(Re)discovering Love Stories

Nikos Manousakis 한국서양고전학회 2018 西洋古典學硏究 Vol.57 No.3

The present paper is an overview and discussion of Byzantine literary criticism concerning the ancient Greek novel from the ninth to the fifteenth century CE. More specifically, I focus here on the opinions and judgments of some of the most prominent Byzantine scholars as regards two fully extant Greek novels: Achilles Tatius’ Leucippe and Clitophon and Heliodorus’ Ethiopian Tale. I review in some detail various aspects of the ‘evaluation practice’ of Patriarch Photios I (ninth century CE) and Michael Psellos (eleventh century CE), and I also – though more briefly – go over the corresponding theories and ideas of (Philip-)Philagathus of Cerami (twelfth century CE) and Ioannis Eugenikos (fifteenth century CE). The main question I attempt to address in this study is how similarly or differently (even idiosyncratically) the Byzantines read and discussed the Greek novels over the centuries.

Sliding mode control for structures based on the frequency content of the earthquake loading

Nikos G. Pnevmatikos,Charis J. Gantes 국제구조공학회 2009 Smart Structures and Systems, An International Jou Vol.5 No.3

A control algorithm for seismic protection of building structures based on the theory of variable structural control or sliding mode control is presented. The paper focus in the design of sliding surface. A method for determining the sliding surface by pole assignment algorithm where the poles of the system in the sliding surface are obtained on-line, based on the frequency content of the incoming earthquake signal applied to the structure, is proposed. The proposed algorithm consists of the following steps: (i) On-line FFT process is applied to the incoming part of the signal and its frequency content is recognized. (ii) A transformation of the frequency content to the complex plane is performed and the desired location of poles of the controlled structure on the sliding surface is estimated. (iii) Based on the estimated poles the sliding surface is obtained. (iv) Then, the control force which will drive the response trajectory into the estimated sliding surface and force it to stay there all the subsequent time is obtained using Lyapunov stability theory. The above steps are repeated continuously for the entire duration of the incoming earthquake. The potential applications and the effectiveness of the improved control algorithm are demonstrated by numerical examples. The simulation results indicate that the response of a structure is reduced significantly compared to the response of the uncontrolled structure, while the required control demand is achievable.

The effects of construction practices on the seismic performance of RC frames with masonry infills

Nikos D. Lagaros,Martha A. Geraki 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

A number of construction practices, implemented during the design process of a reinforced concrete (RC) structural system, may have significant consequences on the behaviour of the structural system in the case of earthquake loading. Although a number of provisions are imposed by the contemporary Greek national design codes for the seismic design of RC structures, in order to reduce the consequences, the influence of the construction practices on the seismic behaviour of the structural system remains significant. The objective of this work is to perform a comparative study in order to examine the influence of three, often encountered, construction practices namely weak ground storey, short and floating columns and two combinations on the seismic performance of the structural system with respect to the structural capacity and the maximum interstorey drifts in three earthquake hazard levels.

Internationalization in Tertiary Education: Intra-European Students Mobility

( Nikos P Rachaniotis ),( Filareti Kotsi ),( George M Agiomirgianakis ) 세종대학교 경제통합연구소 2013 Journal of Economic Integration Vol.28 No.3

The enhanced internationalization and mobility of European students reflects an undoubtedly important aspect of human capital investment. This paper examines the internationalization of European students in tertiary education and the factors that determine the probability of a student moving to a European country other than their own. The main goals of the Bologna Process and a framework of definitions of student mobility are presented, as well as factors that may motivate and hamper this process. A linear regression model of the market shares of intra- European students and a linear regression model of the ratios of foreign incoming/outgoing students of European countries are estimated. Finally, a Classification and Regression Tree (CART) algorithm is applied in order to explain the reasoning behind the decisions of students for long-term study abroad. The paper suggests that policy measures towards increasing student mobility flows will extend economic integration of the countries involved via human capital development and are most likely to increase present and future economic flows in a tangible way.

Influence of time delay and saturation capacity to the response of controlled structures under earthquake excitations

Nikos G. Pnevmatikos,Charis J. Gantes 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.8 No.5

During the last thirty years many structural control concepts have been proposed for the reduction of the structural response caused by earthquake excitations. Their research and implementation in practice have shown that seismic control of structures has a lot of potential but also many limitations. In this paper the importance of two practical issues, time delay and saturation effect, on the performance of controlled structures, is discussed. Their influence, both separately and in interaction, on the response of structures controlled by a modified pole placement algorithm is investigated. Characteristic buildings controlled by this algorithm and subjected to dynamic loads, such as harmonic signals and actual seismic events, are analyzed for a range of levels of time delay and saturation capacity of the control devices. The response reduction surfaces for the combined influence of time delay and force saturation of the controlled buildings are obtained. Conclusions regarding the choice of the control system and the desired properties of the control devices are drawn.

