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Search results for: finite-difference time-domain (fdtd) method
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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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Measurements of Thermal Conductivity of LWC Cement Composites Using Simplified Laboratory Scale Method
PublicationThe implementation of low-energy construction includes aspects related to technological and material research regarding thermal insulation. New solutions are sought, firstly, to reduce heat losses and, secondly, to improve the environment conditions in isolated rooms. The effective heat resistance of insulating materials is inversely proportional to temperature and humidity. Cement composites filled with lightweight artificial...
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2022-2023 - Wytrzymałość materiałów I, PG_00039799
e-Learning CoursesCelem przedmiotu jest zapoznanie studentów z podstawowymi zagadnieniami związanymi z wytrzymałością materiałów. Wykłady dotyczą kolejno: podstawy wytrzymałości materiałów, wytrzymałość pręta prostego na ściskanie/rozciąganie, analiza wytrzymałości dla układów prętowych statycznie niewyznaczalnych, wytrzymałość prętów na skręcanie, wytrzymałość belek zginanie, odkształcenia belki zginanej, ścinanie pręta (pręt ścinany), stany naprężeń,...
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Analysis of wave propagation in a bolted steel joint
PublicationThe paper presents results of numerical and experimental investigations of elastic wave propagation in a bolted single-lap joint. The research was carried out for both symmetric and antisymmetric Lamb wave modes. In experimental studies the PZT transducers were used to excite and register wave propagation signals. The controlled value of the torque during measurements was ensured by the use of high precision torque wrenches. Numerical...
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Maximum transportation growth in energy and solute particles in Prandtl martial across a vertical 3D-heated surface: Simulations achieved using by finite element approach
PublicationThe goal of this study is to determine the maximum energy and solute particles' transportation growth in a 3D-heated region of Prandtl martial through a dynamic magnetic field. The effects of this field on the properties of solvent molecules and heat conduction are studied. A correctly stated functional method and a finite element approach are comparable to a certain type of differential equations. In order demonstrate the effects...
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Stress analysis of a strip under tension with a circular hole
PublicationThe paper addresses stress analysis of a strip with a circular hole under uniform uniaxial tension based oncircumferential stress expressionρπ. Stresses are analyzed in the infinite-length strips under tension with holes, the ratioof the hole radiusa to the strip half-widthb is either equal to:κ =a/b = 0.1 orκ = 0.5. Circumferential stresses aredetermined in selected cross-sections of the strip. The stress diagrams display local...
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Sensitive method for determination of benzoic acid in beverages and food samples using air–assisted hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction
PublicationA simple, reliable and rapid air–assisted hydrophobic deep eutectic solvent-based dispersive liquid–liquid microextraction (AA-HDES-DLLME) was developed for analysis of benzoic acid in various beverages and food samples. The final determination stage was performed via UV–visible spectrophotometry. The key parameters (extraction time, HDES type and volume, dispersant volume, pH and sample volume) of the AA-HDES-DLLME method were...
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Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Using Deep Eutectic Solvents (DESs) for Neutral Red Dye Spectrophotometric Determination
PublicationDeep eutectic solvents (DES), which have low toxicity and are low cost, biodegradable, and easily synthesized, were used for the extraction of neutral red (NR) dye before its spectrophotometric analysis. DES, containing choline chloride as a hydrogen bond acceptor and phenol as a hydrogen bond donor with a molar ratio of 1:2, was used for the extraction of NR dye from aqueous media. The possible interaction of different DESs with...
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Cost-Efficient Surrogate Modeling of High-Frequency Structures Using Nested Kriging with Automated Adjustment of Model Domain Lateral Dimensions
PublicationSurrogate models are becoming popular tools of choice in mitigating issues related to the excessive cost of electromagnetic (EM)-driven design of high-frequency structures. Among available techniques, approximation modeling is by far the most popular due to its versatility. In particular, the surrogates are exclusively based on the sampled simulation data with no need to involve engineering insight or problem-specific knowledge....
