The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Essay assessment within e-learning need to be conducted manually by human expert. This process takes time and costly. Hence, automatic essay scoring is needed. Since the scoring system will be integrated to the e-learning, we need a computationally lightweight method that still does not rule out the accuracy of the assessment. In this paper, we propose an automatic scoring system for essay examination...
Enhanced partial transmit sequence (EPTS) and cross-correlation-PTS are two techniques for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. EPTS is a low complexity technique compared to conventional partial transmit sequence (CPTS) and cross-correlation-PTS techniques which outperforms the cross-correlation-PTS in terms of PAPR reduction while...
In this paper, we provide a new approach based on Fourier series model with time varying coefficients for received signal in ultra short pulse or ultra wide band (UWB) radar using an MMSE estimator for estimating the Fourier coefficients that determine the velocity and range of a moving target without appealing to a matched filter. We demonstrate that it is impossible to determine velocity of a target...
In most cyclone prediction models, sea surface temperature (SST) is the only oceanographic input, even though storms are known to be impacted by the thermal energy available through oceanic heat content, not just by SST alone. In the tropical Indian Ocean (TIO; 30 –30, 30–120 ), there are no studies that examine the relationship between instantaneous...
In this paper, we first demonstrate that a cyclostationary process is an oscillatory process which has a periodic evolutionary spectral, and we determine the relation between spectral correlation function and the periodic evolutionary spectral. Next, based on harmonic series representation (HSR) (a Fourier series with time varying lowpass coefficients representation that reveals the pertinent properties...
In this paper, we provide a new approach in ultra Wideband (UWB) radars based on a Fourier series with time-varying coefficients resulting in a second-order cyclostationary characteristics for stationary (low-mobility) target and almost second-order cyclostationary characteristics in moving target scenario. We also provide a new method for blind detection based on detecting the presence of cyclostationarity...
We introduce a method to control mutual coupling and correlation between two transmitting antennas for multi-antenna applications in the handset. The method is based on controlling the forward and the back-scattering currents at the antenna ports taking each antenna's driving point impedance into account. We achieve this using a six-section connection circuit that is placed between the multi-antenna...
We investigate the effectiveness of designing a multi-antenna system based on reducing the amount of mutual coupling between the antennas and the envelope correlation for spatial multiplexing systems. The investigation is carried out at 1880 MHz for a 2×2 multi-antenna system of vertically polarized dipole antennas. The effectiveness of the coupling and the correlation performance metrics were studied...
The method of correlation analysis of link channel quality and applied software (AS) effectiveness is considered. The goal of this method is to separate task of increasing of AS effectiveness from task of monitoring and diagnosing of computer networks, because these tasks should be solved separately and independently. The practical realization of the proposed method and the results of its applying...
We discuss in this paper the effects of antenna efficiency in the presence of a user and on the performance of a multiple-input multiple-output system. The investigation is carried out in different usage scenarios where the antenna efficiency changes significantly from one scenario to another. The propagation channel is defined to include the 3D antenna electromagnetic properties with the 3GPP spatial...
We investigate the effects of the user presence on a multi-antenna design from the channel perspective. Two usage scenarios are investigated, data and voice. The antennas and the user are electromagnetically simulated and are then integrated into the statistical 3GPP spatial channel model. There, the channel statistics are analyzed through the average channel capacity, correlation, and the channel...
In this paper we suppose to discuss recent results of study influence of Electromagnetic (EM) exposure of mobile phones radiation on a human. After calculations on different existed standard frequencies, with different distances between user's head and antenna using different antenna types were conducted (all calculation are part of ongoing MMFPII research project according to the specified) it appeared...
GPS technique is an essential tool to explore of the near-Earth space environment towards improved space weather prediction and such methods provide suitable platforms for the studies solar-climate relationships. Using the atmospheric precipitable water vapour (PWV) as a terrestrial response and the ionospheric total electron content (TEC) as a measure solar activity which both derived from ground-based...
The discovery of randomness in apparently predictable physical systems have evolved into a new science, the science of chaos. Chaotic systems are unstable and aperiodic, making them naturally harder to identify and to predict. Recently, many researchers have been looking at ways to utilize the characteristics of chaos in communication systems and have actually achieved quite remarkable results. This...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.