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Search results for: error back-propagation
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Simple design criteria and efficiency of hydrodynamic vortex separators
PublicationVortex separators are locally applied for waste water treatment in different systems - from storm waste water sewerage to water treatment in fish ponds. However, the methods for separator design presented in the literature are questionable. The paper presents two simple and functional criteria that were employed to construct a laboratory test stand. The test results gave positive feed back on the efficiency of vortex separators.
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Measurements of drive system properties of the "Magnetic SpeedLine" ultra-fast robot prototype for IML labeling
Open Research DataTests of the drive system of the ultra-fast robot "SpeedLine magnetic" for labeling with the IML method were carried out in order to analyze the influence of the operating parameters of the drive system on the correctness and quality of the drive system.
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About definition of modes and magnetosonic heating in a plasma’s flow: Especial cases of perpendicular and nearly perpendicular wave vector and magnetic field
PublicationDynamics of hydrodynamic perturbations in a plasma depend strongly on an angle between the wave vector and equilibrium straight magnetic field. The case of perpendicular propagation is especial. There are only two (fast) magnetosonic modes since two (slow) ones degenerate into the stationary one with zero speed of propagation. This demands individual definition of wave modes by the links of hydrodynamic relations. These links are...
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Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublicationA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
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Sawsan S. Sayed Prof. Dr.
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Magnetic switching of Kerker scattering in spherical microresonators
PublicationMagneto-optical materials have become a key tool in functional nanophotonics, mainly due to their ability to offer active tuning between two different operational states in subwavelength structures. In the long-wavelength limit, such states may be considered as the directional forward- and back-scattering operations, due to the interplay between magnetic and electric dipolar modes, which act as equivalent Huygens sources. In this...
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Epitaph of George Hojer in St. Mary's Church in Gdańsk
Open Research DataThe data set concerns epigraphy. It refers to the epitaph placed in St. Mary’s Church in Gdańsk, that is dedicated to George Hojer, a citizen of Stralsund, who was travelling all over the Europe and unexpectedly died in Gdańsk in 1585 at the age of 25 during his way back home from Riga. Data set contains one general photo of the epitaph, transcription...
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Analysis of spatial changes in the town of Puck with its surroundings in the years 1926, 1940, 1974, 1985, 2000, 2020 on the basis of topographic maps using the BDOT10K database
Open Research DataSpatial changes over time are extremely valuable due to the possibility of modeling forecasts. This dataset shows how Puck has evolved over a specific period of time. Thanks to this presentation of the data set, it is possible to easily recreate the appearance of the city in particular years.
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Annihilation rates of low-energy positron scattering from simple diatomic molecules
PublicationWe discuss the calculations of Zeff coefficients for a series of diatomic molecules over the range of energies below the positronium formation. During the development of a general code for polyatomic, nonlinear molecules colliding with positrons, it was discovered that the earlier one, employed only for diatomic molecules, had an error. The error is corrected and the corrected results are presented here. We also discuss a way of...
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RECSYS CHALLENGE 2015: a BUY EVENT PREDICTION IN THE E-COMMERCE DOMAIN
PublicationIn this paper we present our approach to RecSys Challenge 2015. Given a set of e-commerce events, the task is to predict whether a user will buy something in the current session and, if yes, which of the item will be bought. We show that the data preparation and enrichment are very important in finding the solution for the challenge and that simple ideas and intuitions could lead to satisfactory results. We also show that simple...
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Fast Fading Characterization for Body Area Networks in Circular Metallic Indoor Environments
PublicationWith the increasing development of 5G and Body Area Network based systems being implemented in unusual environments, propagation inside metallic structures is a key aspect to characterize propagation effects inside ships and other similar environments, mostly composed of metallic walls. In this paper, indoor propagation inside circular metallic structures is addressed and fast fading statistical distributions parameters are obtained...
