Prof. Yannis E. Ioannidis is the recipient of the 2017 ACM SIGMOD Contributions Award

25/04/2017

The SIGMOD Contributions Award is for outstanding services to the data management field through new community initiatives, professional services, standards activities, and research funding. 

Prof. Yannis E. Ioannidis is the recipient of the 2017 ACM SIGMOD Contributions Award for his sustained leadership and dedicated service to the database community, especially as part of the SIGMOD Executive Committee and the VLDB Endowment.

Previous winners of the Contributions Award are: Maria Zemankova (1992), Gio Wiederhold (1993), Yahiko Kambayashi (1995), Jeffrey Ullman (1996), Avi Silberschatz (1997), Won Kim (1998), Raghu Ramakrishnan (1999), Laura Haas and Michael Carey (2000), Daniel Rosenkrantz (2001), Richard Snodgrass (2002), Michael Ley (2003), Surajit Chaudhuri (2004), Hongjun Lu (2005), Tamer Ozsu (2006), Hans-Joerg Schek (2007), Klaus Dittrich (2008), Beng Chin Ooi (2009), David Lomet (2010), Gerhard Weikum (2011), Marianne Winslett (2012), H.V. Jagadish (2013), Kyu-Young Whang (2014), Curtis Dyreson (2015), and Samuel Madden (2016).

1 full time Researcher in the area of “Question Answering in the Web of Data”

05/01/2017

 The Department of Informatics and Telecommunications, National and Kapodistrian University of Athens is searching for 1 full-time Researcher in the area of “Question Answering in the Web of Data” The position is for 1 year only and it is available immediately.The position is offered in the frame of the EU-funded Marie Sklodowska-Curie International Training Network WDAqua: Answering Questions using Web Data, which has started in January 2015.  The project undertakes fundamental and applied research into models, methods and tools for data-driven question answering on the Web. More information about the project is available here: http://wdaqua.informatik.uni-bonn.de/ . Essential FactsThe hired researcher will spend 1 year working in the WDAqua ITN. He/She will spend the majority of his/her time at the University of Athens, but he/she will be encouraged to visit and engage with other partners in the project.The gross monthly salary (including social security, before taxes) is about 2.280,00€ plus a mobility allowance of 600 €/month and, if applicable, a family allowance of 250 €/month. TimelineApplication deadline: 31 January 2017Envisaged job starting date: as soon as possible Eligibility and application procedureCandidates must not have resided for more than 12 months in Greece in the 3 years before starting. They must hold an M.Sc. degree in computer science or a related field and be able to combine both theoretical and practical aspects in their work. Fluent English communication and a passion for developing modern software solutions are fundamental requirements. Knowledge of Greek is a plus but not required. The candidates should have experience and commitment to work in team and on the forefront of research.You will need to submit a CV, university transcripts, a motivation letter including a short research plan, two letters of recommendation, and English writing samples (e.g., prior publication or master thesis excerpt). ContactProfessors Yannis Ioannidis and Manolis Koubarakis (University of Athens, Department of Informatics and Telecommunications, MaDgIK Group, http://www.madgik.di.uoa.gr/)yannis@di.uoa.gr, koubarak@di.uoa.gr 

Second place in the ACM SIGMOD 2016 programming contest for the uoa_team!

06/07/2016

Yannis Foufoulas, Athanasios-Michail Karampatsis, Nikolaos Dimakopoulos, Georgios Alexandropoulos, and Nikolaos Tzamos have participated in the ACM SIGMOD 2016 programming contest, with the team name "uoa_team". They scored the 2nd place globally! 

