background selection of anesthetic approach for lower extremity operations is often a controversial issue for anesthesiologists. objectives the aim of this study was to compare the incidence and severity of back pain between general and spinal anesthesia, and to find effective factors in developing postoperative back pain. patients and methods in a randomized clinical trail, 148 patients with e...

recently a new structure called groove gap waveguide (GGW) is ‎introduced to implement low loss microwave component devices ‎especially for millimeter wave applications. This paper presents a ‎new type of H-plane horn antenna making use of this new technology ‎in which backward radiation is significantly suppressed by ‎introducing a high impedance surface at the antenna aperture. The ‎high impe...

We investigate a digital back-propagation simplification method to enable computationally-efficient digital nonlinearity compensation for a coherently-detected 112 Gb/s polarization multiplexed quadrature phase shifted keying transmission over a 1,600 km link (20 x 80 km) with no inline compensation. Through numerical simulation, we report up to 80% reduction in required back-propagation steps ...

This paper presents an attitude control algorithm for a Reusable Launch Vehicle (RLV) with a low lift/drag ratio (L/D < 0.5), in the presence of external disturbances, model uncertainties, control output constraints and the thruster model. The main novelty of proposed control strategy is a new combination of the attitude control methods included backstepping, dynamic inversion and adaptive cont...

Discrete Element Method (DEM) is extensively used for mathematical modeling and simulating the behavior of discrete discs and discrete spheres in two and three dimensional space, respectively. Prediction of particles flow regime, power draw and kinetic energy for a laboratory or an industrial mill is possible by DEM simulation. In this article, a new approach was used to assess the main paramet...

Background: The present study aimed to introduce a rapid transmission dosimetry through an electronic portal-imaging device (EPID) to achieve two-dimensional (2D) dose distribution for homogenous environments. Material and Methods: In this Phantom study, first, the EPID calibration curve and correction coefficients for field size were obtained from EPID and ionization chamber. Second, the...

The present work deals with an improved back-propagation algorithm based on Gauss-Newton numerical optimization method for fast convergence. The steepest descent method is used for the back-propagation. The algorithm is tested using various datasets and compared with the steepest descent back-propagation algorithm. In the system, optimization is carried out using multilayer neural network. The ...