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Search results for: FIELD OF STUDY
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Short-fuse arc in the magnetic field
PublicationDo wymuszenia przerzutu prądu z bezpiecznika krótkotopikowego o dużym prądzie znamionowym, lecz małej zdolności wyłączania do do innego - o małym prądzie znamionowym, lecz dużej zdolności wyłączania konieczne jest wytworzenie przez bezpiecznik krótkotopikowy wysokiego napięcia łukowego. Do tego celu bezpiecznik z topikiem o długości 1 mm wyposażono w rożki łukowe i płykową komorę dejonizacyjną oraz zastosowano zewnętrzne pole...
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Covariance approach to the free photon field
PublicationWprowadziliśmy teorię fotonu poprzez tą samą zasadę, co dla pojedynczej czą-stki w kwantowej mechanice używając C*-algebraicznego podejścia kowariantychukładów.
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Multidipoles model of ship's magnetic field
PublicationShips made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine...
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Multisource model of ship electric field
PublicationA steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship's cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship's identification and counter-mine protection. The paper presents a simplified model of the ship's multisource electric field, which allows to calculate the electric field distribution...
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Multidipoles model of ship's magnetic field
PublicationShips made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine...
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Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublicationThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
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ANALYSIS OF WIND CONDITIONS AROUND A BUILDING DEVELOPMENT AS A PART OF ITS FORM DESIGNING PROCESS, A CASE STUDY
PublicationAerodynamic phenomena that occurs around building developments exert a significant impact on the quality of climate in cities. Environmental wind engineering is a dynamically developing field of knowledge that offers a chance to study and, in consequence, regulates the air flow around buildings and complexes of building developments. The following paper discusses the issue of wind conditions that may be experienced on pedestrian...
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EXPERIMENTAL STUDY OF SURFACE ROUGHNESS EFFECT ONTHE RHEOLOGICAL BEHAVIOR OF MR FLUID
PublicationPaper presents the results of shear stress measurements of a commercial magnetorheological fluid using a plate-plate type geometry with a modified working surface. The purpose of the study was to determine the effect of changing the roughness of the measuring plate on the obtained shear stress results. Controlled shear rate tests and Magneto Sweep measurements were carried out for three MR fluid layer heights. The tests were...
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A subdomain model for armature reaction field and open‐circuit field prediction in consequent pole permanent magnet machines
PublicationIn this paper, the machine quantity, such as electromagnetic torque, self and mutual inductances, and electromotive force, is analytically calculated for non-overlapping winding consequent pole slotted machine for open-circuit field and armature reaction. The sub-domain approach of (2-D) analytical model is developed using Maxwell's equations and divide the problem into slots, slot-openings, airgap and magnets region, the magnet...
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Application of the discrete Green's function-based antenna simulations for excitation of the total-field/scattered-field interface in the FDTD method
PublicationIn this article, the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method is proposed for simulation of wire antennas irradiating inhomogeneous dielectric scatterers. Surface equivalence theorem in the discrete domain is used to separate the problem into an inhomogeneous domain and a wire antenna that are simulated with the use of FDTD and DGF-FDTD, respectively. Then, the excitation of the...
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A Maximum-Likelihood Approach to Force-Field Calibration
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A PAIR OF PERFECTLY CONDUCTING DISKS IN AN EXTERNAL FIELD
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The use of the electromagnetic field in microbial process bioengineering
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Hearing aid operating in acoustical free field
PublicationAparatowanie bardzo małych dzieci (od 5 miesiąca życia) za pomocą standardowych protez słuchu natrafia na wiele trudności natury praktycznej. Dotyczy to procesu dopasowania aparatu słuchowego, czyli doboru jego ustawień stosownie do aktualnych charakterystyk ubytku słuchu dzieci. Tymczasem wczesne aparatowanie jest zagadnieniem o ogromnym zanczeniu dla rozwoju słuchu, mowy i ogólnej inteligencji dziecka. Referat prezentuje uzyskane...