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Using Decisional DNA to Enhance Industrial and Manufacturing Design: Conceptual Approach
PublicationDuring recent years, manufacturing organizations are facing market changes such as the need for short product life cycles, technological advancement, intense pressure from competitors and the continuous customers’ expectation for high quality products at lower costs. In this scenario, knowledge and its associated engineering/management of every stage involved in the industrial design has become increasingly important for manufacturing...
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Assessing the time effectiveness of trust management in fully synchronised wireless sensor networks
PublicationThe paper presents the results of the time effectiveness assessment of the distributed WSN Cooperative Trust Management Method - WCT2M in a fully synchronized Wireless Sensor Network (WSN). First we introduce some basic types of synchronization patterns in WSN based on the idea of sleep scheduling. Then we explain how WCT2M works in the network applying the fully synchronized sleep scheduling pattern. Such networks were subjected...
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System for characterisation and multidimensional imaging of seafloor using multibeam sonar data
PublicationMultibeam sonars are widely used in applications like high resolution bathymetry measurements, underwater object detection and imaging, etc. Also, they are the promising tool in seafloor characterisation and classification, having several advantages over conventional single beam echosounders. The proposed approach to seafloor classification relies on the combined use of three different techniques. In each of them, a set of descriptors...
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Enhancing Product Innovation Through Smart Innovation Engineering System
PublicationThis paper illustrates the idea of Smart Innovation Engineering (SIE) System that helps in carrying the process of product innovation. The SIE system collects the experiential knowledge from the formal decisional events. This experiential knowledge is collected from the set of similar products having some common functions and features. Due to the fact that SIE system collects, captures and reuses the experiential knowledge of all...
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Subjective and Objective Comparative Study of DAB+ Broadcast System
PublicationBroadcasting services seek to optimize their use of bandwidth in order to maximize user’s quality of experience. They aim to transmit high-quality digital speech and music signals at the lowest bitrate. They intend to offer the best quality under available conditions. Due to bandwidth limitations, audio quality is in conflict with the number of transmitted radio programs. This paper analyzes whether the quality of real-time digital...
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublicationThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...
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Billiard in a rotating half-plane
PublicationThe main objective of this research is to study the properties of a billiard system in an unbounded domain with moving boundary. We consider a system consisting of an infinite rod (a straight line) and a ball (a massless point) on the plane. The rod rotates uniformly around one of its points and experiences elastic collisions with the ball. We define a mathematical model for the dynamics of such a system and write down asymptotic...
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Long‐time scale simulations of virus‐like particles from three human‐norovirus strains
PublicationThe dynamics of the virus like particles (VLPs) corresponding to the GII.4 Houston, GII.2 SMV, and GI.1 Norwalk strains of human noroviruses (HuNoV) that cause gastroenteritis was investigated by means of long-time (about 30 μs in the laboratory timescale) molecular dynamics simulations with the coarse-grained UNRES force field. The main motion of VLP units turned out to be the bending at the junction between the P1 subdomain (that...
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UNRES-GPU for Physics-Based Coarse-Grained Simulations of Protein Systems at Biological Time- and Size-Scales
PublicationThe dynamics of the virus like particles (VLPs) corresponding to the GII.4 Houston, GII.2 SMV, and GI.1 Norwalk strains of human noroviruses (HuNoV) that cause gastroenteritis was investigated by means of long-time (about 30 μs in the laboratory timescale) molecular dynamics simulations with the coarse-grained UNRES force field. The main motion of VLP units turned out to be the bending at the junction between the P1 subdomain (that...
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Quadrotor Flight Controller Design Using Classical Tools
PublicationA principal aspect of quadrocopter in-flight operation is to maintain the required attitude of the craft’s frame, which is done either automatically in the so-called supervised flight mode or manually during man-operated flight mode. This paper deals with the problem of flight controller (logical) structure and algorithm design dedicated for the man-operated flight mode. The role of the controller is to stabilise the rotational...
