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 develop a new approach for pricing both continuous-time and discretetime American options which is based on the fact that any American option is equivalent to a European one with a consumption process involved. This approach admits the construction of an upper bound (a lower bound) on the true price using some lower bound (an upper bound) by Monte Carlo simulation. A number of effective esti...

The polynomial method and Ambainis’s lower bound method are two main quantum lower bound techniques. Recently Ambainis showed that the polynomial method is not tight. The present paper aims at studying the limitation of Ambainis’s lower bounds. We first give a generalization of the three known Ambainis’s lower bound theorems. Then it is shown that all these four Ambainis’s lower bounds have an ...

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...

The isometric embeddings 2;K → p;K (m ≥ 2, p ∈ 2N) over a field K ∈ {R,C,H} are considered, and an upper bound for the minimal n is proved. In the commutative case (K = H) the bound was obtained by Delbaen, Jarchow and Pe lczyński (1998) in a different way. Let K be one of three fields R,C,H (real, complex or quaternion). Let K be the K-linear space consisting of columns x = [ξi] n 1 , ξi ∈ K, ...

Considering a kinematical velocity admissible field, the upper bound method has beenused for predicting the amount of pressure in hydroforming of sheet metals. The effects of workhardening, friction and blank size have been considered in pressure prediction. Also the effect ofsheet thickness variation has been considered in the present work formulations. The relation betweenpressure and punch s...