02337nas a2200193   4500008004100000245006000041210005900101300001500160520169800175100002101873700002201894700002701916700001701943700001901960700001501979700001801994700001702012856011402029       2000                        eng d00aEfficient Web-Based Open and Distance Learning Services0 aEfficient WebBased Open and Distance Learning Services  a 213 - 2373 aIn this paper, we present data management issues faced during the design and development
of an open distance learning system for the University of Patras, Greece. In order to handle
data e&#129;ciently, as required in a web tele-training application, for each type of information
maintained, di&#128;erent strategies must be deployed according to their behaviour and structure.
The diversity and complexity of data, the network aspect of the application and web de®-
ciencies impose an architecture design incorporating a plethora of technologies and tools that
must be integrated in such a fashion that they e&#129;ciently organise these data preserving their
relationships. This presents a software engineering challenge requiring coherence of solutions
at all levels: structures, consistency, security, models, and protocols. The paper presents the
data components of an open and distance learning (ODL) system that access the information
stored in a database and the ®le system, their underlying technology, their interaction with the
network services, and features regarding the ways they address issues faced in an open vendorindependent
distance learning environment and outlines the system's overall architecture. In
addition, this paper presents the architecture, the design and the services of a network-based
information system that supports open and distance learning activities. The open and distance
learning information system (ODLIS) o&#128;ers synchronous and asynchronous distance learning
and management of information system (MIS) services to support the educational procedure.
The ODLIS is a web-based application, which runs over the Internet using real time protocols.1 aBouras, Christos1 aGkamas, Apostolos1 aTsiatsos, Thrasivoulos1 aDestounis, P1 aGarofalakis, J1 aSakalis, G1 aSakopoulos, B1 aTsaknakis, J  uhttps://telematics.upatras.gr/telematics/publications/efficient-web-based-open-and-distance-learning-services01098nas a2200145   4500008004100000245007600041210006900117260002100186520055500207100002100762700001900783700001400802700001600816856012000832       2000                        eng d00aThe Performance of Simple Queueing Theoretic Video On Demand Algorithms0 aPerformance of Simple Queueing Theoretic Video On Demand Algorit  c14 - 17 February3 aVideo On Demand (VOD) Systems comprise an
emerging new technology, which is expected to
significantly affect everyday life. The implementation of
effective commercial VOD systems has to overcome some
technical limitations, such as the low bandwidth offered
by the existing communication channels. In our work we
present some simple queuing theoretic algorithms for the
optimal use of a limited number of communication
channels keeping a fair policy for the users requests. We
compare our algorithms with well-known algorithms, by
means of simulation.1 aBouras, Christos1 aGarofalakis, J1 aTzimas, J1 aPetridis, P  uhttps://telematics.upatras.gr/telematics/publications/performance-simple-queueing-theoretic-video-demand-algorithms01682nas a2200169   4500008004100000245008600041210006900127300001300196520105200209100002101261700002701282700001701309700001901326700001401345700001701359856013601376       1999                        eng d00aA Cooperative Environment for Local Government: An Internet – Intranet Approach0 aCooperative Environment for Local Government An Internet Intrane  a 75 - 893 a<p>In this paper we present a Web-based, database oriented CSCW system to support information dispersal between di€erent Local Government authorities (Region, Prefecture and Municipalities) and the citizens. The system is implemented around the `shared workspace' notion, a group of directories and ®les controlled by the users of the workspace. Intranet and Extranet technologies are exploited to enable asynchronous and synchronous co-operation, manipulation of information from heterogeneous sources, security and easy administration, providing in parallel advanced communication facilities. We propose an innovative approach for the development of shared workspaces over WWW, based on state-of-the-art software platforms, integrating WWW and database technologies. The whole system was developed under a project funded by the Greek General Secretariat of Research and Technology and aims in the ecient distribution and management of information between and within di€erent types of local authorities (Municipalities, Prefectures).</p>
