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Search results for: SURFACE TOPOGRAPHY MEASUREMENT HIGH-FREQUENCY MEASUREMENT NOISE AUTOCORRELATION FUNCTION AUTOCORRELATION FUNCTION SHAPE ANALYSIS
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Time-of-flight fiber optic sensors for strain and temperature measurement
PublicationW pracy przedstawiono światłowodowy sensor czasu przelotu do pomiaru odkształceń i temperatury mogący pracować zarówno w modzie transmisyjnym, jak i odbiciowym. W pomiarach czasu przelotu wykorzystano krótkie impulsy światłowodowe wprowadzane do jednodomowego światłowodu. Pod wpływem czynników zewnętrznych (temperatura, odkształcenie, siła rozciągająca) zmieniała się droga optyczna w światłowodzie, co powodowało zmiany czasu przelotu...
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Comparison of modelling and measurement results of spectra emitted by a programmable lamp
PublicationNowadays artificial light with an optimized spectrum is used in many different applications. For instance, it is widely used in museums and exhibitions to illuminate the art. Moreover, such light stimulates the growth of plants, or can be applied in industry and healthcare. To achieve the best results for each application, the adjusting of a dedicated spectrum is required, which is a complicated task. The ongoing research is focused...
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Quality of Analytical Results: Classifiying Errors and Estimating Measurement Uncertainty
PublicationThe most important parameter of each analytical result is its reliability. An analytical result is not a constant value; each result has two properties, error and uncertainty. The sources of both these parameters have to be known and their values determined (estimated). All analytical results are obtained by applying an appropriate measuring procedure. The need for reliable results requires application of reliable analytical procedures,...
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Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks
PublicationThis paper presents results of investigation on the coherence bandwidth of narrowband radio channels in 430MHz band. The coherence bandwidth values were estimated froma power delay profile obtained by recording CDMA2000 forward channel signals during real-fieldmeasurements in various environments:mediumcity, flat terrain, and hilly terrain in northern Poland.The results of measurements are compared with characteristic parameters...
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HOW EFFICIENT IS NOISE LABELING OF TIRES?
PublicationSince 2012 all new tires in Europe must be labeled. The label contains general information about tire performance concerning rolling resistance (that corresponds to fuel economy), noise emission and wet grip (only for passenger car tires). Measurements of noise performance of tires must be performed according to the Annex 3 of the Regulation No 117 of the Economic Commission for Europe of the United Nations. The regulation specifies...
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Minimum drag shape bodies moving in inviscid fluid - revisited
PublicationThis paper presents the classic approach to minimum drag shape body problem, moving at hypersonic speeds, leading to famous power law shapes with value of the exponent of 3/4. Two- and three-dimensional cases are considered. Furthermore, an exact pseudo solution is given and its uselessness is discussed. Two new solutions are introduced, namely an approximate solution due to form of the functional and solution by means of optimisation...
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A Novel Trust-Region-Based Algorithm with Flexible Jacobian Updates for Expedited Optimization of High-Frequency Structures
PublicationSimulation-driven design closure is mandatory in the design of contemporary high-frequency components. It aims at improving the selected performance figures through adjustment of the structure’s geometry (and/or material) parameters. The computational cost of this process when employing numerical optimization is often prohibitively high, which is a strong motivation for the development of more efficient methods. This is especially...
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Low frequency noise and DLTS as silicon solar cell characterization tools
PublicationPraca zawiera wyniki pomiarów DLTS próbek o powierzchni 1 mm2 krzemowych baterii słonecznych wykazujących znaczne niejednorodności wykryte za pomocą metody LBIV (Light Beam Induced Voltage). Wyniki pomiarów charakterystyk stałoprądowych oraz szumowych tych próbek zostały także przedstawione.
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Modified Preisach model of hysteresis in multi air gap ferrite core medium frequency transformer
PublicationThis article presents the modified Preisach model of hysteresis for a 3-phase medium frequency transformer in a 100 kW dual active bridge converter. The transformer magnetic core is assembled out of ferrite I-cores, which results in multiple parasitic air gaps. For this transformer, the hysteresis loops were measured and parameters of the Preisach model were determined. The Preisach distribution function is approximated with a...
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Application of multisine nanoscale impedance microscopy to heterogeneous alloy surface investigations
PublicationIn the recent years atomic force microscopy is recognized as valuable tool for investigation of surficial features of construction materials. It concerns, among other things, studies of changes caused by such phenomena as galvanic corrosion, passivation associated with the growth of oxide layers, or sensitization of austenitic steels with the formation of carbide phases. In addition, atomic forcemicroscopy allows easy coupling...
