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Search results for: SONAR EQUIPMENT , NAVIGATION , MATHEMATICAL MODEL , ACOUSTIC WAVES , UNDERWATER VEHICLES , DOPPLER SHIFT
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A study on microcrack monitoring in concrete: discrete element method simulations of acoustic emission for non-destructive diagnostics
PublicationThe research is focused on the monitoring of fracture evolution in concrete beams under three-point bending using the acoustic emission technique and the discrete element method. The main objective of the study was to numerically and experimentally investigate the mechanism behind the generation of elastic waves during acoustic emission events and their interaction with micro- and macro-cracking in concrete beams under monotonic...
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Intelligent Autonomous Vehicles
PublicationAdvanced mobile vehicles and robots have long been one of the main issues in engineering. They have various applications in emergency, lifeguarding and entertainment as well as in various industrial, civil and military systems. Among them, you can distinguish robots that can move in an open environment or operate only in predetermined confined spaces. Open world robots are very demanding because they have...
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Measurements of acoustic crosstalk cancellation efficiency in mobile listening conditions
PublicationThe cancellation of acoustic crosstalk is employed to enhance the stereo image in mobile listening conditions. The implementation of the crosstalk cancellation algorithm in Matlab is introduced. The measurement signals and equipment are described. A practical setup employing a mobile computer and a head and torso simulator is employed. The results of the measurements provided conclusions regarding the employment of acoustic crosstalk...
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Mathematical Modeling of Hydrodynamics in Bioreactor by Means of CFD-Based Compartment Model
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Surface finite viscoelasticity and surface anti-plane waves
PublicationWe introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are...
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublicationThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...
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Review of Selected Methods for Prediction of Added Resistance in Following Waves
PublicationThe added resistance in waves is a mean value of non-linear, second order reaction of a ship to incoming waves. In the beginning of the 20th century, the experimental methods for investigation of ship hydrodynamics at model scale were developed. They allowed the evaluation of added resistance by measurements in irregular waves (directly) or by measurements in regular waves (in-direct method). The main goal was to find more precise...
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Seaport equipment and facilities. An offer for today, an investment for the future
PublicationIn order to meet customers' requirements and to adapt to the changing market, producers of port equipment try to provide more and more automated solutions containing future-oriented options.
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Spirometry measurement model - the diagnostic purpose support
Publicationthe paper presents a new model of respiratory mechanism based on the spirometry measurements. the spirometry test assesses the efficiency of the lung ventilation. the respiratory system functioning is based on the ventilation mechanism. thus the quality of the lung depends on the quality of lung ventilation. modelling of the respiratory system supports a diagnostic process. the model parameter estimates are obtained on the basis...
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Magnetic signatures of land vehicles
PublicationThe results of numerical simulations of the magnetic field surrounding of land vehicles' models have been presented in this paper. Vehicle containing of ferromagnetic elements distorts the Earth's magnetic field. This distortion can be measured by magnetometers. It is possible to detect and identify an object on the basis of its magnetic signature.
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Research on GNSS satellite navigation systems
PublicationThis article contains results of research on two GNSS systems, i.e. GPS and GLONASS. Architectures, signal structures and navigation messages of both systems have been described. Some selected investigation results, concerning receiver performance in presence of interference, have been presented.
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Mathematical analysis of transformer insulation state by means of composite indicator
PublicationThe paper is presenting mathematical model – composite indicator (CI), which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.
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Time series of Doppler blood flow recordings
Open Research DataVital signals registration plays a grate role in biomedical engineering and education process. Well acquired data allow future engineers to observe certain physical phenomenons as well learn how to correctly process and interpret the data. This data set was designed for students to learn about Doppler phenomena and to demonstrate correctly and incorrectly...
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Eugeniusz Kozaczka prof. dr hab. inż.
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Combined method of multibeam sonar signal processing and image analysis for seafloor classification
PublicationThe combined approach to seafloor characterisation was investigated. It relies on calculation of several descriptors (parameters) related to seabed type using three types of multibeam sonar data obtained during seafloor sensing: 1) the grey-level sonar images (echograms) of seabed, 2) the 3D model of the seabed surface which consists of bathymetric data, 3) the set of time domain bottom echo envelopes received in the consecutive...
