• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.699-704
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• 2007

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• Journal of the Korean Solar Energy Society
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• v.30 no.4
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• pp.43-48
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• 2010

The performance of photovoltaic systems could be affected by various factors including installing conditions of modules, and their own efficiencies of solar cells and inverters. The installing conditions of a photovoltaic system including array types, tilting angles, azimuth, locations, quantities of sunshine, optimum angles of inclination and separated distance are analyzed using the SolarPro & Minitep SW simulation program, inorder to set up the installing conditions for improving system performance. The result from the simulation of the 500kWp PV system of Kochang with optimal installing conditions compared with normal conditions shows that the capacity factor has been increased from 11.02% to 12.06%.

• Asia-Pacific Journal of Business
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• v.9 no.2
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• pp.137-152
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• 2018

Hofstede cultural value model is one of the most influential model for cross-cultural studies to measure national difference. In this study, we examine that Hofstede Cultural Dimensions can be measured by World Value Surveys. Selected WVS questions for 31 measurable countries after Exploratory Factor Analysis(EFA) and Confirmatory Factor Analysis(CFA), approved valid through empirical analysis. It is applicable that Individualism values(IND) has related to 2 questionnaires including life satisfaction, Power Distance values(PDI) to 2 questionnaires about political action(Signing a petition and Joining in boycotts), Masculinity values(MAS) to 2 sexual-role questionnaires like "University is more important for a boy than for a girl", Uncertainty Avoidance values (UAI) to 3 questionnaires about confidence(Parliament, The Political parties and Justice System), Long-Term Oriented values(LTO) to 4 questionnaires including "How proud of nationality" and Indulgence versus Restraints values (IVR)to 2 questionnaires including Feeling of Happiness.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.257-262
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• 2005

Sleeping cars mean railroad cars which are equipped with facilities available business, travel, rest, sleep for long distance travel. Domestic sleeping cars , as the concept of ‘night train’, provide passenger who travel at night with simple berth . German, Japanese, American sleeping cars are classified with sleeping car, coach car, seat car or first class, standard class, family room, room for the handicapped, which offer not only sleep but various facilities and service such as snack, reading, available shower for daytime travel. Accordingly, through the analyzing spatial factor of domestic and foreign sleeping cars, we first should abstract the demand for fundamental design to enhance our passenger's comfort. And then we should try to improve the quality of travel culture by offering it passenger.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.735-740
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• 2003

In this study, a numerical optimization to find the optimal shape of streamwise periodic ribs mounted on both of the principal walls is performed to enhance turbulent heat transfer in a rectangular channel. The optimization is based on Navier-Stokes analysis of flow and heat transfer with $k-{\varepsilon}$ turbulence model and is implemented using response surface method. The width-to-height ratio of a rib, rib height-to-channel height ratio, rib pitch to rib height ratio and distance between opposite ribs to rib height ratio are chosen as design variables. The object function is defined as a function of heat transfer coefficient and friction drag coefficient with weighting factor. Optimum shapes of the rib have been investigated for the range of 0.0 to 0.1 of weighting factor.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.49-56
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• 1999

A material was formulated with Phenol novolac and HEXA only. The cure kinetics and thermal characteristics of phenol novolac with various HEXA contents were peformed by differential scanning calorimetry and thermal gravimetric analysis. All kinetic parameters of the curing reaction including the reaction order, activation energy, and rate constant were calculated and reported. The results indicate that the curing reaction goes through an autocatalytic kinetic mechanism. The friction and wear characteristics of this material were determined using friction material testing machine. The friction coefficient of phenol novolac with various HEXA contents was determined using the PV(pressure & velocity) factor. The most stable and highest friction coefficient with a various pressure and velocity condition was found at HEXA 10 wt.% material. The specific wear rate per unit sliding distance with a various HEXA contents was reported.

• Tribology and Lubricants
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• v.24 no.6
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• pp.308-314
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• 2008

The thermal stress have an effect on the frictional factor such as applied load, sliding speed, sliding distance and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors on thermal stress of motorcycle break disk. For this, temperature of motorcycle break disk is measured using a disk-on-pad type friction tester with full factorial design containing above 4 elements. and the thermal stress analysis of it was carried out using with ANSYS workbench. From this study, the result was shown that the regression equation which have a trust rate of 95% for thermal stress presumption of motorcycle break disk with frictional factor was composed. It is possible to apply for another automobile parts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.924-928
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• 2002

Response of the rail surface is an important factor for the train safety and comfortable travel, and evaluation of vibration at the area along a rail is an important factor for the vibration. The dominant method to reduce the vibration that reach the ground is installing vibration absorber between rall and the under structure. In this paper, we evaluated the vibration reducing effect of using vibration control sleeper pads to slave and earth at certain distance from the sleepers.

• Fibers and Polymers
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• v.3 no.2
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• pp.73-79
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• 2002

Nanoscaled PVA fibers were prepared by electrospinning. This paper described the electrospinning process, the processing conditions fiber morphology, and some potential applications of the PVA nato-fibers. PVA fibers with various diameters (50-250 nm) were obtained by changing solution concentration, voltage and tip to collector distance (TCD). The major factor was the concentration of PVA solution which affected the fiber diameter evidently. Increasing the concentration, the fiber diameter was increased, and the amount of beads was reduced even to 0%. The fibers were found be efficiently crosslinked by glyoxal during the curing process. Phosphoric acid was used as a catalyst activator to reduce strength losses during crosslinking. Scanning electron micrograph (SEM) and differential scanning calorimetric (DSC) techniques were employed to characterize the morphology and crosslinking of PVA fibers. It was fecund that the primary factor which affected the crosslinking density was the content of chemical crosslinking agent.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.8
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• pp.780-784
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• 2006

We present high aspect ratio air-core solenoid inductors with $100{\mu}m\;and\;200{\mu}m$ tall via structures on Pyrex wafer. The effect of various parameters such as different number of turns, via heights, pitch distance between turns on inductor's radio frequency (RF) characteristics have been studied. The highest Q factor we obtained from various solenoid inductors is 72.8 at 9.7 GHz, which was produced by a 3-turn inductor.