Search

Your search keyword '"Kyzirakos, Kostis"' showing total 42 results
Start Over Author "Kyzirakos, Kostis"
42 results on '"Kyzirakos, Kostis"'

1. Evaluating Geospatial RDF stores Using the Benchmark Geographica 2

Author

Ioannidis, Theofilos, Garbis, George, Kyzirakos, Kostis, Bereta, Konstantina, and Koubarakis, Manolis

Subjects
Computer Science - Databases
Abstract

Since 2007, geospatial extensions of SPARQL, like GeoSPARQL and stSPARQL, have been defined and corresponding geospatial RDF stores have been implemented. In addition, some work on developing benchmarks for evaluating geospatial RDF stores has been carried out. In this paper, we revisit the Geographica benchmark defined by our group in 2013 which uses both real world and synthetic data to test the performance and functionality of geospatial RDF stores. We present Geographica 2, a new version of the benchmark which extends Geographica by adding one more workload, extending our existing workloads and evaluating 5 more RDF stores. Using three different real workloads, Geographica 2 tests the efficiency of primitive spatial functions in RDF stores and the performance of the RDF stores in real use case scenarios, a more detailed evaluation is performed using a synthetic workload and the scalability of the RDF stores is stressed with the scalability workload. In total eight systems are evaluated out of which six adequately support GeoSPARQL and two offer limited spatial support., Comment: 36 pages

Published
2019

3. Geographica: A Benchmark for Geospatial RDF Stores

Author

Garbis, George, Kyzirakos, Kostis, and Koubarakis, Manolis

Subjects
Computer Science - Databases
Abstract

Geospatial extensions of SPARQL like GeoSPARQL and stSPARQL have recently been defined and corresponding geospatial RDF stores have been implemented. However, there is no widely used benchmark for evaluating geospatial RDF stores which takes into account recent advances to the state of the art in this area. In this paper, we develop a benchmark, called Geographica, which uses both real-world and synthetic data to test the offered functionality and the performance of some prominent geospatial RDF stores.

Published
2013

6. Geographica: A Benchmark for Geospatial RDF Stores (Long Version)

Author

Garbis, George, Kyzirakos, Kostis, Koubarakis, Manolis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Alani, Harith, editor, Kagal, Lalana, editor, Fokoue, Achille, editor, Groth, Paul, editor, Biemann, Chris, editor, Parreira, Josiane Xavier, editor, Aroyo, Lora, editor, Noy, Natasha, editor, Welty, Chris, editor, and Janowicz, Krzysztof, editor

Published
2013
Full Text
View/download PDF

7. Sextant: Browsing and Mapping the Ocean of Linked Geospatial Data

Author

Nikolaou, Charalampos, Dogani, Kallirroi, Kyzirakos, Kostis, Koubarakis, Manolis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Cimiano, Philipp, editor, Fernández, Miriam, editor, Lopez, Vanessa, editor, Schlobach, Stefan, editor, and Völker, Johanna, editor

Published
2013
Full Text
View/download PDF

8. The Spatiotemporal RDF Store Strabon

Author

Kyzirakos, Kostis, Karpathiotakis, Manos, Bereta, Konstantina, Garbis, George, Nikolaou, Charalampos, Smeros, Panayiotis, Giannakopoulou, Stella, Dogani, Kallirroi, Koubarakis, Manolis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Nascimento, Mario A., editor, Sellis, Timos, editor, Cheng, Reynold, editor, Sander, Jörg, editor, Zheng, Yu, editor, Kriegel, Hans-Peter, editor, Renz, Matthias, editor, and Sengstock, Christian, editor

Published
2013
Full Text
View/download PDF

9. Strabon: A Semantic Geospatial DBMS

Author

Kyzirakos, Kostis, Karpathiotakis, Manos, Koubarakis, Manolis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Cudré-Mauroux, Philippe, editor, Heflin, Jeff, editor, Sirin, Evren, editor, Tudorache, Tania, editor, Euzenat, Jérôme, editor, Hauswirth, Manfred, editor, Parreira, Josiane Xavier, editor, Hendler, Jim, editor, Schreiber, Guus, editor, Bernstein, Abraham, editor, and Blomqvist, Eva, editor

Published
2012
Full Text
View/download PDF

10. Building Virtual Earth Observatories Using Ontologies, Linked Geospatial Data and Knowledge Discovery Algorithms

Author

Koubarakis, Manolis, Sioutis, Michael, Garbis, George, Karpathiotakis, Manos, Kyzirakos, Kostis, Nikolaou, Charalampos, Bereta, Konstantina, Vassos, Stavros, Dumitru, Corneliu Octavian, Espinoza-Molina, Daniela, Molch, Katrin, Schwarz, Gottfried, Datcu, Mihai, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Meersman, Robert, editor, Panetto, Hervé, editor, Dillon, Tharam, editor, Rinderle-Ma, Stefanie, editor, Dadam, Peter, editor, Zhou, Xiaofang, editor, Pearson, Siani, editor, Ferscha, Alois, editor, Bergamaschi, Sonia, editor, and Cruz, Isabel F., editor

