Handling privacy and concurrency in an online educational evaluation system

Nowadays, all academic institutions exhibit and distribute their material over Internet. Moreover, e-learning and e-evaluation products is one of the most rapidly expanding areas of education and training, with nearly 30% of U.S. college and university students now taking at least one online course. However, Internet increases the vulnerability of digital educational content exploitation since it is a potential hostile environment for secure data management. The challenge is that providing current online educational tools that are accessible by a large number of users, these educational environments handle data of varying sensitivity thus it is increasingly important to reason about and enforce information privacy guarantees in the presence of concurrency. The present paper provides a privacy preserving approach in a concurrent online educational evaluation system. It introduces a privacy preserving approach for utilizing online concurrent evaluation of acquired student competencies that handles the increasingly complex issues of designing, developing and e-competence evaluation systems suitable for educational and e-learning environments. The proposed architecture for an online competence evaluation system offers access control and protect users' private data while, it provides concurrent procedures for evaluating competencies. © 2019 International Press of Boston, Inc. All rights reserved.European Commission, ECThis work has been partially supported by the “Implementation of Software Engineering Com-petence Remote Evaluation for Master Program Graduates (iSECRET)” project No 2015-1-LVo1-KA203-013439 funded by ERASMUS+ of the European Commission

Extensions to Optimistic Concurrency Control with Time Intervals

Although an optimistic approach has been shown to be better suited than locking protocols for real-time database systems (RTDBS), it has the problems of unnecessary restarts and heavy restart overhead. In this paper we identify the unnecessary restart problem in OCC-TI (Optimistic Concurrency Control with Time Intervals), propose a solution to this problem and demonstrate that the solution will produce a correct result. Additionally, two extensions to the basic dynamic adjustment of the serialization order conflict resolution method used in OCC-TI are proposed. Experiments with a prototype implementation of a real-time database system show that the proposed method clearly outperforms the original OCC-TI.

Extensions to Optimistic Concurrency Control with Time Intervals

Although an optimistic approach has been shown to be better suited than locking protocols for real-time database systems (RTDBS), it has the problems of unnecessary restarts and heavy restart overhead. In this paper we identify the unnecessary restart problem in OCC-TI (Optimistic Concurrency Control with Time Intervals), propose a solution to this problem and demonstrate that the solution will produce a correct result. Additionally, two extensions to the basic dynamic adjustment of the serialization order conflict resolution method used in OCC-TI are proposed. Experiments with a prototype implementation of a real-time database system show that the proposed method clearly outperforms the original OCC-TI