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Search results for: DISCRETE CRACKS
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FE-investigations on crack spacing in reinforced concrete beams within non-local continuum mechanics.
PublicationW artykule przedstawiono wyniki numerycznej analizy rozstawu rys w belkach żelbetowych przy zastosowaniu dwóch ciągłych modeli nielokalnych. Zbadano wpływ wielu różnych parametrów na rozstaw rys.
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Recurrence times in the Morse sets for a two-dimensional discrete neuron model (low resolution)
Open Research DataThis dataset contains selected results of rigorous numerical computations conducted in the framework of the research described in the paper “Topological-numerical analysis of a two-dimensional discrete neuron model” by Paweł Pilarczyk, Justyna Signerska-Rynkowska and Grzegorz Graff. A preprint of this paper is available at https://doi.org/10.48550/arXiv.2209.03443.
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A Method of Lathe Checks Measurement; SMOF device and its software
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The dynamic analysis of a cracked Timoshenko beam by the spectral element method
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The dynamic analysisi of cracked Thimoshenko beam by the spectral element method.
PublicationW pracy przedstawiono model belli Timoshenko z pęknięciem poprzecznym oparty o metodę elementów spektralnych. Przedstawiono wyniki propagacji fali sprężystej i jej interakcję z pęknięciem.
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Retrofitted vibro-pressed pavement bricks and their impregnation in modern architecture.
PublicationRecent construction projects require new properties of concrete building materials. The paper describes the technological methods of retrofitting of vibro-pressed concrete pavement brick and shows the results of improving physical properties of concrete by application of different impregnation agents.
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Modelling and Analysis of the Positioning Accuracy in the Loading Systems of Mobile Cranes
PublicationIn this work, the authors analyse the influence of the order and range of sequential movements of a crane's working members on the accuracy of the final cargo positioning. The analysis was conducted on the basis of a specially developed method in which the authors proposed the introduction of a geometrical indicator of positioning the load in the intermediate positions (after completing each movement sequence) and in the target...
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Galerkin finite element analysis of Darcy–Brinkman–Forchheimer natural convective flow in conical annular enclosure with discrete heat sources
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Finite State Machine Based Modelling of Discrete Control Algorithm in LAD Diagram Language With Use of New Generation Engineering Software
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Magnetizability of the relativistic hydrogenlike atom in an arbitrary discrete energy eigenstate: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationThe Sturmian expansion of the generalized Dirac--Coulomb Green function [R.\/~Szmytkowski, J.\ Phys.\ B 30 (1997) 825; erratum 30 (1997) 2747] is exploited to derive a closed-form expression for the magnetizability of an arbitrary discrete state of the relativistic one-electron atom with a point-like, spinless and motionless nucleus of charge $Ze$. The result has the form of a double finite sum involving the generalized hypergeometric...
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Size effect at aggregate level in microCT scans and DEM simulation – Splitting tensile test of concrete
PublicationThe paper describes an experimental and numerical study of size effect on concrete cylindrical specimens in splitting tensile test. Own experimental campaign was performed on specimens with 5 various diameters from D = 74, 105, 150, 192 and 250 mm with hardboard loading strips (distributed load according to standard methods) scaled proportionally to the specimen diameter. The crack opening-control system was applied to obtain the...
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Design of novel highly sensitive sensors for crack detection in metal surfaces: theoretical foundation and experimental validation
PublicationThe application of different types of microwave resonators for sensing cracks in metallic structures has been subject of many studies. While most studies have been focused on improving the sensitivity of planar crack sensors, the theoretical foundation of the topic has not been treated in much detail. The major objective of this study is to perform an exhaustive study of the principles and theoretical foundations for crack sensing...
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Determination of the transverse resistance characteristics in railway track
PublicationW pracy przedstawiono problem oporów poprzecznych podsypki z punktu widzenia budowy, utrzymania oraz bezpieczeństwa w eksploatacji toru kolejowego. Zaprezentowano różne sposoby analitycznego podejścia do badanego zjawiska na przykładzie modeli matematycznych spotykanych w literaturze. Scharakteryzowano aktualny stan badań doświadczalnych związanych z oporami poprzecznymi. Omówiono różne sposoby prowadzenia takich badań w eksploatowanych...