 

 

Παρουσίαση Μεταπτυχιακής Εργασίας Κ. Λεσγίδη, Παρασκευή 13/11 @10:30πμ, Αίθουσα Α3

13/11/2015

Έμβια Μετανάστευση Docker Containers

Το Docker είναι ένας τρόπος virtualization, που προσφέρει άμεση λειτουργική αναδιάταξη και κλιμάκωση εφαρμογών σε περιβάλλον νέφους.  To Docker χρησιμοποιεί τα Linux Containers και προσθέτει νέα χαρακτηριστικά όπως φορητότητα των containers, versioning στα images που χρησιμοποιούνται και επαναχρησιμοποίηση.  Σε αυτή τη διπλωματική εργασία εξετάζουμε το πρόβλημα της Έμβιας Μετανάστευσης (Live Migration) εφαρμογών πάνω σε Docker Containers.  Πιο συγκεκριμένα ενδιαφερόμαστε για τεχνικές που επιτρέπουν την επιτυχή μεταφορά ενός Docker container από ένα φυσικό ή εικονικό μηχάνημα σε ένα άλλο, χωρίς ο τελικός χρήστης να διαπιστώσει κάποια διακοπή στην εργασία του.  Προτείνουμε ένα πρωτόκολλο για το παραπάνω σημαντικά πρακτικό πρόβλημα και παρέχουμε την υλοποίησή ενός πρωτοτύπου που είναι σε θέση να μεταφέρει containers που τρέχουν Apache Web Servers ή/και MySQL βάσεις δεδομένων.  Στην αξιολόγηση του πρωτοτύπου μας παρατηρήσαμε αρκετά καλούς χρόνους ολοκλήρωσης ενός Migration και μικρή επιβάρυνση στις υπηρεσίες του χρήστη από την υλοποίηση μας.

 

Εξεταστές: Μ. Ρουσσοπούλου, Α. Δελής

 

Job Vacancy

09/10/2015

Ζητείται συνεργάτης του Διευθυντή του Ε.Κ. «Αθηνά» και Καθ. Πληροφορικής & Τηλ/νιών ΕΚΠΑ. Τα καθήκοντα περιλαμβάνουν  μεταξύ άλλων επικοινωνία και συντονισμό συνεργατών, διαχείριση συναντήσεων και ταξιδιών, υποστήριξη συμμετοχής σε επιτροπές, προετοιμασία εγγράφων και ομιλιών, παρακολούθηση αλληλογραφίας, ιεράρχηση προτεραιοτήτων, δρομολόγηση αιτημάτων, και οργάνωση γραφείου.

 

Απαραίτητα προσόντα και χαρακτηριστικά:

·    Πτυχίο ΑΕΙ σε οποιοδήποτε κλάδo [1]

·    Άριστη γνώση και χρήση της Ελληνικής και Αγγλικής (στο γραπτό και προφορικό λόγο)

·    Εκτενής εμπειρία στη χρήση των εφαρμογών MS Office και του διαδικτύου

·    Εξαιρετικές ικανότητες στη διαχείριση χρόνου και την ταχεία εκτέλεση πολλών παράλληλων εργασιών

·    Εχεμύθεια, διπλωματικότητα, ορθή κρίση, ανάληψη πρωτοβουλιών

·    Ευελιξία στο ωράριο εργασίας

·    Δίπλωμα οδήγησης αυτοκινήτου

Επιθυμητά προσόντα:

·    Μεταπτυχιακό Δίπλωμα Ειδίκευσης σε οποιοδήποτε κλάδο

·    Τουλάχιστον έναν εκ του προπτυχιακού ή μεταπτυχιακού τίτλου σπουδών σε κλάδο τεχνολογίας, θετικών επιστημών, ή οικονομικών επιστημών

·    Προϋπηρεσία σε αντίστοιχη/παρόμοια θέση, διοικητική θέση σε Ερευνητικό Κέντρο/ΑΕΙ, ή διαχείριση ερευνητικών προγραμάτων

·    Γνώση περισσοτέρων ξένων γλωσσών

 

Οι ενδιαφερόμενοι μπορούν να στείλουν το βιογραφικό τους στη διεύθυνση lthemeli@di.uoa.gr μέχρι τις 23 Οκτωβρίου 2015. Πληροφορίες στα τηλέφωνα 210-727-5207 (κα Θεμελή ή κα Παπαδάκη) ή 210-727-5188 (κα Κατρακάζη).