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Zastosowanie metody galwanostatycznej do wyznaczania błędu fazy elektrod woltamperometrycznych
PublicationW pracy przeanalizowano właściwości metrologiczne elektrod woltamperometrycznych w dziedzinie częstotliwości. Wykazano, że w przypadku, gdy reakcja elektrochemiczna kontrolowana jest procesem transportu jonów, elektroda woltamperometryczna zachowuje się tak jak przetwornik pomiarowy I rzędu. Jej właściwości metrologiczne opisane są przez czułość, częstotliwość graniczną, błąd amplitudy i błąd fazy. Przeprowadzona analiza pokazała,...
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Application of RMS for damage detection by guided elastic waves
PublicationThis paper presents certain results of an experimental study related with a damage detection in structural elements based on deviations in guided elastic wave propagation patterns.
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Multi-objective optimization of tool wear, surface roughness, and material removal rate in finishing honing processes using adaptive neural fuzzy inference systems
PublicationHoning processes are usually employed to manufacture combustion engine cylinders and hydraulic cylinders. A crosshatch pattern is obtained that favors the oil flow. In this paper, Adaptive Neural Fuzzy Inference System (ANFIS) models were obtained for tool wear, average roughness Ra, cylindricity and material removal rate in finish honing processes. In addition, multi-objective optimization with the desirability function method...
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Techniki audytowania zabezpieczeń sieci bezprzewodowej z wykorzystaniem systemów klasy grid
PublicationZaprezentowano efektywne zasady weryfikacji zabezpieczeń sieci bezprzewodowych z wykorzystaniem oprogramowania Back/Track w dystrybucji systemu Linux. Omówiono algorytmy RC4, MIC i AES, które wspierają techniki zabezpieczeń WEP, WPA i WPA2 wchodzące w skład protokołu IEEW 802.11. Zamieszczano także opis wykorzystania systemu rozproszonego Comcute o architekturze typu grid do prowadzenia audytu bezprzewodowej sieci.
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Photoresponsive, amide-based derivative of embonic acid for anion recognition
PublicationThe synthesis and ion-binding properties of amide-based derivative of embonic acid andp-aminoazobenzenewere described. The new compound was characterized by X-ray structural analysis and spectroscopic methods.Ligand interacts in acetonitrile with Y-shaped anions (benzoates and acetates) and dihydrogen phosphatesforming complexes of 1:1 stoichiometry. In more polar DMSO the complexes stoichiometry changes to 2:1(L:anion). Light-inducedtranstocisisomerization...
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The study of acoustic climate of the Southern Baltic
PublicationThis paper presents the statistical characteristics of seawater properties, which are necessary for predicting the propagation of acoustic waves in selected areas of the Baltic Sea. The statistics were elaborated based on long-term measurements of vertical distributions of sound speed, temperature, and salinity, and the nonlinearity parameter B/A. Nonlinear properties of the environment are considered, in connection...
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Hybrid Method Analysis of Unshielded Guiding Structures
PublicationA combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first...
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Application of guided waves in the evaluation of steel-concrete adhesive connection
PublicationThe aim of the paper is the application of guided waves in the evaluation of a condition state of adhesive connection between steel and concrete. The study concerns a push-out specimen consisting of two steel plates glued to opposite faces of a concrete cube with the use of structural adhesive. Wave propagation in the specimen without external load is investigated both experimentally and numerically. The second stage of the investigation...
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Comparison of Doppler Effect Estimation Methods for MFSK Transmission in Multipath Hydroacoustic Channel
PublicationUnderwater wireless communication remains a challenging topic, particularly for applications such as wreck penetration where multipath and Doppler effects are very intense. These effects are becoming even more difficult to mitigate for fast data transmission systems that utilize wideband signals. Due to the low propagation speed of acoustic wave in the water, there is a significant difference between the Doppler shift for lower...
