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Search results for: TIME SERIES ANALYSIS
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Error analysis for European IGS stations
PublicationEach of the GPS time series that describes the changes of topocentric components consists of a deterministic and a stochastic part, whose character influences the errors of the deterministic parameters. As to the uncertainties of reliable velocities of permanent satellite station systems, surveys that estimate and take into account any dependencies that may affect subsequent operational efficiency are very important. For this analysis,...
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Statistical Method for Analysis of Interactions Between Chosen Protein and Chondroitin Sulfate in an Aqueous Environment
PublicationWe present the statistical method to study the interaction between a chosen protein and another molecule (e.g., both being components of lubricin found in synovial fluid) in a water environment. The research is performed on the example of univariate time series of chosen features of the dynamics of mucin, which interact with chondroitin sulfate (4 and 6) in four different saline solutions. Our statistical approach is based on recurrence...
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Multidimensional GIS for satellite imagery analysis
PublicationMultidimensional Geographical Information System allows storing, querying and processing of multidimensional query data. It is able to process satellite imagery and provide tools for its analysis. In the article authors present the developed system that analyzes a time series of SENTINEL - 1 mission satellite imagery acquired over the coast of Poland. The algorithm used finds and detects changes in the shape...
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WIG rate of return histogram and normal distribution curve
Open Research DataThe conducted market analysis covered the period of stock exchange quotations from the beginning of 2010 to the end of 2019 (04/01/2010 - 30/12/2019). Daily data was used, in the form of closing prices of indices operating on the Warsaw Stock Exchange. In order to obtain a complete and generalized picture of the market, the quotations of 4 indices were...
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Chemometric analysis of rainwater and throughfall at several sites in Poland.
PublicationPróbki pobrano w stacjach w różnych rejonach Polski. Stacje te były umieszczone na terenach specjalnie chronionych (Wielkopolski Park Narodowy i Ojcowski Park Narodowy) oraz na niechronionych formacjach leśnych (leśnictwo Stara Piła). Celem badań było porównanie parametrów występujących w opadach atmosferycznych pod względem podobieństwa charakterystyki miejsca a także podobieństw i różnic związanych z przejściem wody opadowej...
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Signals features extraction in radioisotope liquid-gas flow measurements using wavelet analysis
PublicationKnowledge of the structure of a flow is significant for the proper conduct of a number of industrial processes. In this case, a description of a two-phase flow regimes is possible by use of the time-series analysis in time, frequency and state-space domain. In this article the Discrete Wavelet Transform (DWT) is applied for analysis of signals obtained for water-air flow using gamma ray absorption. The presented method was illustrated...
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Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring
PublicationThe main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University...
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Analytical solution of non-stationary heat conduction problem for two sliding layers with time-dependent friction conditions
PublicationIn this article we conduct an overview of various types of thermal contact conditions at the sliding interface. We formulate a problem of non-stationary heat conduction in two sliding layers with generalized thermal contact conditions allowing for dependence of the heat-generation coefficient and contact heat transfer coefficient on time. We then derive an analytical solution of the problem by constructing a special coordinate...
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A higher order transversely deformable shell-type spectral finite element for dynamic analysis of isotropic structures
PublicationThis paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various...
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Karol Flisikowski dr inż.
PeopleKarol Flisikowski works as Associate Professor at the Department of Statistics and Econometrics, Faculty of Management and Economics, Gdansk University of Technology. He is responsible for teaching descriptive and mathematical statistics (in Polish and English), as well as scientific research in the field of social statistics. He has been a participant in many national and international conferences, where he has presented the results...
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Investigation of long-range dependencies in the stochastic part of daily GPS solutions
PublicationThe long-range dependence (LRD) of the stochastic part of GPS-derived topocentric coordinates change (North, East, Up) results with relatively high autocorrelation values with a focus on self-similarity. One of the reasons for such self-similarity in the GPS time series are noises that are commonly recognised to prevail in the form of the flicker noise model. To prove the self-similarity of the stochastic part of GPS time series...
