Chutchavong, Vanvisa

Preferred name

Alternative Name

Chutchavong, V.

Main Affiliation

School of Engineering

vanvisa.ch@kmitl.ac.th

Now showing 1 - 10 of 17

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Sine-Squared pulse approximation using generalized bessel polynomials
(2019-05-29)
Anuwongpinit, Thanavit
;
Chutchavong, Vanvisa
;
Janchitrapongvej, Kanok
;
Benjangkaprasert, Chawalit
This paper presents the approximation of sine-squared pulse based on the generalized Bessel polynomials. For designing a circuit to synthesize a sine-squared pulse test signal. The generalized Bessel polynomials have more parameter than classical Bessel polynomials that have alpha and beta parameters for adjusting the dominator of the transfer function to approximate the sine-squared pulse that closes to the ideal pulse. The simulation results show that the generalized Bessel polynomial can adjust the approximation response close to the ideal response. The orders of the transfer function are decreased that confirm a better performance than the previous works.
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Lifespan Estimation of Closed-Circuit Television (CCTV) Systems Using Weibull Modeling
(2026-02-01)
Chutchavong, Vanvisa
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Pirajnanchai, Virote
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Doungpan, Satawat
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Kasettakarn, Witchapon
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Phungtua-eng, Thanapol
Ensuring the availability and reliability of electronic components or materials during operation necessitates conducting a sampling inspection of their lifespan. This is particularly crucial when comparing equipment or materials deployed in various areas with diverse environments, conditions, and situations. Many studies rely on one-method parameter estimation methods, which fall short in identifying the two explicit parameters of the Weibull distribution. Moreover, inaccurate parameter estimation methods impede the attainment of reliable analysis results. Consequently, this paper introduces three analytical estimation methods to determine the parameters of the Weibull distribution. The accuracy of these methods is evaluated using the mean square error (MSE). Furthermore, we utlized the Kolmogorov–Smirnov and Anderson–Darling test on real datasets, confirming that the data follow a Weibull distribution. Simulation results indicate that the maximum likelihood estimate outperforms the other estimators by minimizing the MSE and yielding optimal parameters. These optimal parameters were then applied to real CCTV datasets, demonstrating a good fit and enabling assessment of CCTV lifespan through the mean time to failure, which is estimated to be 6.6 years. This holds true even when the equipment operates in environments with different conditions and situations.
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Optimized Gaussian Pulse Design for UWB System Using Particle Swarm Optimization Based-on Generalized Bessel Polynomials
(2022-01-01)
Chutchavong, Vanvisa
;
Anuwongpinit, Thanavit
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Purahong, Boonchana
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Archevapanich, Tuanjai
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Janchitrapongvej, Kanok
The ultrawideband system operates a very short pulse with enormous bandwidth to provide high data rates for data transmission. To design the UWB pulse, considering the pulse shape is very necessary, and a spectral emission mask of the designed pulse should meet the FCC spectral mask requirement between frequency range 3.1 GHz to 10.6 GHz. The traditional UWB pulse design is based on the Gaussian derivative. However, the frequency spectrum is not satisfied the FCC spectral mask requirement. In this study, the Gaussian pulse can be designed from the mathematical characteristic of the generalized Bessel polynomial. The spectral efficiency of the proposed pulse can be improved by the combination of the derivative of Gaussian pulse with a weight coefficient optimization with particle swarm optimization (PSO). PSO is a population-based optimization algorithm inspired by animal behavior. PSO is applied with generalized Bessel polynomial transfer function to gain the best weight coefficient, we proposed to optimize its weight vector to design a pulse that exceeds to FCC spectral mask. The results were found in MATLAB software show that generalized Bessel polynomials can approximate the proposed pulse with combination method and PSO. The spectral efficiency is improved to 89.30% and the spectrum is greater close to the FCC spectral mask requirement. To confirm an improved spectral efficiency compared to the previous works.
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Luminance-chrominance gain equalizer based on bernstein polynomials
(2010-01-01)
Chutchavong, Vanvisa
;
Sangaroon, Ornlarp
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Benjangkaprasert, Chawalit
;
Janchitrapongvej, Kanok
This paper presents a linear luminance-chrominance gain equalizer for correcting the linear chrominance gain distortion in the color TV transmission system. The proposed gain equalizer was implemented based on Bernstein polynomials. As it is known that the Bernstein filter has flexible parameters to adjust the circuit performance for the best results. In addition, the modulated 20T sine-squared pulse test signal is generated for testing the performance of the proposed gain equalizer, which can be measured all three types of the linear chrominance distortions. As the results, the proposed gain equalizer is also proved to be efficient in equalizing both the low gain and the high gain chrominance distortions without degrading its phase characteristics. © 2010 The Institute of Electrical Engineers of Japan.