Validity and Reliability of the Greek Version of the Multiple Sclerosis International Quality-of-Life Questionnaire

Nikos Triantafyllou,Aris Triantafillou,Georgios Tsivgoulis 대한신경과학회 2009 Journal of Clinical Neurology Vol.5 No.4

Background and Purpose There are no data regarding psychometrically validated, healthrelated quality-of-life instruments designed specifically for patients with multiple sclerosis (MS) in Greece. Recently, the MS International Quality-of-Life questionnaire (MusiQoL), a multidimensional, self-administered questionnaire, which is available in 14 languages (including Greek), has been validated using a large international sample. We investigated the validity and reliability of the Greek version of the MusiQoL. Methods Consecutive patients with different types and severities of MS were recruited from two tertiary-care centers in Greece. All patients completed the MusiQoL, the Short-Form-36 quality-of-life questionnaire (SF-36), and a symptom checklist at baseline and 21±7 days (mean± SD) later. Data regarding sociodemographic status, MS history, and functional outcome were also collected prospectively. Construct validity, internal consistency, reproducibility, and external consistency were tested. Results A total of 92 patients was evaluated. The construct validity was confirmed in terms of satisfactory item-internal consistency correlations and scaling success (87.5-100%) of itemdiscriminant validity. The dimensions of the MusiQoL exhibited high internal consistency (Cronbach’s alpha: 0.63-0.96), and reproducibility was satisfactory (intraclass correlation coefficients: 0.69-0.99). External validity testing indicated that the MusiQoL correlated significantly with all SF-36 dimension scores (Spearman’s correlation: 0.43-0.76). Conclusions The Greek version of the MusiQoL appears to be a valid and reliable instrument for measuring quality of life in Greek MS patients.

Capacity Performance Analysis of M-ary PPM TH-UWB Systems in the Presence of Narrowband Interference

Nikos V. Kokkalis,P. Takis Mathiopoulos,George K. Karagiannidis,Christos S. Koukourlis 한국통신학회 2008 Journal of communications and networks Vol.10 No.3

The capacity of ultra-wideband (UWB) systems in presence of narrowband interference (NBI) is studied. By appropriately modifying the Shannon capacity formula, an analytical expression for the capacity ofM-ary pulse position modulation (PPM) signals in the presence of NBI is obtained. Performance evaluation results for the capacity of such signals as a function of the NBI carrier frequency and power are also presented.

Managing Conflict and Organizational Change

( Nikos Bozionelos ) 한국행정학회 2003 Bulletins et mémoires de la Societe d'Anthropologi Vol.2003 No.-

Wavelet analysis based damage localization in steel frames with bolted connections

Nikos G. Pnevmatikos,Bartlomiej Blachowski,George D. Hatzigeorgiou,Andrzej Swiercz 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.18 No.6

This paper describes an application of wavelet analysis for damage detection of a steel frame structure with bolted connections. The wavelet coefficients of the acceleration response for the healthy and loosened connection structure were calculated at each measurement point. The difference of the wavelet coefficients of the response of the healthy and loosened connection structure is selected as an indicator of the damage. At each node of structure the norm of the difference of the wavelet coefficients matrix is then calculated. The point for which the norm has the higher value is a candidate for location of the damage. The above procedure was experimentally verified on a laboratory-scale 2-meter-long steel frame. The structure consists of 11 steel beams forming a four-bay frame, which is subjected to impact loads using a modal hammer. The accelerations are measured at 20 different locations on the frame, including joints and beam elements. Two states of the structure are considered: healthy and damaged one. The damage is introduced by means of loosening two out of three bolts at one of the frame connections. Calculating the norm of the difference of the wavelet coefficients matrix at each node the higher value was found to be at the same location where the bolts were loosened. The presented experiment showed the effectiveness of the wavelet approach to damage detection of frame structures assembled using bolted connections.

The effects of construction practices on the seismic performance of RC frames with masonry infills

Lagaros, Nikos D.,Geraki, Martha A. Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.1

A number of construction practices, implemented during the design process of a reinforced concrete (RC) structural system, may have significant consequences on the behaviour of the structural system in the case of earthquake loading. Although a number of provisions are imposed by the contemporary Greek national design codes for the seismic design of RC structures, in order to reduce the consequences, the influence of the construction practices on the seismic behaviour of the structural system remains significant. The objective of this work is to perform a comparative study in order to examine the influence of three, often encountered, construction practices namely weak ground storey, short and floating columns and two combinations on the seismic performance of the structural system with respect to the structural capacity and the maximum interstorey drifts in three earthquake hazard levels.