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Search results for: almost periodic function
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Atomic-Scale Finite-Element Modeling of Elastic Mechanical Anisotropy in Finite-Sized Strained Phosphorene Nanoribbons
PublicationNanoribbons are crucial nanostructures due to their superior mechanical and electrical properties. This paper is devoted to hybrid studies of the elastic mechanical anisotropy of phosphorene nanoribbons whose edges connect the terminals of devices such as bridges. Fundamental mechanical properties, including Young’s modulus, Poisson’s ratio, and density, were estimated from first-principles calculations for 1-layer, 3-layer, and...
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Hydration of Oxometallate Ions in Aqueous Solution
PublicationThe strength of hydrogen bonding to and structure of hydrated oxometallate ions in aqueous solution have been studied by double difference infrared (DDIR) spectroscopy and large-angle X-ray scattering (LAXS), respectively. Anions are hydrated by accepting hydrogen bonds from the hydrating water molecules. The oxygen atom of the permanganate and perrhenate ions form weaker and longer hydrogen bonds to water than the hydrogen bonds...
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Ground tire rubber functionalization as a promising approach for the production of sustainable adsorbents of environmental pollutants
PublicationWaste tires management and further utilization are currently one of the biggest concerns regarding the environment and human health protection. At present, shredding, grinding, or pulverization of waste tires are the most popular options for industrial recycling. Although many solutions for ground tire rubber (GTR) applications were checked and verified so far, their further implementation at an industrial scale is still very limited....
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Modelling of high frequency dynamic responses of engineering structures
PublicationModelling of high frequency dynamic responses of engineering structures, especially those related to wave propagation, is a real numerical challenge. Nowadays most of numerical models, used for that purpose, are based on the application of various finite element techniques. However, finite element discrete models may also be considered as possessing certain periodic structures, which may manifest themselves in particular scenarios....
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublicationA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
PublicationLaser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr...
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Drawing maps with advice
PublicationW pracy podejmujemy temat konstrukcji algorytmu dla agenta, który zostaje umieszczony w dowolnym wierzchołku grafu (wierzchołki są nierozróżnialne, krawędzie mają etykiety portów), po czym realizuje algorytm zmierzający do znalezienia drzewa spinającego grafu lub izomorficznej kopii grafu. Dla obu problemów podajemy asymptotycznie dokładne lub prawie dokładne oszacowania na ilość bitów dodatkowej informacji, którą agent musi otrzymać...
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Spectral Analysis of Capital Markets
PublicationIn this paper the problem of cycles existence in capital markets is addressed. A spectral analysis algorithm, which reduces signal-to-noise ratio, is proposed to derive cycle periodograms for the yield function of DJIA, WIG~20, and NIKKEI 225 indices. Peaks of the the periodograms provide premises to postulate the existence of some possible cycles. The 3.5 year periodicity in all 3 indices, which can be related to Kitchin cycle...
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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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Monitoring Regenerative Heat Exchanger in Steam Power Plant by Making Use of the Recurrent Neural Network
PublicationArtificial Intelligence algorithms are being increasingly used in industrial applications. Their important function is to support operation of diagnostic systems. This paper pesents a new approach to the monitoring of a regenerative heat exchanger in a steam power plant, which is based on a specific use of the Recurrent Neural Network (RNN). The proposed approach was tested using real data. This approach can be easily adapted to...
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CHANGES TAKING PLACE IN THE KINETIC ARCHITECTURE OVER THE 20TH AND 21ST CENTURIES
PublicationKinematics has accompanied architecture from its beginning and is strongly associated with its evolution. Over the centuries, it has changed form and function. However, its rank grew at the beginning of the 20th century. Along with the widespread change of the design method in the early 90s of the twentieth century, its forms have become more complex. The study showed that with the development of design techniques, this time should be...
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Four level inverter's DC bus voltage balancing with 3-terminal DAB converter
Publication—Multilevel inverters become more and more popular, especially in the medium or high voltage and high power applications. Unfortunately, some of inverter topologies require additional DC bus voltage balancing systems. This paper presents a novel approach to such systems, which is based on a multiple terminal DAB converter. Along with the voltage balancing function the proposed solution enables the connection of energy storage devices...
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Basic Hand Gestures Classification Based on Surface Electromyography
PublicationThis paper presents an innovative classification system for hand gestures using 2-channel surface electromyography analysis. The system developed uses the Support Vector Machine classifier, for which the kernel function and parameter optimisation are conducted additionally by the Cuckoo Search swarm algorithm. The system developed is compared with standard Support Vector Machine classifiers with various kernel functions. The average...
