displaying 1000 best results Help
Search results for: SWITCHED-BEAM ANTENNA, ELECTRONICALLY STEERABLE PARASITIC ARRAY RADIATOR (ESPAR) ANTENNA, DIRECTION-OF-ARRIVAL (DOA), MULTIPLANE CALIBRATION METHOD, RECEIVED SIGNAL STRENGTH (RSS), WIRELESS SENSOR NETWORK (WSN)
-
Electrical and noise responses of carbon nanotube networks enhanced by UV light for detection of organic gases (ethanol, acetone)
Open Research DataCarbon nanotube networks of different optical transparencies were investigated via resistance and 1/f noise measurements for detection of ethanol and acetone. The sensor resistive and noise responses were collected for dark and UV-assisted conditions, revealing the improvement in sensor sensitivity and limit of detection after applying UV light (275...
-
Application of ANN and PCA to two-phase flow evaluation using radioisotopes
PublicationIn the two-phase flow measurements a method involving the absorption of gamma radiation can be applied among others. Analysis of the signals from the scintillation probes can be used to determine the number of flow parameters and to recognize flow structure. Three types of flow regimes as plug, bubble, and transitional plug – bubble flows were considered in this work. The article shows how features of the signals in the time and...
-
CRVG - a new model for wireless networks topology generation
PublicationThis paper presents a new model of wireless network topology generator. Its main advantage is the possibility of relatively sparse networks generation. Because no iteration is needed, the model can be used for massive generation of networks for testing. The topological properties of produced graphs place them in the class of scale free networks, resembling real ones.
-
Novel Complementary Resonator for Dielectric Characterization of Substrates Based on Permittivity and Thickness
PublicationThis paper presents a novel complementary resonator featuring high sensitivity, low fabrication cost, and improved performance. The proposed structure consists of a complementary concentric square and circular ring resonator (CCSCRR) with multiple splits to enhance the inductance of the resonator. The proposed CCSCRR is coupled to a microstrip transmission line with an impedance of fifty ohms to create a high-sensitivity sensor....
-
The radiated immunity test of an astable multivibrator at over-normative field strengths
Open Research DataThe dataset presents a result of measurements that are a part of electromagnetic field immunity tests. The radiated, radio frequency, immunity tests were carried out for a typical astable electronic multivibrator. Tests of immunity of electronic systems to radiated radio frequency (RF) disturbances in the frequency range from 80 MHz to 1 GHz were performed...
-
Diagnostics of pillars in St. Mary’s Church (Gdańsk, Poland) using the GPR method
PublicationThe main goal of this study was non-destructive evaluation of pillars in the St. Mary’s Church (Gdańsk, Poland) using the ground penetrating radar (GPR) technique. The GPR inspection was conducted on four brick masonry pillars and five pillars strengthened by reinforced concrete jacketing. Data were acquired with a 2 GHz antenna along longitudinal and transverse profiles. The study involved the estimation of the electromagnetic...
-
Non-destructive Diagnostics of the Floor in the Gdańsk Crane Using Ground Penetrating Radar = Diagnostyka nieniszcząca posadzki w gdańskim Żurawiu z zastosowaniem metody georadarowej
PublicationThis paper presents the results of a ground penetrating radar (GPR) survey carried out at the Crane in Gdańsk. The measurements were conducted on the floor of the southern and northern towers. The aim of the experiment is to assess the possibility of detecting anomalies beneath the floor. The surveys were carried out in a non-destructive manner, using a georadar unit with 2 GHz and 400/900 MHz antennas. This paper compares the...
-
DS-CDMA receiver in Software Defined Radio technology. Admission to the implementation of a RAKE receiver
PublicationProgrammable radio is one of the latest trends in the construction of multi-standard receivers. The technology, called Software Defined Radio (SDR), is also an ideal test platform that allows to try out different algorithms of signal receiving. This particular feature led to choose this platform to implement a DS-CDMA receiver (Direct Sequence Code Division Multiple Access). The use of SDR allows for a gradual upgrade of data processing...
