Search results for "complex"

Probabilistic stability analysis of social obesity epidemic by a delayed stochastic model

2014

Abstract Sufficient conditions for stability in probability of the equilibrium point of a social obesity epidemic model with distributed delay and stochastic perturbations are obtained. The obesity epidemic model is demonstrated on the example of the Region of Valencia, Spain. The considered nonlinear system is linearized in the neighborhood of the positive point of equilibrium and a sufficient condition for asymptotic mean square stability of the zero solution of the constructed linear system is obtained.

Evolutionary Game Dynamics for Collective Decision Making in Structured and Unstructured Environments

2017

Abstract For a large population of players we consider a collective decision making process with three possible choices: option A or B or no option. The more popular option is more likely to be chosen by uncommitted players and cross-inhibitory signals can be sent to attract players committed to a different option. This model originates in the context of honeybees swarms, and we generalise it to accommodate other applications such as duopolistic competition and opinion dynamics. The first contribution is an evolutionary game model and a corresponding new game dynamics called expected gain pairwise comparison dynamics explaining how the strategic behaviour of the players may lead to deadlock…

First-order linear differential equations whose data are complex random variables: Probabilistic solution and stability analysis via densities

2022

[EN] Random initial value problems to non-homogeneous first-order linear differential equations with complex coefficients are probabilistically solved by computing the first probability density of the solution. For the sake of generality, coefficients and initial condition are assumed to be absolutely continuous complex random variables with an arbitrary joint probability density function. The probability of stability, as well as the density of the equilibrium point, are explicitly determined. The Random Variable Transformation technique is extensively utilized to conduct the overall analysis. Several examples are included to illustrate all the theoretical findings.

Singularity tracking for Camassa-Holm and Prandtl's equations

2006

In this paper we consider the phenomenon of singularity formation for the Camassa-Holm equation and for Prandtl's equations. We solve these equations using spectral methods. Then we track the singularity in the complex plane estimating the rate of decay of the Fourier spectrum. This method allows us to follow the process of the singularity formation as the singularity approaches the real axis.

Linked cyclopentadienyl-amido titanium catalysts supported on pyridylethylsilane-modified silica for heterogeneous ethylene homo- and copolymerization

2003

Abstract Linked cyclopentadienyl-amido titanium dimethyl and dichloro complexes, Ti(η 5 :η 1 -C 5 Me 4 SiMe 2 N t Bu)X 2 (X=Me, Cl), were reacted with trityl tetrakis(pentafluorophenyl)borate (TB), Ph 3 C + [B(C 6 F 5 ) 4 ] − , and methylaluminoxane (MAO), followed by treatment with toluene suspension of pyridylethylsilane-modified silica, to give two new supported-type titanium catalysts, PySTiTB and PySTiMAO. PySTiTB polymerized ethylene in the presence of triisobutylaluminum (TIBA) in hexane at 60 °C and 5 bar with slightly higher activity than the corresponding homogeneous system under the same conditions. PySTiMAO showed relatively high activity even without any use of alkylaluminum co…

Non-bridged amido cyclopentadienyl complexes of titanium: synthesis, characterization, and olefin polymerization catalysis

2000

Alkylation of Ti(η 5 -C 5 Me 5 )(NMe 2 )Cl 2 gives thermally stable, crystalline dialkyl complexes Ti(η 5 -C 5 Me 5 )(NMe 2 )R 2 (R=Me, CH 2 Ph, Ph). The molecular structure of the dibenzyl complex reveals an unprecedented conformation of the doubly bonded NMe 2 group which is turned parallel to the η 5 -C 5 Me 5 ligand, according to single-crystal X-ray diffraction studies. Treatment of the dibenzyl complex with B(C 6 F 5 ) 3 in d 5 -bromobenzene solution results in the quantitative formation of a thermally (>10°C) unstable monobenzyl cation as solvent-separated ion pair [Ti(η 5 -C 5 Me 5 )(NMe 2 )CH 2 Ph] + [PhCH 2 B(C 6 F 5 ) 3 ] − which efficiently polymerizes styrene syndiospecifically…

CUDA-Accelerated Alignment of Subsequences in Streamed Time Series Data

2014

Euclidean Distance (ED) and Dynamic Time Warping (DTW) are cornerstones in the field of time series data mining. Many high-level algorithms like kNN-classification, clustering or anomaly detection make excessive use of these distance measures as subroutines. Furthermore, the vast growth of recorded data produced by automated monitoring systems or integrated sensors establishes the need for efficient implementations. In this paper, we introduce linear memory parallelization schemes for the alignment of a given query Q in a stream of time series data S for both ED and DTW using CUDA-enabled accelerators. The ED parallelization features a log-linear calculation scheme in contrast to the naive …

Fluorescent interaction Eu-IL: when the anion plays a role

2020

Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)

2014

Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). W…

On the complexity of the Saccharomyces bayanus taxon: Hybridization and potential hybrid speciation

2014

Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequenc…