Cellular manufacturing system, an application of group technology, has been considered as an effective method to obtain productivity in a factory. For design of manufacturing cells, several mathematical models and various algorithms have been proposed in literature. In the present research, we propose an improved version of discrete particle swarm optimization (PSO) to solve manufacturing cell ...

Long-term spaceflights induce bone loss as a result of profound modifications of bone remodeling, the modalities of which remain unknown in humans. We measured intact parathyroid hormone (PTH) and serum calcium; for bone formation, serum concentrations of bone alkaline phosphatase (BAP), intact osteocalcin (iBGP), and type 1 procollagen propeptide (PICP); for resorption, urinary concentrations ...

in this study, the problem of determining an optimal trajectory of a nonlinear injection into orbit problem with minimum time was investigated. the method was based on orthogonal polynomial approximation. this method consists of reducing the optimal control problem to a system of algebraic equations by expanding the state and control vector as chebyshev or legendre polynomials with undetermined...

In this study, the missile staging process by implementing a side-injected jet is simulated numerically. The problem is considered to be axisymmetric and the thin shear layer approximation of Navier-Stokes equations along with an algebraic turbulence model is used in a quasi-static form for the calculations. The free stream corresponds to a very high altitude flight condition with a Mach number...

Leader election and arbitrary pattern formation are fundammental tasks for a set of autonomous mobile robots. The former consists in distinguishing a unique robot, called the leader. The latter aims in arranging the robots in the plane to form any given pattern. The solvability of both these tasks turns out to be necessary in order to achieve more complex tasks. In this paper, we study the rela...

In this study, the missile staging process by implementing a side-injected jet is simulated numerically. The problem is considered to be axisymmetric and the thin shear layer approximation of Navier-Stokes equations along with an algebraic turbulence model is used in a quasi-static form for the calculations. The free stream corresponds to a very high altitude flight condition with a Mach number...

Unmanned aerial vehicle (UAV) formation rendezvous path planning problem is one of the important research topics in multiple UAV (multi-UAV) coordinated planning. Aiming at solving low computational efficiency and poor scalability traditional multi-UAV method, decentralized method suitable for obstacle environments proposed. Firstly, with constraints such as kinematics UAVs collision-free model...

Abstract In order to ensure that the UAV fleet can maintain maximum electromagnetic silence and minimise emission of signals during formation flight, a theoretical method pure azimuth passive positioning be used optimise their relative positions. This paper analyses different situations UAVs presents best solution for in flight corresponding The first establishes polar coordinates based on know...

the air transport industry is seeking to manage risks in air travels. its main objective is to detect abnormal behaviors in various flight conditions. the current methods have some limitations and are based on studying the risks and measuring the effective parameters. these parameters do not remove the dependency of a flight process on the time and human decisions. in this paper, we used an hmm...