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Wyniki wyszukiwania dla: time-frequency analysis
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Analysis of The Behavior of Foundations of Historical Buildings
PublikacjaThe article is devoted to the analysis of the behavior of the foundations of historic buildings. Some basic aspects of foundation engineering are discussed, with an emphasis placed on its development, applied techniques, and materials. Several different approaches and methods for the analysis of foundations of historical buildings are presented. A particular analysis has been focused on an example of a typical stone foundation...
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Analysis of the chemical composition of sediments
PublikacjaAnalysis of sediments and corrosion products was carried out, including microscoping and spectroscopic measurements with SEM/EDX
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Effect of Time Varying Measurement Conditions on Antenna Pattern in Near Field Measurement and Its Correction Procedure
PublikacjaAuthors present the procedure of taking into account the changes of electrical parameters of setup due to the time drift of temperature during the procedure of near field measurement. It is proposed to make additional measurements in determined positions of probe are next used the results to introduce corrections terms in measured data. Such approach was verified practically in experimental near field measurement system.
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Analysis of unsteady flow forces on the thermowell of steam temperature sensor
PublikacjaIn this paper, 3D numerical analysis of unsteady flow forces acting on the measuring sheath of steam temperature is presented. According to that purpose, the CFD (Computation Fluid Dynamic [1]) approach has been used. The nonstationary of fluid acting on the measuring sheath such as: Strouhal frequency, amplitude of pressure, structure of vortex, peak of pressure, field of pressure, field of velocity etc. are studied analytically...
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The labor market in industrial cluster analysis
PublikacjaThe paper offers a description of methodologies used in industrial cluster analysis in conjunction with the labor market analysis. The author explores many tools utilized in cluster identi-fication: quantitative methods (LQ, shift-share), qualitative methods (MSQA) and mixed tools (cluster analysis in conjunction with discriminant analysis, spider diagram, GEM model, ne-twork analysis). Each tool is described in terms of its connection...
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Anharmonic Infrared Spectroscopy through the Fourier Transform of Time Correlation Function Formalism in ONETEP
PublikacjaDensity 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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A risk analysis of winter navigation in Finnish sea areas
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CFD analysis of fluid flow through the labyrinth seal
PublikacjaSteam and gas turbines are some of the fundamental means of power generation. The energy efficiency of the turbines, however, is not satisfactory. Ever since the start-up of the first turbine in the world, engineers have been striving for their increased efficiency. Multiple solutions to the problem of steam loss in an operating turbine are available. The use of seals is one of them. Empirical methods or numerical calculations...
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Characterisation of asbestos-containing wastes by thermal analysis
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Cylindrical surface irregularities presented by frequency spectra of relative tool displacement to the workpiece
PublikacjaW pracy przedstawiono częstotliwościowe składowe nierówności powierzchni toczonych. Ponieważ nierówności mają charakter szerokopasmowy, trudny do wartościowania parametrami normatywnymi, zastosowano ich analizę amplitudowo-częstotliwościową, opartą na szybkiej transformacie Fouriera. Zaproponowano oryginalny układ pomiaru sygnału przemieszczeń narzędzia względem przedmiotu dla charakteryzowania nierówności wzdłużnych. Dla generowania...
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Cylindrical surface irregularities presented by frequency spectra of relative tool displacement to the workpiece
PublikacjaW pracy przedstawiono częstotliwościowe składowe nierówności powierzchni toczonych. Ponieważ nierówności mają charakter szerokopasmowy, trudny do wartościowania parametrami normatywnymi, zastosowano ich analizę amplitudowo-częstotliwościową, opartą na szybkiej transformacie Fouriera. Zaproponowano oryginalny układ pomiaru sygnału przemieszczeń narzędzia względem przedmiotu dla charakteryzowania nierówności wzdłużnych. Dla generowania...
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Influence of the analyzing window on electrode impedance measurement by the continuous frequency scanning method
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Experimental Investigation of high frequency 3L-NPC qZS inverter for photovoltaic application
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Low Frequency Noise Measurement of Reverse Polarized Silicon Carbide Schottky Diodes
PublikacjaW artykule przedstawiono wyniki pomiaró szumów cz. wstecznie spolaryzowanych diod Schottky'ego.