Published
2012
Full Text
View/download PDF

11. Building Virtual Earth Observatories Using Ontologies and Linked Geospatial Data

Author

Koubarakis, Manolis, Karpathiotakis, Manos, Kyzirakos, Kostis, Nikolaou, Charalampos, Vassos, Stavros, Garbis, George, Sioutis, Michael, Bereta, Konstantina, Manegold, Stefan, Kersten, Martin, Ivanova, Milena, Pirk, Holger, Zhang, Ying, Kontoes, Charalampos, Papoutsis, Ioannis, Herekakis, Themistoklis, Mihail, Dimitris, Datcu, Mihai, Schwarz, Gottfried, Dumitru, Octavian, Molina, Daniela, Molch, Katrin, Giammatteo, Ugo, Sagona, Manuela, Perelli, Sergio, Klien, Eva, Reitz, Thorsten, Gregor, Robert, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Krötzsch, Markus, editor, and Straccia, Umberto, editor

Published
2012
Full Text
View/download PDF

12. Data Models and Query Languages for Linked Geospatial Data

Author

Koubarakis, Manolis, Karpathiotakis, Manos, Kyzirakos, Kostis, Nikolaou, Charalampos, Sioutis, Michael, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Eiter, Thomas, editor, and Krennwallner, Thomas, editor

Published
2012
Full Text
View/download PDF

13. A Semantically Enabled Service Architecture for Mashups over Streaming and Stored Data

Author

Gray, Alasdair J. G., García-Castro, Raúl, Kyzirakos, Kostis, Karpathiotakis, Manos, Calbimonte, Jean-Paul, Page, Kevin, Sadler, Jason, Frazer, Alex, Galpin, Ixent, Fernandes, Alvaro A. A., Paton, Norman W., Corcho, Oscar, Koubarakis, Manolis, De Roure, David, Martinez, Kirk, Gómez-Pérez, Asunción, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Antoniou, Grigoris, editor, Grobelnik, Marko, editor, Simperl, Elena, editor, Parsia, Bijan, editor, Plexousakis, Dimitris, editor, De Leenheer, Pieter, editor, and Pan, Jeff, editor

Published
2011
Full Text
View/download PDF

14. SPARQL Query Optimization on Top of DHTs

Author

Kaoudi, Zoi, Kyzirakos, Kostis, Koubarakis, Manolis, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Patel-Schneider, Peter F., editor, Pan, Yue, editor, Hitzler, Pascal, editor, Mika, Peter, editor, Zhang, Lei, editor, Pan, Jeff Z., editor, Horrocks, Ian, editor, and Glimm, Birte, editor

Published
2010
Full Text
View/download PDF

15. Modeling and Querying Metadata in the Semantic Sensor Web: The Model stRDF and the Query Language stSPARQL

Author

Koubarakis, Manolis, Kyzirakos, Kostis, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Aroyo, Lora, editor, Antoniou, Grigoris, editor, Hyvönen, Eero, editor, ten Teije, Annette, editor, Stuckenschmidt, Heiner, editor, Cabral, Liliana, editor, and Tudorache, Tania, editor

Published
2010
Full Text
View/download PDF

19. The Spatiotemporal RDF Store Strabon

Author

Kyzirakos, Kostis, primary, Karpathiotakis, Manos, additional, Bereta, Konstantina, additional, Garbis, George, additional, Nikolaou, Charalampos, additional, Smeros, Panayiotis, additional, Giannakopoulou, Stella, additional, Dogani, Kallirroi, additional, and Koubarakis, Manolis, additional

Published
2013
Full Text
View/download PDF

21. Building Virtual Earth Observatories Using Ontologies, Linked Geospatial Data and Knowledge Discovery Algorithms

Author

Koubarakis, Manolis, primary, Sioutis, Michael, additional, Garbis, George, additional, Karpathiotakis, Manos, additional, Kyzirakos, Kostis, additional, Nikolaou, Charalampos, additional, Bereta, Konstantina, additional, Vassos, Stavros, additional, Dumitru, Corneliu Octavian, additional, Espinoza-Molina, Daniela, additional, Molch, Katrin, additional, Schwarz, Gottfried, additional, and Datcu, Mihai, additional