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Intelligent algorithms for movie sound track restoration
PublicationW artykule przedstawiono dwa algorytmy do rekonstruowania optycznych ścieżek dźwiękowych. Pierwszy z nich jest zastosowaniem miary nieprzewidywalności do obliczeń parametrów modelu psychoakustycznego stosowanego do redukowania szumów. Drugi stanowi precyzyjną procedurę oceny pasożytniczej modulacji częstotliwości, opartej na analizie składowych harmonicznych. Wyniki zastosowania obu wymienionych algorytmów są zawarte w artykule.
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Intelligent algorithms for optical track audio restoration
PublicationW referacie przedstawiono dwa algorytmy dedykowane redukcji pasożytniczych zniekształceń dźwięku spotykanych w optycznych ścieżkach dźwiękowych. Pierwszy algorytm umożliwia redukcję szerokopasmowego szumu w nagraniach fonicznych. Wykorzystano w nim psycho-akustyczny model słuchu oparty o miarę nieprzewidywalność sygnału (ang. Unpredictability Measure). Ocena jakości redukcji szumu została wykonana z wykorzystaniem metod inteligentnych....
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The ranks of Japanese industrial sectors: 2005-2011
PublicationThe purpose of the current study is to expand the previous study which analyzes the industrial sectors ranks of specific countries. More specifically, the study aims to conduct a comparison in terms of the ranks of Japanese industrial sectors on the specific analysis period. The analysis period of the study is 2005-2011. Using the previous study as a reference, the study employs the Input-Output (IO) approach as an analysis instrument....
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Satellite inventory of tram track geometrical layout
PublicationIn the paper a methodology of restoring of railway track’s geometrical shape in a horizontal plane on the base of conducted mobile satellite surveying was presented. The authors proposed a calculating algorithm for designing the track sections placed in horizontal arcs. In the algorithm an analytical methodology with mathematical formulas is applied. The procedure has an universal character, i.e. provides the possibility of varying...
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The ranks of Japanese industrial sectors: 2005-2011
PublicationThe purpose of the current study is to expand the previous study which analyzes the industrial sectors ranks of specific countries. More specifically, the study aims to conduct a comparison in terms of the ranks of Japanese industrial sectors on the specific analysis period. The analysis period of the study is 2005-2011. Using the previous study as a reference, the study employs the Input-Output (IO) approach as an analysis instrument....
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Vibration-Based Investigation of a Historic Bell Tower to Understand the Occurrence of Damage
PublicationABSTRACT The paper presents a survey of the historic Arch-cathedral bell tower in Vilnius induced by the appearance of cracks in the structure after a new bell system installation. An attempt is undertaken to identify the reason for the crack occurrence and to check a possible crack influence on global structural behaviour. The research is based on dynamic measurements made in the tower during ambient vibrations and during vibrations...
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Instrumented end notched flexure - Crack propagation and process zonemonitoring Part II: Data reduction and experimental
PublicationA mode II instrumented end notched flexure three point bending (ENF) adhesion test is described. The adhesive joint consists of two aluminium alloy (AW7075-T6) plates bonded with a structural epoxy adhesive (Hysol EA 9395™). Strain gauges are attached to the outer surface (backface) of the substrates in the lengthwise direction to measure local surface strain during crack propagation. Simultaneously, load/displacement measurements...
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The effect of multiaxial geocomposite reinforcement on fatigue performance and crack propagation delay in double-layered asphalt beams
PublicationThe presented study investigates the effect of a recently developed multiaxial geocomposite made of polypropylene geogrid and non-woven fabric on the delay of crack propagation, based on four-point bending tests of large asphalt concrete beams – both for reinforced and non-reinforced specimens. Several approaches are described in this study, including analysis of stiffness modulus decrease and analysis of crack propagation using...