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Studies of the Interaction Dynamics in Albumin-Chondroitin Sulfate Systems by Recurrence Method
PublicationThe physicochemical basis of lubrication of articular cartilage is still not fully understood. However, the synergy between components of the synovial fluid can be a crucial factor that could explain this phenomenon. This work presents a nonlinear data analysis technique named the recurrence method, applied to the system involving two components of synovial fluid: albumin and chondroitin sulfate (CS) immersed in a water environment....
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MONITORING OF PERMANENT GPS STATIONS AT THE SUDETY MOUNTAINS
PublicationThe aim of this paper is to show time-dependent baseline variation between GPS stations situated in South-East Poland. This study was based on daily data analysis of selected GPS stations: WROC, GOPE, MOPI, KRAW and KATO. The start date of the analysis is linked at every station with the beginning of its operation and the closing date of the operation is in 2006. The multiresolution signal decomposition method has been used to...
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Magdalena Apollo dr inż.
People2017 - PhD in Civil Engineering, thesis: Risk management in construction investments related to urban regeneration projects, Gdansk University of Technology IX 2012–VI 2013 - Postgraduate Studies at Gdynia Maritime University: Research Project Management (IPMA D Certificate) 2010 – MSc in Management and Marketing, Gdansk University of Technology 2007 – MSc in Civil Engineering, Gdansk University of Technology 2007-2010 - structural...
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Frequency and phase analysis of daily reprocessed solutions from selected EPN stations relating to geological phenomena,
PublicationThe main assumption of this research was to check and verify the behaviour of a few EPN (European Permanent Network) stations on both sides of the Teisseyre-Tornquist zone (T-T zone), which is located on Polish territory and crosses Poland almost in half. The selected EPN stations’ time series were a subject of frequency and phase analysis. The main purpose of the research was to verify if there is any correspondence between stations...
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Analysis of the possibilities in railways shape assessing using GNSS mobile measurements
PublicationIn recent years, a dynamic development of satellite positioning techniques using both static and mobile GNSS coordinates register mode can be observed. In addition, still developing Real-time GNSS Networks, post-processing algorithms and another measurement signal analysis algorithms, make the satellite measurements increasingly used in railway industry sector. In the article the possibilities which follows from the mobile satellite...
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Electrostatic Zipping Actuators—Analysis of the Pull-In Effect Depending on the Geometry Parameters
PublicationContinuous work on a new generation of actuators, referred to as artificial muscles, resulted in the initiation of work on electrostatic zipping actuators, the concept of which is derived from micro electro-mechanical devices. Despite partial knowledge of their basic operating parameters, a question remains whether electrostatic zipping actuators are able to meet the expectations in the context of generated forces and control possibilities....
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GIS for processing multidimensional marine data in SAAS model
PublicationGeographic Information Systems (GIS) have always been a useful tool for visualization and processing of geospatial data. However, their capabilities of analysis non-standard information such as hydroacoustic soundings has thus far been very limited. This paper proposes a general-purpose GIS which uses techniques such as OLAP, WCS and WCPS for processing of multidimensional spatio-temporal data. The versatility of the GIS is exemplified...
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Development of cluster analysis methodology for identification of model rainfall hyetographs and its application at an urban precipitation field scale
PublicationDespite growing access to precipitation time series records at a high temporal scale, in hydrology, and particularly urban hydrology, engineers still design and model drainage systems using scenarios of rainfall temporal distributions predefined by means of model hyetographs. This creates the need for the availability of credible statistical methods for the development and verification of already locally applied model hyetographs....
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Analysis of road accident causes in the voivodships in the years 2014-2021 in the aspect of socio-economic costs – towards the implementation of sustainable development
PublicationThe article addresses the topic of road safety. The objective of the research was to assess road accidents caused by voivodships. The analysis took account of the socio-economic differences in the voivodships, which deter-mine the unit costs of fatalities and injuries. A descriptive analysis is given to show the dynamics of changes in the years 2014-2021 in the voivodships and how different factors influenced change. The article...
