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19
The electronic tabla controller
 Journal of New Music Research
, 2003
"... This paper describes the design of an electronic Tabla controller. The ETabla controls both sound and graphics simultaneously. It allows for a variety of traditional Tabla strokes and new performance techniques. Graphical feedback allows for artistical display and pedagogical feedback. ..."
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Cited by 21 (8 self)
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This paper describes the design of an electronic Tabla controller. The ETabla controls both sound and graphics simultaneously. It allows for a variety of traditional Tabla strokes and new performance techniques. Graphical feedback allows for artistical display and pedagogical feedback.
On the Number of Bouncing Ball Modes in Billiards
, 1997
"... We study the number of bouncing ball modes N bb (E) in a class of twodimensional quantized billiards with two parallel walls. Using an adiabatic approximation we show that asymptotically N bb (E) ¸ ffE ffi for E !1, where ffi 2] 1 2 ; 1[ depends on the shape of the billiard boundary. In partic ..."
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Cited by 12 (0 self)
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We study the number of bouncing ball modes N bb (E) in a class of twodimensional quantized billiards with two parallel walls. Using an adiabatic approximation we show that asymptotically N bb (E) ¸ ffE ffi for E !1, where ffi 2] 1 2 ; 1[ depends on the shape of the billiard boundary. In particular for the class of twodimensional Sinai billiards, which are chaotic, one can get arbitrarily close (from below) to ffi = 1, which corresponds to the leading term in Weyl's law for the mean behaviour of the counting function of eigenstates. This result shows that one can come arbitrary close to violating quantum ergodicity. We compare the theoretical results with the numerically determined counting function N bb (E) for the stadium billiard and the cosine billiard and find good agreement.
Physical Wave Propagation Modeling for RealTime Synthesis of Natural Sounds
, 2002
"... This thesis proposes banded waveguide synthesis as an approach to realtime sound synthesis based on the underlying physics. So far three main approaches have been widely used: digital waveguide synthesis, modal synthesis and finite element methods. Digital waveguide synthesis is efficient and reali ..."
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Cited by 10 (3 self)
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This thesis proposes banded waveguide synthesis as an approach to realtime sound synthesis based on the underlying physics. So far three main approaches have been widely used: digital waveguide synthesis, modal synthesis and finite element methods. Digital waveguide synthesis is efficient and realistic and captures the complete dynamics of the underlying physics but is restricted to instruments that are welldescribed by the onedimensional string equation. Modal synthesis is efficient and realistic yet abandons complete dynamical description and hence cannot used for certain types of performance interactions like bowing. Finite element methods are realistic and capture the behavior of the constituent physical equations but on current commodity hardware does not perform in realtime. Banded waveguides offer efficient simulations for cases for which modal synthesis is appropriate but traditional digital waveguide synthesis is not applicable. The key realization is that the dynamic behavior of traveling waves, which is being used in waveguide synthesis, can be applied to individual modes and that the efficient computational
Semiclassical Transition from an Elliptical to an Oval
 Billiard, J. Phys. A
, 1997
"... Semiclassical approximations often involve the use of stationary phase approximations. This method can be applied when ¯h is small in comparison to relevant actions or action differences in the corresponding classical system. In many situations, however, action differences can be arbitrarily small a ..."
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Cited by 7 (3 self)
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Semiclassical approximations often involve the use of stationary phase approximations. This method can be applied when ¯h is small in comparison to relevant actions or action differences in the corresponding classical system. In many situations, however, action differences can be arbitrarily small and then uniform approximations are more appropriate. In the present paper we examine different uniform approximations for describing the spectra of integrable systems and systems with mixed phase space. This is done on the example of two billiard systems, an elliptical billiard and a deformation of it, an oval billiard. We derive a trace formula for the ellipse which involves a uniform approximation for the Maslov phases near the separatrix, and a uniform approximation for tori of periodic orbits close to a bifurcation. We then examine how the trace formula is modified when the ellipse is deformed into an oval. This involves uniform approximations for the breakup of tori and uniform approximations for bifurcations of periodic orbits. Relations between different uniform approximations are discussed. PACS numbers: 03.65.Ge Solutions of wave equations: bound states. 03.65.Sq Semiclassical theories and applications. 05.45.+b Theory and models of chaotic systems.
SemiClassical Asymptotics in Magnetic Bloch Bands
, 2002
"... This article gives a simple construction of wave packets localized near semiclassical trajectories for an electron subject to external electric and magnetic fields. We assume that the magnetic and electric potentials are slowly varying perturbations of the potential of a constant magnetic field and ..."
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Cited by 7 (1 self)
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This article gives a simple construction of wave packets localized near semiclassical trajectories for an electron subject to external electric and magnetic fields. We assume that the magnetic and electric potentials are slowly varying perturbations of the potential of a constant magnetic field and a periodic lattice potential, respectively.
A Scaling Theory of Bifurcations in the Symmetric WeakNoise Escape Problem
 Journal of Statistical Physics
, 1996
"... We consider the overdamped limit of twodimensional double well systems perturbed by weak noise. In the weak noise limit the most probable fluctuational path leading from either point attractor to the separatrix (the most probable escape path, or MPEP) must terminate on the saddle between the two we ..."