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Some mechatronic solutions for vibration surveillance of mechanical systems idealised discretely
PublicationCelem pracy jest prezentacja wybranych rozwiązań mechatronicznych, których uwzględnienie może poprawić skuteczność procesu nadzorowania drgań modelowanych dyskretnie układów mechanicznych. Proponowane rozwiązania dotyczą sterowania optymalnego przy energetycznym wskaźniku jakości w układzie zredukowanym oraz w układzie hybrydowym, jak również - dopasowania prędkości obrotowej wirujących wałów do optymalnego kąta przesunięcia fazowego....
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Wave-induced stress and breaking of sea ice in a coupled hydrodynamic–discrete-element wave–ice model
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Wave-induced stress and breaking of sea ice in a coupled hydrodynamic–discrete-element wave–ice model
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Wave-induced stress and breaking of sea ice in a coupled hydrodynamic–discrete-element wave–ice model
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Fixed final time and free final state optimal control problem for fractional dynamic systems – linear quadratic discrete-time case
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Tracts of high or low sequence divergence in the mouse major histocompatibility complex.
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Analysis of longitudinal wave propagation in a cracked rod by the spectral element method
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The effect of pumpkin flour on quality and acoustic properties of extruded corn snacks
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Quality and nutritional properties of corn snacks enriched with nanofiltered whey powder
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Pollutant deposition via dew in urban and rural environment, Cracow, Poland
PublicationThis study is a comparative analysis of dew in rural and urban environment. Dew samples were collected between May and October, 2009 in two reference stations in southern Poland: Cracow and Gaik-Brzezowa. The investigation included comparison of volume and chemistry of the collected samples. Due to its formation mechanisms, dew is a good indicator of air pollution. Following parameters were analyzed in 159 collected samples: pH,...
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Ślady przeszłości w miastach przyszłości = Traces of The Past in Cities of The Future
PublicationPamięć zbiorowa we współczesnym mieście wizualizuje się dzięki różnorodnym środkom artystycznego wyrazu. Obok monumentalnych rzeźb na cokołach i wielkoprzestrzennych założeń pomnikowych realizowane są niewielkie nośniki pamięci zbiorowej, których zadaniem jest ukierunkowanie uwagi przechodnia na ''mikrohistorie'' związane nierozerwalnie z dziejami miasta. Powstają symboliczne ''haki'' i ''potykacze'', które wprowadzają do przestrzeni...
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Analysis of ultimate compressive strength of cracked plates with the use of DOE techniques
PublicationThe objective of this work is to investigate the structural compressive response of plates with locked cracks accounting for all relevant factors and correlation between them. The nonlinear FE model considering both geometric and material nonlinearities is employed herein, and the FE model of the structural response of intact plates is validated with the available experimental data. In the common studies, based on One Factor at...
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Hierarchical 2-step neural-based LEGO bricks detection and labeling
PublicationLEGO bricks are extremely popular and allow the creation of almost any type of construction due to multiple shapes available. LEGO building requires however proper brick arrangement, usually done by shape. With over 3700 different LEGO parts this can be troublesome. In this paper, we propose a solution for object detection and annotation on images. The solution is designed as a part of an automated LEGO bricks arrangement. The...
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Mathematical modeling and prediction of pit to crack transition under cyclic thermal load using artificial neural network
PublicationThe formation of pitting is a major problem in most metals, which is caused by extremely localized corrosion that creates small holes in metal and subsequently, it changes into cracks under mechanical load, thermo-mechanical stress, and corrosion process factors. This research aims to study pit to crack transition phenomenon of steel boiler heat tubes under cyclic thermal load, and mathematical modeling...
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Propagacja fali wzdłużnej w pręcie z pęknieciem poprzecznym. Longitudinal wave propagation in a rod with a transverse crack.
PublicationW pracy przedstawiono wyniki analizy propagacji fali wzdłuznej w pręcie z pęknięciem poprzecznym.
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublicationIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...
