We show that the polar as well as the pseudo-polar FFT can be computed very accurately and efficiently by the well known nonequispaced FFT. Furthermore, we discuss the reconstruction of a 2d signal from its Fourier transform samples on a (pseudo-)polar grid by means of the inverse nonequispaced FFT.

Abstract Network Calculus (NC) is an algebraic theory that represents traffic and service guarantees as curves in a Cartesian plane, order to compute performance for flows traversing network. NC uses transformation operations, e.g., min-plus convolution of two curves, model how the profile changes with traversal network nodes. Such while mathematically well-defined, can quickly become unmanagea...

Extensions of the Schur complement and the principal pivot transform, where the usual inverses are replaced by the Moore-Penrose inverse, are revisited. These are called the pseudo Schur complement and the pseudo principal pivot transform, respectively. First, a generalization of the characterization of a block matrix to be an M -matrix is extended to the nonnegativity of the Moore-Penrose inve...

Problems arising when kinematically redundant manipulators are controlled using the Jacobian pseudoinverse are related to the non-integrability of the standard pseudo-inverse. This paper presents a class of generalized inverses which have the property of being integrable within any simply connected, nonsingular region of the workspace. Integrability is obtained by deriving the equations which d...

Network monitoring and diagnosis are key to improving network performance. The difficulties of performance monitoring lie in today’s fast growing Internet, accompanied by increasingly heterogeneous and unregulated structures. Moreover, these tasks become even harder since one cannot rely on the collaboration of individual routers and servers to directly measure network traffic. Even though the ...

Network monitoring and diagnosis are key to improving network performance. The difficulties of performance monitoring lie in today’s fast growing Internet, accompanied by increasingly heterogeneous and unregulated structures. Moreover, these tasks become even harder since one cannot rely on the collaboration of individual routers and servers to directly measure network traffic. Even though the ...

In recent years there has been an increasing need to improve satellite attitude control performance in terms of agility and attitude accuracy in large-angle attitude maneuvers. To achieve such control performance, single-gimbal control moment gyros (SGCMGs) should be mounted as modern-type actuators. Conventionally, based on the torque command calculated by the attitude control system of the sa...

Robust control problems in linear systems are considered on the base of analysis of related linear quadratic differential game. New explicit formulae for the "best" robust optimal control input and the "worst" exogenous disturbance derived with the use of pseudo-inverse matrices ) (t D+ were originally suggested in this author's previously published paper "Reduction of Dimensionality in Choosin...

The objective of this paper is to present and make a comparative study of several inverse kinematics methods for serial manipulators, based on the Jacobian matrix. Besides the well-known Jacobian transpose and Jacobian pseudo-inverse methods, three others, borrowed from numerical analysis, are presented. Among them, two approximation methods avoid the explicit manipulability matrix inversion, w...