• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.362-368
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• 2023

In this paper, we presented the characteristics of the impulse signal which is applicable to the ultra-wideband antennas. In general, the width of the impulse has around sub nano or pico seconds in the time domain, where it corresponds to the wideband in the frequency domain. We confirmed by experiment that the impulse has around 130ps of the pulse width and bandwidth of 4GHz when 10MHz of sine wave excited as an input pulse. The fidelity factor was calculated in the time domain and -10dB bandwidth in the frequency domain was investigated for resistively loaded dipole antennas with different resistance per unit length. The received impulse signal through the wideband antennas is confirmed in the time and frequency domains that received pulse is to be similar to the generated impulse. The fidelity and bandwidth of the quantity value are 0.98 and 3.4GHz, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.2
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• pp.93-98
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• 2024

This paper presents the method to extract the ultrawide-band (UWB) signal and proposes the simple impulse radar system for sensing real-based target within close-range area. The proposed impulse radar system consists of impulse generator, ultrawide-band antennas, function generator, and digital oscilloscope. It is verified by experiment that a differentiated Gaussian pulse is generated with 200ps of pulse width and corresponding spectrum from 0.3 to 4.7 GHz once a sinusoidal wave with 10MHz is excited. The Gaussian doublet is received by identical antennas and it is shown that the UWB pule width of 328ps and its spectrum is from 0.9 to 4.4 GHz. It is confirmed that the UWB pulse is extracted when the real-based targets such as circular target with 4cm radius and corner reflector are placed at the close-range area.

• Journal of IKEEE
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• v.24 no.1
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• pp.120-126
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• 2020

We present a user recognition method using human body impulse response signals. The body compositions vary from person to person depending on the portion of water, muscle, and fat. In the body communication study, the body has been interpreted circuit models using capacitance and resistances, and its characteristics are determined by the body compositions. Therefore, the individual body channel is unique and can be used for user recognition. In this paper, we applied pseudo impulse signals to the left hand and recorded received signals from the right hand. The empirical mode decomposition (EMD) method removed noise from the received signals and 10 peak values are extracted. We set the differences between peak amplitudes as a key feature to identify individuals. We collected data from 6 subjects and achieved accuracy of 97.71% for the user recognition application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.443-446
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• 2005

As modern society needs to process of acquisition, storage and transmission of much information, the importance of signal processing is increasing and various digital filters are used in the two-dimensional signal such as image. And kinds of these digital filters are IIR(infinite impulse response) filter and FIR(finite impulse response) filter. And FIR filter which has the phase linearity, the easiness of creation and stability is applied to many fields. In design of this FIR filter, flatness property is a important factor in pass-band and stop-band. In this paper, we designed a 2-D Circular FIR filter using the Bernstein polynomial, it is presented flatness property in pass-band and stop-band. And we simulated the designed filter with noisy test image and compared the results with existing methods.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.143-150
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• 2021

Prior research on consumer psychology has primarily focused on when and why consumers exhibit impulsive behavior, such as impulse buying. This study focuses on physical stimulation during an impulse purchase as another meaningful factor. Specifically, this study examines whether thirst depletes cognitive resources. The results of two experiments show that impulse purchase tendency increases when consumers are thirsty (Exp. 1), and that the loss of self-control is based on the relationship between thirst and impulse purchase tendency (Exp. 2). These findings suggest that physical stimulation, such as thirst, may be a useful indicator of impulsive behavior in consumers.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.167-170
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• 2005

Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) filter showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error. So, variable methods that modified SM(standard median) filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.352-355
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• 2005

This paper describes an engineering model development of a pulsed plasma thruster, which is capable of an impulse bit of 20uNs and a specific impulse of 800s. The solid fuel which is Teflon allows for a self-contained, inert and stable propellant system. And, the PPT technology makes it possible to consider a revolutionary attitude control system (ACS) concept providing stabilization and pointing accuracies previously obtainable only with reaction wheels, with reduced mass and power requirements.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2362-2367
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• 2005

This paper reports a technique for discriminating double talk and echo path change using the stochastic characteristics of power change for an adaptive noise canceller. The causes of rapid error increasing are double talk and echo path change. When the echo path is changed, the system corrects the impulse response in order to reduce the error. However, in the case of double talk, the system has to suspend the updating impulse response in order to maintain the quality of the voice signal. In the conventional system, it was difficult to discriminate between the two situations. In this research, the stochastic characteristics of the voice power change in the double talk period were experimentally verified to be different from the power change during echo path changing. Based on the results, a new double talk detection method is proposed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.155.4-155
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• 2001

This paper deals with the inertia property-based redundancy resolution in posture control of a mobile manipulator. As a measure for the redundancy resolution of a mobile manipulator, an effective inertia at the end effector in the operational space is proposed and investigated. The reduced effective inertia has a significant effect on reducing the impulse force in collision with environment. To find a posture satisfying both the reduced inertia and joint limit constraints, we propose a combined potential function method that can deal with multiple constraints. The proposed reduced inertia property algorithm is integrated into a damping controller to reduce the impulse force at collision and to regulate the contact force in mobile manipulation ...

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.283-288
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• 2002

This paper has shown that the impulse and the unit step responses of 2nd-order systems can be computed by an analytic method. Three different 2nd-order systems are investigated: the prototype system, the system with one LHP(left half plane) real zero and the system with one RHP(right half plane) real zero. It has also shown that the effects of the LHP or the RHP zero are very serious when the zero is getting closer to the origin on the complex plane. Based on these analytic results, this paper has presented two sufficient and necessary conditions for 2nd-order linear SISO(single-input/single-output) stable systems to have the nonovershooting and the monotone nondecreasing step response, respectively. The latter condition can be extended to the sufficient conditions for the monotone nondecreasing step response of high-order systems.