Publicaciones en Revistas Indizadas.
- Torres, E. Loza-Pacheco, W. Al-Halabi, G. Guzmán, R. Quintero, M. Moreno, “Qualitative spatial reasoning methodology to determine the particular domain of a set of geographic objects”, Computers in Human Behavior, ISSN: 0747-5632, Vol. 59, 2016, pp. 115-133.
- Escamilla, M. Torres, M. Moreno-Ibarra, R. Quintero, G. Guzmán, V. Luna-Soto, “Geocoding tweets approach based on conceptual representations in the context of the knowledge society”, International Journal on Semantic Web and Information Systems, ISSN: 1552-6283, Vol. 12, No. 1, 2016, pp. 44-61.
- Mata, M. Torres, G. Guzmán, R. Quintero, R. Zagal-Flores, M. Moreno-Ibarra, E. Loza-Pacheco, “A mobile information system based on crowd-sensed and official crime data for finding safe routes: a case study of Mexico City”, Mobile Information Systems, ISSN: 1574-017X, Vol. 2016, 2016, pp. 1-11.
- Pineda-Briseño, R. Menchaca-Méndez, E. Chávez, G. Guzmán, R. Menchaca-Méndez, R. Quintero, M. Torres, M. Moreno-Ibarra, J.L. Díaz-de-León, “A probabilistic approach to location estimation in MANETs”, Ad Hoc & Sensor Wireless Networks, ISSN: 1551-9899, Vol. 28, No. 1-2, 2015, pp. 97-114.
- Mata-Rivera, M. Torres, G. Guzmán, M. Moreno-Ibarra, R. Quintero, “A collaborative learning approach for geographic information retrieval based on social networks”, Computers in Human Behavior, ISSN: 0747-5632, Vol. 51, 2015, pp. 829-842.
- Luna-Soto, R. Quintero, M. Torres, M. Moreno-Ibarra, G. Guzmán, I. Escamilla, “An ontology-based approach for representing the interaction process between user profile and its context for collaborative learning environments. Computers in Human Behavior, ISSN: 0747-5632, Vol. 51, 2015, pp. 1387-1394.
- Quintero, G. Guzmán, M. Torres, R. Menchaca-Méndez, M. Moreno-Ibarra, F. Mata, “A Compression Algorithm for Managing Digital Elevation Models in Mobile Devices”, The Journal of Universal Computer Science, ISSN: 0948-695X, Vol. 20, No. 10, 2014, pp. 1433-1442.
- Quintero, G. Guzmán, R. Menchaca-Méndez, M. Torres & M. Moreno, “An ontology driven approach for the extraction and description of geographic objects contained in raster spatial data”. Elsevier Expert Systems with Applications, ISSN: 0957-4174, Vol. 39, No. 10, 2012, pp. 9008–9020.
- Torres, R. Quintero, M. Moreno, R. Menchaca-Méndez & G. Guzmán, “GEONTO-MET: An approach to conceptualizing the geographic domain”, International Journal of Geographic Information Science, ISSN:1365-8816, Vol. 25, No. 10, 2011, pp. 1633 – 1657.
- Moreno, M.Torres, R. Quintero, G. Guzmán & R. Menchaca-Méndez, “Semantic assessment of similarity between raster elevation datasets”, Revista de la Facultad de Ingeniería, Universidad de Antioquia, 59, Junio 2011, ISSN:0120-6230, pp. 37-46.
- Torres, S. Levachkine, M. Moreno, R. Quintero & G. Guzmán, “Retrieving Geospatial Information into a Web-Mapping Application using Geospatial Ontologies”, In N.T. Nguyen, A.Grzech, R.J. Howlett And L.C. Jain, Lecture Notes in Computer Science, Vol. 4496, Springer-Verlag, Berlin Heidelberg, 2007, ISSN: 0302-9743, pp. 267-277.
- Guzmán, R. Quintero, M. Torres and M. Moreno, “Applying a-priori Knowledge for Compressing Digital Elevation Models”, in B. Gabrys, R.J. Howlett and L.C. Jain, Lecture Notes in Artificial Intelligence, Vol. 4251, Springer-Verlag, Berlin Heidelberg, 2006, ISSN: 0302-9743, pp. 614-622.