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Olgun Aydin dr
PeopleOlgun Aydin finished his PhD by publishing a thesis about Deep Neural Networks. He works as a Principal Machine Learning Engineer in Nike, and works as Assistant Professor in Gdansk University of Technology in Poland. Dr. Aydin is part of editorial board of "Journal of Artificial Intelligence and Data Science" Dr. Aydin served as Vice-Chairman of Why R? Foundation and is member of Polish Artificial Intelligence Society. Olgun is...
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Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements—First Tests Based on Transmission System Operator Data
PublicationThe Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim...
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A novel hybrid adaptive framework for support vector machine-based reliability analysis: A comparative study
PublicationThis study presents an innovative hybrid Adaptive Support Vector Machine - Monte Carlo Simulation (ASVM-MCS) framework for reliability analysis in complex engineering structures. These structures often involve highly nonlinear implicit functions, making traditional gradient-based first or second order reliability algorithms and Monte Carlo Simulation (MCS) time-consuming. The application of surrogate models has proven effective...
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Computing algebraic transfer entropy and coupling directions via transcripts
PublicationMost random processes studied in nonlinear time series analysis take values on sets endowed with a group structure, e.g., the real and rational numbers, and the integers. This fact allows to associate with each pair of group elements a third element, called their transcript, which is defined as the product of the second element in the pair times the first one. The transfer entropy of two such processes is called algebraic transfer...
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Spatio-temporal filtering for determination of common mode error in regional GNSS networks
PublicationThe spatial correlation between different stations for individual components in the regional GNSS networks seems to be significant. The mismodelling in satellite orbits, the Earth orientation parameters (EOP), largescale atmospheric effects or satellite antenna phase centre corrections can all cause the regionally correlated errors. This kind of GPS time series errors are referred to as common mode errors (CMEs). They are usually...
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15th Conference on Calorimetry and Thermal Analysis
EventsRegistration for the workshops with Sponsors, which will take place during the free time on Tuesday, September 10, 2024, from 2:30 PM, will be conducted by signing up on a list at the registration desk. We kindly inform you that posters should be prepared in size B1 (707 x 1000 mm). Templates:pptx, pdf Please submit your presentations...
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Michał Bernard Pietrzak dr hab.
PeopleMichal Pietrzak is head of the Department of Statistics and Econometrics at the Faculty of Economics and Management, Gdańsk University of Technology, and Deputy Editor-in-Chief for Statistical Reviewing of the journals: Oeconomia Copernicana and Equilibrium. Quarterly Journal of Economics and Economic Policy. Until October 2021, he worked as an associate professor at the Faculty of Economic Sciences and Management, Nicolaus...
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Horizontal velocity field derived from EPN and ASG-EUPOS satellite data on the example of south-western part of Poland
PublicationPresently the determination of the velocity field in the global reference frame is possible by using different space techniques and dense terrestrial networks from global to local and regional scales. However, the reliability of such determinations is strongly limited by the restricted number of unmodeled effects. Some of them are periodic (atmospheric or hydrological effects), some instantaneous (natural or man-made seismicity)...
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Persistent homology as a new method of the assessment of heart rate variability
PublicationHeart rate variability (hrv) is a physiological phenomenon of the variation in the length of the time interval between consecutive heartbeats. In many cases it could be an indicator of the development of pathological states. The classical approach to the analysis of hrv includes time domain methods and frequency domain methods. However, attempts are still being made to define new and more effective hrv assessment tools. Persistent...
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Impact of the Finite Element Mesh Structure on the Solution Accuracy of a Two-Dimensional Kinematic Wave Equation
PublicationThe paper presents the influence of the finite element mesh structure on the accuracy of the numerical solution of a two-dimensional linear kinematic wave equation. This equation was solved using a two-level scheme for time integration and a modified finite element method with triangular elements for space discretization. The accuracy analysis of the applied scheme was performed using a modified equation method for three different...
