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Search results for: PROPAGATION MODELS ADJUSTMENT
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Computational fluid dynamics simulation of heat transfer from densely packed gold nanoparticles to isotropic media
PublicationThis work aims to determine and compare heat generation and propagation of densely packed gold nanoparticles (Au NPs) induced by a resonant laser beam (532 nm) according to the Mie theory. The heat flux propagation is transferred into the materials, which here are: silica glass; soda-lime-silica glass; borosilicate glass; polymethyl methacrylate (PMMA); polycarbonate (PC); and polydimetylosiloxane (PDMS). This analysis aims to...
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Accurate design of pseudoelliptic inline SIW filters with frequency-dependent couplings
PublicationThis paper presents an accurate synthesis method for inline SIW (Substrate Integrated Waveguide) generalized Chebyshev bandpass filters with frequency-dependent couplings. The technique is based on the synthesis of a coupling matrix that takes into account the impedance of the frequency-dependent stub. Thus, a loading effect compensation in adjacent resonators (via resonant frequency adjustment) and coupling elements (via coupling-value...
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Deregulation of the labour markets in the countries of Central and Eastern Europe — selected issues
PublicationThe countries of Central and Eastern Europe in the 1990s pursued the transformation processes which were to result in introducing systemic changes and building market economies. It was a process requiring adjustment of the regulatory and system framework to the requirements of the EU. One of the areas covered by the changes was the labour market. The reforms related to the functioning of national labour markets necessitated taking...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublicationThe article introduces a design and analysis results of a prototype ORC (organic Rankine cycle) turbo generator rotor assembly of 300kW power, supported by tilting-pad bearings of original design. The calculations were performed for a prototype turbo generator rotor. The shaft of this machine is supported with two radial bearings, lubricated with an unusual lubricant – a low-boiling-point agent. The main objective of the presented...
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Assessing the Significance of Displacements Using Local Coefficients of Variance as an Alternative to the Classical Approach
PublicationThe safety of use of civil engineering structures remains an important issue that is approached by various sciences. Due to this fact, geodetic control measurements are conducted with the purpose of identifying threats connected with the potential displacement of structural elements. In this context, the authors discuss issues connected with determining the displacements of controlled points located in the studied object in a three-dimensional...
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Silver and Silver/Sodium Bisphosphonate Salts: Rare Examples of Molecular Solid Solutions and Their Biological Activity as Dual-Action Compounds
PublicationBisphosphonates (BPs) are an important treatment for osteoporosis and bone metastases due to their low toxicity, high thermostability, and the ability to inhibit bone resorption. Notably, BPs like alendronate, which contain a primary amine group, exhibit potent antiresorptive and antiangiogenic properties. Recent studies have focused on enhancing the BP properties by incorporating bioactive metals to increase their therapeutic...
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A Review: Structural Shape and Stress Control Techniques and their Applications
PublicationThis review article presents prior studies on controlling shape and stress in flexible structures. The study offers a comprehensive survey of literature concerning the adjustment and regulation of shape, stress, or both in structures and emphasizes such control’s importance. The control of systems is classified into three primary classes: nodal movement control, axial force control, and controlling the two classes concurrently....
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Accuracy analysis of 3D model obtained by photogrammetric method on the example of historic room from Wisłoujście Fortress
PublicationThe article presents a comparison of obtained models of a test object. Close range photogrammetry was used to obtain 3D models. As test object was used one of the rooms located in Wisłoujście Fortress in Gdańsk, Poland. Different models were obtained by using different distribution and number of reference points. Article contains analysis of differences between coordinates of control points obtained from total station measurements...
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Estimation of the uncertainty of the AC/AC transducer output voltage
PublicationThe paper presents a methodology for estimating uncertainty of voltage transducers processing function, on the example of CYVS411D07 voltage transducers. The analysis was conducted using the method based on the GUM Guide propagation of uncertainty law and the determination of the coverage factor based on the effective number of degrees of freedom (t-Student distribution). The paper also presents example evaluation results of measured...
