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Numerical analysis of a temporary steel grandstand
PublikacjaThe purpose of this paper is to present the results of the numerical analysis focused on the response of the temporary steel scaffolding grandstand subjected to human-induced vibrations due to jumping. Shell as well as beam elements have been used in the numerical model. Its first stage has involved conducting modal analysis in order to determine the modes of free vibrations and the corresponding natural frequencies for the empty...
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INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
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A concept of heterogeneous numerical model of concrete for GPR simulations
PublikacjaThe Ground Penetrating Radar (GPR) method, which is increasingly being used in the non-destructive diagnostics of reinforced concrete structures, often needs more accurate interpretation tools for analysis of experimental data. Recently, there has been growing interest in developing of various numerical models for exhaustive understanding of GPR data. This paper presents the concept of a heterogeneous numerical model of concrete,...
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A Multi-Antenna Scheme for Early Detection and Mitigation of Intermediate GNSS Spoofing
PublikacjaThis article presents a method for detecting and mitigating intermediate GNSS spoofing. In this type of attack, at its early stage, a spoofer transmits counterfeit signals which have slight time offsets compared to true signals arriving from satellites. The anti-spoofing method proposed in this article fuses antenna array processing techniques with a multipath detection algorithm. The latter is necessary to separate highly correlated...
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Performance of Coherent Modulation Scheme Used in Acoustic Underwater Communication System
PublikacjaThe development of an acoustic underwater communication system for shallow waters is still a big scientificand construction challenge. Currently, non-coherent modulations in combination with strong channel coding are used to achieve reliable communication with low rate in such a channel. To obtain transmission with a higher transmission rate, it is required to use coherent modulation. This paper presents the assumptions of such...
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Phase compensation scheme for feedforward linearised CMOS operational transconductance amplifier.
PublikacjaW pracy opisano technikę kompensacji charakterystyk fazowych linearyzowanego metodą feedforward operacyjnego wzmacniacza transkonduktancyjnego CMOS. Wykazano, że proponowana koncepcja układowa prowadzi do znacznej poprawy liniowości charakterystyki przejściowej wzmacniacza oraz do rozszerzenia zakresu liniowości prądu wyjściowego. Ponadto w pracy przeprowadzono analizę charakterystyk częstotliwościowych, w wyniku której otrzymano...
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An approximative scheme of finding almost homoclinic solutions for a class of Newtonian systems
PublikacjaW niniejszej pracy badamy istnienie rozwiązań prawie homoklinicznych (ang. almost homoclinic solutions) dla pewnej klasy układów Newtona. Rozwiązanie prawie homokliniczne otrzymujemy jako granicę ciągu rozwiązań okresowych dla pewnego ciągu równań różniczkowych.
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Simultaneous handover scheme for IEEE 802.11 WLANs with IEEE 802.21 tiggers
PublikacjaHandover performance in wireless networks is important, especially nowadays, when multimedia services are becoming increasingly available over the wireless devices. However, users expect uncompromised mobility when using the service. Thus, the support of multimedia services is not possible if handover is inefficient. At the same time it is clear that a strict separation between IP Layer and the Link Layer results in built-in sources...
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General scheme for construction of scalar separability criteria from positive maps
PublikacjaStandardowe nierówności entropijne są znanym narzędziem do detekcji splątania dwupodukładowych stanów kwantowych. W pracy podano metodę wyprowadzania nierówności przypominających standardowe nierówności entropijne z dowolnych odwzorowań dodatnich. Ponadto, przebadano nierówności w przypadku kilku znanych z literatury odwzorowań dodatnich.
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Towards modelling of the environmental fate of pharmaceuticals using the QSPR-MM scheme
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Reliable routing and resource allocation scheme for hybrid RF/FSO networks
PublikacjaSignificant success of wireless networks in the last decade has changed the paradigms of communication networks design. In particular, the growing interest in wireless mesh networks (WMNs) is observed. WMNs offer an attractive alternative to conventional cable infrastructures, especially in urban areas, where the cost of new installations is almost prohibitive. Unfortunately, the performance of WMNs is often limited by the cluttered...
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Numerical simulations of novel GFRP sandwich footbridge
PublikacjaIn the following paper some aspects of numerical analysis and designing stages of a footbridge made of composite materials are elucidated. Because of the used materials the design process in this case is not ordinary and requires the development of concepts, material selections, identification of material properties, numerical simulations, strength calculations, serviceability and durability analyses. This contribution presents...
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In Situ Verification of Numerical Model of Water Hammer in Slurries
PublikacjaThis paper presents a numerical model of transient flow in a pressure slurry pipeline network with verification based on in situ measurements. The model, primarily verified in laboratory conditions, has been extended and applied to the case of a large and complex slurry pipeline network in Poland. In the model, the equivalent density concept was applied. In situ experiments were performed for various unsteady flow episodes, caused by...
