Hierarchical Role-Based Access Control with Homomorphic Encryption for Database as a Service

Database as a service provides services for accessing and managing customers data which provides ease of access, and the cost is less for these services. There is a possibility that the DBaaS service provider may not be trusted, and data may be stored on untrusted server. The access control mechanism can restrict users from unauthorized access, but in cloud environment access control policies are more flexible. However, an attacker can gather sensitive information for a malicious purpose by abusing the privileges as another user and so database security is compromised. The other problems associated with the DBaaS are to manage role hierarchy and secure session management for query transaction in the database. In this paper, a role-based access control for the multitenant database with role hierarchy is proposed. The query is granted with least access privileges, and a session key is used for session management. The proposed work protects data from privilege escalation and SQL injection. It uses the partial homomorphic encryption (Paillier Encryption) for the encrypting the sensitive data. If a query is to perform any operation on sensitive data, then extra permissions are required for accessing sensitive data. Data confidentiality and integrity are achieved using the role-based access control with partial homomorphic encryption.Comment: 11 Pages,4 figures, Proceedings of International Conference on ICT for Sustainable Developmen

Magneto-elastic waves in crystals of magnetic molecules

We study magneto-elastic effects in crystals of magnetic molecules. Coupled equations of motion for spins and sound are derived and the possibility of strong resonant magneto-acoustic coupling is demonstrated. Dispersion laws for interacting linear sound and spin excitations are obtained for bulk and surface acoustic waves. We show that ultrasound can generate inverse population of spin levels. Alternatively, the decay of the inverse population of spin levels can generate ultrasound. Possibility of solitary waves of the magnetization accompanied by the elastic twists is demonstrated.Comment: 8 PR pages, 3 figure

Quantum dynamics of a nanomagnet in a rotating field

Quantum dynamics of a two-state spin system in a rotating magnetic field has been studied. Analytical and numerical results for the transition probability have been obtained along the lines of the Landau-Zener-Stueckelberg theory. The effect of various kinds of noise on the evolution of the system has been analyzed.Comment: 7 pages, 7 figure

Field Dependence of the Electron Spin Relaxation in Quantum Dots

Interaction of the electron spin with local elastic twists due to transverse phonons has been studied. Universal dependence of the spin relaxation rate on the strength and direction of the magnetic field has been obtained in terms of the electron gyromagnetic tensor and macroscopic elastic constants of the solid. The theory contains no unknown parameters and it can be easily tested in experiment. At high magnetic field it provides parameter-free lower bound on the electron spin relaxation in quantum dots.Comment: 4 PR pages, no figure

Plyometric Training in Female Volleyball Players. Systematic Review

El voleibol femenino se práctica en todo el mundo a nivel profesional y amateur. Los saltos verticales son una parte fundamental para el desarrollo de este deporte, por lo que el entrenamiento pliométrico puede ser eficaz para un aumento del rendimiento. El propósito de estudio fue describir cuáles han sido los métodos y programas de entrenamiento pliométrico en mujeres que practican voleibol, así como el resultado obtenido en función de estos. El proceso de búsqueda en las bases de datos se llevó a cabo desde Marzo hasta Junio de 2016. Las bases de datos consultadas fueron Pubmed, Web of Science, Cochrane y SPORTDiscus. La revisión sistemática fue realizada bajo las recomendaciones de la declaración PRISMA. La calidad metodológica de los estudios fue evaluada mediante la Escala PEDro. Como resultado, se obtuvieron un total de 205 artículos tras eliminar aquellos que estaban por duplicado. Finalmente 7 artículos fueron seleccionados. Los resultados principales fueron que aquellos estudios que utilizan deportistas amateurs obtienen mejores resultados que los realizados con deportistas profesionales cuando se realizan programas de entrenamiento pliométrico. También se indica que un período de entrenamiento pliométrico de baja intensidad puede prevenir una disminución en la altura del salto vertical; así como es necesario programar la pretemporada para evitar pérdida en la capacidad de salto. Todo ello parece indicar, como conclusión, que es necesario una disminución del volumen y un aumento de la intensidad en el entrenamiento pliométrico.Female volleyball is practiced all over the world at a professional and amateur level. Vertical jumps are a fundamental part of the development of this sport. In this sense, plyometric training can be effective for increased performance. The purpose of the study was to describe the methods and programs of plyometric training in women volleyball players, as well as the results obtained from them. The following electronic databases were searched March to June 2016. Electronic databases consulted were Pubmed, Web of Science, Cochrane and SPORTDiscus. This systematic review was performed following PRISMA statement. PEDro scale was used to evaluated the methodological quality of the included studies. As total of 205 articles were obtained after remove duplicates. Finally 7 articles were selected. The main results were that those studies using amateur athletes obtain better results than those performed with professional athletes when performing plyometric training programs. It is also indicated that a period of low intensity plyometric training could prevent a decrease in vertical jump height; As well as it is necessary to schedule the preseason to avoid loss in the ability to jump. All this seems to indicate, in conclusion, that a decrease in volume and an increase in intensity in the training of plyometric training is necessary