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Search results for: direct dipole approximation
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Low-energy positron scattering from gas-phase tetrahydrofuran: A quantum treatment of the dynamics and a comparison with experiments
PublicationIn this paper we report new quantum calculations of the dynamics for low-energy positrons interacting with gaseous molecules of tetrahydrofuran. The new quantum scattering cross sections are differential and integral cross sections at collision energies between 1.0 and 25.0 eV and include a careful treatment of the additional effects on the scattering process brought about by the permanent dipole moment of the target molecule....
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Rapid dimension scaling of triple-band antennas by means of inverse surrogate modeling
PublicationGeometry scaling of antennas, i.e., finding optimum dimensions of the structure for given operating conditions and material parameters is an important yet challenging problem. In this paper, we discuss fast dimension scaling of triple-band antennas with respect to operating frequencies. We adopt the inverse surrogate modeling approach where the surrogate model is a function of the three operating frequencies of the antenna and...
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Practical aspects of testing superconducting electromagnets by the capacitor discharge method taking into account the non-linearity of circuit parameters
PublicationThe article presents selected issues related to the development and testing of the diagnostics systems dedicated for superconducting electromagnets. The systems were constructed to assess the production quality of superconducting electromagnets of the SIS100 synchrotron, a new accelerator being built as part of the Facility of Antiproton and Ion Research (FAIR). One of the systems is used for automatic checking of electrical connection...
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Laboratory Determination of Burger's Model Parameters for Visco-elastic Analysis of Road Pavement Materials
PublicationBurger's Model is one of those models that describes performance of asphalt mixtures. Its parameters can be used in road construction analysis based on visco-elastic properties in wide variety of temperatures using dedicated programs (e.g. Veroad) or in Finite Element Method (FEM). Parameters of Burger's Model can be used for example in prediction of low temperature cracking in low winter temperatures or permanent deformation...
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Fundamentals of Physics-Based Surrogate Modeling
PublicationChapter 1 was focused on data-driven (or approximation-based) modeling methods. The second major class of surrogates are physics-based models outlined in this chapter. Although they are not as popular, their importance is growing because of the challenges related to construction and handling of approximation surrogates for many real-world problems. The high cost of evaluating computational models, nonlinearity of system responses,...
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A Simplified Method of Trend Removal to Determine Noise Observed During a Supercapacitor’s Discharging
PublicationIn this paper, new method of trend removal is proposed. This is a simplified method based on Empirical Mode Decomposition (EMD). The method was applied for voltage time series observed during supercapacitor discharging process. It assured the determination of an additive noise component after subtracting the identified trend component. We analyzed voltage time series observed between the terminals of the supercapacitor when discharged...
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Oriented Gaussian beams for high-accuracy computation with accuracy control of X-ray propagation through a multi-lens system
PublicationA highly accurate method for calculating X-ray propagation is developed. Within this approach, the propagating wave is represented as a superposition of oriented Gaussian beams. The direction of wave propagation in each Gaussian beam agrees with the local direction of propagation of the X-ray wavefront. When calculating the propagation of X-ray waves through lenses, the thin lens approximation is applied. In this approximation,...
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Exploiting multi-interface networks: Connectivity and Cheapest Paths
PublicationLet G = (V,E) be a graph which models a set of wireless devices (nodes V) that can communicate by means of multiple radio interfaces, according to proximity and common interfaces (edges E). The problem of switching on (activating) the minimum cost set of interfaces at the nodes in order to guarantee the coverage of G was recently studied. A connection is covered (activated) when the endpoints of the corresponding edge share at...
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A Monte Carlo Strategy to simulate Positrons and Positronium in biological Materials
PublicationWe present an algorithm for Monte Carlo simulations of positron tracks in biological materials. The algorithm takes into account the cross-section data for elastic and inelastic collisions between positrons and molecules and processes like direct annihilation, ionization and positronium formation. In the case of positronium formation, the algorithm considers the interactions of positronium with molecules. The algorithm can be used...
