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.

Energy efficient network coding-based MAC for cooperative ARQ wireless networks

Abstract: In this paper we introduce a network coding-aided energy efficient Medium Access Control (MAC) protocol that coordinates the transmissions among a set of relay nodes which act as helpers in cooperative Automatic Repeat reQuest-based (ARQ-based) wireless networks Applying network coding techniques, we achieve to increase the energy efficiency of the network without compromising the system performance in terms of Quality of Service Our proposed solution is evaluated by both analytical and simulation results

On the Competitive Ratio for Online Facility Location

Abstract: We consider the problem of Online Facility Location, where the demand points arrive online and must be assigned irrevocably to an open facility upon arrival. The objective is to minimize the sum of facility and assignment costs. We prove that the competitive ratio for Online Facility Location is Θ $(\frac{\log n}{\log\log n})$. On the negative side, we show that no randomized algorithm can achieve a competitive ratio better than Ω $(\frac{\log n}{\log\log n})$ against an oblivious adversary even if the demands lie on a line segment. On the positive side, we present a deterministic algorithm which achieves a competitive ratio of $\mathrm{O}(\frac{\log n}{\log\log n})$ in every metric space.

Citizen-science for monitoring marine invasions and stimulating public engagement: a case project from the eastern Mediterranean

Abstract: The distribution of marine life has been alarmingly reshaped lately and the number of non-indigenous species and their impacts are rapidly escalating globally. Timely and accurate information about the occurrence of non-indigenous species are of major importance for the mitigation of the issue. However, still large gaps in knowledge about marine bioinvasion exist. Mediterranean Sea is among the most impacted ecoregions globally. In this work we present a comprehensive overview of the project “Is is Alien to you? Share it!!!” which monitors non-indigenous species in Greece and Cyprus with the help of citizen scientists. The goal of this work is to present this project as a case study in order to demonstrate how citizen science can substantially contribute to the monitoring of biological invasions. We compared the projects database with the databased of ELNAIS and EASIN, for discuss weaknesses and advantages and future steps for advancing the effort. In total 691 records of marine alien and cryptogenic species were collected in these 2 years from Greece and Cyprus, with the density of records reaching 20 observations per km2 in some locations. The project has contributed significantly in the assessment of descriptor D2 “Exotic Species” of the Marine Strategy Framework Directive, with 3 new species for Greece. Future steps should focus on training citizens to report less reported taxa and raising the awareness of all relevant stakeholders.

Influence of the familiarization with "scratch" on future teachers' opinions and attitudes about programming and ICT in education

Abstract: Computer programming is considered a very important competence which is usually quite difficult to learn. Teaching computer programming to novices has to overcome important obstacles in order to be successful. The problem is even greater for non computer science majors. In order to overcome the difficulties and increase the rate of students that adopt positive views towards computer science, several educational programming environments have been proposed. Scratch educational programming environment offers innovative programming techniques and enables the rather easy development of games, animations, interactive stories etc. In this paper the effects of using Scratch in an introductory computer programming course for future teachers' attitudes and opinions are explored.