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Wyniki wyszukiwania dla: high position frequency sampling
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A detector of sleep disorders for using at home
PublikacjaObstructive sleep apnea usually requires all-ni ght examination in a specialized clinic, under the supervision of a medical staff. Because of those requirements it is an expensive and a non-widely utilized test. Moving the examination procedure to patients’ home with automatic analysis algorithms involved will decrease the costs and make it available for larger group of patients. The developed device allows all-night recordings...
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Fracture surface topography measurements analysis of low-alloyed corrosion resistant steel after bending-torsion fatigue tests
PublikacjaIn 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...
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Independent dynamics of slow, intermediate, and fast intracranial EEG spectral activities during human memory formation
PublikacjaA wide spectrum of brain rhythms are engaged throughout the human cortex in cognitive functions. How the rhythms of various low and high frequencies are spatiotemporally coordinated across the human brain during memory processing is inconclusive. They can either be coordinated together across a wide range of the frequency spectrum or induced in specific bands. We used a large dataset of human intracranial electroencephalography...
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Low-Profile Interdigitated UHF RFID Tag Antenna for Metallic Objects
PublikacjaThis article presents a novel miniature interdigitated ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna that can be placed on metallic objects. The tag structure comprises two horizontal strip lines, each loaded with seven identical open stubs, and an integrated circuit (IC) chip connected directly to the feed lines in the middle of the structure. The perfect match to the IC chip’s impedance is realized...
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Sathwik Prathapagiri
OsobySathwik was born in 2000. In 2022, he completed his Master’s of Science in Biological Sciences and Bachelor’s of Engineering in Chemical Engineering in an integrated dual degree program from Birla Institute Of Technology And Science, Pilani, India. During his final year, he worked as a research intern under Dr Giri P Krishnan at Bazhenov lab, University of California San Diego school of medicine to pursue his Master’s Thesis on...
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Gamma oscillations precede interictal epileptiform spikes in the seizure onset zone
PublikacjaOBJECTIVE: To investigate the generation, spectral characteristics, and potential clinical significance of brain activity preceding interictal epileptiform spike discharges (IEDs) recorded with intracranial EEG. METHODS: Seventeen adult patients with drug-resistant temporal lobe epilepsy were implanted with intracranial electrodes as part of their evaluation for epilepsy surgery. IEDs detected on clinical macro- and research microelectrodes...
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Pulse-Width Modulation of Power Electronic DC–AC Converter
PublikacjaThe Second Edition of High Performance Control of AC Drives with Matlab®/Simulink delivers an updated and thorough overview of topics central to the understanding of AC motor drive systems. The book includes new material on medium voltage drives, covering state-of-the-art technologies and challenges in the industrial drive system, as well as their components, and control, current source inverter-based drives, PWM techniques for...
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Deflated Preconditioned Solvers for Parametrized Local Model Order Reduction
PublikacjaOne of steps in the design of microwave filters is numerical tuning using full-wave simulators. Typically, it is a time-consuming process as it uses advanced computational methods, e.g. the finite-element method (FEM) and it usually requires multiple optimization steps before the specification goals are met. FEM involves solving a large sparse system of equations at many frequency points and therefore its computational cost is...
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Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
PublikacjaThe results of the microstructural and dielectric measurements of (Ba1-xPbx)(Ti1-xSnx)O3 (BPTSx) (x = 0, 0.05, 0.10, 0.30) polycrystalline samples are presented. The samples were obtained by means of a high temperature synthesis and their expected stoichiometry was confirmed by energy dispersive spectroscopy (EDS) measurements. The dielectric properties of BPTSx were studied with the use of broadband dielectric spectroscopy. The...
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Potential fertilizing properties of sewage sludge treated in the Sludge Treatment Reed Beds (STRB)
PublikacjaIn research the fertilizer value of sludge from reed beds is evaluated based on the sampling sludge on different depths from 4 Danish STRB after long periods of stabilization. The dewatering efficiency of sewage sludge in the STRB is comparable to mechanical dewatering. The long-term stabilization of sewage sludge progressively decreases the concentration of organic matter due to the process of humification. The aim of the work...