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Acoustic Streaming Induced by Periodic and Aperiodic Sound in a Bubbly Liquid
PublicationThe vortex ow which follows intense sound propagating in a bubbly liquid, is considered. The reasons for acoustic streaming are both nonlinearity and dispersion. That makes streaming especial as compared with that in a Newtonian uid. Conclusions concern the vortex ow induced in a half-space by initially harmonic or impulse Gaussian beam. The vortex ow recalls a turbulent ow with increasing in time number of small-scale vortices...
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Analytical modeling of electric drives for vehicle traction control systems
PublicationWheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five...
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Process zone in the Single Cantilever Beam under transverse loading. - Part II: Experimental
PublicationThis paper describes an experimental arrangement to evaluate stress/strain fields in the process zone of asymmetric adhesively bonded joints. A transparent polycarbonate flexible beam was bonded to an aluminium alloy rigid block with an epoxy adhesive in a Single Cantilever Beam (SCB) configuration. The flexible adherend was loaded in the direction parallel to the initial crack front at constant rate. To monitor strains induced...
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The Influence of Global Corrosion Degradation on Localized Damage Detection Using Guided Waves
PublicationThis paper presents the results of a numerical analysis of the influence of corrosion degradation of metal plates on the wave propagation phenomenon. There are several different corrosion types, but general and pitting corrosion are the most common. General corrosion is more or less uniformly distributed over the entire exposed surface of the metal while pitting corrosion takes the form of localized cracks. Because the general...
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Numerical modeling of quantum dynamical processes
PublicationIn this dissertation I present a high-precision (15, 18 or 33 decimal places) C++ implementation of quantum dynamics time propagation algorithms for both time-independent and time-dependent Hamiltonian with an inhomogeneous source term. Moreover I present an extension of both algorithms for time propagation to handle arbitrary number of coupled electronic levels. I have performed a careful validation of these implementations comparing...
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Ekonomiczne aspekty zastosowania techniki Mobilnych Pomiarów Satelitarnych przy regulacji osi toru
PublicationOd 2009 roku interdyscyplinarny zespół naukowy Politechniki Gdańskiej i Akademii Marynarki Wojennej (a obecnie Akademii Morskiej w Gdyni) rozwija technikę Mobilnych Pomiarów Satelitarnych toru kolejowego. Technika ta polega na objeździe trasy ciągnikiem szynowym z przyczepą (wagonem-platformą) lub wózkami, z zainstalowanymi na tych pojazdach odbiornikami sygnałów satelitarnych. Umożliwia ona precyzyjne określenie współrzędnych...
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Stan graniczny nośności dźwigara żelbetowego mostu na zginanie według norm PN-EN 1992-2 oraz PN-S-10042:1991
PublicationPraca włącza się w bogaty w ostatnich latach w krajowym piśmiennictwie nurt porównań dwóch generacji norm projektowania mostów z betonu: polskiej - wycofanej, aczkolwiek powszechnie stosowanej oraz europejskiej – wciąż jeszcze wdrażanej do praktyki projektowej. Nowością w stosunku do dotychczasowych publikacji polskich jest szersze ujęcie różnic pomiędzy obydwiema generacjami norm. Poza rozpatrywanymi przez wielu autorów różnicami...
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A method of the UMTS-FDD network design based on universal load characteristics
PublicationIn the paper an original method of the UMTS radio network design was presented. The method is based on simple way of capacity-coverage trade-off estimation for WCDMA/FDD radio interface. This trade-off is estimated by using universal load characteristics and normalized coverage characteristics. The characteristics are useful for any propagation environment as well as for any service performance requirements. The practical applications...
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An Analysis of Multistrip Line Configuration on Elliptical Cylinder
PublicationA configuration of multistrip lines mounted on a multilayer dielectric coated elliptic cylinder is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. Both open and shielded lines are considered in the analysis. Propagation coefficients and characteristic impedances are calculated for the...
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Application of PL-Grid Platform for Modeling of the Selected Acoustic Phenomena
PublicationDomain grids are specific computational environments, developed within the PLGrid Plus project. For the Acoustic domain grid two supercomputer grid based services were prepared. Dedicated software consists of the outdoor sound propagation module and psychoacoustical noise dosimeter. The results are presented in a form of maps of sound level and Temporary Threshold Shift (TTS) values, therefore the services may play an informative...
