Search results for: FINITE-DIFFERENCE
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On Computational Aspects of Greedy Partitioning of Graphs
PublicationIn this paper we consider a problem of graph P-coloring consisting in partitioning the vertex set of a graph such that each of the resulting sets induces a graph in a given additive, hereditary class of graphs P. We focus on partitions generated by the greedy algorithm. In particular, we show that given a graph G and an integer k deciding if the greedy algorithm outputs a P-coloring with a least k colors is NP-complete for an infinite...
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FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
PublicationA discrete Green's function (DGF) approach to couple disjoint domains in the finite-difference time-domain (FDTD) grid is developed. In this method, total-field/scattered-field (TFSF) FDTD domains are associated with simulated objects whereas the interaction between them is modeled with the use of the DGF propagator. Hence, source and scatterer are simulated in separate domains and updating of vacuum cells, being of little interest,...
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Dataset of phase portraits of the fractional prey-predator model with Holling type-II interaction (without predator harvesting)
Open Research DataThe need for a fractional generalization of a given classical model is often due to new behaviors which cannot be taken into account by the model. In this situation, it can be useful to look for a fractional deformation of the initial system, trying to fit the fractional exponent of differentiation in order to catch properly the data.
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Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations
PublicationThe paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...
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Modeling of the Two-Dimensional Flow Caused by Sea Conditions and Wind Stresses on the Example of Dead Vistula
PublicationThe article presents the results of two-dimensional modeling of flows caused by the sea conditions and wind stresses on the example of Dead Vistula. Based on the available bathymetric data, a numerical model of the river section was created, which was supplemented with data on the position of the water table depending on hydrometeorological conditions. To describe the flow field in steady conditions, a simplified model of two-dimensional...
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Computational aspects of greedy partitioning of graphs
PublicationIn this paper we consider a variant of graph partitioning consisting in partitioning the vertex set of a graph into the minimum number of sets such that each of them induces a graph in hereditary class of graphs P (the problem is also known as P-coloring). We focus on the computational complexity of several problems related to greedy partitioning. In particular, we show that given a graph G and an integer k deciding if the greedy...
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Reinforcement Learning Algorithm and FDTD-based Simulation Applied to Schroeder Diffuser Design Optimization
PublicationThe aim of this paper is to propose a novel approach to the algorithmic design of Schroeder acoustic diffusers employing a deep learning optimization algorithm and a fitness function based on a computer simulation of the propagation of acoustic waves. The deep learning method employed for the research is a deep policy gradient algorithm. It is used as a tool for carrying out a sequential optimization process the goal of which is...
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Inverse Flood Routing Using Simplified Flow Equations
PublicationThe paper considers the problem of inverse flood routing in reservoir operation strategy. The aim of the work is to investigate the possibility of determining the hydrograph at the upstream end based on the hydrograph required at the downstream end using simplified open channel flow models. To accomplish this, the linear kinematic wave equation, the diffusive wave equation and the linear Muskingum equation are considered. To achieve...
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Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions
PublicationAg-based plasmonic nanostructures were manufactured by thermal annealing of thin metallic films. Structure and morphology were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). SEM images show that the formation of nanostructures is influenced by the initial layer thickness as well as the...
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Lagrangian model of an isolated dc-dc converter with a 3-phase medium frequency transformer accounting magnetic cross saturation
PublicationThis article presents a nonlinear equivalent circuit model of an isolated dc-dc converter with a 3-phase medium frequency transformer. The model takes into account the magnetic cross saturation of the 3-phase core-type magnetic circuit. The model is suitable in detailed electromagnetic transient simulations of power systems involving isolated dc-dc converters. The model is developed using the Lagrange energy method. It involves...
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Tensile validation tests with failure criteria comparison for various GFRP laminates
PublicationThe paper studies the mechanical properties of glass fibre reinforced polymers (GFRP) with various types and orientation of reinforcement. Analyzed specimens manufactured in the infusion process are made of polymer vinyl ester resin reinforced with glass fibres. Several samples were examined containing different plies and various fibres orientation [0, 90] or [+45, –45]. To assess the mechanical parameters of laminates, a series...
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Smart Weighing Scale with Feet-Sampled ECG
PublicationIn a smart home, health and well-being monitoring systems could be embedded in everyday devices providing a pervasive care. A home bathroom scale is an example of such a device, typically used to measure body weight and very often its composition (e.g. body water/fat percentage). In this paper, we analyzed a potential use of the bathroom scale to measure electrocardiogram (ECG) from electrodes located on the scale's tile. In particular...
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Designing acoustic scattering elements using machine learning methods
PublicationIn the process of the design and correction of room acoustic properties, it is often necessary to select the appropriate type of acoustic treatment devices and make decisions regarding their size, geometry, and location of the devices inside the room under the treatment process. The goal of this doctoral dissertation is to develop and validate a mathematical model that allows predicting the effects of the application of the scattering...
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On possible applications of media described by fractional-order models in electromagnetic cloaking
PublicationThe purpose of this paper is to open a scientific discussion on possible applications of media described by fractional-order (FO) models (FOMs) in electromagnetic cloaking. A 2-D cloak based on active sources and the surface equivalence theorem is simulated. It employs a medium described by FOM in communication with sources cancelling the scattered field. A perfect electromagnetic active cloak is thereby demonstrated with the use...
