47 research outputs found
Author Correction: RNAs coordinate nuclear envelope assembly and DNA replication through ELYS recruitment to chromatin
No full textIn the original version of this Article, the affiliation details for Antoine Aze, Michalis Fragkos, Stéphane Bocquet, Julien Cau and Marcel Méchali incorrectly omitted ‘CNRS and the University of Montpellier’. This has now been corrected in both the PDF and HTML versions of the Article.</jats:p
An event-trace language for software decoys
No full textCyberspace is becoming the battlespace of the future, and military practices, like deception, seem to be suitable for defending information systems from attacks. In this thesis, we explore the concept of intelligent software decoys, which employ a form of software-based military deception. We developed a prototype of a high-level language for specifying intelligent software decoys. Our approach involves two stages. The specification language is intended to be part of a high-level user interface, making the implementation details of software decoys transparent to the information warrior. We provide a case study in which we demonstrate the utility of our specification language for specifying software decoys to counter a real-word attack program.Approved for public release; distribution is unlimited.Captain, Hellenic Armyhttp://archive.org/details/aneventtracelang10945526
Artificial Intelligence Enabled Distributed Edge Computing for Internet of Things Applications
No full textArtificial Intelligence (AI) based techniques are typically used to model decision-making in terms of strategies and mechanisms that can conclude to optimal payoffs for a number of interacting entities, often presenting competitive behaviors. In this thesis, an AI-enabled multi-access edge computing (MEC) framework is proposed, supported by computing-equipped Unmanned Aerial Vehicles (UAVs) to facilitate Internet of Things (IoT) applications. Initially, the problem of determining the IoT nodes optimal data offloading strategies to the UAV-mounted MEC servers, while accounting for the IoT nodes’ communication and computation overhead, is formulated based on a game-theoretic model. The existence of at least one Pure Nash Equilibrium (PNE) point is shown by proving that the game is submodular. Furthermore, different operation points (i.e., offloading strategies) are obtained and studied, based either on the outcome of Best Response Dynamics (BRD) algorithm, or via alternative reinforcement learning approaches, such as gradient ascent, log-linear and Q-learning algorithms, which explore and learn the environment towards determining the users’ stable data offloading strategies. The respective outcomes and inherent features of these approaches are critically compared against each other, via modeling and simulation
Autonomous Decision-Making in Interdependent Computing Systems based on Artificial Intelligence
No full textWith the advent of Artificial Intelligence (AI), the notion of autonomy, in terms of acting and thinking based on personal experience and judgment, has paved the way towards an autonomous decision-making future. This future can address the complex domain of the interdependent computing systems, whose main challenge is that they interact with each other with unpredictable and often unstable outcomes. It is crucial to envision and design this AI-driven autonomy for the reciprocal computing systems which cover a variety of use-cases ranging from the Internet of Things (IoT) to cybersecurity. This can be achieved by cloning the human decision-making process, which imposes that before humans decide how to act, they sense their unknown and stochastic environment, perform actions, and finally assess their perceived feedback. The feedback is subjectively evaluated as satisfactory or not by each human based on her personal behavioral profile and reasoning. The repetitive iteration of the aforementioned steps constitutes the learning process of humans. Consequently, the core idea is to inject human cognizance into the interdependent computing systems to transform them into AI-enabled decision-making agents who mimic the rational behavioral attributes of humans and optimize their subjective criteria autonomously. The rapid growth of interdependent computing systems, such as Unmanned Aerial Vehicles (UAVs) or Multi-Access Edge Computing servers (MEC), results in huge amounts of data and strict Quality of Service (QoS) requirements. When these systems act in an autonomous manner, they reveal a competitive behavior since each system aims at optimizing its own subjective criteria selfishly. This