• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.995-1000
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• 2016

The maximum cross-correntropy (MCC) algorithm with a set of random symbols keeps its optimum weights undisturbed from impulsive noise unlike MSE-based algorithms and its main factor has been known to be the input magnitude controller (IMC) that adjusts the input intensity according to error power. In this paper, a normalization of the step size of the MCC algorithm by the power of IMC output is proposed. The IMC output power is tracked recursively through a single-pole low-pass filter. In the simulation under impulsive noise with two different multipath channels, the steady state MSE and convergence speed of the proposed algorithm is found to be enhanced by about 1 dB and 500 samples, respectively, compared to the conventional MCC algorithm.

• Journal of electromagnetic engineering and science
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• v.6 no.2
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• pp.123-129
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• 2006

This paper presents a method of reducing penetration of penetrated electromagnetic fields through a narrow slot with parallel wire arrays in a planar conducting screen of infinite extent. An integral equation for the aperture electric field on the narrow slot is derived and solved by applying Galerkin's method of moments. When a plane wave is excited to the narrow slot, the aperture electric field is easily controlled by the parallel wire arrays connected on the slot and therefore the magnitude of the penetrated electric field is effectively reduced by loading the parallel wire arrays. The numerical results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the parallel wire arrays on the slot. The results of the calculated penetration electric fields are in good agreement with that of the measured results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.235-238
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• 2009

This study is performed to investigate shearing characteristics for vibration damping sheet metals which are bonded with dissimilar sheet metals. A shearing tool set is designed and manufactured and shearing tests with the tool set are conducted at varying the magnitude of clearance in order to analyze the shearing characteristics. The shearing characteristics are analyzed for burr height and shape of sheared faces with respect to the magnitude of clearance between the punch and the die. The shearing test results demonstrate that optimum clearance is $8{\sim}12%$ of the sheet thickness at the shearing of the vibration damping sheet metals and the shearing direction has to be controlled deriving occurrence of the burr at the thick sheet of the vibration damping sheet metals.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.311-314
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• 1996

In contactless disk handling systems based on electrostatic suspension in which the stator is to be transferred, the limited stiffness in lateral direction severely restricts the achievable translational acceleration. In existing stator electrode pattern designs, the magnitude of the lateral force is determined by the magnitude of the control voltages which are applied to the individual electrodes to levitate the disk stably. As a result, the lateral force cannot be set arbitrarily. A new stator electrode pattern is presented for the electrostatic levitation of disk-shaped objects, in particular silicon wafers and aluminum hard disks, which allows the lateral forces to be controlled independently from the levitation voltages. Therefore, greater lateral forces can be obtained, compared with the existing stator designs. Experimental results will be presented for a 4-inch silicon wafer that clearly reveal the increased lateral stiffness by using the proposed stator electrode compared to the conventional electrode pattern.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.250-253
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• 2004

Sharpness of the tip of micro needle is very Important quality that should be controlled in the manufacturing processes. Acupuncture needle is one of the most widely used micro-needle. And the tip sharpness of acupuncture needle Is usually checked by the magnitude of resisting force obtained through sharpness test. In this study, some sharpness tests of acupuncture needle were done and the relationship between the misalignment of specimen and the magnitude of resisting force. The diameter of the needle used in the test was $250\;{\mu}m$ and the length of it was 40 mm.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.259-267
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• 1994

This paper describes a current control of a single-phase PWM inverter. The proposed PWM inverter utilizes the instantaneous control method which is based on the real-time digital feedback control and the microprocessor-based deadbeat control. The deadbeat current controller is proposed to control the output current regardless of load component variations by the same method as voltage control. That is, in current control, with a very short sampling time and the successive feedback of the output current, the load current is mainly effected by the magnitude of load impedance rather than load component, the load current is mainly effected by the magnitude of load impedance rather than load component. Therefore, by treating the load as an impedance, the system's order is reduced and the instantaneous current control using the proposed deadeat controller is simplified.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.478-480
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• 1998

We develops a simulator to evaluate the performance of the autosyncronizer. The autosyncronizer is used to automatically syncronize magnitude, frequency, and phase of 3 phase signals of generator with respect to those of the utility grid. This autosyncronizer needs to be evaluated its performance to prevent malfunctions. To do this, 3 phase signals of generator and the utility grid are simulated and signals of the generator should be changed by ouput of the autosyncronizer with high precision. In this paper, we uses TMS320C31 to generate high precision sinusoidal 3 phase signals using Table Lookup method. In this process, it is very desirable to control magnitude, frequency, and phase of the signal with high precision and this is achieved by appropriate interpolation method. The resulted signal is well controlled and has low THD and could be used to evaluate the performance of the autosyncronizer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1179-1185
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• 2012

This paper presents a new approach for the detection of seismic events using accumulated changes on time-frequency domain and variable threshold. To detect seismic P-wave arrivals with rapidness and accuracy, it is that the changes on the time and the frequency domains are simultaneously used. Their changes are parameters appropriated to reflect characteristics of earthquakes over moderate magnitude(${\geq}$ magnitude 4.0) and microearthquakes. In addition, adaptively controlled threshold values can prevent false P-wave detections due to low SNR. We tested our method on real earthquakes those have various magnitudes. The proposed algorithm gives a good detection performance and it is also comparable to STA/LTA algorithm in computational complexity. Computer simulation results shows that the proposed algorithm is superior to the conventional popular algorithm (STA/LTA) in the seismic P-wave detection.

• Journal of KSNVE
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• v.9 no.2
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• pp.258-264
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• 1999

The purpose of this paper is to investigate the damping behavior of a flexible joint. The slip at a structrual joint is selected at the tips of two identical cantilever beams adjoining each other. Both the direction of normal force and its magnitude varies due to the global deformation of the structure from mode to mode in the friction model. The friction dependent on vibration displacements resultsin the same functional behavior of the hysteretic material damping. Linearized energy loss factors are obtained as functions of both linear and torsional spring stiffness for their groups of symmetric and anti-symmetric modes, respectively. Experimental measurements as made for comparisons with analytical estimations by controlling the magnitude of fastening torque in the fastener, Hi-Lite. Trends on damping levelsmeasured in a very common vibration test method make an excellent agreement on the estimated damping levels.

• Proceedings of the KIEE Conference
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• 1986.07a
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• pp.132-135
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• 1986

This paper shows that using the multivariable controller reduces the magnitude of fluctuations of the control signals which result improved control of the steam generator outputs. Comparison of the performance of the multivariable weighted adaptive controller(MWAC) with the performance of the existing PI controller and the self_tuning controller/1/, when the system goes through a transient mode, shows that the out-puts stay closer to their set points when they are controlled by the adaptive controller.