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STUDY OF SEASONAL ACOUSTIC PROPERTIES OF SEA WATER IN SELECTED WATERS OF THE SOUTHERN BALTIC
PublicationClimate Research of the globe is a current task, in particular to confirm the general hypothesis of global warming associated with an increase in average temperature. The sea acoustic climate is derived from the concept of climate and refers to the conditions of propagation of acoustic waves in a particular basin. In this paper, the results of systematic measurements of temperature, salinity and velocity distributions of sound...
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Analysis of High Resolution Clouds of Points as a Source of Biometric Data
PublicationThe article presents the analysis devoted to human face data obtained by means of precise photographic scanners. Collected point clouds were used to make high precision meshes of human face. The essence of these studies is the comparison of relative features as well as the comparison of absolute models which require as precisely as possible matching of face models. The article focuses on the analysis of various parts of the human...
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Outlier detection method by using deep neural networks
PublicationDetecting outliers in the data set is quite important for building effective predictive models. Consistent prediction can not be made through models created with data sets containing outliers, or robust models can not be created. In such cases, it may be possible to exclude observations that are determined to be outlier from the data set, or to assign less weight to these points of observation than to other points of observation....
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Reduced-Cost Microwave Design Closure by Multi-Resolution EM Simulations and Knowledge-Based Model Management
PublicationParameter adjustment through numerical optimization has become a commonplace of contemporary microwave engineering. Although circuit theory methods are ubiquitous in the development of microwave components, the initial designs obtained with such tools have to be further tuned to improve the system performance. This is particularly pertinent to miniaturized structures, where the cross-coupling effects cannot be adequately accounted...
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Binary-Encounter Model for Direct Ionization of Molecules by Positron-Impact
PublicationWe introduce two models for the computation of direct ionization cross sections by positron impact over a wide range of collision energies. The models are based on the binary-encounter-Bethe model and take into account an extension of the Wannier theory. The cross sections computed with these models show good agreement with experimental data. The extensions improve the agreement between theory and experiment for collision energies...
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Symulacja pracy przesuwnika fazowego w sieci elektroenergetycznej przy połączeniu transformatora szeregowego w gwiazdę
PublicationPoniższy artykuł prezentuje sposób regulacji mocy czynnej i biernej za pomocą przesuwnika fazowego, którego uzwojenie transformatora dodawczego (szeregowego) jest połączone w gwiazdę. W artykule pokazano regulację mocy czynnej i biernej na przykładzie wybranego systemu elektroenergetycznego. Omawiany przesuwnik fazowy reguluje jednocześnie przepływem mocy czynnej i biernej w danym systemie elektroenergetycznym.
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Local dynamics of fluids and dielectrics as the foundation of signal-carrying wave properties
PublicationThis paper develops an original approach to fundamental problems of classical linear acoustics and electromagnetics, proving a crucial role of doubly-dynamic local properties of a propagation medium in supporting wave-like fields able to carry information signals. The proof is composed of two steps concerning, subsequently, fluid acoustics and dielectric electromagnetics. The first step consists in complementing a common, practically...
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A New Direct-Sequence Spread Spectrum Signal Detection Method for Underwater Acoustic Communications in Shallow-Water Channel
PublicationDirect-Sequence Spread Spectrum (DSSS) is one of the modulation and coding techniques used in Underwater Acoustic Communication (UAC) systems for reliable data transmision even at low signal levels. However, in a shallow water channel, there is a strong multipath propagation which causes a phase fluctuation of the received signal, affecting the performance of the spread-spectrum system. The article presents a differential method...
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Detection of the First Component of the Received LTE Signal in the OTDoA Method
PublicationIn a modern world there is a growing demand for localization services of various kinds. Position estimation can be realized via cellular networks, especially in the currently widely deployed LTE (Long Term Evolution) networks. However, it is not an easy task in harsh propagation conditions which often occur in dense urban environments. Recently, time-methods of terminal localization within the network have been the focus of attention,...
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Multi-Taper-Based Automatic Correction of Non-Anechoic Antenna Measurements
PublicationPrototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed in non-anechoic conditions and...
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Hysteresis curves for some periodic and aperiodic perturbations in gases
PublicationEvolution of sound in a medium whose properties irreversibly vary in the course of wave propagation, is studied. For example, a gas that is a particular case of a Newtonian fluid is considered. Hysteresis curves, pictorial representations of irreversible attenuation of the sound energy, in the plane of thermodynamic states are plotted. The irreversible losses in internal energy are proportional to the total attenuation and depend...
