• Tribology and Lubricants
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• v.11 no.1
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• pp.44-49
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• 1995

Friction characteristic of an engine crankshaft bearing is affected by revolution speed, applied loads, and viscosity of lubrication. So, experimental investigation is required to observe the friction characteristics using these factors. Hydraulic cylinder, servo controller system which can be modified the applied load, and test rig for the observation of the characteristics of engine crankshaft bearings were designed and fabricated, and some experiments were performed. Friction torque, journal locus and circumferential temperature variation of crankshaft bearing were measured according to applied load, revolution speed, and oil inlet temperature.

• Progress in Superconductivity and Cryogenics
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• v.1 no.2
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• pp.37-42
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• 1999

The stability of high-temperature superconducting current leads for cryogenic devices are investigated. By assuming full transition from superconducting state to normal state at a transition temperature, the HTS current at a transition temperature, the HTS current lead shows bifurcation phenomenon. There is a bifurcation shape-factor, HTS leads have three steady state. Below the bifurcation shape-factor, the superconducting current lead is unconditionally stable, because there exists only one steady-factor HTS current lead is conditionally stable depending on the shape and intensity of disturbance.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.309-312
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• 2003

In this study, the electrical characteristic of Symmetric high voltage MOSFET (SHVMOSFET) for display driver IC were investigated. Measurement data are taken over range of temperature (300K-400K) and various extended drain length. In high temperature condition(>400K), drain current decreased over 20％, and specific on-resistance increased over 30％ in comparison with room temperature.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.47-51
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• 1996

Unsteady-state temperature distributions and thermal deformations of a spindle system are studied in this paper. Three dimensional model is built for analysis, and the amount of heat generation of bearing and the thermal characteristic values including heat transfer coefficient are estimated. Temperature distributions and thermal deformations of a model are analyzed using the finite element method and the termal boundary values. Numerical results are compared with the measured data. The results show that thermal deformations and temperature distributions of a high precision spindle system can be reasonably estimated using the three dimensional model and the finite element method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.335-338
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• 2010

A recent study for tracing the profiles of supersonic axisymmetric Minimum Length Nozzle with uniform and parallel flow at the exit section, the stagnation temperature is taken into account. The aim of this work is to add optimization algorithm to the supersonic nozzle design in order to get the optimum nozzle shape. The comparisons of the nozzle contours based on the method of characteristics are presented. The specific heats and their ratio vary with the stagnation temperature when this temperature of a perfect gas increases. An application is made for air in a supersonic nozzle.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1919-1921
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• 1999

AlN thin films were fabricated by sputter for the application of MIS device with Al/AlN/Si structure. We controled that sub-temperature room-temperature. Sputtering pressure 5 mTorr, flow ratio Ar:$N_2$=1:1(4sccm:4sccm), and appended hydrogen gas $0{\sim}5%$. AlN thin films thickness fabricated to maintain $2700{\AA}$ time control. Before the experiment remove to the contaminated material use the Ultrasonic every 10 minute use the acetone and ethanol, then use the HF remove oxide-substance at 10 second. To analyze characteristic of the $H_2$ gas addition period, C-V and I-V characteristic make and experiment $H_2$ gas at addition period progressive capability of I-V and C-V characteristic.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.79-86
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• 2012

The aim of this general remarks is to introduce the results concerning the thermo physical, charging, developing and fusing characteristics of micro-encapsulated (MC) model toners in order to apply to the toner of electrophotographic system at the condition of a low temperature. In order to clarify the fusing mechanism of MC toner, rheological analysis of the toner was chosen. It was suggested that MC toner had a different fusing mechanism compared with non-MC toner. Some kinds of MC model toners showed a good result on adhesion test as well as cohesion test. Also, it was possible to get the good charging and development characteristic of MC toner for printing test with laser printer.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.127-132
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• 2003

In a today industry, the welding is doing a many portion in structure manufacture. This study is simulated heat of heat-effected zone and researched a mechanical properties and ultrasonic characteristic in used the SS400 and the STS304. As the result mechanical properties of steel that become drawing decreased because of remaining stress by strain gardening according as simulated heat temperature rises, but according as temperature rises in material that do simulated heat after have done annealing, mechanical propensity was improved. The velocity and attenuation become different by effect of remaining stress than effect of material internal microstructure in ultrasonic wave test. In the case of STS304, there was change in mechanical properties by effect that is by strain hardening, but there was no change in material that simulated heat after annealing. When become drawing in ultrasonic waves test, according as simulated heat temperatures rise, change of attenuation coefficient is looked, but material that simulated heat after annealing was no change almost both the volocity and attenuation.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.1-6
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• 2009

The temperature of exhaust gas was raised by increasing of engine movement on developing engine. Thermal of high temperature and pressure reverse in bellows, because of increasing of engine movement and the thermal performance of converter in combustion. As a result, thermal loss is increased and thermal efficiency is decreased rapidly in bellows, it can occur to damage in mechanical structure. In this study, it was necessary to analyze back pressure performance and thermal characteristic on driving condition in exhaust system. It was adapted braid type bellows and straight type exhaust pipe. It was compared with curve type exhaust pipe for lay-out on considering to design of exhaust system. It was necessary to improve thermal characteristic and back pressure performance so that expansion cavity pipe(ECP) was installed between bellows and catalyst convert. Not only decreasing back pressure was solved but also thermal characteristic problems in exhaust pipe because of increasing capacity. According to this study, the basis of data is presented when new exhaust system is designed.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.1
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• pp.1-9
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• 2008

Human has faced in lack of fossil fuel and environmental crisis because of high population growth and development of industry. Hydrogen, unlimited amount and clean resource from water electrolysis, is remarkably known as the solution of recent energy crisis. One of the special characteristics of hydrogen is that a little amount of catalytic such as platinum and palladium makes nonflammable combustion, in other words catalyst combustion. Catalytic combustion fueled by hydrogen is environmentally friendly. This paper considers some comparisons of characteristic of catalytic combustion between a single layer of platinum catalyst, double layer of platinum and nickel catalysts and mixture of platinum and nickel catalysts. Some experiments of temperature distribution at different positions and characteristic of combustion in low temperature region were done in order to find an applicable possibility as a house-cooking burner.