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Search results for: SHIPS, WAVES, WHITE NOISE, DAMPING, DENSITY, HULL, SEAS, SIGNIFICANT WAVE HEIGHTS, TESTING, WAVE FREQUENCY
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Design Methodology for Small Passenger Ships On the Example of the Ferryboat Motława 2 Driven by Hybrid Propulsion System
PublicationDynamic development in practically all elds of science and engineering has not passed over shipbuilding . In last years , engineers got to their use computer soware which makes it possible to perform strength and hydrodynamic calculations as well as to visualize design projects in 3 D space [1-4]. At their disposal they have full spectrum of modern solutions associated with the use of advanced materials and technologies [5-7]....
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Low Cost Hexacopter Autonomous Platform for Testing and Developing Photogrammetry Technologies and Intelligent Navigation Systems
PublicationLow-cost solutions for autonomous aerial platforms are being intensively developed and used within geodetic community. Unmanned aerial vehicles are becoming very popular and widely used for photogrammetry and remote sensing applications. Today’s market offers an affordable price components for unmanned solution with significant quality and accuracy growth. Every year market offers a new solutions for autonomous platforms with better...
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Testing Watermark Robustness against Application of Audio Restoration Algorithms
PublicationThe purpose of this study was to test to what extent watermarks embedded in distorted audio signals are immune to audio restoration algorithm performing. Several restoration routines such as noise reduction, spectrum expansion, clipping or clicks reduction were applied in the online website system. The online service was extended with some copyright protection mechanisms proposed by the authors. They contain low-level music features...
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Chirp-rate estimation of FM signals in the time-frequency domain
PublicationNovel dynamic representations of a complex signal in the time-frequency domain including: a channelized instantaneous complex frequency (CICF), a complex local group delay (CLGD) and a channelized instantaneous chirp-rate (CICR) are introduced. The proposed approach is based on the use of the gradient of the short-time Fourier transform complex phase. An interpretation of the newly-introduced distributions especially of the CICR...
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A parametric method for evaluation of resistance of swath ships
PublicationArtykuł zawiera sformułowania metody parametrycznej służącej do wyznaczania oporu kadłuba statku o konfiguracji swath. Metodę opracowano opierając się na rezultatach obliczeń numerycznych, uzyskanych metodami strukturalnymi, wywiedzionymi ze sformułowań teoretycznej hydromechaniki okrętu, wykonanych na dostatecznie licznej serii kształtów kadłuba, o systematycznie uzmiennianych parametrach kształtu. Następnie przedstawiono rezultaty...
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A model of risk for assessment of ships in damaged conditions
PublicationW pracy omówiono problemy związane z modelowaniem zagrożeń, konsekwencji i ryzyka, w metodzie oceny bezpieczeństwa statków w stanie uszkodzonym. W celu dokonania oceny bezpieczeństwa statku, w metodzie zastosowano podejścia oparte na ocenie zachowania się statku i ocenie ryzyka. Podejście oparte na ocenie zachowania się statku związane jest z oceną charakterystyk hydromechanicznych statku w stanie uszkodzonych w warunkach zbliżonych...
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Optical Fibre, Local Measurement Systems For Ships
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Estimating operability of ships in ridged ice fields
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Investigations of transverse stability of semi-displacement ships
PublicationPrzedstawiono wyniki eksperymentalnych badań modelowych poprzecznej stateczności jednostek półślizgowych, których celem było określenie wpływu prędkości oraz parametrów kształtu kadłuba na stateczność poprzeczną. Na podstawie wyników badań opracowano algorytmy, uwzględniające zmiany ramienia prostującego w funkcji prędkości, kąta przechyłu i parametrów geometrycznych kadłuba które mogą być wykorzystane do oceny stateczności poprzecznej...
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Strength testing machine results
Open Research DataThe aim of the research project is to determine the rotational stiffness of the connection between the purlin and the part of the truss top chord. The attached files are referred to the forces and displacements obtained from the strength testing machine (two sensors). The 16 specimens were tested on the experimental set up.
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Rolling Resistance And Tire/Road Noise on Rubberized Asphalt Pavement In Poland
PublicationThe paper presents results of tire/road noise and rolling resistance measurements performed on stone-matrix asphalt (SMA) that contains rubberized asphalt developed and produced by the company in Poland. Bituminous binder was modified with polymer and additive of crumb rubber. First observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger car...
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Rolling resistance and tyre/road noise on rubberised asphalt pavement in Poland
PublicationThe paper presents results of tyre/road noise and rolling resistance measurements performed on stone mastics asphalt (SMA) that contains rubberised asphalt, developed and produced by a refinery in Poland. Bituminous binder was modified with polymer and addition of crumb rubber. The first observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger...
