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Wyniki wyszukiwania dla: domain wall motion
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Nonlinear generation of non-acoustic modes by low-frequency sound in a vibrationally relaxing gas
PublikacjaTwo dynamic equations referring to a weakly nonlinear and weakly dispersive flow of a gas in which molecular vibrational relaxation takes place. are derived. The first one governs an excess temperature associated with the thermal mode, and the second one describes variations in vibrational energy. Both quantities refer to non-wave types of gas motion. These variations are caused by the nonlinear transfer of acoustic energy into...
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On evolutionary computing in multi-ship trajectory planning, Applied Intelligence
PublikacjaThe paper presents the updated version 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...
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Photophysics of Ru(II) Dyads Derived from Pyrenyl-Substitued Imidazo[4,5-f][1,10]phenanthroline Ligands.
PublikacjaThe photophysics of a series of Ru(II) dyads based on the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline ligand was investigated. The ability of these metal complexes to intercalate DNA and induce cell death upon photoactivation makes them attractive photosensitizers for a range of photobiological applications, including photodynamic therapy. In the present study, time-resolved transient absorption and emission spectroscopy...
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Analiza obciążenia osi pojazdów ciężkich na podstawie danych z ważenia pojazdów w ruchu (WIM)
PublikacjaW artykule przedstawiono rozkłady obciążenia poszczególnych rodzajów osi pojazdów. Podstawą analizy były dane z ważenia 12 mln pojazdów ciężkich w okresie od roku do 3 lat na 10 stacjach ważenia pojazdów w ruchu, z ang. weigh in motion (WIM), w Polsce. Celem artykułu, oprócz przedstawienia rozkładów, jest ocena wpływu dopuszczalnego obciążenia osi na rzeczywiste obciążenia osi pojazdów ciężkich. Przedstawiono opis matematyczny...
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Non-linear behaviour of base-isolated building supported on flexible soil under damaging earthquakes
PublikacjaSeismic isolation is a strategy to reduce damage of structures exposed to devastating earthquake excitations. Isolation systems, applied at the base of buildings, lower the fundamental frequency of the structure below the range of dominant frequencies of the ground motion as well as allow to dissipate more energy during structural vibrations. The effectiveness of the base-isolated buildings in damage reduction has been confirmed...
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WATER LUBRICATED MAIN SHAFT BEAR INGS WITH THREE LAYER BUSH – MODERN SOLUTION FOR MARINE INDUSTRY
PublikacjaWater lubricated sliding bearings are increasingly popular in marine and hydro power industry. Such popularity is partly due to their simple construction which also means a relatively affordable price. Properly designed and installed water lubricated bearings may well last for over a decade. During the last decade their traditional range has been expanded with new, modern products like three layer bearing bush. The work presents...
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Application of advanced CFD simulations in seakeeping analysis of ships (case study)
PublikacjaThe novel design process of many types of ships needs estimation of seakeeping properties. Especially ships like Offshore Supply Vessels, Wind Farm Support Vessels, Research Vessels, ferries, military vessels, rescue vessels require extended analysis of ship behavior on rough sea. The main reason for improving ships operability in different sea conditions is need of rising efficiency of propulsion system, reducing hull added resistance,...
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MODELLING OF TOXIC COMPOUNDS EMISSION IN MARINE DIESEL ENGINE DURING TRANSIENT STATES AT VARIABLE PRESSURE OF FUEL INJECTION
PublikacjaTransient states are an important part of the spectrum of engine loads, especially the traction engines. In the case of marine diesel engines, transient states are of particular importance in reducing the analysis of motion units for special areas and maneuvering in port, the participation of transient states in the load spectrum significantly increases, also, the emission of toxic compounds from this period increases proportionally....
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Mechatronic design o strongly nonlinear systems on a basis of three wheeled mobile platform
PublikacjaRemarkable grow in demand both of mobile platform operability performance and reduction of project leading time development encourage to apply modern algorithms and reliable engineering tools for the design process. The paper discusses the mechatronic design applied for the surveillance system based on the energy performance index algorithm. The exploited mechatronic techniques i.e. virtual prototyping, Hardware-In-the-Loop Simulation...
