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Search results for: optimal thrust allocation
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ANALYSIS AND OPTIMIZATION OF ELECTRIC VEHICLE CHARGING PROCESSES IN TRANSACTIVE ENERGY SYSTEMS
PublicationThe implementation of smart charging of electric vehicles allows operators of local power networks and electricity suppliers to implement new business models for the interaction of electric vehicles with the network. In addition to the optimal selection of Microgrid capacities when charging electric vehicles, it is also important to use different charging methods. To satisfy the interests of all participants of local systems from...
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Genetic Positioning of Fire Stations Utilizing Grid-computing Platform
PublicationA chapter presents a model for determining near-optimal locations of fire stations based on topography of a given area and location of forests, rivers, lakes and other elements of the site. The model is based on principals of genetic algorithms and utilizes the power of the grid to distribute and execute in parallel most performance-demanding computations involved in the algorithm.
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A Stabilized Complex LOBPCG Eigensolver for the Analysis of Moderately Lossy EM Structures
PublicationThis letter proposes a stabilized locally optimal block preconditioned conjugate gradient method for computing selected eigenvalues for complex symmetric generalized non-Hermitian eigenproblems. Effectiveness of the presented approach is demonstrated for a moderately lossy dual-mode dielectric resonator, modeled using finite-element method with higher order elements
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublicationBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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On structural physical approximations and entanglement breaking maps
PublicationVery recently, a conjecture saying that the so-called structural physical approximations (SPAs) to optimal positive maps (optimal entanglement witnesses) give entanglement breaking (EB) maps (separable states) has been posed (Korbicz et al 2008 Phys. Rev. A 78 062105). The main purpose of this contribution is to explore this subject. First, we extend the set of entanglement witnesses supporting the conjecture. Then, we ask whether...
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Evaluation of Three Peptide Immobilization Techniques on a QCM Surface Related to Acetaldehyde Responses in the Gas Phase
PublicationThe quartz-crystal microbalance is a sensitive and universal tool for measuring concentrations of various gases in the air. Biochemical functionalization of the QCM electrode allows a label-free detection of specific molecular interactions with high sensitivity and specificity. In addition, it enables a real-time determination of its kinetic rates and affinity constants. This makes QCM a versatile bioanalytical screening tool for...
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Cooperation of mono- and bi-articular muscles: human lower limb
PublicationObjectives: The aim of this study was to create and analyze a Pareto-optimal problem that would describe cooperation between mono- and bi-articulate lower limb muscles in sagittal plane. Methods: Equations describing the problem were derived and analyzed, additional constrains were introduced and experimental verification based on gait video analysis was performed. Results: Uncertainty of Pareto-optimal solution is shown for the...
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Time versus space trade-offs for randezvous in trees
PublicationTwo identical (anonymous) mobile agents start from arbitrary nodes of an unknown tree and have to meet at some node. Agents move in synchronous rounds: in each round an agent can either stay at the current node or move to one of its neighbors. We consider deterministic algorithms for this rendezvous task. The main result of this paper is a tight trade-off between the optimal time of completing rendezvous and the size of memory...
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Rapid multi-objective design of integrated on-chip inductors by means of Pareto front exploration and design extrapolation
PublicationIdentification of the best trade-offs between conflicting design objectives allows for making educated design decisions as well as assessing suitability of a given component or circuit for a specific application. In case of inductors, the typical objectives include maximization of the quality factor and minimization of the layout area, as well as maintaining a required inductance at a given operating frequency. This work demonstrates...
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Adaptive stochastic and hybrid nonlinear optimization algorithms for improving the effectiveness of the biological processes at WWTP
PublicationWastewater treatment plays an important factor in the modern world. Insufficient treatment may result in environmental pollution which can further lead to disasters and diseases. However, processes that take place inside wastewater treatment plants (WWTP) are highly complex in nature, therefore it is difficult to design an efficient, optimal control system. The problem regarding biochemical reactions inside Sequential Batch Reactor...
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Pareto Ranking Bisection Algorithm for EM-Driven Multi-Objective Design of Antennas in Highly-Dimensional Parameter Spaces
PublicationA deterministic technique for fast surrogate-assisted multi-objective design optimization of antennas in highly-dimensional parameters spaces has been discussed. In this two-stage approach, the initial approximation of the Pareto set representing the best compromise between conflicting objectives is obtained using a bisection algorithm which finds new Pareto-optimal designs by dividing the line segments interconnecting previously...
