• Journal of Korea Society of Industrial Information Systems
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• v.25 no.6
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• pp.1-13
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• 2020

In this paper, the author proposed a nuclear power plant (NPP) instrumentation signal faults identification algorithm. A variational autoencoder (VAE)-based model is trained by using only normal dataset as same as existing anomaly detection method, and trained model predicts which signal within the entire signal set is anomalous. Classification of anomalous signals is performed based on the reconstruction error for each kind of signal and partial derivatives of reconstruction error with respect to the specific part of an input. Simulation was conducted to acquire the data for the experiments. Through the experiments, it was identified that the proposed signal fault identification method can specify the anomalous signals within acceptable range of error.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.9
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• pp.686-692
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• 2016

A Crimp Force Monitor (CFM) is equipment for detecting crimp errors by analyzing crimp signals obtained from force and strain sensors. The analysis is commonly performed by aligning a measured crimp signal with a reference signal and comparing their difference. Current analysis methods often suffer from wrong alignments that result in false negative detections. This paper presents a new crimp signal analysis method in CFM. First, a falling edge alignment is proposed that matches falling edges of the measured and the reference signals by minimizing the absolute difference summation. Second, a signal parameter error is introduced to evaluate the crimp quality difference between the measured signal and the reference. For calculating the signal parameter error, part of a signal is identified and divided into several regions to maximize the signal parameter errors. Experiments showed that the proposed method can improve the signal alignment and accurately detect bad crimps especially with the strain sensor.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.67-72
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• 2021

This paper compare the adative equalization performance of the DSE-MMA (Dithered Signed-Error MMA) and QE-MMA (Quantized-Error MMA) which has a simplifies the computational operation of currently used MMA algorithm. The DSE-MMA possible to improve the rubustness to noise by using the dithered signal consider the polarity of error signal in the multiplication part. In QE-MMA, it use the polarity of error signal after performing the nonlinear power-of-two quantizing operation for easiness of H/W implementation. The same channel environment was applied, and it's performance of the output signal constellation, the residual isi and maximum distortion and MSE that means the convergence characteristics, the SER that means the robustness of external noise of algorithm were compared and evaluated. As a result of computer simulation, the QE-MMA has more good in constellation, residual isi, maximum distortion, MSE performanc than DSE-MMA. In SER, the DSE-MMA has more robust due to dither signal than QE-MMA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.520-521
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• 2017

The converted error is occurred by the time difference between the time interval signal and the clock in a Time-to-Digital Converter of counter-type. If the clock period is $T_{CLOCK}$ the converted error is a maximum $T_{CLOCK}$ by the time difference between the start signal and the clock. And the converted error is a maximum $-T_{CLOCK}$ by the time difference between the stop signal and the clock. However, when the clock is synchronized with the start signal and the colck is generated during the time interval signal the range of converted digital error is from 0 to $(1/2)T_{CLOCK}$.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.23-30
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• 2022

The active phased array antenna system performs beam steering, multi-beam formation and adaptive beam forming by controlling the amplitude and phase of signals fed to each radiating element. In order to obtain the desired radiation characteristics using an active phased array antenna system, the accurate amplitude and phase of the signal must be fed to each radiating element; however, due to various causes, the signal errors occurs in each radiating element. In this paper, a signal error estimation method of each radiating element is proposed. The proposed method simplifies the process of signal error estimation, and can quickly and accurately calculate the signal error.

• Journal of the Korean Institute of Telematics and Electronics
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• v.6 no.3
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• pp.8-11
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• 1969

In the precision measurement of the voltage standing wave ratio (VSWR) or reflection coefficient by means of the slotted line technique, one of the important factors is the maximum error due to the discontinuities and multi-reflection in the slotted line. Particularly, this error becomes a critical factor when the VSWR or the reflection coefficient to be measured is very small. In this paper, the exact expression of this error is obtained by means of the Signal flow graph method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.176.4-176
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• 2001

In this paper, a novel type of iterative learning controller is studied. The proposed learning algorithm utilizes not only the error signal of the previous iteration but also the delayed error signal of the current iteration. The delayed error signal is adopted to improve the convergence speed. The convergence condition is examined and the result shows that the proposed learning algorithm shows the fast convergence speed under the same convergence condition of the traditional iterative learning algorithm. The simulation examples are presented to confirm the validity of the proposed ILC algorithm.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.119-125
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• 2014

In this paper, we developed the signal generator of GNSS navigation signals and analysis the performance of DCO(Digitally Clock Oscillator) compensation algorithm for cumulative distance error thorough simulation. In general, To generate a GNSS signal calculates the Doppler and Initial Pseudorange by using the location information of the receiver and the satellite. The GNSS signal generator generates a signal by determine the carrier and code output frequency using the Doppler information which is calculated as a function of time. The output frequency of the carrier and code would be used the DCO scheme. At this time, It extract the bit and code information on a for each sample by accumulating the DCO. an error of Pseudorange is generated by the cumulative error of the DCO. If Pseudorange error occurs, so that the influence to and operation of the receiver. Therefore, in this paper, we implemented the accumulated error compensation algorithm of the DCO to remove the accumulated error components DCO thereof, Pseudorange accumulated error is removed through the experiment, it was confirmed to be a high accuracy can be operated.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.76-81
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• 2021

This study proposes a method to reduce the phase error of the received signal to detect the object bearing. The phase shift of the received signal occurs due to the multipath of the signal by natural structure or artificial structures. When detecting the direction of the object using radio waves, the phase of the received signal cannot be accurately detected because of the phase bearing error in the object detection direction. The object detection direction estimation depends on the phase difference, antenna installation distance, signal source wavelength, frequency band and bearing angle. This study reduces the error of the phase bearing by using the phase delay of the relative phase difference for the signals incident on the two antennas. Through simulation, we analyzed the object direction detection performance of the proposed method and the existing method. Three targets are detected from the [-15°, 0°, 15°] direction. The existing method detects the target at [-13°, 3°, 17°], and the proposed method detects the at [-15°, 0°, 15°]. As a result of the simulation, the target detection direction of the proposed method is improved by 2 degrees compared to the existing method.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.4
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• pp.71-78
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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.