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The aggregation of objects representing buildings in the Kartuzy district - scale 1:10000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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The aggregation of objects representing buildings in the Kartuzy district - scale 1:25000
Open Research DataThe process of automatic generalization is one of the elements of spatial data preparation for the purpose of creating digital cartographic studies. The presented data include a part of the process of generalization of building groups obtained from the national geodesy and cartography resource from BDOT10k (10k topographic database) [1].
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Assessment of Poland's competitiveness as a location for BPO/SSC projects
Open Research DataIn compiled by A.T. Kearney in subsequent editions of the ranking (2009, 2011, 2016, 2019), the first three positions were taken by the same countries. India received the highest marks with a clear advantage. The country is a world leader in terms of attractiveness for locating business service centers. India can offer English-speaking skilled labor...
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Determination of Moisture Content Profiles of Spruce Wood After High Temperature Process and Air Drying
PublicationThe results of moisture content of wood after the process of its drying under high temperature conditions and air drying are presented. Wood samples, namely spruce (Picea abies Karst.) from the northern part of Pomerania region in Poland, were subject of steam and air drying.The aim of experiments was to measure moisture content of wood in its cross sections using moisture meter WRD-100. The samples of thickness 70 mm and length...
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New RFID readers for scalable RFID system
PublicationRFID systems gives the opportunity to have wide access control integrated with the monitoring of people and goods flow. System's scalability is one of the most important features in such systems as they enable large scale deployments. The concept of the proposed reader's architecture employs new RFID transceivers and microcontrollers, security algorithms which gives very high functionality at low price. Special treatment of system's...
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9-Cyano-10-methylacridinium hydrogen dinitrate
PublicationThe title compound, C15H11N2+·HN2O6−, crystallizes in the monoclinic space group C2/c with four molecules in the unit cell. The planar 9-cyano-10-methylacridinium cations lie on crystallographic twofold axes and are arranged in layers, almost perpendicular to the ac plane, in such a way that neighbouring molecules are positioned in a `head-to-tail' manner. These cations and the hydrogen dinitrate anions are linked through C—H⋯O...
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Buzz-based recognition of the honeybee colony circadian rhythm
PublicationHoneybees are one of the highly valued pollinators. Their work as individuals is appreciated for crops pollination and honey production. It is believed that work of an entire bee colony is intense and almost continuous. The goal of the work presented in this paper is identification of bees circadian rhythm with a use of sound-based analysis. In our research as a source of information on bee colony we use their buzz that have been...
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Position and Orientation Estimation in Radio Network With Groups of Locally Synchronized Nodes
PublicationThis article presents a positioning system with groups of locally synchronized nodes. A mobile object is equipped with a group of several synchronized receivers that are able to measure the difference in the time of arrival of signals from reference transmitters. The reference transmitters are synchronized only in local groups, with no global synchronization between groups. It is assumed that the synchronous operation of transmitters...
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Numerical and experimental study on effect of boundary conditions during testing of stiffened plates subjected to compressive loads
PublicationThis study analyses the effect of boundary conditions during testing on the structural behaviour stiffened plates with different thicknesses subjected to compressive loads. The goal of the compressive tests is to analyse the ultimate strength of a stiffened plate. During the test, relevant physical quantities are measured and investigated. The supporting structure's behaviour is investigated by analysing the force-displacements...
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HISTORY OF INITIAL ENERGY AND WATER NETWORK DEVELOPMENT IN QATAR
PublicationQatar: A country which had to be associated with neighboring countries like UAE or Saudi Arabia for people to know about it, stands proud today due to the ample production and exporting of Black Gold. A country with almost no vegetation or suitable weather to harvest crops, turned from being heavily dependent on trading Pearls to exporting natural oil and gas to all over the globe. The paper outlines in details the history of the...
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Single crystal growth and physical properties of MCo2Al9 (M= Sr, Ba)
PublicationSingle crystals of SrCo2Al and BaCo2Al9 were grown using a self-flux method. A LeBail analysis of the powder X-ray diffraction patterns show that both compounds crystallize in a hexagonal (P6/mmm) crystal structure with lattice parameters: a = 7.8995(1) Å, c = 3.9159(1) Å for SrCo2Al9, and a = 7.9162(2) Å, c = 3.9702(1) Å for BaCo2Al9 aluminide. The low temperature analysis of the heat capacity measurements give a Sommerfeld...
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Space vector modulation in multilevel inverters of the servo drives of the trajectory measurements telescopes
PublicationUsing the MatLab/Simulink mathematical model of a three-phase three-level voltage inverter, the influence of the space-vector modulation (SVM) algorithm on the pulsations of the current (torque) of an AC motor in the range of low rotation speeds is considered. It is shown that the SVM of the second kind does not provide a pulsations level comparable to the pulsations of a sinusoidal pulse-width modulation (SPWM), both in the static...
