We apply the CIP (Cubic Interpolated Profile) scheme to the numerical simulation of the acoustic wave propagation based on characteristic equations.The CIP scheme is based on a concept that both the wavefield and its spatial derivative propagate along the same characteristic curves derived from a hyperbolic differential equation. We describe the derivation of the characteristic equations for th...

Based on analysis of security problems from malicious hosts, a special undetachable threshold digital signature scheme is proposed. This scheme uses a cryptosystem based on conic curves and achieves the most important security characteristic of protecting mobile agents against malicious hosts, that is, undetachability. Furthermore, this scheme solves the case where a host can force an agent to ...

a watermarking scheme for grayscale image isproposed based on a family of the chaotic maps and discretecosine transform. jacobian elliptic mapis employed to encrypt ofwatermarked logo. piecewise nonlinear chaotic map is also usedto determine the location of dct coefficients for the watermarkembedding. the purpose of this algorithm is to improve theshortcoming of watermarking such as small key s...

In this paper,we introduce a new verifiable multi-use multi-secretsharing scheme based on automata and one-way hash function. The scheme has theadversary fuzzy structure and satisfy the following properties:1) The dealer can change the participants and the adversary fuzzy structure without refreshing any participants' real-shadow. 2) The scheme is based on the inversion of weakly invertible fin...

Objective(s): Positron emission tomography/computed tomography (PET/CT) examination is commonly used for the evaluation of pulmonary nodules since it provides both anatomical and functional information. However, given the dependence of this evaluation on physician’s subjective judgment, the results could be variable. The purpose of this study was to develop an automated scheme for the classific...

In this paper we consider a finite element algorithm solving the three dimensional Navier-Stokes equation using the method of characteristics. The algorithm is based on a splitting scheme using a characteristic pressure correction method. It’s well known, that the most expensive part of the characteristic integration scheme consists of the search for the volume that contains the foot of a given...

This paper demonstrates the use of shape-preserving exponential interpolation in a characteristic based numerical scheme for the solution of the linear advective-diiusion equation. The results from this scheme are compared with results from a number of numerical schemes in current use using test problems in one-and two-dimensions. These test cases are used to assess the merits of using shape-pr...