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Numerical investigation of multiphase blood flow coupled with lumped parameter model of outflow
PublikacjaPurpose The purpose of this paper is the application of the computational fluid dynamics model simulating the blood flow within the aorta of an eight-year-old patient with Coarctation of Aorta. Design/methodology/approach The numerical model, based on commercial code ANSYS Fluent, was built using the multifluid Euler–Euler approach with the interaction between the phases described by the kinetic theory of granular flow (KTGF). Findings A...
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Numerical simulation of laminate composite specimens failure
PublikacjaThis work presents some numerical results concerning simulation of failure of laminate composite specimens. In the article two tests to determine ultimate strength in an orthotropic layer, are considered: tension (TT1) and compression (TC1) test. The outcome is compared with experimental data provided by [9,10].
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On the validation of the LS-DYNA Geo Metro numerical model
PublikacjaThe paper presents experiences gained during work with numerical model of Geo Metro vehicle used for simulations of crash tests with road safety barriers. Attention is drawn to the subject of tire/wheel breakage during collision events. Some methods for improvement of the model are presented in the paper. Several results for the normative vehicle numerical tests are introduced. Simulations were carried out using LS-DYNA finite...
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Mathematical and numerical modelling, P, IDE-sem.01, AT-sem. 03, CS-sem. 03, summer 22/23, (PG_00057379)
Kursy OnlineProject on Mathematical and numerical modelling.
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Mathematical and numerical modelling, P, IDE-sem.01, AT-sem. 03, CS-sem. 03, summer 22/23, (PG_00057379)
Kursy OnlineProject on Mathematical and numerical modelling.
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Numerical Methods - Data Engineering - 2023
Kursy Onlinestudia inżynierskie, informatyka i inżynieria danych
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Numerical Methods - Data Engineering - 2024
Kursy OnlineInżynieria danych
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Experimental and Numerical Study on Pounding of Structures in Series
PublikacjaPounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be described as “structures in series”. In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including...
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Numerical aspects of improvement of the unsteady pipe flow equations
PublikacjaW pracy dokonano analizy zaproponowanych w ostatnich latach metod opisu oporów ruchu w przepływie nieustalonym w przewodach pod ciśnieniem. Wykazano,że modyfikacja współczynnika oporów liniowych nie może zapewnić pozytywnych efektów oraz ,że poprawa wyników wykazywana przez autorów modyfikacji wynika z błędu dyfuzji numerycznej generowanej przez metodę rozwiązania.
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Numerical methods for the assessment of bridge safety barriers
PublikacjaThe paper presents a numerical study of the bus crash test for bridge safety barriers. The analysis is conducted with the use of explicit code LS-DYNA. The problem of hourglass effect in shell elements is discussed. The simulations of bus impact against the barrier show that the analyzed barrier withstands the impact forces and restrains the bus trajectory to the bridge road.
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Numerical Simulations of Hydrodynamic Open-Water Characteristics of a Ship Propeller
PublikacjaThe paper presents the results of numerical simulations of ship propeller operation bearing the name of Propeller Open Water (POW) Tests. The object of tests was a sample ship propeller (PPTC1), the geometrical and kinematic data of which are available, along with the results of model tests, on the official page of the research centre involved in the measurements. The research aimed at verifying the correctness of results of numerical...
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Multiacces quantum communication and product higher rank numerical range
PublikacjaIn the present paper we initiate the study of the product higher rank numerical range. The latter, being a variant of the higher rank numerical range, is a natural tool for study- ing a construction of quantum error correction codes for multiple access channels. We review properties of this set and relate it to other numerical ranges, which were recently introduced in the literature. Further, the concept is applied to the construction...
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Numerical testing of numerical generation efficiency in a bubble layer
PublikacjaPraca omawia zagadnienie nieliniowej propagacji w warstwie z pęcherzykami. Przedstawiono model matematyczny zjawiska. Omówiono problem wyznaczania prędkości fazowej, współczynnika tłumienia i częstotliwości rezonansowej pęcherzyków. Analizowano zmiany amplitud pierwszej i drugiej harmonicznych ciśnienia fali odbitej i bieżącej w funkcji grubości warstwy, względnej koncentracji pęcherzyków o różnych promieniach oraz częstotliwości...
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Numerical solutions for large deformation problems in geotechnical engineering
PublikacjaThe problem of large deformations often occurs in geotechnical engineering. Numerical modeling of such issues is usually complex and tricky. The chosen solution has to implicate soil-soil and soil-structure interactions. In this paper, a review of the most popular numerical methods for large deformation problems is presented. The Coupled Eulerian-Lagrangian (CEL) method, the Arbitrary Lagrangian-Eulerian (ALE) method, the Smoothed...