 
 
[1] Η απουσία τέτοιου τίτλου μπορεί να παραβλεφθεί κατ’ εξαίρεση μόνο σε περιπτώσεις ατόμων με άριστες επιδόσεις, εκτενέστατη εμπειρία, και εξαιρετικά χαρακτηριστικά στα υπόλοιπα ζητούμενα στοιχεία.

Υποστήριξη διπλωματικής εργασίας Δημήτρη Θεοδοσάκη

09/07/2015

Η δημόσια υποστήριξη της διπλωματικής του μεταπτυχιακού φοιτητή Δημήτρη Θεοδοσάκη θα πραγματοποιηθεί στην αίθουσα Α56 την Πέμπτη 9 Ιουλίου, και ώρα  16:45μμ.

Ο τίτλος και η περίληψη της διατριβής του κου Θεοδοσάκη δίνονται παρακάτω.

 

Τεχνικές Βελτιστοποίησης Ερωτημάτων σε Υπολογιστικό Νέφος

In the area of database systems, query optimization is a vital process since it aims to find execution plans that satisfy specific requirements inside a search space which is usually very large. It can be likened to a chess game since sometimes decisions must be taken that cost in the short term but then are proved particularly pertinent, since they are part of a good overall strategy.

Because of the ever increasing volume of data that needs to be processed by a wide variety of applications, the use of distributed database systems in a cloud computing infrastructure and therefore the use of a query optimizer are necessary.

In a cloud computing environment apart from the query execution speed, we are equally interested in the cost of rented resources (virtual machines) that are being used. Thus, the plan chosen will have to meet not only the requirements in execution time but also in money paid per time quantum of using the computing resources.

In this thesis, it is presented a query optimizer for the Exareme system, which models its behavior in a high level, takes as input a plan of an algebrized SQL query and finds a satisfying execution plan which is subsequently passed to the underlying system for execution.

As part of this work, there was implemented a series of optimization techniques for various query scenarios that the Exareme is able to answer. More specifically, for a query we emphasize on approaching the Pareto skyline that arises in the two-dimensional search space (time-money). Moreover, it is presented a statistical method for finding the most efficient degree of parallelism for the execution of a certain user defined function (UDF). Finally, it is presented a technique which aims to build indices in advance for future use during query execution that effectively leverages the potential idle time of virtual machines.

CHESS in the European Commission's brochure "Horizon 2020 - Investing in European success"

19/05/2015

The CHESS project is included in the European Commission's brochure, which presents a selection of results from EU funded projects that have shown great strides in innovation!

http://ec.europa.eu/programmes/horizon2020/en/news/horizon-2020-research-and-innovation-boost-growth-and-jobs-europe-issue-2

 

Υποστήριξη διατριβής του υποψήφιου διδάκτορα Χεράλντ Κλλάπι

25/02/2015

Η δημόσια υποστήριξη της διατριβής του υποψήφιου διδάκτορα Χεράλντ Κλλάπι θα πραγματοποιηθεί στην αίθουσα Α56, αύριο Τετάρτη, 25 Φεβρουαρίου, στις 8:45π.μ.

 

Τίτλος διατριβής: Ελαστική Επεξεργασία Ροών Δεδομένων στο Νέφος

Περίληψη: Clouds have become an attractive platform for the large-scale processing of modern applications on Big Data, especially due to the concept of elasticity, which characterizes them: resources can be leased on demand and used for as much time as needed, offering the ability to create virtual infrastructures that change dynamically over time. Such applications often require processing of complex queries that are expressed in a high-level language and are typically transformed into data processing flows, or simply dataflows. A logical question that arises is whether elasticity affects dataflow execution and in which way. It seems reasonable that the execution is faster when more resources are used, however the monetary cost is higher. This gives rise to the concept eco-elasticity, an additional kind of elasticity that comes from economics, and captures the trade-offs between the response time of the system and the amount of money we pay for it as influenced by the use of different amounts of resources.

