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total: 700
Search results for: GNSS TOMOGRAPHY
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Seabed Topography Changes in the Sopot Pier Zone in 2010–2018 Influenced by Tombolo Phenomenon
PublicationBathymetric surveys of the same body of water, performed at regular intervals, apart from updating the geospatial information used to create paper and electronic maps, allow for several additional analyses, including an evaluation of geomorphological changes occurring in the coastal zone. This research is particularly important in places where the shape of the coastal zone has been violently disturbed, including by human activity....
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Thermal Tomography in Medicine. 9th European Congress of Thermology, Kraków, 29.05-01.06.2003. Tomografia termiczna w medycynie.
PublicationArtykuł prezentuje możliwości zastosowań techniki tomografii termicznej w aplikacjach medycznych. Dyskutowane są możliwości i ograniczenia prezentowanej metody w odniesieniu do organizmów żywych.
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Soft Tissue Retraction Maneuver in Cone Beam Computed Tomography Prior to Crown-Lengthening Procedure—A Technical Note
PublicationBackground: An accurate determination of the biological width and the relationship of the cemento-enamel junction with the border of the alveolar bone is crucial during a clinical crown-lengthening (CCL) procedure. The aim of this study was to present a technical note about the retraction techniques in cone beam computed tomography (CBCT) prior to CCL, highlighting the significant enhancement in procedural accuracy and predictability...
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Abdominal Aortic Aneurysm segmentation from contrast-enhanced computed tomography angiography using deep convolutional networks
PublicationOne of the most common imaging methods for diagnosing an abdominal aortic aneurysm, and an endoleak detection is computed tomography angiography. In this paper, we address the problem of aorta and thrombus semantic segmentation, what is a mandatory step to estimate aortic aneurysm diameter. Three end-to-end convolutional neural networks were trained and evaluated. Finally, we proposed an ensemble of deep neural networks with underlying...
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Prędkość uzyskania rozwiązania fazowego GNSS w kontekście wykorzystania aktywnych sieci geodezyjnych do precyzyjnego monitorowania pojazdów
PublicationOddanie do użytku, w 2008 roku, państwowej aktywnej sieci geodezyjnej ASG-EUPOS, która obszarem działania pokrywa cały obszar kraju, oraz w kolejnych latach regionalnych sieci komercyjnych, spowodowało lawinowy wzrost aplikacji precyzyjnych pomiarów fazowych GNSS. Na chwilę obecną głównymi beneficjentami są geodeci. Szybkość i prostota uzyskania współrzędnych punktu z centymetrową dokładnością sprawiła, że zestawy do sieciowych...
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Porównanie wyników pomiarów mas ziemnych wykonanych metodą skaningu laserowego i GNSS w kontekście inwestycji komunikacyjnych
PublicationPomiary objętości mas ziemnych to jeden z etapów związanych z robotami ziemnymi wynikającymi z planowania i prowadzenia inwestycji na danym obszarze. W przypadku inwestycji drogowych i kolejowych są szczególnie istotne, gdyż dąży się do zbilansowania robót ziemnych. Ważny jest także aspekt logistyczny – taki jak masowe przewozy materiałów sypkich (np. żwir). Zarówno przed jak i po wykonaniu robót ziemnych, niezbędny jest pomiar...
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Analysis of GNSS sensed precipitable water vapour and tropospheric gradients during the derecho event in Poland of 11th August 2017
PublicationNowadays, one of the techniques that meets the increasing requirements of meteorologist in terms of monitoring of severe weather events is global navigation satellite systems (GNSS), which can provide information about the tropospheric state independently of the weather conditions and even in real time. In this paper we present the usage of GNSS sensed tropospheric data to monitor sudden and intense weather events. Our analyses...
