We propose a preprocessing methodology for well-log geophysical data based on Fast Independent Component Analysis (FastICA) and Discrete Cosine Transform (DCT), in order to improve the success rate of the K-NN automatic classifier. The K-NN have been commonly applied to facies recognition in well-log geophysical data for hydrocarbon reservoir modeling and characterization. The preprocess was ma...

Multivariate nonlinear mixed-effects models (MNLMM) have received increasing use due to their flexibility for analyzing multi-outcome longitudinal data following possibly nonlinear profiles. This paper presents and compares five different iterative algorithms for maximum likelihood estimation of the MNLMM. These algorithmic schemes include the penalized nonlinear least squares coupled to the mu...

1 Purified membranes retaining a catecholamine responsive adenylate cyclase have been prepared from rabbit heart, lung and (pseudo-pregnant) uterus. 2 These preparations have the characteristics of plasma membranes and both heart and lung respond to P-adrenoceptor agonists in the order: (± )-isoprenaline > (-)-noradrenaline > (-)-adrenaline > ( + )-isoprenaline > salbutamol. The sensitivity of ...

In previous work [10], we presented a class of upper bounds on the log partition function of an arbitrary undirected graphical model based on solving a convex variational problem. Here we develop a class of local message-passing algorithms, which we call tree-reweighted belief propagation, for efficiently computing the value of these upper bounds, as well as the associated pseudomarginals. We a...

Sediments recovered from Ocean Drilling Program (ODP) holes undergo elastic rebound and physical expansion when recovered from great depths below the seabed (about 75 m). This expansion contributes to the artificial “growth” of the composite depth section (Hagelberg et al., 1992). Sediment elastic properties, derived from one-dimensional consolidation tests, are used to correct the expanded sed...

For any positive integer n and fixed integer t ≥ 1, we define function Ut(n) = min{k : 1 t + 2 t + · · · + n t + k = m, n | m, k ∈ N + , t ∈ N + }, where n ∈ N + , m ∈ N + , which is a new pseudo Smarandache function. The main purpose of this paper is using the elementary method to study the properties of Ut(n), and obtain some interesting identities involving function Ut(n). In reference [1], ...

more often clay matrix is the major factor to reduce the porosity and permeability in sandstone facies. consequently determination of clay minerals is of prime importance in reservoir quality assessment. the present study aims to identify four different types of clay mineral namely kaolinite, illite/cholorite, halloysite, and montmorilonite from petrophysical logs (pls) using cation exchange ca...

in this paper, some results of the chebyshev type integral inequality for the pseudo-integral are proven. the obtained results, are related to the measure of a level set of the maximum and the sum of two non-negative integrable functions. finally, we applied our results  to the case of comonotone functions.

Porosity has been frequently observed in solidified, deep penetration pulsed laser welds. Porosity is detrimental to weld quality. Our previous study shows that porosity formation in laser welding is associated with the weld pool dynamics, keyhole collapse, and solidification processes. The objective of this paper is to use mathematical models to systematically investigate the transport phenome...

For this study we selected 20 drill cores covering a wide range of depths (400-3000 m), from 15 wells, that provide a reasonable coverage of the field. Only andesite, the largely predominant rock type in the field, was included in this sample. We measured bulk density, grain (solids) density, effective porosity and (matrix) permeability on a considerable number of specimens taken from the cores...