- Torres, G. Guzmán, R. Quintero, M. Moreno and S. Levachkine, “Semantic Decomposition of LandSat TM Image”, in B. Gabrys, R.J. Howlett and L.C. Jain, Lecture Notes in Artificial Intelligence, Vol. 4251, Springer-Verlag, Berlin Heidelberg, 2006, ISSN: 0302-9743, pp. 550-558.
- Torres, G. Guzmán, R. Quintero, M. Moreno and S. Levachkine, “Semantic Supervised Clustering to Land Classification in Geo-Images”, in R. Khosla, R.J. Howlett and L.C. Jain (Eds.), Lecture Notes in Artificial Intelligence, Vol. 3683, Springer-Verlag, Berlin Heidelberg, 2005, ISSN: 0302-9743, pp. 248-254.
- Moreno, S. Levachkine, M. Torres, R. Quintero and G. Guzmán, “Automatic Geomorphometric Analysis for Digital Elevation Models”, in R. Khosla, R.J. Howlett and L.C. Jain (Eds.), Lecture Notes in Artificial Intelligence, Vol. 3684, Springer-Verlag, Berlin Heidelberg, 2005, ISSN: 0302-9743, pp. 374-381.
- Quintero, M. Torres, M. Moreno and G. Guzmán, “SIGES-PERE: A Collaborative GIS for Radiological Disaster Management”, in M.A. Wimmer, R. Traunmüller, A. Grönlund and K.V. Andersen (Eds), Lecture Notes in Computer Science, Vol. 3591, Springer-Verlag, Berlin Heidelberg, 2005, ISSN: 0302-9743, pp. 174-185.
- Quintero, S. Levachkine, M. Torres, M. Moreno and G. Guzmán, “Managing Resolution in Digital Elevation Models Using Image Processing Techniques”, in J.S. Marques, N. Pérez de la Blanca and P. Pina (Eds), Lecture Notes in Computer Science, Vol. 3522, Springer-Verlag, Berlin Heidelberg, 2005, ISSN: 0302-9743, pp. 316-324.
- Torres, S. Levachkine, M. Moreno, R. Quintero & G. Guzmán, “Implementing Spatial Analyzer Module into a Distributed GIS-Application”, R. Traunmüller (Ed.), Lecture Notes in Computer Science, Vol. 3183, Springer-Verlag, Berlin Heidelberg, 2004, ISSN: 0302-9743, pp. 406-409.
- Juan Luis Díaz de León, C. Yáñez & Giovanni Guzmán, “Thinning Algorithm to Generate k-Connected Skeletons”, Progress in Pattern Recognition, Image Análisis and Applications in Alberto Sanfeliu, José Francisco Martínez Trinidad, Jesús Ariel Carrasco Ochoa (Eds.), Lecture Notes in Computer Science, Vol. 3287, Springer-Verlag, Berlin Heidelberg, 2004, ISSN: 0302-9743, pp. 605-612.
Publicaciones en Revistas Internacionales.
-
Pineda-Briseño, R. Menchaca-Méndez, G. Guzmán, “Integrated Routing and Positioning in Mobile Ad Hoc Networks”, Computación y Sistemas, ISSN: 2007-9737, Vol. 20, No. 2, 2016, pp. 289-307.
- Guzmán, M. López, B. López-Ramírez, D. Ávila, “City-Driven approach to determine health services based on current user location and collaborative information”, International Journal of Knowledge Society Research, ISSN: 1947-8429, Vol. 7, No. 1, 2016, pp. 53-62.
- Saldaña, M. Torres, O. Pogrebnyak, M. Moreno-Ibarra, G. Guzmán, “The GRP Methodology: An Approach to Build Routes Based on Points of Interest”, Journal Mobile Multimedia, ISSN: 1550-4646, Vol. 10, No. 3-4, 2014, pp. 273-293.
- Cadena, R. Quintero, M. Moreno-Ibarra, M. Torres, G. Guzmán, “Comparación semántica de conjuntos de datos geográficos conceptualizados por medio de ontologías”, Computación y Sistemas, ISSN: 1405-5546, No. 17, No. 4, 2013, pp. 569-581.
- Torres, M. Moreno-Ibarra, R. Quintero, G. Guzmán, “Applying Supervised Clustering to Landsat MSS Images into GIS-Application”, International Journal of Knowledge Society Research, ISSN: 1947-8429, Vol. 4, No. 3, 2013, pp. 114-122.
