Chutchavong, Vanvisa

Preferred name

Alternative Name

Chutchavong, V.

Main Affiliation

School of Engineering

vanvisa.ch@kmitl.ac.th

Now showing 1 - 10 of 57

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Study on Damage to Flexible Pavement Road in Thailand: Identification Types of Crack on Roads Using Image Processing Takes
(2025-01-01)
Chutchavong, Vanvisa
;
Doungpan, Satawat
;
Kasettakarn, Witchapon
;
Thiabkhuang, Surapit
;
Phungtua-Eng, Thanapol
The detection and identification of flexible pavement road cracks pose a significant challenge for civil engineers when they start work at the beginning level, as it requires extensive work experience of engineers in classifying types of cracks for planning road maintenance. Inaccurate analysis and identification of cracks can negatively affect the quality of maintenance work and threaten the safety of road users in the future. This paper presents a case study of 60 asphalt roads managed by the Provincial Administrative Organization (PAO) in central of Thailand (case of two provinces, Uthai Thani and Nakhon Sawan), focusing on identification type road cracks. The study aims to address issues related to data preparation and classification across various domains Our data are fed model, which is photography to medium-resolution images of flexible pavement road cracks so that guidelines for engineers' inspection and identification of road cracks. We propose the development of a U-Net model specifically designed for image processing tasks. The results indicate that the U-Net model is effective in converting road cracks images into segmentation masks, and this effectiveness is evaluated using four well-defined key performance indicators.
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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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Equalization of the distorted chrominance signal using IIR digital filter with the bernstein filter
(2005-01-01)
Chutchavong, V.
;
Janchitrapongvej, K.
;
Pirajnanchai, V.
In this paper, we present the use of the Bernstein Polynomials to obtain an IIR digital filter transfer function, which can be applied to video equalizer for compensating the amplitude of chrominance signal in color television. In addition, experimental results are carried out by using the modulated 20T sine squared signal on the color sub carrier 4.43 MHz. It is shown here that the proposed equalizer can either enhance or compress the chrominance signal in color television transmission.
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Approximation of the maximally flat filter by using Bézier curve with an exponential function
(2020-02-24)
Purahong, B.
;
Kanjanasurat, I.
;
Sithiyopasakul, P.
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Chutchavong, V.
;
Pintavirooj, C.
This paper presents a design of filter by using Bézier curve with an exponential function. This paper used the advantage of The Bézier curve which had ability for approximation and an exponential function which had the adaptable parameters of the polynomial. It can adjust the characteristic of frequency response for the best performance. The simulation results of various setting show the frequency response, step response. The comparison of response between the Bernstein filter and Butterworth filter in order two show that the rise time of Bernstein filter better than Butterworth filter and Bézier curve filter has not overshoot. Furthermore, the stability Nyquist criterion has been used to guarantee the stability of the transfer function.
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Bernstein polynomial and rational Bézier curve for blood pressure simulation
(2017-02-08)
Kanjanasurat, I.
;
Chutchavong, V.
;
Pirajnanchai, V.
;
Janchitrapongvej, K.
This paper presents blood pressure waveform simulation using the Bernstein polynomial model, Bézier-Bernstein model, and Rational Bézier-Bernstein model. All mathematical models can generate the blood pressure waveform which is similar to the normal blood pressure waveform. Moreover, all mathematical models can simulate a normal blood pressure waveform as well. As the results, the Rational Bezier-Bernstein model is a simple form, low order, easy to implement in the microcontroller.
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Ultra-wideband slot antenna on flexible substrate for WLAN/WiMAX/UWB Applications
(2014-01-01)
Archevapanich, Tuanjai
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Lertwatechakul, Mayuree
;
Rakluea, Paitoon
;
Anantrasirichai, Noppin
;
Chutchavong, Vanvisa
An ultra-wideband slot antenna on flexible substrate is designed to support a wide range of wireless communication systems. The antenna is a rectangular slot antenna fed by microstrip line with conductor strip and tuning stub on flexible substrate (Mylar Polyester film). The rectangular slot is etched out from the ground plane with conductor strip in the slot, and the other plane contains a microstrip line with tuning stub. The proposed antenna’s effective frequency range covers overall standard bands of WLAN, WiMAX, and UWB. The antenna was simulated and analyzed by using IE3D Zeland software [1]. And the simulation results presents the characteristics of the antenna in terms of bandwidth return loss, VSWR, and radiation patterns.
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An IIR digital video equalizer design with the bernstein polynomial and generalized bilinear transformation for gain chrominance distortion
(2008-12-01)
Chutchavong, V.
;
Sangaroon, O.
;
Pirajnanchai, V.
;
Janchitrapongvej, K.
Video equalizer design for compensated the distortion of the chrominance amplitude in color television transmission system is presented. The approximation is based on the Bernstein Polynomials and generalized bilinear transformation to obtain the transfer function. This approach has several parameters can be varied satisfying stability conditions. And the advantages of the Bernstein Polynomials when compared to the Butterworth, Chebyshev and Thomson Polynomials are three parameters available control the amount of phase and magnitude, linear phase, and flexible for variable of phase. Among all referred advantages so that these methodologies were applied in this paper. In addition, the pulse and bar test signal which has been used to measure linear waveform distortion in TV system is special the modulated 20T sine squared pulse with color sub-carrier 4.43 MHz for PAL system. As a result, the proposed digital video equalizer can be enhance and compress the gain chrominance distortion without degraded it phase characteristic.
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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
;
Kasettakarn, Witchapon
;
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
;
Purahong, Boonchana
;
Archevapanich, Tuanjai
;
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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Implementation of ECG portable device for real-time signal monitoring
(2017-11-24)
Purahong, B.
;
Thongkrairat, S.
;
Anuwongpinit, T.
;
Chutchavong, V.
;
Aoyama, H.
In this paper presents a system for heart rate signal analysis in ECG (Electrocardiography) format using STM32f7 board. Electrode is used for recording the signal with stick on body in lead 2 orientations. Signal processing method are used upper average, slope and interval checking algorithm to process ECG signal in real-time. In experiment, to acquire a frequency of heart beat and display ECG signal and heart rate on STM32f7 board compare with wearable device that result have error rate less than 1%. This system is portable to use and sufficient battery for recording signal to analyze and monitor throughout the day.

Chutchavong, Vanvisa

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