wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: LINEAR SYS- TEMS
-
A simplified channel estimation procedure for NB-IoT downlink
PublikacjaThis paper presents a low-complexity channel estimation procedure which is suitable for use in energy-efficient NB-IoT user equipment devices. The procedure is based on the well-established least squares scheme, followed by linear interpolation in the time domain and averaging in the frequency domain. The quality of channel estimation vs. signal-to-noise ratio is evaluated for two channel models and compared with the performance...
-
TOTAL CROSS SECTION MEASUREMENTS FOR ELECTRON SCATTERING ON METHYL FORMATE (HCOOCH3) MOLECULE: METHYLATION EFFECT
PublikacjaWe present the absolute total cross section (TCS) for electron scattering from the methyl formate (HCOOCH3) molecule measured in the 10-300 eV energy range, with electrostatic electron spectrometer working in the linear transmission mode. Comparison of TCS for the HCOOCH3 molecule with that measured earlier for the formic acid (HCOOH) compound manifests the methylation effect i.e. the response of the electron scattering dynamics...
-
Ellipticity in couple-stress elasticity
PublikacjaWe discuss ellipticity property within the linear couple-stress elasticity. In this theory, there exists a deformation energy density introduced as a function of strains and gradient of macrorotations, where the latter are expressed through displacements. So the couple-stress theory could be treated as a particular class of strain gradient elasticity. Within the micropolar elasticity, the model is called Cosserat pseudocontinuum...
-
Optimally regularized local basis function approach to identification of time-varying systems
PublikacjaAccurate identification of stochastic systems with fast-varying parameters is a challenging task which cannot be accomplished using model-free estimation methods, such as weighted least squares, which assume only that system coefficients can be regarded as locally constant. The current state of the art solutions are based on the assumption that system parameters can be locally approximated by a linear combination of appropriately...
-
Novel Nonlinear High Order Technologies for Damage Diagnosis of Complex Assets
PublikacjaFor the first time worldwide, innovative techniques, generic non-linear higher-order unnormalized cross-correlations of spectral moduli, for the diagnosis of complex assets, are proposed. The normalization of the proposed techniques is based on the absolute central moments, that have been proposed and widely investigated in mathematical works. The existing higher-order, crosscovariances of complex spectral components are not sufficiently...
-
On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublikacjaIn this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...
-
Discrete-time estimation of nonlinear continuous-time stochastic systems
PublikacjaIn this paper we consider the problem of state estimation of a dynamic system whose evolution is described by a nonlinear continuous-time stochastic model. We also assume that the system is observed by a sensor in discrete-time moments. To perform state estimation using uncertain discrete-time data, the system model needs to be discretized. We compare two methods of discretization. The first method uses the classical forward Euler...
-
Markov Model of Disease Development and Recovery
PublikacjaMarkov models are commonly used to simulate diseases and allow modeling of multiple health states and outcomes. Starting with the well known Le Bras multistate model (cascading failure model) with time-independent transitions we will see how simple Markov mortality models may be pressed into the service of survival and event history analysis. We will focus on more complex models which will be able to take into account remission,...
-
Analysis of the Application of Horizontal Directional Drilling
PublikacjaConstruction works are often considered to be very intrusive for the environment. Project designers assume deep excavations, or a complete replacement of the ground within the investment, which sometimes changes the initial conditions drastically. The problem started to appear in places, where the terrain is complicated and the excavation is burdensome. Some of state authorities...
-
Doped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquids
PublikacjaThis paper reports the application of doped nanocrystalline diamond (NCD) films—nitrogen-doped NCD and boron-doped NCD—as reflective surfaces in an interferometric sensor of refractive index dedicated to the measurements of liquids. The sensor is constructed as a Fabry–Pérot interferometer, working in the reflective mode. The diamond films were deposited on silicon substrates by a microwave plasma enhanced chemical vapor deposition...
-
Multistage generalized adaptive notch filter with improved accuracy
PublikacjaGeneralized adaptive notch filters (GANFs) are estimators of coefficients of quasi-periodically time-varying systems. Current state of the art GANFs can deliver highly accurate estimates of system variations’ frequency, but underperform in terms of accuracy of the coefficient estimates. The paper proposes a novel multistage GANF with accuracy improved in this aspect. The processing pipeline consists of three stages. The preliminary...