introduces the concept of interactive decision-making in non-cooperative environments, where the feedback for each system depends on the potentially conflicting actions of the rest. Therefore, we utilize Game Theory to efficiently capture these strategic interactions among the interdependent computing systems within the non-cooperative environments and prove that there exist solutions, i.e., stable Equilibrium points. The Equilibrium points are considered stable solutions because each system does not have a strategic incentive to change its own action unilaterally. To determine these Equilibria in a distributed manner we deploy Reinforcement Learning (RL), which enables the autonomous interdependent computing systems to be intelligent and learn in a stochastic environment by trial and error using the feedback from their own actions and experiences. Furthermore, the traditional RL methodology is enriched with the technique of reward reshaping to consider the Labor Economics-like arrangements among the autonomous interdependent computing systems via Contract Theory as well as their behavioral profiles via a Bayesian belief model. The concurrent utilization of Game Theory and Reinforcement Learning with reward reshaping is a step towards Self-Aware Artificial Intelligence (SAAI). We prove that it has a great potential to be the main component for building autonomous decision-making interdependent computing systems based on AI and can be effectively utilized in various application domains
Τα χαρακτηριστικά της συμμετοχής των ελληνικών επιχειρήσεων, πανεπιστημίων, ερευνητικών ιδρυμάτων και άλλων οργανισμών στα ευρωπαϊκά ανταγωνιστικά ερευνητικά προγράμματα
No full textSpace Entropy: Emergent narrative through systemic game design
No full textThis thesis explored emergent narrative techniques in game design and attempted to explain what is needed to create the potential for emergence in a game. Emergent narrative refers to stories that arise organically from player interaction with the game’s systems rather than being pre-scripted. Literature review and research showed many different ways in which unique narrative can emerge from systems in all kinds of games and research prototypes. Based on collected information from previous work on the topic, we developed our own prototype game, named Space Entropy, to test narrative emergence through systemic design with users in a first-person, sandbox game in a Sci-Fi setting. In this prototype, we utilized some of the techniques that we found most appropriate for our case. From the quantitative and qualitative data gathered from the playtests, we were able to establish the validity of the prototype as well as identify its weaknesses. Finally, our findings led us to formulate a set of guidelines aimed at other developers or teams that want to achieve unexpected, emergent narrative without explicitly designing for it
Hacking Distributed Energy Resource Power Plant Infrastructure Using Reinforcement Learning
No full textAdvancements in Artificial Intelligence (AI) are enabling adversaries to more efficiently penetrate and navigate networks, posing new risks to critical infrastructure such as the electric power grid. This study evaluates three attack strategies—AI-based, Brute-Force, and Random—within the Network Attack Simulator (NASim), a synthetic environment designed for cybersecurity testing. The AI-based methods include Deep Q-Network (DQN) and Deep State-Action-Reward-State-Action (SARSA) reinforcement learning algorithms. Training results show that both AI approaches effectively learn to conduct subnet scans, service/process scans, and privilege escalation attacks to gain root access. During testing, AI agents completed their objectives in fewer than 28 actions, while Brute-Force and Random methods required over 200 actions. These findings demonstrate AI’s efficiency and potential to automate the launch of cyberattacks targeting Distributed Energy Resources (DERs), offering a baseline for future research targeting real-world networks
Ανάπτυξη κατανεμημένων πρωτοκόλλων συναίνεσης και Blockchain με χρήση βάσης δεδομένων γράφου
No full textRadial approach in mechanical thrombectomy procedures