Published
2012
Full Text
View/download PDF

22. Building Virtual Earth Observatories Using Ontologies and Linked Geospatial Data

Author

Koubarakis, Manolis, primary, Karpathiotakis, Manos, additional, Kyzirakos, Kostis, additional, Nikolaou, Charalampos, additional, Vassos, Stavros, additional, Garbis, George, additional, Sioutis, Michael, additional, Bereta, Konstantina, additional, Manegold, Stefan, additional, Kersten, Martin, additional, Ivanova, Milena, additional, Pirk, Holger, additional, Zhang, Ying, additional, Kontoes, Charalampos, additional, Papoutsis, Ioannis, additional, Herekakis, Themistoklis, additional, Mihail, Dimitris, additional, Datcu, Mihai, additional, Schwarz, Gottfried, additional, Dumitru, Octavian, additional, Molina, Daniela, additional, Molch, Katrin, additional, Giammatteo, Ugo, additional, Sagona, Manuela, additional, Perelli, Sergio, additional, Klien, Eva, additional, Reitz, Thorsten, additional, and Gregor, Robert, additional

Published
2012
Full Text
View/download PDF

23. A Semantically Enabled Service Architecture for Mashups over Streaming and Stored Data

Author

Gray, Alasdair J. G., primary, García-Castro, Raúl, additional, Kyzirakos, Kostis, additional, Karpathiotakis, Manos, additional, Calbimonte, Jean-Paul, additional, Page, Kevin, additional, Sadler, Jason, additional, Frazer, Alex, additional, Galpin, Ixent, additional, Fernandes, Alvaro A. A., additional, Paton, Norman W., additional, Corcho, Oscar, additional, Koubarakis, Manolis, additional, De Roure, David, additional, Martinez, Kirk, additional, and Gómez-Pérez, Asunción, additional

Published
2011
Full Text
View/download PDF

25. A columnar architecture for modern risk management systems

Author

Gonçalves, Romulo (author), Zlatanova, S. (author), Kyzirakos, Kostis (author), Nourian, Pirouz (author), Alvanaki, Foteini (author), van Hage, Willem (author), Gonçalves, Romulo (author), Zlatanova, S. (author), Kyzirakos, Kostis (author), Nourian, Pirouz (author), Alvanaki, Foteini (author), and van Hage, Willem (author)

Abstract

3D digital city models form the basis for flow simulations (e.g. wind flow and water runoff), urban planning, underand over- ground formation analysis, and they are very important for automated anomaly detection on man made structures. They consist of large collections of semantically rich objects which have many properties such as material and color. Such user’s data structure perception is leading to complex storage schemas. The number of table relations to manage and the large data storage footprint drawbacks are then extended with the fact that not all the systems have a "real" 3D data type. In this work we would like to show our efforts to develop a new kind of Spatial Data Management System (SDBMS) where topological and geometric functionality for 3D raster manipulation will become part of the relational kernel and not an add-on. With it spatial analysis tailored to different use case scenarios is done on-demand and fast enough to support real-time interaction in modern risk management systems., Accepted Author Manuscript, Design Informatics, Urban Data Science

Published
2016
Full Text
View/download PDF

28. Managing Big, Linked, and Open Earth-Observation Data: Using the TELEIOS\/LEO software stack

Author

Koubarakis, Manolis, primary, Kyzirakos, Kostis, additional, Nikolaou, Charalampos, additional, Garbis, George, additional, Bereta, Konstantina, additional, Dogani, Roi, additional, Giannakopoulou, Stella, additional, Smeros, Panayiotis, additional, Savva, Dimitrianos, additional, Stamoulis, George, additional, Vlachopoulos, Giannis, additional, Manegold, Stefan, additional, Kontoes, Charalampos, additional, Herekakis, Themistocles, additional, Papoutsis, Ioannis, additional, and Michail, Dimitrios, additional

Published
2016
Full Text
View/download PDF

31. Building remote sensing applications using scientific database and semantic web technologies

Author

Koubarakis, Manolis, Garbis, George, Kyzirakos, Kostis, Karpathiotakis, Manos, Nikolaou, Charalampos, Vassos, Stavros, Sioutis, Michael, Bereta, Konstantina, Kontoes, Charis, Papoutsis, Ioannis, Herekakis, Themistoklis, Michail, Dimitris, Manegold, Stefan, Kersten, Martin, Ivanova, Milena, Pirk, Holger, Zhang, Ying, Datcu, Mihai, Schwarz, Gottfried, Dumitru, Octavian, Espinoza-Molina, Daniela, Molch, Katrin, Di Giammatteo, Ugo, Sagona, Manuela, Perelli, Sergio, Reitz, Thorsten, Klien, Eva, and Gregor, Robert

