• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.571-580
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• 2020

In this study, an experimental study on storage media for thermal energy storage system was conducted. For thermal energy storage medium, concrete has excellent thermal and mechanical properties and also has various advantages due to its low cost. In addition, the ultra-high strength concrete reinforced by steel fibers exhibits excellent durability against exposure to high temperatures due to its high toughness and high strength characteristics. Moreover, the high thermal conductivity of steel fibers has an advantageous effect on heat storage and heat dissipation. Therefore, to investigate the temperature distribution characteristics of ultra-high-strength concrete, concrete blocks were fabricated and a heating test was performed by applying high-temperature thermal cycles. The heat transfer pipe was buried in the center of the concrete block for heat transfer by heat fluid flow. In order to explore the temperature distribution characteristics according to different shapes of the heat transfer pipe, a round pipe and a longitudinal fin pipe were used. The temperature distribution at the differnent thermal cycles were analyzed, and the thermal energy and the cumulated thermal energy over time were calculated and analyzed for comparison based on test results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.160-165
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• 2004

At this research, we examined probability of light bulb's life span value and prediction on purpose to inquire out the span of repeat velocity as fracture probability by executing the fatigue test, which is considered property of Tungsten filament's thermal fatigue used as an automobile bulb. As a result we can confirm what the most suitable solution is weibull distribution and log normal distribution. Tungsten filament's span gets longer as the fatigue repeat velocity gets shorter And, repeat span is about 15%~40% shorter than sequence life span.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1121-1122
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• 2010

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.51-53
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• 2004

An analytical method is developed which focused on the end effects for determining the thermal stress distribution in an laminated beam bonded with adhesive layer. This method gives the stress distribution which satisfy the stress-free boundary condition at edge completely. Numerical example, in which an Al-Cu beam bonded with solder(Pb-Sn) is treated, shows that the shear and peeling stresses at the interfaces are significant near the edge and become negligible in the interior region.

• Journal of Biomedical Engineering Research
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• v.8 no.1
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• pp.63-68
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• 1987

The biological effects for the use of hypertherinla to treat malignant tumors has been well studied and encouraging clinical results have been reported. However, the engineering and technical aspects of hyperthermia for the deepseated tumors has not been satisfactory. We have developed the FF capacitive hyperthermia device(GHT RF8)by cooporation with Yonsei Cancer Center and Green Cross Medical Equipment Corporation. It was composed with 8.10 MHz RF generator, capacitive electrode, matching system, cooling system, temperature measuring thermocouples and control PC computer. We have measured the temperature and thermal distribution in agar phantom, animals and human tumors.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.431-433
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• 2006

Accurate information on the ground surface temperature is essential for design of a borehole heat exchanger and thus ensuring the performance of a ground source heat pump system along with knowledge on thermal diffusivity and conductivity of ground. In this study we analyzed the shallow subsurface temperature monitoring data of 58 Korea Meteorological Administration synoptic stations. As a result, we compiled mean annual ground surface temperature distribution map using multiple regression analysis of the monitoring data.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.243-249
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• 2001

In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The inelastic deformation of the reactor baffle cylinder can occur due to the moving temperature distribution along the axial direction as the hot free surface moves up and down under the cyclic heat-up and cool-down of reactor operations. The ratchet deformations were measured with the laser displacement sensor and LVDTs after cooling the structural specimen which experiences thermal load up to $550^{\circ}$ and the temperature differences of about $500^{\circ}C$. During structural thermal ratchet test, the temperature distribution of the test cylinder along the axial direction was measured from 28 channels of thermocouples and the temperatures were used for the ratchet analysis. The thermal ratchet deformation analysis was performed with the NONSTA code whose constitutive model is nonlinear combined kinematic and isotropic hardening model and the test results were compared with those of the analysis. Thermal ratchet test was carried out with respect to 9 cycles of thermal loading and the maximum residual displacements were measured to be 1.8mm. It was shown that thermal ratchet load can cause a progressive deformation to the reactor structure. The analysis results with the combined hardening model were in reasonable agreement with those of the tests.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.226-227
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• 2015

This research is to measure and analyze the thermal performance of the apartment structure and to evaluate and establish standards of thermal insulation defect in order to make the basic data necessary for determining the degree of the thermal performance degradation and for repairing and reinforcing the exterior wall of the existing apartment. The following conclusions could be derived thorough the investigation of outer wall temperature distribution and the insulation assesment experiments using a model of specimens for the apartment houses' outer walls. It was confirmed that for the thermal performance through the insulating material thicknesses 5cm, 8cm in walls, the thermal insulation thickened by 3cm, from 5cm to 8cm, but that the actual temperature difference reached only about 1 ~ 2℃. This implies that the thermal performance improvement using the thermal insulation in walls is not significant and that it is difficult to insulate the thermal bridge area.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.986-996
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• 1994

Insulation system of LNG carrier has made important roles such as maintaining a proper Boil off Ratio(BOR) for the cargo and avoiding the excessive low temperature of the adjacent inner hull beyond the permissible limit. At the same time, safety and economy of the LNG transportation by the ship are connected with the performance of the insulation system. Also, thermal insulation system of LNG carrier is one of the most advanced technique with the structure analysis of tank, welding and assembling. In this study a computer program is developed to calculate the hull temperature distribution and BOR, which are important factors in thermal design for the Moss Rosenberg Verft spherical tank type LNG carrier. Detailed results for hhull temperature distribution close to LNG tank, BOR and the thickness effect of insulation material are reported in this paper in the range of standare design sea condition.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1563-1571
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• 2001

The effect of flow distribution on thermal and flow performance of a parallel flow heat exchanger has been numerically investigated. The flow distribution has been altered by varying the geometrica l parameters that included the locations of the separators, and the inlet/outlet of the heat exchanger. Flow nonuniformities along paths of the heat exchanger, which were believed to be dominantly influential to the thermal performance, have been observed to eventually optimize the design of the heat exchanger. The optimization has been accomplished by minimizing the flow nonuniformity that served as an object function when the Newton's searching method was applied. It was found that the heat transfer of the optimized model increased approximately 7.6%, and the pressure drop decreased 4.7%, compared to those of the base model of the heat exchanger.