Abstract: This paper presents ongoing work on using data mining clustering to support the evaluation of software
systems' maintainability. As input for our analysis we employ software measurement data extracted from
Java source code. We propose a two-steps clustering process which facilitates the assessment of a system's
maintainability at rst, and subsequently an in-cluster analysis in order to study the evolution of each
cluster as the system's versions pass by. The process is evaluated on Apache Geronimo, a J2EE 1.4 opensource Application Server. The evaluation involves analyzing several versions of this software system in
order to assess its evolution and maintainability over time. The paper concludes with directions for future
Abstract: This work proposes a methodology for source code quality and static behaviour evaluation of a software
system, based on the standard ISO/IEC-9126. It uses elements automatically derived from source code
enhanced with expert knowledge, in the form of quality characteristic rankings, allowing software
engineers to assign weights to source code attributes. It is flexible in terms of the set of metrics and
source code attributes employed, even in terms of the ISO/IEC-9126 characteristics to be assessed. We
applied the methodology to two case studies, involving five opensource and one proprietary system.
Results demonstrated that the methodology can capture software quality trends and express expert
perceptions concerning system quality in a quantitative and systematic manner
Abstract: The Greek School Network (GSN) is the nationwide network that connects all units of primary and secondary education in Greece. GSN offers a significant set of diverse services to more than 15.000 schools and administrative units, and more than 60.000 teachers, placing GSN second in infrastructure size nationwide. GSN has relied on the emerging power of opensourcesoftware to build cutting-edge services capable of covering internal administrative and monitoring needs, end user demands, and, foremost, modern pedagogical requirements for tools and services. GSN provides a wide set of advanced services, varying from web mail to virtual classrooms and synchronous/asynchronous tele-education. This paper presents an evaluation of GSN opensource services based on the opinions of users who use GSN for educational purposes, and on usage and traffic measurement statistics. The paper reaches the conclusion that opensourcesoftware provides a sound technological platform that meets the needs for cutting edge educational services deployment, and innovative, competitive software production for educational networks.
Abstract: The Greek School Network (GSN) is a closed nationwide
educational network that offers advanced telematic and
networking services to all primary/secondary education schools
and administration offices in Greece. The primary objective of
GSN is the provisioning of a network infrastructure for the interconnection
of school PC laboratories so that modern educational
methods and pedagogical models can be applied to the school
community. GSN has scaled in size, has reached maturity, and
is currently delivering a wide range of network and telematic
services to its users. The emerging power of open-sourcesoftware
provides a sound technological basis for building cutting-edge
services, capable of meeting internal administrative and monitoring
needs, and modern pedagogical requirements for tools and
services. The current paper presents an overview of GSN and an
evaluation of its services based on the opinions of its users, and on
service utilization and traffic measurement statistics. The paper
reaches the conclusion that open-source solutions provide a sound
technological platform that can cover, to a great extent, the needs
for advanced educational services of the school community.
Abstract: For the Internet of Things to ﬁnally become a reality, obstacles on different levels need to be overcome. This is especially true for the upcoming challenge of leaving the domain of technical experts and scientists. Devices need to connect to the Internet and be able to offer services. They have to announce and describe these services in machine understandable ways so that user-facing systems are able to ﬁnd and utilize them. They have to learn about their physical surroundings, so that they can serve sensing or acting purposes without explicit conﬁguration or programming. Finally, it must be possible to include IoT devices in complex systems that combine local and remote data, from different sources, in novel and surprising ways.
We show how all of that is possible today. Our solution uses open standards and state-of-the art protocols to achieve this. It is based on 6LowPAN and CoAP for the communications part, semantic web technologies for meaningful data exchange, autonomous sensor correlation to learn about the environment, and software built around the Linked Data principles to be open for novel and unforeseen applications.