-
Supply current signal and artificial neural networks in the induction motor bearings diagnostics
PublicationThis paper contains research results of the diagnostics of induction motor bearings based on measurement of the supply current with usage of artificial neural networks. Bearing failure amount is greater than 40% of all engine failures, which makes their damage-free operation crucial. Tests were performed on motors with intentionally made bearings defects. Chapter 2 introduces the concept of artificial neural networks. It presents...
-
Optimization of the efficiency of braking energy recovery in rail transport by changing arrival time
PublicationThe article refers to the previous work of the authors, in which the model of traffic organization of cooperating trains including the optimization of the use of energy returned to the catenary was presented. In the presented article, the model was modified by changing the main control variable, which affects the efficient use of energy. Departure time was changed for the arrival time of the train to the stop or station. The optimization...
-
Analiza porównawcza metod zwiększania nośności i sztywności stalowych, doczołowych węzłów śrubowych.
PublicationInnowacyjna, w porównaniu z dotychczas stosowanym sposobem, metoda obliczania nośności stalowych węzłów została wdrożona wraz z normami europejskimi. Pozwala ona dokładniej odwzo-rować rzeczywistą pracę poszczególnych części węzła, gdyż wynik obliczeń uzależniony jest od znacznie większej liczby zmiennych. Dzięki postępowi technologicznemu w zakresie metalurgii oraz badaniom naukowym obecnie możliwe jest wzmacnianie połączeń...
-
Performance Evaluation of Control Plane Functions in ASON/GMPLS Architecture
PublicationIt is assumed that demands of information society could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded performance evaluation to guarantee society expectations. Practical realization is expensive and simulations models are necessary to examine standardized propositions....
-
Data obtained by computation for X-ray focusing using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of several X-ray refractive lenses is considered. Gaussian beams are exact solutions of the paraxial equation. The Helmholtz equation describes the propagation of a monochromatic electromagnetic wave. Since the widths of the beams are much larger than the wavelength of X-rays, Gaussian...
-
Future research directions in design of reliable communication systems
PublicationIn this position paper on reliable networks, we discuss new trends in the design of reliable communication systems. We focus on a wide range of research directions including protection against software failures as well as failures of communication systems equipment. In particular, we outline future research trends in software failure mitigation, reliability of wireless communications, robust optimization and network design, multilevel...
-
FE investigations of the effect of fluctuating local tensile strength on coupled energetic-statistical size effect in concrete beams
PublicationThe effect of fluctuating local tensile strength on a coupled energetic-statistical size effect in plain concrete beams under bending was numerically investigated. First, the influence of varying autocorrelation length of the random field describing a spatial variation of local tensile strength was studied. Next, the influence of the coefficient of variation of local tensile strength was analyzed. The numerical FE investigations...
-
Wpływ automatycznej kalibracji wizyjnego systemu pozycjonowania na dokładność lokalizacji elementu roboczego
PublicationW artykule przedstawiono strukturę i działanie automatycznego wizyjnego systemu pozycjonowania (PVS), który został zainstalowany na maszynie waterjet (WJ). Ponadto przeprowadzono analizę wpływu kalibracji na działanie PVS. Podstawę systemu stanowią dwie kamery internetowe zamontowane na przemysłowej maszynie WJ. W połączeniu z algorytmem identyfikacji, system przeznaczony jest do pozycjonowania WJ z dużą dokładnością. W tym celu...
-
The development of an underwater telephone for digital communication purposes
PublicationThe underwater telephone HTL-10 has been designed to provide voice and data communication between helicopter and submarines using acoustic waves. It works in a half-duplex mode and uses analogue power-efficient modulation in the form of a single side-band, suppressed carrier, in a wide range of frequencies. It generates the transmitted signal, and processes the received signals. It is implemented with the use of digital signal...
-
High-performance graphene-based biosensor using a metasurface of asymmetric silicon disks
PublicationIn recent years, optical biosensors widely applicable for medical applications, have received much attention. In this paper, we propose a high-performance polarization-insensitive optical biosensor based on a graphene-dielectric metasurface. The metasurface consists of an asymmetric dielectric disk array that supports a high Q-factor Fano resonance. The provided sharp Fano resonance results in an enhanced light-matter interaction...