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A method of measuring RLC components for microcontroller systems
PublicationA new method of measuring RLC components for microcontroller systems dedicated to compact smart impedance sensors based on a direct sensor-microcontroller interface is presented. In the method this direct interface composed of a reference resistor connected in series with the tested sensor impedance is stimulated by a square wave generated by the microcontroller, and then its voltage response is sampled by an internal ADC of the...
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Fluorescence of p-hydroxyazobenzocrowns – Tautomeric equilibrium effect
PublicationThe spectroscopic properties of a series of para-hydroxyazobenzocrowns, including three novel compounds, were investigated using UV–Vis absorption and emission spectroscopy. This study presents, for the first time, determined quantum yield (QY) values for macrocycles of this category, ranging between 0.122 and 0.195. The highest values were obtained for crowns bearing two phenyl substituents in benzene rings. The impact of aromatic...
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Structure and optical parameters of Eu doped tellurium oxide thin films prepared by reactive magnetron sputtering method
PublicationIn this work the structural properties and photoluminescence of tellurium dioxide thin films doped by europium were described. Thin films were deposited by magnetron sputtering method and simultaneously heated at 200 °C. Presence of Eu ions and their valence states was confirmed by X-ray photoemission spectroscopy measurements. The structure of the films as well as the influence of europium dopant on crystalline structure of the...
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Second-order Stark effect and polarizability of a relativistic two-dimensional hydrogenlike atom in the ground state
PublicationThe second-order Stark effect for a planar Dirac one-electron atom in the ground state is analyzed within the framework of the Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian series expansion of the generalized Dirac-Coulomb Green's function. A closed-form analytical expression for the static dipole polarizability of that system is found. The formula involves the generalized hypergeometric function ${}_{3}F_{2}$...
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Closed-form expression for the magnetic shielding constant of the relativistic hydrogenlike atom in an arbitrary discrete energy eigenstate: Application of the Sturmian expansion of the generalized Dirac–Coulomb Green function
PublicationWe present analytical derivation of the closed-form expression for the dipole magnetic shielding constant of a Dirac one-electron atom being in an arbitrary discrete energy eigenstate. The external magnetic field, by which the atomic state is perturbed, is assumed to be weak, uniform, and time independent. With respect to the atomic nucleus we assume that it is pointlike, spinless, motionless, and of charge Ze. Calculations are...
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Words context analysis for improvement of information retrieval
PublicationIn the article we present an approach to improvement of retrieval informationfrom large text collections using words context vectors. The vectorshave been created analyzing English Wikipedia with Hyperspace Analogue to Language model of words similarity. For test phrases we evaluate retrieval with direct user queries as well as retrieval with context vectors of these queries. The results indicate that the proposed method can not...
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Reduced-Cost Constrained Modeling of Microwave and Antenna Components: Recent Advances
PublicationElectromagnetic (EM) simulation models are ubiquitous in the design of microwave and antenna components. EM analysis is reliable but CPU intensive. In particular, multiple simulations entailed by parametric optimization or uncertainty quantification may considerably slow down the design processes. In order to address this problem, it is possible to employ fast metamodels. Here, the popular solution approaches are approximation...
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Karolina Sobieraj mgr inż.
PeopleMSc. Karolina Sobieraj graduated in 2018 in the field of Renewable Energy Sources and Waste Management in the specialization of Waste Management, with a scholarship from the Minister of Science and Higher Education for students for outstanding scientific achievements in the 2017/2018 academic year. From October 2019, she started studies at the UPWr Doctoral School in the discipline of environmental engineering, mining and energy....
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Calculation of electron scattering lengths on Ar, Kr, Xe, Rn and Og atoms
PublicationFocusing on the noble gases, we calculate the scattering potential using the Dirac-Coulomb Hamiltonian supplemented with a model polarization potential. We determine the scattering lengths using two methods, namely phase shifts for very small scattering energies and the shape of the wave function for zero scattering energy. We compare our theoretical electron scattering length results on Ar, Kr and Xe atoms with existing experimental...
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublicationIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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Poly-L-Lysine-modified boron-doped diamond electrodes for the amperometric detection of nucleic acid bases
PublicationBoron-doped diamond (BDD) is a very promising supporting material used in the construction of biosensors for molecular recognition. The direct immobilization of structurally-organized huge molecules, such as poly-L-Lysine (PLL) provides the possibility of determining organic molecules, e.g. nucleic acid bases (e.g. adenine, guanine) or peptides and proteins. This paper describes the direct method for chemical and electrochemical...