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Thermal utilization of meat and bone meals. Performance analysis in terms of drying process, pyrolysis and kinetics of volatiles combustion
PublicationA development of technology of thermal utilization requires a thorough knowledge of the physicochemical properties, as well as kinetics of combustion of volatiles and char. Due to waste management regulations the meat and bone meal (MBM) is regarded as biofuel constituting one of the alternatives to fossil fuels in the energy market. MBM is a heterogeneous material that may consist of several different fractions. The extensive...
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Marcin Kujawa dr hab. inż.
PeopleI have graduated from the Faculty of Civil Engineering, Gdańsk University of Technology (https://pg.edu.pl/en) in 1999. I received my M.Sc. degree in civil engineering structures with specialization in bridge structures. Next, in 2007, I received my doctoral degree in technical sciences under the supervision of professor Czesław Szymczak (Scopus Author ID: 6603993146) at the Faculty of Civil Engineering, Gdańsk University of Technology....
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Ontological Modeling for Contextual Data Describing Signals Obtained from Electrodermal Activity for Emotion Recognition and Analysis
PublicationMost of the research in the field of emotion recognition is based on datasets that contain data obtained during affective computing experiments. However, each dataset is described by different metadata, stored in various structures and formats. This research can be counted among those whose aim is to provide a structural and semantic pattern for affective computing datasets, which is an important step to solve the problem of data...
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Roofing Materials as Pollution Emiters - Concentration Changes During Runoff
PublicationThe influence of roofing material on concentration of pollutants in roof runoff waters and changes of pollution concentration in time were investigated. In field studies four roofing material types were taken into consideration - ceramic tile, bituminous membrane, asbestos tile and zinc sheeting. Samples were collected since November 2007 to March 2008, anions, cations, metals, PAHs, pesticides and PCB were determined. The existence...
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Photogrammetric and total station's measurement of compressed column's model
PublicationModelling studies continue to play an important role. One of such study is stress determination in the reinforcement bars of reinforced columns and determine column's axis deformation. The article presents measurements results of control points located on the model of reinforced concrete column. The column was compressed in few series till it's destruction. In this studies, photogrammetric method and total station measurements...
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Klasyfikacja sygnału EKG przy użyciu konwolucyjnych sieci neuronowych
PublicationAutomation and improvement of diagnostic process is a vital element of medicine development and patient’s condition self-control. For a long time different ECG signal classification methods exist and are successfully applied, nevertheless their accuracy is not always satisfying enough. The lack of identification of an existing abnormality, which is very similar to a normal heartbeat is the biggest issue - for example premature...
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Klasyfikacja sygnału EKG przy użyciu konwolucyjnych sieci neuronowych
PublicationAutomation and improvement of diagnostic process is a vital element of medicine development and patient’s condition self-control. For a long time different ECG signal classification methods exist and are successfully applied, nevertheless their accuracy is not always satisfying enough. The lack of identification of an existing abnormality, which is very similar to a normal heartbeat is the biggest issue - for example premature...
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Karol Grębowski dr inż.
PeopleKarol Grębowski (M.Sc.) works as an assistant at the Department of Technical Fundamentals of Architecture Design of the Faculty of Architecture at Gdansk University of Technology. His scientific research deals with dynamic phenomena occurring during the vibration of structures, bridges, and studies the design methodology of the elements forming passive protection system of the vehicles degraded by struck or explosion in the context...
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Cross-talk Between the Heart and Arteries in Older 65+ Adults
PublicationRegulatory synchronization between the heart and the arterial walls is essential for optimal blood delivery to tissues. We investigated functional coherence between heart rhythm and aortic wall compliance in 30 volunteers aged 65 – 74. ECG and carotid and iliac pulse-wave were recorded and digitized at 2 kHz. Carotid-femoral pulse-wave transit time (cfTT) which reflex aortic compliance was assessed using the intersecting tangent...
