Sharif Digital Repository

In this paper, the agent velocity in robotic swarm was determined by using particle swarm optimization (PSO) to maximize the robotic swarm coordination velocity. A swarm as supposed here is homogenous and includes at least two members. Motion and behavior of swarm members are mostly result of two different phenomena: interactive mutual forces and influence of the agent. Interactive mutual forces comprise both attraction and repulsion. To be more realistic the field of the swarm members' view is not infinity. So influence of the coordinator agent on the robotic swarm would be local. The objective here is to guide the robotic swarm with maximum possible velocity. According to equation motion... 

Global System for Mobile communications (GSM) is a widely spread, reliable and P2P channel through all over the world. These characteristics make GSM a channel suitable for a variety of applications in different domains especially security applications such as secure voice communication. Performance and usage of GSM applications extremely depends on the transmission data rate. Hence, transmitting data over GSM is still an attractive topic for research. This paper considers the problem of digital data transmission through the GSM voice channel. A lower capacity bound for data transmission through the GSM Adaptive Multi Rate (AMR) voice codec is presented. The GSM channel is modeled in a... 

In this paper, we follow two control tasks in a leader following frame with undirected network and local communications. As the first goal, distributed behavioral imitation, which is necessary to fit agents with complicated motion equations in kinematic frames, is discussed. Providing real agents with behavioral controller makes them capable to act as a kinematic particle. The second goal is to design an active leading strategy for the LA to move the group on a predefined path. Both problems can be mathematically modeled in an affine form, which is the reason behind using a unique adaptive controller to solve them. The controller is based on a neuro-fuzzy structure with critic-based leaning... 

In presence of obstacles, inter-agent pulling actions must be bounded. In this case, to remain connected to the group, the leader-agent (LA) must perform an active leading strategy. In this paper, an active leading algorithm is proposed which monitors the neighborhood of the LA and adjusts its velocity. The algorithm is based on the ant colony optimization (ACO) technique. As a real time optimization package, the ACO algorithm maximizes influence of the LA on the group, leading to fast flocking. Comparison with another optimization method is provided as well. Simulations show that the algorithm is successful and cost effective  

Cellular networks provide widespread and reliable voice communications among subscribers through mobile voice channels. These channels benefit from superior priority and higher availability compared with conventional cellular data communication services, such as General Packet Radio Service, Enhanced Data Rates for GSM Evolution, and High-Speed Downlink Packet Access. These properties are of major interest to applications that require transmitting small volumes of data urgently and reliably, such as an emergency call in vehicular applications. This encourages excessive research to make digital communication through voice channels feasible, leading to the emergence of Data over Voice (DoV)... 

In this research, Araldite 2011 has been reinforced using different weight fractions of Reduced Graphene Oxide (RGO). Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses were conducted and it has been shown that introduction of the RGO greatly changes the film morphology of the neat adhesive. Uni-axial tests were carried out to obtain the mechanical characteristics of the adhesive-RGO composites. It has been observed that introducing 0.5 wt% RGO enhances the ultimate tensile strength of the composites by 30%. In addition, single lap joints using neat adhesive and adhesive-RGO composites were fabricated to... 

In this paper, the agent velocity in robotic swarm was determined by using particle swarm optimization (PSO) to maximize the robotic swarm coordination velocity. A swarm as supposed here is homogenous and includes at least two members. Motion and behavior of swarm members are mostly result of two different phenomena: interactive mutual forces and influence of the agent. Interactive mutual forces comprise both attraction and repulsion. To be more realistic the field of the swarm members' view is not infinity. So influence of the coordinator agent on the robotic swarm would be local. The objective here is to guide the robotic swarm with maximum possible velocity. According to equation motion... 

The objective of this study was to investigate the synergistic effect of TBP on the system D2EHPA/kerosense/M2+ with respect to the extraction of some transitional metals. Although the presence of M2EHPA as an impurity in D2EHPA shifts the extraction curves to lower pH, empirical results show that the extraction curves shift to the right due to the addition of TBP and the counterbalance effect of M2EHPA. The results indicate that the equivalent concentration of D2EHPA decreases as a function of concentration of TBP because of the formation of hydrogen bonds between TBP and D2EHPA. Based on this finding, the D2EHPA equivalent concentration was determined by using a modifying factor for TBP... 

Water adsorption by bis-2-ethylhexyl phosphoric acid (D2EHPA) during the extraction of zinc, cobalt and nickel using a D2EHPA-kerosene/H2O mixture is investigated. Based on the experimental results, about 1 mol of water is adsorbed by 2 mol of D2EHPA (which exists in the form of a dimer), irrespective of the pH. Water adsorption decreases with presence of zinc, cobalt and nickel. The stoichiometric coefficients of D2EHPA in water adsorption reactions are determined with and without zinc, cobalt and nickel by applying the slope-analysis method. It is experimentally confirmed that 1.0, 1.8 and 1.2 mol of adsorbed water will be rejected from the organic phase when zinc, cobalt and nickel are...