I introduce a gauge invariant decomposition of the nucleon spin into quark helicity, quark orbital, and gluon contributions. The total quark (and hence the quark orbital) contribution is shown to be measurable through virtual Compton scattering in a special kinematic region where single quark scattering dominates. This deeply-virtual Compton scattering (DVCS) has much potential to unravel the q...

There are observational and theoretical indications that both the visible (stars) and the dark matter density distributions in elliptical galaxies increase significantly up to the galactic center. I present here some analytical results obtained with the aid of self–consistent, spherically symmetric two component galaxy models. These results suggest the possibility that this similar behavior cou...

In this paper, we present an entropy based approach for DOA estimation in Gaussian and non-Gaussian environments. The DOA estimates are obtained by minimizing an entropy measure of the array data in the noise subspace. We show that the entropy approach leads to the MAP algorithm under the Gaussian assumption. Under the non-Gaussian assumption, we apply the varimax norm as an information measure...

If the direction of arrival (DOA) of a source is perturbed due to some reasons in a statistical way as in the environment of wireless mobile communications, a new model appropriate for such environment should be used instead of the point source model. In this paper, an angle-perturbed source model is proposed and an estimation method based on the eigendecomposition technique is investigated und...

We consider the problem of estimating the directions of arrival of multiple communication signals arriving at an uniform linear array. By considering the conjugate cyclic crosscorrelations of the sensor outputsand using a Bayesian framework, we propose a direction finding algorithm that allows us to estimate the directions of arrival for a more signals than sensors scenario. The algorithm does ...

Civil and Environmental Engineering, University of Brasilia, Brasilia, DF, Brazil b Earth & Environmental Engineering, Columbia Water Center, Columbia University, New York, NY, United States Civil and Environmental Engineering, Lehigh University, Bethlehem, United States Department of Civil Engineering, NOAA-Cooperative Remote Sensing Science and Technology Center, City University of New York, ...

Accounting for transverse momenta of the quarks, a longitudinal quark spin asymmetry exists in a transversely polarized nucleon target. The relevant leading quark distribution g1T (x; k 2 T) can be measured in the semi-inclusive deep-inelastic scattering. The average k T weighted distribution function g (1) 1T can be obtained directly from the inclusive measurement of g2. Intrinsic transverse m...

A new model for tacking mutual coupling in wireless communications is introduced. A new concept of receiving mutual impedance is introduced and explained theoretically. Receiving mutual impedances for typical antenna arrays are obtained. Application of the new method is demonstrated in several arrays for direction finding, adaptive nulling, and MIMO communications.

Quaternion models have been developed for both direction of arrival estimation and beamforming based on crossed-dipole arrays in the past. However, for almost all the models, especially for adaptive beamforming, the desired signal is still complex-valued and one example is the quaternion-Capon beamformer. However, since the complex-valued desired signal only has two components, while there are ...

The Digital Economy Act 2010 was hurried into existence in the dying days of the last Labour government, and contains powers designed to resist unauthorised file sharing that are due to be implemented by an Initial Obligations Code authored by Ofcom. Even before the Code has been published, there are several pre-existing key areas of the Act that contain significant evidential problems and pote...