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Unusual divergence of magnetoacoustic beams
PublicationTwo-dimensional magnetosonic beams directed along a line forming a constant angle h with the equilibrium straight magnetic field are considered. Perturbations in a plasma are described by the system of ideal magnetohydrodynamic equations. The dynamics of perturbations in a beam are different in the cases of fast and slow modes, and it is determined by h and equilibrium parameters of a plasma. In particular, a beam divergence may...
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A framework for detection of selfishness in multihop mobile ad hoc networks
PublicationThe paper discusses the need for a fully-distributed selfishness detection mechanism dedicated for multihop wireless ad hoc networks which nodes may exhibit selfish forwarding behaviour. The main contribution of this paper is an introduction to a novel approach for detecting and coping with the selfish nodes. Paper describes a new framework based on Dempster-Shafer Theory called Dempster-Shafer Theory-based Selfishness Detection...
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Numerical modeling of GPR field in damage detection of a reinforced concrete footbridge
PublicationThe paper presents a study on the use of the ground penetrating radar (GPR) method in diagnostics of a footbridge. It contains experimental investigations and numerical analyses of the electromagnetic field propagation using the finite difference time domain method (FDTD). The object of research was a reinforced concrete footbridge over a railway line. The calculations of the GPR field propagation were performed on a selected cross-section...
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High-accuracy computation of hard X-ray focusing and imaging for refractive optics
PublicationA mathematical apparatus for solving problems of X-ray wave propagation through complex optical systems, when the lens thickness can change with jumps, is developed and presented. The developed method is based on the use of the superposition of oriented Gaussian beams, which satisfy the Helmholtz equation with high accuracy. The wave propagation in air and through kinoform and ordinary lenses is considered. Focusing and imaging...
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Wake-Up Receiver for Underwater Acoustic Communication Using in Shallow Water
PublicationA data frame transmitted over the underwater acoustic channel usually begins with a preamble. Therefore, underwater communication systems have a dedicated receiver that constantly listens to the preamble signals. A receiver that is to work effectively in shallow waters must have solutions that effectively reduce the impact of the permanently occurring multipath propagation. The article presents a solution based on complementary...
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Engineer's graphic workshop. Historical review.
PublicationThe paper introduces the history of development of graphic engineering workshop within European culture. The fundamentals of scientific approach to this subject are dated back to the XVIII century. Owning to Gaspard Monge's works descriptive geometry rose to the rank of branch of mathematics. As the time passes we observe the endeavors aiming at accelerating and automating the process of engineering drawing. Since the XX century...
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On the Transcendental Philosophy in the Light of the Kantian Aggregate - System Opposition
PublicationTh e article represents an attempt to determine the essence of critical philosophy in the light of Kantian distinction between aggregate and system. In order to achieve this, the article harks back to Kant’s work and to accomplishments of Marburg School of neo-Kantianism and particularly to Ernst Cassirer’s philosophy. Discrimination between aggregate and system as two possible types of knowledge representation rests on the precedent...
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A Parallax Shift Effect Correction Based on Cloud Height for Geostationary Satellites and Radar Observations
PublicationThe effect of cloud parallax shift occurs in satellite imaging, particularly for high angles of satellite observations. This study demonstrates new methods of parallax effect correction for clouds observed by geostationary satellites. The analytical method that could be found in literature, namely the Vicente et al./Koenig method, is presented at the beginning. It approximates a cloud position using an ellipsoid with semi-axes...
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A Compact Self-Hexaplexing Antenna Implemented on Substrate-Integrated Rectangular Cavity for Hexa-Band Applications
PublicationThis brief introduces a novel architecture of a compact self-hexaplexing antenna (SHA) implemented on a substrate-integrated rectangular cavity (SIRC) for hexa-band applications. The proposed SHA is configured by using an SIRC resonator, two Pi-shaped slots (PSSs), and six 50Ω microstrip feedlines. The PSSs are connected back-to-back and loaded on top of the SIRC resonator to produce six patch radiators (PRs). The PRs are excited...