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Measurement of Unwanted Thought Suppression Strategies with the Thought Control Questionnaire in the General Polish Population: A Confirmatory Factor Analysis and Validation
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Performance properties of rigid polyurethane-polyisocyanurate/brewers’ spent grain foamed composites as function of isocyanate index
PublicationIn the presented work, rigid polyurethane-polyisocyanurate (PUR-PIR) foams filled with brewers’ spent grain (BSG) were prepared. The influence of the isocyanate index (II) on its performance was investigated. Foams obtained with higher isocyanate index required a higher amount of hydrofluorocarbon physical blowing agent to provide the same apparent density of material. An increase of isocyanate index resulted in a slight decrease...
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The non-invasive evaluation of heart function in patients with an acute myocardial infarction: The role of impedance cardiography
PublicationBackground: The purpose of this study was to analyze hemodynamic changes in patients treated with percutaneous coronary intervention (PCI) at an early stage of acute myocardial infarction (AMI) and at one-month follow-up. Methods: Patients with AMI (n = 27) who underwent PCI were analyzed using impedance cardiography (ICG). ICG data were collected continuously (beat by beat) during the whole PCI procedure and thereafter at every...
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Anatomy of noise in quantitative biological Raman spectroscopy
PublicationRaman spectroscopy is a fundamental form of molecular spectroscopy that is widely used to investigate structures and properties of molecules using their vibrational transitions. It relies on inelastic scattering of monochromatic laser light irradiating the specimen. After appropriate filtering the scattered light is dispersed onto a detector to determine the shift from the excitation wavelength, which appears in the form of...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublicationData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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Effect of waviness and roughness components on transverse profiles of turned surfaces
PublicationThis paper presents the authors method of simultaneous analysis of roughness and waviness irregularity components, with the aim of better defining the key qualities and characteristics.Periodical surface machining traces may be analyzed spectrally, with the irregularity's peaks and troughs being used to define the wave's amplitude.In this work the standard composition for filtering waviness and roughness components of a surface...
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HYDROACOUSTIC NOISE MEASUREMENTS
PublicationThe paper deals mainly with investigation of underwater noise that propagation is in shallow water. In this paper has been presented the experimental investigation results concerning the distribution of the sound field pressure generated by moving ships in the shallow water at the small distance from the ship. The main acoustical characteristics describing features of the field are spectrograms in pseudo 3D system – distance and frequency...
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Effect of mid-frequency discharge assistance on dual-high power impulse magnetron sputtering
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Sound quality metrics applied to road noise evaluation
PublicationRoad noise monitoring systems typically measure sound levels in specific time periods. The more insightful approach suggests to measure also the nature of noise. Sound quality of sounds such as car noise can be objectively evaluated by several parameters. One of them is psychoacoustic annoyance, described by loudness, tone color, and the temporal structure of sound. In this paper the assessment of several sound quality parameters, such...
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Surface texture of pine wood beams after planing in industrial conditions
PublicationMeasuring the surface features of wooden components after planing is connected with the rising demands regarding to the quality of the painted window frames. In the paper the complex surface texture analysis especially identifying of surface damages using non-contact 3D measurement techniques for precise area measurement were presented.This enabled the study of irregular surface features with sufficient fidelity and resolution....
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The Design of Cavity Resonators and Microwave Filters Applying Shape Deformation Techniques
PublicationThis article introduces shape deformation as a new approach to the computer-aided design (CAD) of high-frequency components. We show that geometry deformation opens up new design possibilities and offers additional degrees of freedom in the 3-D modeling of microwave structures. Such design flexibility is highly desirable if the full potential of additive manufacturing (AM) is to be exploited in the fabrication of RF and microwave...
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Dynamic Signal Strength Mapping and Analysis by Means of Mobile Geographic Information System
PublicationBluetooth beacons are becoming increasingly popular for various applications such as marketing or indoor navigation. However, designing a proper beacon installation requires knowledge of the possible sources of interference in the target environment. While theoretically beacon signal strength should decay linearly with log distance, on-site measurements usually reveal that noise from objects such as Wi-Fi networks operating in...
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Distribution of Relaxation Times analysis results of impedance measured in function of temperature on porous SrTi0.50Fe0.50O3-d oxygen electrode sintered at 800 °C
Open Research DataThis dataset contains results of Distribution of Relaxation Times analysis (DRT) of impedance of symmetrical cells with porous SrTi0.50Fe0.50O3-d oxygen electrodes sintered at 800 °C. Electrochemical impedance spectroscopy were measured at 800 °C; 750 °C and 700 °C (syntetic air). The DRTTools Matlab GUI, available from prof. Ciucci’s group, was used...
