Predictability Assess of Multipath Phase Using ARIMA Model

© 2020 IEEE. Physical Layer Security is a promising technique for establishing a secret encryption key in wireless communications. The secret key is distilled from the Channel State Information under conditions of its random fast fading. However, random channel variations are quite smooth on short-term intervals and can be predicted using previous samples. This is a serious threat to secrecy of the generated encryption key. In this study, we assess both prediction error and prediction horizon for real data set of a fast fading carrier phase using the ARIMA model. Influence of the autoregressive model order on the prediction accuracy is considered, optimum ARIMA parameters for forecasting the experimental data are found. We also compare prediction accuracy of the ARIMA that uses fixed model parameters versus accuracy of the auto-ARIMA that employs adaptive estimation of model parameters in different timeframes of the data. Our results showed that effective prediction of real samples of multipath phase was possible only at intervals shorter than 150 ms, and maximum prediction gain did not exceed 40 degrees compared to prediction based on the last known sample

Effects of repetitive audiogenic stimulation on open field activity in audiogenic sensitive and non-sensitive wag/rij rats

Item does not contain fulltextA certain part of WAG/Rij rats combines genetically predisposed absence epilepsy with susceptibility to the development of audiogenic seizures. Repeated sound stimulation leads in audiogenic susceptible rats to propagation of epileptic discharges from the brainstem to the forebrain and neocortex. In the present study the influence of repeated audiogenic stimulation on the open field behaviour in audiogenic sensitive (AS, n=8) and non-sensitive (ANS, n=7) female WAG/Rij rats was investigated. All rats were daily tested in the open field, thereafter underwent to audiogenic stimulation, over a period of ten days. A significant influence of audiogenic seizures on number of ambulations, vertical rearings and faecal boli, as well as on total duration of grooming was found. Mean duration of latent period was found markedly dependent on the time factor. There were no factorial interactions. Both AS and ANS groups showed slow habituation to the open field testing, which might be related to high activity of dopaminergic system. The results of analysis of the open field activity in AS rats demonstrate an increased level of anxiety-like behaviour from the beginning onwards. It was suggested that mixed form of epilepsy in AS rats might be used to study the mechanisms of behavioural and emotional disturbances associated with epileptic disorders

Excitation of Terahertz Magnons in Antiferromagnetic Nanostructures: Theory and Experiment

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Effects of repetitive audiogenic stimulation on open field activity in audiogenic sensitive and non-sensitive wag/rij rats

A certain part of WAG/Rij rats combines genetically predisposed absence epilepsy with susceptibility to the development of audiogenic seizures. Repeated sound stimulation leads in audiogenic susceptible rats to propagation of epileptic discharges from the brainstem to the forebrain and neocortex. In the present study the influence of repeated audiogenic stimulation on the open field behaviour in audiogenic sensitive (AS, n=8) and non-sensitive (ANS, n=7) female WAG/Rij rats was investigated. All rats were daily tested in the open field, thereafter underwent to audiogenic stimulation, over a period of ten days. A significant influence of audiogenic seizures on number of ambulations, vertical rearings and faecal boli, as well as on total duration of grooming was found. Mean duration of latent period was found markedly dependent on the time factor. There were no factorial interactions. Both AS and ANS groups showed slow habituation to the open field testing, which might be related to high activity of dopaminergic system. The results of analysis of the open field activity in AS rats demonstrate an increased level of anxiety-like behaviour from the beginning onwards. It was suggested that mixed form of epilepsy in AS rats might be used to study the mechanisms of behavioural and emotional disturbances associated with epileptic disorders

GLONASS

The Global’naya Navigatsionnaya Sputnikova Sistema (GLONASS) is a global navigation satellite system developed by the Russian Federation. Similar to its US counterpart, the NAVSTAR global positioning system (GPS), GLONASS provides dualfrequency L-band navigation signals for civil and military navigation. Initiated in the 1980s, the system first achieved its full operational capability in 1995. Following a temporary degradation, the nominal constellation of 24 satellites was ultimately reestablished in 2011 and the system has been in continued service since then. This chapter describes the architecture and operations of GLONASS and discusses its current performance. In addition, the planned evolution of the space and ground segment are outlined