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Discrete and continuous fractional persistence problems – the positivity property and applications
PublicationIn this article, we study the continuous and discrete fractional persistence problem which looks for the persistence of properties of a given classical (α=1) differential equation in the fractional case (here using fractional Caputo’s derivatives) and the numerical scheme which are associated (here with discrete Grünwald–Letnikov derivatives). Our main concerns are positivity, order preserving ,equilibrium points and stability...
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[IMe] Advanced numerical methods in mechanics
e-Learning Courses{mlang pl} Dyscyplina: inżynieria mechaniczna Zajęcia obowiązkowe dla doktorantów I i II roku Prowadzący: dr hab. inż. Krzysztof Tesch, prof. PG, dr hab. inż. Arkadiusz Żak, prof. PG Liczba godzin: 45 Forma zajęć: wykład {mlang} {mlang en} Discipline: mechanical engineering Obligatory course for 1st and 2nd-year PhD students Academic teachers: dr hab. inż. Krzysztof Tesch, prof. PG, dr hab. inż. Arkadiusz Żak, prof....
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Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulses—A 5-Bromouracil case study
PublicationABSTRACT Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to...
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Coupled nonlinear Schrödinger equations in optic fibers theory
PublicationIn this paper a detailed derivation and numerical solutions of CoupledNonlinear Schr¨odinger Equations for pulses of polarized electromagnetic wavesin cylindrical fibers has been reviewed. Our recent work has been compared withsome previous ones and the advantage of our new approach over other methods hasbeen assessed. The novelty of our approach lies is an attempt to proceed withoutloss of information within the frame of basic...
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Structure, luminescent properties and FDTD simulation of TeO2-BaO-Bi2O3-Ag:Ln3+ glass-ceramics system
PublicationTeO2-BaO-Bi2O3-Ag glass systems (TBB) co-doped with terbium and europium ions have been successfully synthesized through conventional melt-quenching technique. Heat treatment procedure at 350 °C has been conducted in order to synthesize silver nanoparticles embedded in TBB glass matrix. Structural measurements involved XRD studies that revealed no crystallization of glass structure after heat treatment at elevated temperatures....
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ANALIZA NUMERYCZNA WPŁYWU POZIOMU MORZA NA PRZEBIEG WEZBRAŃ W NADMORSKICH CIEKACH POWIERZCHNIOWYCH NA PRZYKŁADZIE POTOKU STRZYŻA W GDAŃSKU
PublicationW dzisiejszych czasach coraz większym problemem stają się podtopienia na terenach zurbanizowanych. Biorąc to pod uwagę, należy większą wagę przyłożyć do prawidłowego obliczania przepustowości koryta. Jednym z czynników wpływających na nie są warunki na odpływie. W przypadku potoków nadmorskich zależą one ściśle od poziomu morza. W pracy podjęto próbę wyznaczenia wpływu poziomu morza na przebieg wezbrań w nadmorskich ciekach powierzchniowych....
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Simulating propagation of coherent light in random media using the Fredholm type integral equation
PublicationStudying propagation of light in random scattering materials is important for both basic and applied research. Such studies often require usage of numerical method for simulating behavior of light beams in random media. However, if such simulations require consideration of coherence properties of light, they may become a complex numerical problems. There are well established methods for simulating multiple scattering of light (e.g....
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Difference functional inequalities and applications.
PublicationThe paper deals with the difference inequalities generated by initial boundary value problems for hyperbolic nonlinear differential functional systems. We apply this result to investigate the stability of constructed difference schemes. The proof of the convergence of the difference method is based on the comparison technique, and the result for difference functional inequalities is used. Numerical examples are presented.
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Weighted difference schemes for systems of quasilinear first order partial functional differential equations
PublicationThe paper deals with initial boundary value problems of the Dirichlet type for system of quasilinear functional differential equations. We investigate weighted difference methods for these problems. A complete convergence analysis of the considered difference methods is given. Nonlinear estimates of the Perron type with respect to functional variables for given functions are assumed. The proof of the stability of difference problems...
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Method of lines for nonlinear first order partial functional differential equations.
PublicationClassical solutions of initial problems for nonlinear functional differential equations of Hamilton--Jacobi type are approximated by solutions of associated differential difference systems. A method of quasilinearization is adopted. Sufficient conditions for the convergence of the method of lines and error estimates for approximate solutions are given. Nonlinear estimates of the Perron type with respect to functional variables...
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Explicit and implicit difefrence methods for quasilinear first order partial functional differential equations.
PublicationInitial boundary value problems of the Dirichlet type for quasilinear functional differential equations are considered. Explicit difference schemes of the Euler type and implicit difference methods are investigated. Suffcient conditions for the convergence of approximate solutions are given and comparisons of the methods are presented. It is proved that assumptions on the regularity of given functions are the same for both classes...
