with the reduction of $CO_2$ expected. Therefore, this research tries to identify the characteristics of engine and emission gas when mixing CNG fuel and hydrogen in each portion and burning them in spark igniting engine, and grasp the combustion stability and emission gas characteristics according and use it as the basic data of hydrogen-CNG premixed engine.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.661-669
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• 2004

In the steel structure of high-rise buildings, a connection analysisand a column design have been made after welding and bolting suitable gaps. Each country, however, has different codes, and such differences are very big. American steel has been designed according to a code that all axial loads can be carried from the upper parts to the lower parts as determined by the designer, but Korean and Japanese steel have been designed by 1/4 of the standard of all axial loads. In this paper, a metal touch experiment was done as an intermediation parameter with a connecting location and a connecting method for economic and constructive efficiency. Every specimen is tested by a low-to-high displacement control to grasp ultimate strength, displacement, the connection's lateral deflection, and stress. The results of the test were compared and analyzed.

• Composites Research
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• v.16 no.6
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• pp.23-32
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• 2003

Applications of advanced composite material in construction field are tending upwards and development of all composite material bridges is making progress rapidly in home and abroad due to their high strength to weight ratio. This paper formulated the dynamic responses of the laminated composite structures subjected to moving load and analyzed the various dynamic behaviors using the finite element method. The nondimensionalized natural frequencies of a simply supported square-laminated composite plate are considered for verifications. Mode superposition and Newmark direct integration method are applied for moving load analysis. For structural models, dynamic magnification factor calculated for various velocities of the moving load and displacements characteristics of laminated composite structures due to the moving load are investigated theoretically Numerical results are presented to study the effects of lamination scheme, stacking sequence, and fiber angle for laminated composite structures during moving load. The various results on moving load and lamination through numerical analysis will present an important basic data for development and grasp the behavior of all composite material bridges.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.267-272
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• 2007

In the construction industry government is not only an owner but also a consumer. Accordingly it should develop the construction industry and this role is important. Among them, the law of the ordering method is standards of selecting a successful bidder and have powerful influence over the construction industry and owners. Therefore this study said how the lowest bid method, which has taken effect still more, has influence on the construction industry and the public sector with the Causal Loop Diagram. According to analyzing this construction law, we can grasp the point of the strength and weakness of this law also examine a trend of how the present law is changed. While we studied, we tried to adhere to neutrality and form a new opinion about it because the previous studies were opposed to each other. As a result, to improve the relation between the government and private company, which were opposed to each other about arguments for and against the lowest bid method, this study suggest the method of making better the relation. The final goal of it is researching the inefficient factors and improving the weakness of this law.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.83-91
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• 2019

Gameplay exists not only in game activities, but also in other art forms. An animated film with strong gameplay whose gameplay narrative follows the presupposition principle, achieved through unimaginable sound effects, exaggerated visual styling, hypothetical time and space concepts, fictional storylines and character performances. The strength or the presence or absence of gameplay in animated films is reflected in the grasp and use of these gameplay elements in the process of animated film narratives. The gameplay narrative of animated films fully utilizes the characteristics of gameplay thinking. In the process of scriptwriting and narrative, it combines entertainment, action, adventure, competition and other elements to fully reflect the characteristics of "gameplay". Gameplay narratives often use the strategies of reverse setting, repetition and interaction, and rules and challenges setting, which not only enhances the fun of animated film narratives, but also attracts the attention of the audience, which then can enhance the audience's viewing experience.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.217-218
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• 2021

With the prolonged Covid-19 epidemic, movement restrictions such as social distancing are prolonged, and as people stay indoors for a longer time, interest in indoor air pollution is increasing. Indoor air quality is not easily purified unlike outdoors. Among indoor building materials, paints and flooring contain formaldehyde that causes sick house syndrome and VOCs that contain carcinogenicity and harmfulness. For modern people who spend a lot of time living indoors for more than an hour, the occurrence of these harmful substances can be said to be fatal. In response to these risks, in July 2019, the government reinforced the standards for indoor air quality to protect the public's health by raising the detection standards for fine dust, ultrafine dust, and formaldehyde in indoor multi-use facilities. People use machines such as air purifiers to improve indoor air quality, or make efforts such as periodic ventilation. In order to reduce or support these other ancillary efforts more effectively, to reduce the generation of pollutants in the building itself, or to adsorb or purify pollutants in the air, use carbon black as an admixture to make a cement hardened body, and to grasp basic physical properties and adsorption capacity. And the result is as follows. As a result of the experiment to determine the appropriate amount of carbon black, it was confirmed that the more the amount of carbon black was added, the better it was in the formaldehyde emission test, but the tendency was not clear when measuring the flexural strength, so a further experiment to improve this is needed.