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Study of the process of biofilm formation by UPEC IH11128 in the LB medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the LB medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Pressure effects on the electronic structure and superconductivity of (TaNb)0.67(HfZrTi)0.33 high entropy alloy
PublicationEffects of pressure on the electronic structure, electron-phonon interaction, and superconductivity of the high entropy alloy ( TaNb ) 0.67 ( HfZrTi ) 0.33 are studied in the pressure range 0–100 GPa. The electronic structure is calculated using the Korringa-Kohn-Rostoker method with the coherent potential approximation. Effects of pressure on the lattice dynamics are simulated using the Debye-Grüneisen model and the Grüneisen...
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Interaction of Novel Ionic Liquids with Soils
PublicationWith the constant development of new ionic liquids, the understanding of the chemical fate of these compounds also needs to be updated. To this effect, in this contribution, the interaction of a number of novel ionic liquids with soils was determined. Therefore, three novel headgroups (ammonium, phosphonium or pyrrolidinium) with single or quaternary substitution were tested on a variety of soils with high to low organic matter...
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Low-energy positron scattering from DNA nucleobases: the effects from permanent dipoles
PublicationAb initio quantum calculations for low-energy positron scattering from gas-phase isolated molecular nucleobases which are part of the DNA structure are presented and discussed over the range of 1 eV to 25 eV. The calculations report the integral cross sections (ICSs) and the momentum-transfer cross sections (MTCSs) for Adenine, Guanine, Thymine and Cytosine. The calculations show very clearly the important role of the dominant...
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Accelerated Re-Design of Antenna Structures Using Sensitivity-Based Inverse Surrogates
PublicationThe paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant reduction of the number of reference designs required to render the surrogate. Rigorous formulation of the approach is supplemented by its comprehensive numerical validation using a...
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Do positrons measure atomic and molecular diameters?
PublicationWe report on density functional calculations (DFT) of elastic integral scattering cross-sections for positron collisions with argon, krypton, nitrogen and methane. The long-range asymptotic polarization potential is described using higher-order terms going much beyond an induced dipole potential (−α / r 4) while the short-range interaction is modeled by two different forms of electron – positron correlation potential (Boroński-Nieminen...
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On Bayesian Tracking and Prediction of Radar Cross Section
PublicationWe consider the problem of Bayesian tracking of radar cross section. The adopted observation model employs the gamma family, which covers all Swerling cases in a unified framework. State dynamics are modeled using a nonstationary autoregressive gamma process. The principal component of the proposed solution is a nontrivial gamma approximation, applied during the time update recursion. The superior performance of the proposed approach...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids+0,2% glycerol medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids+0,2% glycerol medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Residue-Pole Methods for Variability Analysis of S-parameters of Microwave Devices with 3D FEM and Mesh Deformation
PublicationThis paper presents a new approach for variability analysis of microwave devices with a high dimension of uncertain parameters. The proposed technique is based on modeling an approximation of system by its poles and residues using several modeling methods, including ordinary kriging, Adaptive Polynomial Chaos (APCE), and Support Vector Machine Regression (SVM). The computational cost is compared with the traditional Monte-Carlo...
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Fast Basis Function Estimators for Identification of Nonstationary Stochastic Processes
PublicationThe problem of identification of a linear nonsta-tionary stochastic process is considered and solved using theapproach based on functional series approximation of time-varying parameter trajectories. The proposed fast basis func-tion estimators are computationally attractive and yield resultsthat are better than those provided by the local least squaresalgorithms. It is shown that two...
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Theory of valence-band and core-level photoemission from plutonium dioxide
PublicationThe correlated-band theory implemented as a combination of the local-density approximation with the dynamical mean-field theory is applied to PuO2. An insulating electronic structure, consistent with the experimental valence-band photoemission spectra, is obtained. The calculations yield a nonmagnetic ground state that is characterized by a noninteger filling of the plutonium 5f shell. The noninteger filling as well as the satellites...
