In the article we present a variant of the mathematic education’s didactic test created in the program Hot Potatoes, which deal with the theme solving linear equations. The role of the didactic test is not only the investigating of the knowledge and the understanding of students of the topic, but also the verification their thought processes and mathematic reasoning for the solving of the word ...

S.I. Fadeev Institute of mathematic, Siberian department of the Russian Academy of Sciences, Novosibirsk, 630090 S.V. Nikolaev Institute of cytology and genetics, Siberian department of the Russian Academy of Sciences, Novosibirsk, 630090 V.V. Kogay Institute of mathematic, Siberian department of the Russian Academy of Sciences, Novosibirsk, 630090 E. Mjolsness School of Information and Compute...

A significant amount of research efforts has been given to explore the mathematical basis for 3D dimensional and geometric tolerance representation, analysis, and synthesis. However, engineering semantics is not maintained in these mathematic models. In this paper, a new semantic tolerance modeling scheme based on modal interval is introduced to improve interpretability of tolerance modeling. W...

In this paper the effect of corrugated diaphragm on performance of MEMS microphone is described. The corrugated diaphragm is modeled in order to improve the sensitivity of micromachined silicon acoustic sensor. Analytical analyzes have been carried out to derive mathematic expressions for the mechanical sensitivity and displacement of corrugated diaphragm with residual stress. It is shown that ...

We address the problem of carrier frequency offset (CFO) synchronization in Orthogonal Frequency Division Multiplexing (OFDM) communications systems in the context of frequency-selective fading channels. The mathematic model of OFDM systems with cyclic prefix (CP) and virtual subcarrier is derived. And we propose the shift-invariance CFO estimation algorithm based on DOA-MATRIX method. After th...

This paper presents dynamic modeling and simulation of Brushless Doubly Fed Induction Generator (BDFIG) as an alternative for variable speed wind power applications. The mathematic models of active and reactive power for BDFIG have been developed. The power control systems of a 75 kVA generator and wind turbine were simulated in Matlab/Simulink/SymPower Systems. The generator’s control system i...

Contamination of annual ryegrass with perennial ryegrassby physical seed mixing or gene flow can result in a significant reduction in forage production.Therefore, this study aimed to develop a suitable technique using near-infrared spectroscopy (NIRS) for discriminating and quantifying adulteration of annual ryegrass seeds with perennial ryegrass. A partial least squares regression for discrimi...