1 aBouras, Christos1 aTriantafillou, Vasilis1 aDestounis, P1 aGarofalakis, J1 aTzimas, J1 aZarafidis, P  uhttps://telematics.upatras.gr/telematics/publications/cooperative-environment-local-government-internet-%E2%80%93-intranet-approach01478nas a2200181   4500008004100000245006600041210006600107260001800173300001500191520086300206100002101069700002701090700001701117700001901134700001401153700001701167856011201184       1999                        eng d00aCooperative Information Systems over the Internet and the WWW0 aCooperative Information Systems over the Internet and the WWW  c25 - 28 April  a 232 - 2363 aIn this paper we present a WWW-based approach for the
development of a system supporting information sharing
within an organizational environment. The system developed
is exploiting Intranet and Extranet technologies enabling
asynchronous and synchronous cooperation, manipulation of
information from heterogeneous sources, security and easy
administration, providing in parallel advanced communication
facilities. We propose an innovative approach for the
development of shared workspaces over WWW, based on
state-of-the-art software platforms, integrating WWW and
database technologies. The whole system was developed
under a project funded by the Greek General Secretariat of
Research and Technology and aims in the efficient
distribution and management of information between and
within different types of local authorities (Municipalities,
Prefectures).1 aBouras, Christos1 aTriantafillou, Vasilis1 aDestounis, P1 aGarofalakis, J1 aTzimas, J1 aZarafidis, P  uhttps://telematics.upatras.gr/telematics/publications/cooperative-information-systems-over-internet-and-www01862nas a2200193   4500008004100000245006400041210006400105260002000169520120800189100002101397700002201418700002701440700001701467700001901484700001501503700001801518700001701536856011501553       1999                        eng d00aEfficient Data Management to support Educational Activities0 aEfficient Data Management to support Educational Activities  c7 - 8 September3 aIn this paper we present data management issues faced during the design and
development of an Open Distance Learning system for the University of Patras,
Greece. In order to handle data efficiently, as required in a Web Tele-training
Application, for each type of information maintained different strategies must be
deployed according to their behaviourand structure.
The diversity and complexity of data, the network aspect of the application and web
deficiencies impose an architecture design incorporating a plethora of technologies
and tools that must be integrated in such a fashion that they efficiently organise these
data preserving their relationships. This presents a software engineering challenge
requiring coherence of solutions at all levels: structures, consistency, security, models,
and protocols.
The paper presents the data components of a open and distance learning system that
access the information stored in a database and the file system, their underlying
technology, their interaction with the network services, and features regarding the
ways they address issues faced in a open vendor-independent distance learning
environment and outlines the system’s overall architecture.1 aBouras, Christos1 aGkamas, Apostolos1 aTsiatsos, Thrasivoulos1 aDestounis, P1 aGarofalakis, J1 aSakalis, G1 aSakopoulos, B1 aTsaknakis, J  uhttps://telematics.upatras.gr/telematics/publications/efficient-data-management-support-educational-activities01353nas a2200145   4500008004100000245012000041210006900161300001500230520073200245100002100977700001900998700002701017700001901044856014401063       1998                        eng d00aAnalytical Performance Models for Multistage Interconnection Networks with finite, infinite and zero length buffers0 aAnalytical Performance Models for Multistage Interconnection Net  a 169 - 1823 aMultistage Interconnection Networks (MINs) with crossbar switches have been used
to interconnect processors and memory modules in parallel multiprocessor systems.
They also play an increasingly important role in the development of ATM networks.
In this paper we analyze the general case of MINs, made of kxk switches with
finite, infinite or zero length buffers (unbuffered). The exact solution of the steady
state distribution of the first stage is derived for all cases. We use this to get an
approximation for the steady state distributions in the second stage and beyond. In
the case of unbuffered switches we reach the known exact solution for all the stages
of the MIN. Our results are validated by extensive simulations.1 aBouras, Christos1 aSpirakis, Paul1 aTriantafillou, Vasilis1 aGarofalakis, J  uhttps://telematics.upatras.gr/telematics/publications/analytical-performance-models-multistage-interconnection-networks-finite-infinite-and01226nas a2200181   4500008004100000245009800041210006900139260002000208300001500228520054100243100002100784700002700805700001700832700001900849700001400868700001700882856014500899       1998                        eng d00aAn Intranet and Internet based Information System for Administration and Information purposes0 aIntranet and Internet based Information System for Administratio  c29 - 30 October  a 211 - 2153 aThis work presents a system developed within a project funded by the Greek Government.
