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Radioactivity
Published in Michael J. Kennish, Ecology of Estuaries: Anthropogenic Effects, 2019
Because the natural logarithm of 2 equals about 0.693, T12=0.693λ,
Machine learning to classify and predict objective and subjective assessments of vehicle dynamics: the case of steering feel
Published in Vehicle System Dynamics, 2018
Gaspar L. Gil Gómez, Mikael Nybacka, Lars Drugge, Egbert Bakker
The general regression neural network (GRNN), proposed by Specht in 1991 [21], can be used for regression of non-linear functions, it converges to the underlying regression surface, and also works well with sparse data in a multidimensional space. GRNN is similar in form to the probabilistic neural network, using estimators of probability density functions to estimate the values for continuous dependent variables. These density functions have the form of normalised Gaussian Radial Basis Functions (RBF), which are implemented in the hidden layer of the network, where each unit follows the next transfer function, [15]: where x is the input-vector, µi is the vector position (in the weight-space) for hidden neuron i and σi2 is its variance. It can be observed that this function depends only on the Euclidian distance of the input-vector to the weight-vector of the neuron. It is radially symmetric and it works as a basis in which the output function equation (2) is expressed. This is the reason for its name of RBF. The natural logarithm of 2 (ln 2) is used so that the output of the non-normalised Gaussian equals 0.5 for a Euclidian distance equal to σi.
Chlorella-Daphnia consortium as a promising tool for bioremediation of Nile tilapia farming wastewater
Published in Chemistry and Ecology, 2022
Clarissa Vilela Figueiredo da Silva Campos, Carlos Yure B. Oliveira, Elizabeth Pereira dos Santos, Jéssika Lima de Abreu, William Severi, Suzianny Maria Bezerra Cabral da Silva, Luis Otavio Brito, Alfredo Olivera Gálvez
Analysis of D. similis growth included determination of specific growth rate (SGR), doubling time (DT), yield (Y), maximum average density (MAD), and maximum density day (MDD), based on Otero et al. [46]. SGR, DT, and Y were calculated up to the MDD. SGR Equation (1), DT Equation (2), and Y Equation (3) were calculated using the following equations: Where: Nt1: Final number of individuals. Nt0: Initial number of individuals. t1: Day of maximum density. Where: Ln2: Natural logarithm of 2. k: Specific growth rate (SGR) Where: Nt1: Final number of individuals. Nt0: Initial number of individuals. t1: Day of maximum density.
Extraction study on recovery of nickel (II) from concentrated chloride medium with N,N′-bis(salicylaldeyde)ethylenediimine in the presence of CTAB and Brij® 35 surfactants
Published in Journal of Dispersion Science and Technology, 2021
Zeyneb Benfettouma, Mohammed Hadj Youcef, Tayeb Benabdallah, Hasnia Reffas
Where, ln : natural logarithm, [Ni2+]t : concentration of nickel(II) in aqueous phase at time t, [Ni2+]i : initial total concentration of nickel(II) in aqueous phase, t : time under consideration in minute, where the extraction curve shows linearity during extraction, kobs: observed extraction rate constant or mass transfer coefficient of nickel(II) ions in aqueous phase.