In this paper, we generalize a secured direct communication process between N users with partial and full cooperation of quantum server. The security analysis of authentication and communication ...processes against many types of attacks proved that the attacker cannot gain any information during intercepting either authentication or communication processes. Hence, the security of transmitted message among N users is ensured as the attacker introduces an error probability irrespective of the sequence of measurement.
Unexploded Landmines, after wares, represent a serious problem, wastes life and money. Recent research states that contact sensors are promising. In this work, a novel contact sensor for landmine ...detection is presented. The sensor principle is based on the concept of 2-DOF vibration absorber system (two springs and two masses), to detect the presence of an object (landmine) in sand which is modeled as a third spring. The 3 rd spring stiffness (the sand stiffness) can be measured as a function of the vibration absorber frequency ω Abs (the frequency at which the 2nd mass gives minimum amplitude (theoretically proven: zero)) and the 1st mass gives amplitude near to peak. When the sand stiffness changes due to existence of the landmine, the vibration absorber frequency ω Abs changes, and consequently the landmine can be detected. The mathematical proof of the idea is verified by simulation on Matlab and finite element COMSOL Multi-physics. The system parameters are chosen to be appropriate with the sand-landmine stiffness measurement range. The simulation results are optimized to give best sensitivity and linearity of the sensor output. The sensor gives sensitivity of 1559 Hz/(MN/m) and linearity better than 95%. Finally, a detailed design procedure for the contact stiffness sensor for landmine detection is developed.
Landmines are major problems, waste life and money. Much recent research acknowledges that the contact sensors have promising potential. In this work, a new idea of contact sensor for landmine ...detection is introduced. The sensor main principle is based on the concept of 2-DOF vibration absorber system (two springs and two masses), to detect the existence of an object (ex: landmine) in sand which is modeled as a 3 rd spring. The sand stiffness (the 3 rd spring stiffness k o ) can be acquired as function of the frequency vibration absorber mode ω Abs (the frequency at which the 2 nd mass has the lowest amplitude (mathematically proven: zero)). When the sand stiffness changed due to the presence of the landmine, the vibration absorber frequency ω Abs changes, and consequently the landmine can be detected. The mathematical derivation of the (ω Abs -k o ) relation is verified by simulations with Matlab and with finite element COMSOL Multi-physics. The system is succeeded to measure the sand stiffness up to 100kN/m. A physical prototype for the sensor is developed with sensitivity 16.85 (N/m)/Hz.
BGP control mechanism has been offered to be engaged with the existing inter-domain routing protocol (BGP) to be able to fulfill and manage the internet scalability demands of bandwidth, services, ...applications, technologies and off course users. This paper focused on the key features that should be offered by an intelligent mechanism to handle the internet traffic in smarter manner by automatically redistributes the traffic over the multihomed links and considers link utilization in routing process. Significant enhancements in network performance has been shown after using the developed mechanism and this offers an optimum utilization of the available bandwidth and keeps the performance parameters within acceptable ranges as well as the traffic over different links within the links capacity.
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