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Three-dimensional exact elastic analysis of nanoplates

Wang Guoping, Zhang Yu, Arefi Mohammed

Archives of Civil and Mechanical Engineering

2021

Vol. 21, no. 3

63--76

This work investigates the application of three-dimensional nonlocal elasticity theory to elastic static analysis of nanoplates. Unlike all previous papers that considered two-dimensional Laplacian operator to stress components, this work uses the general three-dimensional nonlocal operator with thickness direction operator. The displacement field of nanoplate is assumed a function of three-dimensional coordinate x, y, z. The principle of virtual work is used to derive the governing equations. A solution procedure is developed for simply supported nanoplate. The solution along the thickness direction is derived using the characteristic equation and application of boundary conditions including free transverse shear stress and applied normal stress. The eigenvalue–eigenvector methodology is used to extract general solution along the transverse direction. The stress and deformation distribution along the transverse direction is presented with changes of significant parameters such as nonlocal parameter and aspect ratio.

Edge detection of objects in the medical pictures with genetic algorithm

Gola A.

Prace Instytutu Podstaw Informatyki Polskiej Akademii Nauk

2001

Nr 928

25-30

This paper presents the method of detecting the objects edges in the medical pictures. Thanks to this method you will be able to detect the outline of the objects of our interest and to omit all unnecessary objests edges, that appear in the picture. The starting point of this method is to determine the fragments of the objects edges locally, and then to extend these edges towards their ends. This method employs the technique of determining the liminal values of the histogram in order to divide the picture into two sections, namely into the object and the background. In order to determine the most appropriate limits of the desired object we use a genetic algorithm. After the process of determining the liminal values is completed, our picture is transformed into a binary picture. Once the picture is ready, the operation of shutting is executed, i.e. all the gaps are filled or ejected, and the edges are smoothed. The Laplacian operator is used to determine the edges.