in this paper first we try to analysis the behavior ofthe soas in the optical networks and then have proposed anumerical simple model to simulate the behavior of thesemiconductor optical amplifiers. after that by employing thismodel as inline amplifier for a dwdm optical system, we havesimulated the transmission of 10 channels with bit rate 10 gb/sup to distance 3970 km with rz-dpsk modulation ...

Environmental concerns along with the increasing demand on electrical power, have led to power generation of renewable sources like wind. Connecting wind turbines in large scale powers with transmission network makes new challenges like the impact of these renewable sources on power system protection. This paper studies the impact of fault resistance and its location on voltage and current fund...

In this paper we implement space time trellis code using relay fading scenario. We present here the design of the 4psk with 2 transmit antennas and 1,23,4 receiver antennas at 4,8,16& 32 state. In this paper we constructed 4-psk sttc code using rank, determinant and Euclidean distance criterion over Rayleigh fading scenario.

Wireless communication between sensors allows the formation of flexible sensor networks, which can be deployed rapidly over wide or inaccessible areas. However, the need to gather data from all sensors in the network imposes constraints on the distances between sensors. This survey describes the state of the art in techniques for determining the minimum density and optimal locations of relay no...

The quality signal in a wireless transmission occasionally suffers from severe bad channel quality due to effects like fading caused by multi-path propagation. Diversity is one of the methods that used to reduce such effect whereby different samples of the same signal are transferred over essentially independent channels. Cooperative wireless communication it resolves this problem by transmitti...

in this paper, design and application of a new digital protective relay based on fuzzy logicand value estimation to a radial power system protection was presented. a novel approach based onvalue estimation was investigated for the proposed fuzzy logic based protective relay. in addition to thetheoretical aspect of fuzzy logic, mathematical definition of value estimation, detection andmeasuremen...

Relay attacks are passive man-in-the-middle attacks that aim to extend the physical distance of devices involved in a transaction beyond their operating environment. In the field of smart cards, distance bounding protocols have been proposed in order to counter relay attacks. For smartphones, meanwhile, the natural ambient environment surrounding the devices has been proposed as a potential Pro...