Kazimierz Wielki University in Bydgoszcz

Bydgoszcz, Poland
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Apiecionek L.,Kazimierz Wielki University in Bydgoszcz
Mobile Information Systems | Year: 2017

This article presents the potential of using Multipath Transmission Control Protocol for limiting the energy consumption in 5G network. The number of errors occurring during packet transmissions and in effect the number of retransmissions affect the consumption of energy by the devices in the network. The paper analyzes the potential energy savings from implementing an algorithm for detecting problems and predicting the future retransmissions. Although this is the main object of the paper, it must be emphasized that the proposed method also allows increasing the speed of transmission and improving the security of the data and it is easy to implement in 5G networks. © 2017 Łukasz Apiecionek.

Jackiewicz J.,Kazimierz Wielki University in Bydgoszcz
Materials and Manufacturing Processes | Year: 2017

This article focuses on 3D printing of compound elements, fully connected components or elements, which can be used as instructional aids for students. By means of traditional manufacturing technologies such as machining, forming, or molding, the manufacturing cost of such items would be high, and in addition they would be sometimes difficult to feasible. The majority of the low-cost 3D printers are operated on the basis of the fused deposition modeling technology. In addition, students can be involved in making their own teaching aids. The study of machine components and systems often requires the use of 3D gear models, especially planetary gears or centrifugal compressors. In the article, the numerical optimization of preparing and executing of 3D prints of models of the planetary gear and centrifugal compressor is proposed by the use of genetic algorithm. © 2017 Taylor & Francis.

Chybicki I.J.,Kazimierz Wielki University in Bydgoszcz | Burczyk J.,Kazimierz Wielki University in Bydgoszcz
Molecular Ecology | Year: 2010

The estimates of contemporary gene flow assessed based on naturally established seedlings provide information much needed for understanding the abilities of forest tree populations to persist under global changes through migration and/or adaptation facilitated by gene exchange among populations. Here, we investigated pollen- and seed-mediated gene flow in two mixed-oak forest stands (consisting of Quercus robur L. and Q. petraea [Matt.] Liebl.). The gene flow parameters were estimated based on microsatellite multilocus genotypes of seedlings and adults and their spatial locations within the sample plots using models that attempt to reconstruct the genealogy of the seedling cohorts. Pollen and seed dispersal were modelled using the standard seedling neighbourhood model and a modification - the 2-component seedling neighbourhood model, with the later allowing separation of the dispersal process into local and long-distance components. The 2-component model fitted the data substantially better than the standard model and provided estimates of mean seed and pollen dispersal distances accounting for long-distance propagule dispersal. The mean distance of effective pollen dispersal was found to be 298 and 463 m, depending on the stand, while the mean distance of effective seed dispersal was only 8.8 and 15.6 m, which is consistent with wind pollination and primarily seed dispersal by gravity in Quercus. Some differences observed between the two stands could be attributed to the differences in the stand structure of the adult populations and the existing understory vegetation. Such a mixture of relatively limited seed dispersal with occasional long distance gene flow seems to be an efficient strategy for colonizing new habitats with subsequent local adaptation, while maintaining genetic diversity within populations. © 2010 Blackwell Publishing Ltd.

Moraczewski K.,Kazimierz Wielki University in Bydgoszcz
Polymer Testing | Year: 2014

The effect of multiple (up to 10 times) injection molding of poly(ε-caprolactone) on its mechanical properties, Charpy impact strength, melt flow rate, phase transition temperature and degradation temperature is presented. It was found that the tensile strength at break, impact strength and degradation temperature slightly decreased, while the melt flow rate steadily increased with raising of the number of the injection molding cycles. Variation of the number of these cycles mostly influenced the crystallization temperature. The melting point, enthalpy of crystallization, enthalpy of melting and crystallinity did not vary with the number of injection moldings. The presented results indicate that poly(ε-caprolactone) technological waste is suitable to be reused as an additive to a neat polymer. © 2013 Elsevier Ltd. All rights reserved.

Rytlewski P.,Kazimierz Wielki University in Bydgoszcz
Surface and Coatings Technology | Year: 2014

This article presents the results of laser-assisted metallization of polyurethane coatings containing 5wt.% of Cu(acac)2 and 15wt.% of copper(II) oxide (CuO) or copper(II) hydroxide (Cu(OH)2). Thus, two different coating compositions were compared with regard to becoming active after laser irradiation for direct electroless metallization. Coatings were irradiated with ArF excimer laser using various numbers of laser pulses at a constant fluence of 100mJ/cm2, and then electroless metallized with copper. Surface properties resulting from laser irradiation were evaluated mainly based on surface morphology, chemical alterations and general optical assessment of deposited copper layers. It was evaluated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and optical imaging. It was found that surface layer of the coatings containing Cu(OH)2 could be activated, and thus copper plated at lower energy dose of laser radiation as compared to the coatings containing CuO. It resulted from more efficient laser ablation and formation of metallic copper on the coating surface. Empirical model for the change of copper content resulting from laser radiation and practical conclusions on the applicability of the coatings is presented in this work. © 2014 Elsevier B.V.

