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Wyniki wyszukiwania dla: SWITCHED-BEAM ANTENNA, ELECTRONICALLY STEERABLE PARASITIC ARRAY RADIATOR (ESPAR) ANTENNA, DIRECTION-OF-ARRIVAL (DOA), MULTIPLE CALIBRATION PLANES (MCP) METHOD, RECEIVED SIGNAL STRENGTH (RSS), WIRELESS SENSOR NETWORK (WSN)
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An Analysis of Elliptical-Rectangular Multipatch Structure on Dielectric-Coated Confocal and Nonconfocal Elliptic Cylinders
PublikacjaA rigorous analysis of the resonance frequency problem of an elliptical-rectangular microstrip structure mounted on dielectric-coated elliptic conducting cylinder, with electrically small radius, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. The complex resonance frequencies of...
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T1 RELAXATION TIME CALLIBRATION IN MAGNETIC RESONANCE IMAGING USING NANODIAMOND PHANTOMS
PublikacjaMRI is increasingly used in radiation treatment planning because of the excellent soft tissue contrast in the obtained images. It allows more precise definition of the boundaries between healthy tissues and those affected by cancerous lesions. To obtain good image quality, the difference in signal between two types of tissue must be significant despite the noise so it must be properly calibrated. This calibration includes...
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A Biofeedback System that Uses the Game to Study Electrical Muscle Activity
PublikacjaThe aim of this project was to design a system that will allow performing repetitive muscle exercises using a biofeedback device. It is supposed to enhance the motivation and attractiveness of the performed tasks thanks to an interactive game developed for mobile devices with the Android operating system. The built-in calibration mechanisms enable the users to play a game that is independent of their abilities which evens out the...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Data fusion of GPS sensors using Particle Kalman Filter for ship dynamic positioning system
PublikacjaDepending on standards and class, dynamically positioned ships make use of different numbers of redundant sensors to determine current ship position. The paper presents a multi-sensor data fusion algorithm for the dynamic positioning system which allows it to record the proper signal from a number of sensors (GPS receivers). In the research, the Particle Kalman Filter with data fusion was used to estimate the position of the vessel....
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Low-Cost Behavioral Modeling of Antennas by Dimensionality Reduction and Domain Confinement
PublikacjaBehavioral modeling has been rising in importance in modern antenna design. It is primarily employed to diminish the computational cost of procedures involving massive full-wave electromagnetic (EM) simulations. Cheaper alternative offer surrogate models, yet, setting up data-driven surrogates is impeded by, among others, the curse of dimensionality. This article introduces a novel approach to reduced-cost surrogate modeling of...
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Investigation of the impact of ITRF2014/IGS14 on the positions of the reference stations in Europe
PublikacjaIn January 2017, the new realization of the International Terrestrial Reference Frame (ITRF) – ITRF2014, was released. Besides the higher accuracy and consistency of the new frame, an entirely new element – the post seismic deformation - was included. Moreover, the definition of the fundamental points has also been changed. All changes related to the new reference frame haveconsequences in the precise positioning using GNSS observations....
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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublikacjaData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Coplanar Waveguide-Fed Broadband Microwave Devices with (or without) a Thin Dielectric Substrate for Use in Flexible Electronic Systems
PublikacjaTwo examples of microwave devices, fed by a coplanar waveguide and realized on a thin substrate (or without such a substrate), are employed to investigate the influence of devices’ curvatures and the proximity of different materials on their parameters. To perform the tests, a broadband antenna and a low-pass filter are chosen. A feeding coplanar waveguide is realized on a dielectric material brick attached to an SMA connector...
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Dual-Polarized Wideband Bandpass Metasurface-Based Filter
PublikacjaThis paper presents a novel metasurface-based bandpass filter. The structure is realized by simply patterning a double-sided AD250 substrate, and does not require any vias or insertion of lumped elements. The top layer is an annular- aperture-array with multiple inner conductors, whereas the bottom layer is a first-order Hilbert-curve array. FEM-based simulation results of the filter are obtained using HFSS. The experimental validation...
