• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.84-89
• /
• 2003

Fuzzy controller is one of the succeed controller used in the process control in case of model uncertainties. But it my be difficult to fuzzy controller to articulate the accumulated knowledge to encompass all circumstance. Hence, it is essential to provide a tuning capability. There are many parameters in fuzzy controller can be adapted, scale factor tuning of normalized fuzzy controller is one of the adaptation parameter. Two adaptation methods are implemented in this work on an experimental thermal process, which simulate heating process in liquefied petroleum gases (LPG) recovery process in one of petrochemical industries: Gradient decent (GD) adaptation method; supervisory fuzzy controller. A comparison between the two methods is discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.2
• /
• pp.32-37
• /
• 2021

To realize a zero-energy building, a technology that minimizes the energy loss due to thermal bridges by preventing their formation is emerging as an important design factor. In this study, we develop a thermal bridge breaker to prevent thermal bridging in a metal panel roof and attempt to analyze the effects of its application. To this end, we fabricated a thermal bridge breaker and analyzed it in terms of its strength and heat-transfer characteristics, in addition to conducting a load simulation. The thermal bridge prevention effect of the developed thermal bridge breaker improved the insulation performance of the metal panel roof, and the results of a cooling/heating peak load simulation performed by applying the heat transmission resistance test results to a building proved the existence of this effect.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.2
• /
• pp.157-165
• /
• 2003

A combined process of non-thermal plasma and catalytic technique has been investigated to treat $CH_3$CN gas in the atmosphere. A planar type dielectric barrier discharge (DBD) reactor has been used to generate the non-thermal plasma that produces various chemically active species, such as O, N, OH, $O_3$, ion, electrons, etc. Several different types of the beads. which are Molecular Sieve (MS) 5A, MS 13X, Pt/alumina beads, are packed into the DBD reactor, and have been tested to characterize the effects of adsorption and catalytic process on treating the $CH_3$CN gas in the DBD reactor. The test results showed that the operating power consumption and the amounts of the by-products of the non-thermal plasma process can be reduced by the assistance of the adsorption and catalytic process.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.2
• /
• pp.77-82
• /
• 2008

Rubbing-roller is used for manufacturing liquid crystal display, and static displacement of the rubbing-roller becomes bigger as length of the rubbing roller made of aluminum is getting longer. Therefore, material of the rubbing-roller is changed from aluminum to CFRP(Carbon Fiber Reinforced plastic). Recently thermal spraying is applied to manufacturing process of long rubbing-roller. The thermal spraying has disadvantages such as increment of manufacturing time and fraction defective caused by density of stainless steel particle. In this study, fitting process by drawing was suggested and FEM analysis with Tsai-Wu failure theory and fitting experiments are carried out to find adequate shrink allowance. The suggested shrink allowance gives proper adhesive force, and CFRP failure is not occurred. Furthermore, the fitting process is applied to long rubbing-roller and availability of the fitting process is studied by measurement of roundness, straightness and shear strength.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2001.05a
• /
• pp.126-129
• /
• 2001

LIPCA (LIghtweight Piezo-composite Curved Actuator) is an actuator device which is lighter than other conventional piezoelectric ceramic type actuator. LIPCA is composed of a piezoelectric ceramic layer and fiber reinforced light composite layers, typically a PZT ceramic layer is sandwiched by a top fiber layer with low CTE (coefficient of thermal expansion) and base layers with high CTE. LIPCA has curved shape like a typical THUNDER (thin-layer composite unimorph feroelectric driver and sensor), but it is lighter an than THUNDER. Since the curved shape of LIPCA is from the thermal deformation during the manufacturing process of unsymmetrically laminated lay-up structure, an analysis for the thermal deformation and residual stresses induced during the manufacturing process is very important for an optimal design to increase the performance of LIPCA. To investigate the thermal deformation behavior and the induced residual stresses of LIPCA at room temperature, the curvatures of LIPCA were measured and compared with those predicted from the analysis using the classical lamination theory. A methodology is being studied to find an optimal stacking sequence and geometry of LIPCA to have larger specific actuating displacement and higher force. The residual stresses induced during the cooling process of the piezo-composite actuators have been calculated. A lay-up geometry for the PZT ceramic layer to have compression stress in the geometrical principal direction has been designed.

