• Computers and Concrete
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• v.25 no.5
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• pp.471-478
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• 2020

In this work, the analytical solution for the stresses in piezo-thermo-elastic homogeneous, transversely isotropic material under the effect of the rotation has investigated. The thermoelasticity theory has used to study the problem. The material subjected to boundary conditions. Finally, the numerical solution has carried out piezo - thermo-elastic material under the effect of rotation, to illustrate the analytical development. The corresponding simulated results of various physical quantities such as the displacements and the stresses, the temperature and the electrical displacement have presented graphically.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.295-298
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• 2012

Repair and strengthening is necessary to extend the service life of existing buildings. Polymer-modified cement mortar (PCM) has been extensively used as a high performance material particularly for finishing and repairing works in concrete building because of itsexcellent adhesion, waterproofing, resistance to chemical attack, and workability. As PCM contains organic polymer, it is necessary to clarify its properties at high temperature under fire, on which sufficient data are not available. This paper evaluated the burn-up characteristics of polymer-modified cement mortar with cone calorimeter test, non-combustibility test and flammability test with experimental parameters such as the types of polymer, unit-polymer content, polymer-cement ratio and thickness of the specimen.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.364-368
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• 2011

The super-speed tube train was introduced to increase the speed of ground transportation. It levitates magnetically and runs in a partial vacuum tube, which significantly reduces air resistance. However, strong magnetic force sufficient to propel the massive train can affect the infrastructure. The induced eddy current produces joule heat, and raises the inside temperature of the girder, which might lead to electrochemical corrosion on the girder, thereby weakening its durability. In this paper, the authors analyzed the magnetic flux and induced eddy current in the reinforced concrete girder by using three-dimensional FEM, particularly by varying the number of reinforcing steels of the upper flange of the girder to the condition of almost the same flexural strength and reinforcing steel amount.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.67-71
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• 2007

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.290-293
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• 2012

화재는 콘크리트 구조물의 역학적 특성에 치명적 손상을 일으켜 건축물의 안전성을 급격하게 감소시킬 수 있다. 특히 고강도콘크리트는 폭렬이 발생하여 심각한 단면 손실과 노출된 철근으로 인하여 건축물의 안전성에 치명적인 영향을 미친다. 이러한 폭렬에 대하여 다양한 연구가 진행되고 있지만, 폭렬의 발생원인은 명백하게 밝혀지진 않았다. 이에 본 연구는 콘크리트의 함수율과 열응력이 폭렬에 미치는 영향을 분석하여 폭렬로부터 구조물의 안전성을 확보하기 위한 기초 자료를 제시하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1090-1100
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• 1996

Heating floor is the most profitable system of air heating at poultry houses. THe tubes with heating elements inside are laid into the layer of concrete. To prevent lossese of heat penetration deep into the ground the layer of isolation material is laid below the tubes . The depth of isolation laying in every point of the heating floor may be calculated according to the author's formula using the data of temperature on the floor surface and the tube, the distance between tow nearest tubes, and the distance between the tube and the floor surface. Technological investigations allow to estimate the optimal density for greese and ducks when they are bred on the heatuing floor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1194-1197
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• 2006

Recently, international standard for measurement of sound absorption in a reverberation room has been amended. In the revised version, temperature, humidity and air pressure conditions are strictly restricted and also the concrete procedures are presented to reduce the differences in test results by adding inspection of diffusion, measurement uncertainty etc. In this paper, the systematic tests are conducted based on the inspection guide of diffusion defined by ISO 354 and the effects of diffusers on the measurement of sound absorption ratio are considered. As a result, we perceived that the averaged sound absorption ratio in mid and high frequency range is expected to measure around $0.05{\sim}0.1$ higher in high sound absorption material. Therefore, as for the reverberation room for measurement of sound absorption, we need to take into consideration not only the spatial standard deviation of sound pressure mandated by ISO 3741, but also, inspection regulation of diffusion showed by ISO 354.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.123-127
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• 2005

EVA Powder modified high strength concretes were prepared by varying polymer/binder mass ratio with a constant water/binder mass ratio of 0.3. The effect of EVA powder on the slump, hydration heat, compressive and flexural strength, toughness and water absorption ratio was studied. In hydration heat test, temperature of hydration reaction displayed almost fixed level regardless of containing rate of EVA powder, but peak time of hydration reaction displayed late inclination as containing rate of powder increases. With the same water/binder mass ratio, the compressive strength and water absorption of EVA powder modified concretes decreased slightly when EVA powder was added and the flexural strength of EVA powder modified concretes rised slightly when EVA powder was added. Also, the toughness of the modified concretes can be improved markedly. The interpenetrating structure between the polymeric phase and cement hydrates formed at a $2{\sim}6%$(containing rate of EVA powder). The properties of the polymer modified concretes were influenced by the polymer film, cement hydrates and the combined structure between the organic and inorganic phases.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.409-414
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• 2009

I have not seen each of the existing technology, RFID/USN technology combined with the wireless communication channel for the state of nuclear safety in real-time remote monitoring and operation system technology CARE existing radioactive accident information collected by the nuclear power and nuclear power status, 10-20 second intervals to monitor the safety network (SIDS), and nuclear power plants located on the site within 40 ㎞ radius around the 13~15 of the wind speed from the automatic weather network weather information such as rainfall and temperature every 10 minutes to collect as automatic weather network (REMDAS), Evaluation of atmospheric radiation and radiation of the bomb radiation impact assessment system to calculate the goodness (FADAS) and thicken the radiation-related information consists of real-time web technology to collect, the last robot on behalf of the human will to manage the nuclear power plant accident of the technology to prevent the concrete from the following narrative about to have.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.141-144
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• 2006

The building construction is an essential field to consider weather condition because construction works are performed in a site. From this reason, this study evaluated the effect of weather condition with work sections in building construction by Analytic Hierarchy Proces (AHP) method. The results of this study as follows : (1) The effect of weather condition with work sections is affected by rainfall in summer season, and by a low temperature in winter season (2) The effect of weather condition with work sections is 0.235 for mold work, 0.210 for concrete work, 0.181 for steel-frame work.