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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part II: Gas-chromatography–mass spectrometry analysis
PublicationFlavouring compounds are an essential part of e-liquid products for cigarettes. In general, they are regarded as safe for ingestion, but they may have unrecognized risks when they are inhaled. In some cases, manufactures do not currently abide by the Tobacco Products Directive (2014/40/EU) and do not declare the detailed contents of e-liquids on their labels. To help evaluate the health impact of flavouring substances, there is...
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Influence of hydrochloric acid concentration and type of nitrogen source on the electrochemical performance of TiO2/N-MoS2 for energy storage applications
PublicationIn this work, nitrogen-doped molybdenum sulfide was directly deposited on titanium dioxide nanotubes substrate (TiO2/N-MoS2) during hydrothermal synthesis. The study focuses on the influence of hydrochloric acid concentration used for the synthesis, with the results indicating its essential role in thioacetamide hydrolysis and thus in the effectiveness of the N-MoS2 deposition. The electrode material itself is characterized by...
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Report for the Short Term Scientific Mission within COST Action FP1101: development of the in-field sensor for estimation of fracture toughness and shear strength by measuring cutting forces
PublicationKnowledge on the fracture properties of materials is essential to assure structural integrity and proper design of mechanical connections in timber constructions. Measurement of this property is, however, a very challenging task. The linear fracture mechanics is usually used for its assessment assisted with experimental data acquired by means of various techniques, usually of destructive nature. The cutting force is an energetic...
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Rapid ion-exchange matrix removal for a decrease of detection limits in the analysis of salt-rich reservoir waters for fluorobenzoic acids by liquid chromatography coupled with tandem mass spectrometry
PublicationA matrix removal procedure with ion-exchange resin prior to analysis for 18 fluorinated benzoic acids (FBAs) tracers in saline (>25% salt) reservoir water was optimized. The elimination of >98% of salt and the simultaneous matrix sample cleanup allowed the direct analysis using the supernatant by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This resulted in a gain in detection limits for most of the tracers...
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Hardware-Software Implementation of Basic Principles Simulator of Nuclear Reactor Processes
PublicationThe paper presents implementation process of basic principle simulators of a nuclear reactor processes. Simulators are based on point-models of processes: kinetics of neutrons, heat generation and exchange, poisoning and burning-up nuclear fuel. Reference simulator was developed in MATLAB/Simulink without taking into account real-time operation. Second simulator was built using the toolbox xPC with hard real-time requirements....
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Using Minimum Actuators to Control Shape and Stress of a Double Layer Spherical Model Under Gravity and Lateral Loadings
PublicationSpherical domes are picturesque structures built in developed countries to attract tourists. Due to horizontal and vertical overloading, the structures’ attractive shapes may be disturbed, and some members' stress may exceed the elastic level. In this paper, the shape and stress of a deformed double-layer spherical numerical model due to simultaneous lateral and vertical loadings are controlled, meanwhile, the number of actuators...
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Automatic localization and continous tracking of mobile sound source using passive acoustic radar
PublicationA concept, practical realization and applications of the passive acoustic radar for localization and continuous tracking of fixed and mobile sound sources such as: cars, trucks, aircrafts and sources of shooting, explosions were presented in the paper. The device consists of the new kind of multi-channel miniature three dimensional sound intensity sensors invented by the Microflown company and a group of digital signal processing...
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Broken Rotor Symptons in the Sensorless Control of Induction Machine
PublicationInverter fed sensorless controlled variable speed drives with induction machine are widely used in the industry applications, also in wind power generation and electric vehicles. On-line self diagnostic systems implementation is needed for early stage fault detection and avoiding a critical fault. Diagnostic algorithms in modern DSP-based controllers can operate simultaneously with control system functions. In the closed-loop controlled...
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THE VIBRATION BASED DIAGNOSTICS OF SHIP PROPULSION SYSTEMS
PublicationThe article has been worked out on the basis of the report devoted to the conducted diagnostic investigations of the ship main propulsion unit’s mechanical system. Gdansk University of Technology has been ordered with such investigations by the repair Shipyard carrying out the ship’s overhaul. Diagnostic tests involved measurements and analyses of the vibration signals generated in selected constructional kinematic pairs of the...
