Wardkein, Paramote
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Wardkein, Paramote
Alternative Name
Wardkein, P.
Wardkein, Pramote
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Email
paramote.wa@kmitl.ac.th
47 results
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Item type:Publication, Phase noise phenomenon explanation based multi-time variables differential equation technique(2016-09-06); In this article, the mathematical analysis is proposed to describe phase noise phenomenon. The principle of this proposed scheme is based on the multi-time variables differential equation technique. The analytic result clearly shows that noise is composed of multiplicative noise that spread around an oscillated frequency and additive noise acts as a noise floor of a system. To verify the proposed analysis, the computer simulation results are given which demonstrate that the obtained results agree well with the theoretical counterpart. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A Photoplethysmographic Signal Isolated from an Additive Motion Artifact by Frequency Translation(2018-08-01); Acquiring a precise percentage of oxygen saturation (SpO2) from a finger-probe pulse oximeter is dependent on both artifact-free red and infrared photoplethysmoghaphic (PPG) signals. Nonetheless, in real-life situations, these PPG signals are corrupted by a motion artifact (MA) signal that is generated from either finger or hand movement. To resolve this MA interference, the cause of the adulteration of PPG signals by the MA signal is examined. The MA signal is found to behave like an additive noise. Additionally, the frequency responses of the MA and PPG signals show that these signals are in the same frequency band. Hence, instead of direct current, a sinusoidal wave alternating current is proposed to drive an LED source in order to shift the PPG frequency band away from the MA frequency band. Experimentally, a commercial finger-probe pulse oximeter is employed. To determine the performance of the presented scheme, the resulting PPG signals are compared with those from employing the old-fashioned LED-driving method. In addition, the accuracy is verified by computing the SpO2 value. The results reveal that the proposed approach successfully retains the fundamental morphologies of the PPG structures when motion occurs. Moreover, the calculated SpO2 values from the proposed technique provide an average error of approximately 1.4%, whereas the conventional method yields a mean error approximately 4.2%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heart detection and diagnosis based on ECG and EPCG relationships(2011-08-26); ; Yupapin, PPA new design of a system for preliminary detection of defective hearts is proposed which is composed of two subsystems, in which one is based on the relationship between the electrocardiogram (ECG) and phonocardiogram (PCG) signals. The relationship between both signals is determined as an impulse response (h(n)) of a system, where the decision is made based on the linear predictive coding coefficients of a heart's impulse response. The other subsystem uses a phase space approach, in which the mean squared error between the distance vectors of the phase space of the normal heart and abnormal heart is judged by the likelihood ratio test (Λ) value, on which the decision is made. The advantage of the proposed system is that a heart's diagnosis system based on the ECG and EPCG signals can lead to high performance heart diagnostics. © 2011 Phanphaisarn et al, publisher and licensee Dove Medical Press Ltd. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Distance Detection Technique Using Enhancing Inverse Perspective Mapping(2018-09-11); This paper presents a distance determination technique using an image from the single forward camera. Since too dark or too bright of the image and non-linear relation between height of the object and distance from the camera have effect on the performance of the detection process. Therefore, automatic brightness adjustment and inverse perspective mapping (IMP) is applied in the proposed scheme. In addition, region of interest (ROI) determination is used to decrease the processing time. The experimental results confirm that the proposed technique can detect distance of the object in front of the car where the error is 7.96%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Distance Measurement Technique Using Phase Difference of Two Reflected Ultrasonic Frequencies(2018-09-11); Boonjun, SurapolThis paper proposes a simple method of distance measurement utilizing phase difference of two reflected ultrasonic frequencies. To obtain the phase difference, an alternating signal which contains two sinusoidal signals having different frequencies is fed to an ultrasonic transmitter. When the transmitted signal is reflected and received by the ultrasonic receiver, the received signal is first squared. Then, a time shift property of Fourier transform is applied to the squared signal to acquire the phase difference. The phase difference is converted to a time-of-flight (TOF) value and turned to the distance. To experiment the proposed technique, a DSP TMS620C6713 board is employed to generate the alternating signal as well as to receive the reflected signal, and to process the received signal. In the experiment, two sinusoidal signals having frequencies of 39.85 kHz and 40.6 kHz are used. The results show that the obtained distance by the presented approach has fairly low error only 0.15 centimeters compared to the actual distance. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Estimating an optimal setpoint to lessen errors in filling weighing system based on Kalman filtering(2014-01-01); ; A weighing system in which a sensor is not mounted to a discharger especially in vertical filling gives rise to an excess of weight added to the given target of weight. In addition, the excess is not constant on account of some factors, such as vibration of the machine, flow of the substance, and cycle time of the system. These factors cause the surplus to oscillate. To overcome this problem, Kalman filtering is performed to predict the optimal setpoint to meet the defined target. To illustrate the performance of the proposed technique, the resulting outcome is compared with that of using the conventional statistical method. The results have shown that the proposed approach has significantly increased the speed and lowered the error. It is pointed out that the proposed algorithm may be preferable to the traditional statistical technique due to its effectiveness and its simple implementation. © 2014 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Measuring on Sugar Content of Sugarcane Based on Phase Locked Loop with Capacitive Sensor(2018-06-27) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, First order complex adaptive FIR notch filter(2010-07-30); This paper presents a first order complex adaptive finite impulse response (FIR) notch filter (FIR-ANF) to track and estimate the frequency of complex sinusoidal signal corrupted by Gaussian noise. This research also presents gradient based adaptive algorithm for adjusting the filter coefficient. Computer simulation results have shown that, as compared with the conventional first-order complex adaptive infinite impulse response (IIR) notch filter (IIR-ANF), the proposed technique has faster convergence time, especially, when the initial value of algorithm is far from the true solution. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Statistical performance of the direct frequency estimation algorithm for the adaptive FIR notch filter(2010-07-30); The Mean square error (MSE) of direct frequency estimation algorithm (DFE) for the adaptive FIR notch filter is presented in this paper. The developed analysis technique is capable of tracking the simulations very well in the steady state. The proposed method is based on the merging between the analysis technique for linear predictor and the second-order adaptive FIR notch filter. Computer simulations have been treated to corroborate with the theoretical analysis. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Locked ranges of frequency divider based on injection-locked relaxation oscillator(2015-08-17); ; Koseeyaporn, PoolsakIn this article, the principle for determining locked ranges of the frequency divider based on the injection locked relaxation oscillator (ILRO-FD) is proposed. The proposed principle shows that the ILRO has many frequency-division ratios and can indicate that which ratios are suitable for frequency dividers. In addition, based on the proposed principle, it is found that the patterns of frequency-division ratios of ILRO depend on the charge-pump circuit's current ratio. Moreover, the proposed principle is verified by the simulation results of the ILRO-FD based on 0.35um-CMOS technology of TSMC.