Proof-of-Stake (PoS) protocols have been actively researched for the past five years. PoS finds direct applicability in open blockchain platforms and has been seen as a strong candidate to replace the largely inefficient Proof of Work mechanism that is currently plugged in most existing open blockchains. Although a number of PoS variants have been proposed, these protocols suffer from a number ...

A general equilibrium monetary model is developed to study the optimal design of a cryptocurrency system based on a blockchain. The model is then calibrated to Bitcoin transaction data to perform a quantitative assessment of the scheme. We formalize the critical elements of a cryptocurrency: the blockchain to keep a history of transactions, the distributed updating of information and consensus ...

Short abstract This paper in short1 presents the thesis that insecurity of software is due to interaction of technological and legal shortcomings, fostered by economic rationality. Ineffective liability laws further the distribution of unreliable and insecure software. Copyright protection for software hinders the quality improvement. Patent protection encourages the use of proprietary instead ...

In problem solving situation, cognitive flexibility appears to be a major skill. Fostering cognitive flexibility is therefore a specific stake in mathematics education. This research introduces a learning method to develop mathematical concepts when solving word arithmetic problems. The study was conducted with 8 classes (4-5 Grades) from highpriority education schools in the Paris area followi...

The cloud computing is a paradigm involving many disparate stake holders. Any system built upon this paradigm and a business run on such system architecture would have similarly disparate scope of access, activities and responsibilities for the stake holders. Depending on the scope of the activities and responsibilities, a stakeholder has to device the security measures to secure his activity s...

The aim of this paper is to describe, analyze, and discuss how Swedish schools the national tests in schools, university teaching examination, college admissions test, Scholastic Aptitude Test (SweSAT), have been affected by COVID-19 situation. A further challenges universities test process Sweden which are due Contrary many other countries, remained open, except for upper secondary school wher...