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Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency
PublicationPial artery adjustments to changes in blood pressure (BP)may last only seconds in humans. Using a novelmethod called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of...
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Fault diagnosing system of wheeled tractors
PublicationA defect of complex wheeled tractor assembles most frequently negative influence on exploitation efficiency, safety and exhaust gases emission. Structure complexity of wheeled tractors requires more and more advanced diagnostic methods for identification of their serviceable possibilities as well in manufacturing step as in exploitation. In classical diagnosing methods of wheeled tractor defects states mapping by measured diagnostic...
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Analysis of Lombard speech using parameterization and the objective quality indicators in noise conditions
PublicationThe aim of the work is to analyze Lombard speech effect in recordings and then modify the speech signal in order to obtain an increase in the improvement of objective speech quality indicators after mixing the useful signal with noise or with an interfering signal. The modifications made to the signal are based on the characteristics of the Lombard speech, and in particular on the effect of increasing the fundamental frequency...
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Wczesne wykrywanie spoofingu GNSS typu carry-off
PublicationW referacie przedstawiono klasyfikację ataków typu spoofing ukierunkowanych na odbiorniki satelitarnych systemów nawigacyjnych GNSS. W szczególności opisano zaawansowaną formę spoofingu w wariancie tzw. carry-off, polegającym na płynnym przejęciu kontroli nad blokami śledzenia sygnałów w zakłócanym odbiorniku. Sposób realizacji takiego ataku istotnie utrudnia jego wykrycie z użyciem metod dotychczas proponowanych w literaturze....
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POPRAWA OBIEKTYWNYCH WSKAŹNIKÓW JAKOŚCI MOWY W WARUNKACH HAŁASU
PublicationCelem pracy jest modyfikacja sygnału mowy, aby uzyskać zwiększenie poprawy obiektywnych wskaźników jakości mowy po zmiksowaniu sygnału użytecznego z szumem bądź z sygnałem zakłócającym. Wykonane modyfikacje sygnału bazują na cechach mowy lombardzkiej, a w szczególności na efekcie podniesienia częstotliwości podstawowej F0. Sesja nagraniowa obejmowała zestawy słów i zdań w języku polskim, nagrane w warunkach ciszy, jak również w...
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Sounding of Layered Marine Bottom - Model Investigations
PublicationThe necessary actions connected with interpretations of examining of physical properties of sea bottom structure is developing of proper procedure of modeling of the layered structure. The implementation of the acoustic waves for the determination of seabed stratification requires a precise diagnosis of the topic from both the theoretical and practical side. Little differences between the parameters of sediments, as well as irregular...
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Monitoring of absorptive model biogas purification process using sensor matrices and gas chromatography
PublicationThis study examined the process of purifying model biogas using a new type of absorbent based on a Deep Eutectic Solvent (DES) and a commercially available absorbent (Genosorb) to remove acetone, toluene, and cyclohexane. The main aim of the research was to control the purification efficiency using gas chromatography (GC) and an alternative method based on sensor matrices (SM). As a result of comparing the multidimensional SM signals...
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QUASI-DISTRIBUTED NETWORK OF LOW-COHERENCE FIBER-OPTIC FABRY-PÉROT SENSORS WITH CAVITY LENGTH-BASED ADDRESSING
PublicationDistributed measurement often relies on sensor networks. In this paper, we present the construction of low coherent fiber-optic Fabry-Pérot sensors connected into a quasi-distributed network. We discuss the mechanism of spectrum modulation in this type of sensor and the constraints of assembly of such sensors in the network. Particular attention was paid to separate the signals from individual sensors, which can be achieved by...
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Analysis of the Capability of Deep Learning Algorithms for EEG-based Brain-Computer Interface Implementation
PublicationMachine learning models have received significant attention for their exceptional performance in classifying electroencephalography (EEG) data. They have proven to be highly effective in extracting intricate patterns and features from the raw signal data, thereby contributing to their success in EEG classification tasks. In this study, we explore the possibilities of utilizing contemporary machine learning algorithms in decoding...
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Measurement of Impulse Response of Shallow Water Communication Channel by Correlation Method
PublicationPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission...