- Guzmán & S. Levachine, “General Algorithm for the Semantic Decomposition of Geo-Images”, Computación y Sistemas, ISSN: 1405-5546, Vol. 14, No. 4, 2008, pp. 437 – 450.
- Torres, M. Moreno, R. Menchaca, R. Quintero & G. Guzmán, “Semantic supervised clustering approach to classify land cover in remotely sensed images”, Tai-hoon Kim, Sankar K. Pal, William I. Grosky, Niki Pissinou, Timothy K. Shih, Dominik Ślęzak (Eds.), Coomunications in Computer and Information Science, Vol. 123, Springer-Verlag, Berlin Heidelberg, 2010, ISSN: 1865-0929, pp. 68-78.
- Quintero, M. Torres, M. Moreno & G. Guzmán, “Towards a Semantic Representation of Raster Spatial Data”, Krzysztof Janowicz, Martin Raubal, Sergei Levashkin (Eds.), Lecture Notes in Computer Science, Vol. 5892, Springer-Verlag, Berlin Heidelberg, 2009, ISSN: 0302-9743, pp. 63-82.
- Moreno, S. Levachkine, M. Torres, R. Quintero & G. Guzmán, “Sematinc Similarity Applied to Geomorphometric Analysis of Digital Elevation Modles”, Vasily V. Popovich, Manfred Schrenk, Christophe Claramunt, Kyrill V. Korolenko (Eds.), Lecture Notes in Geoinformation and Cartography, Vol. 2543, Springer-Verlag, Berlin Heidelberg, 2009, ISSN: 1863-2246, pp. 139-153.
- Torres, R. Quintero, S. Levachkine, G. Guzmán & M. Moreno, “Geospatial information integration approach based on geographic context ontologies”, Vasily V. Popovich, Manfred Schrenk, Christophe Claramunt, Kyrill V. Korolenko (Eds.), Lecture Notes in Geoinformation and Cartography, Vol. 2543, Springer-Verlag, Berlin Heidelberg, 2009, ISSN: 1863-2246, pp. 166-182.
- Guzmán, S. Levachkine, M. Torres, R. Quintero & M. Moreno, “Extraction and Specialization of Geo-Spatial Objects in Geo-images using Semantic Compression Algorithm”, Advances in Artificial Intelligence in Alexander Gelbukh, Eduardo F. Morales (Eds.), Lecture Notes in Artificial Intelligence, Vol. 5317, Springer-Verlag, Berlin Heidelberg, 2008, ISSN: 0302-9743, pp. 573-584.
- Torres, R. Quintero, S. Levachkine, G. Guzmán & M. Moreno, “Towards a Methodology to Conceptualize the Geographic Domain”, Advances in Artificial Intelligence in Alexander Gelbukh, Eduardo F. Morales (Eds.), Lecture Notes in Artificial Intelligence, Vol. 5317, Springer-Verlag, Berlin Heidelberg, 2008, ISSN: 0302-9743, pp. 111-122.
- Torres, S. Levachkine, M. Moreno, R. Quintero & G. Guzmán, “Retrieving Geospatial Information into a Web-Mapping Application using Geospatial Ontologies”, In N.T. Nguyen, A.Grzech, R.J. Howlett And L.C. Jain, Lecture Notes in Computer Science, Vol. 4496, Springer-Verlag, Berlin Heidelberg, 2007, ISSN: 0302-9743, pp. 267-277.
Publicaciones en Congresos Internacionales.
- Saldaña, M. Torres, M. Moreno-Ibarra, G. Guzmán, “RRM-A referenced routing model to generate a semantic service of navigation in mobile devices”, 6th International Symposium Information Fusion and Intelligent Geographical Information Systems (IF&GIS 2015), pp. 43-58.
- López, D. Ávila, D. Maya, X. Olvera, G. Guzmán, M. Torres, R. Quintero, M. Moreno, “Geospatial Recommender System for the Location of Health Services”, The 14th International Conference on Computational Science and Its Applications (ICCSA 2014), pp. 200-203.
- Magdalena, G. Guzmán, M. Moreno-Ibarra, M. Torres, R. Quintero, O. Pogrebnyak, “Generation of Routes with Points-of-Interest to Help Users in Their Trip”, The 14th International Conference on Computational Science and Its Applicatiosn (ICCSA 2014), pp. 284-298.
