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Two tests for adhesive bonding long term characterization: principles and applications
PublikacjaThis article describes recent refinement of the traditional wedge test technique used to characterize durability of the adhesive joints. We propose two types of measuring protocols to monitor precisely and continuously the propagation of an "effective" crack during long term mode I fracture mechanic test. First method is directly derived from the traditional wedge test technique and consist in monitoring the surface strain of adherent...
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A comprehensive study on nonlinear hygro-thermo-mechanical analysis of thick functionally graded porous rotating disk based on two quasi three-dimensional theories
PublikacjaIn this paper, a highly efficient quasi three-dimensional theory has been used to study the nonlinear hygro-thermo-mechanical bending analysis of very thick functionally graded material (FGM) rotating disk in hygro-thermal environment considering the porosity as a structural defect. Two applied quasi three-dimensional displacement fields are assumed in which the strain along the thickness is not zero unlike most of the other plate...
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A variational approach of homogenization of piezoelectric composites towards piezoelectric and flexoelectric effective media
PublikacjaThe effective piezoelectric properties of heterogeneous materials are evaluated in the context of periodic homogenization, whereby a variational formulation is developed, articulated with the extended Hill macrohomogeneity condition. The entire set of homogenized piezoelectric moduli is obtained as the volumetric averages of the microscopic properties of the individual constituents weighted by the displacement and polarization...
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Effectiveness of a mathematical model in simulating nonlinear mechanical behaviour of a seismic isolation system made of polymeric bearings
PublikacjaThe present study was focused on determining the effectives of a nonlinear mathematical model in simulating complex mechanical behaviour of a seismic isolation system made of Polymeric Bearings. The proposed mathematical model defines the lateral force as a nonlinear function of the shear displacement and the deformation velocity. The effectiveness of the proposed mathematical model was verified by comparing the seismic response...
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Mixed 4-node shell element with assumed strain and stress in 6-parameter theory
PublikacjaWe propose a mixed hybrid 4-node shell elements based on Hu-Washizu principle. Apart from displacements both strains and stress fields are treated as independent fields. The element is derived in the framework of a general nonlinear 6-field shell theory with drilling rotation which is dedicated to the analysis of multifold irregular shells with intersections. The novelty of the presented results stems from the fact that the measures...
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FEA analysis of the multicell piezoelectric motor
PublikacjaThe presented paper concerns a design, modeling and chosen tests of the prototype multicell piezoelectric motor (MPM). The principle of operation based on three independent traveling wave actuators is presented. The main materials and technologies used in the fabrication process are described. The structure of the motor is modeled using static and modal FEM analysis. The process of traveling wave generation in the MPM structure...
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On stress singularity near the tip of a crack with surface stresses
PublikacjaIn the framework of the simplified linear Gurtin–Murdoch surface elasticity we discuss a singularity of stresses and displacements in the vicinity of a mode III crack. We show that inhomogeneity in surface elastic properties may significantly affect the solution and to change the order of singularity. We also demonstrate that implicitly or explicitly assumed symmetry of the problem may also lead to changes in solutions. Considering...
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Comparison of anti-plane surface waves in strain-gradient materials and materials with surface stresses
PublikacjaHere we discuss the similarities and differences in anti-plane surface wave propagation in an elastic half-space within the framework of the theories of Gurtin–Murdoch surface elasticity and Toupin–Mindlin strain-gradient elasticity. The qualitative behaviour of the dispersion curves and the decay of the obtained solutions are quite similar. On the other hand, we show that the solutions relating to the surface elasticity model...
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Mixed 4-node shell element with assumed strain and stress in 6-parameter theory
PublikacjaWe propose a mixed hybrid 4-node shell elements based on Hu-Washizu principle. Apart from displacements both strains and stress fields are treated as independent fields. The element is derived in the framework of a general nonlinear 6-field shell theory with drilling rotation which is dedicated to the analysis of multifold irregular shells with intersections. The novelty of the presented results stems from the fact that the measures...
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Investigation of abdomen surface deformation due to life excitation: implications for implant selection and orientation in laparoscopic ventral hernia repair
PublikacjaVentral hernia is a common medical problem. Statistically there are around 10% recurrences of the sickness. The authors' former investigation proved edges of the hernia orifice displacements to be one of the factors causing recurrence. Thus, experimental investigation of the abdomen surface deformation due to some normal activities of people is studied.The extreme strains, their localization and directions are identified. The acquired...