Subjects
semantic web, databases, Remote sensing
Published
2012

32. SemSorGrid4Env Architecture

Author

Gray, Alasdair J G, Galpin, Ixent, Fernandes, Alvaro A A, Paton, Norman W, Page, Kevin, Sadler, Jason, Kyzirakos, Kostis, Koubarakis, Manolis, Calbimonte, Jean-Paul, García Castro, Raúl, Corcho, Oscar, Gabaldon, Jesus E., and Aparicio, Juanjo

Abstract

This document specifies, designs, and validates the Semantic Sensor Grid Rapid Application Development for Environmental Management (SemSorGrid4Env) software architecture. The architecture enables the publication and querying of both stored (e.g. database) and streaming (e.g. sensor) data to support the rapid development of applications for environmental monitoring. Significant benefits are provided by the use of semantic technology for service discovery and data integration. The infrastructural backbone of the architecture is provided by four service-oriented services: Stored Data Service for the publication of databases, Streaming Data Service for the publication of sensor data, Registration and Discovery Service to enable resources to found, and Integration and Querying Service to enable multiple data sources to be accessed through a single model. These services will be supplemented with application domain specific services which may offer RESTful interfaces.

Published
2010

37. A Semantic Sensor Web for Environmental Decision Support Applications

Author

Gray, Alasdair J. G., primary, Sadler, Jason, additional, Kit, Oles, additional, Kyzirakos, Kostis, additional, Karpathiotakis, Manos, additional, Calbimonte, Jean-Paul, additional, Page, Kevin, additional, García-Castro, Raúl, additional, Frazer, Alex, additional, Galpin, Ixent, additional, Fernandes, Alvaro A. A., additional, Paton, Norman W., additional, Corcho, Oscar, additional, Koubarakis, Manolis, additional, Roure, David De, additional, Martinez, Kirk, additional, and Gómez-Pérez, Asunción, additional

Published
2011
Full Text
View/download PDF

40. Real Time Fire Monitoring Using Semantic Web and Linked Data Technologies

Author

Kyzirakos, Kostis, Karpathiotakis, Manos, Nikolaou, Charalampos, Bereta, Konstantina, Sioutis, Michael, Papoutsis, Ioannis, Herekakis, Themistoklis, Michail, Dimitrios, Koubarakis, Manolis, and Kontoes, Charalambos

Abstract

Fire monitoring and management in Mediterranean countries such as Greece is of paramount importance. Almost every summer massive forest fires break out, causing severe destruction and even human life losses. Thus, European initiatives in the area of Earth Observation (EO), such as GMES SAFER, have supported the development of relevant operational infrastructures. In the context of the European project TELEIOS, we aim at developing a fire monitoring service, that goes beyond operational systems currently deployed in various EO data centers, by building on Semantic Web and Linked Data technologies. In this demonstration we present the fire monitoring service that we have implemented using TELEIOS technologies focusing on its Semantic Web related functionality. The service implements a processing chain where raw satellite images are analyzed and hotspots (pixels of the image corresponding to geographic regions possibly on fire) are detected. The products of this analysis are encoded in RDF, so they can be combined with auxiliary linked geospatial data (e.g., GeoNames, OpenStreetMap). By comparing detected hotspots with auxiliary data their accuracy can be determined. For example, hotspots lying in the sea are retrieved and marked as invalid. Additionally, we can combine diverse information sources and generate added-value thematic maps which are very useful to civil protection agencies and firefighting teams during emergency situations.

41. SexTant: Visualizing Time-Evolving Linked Geospatial Data

Author

Bereta, Konstantina, Nikolaou, Charalampos, Karpathiotakis, Manos, Kyzirakos, Kostis, and Koubarakis, Manolis

Abstract

We present SexTant, a Web-based system for the visualization and exploration of time-evolving linked geospatial data and the creation, sharing, and collaborative editing of "temporally-enriched" thematic maps which are produced by combining different sources of such data.

42. Developing Registries for the Semantic Sensor Web using stRDF and stSPARQL

Author

Kyzirakos, Kostis, Karpathiotakis, Manos, and Koubarakis, Manolis

Abstract

We address the problem of registering and discovering sensors, sensor services and other related resources in the Semantic Sensor Web. We show how to develop a semantic registry for the storage and manipulation of metadata describing such resources using an implementation of the data model stRDF and the query language stSPARQL. stRDF extends RDF with the ability to represent spatial and temporal metadata using linear constraints. stSPARQL extends SPARQL for querying stRDF metadata. Together they provide a natural modeling framework for the problem at hand, since spatial and temporal metadata figure prominently in the description of sensors and related resources or services. We present Strabon, a storage and query evaluation module for stRDF/stSPARQL for the architecture of the EU FP7 project SemsorGrid4Env and we show how to use Strabon to implement a semantic registry.

Catalog

Books, media, physical & digital resources
See catalog results