Scholarly

Ranking Fuzzy Numbers Based on Lexicographical Ordering

Year: 2009 Volume: 3 Issue: 9 640 - 643 Pages

Authors:
B. Farhadinia

Abstract: Although so far, many methods for ranking fuzzy numbers have been discussed broadly, most of them contained some shortcomings, such as requirement of complicated calculations, inconsistency with human intuition and indiscrimination. The motivation of this study is to develop a model for ranking fuzzy numbers based on the lexicographical ordering which provides decision-makers with a simple and efficient algorithm to generate an ordering founded on a precedence. The main emphasis here is put on the ease of use and reliability. The effectiveness of the proposed method is finally demonstrated by including a comprehensive comparing different ranking methods with the present one.

3D Model Retrieval based on Normal Vector Interpolation Method

Year: 2009 Volume: 3 Issue: 9 636 - 639 Pages

Abstract: In this paper, we proposed the distribution of mesh normal vector direction as a feature descriptor of a 3D model. A normal vector shows the entire shape of a model well. The distribution of normal vectors was sampled in proportion to each polygon's area so that the information on the surface with less surface area may be less reflected on composing a feature descriptor in order to enhance retrieval performance. At the analysis result of ANMRR, the enhancement of approx. 12.4%~34.7% compared to the existing method has also been indicated.

Crank-Nicolson Difference Scheme for the Generalized Rosenau-Burgers Equation

Year: 2009 Volume: 3 Issue: 9 631 - 635 Pages

Abstract: In this paper, numerical solution for the generalized Rosenau-Burgers equation is considered and Crank-Nicolson finite difference scheme is proposed. Existence of the solutions for the difference scheme has been shown. Stability, convergence and priori error estimate of the scheme are proved. Numerical results demonstrate that the scheme is efficient and reliable.

High Performance Computing Using Out-of- Core Sparse Direct Solvers

Year: 2009 Volume: 3 Issue: 9 624 - 630 Pages

Abstract: In-core memory requirement is a bottleneck in solving large three dimensional Navier-Stokes finite element problem formulations using sparse direct solvers. Out-of-core solution strategy is a viable alternative to reduce the in-core memory requirements while solving large scale problems. This study evaluates the performance of various out-of-core sequential solvers based on multifrontal or supernodal techniques in the context of finite element formulations for three dimensional problems on a Windows platform. Here three different solvers, HSL_MA78, MUMPS and PARDISO are compared. The performance of these solvers is evaluated on a 64-bit machine with 16GB RAM for finite element formulation of flow through a rectangular channel. It is observed that using out-of-core PARDISO solver, relatively large problems can be solved. The implementation of Newton and modified Newton's iteration is also discussed.

Broad-Band Chiral Reflectors based on Nano-Structured Biological Materials

Year: 2009 Volume: 3 Issue: 9 619 - 623 Pages

Abstract: In this work we study the reflection of circularly polarised light from a nano-structured biological material found in the exocuticle of scarabus beetles. This material is made of a stack of ultra-thin (~5 nm) uniaxial layers arranged in a left-handed helicoidal stack, which resonantly reflects circularly polarized light. A chirp in the layer thickness combined with a finite absorption coefficient produce a broad smooth reflectance spectrum. By comparing model calculations and electron microscopy with measured spectra we can explain our observations and quantify most relevant structural parameters.

Optimal Control of Viscoelastic Melt Spinning Processes

Year: 2009 Volume: 3 Issue: 9 614 - 618 Pages

Authors:
Shyam S.N. Perera

Abstract: The optimal control problem for the viscoelastic melt spinning process has not been reported yet in the literature. In this study, an optimal control problem for a mathematical model of a viscoelastic melt spinning process is considered. Maxwell-Oldroyd model is used to describe the rheology of the polymeric material, the fiber is made of. The extrusion velocity of the polymer at the spinneret as well as the velocity and the temperature of the quench air and the fiber length serve as control variables. A constrained optimization problem is derived and the first–order optimality system is set up to obtain the adjoint equations. Numerical solutions are carried out using a steepest descent algorithm. A computer program in MATLAB is developed for simulations.

Novel Method for Elliptic Curve Multi-Scalar Multiplication

Year: 2009 Volume: 3 Issue: 9 609 - 613 Pages

Abstract: The major building block of most elliptic curve cryptosystems are computation of multi-scalar multiplication. This paper proposes a novel algorithm for simultaneous multi-scalar multiplication, that is by employing addition chains. The previously known methods utilizes double-and-add algorithm with binary representations. In order to accomplish our purpose, an efficient empirical method for finding addition chains for multi-exponents has been proposed.

A Sandwich-type Theorem with Applications to Univalent Functions

Year: 2009 Volume: 3 Issue: 9 603 - 608 Pages

Abstract: In the present paper, we obtain a sandwich-type theorem. As applications of our main result, we discuss the univalence and starlikeness of analytic functions in terms of certain differential subordinations and differential inequalities.

International Journal of Engineering, Mathematical and Physical Sciences

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