Motivated by a digital halftoning application to convert a continuous-tone image into a binary image, we discusses how to round a [0; 1]-valued matrix into a f0; 1g binary matrix achieving low discrepancy with respect to the family of all 2 2 square submatrices (or regions). A trivial upper bound of the discrepancy is 2 and the known lower bound is 1. In this paper we shall show how to achieve ...

Vortex extrusion (VE) is a severe plastic deformation technique which is based on the synergies between high strain accumulation and high hydrostatic pressure. Such a high amount of pressure, places a mandate to seek the method for investigation of the load under processing conditions. For this, kinematically admissible velocity field and upper bound terms based on Bezier formulation are develo...

Computational cost of metaheuristic based optimum design algorithms grows excessively with structure size. This results in computational inefficiency of modern metaheuristic algorithms in tackling optimum design problems of large scale structural systems. This paper attempts to provide a computationally efficient optimization tool for optimum design of large scale steel frame structures to AISC...

The assessment of the influence of the work-hardening of material on the optimum die profile and drawing force  in rod drawing process is the main objective of the present paper. The upper bound solution, based on the assumption of perfect plasticity, has been extended to consider the work-hardening of the material during the rod drawing process through curved dies. Analytical results of drawin...

For the spatially homogeneous Boltzmann equation with cutoff hard potentials it is shown that solutions remain bounded from above, uniformly in time, by a Maxwellian distribution, provided the initial data have a Maxwellian upper bound. The main technique is based on a comparison principle that uses a certain dissipative property of the linear Boltzmann equation. Implications of the technique t...

In rigid plastic analysis one of the most widely applicable methods that is based on the minimum principle, is the combination of elementary mechanisms which uses the upper bound theorem. In this method a mechanism is searched which corresponds to the smallest load factor. Mathematical programming can be used to optimize this search process for simple fra...

This paper describes an upper bound analysis of cold forward extrusion of spur gears with modified tooth profile. Spur gear geometrical parameters such as module, number of teeth, pressure angle, bore radius and addendum modification factor were input to a computer program written in Visual Basic. Then spur gear, billet and extrusion die cavity were modeled automatically in SolidWorks. For uppe...

We prove that mixtures of continuous alphabet constant modulus sources can be identified with probability 1 with a finite number of samples (under noise-free conditions). This strengthens earlier results which only considered an infinite number of samples. The proof is based on the linearization technique of the analytical constant modulus algorithm (ACMA), together with a simple inductive argu...

In this paper we rederive an old upper bound on the number of halving edges present in the halving graph of an arbitrary set of n points in 2-dimensions which are placed in general position. We provide a different analysis of an identity discovered by Andrejak et al, to rederive this upper bound of O(n). In the original paper of Andrejak et al. the proof is based on a naive analysis whereas in ...

Generalizing a result (the case k = 1) due to M. A. Perles, we show that any polytopal upper bound sphere of odd dimension 2k+1 belongs to the generalizedWalkup class Kk(2k + 1), i.e., all its vertex links are k-stacked spheres. This is surprising since the k-stacked spheres minimize the face-vector (among all polytopal spheres with given f0, . . . , fk−1) while the upper bound spheres maximize...