Hellenic Civil Aviation Authority

Ródos, Greece

Hellenic Civil Aviation Authority

Ródos, Greece

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Ouranos I.,Hellenic Civil Aviation Authority | Ouranos I.,Technological Educational Institute of Crete | Ogata K.,Japan Advanced Institute of Science and Technology | Stefaneas P.,National and Kapodistrian University of Athens
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

The Timed Observational Transition System (TOTS)/CafeOBJ method is a version of the OTS/CafeOBJ method for modeling, specification and verification of distributed systems and protocols with real time constraints. In this paper we report on a case study from the field of source authentication protocols, TESLA protocol, to show the application of the method to such complex systems. We prove that our model of the protocol satisfies that the receiver does not accept as authentic any message unless it was actually sent by the sender. To verify the property we have used several other invariants which include timing information. To our knowledge, this is the first time that the method has been applied to the formal analysis of such a complex protocol. © 2012 Springer-Verlag.


Grant
Agency: European Commission | Branch: H2020 | Program: IA | Phase: GALILEO-1-2015 | Award Amount: 2.30M | Year: 2016

Promoting EGNSS Operational Adoption in BLUEMED FAB BLUEGNSS proposal aims at promote innovation technologies to maximise the potential of the European GNSS and its adoption. The Consortium, led by ENAV, Italian Air Navigation Service Provider, sees the participation of the other BLUE MED FAB ANSPS partners, such as DCAC Cyprus, HCAA Greece, MATS Malta and is complemented by an industrial partner IDS (Italy) to promote a fully integrated approach. The primary objective of the BLUEGNSS Project is to develop European Global Navigation Satellite System (EGNSS) aeronautical applications in accordance with ICAO standards and in particular to design RNP approaches with all 3 minimas (LPV, LNAV/VNAV, LNAV), in selected airports in order to increase their accessibility and safety. The publication of the procedures on the national AIPs will allow the adoption of such technology by civil aviation, demonstrating safety, operational and economic benefits. Other objectives, linked to the primary one, are: Training procedure designers on the design and regular review of RNP APCH procedures; Disseminating EGNSS culture among BLUEMED partners; Implementing a regional EGNSS Monitoring Network and data recording capabilities in support of the validation of RNP APCH and of the introduction of Galileo for aeronautical applications. Design and validation of RNP APCH is a fundamental enabler for the exploitation of EGNSS in the aviation domain and to push forward its adoption in Europe. This is the first time in Europe that a RNP APCH implementation project is coordinated at FAB level. The advantage of such approach is that States that dont have enough experience on RNP APCH operational implementation will take benefit from inter FAB knowledge transfer. Furthermore the BLUEMED PBN Task Force framework will act as catalyst platform to spread knowledge among the area and beyond at whole EU level.


Koukourakis N.,Ruhr University Bochum | Abdelwahab T.,Ruhr University Bochum | Li M.Y.,Ruhr University Bochum | Hopfner H.,Ruhr University Bochum | And 5 more authors.
Optics Express | Year: 2011

We use photorefractive two-wave mixing for coherent amplification of the object beam in digital holographic recording. Both amplitude and phase reconstruction benefit from the prior amplification as they have an increased SNR. We experimentally verify that the amplification process does not affect the phase of the wavefield. This allows for digital holographic phase analysis after amplification. As the grating formation in photorefractive crystals is just driven by coherent light, the crystal works as a coherence gate. Thus the proposed combination allows for applying digital holography for imaging through scattering media, after the image bearing light is coherence gated and filtered out of scattered background. We show experimental proof-of principle results. © 2011 Optical Society of America.


Kontogiannis T.,Technical University of Crete | Malakis S.,Hellenic Civil Aviation Authority
Safety Science | Year: 2013

To meet the increasing air traffic volume, organizations seek better tools to assess the traffic handling capacity of air traffic control (ATC) systems. This effort requires a better understanding of how complex situations are related to controller strategies and how controllers intervene to maintain control. Recent empirical studies and reviews have shown that controllers cope with complexity by adapting priorities, managing their cognitive resources, and regulating their own performance. This study discusses the development of a behavioural marker system to evaluate and provide feedback on the strategies that controllers use to cope with complexity. An extensive literature review provided the basis for an initial classification of strategies for coping with complexity which was tested in an observational study for reliability. After three iterations of adaptation to the taxonomy, two independent raters were able to reach acceptable levels of reliability in classifying video segments of simulated traffic scenarios. A potential application of the study regards the design of refresher training enriched with the principles of error management and the assessment of new technologies and controller tools on the handling capacity of ATC systems. © 2013 Elsevier Ltd.


Ouranos I.,Hellenic Civil Aviation Authority | Stefaneas P.,National Technical University of Athens
Studies in Computational Intelligence | Year: 2014

We sketch some first steps towards the definition of a protocol algebra based on the framework of behavioural algebraic specification. Following the tradition of representing protocols as state machines, we use the notion of Observational Transition System to express them in an executable algebraic specification language such as CafeOBJ. This abstract approach allows defining several useful operators for protocol reasoning and proving properties of them using theorem proving techniques and CafeOBJ term rewriting machine. The proposed protocol algebra is inspired by the module algebra and the hierarchical object composition technique. © 2014 Springer International Publishing Switzerland.


