• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.822-830
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• 2000

A conventional advanced control algorithm is proposed in this paper for improved temperature regulation of a TV-glass melting furnace. The TV-Glass melting furnace is a typical MIMO(Multi-Input Multi Output) system which is subject to various thermal disturbances. Because of its complexity, a detailed mathematical model of the furnace is hard to establish. To design a temperature control control system of the furnace, major input-output variables are selected first, and simple FOPDT(First Order Plus Dead Time) models are established based on the physical meaning and experimental process data. Based on the FOPDT models, a multi-loop control system composed of cascade and single loops are designed for effective control of the MIMO system. Practical implementation on the 150 ton/day furnace using the DCS(Distributed Control System) showed that the proposed control technique performs better than manual control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.7
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• pp.604-610
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• 2003

Cycle test for developed phase change material (PCM) is necessary in order to analyze the variation of latent heat, which decreases with time by deterioration. 7-history method and measurement using heat flux meter are appropriate for the cycle test in a tube filled with PCM because they do not need an extraction of sample in measuring the heat of fusion. In the present study, these methods were applied to a PCM having a melting point below a room temperature, different from the past studies for PCMs melting above a room temperature. As a result of experiment using pure water as specimen, we can obtain reason-able values for heat of fusion by both methods.

• Journal of the Korean Society of Combustion
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• v.9 no.1
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• pp.1-10
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• 2004

The results of a series of experiments executed by using two pilot-scale oxy-fuel burners are presented. The oxy-fuel burners are designed for maximum capacity of 50,000kcal/hr, 200,000kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, and swirl vane angle on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple at various points of the flame. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and momentum. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, optimum burner type, excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

• Resources Recycling
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• v.13 no.4
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• pp.46-52
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• 2004

The present main research direction of waste treatment is the development of incineration system for low pollution. Also, heat value of waste is increased because of the rising of living standard, environmental consideration and collection of sorted waste for recycling. Therefore, many researches have been continued for solving ash problem including heavy metals, dioxin problem and high energy efficiency by use of high heat value. This study is described for the facilities of pyrolysis system, pyrolysis-melting system, pyrolysis-gasification melting system.

• Journal of architectural history
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• v.25 no.5
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• pp.27-40
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• 2016

The purpose of this study was to comprehend the procurement system of iron materials and the production process of ironwork in royal tombs constructions in the later Joseon period. For this purpose, sixteen Sanneung-uigwes were analyzed. The following conclusions have been reached through the study. First, it was procuring five types of iron materials in constructions of royal tombs. Sincheol had been supplied up to the mid-18th century. On the other hand, the amount of jeongcheol was increased rapidly. Because of the procurement system of initial tools was changed from bokjeong(a kind of tribute) to self-production in the Noyaso. Second, the government stockpiles were utilized as much as possible than bokjeong to manage the limited construction period and sudden construction start. Third, before moving the site of tombs, the melting furnace was installed in the Gungisi(armament factory). The amount of the melting furnace was increased from 5 to 8 since producing the initial tools in the Noyaso. Fourth, six kinds of master artisans were worked in the field of producing ironwork. Metal worker was assigned to one person per melting furnace. Fifth, the quality of final iron materials was controlled by use. Since the 19th century, it had been produced enhanced ironwork.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.4
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• pp.362-369
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• 2008

The snow melting system by electric heating wires which is adopted in this research is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, installation place and each country applying the system. A main purpose of this study is figuring out the appropriate range of required heat capacity and installation depth and pitch for solving snowdrifts and freezing problems with minimum electric power consumption. This study was performed under the ambient air temperature($-2^{\circ}C$, $-5^{\circ}C$), the pitches of the electric heating wires(200 mm, 300 mm), heating value($250\;W/m^2$, $300\;W/m^2$, $350\;W/m^2$).

