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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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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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Modification of data transmission filter with generalized bessel transformation
(2010-12-01)
Pirajnanchai, Virote
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Chutchavong, Vanvisa
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Janchitrapongvej, Kanok
This paper present modification of data transmission filter by the application of Generalized Bessel transformations with rational filter. The technique gives the denominator of filter transfer function in analytic closed form, while its numerator is determined by solving a set of transmission zeros and even polynomial of order. The results to filter is straightforward and will be given in a later more detailed contribution together with comparison with the other existing design methods, such a comparison reveals the superiority of the present technique. ©ICROS.
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The modifications of low pass filter responses by the generalized bessel transformation with equal-ripple attenuation in the stopband
(2009-01-01)
Pirajnanchai, Virote
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Songthnapitak, Numyoot
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Janchitrapongvej, Kanok
In this paper modification of low-pass filter responses by the application of Generalized Bessel transformations with equal-ripple attenuation in the stopband. A function has been developed which enable filter designs to place the flattest portion of the magnitude curve at a frequency in the passband other than ω = 0. In comparison with Maximally Fate Delay (MFD), these filters have steeper slops at cutoff and provide more high-frequency attenuation.
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Active notch uniformly distributed RC circuit and their application
(2008-12-01)
Tangthong, Nipont
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Pirajnanchai, Virote
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Janchitrapongvej, Kanok
Many application of the RC parallel-T network, only two performance characteristics are considered important the frequency and depth of the attenuation notch. In this paper the design presented, active notch distributed RC network (URC̄) circuit from design values. The proposed circuit configuration consists of URC̄, one external resistor (Rn) or capacitor (Cn) and single gain amplifier. The parameters of the proposed circuit can be adjusted to improve the magnitude response with notch tunable frequency. This structure reduces an amount of circuit complexity and is simple to use for application. The experiments and computer simulation showed good agreement with theoretical values. The active notch URC̄ can application to experiments high frequency active band-pass filter, sinusoidal wave oscillator and frequency discriminator.
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Design all-pass transfer function configuration using a notch distributed RC network
(2007-12-01)
Pirajnanchai, Virote
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Luangphakorn, Supachai
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Janchitrapongvej, Kanok
In this paper describers a new and interesting notch distributed RC networks configuration that realizes an all-pass network function is proposed. The circuit is presented with which an all-pass transfer function of arbitrary order, having simple negative real poles, has been realized by combining the output of notch distributed RC networks with a portion of its input in a differential amplifier. The experimental results for such an all-pass function is also indicated. This network circuit has the advantage that the gain constant of all-pass function may be varied by varying the gain of differential amplifier.
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High frequency active high-pass filter used distributed MOSFET
(2005-12-01)
Pirajnanchai, Virote
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Janchitrapongvej, Kanok
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Panyanouvong, Nouanchanh
In many signal processing situations, filters must interface with the real world where the input and output signal take on continuous values functions of the continuous variable time, In this paper describes a new high frequency continuous-time high-pass filter. The filter is realized for converting an active distributed RC to a transistor-only high pass filter circuit. The frequency response of high-pass was examined by a MOSFET model. Preliminary experimental simulation results by PSpice programs for high frequency high-pass filter is presented. © 2005 IEEE.
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Continuous-time low-pass filter using an active distributed MOSFET transistor
(2004-12-01)
Pirajnanchai, Virote
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Janchitrapongvej, Kanok
This paper describes continuous-time low-pass filter using an enhancement MOSFET transistor as a double uniformly distributed RC line (DU RC̄). The proposed circuit configuration consists of a new low-pass active distributed MOSFET filter and one pole gain amplifier. For continuous-time low-pass filter using proposed frequency adjustable type circuit, the experimental result of the frequency characteristics give us a good agreement with theoretical values. The proposed circuit can all used in modern electronic communication systems and most measuring equipments. ©2004 IEEE.

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