• Proceedings of the KWS Conference
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• v.43
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• pp.58-60
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• 2004

In the field of welding the behavior of a welded structure under consideration may be predicted via heat transfer and residual stress analysis. In order to facilitate the industrial applications of welding, numerical modeling of heat transfer and residual stress in weldment has been carried out applying Finite Element Method (FEM) and the analysis with the external load including this residual stress due to welding has been done. The present work includes the specialized finite element codes for the calculation of nonlinear heat transfer details and residual stress redistributed along with the external load in the welded structures. A basic interface, which allows models, built in commercial preprocessing package access to the data necessary to build standard input decks for these specialized FEM codes, which are not supported by commercial package. The results from the FEM codes are imported back into commercial package for visualization. In addition the residual stress values are exported to commercial package (such as ANSYS, PATRAN etc.) for further analysis with the external loads, which make the FEM codes fully applicable to the industrial purpose.

• KIEAE Journal
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• v.15 no.4
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• pp.77-84
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• 2015

Purpose: In 2008, As the green growth policy was presented, Green Building is made any effort to propagation. In this paper, the respective technologies that are able to considerably reduce the energy demands for heating, cooling, hot-water, lighting and ventilation among the variety of technologies were selected. Method: Design factors such as (1) External insulation, (2) Triple glazing window, (3) LED lighting, (4) External venetian blind, (5) Geothermal and (6) Heat recovery ventilator were derived. In addition, energy saving effects in terms of energy demand, energy consumption and energy cost were investigated using EnergyPlus, building energy analysis tool. Result : The results were as follows. (1) It can be seen that high insulated triple glazing window, heat recovery ventilator and external insulation technology is excellent for energy demand. (2) Unlike energy demand, saving effect of energy consumption and energy cost was shown in order of Geothermal > Triple Window > Heat recovery Ventilation> Insulation> LED Lighting > EVB Blind.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.3
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• pp.8-17
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• 2015

In this research, low fidelity air/heat load analysis was conducted for the intake of high speed vehicle. For air/heat load calculations, aerodynamic properties at the surface and the boundary layer edge were estimated using Taylor-Maccoll equation for conical flow, shockwave relation and Prandtl-Meyer expansion equation for internal and external flow. Couette flow assumption and Reynolds analogy were used in order to calculate convective heat transfer coefficient. In order to calculate skin friction coefficient for heat transfer coefficient analysis, Van Driest method II and Reference Enthalpy method were considered. An axis symmetric SCRAMJET model was selected as a reference configuration for verifying the proper implementation of the present method. Comparison of the results using the present method and Computational Fluid Dynamic analysis showed that the present method is valuable for efficiently providing pressure and heat loads for air-intake structure design of the high speed air vehicle.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.383-391
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• 2020

Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.10 no.1
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• pp.284-305
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• 1997

A Literatural study on the etiological factors, classification, prescription of hemorrhoids and hemorrhoids complicated by anal fistula following results were obtained. 1. The cause of hemorrhoids are long time sit, long time gate, overfatigue, overeating, imbalance of stool( constipation or diarrhea), pregnant fertility(overfatigue after childbirth, insufficiency of middle warmer energy), uncontrol sexual excess, pathgenic factors of wetness, heat, wind, dry, genetic cause, excess of anxiety, pile up of heat poison, weakness of entrails and viscera. The cause of hemorrhoid complicated by anal fistula are attack of external wind, heatness, dry, fire, wetness(pathgenic factors), inapporiate treatment and chronic disease, greasy diet, excess of anxiety, constipation, uncontrol sexual excess, obstacle of circulation of vital energy and blood on anal site. 2. Classification of hemorrhoids are female hemorrhoids, male hemorrhoids, pulse hemorrhoids, intestines hemorrhoids, vital energy hemorrhoids, wine hemorrhoids, blood hemonhoids, flowing hemorrhoids. Classification with other method are external hemorrhoids, internal hemorrhoids, mixed hemorrhoids, excrescence hemorrhoids, nipple homorrhoids. External hemorrhoids is classified of varicosis of hemorrhoidal vein, connective tissue form, thrombus form. Classification of hemorrhoid complicated by anal fistula are simple lower hemorrhoid, lower mixed hemorrhoid, deep hemorrhoid, outer of one hole hemorrhoid, a horseshoe hemorrhoids. Once more classificated of four are space of sphincter muscle form, penetration sphincter muscle form, upper of sphincter muscle form, outer of sphincter muscle form. 3. Therapy method of hermorrhoid and hemorrhoid complicated by anal fistula are internal method, fumigation method method, ointment, method of close with medicine, necrotizing method, hot medicated compress( gxternal method), injection, insertion, bind, (operation) and acupuncture therapy (the others method) 4. Herb medicine for many used of internal method are Scutellaria baikalensis George(黃芩), Coptis japonia Makino(黃連), Rehmania giutinosa Liboschitz ex Fischer & Meyer(生地黃), Poncirus trifoliata Refinesque(枳殼), Sanguisorba officinalis Linne(地楡), Sophora japonica L.(槐花), Cnidium officinale Makino (川芎), Astragalus membranaceus Bunge(황기), Angelica gigas Nakai (當歸). 5. Herb medicine for many used of fumigation are Schlechtendalia Chinesis J. Bell (五倍子), Artemisia Vulgaris L. var indica Maxim(艾葉), Poncirus trifoliata Refinesque (枳殼), Nepeta japonica Maximowicy(荊芥), And herb medicine for many used of ointment are Calomelas(輕粉), Alum(白礬), Boswellia carterii Birdwood(乳香), Os Draconis Fossilia Ossis Mastodi(龍骨).

