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Wyniki wyszukiwania dla: BOUNDARY-PRESERVING MAPS
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NUMERICAL SIMULATION OF CRATER CREATING PROCESS IN DYNAMIC REPLACEMENT METHOD BY SMOOTH PARTICLE HYDRODYNAMICS
PublikacjaA theoretical base of SPH method, including the governing equations, discussion of importance of the smoothing function length, contact formulation, boundary treatment and finally utilization in hydrocode simulations are presented. An application of SPH to a real case of large penetrations (crater creating) into the soil caused by falling mass in Dynamic Replacement Method is discussed. An influence of particles spacing on method...
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Novel Analytic-Numerical Model of Free Convection: with Leading Edge Considered
PublikacjaA novel solution of the free convection boundary problem is represented in analytical form for velocity and temperature for an isothermal vertical plate, as an example. These fields are built as a Taylor Series in the x coordinate with coefficients as functions of the vertical coordinate (y). We restrict ourselves by cubic approximation for both functions. The basic Navier-Stokes and Fourier-Kirchhoff equations and boundary conditions...
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Bending analysis of functionally graded nanoplates based on a higher-order shear deformation theory using dynamic relaxation method
PublikacjaIn this paper, bending analysis of rectangular functionally graded (FG) nanoplates under a uniform transverse load has been considered based on the modified couple stress theory. Using Hamilton’s principle, governing equations are derived based on a higher-order shear deformation theory (HSDT). The set of coupled equations are solved using the dynamic relaxation (DR) method combined with finite difference (FD) discretization technique...
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"Creating a numerical model of noise conditions based on the analysis of traffic volume changes in cities with low and medium structure.
PublikacjaThe subject of this research study is to analyze noise conditions of the selected area in the city of Gdańsk using data related to traffic volume changes during a day. This is because daily distribution of noise levels is much more helpful for noise control and reduction than traditional maps with Lden levels indicated. Calculations are made with the use of a numerical model developed at the Gdansk Univ. of Technology and implemented...
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"Creating a numerical model of noise conditions based on the analysis of traffic volume changes in cities with low and medium structure.
PublikacjaThe subject of this research study is to analyze noise conditions of the selected area in the city of Gdańsk using data related to traffic volume changes during a day. This is because daily distribution of noise levels is much more helpful for noise control and reduction than traditional maps with Lden levels indicated. Calculations are made with the use of a numerical model developed at the Gdansk Univ. of Technology and implemented...
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Architecture at the Sites of the Former Nazi Concentration Camps. Functional Changeability of Commemoration
PublikacjaThe monograph presents a comprehensive analysis of the architectural structures created in the former concentration camps in Europe under the SS Main Economy and Administration Office. It delves into the history of memorial site creation in these areas, emphasizing the unique characteristics of monuments dedicated to the victims of terror. Additionally, the study covers the post-war architectural transformations in these areas,...
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Rothe’s method for physiologically structured models with diffusion
PublikacjaWe consider structured population models with diffusion and dynamic boundary conditions. The respective approximation, called Rothe’s method, produces positive and exponentially bounded solutions. Its solutions converge to the exact solution of the original PDE.
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Investigation of some magnetospheric phenomena of geomagnetic storm on March 17, 2013 based on observations from GNSS and NOAA-15 satellite
PublikacjaSubstantial variations of magnetospheric electron fluxes of low and intermediate energies at an altitude of ~ 800 km at different phases of the geomagnetic storm were investigated. The ionosphere and plasmasphere response was analyzed using TEC variation maps over the Central Europe. A concept of the connection of TEC variations above the Central Europe and spatially inhomogeneous fluxes of energetic particles is being proposed.
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AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublikacjaThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
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Direct detection of quantum entanglement
PublikacjaBasing on positive maps separability criterion we propose the experimentally viable, direct detection of quantum entanglement. It is efficient and does not require any a priori knowledge about the state. For two qubits it provides a sharp (i.e., “if and only if”) separability test and estimation of amount of entanglement. We view this method as a new form of quantum computation, namely, as a decision problem with quantum data structure.
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Structured populations with diffusion and Feller conditions
PublikacjaWe prove a weak maximum principle for structured population models with dynamic boundary conditions. We establish existence and positivity of solutions of these models and investigate the asymptotic behaviour of solutions. In particular, we analyse so called size profile.
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Natural convective heat transfer from isothermalconic
PublikacjaTheoretical considerations on convective heat transfer from isothermal upward conicalsurfaces have been presented. The physical model of this phenomenon consists of an isothermalcone of inclination angle (φ) between the cone generating line (X) and the radius (R) of the cone base. The angle is a parameter of conical surface which varied from (φ = 0−circular horizontal plate) to (φ = π/2—vertical cylinder) . Onthe basis of Navier–Stokes...
