• 모자간호학회지
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• v.3 no.2
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• pp.172-186
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• 1993

The survey was performed on 201 cases of mothers who visited pediatric hospitals and public health clinics in Pusan and Kyeong-nam provinces from Dec. 10 to Dec. 30 of 1993. If this study, each infant weighed over 2500gm and between 2 months and 12 months old. The research was statistically analyzed according to the percentage, Pearson correlation, $x^2$-test. The result of this study were as follows ; 1. Feeding method related to the job of mother (p<0.01). 2. Feeding method related to the way of bringing up child(p<0.05). 3. Whether the mother and child shared the same room effected the feeding method (p<0.01). 4. The shape of nipple before breast feeding related to feeding method. 5. The reason for stopping breast feeding related to feeding method(p<0.01). 6. First breast feeding related to period of seperation after delivery(p<0.05). 7. Plan of breast feeding related to birth weight (p<0.05).

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.183-185
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• 2002

This paper proposes the test method for the testing of a RLC parallel circuit on the electronic circuit board. This method utilizes a guarding circuit and a phase detection circuit. The guarding circuit separates electrically the tested device or circuit from printed circuit board. Phase detector estimates the phase difference from two signals, voltage and current. This method computes R. L and C value from phase difference($\theta$) and impedance value(Z) obtained by enforcing two other frequence stimulus under the guarding state.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.154-157
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• 2003

The exicting short circuit analysis calculate the current with the balance system and unbalance fault impedance. That method deal with only bus fault with the consequence that line fault study is irrational. This paper propose the line fault, shunt unbalance and series unbalance analysis method using template concept that is one of advantages for OOP(Object-Oriented Programming). This method is possible to use for calculating inductive distrubance.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.762-763
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• 2015

Magnetic coupling is used where required high reliability. because magnetic coupling's durability is stronger than mechanical coupling's durability. This paper shows the force characteristics of halbach array magnetized tubular type magnetic coupling using Analytical method. Analytical method was used, to find force characteristics. Finite element method (FEM) is used to validate force characteristics.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.139-142
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• 1990

This paper presents a new approach to optimal power flow (OPF) problem using conjugate gradient method, using this method. We can obtain initial feasible solution and lagrangian multiplier without calculation of matrix inversion.Test experiment shows a desiriable result and a stable convergence characteristic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.439-442
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• 2003

The test method of ASTM E 756 and JIS G 0602 to estimate vibration-damping properties is presented. Measurement method depending on specimen support, exciting method and calculation method for loss factor is used. Half-power bandwidth method and vibration decay method is used in the calculation method for loss factor, and Young's modulus is decided by geometric character and density for specimen and resonance frequency. Vibration measurement sensor is compared by using non-contact displacement detector, velocity detector and accelerometer. The cause of measurement error is also presented.

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.786-791
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• 1994

A simple and rapid sample pretreatment process necessary for determination of metal oxides in water was proposed. Samples were injected into the continuous-flow tube installed inside the microwave oven and the treated samples were cooled before entered to the Ion Chromatography (IC) or Inductively Coupled Plasma (ICP). By coupling this microwave digestion system with IC or ICP, a fully automatic analytical procedures may be easily established. In this study, two different types of digestion methods were considered; the open tubing method (OTM) and the restraint tubing method (RTM). The RTM was proved to be 3 times faster in digestion period and 10 times higher in detection range than the OTM. Validation of proposed sample digestion system was carried out by using an ICP. The results showed that both of continuous-flow methods, the OTM and the RTM were comparable in accuracies with the conventional batch-type vessel digestion method.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.107-109
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• 2000

This paper deals with the method of solving the problem of editing data in the former file-based power system analγsis program. It gives more convenient and effective to user. Also, a method to use the rowel-system analysis program based in the web interface is presented.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.139-142
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• 2002

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM) voltage control for Ozone Generator are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with 6.5[kHz], 1.8[kW] inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.185-187
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• 1995

A boost converter proposed in this paper operates with high power factor due to input current of sinusoidal waveform. If there were no input LPF, the current is got to be discontinuos form in proportion to AC input voltage magnitude under the constant duty factor switching. Thereupon, the harmonics of input current waveform is reduced and the LPF is made with few elaboration and the control circuit is simple. The switching devices in proposed circuit are operated with soft switching by the partial resonant method. The patial resonant circuit makes use of a reactor using step-up and a capacitor of loss-less snubber. The result is that switching loss is very low and efficiency of system is high.