• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.638-641
• /
• 1999

In consideration of Dielectric loss and Temperature stability, 3-element system dopped with NiO, $Cr_2O_3$, well-known as Hardner and Stabilizer whose primary element is PZT was eximanated its structure, Temperature Coefficient of Capacitor, relative resistivity for Temperature Compensation condensor study. dopping with Nio, $Cr_2O_3$, Temperature Characteristic is developed, Dielectric loss largely represented useful1 small values in specimens dopped with NiO 0.2wt%, and specimence sintered at $110^{\circ}C$ dopped with $Cr_2O_3$, 0.1wt% also relative resistivity largely showed tendency of decrement According to dopping NiO more.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.8
• /
• pp.629-634
• /
• 2009

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as the backduct component to decrease the power consumption of an electric clothes dryer.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2262-2267
• /
• 2008

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as backduct component to decrease the power consumption of an electric clothes dryer.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.361-366
• /
• 2003

For regenerative pump performance test we made 5 times enlarged and 3 different kinds blade types impeller with similarity. Due to geometrical characteristic of regenerative pump, there are two kinds of groups which effect on performance of it. One is geometric shape of impeller blade and the other is clearance and inlet/outlet head loss. To study performance of regenerative pump with impeller shape changes, we tested it with reducing clearance. And we reconcile performance data in the case of zero clearance and zero inlet/outlet head loss. Finally we could verify the influence of each group.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.379-383
• /
• 2000

This paper describes the design program of duct silencer. Duct silencer is used ventilating system. Variables in the program for predicting transmission loss are width of splitter, airway width, perforate plate, absorption material and frequency. Generally used expression for predicting transmission loss has something that don't think about frequency characteristic. Therefore we propose the new expression that considered frequency characteristic. In the 1/1 octave band center frequency, the expected weighting number(K) is fitted with absorption ratio and airway width. The fitted 2nd degree polynomial expression is based on the test data performed in YOUIL Industrial Corperation. This program's accuracy is about 90 percent.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.9
• /
• pp.1228-1233
• /
• 2013

In this paper, design of Wound Rotor Synchronous Motor(WRSM) for Integrated Starter and Generator(ISG) is performed based on Finite Element Analysis(FEA). WRSM can control not only magnitude and phase of armature current, but also field current. Thus, various control methods can be considered. Since driving characteristic of WRSM depends greatly on the control method, characteristic analysis accoding to possible driving current combination is reguired. Especially in high speed region, the control method that reduces unnecessary d-axis current by reducing field current is possible, which is similar to field weakening control. By the current combination reducing field and d-axis current, the design minimizing copper loss to increase efficiency on identical driving point is possible. In this paper, high efficient WRSM is designed applying the current combination which can minimize copper loss on each driving point.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.2
• /
• pp.141-147
• /
• 2015

This paper deals with thermal characteristic analysis of induction motors for machine tool spindle for motion error prediction. Firstly, the inverse design of general induction motors for machine tool spindle has been performed by design principles. Characteristics considering VVVF inverter of induction motors were analyzed. Secondary, power loss and thermal characteristics of induction motors analyzed by equivalent thermal resistance model from Motor-CAD S/W. To develop a second-order fitted power-loss distribution model for the constant-torque operating range of the induction motor, we employed the design of experiment and response surface methodology techniques. Finally, the analysis results were experimentally verified, and the validity of the proposed analysis method was confirmed.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.4
• /
• pp.431-441
• /
• 1998

Polyester microfiber fabrics were decomposed at 100, 110, 120 and 140 t of temperature and 0.5, 1.0 and 1.5% of sodium propyleneglycolate/propyleneglycol solution(SPG-PG). Characteristic decomposition feature and physical and chemical properties of the decom- posed PET microfiber fabrics were discussed. The activation energy was 18.77 kcal/mol and the dyeability of the decomposed PET microfiber fabrics was found to be improved as it was supported by the examined K/S values. Up to the 20% of the weight loss of the PET microfiber fabrics, K/S values incresed with increasing the weight loss. The melting temperature of PET microfiber fabrics decomposed by SPG-PG showed no fundamental change. Tensile strength of the decomposed PET microfiber fabrics decreased linearly in accordance with the increased the weight loss of the PET microfiber fabrics. The moisture regain and the tactilities increased in accordance with the increased the weight loss of the PET microfiber fabrics.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.22 no.1
• /
• pp.70-78
• /
• 1998

The present study has tested semi-empirical loss models for a reliable performance prediction of mixed-flow pumps with four different specific speeds. In order to improve the predictive capabilities, this paper recommends a new internal loss model and a modified parasitic loss model. The prediction method presented here is also compared with that based on two-dimensional cascade theory. Predicted performance curves by the proposed set of loss models agree fairly well with experimental data for a variety of mixed-flow pumps in the normal operating range, but further studies considering 'droop-like' head performance characteristic due to flow reversal in mixed-flow impellers at low flow range near shut-off head are needed.

• Journal of Korean Society for Quality Management
• /
• v.21 no.2
• /
• pp.61-70
• /
• 1993

The concept of producer's tolerance, in contrast to the consumer's tolerance, is a natural consequence of continuous loss functions. It is based on the premise that any unit product whose quality characteristic deviated from its traget value inflicts a loss, and that this less is a continuous monotonically increasing function of the magnitude of deviation. This concept of the emphasis on loss function to improve quality of products on the side of customer is introduced by Taguchi. This paper considers the problem of determining the optimum producer's tolerance by continous loss fuction of Taguchi and proposes a probablistic model for the problem. The difference between the proposed probablistic approach and the approach taken in Taguchi is also pointed out.