No full textΒιβλιογραφία : σ. 38 - 47Η μηχανική θρομβεκτομή αποτελεί σήμερα τη θεραπεία εκλογής του οξέος ισχαιμικού εγκεφαλικού επεισοδίου. Η ταχεία επέμβαση σχετίζεται θετικά με την κλινική έκβαση των ασθενών. Η ανάγκη αντιμετώπισης των περιστατικών, στα οποία ο καθετηριασμός των μεγάλων αγγείων του τραχήλου είναι τεχνικά δυσχερής οδήγησε στη διενέργεια μελετών της διακερκιδικής αντιμετώπισης. Σκοπός της παρούσας συστηματικής ανασκόπησης είναι η παρουσίαση και ανάλυση τους. Μετά από βιβλιογραφική αναζήτηση και χρήση του διαγράμματος ροής Prisma, ανευρέθηκαν δώδεκα μελέτες οι οποίες ταξινομήθηκαν σε τρεις κατηγορίες προκειμένου να γίνει καλύτερη διερεύνηση. Στην πρώτη κατηγορία εντάχθηκαν αυτές που παρουσιάζουν μηχανικές θρομβεκτομές τόσο της πρόσθιας όσο και της οπίσθιας κυκλοφορίας και συμπεριλαμβάνουν περιστατικά, στα οποία ενώ αρχικά επιλέχθηκε η μηριαία παρακέντηση, στη συνέχεια εξαιτίας της αδυναμίας προσπέλασης προτιμήθηκε η κερκιδική. Στη δεύτερη κατηγορία εντάχθηκαν αποκλειστικά επεμβάσεις της οπίσθιας κυκλοφορίας. Αμφότερες ανέδειξαν την διακερκιδική προσπέλαση ως τεχνικά εφικτή και ασφαλή μέθοδο. Συγκριτικές μελέτες της τρίτης κατηγορίας μεταξύ των δύο σημείων παρακέντησης, αν και είχαν μεγαλύτερο δείγμα ασθενών, κατέληξαν σε ετερογενή αποτελέσματα ή στατιστικά μη σημαντικές διαφορές, με μόνη εξαίρεση τις επιπλοκές που σχετίζονται με το σημείο παρακέντησης που ήταν σταθερά λιγότερες στην διακερκιδική αντιμετώπιση σε όλες τις μελέτες και στατιστικά σημαντική σε μία από αυτές. Η σημασία της μηχανικής θρομβεκτομής στην αντιμετώπιση του οξέος ισχαιμικού εγκεφαλικού επεισοδίου και η ανάγκη αναζήτησης μεθόδων βελτιστοποίησης της τεχνικής και αύξησης της αποτελεσματικότητας καθιστούν απαραίτητη την ανεύρεση εναλλακτικών τρόπων παρακέντησης πέρα της κοινής μηριαίας αρτηρίας. Η διενέργεια τυχαιοποιημένων κλινικών δοκιμών είναι ο ενδεδειγμένος τρόπος για την επιβεβαίωση της αξίας της κερκιδικής προσπέλασης και τον καθορισμό των ενδείξεων εφαρμογής της στην αντιμετώπιση του οξέος ισχαιμικού εγκεφαλικού επεισοδίου.Mechanical thrombectomy is currently the treatment of choice for acute ischemic stroke. Rapid intervention is positively associated with clinical outcome. The need to deal with cases in which the catheterization of the great vessels of the neck is technically difficult led to studies of transradial treatment. The purpose of this systematic review is the presentation and analysis of those studies.
Following literature search and Prisma flow chart, twelve studies were found and then they were classified into three categories for better investigation. The first category included mechanical thrombectomies of both anterior and posterior circulation and cases in which, while the femoral puncture was initially chosen, then, due to lack of access, the radial puncture was preferred. The second category included exclusively operations of the posterior circulation. Both highlighted transradial approach as a technically feasible and secure method. Third category included comparative studies which, despite larger sample of patients, resulted in heterogeneous results or statistically non-significant differences, with the only exception of puncture site-related complications which were consistently fewer in transradial puncture in all studies and statistically significant in one of them. The importance of mechanical thrombectomy in treatment of acute ischemic stroke and the need to search for methods to optimize the technique and increase its efficiency make it necessary to find alternative ways of puncture beyond common femoral artery. Conducting randomized clinical trials is the appropriate way to confirm the value of radial access and to define its indications in management of acute ischemic stroke.48 σ
EU Development Aid towards Sub-Saharan Africa: Exploring the Normative Principle
No full textThe EU and most aid donors invoke a strong normative power face by explicitly connecting foreign aid with human and social development. However, how well the EU’s rhetoric is consistent with its practices as a multilateral development actor has not been explored extensively. In this study, we challenge the normative dimension of the EU’s development policy and explore whether the EU’s Official Development Assistance to Sub-Saharan Africa is based on objective deprivation on the part of recipient countries or whether it is “interest driven”. We use a least squares dummy variable model regression to examine aid flows from the EU to all 48 Sub-Saharan African states for the period 2000 to 2010. The evidence found indicates that in certain instances, aid allocation contradicts the normative rhetoric that the EU uses to describe its development policy, as the donor’s own interests in the region seem to supersede priority given to the needs of the aid recipient states. A limitation to the findings is the fact that normative values and strategic interests are not mutually exclusive. Nevertheless, the present study suggests that the EU’s portrayal as a force for good in international relations requires cautious critique