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Selected acoustic images of the Gdansk Bay
PublikacjaThe main goal of the paper is to describe the results of sounding the Gdansk Bay seabed by using a parametric sub-bottom profiler, multibeam echosounder and side scan sonar. Quality of dsata obtained during trials depends interalia on a proper location of antenna to reduce influence of pitch, roll and heave motions as well as ship noise.
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Opracowanie procedury i badania wytrzymałościowe połączeń spawanych pomiędzy rurą kwadratowa a elementami giętymi na zimno ze stali S355 oraz testowanie połączeń o grubości 4, 6, 8mm typu S355
PublikacjaCelem pracy było: - opracowanie procedury badania wytrzymałości połączeń spawanych rozciąganych w kierunku prostopadłym i w kierunku równoległym (ścinanych) do osi spoiny. Spoiny te łączyły elementy rur kwadratowych o różnej grubości z elementami w kształcie ceownika giętymi na zimno. - wykonanie próbek do badań wytrzymałościowych wyciętych z elementów spawanych dostarczonych przez Zakład Produkcyjny firmy Borga obciążonych prostopadle...
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Resilient Routing in Communication Networks
PublikacjaThis important text/reference addresses the latest issues in end-to-end resilient routing in communication networks. The work highlights the main causes of failures of network nodes and links, and presents an overview of resilient routing mechanisms, covering issues related to the Future Internet (FI), wireless mesh networks (WMNs), and vehicular ad-hoc networks (VANETs). For each of these network architectures, a selection of...
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Fluctuation-Enhanced Sensing
PublikacjaFluctuation-enhanced sensing (FES) is an exciting and relatively new research field that promises to extend the range of information that can be extracted from a single sensor. In FES, the stochastic fluctuations of the sensor signal, rather than its average value, are recorded and analyzed. Typical components of such fluctuations are due to interactions at the microscopic level. Proper statistical analysis provides optimum sensory...
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Functional fluorine-doped tin oxide coating for opto-electrochemical label-free biosensors
PublikacjaSensors operating in multiple domains, such as optical and electrochemical, offer properties making biosensing more effective than those working in a single domain. To combine such domains in one sensing device, materials offering a certain set of properties are required. Fluorine-doped tin oxide (FTO) thin film is discussed in this work as functional optically for guiding lossy modes and simultaneously electrochemically, i.e....
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Application of passive acoustic radar to automatic localization, tracking and classification of sound sources
PublikacjaA concept, practical realization and applications of the passive acoustic radar to automatic localization, tracking and classification of sound sources were presented in the paper. The device consists of a new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. Contrary to active radars, it does not emit the scanning beam but after receiving surrounding sounds it provides...
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Improving the accuracy of bearing in active sonar with cylindrical array using spectrum estimation.
PublikacjaThe articles presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. Based on a known spatial spectrum estimation technique, the method has been successfully used in linear array systems. Its accuracy of bearing is satisfactory and ensures a relatively low computational effort. The article discusses certain simplifications and assumptions to adapt the spatial spectrum estimation technique...
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Enhanced Eye-Tracking Data: a Dual Sensor System for Smart Glasses Applications
PublikacjaA technique for the acquisition of an increased number of pupil positions, using a combined sensor consisting of a low-rate camera and a high-rate optical sensor, is presented in this paper. The additional data are provided by the optical movement-detection sensor mounted in close proximity to the eyeball. This proposed solution enables a significant increase in the number of registered fixation points and saccades and can be used...
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Signal propagation in electromagnetic media described by fractional-order models
PublikacjaIn this paper, signal propagation is analysed in electromagnetic media described by fractional-order (FO) models (FOMs). Maxwell’s equations with FO constitutive relations are introduced in the time domain. Then, their phasor representation is derived for one-dimensional case of the plane wave propagation. With the use of the Fourier transformation, the algorithm for simulation of the non-monochromatic wave propagation is introduced....