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Degradation of stiffness of building columns exposed to bending and impact load during ground motions
PublikacjaThe safety of civil engineering structures under external loads, including ground motions, is one of the issues related to the idea of sustainable society. The earthquake-induced soft-storey failure is a typical type of damage observed in buildings due to seismic excitation. The failure of an intermediate soft storey of a structure results in large vertical impact loading acting on the lower floors due to the fall of the upper...
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Mechatronics design, modelling and controlling of the Stewart-Gough platform
PublikacjaThis paper presents a mechatronics design of a low cost Stewart-Gough platform (SGP) with rotary actuators. The designed SGP is supposed to be applied in a ball & plate control system. The synthesis of the ball & plate control system is also within the subject of the paper. A mechatronics design process of the SGP was conducted with computer-aided design (CAD) software. Unique analytical solutions of an inverse kinematics problem...
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Nonlinear planar modeling of massive taut strings travelled by a force-driven point-mass
PublikacjaThe planar response of horizontal massive taut strings, travelled by a heavy point-mass, either driven by an assigned force, or moving with an assigned law, is studied. A kinematically exact model is derived for the free boundary problem via a variational approach, accounting for the singularity in the slope of the deflected string. Reactive forces exchanged between the point-mass and the string are taken into account via Lagrange...
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The experience of movement in the built form and space: A framework for movement evaluation in architecture
Publikacja“Movement in architecture” is an organized system of various types of movements stimulated by specific architectural elements. This research was conducted through a qualitative-analytical method and empirical and bibliographical research methods with the aim to categorize different types of movements based on the explorer and observer relationships with the built space and form. So far, most of the related studies have focused...
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Incremental Dynamic Analysis and Fragility Assessment of Buildings with Different Structural Arrangements Experiencing Earthquake-Induced Structural Pounding
PublikacjaStructural pounding is considered as one of the most critical phenomena occurring during earthquakes. This paper presents the incremental dynamic analysis and fragility assessment of buildings experiencing earthquake-induced pounding. Three 3-D buildings with different number of storeys and under different structural arrangements have been considered. Three pounding scenarios have been taken into account, i.e. pounding between...
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Erroneous GNSS Strain Rate Patterns and their Application to Investigate the Tectonic Credibility of GNSS Velocities
PublikacjaThe paper concerns investigation of the credibility of tectonic interpretation of GNSS strain rates. The analysis was focused on stable regions, where the crustal deformations are small and the reliability of GNSS velocities is questionable. We are showing how the unreliable motion of stations affects calculated strains around them. We expressed distribution of local principal strains by a sinusoidal function and used them to investigate...
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About definition of modes and magnetosonic heating in a plasma’s flow: Especial cases of perpendicular and nearly perpendicular wave vector and magnetic field
PublikacjaDynamics of hydrodynamic perturbations in a plasma depend strongly on an angle between the wave vector and equilibrium straight magnetic field. The case of perpendicular propagation is especial. There are only two (fast) magnetosonic modes since two (slow) ones degenerate into the stationary one with zero speed of propagation. This demands individual definition of wave modes by the links of hydrodynamic relations. These links are...
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Transient response of oscillated carbon nanotubes with an internal and external damping
PublikacjaThe present works aims at modeling a viscoelastic nanobeam with simple boundary conditions at the two ends with the introduction of the Kelvin-Voigt viscoelasticity in a nonlocal strain gradient theory. The nanobeam lies on the visco-Pasternak matrix in which three characteristic parameters have a prominent role. A refined Timoshenko beam theory is here applied, which is only based on one unknown variable, in accordance with the...
