Wyniki wyszukiwania dla: DAMPING, DYNAMICS, DIFFERENTIAL EQUATIONS, LOWERING A LIFEBOAT, NUMERICAL SIMULATIONS

• Modal Adjustment of Rayleigh Based Structural Damping and Coordinate-Partitioning Algorithm Dedicated to Frictionless Contact Constraints between Multibody System and Structure Modelled with Finite Elements

  Publikacja

  • K. Lipiński

  - SSRN Electronic Journal - Rok 2023

  The paper presents a dedicated numerical algorithm. The algorithm is advantageous during investigations of the dynamics of a hybrid multibody / finite-elements system. We focus our attention on interactions resulting from mechanical contact. Pointwise contact connects a vertex of the multibody structure and a surface of the elastic reference body. Instead of a positive value of the relative penetration factor, constraint equations...

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• Numerical Methods for Partial Differential Equations

  Kursy Online

  • M. Rewieński

  Course description: This course focuses on modern numerical techniques for linear and nonlinear elliptic, parabolic and hyperbolic partial differential equations (PDEs), and integral equations fundamental to a large variety of applications in science and engineering. Topics include: formulations of problems in terms of initial and boundary value problems; finite difference and finite element discretizations; boundary element approach;...

• Vertical motions damping model test of a lifeboat lowered onto a flat sea surface

  Publikacja

  • A. Kniat
  • P. Dymarski

  - Polish Maritime Research - Rok 2018

  The article presents the experiment’s results of the lifeboat model lowered with an initial speed and then released to fall onto a flat water surface. The purpose of the research is to determine the trajectory of the vertical boat motion and describe it with a mathematical model. This is closely related to determining the damping factor since the vertical motion is damped and the lifeboat gets balanced and stops moving after some...

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• Visualization of a lifeboat motion during lowering along ship’s side

  Publikacja

  • A. Kniat

  - Polish Maritime Research - Rok 2017

  This paper presents description of a computer program for motion visualization of a lifeboat lowered along ship’s side. The program is a post-processor which reads results of numerical calculations of simulated objects’ motions. The data is used to create scene composed of 3D surfaces to visualize mutual spatial positions of a lifeboat, ship’s side and water waving surface. Since the numerical data contain description of a simulation...

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• Searching for Critical Conditions During Lifeboat Launching – Simulations

  Publikacja

  • C. Dymarski
  • P. Dymarski
  • A. Kniat

  - Polish Maritime Research - Rok 2017

  The article describes numerical simulations of the process of lifeboat launching at the ship’s side. The research is aimed at finding the values of ship motion parameters which appear to be most dangerous for people in the lowered lifeboat due to the generated accelerations. The simplified model of ship hull motion adopted at this research stage bases on a superposition of harmonic motions with given amplitudes and periods in six...

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• Application of the numerical-analytic method for systems of differential equations with parameter

  Publikacja

  • T. Jankowski

  - Ukrainian Mathematical Journal - Rok 2002

  The numerical-analytic method is applied to systems of differential equations with parameter under the assumption that the corresponding functions satisfy the Lipschitz conditions in matrix notation. We also obtain several existence results for problems with deviations of an argument

• On the Peano Theorem for Some Functional Differential Equations on Time Scale

  Publikacja

  • A. Augustynowicz
  • A. Gołaszewska

  - Functional Differential Equations - Rok 2014

  The Peano Theorem for some functional differential equations on time scale is proved. Assumptions are of Caratheodory type. Two counter examples for false Peano theorems in the literature are presented.

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• On neutral differential equations and the monotone iterative method

  Publikacja

  • T. Jankowski
  • R. Jankowski

  - DYNAMIC SYSTEMS AND APPLICATIONS - Rok 2011

  The application of the monotone iterative method to neutral differential equations with deviating arguments is considered in this paper. We formulate existence results giving sufficient conditions which guarantee that such problems have solutions. This approach is new and to the Authors' knowledge, this is the first paper when the monotone iterative method is applied to neutral first-order differential equations with deviating...

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• Dynamics of Partial Differential Equations

  Czasopisma

  ISSN: 1548-159X

• Monotone and numerical analytic- methods for differential equations.

