In this paper, a mathematical model for symmetrical multi-layer sheet rolling, in which the layers are unbounded before rolling, by using the upper bound method and stream function theorem is proposed. Using this model, we can investigate the plastic deformation behavior of sheets at the roll gap during rolling. Effect of various rolling conditions such as initial and final thickness and flow s...

A key derivation function is used to generate one or more cryptographic keys from a private (secret) input value. This paper proposes a new method for constructing a generic stream cipher based key derivation function. We show that our proposed key derivation function based on stream ciphers is secure if the underlying stream cipher is secure. We simulate instances of this stream cipher based k...

Computational fluid mechanics based on the finite element method has been developed so far following two distinct approaches (a) using a stream function, or stream functlon-vortlcity formulation [1,2], and (b) using a primitive variables formulation [3,4,5]. Within the first approach a stream function is defined such that the continuity equation is identically satisfied and the momentum equatio...

Digital Elevation Models (DEMs) are used to estimate different morphologies, analysis of river profile, delineating drainage basin and drainage pattern associated with lithological and structural changes. The study area is Maroon River located in Khuzestan Province, Iran. In this study geomorphometric analysis based on DEM carried out to understand Maroon river uplift rate and tectonic- erosion...

A simple one-way function along with its proposed application in symmetric cryptography is described. The function is computable with three elementary operations on permutations per byte. Inverting the function, using the most efficient method known to the author, is estimated to require an average computational effort of about 2 operations. The proposed stream cipher based on the function was ...

In the present study, a modified Structure Function was introduced. In this modified Structure Function model, the coefficient of model was computed dynamically base on the coherent structure in the flow field. The ability of this Modified Structure Function was investigated for complex flow over a square cylinder in free stream and a low aspect ratio cylinder confined in a channel. The Results...

Hash functions are fundamental components of many cryptographic applications. Due to the recent attacks on classical designs, alternative design approaches are proposed. In this paper, we give a survey for hash function constructions based stream ciphers mainly concentrating on Panama, RadioGatún and RC4-hash. Also, we propose an example hash function Dragon-Hash based on the stream cipher Dragon.