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Simulation-driven size-reduction-oriented design of multi-band antennas by means of response features
PublicationThis study addresses the problem of explicit size reduction of multi-band antennas by means of simulation-driven optimisation. The principal difficulty of electromagnetic (EM)-based miniaturisation of multi-band antennas is that several resonances have to be controlled independently (both in terms of their frequency allocation and depth) while attempting to reduce physical dimensions of the structure at hand. The design method...
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Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning
PublicationFollowing the continuous development of the information technology, the concept of dense urban networks has evolved as well. The powerful tools, like machine learning, break new ground in smart network and interface design. In this paper the concept of using deep learning for estimating the radio channel parameters of the LTE (Long Term Evolution) radio interface is presented. It was proved that the deep learning approach provides...
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High-Power Jamming Attack Mitigation Techniques in Spectrally-Spatially Flexible Optical Networks
PublicationThis work presents efficient connection provisioning techniques mitigating high-power jamming attacks in spectrally-spatially flexible optical networks (SS-FONs) utilizing multicore fibers. High-power jamming attacks are modeled based on their impact on the lightpaths’ quality of transmission (QoT) through inter-core crosstalk. Based on a desired threshold on a lightpath’s QoT, the modulation format used, the length of the path,...
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Induced Sheath Voltages In 110 Kv Power Cables – Case Study
PublicationThe paper considers shock hazard due to induced sheath voltages in 110 kV power cables. Various configurations of the metallic sheaths bonding and earthing (single-point bonding, both-ends bonding, cross-bonding) are analysed. Taking into account shock hazard and ability of the system to power transfer an optimal configuration is proposed.
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Consequences of suboptimal design of Building Integrated Photovoltaic Installation – a case study for Gdansk, Poland
PublicationThe carried out analysis concerns 2 kWp building integrated photovoltaic installation (BIPV) at the Chemistry Faculty of Gdansk University of Technology. It was proven that the generated energy data for every month diverge significantly from the expected vales. It is corelated with suboptimal orientation of the installation itself, as well as with the tilt angle varying from optimal.
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A BRIEF REVIEW AND COMPARISON OF SELECTED EXPERIMENTAL METHODS FOR MEASURING NATURAL FREQUENCIES OF CIRCULAR SAW BLADES
PublicationDifferent methods for the empirical determination of the natural frequencies of circular saw blades are presented. Stationary methods, such as the harmonic and impulse tests, are discussed and the results of related comparison are given. The comparison of the methods revealed their degree of practical usefulness and their accuracy in determining natural frequencies. A combination of specific methods is proposed, which should allow...
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THE METHODS OF TEACHING / LEARNING STRUCTURAL MECHANICS
PublicationStructural mechanics is a key issue to study for engineers. A high rank and high social responsibility profession requires both a high graded and intuitive approach. The evolution of learning / teaching methodology follows the novel technical achievements of every decade. The aim remains the same: to produce a professional to perform advanced relevant analysis and safe, optimal structural design
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Skład i zawartość kwasów tłuszczowych w mleku kobiet z gdańska i okolic w różnych okresach laktacji = Fatty acid composition in breast milk of women from gdańsk and the surrounding district in the course of lactation
PublicationCelem pracy była ocena składu i zawartości kwasów tłuszczowych w tłuszczu mleka kobiet w różnych okresach laktacji, z uwzględnieniem składu KT pokarmu spożywanego przez matki. Do badań zakwalifikowano 80 położnic od których uzyskano próbki mleka w 2, 14, 30 i 90 dobie laktacji. Jednocześnie przeprowadzono badania ankietowe na podstawie których oszacowano zawartość poszczególny grup KT w dziennej racji pokarmowej matek. Skład i...
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A comparative study of pentanol (C5 alcohol) and kerosene blends in terms of gas turbine engine performance and exhaust gas emission
PublicationThe growing demand for sustainable and clean energy sources provides the incentive for the development of alternative fuels. Simultaneously, the development of gas turbine technologies with flexible fuel supply systems enables the use of alternative non-fossil fuels that can play key roles in contributing to global efforts in meeting emissions targets. This paper presents the current state of knowledge on the production and potential...
