Influence of the type of membership functions of fuzzy variables on transient processes in an electric drive

The paper deals with the influence of the type of membership functions of fuzzy variables on transient processes in an electric drive. The membership functions of fuzzy variables of S-shaped type and triangular type are proposed for consideration. To identify the dependencies of the influence of these functions, the article offers simulation modeling in the Matlab software environment, the Simulink application. The system of frequency converter - asynchronous motor (FC-AM) was chosen as the considered control system. Transient processes in the considered system with various types of membership functions are shown. The results of the work are summarized in the conclusions.

Modulation instability analysis and perturbed optical soliton and other solutions to the Gerdjikov-Ivanov equation in nonlinear optics

In this work, we investigate the perturbed optical solitons to the Gerdjikov-Ivanov equation consisting of group velocity dispersion and quintic nonlinearity coefficients, which communicate the propagation of pulses in nonlinear optics. The various kinds of solitons in single and combined forms like dark, singular, dark-singular, bright-dark are derived by Fan-extended sub equation method. Moreover, the singular periodic, triangular type solutions are also obtained. And, we also discuss the stability analysis of the studied nonlinear model with the concept of linear stability, we prove that the governing model is stable. Parametric conditions on physical parameters to ensure the existence criteria of optical solitons are also listed. We also plot 3D profiles for the physical behavior of the obtained solutions by selecting the suitable values of the parameters.

Weak exchange coupling effects leading to fast magnetic relaxations in a trinuclear dysprosium single-molecule magnet

In this work, we investigated the magnetic anisotropy and the influence of weak exchange interactions on the magnetic relaxations of a triangular type dysprosium single-molecule magnet.

Nasal Parameters, Nostrils Shapes and Philtral Column Shape: A Morphometric Analysis in Nepalese Medical Undergraduate Students

Background: The nose is a pyramidal shaped structure situated in the midline of midface being attached to the facial skeleton. The shape, size and spatial location of the nose-philtrum-upper lip complex are important from aesthetic point of view. Hence, to study the nasal parameters, shape of nostril and philtrum among the undergraduate students remained as the main aim of this study.Methods: This was a cross-sectional study enrolling 250 students of age 18-25 years. Nasal height, nasal width was measured and the shape of the nostrils and philtrum was recorded separately for each participant.Results: Out of 250 participants 113 were males and 137 were females. The mean nasal index of male was 75.36 while that of female was 71.72 suggesting that both genders had mesorrhine nasal type. The rectangular shaped nostrils and triangular type of philtrum was the most common types found in the studyConclusions: The study concluded that, the nasal index was mesorrhine type, the nostril was rectangular and the philtrum column was triangular in this study population.Keywords: Anthropometric; nasal index; nostrils; philtrum column shape.

Shooting/continuation based bifurcation analysis of large order nonlinear rotordynamic systems

This study introduces an improved numerical algorithm that is capable of analyzing nonlinear vibrations and bifurcations of general, finite, large-order rotordynamic systems supported on nonlinear bearings. An industrial rotor generally consists of several sections and stages, but numerical shooting/continuation method has been applied to a simple Jeffcott type rotor instead of complex models due to the computational burden of the numerical procedure; it becomes significant when the rotor combined with nonlinear finite bearing models. Here, some mathematical/computational techniques such as a deflation algorithm and the parallel computing are suggested for acceleration along with the conventional treatment of model reduction scheme. An eight-stage compressor rotor supported by two identical five-pad tilting pad journal bearings (TPJB) is selected as a mechanical model to test the numerical incorporation of the algorithms. The rotor beam is modelled with 35 nodes, 140 DOF based on Euler beam theory, and the fluid reaction forces from the two TPJB are calculated using simplex, triangular type finite meshes on the pads. In the numerical procedure, the shooting/continuation combined with the acceleration schemes identifies the solution curves of periodic responses and determines their stability. The orbital motions of coexistent responses are obtained from the solution manifolds.