in this article, the sliding mode control of frequency load control of power systems is studied. the study areaconsists of a system of water and heat. first, a mathematical model of the proposed system disturbances ismade and then sliding control mode for frequency load control is provided. by the system simulation andsliding mode control, it can be shown that the damping of oscillations is wel...

today, chronic viral hepatitis is considered as a public health problem in the world. totally, 5% of the world population, especially in asia and africa suffer from this problem. the prevalence of acute hepatitis in america is 0.1-0.2 percent, 50% of those with hepatitis c (hcv) and 5-10% of them with hepatitis b (hcv) develop chronic hepatitis. determining hbv and hcv genotypes is important to...

Introduction: The main goal of SPECT imaging is to determine activity distribution inside the organs of the body. However, due to photon attenuation, it is almost impossible to do a quantitative study. In this paper, we suggest a mathematical relationship between activity distribution and its corresponding projections using a transfer matrix. Monte Carlo simulation was used to find a precise tr...

We show that laser mode stability can be improved with an intracavity mode selecting phase element. Without the phase element, a sub-wavelength change of the distance between the mirrors of a CO2 laser leads to a substantial change of the transverse mode distribution, whereas with it the distribution remains essentially the same. 2004 Elsevier B.V. All rights reserved. PACS: 42.60.Lh; 42.60.Jf;...

Variable optical attenuation (VOA) for three-mode fiber is experimentally presented, utilizing an amplitude spatial light modulator (SLM), achieving up to -28dB uniform attenuation for all modes. Using the ability to spatially vary the attenuation distribution with the SLM, we also achieve up to 10dB differential attenuation between the fiber's two supported mode group (LP₀₁ and LP₁₁). The spat...

We theoretically investigated the effect of the spatial distribution of the active-ion concentration in multimode step-index waveguides on transverse-mode selection for continuous-wave laser operation. We found that uniform doping of a central portion of as much as 60% of the full waveguide core width is highly effective for the selection of fundamental-mode operation, even under highly saturat...