- Eduardo Loza Pacheco, Miguel Torres Ruiz & Giovanni Guzmán, “Uso de marcos conceptuales como medio para poblar una ontología en un modelo de datos persistente”, IX Congreso Internacional Sobre Innovación y Desarrollo Tecnológico (CIINDET 2011), pp. 353-359.
- Guzmán, M. Torres, R. Quintero, M. Moreno & R. Menchaca, “Metolodología para la identificación de objetos geográficos mediante análisis orientado a objetos”, IX Congreso Internacional Sobre Innovación y Desarrollo Tecnológico (CIINDET 2011), pp. 493-499.
- Menchaca Méndez, G. Guzmán Lugo, F. Rolando Menchaca García, R. Quintero Téllez, M. J. Torres Ruiz & M. A. Moreno Ibarra, “EEDP: Efficient and Energy-aware Dissemination Protocol for Multihop Sensor Network”, IX Congreso Internacional Sobre Innovación y Desarrollo Tecnológico (CIINDET 2011), pp. 524-531.
- Torres Ruiz, M. Moreno Ibarra, R. Quintero, G. Guzmán Lugo & R. Menchaca Méndez, “Descripción de datos geográficos por medio de un sistema basado en conocimiento”, IX Congreso Internacional Sobre Innovación y Desarrollo Tecnológico (CIINDET 2011), pp. 406-413.
- Pineda Briseño, G. Guzmán Lugo & R. Menchaca Méndez, “Entorno ubicuo para la interoperabilidad de dispositivos móviles”, IX Congreso Internacional Sobre Innovación y Desarrollo Tecnológico (CIINDET 2011), pp. 494-501.
- Horna, R. Barrón & G. Guzmán, “Conformal geometric algebra and sphere fitting applied to color image segmentation”, in Advances in Computer Science and Engineering, M. Martínez & A. Alarcón (Eds.), Research in Computing Science, Vol. 45, 2010, ISSN: 1870-4069, pp. 53-57.
- Torres, M. Moreno, R. Quintero & G. Guzmán, “Web-Mapping to Retrieve Spatial Data by means of Spatial Ontologies”, in Advances in Computer Science and Engineering, M. Martínez & A. Alarcón (Eds.), Research in Computing Science, Vol. 45, 2010, ISSN: 1870-4069, pp. 191-208.
- Guzmán, A. Pineda, M. Torres, R. Menchaca & M. Moreno, “Geographic-Aware Architecture for the Interoperability of Ubiquitous Componentes”, International Conference on Networked Computing and Advanced Information Management, Jinhwa Kim, Dursun Delen, Park, Franz Ko & Dr. Yun Ji Na (Eds.), Vol. 1, pp. 416-421.
- Torres, S. Levachkine, R. Quintero, G. Guzmán & M. Moreno, “Geospatial information integration based on the conceptualization of geographic domain”, in 16th ACM SIGSPATIAL International Conference On Advances In Geographic Information Systems (ACM GIS 2008), W. Aref, M. Mokbel, H. Samet, M. Schneider, C. Shahabi & O. Wolfson (Eds.), pp. 495-498.
- Pineda, R. Menchaca, & G. Guzmán, “Architecture for the interoperability among ubiquitous components”, in Advances in Advances in Computer Science and Engineering, Alexander Gelbukh, Sergio Suárez & Hiram Calvo (Eds.), Research in Computing Science, Vol. 29, 2007, ISSN: 1870-4069, pp. 211-224.
- Guzmán, S. Levachkine, K. Verastegui, V. Villegas & B. Martínez, “Un algoritmo general para la descomposición semántica de geo-imágenes”, SELPER 2006. (http://www.selper.org.co/simposio.php), e-Proceedings, 2006.
- Guzmán & R. Quintero, “Compressin Digital Elevation Models base don Run Length Encoding Approach”, in Speccial Issue: Semantics in Geoinformatics Applications, Marco Moreno & Serguei Levachkine (Eds.), Research in Computing Science Vol. 25, 2006, ISSN: 1870-4069.
