Motivated by questions in computer vision and sensor networks, Alpert et al. [3] introduced the following definitions. Given a graph G, an obstacle representation of G is a set of points in the plane representing the vertices of G, together with a set of connected obstacles such that two vertices of G are joined by an edge if an only if the corresponding points can be connected by a segment whi...

This article proposes a new approach for centralized path planning of multiple aircraft in presence of the obstacle-laden environment under low flying rules. The problem considers as a unified nonlinear constraint optimization problem. The minimum time and control investigate as the cost functions and the maximum velocity and power consider as the constraints. The pseudospectral method applies ...

In this research, the effects of the rotational speed, feed rate, tool material and lubricants on the tool life and the hole quality are studied in the frictional drilling of the titanium sheets. The friction drilling tests are performed on a CNC milling machine. Furthermore, 5 specimens are selected and their metallurgical structures are studied. The results show thatamong the input parameters...

Obstacle representations of graphs have been investigated quite intensely over the last few years. We focus on graphs that can be represented by a single obstacle. Given a (topologically open) polygon C and a finite set P of points in general position in the complement of C, the visibility graph GC(P ) has a vertex for each point in P and an edge pq for any two points p and q in P that can see ...

Abstract: Perovskite solar cells have become an attractive subject in the solar energydevice area. During ten years of development, the energy conversion efficiency has beenimproved from 2.2% to more than 22%, and it still has a very good potential for furtherenhancement. In this paper, a numerical model of the perovskite solar cell with thestructure of glass/ FTO/ TiO2/...

In this letter, we consider static black hole in f(R) gravity.We take advantage from corrected entropy and temperature and investigate such black hole. Finally, we study the $ P - V $ critically and phase transition of corrected black hole with respect to entropy and temperature. Here also, we obtain the heat capacity for the static black hole in $ f(R) $ gravity. This calculation help us...

in this paper, trajectory generation for the 4 dof arm of surena iii humanoid robot with the purpose of optimizing energy and avoiding a moving obstacle is presented. for this purpose, first, kinematic equations for a seven dof manipulator are derived. then, using the lagrange method, an explicit dynamics model for the arm is developed. in the next step, in order to generate the desired traject...