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Performance Analysis and Quantification of BeiDou Navigation Satellite System (BDS-3)
PublikacjaPositioning, Navigation, and Timing (PNT) information play a vital role in everyday life of common persons. People greatly rely on Global Navigation Satellite System (GNSS)-enabled applications for navigation to reach their desired destination. However, GNSS navigation performance is highly degraded in urban environments due to the high probability of signal interruption, multipath (MP), and/or non-line-of-sight (NLOS) signal...
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Video recordings of bees at entrance to hives
Dane BadawczeVideo recordings of bees at entrance to hives from 2017-04-22, 2017-04-23 and 2018-05-22. All recordings were made using hand-held full HD camera (Samsung Galaxy S3) and encoded using H.264 video codec (Standard Baseline Profile for mov files from 2017, High Profile for mp4 files from 2018) , 30 FPS and bit rate 14478 kb/s (mov files from 2017) or 16869 kb/s...
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Accurate Modeling of Frequency Selective Surfaces Using Fully-Connected Regression Model with Automated Architecture Determination and Parameter Selection Based on Bayesian Optimization
PublikacjaSurrogate modeling has become an important tool in the design of high-frequency structures. Although full-wave electromagnetic (EM) simulation tools provide an accurate account for the circuit characteristics and performance, they entail considerable computational expenditures. Replacing EM analysis by fast surrogates provides a way to accelerate the design procedures. Unfortunately, modeling of microwave passives is a challenging...
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The problem of infections associated with implants – an overview
PublikacjaImplant-associated infections are serious and relatively common complication that leads to implant loss. The purpose of this paper is to gather knowledge about this issue. A literature review of the epidemiology, risk factors and pathogenesis of infections related to implants was carried out. This position collects data on commonly used implants and infections associated with them from various fields of medicine and contains classifications...
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Noise spectral density computation based on finite element model of piezoceramic sensor
PublikacjaThe high sensitivity with wide bandwidth is required for sensor applications in non-destructive testing (NDT). The sensitivity of piezoceramic sensors demands to minimize their noise especially thermal noise, polarisation noise and low frequency 1/f noise,which are the main sources of voltage or current fluctuation in this sort of sensors. For simplicity, only the piezoceramic part of sensor was under study. the theoretical and...
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Multichannel Human Body Communication
PublikacjaHuman Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog...
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The forming and emission of high power electromagnetic pulses
PublikacjaAn impulse energy source, a power conditioning system and an electromagnetic field emitter are essential to generate an electromagnetic field pulse (EMFP) with a specific frequency bandwidth. Selected simulation results for a power conditioning system consisting of a fuse opening switch and a paraboloidal electromagnetic emitter have been presented in this article. The synthetic system examined in the simulation is powered by an...
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Optimization of clamping stiffness during milling of high-dimensional structures with the use of techniques of experiment – aided virtual prototyping
PublikacjaThe subject of this paper is a method of searching for conditions of minimizing the vibration level of a tool-high dimensional flexible workpiece, at unchangeable technological parameters of the machining process. It depends on repeatable change of the values of the stiffness coefficients as soon as an optimal vibration state of the workpiece approaches. There are assessed the values of dominant ”peaks” in the frequency spectra...
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The voltage on bus bars of the main switchboard of the car carrier electrical power system at sea trials during a bow thruster start-up
Dane BadawczeThe dataset is a part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. In ships' electrical power systems, disturbances occurring in voltage waveforms on bus bars of the main switchboard are connected mainly with the processes...
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Power of the SMR brainwaves in the mental imagery experiment in sport: the "Start in High Level Championship" scenario.
Dane BadawczeThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
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Low-Cost 3-D Printed Lens Antenna for Ka-Band Connectivity Applications
PublikacjaThis paper discusses the use of low-cost 3-D printing technology to fabricate dielectric lenses for Ka-band wireless networks. A low-cost FDM alternative to previously presented 3-D printed lens in SLA technology with high performance resin is presented. The presented approach has been demonstrated for a 39 GHz MU-MIMO antenna array modified to realize multibeam or switched-beam antenna that can support demanding energy-efficient...