-
Verification of Formulas for Periods of Adjacent Buildings Used to Assess Minimum Separation Gap Preventing Structural Pounding during Earthquakes
PublikacjaInsufficient separation distance between adjacent buildings may lead to serious damages during earthquakes due to structural pounding. The best way to prevent collisions is to provide sufficiently large separation distance between the structures. In this paper, the periods of two closely-spaced linear and nonlinear buildings have been investigated so as to accurately assess the minimum in-between separation gap. A new equation...
-
Equivalent single-layer models in deformation analysis of laminated multilayered plates
PublikacjaThe performance of selected Equivalent Single-Layer (ESL) models is evaluated within several classical benchmark tests for linear static analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation theory (FOSD) with some modifications incorporated including a correction of the transverse shear stiffness and an application of zig-zag type functions. Seven...
-
Nitrogen-Doped Diamond Film for Optical Investigation of Hemoglobin Concentration
PublikacjaIn this work we present the fabrication and characterization of a diamond film which can be utilized in the construction of optical sensors for the investigation of biological samples. We produced a nitrogen-doped diamond (NDD) film using a microwave plasma enhanced chemical vapor deposition (MWPECVD) system. The NDD film was investigated with the use of scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman...
-
Monitoring of n-butanol vapors biofiltration process using an electronic nose combined with calibration models
PublikacjaMalodours, by definition, are generally unpleasant, nuisance smells that are a mixture of volatile chemical compounds which can be perceptible even at low concentrations. Due to the more frequent occurrence of odour nuisance associated with the odour sensations, and thus the need to remove them from the air, deodorization techniques are commonly used. Biofiltration is one of the methods of reducing odorants in the air stream. In...
-
The analysis of the accuracy of spatial models using photogrammetric software: Agisoft Photoscan and Pix4D
PublikacjaThis article was created as a result of research conducted within the master thesis. The purpose of the measurements was to analyze the accuracy of the positioning of points by computer programs. Selected software was a specialized computer software dedicated to photogrammetric work. For comparative purposes it was decided to use tools with similar functionality. As the basic parameters that affect the results selected the resolution...
-
On the interspike-intervals of periodically-driven integrate-and-fire models
PublikacjaWe analyze properties of the firing map, which iterations give information about consecutive spikes, for periodically driven linear integrate-and-fire models. By considering locally integrable (thus in general not continuous) input functions, we generalize some results of other authors. In particular, we prove theorems concerning continuous dependence of the firing map on the input in suitable function spaces. Using mathematical...
-
Nonlinear phenomena of small-scale sound in a gas with exponential stratification
PublikacjaThe nonlinear dynamics of perturbations, quickly varying in space, with comparatively large characteristic wavenumbers k: k>1/H, is considered. H is the scale of density and pressure reduction in unperturbed gas, as the coordinate (H is the so-called height of the uniform equilibrium gas). Coupling nonlinear equations which govern the sound and the entropy mode in a weakly nonlinear flow are derived. They describe the dynamics...
-
Central-force decomposition of spline-based modified embedded atom method potential
PublikacjaCentral-force decompositions are fundamental to the calculation of stress fields in atomic systems by means of Hardy stress. We derive expressions for a central-force decomposition of the spline-based modified embedded atom method (s-MEAM) potential. The expressions are subsequently simplified to a form that can be readily used in molecular-dynamics simulations, enabling the calculation of the spatial distribution of stress in...
-
The luminescence study of Bi-doped Cs2AgInCl6 double perovskite.
Dane BadawczeHere, we report a halide precursor acid precipitation method to synthesize Cs2AgIn1−xBixCl6 (x = 0, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, and 1) microcrystals. Cs2AgInCl6 and Bi derivative double perovskites show broadband white light emission via self-trapped excitons (STEs) and have achieved the highest internal quantum efficiency of up to 52.4% at...
-
Computing dynamical curlicues
Dane BadawczeA curlicue is a piece-wise linear curve in the complex plane which can be generated by an arbitrary sequence of real numbers u_n. It can be interpreted as a trajectory of a particle in the plane which starts in the origin at time t=0 and moves with a constant velocity, changing its direction at instances t=0,1,2,3,..., where the new direction is given...
-
Unmasking the COVID-19 Pandemic Prevention Gains: Excess Mortality Reversal in 2022
PublikacjaObjectives: The purpose of this study was to assess the long-term effectiveness of COVID-19 pandemic prevention measures in saving lives after European governments began to lift restrictions. Study design: Excess mortality interrupted time series.Methods: Country-level weekly data on deaths were fitted to the Poisson mixed linear model to estimate excess deaths. Based on this estimate, the percentage of excess deaths...