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Specification of private art galleries used in the central part of old town Belgrade
PublicationIn Belgrade, since the late 1990s, private art galleries have appeared that indirectly create the image of the city through the propagation of art, take part in the education process of the residents and undertake criticism of local and global events. The article is an answer to the following questions: [1] why and how do the bottom-up art oriented places appear in Belgrade, [2] how do they function, and (3) what is their architectural...
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An interactive system for remote modeling and design validation of hybrid photovoltaic systems
PublicationAbstract: A multi-functional demonstrator of the interactive system is presented. The demostrator enables modeling, monitoring and design validation of hybrid photovoltaic systems assisted by fuel cells and thermoelectric generators, as well as experimentation and scientific research. A block diagram of the system is presented and the selection of its components is discussed. Availability of the system via Ethernet or GSM...
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One-step recovery of REE oxalates in electro-leaching of spent NdFeB magnets
PublicationRecovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great attention because of high amount of neodymium and potential risk of environmental pollution. In this study, a novel environment-friendly hydrometallurgical route is proposed for efficient recovery of REEs during electrochemical leaching with sulfuric and oxalic acids. With proper adjustment of the electrolyte composition and operating conditions,...
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Improving SBR Performance Alongside with Cost Reduction through Optimizing Biological Processes and Dissolved Oxygen Concentration Trajectory
PublicationAuthors of this paper take under investigation the optimization of biological processes during the wastewater treatment in sequencing batch reactor (SBR) plant. A designed optimizing supervisory controller generates the dissolved oxygen (DO) trajectory for the lower level parts of the hierarchical control system. Proper adjustment of this element has an essential impact on the efficiency of the wastewater treatment process as well...
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Assessment of Trajectories of Non-bankrupt and Bankrupt Enterprises
PublicationThe aim of this study is to show how long-term trajectories of enterprises can be used to increase the forecasting horizon of bankruptcy prediction models. The author used seven popular forecasting models (two from Europe, two from Asia, two from North America and one from Latin America). These models (five multivariate discriminant analysis models and two logit models) were used to develop 17-year trajectories separately for non-bankrupt...
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Prediction of protein assemblies, the next frontier: The CASP14‐CAPRI experiment
PublicationWe present the results for CAPRI Round 50, the 4th joint CASP-CAPRI protein assembly prediction challenge. The Round comprised a total of 12 targets, including 6 dimers, 3 trimers, and 3 higher-order oligomers. Four of these were easy targets, for which good structural templates were available either for the full assembly, or for the main interfaces (of the higher-order oligomers). Eight were difficult targets for which only distantly...
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Path Loss Modelling for Location Service Applications
PublicationThe aim of this paper is the path loss modeling for the radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the UMTS are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation of the distance between the mobile station (MS) and the base station (BS) is outlined. This...
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Routing decisions independent of queuing delays in broadband leo networks
PublicationThis paper presents an analysis of queuing and propagation delays of Inter-Satellite Links (ISLs) in broadband Low-Earth Orbit (LEO) satellite networks. It is shown that queuing delays are negligible in all reasonable working conditions of the broadband ISL network. This fact makes it possible to simplify the routing protocols in such networks and permits using already known multi-commodity flow solutions for routing. The performance...
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Experimental and numerical investigations for GPR evaluation of reinforced concrete footbridge
PublicationThe GPR method has increasingly found application in non-destructive testing of reinforced concrete structures. This paper presents the new approach of modelling of the electromagnetic wave propagation for reinforced concrete structures with a complex system of the reinforcement. Simulations of the GPR field were performed on a three-dimensional model of a footbridge using the FDTD method. Numerical maps were compared with results...
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Efficient quadrature for fast oscillating integralof paraxial optics
PublicationThe study concerns the determination of quadrature for the integral solutionof the paraxial wave equation. The difficulty in computation of the integral isassociated with the rapid change of the integrand phase. The developed quadraturetakes into account the fast oscillating character of the integrand. The presentedmethod is an alternative to the commonly used methods based on the use of theFourier transform. The determination...