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Asynchronous time difference of arrival (ATDOA) method
PublicationA new method for a location service in the asynchronous wireless sensor networks is outlined. This method, which is called asynchronous time difference of arrival (ATDOA), enables calculation of the position of a mobile node without knowledge of relative time differences (RTDs) between measuring sensors. The ATDOA method is based on the measurement of time difference of arrival between the node and the same sensor at the discrete...
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Does one currency mean one price? An analysis of the euro effect on price dispersion and convergence
PublicationThis paper examines price differentials in the European Union to investigate whether the European Monetary Union has lowered the degree of price dispersion in the euro zone and increased the speed of price convergence. Both euro effects are evaluated using difference-in-difference methodology. Applied to the issue of introducing a single currency, the euro effects identified are the estimated differences in price dispersion and...
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On the hardness of computing span of subcubic graphs
PublicationIn the paper we study the problem of finding ξ-colorings with minimal span, i.e. the difference between the largest and the smallest color used.
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Straightened characteristics of McKendrick-von Foerster equation
PublicationWe study the McKendrick-von Foerster equation with renewal (that is the age-structured model, with total population dependent coefficient and nonlinearity). By using a change of variables, the model is then transformed to a standard age-structured model in which the total population dependent coefficient of the transport term reduces to a constant 1. We use this transformation to get existence, uniqueness of solutions of the problem...
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Assessment of User Mobility’s Influence on System Loss in Several Body-to-Body Scenarios
PublicationIn this paper, Body-to-Body communications in indoor and outdoor environments for different on-body antenna configurations and different mobility scenarios were studied, based on system loss measurements at 2.45 GHz. The main objective is to properly characterise the influence of the Transmitter-Receiver configuration on system loss and fast fading behaviour, the latter being modelled by the Rice Distribution. Globally, it is observed...
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Does one currency mean one price?
PublicationEuropean Monetary Union was expected to have many consequences for the economies of participant countries. Theory suggested that through a higher volume of trade and stronger competition in the Eurozone, a single currency would lead to a reduction in price dispersion. As far as prices are concerned, two effects were expected: an immediate effect due to the technical characteristics of the changeover process, and a long-term one...
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On the acoustic backscattering by Baltic herring and sprat
PublicationAccurate abundance estimate of Baltic clupeids, herring and sprat, is required for theirsustainable exploitation. The understanding the sound backscattering of individual fish isimportant for employing the acoustical techniques, which are widely used in the estimation.The previous studies demonstrated that the improvement of the understanding is critical forthe Baltic herring and sprat. It was the main...
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Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
PublicationThis article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation...
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The Evaluation of Use of Colors in Graphical User-Interfaces in Healthcare
PublicationIn this paper, color difference/contrast measures are investigated in reference to results of experiments with the participation of average, color-normal observers and with individuals with deuteranopia. Additionally, a new method for the automatic analysis of color contrast is proposed, which supports designers of graphical user- interfaces in healthcare. The method was verified using the GUI phantom of a vital signs monitor (the...
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The Influence of Loop Heat Pipe Evaporator Porous Structure Parameters and Charge on Its Effectiveness for Ethanol and Water as Working Fluids
PublicationAbstract: This paper presents the results of experiments carried out on a specially designed experimental rig designed for the study of capillary pressure generated in the Loop Heat Pipe (LHP) evaporator. The commercially available porous structure made of sintered stainless steel constitutes the wick. Three different geometries of the porous wicks were tested, featuring the pore radius of 1, 3 and 7 um. Ethanol and water as two...
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The Influence of Drying Temperature on Color Change of Hornbeam and Maple Wood Used as Surface and Inner Layers of Wood Composites
PublicationThe thermal treatment of wood changes its structure due to the degradation of wood polymers (cellulose, hemicellulose and lignin), so the physical properties of wood are either improved or degraded. Color changes apply not only to natural wood, but also to such wood composites for which some amount of glue is used in their construction (e.g., plywood, blockboard or laminboard). This article is focused on the analysis of hornbeam...
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Difference in Perceived Speech Signal Quality Assessment Among Monolingual and Bilingual Teenage Students
PublicationThe user perceived quality is a mixture of factors, including the background of an individual. The process of auditory perception is discussed in a wide variety of fields, ranging from engineering to medicine. Many studies examine the difference between musicians and non-musicians. Since musical training develops musical hearing and other various auditory capabilities, similar enhancements should be observable in case of bilingual...
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Numerical solutions for blood flow in elastic vessels
PublicationWe consider the differential–algebraic system for the blood flow and pressure in the systemic arteries. By the operator splitting method, we transform the system into the hyperbolic one, introduce the bicharacteristics, and perform the time–space nonuniform discretization, obtaining the innovative difference scheme. Our results are illustrated with numerical experiments.
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A Comparability of Renal Length and Volume Measurements in MRI and Ultrasound in Children
PublicationIntroduction: Despite the significant increase in use of magnetic resonance imaging (MRI) in children, there is still a lack of normal reference values of renal size in this method and reference values are being interpolated from the ultrasound (US) studies. The study provides comparative analysis of agreement in renal length and volume measurements between MRI and ultrasound. Materials and Methods: Ninety-three children with a...