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Selective monitoring of noise emitted by vehicles involved in road traffic
PublicationAn acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound...
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Modelling of Longitudinal Elastic Wave Propagation in a Steel Rod Using the Discrete Element Method
PublicationThe paper deals with the issue of modelling elastic wave propagation using the discrete element method (DEM). The case of a longitudinal wave in a rod with a circular cross-section was considered. A novel, complex algorithm consisting of the preparation of models and simulation of elastic waves was developed. A series of DEM models were prepared for simulations, differing in discretisation and material parameters. Additional calculations...
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Subjective and Objective Comparative Study of DAB+ Broadcast System
PublicationBroadcasting services seek to optimize their use of bandwidth in order to maximize user’s quality of experience. They aim to transmit high-quality digital speech and music signals at the lowest bitrate. They intend to offer the best quality under available conditions. Due to bandwidth limitations, audio quality is in conflict with the number of transmitted radio programs. This paper analyzes whether the quality of real-time digital...
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The role of analytical chemistry in the study of the Anthropocene
PublicationThe term “Anthropocene” refers to not yet formalized epoch of geologic time during which geologic processes have been dominated by the human impact. This impact takes on many forms. Biological, physical and chemical changes to the Earth System caused by anthropogenic activity are recorded in natural archives either as new fossil assemblages (neobiota), anthropogenic deposits or a wide variety of pollutants emitted to the environment....
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Approach for Determination of Functioning of Lower Limb Muscles
PublicationThe purpose of the study is elaboration of approach for determination of functioning of chosen muscles that are essential for gait performance (Tibialis Anterior, Rectus Femoris, Gastrocnemius Medialis, Biceps Femoris). The scope of the study involves the analysis of the symmetric planar motion performing in the sagittal plane of the body by applying planar multibody model and electromyography signals (EMG) registered over normal...
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Application of the Barkhausen effect probe with adjustable m agnetic field direction for stress state determination in the P91 ste el pipe
PublicationThe paper presents the results of application of a novel Barkhausen effect (BE) probe with adjustable magnetizing field direction for the stress level evaluation in ferromagnetic materials. The investigated sample was in a form of a pipe, made of P91 steel that was anisotropic due to the production process. The measurements were performed before and after welding, revealing the influence of welding process on the residual stress...
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Real and Virtual Instruments in Machine Learning – Training and Comparison of Classification Results
PublicationThe continuous growth of the computing power of processors, as well as the fact that computational clusters can be created from combined machines, allows for increasing the complexity of algorithms that can be trained. The process, however, requires expanding the basis of the training sets. One of the main obstacles in music classification is the lack of high-quality, real-life recording database for every instrument with a variety...
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Signal Reconstruction from Sparse Measurements Using Compressive Sensing Technique
PublicationThe paper presents the possibility of applying a new class ofmathematical methods, known as Compressive Sensing (CS) for recovering thesignal from a small set of measured samples. CS allows the faithful recon-struction of the original signal back from fewer random measurements bymaking use of some non-linear reconstruction techniques. Since of all thesefeatures, CSfinds its applications especially in the areas where, sensing is...
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Impact of surface skin temperature change on blood flow characteristics in palm
PublicationHeating a human palm during 3 minutes period causes changes in superficial skin temperature and leads to thermoregulation system response. The response time and level of flow characteristics change depend on the subject hand size and health of his vascular tree. A solution of Pennes bioheat propagation model was analyzed in order to see how much heat has to be transferred into the tissue to extort the observable reaction. The reflective...
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Angle Tracking Observer for Filtering Rotor Position Estimates in Sensorless Electric Drives
PublicationSensorless electric drives use measurements of electrical quantities to estimate rotor position and speed. Measurement errors deteriorate the estimation accuracy, thus additional means are necessary to remove high-frequency components from estimated signals. This paper proposes to use an Angle Tracking Observer (ATO) for reducing noise in rotor position estimates, which is related to random errors in the measurements. A simplified,...