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The measurement of input power of power supply in network disturbed by low frequency distortions
PublikacjaIn the paper authors present results of observation of input power changes versus harmonics amplitude in supply voltage of low-power power supply device. In the study, the electrical measurements supported with thermal imaging were used. The input circuit elements of studied device responsible for input power increase are pointed
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Low frequency of itraconazole resistance found among avian Aspergillus fumigatus isolates
PublikacjaAspergillus fumigatus is the most frequent etiological factor of invasive aspergillosis in human as well as animals, including birds. Aspergillosis caused by drug-resistant strains poses a significant therapeutic issue, especially if resistance pattern includes insensitivity to triazoles, i.e. drugs recommended for the primary therapy purposes. Majority of resistant isolates hold the TR34/L98H...
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DoA Estimation Using Reconfigurable Antennas in Millimiter-Wave Frequency 5G Systems
PublikacjaTo achieve low latency and high throughputs, future 5G systems will have to utilize complex antenna systems able to provide beamforming and direction-of-arrival (DoA) estimation capabilities. Most of the concepts available in the literature rely on analog or digital beamforming, which is well developed and can be used both at a base station and in a user terminal. However, in applications, in which...
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Detection of low- and high-frequency rhythms in the variability of skin sympathetic nerve activity
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Silicon-based all-electronic quasi-optical pairs for THz frequency range
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Low frequency noise and trap density in GaN/AlGaN field effect transistors
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NDE of two-layered mortar samples using high-frequency Rayleigh waves
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Excitation of Non-Wave Modes by Sound of Arbitrary Frequency in a Chemically Reacting Gas
PublikacjaThe nonlinear phenomena in the field of high intensity sound propagating in a gas with a chemical reaction, are considered. A chemical reaction of A → B type is followed by dispersion and attenuation of sound which may be atypical during irreversible thermodynamic processes under some conditions. The first and second order derivatives of heat produced in the chemical reaction evaluated at the equilibrium temperature, density and...
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Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters
PublikacjaBuffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more...
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The influence of frequency controlled ac drives on vibration and audible noise level on ships
PublikacjaOkreślono korelacje między zakłóceniami elektrycznymi a wibracjami i hałasem w okrętowych układach napędowych z przemiennikami częstotliwości. Wskazano na destrukcyjny wpływ tych czynników na jakość życia załóg pływających.
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Compatible DC and small-signal MOSFET models for radio and microwave frequency simulation
PublikacjaZaprezentowano nowy model stałoprądowy tranzystora MOS i kompatybilny z nim uogólniony nie-quasi-statyczny model małosygnałowy. Model stałoprądowy został eksperymentalnie zweryfikowany dla tranzystorów MOS o długości kanału od 75 nm do kilkunastu mikrometrów, a model małosygnałowy od zera herców do 30 GHz.
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The analysis of firms’ involvement in internationalisation and determinants of its intensity – an analysis for developing and post-transition economies
PublikacjaThe study presents the empirical analysis of firms’ involvement in different forms of internationalisation: export, indirect export, import, indirect import and finally simultaneous exporting and importing. The analysis is based on firm-level data from the World Bank Enterprise Survey (March 2017 release). The empirical part is divided into two stages. Firstly account is taken of firms’ heterogeneity and then a Melitz type analysis...
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Urine headspace analysis in medical diagnostics
PublikacjaThe analysis of the volatile organic compounds in the bodily fluids such as urine may provide useful information on the patients’ general health. The potential application of urine headspace analysis could facilitate the diagnostics of various diseases such as metabolic disorders, urinary tract diseases and gastrointestinal conditions. Described in this paper are the currently available techniques of urine sample analysis as well...
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Modeling and analysis of the effectiveness of the guard systemswith dynamic graphs
PublikacjaIn the following paper it will be presented a new model for analysis (in polynomial time) of the effectiveness of the guard systems. Therewill be presented its practical applications in problems such as searching for the weakest points of the system, planning guards' paths or cameras deployment, switching image from multiple cameras on several monitors, or interception of the intruder. This model is based on describing the guarded...
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Food analysis using artificial senses.
PublikacjaNowadays, consumers are paying great attention to the characteristics of food such as smell, taste, and appearance. This motivates scientists to imitate human senses using devices known as electronic senses. These include electronic noses, electronic tongues, and computer vision. Thanks to the utilization of various sensors and methods of signal analysis, artificial senses are widely applied in food analysis for process monitoring...
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A Time Delay Controller Included Terminal Sliding Mode and Fuzzy Gain Tuning for Underwater Vehicle-Manipulator Systems
PublikacjaAn improved Time Delay Control (TDC) method for an Underwater Vehicle-Manipulator System (UVMS) is proposed. The proposed controller consists of three terms: a time-delay-estimation term that cancels nonlinearities of the UVMS dynamics, a Terminal Sliding Mode (TSM) term that provides a fast response and a PID term that reduces the tracking error. In addition the proposed controller uses fuzzy rules to adaptively tune the gains...
