University of Piraeus

About: University of Piraeus is a education organization based out in Piraeus, Attiki, Greece. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1731 authors who have published 6209 publications receiving 106699 citations.

Towards Improving Visual-Facial Emotion Recognition through Use of Complementary Keyboard-Stroke Pattern Information

Abstract: In this paper, we investigate the possibility of improving the accuracy of visual-facial emotion recognition through use of additional (complementary) keyboard-stroke information. The investigation is based on two empirical studies that we have conducted involving human subjects and human observers. The studies were concerned with the recognition of emotions from a visual-facial modality and keyboard-stroke information, respectively. They were inspired by the relative shortage of such previous research in empirical work concerning the strengths and weaknesses of each modality so that the extent can be determined to which the keyboard-stroke information complements and improves the emotion recognition accuracy of the visual-facial modality. Specifically, our research focused on the recognition of six basic emotion states, namely happiness, sadness, surprise, anger and disgust as well as the emotionless state which we refer to as neutral. We have found that the visual-facial modality may allow the recognition of certain states, such as neutral and surprise, with sufficient accuracy. However, its accuracy in recognizing anger and happiness can be improved significantly if assisted by keyboard-stroke information.

Evaluating Web 2.0 technologies in higher education using students' perceptions and performance

Abstract: In this work, Web 2.0 technologies in higher education are evaluated using students' perceptions, satisfaction, performance and behaviour. The study evaluates the Web 2.0 tools as stand-alone entities as well in terms of their cross-operability and integration confluence to synergistic contributions towards the enhancement of student learning. Significant correlations and interdependencies on the students' behaviour over the used platform and their performance in various time points within the course time line have been revealed.

Escape the bubble: guided exploration of music preferences for serendipity and novelty

Abstract: In order to predict user behaviour recommender systems generate views of the world according to expressed and known user preferences resulting in 'filter bubbles'. This kind of bubbles generally help users to easily identify objects they like. However, it is becoming increasingly difficult for users to escape their personalized world and change their perspectives especially in domains such as music. In this work we present a methodology and related system that allows users to initiate explorations of music genres by taking a gradual path towards the desired genre while viewing the preferences of other users. The proposed methodology is based on identifying 'latent genres' and using user preference graphs for detecting optimal paths towards a selected target latent genre. In this process we generate suggestions of artists a user should listen to, aiming towards serendipitous and novel encounters. We have implemented our approach in a music recommendation system and evaluated it with encouraging results.

Current account determinants and external sustainability in periods of structural change

Abstract: The aim of this paper is to study the main macroeconomic, financial and structural characteristics that affected current account developments in Greece over the period 1960-2007 and link these to the issue of external sustainability. Concerns over Greece’s external sustainability have emerged since 1999 when the current account deficit widened substantially and exhibited high persistence. The empirical model used, which theoretically rests on the intertemporal approach, treats the current account as the gap between domestic saving and investment. We examine the behaviour of the current account in the long run and the short run using co-integration analysis and a variety of econometric tests to account for the effect of significant structural changes in the period under review. We find that a stable equilibrium current account model can be derived if the ratio of private sector financing to GDP, as a proxy for financial liberalization, is included in the specification. Policy options to restore the country’s external sustainability are explored by performing a simulation exercise based on the estimated equilibrium model.