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Loudness Scaling Test Based on Categorical Perception
PublicationThe main goal of this research study is focused on creating a method for loudness scaling based on categorical perception. Its main features, such as: way of testing, calibration procedure for securing reliable results, employing natural test stimuli, etc., are described in the paper and assessed against a procedure that uses 1/2-octave bands of noise (LGOB) for the loudness growth estimation. The Mann-Whitney U-test is employed...
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Detection, classification and localization of acoustic events in the presence of background noise for acoustic surveillance of hazardous situations
PublicationEvaluation of sound event detection, classification and localization of hazardous acoustic events in the presence of background noise of different types and changing intensities is presented. The methods for discerning between the events being in focus and the acoustic background are introduced. The classifier, based on a Support Vector Machine algorithm, is described. The set of features and samples used for the training of the...
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In uence of Low-Level Features Extracted from Rhythmic and Harmonic Sections on Music Genre Classi cation
PublicationWe present a comprehensive evaluation of the infuence of 'harmonic' and rhythmic sections contained in an audio file on automatic music genre classi cation. The study is performed using the ISMIS database composed of music files, which are represented by vectors of acoustic parameters describing low-level music features. Non-negative Matrix Factorization serves for blind separation of instrument components. Rhythmic components...
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Improving listeners' experience for movie playback through enhancing dialogue clarity in soundtracks
PublicationThis paper presents a method for improving users' quality of experience through processing of movie soundtracks. The dialogue clarity enhancement algorithms were introduced for detecting dialogue in movie soundtrack mixes and then for amplifying the dialogue components. The front channel signals (left, right, center) are analyzed in the frequency domain. The selected partials in the center channel signal, which yield high disparity...
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Ultrasonic Tomography of Brick Columns Based on FEM Calculations
PublicationUltrasonic tomography is one of the most developed method of non-destructive testing. Despite being used mainly in medicine, it is becoming more and more popular as a method for monitoring of structural elements. It allows to examine the internal structure and technical condition of the tested element. This paper investigates the influence of crosssectional geometry on an obtained tomographic image. Wave propagation signals were...
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Soft-decision schemes for radar estimation of elevation at low grazing angles
PublicationIn modern radars, the problem of estimating elevation angle at low grazing angles is typically solved using superresolution techniques. These techniques often require one to provide an estimate of the number of waveforms impinging the array, which one can accomplish using model selection techniques. In this paper, we investigate the performance of an alternative approach, based on the Bayesian-like model averaging. The Bayesian...
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Simulation of Direct-Sequence Spread Spectrum Data Transmission System for Reliable Underwater Acoustic Communications
PublicationUnderwater acoustic communication (UAC) system designers tend to transmit as much information as possible, per unit of time, at as low as possible error rate. It is a particularly difficult task in a shallow underwater channel in which the signal suffers from strong time dispersion due to multipath propagation and refraction phenomena. The direct-sequence spread spectrum technique (DSSS) applied successfully in the latest standards...
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Intra-subject class-incremental deep learning approach for EEG-based imagined speech recognition
PublicationBrain–computer interfaces (BCIs) aim to decode brain signals and transform them into commands for device operation. The present study aimed to decode the brain activity during imagined speech. The BCI must identify imagined words within a given vocabulary and thus perform the requested action. A possible scenario when using this approach is the gradual addition of new words to the vocabulary using incremental learning methods....
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Czynniki kształtujące środowisko pacjenta w szpitalu
PublicationSzpital jest miejscem szczególnym – z założenia przebywają w nim osoby, znajdujące się w sytuacji niekomfortowej. Możliwości adaptacji w nowym środowisku u osób chorych, osłabionych lub osób z niepełnosprawnościami są znacząco obniżone, a przecież szpital należy do budynków o najbardziej skomplikowanej strukturze funkcjonalno-przestrzennej. Stan emocjonalny pacjenta w środowisku szpitalnym jest uzależniony od relacji z lekarzami...
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Kinematyczne pomiary GNSS na linii kolei wąskotorowej w Koszalinie
PublicationW artykule opisano metodę kinematycznych pomiarów geodezyjnych GNSS zastosowaną dla inwentaryzacji trasy kolejowej w terenie silnie zalesionym. W badaniach wskazano możliwości wykorzystania tej metody dla inwentaryzacji układu geometrycznego trasy kolei wąskotorowej w Koszalinie. Opisano najważniejsze różnice pomiędzy koleją o rozstawie szyn 1000 mm a 1435 mm oraz przyszłościowe zagadnienie planowanej rewitalizacji tego odcinka....
