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Search results for: UNDERWATER ACOUSTIC CLIMATE
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Estimating Traffic Intensity Employing Passive Acoustic Radar and Enhanced Microwave Doppler Radar Sensor
PublicationInnovative road signs that can autonomously display the speed limit in cases where the trac situation requires it are under development. The autonomous road sign contains many types of sensors, of which the subject of interest in this article is the Doppler sensor that we have improved and the constructed and calibrated acoustic probe. An algorithm for performing vehicle detection and tracking, as well as vehicle speed measurement,...
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Te use of acoustic emission for assessment of the oil lubricity in a four-ball tester
Publicationin view of the increased dynamic and temperature load in the compression-ignition engine tribological systems, particular attention is drawn to the problem of such lubrication of the friction nodes that after breaking the boundary layer it could be restored without any wear occurring. therefore, an idea has been devised of introducing to friction nodes, with the lubrication oils, of new substances (operational preparations) modifying...
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Thermal Self-Action Effects of Acoustic Beam in a Gas with Reversible or Irreversible Chemical Reaction
PublicationThermal self-action of acoustic beam in a gas where an exothermic chemical reaction takes place, is studied. This kind of thermal self-action differs from that in a newtonian fluid. In dependence on the type of a chemical reaction, reversible or not, heating or cooling of a medium occurs. A beam in the case of the irreversible reaction may be unusually self-focusing. The self-action effects relating to wave beams containing shock...
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A Time Delay Controller Included Terminal Sliding Mode and Fuzzy Gain Tuning for Underwater Vehicle-Manipulator Systems
PublicationAn improved Time Delay Control (TDC) method for an Underwater Vehicle-Manipulator System (UVMS) is proposed. The proposed controller consists of three terms: a time-delay-estimation term that cancels nonlinearities of the UVMS dynamics, a Terminal Sliding Mode (TSM) term that provides a fast response and a PID term that reduces the tracking error. In addition the proposed controller uses fuzzy rules to adaptively tune the gains...
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Application of unmanned USV surface and AUV underwater maritime platforms for the monitoring of offshore structures at sea
PublicationThe operation of offshore structures at sea requires the implementation of advanced systems for their permanent monitoring. There is a set of novel technologies that could be implemented to deliver a higher level of effective and safe operation of these systems. A possible novel solution may be the application of a new maritime unmanned (USV) surface and underwater vehicles/platforms (AUV). Application of such vehicles/platforms...
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3D Object Shape Reconstruction from Underwater Multibeam Data and Over Ground Lidar Scanning
PublicationThe technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation,...
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Gaze-tracking and acoustic vector sensors technologies for PTZ camera steering and acoustic event detection
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On the theory and numerical simulation of acoustic and heat modes interaction in a liquid with bubbles: acoustic quasi-solitons
PublicationTeoria rzutowania zaburzenia ogólnego na mody. Zastosowanie metody do badań układu równań typu Korteweg`a-de Vries`a. Rozwiązania analityczne i simulacje numeryczne.
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Analysis of Roughness, the Material Removal Rate, and the Acoustic Emission Signal Obtained in Flat Grinding Processes
PublicationIn this work, the analysis of the acoustic emission (AE) signal in grinding processes is addressed. The proposed analysis method decomposes the acoustic signal into three frequency ranges. The total energy of each range is determined, as well as the highest frequency. Different grinding experiments were carried out, according to a full factorial design of experiments (DOE), in which feed speed, depth of cut, and transversal step...
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Codesigned Digital Tools for Social Engagement in Climate Change Mitigation
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A global atmospheric electricity monitoring network for climate and geophysical research
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Assessment of the Water Needs of Fruit Plants in the Perspective of Climate Change
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Side Fins Performance in Biomimetic Unmanned Underwater Vehicle
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Low-Cost Underwater Communication System: A Pilot Study
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The analysis of hydrodynamic forces and shape of towrope for an underwater vehicle
PublicationOpisano metodę obliczania sił hydrodynamicznych oraz kształtu liny holującej pojazd podwodny pod wpływem sił indukowanych przez opływ wody wokół liny i pojazdu. Siły indukowane na linie obliczane są za pomocą równania Morison'a, natomiast siły i momenty na kadłubie pojazdu za pomocą współczynników sił hydrodynamicznych, zależnych od kątów natarcia i prękości holowania pojazdu. Przykłady obliczeń dla pojazdu podwodnego zostały wykonane...
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Underwater robot actuated by shape memory alloy wires
PublicationW pracy przedstawiono koncepcję projektu robota podwodnego z napędem wykorzystującym materiały SMA ze stopów z pamięcią kształtu. Rozpatrywany układ ma budowę modułową złożoną z segmentów na podobieństwo do anatomicznej budowy dżdżownicy. Pojedyńczy segment składa się z dwóch okrągłych tarcz, pomiędzy którymi umieszczono balon wypełniony wodą. Wielkość balonu jest dopasowana w taki sposób do rozmiarów tarcz oraz długości sprężyn...