-
Quality Evaluation of Agricultural Distillates Using an Electronic Nose
PublicationThe paper presents the application of an electronic nose instrument to fast evaluation of agricultural distillates differing in quality. The investigations were carried out using a prototype of electronic nose equipped with a set of six semiconductor sensors by FIGARO Co., an electronic circuit converting signal into digital form and a set of thermostats able to provide gradient temperature characteristics to a gas mixture. A volatile fraction...
-
Process zone in the Single Cantilever Beam under transverse loading. - Part II: Experimental
PublicationThis paper describes an experimental arrangement to evaluate stress/strain fields in the process zone of asymmetric adhesively bonded joints. A transparent polycarbonate flexible beam was bonded to an aluminium alloy rigid block with an epoxy adhesive in a Single Cantilever Beam (SCB) configuration. The flexible adherend was loaded in the direction parallel to the initial crack front at constant rate. To monitor strains induced...
-
Trust-Based Model for the Assessment of the Uncertainty of Measurements in Hybrid IoT Networks
PublicationThe aim of this paper is to introduce a NUT model (NUT: network-uncertainty-trust) that aids the decrease of the uncertainty of measurements in autonomous hybrid Internet of Things sensor networks. The problem of uncertainty in such networks is a consequence of various operating conditions and varied quality of measurement nodes, making statistical approach less successful. This paper presents a model for decreasing the uncertainty...
-
Model organizacji ruchu na sieci kolejowej z uwzględnieniem rekuperacji energii
PublicationNa wstępie przeanalizowano aktualny stan wiedzy z zakresu metod wykorzystywania energii z rekuperacji oraz istniejących modeli optymalizujących ich efektywność. Na tej podstawie za główny cel pracy wyznaczono opracowanie metody modyfikacji kolejowego rozkładu jazdy, która doprowadzi do zwiększenia efektywności wykorzystania energii pochodzącej z rekuperacji. W związku z powyższym postawiono tezę, że możliwe jest zwiększenie efektywności...
-
A Novel Method for Intelligibility Assessment of Nonlinearly Processed Speech in Spaces Characterized by Long Reverberation Times
PublicationObjective assessment of speech intelligibility is a complex task that requires taking into account a number of factors such as different perception of each speech sub-bands by the human hearing sense or different physical properties of each frequency band of a speech signal. Currently, the state-of-the-art method used for assessing the quality of speech transmission is the speech transmission index (STI). It is a standardized way...
-
Path Loss Measurements in Wideband Radio Link Designed for Maritime Environment
PublicationIn the article, the research and analysis of path loss in designed and evaluated digital radio link for high-speed data transmission in maritime environment is presented. Collected samples of received signal were used to determine the mean path loss and its standard deviation. Measuring campaign was carried out in a real maritime conditions. The mean value of path loss reached 126 dB on a distance of 11.16 km.
-
Triangulation-based Constrained Surrogate Modeling of Antennas
PublicationDesign of contemporary antenna structures is heavily based on full-wave electromagnetic (EM) simulation tools. They provide accuracy but are CPU-intensive. Reduction of EM-driven design procedure cost can be achieved by using fast replacement models (surrogates). Unfortunately, standard modeling techniques are unable to ensure sufficient predictive power for real-world antenna structures (multiple parameters, wide parameter ranges,...
-
Multi-fidelity EM simulations and constrained surrogate modelling for low-cost multi-objective design optimisation of antennas
PublicationIn this study, a technique for low-cost multi-objective design optimisation of antenna structures has been proposed. The proposed approach is an enhancement of a recently reported surrogate-assisted technique exploiting variable-fidelity electromagnetic (EM) simulations and auxiliary kriging interpolation surrogate, the latter utilised to produce the initial approximation of the Pareto set. A bottleneck of the procedure for higher-dimensional...