  Publikacja

  • T. Jankowski

  - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS - Rok 2003

  Praca dotyczy problemu różniczkowo-całkowego (typu Fredholma) z ogólnym warunkiem początkowo-brzegowo-całkowym. W pierwszej części pracy, stosując metodę iteracji monotonicznych, sformułowano warunki dostateczne które gwarantują, że dyskutowany problem ma rozwiązanie ekstremalne w zbiorze generowanym przez dolne i górne rozwiązania. Rozważania teoretyczne poparto przykładem i dyskusją. W drugiej części pracy zastosowano metodę...

• JOURNAL OF DIFFERENTIAL EQUATIONS

  Czasopisma

  ISSN: 0022-0396 , eISSN: 1090-2732

• Systems of Nonlinear Fractional Differential Equations

  Publikacja

  • T. Jankowski

  - Fractional Calculus and Applied Analysis - Rok 2015

  Using the iterative method, this paper investigates the existence of a unique solution to systems of nonlinear fractional differential equations, which involve the right-handed Riemann-Liouville fractional derivatives D(T)(q)x and D(T)(q)y. Systems of linear fractional differential equations are also discussed. Two examples are added to illustrate the results.

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• Numerical solution of threshold problems in epidemics and population dynamics

  Publikacja

  • Z. Bartoszewski
  • Z. Jackiewicz
  • Y. Kuang

  - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS - Rok 2015

  A 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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• Boundary problems for fractional differential equations

  Publikacja

  • T. Jankowski

  - APPLIED MATHEMATICS LETTERS - Rok 2014

  In this paper, the existence of solutions of fractional differential equations with nonlinear boundary conditions is investigated. The monotone iterative method combined with lower and upper solutions is applied. Fractional differential inequalities are also discussed. Two examples are added to illustrate the results.

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• NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS

  Czasopisma

  ISSN: 0749-159X , eISSN: 1098-2426

• Fractional differential equations with causal operators

  Publikacja

  • T. Jankowski

  - Advances in Difference Equations - Rok 2015

  We study fractional differential equations with causal operators. The existence of solutions is obtained by applying the successive approximate method. Some applications are discussed including also the case when causal operator Q is a linear operator. Examples illustrate some results.

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• Numerical methods for systems of nonlinear differential functional equations

  Publikacja

  • A. Szafrańska

  - Rok 2009

  Praca dotyczy zagadnień początkowo brzegowych dla nieliniowych układów różniczkowo funkcyjnych. Rozważana jest aproksymacja rozwiązań rozważanego problemu różniczkowo funkcyjnego przez rozwiązania odpowiedniego problemu różnicowego. W pracy analizowana jest zbieżność prezentowanych metod. Dowód zbieżności opiera się na technice porównawczej z nieliniowym oszacowaniem typu Perron'a dla danych operatorów.

• Justyna Signerska-Rynkowska dr inż.

  Osoby

  Instytut Matematyki Stosowanej

  Since 2021 visiting assistant professor in Dioscuri Centre in Topological Data Analysis (Institute of Mathematics of the Polish Academy of Sciences, IMPAN)  Since 2016   assistant professor at Gdańsk University of Technology, Faculty of Applied Physics and                      Mathematics, Department of Differential Equations and Mathematics Applications  2020 - 2023  Principal Investigator in "SONATA" grant “Challenges of low-dimensional...

• Method of lines for Hamilton-Jacobi functional differential equations.

  Publikacja

  • Z. Kamont
  • A. Szafrańska

  - DYNAMIC SYSTEMS AND APPLICATIONS - Rok 2013

  Initial boundary value problems for nonlinear first order partial functional differential equations are transformed by discretization in space variables into systems of ordinary functional differential equations. A method of quasi linearization is adopted. Suffcient conditions for the convergence of the method of lines and error estimates for approximate solutions are presented. The proof of the stability of the diffrential difference...

• Journal of Dynamics and Differential Equations

  Czasopisma

  ISSN: 1040-7294 , eISSN: 1572-9222

• Quasi-solutions for generalized second order differential equations with deviating arguments

  Publikacja

  • W. Szatanik

  - JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS - Rok 2008

  This paper deal with boundary value problems for generalized second order differential equations with deviating arguments. Existence of quasi-solutions and solutions are proved by monotone iterative method. Examples with numerical results are added.