In this thesis, we approach the elasticity of clouds in a unified way that combines both the traditional notion and eco-elasticity. This unified elasticity concept is essential for the development of auto-tuned systems in cloud environments. First, we demonstrate that eco-elasticity exists in several common tasks that appear in practice and that can be discovered using a simple, yet highly scalable and efficient algorithm. Next, we present two cases of auto-tuned algorithms that use the unified model of elasticity in order to adapt to the query

workload: 1) processing analytical queries in the form of tree execution plans in order to maximize profit and 2) automated index management taking into account compute and storage resources. Finally, we describe EXAREME, a system for elastic data processing on the cloud that has been used and extended in this work. The system offers declarative languages that are based on SQL with user-defined functions (UDFs) extended with parallelism primitives. EXAREME exploits both elasticities of clouds by dynamically allocating and de-allocating compute resources in order to adapt to the query workload.

 

1 PhD position in Semantic Web, Linked data, Web Science and Data Science

09/02/2016
 
The Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, is searching for 1 full-time PhD student 
in Semantic Web, Linked data, Web Science and Data Science
 
========
 
 
The position is offered in the frame of the EU-funded Marie Sklodowska-Curie International Training Network WDAqua: Answering Questions using Web Data, which started in January 2015. 
 
The project will undertake fundamental and applied research into models, methods, and tools for data-driven question answering on the Web. More information about the project is available here: http://www.iai.uni-bonn.de/~langec/wdaqua/
 
The topics of the PhD will cover the domains of context awareness, coherence, and user interaction for handling inherent question ambiguity.
 
 
== Essential Facts ==
The PhD student will spend 3 years working in the WDAqua ITN (a total of 15 PhD students registered in the Universities of Bonn, Athens, Saint-Étienne, and Southampton). He/She will spend the majority of his/her time at the University of Athens where he/she will research and write a dissertation leading to a PhD, supervised by at minimum two academic supervisors from the WDAqua partners. He/She will have the possibility to participate in an outstanding Web science and data science training programme, and to visit and engage with other partners in the project. 
 
The gross monthly salary (including social security, before taxes) is about 2.280,00€ plus a mobility allowance of 600 €/month and, if applicable, a family allowance of 250 €/month.
 
 
== Timeline ==
29 February 2016: application deadline
March 2016: Envisaged Job starting date
 
 
== Eligibility and application procedure ==
Candidates must not have resided for more than 12 months in Greece in the 3 years before starting. They must hold an M.Sc. degree in computer science or a related field and be able to combine both theoretical and practical aspects in their work. Fluent English communication and a passion for developing modern software solutions are fundamental requirements. Knowledge of Greek is a plus but not required. The candidates should have experience and commitment to work in team and on the forefront of research.
You will need to submit a CV, university transcripts, a motivation letter including a short research plan targeting some topics of the above list, two letters of recommendation, and English writing samples (e.g., prior publication or master thesis excerpt).
 
== Contact ==
Professors Yannis Ioannidis and Manolis Koubarakis (University of Athens, Department of Informatics and Telecommunications, MaDgIK Group, http://www.madgik.di.uoa.gr/
 
yannis@di.uoa.gr, koubarak@di.uoa.gr
 

“Kore, what is your story? Advancing cultural experience through the use of ICT”

08/12/2014

In the context of eCultValue project, an eCult Ambassadors Winter stage entitled “Kore, what is your story? Advancing cultural experience through the use of ICT” takes place in the Acropolis Museum (Athens, Greece), on 8 – 9 December 2014. Participation in the eCult Winter Stage will assist eCult Ambassadors in becoming the proactive mediators between technology providers and cultural heritage stakeholders to promote and facilitate the ICT adoption in museums. The Stage will offer novel hands-on activities to provide participants with a deeper insight into the state of the art technologies for Cultural Heritage!

http://www.ecultobservatory.eu/events/ecult-winter-stage-athens-greece 

MaDgIK 2009-2016