• Fashion & Textile Research Journal
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• v.15 no.3
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• pp.467-476
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• 2013

This study investigates the dyeability and the fastness of flame retardant polyester fabric developed by a thermal bonding with a low melting component of flame retardant bicomponent filament (LMFRPC). The fabrics were prepared with flame retardant polyester filaments (FRP) as warp and blended filaments of FRP and LMFRPC as weft. The LMFRPC have a sheath and a core where the core comprises a flame retardant polyester and the sheath comprises a thermoplastic polyester with a low-melting point. The thermal bonding of fabric was conducted in a pin tenter at $170^{\circ}C$ for 60 seconds. Fabric dyeing was conducted with an infrared dyeing machine at various dyeing temperatures and dyeing times. The dyestuffs used in this study were CI disperse Yellow 54, Red 60 and Blue 56 of E-type dyestuff and Orange 30, Red 167 and Blue 79 of S-type dyestuff. This study investigated the morphology of thermal bonded fabric, dyeability and fastness of dyed fabric. Dyeability increased with an increased dyeing temperature. The thermal bonded area increased with the increased LMFRPC content. The dyeability of S-type dyestuff was higher than E-type dyestuff; in addition, the saturated dyeing time was about 20minutes at $130^{\circ}C$ for E and S-type dyestuff. The fastness to washing and rubbing were excellent at a 4-5 Grade.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.324-329
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• 2008

The liquid cooling effect of a natural convection type radiator by using the PCM has been investigated experimentally. The radiator size is $423{\times}295{\times}83$ mm and PCM container size is $398{\times}270{\times}26$ mm. The objective is elapsed time higher than maximum time to reach for maximum operating temperature of a general liquid cooling radiator. This study, in order to study on the effects of the phase-change phenomenon, carried out the various mass flow rate, input electric power, ambient and melting point of three type PCM. For the above experimental parameter, the melting time was performed about 180/250/560 min at input power 150 W and ambient $30^{\circ}C$ from using the three type PCM(PCM_S1/S2/S3) respectively. Furthermore, the effects of the thermal dissipation was decreased higher input power than lower input power at heating block and melting time of PCM. However, the effects of mass flow rate did not nearly affect of the thermal performance especially.

• Solar Energy
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• v.6 no.2
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• pp.43-53
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• 1986

The objective of this study is to report on the characterics of convective flow and heat transfer during metling process in order to provide design information for thermal energy storage systems which use phase change material. In present study, flow and heat transfer characteristics of the Phase Change Material in the Open Top Model (O.T.M) and in the Closed Top Model (C.T.M) were studied numerically by the control volume formulation using the algebraic non-orthogonal coordinate transformation. For the calculation procedure, the physical properties of fluid are assumed to be constant except density which is linely dependent on temperature in the bouyancy term of momentum equations. At start of melting process, the thickness of melting layer is assumed from the Stefan Problem assumption. The heat transfer results of Open Top Model and Closed Top Model are compared with the parameters of Grashof number and aspect ratio. It was found that heat transfer phenomena in melted region was greatly affected by buoyancy-driven natural convection and the melting distance of Open Top Model at the upper region is greater than that of Closed Top Model.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.457-464
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• 2010

The low melting alloy impregnated wood composites with natural grain of thinned Juglans mandshurica was made and evaluated in this study. And the proper manufacturing conditions was also investigated in this study. The low melting alloy with bismuth(Bi) and tin(Sn) which are harmless to humans, was applied for this novel composites, which showed not only no defects of discoloration, delamination, swelling, and cracking, because of high dimensional stability and low thickness swelling, but also much improved performance such as high bending strength, high hardness, low abrasion, high thermal conductivity as floor materials. This study also suggested the proper impregnating condition, such as 10 minutes of the preliminary vacuum time, $187^{\circ}C$ of the heating temperature and 10 minutes of the maintaining pressure time at the pressure of 30kgf/$cm^2$. The produced composites showed 9 times higher density for small specimen, 6.6 times for actual size sample and great increase in bending strength from 102.05N/$mm^2$ to 189.47N/$mm^2$ for small size sample and to 205.4N/$mm^2$ for actual size sample, also great increase in hardness from 15.1N/$mm^2$ to 73.38N/$mm^2$ for small size sample and 64.87N/$mm^2$ for actual size sample. And the composites demonstrated great decrease in abrasion depth and in water absorption.