Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Digital Waveguides versus Finite Difference Structures: Equivalence and Mixed Modeling | EURASIP Journal on Applied Signal Processing 2004 7 978-989 2004 Hindawi Publishing Corporation Digital Waveguides versus Finite Difference Structures Equivalence and Mixed Modeling Matti Karjalainen Laboratory of Acoustics and Audio Signal Processing Helsinki University of Technology 02150 Espoo Finland Email Cumhur Erkut Laboratory of Acoustics and Audio Signal Processing Helsinki University of Technology 02150 Espoo Finland Em ail Received 30 June 2003 Revised 4 December 2003 Digital waveguides and finite difference time domain schemes have been used in physical modeling of spatially distributed systems. Both of them are known to provide exact modeling of ideal one-dimensional 1D band-limited wave propagation and both of them can be composed to approximate two-dimensional 2D and three-dimensional 3D mesh structures. Their equal capabilities in physical modeling have been shown for special cases and have been assumed to cover generalized cases as well. The ability to form mixed models by joining substructures of both classes through converter elements has been proposed recently. In this paper we formulate a general digital signal processing DSP -oriented framework where the functional equivalence of these two approaches is systematically elaborated and the conditions of building mixed models are studied. An example of mixed modeling of a 2D waveguide is presented. Keywords and phrases acoustic signal processing hybrid models digital waveguides scattering FDTD model structures. 1. INTRODUCTION Discrete-time simulation of spatially distributed acoustic systems for sound and voice synthesis finds its roots both in modeling of speech production and musical instruments. The Kelly-Lochbaum vocal tract model 1 introduced a onedimensional transmission line simulation of speech production with two-directional delay lines and scattering junctions for nonhomogeneous vocal tract profiles. Delay sections discretize the d Alembert .