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The effect of heating and fermenting on antioxidant properties of white cabbage
PublicationIt is widely believed that natural antioxidants found in food are significantly lost during processing. Nevertheless, it was recently demonstrated that processed fruits and vegetables may retain their antioxidant activity. In the present work, the changes in the overall antioxidant properties as a consequence of fermentation of cabbage and/or heat treatment of cabbage juices and extracts were studied. Fermentation processes as...
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Effects of cooking on the bioactivity of lotus roots and white onions
PublicationW pracy przedstawiono wyniki badań wpływu obróbki termicznej (gotowanie) na zawartość związków bioaktywnych i potencjału przeciwutleniającego korzenia lotosu i cebuli białej.Wyniki badań jednoznacznie wskazują na fakt, że taki proces obróbki wpływa w znaczącym stopniu na spadek stężenia związków bioaktywnych i potencjału przeciwutleniającego.
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Anaerobic co-digestion of white cabbage and sewage sludge
PublicationPrzedstawiono badania nad możliwością redukcji biomasy kapusty białej w procesie mezofilowej ko-fermentacji z przefermentowanym osadem ściekowym w procesie jednostopniowej fermentacji. Wykazano, że biomasę kapusty białej można poddać ko-fermentacji z osadem ściekowym przy obciążeniu komory fermentacyjnej na poziomie 1,87 kg smo m-3d-1. Zaobserwowano, że w wyniku fermentacji metanowej wsadu można uzyskać biogaz o średnim składzie...
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White-light interferometric temperature sensor for biomedical diagnostic.
PublicationW artykule opisano opracowany model miniaturowego, światłowodowego czujnika temperatury z interferometrem Fabry-Perot wykorzystującego interferencję światła białego przeznaczonego do zastosowań biomedycznych. Analizowano czujnik wykonany ze światłowodu wielomodowego o skokowym profilu współczynnika załamania oraz ze światłowodu monomodowego. Zasadniczym celem był dobór parametrów mający na celu uzyskania maksymalnej widzialności...
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Testing Situation Awareness Network for the Electrical Power Infrastructure
PublicationThe contemporary electrical power infrastructure is exposed to new types of threats. The cause of such threats is related to the large number of new vulnerabilities and architectural weaknesses introduced by the extensive use of Information and Communication Technologies (ICT) in such complex critical systems. The power grid interconnection with the Internet exposes the grid to new types of attacks, such as Advanced Persistent...
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A Mesh Deformation Technique Based on Solid Mechanics for Parametric Analysis of High-Frequency Devices With 3-D FEM
PublicationIn this paper, a versatile technique for mesh defor- mation is discussed, targeted at the electromagnetic (EM) field simulation of high-frequency devices using the 3-D finite element method (FEM). The approach proposed applies a linear elasticity model to compute the displacements of the internal mesh nodes in 3-D when the structure geometry is changed. The technique is compared with an alternative approach...
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The fast identification of explosives, natcotics and other chemicals carried on board of ships or transported in containers
PublicationThe fast identification of explosives, narcotics and other chemicals carried on board of ships or transported in containers to the harbors is an important problem of maritime security. Raman spectroscopy is an advanced technique used in state-of-the art laboratories for fast identification of chemicals. No sample preparation is required, and identification can be carried out through transparent packing, such as plastic or glass,...
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Modal Adjustment of Rayleigh Based Structural Damping and Coordinate-Partitioning Algorithm Dedicated to Frictionless Contact Constraints between Multibody System and Structure Modelled with Finite Elements
PublicationThe paper presents a dedicated numerical algorithm. The algorithm is advantageous during investigations of the dynamics of a hybrid multibody / finite-elements system. We focus our attention on interactions resulting from mechanical contact. Pointwise contact connects a vertex of the multibody structure and a surface of the elastic reference body. Instead of a positive value of the relative penetration factor, constraint equations...
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Nonlinear impedance of as-quenched Bi2VO5.5 glass-ceramic was measured with impedance spectroscopy method at low temperature region
Open Research DataThe nonlinear electrical properties of as-quenched Bi2VO5.5 glass-ceramic was measured by impedance spectroscopy method.
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Comparison of noise reduction methods in radiometric correlation measurements of two-phase liquid-gas flows
PublicationTwo-phase liquid-gas flows occur frequently in the mining, energy, chemical, and petrochemical industries. One of non-contact methods used to analyse these flows is the gamma ray absorption method. However, the signals received from radiation detectors contain a significant stochastic noise, which makes them difficult to analyse. The article describes four methods of noise reduction in cross-correlation measurements of water-air...