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Determining the Seasonal Variability of the Territorial Sea Baseline in Poland (2018–2020) Using Integrated USV/GNSS/SBES Measurements
PublicationThe Territorial Sea Baseline (TSB) allows coastal states to define the maritime boundaries, such as: contiguous zone, continental shelf, exclusive economic zone and territorial sea. Their delimitations determine what rights (jurisdiction and sovereignty) a given coastal state is entitled to. For many years, the problem of delimiting baseline was considered in two aspects: legal (lack of clear-cut regulations and different interpretations)...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
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Application of image processing methods for the characterization of selected features and wear analysis in surface topography measurements
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Evaluation of the Surface Topography of Ti6Al4V Alloy after the Finish Turning Process under Ecological Conditions
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Fracture Surface Topography Parameters for S235JR Steel Adhesive Joints After Fatigue Shear Testing
PublicationThis paper presents the experimental results of a study investigating the effect of holes and notches made on the overlap ends on the strength of adhesive joints. Single-lap joints made of S235JR steel sheets bonded with Araldite 2024-2 epoxy adhesive were tested. For comparative reasons, static shear strength tests and high-cycle fatigue strength tests were performed. Adhesive-filled joints having three holes, each with a diameter...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublicationThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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Laser-textured cross-hatched surface topography analysis with evaluation of high-frequency measurement noise
PublicationThe precision of surface roughness determination using ISO 25178 parameters relies on various factors that directly impact the measurement process. In industry applications, the contactless roughness measurement reduces data collection time. However, it introduces several potential errors, including those stemming from the environment. One of the main types of errors encountered during topography analysis is measurement noise,...
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An optimized controlled rate slow cooling protocol for bovine ovarian tissue cryopreservation by means of X-ray computed tomography
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Bimodal Nd-Doped LuVO4 Nanoprobes Functionalized with Polyacrilic Acid for X-Ray Computed Tomography and NIR Luminescent Imaging
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Microstructure–Property Relationship of Polyurethane Foams Modified with Baltic Sea Biomass: Microcomputed Tomography vs. Scanning Electron Microscopy
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Microstructure–Property Relationship of Polyurethane Foams Modified with Baltic Sea Biomass: Microcomputed Tomography vs. Scanning Electron Microscopy
PublicationIn this paper, novel rigid polyurethane foams modified with Baltic Sea biomass were compared with traditional petro-based polyurethane foam as reference sample. A special attention was focused on complex studies of microstructure, which was visualized and measured in 3D with high-resolution microcomputed tomography (microCT) and, as commonly applied for this purpose, scanning electron microscopy (SEM). The impact of pore volume,...
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Tropospheric delays derived from GNSS observations during the derecho event in Poland of 11th August 2017
Open Research DataPropagation of global navigation satellite systems (GNSS) radio signals is disturbed by the current state of the Earth's atmosphere. For this reason, advances processing of GNSS signals can be used for investigation of the atmospheric condition. In case of troposphere, the GNSS signals allow for obtain information of tropospheric delay, which is mainly...
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Dostępność poprawek sieciowych w pomiarach GNSS/RTN na Zatoce Gdańskiej, w kontekście określania parametrów ruchu statku
PublicationW niniejszym artykule przedstawiono wyniki badań dotyczących dostępności poprawek sieciowych RTN (z ang. Real Time Network) w pomiarach GNSS realizowanych na obszarze Zatoki Gdańskiej. Ich celem było oszacowanie możliwości praktycznego zastosowania precyzyjnych pomiarów satelitarnych, z wykorzystaniem aktywnych sieci geodezyjnych, do określania parametrów ruchu statków. Ponieważ wstępna analiza wykazała, że z trzech funkcjonujących...
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Testing the positioning accuracy of GNSS solutions during the tramway track mobile satellite measurements in diverse urban signal reception conditions
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Investigation of some magnetospheric phenomena of geomagnetic storm on March 17, 2013 based on observations from GNSS and NOAA-15 satellite
PublicationSubstantial variations of magnetospheric electron fluxes of low and intermediate energies at an altitude of ~ 800 km at different phases of the geomagnetic storm were investigated. The ionosphere and plasmasphere response was analyzed using TEC variation maps over the Central Europe. A concept of the connection of TEC variations above the Central Europe and spatially inhomogeneous fluxes of energetic particles is being proposed.
