Nonlinear Spatio - Temporal Processing

Detecting nonlinear dynamics in spatio-temporal systems, examples from ecological models

Mathematical models of marine populations exhibit chaotic dynamics. However, we hypothesize that in moving water, Eulerian sampling of spatially heterogeneous populations may obscure any deterministic signal beyond the resolving capabilities of presently available nonlinear signal processing techniques. To examine this hypothesis we created two spatio-temporal models of population dynamics. To ...

Assessment of Neonate's Congenital Hypothyroidism Pattern Using Poisson Spatio-temporal Model in Disease Mapping under the Bayesian Paradigm during 2011-18 in Guilan, Iran

Background: Congenital Hypothyroidism (CH) is one of the reasons for mental retardation and defective growth in neonates. It can be treated if it is diagnosed early. The congenital hypothyroidism can be diagnosed using newborn screening in the first days after birth. Disease mapping helps to identify high-risk areas of the disease. This study aimed to evaluate the pattern of CH using the Poisso...

An Artificial Neural Network for Spatio-Temporal Bipolar Patterns: Application to Phoneme Classification

An artificial neural network is developed to recognize spatio-temporal bipolar patterns associatively. The function of a formal neuron is generalized by replacing multiplication with convolution, weights with transfer functions, and thresholding with nonlinear transform following adaptation. The Hebbian learning rule and the delta learning rule are generalized accordingly, resulting in the lear...

Spatio-Temporal Parameters' Changes in Gait of Male Elderly Subjects

Objectives: The purpose of this study was to compare spatio-temporal gait parameters between elderly and young male subjects. Methods & Materials: 57 able-bodied elderly (72±5.5 years) and 57 healthy young (25±8.5 years) subjects participated in this study. A four segment model consist of trunk, hip, shank, and foot with 10 reflective markers were used to define lower limbs. Kinematic data c...

Evaluation of Tests for Separability and Symmetry of Spatio-temporal Covariance Function

In recent years, some investigations have been carried out to examine the assumptions like stationarity, symmetry and separability of spatio-temporal covariance function which would considerably simplify fitting a valid covariance model to the data by parametric and nonparametric methods. In this article, assuming a Gaussian random field, we consider the likelihood ratio separability test, a va...

Assessment of spatio-temporal variations of surface water quality and prioritization of pollution Sources (case Study: Talar Watershed, Mazandaran province)