in order to evaluate the effect of nitrogen absorption and use efficiency in relay intercropping for winter wheat and maize, a field experiment was conducted during 2008-2009 at the agricultural research station of ferdowsi university of mashhad, iran. a randomized block design with three replications was used. treatments included four combinations of relay intercropping of wheat and maize (thr...

This paper presents a novel impedance-based approach for out-of-step (OOS) protection of a synchronous generator. The most popular and commonly used approaches for detecting OOS conditions are based on the measurement of positive sequence impedance at relay location. However, FACTS devices change the measured impedance value and thus disrupt the performance of impedance-based relay function. In...

Polar codes, that have been recently introduced by Arikan, are one of the first codes that achieved the capacity for vast numerous channels and they also have low complexity in symmetric memoryless channels. Polar codes are constructed based on a phenomenon called channel polarization. This paper discusses relay channel polarization in order to achieve the capacity and show that if inputs of tw...

in this paper, an interval approach is presented to achieve perfect selectivity and maximum sensitivity in distance relay zones, considering uncertainties. for this purpose, first, the uncertainties affecting the settings of the three zones of a distance relay are discussed. then, by using the monte-carlo simulation, the uncertainties are modelled and the impedances seen by the distance relay a...

Abstract—In this paper, the problem of secure transmission in two-hop amplify-and-forward (AF) systems with an untrusted relay is investigated. To prevent the untrusted relay from intercepting the source message and to achieve positive secrecy rate, the destination-based cooperative jamming (DBCJ) technique is used. In this method the destination sends an intended jamming signal to the relay. T...

The transmission of signals in a hybrid satellite-terrestrial system (HSTS) in the presence of co-channel interference (CCI) is considered in this study. Specifically, we examine the problem of amplify-and-forward (AF)-based relaying in a hybrid satellite-terrestrial link, where the relay node is operating in the presence of a dominant co-channel interferer. It is assumed that direct connection...

The paper studies a new model and network coding algorithm for orthogonal frequency division multiplexing (OFDM) system. Cooperation diversity consists on using relay nodes to combat the effects of fading channels by means of spatial diversity. Physical-layer network coding is used to make the two-way s relay network achieving higher bandwidth efficiency than the traditional four-phase and thre...

Orthogonal synchronization has been a major problem in Cooperative Orthogonal Frequency Division Multiplexing (CO-OFDM) under the influence of both carrier frequency offset and timing offset with unknown channel gains. CO-OFDM network performance can be improved by employing Amplify-and-Forward (AF) relay strategy. The OFDM network comprises of many sub-carriers which requires an adjustment of ...

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...