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Design of linear phase filter by using q-Bernstein polynomial
(2018-01-01)
Purahong, Boonchana
;
Kanjanasurat, Isoon
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Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
;
Archevapanich, Tuanjai
The aim of this paper presents a design of IIR filter by using q-Bernstein polynomial. There are two parameters for adjusting a characteristic of frequency response. Stopband and slope of phase are adjusted by varying parameter ɛ. The advantage is a linear phase and maximally flat more than Butterworth and Chebyshev. The stability can guarantee with Mihailov’s criterion.
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New adjustable non-linear characteristic approximated by bernstein polynomial for guitar effect
(2017-11-24)
Sookcharoenphol, Dolchai
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Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
This paper presents approximating non-linear behavior of distortion guitar effect such as Fuzz and Overdrive by Bernstein polynomial with low orders in the form of electrical signal. The Bernstein method can be adjusted parameters by manual, in order to designing a new sound of distortion effect. The method was confirmed effectively by a ratio of harmonics. Original effects were generated by electronic circuit, which couldn’t be adjusted. In the other hand, the Bernstein method can be identified a dominant feature sound and developed on other devices such as software or application not the same as distortion effect circuit.
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New flat pass-band of low-pass responses with varying attenuation in stop-band
(2017-11-24)
Sookcharoenphol, Dolchai
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Chutchavong, Vanvisa
;
Janchitrapongvej, Kanok
This paper presents an approximation of low-pass filter responses with adjustable stop-band attenuation in order to designing a high quality filter. The filter is based on QBernstein polynomial, which can be adjusted attenuation in stop-band by varying three parameters of the transfer function. A coarse attenuation in stop-band is provided by adjusting two parameters (epsilon and alpha) and a fine attenuation step is determined by Q parameters. The results of simulation were shown the filter, given attenuation in stop-band better than conventional filter at a second-order. Moreover, this paper proposes the filter which provides both flat magnitude and group delay characteristics in the pass-band. Therefore, it can useful for the high quality filter network as an audio crossover network.
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Train speed curve of electric railway based on bezier-bernstein curve
(2019-07-01)
Chutchavong, Vanvisa
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Srisuk, Kanyaphak
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Vijittanasan, Alongkon
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Anuntahirunrat, Kongsak
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Janchitrapongvej, Kanok
This paper presents a new train speed curve model for an electric railway system based upon the Bernstein polynomials and Bezier-Bernstein curve. Experimental results are included to demonstrate the effectiveness of the new model and its accuracy.
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Modeling ECG waveform using optimal smoothing Bézier-Bernstein curves
(2017-12-19)
Soontornvorn, Rachanart
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Fujioka, Hiroyuki
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Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
This paper considers a problem for modeling mathematically waveform of some Electrocardiogram (ECG) which is the process of measuring and recording the electrical activity of the heart over a period of time. Such a modeling is done by using the smoothing Bézier-Bernstein curves. A concise representation for desigining the optimal curves with high precision is derived, which has the additional merit of lending itself to the development of computational procedures in a straightforward manner. The usefulness and effectiveness are demonstrated by some experimental studies.
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Approximation of linear gain slope equalizer using Bernstein-Stancu polynomials
(2017-02-08)
Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
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Nomura, Hideyuki
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Kanamori, Chisato
;
Aoyama, Hisayuki
This paper presents a design of linear gain slope equalizer for correcting the linear gain distortion. It is based on the Bernstein-Stancu polynomials, where the well-known and readily available approximated of the desired transfer function are applied. As it is known that the Bernstein-Stancu polynomials have the several advantages. For example, there is a flexible parameter as a that can be used to adjust the magnitude response for the best result. If the parameter a equals to zero, it becomes to the classical Bernstein polynomial. In addition, the phase response is linear. As the results, the proposed method is capable of designing linear gain slope equalizer which is also shown to be efficient performance without degrading its phase characteristics. The stability of the approximated of the transfer function can guarantee with Mihailov's criterion.

Chutchavong, Vanvisa

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