-
Feedline Alterations for Optimization-Based Design of Compact Super-Wideband MIMO Antennas in Parallel Configuration
PublicationThis letter presents a technique for size reduction of wideband multiple-input-multiple-output (MIMO) antennas. Our approach is a two-stage procedure. At the first stage, the antenna structure is modified to improve its impedance matching. This is achieved through incorporation of an n-section tapered feedline, followed by reoptimization of geometry parameters. Reducing the maximum in-band reflection well beyond the acceptance...
-
Simulator for Performance Evaluation of ASON/GMPLS Network
PublicationThe hierarchical control plane network architecture of Automatically Switched Optical Network with utilization of Generalized Multi-Protocol Label Switching protocols is compliant to next generation networks requirements and can supply connections with required quality of service, even with incomplete domain information. Considering connection control, connection management and network management, the controllers of this architecture...
-
A three-dimensional periodic beam for vibroacoustic isolation purposes
PublicationThis paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequency band gaps that are present in the frequency spectrum of the beam. Since the dynamic...
-
Badanie metod i projektowanie usług lokalizacyjnych w sieciach radiokomunikacyjnych
PublicationW pracy przedstawiono wybrane problemy lokalizowania obiektów w sieciach radiokomunikacyjnych, w tym komórkowych. W pierwszej kolejności zostały przedstawione nowe zasady budowy i działania systemu wywołania w niebezpieczeństwie na morzu, z wykorzystaniem infrastruktury sieci komórkowej. Na podstawie zebranych danych pomiarowych w warunkach morskich została opracowana nowa, bardziej dokładna metoda estymacji położenia terminala...
-
Pilotażowa instalacja sieci bezprzewodowej bezprzewodowej standardu WiMax na Politechnice Gdańskiej
PublicationRozdział przedstawia analizę teoretyczną oraz opis pilotażowego wdrożenia standardu IEEE 802.11 (WiMAX) na Politechnice Gdańskiej. Przedstawiono unikalną funkcjonalność oferowaną przez technologię WiMAX według ustaleń standaryzacyjnych oraz realizowaną na dostępnych w tej chwili na rynku urządzeniach, a także możliwe scenariusze zastosowania tego rodzaju systemów
-
O obliczaniu kablobetonowych ciągłych dźwigarów mostowych
PublicationPrzedstawiono analityczną metodę obliczania kablobetonowych ciągłych dźwigarów z wykorzystaniem metody sił. Podano przykład analizy zrealizowanego kablobetonowego wiaduktu o schemacie dwuprzęsłowej belki ciągłej. Porównano wyniki obliczeń analitycznych i numerycznych (model belkowy, program Sofistik).
-
The Weibull model of the multipath fading channel
Open Research DataThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Weibull fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
-
Influence of Bitumen Type and Asphalt Mixture Composition on Low-Temperature Strength Properties According to Various Test Methods
PublicationIn regions with low-temperatures, action transverse cracks can appear in asphalt pavements as a result of thermal stresses that exceed the fracture strength of materials used in asphalt layers. To better understand thermal cracking phenomenon, strength properties of different asphalt mixtures were investigated. Four test methods were used to assess the influence of bitumen type and mixture composition on tensile strength properties...
-
Damian Duraj mgr inż.
People -
High precision and accuracy using low cost GNSS receivers and supporting technologies
PublicationThis chapter focuses on methods and techniques of positioning, based on the highly accurate and precise Global Navigation Satellite System (GNSS), which are available at a relatively low price. In this context, a comparison of different positioning methods provided by the free and open source software (FOSS) package called RTKLIB is given. Other aspects related to price reduction are also considered, including availability and...
-
EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublicationLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
-
Estimation of the Ultimate Strength of FRP Strips-to-Masonry Substrates Bond
PublicationFiber-Reinforced Polymers (FRP) were developed as a new method over the past decades due to their many beneficial mechanical properties, and they are commonly applied to strengthen masonry structures. In this paper, the Artificial Neural Network (ANN), K-fold Cross-Validation (KFCV) technique, Multivariate Adaptive Regression Spline (MARS) method, and M5 Model Tree (M5MT) method were utilized to predict the ultimate strength of...
