We obtain the Killing equations and the corresponding infinitesimal isometries for the ten dimensional space generated by a large number of coincident D3-branes. In a convenient limit this space becomes an AdS5 × S 5 which is relevant for the AdS/CFT correspondence. In this case, using Poincaré coordinates, we also write down the Killing equations and infinitesimal isometries. Then we obtain a ...

Among the learning environment design tasks, we interest in this paper in the student-computer dialogue specification and management. We show that it is possible to define decisional latitude intervals in which the student may work. The specification of dialogue is made through a userinterface design method called Diane+ and it allows us to simulate the evolution of the student’s level and to e...

Normal and almost normal surfaces are essential tools for algorithmic 3-manifold topology, but to use them requires exponentially slow enumeration algorithms in a high-dimensional vector space. The quadrilateral coordinates of Tollefson alleviate this problem considerably for normal surfaces, by reducing the dimension of this vector space from 7n to 3n (where n is the complexity of the underlyi...

Now, It is believed that the best costs of a point doubling and addition on elliptic curves over binary fields are S M 5 4 + (namely, four finite field multiplications and five field squarings) and , respectively. In this paper we reduce the costs to less than S M 5 8 + S M 3 3 + and , respectively, by using a new projective coordinates we call PL-coordinates and rewriting the point doubling fo...

This paper discusses scaling issues of a mobile multimedia tour guide. Making tourist-information available in a substantially large geographical area (e.g. a federal state in Austria) raises new questions, compared to providing similar information in a limited area (such as a museum). First, we have to assume a heterogeneous network infrastructure containing high and low bandwidth links and ev...

In this paper, we describe our approach to estimating the geographic location of videos. Our system relies on textual meta-data and includes two basic term filtering strategies: filtering according to the general use of terms and filtering according to the geographic spread. Combining both filtering steps yields 50% accuracy within a 10km range.

This paper presents a novel circular effect generation approach. In general, pixel location in an image can be represented with i and j coordinate. To manipulate (i,j) coordinate system easier, we transform (i,j) coordinate system into (ρ,θ) coordinate system. Two parameters are used for generating circular effect: R and T. After applying selected R and T in (ρ,θ) coordinate system, (ρ2,θ2) are...

In Cartesian coordinate systems, the angular separation-based star identification algorithms involve much trigonometric function computing. That delays the algorithm process. As in a polar coordinate system, the coordinates are denoted by angular values, it is potential to speed up the star identification process by adopting a polar coordinate system. An angular polar coordinate system is intro...

This research develops thermo-elastic analysis of a functionally graded cylinder under thermo-mechanical loadings. Heat conduction equation in cylindrical coordinate system is solved. Thermal conductivity coefficient is graded along the radial direction. By considering a symmetric distribution of temperature, loading and boundary conditions, strain-displacement and stress-strain relations can b...