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A Time Delay Controller Included Terminal Sliding Mode and Fuzzy Gain Tuning for Underwater Vehicle-Manipulator Systems
PublicationAn improved Time Delay Control (TDC) method for an Underwater Vehicle-Manipulator System (UVMS) is proposed. The proposed controller consists of three terms: a time-delay-estimation term that cancels nonlinearities of the UVMS dynamics, a Terminal Sliding Mode (TSM) term that provides a fast response and a PID term that reduces the tracking error. In addition the proposed controller uses fuzzy rules to adaptively tune the gains...
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublicationThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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Numerical Study of Concrete Mesostructure Effect on Lamb Wave Propagation
PublicationThe article presents the results of the numerical investigation of Lamb wave propagation in concrete plates while taking into account the complex concrete mesostructure. Several concrete models with randomly distributed aggregates were generated with the use of the Monte Carlo method. The influence of aggregate ratio and particle size on dispersion curves representing Lamb wave modes was analyzed. The results obtained for heterogeneous...
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DETERMINING THE TIME CONSTANT USING TWO METHODS AND DEFINING THE THERMOCOUPLE RESPONSE TO SINE EXCITATION OF GAS TEMPERATURE
PublicationThis paper describes the two methods of determining the time constant of type K thermocouple, for two construction solutions: the exposed weld and the mantle fillet weld. This is an important parameter indicating the response time of the thermocouple on the recorded signal. The first method consists of determining the value of τ in the way of numerical simulation of heat exchange between the thermocouple and the current of gas...
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Optimization of a Fabric Phase Sorptive Extraction protocol for the isolation of six bisphenols from juice pouches to be analysed by high performance liquid chromatography coupled with diode array detector
PublicationFabric Phase Sorptive Extraction (FPSE) combined with high pressure liquid chromatography using to diode array detection (HPLC-DAD) was applied for the simultaneous determination of bisphenols (BPA, BPB, BPC, BPE, BPF, BPS) in juice pouches. The FPSE procedure was optimized with regards to the critical parameters that affect the performance of the method including the selection of the FPSE membrane type and size, adsorption time,...
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An in situ technique for the assessment of adhesive properties of a joint under load
PublicationSlow crack propagation in adhesive bonded joints has been characterised using an asymmetric wedge test. Crack position was evaluated from strain gauge measurements, both in the debonded partof the joint and in the bonded zone. Test temperature was changed during loading, giving insight into bond evolution. The technique allows accurate, and virtually continuous, determination of crack position to be made, and therefore the evaluation...
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Numerical modelling of the mesofracture process of sintered 316L steel under tension using microtomography
PublicationThis paper concerns numerical modelling of the deformation process, taking into account the local fracture of porous 316L sinters at the mesoscopic scale using the finite element method. Calculations are performed with the use of geometrical models, to map the realistic shape of the porous mesostructure of the material, obtained by means of computed microtomography. The microtomographic device has limited and insufficient measurement...
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Kinetics of cyclohexane removal by Candida subhashii and Fusarium solani
Open Research DataDataset presents cyclohexane biodegradation in gas phase using two species of microorganisms: Candida Subhashii and Fusarium solani. Biodegradation was carried out in sealed chambers with a capacity of 1000 ml. In each of them there are two discs inhabited with microorganisms, made of polyurethane foam, 80 mm in diameter and 20 mm thick.
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Impulse Impedance Measurements of Lightning Protection Earthings
PublicationLightning protection earthing systems should be tested at currents with time parameters similar to those of lightnings. A method and definition of a measured value of impulse impedance are introduced. The impulse impedance was determined by a quotient of voltage drop on the tested earthing to a value of current in measure circuit. The usefulness of the impulse method for lightning protection evaluation is tested on radio base stations...
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Influence analysis of selected parameters on the ASON/GMPLS control plane performance
PublicationThe paper regards the problem of ASON/GMPLS performance. The authors present influence analysis of selected parameters on the ASON/GMPLS control plane performance represented in mean Connection Set-up Time E(CST) and mean Connection Release Time E(CRT). The selected parameters are: offered traffic, request intensity and proportion of requests class. The influence analysis is performed with simulation method by using OMNeT++ discrete-event...