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A Regional ITRF Densification by Blending Permanent and Campaign Data — The CEGRN campaigns and the Central European Velocity Field
PublicationThe CERGOP Project of the Central European Countries initiated six GPS observation campaigns from 1994 to 2001. By the high standards set within this project for site selection, observation and analysis a consistent set of epoch solutions with a precision in the 3–5 mm range was created. The network contains about 19 permanent and 38 epoch stations. In this paper a first combination solution over the seven years with a velocity...
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Recurrence times in the Morse sets for a two-dimensional discrete neuron model (low resolution)
Open Research DataThis dataset contains selected results of rigorous numerical computations conducted in the framework of the research described in the paper “Topological-numerical analysis of a two-dimensional discrete neuron model” by Paweł Pilarczyk, Justyna Signerska-Rynkowska and Grzegorz Graff. A preprint of this paper is available at https://doi.org/10.48550/arXiv.2209.03443.
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Detection of Anomalies in the Operation of a Road Lighting System Based on Data from Smart Electricity Meters
PublicationSmart meters in road lighting systems create new opportunities for automatic diagnostics of undesirable phenomena such as lamp failures, schedule deviations, or energy theft from the power grid. Such a solution fits into the smart cities concept, where an adaptive lighting system creates new challenges with respect to the monitoring function. This article presents research results indicating the practical feasibility of real‐time...
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A headspace solid-phase microextraction method development and itsapplication in the determination of volatiles in honeys by gas chromatography
PublicationThe first part of the paper presents the detailed optimisation of all steps of the determination procedureof volatiles from Polish honeys by headspace solid-phase microextraction (HS-SPME) as the sample preparationmethod and gas chromatography/mass spectrometry (GC-MS) as the method of final determination.The methodology of semi-quantative analysis allowed the isolation and identification of volatile fractioncompounds from popular...
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Non-isolated resonant quasi-Z-source network DC–DC converter
PublicationA novel non-isolated resonant quasi-impedance (quasi-Z)-source network DC–DC converter is proposed. The resonant impedance source network is derived from the quasi-Z-source network by including the autotransformer-based resonant cell instead of the second inductor of the quasi-Z-network. The leakage inductance of the autotransformer and two resonant capacitors connected in series with the autotransformer windings constitute a high-frequency...
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Zbigniew Kaźmierczyk dr hab.
PeopleProf. Zbigniew Kaźmierczyk, PhD in Literature, associate professor in the Department of History of Literature at the Institute of Polish Language and Literature at the University of Gdańsk. He has displayed the Gnostic – Manichaean dimension of existence in Miłosz’s writings ('The Work of Demiurge', 2011) by applying the language of access to apocrypha of the religion of gnosis. He has gathered linguistic, historic, religious,...
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Experimental investigation of the weight averaging of pulse frequency modulated sensor output signal
Open Research DataThe research aims to practically verify the results of theoretical analysis and simulations of the efficiency of weight averaging of pulse frequency modulated signal. For this purpose, a suitable test stand was built, and the control software in the LabVIEW environment was prepared. Then, a series of experiments were carried out to process and analyze...
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Pounding mitigation of a short-span cable-stayed bridge using a new hybrid passive control system
PublicationThis paper investigates the effectiveness of a new hybrid passive control system on the seismic response of an existing steel cable-stayed bridge considering the pounding effect. The proposed hybrid passive control system comprises a seismic isolator and a metallic damper. The bridge is located in a high seismic zone and has suffered several damages including the earthquake-induced pounding damage during the 1988 earthquake....
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Change of reaction quotients for SOFC fueled by biogas mixture at 750 C
Open Research DataThe dataset contains the Change of reaction quotients for SOFC fueled by biogas mixture at 750 C (60:40 CH4:CO2). The outlet concentration of the gases from SOFC were measured using novel FTIR-based unit.
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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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Chemical composition analysis of the LSNO ceramics
Open Research DataThe chemical composition of a series of La-Sb-Nb-O ceramics manufactured by the solid-phase reaction method was analyzed. The samples with a various antimony content were measured by XPS method (OmicronNanotechnology UHV system). Analysis confirmed presence of elements: La, Sb, Nb.