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Interference and FCC Action
Published in Gilbert Held, Understanding Broadband over Power Line, 2016
As noted earlier in this chapter, attenuation represents a reduction in signal strength that occurs due to the resistance, inductance, and capacitance encountered as a signal flows on a transmission facility. Although transmission distance represents a major cause of attenuation, other factors, including changes in a feeder line from an overhead to an underground facility and spliced and tapped connections, also affect attenuation. In addition, because high frequencies attenuate more rapidly than lower frequencies, the level of attenuation is not uniform.
Analog Motion Sensors
Published in Clarence W. de Silva, Sensor Systems, 2016
Signal conditioning associated with differential transformers includes filtering and amplification. Filtering is needed to improve the SNR of the output signal. Amplification is necessary to increase the signal strength for data acquisition, transmission, and processing. Since the reference frequency (carrier frequency) is induced into (and embedded in) the output signal, it is also necessary to interpret the output signal properly, particularly for transient motions.
Basics of Electrical Communication Systems
Published in P. S. Neelakanta, ATM Telecommunications, 2018
Attenuation represents a fall in the signal strength as the signal is transported along a medium (channel) over a distance. It is a characteristic of the type of medium. The typical channel (wireline or wireless) which attenuates the signal by absorbing a part of energy in it, is known as a lossy channel or a lossy transmission system [2.3].
Leak detection and size identification in fluid pipelines using a novel vulnerability index and 1-D convolutional neural network
Published in Engineering Applications of Computational Fluid Mechanics, 2023
Zahoor Ahmad, Tuan-Khai Nguyen, Jong-Myon Kim
According to the ISO standard 18211:2016 before acquiring the data from the AE sensor the surveillance zone is determined based on the AE signal attenuation characteristics according to the AE source-induced noise. In AE the term attenuation refers to the loss of signal strength measured in decibels (dB). The attenuation characteristic of an AE sensor can be calculated using the following equation. In Equation (12), the measured potential is represented by V and the reference potential is represented by . The term measured AE potential refers to the AE signal obtained from the AE sensor. In acoustic emission, the reference 0 dB is the AE signal potential of 1 at the AE sensor without any amplification.
ABAFT: an adaptive weight-based fusion technique for travel time estimation using multi-source data with different confidence and spatial coverage
Published in Journal of Intelligent Transportation Systems, 2023
Sara Respati, Edward Chung, Zuduo Zheng, Ashish Bhaskar
The noise magnitude information could be obtained from field observation, for example, by validating the sensor travel time estimation with ground truth travel time. As this study used a simulation model, synthetic noise was introduced to the data. To imitate real datasets, studies have added noise to their data in terms of signal-to-noise ratio (SNR) to model data abnormality (de Rochefort et al., 2010; Liao & Gales, 2007; Zheng & Su, 2016). SNR measures the ratio between the signal strength, which is the time series, and the background noise. The level of noise added to the data can be adjusted. The applied SNR ranges between 5 dB to 30 dB. In this study, the noise was simulated by adding SNR 20 to the aggregated travel time data. Table 4 shows the pseudocode to apply SNR for adding white Gaussian noise into the travel time series. The awgn function in Matlab can also be applied to add noise to the series.
NomadicBTS: Evolving cellular communication networks with software-defined radio architecture and open-source technologies
Published in Cogent Engineering, 2018
Emmanuel Adetiba, Victor O. Matthews, Samuel N. John, Segun I. Popoola, Abdultaofeek Abayomi
The signal strength of the NomadicBTS prototype cell that was set up in a laboratory was measured using the Network Signal Info Pro tool. This software is a signal strength measurement mobile app. The prototype cell was configured to operate at the 900 MHz band using an Absolute Radio Frequency Channel Number (ARFCN) of 1. The signal strength measurement was used to determine how seamless the mobile device can connect to the NomadicBTS prototype cell in the context of this study. Signal strength was represented with Received Signal Strength Indicator (RSSI) measured in dBm in Network Signal Info Pro. Arbitrary Strength Unit (ASU)—an integer value that is proportional to RSSI was also used to present the signal strength alongside the RSSI by Network Signal Info Pro. The interpretation of the ASU values is shown in Table 2.