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ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
PublikacjaPolycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure...
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High-Gain Compact Circularly Polarized X-Band Superstrate Antenna for CubeSat Applications
PublikacjaIn this letter, a concept of high-gain circularly polarized X-band antenna employing a partially reflecting surface (PRS) has been presented. In the initial antenna analysis, the influence of parasitic elements size in the PRS structure on antenna radiation pattern parameters has been investigated and the optimal arrangement of the elements has been identified. The proposed antenna provides wide bandwidth of return loss above 10...
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DMI measurements impact on a position estimation with lack of GNSS signals during Mobile Mapping
PublikacjaNowadays, Mobile Laser Scanning is common in use in addition to geodesy measurements. The data which are provided by the system characterizes with high precision and flexibility. To precise mapping, the accuracy of the data should be maintained. In Poland, according to the minister’s dispositions, the accuracy of the data should not exceeded 10 cm. With fully operated system it is easy to uphold, but there is a situation when a...
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Highly Miniaturized Self-Diplexed U-Shaped Slot Antenna Based on Shielded QMSIW
PublikacjaThis article presents an efficient yet simple design approach to highly miniaturized cavity-backed self-diplexing antenna (SDA) with high-isolation. The structure employs a shielded quarter-mode substrate integrated waveguide (QMSIW). Two U-shaped slots are engraved on the top conducting plane, which realize two frequency bands and significant size reduction. The slots are excited by two independent 50Ω orthogonal feed-lines to...
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Advanced Sensor for Non-Invasive Breast Cancer and Brain Cancer Diagnosis Using Antenna Array with Metamaterial-Based AMC
PublikacjaMicrowave imaging techniques can identify abnormal cells in early development stages. This study introduces a microstrip patch antenna coupled with artificial magnetic conductor (AMC) to realize improved sensor for non-invasive (early-stage) breast cancer and brain cancer diagnosis. The frequency selectivity of the proposed antenna has been increased by the presence of AMC by creating an additional resonance at 2.276 GHz associated...
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Expedited Geometry Scaling of Compact Microwave Passives by Means of Inverse Surrogate Modeling
PublikacjaIn this paper, the problem of geometry scaling of compact microwave structures is investigated. As opposed to conventional structures (i.e., constructed using uniform transmission lines), re-design of miniaturized circuits (e.g., implemented with artificial transmission lines, ATSs) for different operating frequencies is far from being straightforward due to considerable cross-couplings between the circuit components. Here, we...
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Modulation of dielectric properties in low-loss polypropylene-based composites at GHz frequencies: theory and experiment
PublikacjaPolymer composites with high dielectric constant and low loss tangent are highly regarded as substrates for modern high-speed electronics. In this work, we analyze the high-frequency dielectric properties of two types of composites based on polypropylene infused with high-dielectric-constant microparticles. Two types of fillers are used: commercial ceramics or titanium oxide ( TiO2) with different concentrations. The key observation...
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Frequency Response Functions for Sandvik CoroBore 825 XL boring tool, 733 mm
Dane BadawczeFrequency Response Functions (FRF) obtained for Sandvik CoroBore® 825 XL mounted at WHN 13-15 TOS VARNSDORF CNC machine at the minimum extension of the spindle adaptor. Tool set to bore a hole with a diameter 733mm
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Optimization of Chemical Functionalities of Indole-2-carboxamides To Improve Allosteric Parameters for the Cannabinoid Receptor 1 (CB1)
Publikacja5-Chloro-3-ethyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (1; ORG27569) is a prototypical allosteric modulator for the cannabinoid type 1 receptor (CB1). Here, we reveal key structural requirements of indole-2-carboxamides for allosteric modulation of CB1: a critical chain length at the C3-position, an electron withdrawing group at the C5-position, the length of the linker between the amide bond and the phenyl ring...
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Fast geometry scaling of UWB band-notch antennas
PublikacjaImplementation of band-notch capability plays an important role in the design of ultra-wideband (UWB) antennas. At the same time, appropriate sizing of antenna geometry parameters in order to precisely allocate the notch at the required frequency as well as to ensure sufficient reflection level is quite challenging and has to be based—for reliability reasons—on full-wave electromagnetic (EM) simulations of the structure. In this...
