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

A Taxonomy of Knowledge Spillovers for High-Tech Start-ups Development

Entrepreneurship is considered of utmost importance for national economic and industrial growth. A leading theory related to economic development is the Knowledge Spillover Theory of Entrepreneurship (KSTE), which aims to uncover the effects that economic agents have on the creation of new companies. By following the KSTE process, companies can commercialize and implement newly acquired knowledge in the market more quickly. Typically, economic growth evaluation is conducted at the country or regional level through global monitoring indexes, assessment on the generation of patents, and identification of the number of companies created. However, since knowledge is sometimes unattached to a physical document or item, it remains necessary to clarify a taxonomy and flow of knowledge spillovers at the individual level for start-ups in their first three to five years of development from the time that the company is funded. The purpose of this paper is to identify and discuss possible strategies for evaluating the effects of knowledge spillovers on start-ups in high-tech sections which, in turn, will aid the decision-making process of Chief Executive Officers (CEOs)

A Taxonomy of Knowledge Spillovers for High-Tech Start-ups Development

Entrepreneurship is considered of utmost importance for national economic and industrial growth. A leading theory related to economic development is the Knowledge Spillover Theory of Entrepreneurship (KSTE), which aims to uncover the effects that economic agents have on the creation of new companies. By following the KSTE process, companies can commercialize and implement newly acquired knowledge in the market more quickly. Typically, economic growth evaluation is conducted at the country or regional level through global monitoring indexes, assessment on the generation of patents, and identification of the number of companies created. However, since knowledge is sometimes unattached to a physical document or item, it remains necessary to clarify a taxonomy and flow of knowledge spillovers at the individual level for start-ups in their first three to five years of development from the time that the company is funded. The purpose of this paper is to identify and discuss possible strategies for evaluating the effects of knowledge spillovers on start-ups in high-tech sections which, in turn, will aid the decision-making process of Chief Executive Officers (CEOs)

Collective electromagnetic relaxation in crystals of molecular magnets

We study the magnetization reversal and electromagnetic radiation due to collective Landau-Zener relaxation in a crystal of molecular magnets. Analytical and numerical solutions for the time dependence of the relaxation process are obtained. The power of the radiation and the total emitted energy are computed as functions of the crystal parameters and the field sweep rate.Comment: 7 pages, 9 figure

The Effects of Knowledge Spillovers and Accelerator Programs on the Product Innovation of High-Tech Start-Ups: A Multiple Case Study

The Knowledge Spillover Theory of Entrepreneurship (KSTE) explores the effects that new knowledge and proximity have on the exploitation of entrepreneurial opportunities and the resultant creation of start-ups. This paper aims to identify the types of knowledge spillovers that affect entrepreneurs in the early stages of start-up development. A conceptual model is proposed, using a multi-case study approach involving High-Tech start-ups that have attended accelerator and incubator programmes in Greater London, United Kingdom (UK). The research involved 32 semistructured interviews with Chief Executive Officers (CEOs) and co-founders of start-up companies. Our findings suggest that entrepreneurs are influenced by various forms of knowledge spillover which assist in determining the strategic decision of the company, in terms of formation, including partnerships or alliances, allocation of Research and Development (R&D) budgets, and engagement in product innovation. Further observations confirm that High-tech start-ups focus on a fast pace of constant product innovation to cover identified gaps in the market. One significant finding is that start-ups use various technological platforms to access knowledge spillovers which challenges the ideas of geographical proximity present in existing KSTE understanding

Liberalismo y división provincial

La división provincial decretada por Javier de Burgos en 30 de noviembre de 1833 que, con ligeras modificaciones, continúa vigente en la actualidad, ha sido enjuiciada negativamente por la casi totalidad de quienes se han ocupado de ella, en particular por administrativistas y geógrafos. La acusación más repetida, convertida en un lugar común político, es la de que fue una división artificial, realizada poco menos que a partir de cero, sin tener en cuenta la geografía ni la historia. Las investigaciones históricas llegan a conclusiones diferentes. Han demostrado, en primer lugar, que la obra de Javier de Burgos no fue una decisión repentina ni de ejecución expeditiva, sino el resultado de un proceso que, sobre la base de la división provincial del Antiguo Régimen, arranca de las Cortes de Cádiz y, pasando por las del Trienio Constitucional, culmina en el citado decreto de 1833. En segundo lugar, que el proceso fue meditado, discutido, razonado y coherente con los objetivos político-administrativos propuestos: definir el marco territorial de las nuevas instituciones, la dimensión espacial del nuevo Estado. En este trabajo nos proponemos ampliar aquellas investigaciones con la aportación de fuentes inéditas, no utilizadas hasta ahora, y analizar la relación existente entre la implantación del régimen liberal y la utilización de la división provincial como uno de los instrumentos para conseguirla, mostrando la lógica interna del proceso, independiente­mente de cuál sea el juicio que merezcan los objetivos políticos a que sirvió

Elementos descriptivos de la fonética del saboyano.

Sin resume

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