-
The geometry of free-standing titania nanotubes as a critical factor controlling their optical and photoelectrochemical performance
PublikacjaTitanium dioxide nanotubes are regarded as one of the most important functional materials and due to their unique electronic properties, chemical stability and photocorrosion resistance, they find applications in, for example, highly efficient photocatalysis or perovskite solar cells. Nevertheless, modification of TiO2 nanotubes is required to overcome their main drawback, i.e. large energy bandgap (>3.2 eV) limiting their ability...
-
Stateczność i niezawodność pełnomorskich platform wiertniczych
PublikacjaW pracy przedstawiono wieloletnie doświadczenia Autora w zakresie wybranych aspektów numerycznej analizy pełnomorskich platform wiertniczych, w szczególności stacjonarnych platform stalowych poddanych działaniu fal wiatrowych i wiatru. W opisie zachowania się platform uwzględniono współoddziaływanie trzech ośrodków: materiału konstrukcji, morskich fal wiatrowych i podłoża gruntowego. Przyjęcie do opisu stochastycznych właściwości...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K01
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate folders).Specimen...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K09 - full run
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K06
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K04
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate folders).Specimen...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K09 - pre-run (10s)
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - PARAFFIN OIL. Specim. set K08
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: PARAFFIN OIL. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K07
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K05
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate folders).Specimen...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). Lubricant - DISTILLED WATER. Specim. set K02
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DISTILLED WATER. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate...
-
Wear in reciprocating siding friction tests. Ball-on-flat contact. Sintered alumina ceramics (98%). No lubrication (DRY). Specim. set K03
Dane BadawczeFriction and wear tests in ball-on-flat contact. Both specimens made of sintered alumina ceramics (98%) - self-mated contact.Linear reciprocating motion.Lubrication: DRY. Sliding velocity (peak): 0.1 m/s. Load (normal force): 5N. Test rig: TPZ-1 Tribometer.Running time: progressive increments of 10, 15, 30, 60, 180 and 300s. (stored in separate folders).Specimen...
-
Evolution of artificial single-cell organisms foraging for resources in a 3-dimensional environment
PublikacjaForaging for resources is a simple cognitive task that even one-celled biological organisms can ac- complish. We present an Artificial Life system in which artificial unicellular organisms (animats) forage for food in a 3-dimensional simulated liquid environment. The movement of animats is controlled by evolving artificial gene regulatory networks encoded in linear genomes. When an animat consumes enough food, it produces offspring...
-
Multi-sensor monitoring of the corrosion rate and the assessment of the efficiency of a corrosion inhibitor in utility water installations
PublikacjaThis paper presents an implementation of the monitoring of the corrosion rate and the assessment of the efficiency of a corrosion inhibitor in a utility water installation using an automated corrosion monitoring system. Due to the fact that the corrosion inhibitor was added to water intended for human consumption, it was necessary to build a multi-sensor monitoring system. In order to implement corrosion monitoring using a linear...
-
Parameters’ Identification of Perzyna and Chaboche Viscoplastic Models for Aluminum Alloy at Temperature of 120◦C
PublikacjaThe main purpose of this paper is the parameters identification of the Perzyna and the Chaboche models for the aluminum alloy at elevated temperature. The additional purpose is comparison of the results for these viscoplastic models. The results have been verified by the numerical simulation of the laboratory tests. The material parameters have been calculated on the basis of the uniaxial tension test. The determination of the...
-
Formation enthalpies of LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) interlanthanide perovskites
PublikacjaHigh-temperature oxide melt solution calorimetry using 3Na2O·MoO3 at 802 °C was performed for interlanthanide perovskites LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) and lanthanide oxides (La2O3, Ho2O3, Er2O3, Tm2O3 and Yb2O3). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO3, −9.9±3.0 kJ/mol for LaErO3, −10.8±2.7 kJ/mol...
-
Applicability of an effective conductivity approach in modeling thoracic impedance changes
PublikacjaThis paper describes numerical simulations of the influence of conductivity changes inside a volume conductor on impedance changes measured on its surface. A simple model based on the finite element method has been developed to estimate an applicability of the effective conductivity theory in human chest modeling. The model consisted of a cylinder with two concentric spheres inside. Simulations were performed for two cases: first...
-
BLOOD PRESSURE ESTIMATION BY MEANS OF A JOINT IMPEDANCE– PHOTOPLETYSMOGRAPHIC METHOD
PublikacjaThe knowledge of patient’s day to day blood pressure changes is invaluable to physicians for both diagnostics and health monitoring reasons. Constant observation of the pressure throughout a day would provide even more valuable clinical information. A convenient non-invasive methods of blood pressure estimation for monitoring purposes are widely proposed. This work shows a statistical approach to...