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Kinematic analysis of crank -cam mechanism of process equipment
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Atypical application of the parametric method for track infrastructure inventory
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Detection of neutrons with LiF fluorescent nuclear track detectors
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LITHIUM FLUORIDE CRYSTALS AS FLUORESCENT NUCLEAR TRACK DETECTORS
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The ranks of Indonesian and Japanese industrial sectors: A further study
PublicationThe purpose of the current study is to extend the previous study which analyzes the industrial sectors ranks of specific countries. More specifically, the study aims to conduct a further analysis regarding the ranks by using the new data as well as new analysis periods. The study focuses on the cases of Indonesia and Japan. In this study, the analysis period of the Indonesian case is 2010 while for the case of Japan is 2011. Using...
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Shaping of the turnout diverging track with variable curvature sections
PublicationThe paper presents an analytical method of shaping the turnout diverging railroad track with variable curvature segments on its length, which in an evident way distinguished it from a typical solution, made up of a single circular arc with no transition curves. Two separate causes including a linear and a nonlinear curvature one in the form of a polynomial have been examined. The obtained solutions of the problem have a universal...
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New Approach to Arc Fitting for Railway Track Realignment
PublicationThis article presents a new method of arc fitting for railway track realignment. The theoretical foundations are presented, along with a detailed algorithm of the iterative computational process. This method is based on solving a set of linearized pseudo-observation equations. The formulas of the functional model of the fitting problem were derived, and a special form of objective function is proposed. An iterative method for optimization...
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Design of rail-track geometric systems by satellite measurement
PublicationW pracy przedstawiono rezultaty zastosowania ciągłych pomiarów satelitarnych toru kolejowego, z antenami zainstalowanymi na poruszającym się pojeździe szynowym. Wykazano, że zastosowana pilotażowo technika pomiarowa umożliwia bardzo precyzyjne określenie podstawowych danych do projektowania modernizacji linii kolejowej (kierunków głównych trasy i jej kąta zwrotu), a także - ze stosunkowo niewielkim błędem - współrzędnych istniejącej...
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Finding deformation of the straight rail track by GNSS measurements
PublicationW 2009 roku na Politechnice Gdańskiej i Akademii Marynarki Wojennej w Gdyni zostały przeprowadzone, po raz pierwszy, ciągłe pomiary satelitarne toru kolejowego z wykorzystaniem względnej metody fazowej na bazie polskiej Aktywnej Sieci Geodezyjnej ASG-EUPOS i serwisu czasu rzeczywistego RTK (GPRS) - NAVGEO. Przeprowadzona analiza wykazała silny związek między lokalizacją odbiornika GNSS i dokładnością wyznaczania pozycji, wpływ...
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The application of nonlinear curvature sections in the turnout diverging track
PublicationThe paper presents the analytical method of modelling the diverging track of railway turnout with nonlinear curvature sections. These sections were used for smoothing the graph of curvature in the extreme areas of turnout. The problem of the curvature distribution was identified with the use of differential equations. The resulting solutions are of universal nature for example the ability of assuming any values of curvature at...
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Modeling variable curvature on the turnout diverging track length
PublicationThe paper presents three variants of variable curvature application on the entire length of the turnout diverging track. One linear and two nonlinear curvature cases: described the function of C1 and C0 class were considered. It turned out that both linear curve and the function of C1 class requires a significant (even twice) length of diverging track extending with respect to the base turnout. The curvature described by the function...
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The ranks of Indonesian and Japanese industrial sectors: A further study
PublicationThe purpose of the current study is to extend the previous study which analyzes the industrial sectors ranks of specific countries. More specifically, the study aims to conduct a further analysis regarding the ranks by using the new data as well as new analysis periods. The study focuses on the cases of Indonesia and Japan. In this study, the analysis period of the Indonesian case is 2010 while for the case of Japan is 2011. Using...
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System for tracking multiple trains on a test railway track
PublicationSeveral problems may arise when multiple trains are to be tracked using two IP camera streams. In this work, real-life conditions are simulated using a railway track model based on the Pomeranian Metropolitan Railway (PKM). Application of automatic clustering of optical flow is investigated. A complete tracking solution is developed using background subtraction, blob analysis, Kalman filtering, and a Hungarian algorithm. In total,...