Secure Precise Clock Synchronization for Interconnected Body Area Networks

Secure time synchronization is a paramount service for wireless sensor networks (WSNs) constituted by multiple interconnected body area networks (BANs). We propose a novel approach to securely and efficiently synchronize nodes at BAN level and/or WSN level. Each BAN develops its own notion of time. To this effect, the nodes of a BAN synchronize with their BAN controller node. Moreover, controller nodes of different BANs cooperate to agree on a WSN global and/or to transfer UTC time. To reduce the number of exchanged synchronization messages, we use an environmental-aware time prediction algorithm. The performance analysis in this paper shows that our approach exhibits very advanced security, accuracy, precision, and low-energy trade-off. For comparable precision, our proposal outstands related clock synchronization protocols in energy efficiency and risk of attacks. These results are based on computations

The use of HL7 as an interoperability framework in a regional healthcare system in Greece, Journal of Telecommunications and Information Technology, 2005, nr 4

The integration of information systems represents one of the most urgent priorities of a regional healthcare authority in order to meet its clinical, organizational and managerial needs. Current practice shows that the most promising approach to achieve a regional healthcare information system is to use a health level 7 (HL7) messagebased communication system implemented by an asynchronous common communication infrastructure between healthcare sites. The system is a complete and integrated information system at a regional level that comprises all types of healthcare levels, that includes interoperability issues, that covers most of the needed components, and that is able to work efficiently in a secure wide area network to ensure data privacy and confidentiality. Another important feature of the proposed solution is that it creates an interoperability framework that can be replicated from one healthcare institution to another. In that sense, common interoperability messages can be used to interconnect heterogeneous information systems. In response to this strategy, more than 10 different consortiums have submitted proposals to the Greek government and the proposed interoperability framework seems to be widely accepted as a solution to enhance information and communication technologies developments in the healthcare sector in Greece

A roadmap towards healthcare information systems interoperability in Greece, Journal of Telecommunications and Information Technology, 2006, nr 2

The advantages of the introduction of information and communication technologies (ICT) in the complex healthcare sector are already well known and well stated in the past. It is common knowledge that in order to install any type of information system in healthcare, six main groups of issues have to be dealt with: organizational and cultural matters related to healthcare, technological gap between healthcare professionals and information science experts, legal requirements on the confidentiality of personal data, of patient related data and on data privacy, industrial and market position of healthcare informatics and interoperability complexity, lack of vision and leadership of the health care managers and health authorities and user acceptability and usability of the proposed information systems. In order to meet these issues stated above, a special focus group (Z3) performed an assessment of the situation of healthcare informatics in Greece and of the main key points that would lead to success. In that sense it is now common knowledge that Greece is lagging information and communication technology progress in healthcare because almost none of the above mentioned issues were dealt with. This assessment is the result of the interaction of more than 150 decision makers, medical informaticians, healthcare practitioners and other individual involved in healthcare. As a conclusion, this focus group resulted in 4 major propositions that will lead to healthcare informatics introduction with better success chances: focus on terminologies and standards, focus on interoperability and information systems sustainability, focus on clear goals and system metrics that can create a healthcare performance management cockpit, and focus on people and what they have to say, by creating a e-health forum. These conclusions were taken into consideration by the Greek government and are incorporated the IASYS project, the national healthcare informatics framework for the next ten years

Bandwidth allocation in cooperative wireless networks: Buffer load analysis and fairness evaluation.

In modern cooperative wireless networks, the resource allocation is an issue of major significance. The cooperation of source and relay nodes in wireless networks towards improved performance and robustness requires the application of an efficient bandwidth sharing policy. Moreover, user requirements for multimedia content over wireless links necessitate the support of advanced Quality of Service (QoS) features. In this paper, a novel bandwidth allocation technique for cooperative wireless networks is proposed, which is able to satisfy the increased QoS requirements of network users taking into account both traffic priority and packet buffer load. The performance of the proposed scheme is examined by analyzing the impact of buffer load on bandwidth allocation. Moreover, fairness performance in resource sharing is also studied. The results obtained for the cooperative network scenario employed, are validated by simulations. Evidently, the improved performance achieved by the proposed technique indicates that it can be employed for efficient traffic differentiation. The flexible design architecture of the proposed technique indicates its capability to be integrated into Medium Access Control (MAC) protocols for cooperative wireless networks