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Stress-driven nonlocal elasticity for nonlinear vibration characteristics of carbon/boron-nitride hetero-nanotube subject to magneto-thermal environment
PublikacjaStress-driven nonlocal theory of elasticity, in its differential form, is applied to investigate the nonlinear vibrational characteristics of a hetero-nanotube in magneto-thermal environment with the help of finite element method. In order to more precisely deal with the dynamic behavior of size-dependent nanotubes, a two-node beam element with six degrees-of freedom including the nodal values of the deflection, slope and curvature...
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Towards an experience based collective computational intelligence for manufacturing
PublikacjaKnowledge based support can play a vital role not only in the new fast emerging information and communication technology based industry, but also in traditional manufacturing. In this regard, several domain specific research endeavors have taken place in the past with limited success. Thus, there is a need to develop a flexible domain independent mechanism to capture, store, reuse, and share manufacturing knowledge. Consequently,...
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Expedited Yield Optimization of Narrow- and Multi-Band Antennas Using Performance-Driven Surrogates
PublikacjaUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of antenna systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the antenna characteristics. In the case of narrow- or multi-band antennas, this usually leads to...
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Flood Modelling and Risk Analysis of Cinan Feizuo Flood Protection Area, Huaihe River Basin
PublikacjaThis study evaluated multiple aspects of flood risks and effects on the Cinan Feizuo flood protection area in the Huaihe River basin. Flooding remains a leading problem for infrastructure, especially in urban, residential areas of the region. Effective flood modeling for urbanized floodplains is challenging, but MIKE (ID-2D) is paramount for analyzing and quantifying the risk in the vulnerable region. The Saint-Venant equation...
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Gaining knowledge through experience: developing decisional DNA applications in robotics
PublikacjaOmówiono nowatorskie podejscie do zastosowania wiedzy opartej na doświadczeniu i budowie decyzyjnego DNA w obszarach związanych z robotyką.In this article, we explore an approach that integrates Decisional DNA, a domain-independent, flexible, and standard knowledge representation structure, with robots in order to test the usability and suitability of this novel knowledge representation structure. Core issues in using this Decisional...
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Examining Classifiers Applied to Static Hand Gesture Recognition in Novel Sound Mixing System
PublikacjaThe main objective of the chapter is to present the methodology and results of examining various classifiers (Nearest Neighbor-like algorithm with non-nested generalization (NNge), Naive Bayes, C4.5 (J48), Random Tree, Random Forests, Artificial Neural Networks (Multilayer Perceptron), Support Vector Machine (SVM) used for static gesture recognition. A problem of effective gesture recognition is outlined in the context of the system...
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Fast implementation of FDTD-compatible green's function on multicore processor
PublikacjaIn this letter, numerically efficient implementation of the finite-difference time domain (FDTD)-compatible Green's function on a multicore processor is presented. Recently, closed-form expression of this discrete Green's function (DGF) was derived, which simplifies its application in the FDTD simulations of radiation and scattering problems. Unfortunately, the new DGF expression involves binomial coefficients, whose computations...
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ENISA Study: Challenges in Securing Industrial Control Systems
PublikacjaIn 2011, the European Network and Information Security Agency (ENISA) conducted a study in the domain of Industrial Control Systems (ICS). Its objective was to obtain the current view on the ICS protectionprimarily in Europe but also in the international context. The portrait' included threats, risks, and challenges in the area of ICS protection as well as national, pan European, and international initiatives on ICS security. The...
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Call and Connections Times in ASON/GMPLS Architecture
PublikacjaIt is assumed that demands of information soci- ety could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded by performance evaluation to guarantee society expectations. Call and connections times are in ASON/GMPLS architecture important for real-time applications. Practical...
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Bringing Common Sense to WordNet with a Word Game
PublikacjaWe present a tool for common sense knowledge acquisition in form of a twenty questions game. The described approach uses WordNet dictionary, which rich taxonomy allows to keep cognitive economy and accelerate knowledge propagation, although sometimes inferences made on hierarchical relations result in noise. We extend the dictionary with common sense assertions acquired during the games played with humans. The facts added to the...