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Dynamic risk assessment in autonomous vehicles motion planning
PublicationArguing that an autonomous mobile system is sufficiently safe to operate in presence of other vehicles and objects is an important element in development of such systems. Traditional approach to assure safety is to distinguish between safe and unsafe area and prevent the autonomous vehicle from entering the unsafe area. The paper presents a model of autonomous vehicle control system which uses risk assessment...
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Estimation of the Regenerative Braking Process Efficiency in Electric Vehicles
PublicationIn electric and hybrid vehicles, it is possible to recover energy from the braking process and reuse it to drive the vehicle using the batteries installed on-board. In the conditions of city traffic, the energy dissipated in the braking process constitutes a very large share of the total resistance to vehicle motion. Efficient use of the energy from the braking process enables a significant reduction of fuel and electricity consumption...
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Designing acoustic scattering elements using machine learning methods
PublicationIn the process of the design and correction of room acoustic properties, it is often necessary to select the appropriate type of acoustic treatment devices and make decisions regarding their size, geometry, and location of the devices inside the room under the treatment process. The goal of this doctoral dissertation is to develop and validate a mathematical model that allows predicting the effects of the application of the scattering...
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Remote Sensing in Vessel Detection and Navigation
PublicationThe Special Issue (SI) “Remote Sensing in Vessel Detection and Navigation” highlighted a variety of topics related to remote sensing with navigational sensors. The sequence of articles included in this Special Issue is in line with the latest scientific trends. The latest developments in science, including artificial intelligence, were used. The 15 papers (from 23 submitted) were published.
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Cast iron in the 19th-century building equipment
PublicationCast iron is a material, characteristics of which enable to receive extremely artistic elements. It maintains good strength properties at the same time. That combination of these seemingly contrary traits makes it a commodity that was widely used in the 19th century industry and architecture. These usages were not only as decorative elements, technical and structural ones. The production of new household utilities started, which...
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LOW NOISE TIRES FOR HYBRID AND ELECTRIC VEHICLES
PublicationLow Emission Vehicles that are hybrid and electric cars may benefit from specially designed tires that are optimized for driving conditions typical for such vehicles. It is possible that in the future Low Emission Vehicles, especially passenger cars, will substitute conventional vehicles in all applications, however for the time being they are mostly used in urban and suburban areas. Urban traffic has a rather low demand for grip...
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Reliability model of the crankshaft-piston assembly
PublicationThe laws that govern the durability of crankshaft-piston assembly friction nodes can be proved or at least derived or justified in an intuitive way. Operation of all the friction nodes is disturbed by external factors occurring with randomly changing intensity and also appearing at random. As the crankshaft-piston assembly friction nodes have a series structure and effects of those disturbances accumulate, their fitness for use...
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Analysis of distance measurement errors in CW FM sonar with MLS code modulation
PublicationAlthough used in the classic silent sonar, the CW FM sounding signal has a major flaw which is its inaccuracy in determining the distance to a target. The authors of the article have developed a concept of silent sonar using frequency modulation signals switched by pseudorandom codes, already discussed in their previous work. This article presents a detailed analysis of errors in CW FM sonar with pseudo-random sequence code modulation...
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Mathematical Modelling in Diagnosis of Wastewater Treatment Plant
PublicationThe paper reports development of mathematical modeling in diagnosis of the WWTP. The algorithm is based on a comparition of data from the mathematical modeling and measurments of real datefrom WWTP, until it will detect any malfunction of the sensors in th case of study.
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Efficiency of acoustic heating in the Maxwell fluid
PublicationThe nonlinear effects of sound in a fluid describing by the Maxwell model of the viscous stress tensor is the subject of investigation. Among other, viscoelastic biological media belong to this non-newtonian type of fluids. Generation of heating of the medium caused by nonlinear transfer of acoustic energy, is discussed in details. The governing equation of acoustic heating is derived by means of the special linear combination...