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Waves in Random and Complex Media
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COMBUSTION EXPLOSION AND SHOCK WAVES
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JOURNAL OF INFRARED AND MILLIMETER WAVES
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Parametric impulsive noise detector for corrupted audio signals based on hidden Markow model
PublicationThe paper addresses the problem of impulsive noise detection for audio signals. A structure of threshold parameter detectors using modelingof signals was introduced. the algorithm of the noise detection, based on discrete-time hidden Markow model (HMM)of whitened audio signal is elaborated
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Cheap Cancellation of Strong Echoes for Digital Passive and Noise Radars
PublicationThe problem of cancellation of strong, potentially nonstationary,echoes in noise radars and passive radars utilizing digitaltransmissions is considered. The proposed solution is a multi-stage procedure.Initial clutter estimates, obtained using the least mean squares(LMS) algorithm, are refined using specially designed filters, "matched"to spectral densities of targets and clutter. When the postprocessing filtersare noncausal, the...
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Significant Parameters Identification for Optimal Modelling of the Harp-Type Flat-Plate Solar Collector
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The association analysis for risk evaluation of significant delay occurrence in the completion date of construction project
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Failure Monitoring and Condition Assessment of Steel-Concrete Adhesive Connection Using Ultrasonic Waves
PublicationAdhesive bonding is increasingly being incorporated into civil engineering applications. Recently, the use of structural adhesives in steel-concrete composite systems is of particular interest. The aim of the study is an experimental investigation of the damage assessment of the connection between steel and concrete during mechanical degradation. Nine specimens consisted of a concrete cube and two adhesively bonded steel plates...
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Damping Amplification Caused by a Mechanism that Trans-pass Trough its singular Position
PublicationW artykule przedstawiono badania dotyczące drgania hybrydowego systemu składającego się z mechanizmu i układu ciągłego. Pomimo ich obecności w wielu codziennych doświadczeniach to w większości przypadków technicznych obecność drgań jest niepożądana. Jednym z podstawowych problemów jest tu długie utrzymywanie się i konieczność tłumienia drgań o niskiej częstotliwości. W artykule badana jest metoda tłumienia oparta na niewspółmierności...
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Identification of inertia, damping and stiffness parameters for low pressure steam turbine framework.
PublicationW pracy przedstawiono metodę identyfikacji masy tłumienia i sztywności kadłuba części niskoprężnej turbiny parowej 200MW.
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A Taxonomy of Model-Based Testing for Embedded Systems from Multiple Industry Domains
PublicationThis chapter provides a taxonomy of Model-Based Testing (MBT) based on the approaches that are presented throughout this book as well as in the related literature. The techniques for testing are categorized using a number of dimensions to familiarize the reader with the terminology used throughout the chapters that follow. In this chapter, after a brief introduction, a general definition of MBT and related work on available MBT...
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Journal of Low Frequency Noise Vibration and Active Control
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The Examination of the Upper Layers of the Seabed by the Means of the Acoustic Methods
PublicationPropagation of acoustic waves in the sea, in particular in shallow sea, depends on several factors. The basic of them are source power and frequency of acoustic waves, spatial distribution inhomogeneous medium in which acoustic wave propagates, and distributions of speed of sound and density of seawater. The coastal conditions, which limit water medium from above (free surface of the sea) and from bottom (the seabed), are no less...
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A Model-Order Reduction Approach for Electromagnetic Problems With Nonaffine Frequency Dependence
PublicationThe aim of this paper is to present a novel model-order reduction (MOR) technique for the efcient frequency-domain nite-element method (FEM) simulation of microwave components. It is based on the standard reduced-basis method, but the subsequent expansion frequency points are selected following the so-called sparsied greedy strategy. This feature makes it especially useful to perform a fast-frequency sweep of problems that lead...
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Modelling and analysis of medium frequency transformers for power converters
PublicationThe evolutions in power systems and electric vehicles, related to the economic opportunities and the environmental issues, bring the need of high power galvanically isolated DC-DC converter. The medium frequency transformer (MFT) is one of its key components, enabled by the increasing switching frequency of modern power semiconductors like silicon carbide transistors or diodes. The increased operating frequency offers small...
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Antimony substituted lanthanum orthoniobate proton conductor – structure and electronic properties.
PublicationX‐ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X‐ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found...
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Automatic Optimization Of Adaptive Notch Filter’s Frequency Tracking
PublicationEstimation of instantaneous frequency of narrowband com- plex sinusoids is often performed using lightweight algo- rithms called adaptive notch filters. However, to reach high performance, these algorithms require careful tuning. The paper proposes a novel self-tuning layer for a recently intr o- ducedadaptive notch filtering algorithm. Analysis shows th at, under Gaussian random-walk type assumptions, the resultin g solution converges...
