This paper describes a new approach to solving the problem of slab design in the iron and steel industries. The problem is a kind of bin-packing problems, which are known as NP-complete (Nondeterministic Polynomial-complete) problem. Getting the optimal solution for slab design problem is very difficult, because which involves many restrictions of order, rolling and slab. We propose an approach applying a Genetic Algorithm (GA). This paper's GA is a Hybrid GA which is combined with heuristics in order to carry out an effective search process and obtain a near-optimal solution. The main feature of this approach is a coding scheme designed to combined ordered plates by using heuristics. The results demonstrate that a Hybrid Genetic Algorithm within certain restrictions is a viable tool for solving large scale combinatorial optimization problems.
This paper presents a design method of the zero phase two-dimensional (2-D) finite impulse response (FIR) fan filters having rotated frequency response of a given prototype fan filter. The first step of our approach is to design a prototype filter with the impulse response whose domain is restricted within a circular region. This restriction prevents rotated impulse array to moving out from the rectangular region. Then, the rotation of prototype impulse response, which is given no more than on the rectgngular lattice grid, may cause the same rotation in the frequency domain. The second step is the interpolation of the impulse response on the new grids by the reconstruction algorithm of 2-D bandlimited discrete signals. Previous other methods for the rotation and the interpolation are compared with the proposed method. The obtained results for fan-type filter approximation by the proposed method show its validity.
Authors developed a laser tracking system which measures six degrees of freedom in real time. This system uses a laser interferometer which can measure displacement with a high accuracy. In order to compute the position of a target in three dimensions space, however, the initial distance between the center of the tracking mirror and the start point of the target must be known. This paper proposes an automatic initial distance measurement method which calculates initial distance measuring the direction of laser beam and the displacement. Then, revision computing with the calculated data and the position of reflective beam increases the measuring accuracy of initial distance.
This paper proposes a controller reduction method based on experimental data. In this method, using an appropriate subspace projection on the state-space sequence of the original controller, we obtain the reduced-order one. This method is applicable to unstable controllers and provides some indices by which we can determine the reduced order. Furthermore, we evaluate its effectiveness by experiment on an inverted pendulum system.
In this paper, a computational method of the formal linearization by a cubic Hermite interpolation is proposed. A discrete nonlinear system represented by nonlinear difference equation is converted into an approximated linear system. We introduce a linearizing function that consists of the state variables, their squares, and the cubes. The nonlinear terms are approximated in the form of piecewise cubic polynomials by the cubic Hermite interpolation and linearized with respect to the linearizing function. Numerical computations are very easy because both the conversion into the linear system and the inversion are done by simple matrix calculations. Error analysis of the linearization is discussed. As an application of the linearization a nonlinear filter is synthesized. Through some numerical examples, the accuracy of the linearization and the state estimation is improved as the size of subdomain is shortened.