An improved Quasi Cyclic Low Density Parity Check code (QC-LDPC) is proposed to reduce the complexity of the Low Density Parity Check code (LDPC) while obtaining the similar performance. The proposed QC-LDPC presents an improved construction at high SNR with circulant sub-matrices. The proposed construction yields a performance gain of about 1 dB at a 0.0003 bit error rate (BER) and it is teste...

Progress in digital data acquisition and storage technology has resulted in the growth of huge databases. Nevertheless, these techniques often have high computational cost. Then, it is advisable to apply a preprocessing phase to reduce the time complexity. These preprocessing techniques are fundamentally oriented to either of the next goals: horizontal reduction of the databases or feature sele...

Abstract —A motion adaptive deinterlacing algorithm is presented in this paper. It consists of the ELA-Median directional interpolation, same-parity 4-field horizontal motion detection, morphological operation for noise reduction and adaptive threshold adjusting. The edges can be sharper when the ELA-Median directional interpolation is adopted. The same-parity 4-field horizontal motion detectio...

The problem of optimizing distributed database includes: fragmentation and positioning data. Several different approaches and algorithms have been proposed to solve this problem. In this paper, we propose an algorithm that builds the initial equivalence relation based on the distance threshold. This threshold is also based on knowledgeoriented clustering techniques for both of horizontal and ve...

The main motivation of this paper arises from the study of Carnot–Carathéodory spaces, where the class of 1-rectifiable sets does not contain smooth non-horizontal curves; therefore a new definition of rectifiable sets including non-horizontal curves is needed. This is why we introduce in any metric space a new class of curves, called continuously metric differentiable of degree k, which are Hö...

A global coupled General Circulation Model is used to investigate effects of the lateral ocean mixing on the amplitude and spectral characteristics of the ENSO-like variability. Three 40-year coupled simulations are analysed. They only differ by the lateral ocean physics parametrized: a horizontal diffusion scheme; an isopycnal scheme ; isopycnal scheme with an Eddy Induced Velocity (EIV) term....

The complexity of dynamical laws governing 3D atmospheric flows associated to incomplete and noisy observations makes very difficult the recovery of atmospheric dynamics from satellite images sequences. In this paper, we face the challenging problem of joint estimation of timeconsistent horizontal motion fields and pressure maps at various atmospheric depths. Based on a vertical decomposition o...

We present a fast and accurate numerical scheme for the approximation of the primitive equations of the atmosphere. The temporal variable is discretized by using a special semiimplicit scheme which requires only to solve a Helmholtz equation and a nonlocal Stokes problem at each time step; the spatial variables are discretized by a spectral-Galerkin procedure with the horizontal components of v...

A skew estimation algorithm for printed and handwritten documents, based on the document’s horizontal projection profile and its Wigner–Ville distribution, is presented. The proposed algorithm is able to correct skew angles that range between 289 and þ898 detecting the right oriented position of the page by the alternations of the horizontal projection profile. It is able of processing successf...

JPEG-LS is the latest pixel based lossless to near lossless still image coding standard introduced by the Joint Photographic Experts Group (JPEG) '. In this standard simple localized edge detection techniques are used in order to determine the predictive value of each pixel. These edge detection techniques only detect horizontal and vertical edges and the corresponding predictors have only been...