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Highly sensitive microwave sensors based on open complementary square split-ring resonator for sensing liquid materials
PublikacjaThis paper presents high-sensitivity sensors based on open complementary square split-ring resonator and modified open complementary split-ring resonator operating at 4.5 GHz and 3.4 GHz, respectively. The sensors are designed for the detection of multiple liquid materials, including distilled water, methanol, and ethanol. The liquid under test is filled in a glass container loaded using a pipette. Compared to the conventional...
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THE APPLICATION OF THE MECHANOCHEMICAL SYNTHESIS FOR THE PREPARATION OF ADVANCED CERAMICS BASED ON BARIUM TITANATE
PublikacjaIn the present study, the lead-free BaTi1-xZrxO3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to...
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The forming and emission of high power electromagnetic pulses
PublikacjaAn impulse energy source, a power conditioning system and an electromagnetic field emitter are essential to generate an electromagnetic field pulse (EMFP) with a specific frequency bandwidth. Selected simulation results for a power conditioning system consisting of a fuse opening switch and a paraboloidal electromagnetic emitter have been presented in this article. The synthetic system examined in the simulation is powered by...
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Electrical conductivity and relaxation processes in V2O5 nanorods prepared by sol–gel method
PublikacjaProperties of high purity V2O5 nanorods prepared by a sol – gel method are presented. The studied materials were characterized by: X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electrical impedance was measured as a function of temperature and frequency. The obtained results show that the electrical conductivity increases with increasing temperature. The d.c. conductivity...
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Adaptive Hyperparameter Tuning within Neural Network-based Efficient Global Optimization
PublikacjaIn this paper, adaptive hyperparameter optimization (HPO) strategies within the efficient global optimization (EGO) with neural network (NN)-based prediction and uncertainty (EGONN) algorithm are proposed. These strategies utilize Bayesian optimization and multiarmed bandit optimization to tune HPs during the sequential sampling process either every iteration (HPO-1itr) or every five iterations (HPO-5itr). Through experiments using...
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Digits Recognition with Quadrant Photodiode and Convolutional Neural Network
PublikacjaIn this paper we have investigated the capabilities of a quadrant photodiode based gesture sensor in the recognition of digits drawn in the air. The sensor consisting of 4 active elements, 4 LEDs and a pinhole was considered as input interface for both discrete and continuous gestures. Index finger and a round pointer were used as navigating mediums for the sensor. Experiments performed with 5 volunteers...
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Power of the low alpha brainwaves in the mental imagery experiment in sport: the "Start in High Level Championship" scenario.
Dane BadawczeThe data were collected to perform research on the neural oscillation during mental imagery in sport. The main aim of the study was to examine the cortical correlates of imagery depending on instructional modality (guided vs self-produced) using various sport-related scripts. The research was based on the EEG signals recorded during the session with...
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High gain/bandwidth off‑chip antenna loaded with metamaterial unit‑cell impedance matching circuit for sub‑terahertz near‑field electronic systems
PublikacjaAn innovative off-chip antenna (OCA) is presented that exhibits high gain and efficiency performance at the terahertz (THz) band and has a wide operational bandwidth. The proposed OCA is implemented on stacked silicon layers and consists of an open circuit meandering line. It is shown that by loading the antenna with an array of subwavelength circular dielectric slots and terminating it with a metamaterial unit cell, its impedance...
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Design of compact self-quintuplexing antenna with high-isolation for penta-band applications
PublikacjaThis article presents a novel compact self-quintuplexing antenna architecture based on a substrate-integrated rectangular cavity (SIRC) for pentaband applications. The proposed self-quintuplexing antenna is constructed by employing an SIRC, one Pi-shaped slot (PSS), one T-shaped slot (TSS), and five 50Ω microstrip feedlines. The PSS and TSS are engraved on the top of the SIRC to create five radiating patches, which are excited...