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The influence of compensate coils on own ship magnetic field
PublikacjaA ferromagnetic object placed in the earth magnetic field causes a local disturbance in this field distribution. The field distribution disturbance is a function of many arguments like the dimensoins and shape of the object, its ferromagnetic properties ande its positon in relation to the earth magnetic field. in order to minimize the influence of this disturbance one places compensate coils on the ship. Some chosen results of...
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Badania charakterystyki obciążeń oddziałujących na modułowe urządzenie dylatacyjne w pasie ruchu ciężkiego autostrady A8
PublikacjaPrzedstawiono badania urządzenia dylatacyjnego typu nożycowego. Dokonano statycznych i dynamicznych pomiarów odkształceń oraz przemieszczeń konstrukcji nożyc na najbardziej obciążonym pasie autostrady A8. Określono wpływ oddziaływania dynamicznego oraz sporządzono histogramy obciążeń i współczynników przewyższenia dynamicznego na podstawie pomiarów ciągłych w okresie nasilonego ruchu. Wskazano przyczyny degradacji urządzenia. Odniesiono...
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A numerical model to simulate the motion of a lifesaving module during its launching from the ship’s stern ramp
PublikacjaThe article presents a numerical model of object motion in six degrees of freedom (DoF) which is intended to be used to simulate 3D motion of a lifesaving module during its launching from a ship using a stern ramp in rough sea. The model, of relatively high complexity, takes into account both the motion of the ship on water in changing sea conditions, and the relative motion of the ramp with respect to the ship. The motion of the...
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Techniki sprzętowej teselacji do wygładzania i uszczegóławiania modeli trójwymiarowych
PublikacjaDirectX 11 oraz OpenGL 4 wprowadziły do potoku renderującego bardzo oczekiwaną teselację. Wraz z upływem czasu coraz więcej silników graficznych zostaje dostosowywanych do wspierania tej technologii. W artykule przedstawiona została koncepcja teselacji od strony teoretycznej oraz praktycznej. Opisany został nowy potok renderujący, a w szczególności dedykowane teselacji programy cieniujące (ang. shaders). Główną część artykułu stanowi...
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Isogeometric Shell FE Analysis of the Human Abdominal Wall
PublikacjaIn this paper a nonlinear isogeometric Kirchhoff-Love shell model of the human abdominal wall is proposed. Its geometry is based on in vivo measurements obtained from a polygon mesh that is transformed into a NURBS surface, and then used directly for the finite element analysis. The passive response of the abdominal wall model under uniform pressure is considered. A hyperelastic membrane model based on the Gasser-Ogden-Holzapfel...
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A method to determine the tightening sequence for standing rigging of a mast
PublikacjaThe article proposes an alternative method to determine the sequence of generation of pre-tension forces in standing rigging of a mast. The proposed approach has been verified on both a virtual simulation experiment and laboratory tests. In this method, the desired tension values are obtained using the influence matrix which allows to calculate the effect of tension change in an individual rope on the tension distribution in the...
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Extending transition curve in analytical design method
PublikacjaThe paper presents the problem of extending the transitional curves, using for this purpose an analytical design method. The basis for the analysis of numerical calculations were carried out for a wide set of parameters characterizing the standard geometric system. We considered an importance of the size of radius of the circular arc and return angle of route on the obtained results after the formulation of appropriate theoretical...
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MONITORING OF PERMANENT GPS STATIONS AT THE SUDETY MOUNTAINS
PublikacjaThe aim of this paper is to show time-dependent baseline variation between GPS stations situated in South-East Poland. This study was based on daily data analysis of selected GPS stations: WROC, GOPE, MOPI, KRAW and KATO. The start date of the analysis is linked at every station with the beginning of its operation and the closing date of the operation is in 2006. The multiresolution signal decomposition method has been used to...
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Spatial variability of throughfall in a stand of Scots pine (Pinus sylvestris L.) with deciduous admixture as influenced by canopy cover and stem distance
PublikacjaVegetation cover affects the amount of precipitation, its chemical composition and its spatial distribution, and this may have implications for the distribution of water, nutrients and contaminants in the subsurface soil layer. The aim of this study was a detailed diagnosis of the spatio-temporal variability in the amount of throughfall (TF) and its chemical components in a 72-year-old pine stand with an admixture of oak and birch....