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Nanoindentation tests titanium alloy Ti-6Al-4V after interference laser treatment
PublicationThe study aimed was to assess selected mechanical properties of surface layers obtained after interference laser treatment – DLIL of titanium alloy Ti-6Al-4V used for implants. The samples were melted in still air at room temperature, for this purpose Nd:YAG laser was used, the number of laser shots was variable. Next, nanoindentation tests were performed, based on which Young’s modulus and nanohardness in the obtained surface...
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Preliminary Citation and Topic Analysis of International Conference on Agile Software Development Papers (2002-2018)
PublicationThis study utilizes citation analysis and automated topic analysis of papers published in International Conference on Agile Software Development (XP) from 2002 to 2018. We collected data from Scopus database, finding 789 XP papers. We performed topic and trend analysis with R/RStudio utilizing the text mining approach, and used MS Excel for the quantitative analysis of the data. The results show that the first five years of XP...
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Syntheses, Structures and Reactivity of Terminal Phosphido Complexes of Iron(II) Supported by a β-Diketiminato Ligand
PublicationWe report the synthesis of the first series of terminal phosphido iron complexes supported by a β‐diketiminato ligand (Dippnacnac) and their catalytic activity in dehydrocoupling of secondary phosphines. Anionic and neutral mono‐ or diphosphido complexes were obtained from the reaction of [(Dippnacnac)FeCl2Li(dme)2] with the R2PLi (R = iPr, tBu, Cy, Ph) phosphides by tuning the stoichiometric ratio, polarity of the solvent, and...
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A Meta-Analysis of Pulse Arrival Time Based Blood Pressure Estimation
PublicationThe paper presents a preliminary meta-analysis of the sample correlation between pulse arrival time (PAT) and blood pressure (BP). The aim of the study was to verify sample correlation coefficient between PAT and BP using an affine model BP = a · P AT + b for systolic and diastolic blood pressure. The databases included in the search were the IEEE Xplore Digital Library, Springer Link and Google Scholar. Only papers from 2005 to...
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The bismuth vanadate thin layers modified by cobalt hexacyanocobaltate as visible-light active photoanodes for photoelectrochemical water oxidation
PublicationBismuth vanadate thin films deposited using the pulsed laser deposition technique were modified using cobalt hexacyanocobaltate (Cohcc). The 2-step method of Cohcc nanocubes preparation was applied: i) metallic cobalt deposition and ii) cobalt electrooxidation in Co(CN)63− containing electrolyte. The presence of CN stretching vibrations was confirmed by Raman spectroscopy. The energy band gap was equal to 2.5 eV and was estimated...
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RSS-based DoA Estimation Using ESPAR Antennas and Interpolated Radiation Patterns
PublicationIn this letter, it is shown how an algorithm, which employs received signal strength (RSS) values in order to estimate direction-of-arrival (DoA) of impinging signals in wireless sensor network (WSN) nodes equipped with electronically steerable parasitic array radiator (ESPAR) antennas, can easily be improved by applying an interpolation algorithm to radiation patterns recorded in the calibration phase of the DoA estimation process....
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Completeness and Consistency of the System Requirement Specification
PublicationAlthough the System Requirement Specification, as a first formal and detailed document, is the base for the software project in classic software methodologies, there is a noticeable problem of assuring the completeness of this document. The lack of its completeness causes uncertainty of the project foundations. This was one of motivations for agile methodologies – if the SRS cannot be easily validated, if it can change in late project...
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Programmable Input Mode Instrumentation Amplifier Using Multiple Output Current Conveyors
PublicationIn this paper a programmable input mode instrumentation amplifier (IA) utilising second generation, multiple output current conveyors and transmission gates is presented. Its main advantage is the ability to choose a voltage or current mode of inputs by setting the voltage of two configuration nodes. The presented IA is prepared as an integrated circuit block to be used alone or as a sub-block in a microcontroller or in a field...
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About definition of modes and magnetosonic heating in a plasma’s flow: Especial cases of perpendicular and nearly perpendicular wave vector and magnetic field
PublicationDynamics of hydrodynamic perturbations in a plasma depend strongly on an angle between the wave vector and equilibrium straight magnetic field. The case of perpendicular propagation is especial. There are only two (fast) magnetosonic modes since two (slow) ones degenerate into the stationary one with zero speed of propagation. This demands individual definition of wave modes by the links of hydrodynamic relations. These links are...
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Insights into Seawater Biodegradation of Sustainable Mater-Bi/Poly(ε-caprolactone)-Based Biocomposites Filled with Diisocyanate-Modified Cellulose Particles
Publication: Due to rapid economic growth, the use of plastics in almost all areas of human life has significantly increased over recent decades, leading to massive pollution. Therefore, works dealing with sustainable and biodegradable polymer materials are vital now. Herein, sustainable MaterBi/poly(ε-caprolactone) (PCL)-based biocomposites, filled with diisocyanate-modified cellulose particles, were prepared and subjected to 12-week seawater...
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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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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublicationThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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New Approach to Noncasual Identification of Nonstationary Stochastic FIR Systems Subject to Both Smooth and Abrupt Parameter Changes
PublicationIn this technical note, we consider the problem of finite-interval parameter smoothing for a class of nonstationary linear stochastic systems subject to both smooth and abrupt parameter changes. The proposed parallel estimation scheme combines the estimates yielded by several exponentially weighted basis function algorithms. The resulting smoother automatically adjusts its smoothing bandwidth to the type and rate of nonstationarity...
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Simulation of influence of the air gap asymmetryon voltage waveforms of a synchronous machine
PublicationResults of simulation of a synchronous generator with the air gap asymmetry characterised by eccentricity are presented in the paper. The Lagrange's energy method has been used in derivation of the model equations. Analysis of influence of the air gap asymmetry on characteristics of self and mutual inductances of windings, as well as analysis of induced voltage waveforms as a function of the air gap asymmetry have been performed....
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Distorsional analysis of I-section beam
PublicationAn elastic stiffness matrix was derived in the case of distortion of a restrained thin-walled I-section beam using the minimum total stationary elastic energy condition. The function describing the angle of distortion was adopted form the solution of differential equation in the case of restrained distortion. The example presented in the paper helps to assess the correctness of the proposed solution. The proposed elastic stiffness...
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Mechanical Properties of Human Stomach Tissue
PublicationThe dataset entitled Determination of mechanical properties of human stomach tissues subjected to uniaxial stretching contains: the length of the sample as a function of the corresponding load (tensile force) and the initial values of the average width and average thickness of the sample. All tests were conducted in a self-developed tensile test machine: PG TissueTester. The dataset allows the coefficients of various models of...
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A novel concept for tissue-metal detection and differentiation using an inductive proximity sensor
PublicationIn this paper a novel application of inductive proximity sensors for detection of living tissue by means of measurements of the coil impedance changes at different frequencies is described. The mathematical analyses utilizing Bessel function estimation include detected object size and its distance from a sensor. The main aim of this study is to prove the possibility of distinguishing between metal objects and living tissues. The...
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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublicationThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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A method of self-testing of analog circuits based on fully differential op-amps with theTCBF classifier
PublicationA new approach of self-testing of analog circuits based on fully differential op-amps of mixed-signal systems controlled by microcontrollers is presented. It consists of a measurement procedure and a fault diagnosis procedure. We measure voltage samples of a time response of a tested circuit on a stimulation of a unit step function given at the common-mode reference voltage input of the op-amp. The fault detection and fault localization...
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Zero-Pole Electromagnetic Optimization
PublicationA fast technique for the full-wave optimization of transmission or reflection properties of general linear timeinvariant high-frequency components is proposed. The method is based on the zeros and poles of the rational function representing the scattering parameters of the device being designed and it is the generalization of the technique developed for the design by optimization of microwave filters. The performance of the proposed...
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Systemic analysis of a manufacturing process based on a small scale bakery
PublicationThe main aim of the article is to present two new innovative concepts of reliability of a functioning manufacturing system in the process of making bread in small-scale bakeries. Reliability is understood as one of the representations of an operator acting on specifc streams in time to - t. One of these represents the global reliability of a system as a function of parallel action of all the streams of the system in time to to...
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Force-deformation spectroscopy in contact mode
Open Research DataThe deformation-distance spectroscopic curve is obtained by registering the value of the probe cantilever deflection as a function of the elongation of the piezoelectric scanner. It assumes a simple relationship in the form of Hooke’s law, linking the deformation of the lever with the amount of its deflection caused by the proximity of the probe and...
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Analityczna weryfikacja dokładności komercyjnych programów komputerowych wspomagających projektowanie układów geometrycznych toru
PublicationW pracy podjęto próbę wyjaśnienia kwestii uzyskiwanej dokładności w projektowaniu układów geometrycznych toru z wykorzystaniem komercyjnych programów komputerowych typu CAD. Użytkownikowi najczęściej nie są znane zasady działania tych programów, w tym również wykorzystywane algorytmy obliczeniowe. Opisano w sposób ogólny funkcjonowanie dwóch wiodących programów. Przedstawiono własną, analityczną metodę projektowania układów torowych,...
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Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve
PublicationThe main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number...
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Fast EM-Driven Nature-Inspired Optimization of Antenna Input Characteristics Using Response Features and Variable-Resolution Simulation Models
PublicationUtilization of optimization technique is a must in the design of contemporary antenna systems. Often, global search methods are necessary, which are associated with high computational costs when conducted at the level of full-wave electromagnetic (EM) models. In this study, we introduce an innovative method for globally optimizing reflection responses of multi-band antennas. Our approach uses surrogates constructed based on response...