-
IMPACT OF DIRECT CURRENT ON NITRIFYING BIOMASS
PublikacjaEffects of short term exposure of nitrifying biomass to direct current were studied. DC was applied to mixed liquor from municipal BNR plant using graphite electrodes in no substrate limiting conditions. Both, ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) populations were affected by the current, however in opposite ways. The AOB population activity was inhibited by applied voltage. Activity decrease was...
-
Z type Observer Backstepping For Induction Machines
PublikacjaThis paper contains a relatively new synthesis method for non-linear objects, named backstepping. This method can be used to obtain the observer structure. The paper presents the structure of the speed observer which is a new proposition of observer backstepping with additional state variables marked Z. The rotor speed can be estimated in three different ways. The first is based on the adaptive approach, the second on the nonadaptive...
-
1+1 Protection of Overlay Distributed Computing Systems: Modeling and Optimization
PublikacjaW niniejszym artykule przedstawiono autorską koncepcję ochrony transmisji od krańca do krańca (ang. 1+1 protection) dla systemów przetwarzania rozproszonego (ang. distributed computing systems). Artykuł prezentuje nowatorskie rozwiązanie dedykowane systemom typu ''overlay'', w których system przetwarzania rozproszonego stanowi warstwę najwyższą w warstwowej architekturze sieci, korzystającą z usług warstwy sieci transportowej....
-
Measurement of benzene concentration in urban air using passive sampling
PublikacjaAbstract The concentration of benzene in urban air in theTri-City area of Poland (Gdańsk-Sopot-Gdynia, andTczew) was assessed using diffusive passive samplers (Rad-iello). Samples were collected during a four-year monitoringcampaign (2007-2010) at selected monitoring stations man-aged by the Agency of Regional Air Quality Monitoring inthe Gdańsk Metropolitan Area (ARMAAG) Foundation.The performance of the passive samplers was investigatedin...
-
A Mechatronic System for Building the Map of Optimal Spindle Speeds During High Speed Milling of Flexible Details
PublikacjaW pracy przedstawiono mechatroniczny system tworzenia mapy optymalnych prędkości obrotowych wrzeciona w celu nadzorowania drgań typu chatter podczas frezowania szybkościowego przedmiotów podatnych. System ten składa się z części pomiarowej oraz części obliczeniowej, w której wykorzystuje się oprogramowanie autorskie i komercyjne. Na bazie uogólnionego warunku Liao-Younga utworzono mapy optymalnych prędkości obrotowych wrzeciona,...
-
Novel Interpolation Method of Multi-DFT-Bins for Frequency Estimation of Signal with Parameter Step Change
PublikacjaThe IpDFT(Interpolation Discrete Fourier Trans-form) method is one of the most commonly used non-parametric methods. However, when a parameter (frequency, amplitude or phase) step changes in the DFT period, the DFT coefficients will be distorted seriously, resulting in the large estimation error of the IpDFT method. Hence, it is a key challenge to find an IpDFT method, which not only can eliminate the effect of the step-changed...
-
The Methodology for Determining the Theoretical Based on the Characteristics of Effective Absorbency Versus Pressure Drop in the Motor
PublikacjaThis article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in...
-
System Loss Model for Body Area Networks in Room Scenarios
PublikacjaThis paper presents an analysis of system loss in Body Area Networks for room scenarios, based on a wideband measurement campaign at 5.8 GHz. The measurements were performed with a fixed antenna transmitting vertically and horizontally polarised signals, while the user wears dualpolarised antennas. The average system losses in co- and crosspolarised channels are 41.4 and 42.6 dB for vertically polarised transmitted signals and...
-
ICT-enabled circular economy: conceptualising the links
PublikacjaThis chapter sets conceptual backgrounds regarding the potentially emerging causal links between digital technologies and circular economy ideas implementation. We argue that digital technologies may constitute an effective element enabling the transformation from linear to circular and environmentally friendly economic activities. This work draws the general picture at the macro and micro level. The macro perspective shows how...
-
Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures
PublikacjaThis article discusses the application of impedance analysis for diagnosing the cathode of a direct methanol fuel cell at various operating temperatures. The Dynamic Electrochemical Impedance Spectroscopy technique coupled with a linear current scan was applied for this purpose. This technique allowed the observation of changes in the cathode's properties in the fuel cell operating under real working conditions. An equivalent model...