Publications by authors named "Klopotek M"

This paper describes a new method of classification based on spectral analysis. The motivations behind developing the new model were the failures of the classical spectral cluster analysis based on combinatorial and normalized Laplacian for a set of real-world datasets of textual documents. Reasons of the failures are analysed.

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Thin-film growth is investigated in two types of lattice gas models where substrate and film particles are different, expressed by unequal interaction energy parameters. The first is of solid-on-solid type, whereas the second additionally incorporates desorption, diffusion in the gas phase above the film and readsorption at the film (appropriate for growth in colloidal systems). In both models, the difference between particle-substrate and particle-particle interactions plays a central role for the evolution of the film morphology at intermediate times.

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Using grand-canonical Monte Carlo simulations, we investigate the phase diagram of hard rods of length L with additional contact (sticky) attractions on square and cubic lattices. The phase diagram shows a competition between gas-liquid and ordering transitions (which are of demixing type on the square lattice for L≥7 and of nematic type on the cubic lattice for L≥5). On the square lattice, increasing attractions initially lead to a stabilization of the isotropic phase.

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Using grand-canonical Monte Carlo (GCMC) simulations, we investigate the isotropic-nematic phase transition for hard rods of size L×1×1 on a three-dimensional cubic lattice. We observe such a transition for L≥6. For L=6, the nematic state has a negative order parameter, reflecting the co-occurrence of two dominating orientations.

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Background: The balloon catheter has been used for a decade to dilate paranasal sinus outflow tracts. The question is: how wide and how durable is the dilation of drainage pathways in patients in long-term observations after this procedure?

Objective: The objective of our study was to observe the changes occurring in the frontal sinus drainage pathway (FSDP) in patients with frontal sinusitis at least 6 months after surgery using balloon catheters in an isolated procedure.

Materials And Methods: We analyzed and measured the FSDP width on computed tomography (CT) of 23 images before and after the use of balloon catheters.

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Growth of hard-rod monolayers via deposition is studied in a lattice model using rods with discrete orientations and in a continuum model with hard spherocylinders. The lattice model is treated with kinetic Monte Carlo simulations and dynamic density functional theory while the continuum model is studied by dynamic Monte Carlo simulations equivalent to diffusive dynamics. The evolution of nematic order (excess of upright particles, "standing-up" transition) is an entropic effect and is mainly governed by the equilibrium solution, rendering a continuous transition [Paper I, M.

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The equilibrium properties of hard rod monolayers are investigated in a lattice model (where position and orientation of a rod are restricted to discrete values) as well as in an off-lattice model featuring spherocylinders with continuous positional and orientational degrees of freedom. Both models are treated using density functional theory and Monte Carlo simulations. Upon increasing the density of rods in the monolayer, there is a continuous ordering of the rods along the monolayer normal ("standing up" transition).

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In this paper we briefly report a set of programming tools designed to support the analysis of some aspects of radiological contamination caused by Tchernobyl catastrophe. First of all a system for data storing is characterized; after mentioning basic data structures, two mutations of this system are described (one version for data collected during a pilot study and the second for the main investigation). Next the problems of data analysis are discussed.

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