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Assessment of the Steering Precision of a Hydrographic USV along Sounding Profiles Using a High-Precision GNSS RTK Receiver Supported Autopilot
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Testing the Positioning Accuracy of GNSS Solutions during the Tramway Track Mobile Satellite Measurements in Diverse Urban Signal Reception Conditions
PublicationMobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which...
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Effect of exercise training on insulin sensitivity, mitochondria and computed tomography muscle attenuation in overweight women with and without polycystic ovary syndrome
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Mitigation effect of face shield to reduce SARS-CoV-2 airborne transmission risk: Preliminary simulations based on computed tomography
PublicationWe aimed to develop a model to quantitatively assess the potential effectiveness of face shield (visor) in reducing airborne transmission risk of the novel coronavirus SARS-CoV-2 during the current COVID-19 pandemic using the computational fluid dynamics (CFD) method. The studies with and without face shield in both an infected and healthy person have been considered in indoor environment simulation. In addition to the influence...
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The effect of impacted third molars on second molar external root resorption, a cross-sectional cone beam computed tomography study
PublicationBackground: Third molars have the highest prevalence of impaction in teeth and can cause pathological damage on the adjacent second molars. This study aims to evaluate the effects of factors related to impacted third molars on external root resorption (ERR) in adjacent second molars using cone-beam computed tomography (CBCT). Material and Methods: In CBCTs, the effect of impacted third molars on the root surface of adjacent second...
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Selection of material for X-ray tomography analysis and DEM simulations: comparison between granular materials of biological and non-biological origins
PublicationPhysical properties and X-ray tomography images of five different granular materials: glass bead, glass grit, short grain white rice, sorghum and clay granules (Seramis) are investigated to select the most promising materials for numerical simulations and time-lapse X-ray tomography imaging. The examined materials represent granular materials of non-biological origin (glass bead, glass grit and Seramis) and granular plant materials...
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Mitigation effect of face shield to reduce SARS-CoV-2 airborne transmission risk: Preliminary simulations based on computed tomography
PublicationWe aimed to develop a model to quantitatively assess the potential effectiveness of face shield (visor) in reducing airborne transmission risk of the novel coronavirus SARS-CoV-2 during the current COVID-19 pandemic using the computational fluid dynamics (CFD) method. The studies with and without face shield in both an infected and healthy person have been considered in indoor environment simulation. In addition to the influence...
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Investigations of porosity changes during granular silo flow using Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV)
PublicationArtykuł omawia pomiary zmian porowatości podczas przepływu silosowego materiału granulowanego. Zastosowano 2 techniki: tomografie i optoelektroniczną DIC. Pomiary wykonano dla różnych początkowych zagęszczeń oraz szorstkości ścian.
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Suppression of the High-Frequency Errors in Surface Topography Measurements Based on Comparison of Various Spline Filtering Methods
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Formation of Surface Topography During Turning of AISI 1045 Steel Considering the Type of Cutting Edge Coating
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Evaluation of Surface Topography after Face Turning of CoCr Alloys Fabricated by Casting and Selective Laser Melting
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Topography measurement methods evaluation for entire bending-fatigued fracture surfaces of specimens obtained by explosive welding
PublicationIn this paper, the methods of compensation of differences in the results of entire bending-fatigued fracture surface topographies were presented. The roughness evaluation was performed with a focus variation microscope and confocal surface topography measurement techniques. The differences in the ISO 25178 roughness parameters were investigated and procedures for their compensation were studied. It was found that various types...
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JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY
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Wizyjna metoda oceny przemieszczeń poprzecznych mobilnych systemów GNSS i INS w procesie wyznaczania trajektorii osi toru kolejowego
PublicationW referacie przedstawiono metodę pomiaru przemieszczeń poprzecznych kolejowej platformy zawierającej systemy pomiarowe GNSS, INS, MLS oraz fotogrametryczny. Do pomiaru przemieszczeń poprzecznych zastosowano system fotogrametryczny składający się z kamer wizyjnych, oświetlaczy, kontrolera systemu pomiarowego, oraz oprogramowania do akwizycji plików. Zaprezentowano algorytm przetwarzania plików rastrowych w celu pomiaru przemieszczeń....
