Influence of Heat Treatment on the Mechanical Characteristics of Diamond Powders

Powder Metallurgy and Metal Ceramics - Improvement in the efficiency of diamond tools is inextricably linked with the use of high-strength heat-resistant diamond grains for tooling. Hence, study of...     

Modeling of UAV/RPAS data traffic in space,air, and ground networks

Remotely piloted air systems (RPASs) are increasingly used for data transmission in the space-air-ground integrated networks (SAGINs). That is why it is important to know the possibilities and ways of integrating existing space, air and terrestrial networks for effective interaction with RPASs. This paper studies the issues of ensuring the required quality of service during heavy traffic in SAGIN and the choice of the necessary data transmission modes for this. Models of communication channels were created, including line-of-sight transmission (Model 1), public terrestrial network (PTN) (Model 2), low-orbit satellite transmission (Model 3) and PTN plus satellite transmission (Model 4). The relationships between models' performance and traffic parameters, channel bandwidths, bit errors, lost packets and models' topology were investigated using NetCracker Professional 4.1 software. The dependencies of the average utilization on the transaction size and the time between transactions with different statistical distribution laws were analyzed. The effect of different bandwidths was investigated. The influence of the bit error rate and the probability of packet fail chance on the channel performance was studied. The traffic characteristics in all models were compared.