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Existence of periodic orbits for a perturbed vector field
PublicationPrzy nałożeniu pewnego warunku na odwzorowanie Poincarego, wyrażonego w języku indeksów iteracji, dowodzi się istnienia orbit periodycznych dla zaburzonego pola wektorowego.
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Magnetic field microsensor based on GaAs MESFET
PublicationA novel concept of the drain separation design in a horizontally-split-drain GaAs MAGFET sensor, based on epitaxial layer growth, was developed. Proper choice of GaAs/AlAs/GaAs epitaxial layer sequence provided good electrical isolation between the drain regions. The measured leakage current between the drain regions was in the range of nA for up to 2V drain voltage bias difference. Performed analytical and numerical calculations...
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Forecasting of the Employment Rate in the EU ICT Field
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Hydrodynamic Pressure Field of a Ship on Shallow Water
PublicationResults of calculations of the hydrodynamic pressure field around the ship were obtained by application of the boundary element method. Hydrodynamic field was calculated for a Polish Navy’s tugboat and transport ship using a program called SHiPP and compared with measurements of the field taken on river near Swinoujscie for two identical tugs H-4 and H-10. Next, a series of HPF calculations was carried out on planes situated at...
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Velocity Field Characteristics at the Inlet to a Pipe Culvert
PublicationA poorly designed culvert inlet structure causes scouring, which can lead to the collapse of the culvert and significant damage to the neighboring land. A set of laboratory tests was evaluated to examine velocity distribution at the culvert inlet. A three-dimensional acoustic Doppler velocimeterwas used to measure instantaneous flowvelocity upstream of the culvert. The analysis of mean velocities, turbulence strength, and Reynolds...
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Performance of lubricated sliding contact in magnetic field
PublicationResults of experimental studies concerning theinfluence of permanent magnetic field on wear of lubricatedsliding contact operating at short stroke and highfrequency are presented. It was found that horizontalmagnetic is affecting performance of the contact. Thejagged delamination regions produced in the presence of amagnetic field can be regarded as easily undergoing oxidisationbecause oxygen is readily adsorbed there. Magneticfield...
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On numerical calculation of acoustic field of plane source.
PublicationSkładowe harmoniczne wiązki akustycznej zostały obliczone na podstawie reprezentacji w postaci całek według teorii reprezentacji. Zastosowano nowe metody do obliczania całek od funkcji szybko oscylacyjnych.
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Potential changes in an electric field and electrolytic corrosion.
PublicationSources have been described of corrosively hazardous electric fields and methods of determination of the corrosion hazard to metal structures caused by electrolytic corrosion. Results of potential and impedance investigations in the field of stray currents flowing out of a tram traction and in the presence of a defined electric field of low frequency have been presented. Uncertainties have been indicated relating to the generally...
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The behavioural model of graphene field-effect transistor
PublicationThe behavioural model of a graphene field-effect transistor (GFET) is proposed. In this approach the GFET element is treated as a “black box” with only external terminals available and without considering the physical phenomena directly. The presented circuit model was constructed to reflect steady-states characteristics taking also into account GFET capacitances. The authors’ model is defined by a relatively small number of equations...
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Near Field Coupled Wireless Microwave Sensor
PublicationThis paper presents a wireless planar microwave sensor operating at industrial scientific and medical (ISM) frequency for the detection of dielectric materials. The microwave sensor consists of a reader (ground defected microstrip coupled line) and a passive tag where a complementary split-ring resonator (CSRR) is made on the commercially available copper-foil. The CSRR is a peel-off type tag that is excited using the near field...
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Modelling and computer animation of geodetic field work
Publication3D modelling of objects is a way of obtaining information, while the visualization of geospatial data is becoming a production task in the scope of surveying. Visualization of geospatial data provides effective tools for analysis information about the land surface, land cover, its features, properties etc. Computer animations, both 2D images and 3D are becoming additional, expected and clear form for presentation results of geodetic...