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Non-linear static stability of bi-layer carbon nanosheets resting on an elastic matrix under various types of in-plane shearing loads in thermo-elasticity using nonlocal continuum
PublikacjaIn this research, the shear and thermal buckling of bi-layer rectangular orthotropic carbon nanosheets embedded on an elastic matrix using the nonlocal elasticity theory and non-linear strains of Von-Karman was studied. The bi-layer carbon sheets were modeled as a double-layered plate, and van der Waals forces between layers were considered. The governing equations and boundary conditions were obtained using the first order shear...
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Simulation of unsteady flow over floodplain using the diffusive wave equation and the modified finite element method
PublikacjaWe consider solution of 2D nonlinear diffusive wave equation in a domain temporarily covered by a layer of water. A modified finite element method with triangular elements and linear shape functions is used for spatial discretization. The proposed modification refers to the procedure of spatial integration and leads to a more general algorithm involving a weighting parameter. The standard finite element method and the finite difference...
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Parki tematyczne w rozwoju lokalnym miasteczek i wsi
PublikacjaObecnie niemal każde polskie miasto i wieś ma na celu znalezienie dobrego pomysłu na swój rozwój społeczno-gospodarczy. Najczęściej jest nim założenie parku tematycznego. Dobrze się dzieje, gdy takie przedsięwzięcie wspiera lokalne tradycje, zwyczaje i walory kulturowe miasta czy wsi; gdy promowane są miejscowe produkty i żywność. Niestety, nie zawsze tak jest. Niektóre miasta i gminy chętniej przyjmują zupełnie inną politykę...
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The Hopf theorem for gradient local vector fields on manifolds
PublikacjaWe prove the Hopf theorem for gradient local vector fields on manifolds, i.e., we show that there is a natural bijection between the set of gradient otopy classes of gradient local vector fields and the integers if the manifold is connected Riemannian without boundary.
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Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublikacjaThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
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3D Vision System for a Robotic Arm Based on Equal Baseline Camera Array
PublikacjaThis paper presents a lightweight 3D vision system called Equal Baseline Camera Array (EBCA). EBCA can work in different light conditions and it can be applied for measuring large range of distances. The system is a useful alternative to other known distance measuring devices such as structured-light 3D scanners, time-of-flight cameras, Light Detection and Ranging (LIDAR) devices and structure from motion techniques. EBCA can be...
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Linear Pantographic Sheets: Existence and Uniqueness of Weak Solutions
Publikacjawe address the well-posedness of the planar linearized equilibrium problem for homogenized pantographic lattices. To do so: (i) we introduce a class of subsets of anisotropic Sobolev’s space as the most suitable energy space E relative to assigned boundary conditions; (ii) we prove that the considered strain energy density is coercive and positive definite in E ; (iii) we prove that the set of placements for which the strain...
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Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublikacjaThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
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Automatic music set organizatio based on mood of music / Automatyczna organizacja bazy muzycznej na podstawie nastroju muzyki
PublikacjaThis work is focused on an approach based on the emotional content of music and its automatic recognition. A vector of features describing emotional content of music was proposed. Additionally, a graphical model dedicated to the subjective evaluation of mood of music was created. A series of listening tests was carried out, and results were compared with automatic mood recognition employing SOM (Self Organizing Maps) and ANN (Artificial...
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Verification of algorithms determining wave loads on support structure of wind turbine
PublikacjaThe offshore wind turbines require determination of wave loads on their support structure. This structure is fixed and, therefore, this problem is reduced to solving only the diffraction problem, which is determined by Laplace equation and conditions on the following boundaries: on the support structure, on the sea free surface and on its bottom, and at infinity on free surface. The linear problem was applied to determine the wave...
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Phase Transition in a Sequence-Structure Channel
PublikacjaWe study an interesting channel which maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein folding from statistical physics. The channel is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. We estimate the conditional entropy between the input sequence and the output fold, giving an upper bound which exhibits an unusual phase transition...
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Integration of thermographic data with the 3D object model
PublikacjaThe aim of the paper is to present new method for merging the 3D model data of the measured object with thermograms. Our technique is based on the combination of visual 3D imaging technique and thermal imaging technique, which maps the 2D thermograms on to 3D anatomical mesh model. The combination of these imaging modalities allows the generation of combined 3D and thermal data from which thermal signatures can be verified and...