Malakis S.,Hellenic Civil Aviation Authority | Kontogiannis T.,Technical University of Crete
International Journal of Aviation Psychology | Year: 2012

An observational field study was carried out to examine the degree that refresher training in air traffic control can account for the demands of real-world emergencies. The refresher-training exercises of 21 teams of en route controllers were observed and a number of real incidents were analyzed at a major European Area Control Centre. Expert controllers were observed handling 53 simulated emergencies and abnormal situations during their annual refresher training and their companion team resource management course. The training curriculum was found to be technically oriented. Responding to emergencies was practiced in scenarios less representative of real situations where the controllers do their job in the context of many interruptions, flight crew deviations, and unrecovered errors. Results indicated a substantial gap between formal training requirements and operational demands. An advanced safety training course is proposed on the basis of cognitive task analysis to increase the cognitive fidelity of simulations and focus on cultivating taskwork and teamwork skills. © 2012 Copyright Taylor and Francis Group, LLC.


Kontogiannis T.,Technical University of Crete | Malakis S.,Hellenic Civil Aviation Authority
Accident Analysis and Prevention | Year: 2012

A recursive model of accident investigation is proposed by exploiting earlier work in systems thinking. Safety analysts can understand better the underlying causes of decision or action flaws by probing into the patterns of breakdown in the organization of safety. For this deeper analysis, a cybernetic model of organizational factors and a control model of human processes have been integrated in this article (i.e.; the viable system model and the extended control model). The joint VSM-ECOM framework has been applied to a case study to help safety practitioners with the analysis of patterns of breakdown with regard to how operators and organizations manage goal conflicts, monitor work progress, recognize weak signals, align goals across teams, and adapt plans on the fly. The recursive accident representation brings together several organizational issues (e.g.; the dilemma of autonomy versus compliance, or the interaction between structure and strategy) and addresses how operators adapt to challenges in their environment by adjusting their modes of functioning and recovery. Finally, it facilitates the transfer of knowledge from diverse incidents and near misses within similar domains of practice. © 2012 Elsevier Ltd. All rights reserved.


The existing formulae for the elastic repulsions between equi-sized/equi-pressurized pores/holes are generalized to include any combination of hole surface tractions. This is done utilizing an exceptional case where superposition can be used for applied stresses and resultant strain energies. © 2013 by Begell House, Inc.


Kontogiannis T.,Technical University of Crete | Malakis S.,Hellenic Civil Aviation Authority
Cognition, Technology and Work | Year: 2013

The continued growth of civil aviation and the introduction of new air traffic management systems have increased the complexity of the system, hence requiring more adaptable patterns of control and coordination. There is a need to look deeper into the patterns of control, the transfer of control and coordination across boundaries or sectors and the adaptation to unexpected scenarios that may contribute to 'loss of control' events. To this end, this article elaborates on the extended control model (Hollnagel and Woods 2005) and complements a functional description of the air traffic control (ATC) system with several strategies required in 'being in control' of the joint cognitive system. Reviews of the literature, field studies and observations of performance in ATC have been used to model 'loss of control' events as problems in adapting control strategies in order to (1) maintain control of actions, (2) transfer control, (3) coordinate and (4) choose new modes of functioning and recovery when control breaks down. These control aspects are useful for debriefing controllers after critical events and identifying system performance flaws that can provide input to ergonomic interventions, such as the design of new air traffic management systems, decision aids and role allocation. © 2011 Springer-Verlag London Limited.


Kontogiannis T.,Technical University of Crete | Malakis S.,Hellenic Civil Aviation Authority
Reliability Engineering and System Safety | Year: 2012

In recent years, many accident models and techniques have shifted their focus from shortfalls in the actions of practitioners to systemic causes in the organization. Accident investigation techniques (e.g., STAMP) have been developed that looked into the flaws of control processes in the organization. Organizational models have looked into general patterns of breakdown related to structural vulnerabilities and gradual degradation of performance. Although some degree of cross-fertilization has been developed between these two trends, safety analysts are left on their own to integrate this gap between control flaws and patterns of organizational breakdown in accident investigation. This article attempts to elaborate the control dynamics of the Systems Theoretic Accident Model and Process (STAMP) technique on the basis of a theoretical model of organizational viability (i.e., the Viable Systems Model). The joint STAMPVSM framework is applied to an accident from a Helicopter Emergency Medical Service (HEMS) organization to help analysts progress from the analysis of control flaws to the underlying patterns of breakdown. The joint framework may help analysts to rethink the safety organization, model new information loops and constraints, look at the adaptation and steering functions of the organization and finally, develop high leverage interventions. © 2011 Elsevier Ltd All rights reserved.

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