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Numerical Model of Femur Part
PublicationThe aim of the study is to create a new more accurate method of femur part modelling by using the finite element method. According to this new method, a femur part is treated as a complex structure composed of trabecular bone (internal part) and cortical bone (external part). The internal part is modelled as a scaffold, thus the external part is modelled as a coat (i.e. covering). Applying the programme ABAQUS, there were created...
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Karolina Lademann Mgr
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Estimation of Selected Synchronous Generator Parameters Based on the Gradient Method
PublicationThe authors present a method for the estimation of synchronous generator model parameters using a gradient algorithm. The paper shows an example of model parameter estimation for a turbogenerator and hydrogenerator, based on the generator voltage time responses obtained during an active and reactive power rejection test.
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Nondestructive Testing of the Miter Gates Using Various Measurement Methods
PublicationWhen any problems related to civil engineering structures appear, identifying the issue through the usage of only one measuring method is difficult. Therefore, comprehensive tests are required to identify the main source. The strains and displacement measurements, as well as modal identification, are widely used in the nondestructive testing of structures. However, measurements are usually carried out at several points and confirm...
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Creating Acoustic Maps Employing Supercomputing Cluster
PublicationThe implemented online urban noise pollution monitoring system is presented with regard to its conceptual assumptions and technical realization. A concept of the noise source parameters dynamic assessment is introduced. The idea of noise modeling, based on noise emission characteristics and emission simulations, was developer and practically utilized in the system. Furthermore, the working system architecture and the data acquisition...
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FPGA Acceleration of Matrix-Assembly Phase of RWG-Based MoM
PublicationIn this letter, the field-programmable-gate-array accelerated implementation of matrix-assembly phase of the method of moments (MoM) is presented. The solution is based on a discretization of the frequency-domain mixed potential integral equation using the Rao-Wilton-Glisson basis functions and their extension to wire-to-surface junctions. To take advantage of the given hardware resources (i.e., Xilinx Alveo U200 accelerator card),...
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Study on the Influence of an Axial Distance Between Rotors on a Performance of a Small Counter-Rotating Wind Turbine
PublicationIn this paper, results of the investigation on the performance of a small counter-rotating wind turbinehas been presented. Computational Fluid Dynamics methodshave been used forwind turbine simulations. Rotors representation were introduced into computational domain by means of Actuator Line Model. Influence of an axial distance of CRWTrotorshas been investigated. In all studied configurations rotors were counter-rotating...
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OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD
PublicationThis paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead...
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Modelling of dielectric properties of BiNbO4-based microwave ceramics
PublicationIn the present paper results of the studies devoted to computer simulations of dielectric response of electroceramics in a frequency domain as well as analysis of the experimental data are given. As an object of investigations BiNbO4-based microwave ceramics was taken. Simulations of the hypothetical impedance response of the ceramic system were performed under assumption of the brick-layer model. A strategy for analysis and modelling...
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Scaled agile framework. Dealing with software process‐related challenges of a financial group with the action research approach
PublicationThis article reports on a domain-specific software development venture at Nordea. We explore organizational constraints, challenges, and corrective actions undertaken when scaling the agile development approach of their Core Banking Platform program. The fit and required customizations of the rather complex and rigid SAFe framework in a policy-heavy financial institution are audited against the organic growth of the program. In...
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IR-THERMAL IMAGING IN CARDIOSURGERY
PublicationA method for monitoring the state of the myocardium during cardiosurgical interventions based on thermal IR imaging is presented. These methods called Static Thermography and Active Dynamic Thermography (ADT) uses information about distribution of temperature on the surface and an external excitation source to induce thermal transient processes in a tested object. Recording time series of thermograms allows to calculate parametric...
