Ανάπτυξη διαλογικού πράκτορα γιαυποβοήθηση της επεξήγησης τεχνικών µηχανικής µάθησης

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) "Επιστήμη Δεδομένων και Μηχανική Μάθηση

Defense Implementation for Website Fingerprinting Attacks on Nginx Web Server

Η επίθεση Website Fingerprinting δίνει σε κάποιον παθητικό επιτιθέμενο την δυνατότητα να ξέρει ποιους ιστοτόπους επισκέπτεται κάποιος πελάτης, ακόμα και όταν τα πακέτα που ανταλλάσσονται μεταξύ του πελάτη και του ιστοτόπου είναι κρυπτογραφημένα. Αυτό είναι δυνατό μέσω της ανάλυσης της διαδικτυακής κίνησης μεταξύ αυτών των δύο, και της εξαγωγής μοτίβων δικτύου που είναι μοναδικά για κάθε ιστότοπο. Για αυτό το είδος επίθεσης, υλοποιούμε μια άμυνα επιπέδου εφαρμογής που ονομάζεται ALPaCA (Application Layer Padding Concerns Adversaries), όπως προτάθηκε από τους Giovanni Cherubin, Jamie Hayes, και Marc Juarez. Υλοποιούμε το ALPaCA σαν βιβλιοθήκη της Rust και αναπτύσσουμε ένα module του web server Nginx το οποίο χρησιμοποιεί το ALPaCA για να προστατεύσει τους ιστοτόπους για τους οποίους είναι ενεργοποιημένο. Στην πτυχιακή αυτή, υλοποιούμε την πρώτη άμυνα για Website Fingerprinting επιθέσεις που μπορεί να χρησιμοποιηθεί σε web server. Ο σκοπός της άμυνας είναι να μειώσει την ακρίβεια πρόβλεψης του επιτιθέμενου όσο αφορά τον ιστότοπο που επισκέπτεται ο πελάτης, τροποποιώντας την διαδικτυακή κίνηση, και συγκεκριμένα τα πακέτα από τον server του ιστότοπου προς τον πελάτη. Ο κώδικας της πτυχιακής βρίσκεται στους ακόλουθους συνδέσμους: https://github.com/PanosKokk/ngx_http_alpaca_module https://github.com/PanosKokk/libalpacaWebsite Fingerprinting attack gives a passive adversary the ability to know which sites a client visits, even when the packages that are being exchanged between the client and the site are encrypted. This is possible by analyzing the network traffic between those two, and extracting network patterns that are unique to each site. For this kind of attacks, we implement an application-level defense called ALPaCA (Application Layer Padding Concerns Adversaries), as proposed by Giovanni Cherubin, Jamie Hayes, and Marc Juarez. We implement ALPaCA as a Rust library, and develop an Nginx module which uses ALPaCA to protect the sites for which it is enabled. In this thesis, we implement the first Website fingerprinting defense which can be used on a web server. The defense’s purpose is to lower the adversary’s predictive accuracy as of which site the client visits, by altering the network traffic, and specifically the packages from the site’s server towards the client. The code of this thesis can be found at the following links: https://github.com/PanosKokk/ngx_http_alpaca_module https://github.com/PanosKokk/libalpac

From Understanding to Use and Compete: A translational Platform for Business Transformation

This article discusses a translational cycle and a translational platform which have been designed in the context of the FutureEnterprise project, a European Commission funded support action. One of the main strategic axes of the FutureEnterprise project is related to a specific focus on translational research activities, aiming to bridge academic and industrial research with Internet-based entrepreneurship and digital business innovation. The term ‘translational research’ appeared in Pubmed illustrates, for the first time around 1993 to identify the “translational gaps’’, hindering the transformation of discoveries in the life sciences into improvements having societal profit from basic research. As for the management research, translational issues have been pointed out as relevant and critical factors within Academy of Management (AOM) research community, identifying two types of translational challenges for an effective impact of management research on practice: a “lost in translation” (fail to find the right way to transfer research results in the practitioners language, understanding, and needs) and “lost before translation” (fail to identify an appropriate and systematic translation process as the one leading from “bench to bedside” in life sciences ). The contribution presented in this article aims to face the challenges of ‘translational research’ in the context of technology management and innovation from a design science stance, thus identifying key constructs further developed through a translational platform which represents the resulting IT artifact (existing MOOC) from a “tool view”

Social Analytics in an Enterprise Context: From Manufacturing to Software Development

Although customers become more and more vocal in expressing their experiences, demands and needs in various social networks, companies of any size typically fail to effectively gain insights from such social data and to eventually catch the market realm. This paper introduces the Anlzer analytics engine that aims at leveraging the "social" data deluge to help companies in their quest for deeper understanding of their products' perceptions as well as of the emerging trends in order to early embed them into their product design phase. The proposed approach brings together polarity detection and trend analysis techniques as presented in the architecture and demonstrated through a simple walkthrough in the Anlzer solution. The Anlzer implementation is by design domain-independent and is being tested in the furniture domain at the moment, yet it brings significant added value to software design and development, as well, through its experimentation playground that may provide indirect feedback on future software features while monitoring the reactions to existing releases