The system deals with the distribution of information and the exchange of documents within,
from and towards (region, municipalities, citizens, various groups etc.) the prefecture of
Corfu. It is exploiting Intranet and Extranet technologies in order to enable asynchronous
and synchronous cooperation, manipulation of information from heterogeneous sources,
security and easy administration, providing in parallel advanced communication facilities.1 aBouras, Christos1 aTriantafillou, Vasilis1 aDestounis, P1 aGarofalakis, J1 aTzimas, J1 aZarafidis, P  uhttps://telematics.upatras.gr/telematics/publications/intranet-and-internet-based-information-system-administration-and-information-purposes02190nas a2200193   4500008004100000245014800041210006900189300001300258520143500271100002101706700001901727700001501746700002201761700001901783700001501802700001401817700002001831856014501851       1998                        eng d00aResults and experience from the application of a common methodology for Users Requirements Specification in Distance Education using Telematics0 aResults and experience from the application of a common methodol  a 61 - 743 aThe cooperation of the Information and Communications Technologies (ICT) and the Educational communities, is
recognised as a necessity that must result in the adaptation and tuning of the education processes in terms of
pedagogical methodologies, school infrastructure, human resources development and organisational restructuring, in
order to efficiently absorb and utilize technological developments. The ICT community has to realize the significance
of the users’ needs, the difficulties of the intervention to an old and traditional process. And the need to view their
technology applications not only as a technical exercise. The initial phases of the TRENDS project, which are
described in this paper, resulted in an agreed common methodology for carrying out the necessary investigation of
the user needs in secondary education. This methodology, which was followed more or less in all participating
countries, produced answers to questions concerning the role of the educators and their basic training, their
familiarity with technology, education policies from a trans-European perspective, the content, forms and aims of
further training, the distance training of teachers in the use of new technologies, the motives, incentives and
organisational schemes for enhancing re-education, the needs of the educational environment and technology-based
training, the needs of the educators in practical didactic methods, etc.1 aBouras, Christos1 aSpirakis, Paul1 aLampsas, P1 aTsakarissianos, G1 aGarofalakis, J1 aAntonis, K1 aKastis, N1 aKontogiannis, S  uhttps://telematics.upatras.gr/telematics/publications/results-and-experience-application-common-methodology-users-requirements-specification01620nas a2200205   4500008004100000245010300041210006900144260001700213300001300230520089300243100002101136700001901157700001501176700002201191700001901213700001501232700001401247700002001261856013301281       1997                        eng d00aConclusions on the Analysis of User Requirements concerning the use of ICT in the Didactic Process0 aConclusions on the Analysis of User Requirements concerning the   c14 - 19 June  a 13 - 183 aThe co-operation of the Information and Communications Technologies (ICT)
and the Educational Society, is deemed necessary for the adaptation and tuning of the
didactic process in terms of pedagogical methodologies, school infrastructure, human
resources utilisation and organisational restructuring. The use of ICT in the classroom
should be viewed as a highly influencing tool that will support the educators’ effort for
interaction with their students, rather than as a technical exercise. The initial phases of the
TRENDS project, which are described in this paper, resulted in a widely accepted common
methodology, that complies with the international standards for determining the User
Requirements in the Secondary Education. The major results emerged from this survey are
presented here, as well as some common axes that deal with the application of ICT in the