- Torres, M. Moreno, R. Quintero, & G. Guzmán, “Web-Mapping Application Based on Ontologies to Retrieve Geo-Information”, in Electronic Government, Kim V. Andersen, Ake Gröunlund, R. Traunmüller, Maria Wimmer (Eds.), Schriftenreihe Informatik Vol. 13, 2005, ISBN: 3-85487-830-3, pp. 166-173.
- Torres, R. Quintero, M. Moreno & G. Guzmán, “Spatial Semantic Definition to Generate Semantic Description for Sptatial Data”, in Advances in Artificial Intelligence and Computer Science, Alexander Gelbukh, Cornelio Yáñez, Oscar Camacho Nieto (Eds.), Rearch on Computing Science, Vol. 14, 2005, ISSN: 1665-9899, pp. 297-310.
- Moreno, S. Levackine, M. Torres, R. Quintero & G. Guzmán, “Distributed GIS Environment to Detect Geomorphometric Characteristics in Geo-Images”, in Advances in Artificial Intelligence and Computer Science, Alexander Gelbukh, Cornelio Yáñez, Oscar Camacho Nieto (Eds.), Rearch on Computing Science, Vol. 14, 2005, ISSN: 1665-9899, pp. 311-322.
- Guzmán, M. Torres, R. Quintero y M.Moreno, «Manejo de información cartográfica mediante base de datos espaciales distribuida», in Advances in Computer Science in Mexico, A. Gelbukh, H. Calvo (Eds.), Rearch on Computing Sciente, Vol. 13, 2005, ISSN: 1665-9899, pp. 203-210.
- Torres, M. Moreno, R. Quintero & G.Guzmán, “Applying Supervised Clustering to Landsat MSS Images into GIS-Application”, in Advances in Artificial Intelligence, Computing Science and Computer Engineering, Jesús Figueroa Nazuno, Alexander Gelbukh Khan, Cornelio Yáñez Márquez, Oscar Camacho Nieto (Eds.), Research on Computing Science, Vol. 10, 2004, ISSN: 1665-9899, pp. 167-176.
- Guzmán, R. Menchaca, M. Moreno, M. Torres & R. Quintero, “Algorithm to Compute the Depth of a Basin using 8-Connected Skeletons”, in Advances in Artificial Intelligence, Computing Science and Computer Engineering, Jesús Figueroa Nazuno, Alexander Gelbukh Khan, Cornelio Yáñez Márquez, Oscar Camacho Nieto (Eds.), Research on Computing Science, Vol. 10, 2004, ISSN: 1665-9899, pp. 201-209.
- Quintero, M. Torres, M. Moreno, C. Carreto & G. Guzmán, “General Collaboration Architecture to Work with Geographical Information Systems”, in Advances in Artificial Intelligence, Computing Science and Computer Engineering, Jesús Figueroa Nazuno, Alexander Gelbukh Khan, Cornelio Yáñez Márquez, Oscar Camacho Nieto (Eds.), Research on Computing Science, Vol. 10, 2004, ISSN: 1665-9899, pp. 265-276.
- Torres, M. Moreno, R. Quintero, G. Guzmán & S. Levachkine, “Implementing Web-Mapping Technology into GIS-Applitcation to Recover Spatial Data”, in Proceedings of the IASTED Internacional Conferentece on Computer Science and Technology in S. Sahni (Ed.), Internacional Association of Science and Technology Development – IASTED, 2003, ISBN: 0-88986-349-0, pp, 170 – 175.
- Quintero, G. Guzmán, M. Torres & M. Moreno, “Spatial Analysis Base don 3D Rendering Techniques”, in 6th AGILE Conference on Geographic Information Science, Michael Goud, Robert Laurini, Stéphane Coulondre (Ed.), 2003, ISBN: 2-88074-541-1, pp. 401-408.
- Moreno, S. Levachkine, M. Torres, R. Quintero & G. Guzmán, “Corrección automática del flujo en una red hidrológica” en Avances en Informática y Computación, Juan Humberto Sossa Azuela, María de Lourdes Sánchez Guerrero, Jesús Polito Olvera, Sergio Fuenlabrada Velázquez (Eds.), 2003, ISBN: 970-36-0100-6, pp. 137 – 143.
- Guzmán, M. Torres, R. Quintero, M. Moreno & S. Levachkine, “Arquitectura para consulta de información vectorial en bases de datos distribuidas” en Avances en Informática y Computación, Juan Humberto Sossa Azuela, María de Lourdes Sánchez Guerrero, Jesús Polito Olvera, Sergio Fuenlabrada Velázquez (Eds.), 2003, ISBN: 970-36-0100-6, pp. 215 – 220.