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Pressure-induced flow processing behind the superior mechanical properties and heat-resistance performance of poly(butylene succinate)
PublikacjaWe propose a pressure-induced flow (PIF) processing method for the simultaneous enhancement of strength, toughness, and heat resistance of biodegradable poly(butylene succinate) (PBS). The pressure and temperature were systematically adjusted to optimize the tensile strength of PBS. Under the optimized processing conditions, the structured PBS was characterized by relatively high strength of 89.5 MPa, toughness of 21.4 kJ·m−2 ,...
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Experimental evaluation of estimator mean square error curve for cognitive tracking radar
PublikacjaTo make decisions, cognitive radar must rely on predictions of its own performance. In the literature, these predictions are usually based on some form of Cram\'er-Rao lower bound. This approach is scientifically sound, but it also brings a possibility of the cognitive controller overestimating radar performance. It therefore makes sense to back theoretical predictions with careful experiments which will verify their applicability....
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Intelligent PI controller and its application to dissolved oxygen tracking problem
PublikacjaThe paper addresses design, calibration, implementation and simulation of the intelligent PI controller used for dissolved oxygen (DO) tracking in wastewater treatment plant (WWTP). The calibration process presented in this paper utilizes both engineering and scientific methods. Verification of the control system design method was obtained via simulation experiments.
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Laboratory investigation with subbottom parametric echosounder SES-2000 standard with an emphasis on reflected pure signals analysis
PublikacjaThe main goal of the paper is to describe correlations between measurements results of trials taken on Gulf of Gdańsk bottom sounded with parametric echosounder SES-2000 Standard and laboratory research where collected during survey sediments were measured. Stationary tests took place at Gdansk University of Technology where 30 meters long 1.8 meter deep and 3 meters wide water tank is located. Main lobe of antenna was directed...
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COMPARISON OF SYSTEM ON CHIP TECHNOLOGIES FOR SPACE APPLICATIONS
PublikacjaThe paper presents a review of technologies available for the implementation of digital and mixed signal systems, particularly the system on a chip (SoC) for space applications. The phenomena encountered in the space environment are briefly presented, together with the known solutions, regarding the design of complex electronic systems. The most important norms regarding single die integrated circuits designed for space are also...
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Artificial Neural Networks as an architectural design tool- generating new detail forms based on the Roman Corinthian order capital
PublikacjaThe following paper presents the results of the research in the field of the machine learning, investigating the scope of application of the artificial neural networks algorithms as a tool in architectural design. The computational experiment was held using the backward propagation of errors method of training the artificial neural network, which was trained based on the geometry of the details of the Roman Corinthian order capital....
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Sensitivity analysis of a composite footbridge
PublikacjaThis work include an example of sensitivity analysis for the design of a composite footbridge. A sandwich structure is used, consisting two high-strength skins separated by a core material. The analysis was conducted for two numerical models. The first one is a simple, single-span beam of a composite cross-section (laminate and foam), with different Young’s modulus for each material. Calculations were made by means of a MATLAB-based...
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How to provide fair service for V2I communications in VANETs?
PublikacjaIn this paper, we focus on fairness issues of Vehicle-to-Infrastructure (V2I) communications. In particular, we show that under a common technique of selection of RSUs by OBUs based on the received signal strength, a vast variability of a number of OBUs connected to RSUs can be observed leading to inefficient/unfair service provided by RSUs. To overcome this problem, we propose an algorithm for RSU selection called RSEL to obtain...
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Określenie położenia za pomocą sieci bezprzewodowej w standardzie ZigBee
PublikacjaMimo wprowadzenia systemu nawigacji GPS, nadal istnieje zapotrzebowanie na inne, tańsze systemy lokalizacji położenia, w szczególności pracujące w pomieszczeniach, gdzie często nie dochodzi sygnał z satelity. Taki system można zrealizować za pomocą bezprzewodowej sieci czujników w standardzie ZigBee za pomocą kilku różnych metod. W pracy przedstawiono metodę RSSI (ang.: Received Signal Strength Indicator) oceny odległości za pomocą...