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Multi-Fidelity Local Surrogate Model for Computationally Efficient Microwave Component Design Optimization
PublicationIn order to minimize the number of evaluations of high-fidelity (“fine”) model in the optimization process, to increase the optimization speed, and to improve optimal solution accuracy, a robust and computational-efficient multi-fidelity local surrogate-model optimization method is proposed. Based on the principle of response surface approximation, the proposed method exploits the multi-fidelity coarse models and polynomial interpolation...
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Low-Cost Multi-Objective Optimization Yagi-Uda Antenna in Multi-Dimensional Parameter Space
PublicationA surrogate-based technique for fast multi-objective optimization of a multi-parameter planar Yagi-Uda antenna structure is presented. The proposed method utilizes response surface approximation (RSA) models constructed using training samples obtained from evaluation of the low-fidelity antenna model. Utilization of the RSA models allowsfor fast determination of the best possible trade-offs between conflicting objectives in multi-objective...
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Constrained aerodynamic shape optimization using neural networks and sequential sampling
PublicationAerodynamic shape optimization (ASO) involves computational fluid dynamics (CFD)-based search for an optimal aerodynamic shape such as airfoils and wings. Gradient-based optimization (GBO) with adjoints can be used efficiently to solve ASO problems with many design variables, but problems with many constraints can still be challenging. The recently created efficient global optimization algorithm with neural network (NN)-based prediction...
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Analytical progress on symmetric geometric discord: Measurement-based upper bounds
PublicationQuantum correlations may be measured by means of the distance of the state to the subclass ofstates having well defined classical properties. In particular, a geometric measure of asymmetricdiscord [Daki´c et al., Phys. Rev. Lett. 105, 190502 (2010)] was recently defined as the Hilbert-Schmidt distance of a given two-qubit state to the closest classical-quantum (CQ) correlated state.We analyze a geometric measure of symmetric...
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Shading, Dusting and Incorrect Positioning of Photovoltaic Modules as Important Factors in Performance Reduction
PublicationThe amount of solar radiation reaching the front cover of a photovoltaic module is crucial for its performance. A number of factors must be taken into account at the design stage of the solar installation, which will ensure maximum utilization of the potential arising from the location. During the operation of a photovoltaic installation, it is necessary to limit the shading of the modules caused by both dust and shadowing by trees...
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Selected Problems of Cogeneration Energy Systems Designing, Fueled with Landfill Biogas
PublicationThe article discusses the impact of the quality of biogas fuel for operation of generating sets with internal combustion engines. There are presented selected investigation results of landfill biogas fueled gensets operation. The article includes also discussion of the possibility of increasing the efficiency of biogas fuelled cogeneration systems. It also presents guidelines for the optimal design of landfill biogas fueled engines,...
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Analiza skuteczności wybranych strategii kontrariańskich na warszawskiej GPW w latach 2014–2018
PublicationCapital multiplication is the main goal of investors and for many years they have been looking for methods and strategies that would enable them to achieve it to the greatest possible extent. Due to the fact that the expectations and characteristics of investors, including those concerning the investment period, are diverse, multiple strategies have emerged. One of such strategies, mainly long-term in nature, is the so-called...
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Microfluidically Frequency-Reconfigurable Self-Quadruplexing Antenna Based on Substrate Integrated Square-Cavity
PublicationIn this article, a novel concept of self-quadruplexing tunable antenna (SQTA) enabled by microfluidic channels is investigated. The operating channels are either filled with air or dielectric liquids to enable frequency tunability. The proposed SQTA is implemented on the substrate-integrated square-cavity (SISC). A swastika-shaped slot is milled on the top-surface of the SISC to create four quarter-mode resonators. The resonators...
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Optymalizacja efektywności hamowania odzyskowego w transporcie szynowym przez sterowanie czasem przyjazdu na stację
PublicationArtykuł nawiązuje do poprzednich prac autorów, w których przedstawiono model organizacji ruchu kooperujących pociągów z uwzględnieniem optymalizacji wykorzystania energii zwracanej do sieci jezdnej. W przedstawionej pracy zmodyfikowano model zmieniając główną zmienną sterującą, mającą wpływ na efektywne wykorzystanie energii, z czasu odjazdu na czas przyjazdu pociągu na stację lub przystanek. Optymalizacja dokonywana jest przez...
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Nodal cooperation equilibrium analysis in multi-hop wireless ad hoc networks with a reputation system
PublicationMotivated by the concerns of cooperation security, this work examines selected principles of state-of-the-art reputation systems for multi-hop ad hoc networks and their impact upon optimal strategies for rational nodes. An analytic framework is proposed and used for identification of effective cooperation-enforcement schemes. It is pointed out that optimum rather than high reputation can be expected to be sought by rational nodes.