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Realistic noise-tolerant randomness amplification using finite number of devices
PublicationRandomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification...
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IT- enabled comparison of environmental noise levels and noise-evoked hearing impairments.
Publication[Abstrakt] Tematem pracy jest telemetryczny system monitorowania hałasu, opracowany w katedrze Systemów Multimedialnych Politechniki Gdańskiej, przeznaczony do zdalnego monitorowania poziomów hałasu środowiskowego. Oprócz ogólnej charakterystyki systemu zaprezentowano również szereg szczegółów implementacyjnych. Przedstawiono m.in. mobilne urządzenie pomiarowe, oprogramowanie do pomiarów hałasu, dźwiękowy interfejs USB wyposażony...
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IT- Enabled Comparison of Environmental Noise Levels and Noise-Evoked Hearing Impairments.
PublicationTematem pracy jest telemetryczny system monitorowania hałasu, opracowany w katedrze Systemów Multimedialnych Politechniki Gdańskiej, przeznaczony do zdalnego monitorowania poziomów hałasu środowiskowego. Oprócz ogólnej charakterystyki systemu zaprezentowano również szereg szczegółów implementacyjnych. Przedstawiono m.in. mobilne urządzenie pomiarowe, oprogramowanie do pomiarów hałasu, dźwiękowy interfejs USB wyposażony w mikrofon...
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Noise Scattering Patterns Method for Recognition of RTS Noise in Semiconductor Components
PublicationOpisano nową metodę identyfikacji i wizualizacji szumów RTS. Metoda ta oparta na graficznym przedstawieniu przebiegu szumowego jest szczególnie użyteczna do szybkiej selekcji elektronicznych elementów półprzewodnikowych. Przedstawiono także rezultaty filtacji medianowej szumu zawierającego składową RTS. Filtrację medianową zastosowano do poprawienia obrazu szumu uzyskanego w wyniku zastosowania metody NSP.
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Noise modeling of static CMOS gates for low-noise circuit synthesis
PublicationW artykule przedstawiono efektywną metodę modelowania widma szumu napięcia zasilającego generowanego przez statyczne bramki cyfrowe CMOS. Metoda modelowania uwzględnia krótkie impulsy prądowe powstające w czasie przełączania bramek i pozwala oszacować górne limity widma szumu napięcia zasilającego co umożliwia niskoszumową syntezę układów cyfrowych.
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Noise as stimulus signal for digital circuits noise immunity measurementand simulation
PublicationWyniki pomiarów podatności na zakłócenia układów cyfrowych istotnie zależą od parametrów sygnału stymulujacego. Przedstawiono metodę pomiaru i symulacji dynamicznej odporności na zakłócenia z zastosowaniem sygnału szumu białego o różnej szerokości pasma częstotliwości. Modele symulacyjne dla sygnału pobudzającego (gaussowskiego szumu białego) zarówno szerokopasmowego jak i wąskopasmowego opracowano w środowisku programistycznym...
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Determinants of the surface quality, density and dimensional correctness in selective laser melting of the Ti-13Zr-13Nb alloy
PublicationSelective laser melting is widely used for custom-designed elements. Successful manufacturing depends on laser treatment parameters and material features. This research aimed to determine the effects of laser power, scan time and hatch distance on surface quality, relative density and dimensional precision for cuboids made of the Ti-13Zr-13Nb alloy. The influence of energy density, energy flux and pre-heating was seen to be decisive...
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Frequency based criterion for distinguishing tonal and noisy spectral components
PublicationA frequency-based criterion for distinguishing tonal and noisy spectral components is proposed. For considered spectral local maximum two instantaneous frequency estimates are determined and the difference between them is used in order to verify whether component is noisy or tonal. Since one of the estimators was invented specially for this application its properties are deeply examined. The proposed criterion is applied to the...
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Investigating the current environmental situation in the Middle East and North Africa (MENA) region during the third wave of COVID-19 pandemic: urban vs. rural context
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Statistically efficient smoothing algorithm for time-varying frequency estimation
PublicationThe problem of extraction/elimination of a nonstationary sinusoidal signal from noisy measurements is considered. This problem is usually solved using adaptive notch filtering (ANF) algorithms. It is shown that the accuracy of frequency estimates can be significantly increased if the results obtained from ANF are backward-time filtered by an appropriately designed lowpass filter. The resulting adaptive notch smoothing (ANS) algorithm...