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The protection of database systems content using digital watermarking is nowadays an emerging research direction in information security. In the literature, many solutions have been proposed either for copyright protection and ownership proofing or integrity checking and tamper localization. Nevertheless, most of them are distortion embedding based as they introduce permanent errors into the cover data during the encoding process, which inevitably affect data quality and usability. Since such distortions are not tolerated in many applications, including banking, medical, and military data, reversible watermarking, primarily designed for multimedia content, has been extended to relational databases. In this article, we propose a novel prediction-error expansion based on reversible watermarking strategy, which not only detects and localizes malicious modifications but also recovers back the original data at watermark detection. The effectiveness of the proposed method is proved through rigorous theoretical analysis and detailed experiments.

A hydromagnetic free convection flow has been modeled and simulated. The flow is considered unsteady, near a moving infinite flat plate in a rotating fluid. For the radiative heat transfer to be significant, very high temperatures are involved rendering the problem highly non-linear. The simulation is based on a generic finite element scheme coupled with a stepwise Lagrange polynomial. The equations and other parameters entering into the description of the flow are transformed into interpretable postfix codes. Numerical values are computed for the temperature and velocity distributions. The results obtained are depicted graphically and discussed.

In this article, a computer tool for processing African languages has been designed. It is intended to be a contribution to the automatic processing of African languages. The current study is focused on West African languages where five main languages from Niger, two from Mali and one from Burkina Faso are considered. After a brief review of African languages processing, we designed a tool which uses minimum resources and operates essentially on a dictionary and the characteristics of the language alphabet. The dictionary is represented using a trie data structure. For the sake of application, the designed tool operates as a spell checker. To detect and correct spelling errors, the edit distance and the specificities of the language are used. Although they do not have processing tools, it was shown that existing tools for computerized languages can be adapted to African languages efficiently. To extend the designed tool to any African language, we only need to provide an appropriate dictionary and alphabet.

A simulation was carried out on an unsteady flow of a viscous, incompressible and electrically conducting fluid past an infinite vertical porous plate. A generic computer program using the Galerkin finite element method is employed to solve the coupled non-linear differential equations for velocity and temperature fields. The diffusion equation, the energy equation, the momentum equations and other relevant parameters are transformed into interpretable postfix codes. Numerical calculations are carried out on the flow fields both in the presence of cooling and heating of the plate by free convection currents. The effects of the dimensionless parameters, namely, the Prandtl number, the Eckert number, the modified Grashof number, the Schmidt number and the time on the temperature and velocity distributions are discussed.

In this paper, a numerical simulation has been carried out on unsteady hydromagnetic free convection near a moving infinite flat plate in a rotating medium. The temperatures involved are assumed to be very high so that the radiative heat transfer is significant, which renders the problem highly non-linear even with the assumption of a differential approximation for the radiative heat flux. A numerical method based on the Nakamura scheme has been employed to obtain the temperature and velocity distributions which are depicted graphically. The effects of the different parameters entering into the problem have been discussed extensively.

A mathematical model is presented for the unsteady magnetohydrodynamic heat-generating free convection flow of a partially-ionized gas past an infinite vertical porous plate in a rotating frame of reference. Hall and ion-slip current effects are incorporated in the model. A finite element solution to the coupled non-linear differential equations is presented under physically realistic boundary conditions. The effects of Hall current parameter, ion-slip current parameter, Prandtl number, heat generation parameter, rotational parameter, Grashof (buoyancy) parameter and also time on the velocity and temperature fields are presented graphically. Primary velocity profile (u) decreases due to an increase in the Hall parameter and the ionslip parameter; however it is boosted with time for positive Grashof numbers (cooling of the plate by free convection currents) and decreases with time for negative Grashof numbers (heating of the plate by free convection currents). Secondary velocity profile (v) is also reduced with rising Hall parameter and ionslip parameter but boosted with time and stronger rotation. The temperature profile (θ) is enhanced with a rise in the heat generating parameter and also increases with time. The flow regime has important applications in MHD energy systems, plasma aerodynamics and induction flow meter technologies.