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Analysis of magnetic field of Helmholtz's coils
PublikacjaThe 3-axis fluxgate magnetometer requires conducting a precise calibration in the magnetic field whose value is determined and which is characterized by the high uniformity of the distribution of the field, especially along the axis of the sensors. The generation of the magnetostatic field characterized by the high uniformity, can be achieved by using the Helmholtz's coils. The requirements of the uniformity of distribution of...
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Stress anisotropy characterisation with the help of Barkhausen effect detector with adjustable magnetic field direction
PublikacjaIn the paper we describe a novel apparatus for the measurement of the Barkhausen noise (BN) angular dependence, which in turn may be indicative of the stress induced anisotropy of magnetic properties. Such dependence can be further used for the stress distribution evaluation. The change of magnetization direction in the material is obtained by varying the magnetic flux density in two perpendicular yokes of the apparatus. We present...
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Techniki sprzętowej teselacji do wygładzania i uszczegóławiania modeli trójwymiarowych
PublikacjaDirectX 11 oraz OpenGL 4 wprowadziły do potoku renderującego bardzo oczekiwaną teselację. Wraz z upływem czasu coraz więcej silników graficznych zostaje dostosowywanych do wspierania tej technologii, więc nie można pozostawać wobec niej obojętnym. W artykule przedstawiona zostanie koncepcja teselacji od strony teoretycznej oraz praktycznej. Opisany zostanie nowy potok renderujący, a w szczególności dedykowane teselacji programy...
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A Multifunctional Microwave Filter/Sensor Component Using a Split Ring Resonator Loaded Transmission Line
PublikacjaThis research is focused on the design and realiza2 tion of a microwave component with multifunctional filter/sensor 3 operation using a resonator-loaded transmission line (TL). It is 4 shown that while the structure acts as a bandstop filter, the 5 phase of the reflection coefficient from the loading resonator(s) 6 on a movable layer can be used for displacement sensing, thus 7 allowing for combining filtering with sensing in...
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A New Geodetic Method of Examination of Geometrical Conditions of a Crane Bridge
PublikacjaSafety is one of the key aspects related to crane-based material transport. In order to ensure safe crane operation and material transport, it is necessary to meet certain geometrical conditions. The authors addressed the geometrical conditions of a crane bridge, a substantial crane component. The paper presents the method to compute displacement components of points on the top of a bridge crane relative to their design position....
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Fractional Calculus Evaluation of Hyaluronic Acid Crosslinking in a Nanoscopic Part of Articular Cartilage Model System
PublikacjaThis work presents a study of the mechanism of physical crosslinking of hyaluronic acid in the presence of common phospholipids in synovial joint organ systems. Molecular dynamic simulations have been executed to understand the formation of hyaluronan networks at various phospholipid concentrations. The results of the simulations suggest that the mechanisms exhibit subdiffusion characteristics. Transportation quantities derive...
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AN ATTEMPT AT IDENTIFYING THE INFLUENCE OF TEST HEAD ASSEMBLY STIFFNESS ON THE RESULTS OF A TRIBOLOGICAL EXPERIMENT CONDUCTED UNDER MICRO-OSCILLATION CONDITIONS
PublikacjaThe outcome of experimental research on a group of dry bearing materials carried out under small oscillation conditi ons and using a test rig designed and made at Gdansk University of Technology inspired the decision to find out if the stiffness of test head elements in fluenced the generated results. Therefore, a computer model utilising finite elements was devised and used to simulate the workings of the test head. The mode l...
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Timber-frame house resistant to dynamic loads - analysis of wall panel filled with polyurethane foam
PublikacjaThe present study shows the experimentally and numerically determined response of a single timber-frame house wall panel filled with polyurethane (PU) foam under dynamic loads. The harmonic tests were conducted for the following frequencies: 0.5 Hz, 1.0 Hz, 2.0 Hz and 5.0 Hz for various values of the specified displacement. Based on the results of the comparison between the experimental tests and the numerical analyses, the numerical...
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Load Tests of the Movable Footbridge Over the Port Canal in Ustka
PublikacjaThe paper presents the acceptance tests carried out on the open footbridge over the port canal in the Port of Ustka. The steel footbridge construction is created by a single pylon to which a movable truss span is suspended with a theoretical span of 52.3 m. The studies about load test of the object included static and dynamic extortion and measurements. In static tests the ballast was of pallets with concrete blocks. Dynamic studies...
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An innovative method of measuring the extension of the piston rod in hydraulic cylinders, especially large ones used in the shipbuilding and offshore industry
PublikacjaThe article presents the results of selected works related to the wider subject of research conducted at the Faculty of Mechanical Engineering and Shipbuilding at the Gdańsk University of Technology, regarding designing various on board devices with hydraulic drive for ships and other offshore facilities. One of the commonly used these mechanisms are hydraulic actuators with the measurement of the piston rod extension. The issue...