• Journal of Advanced Research in Ocean Engineering
• /
• v.1 no.3
• /
• pp.148-156
• /
• 2015

Deck plates of ships or offshore structures would make out-of-plane distortion for their thin thickness. These distortions are usually straightened by thermal straightening such as flame heating method. After thermal straightening, the blocks are lifted and moved by cranes to assemble it at dry-dock stage. After this lifting process, out-of-plane deformation again happens frequently. And then, they continuously cause quality and accuracy problems in the final dry-dock process. So, it takes more time for repair and correction working. According to preceding research, the lifting process by cranes would offset the effect on thermal straightening. The target of this study is to develop a methodology analyzing the remaining efficiency of thermal straightening after block lifting. The development was based on the assumption of yield state at straightening region. Therefore the remaining efficiency was obtained by different stiffness slope while lifting & relieving. The efficiency formula was designed using inherent strain, and we made a table of zero-efficiency by cooling speed and class rule's steels. As a result, if the stress orthogonal to straightened line is calculated during lifting analysis by FEA, the efficiency can be obtained linearly to the values in the table. Finally, even optimized carling position can be designed by considering the regional data from series project and welding region on deck.

• Journal of IKEEE
• /
• v.18 no.4
• /
• pp.532-535
• /
• 2014

This paper analyzed thermal characteristics of super junction MOSFET using process and design parameters. Trench process is very important to super junction MOSFET process. We analyzed the difference of temperature, thermal resistance, total power consumption according to trench etch angle. As a result we obtained minimum value of temperature difference and thermal resistance at $89.3^{\circ}$ of trench etch angle. The electrical characteristics distribution of super junction MOSFET is not showed tendency according to trench etch angle. We need iterative experiments and simulation for optimal value of electrical characteristics. The super junction power MOSFET that has superior thermal characteristics will use automobile and industry.

• Environmental Engineering Research
• /
• v.15 no.4
• /
• pp.225-230
• /
• 2010

In order to treat soil contaminated with high percentages of water and petroleum, the combined microwave and thermal desorption process was studied, which was composed of the consecutive connection of two pre-treatment processes. For the thickness of the contaminated soil layer on the transfer conveyor belt, the optimal total petroleum hydrocarbon (TPH) removal rate was studied with respect to the duration of microwave exposure in the consecutive process combined with thermal desorption. The TPH removal rate when the contaminated soil layer thickness was 1 cm at 6 kW of microwave power was 80%. The removals rates for 2 and 3 cm soil layer thicknesses were both 70%. Under identical experimental conditions, the TPH removal rate for the microwave pre-treatment, when considering the soil particle size, was over 70%. The lowest TPH removal rate was achieved with a particle diameter of 2.35 mm. For contaminated soil with 30% water content, 6 kW and a thermal desorption temperature of $600^{\circ}C$ were the optimal operational conditions for the removal of THP. However, considering the fuel consumption cost, 4 kW and a thermal desorption temperature of $300^{\circ}C$ would be the most economic conditions.

• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.4
• /
• pp.487-494
• /
• 1996

Simultaneous effects of $C_2H_4$ injection and heterogeneous chemical reactions on non-thermal plasma process to remove $SO_2$ and NOx from flue gas were investigated in the present experimental study. The present results showed that 40% of the electrical power can be reduced in $C_2H_4$ injection and heterogeneous chemical reaction are simultaneously included in the non-thermal plasma precess. As an effort to apply the non-thermal plasma technique to practical flue gas treatment system, a wire-plate type reactor which has technically similar geometry of industrial electrostatic precipitators is used instead of other types of reactors, such as wire-cylinder, packed-bed and surface discharge which are inappropriate to industrial application. In the present study, the photo pictures of positive streamer corona taken by ICCD camera, voltage and current oscillograms, and design criteria of a wire-plate type reactor are also shown, which are needed for industrial application of the non-thermal plasma process.

• Aerospace Engineering and Technology
• /
• v.4 no.2
• /
• pp.126-134
• /
• 2005

Before the launch, launch vehicle is set up a few days ago at launch pad to check process and to supply fuels, etc. During the prelaunch process, the payload is exposed to the thermal environments. The purpose of a prelaunch thermal analysis is to predict maximum/minimum liftoff temperature of payload fairing and to evaluate air conditioning performance. The prelaunch thermal analysis of Delta II PLF is performed using Sinda/fluint, general thermal/fluid analyzer. The results are analyzed and compared with Delta II report.