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Classification and fingerprinting of kiwi and pomelo fruits by multivariate analysis of chromatographic and spectroscopic data
PublikacjaThe fingerprinting capacity of two analytical techniques, HPLC and UV-Vis spectroscopy in the case of fruits samples (kiwi and pomelo) has been investigated. The multivariate exploratory techniques were used for sample discrimination according to the fruit species and subspecies. The combination of principal component analysis with linear discriminant analysis is opening new directions in the fingerprinting analysis. The classifications...
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TIME-DOMAIN NUMERICAL EVALUATION OF SHIP RESISTANCE AND MOTION IN REGULAR WAVES BY USING THE CFD URANS METHOD
PublikacjaTaking into account the International Maritime Organization's (IMO) strategy to radically reduce the...
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Estimation of Conservative Contaminant Travel Time through Vadose Zone Based on Transient and Steady Flow Approaches
PublikacjaEstimation of contaminant travel time through the vadose zone is needed for assessing groundwater vulnerability to pollution, planning monitoring and remediation activities or predicting the effect of land use change or climate change on groundwater quality. The travel time can be obtained from numerical simulations of transient flow and transport in the unsaturated soil profile, which typically require a large amount of data and...
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Study of Nanohydroxyapatite Coatings Prepared by the Electrophoretic Deposition Method at Various Voltage and Time Parameters
PublikacjaThe aim of the work is to compare the properties of nanohydroxyapatite coatings obtained using the electrophoretic deposition method (EDP) at 10 V, 20 V, and 30 V, and with deposit times of 2 and 5 min. The primary sedimentation was used to minimize the risk of the formation of particle agglomerates on the sample surface. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy...
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Research of chitosan coatings deposited by electrophoretic deposition method at various voltage and time parameters
PublikacjaThe aim of this research is to estimate the electrophoretic deposition main parameters, such as voltage and time duration, that will provide optimal characteristics of the surface layer. Chitosan coatings were synthesized on biomedical Ti13Zr13Nb alloys at 20 V and 30 V and with deposit times of 2min, 5 min, 10 min, and 15 min. Evaluation of the coating was performed by using Scanning Electron Microscope (SEM), Energy-Dispersive...
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PCR and real-time PCR approaches to the identification of Arthroderma otae species Microsporum canis and Microsporum audouinii/Microsporum ferrugineum
PublikacjaObjectives The identification of species in the Arthroderma otae complex is essential to determine the origin of infection and to eliminate the risk of transmission. Microsporum canis is a zoophilic species, whereas Microsporum audouinii and Microsporum ferrugineum are anthropophilic species. In this paper, we propose alternative methods that permit species-specific identification of both anthropophilic and zoophilic members of...
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Analysis of Failures of High Speed Shaft Bearing System in a Wind Turbine
PublikacjaDuring 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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The dying medium temperature impact on the final moisture content of pine wood at constant drying time
PublikacjaThe results of final moisture content of pine wood (Pinus sylvestris L.) after drying process are presented. The wood in the experiments was taken from the northern part of Pomeranian region in Poland. The drying process was performed in the experimental chamber equipped with the micro-jet heat exchanger. The air at temperatures of 40°C, 60°C, 80°C, 100°C and 120°C with relative humidity about 60% and atmospheric pressure was the...
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Parametric method applicable in assessing breakout force and time for lifting slender bodies from seabed
PublikacjaThe article presents a parametric method applicable in assessing the suction force of a slender body to the seabed, and prognosing the body extrication time. Along with the body weight in water, the information on the suction force is essential for assessing the force needed to lift the object from the seabed. Based on the Foda theory and the resulting integral equation, which relates the maximum suction force with basic parameters...
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Security aspects in functional safety analysis
PublikacjaA security level of distributed control and protection system may have a significant impact on the results of functional safety analysis. However, the issue of integrating the safety and security aspects is difficult and usually is neglected during the functional safety analysis. This article presents a method of functional safety analysis which takes into consideration a concept of integrating these two aspects. It is based on...
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Interface analysis of compatibilized polymer blends
PublikacjaThis chapter seeks to address the interface location in the compatibilized polymer blends and paves the way for quantitative analysis of interface in terms of interfacial tension and interfacial adhesion to provide support for understanding the relationship between morphology and ultimate properties in the compatibilized polymer blends through the lens of interface. Since understanding and analysis of interfacial phenomena in the...
