Fuel laminar burning velocity is an important parameter in internal combustion engine modeling and combustion analysis.
The present paper deals with the development of a mathematical correlation able ...to provide laminar burning velocity for fuels/air mixture at different thermodynamic conditions. Therefore, a mathematical investigation of laminar burning velocity for most significant and used fuels was carried out.
Fifth order logarithmic polynomial functions were implemented to predict the propagating laminar burning velocity of combusting fuels as a function of equivalent ratio at different conditions of temperature and pressure.
On the basis of results obtained, the mathematical model proposed in this paper showed a higher precision in experimental data fitting and the possibility to interpolate and use a single mathematical function for a wider operation field.
In-situ permeability is an important factor in determining whether an economical drilling oil wells to be mined. Therefore, the calculation in determining the true value of permeability with an ...attempt to take a further decision, whether the industry is continued or not. Research through study literature is obtained a mathematical modeling from Matheu and Toksoz's work which contains the components of acoustic wavesattenuation factor and rock permeability factor. Furthermore, by combining some of the concepts and theories, mathematical models are used for acoustic field data logs and other data which are required to get permeability. Data from the acoustic log is analyzed to determine the time delay for P, S and Stoneley waves, then determination of the speed, frequency and attenuation factor, especially for wave Stoneley. In this permeability calculations, it is assumed that the condition of the rock formations in the area of measurement is a permeable rock and contains fractures. The results show that the permeability in measurement area at a depth position indicates suitable with the data of rock state.
Evaluation plays an important role in interactive question answering systems like many computational linguistics fields. The coherence between the questions and the answers exchanged between the user ...and the system is one of the important criteria in evaluating these systems. In this paper, a new approach to determine the degree of coherence of generated text by the IQA systems is presented. The proposed model is a probabilistic model in which for feature extraction, the similarity between different N-grams is derived based on four defined criteria. Then using a prediction of the best density function among the 18 functions considered for each feature, a model for determining the coherence is selected. The results of implementation on two databases provided by several interactive question answering systems indicate that the proposed probabilistic model is highly adapted and its accuracy in determining the degree of coherence in the conversation text has been made. The Kolmogorov-Smirnov, Anderson, Darling and Cramer van Meys trials were used to matching or non-matching probability density function. According to the presented results, the probability density factor with the least error was the best performance in determining the coherence of each conversation.
The article is an attempt to generalize the theory of the mathematical description of synchronous ma-chines with multiple three-phase windings on the sta-tor and arbitrary location in space of the ...machine. The features of the transformations of coordinates in the mathematical description of the machine are shown
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