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• Numerical approximations of parabolic functional differential equations on unbounded domains

  Publikacja

  • A. Baranowska

  - Commentationes Mathematicae - Rok 2008

  Skonstruowano schematy różnicowe zagadnień początkowych dla nieliniowych parabolicznych równań różniczkowo funkcyjnych. Przedstawiono twierdzenie o oszacowaniu błędu rozwiązań przybliżonych dla równań różnicowo funkcyjnych typu Volterry z niewiadomą funkcją kilku zmiennych. Udowodniono twierdzenie o zbieżności jawnych schematów różnicowych. Podano przykłady numeryczne.

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• DIFFERENTIAL EQUATIONS

  Czasopisma

  ISSN: 0012-2661 , eISSN: 1608-3083

• Systems of boundary value problems of advanced differential equations

  Publikacja

  • T. Jankowski
  • R. Jankowski

  - DYNAMIC SYSTEMS AND APPLICATIONS - Rok 2015

  This paper considers the existence of extremal solutions to systems of advanced differential equations with corresponding nonlinear boundary conditions. The monotone iterative method is applied to obtain the existence results. An example is provided for illustration.

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• Weighted difference schemes for systems of quasilinear first order partial functional differential equations

  Publikacja

  • A. Szafrańska

  - Mathematica Applicanda (Matematyka Stosowana) - Rok 2015

  The paper deals with initial boundary value problems of the Dirichlet type for system of quasilinear functional differential equations. We investigate weighted difference methods for these problems. A complete convergence analysis of the considered difference methods is given. Nonlinear estimates of the Perron type with respect to functional variables for given functions are assumed. The proof of the stability of difference problems...

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• Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations

  Publikacja

  • J. Barański
  • P. Dudek

  - ACTA FACULTATIS XYLOLOGIAE ZVOLEN - Rok 2021

  The experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...

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• Method of lines for nonlinear first order partial functional differential equations.

  Publikacja

  • A. Szafrańska

  - BULLETIN OF THE BELGIAN MATHEMATICAL SOCIETY-SIMON STEVIN - Rok 2013

  Classical solutions of initial problems for nonlinear functional differential equations of Hamilton--Jacobi type are approximated by solutions of associated differential difference systems. A method of quasilinearization is adopted. Sufficient conditions for the convergence of the method of lines and error estimates for approximate solutions are given. Nonlinear estimates of the Perron type with respect to functional variables...

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• Implicit difference methods for first order partial differential functional equations

  Publikacja

  • A. Szafrańska

  - Functional Differential Equations - Rok 2007

  Klasyczne rozwiązania problemów początkowo brzegowych przybliżane są rozwiązaniami uwikłanych metod różnicowych. Wykazana została zbieżność i stabilność uwikłanych schematów. Dowód stabilności opiera się na technice porównawczej z nieliniowym oszacowaniem typu Perrona dla funkcji danych.

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• Numerical approximation of first order partial differential equations withdeviated variables.

  Publikacja

  • A. Baranowska
  • Z. Kamont

  - Commentationes Mathematicae - Rok 2003

  Klasyczne rozwiązania nieliniowego zagadnienia Cauchy´ego określone na piramidzie Haara są aproksymowane za pomocą rozwiązań układów quasiliniowych równań różnicowych. Stabilność schematu różnicowego jest wykazana metodą porównawczą z zastosowaniem nieliniowych oszacowań typu Perrona dla danych funkcji. Podano przykłady numeryczne.

• Numerical method of lines for first order partial differential functional equations

  Publikacja

  • A. Baranowska
  • Z. Kamont

  - ZEITSCHRIFT FUR ANALYSIS UND IHRE ANWENDUNGEN - Rok 2002

  Udowodniono zbieżność numerycznej metody prostych dla równań różniczkowofunkcyjnych o pochodnych cząstkowych pierwszego rzędu i ich rozwiązań klasycznych określonych na piramidzie Haara. Zastosowano metodę nierówności różniczkowych.

