University of the Aegean

About: University of the Aegean is a education organization based out in Mytilene, Greece. It is known for research contribution in the topics: Population & Context (language use). The organization has 2818 authors who have published 8100 publications receiving 179275 citations. The organization is also known as: UAEG.

On the Resistance of Boolean Functions Against Algebraic Attacks Using Univariate Polynomial Representation

Abstract: In the past few years, algebraic attacks against stream ciphers with linear feedback function have been significantly improved. As a response to the new attacks, the notion of algebraic immunity of a Boolean function f was introduced, defined as the minimum degree of the annihilators of f and f + 1. An annihilator of f is a nonzero Boolean function g , such that f · g = 0. While several constructions of Boolean functions with optimal algebraic immunity have been proposed, there is no significant progress concerning the resistance against the so-called fast algebraic attacks. In this paper, we provide a framework to assess the resistance of Boolean functions against the new algebraic attacks, including fast algebraic attacks. The analysis is based on the univariate polynomial representation of Boolean functions and necessary and sufficient conditions are presented for a Boolean function to have optimal behavior against all the new algebraic attacks. Finally, we introduce a new infinite family of balanced Boolean functions described by their univariate polynomial representation. By applying the new framework, we prove that all the members of the family have optimal algebraic immunity and we efficiently evaluate their behavior against fast algebraic attacks.

Measuring customer value in online collaborative trip planning processes

Abstract: Purpose – The paper first aims to analyse the role and functionality of geocollaborative portals in assisting collaborative trip planning processes and then it seeks to develop and test a model for measuring the multi‐dimensionality of customer value perceived by system users.Design/methodology/approach – Primary data are collected from students assigned to use Yahoo! Trip Planner for collaboratively designing an hypothetical trip. A two step approach of an exploratory factor analysis and confirmatory factor analysis was used for testing the model measuring the types of customer value derived from the system use.Findings – Findings provide evidence of the existence of both “give” (risk, time and effort to use the system) and “get” (functional, social and emotional) customer values.Research limitations/implications – Findings are limited to the demographics of the students' sample, while future research should also try to replicate the study in other contexts (e.g. cultures, type of trips and destinations)...

A Buffer-Aided Successive Opportunistic Relay Selection Scheme With Power Adaptation and Inter-Relay Interference Cancellation for Cooperative Diversity Systems

Abstract: In this paper, we present a relay selection scheme which combines the spectral efficiency of successive opportunistic relaying with the robustness of single-link relay selection. More specifically, we propose a scheme that minimizes the total energy expenditure per time slot under an inter-relay interference cancellation scheme. The new relay selection policy is analyzed in terms of outage probability and diversity by modeling the evolution of relay buffers as a Markov Chain. We construct the state transition matrix of the Markov Chain and obtain its stationary distribution, which in turn, yields the outage probability. The proposed scheme outperforms relevant state-of-the-art relay selection schemes in terms of throughput, diversity, energy efficiency and average delay, as demonstrated via representative numerical examples.