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Patras, Greece

The Hellenic Open University is a multi-school public university run by the Greek State. The institution, which is based in Patras, is unique in the Greek context in that it exclusively provides distance education at both undergraduate and postgraduate level. Wikipedia.

Hatzigeorgiou G.D.,Hellenic Open University | Pnevmatikos N.G.,Technological Educational Institute of Athens
Engineering Structures | Year: 2014

This paper examines the inelastic response behaviour of structures with supplemental viscous dampers under near-source pulse-like ground motions. It is well known that the design of dampers requires the effective evaluation of maximum seismic velocities or maximum damping forces. In order to avoid complicated methods, such as the dynamic inelastic analysis, this study proposes a simple and effective evaluating method for these maximum values using the inelastic velocity ratio. This ratio is a modification factor which allows the evaluation of the maximum inelastic velocity or damping force from their corresponding elastic counterparts. The paper focuses on structures. Extensive parametric studies are conducted to examine the influence of characteristics of structure (period of vibration, post-elastic stiffness, force reduction factor), of supplemental damping (equivalent viscous damping ratio) and of ground motion (type of earthquake fault) on the maximum seismic velocities and damping forces. © 2014 Elsevier Ltd. Source

Zervas E.,Hellenic Open University
Fuel | Year: 2011

Engines of new passenger cars are tuned at the sea level. However, in several countries, a significant part of the engine operation is performed at higher altitudes than that of the sea level. The different air density can have a significant impact on fuel consumption. In the case of gasoline engines, the higher altitude theoretically leads to lower fuel consumption due to lower throttle frictions due to the wider throttle opening. From the other side, as the air is less dense at higher altitudes, the vehicle aerodynamic is changed and this also leads to lower fuel consumption. This work studies, on three regulated driving cycles, the impact of high altitude on the fuel consumption of a gasoline passenger car. The impact of changed vehicle aerodynamics of higher altitudes, through the change of deceleration times, on fuel consumption is also analyzed. © 2011 Elsevier Ltd. All rights reserved. Source

Verykios V.S.,Hellenic Open University
Wiley Interdisciplinary Reviews: Data Mining and Knowledge Discovery | Year: 2013

Privacy preserving data mining has been recently introduced to cope with privacy issues related to the data subjects in the course of the mining of the data. It has also been recognized that it is not only the data that need to be protected but sensitive knowledge hidden in the data as well. Knowledge hiding is an emerging area of research focusing on appropriately modifying the data in such a way that sensitive knowledge escapes the mining and is not communicated to the public for privacy purposes. This article investigates the development of techniques falling under the knowledge-hiding umbrella that pertain to the association rule-mining task. These techniques are known as association rule hiding or frequent pattern hiding approaches, and have been receiving a lot of attention lately because they touch upon important issues of handling a sort of commonly used patterns such as the frequent patterns and the association rules. We present an overview of this area as well as a taxonomy and a presentation of an important sample of algorithms. © 2013 Wiley Periodicals, Inc. Copyright © 2013 John Wiley & Sons, Inc.. Source

The transition from fast spontaneous urbanisation in southern Europe, with popular squatting as a form of civil disobedience, to 'new social movements' (NSMs) for democratic globalisation in cities, is taking place in the context of a broader transition. In the 20th century, there were unstable politics, civil wars and also still dictatorships in the south, which contributed in a north-south divide in Europe, engulfing civil societies, the welfare state, planning and grassroots mobilisations for a 'right to the city'. This paper focuses on social transformation during the 21st century and points to three directions. First, it explores the nature of several NSMs as urban social movements (USMs) organised by loosely networked cosmopolitan collectivities, social centres and flâneur activists demanding a 'right to the city', and interprets this with reference to globalisation, democratisation and the Europeanisation of southern civil societies. Secondly, it unveils innovative forms of 'urban' mobilisations in the south, influencing the rest of the Europe: squatting in the past, social centres and the ESF (both starting in Italy) at present. Thirdly, it traces transformations of USMs between two centuries and argues about the deconstruction of the north-south divide in Europe with regard to movements and definitions of the 'right to the city'. Mediterranean USMs have offered new insights and have broadened geographical imaginations in Europe. © 2010 Urban Studies Journal Limited. Source

Niakas D.,Hellenic Open University
International Journal of Health Services | Year: 2013

In an era of economic crisis in Greece and with many uninsured citizens, the Troika (lenders of Greece) suggests reforms and promotes the internal market, resulting in a public-private system becoming more privatized. This article contradicts these proposals and attempts to suggest the necessary reforms to achieve equity of access for all and to promote efficiency, taking into account the existing needs of the population and the recession of the Greek economy. © 2013, Baywood Publishing Co., Inc. Source

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