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Application of response surface methodology to optimize solid-phase microextraction procedure for chromatographic determination of aroma-active monoterpenes in berries
PublicationMost of scientific papers concern the qualitative or semi-quantitative analysis of aroma-active terpenes in liquid food matrices. Therefore, the procedure based on solid-phase microextraction and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for determination of monoterpenes in fresh berries was developed. The optimal extraction conditions using divinylbenzene-carboxen-polydimethylsiloxane fiber...
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Determination of Pesticide Residues in Honey using the GC×GC-TOFMS Technique
PublicationIn this study, a QuEChERS method and gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) was developed for rapid extraction and simultaneous determination of 12 pesticide residues in honey. The GCxGC-TOFMS method was validated according to the SANCO guidance in terms of linearity, selectivity, reproducibility and recovery. Regarding the results, recovery rates ranged between 70-120% with relative standard...
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Framework of an Evolutionary Multi-Objective Optimisation Method for Planning a Safe Trajectory for a Marine Autonomous Surface Ship
PublicationThis paper represents the first stage of research into a multi-objective method of planning safe trajectories for marine autonomous surface ships (MASSs) involved in encounter situations. Our method applies an evolutionary multi-objective optimisation (EMO) approach to pursue three objectives: minimisation of the risk of collision, minimisation of fuel consumption due to collision avoidance manoeuvres, and minimisation of the extra...
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Acceleration of Electromagnetic Simulations on Reconfigurable FPGA Card
PublicationIn this contribution, the hardware acceleration of electromagnetic simulations on the reconfigurable field-programmable-gate-array (FPGA) card is presented. In the developed implementation of scientific computations, the matrix-assembly phase of the method of moments (MoM) is accelerated on the Xilinx Alveo U200 card. The computational method involves discretization of the frequency-domain mixed potential integral equation using...
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A New Approach of Solidification Analysis in Modular Latent Thermal Energy Storage Unit Based on Image Processing
PublicationThe solidification process of RT18HC in a cylindrical shell and tube storage unit has been studied using a new methodology based on image processing. The main idea of the algorithm is to label the region of solidification and use statistical functions to calculate the dimensions of the solidification front over time. Said analysis includes two methods. The first method is to measure the solid fraction changes during solidification....
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Hybrid Multi-Criteria Method of Analyzing the Location of Distributed Renewable Energy Sources
PublicationThis paper presents the development and the application of a hybrid multi-criteria method, the combination of the Analytic Hierarchy Process (AHP), and numerical taxonomy (NT),to support the decision making on the location of distributed renewable energy sources meetingvarious types of assessment criteria. Finding criteria weights, using the AHP method, eliminates thedisadvantage of NT—which, in current form, is defined by its...
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Testing the Wide-Sense Stationarity of Bandpass Signals for Underwater Acoustic Communications
PublicationThe Underwater Acoustic Communication (UAC) systems work in communication channels characterized by a large variety of multipath propagation conditions that can additionally change over time. Designing a reliable communication system requires knowledge of the transmission parameters of the channel. There is a need for the development of adaptive signaling schemes that would dynamically optimize the signal parameters of the physical...
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Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique
PublicationReal-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging...
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ECHOES REDUCTION DURING DIGITAL DATA TRANSMISSION IN HYDROACOUSTIC CHANNEL – LABORATORY EXPERIMENT
PublicationThe possibility of using a hydroacoustic channel for digital data transmission is very limited. This is due to the effect of multipath propagation of the emitted acoustic wave and the damping of the mechanical wave in this medium, which increase with frequency. The first of these phenomena results in inter-symbol interference disturbances in data transmission systems, including even hundreds of symbols. Due to the number of reflections...
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Customized crossover in evolutionary sets of safe ship trajectories
PublicationThe paper presents selected aspects of evolutionary sets of safe ship trajectories-a method which applies evolutionary algorithms and some of the assumptions of game theory to solving ship encounter situations. For given positions and motion parameters of the ships, the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The method works in real time and the solutions must be returned within...