Andreas Papadakis

External service provision in telecommunications networks using open interfaces

The strict service provision model used in telecommunications is following new technological trends. The service provision architectures and the services characteristics of the Next Generation Networks are altered. Telecommunications networks can become open, allowing third parties to use their resources. This creates the prospect for the rapid and flexible provision of highly personalized services. Moreover, the business model is expanded, allowing members of the Information Technology society to enter into the telecommunication market. Considering the state of the art in the service provision architectures and the specifications of standardized open interfaces; we describe how existing telecommunication infrastructure can open its functionality to third party vendors in a secure and unified way. In addition, we propose an architectural object model for the implementation of advanced applications by external parties.

Introduction of DOT/MAT into a Broadband IN Architecture for Flexible Service Provision

Fast and effective provisioning of new services to end users is one of the key issues in modern telecommunication environments, such as the IN (Intelligent Network). The IN is, in principle, promoting the application of advanced Information Technologies (IT) to telecommunications in order to provide a flexible service platform. With the appearance of new software technologies like DOT (Distributed Object Technology) promoting transparent distribution of service intelligence, and MAT (Mobile Agent Technology) enabling flexible and dynamic service deployment, the IN architecture may be revised in order to meet the above requirements in face of an increasing number of IN-based services. This paper discusses the approach of the ACTS MARINE (AC340) project, where the above mentioned technologies are experimented in the framework of Intelligent Broadband Networks.

Parlay-based service provision in circuit- and packet-switched telecommunications networks

The spectrum of potential value added services over Internet telephony is wide, but the current service provision solutions are inadequate or proprietary. The nature of Internet differs significantly from that of circuit switched network, however, VoIP architectures can capitalize service control architectures in the PSTN world. We describe such an architecture based on the intelligent network and the Parlay, employing distributed objects and mobile agents as enabling technologies. This architecture has been implemented in the PSTN and the Internet and it has provided a framework for service provisioning, augmenting the space of supported services. Copyright

Simulation framework for adaptive overlay content caching

Current Internet architecture is challenged by the overwhelming multiplication of available content and the increasing requirements of the content delivery applications. Content Delivery Networks have been playing a catalytic role in content delivery solutions, replicating (caching) content at the edges of the network. In this paper, we investigate the role and the benefits of a more flexible and adaptive form of overlay content replication, considering changing conditions such as the popularity and the size of the content objects. We have designed and simulated a cache evaluator framework which considers the external varying conditions and can provide guidance on the operations of in - network caches.

Adaptive content caching simulation with visualization capabilities

Current Internet architecture is being challenged by the overwhelming multiplication of available content and the increasing requirements of the content delivery applications. Content Delivery Networks have been playing a catalytic role in content delivery solutions, replicating (caching) content at the edges of the network. In this paper, we have investigated the potential benefits offered by adaptability in overlay content replication, considering changing conditions such as the popularity and the size of the content objects and a system of collaborating content caches. Pursuing the understanding of the influence of these parameters we have designed and implemented a simulation framework, with enhanced visualization and parameterization capabilities, and performed a series of experiments, under varying conditions.

Promoting e-Gov Services: e-Document Interoperability across EU

The wide deployment of cross-border e-government services in EU has highlighted the interoperability problems caused by different solutions adopted by Member States. This paper focuses on one of those areas that form the interoperability puzzle: signed e-documents. It identifies interoperability issues related to secure e-document exchange, provides a survey of currently available e-documents and e-signatures standards and presents solutions proposed by various ongoing activities in EU, emphasizing on the one specified by the large scale pilot project SPOCS.

Teaching fundamentals of photovoltaic array performance with simulation tools

This paper presents a course module containing exercises based on simulation tools that can be used to efficiently educate Electrical and Electronic Engineering undergraduate students on the electrical behavior of solar cells and photovoltaic arrays. This module is taught as part of the “Alternative Energy Sources” course added to the curriculum of the Electrical and Electronic Engineering Educators Department of ASPETE in 2013. The concept is to offer our undergraduate students the opportunity to deeply understand the electrical behavior of solar cells and photovoltaics by virtually experimenting with individual solar cells and photovoltaic arrays creating their necessary models in the popular platform of MULTISIM (the simulator from National Instruments). This is important for the success of the learning process of this course, which is not accompanied with a real-world laboratory that would be expensive to implement.

Design of motion-tracking device for intuitive and safe human-robot physical interaction

During the last decade there is an ever increasing interest for human-robot and, in general, user-machine interaction schemes of low-complexity and high-accuracy. In this context, intuitive and user-friendly interfaces based on hand gestures and movements are particular important for everyday users (especially older ones) of service robotics applications. In this paper, we explore the use of Inertial Measurement Unit (IMU) in a versatile movement sensing device that can be used by an elderly person to tele-manipulate a robot arm that helps him/her to complete bathing tasks. We present tele-manipulation system requirements taking into account the required accuracy in motion tracking and the need to address the limited physical abilities of the targeted user. We also discuss the integration of the tele-manipulation component into the envisaged service robotics environment and present an approach for its realization. Preliminary results assessing the performance of the proposed motion tracking system are also presented.

How an open learning environment affects the motivation of secondary and higher education students

Technology mediated learning is very actively and widely researched, yet there are few studies on if and how open learning environments (OLEs) affect the motivation of students. It is very important to showcase not only the effect on different groups of students but on students in various educational levels. This paper is a report on the findings of a study conducted in parallel, using the same OLE, on the students of a postgraduate engineering course and on the lyceum students attending their mandatory secondary education curriculum. The students used the Student Diagnosis, Assistance, Evaluation System based on Artificial Intelligence (StuDiAsE), an open learning system for unattended student diagnosis, assistance and evaluation based on artificial intelligence. The report indicates that the use of the OLE has particularly beneficial effects on the performance of certain student groups.

Monitoring and tailoring the usage of network resources for smoothing the provision of interactive 3D services

The performance of next-generation interactive 3D networked applications and services depends upon the availability and proper usage of network resources. In this work we have designed and implemented a flexible and reliable mechanism for extracting quantitative information related to the availability of network resources in order to enhance the provision of distributed and resource-demanding 3D applications. Individually weighted metrics have been combined towards composite overlay node selection criteria. We have made the pragmatic assumption of minimal or no collaboration with the networking elements, relying on an end to end scenario. The network - based information is coupled with application dynamics, used for topology enhancement.