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Research and development on underwater acoustic systems at Polish Naval Academy and Gdansk University of Technology for the Polish Navy
PublicationWe wstępie artykułu wymieniono korzystne aspekty prawie pięćdziesięcioletniej współpracy obu Uczelni z polską Marynarką Wojenną. W dalszych częściach omówiono prace z dziedziny hydroakustyki wykonywane na rzecz Marynarki Wojennej w ciągu ostatnich dziesięciu lat. W Akademii MW w tym okresie były to głównie prace związane z pomiarami i analizami hydroakustycznych pól okrętów wraz z aplikacjami technicznymi tych analiz oraz aplikacje...
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A Quality Model for UML tools
PublicationJakość narzędzi UML wpływa na efektywność wykonywania zadań związanych z modelowaniem systemów w procesie wytwarzania oprogramowania. Celem badań prezentowanych w tym referacie jest wyodrębnienie kryteriów jakości narzędzi UML. Omówiono rolę narzędzi UML w projekcie informatycznym, a następnie zaprezentowano szereg kryteriów jakości narzędzi UML wraz z aspektami oceny oraz opisem ankiety, która służy do oceny narzędzi względem...
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The elasto-viscoplstic Chaboche model
PublicationW artykule przedstawiono rozwoj i numeryczną aplikacje sprężysto-lepkoplastycznego modelu Chabocha. Przedstawione są także szczegółowe opisy kilkunastu wariantów modelu Chaboche'a wraz z parametrami materiałowymi.
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DETERMINATION OF ADDITIONAL TENSION IN TOWED STREAMER CABLE TRIGGERED BY COLLISION WITH UNDERWATER MOVING OBJECT
PublicationThe paper deals with issues connected with the behaviour of a streamer cable towed by a survey seismic vessel when the cable undergoes a strike triggered by collision with an underwater moving object. The consequences of such collisions may be both threat to the life of marine animals or damage to underwater units and large economic losses suffered by vessel owners. The risk of such collisions has increased over the last years...
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Comparison of perforator location in dynamic and static thermographic imaging with Doppler ultrasound in breast reconstruction surgery
PublicationThis paper co mpares the effectiveness of the dTnorm and t90_10 parametrizations in dynamic thermography for imaging location of perforators in TRAM flaps in the intraoperative period. The results were compared with the location detected in a Doppler ultrasound examination. Cold and heat stimulation was used in dynamic thermography. Additionally, these results were compared with static...
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Action-reaction based synthesis of acoustic wavefield equations
PublicationThe analysis of acoustic fields is usually based on the well-known mathematics of second order partial differential equations called wave equations. The author explores the duality and symmetry of linear fluid mechanics and develops two distinct equations of acoustics on the basis of a causal approach to local small-scale phenomena. Wavefields that are solutions of these equations have different composition, the spherical pressure...
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MEAN SHIFT BASED SEGMENTATION FOR BLEEDING REGIONS IN ENDOSCOPIC VIDEOS
PublicationWith a set of 38 manually marked bleeding regions form endoscopic videos, the authors attempted to find an optimal image segmentation method for reproducing doctor’s markup. Mean shift segmentation combined with HSV histogram segmentation were used as a segmentation method, which was then optimized by tuning the parameters of the method using global optimization algorithm. A target function for measuring the quality of segmentation was...
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Safety assurance strategies for autonomous vehicles
PublicationAssuring safety of autonomous vehicles requires that the vehicle control system can perceive the situation in the environment and react to actions of other entities. One approach to vehicle safety assurance is based on the assumption that hazardous sequences of events should be identified during hazard analysis and then some means of hazard avoidance and mitigation, like barriers, should be designed and implemented. Another approach...
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Autonomous (systems) vehicles control
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Comparative Analysis of Unmanned Aerial Vehicles Used in Photogrammetric Surveys
PublicationThere are many manufacturers on the market offering various types of Unmanned Aerial Vehicles (UAV). The multitude of drones available on the market means that the choice of a UAV for a specific application appears to be a decision problem to be solved. The aim of this article is a comparative analysis of drones used in photogrammetric surveys. The criteria for evaluating the UAVs were: availability and product support, payload...