• Numerical Comparison of Damping Amplification Effects Obtained in Neighborhood of a Mechanism Singular Position - Viscous and Electromagnetic Cases

  Publikacja

  • K. Lipiński

  - Key Engineering Materials - Rok 2014

  In the paper, results of numerical investigations are presented. A continuous beam is considered as the main vibrating element. Two energy dissipations methods are compared: viscous dampers and DC generators. To increase the damping effectiveness, velocity amplification is proposed, i.e., a mechanism is introduced between the beam and the damping element, and the mechanism configuration is set as closed to the singular position...

• Existence of solutions with an exponential growth for nonlinear differential-functional parabolic equations

  Publikacja

  • A. Bartłomiejczyk
  • H. Leszczyński

  - Annales Polonici Mathematici - Rok 2014

  We consider the Cauchy problem for nonlinear parabolic equations with functional dependence.We prove Schauder-type existence results for unbounded solutions. We also prove existence of maximal solutions for a wide class of differential functional equations.

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• Positive solutions to boundary value problems for impulsive second-order differential equations

  Publikacja

  • T. Jankowski
  • R. Jankowski

  - Dynamics of Continuous, Discrete and Impulsive Systems Series A: Mathematical Analysis - Rok 2011

  In this paper, we discuss four-point boundary value problems for impulsive second-order differential equations. We apply the Krasnoselskii's fixed point theorem to obtain sufficient conditions under which the impulsive second-order differential equations have positive solutions. An example is added to illustrate theoretical results.

• Monotone iterative method for first-order differential equations at resonance

  Publikacja

  • T. Jankowski

  - APPLIED MATHEMATICS AND COMPUTATION - Rok 2014

  This paper concerns the application of the monotone iterative technique for first-order differential equations involving Stieltjes integrals conditions. We discuss such problems at resonance when the measure in the Stieltjes integral is positive and also when this measure changes the sign. Sufficient conditions which guarantee the existence of extremal, unique and quasi-solutions are given. Three examples illustrate the results.

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• Balance errors in numerical solutions of shallow water equations

  Publikacja

  • D. Gąsiorowski

  - TASK Quarterly - Rok 2007

  The analysis of the conservative properties of the shallow water equations is presented in the paper. The work focuses on the consistency of numerical solution of these equations with the conservation laws of mass and momentum. The investigations involve two different conservative forms which are solved by an implicit box scheme. The theoretical analysis supported by numerical experiments is carried out for rectangular channel...

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• Numerical method of lines for first order partial differential equations with deviated variables

  Publikacja

  • W. Czernous

  - Rok 2005

  Praca traktuje o przybliżaniu rozwiązań klasycznych równańróżniczkowo-funkcyjnych cząstkowych pierwszego rzędu rozwiązaniamiukładów quasiliniowych równań różnicowych. Nowe podejście dorozwiązywania równań nieliniowych zawdzięczamy metodziequasilinearyzacji dla zagadnień początkowo - brzegowych z odchylonymargumentem. Dla przyrostów pochodnych funkcji danej zakładamy nieliniowe oszacowanie typu Perrona. Załączone są wyniki eksperymentów...

• Numerical methods for nonlinear first-order partial differential equations with deviated variables

  Publikacja

  • A. Baranowska

  - Rok 2005

  Klasyczne rozwiązania zagadnień początkowych dla nieliniowych równań cząstkowych z odchylonym argumentem aproksymowano za pomocą rozwiązań układów quasiliniowych równań różnicowych określonych na piramidzie Haara. Podano warunek dostateczny zbieżności metody. Stabilność schematu różnicowego wykazano metodą porównawczą. Przedstawiono metodę rozwiązywania nieliniowych równań różniczkowych cząstkowych z odchylonym argumentem bazującą...

• Numerical Simulations for Transonic Flow in Control Valve

  Publikacja

  • P. Flaszyński
  • P. Doerffer
  • G. Mikułowski
  • J. holnicki-Szulc

  - Rok 2013

  Results of numerical simulations for transonic flow in control valve are presented. The valve is the main part of an adaptive pneumatic shock absorber. Flow structure in the valve domain and the influence of the flow non-uniformity in the valve on a mass flow rate is investigated. Numerical simulation results are compared with experimental data.

• Numerical tests of time-stepping schemes in the context of FEM for 6-field shell dynamics

  Publikacja

  • J. Chróścielewski
  • I. Lubowiecka

  - Rok 2011

  The paper deals with integration of dynamic equations of irregular shells performed with relatively long time steps. Numerical instability appearing often in this kind of analysis motivated the authors to present some studies based on numerical tests referring to convergence problems of finite element analysis as well the applied stability conditions. The analysis is carried out on simulations of shell dynamics with the where the...

• Application of Pierson-Moskowitz wave spectrum to solution differential equations of multihull vessel

  Publikacja

  • A. Królicka-Gałązka
  • K. Trębacki

  - Logistyka - Rok 2011

  Motion of a dynamic system can be generated by different external or internal factors. At mathematical modelling external excitation factors of the most significant effect on the system, are selected. Such external factors are usually called excitations. Response of the system to given excitations is mathematically characterized by a definite transformation called operator of a system. For a broad class of dynamic systems the...

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• Functional differential equations

  Publikacja

  • T. Jankowski

  - CZECHOSLOVAK MATHEMATICAL JOURNAL - Rok 2002

  Sformułowano dość ogólne warunki dostateczne na to, aby odpowiednio zdefiniowane ciągi monotoniczne były zbieżne do jedynego, w pewnym segmencie, rozwiązania zagadnienia początkowego dla funkcyjnych równań różniczkowych. Omawiane równanie jest ogólne, a np. zwyczajne równania różniczkowe czy równania różniczkowo-całkowe są jego szczególnymi przypadkami.

• Successive Iterative Method for Higher-Order Fractional Differential Equations Involving Stieltjes Integral Boundary Conditions

  Publikacja

  • T. Jankowski

  - TASK Quarterly - Rok 2016

  In this paper, the existence of positive solutions to fractional differential equations with delayed arguments and Stieltjes integral boundary conditions is discussed. The convergence of successive iterative method of solving such problems is investigated. This allows us to improve some recent works. Some numerical examples illustrate the results.

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• Positive solutions to advanced fractional differential equations with nonlocal boundary conditions

  Publikacja

  • T. Jankowski

  - Applicable Analysis and Discrete Mathematics - Rok 2015

  We study the existence of positive solutions for a class of higher order fractional differential equations with advanced arguments and boundary value problems involving Stieltjes integral conditions. The fixed point theorem due to Avery-Peterson is used to obtain sufficient conditions for the existence of multiple positive solutions. Certain of our results improve on recent work in the literature.

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• Numerical Simulations of Hydrodynamic Open-Water Characteristics of a Ship Propeller

  Publikacja

  • J. Felicjancik
  • K. Sebastian
  • K. Felicjancik
  • K. Krzysztof

  - Polish Maritime Research - Rok 2016

  The 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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• Multimode systems of nonlinear equations: derivation, integrability, and numerical solutions

  Publikacja

  • S. Leble
  • B. Reichel
  • M. Kuszner

  - THEORETICAL AND MATHEMATICAL PHYSICS - Rok 2011

  We consider the propagation of electromagnetic pulses in isotropic media taking a third-order nonlinearityinto account. We develop a method for transforming Maxwell's equations based on a complete set ofprojection operators corresponding to wave-dispersion branches (in a waveguide or in matter) with thepropagation direction taken into account. The most important result of applying the method is a systemof equations describing the...

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• Advances in Differential Equations

  Czasopisma

  ISSN: 1079-9389

• Differential Equations & Applications

  Czasopisma

  ISSN: 1847-120X , eISSN: 1848-9605

• Numerical simulations of novel GFRP sandwich footbridge

  Publikacja

  • J. Chróścielewski
  • W. Witkowski
  • B. Sobczyk
  • K. Daszkiewicz

  - Rok 2014

  In 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...

• Positive solutions to fractional differential equations involving Stieltjes integral conditions

  Publikacja

  • T. Jankowski

  - APPLIED MATHEMATICS AND COMPUTATION - Rok 2014

  In this paper, we investigate nonlocal boundary value problems for fractional differential equations with dependence on the first-order derivatives and deviating arguments. Sufficient conditions which guarantee the existence of at least three positive solutions are new and obtained by using the Avery–Peterson theorem. We discuss problems (1) and (2) when argument b can change the character on [0, 1], so in some subinterval I of...

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• Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations

  Publikacja

  • D. Gąsiorowski

  - JOURNAL OF HYDROLOGY - Rok 2013

  The paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...

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