Cost-effective health services for interactive lifestyle management: the PANACEIA-iTV and the e-Vital concepts, Journal of Telecommunications and Information Technology, 2005, nr 4

Information technology applications in medicine are rapidly expanding, and new methods and solutions are evolving since they are considered pivotal in the success of preventive medicine. In this paper two different concepts will be presented, the PANACEIA-iTV and the e-Vital concept. PANACEIA-iTV is a home care service provision system based on interactive TV technology and supported by the IST programme of the European Commission. The e-Vital service, supported by the eTEN programme of the European Commission, regards an integrated home care and telemonitoring service chain aimed at large sensitive parts of the European population, the "at-risk" citizens, who are usually patients with a stable medical condition that allow a near normal life but may suddenly deteriorate and put life at risk

Monitoring Quality-of-Life Parameters in Wearable Environments

The paper presents a new cross-layer bridge protocol between IEEE 802.15.4, IEEE 11073 and IEEE 802.11 for wearable-enabled health-data aggregation formations. The protocol addresses the new reality as imposed by the recent evolution of sensors and networking in situations where backbone infrastructure is experiencing congestion. We discuss real-life application scenarios of nimble-network formations. The main novelty of the proposed algorithm is that it defines presence as a new way of routing

NEWER MAGNETIC RESONANCE IMAGE RECONSTRUCTION ALGORITHMS: DIRECT CALCULATION OFTHE FULL T2 RELAXATION CURVES

ΟΙ ΑΛΓΟΡΙΘΜΟΙ ΠΟΥ ΠΕΡΙΓΡΑΦΟΝΤΑΙ ΣΤΗΝ ΠΑΡΟΥΣΑ ΕΡΓΑΣΙΑ ΣΥΜΒΑΛΛΟΥΝ ΣΤΗΝ ΑΣΦΑΛΕΣΤΕΡΗ, ΤΑΧΥΤΕΡΗ ΚΑΙ ΠΙΟ ΑΞΙΟΠΙΣΤΗ ΑΠΟΚΑΛΥΨΗ ΤΗΣ ΧΡΗΣΙΜΗΣ ΠΛΗΡΟΦΟΡΙΑΣ ΑΠΟ ΤΟ ΣΗΜΑΤΟΥ ΜΑΓΝΗΤΙΚΟΥ ΣΥΝΤΟΝΙΣΜΟΥ. ΑΥΤΟ ΕΞΕΤΑΖΕΤΑΙ ΑΠΟ ΘΕΩΡΗΤΙΚΗ ΣΚΟΠΙΑ, ΑΝΑΛΥΟΝΤΑΙΟΙ ΧΑΡΑΚΤΗΡΙΣΤΙΚΕΣ ΤΟΥ ΙΔΙΟΤΗΤΕΣ ΚΑΙ ΔΙΑΠΙΣΤΩΝΟΝΤΑΙ ΤΑ ΣΗΜΕΙΑ ΙΔΙΑΙΤΕΡΟΤΗΤΑΣΤΟΥ. ΥΠΟΛΟΓΙΖΕΤΑΙ Η ΣΥΝΑΡΤΗΣΗ ΧΡΟΝΙΚΗΣ ΑΥΤΟΣΥΣΧΕΤΙΣΗΣ ΑΥΤΟΥ, Η ΟΠΟΙΑ ΑΠΟΤΕΛΕΙ ΣΗΜΕΙΟ ΕΚΚΙΝΗΣΗΣ ΓΙΑ ΤΗΝ ΑΝΑΠΤΥΞΗ ΤΡΙΩΝ ΑΛΓΟΡΙΘΜΩΝ ΥΠΟΛΟΓΙΣΜΟΥ ΤΩΝ ΠΑΡΑΜΕΤΡΩΝ ΠΛΑΤΟΥΣ, ΔΙΑΦΟΡΕΤΙΚΗΣ ΕΦΑΡΜΟΓΗΣ Ο ΚΑΘΕΝΑΣ ΑΝΑΛΟΓΑ ΜΕ ΤΗ ΦΥΣΗ ΤΟΥ ΕΞΕΤΑΖΟΜΕΝΟΥ ΑΝΤΙΚΕΙΜΕΝΟΥ ΚΑΙ ΤΗ ΜΕΘΟΔΟ ΔΙΕΓΕΡΣΗΣ. ΟΡΙΖΕΤΑΙ Ο ΜΟΝΟΔΙΑΣΤΑΤΟΣ ΚΑΙ Ο ΠΟΛΥΔΙΑΣΤΑΤΟΣ ΜΕΤΑΣΧΗΜΑΤΙΣΜΟΣ ΓΡΑΜΜΙΚΗΣ ΜΕΤΑΤΟΠΙΣΗΣ ΣΤΟ ΧΡΟΝΟ. ΜΕ ΧΡΗΣΗ ΑΥΤΟΥ ΓΙΝΕΤΑΙ ΓΙΑ ΠΡΩΤΗ ΦΟΡΑ ΔΥΝΑΤΗ Η ΠΑΡΑΓΩΓΗ ΠΟΛΛΑΠΛΩΝ ΕΙΚΟΝΩΝ ΒΑΡΟΥΣ ΑΠΟ ΕΝΑ ΚΑΙ ΜΟΝΟΣΕΤ ΔΕΔΟΜΕΝΩΝ. ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΔΙΑΚΡΙΤΕΣ ΜΟΡΦΕΣ ΤΟΥ ΚΑΙ ΔΙΑΤΥΠΩΝΟΝΤΑΙ ΟΙ ΝΕΟΙ ΑΛΓΟΡΙΘΜΟΙ ΑΝΑΚΑΤΑΣΚΕΥΗΣ ΚΑΙ ΓΡΗΓΟΡΕΣ ΥΛΟΠΟΙΗΣΕΙΣ ΑΥΤΩΝ.THE ALGORITHMS PRESENTED IN THE PH.D. THESIS CONTRIBUTE TO THE SAFER, FASTER AND MORE RELIABLE DISCLOSURE OF THE USEFUL INFORMATION ENCODED WITHIN THE NUCLEAR MAGNETIC RESONANCE SIGNAL. THE LATTER IS ANALYSED THEORETICALLY TO CONFINE ITS CHARACTERISTIC PROPERTIES. ITS TEMPORAL AUTOCORRELATION FUNCTION IS EVALUATED. THE RESULT IS USED FOR THE DEVELOPMENT OF THREE NEW ALGORITHMS FOR AMPLITUDE ESTIMATION, EACH ONE OF THEM IS APPLIED TO DIFFERENT EXCITATION DATA.THE ONE DIMENSIONAL AND MULTIDIMENSIONAL LINEAR TIME SHIFTING TRANSFORM IS DEFINED. USING IT, MAKES POSSIBLE, FOR THE FIRST TIME, THE PRODUCTION OF MULTIPLE WEIGHTED IMAGES USING ONLY ONE DATA SET. THE DISCRETE TRANSFORMS ARE DEVELOPED AS WELL AS FAST REALISATIONS OF THEM

Secure Precise Clock Synchronization for Interconnected Body Area Networks

Secure time synchronization is a paramount service for wireless sensor networks (WSNs) constituted by multiple interconnected body area networks (BANs). We propose a novel approach to securely and efficiently synchronize nodes at BAN level and/or WSN level. Each BAN develops its own notion of time. To this effect, the nodes of a BAN synchronize with their BAN controller node. Moreover, controller nodes of different BANs cooperate to agree on a WSN global and/or to transfer UTC time. To reduce the number of exchanged synchronization messages, we use an environmental-aware time prediction algorithm. The performance analysis in this paper shows that our approach exhibits very advanced security, accuracy, precision, and low-energy trade-off. For comparable precision, our proposal outstands related clock synchronization protocols in energy efficiency and risk of attacks. These results are based on computations.</p