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SEM micrographs and photos of salivary gland stones
Open Research DataThis dataset contains SEM micrographs and high-resolution photographs taken for salivary gland stones (sialolith) extracted during joint studies between Medical University of Gdansk and Gdansk University of Technology.
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Two tests for adhesive bonding long term characterization: principles and applications
PublicationThis article describes recent refinement of the traditional wedge test technique used to characterize durability of the adhesive joints. We propose two types of measuring protocols to monitor precisely and continuously the propagation of an "effective" crack during long term mode I fracture mechanic test. First method is directly derived from the traditional wedge test technique and consist in monitoring the surface strain of adherent...
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Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
PublicationEvolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy...
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The conducted EMI in DC-DC converters
PublicationThis book presents the phenomena of conducted electromagnetic interference (EMI) generation in DC-DC converters. The measurement and simulation are used to analyze the impact of the most important parameters on the character, level and propagation path of interference. In this book, the analysis of the interference generation and propagation is presented on the example of three basic converters. The wide banded behavior of all...
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Odbiór zbiorczy polaryzacyjny w środowisku wewnątrzbudynkowym
PublicationNiniejszy referat dotyczy oceny efektywności odbioru zbiorczego polaryzacyjnego warunkach propagacji sygnałów wewnątrz budynków. W artykule scharakteryzowano warianty odbioru zbiorczego oraz stosowane w nich metody łączenia sygnałów. Ponadto, zdefiniowano wyrażenia służące szacowaniu zysku odbioru zbiorczego dla tych metod. Przedstawiono również metodykę przeprowadzonych badań pomiarowych oraz dokonano analizy wyników tych badań.
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Nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów
PublicationW referacie zaprezentowano nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów WAP. W algorytmie tym uwzględnia się właściwości środowiska propagacyjnego, dzięki czemu dokładność estymat położenia obiektów wyznaczonych algorytmem WAP jest większa niż wyznaczonych znanymi algorytmami Chana oraz Foy’a. W referacie przedstawiono wyniki analizy porównawczej tych trzech algorytmów z użyciem rzeczywistych pomiarów odległości...
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Elastic waves in the railroad track substructures and its surroundings analyzed with non-classical operational methods
PublicationWe analyze the propagation of the waves generated by the rolling stock and the interaction of those waves on the medium and its surroundings. We use non-classical operational methods for monitoring construction of the railway infrastructure and for noise damping.
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Analiza ograniczeń technologicznych systemów lokalizacji inercyjnej
PublicationW artykule opisano kluczowe ograniczenia technologiczne zmniejszające dokładność inercyjnych systemów lokalizacyjnych. Każdy z czynników został przedstawiony w kontekście swego źródła oraz wpływu na proces lokalizacyjny. Dodatkowo w artykule zawarto opis metod kompensacji błędów występujących w procesie lokalizacji inercyjnej. W treści artykułu analizie poddano rozwiązania obecne w systemach lokalizacji inercyjnej dla wolno poruszających...
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A Cross-Team Collaborative Evaluation of a CRM System
PublicationThis paper presents an analysis of an usability evaluation a CRM (Customer Relationship Management) performed by a team composed of external usability experts jointly with a CRM staff. The evaluation process differed from a classical scheme known from former projects, including some new elements resulting from a specific context of this study. These novel elements resulted in reshaping the role of the CRM system and considering...
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Symulator sieci Ad Hoc
PublicationW pracy przedstawiono symulator sieci Ad Hoc umożliwiający przeprowadzenie szerokiego zakresu badań. Jednym z nich jest modelowanie warstwy fizycznej oraz badanie jakości transmisji przedstawione w postaci wykresów bitowej stopy błędów BER (Bit Error Rate) i ramkowej stopy błędów FER (Frame Error Rate) w funkcji odległości pomiędzy terminalami ruchomymi. Terminale ruchome mogą znajdować się w pojazdach mechanicznych, statkach,...
