A Distributed and Accountable Approach to Offline Recommender Systems Evaluation

Different software tools have been developed with the purpose of performing offline evaluations of recommender systems. However, the results obtained with these tools may be not directly comparable because of subtle differences in the experimental protocols and metrics. Furthermore, it is difficult to analyze in the same experimental conditions several algorithms without disclosing their implementation details. For these reasons, we introduce RecLab, an open source software for evaluating recommender systems in a distributed fashion. By relying on consolidated web protocols, we created RESTful APIs for training and querying recommenders remotely. In this way, it is possible to easily integrate into the same toolkit algorithms realized with different technologies. In details, the experimenter can perform an evaluation by simply visiting a web interface provided by RecLab. The framework will then interact with all the selected recommenders and it will compute and display a comprehensive set of measures, each representing a different metric. The results of all experiments are permanently stored and publicly available in order to support accountability and comparative analyses.Comment: REVEAL 2018 Workshop on Offline Evaluation for Recommender System

Optimization of force-limiting seismic devices connecting structural subsystems

This paper is focused on the optimum design of an original force-limiting floor anchorage system for the seismic protection of reinforced concrete (RC) dual wall-frame buildings. This protection strategy is based on the interposition of elasto-plastic links between two structural subsystems, namely the lateral force resisting system (LFRS) and the gravity load resisting system (GLRS). The most efficient configuration accounting for the optimal position and mechanical characteristics of the nonlinear devices is obtained numerically by means of a modified constrained differential evolution algorithm. A 12-storey prototype RC dual wall-frame building is considered to demonstrate the effectiveness of the seismic protection strategy

Sequeval: A Framework to Assess and Benchmark Sequence-based Recommender Systems

In this paper, we present sequeval, a software tool capable of performing the offline evaluation of a recommender system designed to suggest a sequence of items. A sequence-based recommender is trained considering the sequences already available in the system and its purpose is to generate a personalized sequence starting from an initial seed. This tool automatically evaluates the sequence-based recommender considering a comprehensive set of eight different metrics adapted to the sequential scenario. sequeval has been developed following the best practices of software extensibility. For this reason, it is possible to easily integrate and evaluate novel recommendation techniques. sequeval is publicly available as an open source tool and it aims to become a focal point for the community to assess sequence-based recommender systems.Comment: REVEAL 2018 Workshop on Offline Evaluation for Recommender System

Reconstrucción digital no métrica de mosaicos romanos excavados en la ciudad de Rávena (Italia)