didactic process.1 aBouras, Christos1 aSpirakis, Paul1 aLampsas, P1 aTsakarissianos, G1 aGarofalakis, J1 aAntonis, K1 aKastis, N1 aKontogiannis, S  uhttps://telematics.upatras.gr/telematics/publications/conclusions-analysis-user-requirements-concerning-use-ict-didactic-process01832nas a2200241   4500008004100000245010200041210006900143260001900212300001500231520099200246100002101238700001901259700002701278700001901305700001701324700001401341700001801355700001601373700002401389700001801413700001401431856014501445       1997                        eng d00aThe Design and Development of Advanced Network Services over the Patras University Campus Network0 aDesign and Development of Advanced Network Services over the Pat  c2 - 6 December  a 420 - 4273 aThis paper presents some results of the initial phases of a big internal
project running at the University of Patras. In this project - which is co-funded by the
European Union - our team is responsible for the development of the Advanced
Network Services over the Campus Network, which is being established during the
project. In the following chapters we first present the general perspective and the
architecture of the integrated system which offers the set of advanced services to the
University community. We then describe in detail the different services (WWW and
Intranet, On-line teletraining, Computer supported cooperative work, and Off-line
teletraining). A key characteristic of the system is the integration of existing
commercial tools, with tools that we are developing for the specific needs of the
foreseen users. It is evident that this system can be considered as a pilot project for
large and demanding user communities, as is the case with the University of Patras.1 aBouras, Christos1 aSpirakis, Paul1 aTriantafillou, Vasilis1 aGarofalakis, J1 aTsaknakis, J1 aTzimas, J1 aTsakalidis, A1 aAntoniou, I1 aKarageorgopoylos, D1 aBasiliadis, B1 aKappos, P  uhttps://telematics.upatras.gr/telematics/publications/design-and-development-advanced-network-services-over-patras-university-campus-network01284nas a2200157   4500008004100000245007200041210006900113260001900182300001600201520070300217100002100920700001900941700002700960700001900987856012001006       1997                        eng d00aA General Performance Model for Multistage Interconnection Networks0 aGeneral Performance Model for Multistage Interconnection Network  c25 - 29 August  a 993 - 10003 aMultistage Interconnection Networks (MINs) with crossbar
switches are used to interconnect processors and memory modules in
parallel multiprocessor systems. In this paper we analyze the general case
of MINs, made of kk switches with nite, innite or zero length buers
(unbuered). The exact solution of the steady state distribution of the
rst stage is derived for all cases. We use this to get an approximation
for the steady state distributions in the second stage and beyond. In the
case of unbuered switches we reach the known exact solution for all the
stages of the MIN. Our results are validated by extensive simulations.
Keywords: analytical models, queueing theory models, evaluation.1 aBouras, Christos1 aSpirakis, Paul1 aTriantafillou, Vasilis1 aGarofalakis, J  uhttps://telematics.upatras.gr/telematics/publications/general-performance-model-multistage-interconnection-networks00583nas a2200157   4500008004100000245007100041210006900112260001400181300001300195100002100208700001900229700001900248700002200267700001800289856011800307       1991                        eng d00aRECPHONE: A new environment for medical remote expert consultation0 aRECPHONE A new environment for medical remote expert consultatio  c2 -3 July  a 22 - 231 aBouras, Christos1 aSpirakis, Paul1 aGarofalakis, J1 aPapoutsopoulos, G1 aBasiroglou, P  uhttps://telematics.upatras.gr/telematics/publications/recphone-new-environment-medical-remote-expert-consultation00559nas a2200145   4500008004100000245006800041210006800109260001600177300001500193100002100208700001900229700002700248700001900275856011900294       1987                        eng d00aQueueing Delays in Buffered Multistage Interconnection Networks0 aQueueing Delays in Buffered Multistage Interconnection Networks  c11 - 14 May  a 111 - 1211 aBouras, Christos1 aSpirakis, Paul1 aTriantafillou, Vasilis1 aGarofalakis, J  uhttps://telematics.upatras.gr/telematics/publications/queueing-delays-buffered-multistage-interconnection-networks