In 1985 a powerful and practical public-key scheme was produced by ElGamal; his work was applied using large prime integers. El-Kassar et al. and El-Kassar and Haraty modified the ElGamal public-key encryption scheme from the domain of natural integers, Z, to two principal ideal domains, namely the domain of Gaussian integers, Z[ i ], and the domain of the rings of polynomials over finite field...

Thanks to INTEGRAL’s long exposures of the Galactic Plane, the two brightest Soft Gamma-Ray Repeaters, SGR 1806-20 and SGR 1900+14, have been monitored and studied in detail for the first time at hard-X/softgamma rays. SGR 1806-20, lying close to the Galactic Centre, and being very active in the past two years, has provided a wealth of new INTEGRAL results, which we will summarise here: more th...

The recent discoveries of giant planets around nearby stars has galvanized the planetary science community, astronomers, and the public at large. Since direct detection is now feasible, and is suggested by the recent acquisition of Gl229 B, it is crucial for the future of extrasolar planet searches that the fluxes, evolution, and physical structure of objects from Saturn's mass to 15 Juipter ma...

Using a new technique we have determined a value for the constant of proportionality between submillimetre (submm) emission and dust mass, the dust mass absorption coefficient (κd) at 850μm. Our method has an advantage over previous methods in that we avoid assumptions about the properties of dust in the interstellar medium. Our only assumption is that the fraction of metals incorporated in the...

We present a discovery of a giant stellar halo in NGC 6822, a dwarf irregular galaxy in the Local Group. This halo is mostly made of old red giants, showing striking features: 1) it is several times larger than the main body of the galaxy seen in the optical images, and 2) it is elongated in the direction almost perpendicular to the HI disk of NGC 6822. The structure of this stellar halo looks ...

An expression for the radiation force from a cw-laser on a fluidfluid interface is derived that is able to model the giant deformations observed in modern experiments when the fluid system is close to the critical point implying that the surface tension is very small. The core of our argument is that the system is modelled as a step-index optical fiber. Then, observing that the dominant HE11 mo...

The polarity shift problem is amajor factor that affects classification performance ofmachinelearning-based sentiment analysis systems. In this paper, we propose a three-stage cascade model to address the polarity shift problem in the context of document-level sentiment classification. We first split each document into a set of subsentences and build a hybrid model that employs rules and statis...

This paper describes a new approach for precise image shift detection between two images. The approach is based on an analysis of the phase difference spectrum between two images. Image shifts are directly evaluated from the phase difference spectrum without Fourier inversion. The cross s~ectrum is utilized as the weight parameter distribution. Synthetic and real images of typical image pattern...