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The analysis of the system towing rope with long underwater object
PublicationW artykule zawarta jest analiza zestawu złożonego z liny holującej i długiego obiektu podwodnego o małej sprężystości.Sformułowane zagadnienie brzegowe rozwiązywane jest iteracyjnie z zastosowaniem metody elementów skończonych. Z warunków brzegowych znany jest punkt zaczepienia liny holującej na okręcie oraz głębokość na jaką zanurza się koniec holowanego obiektu. Rozwiązanie tego zagadnienia doprowadziło do równań źle uwarunkowanych...
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Adaptation of telecommunication modem techniques for underwater communication systems.
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Acoustic evaluation of road surfaces using different Close Proximity testing devices
PublicationAccording to the valid standard, Close Proximity (CPX) method intends to evaluate the influence of road surfaces on traffic noise. Measurements may be carried out with the use of a self-powered vehicle or a special test trailer equipped with testing tyre towed by another vehicle. Two different testing devices took part in the research organized in Poland in order to determine the ranking of road surfaces in terms of acoustic parameters....
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Measurement of Seafloor Acoustic Backscatter Angular Dependence at 150 kHz Using a Multibeam Echosounder
PublicationAcoustic seafloor measurements with multibeam echosounders (MBESs) are currently often used for submarine habitat mapping, but the MBESs are usually not acoustically calibrated for backscattering strength (BBS) and cannot be used to infer absolute seafloor angular dependence. We present a study outlining the calibration and showing absolute backscattering strength values measured at a frequency of 150 kHz at around 10–20 m water...
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Application of acoustic emission for detection of fatigue microdemage in main and crank bearings for diesel engines
PublicationThe article presents reasons for applying the acoustic emission (AE) to detect fatigue microdamage in main bearings and crank bearings of ship main engines. Problem of determination of the fatigue life for slide bearing bushes was characterized in general. There were demonstrated properties of the objects of research, which were bushings made of the MB58 alloy, as well as an overall description of the research. It was shown that...
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Analysis and assessment of the acoustic emission suitability for determination of the energy states of a tribological system in the form of a four-ball tester friction node
PublicationThe present operating safety and cost reduction requirements of the compression ignition engines make it necessary to search for new methods of detecting their defects, e.g. by the analysis of acoustic emission signals coming from the slide bearings. The paper presents non-destructive measurements of acoustic emission (AE) in order to obtain information on the processes taking place in a tribological system under the continuously...
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Archaeologia Maritima Mediterranea. An International Journal on Underwater Archaeology
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Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublicationResults of a study to examine a unique idea of self-levitating journal bearing are presented in this paper. the idea represents a radical departure from the current bearing technology. it utilisesacoustic levitation, which relies on the sound energy radiated by an object supporting a load. acoustic levitation has been demonstrated to support loads of up to 10 kg. in order to support a load theacoustic wave emitted by the radiating...
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Effective method of treatment of industrial effluents under basic pH conditions using acoustic cavitation – a comprehensive comparison with hydrodynamic cavitation processes
PublicationThe use of acoustic cavitation in advanced oxidation processes (AOPs) is a promising trend in research for treatment of industrial effluents. The paper presents the results of investigations on the use of acoustic cavitation aided by additional oxidation processes (ozonation/H2O2 oxidation/Peroxone/UV-C) for the treatment of effluents from the production of bitumens. Under these conditions, the total contaminant load, expressed...
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Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
PublicationIn 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved...
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Selected acoustic images of the Gdansk Bay
PublicationThe main goal of the paper is to describe the results of sounding the Gdansk Bay seabed by using a parametric sub-bottom profiler, multibeam echosounder and side scan sonar. Quality of dsata obtained during trials depends interalia on a proper location of antenna to reduce influence of pitch, roll and heave motions as well as ship noise.
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Diver Observations by Means of Acoustic Methods
PublicationSearching for objects, especially small ones, moving under water near its the free surface, is always not an easy task. Designing tools for the detection of such targets is a real challenge when the possibility of a terrorist attack is a real threat. This paper presents some aspects of diver detection by means of acoustics methods, both active (side scan sonar) and passive ones (linear receiving antenna). This approach is quite...
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The reflected wave caused by acoustic pulses.
PublicationPowstanie fali przeciwnego kierunku w odnoszeniu do dominującej fali akustycznej w przepływach lepkich nieliniowych przeanalizowane. Równania kierujące powstaniem fali odbicia i odpowiednie wykresy przedstawione.
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Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
PublicationA procedure of calibration of a custom 3D acoustic vector sensor (AVS) for the purpose of direction of arrival (DoA) estimation, is presented and validated in the paper. AVS devices working on a p-p principle may be constructed from standard pressure sensors and a signal processing system. However, in order to ensure accurate DoA estimation, each sensor needs to be calibrated. The proposed algorithm divides the calibration process...