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Visualization of events using various kinds of synchronized data for the Border Guard
PublikacjaSTRADAR project is dedicated to streaming real-time data in a distributed dispatcher and teleinfor-mation system of the Border Guard. The Events Visualization Post is a software designed for simultaneous visualization of data of different types in BG headquarters. The software allows the operator to visualize files, images, SMS, SDS, video, audio, and current or archival data on naval situation on digital maps. All the visualized...
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On the interspike-intervals of periodically-driven integrate-and-fire models
PublikacjaWe analyze properties of the firing map, which iterations give information about consecutive spikes, for periodically driven linear integrate-and-fire models. By considering locally integrable (thus in general not continuous) input functions, we generalize some results of other authors. In particular, we prove theorems concerning continuous dependence of the firing map on the input in suitable function spaces. Using mathematical...
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Numerical single-phase modeling of turbulent flow and heat transfer of nanofluids
PublikacjaIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (6 000< Re < 12 000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with published experimental data.
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Application of PL-Grid Platform for Modeling of the Selected Acoustic Phenomena
PublikacjaDomain 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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Thermal Buckling Analysis of Circular Bilayer Graphene sheets Resting on an Elastic Matrix Based on Nonlocal Continuum Mechanics
PublikacjaIn this article, the thermal buckling behavior of orthotropic circular bilayer graphene sheets embedded in the Winkler–Pasternak elastic medium is scrutinized. Using the nonlocal elasticity theory, the bilayer graphene sheets are modeled as a nonlocal double–layered plate that contains small scale effects and van der Waals (vdW) interaction forces. The vdW interaction forces between the layers are simulated as a set of linear springs...
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On instabilities and post-buckling of piezomagnetic and flexomagnetic nanostructures
PublikacjaWe focus on the mechanical strength of piezomagnetic beam-like nanosize sensors during post-buckling. An effective flexomagnetic property is also taken into account. The modelled sensor is selected to be a Euler-Bernoulli type beam. Long-range interactions between atoms result in a mathematical model based on the nonlocal strain gradient elasticity approach (NSGT). Due to possible large deformations within a post-buckling phenomenon,...
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The calculation long-term physical field created by water flow around the ship
PublikacjaThe paper presents a description of the problems with fluid flow around a ship. Using the described solution of the problem were performed numerical calculations using the boundary element method. Were also presented preliminary results of the calculation of pressure fields at the bottom of the ship, taking into account the impact of the bottom.
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Aerodynamic shape optimization by variable-fidelity computational fluid dynamics models: a review of recent progress
PublikacjaA brief review of some recent variable-fidelity aerodynamic shape optimization methods is presented.We discuss three techniques that—by exploiting information embedded in low-fidelity computationalfluid dynamics (CFD) models—are able to yield a satisfactory design at a low computational cost, usu-ally corresponding to a few evaluations of the original, high-fidelity CFD model to be optimized. Thespecific techniques considered here...
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OBTAINING FLUID FLOW PATTERN FOR TURBINE STAGE WITH NEURAL MODEL.
PublikacjaIn the paper possibility of applying neural model to obtaining patterns of proper operation for fluid flow in turbine stage for fluid-flow diagnostics is discussed. Main differences between Computational Fluid Dynamics (CFD) solvers and neural model is given, also limitations and advantages of both are considered. Time of calculations of both methods was given, also possibilities of shortening that time with preserving the accuracy...
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Analysis of Properties of an Active Linear Gesture Sensor
PublikacjaBasic gesture sensors can play a significant role as input units in mobile smart devices. However, they have to handle a wide variety of gestures while preserving the advantages of basic sensors. In this paper a user-determined approach to the design of a sparse optical gesture sensor is proposed. The statistical research on a study group of individuals includes the measurement of user-related parameters like the speed of a performed...
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Geometry Parametric Model Order Reduction with Randomly Generated Projection Bases
PublikacjaIn this work, a reduced-order model for geometry parameters and fast frequency sweep is proposed. The Finite Element Method is used to solve time-harmonic Maxwell’s equations. Taking into account the electromagnetic field does not arbitrarily vary as a function of frequency and geometry parameters, a low dimension system manifold is identified. Thus, the original Finite Element problem can be approximated by a model of reduced...
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Zabytkowa infrastruktura kolejowa jako potencjał krajobrazu kulturowego
PublikacjaW dobie obecnych działań rewitalizacyjnych oraz przemian kolejnictwa, prowadzonych lub przewidywanych w licznych miastach Polski, konieczne jest wskazanie wartości, jakie często niesie z sobą infrastruktura kolejowa. Może się ona stać istotnym elementem przekształcanych przestrzeni miejskich – nie tylko pod względem transportowym. Odpowiednio zaplanowane działania pozwalają uchronić przed destrukcją historyczne obiekty, m.in. wprowadzając...