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Cited by 6 (1 self)
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We consider the overdamped limit of twodimensional double well systems perturbed by weak noise. In the weak noise limit the most probable fluctuational path leading from either point attractor to the separatrix (the most probable escape path, or MPEP) must terminate on the saddle between the two wells. However, as the parameters of a symmetric double well system are varied, a unique MPEP may bifurcate into two equally likely MPEP's. At the bifurcation point in parameter space, the activation kinetics of the system become nonArrhenius. In this paper we quantify the nonArrhenius behavior of a system at the bifurcation point, by using the MaslovWKB method to construct an approximation to the quasistationary probability distribution of the system that is valid in a boundary layer near the separatrix. The approximation is a formal asymptotic solution of the Smoluchowski equation. Our analysis relies on the development of a new scaling theory, which yields `critical exponents' describing...
Ray techniques in electromagnetics
 Proceedings of the IEEE
, 1972
"... AbsfracfThe principles of ray optics and, in more detail, some selected applications of ray techniques to electromagnetic8 are reviewed briefly. It is shown how a systematic use of matrix representation for the wavefront curvature and for its transformations simplify the handling of arbitrary penci ..."
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Cited by 6 (0 self)
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AbsfracfThe principles of ray optics and, in more detail, some selected applications of ray techniques to electromagnetic8 are reviewed briefly. It is shown how a systematic use of matrix representation for the wavefront curvature and for its transformations simplify the handling of arbitrary pencils of rays and, consequently, the field computations. The same methods apply to complex rays which give a means of describing the effects of reflections and refractions on Gaussian beams. The relations of ray optics to other disciplines are also briefly discussed. I.
PROGRESS IN ASYMMETRIC RESONANT CAVITIES: USING SHAPE AS A DESIGN PARAMETER IN DIELECTRIC MICROCAVITY LASERS
"... We report on progress in developing optical microresonators and microlasers based on deformations of dielectric spheres and cylinders. We review the different semiconductor and polymer dye microlasers which have been developed and demonstrated using this approach. All the lasers exhibit highly direc ..."
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Cited by 3 (1 self)
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We report on progress in developing optical microresonators and microlasers based on deformations of dielectric spheres and cylinders. We review the different semiconductor and polymer dye microlasers which have been developed and demonstrated using this approach. All the lasers exhibit highly directional emission despite the presence of ray chaos in the system. Lasing has been demonstrated using both optical pumping and electrical pumping in the case of InGaP quantum cascade lasers and very recently in GaN MQW lasers. Lasing modes based on stable and unstable periodic orbits have been found as well as modes based on chaotic whispering gallery orbits; the lasing mode depending on the material, shape and index of refraction. The lasing from modes based on unstable orbits dominated for certain shapes in the GaN cylinder lasers, and is related to the “scarred ” states known from quantum chaos theory. Extreme sensitivity of the emission pattern to small shape differences has been demonstrated in the polymer microlasers. Large increases in output power due to optimization of the resonator shape has been demonstrated, most notably in the quantum cascade “bowtie ” lasers. Efficient numerical approaches have been developed to allow rapid calculation of the resonant modes and their directional emission patterns for general resonator shapes. These are necessary because the lasing modes are not usually amenable to standard analytic techniques such as Gaussian optical or eikonal theory. Theoretical analysis of the directional emission from polymer lasers has shown that highly directional emission is compatible with strongly chaotic ray dynamics due to the nonrandom character of the shortterm dynamics. Very recently unidirectional emission and electrical pumping have been demonstrated in the GaN MQW system using a spiralshaped resonator design, bringing this general approach in which shape is used as a design parameter closer to useful applications.
2d Microcavities: Theory and Experiments
 Experimental Methods in the Physical Sciences 40
, 2002
"... Contents 1 Introduction 3 2 Dielectric microcavities as highquality resonators 4 3 Whisperinggallery modes 8 4 Scattering resonances and quasibound states 10 5 Cavity ringdown and light emission 13 6 Wigner delay time and the density of states 15 7 Lifetime versus linewidth in experiments 18 8 H ..."
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Cited by 2 (2 self)
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Contents 1 Introduction 3 2 Dielectric microcavities as highquality resonators 4 3 Whisperinggallery modes 8 4 Scattering resonances and quasibound states 10 5 Cavity ringdown and light emission 13 6 Wigner delay time and the density of states 15 7 Lifetime versus linewidth in experiments 18 8 How many modes does a cavity support? 19 9 Cavities without chaos 22 10 Chaotic cavities 25 11 Phase space representation with Poincare sections 26 12 Uncertainty principle 29 13 Husimi projection 30 14 Constructive interference with chaotic rays 32 15 Chaotic whisperinggallery modes 34 16 Dynamical eclipsing 36 17 Conclusions 37 1 Introduction Maxwell's equations of electrodynamics exemplify how the beauty of a theory is captured in the formal simplicity of its fundamental equations. Precisely for this reason, they also illustrate that physical insight cannot be gleaned from the defining equations of a theory per se unless we understand how these equations are solved in practice. In optics
Aspects of the topology of interactions on loop dynamics in one and two dimensions
 of Lecture
"... Abstract. This paper discusses aspects of topology as relevant for loop dynamics as they occur in physical modeling synthesis algorithms. Boundary and interaction point behavior is treated purely from a topological perspective for some dynamical systems in one and two dimensions. 1 ..."
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Abstract. This paper discusses aspects of topology as relevant for loop dynamics as they occur in physical modeling synthesis algorithms. Boundary and interaction point behavior is treated purely from a topological perspective for some dynamical systems in one and two dimensions. 1