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Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
PublikacjaObjective. The aim of the study is to investigate the effect of the signal sampling frequency and low-pass filtering on the accuracy of the localisation of the fiducial points of the photoplethysmographic signal (PPG), and thus on the estimation of the blood pressure (i.e. the accuracy of the estimation). Approach. Statistical analysis was performed on 3,799 data samples taken from a publicly available database. Four PPGfiducial...
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Multi-objective optimization of expensive electromagnetic simulation models
PublikacjaVast majority of practical engineering design problems require simultaneous handling of several criteria. For the sake of simplicity and through a priori preference articulation one can turn many design tasks into single-objective problems that can be handled using conventional numerical optimization routines. However, in some situations, acquiring comprehensive knowledge about the system at hand, in particular, about possible...
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A Novel Trust-Region-Based Algorithm with Flexible Jacobian Updates for Expedited Optimization of High-Frequency Structures
PublikacjaSimulation-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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The structure of the control system for a dynamically positioned ship
PublikacjaThe article discusses functions and tasks of dynamic positioning (DP) systems for ships. The analysed issues include ship steering, in particular stabilisation of ship position and direction of motion (real course) at low manoeuvring speeds, and commonly used DP ship models. Requirements imposed by classification societies on DP ships are quoted. A multi-layer structure of the DP control system is presented, with special attention...
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Fitting the mobile device characteristics to the user's hearing preferences
PublikacjaA method for fitting the mobile computer audio characteristics to the user's hearing preferences is proposed. The process consists of two stages: calibration and dynamics processing. During the calibration phase the user performs a loudness scaling test giving their response regarding the perceived loudness. The dynamics processing made on above basis sets the loudness to the most comfortable level. The processing accounts both...
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MSIS sonar image segmentation method based on underwater viewshed analysis and high-density seabed model
PublikacjaHigh resolution images of Mechanically Scanned Imaging Sonars can bring detailed representation of underwater area if favorable conditions for acoustic signal to propagate are provided. However to properly asses underwater situation based solely on such data can be challenging for less than proficient interpreter. In this paper we propose a method to enhance interpretative potential of MSIS image by dividing it in to subareas depending...
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Investigation of Continuous Wave Jamming in an IEEE 802.15.4 Network
PublikacjaThis paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...
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Wzmocnienie uszkodzonej belki typu T w przęśle wiaduktu drogowego
PublikacjaW artykule opisano metodę wzmocnienia belki prefabrykowanej typu T dźwigara wiaduktu drogowego uszkodzonej przez pojazd „wozidło”. Beton belki uległ zarysowaniom w wielu miejscach. Wystąpiły też ubytki otuliny strun sprężających. Zaproponowano naprawę i wzmocnienie przez dobetonowanie dodatkowej belki. Podczas naprawy zastosowano balastowanie przęsła w celu wciągnięcia nowego dźwigara do współpracy od ciężaru własnego i sprężenia....
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Cooperative Data Transmission in Wireless Vehicular Networks
PublikacjaThe paper presents issues related to the cooperative transmission in wireless vehicular networks. Cooperative transmission involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. The paper presents the methods used to implement cooperative transmission and the types of cooperative networks.
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Numerical Modeling of Cone Penetration Test in Slightly Overconsolidated Clay with Arbitrary Lagrangian-Eulerian Formulation
PublikacjaIn this paper the results of the cone penetration test (CPT) modeling with the arbitrary Lagrangian-Eulerian (ALE) formulation provided by Abaqus software package have been presented. The study compares the cone resistance and sleeve friction obtained in numerical analysis with values measured in soundings performed in the uniform layer of clayey soil in the Koszalin area. The clay layer was found to be slightly overconsolidated...
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Selected properties and parameters of radio channel impulse response estimation in ISM 2.4 GHz band
PublikacjaThe article presents experimental research indicating that the impulse response of the communication channel, determined in practice, are not of an universal character, but only represent its approximate value for the frequency on which this measurement was made. Phases for each of the replicas of the measurement signal were determined during the analysis of the received signals in the baseband. Phase changes of individual replicas...