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INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
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Wind Conditions in Urban Layout – Numerical and Experimental Research
PublikacjaThis paper presents research which compares the numerical and the experimental results for different cases of airflow around a few urban layouts. The study is concerned mostly with the analysis of parameters, such as pressure and velocity fields, which are essential in the building industry. Numerical simulations have been performed by the commercial software Fluent, with the use of a few different turbulence models, including...
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Numerical and Analytical Investigation of Aluminium Bracket Strengthening
PublikacjaThis paper focuses on an analytical and numerical investigation of aluminium brackets used to fasten light-weight curtain walls to building facilities. The authors propose a solution to increase the load capacity of aluminium brackets by means of additional cover plates (straps). This paper also includes a short survey of literature and material properties concerning the EN AW-6060 T6 aluminium alloy. This paper suggests an initiation...
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Prediction of Weld Deformations by Numerical Methods - Review
PublikacjaThe welding process is the basic technique of joining in the shipbuilding industry. This method generates welding distortions that cause a lot of problems during the manufacturing process due to both the time and cost of straightening as well as their influence on later stages of production. Proper preparation of welding processes plays a growing role in the shipbuilding industry and the development of calculating tools is being...
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Excavation induced cast iron pipeline failure – a numerical study
PublikacjaNumerical study on impact of an unsecured excavation on an underground pipeline. Analysis focused on investigation of pipeline displacement generated by soil movement caused by excavation and heavy traffic. Numerical calculations and soil parameter sensitivity analysis based on Finite Element Method. Some comparisons of results with real-life failure cases.
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Numerical analysis of pile installation effects in cohesive soils
PublikacjaIn this thesis the empirical equation for radial effective stress calculation after displacement pile installation and following consolidation phase has been proposed. The equation is based on the numerical studies performed with Updated Lagrangian, Arbitrary Lagrangian-Eulerian and Coupled Eulerian-Lagrangian formulations as well as the calibration procedure with database containing world-wide 30 pile static loading tests in cohesive...
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Numerical solution of threshold problems in epidemics and population dynamics
PublikacjaA new algorithm is proposed for the numerical solution of threshold problems in epidemics and population dynamics. These problems are modeled by the delay-differential equations, where the delay function is unknown and has to be determined from the threshold conditions. The new algorithm is based on embedded pair of continuous Runge–Kutta method of order p = 4 and discrete Runge–Kutta method of order q = 3 which is used for the...
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A Numerical Model Study on Ice Boom in a Coastal Lake
PublikacjaA numerical study on the effectiveness of the proposed ice boom to be installed near the entrance of Lake Notoro, Hokkaido, Japan to prevent sea ice moving into the lake is presented. A two-dimensional hydro–ice dynamics model was modified to allow for the treatment of ice-boom interaction with the effect of tidal current. The numerical model is a coupled hydrodynamic and ice dynamic model. The ice dynamic component uses a Lagrangian...
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Numerical solution of fractional neutron point kinetics in nuclear reactor
PublikacjaThis paper presents results concerning solutions of the fractional neutron point kinetics model for a nuclear reactor. Proposed model consists of a bilinear system of fractional and ordinary differential equations. Three methods to solve the model are presented and compared. The first one entails application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. Second involves building an analog scheme...
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Monitoring of concrete curing in extradosed bridge supported by numerical simulation
PublikacjaThe paper describes a mathematical model of concrete curing taking into account kinetics of setting reactions. The numerical model is implemented in the author’s program that was used to monitor thermal effects recorded in the concrete bottom plate of the extradosed bridge. Numerical approach was verified by experimental measurements and used for assessment of the current compressive strength due to degree of hydration of fresh...