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Improved model of isothermal and incompressible fluid flow in pipelines versus the Darcy–Weisbach equation and the issue of friction factor
PublicationIn this article, we consider the modelling of stationary incompressible and isothermal one-dimensional fluid flow through a long pipeline. The approximation of the average pressure in the developed model by the arithmetic mean of inlet and outlet pressures leads to the known empirical Darcy–Weisbach equation. Most importantly, we also present another improved approach that is more accurate because the average pressure is estimated...
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Phase-difference positioning in asynchronous system
PublicationThis paper presents concept and implementation of digital positioning system based on phase difference measurements, designed as a navigational aid for marine applications. Main feature of proposed system is the ability to work in both synchronous mode, with one master station and set of slave stations synchronized with master, and in asynchronous mode with independent clocking of all stations.
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Backscattering properties of southern Baltic herring
PublicationReliable TS(L) relationship is required to improve acoustic algorithms of abundanceestimation of Baltic herring. The relationships, empirically obtained in different parts of theBaltic Sea, produce up to 8 dB – difference in the herring TS. In order to develop an accurateTS(L) relationship, it is important to analyze factors controlling the TS variability. Thepossible impact of the regional difference...
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EFFECT OF PRESS DRYING ON DIMENSION STABILITY AND DENSITY OF BEECH WOOD,
PublicationTimber is traditionally dried in kilns by processes that often take several days or weeks to complete. At present, it is possible to apply several methods of rapid drying of timber, including, for example, press drying. This research is based on the use of this process. Drying was performed using the heating plates with a temperature of 160 °C. Three pressures were compared in the research 1.0 MPa, 1.4 MPa, and 1.8 MPa. The density...
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Greencoin: prototype of a mobile application facilitating and evidencing pro-environmental behavior of citizens
PublicationAmong many global challenges, climate change is one of the biggest challenges of our times. While it is one of the most devastating problems humanity has ever faced, one question naturally arises: can individuals make a difference? We believe that everyone can contribute and make a difference to the community and lives of others. However, there is still a lack of effective strategies to promote and facilitate pro-environmental...
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New First - Path Detector for LTE Positioning Reference Signals
PublicationIn today's world, where positioning applications reached a huge popularity and became virtually ubiquitous, there is a strong need for determining a device location as accurately as possible. A particularly important role in positioning play cellular networks, such as Long Term Evolution (LTE). In the LTE Observed Time Difference of Arrival (OTDOA) positioning method, precision of device location estimation depends on accuracy...
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Electrohydrodynamic Secondary Flow and Particle Collection Efficiency in a One-sided Spike-plate Type Electrostatic Precipitator
PublicationIn this work, results of electrohydrodynamic secondary flow and particle collection efficiency measurements in an electrostatic precipitator under positive and negative voltage polarity are presented. The electrostatic precipitator had two plate collecting electrodes and a single spike discharge electrode. The spike tips were only on one side of the discharge electrode, therefore called a one-sided spike electrode. The electrohydrodynamic...
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Broadband Compact Single-Layer Magic-T Junction with Separation of DC Signals between All Ports
PublicationA novel structure for a four-port microstrip magic-T junction is presented. The device is composed of microstrip and slotline circuits etched onto two sides of a dielectric substrate. The device is extremely compact and occupies an area more than three times smaller than similar structures recently reported in the literature. The novelty of the device lies in the use of microstrip/slotline transitions for both input ports: summation...
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Application of method of differential magnetometric system for detection of sunken objects
PublicationThis paper presents a magnetometric system with scalar sensors mounted on two independent platforms, which is used to detect sunken shipwrecks. Increasing the distance between the sensors allows for more precise measurement of the difference in the magnetic induction module than in the case of sensors mounted e.g. on the aeroplane’s wings. This type of system makes it possible to enlarge detection range of the sunken wrecks.
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On some open questions for Ramsey and Folkman numbers
PublicationWe discuss some of our favorite open questions about Ramsey numbers and a related problem on edge Folkman numbers. For the classical two-color Ramsey numbers, we first focus on constructive bounds for the difference between consecutive Ramsey numbers. We present the history of progress on the Ramsey number R(5,5) and discuss the conjecture that it is equal to 43.
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The nonlinear effects of sound in a liquid with relaxation losses
PublicationThe nonlinear effects of sound in electrolyte with a chemical reaction are examined. The dynamic equations that govern non-wave modes in the field of intense sound are derived, and acoustic forces of vortex, entropy, and relaxation modes are determined in the cases of low-frequency sound and high-frequency sound. The difference in the nonlinear effects of sound in electrolyte and in a gas with excited vibrational degrees of molecules,...
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Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublicationTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
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Influence of geometrical and operational parameters on tooth wear in the working mechanism of a satellite motor
PublicationThis article describes the phenomena affecting the wear of the rotor of the working mechanism in a hydraulic satellite motor. The basic geometrical relationships that allow the calculation of the coordinates of the points of contact between the satellite and the rotor and the curvature are presented. A method for calculating the number of contacts of the satellite teeth with the rotor teeth and of the satellite teeth with the curvature...
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Frequency based criterion for distinguishing tonal and noisy spectral components
PublicationA frequency-based criterion for distinguishing tonal and noisy spectral components is proposed. For considered spectral local maximum two instantaneous frequency estimates are determined and the difference between them is used in order to verify whether component is noisy or tonal. Since one of the estimators was invented specially for this application its properties are deeply examined. The proposed criterion is applied to the...
