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.
This paper presents numerical simulation of transcranial magnetic stimulation by employing figure-of-eight coil (fo8) with bending wings. Various fo8 coils with different bending angles were numerically designed. Three-dimensional distributions of the magnetic fields and induced electric fields in realistic head model were calculated by impedance method. Results were compared with those obtained from...
We report on the current status of the Effelsberg-Bonn HI Survey, a new large-scale single-dish observing campaign to map the 21-cm line emission across the full northern hemisphere. Using state-of-the-art spectrometers it is feasible to survey the Milky Way Galaxy as well as the local universe within a single run. The improvement in terms of sensitivity, angular resolution, and data quality is demonstrated...
The Hydrogen Epoch of Reionization Arrays (HERA) roadmap is a staged plan for using the unique properties of the 21cm line from neutral hydrogen to probe our cosmic dawn, from the birth of the first stars and black holes, through the full reionization of the primordial intergalactic medium (IGM). HERA is a collaboration between the Precision Array Probing the Epoch of Reionization (PAPER), US-Murchison...
The challenging goal of detecting faint and wideband spectral features arising from cosmological evolution in the thermal state of the baryons has driven recent progress in radiometer technology. Because these faint signals are received with foregrounds and terrestrial RFI that are overwhelmingly larger in power, the design of sensors of the EM field and associated receiver configuration need special...
Sprites are spectacular optical emissions in the mesosphere induced by transient lightning electric fields above thunderstorms. Recently, significant efforts have been devoted to the understanding of the inception mechanism of sprite streamers, the origin of different sprite morphologies, and the lightning polarity asymmetry in producing sprites. In this paper, we present a combination of observational...
To examine the quality and propagation characteristics of the radio waves in a very long propagation path, Indian Centre for Space Physics, Kolkata, participated in the 27th Indian scientific expedition to Antarctica during 2007–2008. One Stanford University made AWESOME Very Low Frequency (VLF) receiving system was installed at the Indian Antarctic station Maitri and about five weeks of data was...
In this study we will present a description of the FP7 Space Weather project PLASMON-developed model of energetic electron precipitation (EEP) fluxes that occur inside and outside of the plasmasphere during space weather events. The aim of the PLASMON EEP model is to identify 3 or 4 MLT zones which are populated by ULF/VLF waves that can generate energetic electron precipitation. The MLT zones contain...
The technique for remote sensing the plasma mass density in magnetosphere by geomagnetic field line resonances detected at ground-based stations is getting more and more popular after the establishment in the last few years of extended magnetometer arrays, such as the EMMA network recently formed in the framework of the EU FP-7 PLASMON project [1]. It is important therefore to quantify the level of...
Sudden pulses in the model solar wind sets the Earth's magnetosphere into damped oscillatory motions. A simple model is capable of explaining many of the basic properties of these oscillations, giving scaling laws for their characteristics in terms of the parameters of the problem, such as the Solar wind momentum density. The period of the oscillations, their damping and anharmonic nature are accounted...
In this paper, a new model based on Copula functions for modeling joint exceedance probability of rain attenuation for time diversity satellite systems is presented. Time diversity is an efficient fade mitigation technique, which exploits the decrease of correlation of rainfall medium within time. Copulas theory is used for the coupling of rain attenuation random variables which are considered correlated...
To quantify the impacts of random inputs on hybrid electromagnetics (EM)-circuit systems or EM scattering from objects, an adaptive hierarchical sparse grid collocation (ASGC) algorithm combined with discontinuous Galerkin time-domain (DGTD) method is presented in this work. As a stochastic polynomial chaos modality, the ASGC method approximates the interested stochastic observables using interpolation...
The paper presents a planar stochastic EMI sources localization approach based on two-point time-domain data of electromagnetic near-field tangential components. The radiating structure is considered as a set of simple electrical dipoles arranged on a grid in the object plane. The autocorrelation and cross-correlation spectra of eradiated signals in two different space points are used to determine...
Idealized complex Gaussian fields with Dirac's delta correlation are able to reproduce the asymptotic statistics of irregular, wave chaotic, electromagnetic cavities. However, in many practical scenarios involving (objects with) losses and (other) perturbations, deviations from those statistics are observed and still await a proper explanation. We develop the concept of correlated plane-wave angular...
Numerical simulations are a common procedure to characterize electromagnetic radiators. For the derivation of stochastic approaches to describe unintentional radiators, these simulations are useful. Nevertheless, the stochastic assessment comes with some important requirements. This paper presents the necessity of a uniformly distributed sampling of the far-field radiation pattern. It is shown that...
In this report, we present THz wireless communications using photonically generated 300-GHz carrier signals with an output power of more than 1 mW. We have examined two approaches to increasing the output power; one is to use a photodiode array, and the other is to use a frequency multiplier. We have demonstrated an error-free transmission at data rates of 30 Gbit/s and 20 Gbit/s with a photodiode...
In this paper, we introduce by far the most promising schemes to realize excited state atomic filter. Excited state Faraday anomalous dispersion optical filter (ES-FADOF) with direct pumping, as the traditional method, provides a very direct way, while ES-FADOF with indirect pumping, as proposed very recently, provides much more choices. Moreover, induced dichroism excited state atomic line filter...
Single photon detection technology is a frontier in the field of photon detection. As a newly developed technique, superconductor single photon detector (SSPD) has many attractive advantages such as wide response bandwidth, low noise, and fast speed. In this paper, we experimentally demonstrate a high performance SSPD with large system efficiency and low dark count rate at infrared wavelengths. The...
This paper presents a bandpass filter (BPF) that can change its frequency response. The BPF employs tunable ring resonators that consist of ring resonators, parallel resonance circuits, and digitally tunable capacitors applying a micro electromechanical systems (MEMS) technology. Since the tunable ring resonator can tune its BW without shifting the resonant frequency, the BPF can change its bandwidth...
SAR scattering mechanics is dominated by the surface scattering, which provides the potential for offshore oil spills detection. On the basis of analyzing the SAR imaging mechanics about oil slicks, several factors, such as the wind speed, the wave length of the SAR sensor, the polarization of the SAR sensor, and quasi oil slicks are provided and analyzed. Finally, the present popular oil slicks detection...
We develop a noise-robust radar target classification method to discriminate the moving vehicle and walking human. The traditional real-valued Probabilistic Principal Component Analysis (PPCA) model is extended to the complex-value domain for modeling the low resolution radar echoes from the ground moving targets. The denoising preprocessing is accomplished by signal reconstruction with the proposed...
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.