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[IMe] Advanced numerical methods in mechanics
Kursy Online{mlang pl} Dyscyplina: IMe Zajęcia obowiązkowe dla doktorantów I roku Prowadzący: K. Tesch, A. Żak Liczba godzin: 45 Forma zajęć: wykład/laboratorium {mlang} {mlang en} Discipline: IMe Obligatory course for 1st year PhD students Academic teacher: K. Tesch, A. Żak Total hours of training: 45 teaching hours Course type: lecture/Laboratories {mlang}
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[IMe] Advanced numerical methods in mechanics
Kursy Online{mlang pl} Dyscyplina: IMe Zajęcia obowiązkowe dla doktorantów I roku Prowadzący: K. Tesch, A. Żak Liczba godzin: 45 Forma zajęć: wykład/laboratorium {mlang} {mlang en} Discipline: IMe Obligatory course for 1st year PhD students Academic teacher: K. Tesch, A. Żak Total hours of training: 45 teaching hours Course type: lecture/Laboratories {mlang}
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[IMe] Advanced numerical methods in mechanics
Kursy Online{mlang pl} Dyscyplina: IMe Zajęcia obowiązkowe dla doktorantów I roku Prowadzący: K. Tesch, A. Żak Liczba godzin: 45 Forma zajęć: wykład/laboratorium {mlang} {mlang en} Discipline: IMe Obligatory course for 1st year PhD students Academic teacher: K. Tesch, A. Żak Total hours of training: 45 teaching hours Course type: lecture/Laboratories {mlang}
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[IMe] Advanced numerical methods in mechanics
Kursy Online{mlang pl} Dyscyplina: IMe Zajęcia obowiązkowe dla doktorantów I roku Prowadzący: K. Tesch, A. Żak Liczba godzin: 45 Forma zajęć: wykład/laboratorium {mlang} {mlang en} Discipline: IMe Obligatory course for 1st year PhD students Academic teacher: K. Tesch, A. Żak Total hours of training: 45 teaching hours Course type: lecture/Laboratories {mlang}
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PROPELLER INVESTIGATIONS BY MEANS OF NUMERICAL SIMULATION
PublikacjaThe analyses of hydroacoustics are of high interest at the moment due to strong impact of hydroacoustic phenomena on marine environment; the noises, generated e.g. by marine traffic, may be harmful for sea life. The analyses presented here are focused on one of main sources of noises generated by ships, i.e. cavitating propeller. The goal of the work is the assessment of the cavitation phenomenon, carried out with the standard...
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An Experimental and Numerical Analysis of Water Hammer Phenomenon in Slurries
PublikacjaThe analysis of slurry transportation in pressure pipelines is important both from practical and theoretical point of view. Due to the nature of the medium, the number of problems arising in the course of design, operation, measurements and mathematical modeling is much higher compared to the cases where the flowing liquid is homogeneous. The equations describing the flow are more complex, and higher number of the parameters is...
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On the necessity of experimental verification of numerical results in biomedical applications
PublikacjaPorous structures made of metal or biopolymers with a structure similar in shape and mechanical properties to human bone can be easily produced by stereolitography techniques, e.g. selective laser melting (SLM). Numerical techniques, like finite element method (FEM) have great potential in testing new, even the most sophisticated designs, according to their mechanical properties, i.e. strength or stiffness. However, due to different...
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Relativistic Bennett Brassard cryptographic scheme, relativistic errors,and how to correct them.
PublikacjaWprowadzono opis polaryzacji liniowej oparty o główne zerowe kierunki transformacji Lorentza. Formalizm ten został zastosowany do problemu eliminacji błędów w kryptografii kwantowej.
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Dynamics based on six-field theory of shells in the context of energy-conserving scheme
PublikacjaPraca dotyczy zaproponowanego algorytmu zachowującego energię w całkowaniu równań ruchu powłok sprężystych sformułowanych w ramach teorii sześcioparametrowej. Zawiera podstawowe założenia konieczne do formułowania schematów i podstawowe testy numeryczne. Aproksymacja przestrzenna zagadnienia oparta jest o Metodę Elementów Skończonych zaś aproksymacja w czasie wykorzystuje regułę punktu środkowego. Przykłady analizy dynamicznej...
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A perfect hashing incremental scheme for unranked trees using pseudo-minimal automata
PublikacjaWe describe a technique that maps unranked trees to arbitrary hash codes using a bottom-up deterministic tree automaton (DTA). In contrast to other hashing techniques based on automata, our procedure builds a pseudo-minimal DTA for this purpose. A pseudo-minimal automaton may be larger than the minimal one accepting the same language but, in turn, it contains proper elements (states or transitions that are unique) for every input...
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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
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Comparative testing of numerical models of river ice jams
PublikacjaIce processes in general, and ice jams in particular, play a dominant role in the hydrologic regime of Canadian rivers, often causing extreme floods and affecting the life cycle of many aquatic, terrestrial, and avian species. Various numerical models have been developed to help simulate the formation and consequences of these very dynamic and often destructive jam events. To test and compare the performance of existing models,...
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Numerical modelling of 3D printout using line (1D) elements
PublikacjaA proposition of some numerical modelling of the 3D printout is presented in the paper. The proposed model is composed of some 1D elements. The resulting numerical model of the infill consist of beam, spring and rigid elements. Obtained results confirm correctness of the proposed modelling method. Two methods of estimation of the spring parameters are proposed in the paper. In the first method, mechanical properties of the connecting...