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Resonance Frequency Calculation of a Multilayer and Multipatch Spherical Microstrip Structure Using a Hybrid Technique
PublikacjaThis communication offers a rigorous analysis of the resonance frequency problem of a spherical microstrip structure mounted on a multilayer, dielectric-coated metallic sphere, with an electrically small radius. The structure consists of single or multiple metallic patches with arbitrary shapes. A full-wave analysis is employed with the use of proposed hybrid approach, combining the finite-difference technique with a spectral domain...
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Optimized Stress and Geometry Control of Spherical structures under Lateral Loadings
PublikacjaIn this paper, a numerical model of a double-layer spherical structure has been examined under lateral loadings. When the structure has been distorted due to loadings, the dislocated joints have been moved to their original positions utilizing the adjustment techniques based on the force method. Meanwhile, the members’ internal forces were kept in the desired domain. Optimization techniques were also implemented in order to minimalize...
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Application of ANN and PCA to two-phase flow evaluation using radioisotopes
PublikacjaIn the two-phase flow measurements a method involving the absorption of gamma radiation can be applied among others. Analysis of the signals from the scintillation probes can be used to determine the number of flow parameters and to recognize flow structure. Three types of flow regimes as plug, bubble, and transitional plug – bubble flows were considered in this work. The article shows how features of the signals in the time and...
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On the correlation between magnetoacoustic emission and magnetostriction dependence on the applied magnetic field
PublikacjaThe correlation between magnetoacoustic emission signal envelopes and magnetostriction curves is investigated. Two sets of samples are being considered: tempered martensitic steel and plastically deformed ferritic steel. It is shown that even though some general relations may be observed, as was demonstrated in the literature, the correlation is not always present. One may not expect to change both quantities in the same way if...
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The Impact of Lexicon Adaptation on the Emotion Mining From Software Engineering Artifacts
PublikacjaSentiment analysis and emotion mining techniques are increasingly being used in the field of software engineering. However, the experiments conducted so far have not yielded high accuracy results. Researchers indicate a lack of adaptation of the methods of emotion mining to the specific context of the domain as the main cause of this situation. The article describes research aimed at examining whether the adaptation of the lexicon...
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Analiza drgań przewodów jezdnych sieci trakcyjnej w aspekcie oceny jej stanu technicznego
PublikacjaW pracy przedstawiono możliwości wykorzystania analizy drgań przewodów jezdnych sieci trakcyjnej do oceny jej stanu technicznego. Zaprezentowano wyniki badań laboratoryjnych, w których rejestrowano drgania odcinka przewodu jezdnego o zróżnicowanym stopniu zużycia i przy różnych warunkach jego zawieszenia. Na bazie przeprowadzonych analiz w dziedzinie czasu i częstotliwości, wskazano zależności między stanem sieci a wybranymi parametrami...
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Impact of the Alkyl Side Chains of Cations and Anions on the Activity and Renaturation of Lysozyme: A Systematic Study Performed Using Six Amino‐Acid‐Based Ionic Liquids
PublikacjaThe impact of the structure of ionic liquid on the activity and renaturation of lysozyme from the hen egg white (HEWL) was investigated. A set of six ionic liquids based on morpholinium cation and N-acylated amino acids as anions were exploited. The matrix used was based on two homologous series: one with N-acetyl-L-valinate [Val] as a common anion and morpholinium cation with a different number of...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Experimental and comparative study on the two-phase pressure drop of air-water mixture in U-bend and straight pipe annuli
PublikacjaIn this paper, the experimental and theoretical analysis of pressure drop in singlephase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range,...
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Postquarter-Point Case of Ship’s Side-Berthing and Its Influence on Marine Fender Pitch
PublikacjaThis paper presents a critical analysis of some selected codes and practical recommendations used as basic rules in the design procedures of modern marine fender systems. The first part of the discussion pertains to the existing equations used in calculating the eccentricity coefficient in the ship’s kinetic energy equation and the maximum allowable fender pitch (spacing) in a set of fenders installed along a quay wall. A new approach...