Exploiting the social web in the policy cycle

The thematic area of the PhD dissertation at hand is the in-depth study of the way and the extent to which the social web, along with the phenomena that accompany it and the tools and technologies related to its exploitation and analysis can contribute to the policy cycle.As far as the contribution of the dissertation is concerned, a study on whether tools and/ or techniques that have an applied in the scientific area of artificial intelligence can contribute to the exploitation of the very large volume of (structured and unstructured) information available in the social web, towards serving the needs of the different phases of the policy cycle. In particular, the dissertation focuses on:•The potential contribution of argumentation techniques, so that the stakeholders can effectively and efficiently exploit the ""wisdom of the crowd"" for the needs of the policy cycle.•The potential contribution of causal models, mainly focusing on fuzzy cognitive maps, in order to take advantage of existing information and existing data towards both reasoning on the outcomes of past policies, as well as being able to predict the potential impact of future initiatives.Towards testing and validating the dissertation’s proposals/ hypotheses regarding argumentation techniques, five (5) carefully selected unstructured dialogues from the Greek social web were analyzed, leading to valuable conclusions on both the techniques to be applied so that the analyst can effectively and efficiently exploit unstructured dialogues, as well as on the way unstructured dialogue takes place in the Greek social web in general.Towards testing and validating the proposals/ hypotheses regarding causal models, three (3) alternative scenarios on the Greek economy were designed and run, leading to valuable conclusions in relation to the suitability of fuzzy cognitive maps (as well as causal models in general) in the policy cycle.In addition, the dissertation aims to contribute to the cornerstone of not just policies, but also of any initiative towards creating added value: requirements. Therefore, a framework consisting of a set of ten (10) requirements that can guide conception, design and implementation of policies is presented.Θεματική περιοχή της παρούσας διδακτορικής διατριβής αποτελεί η εις βάθος μελέτη του τρόπου και του βαθμού στον οποίο ο κοινωνικός ιστός, τα φαινόμενα που τον συνοδεύουν καθώς και τα εργαλεία και οι τεχνολογίες που σχετίζονται με την εκμετάλλευση και ανάλυσή του συμβάλλουν στον κύκλο ζωής των πολιτικών. Όσον αφορά στη συμβολή της διατριβής, μελετάται κατά πόσο ευφυείς τεχνικές που έχουν εφαρμοσμένο χαρακτήρα στην περιοχή της τεχνητής νοημοσύνης μπορούν να συμβάλουν στην εκμετάλλευση του ιδιαίτερα μεγάλου όγκου (δομημένης και αδόμητης) πληροφορίας που υπάρχει στον κοινωνικό ιστό για τις ανάγκες των διαφόρων φάσεων του κύκλου ζωής των πολιτικών. Συγκεκριμένα, η διατριβή εστιάζει: •Στη συμβολή τεχνικών δομημένης επιχειρηματολογίας, ώστε ο ενδιαφερόμενος να μπορεί να εκμεταλλευτεί αποτελεσματικά και αποδοτικά τη «βουή του πλήθους», για τις ανάγκες των πολιτικών. •Στη συμβολή μοντέλων αιτιότητας, εστιάζοντας στα ασαφή γνωστικά δίκτυα, ώστε εκμεταλλευόμενος υπάρχουσα πληροφορία και υπάρχοντα δεδομένα να δύναται κατ’ αρχάς να εξηγήσει τα αποτελέσματα παρελθοντικών πολιτικών και στη συνέχεια να μπορεί να προβλέψει τον (πιθανό) αντίκτυπο που θα έχουν πολιτικές υπό σχεδιασμό. Για τη δοκιμή και επικύρωση των προτάσεων/ υποθέσεων της διατριβής αναφορικά με τις τεχνικές δομημένης επιχειρηματολογίας, πέντε (5) προσεκτικά επιλεγμένοι αδόμητοι διάλογοι από τον ελληνικό κοινωνικό ιστό αναλύθηκαν, οδηγώντας σε πολύτιμα συμπεράσματα τόσο για τις τεχνικές που θα πρέπει να εφαρμοστούν ώστε ο αναλυτής να μπορεί να αξιοποιήσει αποδοτικά και αποτελεσματικά τον αδόμητο διάλογο για τις ανάγκες του κύκλου ζωής πολιτικών, όσο και για τον τρόπο που ο αδόμητος διάλογος πραγματοποιείται στον ελληνικό κοινωνικό ιστό γενικότερα. Για τη δοκιμή και επικύρωση των προτάσεων/ υποθέσεων της διατριβής αναφορικά με τα μοντέλα αιτιότητας, τρία εναλλακτικά σενάρια επάνω στην ελληνική οικονομία σχεδιάστηκαν και εκτελέστηκαν, οδηγώντας σε πολύτιμα συμπεράσματα για την καταλληλότητα των ασαφών γνωστικών δικτύων (αλλά και των μοντέλων αιτιότητας εν γένει) στον κύκλο ζωής πολιτικών. Επιπρόσθετα, η διατριβή στοχεύει στο να συμβάλλει ουσιαστικά και στο θεμέλιο λίθο, όχι μόνο των πολιτικών, αλλά και κάθε προσπάθειας που στοχεύει στο να δημιουργήσει κάτι νέο προς ένα συγκεκριμένο κοινό: τις απαιτήσεις. Παρουσιάζεται, λοιπόν, ένα πλαίσιο δέκα (10) απαιτήσεων το οποίο μπορεί να καθοδηγήσει τη σύλληψη, το σχεδιασμό και την υλοποίηση των πολιτικών