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Bio‐polyols synthesized by liquefaction of cellulose: Influence of liquefaction solvent molecular weight
PublicationCurrently, the plastics industry including polyurethanes is based on the use of petrochemicals. For this reason, scientists are looking for new types of renewable resources for the substitution of petrochemical substances. This work aims to evaluate the effect of polyethylene glycols (PEG) with different molecular mass impact on properties of bio-based polyols synthesized via biomass liquefaction of cellulose. To date, research...
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Reliability and Validity of Optoelectronic Method for Biophotonical Measurements
PublicationReliability and validity of measurements is of utmost importance when assessing measuring capability of instruments developed for research. In order to perform an experiment which is legitimate, used instruments must be both reliable and valid. Reliability estimates the degree of precision of measurement, the extent to which a measurement is internally consistent. Validity is the usefulness of an instrument to perform accurate...
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Mind the Gender Wage Gap – the Impact of Trade and Competition on Sectoral Wage Difference
PublicationThis article examines differences between women’s and men’s wages in 18 selected OECD countries in the period 1970-2005. The study is based on 12 manufacturing sector- and skill-specific sets of panel data on the gender wage gap. We apply a system GMM estimator to the extended version of the conditional gender wage gap convergence equation, controlling for sector concentration and industry-specific measures of openness using a...
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Service time distribution influence on end-to-end call setup delay calculation in networks with Session Initiation Protocol
PublicationThe most important GoS parameter for networks with SIP protocol is end-to-end call setup delay. So far there were no coherent models allowing calculation of these parameters for networks with SIP protocol. Few models were developed but they are insufficient. In the paper we propose model which allows end-to-end call setup delay calculation for networks with SIP protocol. The model is using chain of M/G/1/K models and is applicable...
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Study Analysis of Transmission Efficiency in DAB+ Broadcasting System
PublicationDAB+ is a very innovative and universal multimedia broadcasting system. Thanks to its updated multimedia technologies and metadata options, digital radio keeps pace with changing consumer expectations and the impact of media convergence. Broadcasting analog and digital radio services does vary, concerning devices on both transmitting and receiving side, as well as content processing mechanisms. However, the biggest difference is...
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On the connected and weakly convex domination numbers
PublicationIn this paper we study relations between connected and weakly convex domination numbers. We show that in general the difference between these numbers can be arbitrarily large and we focus on the graphs for which a weakly convex domination number equals a connected domination number. We also study the influence of the edge removing on the weakly convex domination number, in particular we show that a weakly convex domination number...
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Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublicationIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
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Evolution of chemotaxis in single-cell artificial organisms
PublicationThe model of a liquid two-dimensional environment, which is based on physics of diffusion, allows us to simulate the diffusion of morphogenes. Artificial organisms move using a chemotaxis reacting to concentration difference. Organisms are controlled by a gene regulatory network coded in a linear genome and reproduce by division. We made a lot of experiments presenting organisms’ behaviour in various environment conditions. We...
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Detecting coupling directions with transcript mutual information: A comparative study
PublicationCausal relationships are important to understand the dynamics of coupled processes and, moreover, to influence or control the effects by acting on the causes. Among the different approaches to determine cause-effect relationships and, in particular, coupling directions in interacting random or deterministic processes, we focus in this paper on information-theoretic measures. So, we study in the theoretical part the difference between...
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ASYNCHRONICZNY MULTILATERACYJNY SYSTEM DOZOROWANIA OBSZAROWEGO
PublicationW artykule przedstawiono nową metodę lokalizowania samolotów w multilateracyjnych systemach dozorowania obszarowego WAM (Wide Area Multilateration). Metoda ta, nazwana AWAM (Asynchronous Wide Area Multilateration), umożliwia estymację położenia samolotu bez znajomości różnicy w rytmie pracy RTD (Relative Time Difference) pomiędzy stacjami naziemnymi (sensorami). Metoda AWAM znacząco upraszcza proces lokalizowania samolotów w rzeczywistych...
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Labyrynths generators, their properties and practical application in computer games
Publicationthis paper presents three basic algorithms for generation of mazes, and many of their modifications and examples showing their practical application in creating random structures that resembles those from the real world. the paper highlights the difference in the labyrinths classes generated by listed algorithms and describes a specific and highly likely to occur shapes that occur in generated mazes. particular attention was paid...
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ZEUS Concept and Its Wider European Application
PublicationThe objectives of the ZEUS project and the resulting concept of an integrated system of transport safety are recapitulated in the article. The context for transport safety management that has evolved since this became a concern of the European Union under the Treaty of Union in 1993 is outlined, and some issues related to applying the ZEUS concept across Europe are discussed. It is concluded that there is scope for exploring ways...
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Silent Sonar with matched filtration
PublicationRadars with continuous wave frequency (CW FM sonars) are used in radiolocation as 'silent sonars'. They determine the distance to target by measuring the difference between the frequency of the sounding signal and echo signal. The article presents the principle of operation and parameters of silent CW FM sonars. Target distance determined by these sonars is based on the signal at the output of the matched filter. The Doppler effect...