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Enhanced voice user interface employing spatial filtration of signals from acoustic vector sensor
PublicationSpatial filtration of sound is introduced to enhance speech recognition accuracy in noisy conditions. An acoustic vector sensor (AVS) is employed. The signals from the AVS probe are processed in order to attenuate the surrounding noise. As a result the signal to noise ratio is increased. An experiment is featured in which speech signals are disturbed by babble noise. The signals before and after spatial filtration are processed...
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Mechanical and structural behavior of high-strength low-alloy steel pad welded by underwater wet welding conditions
PublicationThe aim of the paper was to determine the metallurgical and mechanical behaviors of a high-strength low-alloy (HSLA) steel pad-welded specimen used in the structures of industrial and naval parts. Then to predict the metallurgical consequences (nature of the phases present) and the mechanical properties (hardness and impact strength) of the pad-welded steel obtained by underwater wet welding with different heat input values. The...
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Trees as a solar control measure for southern-oriented street frontages. Analysis of a selected street model for a humid continental climate
PublicationThe present study is aimed at the analysis of possibilities for shading southern frontage of street oriented along the E-W axis by the single row of trees, parallel to the southern elevations. The effectiveness of solar control shading was tested depending on the geometric relationships between trees and buildings. Numerical simulation analyses were conducted in Rhinoceros® program for the street located in humid continental climate...
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Panel obywatelski z perspektywy obserwatora – przypadek Warszawskiego Panelu Klimatycznego - Citizen Assembly from observer perspective – case of Warsaw Climate Assembly
PublicationPanele obywatelskie są coraz częściej stosowanym w polskich miastach instrumentem demokratycznym. Przykładem tej deliberacyjnej fali był Warszawski Panel Obywatelski, który odbył się jesienią 2020 r. Autor artykułu pełnił rolę obserwatora przy WPK i miał okazję zapoznać się dokładnie z przebiegiem panelu i jego pracami. Praca obejmuje ana-lizę pięciu kluczowych aspektów dla funkcjonowania panelu obywatelskiego, tzn. dobór tematu,...
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Development of a new generation of unmanned surface and underwater vehicles using the advanced technologies and achievements towards the application of control systems by the artificial intelligence AI.
PublicationThe operation of offshore structures at sea requires implementation of the advanced systems of permanent monitoring of work of such the installations. Novel solutions concerning such the systems should be associated with application of unmanned maritime surface and underwater platforms. The unmanned maritime platforms are and will be based on application of the newest achievements of some important technologies. Between these technologies...
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Climate Challenges and Financial Institutions: An Overview of the Polish Banking Sector’s Practices
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Wind wave climate of west Spitsbergen: seasonal variability and extreme events
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Tropospheric thermal field variability over Poland in the context of climate change
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Nitrogen pathways during sewage treatment in constructed wetlands in temporary climate
PublicationThe objectives of this paper is to estimate the role and quantity of the unit process responsible for removal or/and retention of nitrogen in different types of constructed wetlands in vegetation season and outside vegetation season. To estimate the role of the plant two objects inhabited one with willow and the other with reed were selected to assessment. Among anthers it was indicated that the concentrations of contamination...
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Carbon dioxide ocean and ground storage as a method of climate change mitigation
PublicationW pracy dokonano krytycznego przeglądu negatywnego wpływu globalnego ocieplenia na środowisko i przedstawiono dwie nowatorskie metody zmniejszenia stężenia atmosferycznego ditlenku węgla. Obie metody: magazynowanie antropogenicznego ditlenku węgla, pochodzącego z dużych źródeł emisji, w oceanach i w glebie są technologicznie możliwe do przeprowadzenia, co potwierdzają przykłady z różnych regionów świata. W pracy przedyskutowano...
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Efficiency of pollutant removal by five multistage constructed wetlands in a temperate climate
PublicationIn recent years, an increase in interest in hybrid constructed wetland systems (HCWs) has beenobserved. These systems are composed of two or more filters with different modes of sewage flow.Based on over eight years of monitoring, carried out at five local HCWs located in the PomeraniaRegion of Northern Poland, the effective removal of organic matter (from 74.9 to 95.5% COD) in theloading range 1.5-17.0 g COD·m-2·d-1 was confirmed....
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Geographic information system for remote integration of diverse under-water acoustic sensor data
PublicationMaritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriateesponse strategies is especially important in the case of semi-enclosed basins like the Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents...
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Pursuing Analytically the Influence of Hearing Aid Use on Auditory Perception in Various Acoustic Situations
PublicationThe paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken...
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Journal of Water and Climate Change
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Advances in Climate Change Research
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npj Climate and Atmospheric Science
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Carbon and Climate Law Review
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Current Climate Change Reports
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Digital Signal Processing for Hydroacoustic System in Biomimetic Underwater Vehicle
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Investigation of the underwater noise produced by ships by means of intensity method
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