Studying geomagnetic pulsation characteristics with the local approximation method

The method of truncated chaotic synchronization is suggested for digital speech communication. The sequence, composed by truncating some byte segments from the low-dimensional chaotic attractor, demonstrates complicated dynamics and high dimension. Predicting the dynamics of the truncated map through the local approximation method becomes very difficult. However, synchronization lets the message be exactly recovered. The synchronization condition is deduced to synchronize two systems of the truncated one-way coupled ring maps. The sensitivity of synchronization to parameter mismatch is discussed for the security in communication. For the mismatch of parameters or keys, the probability of decoding the message through guessing the keys is below 2-200. The scheme of truncated chaotic synchronization has strong security in encoding message.

Download Full-text

DYNAMIC SIGNALS FILTRATION IN HIGH LEVEL NOISE CONDITION

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2020.11487 ◽

2020 ◽

Vol 12 (0) ◽

pp. 1-3 ◽

Cited By ~ 1

Author(s):

Matsvei Hvozdzeu ◽

Maksim Karpovich

Keyword(s):

Approximation Method ◽

Harmonic Signal ◽

Local Approximation ◽

Experimental Setup ◽

Approximation Methods ◽

Noise Condition ◽

Bulk Solids ◽

Harmonic Signals ◽

High Level ◽

To Receive

To examine the opportunity of measuring bulk solids consumption the experimental setup was developed. The main problem was the presence of a non-harmonic signal at the output. Almost always there are some difficulties to build measuring circuits using non-harmonic signals. It is necessary to use one of the approximation methods to receive a wanted signal without noise. For this purpose, the local approximation method was chosen. The developed technique confirmed its positive aspects and allowed to solve the questions that were posed before the experimental setup.

Download Full-text

The Local Approximation Method for Structural Optimization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.575.854 ◽

2014 ◽

Vol 575 ◽

pp. 854-858

Author(s):

Yi Nie ◽

Yan Wang ◽

Wei Sun ◽

Yan He ◽

Jing Hao ◽

...

Keyword(s):

Structural Optimization ◽

Approximation Method ◽

Optimization Problems ◽

Broad Class ◽

Local Approximation ◽

Optimized Design ◽

Guide Rail ◽

Original Design ◽

Design Variables

The local approximation method exhibits many advantage features and it is popular to a broad class of structural optimization problems. In this paper, both the mathematical modeling and case study of the local approximation method were studied. The theoretical analysis indicates that the primary optimization problem can be replaced with a sequence of explicit approximate problems by using the local approximation method. The explicit subproblems are convex and separable, which can be solved efficiently by using a dual method approach. The topology optimization of a guide rail design is then solved to testify the proposed method, which has been coded by Altair OptiStruct. The optimized design of a widely used guide rail with an “I” shape cross section is obtained and compared with the original design. The numerical results have shown that the local approximation method can effectively solve the structure optimization problems, especially the ones with hundreds of design variables or constraints.

Download Full-text