[EN] During the excavations carried out in summer 2011 in Piazza Anita Garibaldi in Ravenna, during construction of the new underground waste containers, five rooms decorated with mosaic floors were found, probably dating back to the early Roman Empire (1st-2ndcentury AD). The mosaics were removed for restoration and musealisation, however –given the size of the large lacunae-it would not be possible to reintegrate them in a traditional restoration without creating arbitrary reconstructions. Therefore, we opted for a digital reconstruction of the lacunae, attempting virtual restoration hypotheses for the recovered mosaics. Subsequently, it was possible to grasp the trend of the figuration and how it could have appeared in the past. The characteristics of many mosaics, such as the symmetry and the repetition of geometric patterns, make them suitable for both a simulated integration and are construction by the analogies of the pattern. As a matter of fact, we used simple and easily accessible software to perform this work. The purpose of this digital workflow was to give an example of virtual processing useful for conservators and restorers, as well as for scholars (archaeologists, art historians, etc.) that can be carried out without specific information technology expertise and computer skills. After the images were acquired digitally, we were able to proceed with the reconstruction of the floor, by taking into account the geometric motifs that make up the mosaic assembly and that made the recomposition the most reliable. The virtual restoration also provides the opportunity of simulating the type of integration and the colour so that scholars, restorers and conservators may evaluate the final appearance of the work and the different aesthetic choices. The virtual restoration is finally considered an essential tool for the enhancement of cultural heritage.[ES] Durante las excavaciones llevadas a cabo en el verano de 2011 en la Plaza Anita Garibaldi en Rávena para la fabricación de nuevos contenedores soterrados, se encontraron cinco habitaciones decoradas con mosaicos en el piso, que probablemente datan de principios del imperio romano (siglo I-II d. C.). Los mosaicos fueron retirados para la restauración y musealización, sin embargo –dado el tamaño de las lagunas grandes-no sería posible reintegrarlos siguiendo una restauración tradicional sin crear reconstrucciones arbitrarias. Por esta razón, hemos optado por una reconstrucción digital de las lagunas, haciendo algunas hipótesis de restauración virtual delos mosaicos recuperados. De esta manera, es posible figurar cómo podría haber sido en el pasado. Las características de muchos mosaicos, como son la simetría y la repetición de los patrones geométricos, los hacen adecuados tanto para una integración simulada como para la reconstrucción por analogía del patrón geométrico. De hecho, utilizamos software muy simple para realizar este trabajo, ya que nuestro propósito era dar un ejemplo de procesamiento virtual útil para conservadores y restauradores, así como para académicos (arqueólogos, historiadores del arte, etc.) que puede llevarse a cabo sin conocimientos específicos ni conocimientos informáticos. Una vez adquiridas las imágenes en formato digital, pudimos proceder a la reconstrucción real del piso, teniendo en cuenta los motivos geométricos que conforman el ensamblaje del mosaico y que hicieron la recomposición más fiable. La restauración virtual también brinda la oportunidad de simular en la imagen digital el tipo de integración y el color para que los estudiosos puedan evaluar la apariencia final del trabajo y las diferentes elecciones estéticas. La restauración virtual se considera finalmente una herramienta esencial para la mejora del patrimonio cultural.We are grateful to the Editor-in-Chief Prof. José Luis Lerma for useful suggestions. Pictures of the excavations were taken by RavennAntica Foundation and Superintendence for Archaeological Heritage of Emilia-Romagna, Italy. Virtual restorationswere carried out by Mariapaola Monti.Monti, M.; Maino, G. (2018). Non-metric digital reconstruction of Roman mosaics excavated in the city of Ravenna (Italy). Virtual Archaeology Review. 9(19):66-75. doi:10.4995/var.2018.7227SWORD6675919Bennardi, D., &Furferi, R. (2007). Il restauro virtuale. Tra ideologia e metodologia. Florence: Edifir.Biagi Maino, D., &Maino, G. (2017). 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Skopje: Euro-Balkan University.Degrigny, C., Piqué, F., Papiashvili, N., Guery, J., Mansouri, A., Le Goïc, G., Detalle, V.,Martos-Levif, D., Mounier, A., Wefers, S., Tedeschi, C., Cucchi, M., Vallet, J., Pamart, A., & Pinette, M. (2016). Technical study of Germolles' wall paintings: the input of imaging techniques. Virtual Archaeology Review, 7(15), 1-8.doi:10.4995/var.2016.5831Fiori, C., &Vandini, M. (2002). Teoria e tecniche per la conservazione del mosaico. Padova: Il PratoGonzalez, R.C., &Woods, R.E. (1993). Digital Image Processing. New York: Addison-Wesley.Higuchi, R., Suzuki, T., Shibata, M., Taniguchi, Y., & Galyaz, M. (2016). Digital non-metric image-based documentation for the preservation and restoration of mural paintings: the case of the Ozomlo Rock-Hewn church, Turkey. Virtual Archaeology Review, 7(14), 31-42.doi:10.4995/var.2016.4241Maino, G., &Visparelli, D. (2003). Il museo virtuale dei mosaici. In Atti del Convegno Contesti virtuali e fruizione dei beni culturali, Naples, May 22-23,2003 (pp.1-6). Naples, Italy.Maino, G., Orlandi, M., & Malkowski, G. (2005). Documentare i mosaici tramite GIS.In La tecnologia al servizio dei beni culturali. Nuovi sistemi di catalogazione, visualizzazione e salvaguardia (pp.17-19).Rome: ENEA Technical Report.Maino, G. (2007).Digitization and multispectral analysis of historical books and archival documents: Two exemplary cases. In 14th International Conference on Image Analysis and Processing-Workshop (ICIAPW 2007), vol.II, (pp.119-124).doi:10.1109/ICIAPW.2007.23Maino, G., &Massari, S. (2010).Digitization and multispectral analysis of artistic objects: exemplary cases and web documentation. In Science for Cultural Heritage (pp.164-171).Singapore: World Scientific.doi:10.1142/9789814307079_0014Maino, G. (2015).The mosaics of Macedonia: conservation and restoration issues. In L. Kniffitz, & E. Carbonara (Eds.), Ravenna Musiva. Preservation and restoration of architectural decoration, mosaics and frescoes (pp.316-331, plates 44-47).Maino, G., &Monti, M. (2015). Color Management and Virtual Restoration of Artworks. In E. Celebi, M.Lecca, &B. Smolka (Eds.), Color Image and Video Enhancement (pp.183-231).Cham: Springer. doi:10.1007/978-3-319-09363-5_7Menghi, R., Monti, M., &Maino, G. (2012).Principles of virtual restoration and application to artistic and archaeological objects. In G. Vezzalini, & P. Zannini (Eds.), Proceedings of A.I.Ar. 2012 Modena -VII Congresso nazionale di Archeometria (pp. 618-631).Bologna: Patron.Monti, M., &Maino, G. (2011).Image processing and a virtual restoration hypothesis for mosaics and their cartoons. In G. Maino, & G. L. Foresti (Eds.), Image Analysis and Processing -ICIAP 2011.Lecture Notes in Computer Science, 6979, 486-495. doi:10.1007/978-3-642-24088-1_50Nencini, E., & Maino, G. (2011).From the physical restoration for preserving to the virtual restoration for enhancing. In G. Maino, & G. L. Foresti (Eds.), Image Analysis and Processing -ICIAP 2011.Lecture Notes in Computer Science, 6978, 700-709. doi:10.1007/978-3-642-24085-0_71Rivola, R., Castagnetti, C., Bertacchini, E., &Casagrande, F. (2016). Le tecniche geomatiche a supporto dei Beni Culturali.Archeomatica,1,34-37