In this paper, optical target tracking, by regular target bearing measurements and target range in a lower and scheduled measurement rate is considered. Variance of the target range estimation error is used as scheduling criterion. For this purpose, target dynamic state vector in modified spherical coordinates is stated in such a way that all target states be decoupled from range-related target...

In non-uniform sampled systems, the measurements are arriving at irregular time intervals. However, the control is updated at regular time intervals. An observer is required to obtain the estimate of the states during the control update times. We evaluate two observer designs: A Kalman filter and a gain-scheduling observer. The Kalman filter has the optimal performance. However, it is computati...

In this paper, we proposed a new error diffusion filter construction method for digital halftoning with random space-filling curve. A random space-filling curve is introduced to incorporate some randomness for regular space-filling curve such as Peano curve and Hilbert curve. Since the round error is propagated to adjacent pixels whose output values have not been determined, the error diffusion...

We report on the feedback control of a periodically driven FitzHugh-Nagumo system displaying various dynamical regimes, regular and chaotic, including chaotic spiking. The feedback term is composed of a high-pass or an all-pass filter. We provide a characterization of the efficiency of the filters in controlling the dynamical state of the system, both experimentally (electronic circuit) and num...

In this note we obtain necessary and sufficient conditions for a convergence space to have a smallest Hausdorff compactification and to have a smallest regular compactification. Introduction. A Hausdorff convergence space as defined in [1] always has a Stone-Cech compactification which can be obtained by a slight modification of the result in [3]. But in general this need not be the largest Hau...

The Aleksandrov-Fenchel inequalities from the theory of mixed volumes are used to prove that certain sequences of combinatorial interest are log concave (and therefore unimodal). 1. MIXED VOLUMES We wish to show how the Aleksandrov-Fenchel inequalities from the theory of mixed volumes can be used to prove that certain sequences of combinatorial interest are log concave (and therefore unimodal)....

x.1. Elliptic Surfaces Deenition. An elliptic surface consists of a smooth (projective) surface E, a smooth (projective) curve C, and a morphism : E ?! C such that almost all bers E t = ?1 (t) are (smooth projective) curves of genus 1. In addition, we will generally assume that our elliptic surfaces come equipped with an identity section 0 : C ?! E which serves as the identity element of the gr...

The equational theory generated by all algebras of binary relations with operations of union, composition, converse and reflexive transitive closure was studied by Bernátsky, Bloom, Ésik, and Stefanescu in 1995. We reformulate some of their proofs in syntactic and elementary terms, and we provide a new algorithm to decide the corresponding theory. This algorithm is both simpler and more efficie...

Evaluation of a spatial join typically has two steps: a filter step that applies the join on approximations of spatial objects and a refinement step that determines the actual intersection of two spatial objects. In this paper, we study the effectiveness of filters with different approximations including minimum bounding rectangles, rectilinear approximations, minimum 5-corner bounding convex p...

The exact string matching problem is to find the occurrences of a pattern of length m from a text of length n symbols. We develop a novel and unorthodox filtering technique for this problem. Our method is based on transforming the problem into multiple matching of carefully chosen pattern subsequences. While this is seemingly more difficult than the original problem, we show that the idea leads...