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Analysis of Airport Runoff Waters
PublikacjaA particularly important facet of airport operation is the impact of the pollution caused byrunoff waters. Runoff waters at an airport may contain relatively high concentrations of differentcontaminants resulting from the various aspects of its operation: de/anti-icing operations,washing and cleaning operations, spills of fuel and lubricants, exhaust fumes, and weed removal.The pollution caused by airport operations affects soil,...
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Drug-resistant and hospital-associated Enterococcus faecium from wastewater, riverine estuary and anthropogenically impacted marine catchment basin.
PublikacjaEnterococci, ubiquitous colonizers of humans and other animals, play an increasingly important role in health-care associated infections (HAIs). Acquisition of resistance determinants not only seriously limits available therapeutic options but also increases available gene pool for other species. It is believed that the recent evolution of two clinically relevant species, Enterococcus faecalis and Enterococcus faecium occurred...
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Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublikacjaThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...
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The geodetic monitoring of the engineering structure – a practical solution of the problem in 3D space
PublikacjaThe study raises the issues concerning the automatic system designed for the monitoring of movement of controlled points, located on the roof covering of the Forest Opera in Sopot. It presents the calculation algorithm proposed by authors. It takes into account the specific design and location of the test object. High forest stand makes it difficult to use distant reference points. Hence the reference points used to study the stability...
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Hidden Champions of Poland
PublikacjaPoland is a country with a strong entrepreneurial spirit. The hidden champions’ performance has been closely related to political and economic changes: the fall of communism in 1989 and the transition from a centrally planned economy to a market economy. This led to the emergence of small private businesses focused on the domestic market. The accession to the European Union in 2004 created new perspectives for the hidden champions’...
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Pupil detection supported by Haar feature based cascade classifier for two-photon vision examinations
PublikacjaThe aim of this paper is to present a novel method, called Adaptive Edge Detection (AED), of extraction of precise pupil edge coordinates from eye image characterized by reflections of external illuminators and laser beams. The method is used for monitoring of pupil size and position during psychophysical tests of two-photon vision performed by dedicated optical set-up. Two-photon vision is a new phenomenon of perception of short-pulsed...
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Degradation of Kinematic PPP of GNSS Stations in Central Europe Caused by Medium-Scale Traveling Ionospheric Disturbances During the St. Patrick’s Day 2015 Geomagnetic Storm
PublikacjaIn solar cycle 24, the strongest geomagnetic storm took place on March 17, 2015, when the geomagnetic activity index was as high as -223 nT. To verify the impact that the storm had on the Global Navigation Satellite System (GNSS)’s positioning accuracy and precision, we used 30-s observations from 15 reference stations located in Central Europe. For each of them, we applied kinematic precise point positioning (PPP) using gLAB software...
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Wpływ wysokiej osteotomii piszczelowej na mechanikę stawu kolanowego
PublikacjaW rozprawie podjęto próbę weryfikacji wpływu zabiegu chirurgicznego wysokiej osteotomii piszczelowej na mechanikę stawu kolanowego. Po wykonanym przeglądzie literatury, postawiono trzy hipotezy, które poddano weryfikacji na drodze badań numerycznych. Otrzymane wyniki zwalidowano poprzez badania nacisków powierzchniowych występujących w stawach kolanowych świni domowej, prowadzonych na maszynie do jednoosiowego ściskania. Praca...
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Testing HIADAC high impedance analyzer in Trento University laboratory on Baunier's RC model using 2 wire probe
Dane BadawczeThe dataset presents impedance spectrum of Baunier's RC model. This object was used to test high-impedance analyzer for diagnostic of anticorossion coatings (HIADAC) realized in the frame of Eureka project E!3174. The impedance spectrum frequency range (1 mHz – 100 kHz) was selected in order to test the whole measureement range of the analyzer. In...
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Combined environmental testing device for picosatellites
PublikacjaAs access to space conditions becomes more available, both technically and economically, scientists’ interest in launching finer and more sophisticated experiments grows. To be qualified for launch, such experiments need to be carefully tested prior to the event. The tests should represent actual launch conditions as closely and in a detailed manner. Typical tests for payload include: vibration tests, thermal and vacuum tests,...