- Quintero, M. Torres, M. Moreno, S. Levachkine & G. Guzmán, “Sistema de información geográfica de localización, navegación y posicionamiento móvil” en Avances en Informática y Computación, Juan Humberto Sossa Azuela, María de Lourdes Sánchez Guerrero, Jesús Polito Olvera, Sergio Fuenlabrada Velázquez (Eds.), 2003, ISBN: 970-36-0100-6, pp. 245 – 249.
- L. Díaz, C. Yáñez & G. Guzmán, “Algoritmos para generar esqueletos k-conectados basados en criterios de conectividad”, en Avances en Ciencias de la Computación, Juan Luis Díaz de León Santiago, Germán González Santos, Jesús Figueroa Nazuno (Eds.), Volumen 3, 2003, ISBN: 970-36-0098-0, pp. 165 – 170.
- Sossa, G. Guzmán, O. Pogrebnyak & F. Cuevas, “Object Counting without Conglomerate Separation”, in Fourth Mexican Internacional Conference on Computer Science, Edgar Chávez, Jesús Favela, Marcelo Mejía, Alberto Oliart (Eds.), IEEE Computer Society, 2003, ISBN: 0-7695-1915-6, pp. 216-220.
- Sossa, F. Cuevas, G. Guzmán & O. Pogrebnyak, “Improved Technique to Determine the Number of Blobs in an Image”, in Visualization, Imaging and Image Processing, J. J. Villanueva (Ed.), International Association of Science and Technology for Development – IASTED 2002, ISBN: 0-88986-354-3, pp. 1086-1089.
- Guzmán, H. Sossa, F. Cuevas, & O. Pogrebnyak, “Técnica mejorada para contar objetos en una imagen”, en Avances en Inteligencia Artificial, Juan Humberto Sossa Azuela, Gustavo Arroyo Figueroa (Eds.), 2002, ISBN: 970-17-7825-6, pp. 381-389.
- Quintero, G. Guzmán, M. Torres & M. Moreno, “Real-Time Elevation Map Viewer for 3D Spatial Analysis, in International Workshop on Semantic Processing of Spatial Data, Serguei Levechkine, Anne Ruas, Eugene Bodansky (Eds.), 2002, ISBN: 970-18-8521-X, pp. 83-88.
- Sossa, G. Guzmán & R. Sotelo, “Counting the Number of Blobs in an Image”, in IEEE International Conference on Image Processing, IEEE Signal Processing Society, Vol. 1, 2001, ISBN: 0-7803-6725-1 pp. 1086-1089.
- Sossa & G. Guzmán, “New Method to Count Objects into an Image”, in International Conference on Pattern Recognition, A. Sanfeliu, J. J. Villanueva, M. Vanrell, R. Alquézar, J. O. Eklundh, Y. Aloimonos (Eds), IEE Computer Society, Vol. 1, 2000, ISBN: 0-7695-0750-6, pp. 470-473.
Publicaciones en Congresos Nacionales.
- Eduardo Eloy Loza Pacheco, Miguel Jesús Torres Ruiz & José Giovanni Guzmán Lugo, “Razonamiento espacial para determinar la semántica en geo-imágenes: Parte 1”, VII Congreso Internacional Sobre Innovación y Desarrollo Tecnológico CIINDET 2009, Octubre de 2009.
- Eduardo Eloy Loza Pacheco, José Giovanni Guzmán Lugo & Miguel Jesús Torres Ruiz, “Razonamiento espacial para determinar la semántica de geo-imágenes”, 5º. Congreso Internacional “Tendencias Tecnológicas en Computación”, Octubre de 2009.
- Carreto, M. Torres, R. Quintero, M. Moreno & G. Guzmán, “Arquitectura de Colaboración para Entornos/Ambientes de Sistemas de Información Geográfica”, Encuentro Nacional de Computación (ENC-2007), Digital Proceedings, 2007.
- Rolando Quintero, & Giovanni Guzmán, “Modelo de interacción distribuida para videojuegos basados en leyes físicas”, , XIV Congreso Nacional de Informática y Computación de ANIEI, Digital Proceedings, 2001.