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Measures of Dispersion and Shape
Published in Alan R. Jones, Probability, Statistics and Other Frightening Stuff, 2018
The Mean or Average Absolute Deviation is often abbreviated to AAD. Some sources may refer to it as MAD (Mean Absolute Deviation) but this then causes confusion with the next measures. We will refer to the Mean or Average Absolute Deviation as AAD.
Estimating water content of natural gas mixtures considering heavy hydrocarbons contribution using artificial neural networks
Published in Petroleum Science and Technology, 2023
Jhon Montenegro, Carlos Veloz, Marvin Ricaurte
To the best of our knowledge, methods for estimating the water content in natural gas that consider the composition of heavy hydrocarbons in natural gas are not reported in the literature. As a result, available methods could not predict water content in natural gas mixtures with a large composition of heavy hydrocarbons, such as rich gases, gas condensates, or liquefied petroleum gases (LPG). This work focuses on developing an alternative and accurate predictive model of water content based on artificial neural networks, considering the contribution of heavy hydrocarbons. The novelty of the proposed model is the incorporation of the natural gas richness as an input parameter, i.e., the GPM term, or gallons of liquids recoverable per thousand standard cubic feet (Mscf) of gas. This term is commonly applied to ethane and heavier hydrocarbon compounds present in natural gas (Kidnay, Parrish, and McCartney 2020). The ANN training and validation steps used experimental data from the literature on the water content in various gas types (including rich, lean, sweet, and sour gases). The BigML (2021) machine learning platform helped develop and implement the proposed model to estimate the water content in natural gas. Comparisons with semi-empirical and thermodynamic methods are made to show the applicability of the model proposal. The average absolute deviation (AAD) is the parameter defined to evaluate the performance and accuracy.
Application of percent within limits concepts on a balanced mix design of asphalt mixtures
Published in International Journal of Pavement Engineering, 2022
Elvis A. Castillo-Camarena, Stacy Williams
There are a number of ways to measure the overall quality of a placed HMA pavement (Hughes 2005, National Research Council and Transportation Research Board 2013). Individual values – the least effective acceptance specification due to the large variability associated.Range – the difference between the largest and smallest value in a sample.Percentage within limits (PWL) – the percentage of a lot falling above the lower specification limit (LSL), beneath the upper specification limit (USL), or between the LSL and the USL.Average – assume the variability is known or constant. Actual construction variability is not measured.Average absolute deviation (AAD) – the mean of absolute deviation from a target value.