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Estimation of transmission quality in cellular systems based on indicators measured by the radio module
PublicationThe article presents a measurement stand for testing transmission quality in cellular systems such as LTE, NB-IoT, UMTS and GSM. The results of BLER and throughput measurements for various propagation conditions as well as results of quality indicators appropriate for mentioned technologies measured by commercial radio module are presented. Those measurements were utilized to analyze the possibility of estimating the transmission...
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Application of a cellular automaton to simulations of granular flow in silos
PublicationA cellular automaton based on a gas model of hydrodynamics was used to calculate the kinematics of non-cohesive granular materials during confined flow in a mass flow and funnel flow model silo. In the model, collisions of particles were taken into account during granular flow. In addition, a simplified automaton was used wherein granular flow was assumed as an upward propagation of holes through a lattice composed of cells representing...
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Robustness in Compressed Neural Networks for Object Detection
PublicationModel compression techniques allow to significantly reduce the computational cost associated with data processing by deep neural networks with only a minor decrease in average accuracy. Simultaneously, reducing the model size may have a large effect on noisy cases or objects belonging to less frequent classes. It is a crucial problem from the perspective of the models' safety, especially for object detection in the autonomous driving...
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Road noise mapping in the city area: measurements compared to model-based estimations
PublicationThe paper presents an approach to the verification of noise prediction models in selected localization in the city of Gdansk. The experiments described include a comparison between environmentalmeasurement results performed in the terrain and the noise level prediction results. The NMPB-96 (Nouvelle Méthode de Prévision du Bruit) and Harmonoise models outcomes provide the subject ofthe analysis. The proposed solution of continuous...
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Derecho Evolving from a Mesocyclone—A Study of 11 August 2017 Severe Weather Outbreak in Poland: Event Analysis and High-Resolution Simulation
PublicationThis study documents atmospheric conditions, development, and evolution of a severe weather outbreak that occurred on 11 August 2017 in Poland. The emphasis is on analyzing system morphology and highlighting the importance of a mesovortex in producing the most significant wind damages. A derecho-producing mesoscale convective system (MCS) had a remarkable intensity and was one of the most impactful convective storms in the history...
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Numerical Investigation of Nuclear Reactor Kinetic and Heat Transfer Fractional Model with Temperature Feedback
PublicationAbstract—In the paper, the numerical results concerning the kinetics and proposed heat exchange models in nuclear reactor based on fractional calculus are presented for typical inputs. Two fractional models are proposed and compared with the model based on ordinary derivative. The first fractional model is based on one of the generalized Cattaneo equations. The second one is based on replacing the ordinary to fractional order of...
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Nuclear Power Plant Steam Turbine - Modeling for Model Based Control Purposes
PublicationThe nature of the processes taking place in a nuclear power plant (NPP) steam turbine is the reason why their modeling is very difficult, especially when the model is intended to be used for on-line optimal model based process control over a wide range of operating conditions, caused by changing electrical power demand e.g. when combined heat and power mode of work is utilized. The paper presents three nonlinear models of NPP steam...
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Two- and three-dimensional elastic networks with rigid junctions: modeling within the theory of micropolar shells and solids
PublicationFor two- and three-dimensional elastic structures made of families of flexible elastic fibers undergoing finite deformations, we propose homogenized models within the micropolar elasticity. Here we restrict ourselves to networks with rigid connections between fibers. In other words, we assume that the fibers keep their orthogonality during deformation. Starting from a fiber as the basic structured element modeled by the Cosserat...
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Reliable testbed for indoor positioning systems
PublicationThis paper proposes a test environment for indoor localization system, based on radio wave propagation prosperities. The following sections presents variety of problems from the assessment of the existing localization system to the analysis of inconveniences which occur when comparison of different localization systems is implemented. The problem is associated with different testing environments presented in published papers is...
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Computational simulation of motion of a rescue module during its launching from ship at rough sea
PublicationThis paper is a continuation of the work titled : “A comp utational model for simulation of motion of rescue module during its launching from stern ramp of a ship at rough sea”. It presents results of computer simulations of motion of a rescue module with embarked persons during its launching on rollers along stern ramp of a ship at rough sea. The simulations were conducted for a selected ship fitted with a launching ramp , for...