• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.115-123
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• 2005

This paper presents the development of an algorithm for position control of feed drives in machine tools. The algorithm is constructed through an experimental method based on proportional control with a ramp input. In the first step of designing, a tracking-error curve is generated with the proportional control, and then an error model is decided to reduce the tracking error, Next, the output signal of the error model is added to the current error signal to yield the actuating error signal. The effectiveness of the proposed scheme is confirmed through simulation and experiments.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.1
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• pp.51-57
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• 2010

This study was to analyze the difference in pilot error by using the Signal Detection Theory. The task was to detect the targeted aircraft(signal) which is different shape from many other aircraft(noise). From the two experiments, we differentiated the task difficulty followed by change in noise stimuli. Experiment 1 was to search the signal stimuli(fighter plane) while the noise stimuli(cargo plane) were increasing. The results from the Experiment 1 showed the tendency to decrease the hit rate by increasing the number of noise stimuli. However, the false alarm rate was not increased. The sensitivity(d') showed quite high. In Experiment 2, a disturbance stimulus(helicopter) was added to noise stimuli. The result was generally similar to those of Experiment 1. However, the hit rate was lower than that of Experiment 1.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.3-8
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• 2015

In this paper, we propose a blind equalization algorithm based on the error signal linearly combined a constellation-matched error (CME) and a non-constellation-matched error (non-CME). The new error signal was designed to include the non-CME term for reaching initial convergence and the CME term for improving intersymbol interference (ISI) performance of output signals, and it controls the error terms through a combining factor. By controlling the error terms, it generates an appropriate error signal for equalization process and improves convergence speed and ISI cancellation performance compared to those of conventional algorithms. In the simulation for 64-QAM and 256-QAM signals under the multipath channel and additive noise conditions, the proposed method was superior to CMA and CMA+DD concurrent equalization.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.321-324
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• 1997

In this paper, Active Noise Control(ANC) algorithm is proposed based on the estimated frequency estimator of the reference signal. The conventional feedforward ANC algorithms should measure the reference and use it to calculate the gradient of the squared error and filter coefficients. For ANC systems applied to aircrafts and passenger ships, engines from which reference signal is usually measured is so far from seats where main part of controller is placed that the scheme might be difficult to implement or very costly. Feedback ANC algorithm which doesn't need to measure the reference uses the error signal to update the filter and is sensitive to unexpected transient noise like a sneeze, clapping of hands and so on The proposed algorithm estimates frequencies of the desired signal in real time using adaptive notch filter. New frequency estimation algorithm is proposed with the improved convergence rate, threshold SNR and computational simplicity. Reference is not measured but created with the estimated frequencies. It has strong similarity to the conventional feedback control because reference is made from error signal. Enhanced error signal is used to update the controller for better performance under the measurement noise and impact noise. The proposed ANC algorithm is compared with the conventional feedback control.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.75-81
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• 2010

Adaptive array antenna system estimates target signal, as making a null pattern toward the interference signal. However, receiving a coherent interference signal at adaptive array antenna system, as target signal is regarded as interference signal, the performance of system rapidly decreases. The main beam does not direct an incidence direction of target signal due to sensitivity in directivity error. This paper proposes beamforming algorithm which combines high order limit condition and directivity error modify method. And it minimizes degree of freedom and decreases interference signal and directivity error using proposed algorithm. This paper compares and analyzes the performance of proposed algorithm and general algorithm using simulation. In this paper, the proposed algorithm correctly estimates an incident angle, but general algorithm occurs an error of about $0.8^{\circ}$.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.63-70
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• 2014

Method a target estimation in spatial are mobile wireless communication using network cell and GPS. It have much error that mobile wireless communication depend on cell size. GPS method can't find a target in shadow and inner area. In this paper, we estimate a target as direction of arrival method using adaptive array antenna system. Adaptive array antenna system can obtain desired signal to remove other signal This paper studied digital beamforming method in order to estimation a target. Proposed method is modified optimum weight and antenna error correction to estimation an optimal receive signal. Digital beamforming method decided a signal phase and amplitude from received signal on array antenna element. But if it is not to do error correction of received signal, system performance have decreased. Firstly, we proposed modified optimum weight in order to finding desired target. Secondly, we are error correction of antenna incident signals by optimal weight before digital beamforming method. Thirdly, throughly simulation, we showed that system performance of proposed method compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.182-188
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• 2024

Hardware components are an integral part of Hardware Define Radio (HDR) for seamless operations and optimal performance. On the other hand, Software Define Radio (SDR) is a program that does not rely on any hardware components for its performance. Both of the latter radio programmers utilize modulation functions to make their core components from signal processing viewpoint. The following paper concentrates on SDR based modulation and their performance under different modulations. The bit error rate (BER) of modulations such as PSK, QAM, and PSAM were used as indicators to test channel quality estimation in planar Rayleigh fading. Though it is not commonly used for channel fading, the method of the adder determines the regionally segmented channel fading. Thus, the estimation error of the channel change substantially reduces the performance of the signal, hence, proving to be an effective option. Moreover, this paper also elaborates that BER is calculated as a function of the sample size (signal length) with an average of 20 decibels. Consequently, the size of the results for different modulation schemes has been explored. The analytical results through derivations have been verified through computer simulation. The results focused on parameters of amplitude estimation error for 1dB reduction in the average signal-to-noise ratio, while the combined amplitude deviation estimation error results are obtained for a 3.5 dB reduction

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.190-195
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• 2016

In this paper, we are comparative analysis both class method and proposal method in order to estimation of incident signal direction on uniform array antenna system. Proposal method of this paper decrease error probability for a signal direction of arrival estimation using maximum posterior probability estimator. If it decrease to signal estimation direction error probability, signal direction of arrival can correctly estimate. Through simulation, we were comparative analysis proposed method and class method. Also, we were comparative analysis about signal estimation error probability with increasing array antenna element. We show the superior performance of the proposed method relative to the class method to decrease of signal estimation error probability about 12%.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.17-20
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• 2000

In a digital communication system, the transmission channel may introduce error into the digital signal being transmitted. It would be useful if a process could be devised so that the error could be removed in order to recover the transmitted digital signal. We design a corrective filter that is inverse filter, which will generate an output signal identical to the input signal. in order for two systems connected in cascade to produce an output which is identical to the input signal, the over-all unit sample response of the cascade connection must be a unit sample function.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.10
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• pp.1003-1010
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• 2008

In this paper, we propose the new method to decrease the navigation error by measurement time synchronization error in RLG Trapping signal processing. There are two methods to eliminate the dither motion in RLG. One is the stripping signal processing method. Another is the trapping signal processing method. This two methods have various error sources in measurement output. We perform the error modelling and analysis for the measurement time synchronization error between angular rate from RLG and acceleration from accelerometer in the trapping signal processing method. And we verify the navigation performance through simulation and experiment. Results of simulation and experiment show that the proposed method is very effective in decreasing the navigation error.