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Methodology for the Correction of the Spatial Orientation Angles of the Unmanned Aerial Vehicle Using Real Time GNSS, a Shoreline Image and an Electronic Navigational Chart
PublicationUndoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical...
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Wave propagation signals for ultrasonic tomography of concrete during splitting
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete cube with dimensions 70 x 70 x 70 cm3under the splitting test. Three cubes were tested: cube 1 (concrete with polymer fibres), cube 2 (concrete with steel fibres) and cube 3 (plain concrete).
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The topography of various sialoliths by scanning electron microscopy
Open Research DataThis dataset contains SEM micrographs taken for salivary gland stones (sialolith) extracted during joint studies between the Medical University of Gdansk and Gdansk University of Technology. Three different types of stones were examined, as discussed in the article: 10.1111/odi.13708
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Morphometric evaluation of the delayed cerebral arteries response to acetazolamide test in patients with chronic carotid artery stenosis using computed tomography angiography
PublicationBackground: The evidence accumulates that the response to acetazolamide test is delayed on the ipsilateral side to stenosis. However, the effect of acetazolamide beyond 30 minutes after acetazolamide administration remains unknown. The aim of this study was to assess the diameters of: anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) before and 60 minutes after the acetazolamide...
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Reconstructing human impact on peatland development during the past 200 years in CE Europe through biotic proxies and X-ray tomography
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Performance evaluation of an improved optical computed tomography polymer gel dosimeter system for 3D dose verification of static and dynamic phantom deliveries
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Concept of an Innovative System for Dimensioning and Predicting Changes in the Coastal Zone Topography Using UAVs and USVs (4DBatMap System)
PublicationThis publication is aimed at developing a concept of an innovative system for dimensioning and predicting changes in the coastal zone topography using Unmanned Aerial Vehicles (UAVs) and Unmanned Surface Vehicles (USVs). The 4DBatMap system will consist of four components: 1. Measurement data acquisition module. Bathymetric and photogrammetric measurements will be carried out with a specific frequency in the coastal zone using...
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Combining X-ray tomogrpahy imaging and DEM simulations to investigate granular material flow during silo discharging
PublicationEven after few decades of research, the study of particle motion taking place during silo discharging hasn’t been fully addressed, both experimentally and numerically, because of nontrivial behaviors that occur during associated flow patterns. For instance, discrete element method (DEM) has shown good qualitative prediction potential of velocity profile, but, on the other hand, frequently failed to match quantitatively experimental...
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Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
PublicationThis paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods...
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Diurnal variability of atmospheric water vapour, precipitation and cloud top temperature across the global tropics derived from satellite observations and GNSS technique
PublicationThe diurnal cycle of convection plays an important role in clouds and water vapour distribution across the global tropics. In this study, we utilize integrated moisture derived from the global navigation satellite system (GNSS), satellite precipitation estimates from TRMM and merged infrared dataset to investigate links between variability in tropospheric moisture, clouds development and precipitation at a diurnal time scale. Over...
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Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublicationThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...
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A fractographic study exploring the fracture surface topography of S355J2 steel after pseudo-random bending-torsion fatigue tests
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The Effect of Surface Topography Feature Size Density and Distribution on the Results of a Data Processing and Parameters Calculation with a Comparison of Regular Methods
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Fracture surface topography measurements analysis of low-alloyed corrosion resistant steel after bending-torsion fatigue tests
PublicationIn this paper, an assessment of a topography measurement method for fracture surfaces of 10HNAP steel after bending-torsion fatigue tests was performed. Surface roughness was measured by using a non-contact Focus Variation Microscopy (FVM) technique in which the non-measured points (NMPs) and outliers (spikes) were removed by the application of general methods. The results revealed, that the optical measurement method introduced...