Hierarchical structuring of Cultural Heritage objects within large aggregations

Huge amounts of cultural content have been digitised and are available through digital libraries and aggregators like Europeana.eu. However, it is not easy for a user to have an overall picture of what is available nor to find related objects. We propose a method for hier- archically structuring cultural objects at different similarity levels. We describe a fast, scalable clustering algorithm with an automated field selection method for finding semantic clusters. We report a qualitative evaluation on the cluster categories based on records from the UK and a quantitative one on the results from the complete Europeana dataset.Comment: The paper has been published in the proceedings of the TPDL conference, see http://tpdl2013.info. For the final version see http://link.springer.com/chapter/10.1007%2F978-3-642-40501-3_2

Charge Ordering in Organic ET Compounds

The charge ordering phenomena in quasi two-dimensional 1/4-filled organic compounds (ET)_2X (ET=BEDT-TTF) are investigated theoretically for the $\theta$ and $\alpha$-type structures, based on the Hartree approximation for the extended Hubbard models with both on-site and intersite Coulomb interactions. It is found that charge ordered states of stripe-type are stabilized for the relevant values of Coulomb energies, while the spatial pattern of the stripes sensitively depends on the anisotropy of the models. By comparing the results of calculations with the experimental facts, where the effects of quantum fluctuation is incorporated by mapping the stripe-type charge ordered states to the S=1/2 Heisenberg Hamiltonians, the actual charge patterns in the insulating phases of $\theta$-(ET)_2MM'(SCN)_4 and $\alpha$-(ET)_2I_3 are deduced. Furthermore, to obtain a unified view among the $\theta$, $\alpha$ and $\kappa$-(ET)_2X families, the stability of the charge ordered state in competition with the dimeric antiferromagnetic state viewed as the Mott insulating state, which is typically realized in $\kappa$-type compounds, and with the paramagnetic metallic state, is also pursued by extracting essential parameters.Comment: 35 pages, 27 figures, submitted to J. Phys. Soc. Jp

Seismic Response of a Historical Unreinforced Masonry Building Damaged in the 2014 South Napa Earthquake

Several unreinforced masonry buildings damaged during the 2014 South Napa earthquake, California, USA, were investigated after the earthquake. The numerical analyses conducted on a representative example are presented in this paper. The building is the Sam Kee laundry building, the oldest stone commercial building in Napa, built in 1875. The geometry of the building was accurately captured by a laser scanner. Using this geometry information and material data available in literature for similar buildings, a finite element model of the building was developed according to the equivalent frame approach and was subjected to nonlinear time history analyses. The investigated building was closely located to a strong motion station on Main Street, Napa, California. This record was used as seismic excitation input to the numerical model. Results of the conducted analyses accurately predicted the observed damage in the building which consisted of shear cracks and shear damage in the south and north walls and failure of piers from the east wall. Analysis results are used to describe the reasons of the observed damage

A Novel Vision for Navigation and Enrichment in Cultural Heritage Collections

International audienceIn the cultural heritage domain, there is a huge interest in utilizing semantic web technology and build services enabling users to query, explore and access the vast body of cultural heritage information that has been created over decades by memory institutions. For successful conversion of existing data into semantic web data, however, there is often a need to enhance and enrich the legacy data to validate and align it with other resources and reveal its full potential. In this visionary paper, we describe a framework for semantic enrichment that relies on the creation of thematic knowledge bases, i.e., about a given topic. These knowledge bases aggregate information by exploiting structured resources (e.g., Linked Open Data cloud) and by extracting new relationships from streams (e.g., Twitter) and textual documents (e.g., web pages). Our focused application in this paper is how this approach can be utilized when transforming library records into semantic web data based on the FRBR model in the process that commonly is called FRBRization