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.4
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• pp.458-467
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• 2018

Efforts have been made in this paper to develop the measuring device for the insulation performance of full scale NO96 LNG CCS. The facility was designed to maintain environmental conditions which are similar to operation conditions of full scale LNG CCS. In the facility, the heat sink boundary was kept cryogenic temperature by cold chamber which contains liquefied nitrogen and heat source boundary was made by external case heated by natural convection. Heat Flow Meter method (HFM) was applied to this facility, hence Heat Flux Sensors (HFS) were attached to specimen. The equivalent thermal conductivity of full scale NO96 unit box was targeted to measure and PUF of same size was used for the calibration test. Additionally, the finite element analysis was carried out to check the performance of the developed test facility and experimental results were also compared with those predicted by the numerical method.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2039-2042
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• 2008

Recently, Electronic & Electrical Products have problems how to reduce heat in trend reducing size and increasing speed. heat pipes worked by latent heats can solve problems for effective and quiet electronic applications. Heat Pipes have to be suitably designed for the external conditions due to showing optimum performance. it has influence on efficiency of heat pipes to the exterior structure changed by length, bending angle, diameter. Designing heat pipes has depended on experience from trial and error. this method wasted too many resources, but can't guarantee efficiency. to prevent those wastes, this study aims at making the thermal transfer coefficient predicting efficiency. In this study, the thermal transfer coefficient has been made from experimental results that used variables - lengths between heat source and radiation, bending angles, diameters of heat pipes. variables become non-dimensional in modeling process for making the coefficient.

• Journal of Industrial Technology
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• v.43 no.1
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• pp.15-23
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• 2023

Lithium-ion batteries are predominantly employed in electric vehicles and energy storage devices, offering the advantage of high energy density. However, they are susceptible to efficiency degradation when operated at high temperatures due to their sensitivity to the external environment. In this study, we conducted experiments using an indirect cooling method to prevent thermal runaway and explosions in lithium-ion batteries. The results were validated by comparing them with heat transfer simulations conducted through a commercial finite element analysis program. The experiments included single-cell exothermic tests and cooling experiments on a battery pack with 10 cells connected in series, utilizing 21700 lithium-ion batteries. To block external temperature influences, the experimental environment featured an extrusion method insulation in the environmental chamber. The cooling system, suitable for indirect cooling, was constructed with copper tubes and pins. The heat transfer analysis began by presenting a single-cell heating model using commercial software, which was then employed to analyze the heating and cooling of the battery pack.

• Journal of Ocean Engineering and Technology
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• v.28 no.5
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• pp.452-465
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• 2014

The application of friction stir welding (FSW) technology has been extended to all industries, including shipbuilding. A heat transfer analysis evaluates the weldability of a welded work piece, and elasto-plastic analysis predicts the residual stress and deformation after welding. A thermal elasto-plastic analysis based on the heat transfer analysis results is most frequently used today. However, its application to large objects such as offshore structures and hulls is impractical owing to its long computational time. This paper proposes a new method, namely an equivalent strain method using the inherent strain, to overcome the disadvantages of the extended analysis time. In the present study, a residual stress analysis of FSW was performed using this equivalent strain method. Additionally, in order to reflect the external constraints in FSW, the reaction force was predicted using a neural network, Finally, the approach was verified by comparing the experimental results and thermal elasto-plastic analysis results for the calculated residual stress distribution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.740-746
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• 2009

Two step serial load induction superheater has been proposed using resonance type induction heat method in this paper. Heat method is a type of flowing the electron induction and current to special alloy heater in body from external heat coil with non-contact method. Inverter was a full bridge serial load resonance type and inductor was used as load in LC resonance design to maximize the efficiency. The developed system is a new heat exchanging method combined with electromagnetic induction heater and fluid movement, ana very accurate to control of heating the gas, liquid and evaporated mass, so on without combustion process.