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MAKING OF FERROMAGNETIC ELLIPTICAL SHELL IN TRANSVERSE MAGNETIC
PublikacjaA ferromagnetic object, located in the Earth’s magnetic field, changes its distribution. Through measuring such disturbances, one can locate the object and destroy it. To conceal the object, a special winding is placed inside its ferromagnetic shell, and its task is to eliminate the disturbances in the distribution of the Earth’s magnetic field.
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Distributed Detection of Selected Features in Data Streams Using Grid-class Systems
PublikacjaThis chapter describes basic methodology of distributed digital signal processing. A choice of distributed methods of detection of selected features in data streams using grid-class systems is discussed. Problems related to distribution of data for processing are addressed. A mitigating method for data distribution and result merging is described.
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Gender wage gap convergence and skills heterogeneity in Poland (2005-2014) - quantile regression analysis based on microdata from EUSILC.
PublikacjaIn this article we quantify the magnitude and evolution of gender wage differentials in Poland over the years 2005 – 2014 using microlevel data from EU-SILC database (Statistics on Income and Living Conditions). In the study gender wage gap is examined through quantile regression analysis. It is shown that the gender wage gap varies along the wage distribution with workers’ skills heterogeneity playing a role. Additionally, the...
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A COMPARISON OF THE WIND SPECTRUM ACCORDING TO DIFFERENT METHODS - AN ORIGINAL PROJECT OF A BUILDING ON A CLIFF IN GDYNIA
PublikacjaThe article presents numerical simulations of the dynamic wind loads on the structure of a building designed on a cliff in Gdynia. The results obtained from the two methods: Davenport’s and Karman’s are compared. The results allowed a comparison of the two methods, and they provided an answer to the question how a construction, designed in such an unusual condition of a cliff behaves under the influence of the gusting wind. The...
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Flow visualization and heat transfer investigations on the flat plate with streamwise pressure gradient
PublikacjaPaper presents experimental investigations results for film cooling on a flat plate. The main objective of the design is the streamwise pressure distribution on the flat plate as in the blade cascade. The transient and steady-state technique with liquid crystals for the surface temperature distribution with film cooling has been used in experiments in a low speed wind tunnel.
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Reactive Energy Billing in Operator Tariffs in Poland
PublikacjaThe paper describes the current method of reactive energy billing in the tariffs of distribution grid operators in Poland. The current solutions are subject to critical assessment. Issues related to the motivation effect of the current solutions on consumers are analysed. Problems that occur in relation with connecting distributed generators to the distribution grid and challenges related to prosumer billing are indicated.
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Analysis of magnetic field of Hemholtz's coils and ferromagnetic objects
PublikacjaThe 3-axis fluxgate magnetometer requires conducting a precise calibration in the magnetic field whose value is determined and which is characterized by the high uniformity of the distribution of the field, especially along the axis of the sensors. The generation of the magnetostatic field characterized by the high uniformity, can be achieved by using the Helmholtz's coils. The requirements of the uniformity of distribution of...
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Numerical analysis of a temporary steel grandstand
PublikacjaThe purpose of this paper is to present the results of the numerical analysis focused on the response of the temporary steel scaffolding grandstand subjected to human-induced vibrations due to jumping. Shell as well as beam elements have been used in the numerical model. Its first stage has involved conducting modal analysis in order to determine the modes of free vibrations and the corresponding natural frequencies for the empty...
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Performance of isotropic constitutive laws in simulating failure mechanisms in scaled RC beams
PublikacjaResults of numerical calculations of reinforced concrete (RC) beams are presented. Based on experimental results on longitudinally reinforced specimens of different sizes and shapes are investigated. Four different continuum constitutive laws with isotropic softening are used: one defined within continuum damage mechanics, an elasto-plastic with the Rankine criterion in tension and the Drucker-Prager criterion in compression, a...
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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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1,3,4-Thiadiazole-based diamides: Synthesis and complexation properties
PublikacjaAromatic diamides, derivative of 2,6-pyridinedicarboxylic acid and isophthalic acid, bearing 1,3,4-thiadiazole residue were prepared with satisfactory yields in conventional procedures and microwave stimulated reactions. X-ray structure of N,N-bis (1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide (2) DMSO solvate (2DMSO) was described. Selective zinc(II), lanthanum(III), terbium(III) and L-tyrosine recognition was found for N,N-bis(1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide...