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Victor Eremeev prof. dr hab.
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Problem of proper decomposition and initialization of acoustic and entropy modes in a gas affected by the mass force
PublicationThe relations connecting perturbations specific for acoustic and entropy modes in an accelerated fluid or in a fluid affected by constant mass force, are derived. They allow to decompose the total vector of perturbations and the overall energy into acoustic and non-acoustic parts uniquely at any instant. In order to do this, three quantities are required, for example total perturbations in entropy, pressure and velocity. The evaluations...
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Triangular 3D Laser Scanning in Underwater Photogrammetry
PublicationThe use of triangular 3D laser scanning may significantly enhance the visual inspection of underwater objects. In these days of high demand for accurate information, exclusively photographic documentation is not enough, as it is geometrically flawed. The authors of this article are trying to present the rudiments of laser scanning, a modern means of measuring, which is reliable, relatively easy to use and works in accordance with...
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TDOA Navigation Using CDMA2000 Signals – Experimental Results
PublicationThis 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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Methods of navigation in the mobile application supporting movement of the blind
PublicationThis paper presents conclusions from the last development phase of the “Voice Maps” project. Authors specify newly found available options for navigation in affordable system for the blind with all their related aspects. System uses dedicated geographical data, built-in smartphone GPS receivers and DGPS external device in order to assist blind users in their everyday travelling. Authors also discuss new methods to improve positioning...
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On the peculiarities of anti-plane surface waves propagation for media with microstructured coating
PublicationWe discuss new type of surface waves which exist in elastic media with surface energy. Here we present the model of a coating made of polymeric brush. From the physical point of view the considered model of surface elasticity describes a highly anisotropic surface coating. Here the surface energy model could be treated as 2D reduced strain gradient continuum as surface strain energy depends on few second spatial derivatives of...
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Time frequency representation of Doppler boold flow recordings
Open Research DataVital signals registration plays a grate role in biomedical engineering and education process. Well acquired data allow future engineers to observe certain physical phenomenons as well learn how to correctly process and interpret the data. This data set was designed for students to learn about Doppler phenomena and to demonstrate correctly and incorrectly...
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RESEARCH ON ORGANIC COATINGS DESIGNED FOR UNDERWATER APPLICATIONS
PublicationUnderwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and...
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Mathematical Modelling of a Seismic Isolation System to Protect Structures During Damaging Earthquakes
PublicationThe present study aims to determine the effectiveness of a nonlinear mathematical model in simulating complex mechanical behaviour of a seismic isolation system to protect structures during strong and damaging earthquakes. In order to construct the Polymeric Bearings considered in this research, a specially prepared flexible polyurethane elastomer with increased damping properties has been used. The usefulness of the proposed mathematical...
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Detection of Water on Road Surface with Acoustic Vector Sensor
PublicationThis paper presents a new approach to detecting the presence of water on a road surface, employing an acoustic vector sensor. The proposed method is based on sound intensity analysis in the frequency domain. Acoustic events, representing road vehicles, are detected in the sound intensity signals. The direction of the incoming sound is calculated for the individual spectral components of the intensity signal, and the components...
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The Empirical Application of Automotive 3D Radar Sensor for Target Detection for an Autonomous Surface Vehicle’s Navigation
PublicationAvoiding collisions with other objects is one of the most basic safety tasks undertaken in the operation of floating vehicles. Addressing this challenge is essential, especially during unmanned vehicle navigation processes in autonomous missions. This paper provides an empirical analysis of the surface target detection possibilities in a water environment, which can be used for the future development of tracking and anti-collision...
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Usage of the Gstreamer framework for generation, analysis, processing and visualization of sonar signal
PublicationIn this paper a novel method of the bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of the bearing estimation based on the spatial spectrum is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. The usage of this method leads to the precise bearing estimation. The proposed method requires a relatively small amount...
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On Anti-Plane Surface Waves Considering Highly Anisotropic Surface Elasticity Constitutive Relations
PublicationWithin 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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Application of PL-Grid Platform for Modeling of the Selected Acoustic Phenomena
PublicationDomain 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...