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Information retrieval with semantic memory model
PublicationPsycholinguistic theories of semantic memory form the basis of understanding of natural language concepts. These theories are used here as an inspiration for implementing a computational model of semantic memory in the form of semantic network. Combining this network with a vector-based object-relation-feature value representation of concepts that includes also weights for confidence and support, allows for recognition of concepts...
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Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland
PublicationKlebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended-spectrum beta-lactamases (ESBLs). Metallo-β-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates...
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KM Challenges in Small KIBS Companies: Multi-case Analysis in Two Countries
PublicationKnowledge Intensive Business Services (KIBS) – i.e. companies like e.g. computer services, consulting, engineering, business communication, and R&D support - are key players in the modern economies. They stimulate the innovativeness of businesses and societies. Their competitiveness is based on knowledge, which is their key production factor and also the kind of “goods” they sell. The large majority of KIBS companies have a small...
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Optimal Design of Transmitarray Antennas via Low-Cost Surrogate Modelling
PublicationOver the recent years, reflectarrays and transmitarrays have been drawing a considerable attention due to their attractive features, including a possibility of realizing high gain and pencil-like radiation patterns without the employment of complex feeding networks. Among the two, transmitarrays seem to be superior over reflectarrays in terms of achieving high radiation efficiency without the feed blockage. Notwithstanding, the...
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Unveiling the Pool of Metallophores in Native Environments and Correlation with Their Potential Producers
PublicationFor many organisms, metallophores are essential biogenic ligands that ensure metal scavenging and acquisition from their environment. Their identification is challenging in highly organic matter rich environments like peatlands due to low solubilization and metal scarcity and high matrix complexity. In contrast to common approaches based on sample modification by spiking of metal isotope tags, we have developed a two-dimensional...
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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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Cost‐efficient performance‐driven modelling of multi‐band antennas by variable‐fidelity electromagnetic simulations and customized space mapping
PublicationElectromagnetic (EM) simulations have become an indispensable tool in the design of contemporary antennas. EM‐driven tasks, for example, parametric optimization, entail considerable computational efforts, which may be reduced by employing surrogate models. Yet, data‐driven modelling of antenna characteristics is largely hindered by the curse of dimensionality. This may be addressed using the recently reported domain‐confinement...
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Psychosocial risks associated with the profession of train driver
PublicationExcellent competencies as well as a good physical and mental health are required in train drivers’ profession. Despite the changes in the structure of employment the train drivers above 46 years and job tenure longer than 30 years are the largest group. The generation gap is becoming more pronounced, and its fulfilment will not be easy. It is related not only to training of new personnel but also promotion of healthy work environment...
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Pedestrian detection in low-resolution thermal images
PublicationOver one million people die in car accidents worldwide each year. A solution that will be able to reduce situations in which pedestrian safety is at risk has been sought for a long time. One of the techniques for detecting pedestrians on the road is the use of artificial intelligence in connection with thermal imaging. The purpose of this work was to design a system to assist the safety of people and car intelligence with the use...
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Functioning and legal regulations of perpetual usufruct right in Poland in relation to similar rights in other countries of the European Union
Publication1 May 2004, Poland became part of the European Union, which main aim is the political, economic and social integration of democratic European countries as well as the construction of a common market ensuring of persons, goods, services and capital move freely. The Accession Treaty provides some transitional periods for the adjustment of the right of Member States to the EU regulations. Next year, 12 years after joining the EU,...
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AUTOMATED SYSTEM FOR FLUCTUATION ENHANCED GAS SENSING
PublicationResistance gas sensors exhibit random phenomena (resistance noise) which can be utilized to improve gas sensitivity and selectivity. That new emerging technique has to be investigated to recognize optimal parameters for gas detection. It means that a measurement system has to have ability of numerous parameters adjustment (e.g., sampling frequency, heater voltage, polarization current, voltage noise amplification). That fact induced...