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Static Shunt PE Voltage-Quality Controllers
PublikacjaThis chapter focuses on power electronics (PE)-based solutions used in distribution networks for reduction of supply-voltage-quality deterioration, from long interruptions to the harmonics. Various PE devices and their combinations are addressed for particular or a range of voltage disturbances. A particular solution is applied taking into account demands for voltage quality and network configuration. In general, there are three...
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Fading Modeling in Maritime Container Terminal Environments
PublikacjaIn this paper, an analytical model for slow and fast fading effects in maritime container terminals is derived, from fitting distributions to the results of measurements performed in an actual operational environment. The proposed model is composed of a set of equations, enabling to evaluate fading statistical distribution parameters for different system and environments conditions, as a function of frequency, base station antenna...
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Equivalent 4-node enhanced assumed strain and hybrid stress shell elements in 6-parameter theory
PublikacjaWe discuss the equivalence of semi-enhanced assumed strain (EAS) and semi-hybrid stress (SEM) shell finite elements. We use the general nonlinear 6-field shell theory with kinematics composed of generalized displacements composed of the translation field and the rotation field. Due to the presence of rotation tensor the elements have naturally six nodal engineering degrees of freedom. We propose interpolation for a strain field...
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Continuum models for pantographic blocks with second gradient energies which are incomplete
PublikacjaWe postulate a deformation energy for describing the mechanical behavior of so called pantographic blocks, that is bodies constituted by stacking of layers of pantographic sheets. We remark that the pantographic effect is limited in the plane of pantographic sheets and therefore only the second derivatives of transverse displacements along the pantographic fibers appear in the chosen deformation energy. We use this novel energy...
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On Anti-Plane Surface Waves Considering Highly Anisotropic Surface Elasticity Constitutive Relations
PublikacjaWithin the framework of highly anisotropic surface elasticity model we discuss the propagation of new type of surface waves that are anti-plane surface waves. By the highly anisotropic surface elasticity model we mean the model with a surface strain energy density which depends on incomplete set of second derivatives of displacements. From the physical point of view this model corresponds to a coating made of a family of parallel...
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A Nonlinear Model of a Mesh Shell
PublikacjaFor a certain class of elastic lattice shells experiencing finite deformations, a continual model using the equations of the so-called six-parameter shell theory has been proposed. Within this model, the kinematics of the shell is described using six kinematically independent scalar degrees of freedom — the field of displacements and turns, as in the case of the Cosserat continuum, which gives reason to call the model under consideration...
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A fast procedure of stress state evaluation in magnetically anisotropic steels with the help of a probe with adjustable magnetizing field direction
PublikacjaThe paper presents a novel approach to the stress state evaluation issue. It deals with a strongly (magnetically) anisotropic materials for which a direct interpretation of the Barkhausen effect (BE) intensity would lead to erroneous results. In such a case one has to take into account both the measured BE intensity and the orientation of the magnetisation direction relative to the magnetic easy axis. For the in plane stress distribution...
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Selection of main engines for hopper suction dredgers with the use oobability models
PublikacjaThis paper presents a new original method of selection of main engines for hopper suction dredgers with regard to probabilistic models. It was proposed to use the normal distribution to describe the operational loads of the main receivers. The principles for determination of parameters of load distribution and design power of the main engines were formulated. Lastly, the principles of selection of the size and number of main engines...
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Ordinal Pattern Statistics for RR Intervals during Head-Up Tilt Test in Patients with the History of Vasovagal Syncope
PublikacjaWe apply ordinal pattern analysis to quantify differences in distribution of patterns of length 3 and 4 in basal state and during head-up tilt test (HUTT) in patients with the history of syncope and positive (HUTT(+)) or negative (HUTT(-)) responses to the test. We identify the patterns related to prevalence of sympathetic or parasympathetic cardiac modulation as well as describe the relations between the response to the test and...
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Fading Analysis in Off-Body Channels in a Straight Metallic Corridor in a Passenger Ferry Environment
PublikacjaThis paper presents a fading analysis for Body Area Networks off-body communications at 2.45 GHz in a passenger ferry environment. The results are based on measurements performed for dynamic scenarios in a straight metallic corridor. Two components, extracted from instantaneous system loss values, have been analysed: small- and large-scales fading, separately for each scenario. Well-known probability distribution functions have...