• Journal of Korean Society for Atmospheric Environment
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• v.13 no.4
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• pp.297-305
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• 1997

The experimental study by use of SPCP was fulfilled to remove toluene emitted from various industrial processes. First of all, discharge characteristic was experimented as the change of applied voltage and frequency. Then toluene removal characteristic was tested with the analysis of by-products. As a result, optimum electrical discharge condition was from 20.0 kHz to 25.0 kHz of frequency and from 3.5 kV to 4.0 kV of voltage range. The variation of applied voltage had a more important effect on the removal characteristic of toluene than the frequency variation. The toluene removal efficiency was proportioned to ozone concentration and retention time on discharge plate. It was dropped as increase of toluene concentration, but total treated volume of tolene per power consumption was high. The decomposed toluene was transformed to $CO, CO_2$ and particulates, and the rate of transformation to particulates was higher than CO and $CO_2$ at high toluene concentration. Particulates were increased from 0.017 $\mum$ to 0.3 $\mum$ range of size distribution.

• Journal of Aerospace System Engineering
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• v.5 no.2
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• pp.33-39
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• 2011

The vibration characteristic of tires is one of very important issues which heavily affect the noise and comfort on driving. Therefore, when the new tire is designed, the vibration characteristic of tire should be considered. In this paper, the vibration characteristic of non-pneumatic tire is investigated for geometric of NPT which is designed by cell angle of spoke. The analysis is based on the finite element method and used ABAQUS program, which is able to non-linear analysis. The material of NPT is used for the Ogden energy model, which is model of hyperelastic material. This paper investigate natural frequency and modal of NPT and compare result of NPT with it of pneumatic tire.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.45-54
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• 2015

This paper presents the influence of backlash can be greatly increased on the frequency response characteristic which is presented as the angular velocity of a motor to the motor input voltage, if the motor input voltage is adequately reduced. And, this paper verifies theoretically, analytically and experimentally the availability on the method of detecting the change of backlash magnitude by investigating on the change of the anti-resonance and resonance frequencies in the frequency response characteristic due to the change of backlash magnitude. The amount of change of anti-resonance frequency is more useful that of resonance frequency when detecting the change of backlash magnitude, because the change of anti-resonance frequency can be measured more stable. This paper also shows the sharp change of resonance frequency can be investigated when the motor input voltage is enough reduced. The work will be useful for the further research on the backlash estimation method of a servo system with a gear reducer.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.3
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• pp.179-186
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• 2002

This paper proposed LC resonant current fed high frequency inverter for high frequency induction heating using leakage inductance of transformer and, its described operating principle. The analysis of circuit presented by using normalized parameter in considering leakage inductance of transformer and, discussed characteristic evaluation of inverter circuit in detail. The proposed inverter is operating ZVS to reduce turn-on and turn-off loss of switching devices so, raised an efficiency. And, the experimental apparatus was made on base characteristic evaluation of theoretical analysis to discuss possibility on high frequency source and confirmed a rightfulness theoretical analysis. A result of study, the proposed inverter is higher utilizing factor using on leakage inductance of transformer and show possibility, which is application on high frequency power system.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.350-353
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• 1994

This paper presents a method to calculate the characteristic root areas and loci band of control systems with uncertainties. First, equations of boundary curves of root areas in the case of additive and multiplicative perturbation are derived. Then, an algorithm for the calculation of the array of closed curves is presented. When the upper bound of the absolute values of frequency responses for the uncertain part, is also frequency-dependent, the frequency-dependent, terms are included in the characteristic equation of the nominal system. This lead to the boundary equations of the root, areas for control systems with frequency-dependent uncertainty. Numerical examples of the control systems with multiplicative perturbations including frequency-dependent terms are presented to verify this calculation method. Finally, its applications to the design of robust control systems, e.g., passive adaptive control systems are also discussed.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.138-142
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• 2004

Recently over dropped frequencies of power system were recorded when power system was unbalanced between generation and demand. Therefore load following characteristic analysis of thermal and combined cycle power plant generators is necessary for low frequency condition analysis of power system. Frequency simulator supplies simulated frequency to the online generator for prescribed goal. This simulator needs to minimize effects to power system and requires stability first. This paper introduces design and manufacturing case of frequency simulator for load following characteristic analysis of generators.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.291-294
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• 2003

The circuit substrate was made from the Low Temperature Cofired Ceramics(LTCC) that a $\varepsilon_\gamma$ was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimension in the multilayer substrate circuit inside, and one structure accumulate band-pass filter, resonator, a bias line, a matching circuit, and made it. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO(Voltage Controlled Oscillator), and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], hamonics characteristic -45[dBc] in control voltage 1.5[V], A phase noise is -68.22[dBc/Hz] in 100 KHz offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA].

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.54-57
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• 2003

A new non linear, mean value, instantaneous following control technique to design half bridge converter is proposed in witch control principle uses characteristic that reset time of analog integrator is inverse proportion In input voltage. It is Important characteristic that compensation and follow-up control time are same with switching frequency. Is completed in one cycle that base control frequency. Have excellence characteristic that follow in order instruction value exactly stationary state as well as transient state. Half bridge converter that apply this control principle can know that have stabilize and excellence characteristic. This technique is verified through an experiment, and know that experiment result and theory agree well.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1529-1533
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• 2005

In this paper designed available pre-amplifier to Intrabroadband power amplifier. Designed pre-amplifier used WJ company's AMI which frequency characteristic and noise characteristic are superior. Designed to have superior VSWR characteristic and frequency characteristic covering broadband of 100MHz ${\~}$ 3GHz using feedback. Designed ye-amp broadband special qualify such as EMC measurement equipment roll important position do to utilize to power amplifier of equipment that how consider.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.175-182
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• 1994

In this study, we present unvoiced consonant recognition system using characteristic parameters of the phoneme of the each syllable. For the recognition, the characteristic parameters on the time domain such as ZCR, total energy of the consonant region and half region energy of the consonant region, and those on the frequency domain such as the frequency spectrum of the transition region are used. The objective unvoiced consonants in this study are /ㄱ/,/ㄷ/,/ㅂ/,/ㅈ/,/ㅋ/,/ㅌ/,/ㅍ/ and /ㅊ/. Each characteristic parameter of two regions extracted from these segmented unvoiced consonants are used for each recognition system of the region, independently, And complementing two outputs of each other system, the final output is to be produced. The recognition system is implemented using MLP which has learning ability. The recognition simulation results for 112 unvoiced consonant samples are that average recognition rates are 96.4$\%$ under 80$\%$ learning rates and 93.7$\%$ under 60$\%$ learning rates.