Technical-economical analysis of chp plant in a hotel

94 σ.Μελετήθηκε η εγκατάσταση μονάδας συμπαραγωγής ως επένδυση σε ξενοδοχειακό συγκρότημα από εταιρεία παροχής ενεργειακών υπηρεσιών και έγινε ανάλυση ευαισθησίας ως προς οικονομικές παραμέτρουςA technical and economical analysis for a CHP plant installed in a hotel and sensitivity analysisΠαναγιώτης Γ. Κοκκινάκο

The Decalogue of Policy Making 2.0: Results from Analysis of Case Studies on the Impact of ICT for Governance and Policy Modelling

Despite the availability of a myriad of ICT tools and methodologies for supporting governance and the formulation of policies, including modelling ex-pected impacts, they have proved unable to cope with the dire challenges of the contemporary society. In this chapter we present the results of the analysis of a set of promising cases researched in order to understand the possible impact of what we define 'Policy Making 2.0', which refers to 'a set of methodologies and technological solutions aimed at enabling better, timely and participative policy-making (CROSSOVER, 2012; Misuraca et al., 2014). Based on the analysis of these cases we suggest a bouquet of (mostly ICT-related) policy implications and practical recommendations stemming that are relevant to researchers, practitioners and policy makers in order to guide a the introduction and implememntation of Policy Making 2.0 initiatives. We argue that this 'decalogue' of Policy Making 2.0 could be an operational checklist for future research and policy to further explore the potential of ICT tools for governance and policy modelling, so to make next generation policy making more 'intelligent' and hopefully able to solve or anticipate the societal challenges we are (and will be) confronted today and in the future.JRC.J.3-Information Societ

Dynamic Manufacturing Networks Monitoring and Governance

Part VI: Services, Supply Chains and OperationsInternational audience“Monitoring and Governance” is the most important phase of every Dynamic Manufacturing Network (DMN) lifecycle and aims at managing and controlling in a continuous way the operations of the network, resulting either in “small and corrective” actions towards the network’s operation optimisation or to “larger and structural” changes, which are fed back to the initial phases of the network’s lifecycle, for reconstructing the network towards better results. The study at hand aims to review current approaches for controlling and monitoring plant operation or traditional supply chains, and to examine thereby their maturity and adequacy for the management and monitoring of dynamic manufacturing networks, leading to useful conclusions with regard to the requirements and challenges encountered in this particular phase of the DMN lifecycle

Reasoning on the Risks of Dynamic Manufacturing Networks through Cognitive Mapping

Part 17: Risk AnalysisInternational audienceDynamic Manufacturing Networks (DMNs) are increasingly deemed to be the evolution of typical supply chains in the manufacturing sector and a promising solution in the light of the enterprises’ effort to remain flexible and competitive in today’s rapid changing and demanding environment. The decision of joining a DMN however is quite important for any enterprise, since beside significant benefits it brings about changes in the way it operates, bearing thus also considerable risks. This paper attempts to cultivate an understanding around the risks of DMN participation, utilizing the causal characteristics of Cognitive Maps (CMs) for identifying the causes of unsatisfactory or unaccepted DMN operation outcomes. It further elaborates on how DMN risks are inherently dealt with through the IMAGINE framework that guarantees business alignment and interoperability

Bridging the Gap between Technological Education and Job Market Requirements through Data Analytics and Decision Support Services

In the 21st century, technology evolves extremely fast. The same applies to technology-related professions, mostly in terms of skills requirements. Contradictorily, higher education technological institutions are not always in the position to keep up with the labor market requirements. As a result, some of the skills taught in their courses are oftentimes outdated. From a learner’s perspective, the main goal should be to avoid such outdated courses, as for most university students, the long-term objective is to land a job, where they will utilize the skills they acquired from their studies. On the other hand, from an educational decision maker’s perspective, the most important goal is to keep up with the changes in the labor market, offering courses that will be valuable for the prospective careers of students. The work conducted in the context of this publication aims to bridge the gap between education offered in universities and job market skills’ requirements in technology. Specifically, a skill and course recommender system was developed to help learners select courses that are valuable for the job market, as well as a curriculum design service, which recommends updates to a given curriculum based on the job market needs. Both services are built on top of a text mining service that retrieves job posts from several online sources and performs skill extraction from them based on text analytics techniques. Moreover, a decision support service was developed to facilitate optimal decisions for both learners and education decision makers. All services were evaluated positively by 31 early users