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Performance analysis of data transmission in MC-CDMA radio interface with turbo codes
PublicationMulti-carrier code division multiple access (MC-CDMA) technique is a combination of two radio access techniques: CDMA and orthogonal frequency division multiplexing and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface. It also presents encoders and decoders of turbo codes which were used in simulation of the MC-CDMA technique. Two turbo codes with 8-state...
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Analysis of Measurement Errors in Rail Vehicles’ Pantograph Inspection System
PublicationThe paper presents an approach to evaluation of height measurement errors in laser scanning inspection system. The system, consisting of a laser line generator and a specialized camera, is dedicated to diagnosing carbon contact strips of railway vehicles’ pantographs. While height measurement resolution is easily computable based on system parameters, determining the measurement error is troublesome due to numerous impacts. As...
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublicationIn 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...
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Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
PublicationA voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology,...
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The XRD diffraction patterns of as-prepared (La0.3Sr0.6Ce0.1)0.9Me0.1Ti0.9O3-δ (Me= Co, Cu, Fe, Mn, Ni) materials synthesized via the solid state reaction method
Open Research DataThe (La0.3Sr0.6Ce0.1)0.9Me0.1Ti0.9O3-δ (Me= Co, Cu, Fe, Mn, Ni) materials were synthesized via the solid state reaction method and examined as a potential anode material. First, the mixed oxide reagents were pressed into pellets and calcined at 1200 °C for 12 hours to decompose most of the organic compounds. The resulting calcined pellet was ground...
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Automatic Reduction-Order Selection for Finite-Element Macromodels
PublicationAn automatic reduction-order selection algorithm for macromodels in finite-element analysis is presented. The algorithm is based on a goal-oriented a posteriori error estimator that operates on low-order reduced blocks of matrices, and hence, it can be evaluated extremely quickly.
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A Finer Point on Vision
PublicationAs an IES Member, I look forward to each issue of LD+A and read them with great interest as they are often very informative. To my surprise, the Research article (May 2019, p. 76) has an error which should be corrected.
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20+ years of Polish residential real estate prices – a house price index proxy
PublicationInformation on house prices is often considered crucial when assessing developments in economy. However, in Poland for the long time house prices haven’t been tracked in an organized manner. Recent developments, most notably house price indices developed by Poland’s national bank and by the statistical office do not go back more than 10 years, therefore data series are relatively short compared to those of other macroeconomic data. In...
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Plant-based meat substitute analysis using microextraction with deep eutectic solvent followed by LC-MS/MS to determine acrylamide, 5-hydroxymethylfurfural and furaneol
PublicationFor the analysis of plant-based meat substitutes and the determination of Maillard reaction products such as acrylamide, 5-hydroxymethylfurfural and furaneol, a novel and effective procedure based on hydrophobic natural deep eutectic solvent and liquid chromatography coupled with tandem mass spectrometry was developed for the first time. The 49 compositions of the deep eutectic solvents were designed and screened to select the...
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A Development of a Capacitive Voltage Divider for High Voltage Measurement as Part of a Combined Current and Voltage Sensor
PublicationThis article deals with the development of capacitive voltage divider for high voltage measurements and presents a method of analysis and optimization of its parameters. This divider is a part of a combined voltage and current sensor for measurements in high voltage power networks. The sensor allows continuous monitoring of the network distribution status and performs a quick diagnosis and location of possible network failures....
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Elastic wave propapagation in diagnostics of self-drilling system of grouted anchors
PublicationThe paper presents an experimental investigation of elastic wave propagation in a self-drilling hollow bar system, which is commonly used in geotechnical industry as the element of grouted ground anchors and soil nails. The single self-drilling hollow bar and self-drilling system of two bars connected by a coupler were considered. Longitudinal waves were excited at one end of the bar and registered at both ends, by means of PZT...