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Architecture in the field of art on the example of author’s realizations
PublicationThe aim of the article was to show the place of architecture in the space of art on the example of original projects. In the author's opinion, architecture, using an artistic object as a means of expression, influences the process of living by showing the recipient, who is an inhabitant, important values from the point of view of creating a house that ensures a good quality of life and strengthening the understanding of both various...
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Research of leakage magnetic field in deenergized transformer
PublicationThe article deals with the issue of the numerical analysis of the magnetic field occurring around the transformer after it has been powered down. The main goal of this analysis was to examine if it is possible to identify the residual fluxes in the transformer legs based on this fields’ measurements. It was also intended to determine the type and the location of magnetic sensors. Numerical analysis of the magnetic field was performed....
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Pronouncement of embedded agency in the field of social entrepreneurship
PublicationThe paper provides insights into how social entrepreneurship and the institutional theory framework can be combined. The author situates the social entrepreneurship phenomenon here, and embarks on the traditional structure vs agency debate from social sciences, sociology of organizations in particular. The concept of embedded agency is referred to and employed to explain the phenomenon of social entrepreneurship. In this paper,...
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Advanced field investigations of screw piles and columns
PublicationPrzedstawiono opis badań pali i kolumn wkręcanych na terenowym poletku doświadczalnym, wykonanych w ramach projektu badawczego MNiSW. Badania statyczne pali i kolumn wykonano z zaawansowanym systemem do pomiaru rozkładu siły wzdłuż trzonów. Przedstawiono podstawowe wyniki badań z rozdziałem obciążenia na podstawę i pobocznicę pali i kolumn.
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Magnetic disturbances caused by magnetic contamination of plastics
PublicationIn the study of low magnetic fields precision magnetometers working in a differential system are used. Two optically pumped magnetometers working in a differential system allow for precise measuring of disturbances in the magnetic field. In order to attain high accuracy of magnetic field measurement, it is necessary to use appropriate materials for the construction of a magnetometric system, particularly of those located closely...
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MARSTRUCT benchmark study on nonlinear FE simulation of an experiment of an indenter impact with a ship side-shell structure
PublicationThis paper presents a benchmark study on collision simulations that was initiated by the MARSTRUCT Virtual Institute. The objective was to compare assumptions, finite element models, modelling techniques and experiences between established researchers within the field. Fifteen research groups world-wide participated in the study. An experiment involving a rigid indenter penetrating a ship-like side structure was used as the case...
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Using the ultrasonic tomography method to study the condition of wooden beams from historical buildngs
PublicationThe need to evaluate the integrity of wooden structural elements is constantly increasing. Non-destructive methods are becoming more popular in this field of research. One type of non-destructive testing is the ultrasonic imaging method, which allows the analysis of internal wood structures without disturbing their state and integrity. In this study, we are interested in assessing the effect of wood condition on the ultrasound...
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AI-powered Digital Transformation: Tools, Benefits and Challenges for Marketers – Case Study of LPP
PublicationThe article aims to show the role (benefits and challenges) of AI-powered digital marketing tools for marketers in the age of digital transformation. The considerations were related to the Polish market and a case study of LPP, a Polish clothing retailer. The starting point for this study was the analysis of the literature on the concept of artificial intelligence (AI) with reference to digital marketing. In the next steps, the...
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Analysis of magnetic field of Hemholtz's coils and ferromagnetic objects
PublicationThe 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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Composite shells in 6-field nonlinear shell theory
PublicationW pracy przedstawiono równanie konstytutywne uwzględniające wielowarstwowość materiału powłoki. Równania wyprowadzono bazując na podejściu Equivalent Single Layer
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Disturbances of magnetic field in surrounding of mobile, metalic plate
PublicationThe uniform magnetic field of the Earth in the surrounding of a mobile, metalic object undergoes deformation by eddy currents. The influence of the moving conducting object on total magnetic field of the Earth depends on the object's shape, position and speed of the changes relative to the magnetic field's vector of the Earth as well as the electric conductivity and the relative magnetic permeability of the material. The disturbances...
