• Analytical Science and Technology
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• v.5 no.1
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• pp.79-82
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• 1992

A bipolar pulse conductometric detector has been developed for continuous on-line monitroring of the flowing sample streams. The conductometric detector was fast and easy to use due to the free of interferences by serial or parallel capacitances. The performance of the bipolar pulse conductometric detector was tested using dummy cells with $10^1{\sim}10^8$ ohm resistance range and found a linear response with a 0.01% relative standard deviation. The possible applications of the bipolar pulse conductometric detector was discussed.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.528-533
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• 2006

Electrical discharges may occur in gas, liquid as well as solid insulating materials. This paper describes the investigation results on the discharges in air, silicone oil and low density polyethylene (LDPE) using needle plane electrode system under AC voltage of 50 Hz. The experimental results showed that for discharge in air (corona), discharge pulses were concentrated around the peak of applied voltage at negative half cycle. For silicone oil positive as well as negative discharges were observed which concentrated around the peak of applied voltage. The positive pulse number was smaller but the magnitude was higher than that of negative discharge. Discharges in void took place at wider range of phase of applied voltage. The unbalance in pulse number and magnitude similar to that of oil discharges were observed. For electrical treeing in LDPE, the discharges were spread before the zero cross of the applied voltage up to the peak at both positive and negative half cycles. The discharge pulse sequence analysis indicated that the PD occurrence in air, oil and void were strongly affected by the magnitude of applied voltage. However, for electrical treeing it was observed that the discharge occurrence was strongly affected by the time derivative of the applied voltage (dv/dt).

• Journal of Welding and Joining
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• v.28 no.6
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• pp.28-34
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• 2010

This paper was described on investigation to prevent porosity in high speed MIG Welding of Al 6082-T6. Porosity measurement was carried out by using image analysis of micrographs with the help of an analysis software. The main parameter was arc length and torch progressive angle. The porosity ratio was increased as arc length was increased. The arc length was increased depending upon the output voltage. By proper selection of pulse waveform parameter, the stable arc of one pulse one drop was generated. The porosity ratio of optimum condition in one pulse one drop was lower than high voltage condition. When torch progressive angle was an angle of advance $10^{\circ}$, porosity ratio was minium.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.11
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• pp.981-986
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• 2000

A pulse amplitude modulation(PAM) controller is designed for the 3 axis attitude control of a sounding rocket. a certain number of fixed level of thrust are used for the pulse amplitude modulation and the nonlinearity of the controller is considered to examine the existence of the limit cycles and the stability analysis is carried out with the aid of Nyquist plot.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.55-57
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• 2003

This paper presents a new method for finding the Block Pulse series coefficients and deriving the Block Pulse integration operational matrices which are necessary for the control fields using the Block Pulse functions. In this paper, the accuracy of the Block Pulse series coefficients derived by using the Lagrange second order interpolation polynomial is approved by the mathematical method.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.66-72
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• 2002

This paper describes numerical modeling for thermal characteristic of vapor-cooled current leads under pulse operation. The transient thermal analysis considers the temperature difference between a helium gas (low and a copper lead and temperature dependent properties of helium gas, copper and stainless steel. This numerical modeling was compensated and validated by an experiment with commercially available 100 A vapor-cooled current leads. A proper overloading factor was suggested for the current leads under pulse operation through this modeling, which can significantly reduce heat input to a cryostat.

• Proceedings of the Korean Magnestics Society Conference
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• 2013.12a
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• pp.77-78
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• 2013

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1247-1251
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• 2016

This study aims to investigate the effect of sampling frequency to the time domain and frequency domain analysis of pulse rate variability (PRV). Typical time domain variables - AVNN, SDNN, SDSD, RMSSD, NN50 count and pNN50 - and frequency domain variables - VLF, LF, HF, LF/HF, Total Power, nLF and nHF - were derived from 7 down-sampled (250 Hz, 100 Hz, 50 Hz, 25 Hz, 20 Hz, 15 Hz, 10 Hz) PRVs and compared with the result of heart rate variability of 10 kHz-sampled electrocardiogram. Result showed that every variable of time domain analysis of PRV was significant at 25 Hz or higher sampling frequency. Also, in frequency domain analysis, every variable of PRV was significant at 15 Hz or higher sampling frequency.

• The Journal of Korean Obstetrics and Gynecology
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• v.28 no.4
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• pp.31-45
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• 2015

Objectives : The purpose of this study is to examine the relationship between the symptoms of primary dysmenorrhea and pulse energy of Chon, Gwan and Cheok. Methods The subjects of this study who had certain range of dysmenorrhea symptom. The degree of dysmenorrhea were assessed by Visual Analog Scale (VAS), Multidimensional Verbal Rating Scale (MVRS), Cox Menstrual Symptom Scale (CMSS) and measured by 3D Blood Pressure Pulse Analyzer(3D-MAC) tests at menstruation start date. Data analysis included descriptive statistics and multiple linear regression using the SPSS/WIN 18.0 program. Results : The induced results are as follows;The induced results are as follows 1. There were no significant relationship between the pulse energy and the sum values of VAS, MVRS and checking part of severity of CMSS. 2. The frequency domain of CMSS were significantly associated with pulse energy. 3. In linear regression models, the model of Left Chon had the especially highest value of explanatory power. (R ² = 0.517) Conclusions : The pulse energy changes are related to the symptoms of primary dysmenorrhea.

• The Journal of Korean Obstetrics and Gynecology
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• v.28 no.1
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• pp.73-84
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• 2015

Purpose: The purpose of this study is to analyze the characteristics of the pulse energy in women who complain of climacteric and menopausal symptoms. Methods: We analyzed the values of pulse energy on 45 climacteric and menopausal women. The patients' symptoms were assessed by Kupperman's index and Menopause Rating Scale (MRS). Statistical analysis was performed using SPSS 18.0 for window program, one way ANOVA, pearson correlation coefficient. Results: The results were as follows. 1. The pulse energy of the Left Chon was significantly largest and Left Cheok was comparatively smallest. 2. There was no statistically significant correlation in the pulse energy of Left Chon minus Left Cheok, Kupperman's index, MRS total sum score. Conclusions: The results suggest that the pulse energy of the Left Chon tends to be increased and Left Cheok decreased in climacteric and menopausal women.