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Estymacja położenia węzłów ruchomych w sieci UWB synchronizowanej emisją z węzła nieruchomego
PublicationW referacie przedstawiono wyniki testów możliwości wykorzystania modemów IR UWB (Impulse Radio Ultra-Wide Band) typu DWM1000 do budowy sieci radiolokalizacyjnej, w której położenie węzłów ruchomych jest estymowane na podstawie pomiarów różnic odległości metodą TDOA (Time Difference of Arrival). Opisana została struktura sieci i sposób synchronizacji pomiarów czasów w nieruchomych węzłach referencyjnych przez cykliczny odbiór sygnałów...
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Filtracja danych TDOA w filtrze UKF w systemie multilateracyjnym
PublicationW artykule przedstawiono implementację metody filtracji danych pomiarowych w systemie MLAT(Multilateration), która ma na celu zwiększenie dokładności estymacji położenia poruszającego się statku powietrznego poprzez kompensację błędów pomiarowych. Opisano sposób implementacji algorytmu bezśladowego filtru Kalmana dla danych pomiarowych TDOA (Time Difference of Arrival), a następnie na podstawie zarejestrowanych rzeczywistych tras...
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Identification of Parameters Influencing the Accuracy of the Solution of the Nonlinear Muskingum Equation
PublicationTwo nonlinear versions of the Muskingum equation are considered. The difference between both equations relates to the exponent parameter. In the first version, commonly used in hydrology, this parameter is considered as free, while in the second version, it takes a value resulting from the kinematic wave theory. Consequently, the first version of the equation is dimensionally inconsistent, whereas the proposed second one is consistent. It...
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The Economic Legacy of Mega Sporting Events. The Impact of Hosting European Olympic Games on GDP Growth Through Infrastructure Development
PublicationIntroduction. The positive legacy of the Olympics is often cited by the International Olympic Committee and national or-ganizers. Some scholars, however, question an uncritical approach to an exclusively positive economic legacy. The aim of this study is to evaluate the impact of hosting the Olympics on infrastructure development, with a potential impact on economic growth in the form of Gross Domestic Product (GDP) in three phases...
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Experimental analysis of the behaviour of different types of joints in the steel structure model subjected to earthquake loading
PublicationThe present paper reports the results of the experimental study performed to investigate the behaviour of two different types of joints (destroyed and welded ones) in the model of the steel structure under seismic excitations. The structure was subjected to three earthquakes, namely Kobe, Loma Prieta and Northridge, using the shaking table investigation. The results obtained from the study...
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Method of lines for Hamilton-Jacobi functional differential equations.
PublicationInitial boundary value problems for nonlinear first order partial functional differential equations are transformed by discretization in space variables into systems of ordinary functional differential equations. A method of quasi linearization is adopted. Suffcient conditions for the convergence of the method of lines and error estimates for approximate solutions are presented. The proof of the stability of the diffrential difference...
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Magnetic field microsensor based on GaAs MESFET
PublicationA novel concept of the drain separation design in a horizontally-split-drain GaAs MAGFET sensor, based on epitaxial layer growth, was developed. Proper choice of GaAs/AlAs/GaAs epitaxial layer sequence provided good electrical isolation between the drain regions. The measured leakage current between the drain regions was in the range of nA for up to 2V drain voltage bias difference. Performed analytical and numerical calculations...
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Impact of radio wave polarisation on off-body communications in indoor environments
PublicationThis paper describes the measurements and the analysis of the impact of radio wave polarisation on off-body communications in Body Area Networks in indoor environments. Measurements on polarisation impact are briefly described. Five investigated scenarios with different body postures and different antenna placements are characterised. The difference between the vertical and horizontal components of the received radio signal are...
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High-Resolution, Broad-Range Detection Setup for Polarimetric Optical Fiber Sensors
PublicationA common-path polarization interferometer using a Wollaston prism and an area detector for the measurement of retardation or optical path difference is presented. Employing a moderate-resolution 1280 by 1024 pixel monochrome camera, it offers a measurement range of approximately 780 radians at 830 nm and 1350 radians at 515 nm while maintaining a high measurement resolution. Retardation introduced by a zero-order waveplate or a...
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Modal analysis of a fish-belly flap type of steel water gate
PublicationABSTRACT: The results of a modal analysis of the fish-belly flap type of steel water gate are presented in the paper. The analysis was conducted for a detailed numerical model of the structure using four-node quadrilateral shell elements. The study was focused on the examination of the influence of positioning of the flap gate and hydrostatic pressure of water on the eigenvalues and eigenmodes of the structure. The results of the study...
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Numerical Analysis of Steady Gradually Varied Flow in Open Channel Networks with Hydraulic Structures
PublicationIn this paper, a method for numerical analysis of steady gradually varied fl ow in channel networks with hydraulic structures is considered. For this purpose, a boundary problem for the system of ordinary differential equations consisting of energy equation and mass conservation equations is formulated. The boundary problem is solved using fi nite difference technique which leads to the system of non-linear algebraic equations....