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Temperature influences on shear stability of a nanosize plate with piezoelectricity effect
PublikacjaPurpose The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment. Design/methodology/approach Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account...
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An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater
PublikacjaThe paper presents a new analytical four‑layer (air–water–bottom–non‑conductive layer) horizontal electric dipole model which allows an accurate approximation of ship’s Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of...
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TDOA Navigation Using CDMA2000 Signals – Experimental Results
PublikacjaThis paper presents results of an experiments on the possibility to estimate position of a CDMA2000 receiver on the basis of TDOA measurements. The hardware and software structure of a navigation receiver used during investigation is briefly described with focus on drawbacks and limitations. The main part of this paper contains basic information about CDMA2000 network in northern Poland, which signals were recorded during tests...
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Difference functional inequalities and applications.
PublikacjaThe paper deals with the difference inequalities generated by initial boundary value problems for hyperbolic nonlinear differential functional systems. We apply this result to investigate the stability of constructed difference schemes. The proof of the convergence of the difference method is based on the comparison technique, and the result for difference functional inequalities is used. Numerical examples are presented.
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Improving the accuracy of subgridding scheme in finite differences method based on Legendre polynomials expansion
PublikacjaIn this article the Legendre polynomials have been used to interpolate the field at the boundary of the meshes of different densities. The numerical verification of the proposed technique has been carried out in frequency domain. It has been shown that the accuracy of the presented method is very high and stable - the error monotonically decreases as a function of the refinement factor.
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Analysis of ship's magnetic field with consideration of inner ferromagnetic devices
PublikacjaThis paper presents computer simulations of ship’s magnetic signatures. The influence of ship’s inner ferromagnetic devices on the signature was presented. The magnetic fields of the ship’s model were calculated in Opera 3D 18R2. The model was built from thin plates. The new, thin plate boundary condition was introduced on all ship’s surfaces.
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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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Analytical predictions for the buckling of a nanoplate subjected to non-uniform compression based on the four-variable plate theory
PublikacjaIn the present study, the buckling analysis of the rectangular nanoplate under biaxial non-uniform compression using the modified couple stress continuum theory with various boundary conditions has been considered. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using the Hamilton’s principle. An analytical approach has been applied to obtain...
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An isogeometric finite element formulation for frictionless contact of Cosserat rods with unconstrained directors
PublikacjaThis paper presents an isogeometric finite element formulation for nonlinear beams with impenetrability constraints, based on the kinematics of Cosserat rods with unconstrained directors. The beam cross-sectional deformation is represented by director vectors of an arbitrary order. For the frictionless lateral beam-to-beam contact, a surface-to-surface contact algorithm combined with an active set strategy and a penalty method...
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Analysis of hydrodynamic pressure fields of motorboats and pontoons in shallow water
PublikacjaThe article presents the results of calculations of the pressure fields generated by a motorboat at the bottom of a shallow sea. Calculations were made using the boundary elements method (BEM), arranged on the surface of the boat and the bottom of the sea. This method is described in [3], and applied on a free surface linearized boundary condition. Results for four different lengths of motorboats, from 2.85 m to 9.5 m, sea depth...
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FEM approach to estimate the behaviour of biocomposite metal-surface coating system
PublikacjaA three dimensional (3D) model of biocomposite metal-surface coating system, which is influenced byknown external forces, is proposed. This model consists of the metallic substrate (Ti6Al4V) and thehydroxyapatite (HA) coating. Using FEM (finite element method), strain-stress maps of model weregenerated for investigating relations between the extreme stress of HA coating and the magnitude ofexternal force and the thickness of the...
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Separability in terms of a single entanglement witness
PublikacjaThe separability problem is formulated in terms of a characterization of a single entanglement witness. More specifically, we show that any (in general multipartite) state rho is separable if and only if a specially constructed entanglement witness W-rho is weakly optimal, i.e., its expectation value vanishes on at least one product vector. Interestingly, the witness can always be chosen to be decomposable. Our result changes the...
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Diagnostics of historic columns using wave propagation
PublikacjaThis paper presents a numerical analysis of elastic wave propagation in columns of historical buildings for diagnostics purposes. Numerical calculations were performed using the finite element method in the Abaqus software package. The analysis was carried out for three types of brick columns: a full column, a column filled with debris, and a column empty inside. The excitation was in the form of a wave packet and signals of propagating...
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Numerical FDM modelling of wave propagation in concrete structure
PublikacjaThe article presents application of finite difference method to damage detection and its size evaluation in concrete structure by elastic wave propagation method. The simulations of wave propagation in concrete structure were performed for six different damage scenarios. Damages were modelled as areas with changed material properties. Investigation focused on the influence of damage size on the energy of wave reflection. Presented...