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Distribution of Relaxation Times analysis results of impedance measured in function of temperature on porous SrTi0.30Fe0.70O3-d oxygen electrode sintered at 800 °C
Open Research DataThis dataset contains results of Distribution of Relaxation Times analysis (DRT) of impedance of symmetrical cells with porous SrTi0.30Fe0.70O3-d oxygen electrodes sintered at 800 °C. Electrochemical impedance spectroscopy were measured at 800 °C; 750 °C and 700 °C (syntetic air). The DRTTools Matlab GUI, available from prof. Ciucci’s group, was used...
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Distribution of Relaxation Times analysis results of impedance measured in function of temperature on porous SrTi0.65Fe0.35O3-d oxygen electrode sintered at 800 °C
Open Research DataThis dataset contains results of Distribution of Relaxation Times analysis (DRT) of impedance of symmetrical cells with porous SrTi0.65Fe0.35O3-d oxygen electrodes sintered at 800 °C. Electrochemical impedance spectroscopy were measured at 800 °C; 750 °C and 700 °C (syntetic air). The DRTTools Matlab GUI, available from prof. Ciucci’s group, was used...
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Analysis of Failures of High Speed Shaft Bearing System in a Wind Turbine
PublicationDuring the operation of wind turbines with gearbox of traditional configuration, consisting of one planetary stage and two helical stages high failure rate of high speed shaft bearings is observed. Such a high failures frequency is not reflected in the results of standard calculations of bearing durability. Most probably it can be attributed to atypical failure mechanism. The authors studied problems in 1.5 MW wind turbines of...
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Elastic-contractile model proteins: Physical chemistry, protein function and drug design and delivery
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Characteristics of olfactory function in a healthy geriatric population. Differences between physiological aging and pathology
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Heritability and other determinants of left ventricular diastolic function in the family-based population study
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Single Mathematical Parameter for Evaluation of the Microorganisms’ Growth as the Objective Function in the Optimization by the DOE Techniques
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Revelations About Carotid Body Function Through its Pathological Role in Resistant Hypertension
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Arterial structure and function in subjects with acute coronary syndrome after one-year of treatment
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Piecewise continuous distribution function method: Fluid equations and wave disturbances at stratified gas
PublicationUkład równań typu hydrodynamicznego dla warstwowych gazów w polu grawitacyjnym pochodzi od równania BGK metodą częściowej ciągłej funkcji dystrybucji. Otrzymany system równań uogólnia układ Naviera-Stokesa w dowolnych liczbach Knudsena. Rozwiązania WBK dla ultradźwięku wprowadza się w przypadku stratyfikacji exponecjalnej.
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7-Score Function for Assessing the Strength of Association Rules Applied for Construction Risk Quantifying
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Free convective heat transfer structures as a function of the width of isothermal horizontal rectangular plates
PublicationZaprezentowano rezultaty badań eksperymentalnych konwekcyjnej wymiany ciepła od izotermicznych płyt prostokątnych skierowanych ku górze. Na podstawie przeprowadzonych wizualizacji zaproponowano dwa modele struktur przepływu. Rozwiązania analityczne dla tych modeli przedstawiono w postaci zależności liczb Nusselta Rayleigh'a. Stwierdzono, że przepływ koncentryczny występuje dla małych wartości liczb Ra, szczególnie w przypadku płyt...
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Anharmonic Infrared Spectroscopy through the Fourier Transform of Time Correlation Function Formalism in ONETEP
PublicationDensity functional theory molecular dynamics (DFT-MD) provides an efficient framework for accurately computing several types of spectra. The major benefit of DFTMD approaches lies in the ability to naturally take into account the effects of temperature and anharmonicity, without having to introduce any ad hoc or a posteriori corrections. Consequently, computational spectroscopy based on DFT-MD approaches plays a pivotal role in...
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Bisquare robust polynomial fitting method for dimple distortion minimization in surface quality analysis
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Ljung-Box test values of selected companies of the Warsaw Stock Exchange
Open Research DataThe following dataset includes the Warsaw Stock Exchange market analysis using the Ljung-Box test. Partial autocorrelations up to the 5th order were analyzed, because it will allow to observe the relationship within one week of stock exchange quotations. In the case of the WIG index, the 1st and 2nd order correlation turned out to be statistically significant....