-
Parallel Implementation of the Discrete Green's Function Formulation of the FDTD Method on a Multicore Central Processing Unit
PublicationParallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method was developed on a multicore central processing unit. DGF-FDTD avoids computations of the electromagnetic field in free-space cells and does not require domain termination by absorbing boundary conditions. Computed DGF-FDTD solutions are compatible with the FDTD grid enabling the perfect hybridization of FDTD...
-
Multimodal Particle Swarm Optimization with Phase Analysis to Solve Complex Equations of Electromagnetic Analysis
PublicationIn this paper, a new meta-heuristic method of finding roots and poles of a complex function of a complex variable is presented. The algorithm combines an efficient space exploration provided by the particle swarm optimization (PSO) and the classification of root and pole occurrences based on the phase analysis of the complex function. The method initially generates two uniformly distributed populations of particles on the complex...
-
A concept of measurement system based on the Z-Wave standard
PublicationIn the paper a new concept of measurement system based on the Z-Wave standard is presented. This standard is dedicated to use mainly in home automation systems, but its properties enable to use it in dispersed measurement systems and support wireless communication between measurement nodes in a mesh-type network. In the paper basic metrological aspects of the Z-Wave standard and an example of impedance measurement system are discussed.
-
Data obtained by computation for X-ray imaging of grating without magnification using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of grating and X-ray refractive lenses is considered. In this approach, the propagating wave is represented as a superposition of the oriented Gaussian beams. The direction of wave propagation in each Gaussian beam is consistent with the local propagation direction of the X-ray wavefront.
-
Data obtained by computation for X-ray imaging of grating with magnification factor equal 2 using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of grating and X-ray refractive lenses is considered. In this approach, the propagating wave is represented as a superposition of the oriented Gaussian beams. The direction of wave propagation in each Gaussian beam is consistent with the local propagation direction of the X-ray wavefront.
-
Data obtained by computation for X-ray imaging of grating with magnification factor equal 4 using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of grating and X-ray refractive lenses is considered. In this approach, the propagating wave is represented as a superposition of the oriented Gaussian beams. The direction of wave propagation in each Gaussian beam is consistent with the local propagation direction of the X-ray wavefront.
-
Data obtained by computation for X-ray imaging of grating with magnification factor equal 8 using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of grating and X-ray refractive lenses is considered. In this approach, the propagating wave is represented as a superposition of the oriented Gaussian beams. The direction of wave propagation in each Gaussian beam is consistent with the local propagation direction of the X-ray wavefront.
-
Acoustic emission studies of the 7075 aluminium alloy pitting corrosion process
Open Research DataThe dataset contains the cyclic polarization studies and corresponding acoustic emission measurements, revealing the pitting corrosion process of the passive layer at the surface of the 7075 aluminum alloy in the borate buffer with different chloride ions concentrations, in the range between 0.05 and 25 mM.
-
Selectivity of amperometric gas sensors in multicomponent gas mixtures
PublicationIn recent years smog and poor air quality became a growing environmental problem. There is a need to continuously monitor the quality of air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, a selectivity of the six amperometric gas sensors is being investigated. Calibration of sensors has been performed in order to find a correlation between concentration...
-
Proposal of a System Loss Model for Body Area Network in Passenger Ferry Environment
PublicationIn the paper, proposal of an empirical off-body system loss model for Body Area Networks working in a passenger ferry environment at 2.45 GHz has been presented. The measurements were carried out for dynamic scenarios in the discotheque passenger ferry environment. The general model formula consists of three components: mean system loss, attenuation resulting from the variable antenna position on the human body, and attenuation...
-
Low-coherence sensors with nanolayers for biomedical sensing
PublicationIn this paper, we describe the fiber optic low-coherence sensors using thin film. We investigated their metrological parameters. Presented sensors were made with the use of standard telecommunication single mode optical fiber (SMF28). Different materials were applied to obtain thick layers, such as boron doped diamond, silver and gold. The thickness of layers used in the experiments ranged from 100 nm to 300 nm. Measurements were...
-
Maciej Matciak doktor
People