Chybicki I.J.,Kazimierz Wielki University in Bydgoszcz
Journal of Heredity | Year: 2013

Measuring genetic structure of pollen gametes has become the standard approach in studies on plant mating system and pollen flow. However, the popular statistical procedure, TwoGener, provides the point estimate of the pollen pool heterogeneity based on AMOVA, implying any statistical tests regarding pollen pool structure to be based on permutation procedures. In this article, the Bayesian approach was developed based on the Dirichlet-multinomial model (the so-called F-model). Computer simulations revealed the applicability of the Bayesian method in the analysis of pollen pool heterogeneity. Compared with TwoGener, the Bayesian method appeared to have better statistical properties when estimating the inverse of heterogeneity index, mostly due to the relatively high accuracy of the Bayesian estimate when the actual heterogeneity is low. Hence, the Bayesian approach may be preferred, for example, when the effective number of pollen parents is to be assessed. Other applications and potential further developments of the Bayesian method are also briefly discussed. © The American Genetic Association. 2013. All rights reserved.

Prokopowicz P.,Kazimierz Wielki University in Bydgoszcz
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The publication shows the way of implementing arithmetic operations on fuzzy numbers based on Ordered Fuzzy Numbers calculation model [12], [13], [14]. This model allows to perform calculations on fuzzy numbers in a way that the outcomes meet the same criteria as the outcomes of calculations on real numbers. In this text, to the four basic operations with Ordered Fuzzy Numbers, a logarithm and exponentiation was added. Several examples of the calculations are included, the results of which are obvious and typical of real numbers but not achievable with the use of conventional computational methods for fuzzy numbers. From these examples one can see that the use of Ordered Fuzzy Numbers allows to obtain outcomes for real numbers in spite of using the fuzzy values. © 2013 Springer-Verlag.

Marcysiak K.,Kazimierz Wielki University in Bydgoszcz
Plant Systematics and Evolution | Year: 2012

The morphology of Salix herbacea leaves was examined to find possible reasons for the observed intra-specific morphological variation. Seventeen samples were collected from the following regions: the Southern and Eastern Carpathians, the Northern Carpathians, the Alps: Eastern, Central and Western, the Pyrenees, Western Scandinavia, and Northern Scandinavia. The leaves were dried in an herbarium, scanned and measured. A total of 3,890 leaves from 503 individuals were statistically analyzed. The analyses were based on the shape-describing characters. A notable variation of shape characters of leaves of S. herbacea was found on different levels: intra- and inter-individual, between samples and between regions. The local environmental conditions did not affect the leaf shape much, but the regional climatic factors influenced them statistically significantly. The most important factor-the summer precipitation-was positively correlated with leaf elongation, while the mean wind velocity was negatively correlated with leaf elongation. The latter was also positively correlated with the tooth number. The hypothesis that glacial migrations and isolations of S. herbacea populations were responsible for the contemporary morphological differentiation of the species was not confirmed; however, some similarities between the biogeographical structures revealed in the previously published results of molecular analyses and in the present morphological study were also noticed. © 2012 Springer-Verlag.

Marcysiak K.,Kazimierz Wielki University in Bydgoszcz
Plant Biosystems | Year: 2012

Leaves of 279 individuals of Salix reticulata, collected from eight populations in contemporary isolated parts of the species range in Europe, and for comparison, from one population in the Rocky Mountains, were measured and analysed statistically. The characters describing the leaf size were more variable than the shape characters. All size characters were statistically significantly correlated, as well as they positively correlated to the northern latitude and eastern longitude, and negatively related to the altitude. The shape describing characters were assumed to be independent of the environmental conditions. Relations between samples based on multivariate analyses showed that the biogeographical structure of the studied S. reticulata populations is not quite clear. The present results suggest early transatlantic migrations of the species, possibly at least two migration routes to Scandinavia, and close relations between the Tatra Mountains, the Alps and the Western Scandinavia. © 2012 Copyright Taylor and Francis Group, LLC.

Rytlewski P.,Kazimierz Wielki University in Bydgoszcz
Materials and Manufacturing Processes | Year: 2014

The aim of this work was to verify the influence of Nd:YAG laser radiation (λ = 1064 nm) on the formation of catalytic surface in polyamide (PA6) composites. Three different polyamide composites containing copper compounds and varied with glass fiber content were irradiated with three different energy doses. After laser ablation, composites were electroless metalized without any pre-treatments using commercial metallization bath. The composites were analyzed based on photographic and scanning electron microscopy images. Chemical alterations resulted from laser ablation of the composite surface layers were determined by energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. After laser ablation, the composites without glass fibers were melted and did not become preferably catalytic, while those containing glass fibers could be successfully metalized. It was concluded that Nd:YAG laser can be applied in direct electroless metallization of polyamide composites, however, it requires both strict process control of irradiation and proper material design. © 2014 Copyright Taylor & Francis Group, LLC.

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