Abstract In this paper, the design of non-uniform circular antenna arrays of isotropic radiators with optimum side lobe level reduction is investigated. Two global evolutionary optimization methods (namely; the biogeography based optimization and the self-adaptive differential evolution) are used to determine an optimum set of weights and positions that provide a radiation pattern with optimum ...

The contourlet transform can deal effectively with images which have directional information such as contour and texture. In contrast to wavelets for which there exists many good filters, the contourlet filter design for image processing applications is still an ongoing work. Therefore, this paper presents an approach for designing the contourlet filter based on the Chebyshev best uniform appro...

This paper introduces the application of uniform experimental design to improve dental implant systems subjected to dynamic loads. The dynamic micromotion of the Zimmer dental implant system is calculated and illustrated by explicit dynamic finite element analysis. Endogenous and exogenous factors influence the success rate of dental implant systems. Endogenous factors include: bone density, co...

In this paper we present a parameter-based approach for synthesizing systolic architectures from uniform recurrence equations. The scheme presented is a generalization of the Parameter Method proposed by Li and Wah 1]. The approach synthesizes optimal arrays of any lower dimension from a general uniform recurrence description of the problem. In other previous attempts for mapping uniform recurr...

The parameters design of 1-bit adaptive delta modulations (ADM) systems with uniform sampling rate is well known. Analytical study of delta modulations with sampling rate adaptation have been carried out few years ago. The described ADM systems encode the input signal by changing the sampling intervals and/or step size according to its time-varying slope characteristics. A proposition for desig...

NURBS curve is widely used in Computer Aided Design and Computer Aided Geometric Design. When a single weight approaches infinity, the limit of a NURBS curve tends to the corresponding control point. In this paper, a kind of control structure of a NURBS curve, called regular control curve, is defined. We prove that the limit of the NURBS curve is exactly its regular control curve when all of we...

This paper proposes a new digital beamformer for uniform concentric circular array (UCCA) having nearly frequency invariant (FI) characteristics. The basic principle is to transform the received signals to the phase mode and remove the frequency dependency of the individual phase mode through the use of a digital beamforming network. The far field pattern of the array is determined by a set of ...

In this paper, uniform, critically decimated lter banks are used to approximate nonuniform lter banks wherein di erent lters have approximately the same magnitude response, but di erent phase, thus forming a linear periodically timevarying lter whose characteristics are similar to those of a nonuniform bank. This is done by post-processing a number of selected subbands of a uniform bank using a...

We propose a framework in support of the supply chain network design and management of densified biomass. This framework relies in the use of trucks for short distance biomass transportation, and relies in the use of rail for long-haul, and highvolume transportation of densified biomass. We propose a hub-and-spoke network design model in support of biomass delivery using rail transportation. We...

Synthesis is a complex task spanning many levels of abstractions and information domains. Hence, CAD systems utilize a global design database to achieve the much needed integration of this diverse design information into one central data model. Such a central database represents a serious bottleneck for the CAD system. First, it prevents the extensibility of the CAD system over time, since a ch...