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[IEEE 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Guangzhou, China (2018.7.14-2018.7.16)] 2018 IEEE 2nd International Conference on Circuits, System and Simulation (ICCSS) - Application of an Infinite Gain Multiple Feedback Filter in VLC Link Range Extension
摘要： This paper presents a visible light communication (VLC) link range extension, achieved by establishing a VLC system using simple, low-cost, and reliable electronic circuitry, and employing a design of a highly resonant frequency selective active band pass filter (infinite gain multiple feedback filter) at the receiver section of the system. The filter was designed for a specific center (resonant) frequency with high Quality factor and gain. An outline of the relationship between Signal-to-Noise ratio (SNR) and transmission distance for three different center frequencies was presented. Results show that by utilizing an IGMF filter at the receiver, a signal-to- noise ratio above 10dB at a distance beyond 1.5 meters can be achieved without any form of lensing at either the transmitter or receiver.
关键词： Signal-to-Noise Ratio (SNR),Infinite Gain Multiple Feedback (IGMF),Visible Light Communications (VLC),LED,Trans-Impedance Amplifier (TIA)
更新于2025-09-10 09:29:36
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Detectability of Delamination in Concrete Structure Using Active Infrared Thermography in Terms of Signal-to-Noise Ratio
摘要： Detecting subsurface delamination is a dif?cult and vital task to maintain the durability and serviceability of concrete structure for its whole life cycle. The aim of this work was to obtain better knowledge of the effect of depth, heating time, and rebar on the detectability capacity of delamination. Experimental tests were carried out on a concrete specimen in the laboratory using Long Pulsed Thermography (LPT). Six halogen lamps and a long wavelength infrared camera with a focal plane array of 640 × 480 pixels were used as the heat source and infrared detector, respectively. The study focused on the embedded imitation delaminations with the size of 10 cm × 10 cm × 1 cm, located at depths varying from 1 to 8 cm. The signal-to-noise ratio (SNR) was applied as a criterion to assess the detectability of delamination. The results of this study indicate that as the provided heating time climbed, the SNR increased, and the defect could be identi?ed more clearly. On the other hand, when using the same heating regime, a shallow delamination displayed a higher SNR than a deeper one. The moderate fall of the SNR in the case of imitating defect located below reinforced steel was also observed. The absolute contrast was monitored to determine the observation time, and the nondimensional prefactor k was empirically proposed to predict the depth of delamination. The mean absolute percentage error (MAPE) was used to quantitatively evaluate the difference between forecasted and real depth, which evaluation con?rmed the high reliability of the estimated value of the prefactor k.
关键词： signal-to-noise ratio (SNR),nondestructive technique (NDT),reinforced concrete,infrared thermography,long pulsed thermography,delamination
更新于2025-09-10 09:29:36