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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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Synthesis of Video Gain Equalizer via Distributed circuits
(2025-01-01)
Chutchavong, Vanvisa
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Pirajnanchai, Virote
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Rattanathanawan, Pongpan
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Ngammongkolwong, Sudasawan
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Puntapa, Vorawut
This paper presents a linear luminance and chrominance gain equalizer in video waveform transmission. Practically, the distributed devices have physical characteristics similar to the transmission line. Therefore, it can be employed to function in approximately as a passive lumped element. For this purpose, a novel transformation can be realized on equalizer using commemorated passive and active filters with uniformly distributed URC lines. In this paper we introduce two types of gain equalizers. The first type consists of resistive, conductive and capacitive, known as uniform GCR elements. The second type approximated by the uniformly distributed RC transfer function. As the results the proposed gain equalizer prove in equalizing both the luminance and chrominance gain distortions correction. From the simulation results, it is shown that the proposed distributed circuit gives good amplitude chrominance characteristic for both types of luminance gain equalizers.
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Improvement of Renz's Active Band-Pass Filter Using Uniformly Distributed RC Circuit
(2024-01-01)
Wachirarattanapornkul, Sorapong
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Chutchavong, Vanvisa
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Attavunich, Pornsak
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Rattanathanawan, Pongpan
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Ngammongkolwong, Sudasawan
This paper presents the improvement of Renz' s active band-pass filter. We proposed two types of band-pass filter. The first type of filter circuit structure, resembles to Renz's band-pass filter. The circuit comprising a single gain amplifier and three uniformly distributed RC network (URC). The second type band-pass filter circuit configuration consists of a gain amplifier with one URC and a double capacitive layer (DURC). From the experimental results, it is showed that the behavior of the proposed band-pass filter gives good narrow bandwidth, high Q and low sensitivities compared to the Renz's filter.
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Multi-Band Magnitude Complementary Crossover Network by Using Q-Bernstein Filter
(2024-01-01)
Sookcharoenphol, Dolchai
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Janchitrapongvej, Kanok
This paper presents a multi-band magnitude complementary (MC) crossover network by using Q-Bernstein filter (QBF). The prototype low-pass filter is used the Q-Bernstein polynomial (QBP) to approximate a desired function. The QBF gives parameters which can be changing stop-band attenuation of the filter. The magnitude responses show that the filter gives high attenuation values in the stop-band of degree 2. The two-band MC crossover network can be realized by cascading an all-pass filter and a constant voltage of degree 1, which sums up to the all-pass filter (APF) of degree 2. The multiple-bands crossover network can be realized by cascading two identical all-pass filter stages of degree 2. The simulation results show that the proposed crossover network has a constant summed magnitude response and also an in-phase response over an audio band.
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Design of Luminance-Chrominance Gain Equalizer Using Uniformly Distributed RC Circuits
(2024-01-01)
Chutchavong, Vanvisa
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Pirajnanchai, Virote
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Doungpan, Satawat
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Ngammongkolwong, Sudasawan
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Rattanathanawan, Pongpan
The propose of this paper is to design the luminance-chrominance gain equalizer use in the video waveform transmission. As it is known, the conventional measurement and gain corrector of chrominance distortion equipment is not so simple. This network corrector has to use fillers and delay time to separate the luminance signal and chrominance signal by means of low-pass and high-pass filter in connection. Here in, we deploy the uniformly distributed RC circuit (URC). We introduce two types of equalizers. The first type is to correct the luminance signal without deteriorating the chrominance signal. The second type is designed to correct the chrominance signal with no effect to luminance signal. Both equalizers comprise of a few gain amplifiers and URC circuits. From the simulation results, it is shown that the frequency response of gain equalizer given good effective in correcting video signal distortion. We also introduce the modulated sine-squared pulse test signal for measuring and correcting the amount of low gain and high gain of the chrominance signal.
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Synthesis of Crossover Network Using O′Shea′s Transformation via URC
(2024-01-01)
Janchitrapongvej, Kanok
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Chutchavong, Vanvisa
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Doungpan, Satawat
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Ngammongkolwong, Sudasawan
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Rattanathanawan, Pongpan
This paper describes method of synthesis two-way cross-over network, namely low-pass filter and high-pass filter. Firstly, we introduce synthesis method of obtain all-pass filter. We introduce O′Shea′s transformation P(s) = cosh√SRC and Wyndrum′s transformation W(s) = tanh√SRC via uniformly distributed RC (URC) network. After obtaining a desired all-pass filter, as an elementary process. We construct low-pass filter and high-pass filter by means of all-pass filter basis. Simulation results MATLAB are carried out and stability are also investigated.
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Applicability of Weibull distribution in Generating Model for Evaluating Lifespan Closed Circuit Television System (CCTV)
(2023-01-01)
Doungpan, Satawat
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Chatchavong, Vanvisa
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Janchitrapongvej, Kanok
CCTV is an expedient tool for monitoring and investigating. Since it can record emergency and routine events in memory of the electronic circuit board. However, in the process of operating CCTV, it is necessary to carry out a sampling inspection on its lifetime to predicate its availability and reliability. According to previous literature, most of the parameter estimation methods used only one parameter estimation method, which is not sufficient for identifying two explicit parameters of Weibull distribution. Moreover, the bad parameter estimation method cannot achieve reliable analysis results. Therefore, this paper presented the four methods of estimation in both graphical and analytical methods for estimating parameters of Weibull distribution. These methods have measured the accuracy by using mean square error (MSE). In addition, the real data set confirmed that there is the Weibull distribution by using the Kolmogorov-Smirnov test. The simulation results found that the maximum likelihood method (MLM) can outperform the other estimator because it can provide a minimum MSE, there is an optimal parameter in which the shape is 4.3881 and the scale is 86.8207. Finally, the two optimal parameters are applied to real data sets of the CCTV. As a result, the optimal parameter fits with real data sets, and it can evaluate the lifespan of CCTV by using the mean time to failure (MTTF) as 6.6 years.
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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
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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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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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Sine-Squared pulse approximation using generalized bessel polynomials
(2019-05-29)
Anuwongpinit, Thanavit
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Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
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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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