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Feature Weighted Attention-Bidirectional Long Short Term Memory Model for Change Detection in Remote Sensing Images
PublicationIn remote sensing images, change detection (CD) is required in many applications, such as: resource management, urban expansion research, land management, and disaster assessment. Various deep learning-based methods were applied to satellite image analysis for change detection, yet many of them have limitations, including the overfitting problem. This research proposes the Feature Weighted Attention (FWA) in Bidirectional Long...
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Impact evaluation of a cycling promotion campaign using daily bicycle counters data: The case of Cycling May in Poland
PublicationThe promotion of active and sustainable transport modes as an alternative to motorised individual transport has become a key policy priority in Europe, to reduce air pollution, road congestion, noise, traffic injuries, and the adverse health outcomes of sedentary lifestyles. Policymakers are implementing a wide range of measures to encourage this shift in attitudes and behaviours. These interventions are most valuable when targeting...
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The influence of combination of binding agents on fatigue properties of deep cold in-place recycled mixtures in Indirect Tensile Fatigue Test (ITFT)
PublicationThe publication presents fatigue properties of cold recycled mixtures for eight combinations of binding agents (cement and bituminous emulsion). Cold recycled mixtures were evaluated in Indirect Tensile Fatigue Test (ITFT) at the temperature of 20 C in controlled stress mode. As a function of horizontal stress, fatigue life is strongly influenced by combination of the binding agents. When fatigue life is analyzed as a function...
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Dynamic analysis of lightweight structure of the Viaduct Millau in France subjected to the wind fluctuations described by Karman’s and Davenport’s spectrum
PublicationThe article presents numerical simulations for wind impact modelling on the Millau Viaduct structure in France performed with two independent spectrum generation methods. The viaduct's construction in affected by strong forces, as it is situated in the Tarn river's valley. Thus, the loading coming from the wind cannot be modelled, the way it is in case of simple structures as static loading, but as a loading in a form of a spectrum...
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The accuracy of pulse rate estimation from the sequence of face images
PublicationThe goal of this paper is to analyze the accuracy of pulse rate estimation from the sequence of face images. Simulated and real signals were used to evaluate two pulse rate estimators; one for frequency domain and the second one for time domain using the autocorrelation function. The results show that the mean difference between the reference measurements and estimated pulse rate values are about 2bpm. In the analysis of short...
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GPU based implementation of Temperature-Vegetation Dryness Index for AVHRR3 Satellite Data
PublicationPaper presents an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland. All phases of TVDI implementation on GPU are modified in respect to CUDA platform....
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Image simulation and annotation for color blinded
PublicationIn this paper methods for image simulation as seen by a color blinded and a method for constructing images of perceived color difference are presented. The work is also focused on the interactive color description of an image contents. As a result, the individuals having problems with color discrimination can identify colors in an image.W artykule prezentowane są metody symulacji kolorów w obrazach postrzeganych przez osoby ze...
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ASYNCHRONICZNA METODA TDOA
PublicationPrzedstawiono nową metodę lokalizowania terminali ruchomych MT (Mobile Terminal) w sieciach radiowych, w których stacje bazowe BS (Base Station) pracują asynchronicznie względem siebie. Metoda ta, nazwana ATDOA (Asynchronous Time Difference of Arrival), umożliwia estymację położenia MT na podstawie pomiarów różnicy czasów propagacji sygnałów radiowych pomiędzy terminalem ruchomym będącym w ruchu, a pojedynczą stacją bazową w różnych...
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Improvement of time difference of arrival measurements resolution by using fractional delay filters in a direct sequence-code division multiple access radionavigation system
PublicationThis study presents a method of improving time measurements resolution in a direct sequence-code division multiple access receiver by using a fine code tracking loop based on fractional delay filtering of a despreading sequence. It briefly describes the structure of a generic digital code tracking loop and the proposed modification which allows to measure time difference of arrival values with the subsample resolution, together...
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Performance of a new commercial high-definition 3D patient specific quality assurance system for CyberKnife robotic radiotherapy and radiosurgery
PublicationConventional two dimensional and low-definition measurement techniques for dosimetric verification of radiotherapy treatment deliveries are no longer adequate in the era of hypofractionation and extremely high dose gradients. New quality assurance (QA) tools with 3D capability and high definition are urgently needed. The purpose of this study was to evaluate the performance of one of the first such commercial systems as applied...
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Emission profile of butan-2-one oxime from commercially available neutral silicone sealant
PublicationThe paper presents results of research on emission profile of butan-2-one oxime (methyl ethyl ketoxime, MEKO) released from two types of commercially available neutral silicone sealants: silicone type ‘S’ and silicone type ‘T’. To determine the emissions from silicone samples, the system consists of a stationary emission chamber, and the thermal desorption-gas chromatography-mass spectrometry system was applied. First, the research...
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An effective method for studying intermolecular interactions in binary liquids with hydrogen bonds: FTIR spectra and ab initio calculations in the N-methylformamide - methanol system
PublicationMolecular complexes in methanol (MeOH)−N-methylformamide (NMF) mixtures were studied based on their FTIR-ATR spectra, to which two methods of analysis were applied: factor analysis and a quantitative version of the difference-spectra method. The mean composition of a complex between NMF and MeOH molecules over the whole range of mixture compositions was determined. Absorbing species differentiated with regard to the interaction...