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Fiber optic microsphere with a ZnO thin film for potential application in a refractive index sensor – theoretical study
PublikacjaOptical fiber sensors of refractive index play an important role in analysis of biological and chemical samples. This work presents a theoretical investigation of spectral response of a fiber optic microsphere with a zinc oxide (ZnO) thin film deposited on the surface and evaluates the prospect of using such a structure for refractive index sensing. A microsphere is fabricated by an optical fiber tapering method on the base of...
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Dual polarization antennas for UHF RFID readers
PublikacjaThis paper presents various concepts of switching polarization in patch antenna dedicated for UHF RFID readers. Proposed designs allow for switching between linear and circular polarization. The first design does not require electronic switching as the polarization can be changed by choosing one of two available feeding terminals. Two remaining designs use PIN diode or FET SPDT switch.
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System Weryfikacji Autentyczności Podpisu Odręcznego
PublikacjaW referacie przedstawiono system statycznej i dynamicznej weryfikacji autentyczności podpisu odręcznego, składanego piórem biometrycznym, wyposażonym w 2 akcelerometry, 2 żyroskopy i 3 czujniki ścisku, na rezystancyjnej powierzchni dotykowej, łączącym się bezprzewodowo z urządzeniami komputerowymi. We wstępie przedstawiono architekturę sieciową wielomodalnego systemu biometrii. Przedstawiono warstwę sprzętową systemu weryfikacji...
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Comparative analysis of switched reluctance motor control algorithms
PublikacjaПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Comparative analysis of switched reluctance motor control algorithms
PublikacjaПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Automatic labeling of traffic sound recordings using autoencoder-derived features
PublikacjaAn approach to detection of events occurring in road traffic using autoencoders is presented. Extensions of existing algorithms of acoustic road events detection employing Mel Frequency Cepstral Coefficients combined with classifiers based on k nearest neighbors, Support Vector Machines, and random forests are used. In our research, the acoustic signal gathered from the microphone placed near the road is split into frames and converted...
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Analysis of IMS/NGN call processing performance using phase-type distributions
PublikacjaThis work is a continuation of our research on the traffic model dedicated for design and analysis of the Next Generation Network (NGN), which is standardized for distribution of current and future multimedia services based on the IP Multimedia Subsystem (IMS). Our analytical and simulation models allow evaluation of mean Call Set-up Delay E(CSD) as well as mean Call Disengagement Delay E(CDD) in a single domain of IMS/NGN. Ensuring...
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Electric transport in organic system with planar DBP/F16ZnPc junction on the basis of direct current and small signal admittance spectra analysis
PublikacjaThe objective of this work was to determine electric transport in the organic device based on a planar junction of electron donor and electron acceptor materials, namely ITO/MoO3/DBP/F16ZnPc/BCP/Ag. The analysis reported herein was based on direct current-voltage measurements and small-signal admittance spectra in the dark and under illumination. Such analysis may provide information on potential barriers, parasitic resistances...
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Performance-Driven Inverse/Forward Modeling of Antennas in Variable-Thickness Domains
PublikacjaDesign of contemporary antenna systems is a challenging endeavor. The difficulties are partially rooted in stringent specifications imposed on both electrical and field characteristics, demands concerning various functionalities, but also constraints imposed upon the physical size of the radiators. Furthermore, conducting the design process at the level of full-wave electromagnetic (EM) simulations, otherwise dictated by reliability,...
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Spatio-temporal filtering for determination of common mode error in regional GNSS networks
PublikacjaThe spatial correlation between different stations for individual components in the regional GNSS networks seems to be significant. The mismodelling in satellite orbits, the Earth orientation parameters (EOP), largescale atmospheric effects or satellite antenna phase centre corrections can all cause the regionally correlated errors. This kind of GPS time series errors are referred to as common mode errors (CMEs). They are usually...