Download or read book Quadratic Optimization in the Problems of Active Control of Sound written by Josip Lončarić and published by DIANE Publishing. This book was released on 2002 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quadratic Optimization in the Problems of Active Control of Sound written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-04 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: We analyze the problem of suppressing the unwanted component of a time-harmonic acoustic field (noise) on a predetermined region of interest. The suppression is rendered by active means, i.e., by introducing the additional acoustic sources called controls that generate the appropriate anti-sound. Previously, we have obtained general solutions for active controls in both continuous and discrete formulations of the problem. We have also obtained optimal solutions that minimize the overall absolute acoustic source strength of active control sources. These optimal solutions happen to be particular layers of monopoles on the perimeter of the protected region. Mathematically, minimization of acoustic source strength is equivalent to minimization in the sense of L(sub 1). By contrast. in the current paper we formulate and study optimization problems that involve quadratic functions of merit. Specifically, we minimize the L(sub 2) norm of the control sources, and we consider both the unconstrained and constrained minimization. The unconstrained L(sub 2) minimization is certainly the easiest problem to address numerically. On the other hand, the constrained approach allows one to analyze sophisticated geometries. In a special case, we call compare our finite-difference optimal solutions to the continuous optimal solutions obtained previously using a semi-analytic technique. We also show that the optima obtained in the sense of L(sub 2) differ drastically from those obtained in the sense of L(sub 1).Loncaric, J. and Tsynkov, S. V. and Bushnell, Dennis M. (Technical Monitor)Langley Research CenterNOISE SPECTRA; ACOUSTIC FREQUENCIES; NOISE REDUCTION; OPTIMIZATION; ACTIVE CONTROL; MATHEMATICAL MODELS; NUMERICAL ANALYSIS; MONOPOLES; SOUND FIELDS; SOUND GENERATORS
Download or read book Active Control of Noise and Vibration written by Colin Hansen and published by CRC Press. This book was released on 1996-11-21 with total page 1292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This major work is the first to treat the active control of both sound and vibration in a unified way. It outlines the fundamental concepts, explains how a reliable and stable system can be designed and implemented, and details the pitfalls . It covers sound in ducts, sound radiation, sound transmission into enclosures, structural vibration and isolation, electronic control system design, and sensors and actuators.
Download or read book Active Control of Vibration written by Christopher C. Fuller and published by Academic Press. This book was released on 1996-02-08 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a companion text to Active Control of Sound by P.A. Nelson and S.J. Elliott, also published by Academic Press. It summarizes the principles underlying active vibration control and its practical applications by combining material from vibrations, mechanics, signal processing, acoustics, and control theory. The emphasis of the book is on the active control of waves in structures, the active isolation of vibrations, the use of distributed strain actuators and sensors, and the active control of structurally radiated sound. The feedforward control of deterministic disturbances, the active control of structural waves and the active isolation of vibrations are covered in detail, as well as the more conventional work on modal feedback. The principles of the transducers used as actuateors and sensors for such control strategies are also given an in-depth description. The reader will find particularly interesting the two chapters on the active control of sound radiation from structures: active structural acoustic control. The reason for controlling high frequency vibration is often to prevent sound radiation, and the principles and practical application of such techniques are presented here for both plates and cylinders. The volume is written in textbook style and is aimed at students, practicing engineers, and researchers. Combines material from vibrations, signal processing, mechanics, and controls Summarizes new research in the field
Download or read book Computational Science and Its Applications ICCSA 2003 written by Vipin Kumar and published by Springer. This book was released on 2003-08-03 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three-volume set, LNCS 2667, LNCS 2668, and LNCS 2669, constitutes the refereed proceedings of the International Conference on Computational Science and Its Applications, ICCSA 2003, held in Montreal, Canada, in May 2003.The three volumes present more than 300 papers and span the whole range of computational science from foundational issues in computer science and mathematics to advanced applications in virtually all sciences making use of computational techniques. The proceedings give a unique account of recent results in computational science.
Download or read book Advances in Inverse Problems for Partial Differential Equations written by Dinh-Liem Nguyen and published by American Mathematical Society. This book was released on 2023-04-12 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of two AMS Special Sessions “Recent Developments on Analysis and Computation for Inverse Problems for PDEs,” virtually held on March 13–14, 2021, and “Recent Advances in Inverse Problems for Partial Differential Equations,” virtually held on October 23–24, 2021. The papers in this volume focus on new results on numerical methods for various inverse problems arising in electrical impedance tomography, inverse scattering in radar and optics problems, reconstruction of initial conditions, control of acoustic fields, and stock price forecasting. The authors studied iterative and non-iterative approaches such as optimization-based, globally convergent, sampling, and machine learning-based methods. The volume provides an interesting source on advances in computational inverse problems for partial differential equations.
Download or read book Optimization of Acoustic Source Strength in the Problems of Active Noise Control written by Josip Lončarić and published by . This book was released on 2002 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: We consider a problem of eliminating the unwanted time-harmonic noise on a predetermined region of interest. The desired objective is achieved by active means, i.e., by introducing additional sources of sound called control sources, that generate the appropriate annihilating acoustic signal (anti-sound). A general solution for the control sources has been obtained previously in both continuous and discrete formulation of the problem. In the current paper, we focus on optimizing the overall absolute acoustic source strength of the control sources. Mathematically, this amounts to the minimization of multi-variable complex-valued functions in the sense of L1 with conical constraints, which are only 'marginally' convex. The corresponding numerical optimization problem appears very challenging even for the most sophisticated state-of-the-art methodologies, and even when the dimension of the grid is small, and the waves are long. Our central result is that the global L1-optimal solution can, in fact, be obtained without solving the numerical optimization problem. This solution is given by a special layer of monopole sources on the perimeter of the protected region. We provide a rigorous proof of the global L1 minimality for both continuous and discrete optimization problems in the one-dimensional case. We also provide numerical evidence that corroborates our result in the two-dimensional case, when the protected domain is a cylinder. Even though we cannot fully justify it, we believe that the same result holds in the general case, i.e., for multi-dimensional settings and domains of arbitrary shape. We formulate it as a conjecture at the end of the paper.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Journal of Integral Equations and Applications written by and published by . This book was released on 2014 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise Control Engineering Journal written by and published by . This book was released on 1995 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Control of Noise and Vibration 1992 written by Clark Jeffrey Radcliffe and published by . This book was released on 1992 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Analysis and Applied Mathematics written by Theodore E. Simos and published by American Institute of Physics. This book was released on 2007-09-14 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains peer-reviewed papers presented at the International Conference on Numerical Analysis and Applied Mathematics 2007, ICNAAM-2007. This conference brought together leading scientists of the international Numerical and Applied Mathematics community. More than 350 papers were submitted to be considered for presentation at ICNAAM-2007. From these submissions, 189 papers were selected after an international peer review by at least two independent reviewers.
Download or read book Paper written by and published by . This book was released on 1993 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 15th AIAA Aeroacoustics Conference 93 4401 93 4450 written by and published by . This book was released on 1993 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Congress on Acoustics written by and published by . This book was released on 1995 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Reviews written by and published by . This book was released on 2005 with total page 1884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