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Cost-Effective and Sufficiently Precise Integration Method Adapted to the FEM Calculations of Bone Tissue
PublikacjaThe technique of Young’s modulus variation in the finite element is not spread in biomechanics. Our future goal is to adapt this technique to bone tissue strength calculations. The aim of this paper is to present the necessary studies of the element’s integration method that takes into account changes in material properties. For research purposes, a virtual sample with the size and distribution of mechanical properties similar...
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SIMULATION OF PROCEED® SURGICAL MESH APPLIED TO VENTRAL HERNIA REPAIR
PublikacjaIn the present research, Proceed® implant is considered. The system is subjected to short-time dynamic pressure load, similar to post-operative cough naturally occurring in human abdomen. The model refers to a clinical case of 5cm of hernia operated by Proceed implant fixed by 15 joints every 3cm around the orifice. The simulations of the implanted mesh are performed by means of the Finite Element Method. The implant is modelled...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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The Proposition of an Automated Honing Cell with Advanced Monitoring
PublikacjaHoning of holes allows for small shape deviation and a low value of a roughness profile parameter, e.g., Ra parameter. The honing process heats the workpiece and raises its temperature. The increase in temperature causes thermal deformations of the honed holes. The article proposes the construction of a honing cell, containing in addition to CNC honing machine: thermographic camera, sound intensity meter, and software for collecting...
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Mechanical Behavior of Bi-Layer and Dispersion Coatings Composed of Several Nanostructures on Ti13Nb13Zr Alloy
PublikacjaTitanium implants are commonly used because of several advantages, but their surface modification is necessary to enhance bioactivity. Recently, their surface coatings were developed to induce local antibacterial properties. The aim of this research was to investigate and compare me-chanical properties of three coatings: multi-wall carbon nanotubes (MWCNTs), bi-layer composed of an inner MWCNTs layer and an outer TiO2 layer, and...
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Analysis of the possibility of creep damage detection in T24 heat resistant steel with the help of magnetic nondestestructive testing methods
PublikacjaThe paper presents the result of an analysis of applicability of various electromagnetic methods of nondestructive evaluation for creep damage detection in a novel heat resistant steel - T24 grade. Two sample sets, cut out from membrane wall tubes, were investigated – the as-delivered one and another exploited for 36,000 h in a power plant. There are described results of magnetic hysteresis loops B(H), Barkhausen noise (BN) and...
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The experience of movement in the built form and space: A framework for movement evaluation in architecture
Publikacja“Movement in architecture” is an organized system of various types of movements stimulated by specific architectural elements. This research was conducted through a qualitative-analytical method and empirical and bibliographical research methods with the aim to categorize different types of movements based on the explorer and observer relationships with the built space and form. So far, most of the related studies have focused...
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Algorithms for Ship Movement Prediction for Location Data Compression
PublikacjaDue to safety reasons, the movement of ships on the sea, especially near the coast should be tracked, recorded and stored. However, the amount of vessels which trajectories should be tracked by authorized institutions, often in real time, is usually huge. What is more, many sources of vessels position data (radars, AIS) produces thousands of records describing route of each tracked object, but lots of that records are correlated...
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Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublikacjaPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
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Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
PublikacjaIn this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze...
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Four Degree-of-Freedom Hydrodynamic Maneuvering Model of a Small Azipod-Actuated Ship With Application to Onboard Decision Support Systems
PublikacjaThe main contribution of this paper is a numerical ship motion model of NTNU’s research vessel Gunnerus, capturing the surge, sway, roll, and yaw dynamics when sailing in uniform and steady currents. The model utilizes a crossflow drag formulation for the transverse viscous loads, and it includes a nonlinear formulation for the propulsion and steering loads provided by two azipod thrusters. A wide range of experimental data obtained...
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Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
PublikacjaState-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements...
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Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
PublikacjaState-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements...