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Dittrich, M.G. (author), Berkhoff, A.P. (author), Kurylek, R. (author)Geluid van stalen verkeersbruggen, met name laagfrequent geluid, is nog steeds een potentiële bron van hinder bij zowel nieuwe als bestaande verkeersbruggen. Hoewel diverse maatregelen bekend zijn en methodes voor modellering beschikbaar zijn, zijn er nog open vragen ten aanzien van modellering en effectiviteit van maatregelen. In 2019 is een...report 2023
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Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)This paper focuses on extensive numerical and experimental investigations of a thin sandwich acoustic source. Due to an energy inefficient actuation design, a thin sandwich acoustic source that was proposed in an early study is redesigned and reconstructed in the current research. The thin acoustic source in the present paper is actuated by long...article 2020
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- Tajdari, F. (author), Berkhoff, A.P. (author), van der Zee, R.A.R. (author), de Boer, A. (author) article 2020
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Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)This paper studies an acoustic source with a relatively small thickness and a high bending stiffness. The acoustic source operates in the low frequency, quasi-static regime. The focus of the current study is on the actuation part in order to design an appropriate excitation mechanism. A flexural mechanism is modeled in combination with a...article 2020
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- Tajdari, F. (author), Berkhoff, A.P. (author), Naves, M. (author), Nijenhuis, M. (author), de Boer, A. (author) article 2020
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Dittrich, M.G. (author), Berkhoff, A.P. (author)Rijkswaterstaat en andere wegbeheerders worden regelmatig geconfronteerd met geluidklachten van omwonenden nabij bruggen met een stalen brugdek. Deze hinderklachten zijn vanwege de afstraling van laagfrequent geluid van de brugconstructie met name tijdens het passeren van zware vrachtwagens, maar ook piekgeluid van voegen en rolgeluid van lichte...report 2020
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Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)This paper studies an acoustic source with a relatively small thickness and high bending stiffness. Piezoelectric actuators are used to drive the moving component of the acoustic source. In the current study, a lumped model is used to represent the acoustic source that is excited by a piezoelectric stacked actuator. The equivalent electrical...conference paper 2018
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van Neer, P.L.M.J. (author), Volker, A.W.F. (author), Berkhoff, A.P. (author), Akkerman, H.B. (author), Schrama, T. (author), van Breemen, A. (author), Gelinck, G.H. (author)Recently, there has been considerable interest in the development of ultrasound based mid-air haptic feedback devices. These devices allow for tactile sensations to be induced at any position and time without constraints to human motion, which is useful for virtual user interfaces, augmented/virtual reality and feedback buttons. The haptic...conference paper 2018
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Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)This paper studies a lumped model of an acoustic source with a relatively small thickness and high bending stiffness. Voice coil and piezoelectric actuators are used to drive moving components of the acoustic source. Feedback and feedforward damping control techniques are used to actively obtain a smooth frequency response, especially at low...conference paper 2017
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- Berkhoff, A.P. (author), Meijer, H.J. (author), van Ophem, S. (author) conference paper 2016
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van Ophem, S. (author), Berkhoff, A.P. (author)Summary For broadband active noise control applications with a rapidly changing primary path, it is desirable to find algorithms with a rapid convergence, a fast tracking performance, and a low computational cost. Recently, a promising algorithm has been presented, called the fast-array Kalman filter, which uses rotation matrices to calculate...article 2016
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Tajdari, F. (author), Berkhoff, A.P. (author), de Boer, A. (author)The present work describes the electrical, mechanical and acoustical behavior of a thin honey-comb structure as an acoustic source. The acoustic source has to operate in the low frequency, quasi-static regime and is driven by a piezoelectric stack actuator. In addition, a two-way energy flow between the actuator and a connected amplifier is...conference paper 2016
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- Berkhoff, A.P. (author), Meijer, H.J. (author), van Ophem, S. (author) conference paper 2016
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van der Rots, R. (author), Berkhoff, A.P. (author)This paper describes numerical and experimental results of beamforming algorithms for generation of directional sound. The intended application is a sound source for cars with the objective to warn vulnerable road users while minimising noise pollution. Nowadays, sensors exist which are able to reveal the position of the vulnerable road users,...article 2015
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Ho, J.H. (author), Berkhoff, A.P. (author)This paper presents an acoustic source with a small thickness and high bending stiffness. The high bending stiffness is obtained with a sandwich structure in which the face of the sandwich structure internal to the source is perforated to increase the acoustic compliance, thereby leading to increased electroacoustic conversion efficiency....article 2015
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Berkhoff, A.P. (author), van Ophem, S. (author)Noise reduction in feedforward active noise control systems with a rapidly changing primary path requires rapid convergence and fast tracking. This can be accomplished with a fast-array Kalman method which uses an efficient rotation matrix technique to calculate the filter parameters. However, finite precision effects lead to unstable behavior....conference paper 2015
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Ho, J.H. (author), Berkhoff, A.P. (author)This paper compares various decentralised control strategies, including structural and acoustic actuator-sensor configuration designs, to reduce noise transmission through a double panel structure. The comparison is based on identical control stability indexes. The double panel structure consists of two panels with air in between and offers the...article 2014
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Berkhoff, A.P. (author), Van Genechten, B. (author)In this paper, methods are presented to design an acoustic source array for both directional sound generation and non-directional sound generation. The methods are based on measured transfer functions to be able to take into account different source sensitivities, to use extended sources that cannot be regarded as point sources, and complex...conference paper 2014
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van Ophem, S. (author), Berkhoff, A.P. (author)Recently, a multiple-input/multiple-output Kalman filter technique was presented to control time-varying broadband noise and vibrations. By describing the feed-forward broadband active noise control problem in terms of a state estimation problem it was possible to achieve a faster rate of convergence than instantaneousgradient least-mean-squares...conference paper 2014
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Berkhoff, A.P. (author), van Ophem, S. (author)The feed-forward broadband active noise control problem can be formulated as a state estimation problem to achieve a faster rate of convergence than the filtered reference least mean squares algorithm and possibly also a better tracking performance. A multiple input/multiple output Kalman algorithm is used to perform this state estimation. To...conference paper 2013