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FIR Filter Design Using Distributed Maximal Flatness Method
PublicationIn the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness”...
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RANS-based design optimization of dual-rotor wind turbines
PublicationPurpose An improvement in the energy efficiency of wind turbines can be achieved using dual rotors. Because of complex flow physics, the design of dual-rotor wind turbines (DRWTs) requires repetitive evaluations of computationally expensive partial differential equation (PDE) simulation models. Approaches for solving design optimization of DRWTs constrained by PDE simulations are investigated. The purpose of this study is to determine...
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Expedited constrained multi-objective aerodynamic shape optimization by means of physics-based surrogates
PublicationIn the paper, computationally efficient constrained multi-objective design optimization of transonic airfoil profiles is considered. Our methodology focuses on fixed-lift design aimed at finding the best possible trade-offs between the two objectives: minimization of the drag coefficient and maximization of the pitching moment. The algorithm presented here exploits the surrogate-based optimization principle, variable-fidelity computational...
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On refined constitutive equations in the six-field theory of elastic shells
PublicationWithin the resultant six-field shell theory, the second approximation to the complementary energy density of an isotropic elastic shell undergoing small strains is constructed. In this case, the resultant drilling couples are expressed explicitly by the stress resultants and stress couples as well as by amplitudes of the quadratic and cubic distributions of an intrinsic deviation vector. The refined 2D strain-stress and stress-strain...
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Trust Dynamics Analysis of CTR Scheme Subversion under Virtual Anonymity and Trust-Unaware Partner Selection
PublicationWe propose a framework to study Markovian trust value dynamics in a centralized Computational Trust and Reputation (CTR) scheme under trust-unaware partner selection using a mean-value approximation. Analytically founded answers are sought to questions like: Can dishonest agents subvert the CTR scheme (i.e., acquire higher trust values than honest agents)? Is indirect reciprocity incentivized? Is there a qualitative impact of a...
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Optimization of the femtosecond laser impulse for excitation and the spin-orbit-mediated dissociation in the NaRb molecule
Open Research DataHigh accuracy ab initio potential energy curves (1tSigma+, 2sSigma+, 1tPi), electronic transition dipole moment function (1tSigma+ - 1tPi), and spin-orbit coupling (2sSigma+ - 1tPi) have been calculated for the NaRb molecule. The time-dependent excitation and dissociation processes in the polar alkali diatomic NaRb molecule and the quantum properties...
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Tax preferences in CIT in numbers 2009-2015
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support in Corporate Income Tax (CIT) between 2009-2015.
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Evaluation of the Effectiveness of Methods for Delimitation of the Boundaries of Registered Parcels in the Process of Modernization of Land and Building Registration
PublicationIn the article, a comparative analysis of two methods for delimitation of the boundaries of registered parcels was carried out: the method of direct measurement in the field and the photogrammetric method. One of the analyzed factors was the attendance of parcels’ owners during the development of boundary recognition agreements. Research has shown that in this aspect the method of direct measurement...
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A Simulative Comparison of Ship Domains and Their Polygonal Approximations
PublicationThe paper investigates the impact of a precise ship domain shape on the size of collision avoidance manoeuvres. The considered collision avoidance manoeuvres include both course and speed alterations. Various ship domains are compared with their polygonal approximations, which vary in the number of points of a domain contour and placement of these points. The best of all considered approximations is determined in the course of...
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Response features for fast EM-driven design of miniaturized impedance matching transformers
PublicationA framework for low-cost EM-driven design optimization of compact impedance matching transformers is presented. Our technique is based on a bottom-up design where design requirements for the transformer circuit are translated into specifications for its building blocks. These elementary cells are optimized using response features. Subsequently, the entire circuit is fine-tuned using local response surface approximation models and...
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A Method for Optimising the Blade Profile in Kaplan Turbine
PublicationThis paper introduces a method of blade profile optimisation for Kaplan-type turbines, based on modelling the interaction between rotor and stator blades. Rotor and stator blade geometry is described mathematically by means of a midline curve and thickness distribution. Genetic algorithms are then used to find a global optimum that minimises the loss coefficient. This allows for variety of possible blade shapes and configurations....