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The compositional space of exhaled breath condensate and its link to the human breath volatilome
PublicationBreath analysis is commonly understood to target gaseous or volatile organic compounds (VOCs) for the characterization of different pathologies. Targeted analysis is most effective if a working hypothesis can be based on a plethora of data. The recently published volatilome builds an optimal basis for organizing powerful target sets. However, the origin and pathways of biosynthesis of many VOCs are not known, which complicates...
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Analiza efektywności metod estymacji położenia terminala ruchomego w środowisku propagacji wielodrogowej
PublicationW referacie została zaprezentowana analiza efektywności metod estymacji położenia terminala ruchomego w systemie WCDMA/FDD (Wideband Code Division Multiple Access / Frequency Division Duplex) w warunkach propagacji wielodrogowej. Analizie poddano cztery, najczęściej spotykane w literaturze przedmiotu, metody: Chan'a, Foy'a, Fang'a oraz Friedlander'a. Metody te umożliwiają wyznaczanie położenia geograficznego termi-nala ruchomego...
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Methods of determination of C coefficient for period of rolling vessel in calm water for example of pax cargo ship
PublicationThis article presents a different approach to calculate the C coefficient needed to determine the period of own rolling vessel in calm water. The C coefficient is usually adopted as the approximate value from the available literature, usually depending on the type of vessel, and less dependent on the loading condition. In experimental studies of marine properties (seakeeping) often have a problem with the selection of the correct...
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T1 RELAXATION TIME CALLIBRATION IN MAGNETIC RESONANCE IMAGING USING NANODIAMOND PHANTOMS
PublicationMRI is increasingly used in radiation treatment planning because of the excellent soft tissue contrast in the obtained images. It allows more precise definition of the boundaries between healthy tissues and those affected by cancerous lesions. To obtain good image quality, the difference in signal between two types of tissue must be significant despite the noise so it must be properly calibrated. This calibration includes...
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Implementation of TVDI calculation for coastal zone
PublicationPaper will show an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland, especially from region of Gdańsk coastal zone. All phases of TVDI implementation...
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Efektywne metody lokalizowania terminala ruchomego w systemie WCDMA/FDD
PublicationZaproponowano, poddano analizie i zbadano na drodze symulacyjnej dwie nowe, efektywne metody lokalizowania terminala ruchomego w systemie WCDMA/FDD (Wideband Code Division Multiple Access/Frequency Division Duplex). Metody te umożliwiają estymację położenia terminala ruchomego bez konieczności znajomości różnicy czasów w synchronizacji stacji bazowych RTD (Relative Time Difference). Eliminacja różnicy czasów RTD znacząco upraszcza...
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Implementation of DEIS for reliable fault monitoring and detection in PEMFC single cells and stacks
PublicationDynamic Electrochemical Impedance Spectroscopy (DEIS) was presented as novel method for diagnostic and monitoring of PEMFC stack and single cells operation. Impedance characteristics were obtained simultaneously with current - voltage characteristics for stack and each individual cell. Impedance measurements were performed in galvanodynamic mode. It allowed to compare performance of each cell and identification of faulty cell operation...
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SPATIAL APPROACH TO HETEROGENEITY OF INFLATION EXPECTATIONS IN THE EURO AREA
PublicationIn this article, we examine the spatial heterogeneities in inflation expectations of the euro area consumers. We expect to find them heterogeneous in our research period of 2001-2016. Contrary to standard examination of heterogeneity, a spatial correlation analysis is applied by referring to global and local correlation measures. It is performed with the economic distance-based weights (the difference in HICP rates). Application...
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Determination of the uncertainty of mass flow measurement using the orifice for different values of the Reynolds number
PublicationStandard orifice flowmeters are widely used in the chemical and energy industry. Therefore, it is essential to know how accurate the measurements made with these instruments are. The paper presents an estimation of measurement uncertainty of a liquid mass flow using the orifice plate. The authors will present the influence of ranges of the Reynolds number on the estimated uncertainty, obtained on the basis of simulation and laboratory...
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COMPUTER ANALYSIS OF HYDRAULIC CONDITIONS IN A SANITARY CHAMBER
PublicationThis paper presents analysis of hydraulic conditions of sewage flow down the slipway (ramp) in the collecting sanitary chamber connecting 3 collectors on the inlet: ⌀600, ⌀800 and ⌀1400 and one on the outlet ⌀1600 mm, with a maximum difference of elevation 5 m. The mathematical model has been made and hydraulic calculations were carried out in steady flow conditions. Then wastewater surface elevation, energy grade line elevation,...
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A Method of Real-Time Non-uniform Speech Stretching
PublicationDeveloped method of real-time non-uniform speech stretching is presented.The proposed solution is based on the well-known SOLA algorithm(Synchronous Overlap and Add). Non-uniform time-scale modification isachieved by the adjustment of time scaling factor values in accordance with thesignal content. Dependently on the speech unit (vowels/consonants), instantaneousrate of speech (ROS), and speech signal presence, values of the scalingfactor...