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Divide and not forget: Ensemble of selectively trained experts in Continual Learning
PublicationClass-incremental learning is becoming more popular as it helps models widen their applicability while not forgetting what they already know. A trend in this area is to use a mixture-of-expert technique, where different models work together to solve the task. However, the experts are usually trained all at once using whole task data, which makes them all prone to forgetting and increasing computational burden. To address this limitation,...
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Finger Vein Presentation Attack Detection Method Using a Hybridized Gray-Level Co-Occurrence Matrix Feature with Light-Gradient Boosting Machine Model
PublicationPresentation Attack Detection (PAD) is crucial in biometric finger vein recognition. The susceptibility of these systems to forged finger vein images is a significant challenge. Existing approaches to mitigate presentation attacks have computational complexity limitations and limited data availability. This study proposed a novel method for identifying presentation attacks in finger vein biometric systems. We have used optimal...
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Decentralized Microgrid Energy Management System with Market-Based Energy Trade System
PublicationThis paper presents a decentralized energy management system for a power microgrid, which integrates individual users, who own renewable energy sources and energy storages. The purpose of the system is to make optimal use of available resources to cover the electricity needs of the whole microgrid. Thanks to the energy exchange system, in addition to exchanges with the distribution network, the system also allows trades within...
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Surface Structure of Components Created by Stereolitography
PublicationStereolithography is an additive rapid prototyping method. This method is based on the principle of solidifying a liquid photopolymer (resin) by laser radiation. Models obtained with this method are characterized by a specific surface structure called “stairstep effect”. It causes that, the surface should be processed by additional finishing (postprocessing). To minimize the additional machining process, the model should be set...
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Comments on “Closed Form Variable Fractional Time Delay Using FFT”
PublicationIn this letter drawbacks of the aforementioned paper are pointed out. The proposed approach is improved with minor modifications of the discrete frequency response. This allows for design of fractional delay filters which are close to optimal and can be efficiently implemented in the frequency domain using the sliding DFT based structure. Alternatively, the derived equivalent closed form formulae for offset windows can be used...
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How does environmental regulation affect the city's domestic value-added rate of export? New spatial evidence from Chinese cities
PublicationProtecting the environment and increasing the domestic value-added rate of exports (DVARE) are hot issues for high-quality economic development. This paper explores how environmental regulation affects the DVARE. This paper constructs a dynamic spatial econometric model using the data of 285 Chinese cities from 2000 to 2020. It empirically tests the impact of environmental regulation on the DVARE. The research results show that...
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Macroeconomic functions of the Russian stock market
PublicationThe purpose of this article is to present the structure of the stock market in the Russian Federation and the significance of this part of national financial system for the whole economy, particularly the degree of main macroeconomic functions fulfillment. First part of the text includes an overview of the main theoretical concepts linked with the stock market roles as well as a brief description of results of selected studies...
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Performance evaluation of unified memory and dynamic parallelism for selected parallel CUDA applications
PublicationThe aim of this paper is to evaluate performance of new CUDA mechanisms—unified memory and dynamic parallelism for real parallel applications compared to standard CUDA API versions. In order to gain insight into performance of these mechanisms, we decided to implement three applications with control and data flow typical of SPMD, geometric SPMD and divide-and-conquer schemes, which were then used for tests and experiments. Specifically,...
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Complexity Issues on of Secondary Domination Number
PublicationIn this paper we study the computational complexity issues of the problem of secondary domination (known also as (1, 2)-domination) in several graph classes. We also study the computational complexity of the problem of determining whether the domination and secondary domination numbers are equal. In particular, we study the influence of triangles and vertices of degree 1 on these numbers. Also, an optimal algorithm for finding...
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A Surveillance Of Dynamic Processes in Selected Mechatronic Systems
PublicationThe paper concerns development of original method of optimal control at energy performance index and its application to dynamic processes surveillance of some mechatronic systems. The latter concerns chatter vibration surveillance during highspeed slender milling of rigid details, as well as motion control of two-wheeled mobile platform. Results of on-line computer simulations and real performance on the target objects reflect...