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THE INTERNATIONAL COMPETITIVENESS OF EUROPEAN UNION COUNTRIES AND STRATEGIES FOR ITS ENHANCEMENT: A TAXONOMIC ANALYSIS
PublikacjaThe aim of this article is to identify clusters of countries with similar levels of competitiveness among the EU-27 countries and to identify for each of the 27 EU countries the path to growth in competitiveness. The taxonomic cluster analysis conducted confirms the hypothesis that the European Union is an area with a high differentiation in terms of levels of competitiveness. The analysis shows that the strategy to increase competitiveness...
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Cost-Efficient Surrogate Modeling of High-Frequency Structures Using Nested Kriging with Automated Adjustment of Model Domain Lateral Dimensions
PublikacjaSurrogate models are becoming popular tools of choice in mitigating issues related to the excessive cost of electromagnetic (EM)-driven design of high-frequency structures. Among available techniques, approximation modeling is by far the most popular due to its versatility. In particular, the surrogates are exclusively based on the sampled simulation data with no need to involve engineering insight or problem-specific knowledge....
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Statistics with R A Handbook for Statistical Analysis with R and R-Studio
PublikacjaIf you are to perform any kind of data (statistical) analysis and use tools in the data science ecosystem, you may have seen a variety of tutorials, handbooks online (I’m not mentioning traditional bibles of statistics). Unfortunately most of them is written intentionally for specific purposes and/or target group of people and does not include many aspects, data types, difficult aspects, usually hiding them trying to solve theoretical...
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EXPERIMENTAL ANALYSIS OF CONNECTION BETWEEN OBJECT-ORIENTED METRICS AND SOFTWARE CHANGEABILITY
PublikacjaFor the purpose of video surveillance software quality assessment in this work the ISO/IEC-9126 norm was used with a particular focus on maintainability of the software system. The paper presents a study on the connection between software metrics derived from the static analysis of the source code and changeability of the video surveillance software system. It is shown that meeting requirements of software quality metrics may result...
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System do diagnostyki dermatofitowych zakażeń powierzchniowych oparty na technice Real-Time PCR
PublikacjaDermatofity należą do blisko spokrewnionej grupy grzybów, które wykazują wysokie powinowactwo do skeratynizowanych tkanek. Cecha ta czyni je odpowiedzialnymi za powierzchniowe grzybice skóry, paznokci oraz włosów. Szacuje się, iż nawet do 20% ludzi na całym świecie dotkniętych jest infekcjami powodowanymi przez dermatofity. Ich leczenie wymaga długotrwałego zastosowania leków przeciwgrzybiczych. W celu dobrania odpowiedniego leczenia...
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Automatic analysis of the aggressive behavior of laboratory animals using thermal video processing
PublikacjaThe bite detection is very important but difficult element of the social interaction analysis. Standard observation methods like human observer or a camcorder of visible light frequencies fail in this case. However, it is possible to discern cooler spots on the rodent's body that appear after body contact with another individual, and vanish after short time. These spots are assumed to be a saliva trace left on fur after bite. In...
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On FEM analysis of Cosserat-type stiffened shells. Static and stability linear analysis
PublikacjaThe present research investigates the theory and numerical analysis of shells stiffened with beams in the framework based on the geometrically exact theories of shells and beams. Shell’s and beam’s kinematics are described by the Cosserat surface and the Cosserat rod respectively, which are consistent including deformation and strain measures. A FEM approximation of the virtual work principle leads to the conforming shell and beam...
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A framework estimating the minimum sample size and margin of error for maritime quantitative risk analysis
PublikacjaThe average accident frequency is essential for quantitative risk analysis and is conventionally estimated from accident statistics. This paper has systematically synthesised the knowledge on statistical errors and offered the missing instructions, a framework, for determining the minimum sample size and the margin of error (MOE) when calculating the average accident frequency from an accident database at hand. We have applied...
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Low-cost and reliable geometry scaling of compact microstrip couplers with respect to operating frequency, power split ratio, and dielectric substrate parameters
PublikacjaA technique for rapid re-design of miniaturised microstrip couplers with respect to operating conditions as well as material parameters of the dielectric substrate is proposed. The dimension scaling process is based on a set of pre-optimised reference designs, obtained for an equivalent circuit model of the coupler at hand. The reference designs are utilised to construct an inverse surrogate model which – upon suitable correction...