A New Approach to Investigation of the Relationship of VLF Signals by Using Longitudinal Analysis Models

Guzel, E.
Yaşar, M.
Kılıç, M. B.
Canyılmaz, M.
Longitudinal analysis models are applied to analyze very low frequency (VLF) electromagnetic waves signals. They are useful in realization of nuance of relationship between parameters of concern which change over time. VLF data are so important for the communication and determining the disturbances in the lower ionosphere. In this study, we used a four-day VLF signal data which come from transmitter stations located at two different countries to Elazi. g receiver system. A very important feature of this data is that there is a strong relationship between days and signals. At first, the exploratory data analysis was applied for identification of data. Then, marginal, random-effects, and transitional models were used to analyze the data, respectively. The marginal model is found more appropriate than the other models used for VLF data analyses. As a result of this process, a new method has been added to the analysis of VLF signal data.
International Journal of Antennas and Propagation


A Generalized Scalar PWM Approach With Easy Implementation Features for Three-Phase, Three-Wire Voltage-Source Inverters
Hava, Ahmet Masum (Institute of Electrical and Electronics Engineers (IEEE), 2011-05-01)
The generalized scalar pulse width modulation (PWM) approach, which unites the conventional PWM methods and most recently developed reduced common mode voltage PWM methods under one umbrella, is established. Through a detailed example, the procedure to generate the pulse patterns of these PWM methods via the generalized scalar PWM approach is illustrated. With this approach, it becomes an easy task to program the pulse patterns of various high performance PWM methods and benefit from their performance in mo...
A Domain Decomposition Finite-Element Method for Modeling Electromagnetic Scattering From Rough Sea Surfaces With Emphasis on Near-Forward Scattering
ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2019-01-01)
A high-fidelity full-wave simulator is presented to perform numerical experiments for rough sea scattering problem by considering different polarizations, frequencies, grazing angles, wind speeds, and sea surface spectra. The simulator is based on a novel finite-element domain decomposition (FEDD) method for solving the problem of 2-D electromagnetic scattering over 1-D sea surface. This noniterative method partitions the computational domain into a number of overlapping subdomains and solves each domain in...
Identification of electromagnetic scattering mechanisms by two dimensional windowed fourier transform approach
Germeç, K. Egemen; Kuzuoğlu, Mustafa; Department of Electrical and Electronics Engineering (2004)
In this thesis, it is demonstrated that the two-dimensional Windowed Fourier Transform (WFT) can be effectively used to analyze the local spectral characteristics of electromagnetic scattering signals in the two-dimensional spatial frequency domain. The WFT is the extension of the Short Time Fourier Transform (STFT), which was originally derived to analyze the local spectral characteristics of one dimensional time functions. Since the WFT focuses on the local spectral behavior of the scattered field, the si...
Joint spatial and temporal channel-shortening techniques for frequency selective fading MIMO channels
Toker, Canan; Chambers, JA; Baykal, Buyurman (2005-02-01)
It is well understood that the maximum likelihood estimator is a powerful equalisation technique for frequency selective fading channels, and in particular for MIMO systems. The complexity of this estimator, however, grows exponentially with the number of users and multipath taps, hence limiting the use of this algorithm in MIMO systems. In the paper, the authors propose a joint spatial and temporal channel-shortening filter as a pre-processor to reduce significantly the complexity of a maximum likelihood e...
Methodology for performance analysis of randomly-spread CDMA systems over multipath fading channels via crosscorrelation matrix non-asymptotic average eigenvalue densities
Ertug, O; Baykal, Buyurman; Unal, BS (Institution of Engineering and Technology (IET), 2003-08-07)
A new methodology for closed-form theoretical performance analysis of randomly-spread CDMA systems over multipath fading channels with multiuser receivers is presented. The basis of the analysis is the representation of the random signal to interference ratios at finite system parameters in terms of the eigenvalues of crosscorrelation matrices for which the non-asymptotic average densities are found or known, The methodology presented complements the asymptotic Ruining theory used in similar previous work o...
Citation Formats
E. Guzel, M. Yaşar, M. B. Kılıç, and M. Canyılmaz, “A New Approach to Investigation of the Relationship of VLF Signals by Using Longitudinal Analysis Models,” International Journal of Antennas and Propagation, pp. 1–7, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/51202.