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Journal of Measurement and Evaluation in Education and Psychology-EPOD
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Investor confidence and high financial literacy jointly shape investments in risky assets
PublicationHouseholds consistently invest less in equities and bonds than predicted by economic theory. We explain this from a behavioral economics perspective and distributional analysis using rich US survey microdata. We find that higher investor self-confidence in her financial abilities and financial literacy jointly increase the probability of investing in equities. Conditional on participation, confidence in the macroeconomy additionally...
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Frequency Guided Generalized Adaptive Notch Filtering - Tracking Analysis and Optimization
PublicationGeneralized adaptive notch filters (GANFs) are estimators of coefficients of quasi-periodically time-varying systems, encountered e.g., in RF applications when Doppler effect takes place. Current state of the art GANFs can deliver highly accurate estimates of system variations’ frequency, but underperform in terms of accuracy of system coefficient estimates. The paper proposes a novel multistage GANF with improved coefficient...
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Widespread theta synchrony and high-frequency desynchronization underlies enhanced cognition
PublicationThe idea that synchronous neural activity underlies cognition has driven an extensive body of research in human and animal neuroscience. Yet, insufficient data on intracranial electrical connectivity has precluded a direct test of this hypothesis in a whole-brain setting. Through the lens of memory encoding and retrieval processes, we construct whole-brain connectivity maps of fast gamma (30-100 Hz) and slow theta (3-8 Hz) spectral...
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Quality assessment of ZnO-based varistors by 1/f noise
PublicationNoise has been used as a diagnostic tool of surge arrester varistor structures comprising of ZnO grains of various type and size. The physical and electrical properties of the measured samples have been described. In the experimental study, the applied measurement system and the results of noise measurements for the selected structures of varistors designed for the continuous working voltage 280 V, 440 V and 660 V have been presented....
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Investor confidence and high financial literacy jointly shape investments in risky assets
PublicationHouseholds consistently invest less in equities and bonds than predicted by economic theory. We explain this from a behavioral economics perspective and distributional analysis using rich US survey microdata. We find that higher investor self-confidence in her financial abilities and financial literacy jointly increase the probability of investing in equities. Conditional on participation, confidence in the macroeconomy additionally...
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Nonlinear impedance as a function of temperature and frequency for Bi2VO5.5 ceramic of thickness 2.52 mm was measured at different A.C. voltage with impedance spectroscopy method
Open Research DataThe nonlinear electrical properties of Bi2VO5.5 ceramic of thickness 2.52 mm was measured by impedance spectroscopy method.
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The current amplifier in low frequency noise measurements; Absolute calibration and rigorous 1/f noise extraction for MOSFET´s
PublicationPrzedstawiono budowę wzmacniacza prądowego i sposób obliczania szumów wyjściowych przy dołączonym do wejścia rezystorze wzorcowym. Przedstawiono wyniki eksperymentów potwierdzających prawidłowość przyjętego sposobu postępowania. Zaproponowano metodę wyznaczania składowej 1/f szumów drenu tranzystora MOSFET.
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The accuracy of pulse rate estimation from the sequence of face images
PublicationThe goal of this paper is to analyze the accuracy of pulse rate estimation from the sequence of face images. Simulated and real signals were used to evaluate two pulse rate estimators; one for frequency domain and the second one for time domain using the autocorrelation function. The results show that the mean difference between the reference measurements and estimated pulse rate values are about 2bpm. In the analysis of short...
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Sylwester Kaczmarek dr hab. inż.
PeopleSylwester Kaczmarek received his M.Sc in electronics engineering, Ph.D. and D.Sc. in switching and teletraffic science from the Gdansk University of Technology, Gdansk, Poland, in 1972, 1981 and 1994, respectively. His research interests include: IP QoS and GMPLS and SDN networks, switching, QoS routing, teletraffic, multimedia services and quality of services. Currently, his research is focused on developing and applicability...
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SURFACE & COATINGS TECHNOLOGY
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Microfluidically Frequency-Reconfigurable Compact Self-Quadruplexing Tunable Antenna with High Isolation Based on Substrate Integrated Waveguide
PublicationThis communication presents a novel concept of microfluidically frequency-reconfigurable self-quadruplexing tunable antenna for quad-band applications. At the initial design stage, a substrate-integrated square cavity is divided into four unequal quarter-mode cavity resonators by inserting an X-shaped slot on the top surface of the cavity. Applying four 50-ohm microstrip feed-lines to these four quarter-mode cavity resonators enables...