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Calculation of Induced Sheath Voltages in Power Cables – Single Circuit System versus Double Circuit System
PublicationThis paper presents comparison of values of induced sheath voltages in power cable metallic sheaths when one or two cables per phase are used. Calculation of voltages is performed for various phase sequences of the power cables. Three types of the sheaths bonding and earthing are considered. Shock hazard and voltage stress of non-metallic outer sheath of cables are evaluated. The proposed, optimal configuration of the power cable...
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Redukcja obciążeń odmorskich ścian falochronów pionowościennych przy zastosowaniu ścian ażurowych i komór wygaszających
PublicationPoszukiwanie optymalnych rozwiązań w projektowaniu falochronów portowo-morskich stanowi ciągłe wyzwanie dla projektantów w dziedzinie hydrotechniki portowo-morskiej. W przypadku falochronów morskich jednym z decydujących czynników mających wpływ na wybór rodzaju konstrukcji jest uzyskanie maksymalnej możliwej redukcji obciążeń od falowania morskiego. Niniejsza praca poświęcona jest rozwiązaniom konstrukcyjnym skrzyń żelbetowych,...
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Application of chemometric modeling for ionic liquid-based ultrasonic-assisted dispersive liquid-liquid microextraction: Analysis of fosetyl-aluminum in fruit and vegetable samples
PublicationThis manuscript presents a new method for selective extraction and determination of fosetyl-aluminum in fruits and vegetable samples based on ultrasonic-assisted dispersive liquid-liquid microextraction method using ionic liquids (IL-UA-DLLME). A UV-Visible spectrophotometer was used for detection and quantification. Plants used for sample collection were grown under controlled conditions in a greenhouse. Central composite design...
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Detection of Delamination in Laminate Wind Turbine Blades Using One-Dimensional Wavelet Analysis of Modal Responses
PublicationThis paper demonstrates the effectiveness of a nondestructive diagnostic technique used to determine the location and size of delamination in laminated coatings of wind turbine blades. This is realized based on results of numerical and experimental investigations obtained by the use of the finite element method (FEM) and laser scanning vibrometry (LSV). The proposed method is based on the one-dimensional continuous wavelet transform...
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THE EFFECT OF LOG SORTING STRATEGY ON THE FORECASTED LUMBER VALUE AFTER SAWING PINE WOOD
PublicationThe optimal transformation path for the resource is determined by the quality of a log combined with its dimension. The commercial value of derived products is also closely connected with the size and extent of containing wood deficiencies. The results of studies with three diverse strategies for log sorting are presented in the paper. Resource assessment by a worker without extensive experience in sorting logs, the certified grading...
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Evolutionary Sets of Safe Ship Trajectories: the Method's Development and Selected Reaserch Results
PublicationThe Evolutionary Sets of Safe Ship Trajectories is a method solving ship encounter situations. The method combines evolutionary approach to planning ship trajectory with some of the assumption of game theory. For given positions and motion parameters the method finds a near optimal set of safe trajectories of all ships involved in an encounter. This paper presents framework of the method and its development. Additionally, selected...
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Lithuania inland waterways and its prospects
PublicationInland waterways have some traditions in Lithuania and in neighbor Countries, but during last 50 years other modes of transport move out inland waterway transport from real economical activity. In the same time inland waterways is the main green and sustainable transport system. In this article are presented analysis situation, methodology for the ships optimal using in inland waterways, forecasting of the possible cargo and passenger...
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Multichannel self-optimizing active noise control scheme
PublicationThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. The proposed cancellation scheme is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. In the important benchmark case - for disturbances with randomwalk-type amplitude...
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Non-monotone graph searching models
PublicationGraph searching encompasses a variety of different models, many of which share a property that in optimal strategies fugitive can never access once searched regions. Monotonicity, as it is called, is vital in many established results in the field however its absence significantly impedes the analysis of a given problem. This survey attempts to gather non-monotone models, that are less researched in effort of summarizing the results...
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Analiza właściwości emiterów impulsowych pola elektromagnetycznego
PublicationW pracy przedstawiono analizę porównawczą wybranych emiterów pola elektromagnetycznego w oparciu o badania symulacyjne. Badane emitery różnią się kształtem i rozmiarem elementów składowych. Analiza dotyczy właściwości impulsów pola elektromagnetycznego. Porównano właściwości kierunkowe, efektywności emisji oraz częstotliwości własne emiterów. Wskazano na najbardziej korzystną z punktu widzenia tych parametrów konstrukcje emitera.