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Some Aspects of Potential Measurements in a Stray Current Field
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Delivering Usability in IT Products: Empirical Lessons from the Field
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Structure of the scalar field around unidirectional circular cylinders
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Methods of Bacteriophages Production with Application of Alternate Magnetic Field
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Simple and accurate field interpolation in finite difference methods
PublicationW artykule wprowadzono nową metodę interpolacji pól w metodzie różnic skończonych. Metoda jest prosta i daje wyniki bardziej dokładne niż w przypadku interpolacji liniowej. Proponowana metoda interpolacji może zostać użyta do poprawienia dokładności takich metod, jak subgridding.
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The influence of compensate coils on own ship magnetic field
PublicationA 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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Turbulence Flow Modeling of One-Sharp-Groyne Field
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The hydrodynamic pressure field of the ship Zodiak, measurements and calculations
PublicationThe article presents the results of measurements of the slowly changing hydrodynamic pressure field HPF generated by the movement of the ship, Zodiak, in the Bay of Gdansk. The measurement results have been obtained in the framework of the program of the work in Siramis, under the auspices of the European Defence Administration of the EU, by the research team of the Naval Academy in Gdynia. The measurement results were compared with...
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Disturbances of magnetic field of plane caused by eddy currents
PublicationResults of the numerical analysis of the magnetic disturbances of a plane caused by eddy currents induced in conducting elements of the plane were presented in this paper. Magnetic disturbances of the object's model were carried out in Opera 3D.
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The influence of the filler on the magnetic field distribution in ferromagnetic objects.
PublicationDuże obiekty ferromagnetyczne umieszczone w zewnętrznym polu magnetycznym (np. ziemskim polu magnetycznym) ulegają namagnesowaniu. W pewnych przypadkach konieczna jest demagnetyzacja obiektu ferromagnetycznego. Demagnetyzacja polega na umieszczeniu obiektu w wytworzonym w układzie zewnętrznym polu magnetycznym o określonych właściwościach. Jeżeli obiekt ferromagnetyczny posiada duże rozmiary, wówczas jego demagnetyzacja jest problemem...
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Simulation and discretization of random field in the slip line method.
PublicationW pracy rozpatrywany jest problem nośności granicznej podłoża o własnościach stochastycznych przy obciążeniu spoczywającym na nim ciężkim sztywnym bloku.Opisano sposób generacji wielowymiarowego pola losowego oparty na diagonalizacji macierzy kowariancji przy wykorzystaniu macierzy dolnotrójkątnej .Szczególną uwagę zwrócono na wpływ dyskretyzacji ośrodka na rozwiązanie oraz jego zbieżność.
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Detection of broadband signals in the field of aperture and array systems.
PublicationAnteny i szyki anten w dolnopasmowych systemach hydroakustycznych wnoszą istotne zniekształcenia liniowe wpływające na możliwości detekcji sygnałów szerokopasmowych. W artykule analizowany jest charakter takich zniekształceń metodą przestrzenno - czasowych odpowiedzi impulsowych. Sygnał odbierany w różnych kierunkach przestrzeni poddano filtracji na dwa sposoby z filtrem dopasowanym do sygnału nadawanego i filtrem dopasowanym...
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Random field model of foundations at the example of continuous footing
PublicationThe purpose of the paper is to indicate an efficient method of foundation settlement analysis taking into account the variability of soil properties. The impact of the random variable distribution (Gauss or Lognormal) describing soil stiffness on foundation deposits was assessed. The Monte Carlo simulation method was applied in the computations. The settlements of the strip foundation with the subsoil described by a single random...
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Necessary covariance conditions for a one-field Lax pair
PublicationBadamy kowariancje w odniesieniu do transformacji Darboux wielomianowych różniczkowych i różnicowych operatorów z współczynnikami danymi przez funkcje jednego bazowego pola.