Novel Perspectives for the Management of Multilingual and Multialphabetic Heritages through Automatic Knowledge Extraction: The DigitalMaktaba Approach

The linguistic and social impact of multiculturalism can no longer be neglected in any sector, creating the urgent need of creating systems and procedures for managing and sharing cultural heritages in both supranational and multi-literate contexts. In order to achieve this goal, text sensing appears to be one of the most crucial research areas. The long-term objective of the DigitalMaktaba project, born from interdisciplinary collaboration between computer scientists, historians, librarians, engineers and linguists, is to establish procedures for the creation, management and cataloguing of archival heritage in non-Latin alphabets. In this paper, we discuss the currently ongoing design of an innovative workflow and tool in the area of text sensing, for the automatic extraction of knowledge and cataloguing of documents written in non-Latin languages (Arabic, Persian and Azerbaijani). The current prototype leverages different OCR, text processing and information extraction techniques in order to provide both a highly accurate extracted text and rich metadata content (including automatically identified cataloguing metadata), overcoming typical limitations of current state of the art approaches. The initial tests provide promising results. The paper includes a discussion of future steps (e.g., AI-based techniques further leveraging the extracted data/metadata and making the system learn from user feedback) and of the many foreseen advantages of this research, both from a technical and a broader cultural-preservation and sharing point of view

Spectroscopy of the Hubbard dimer: the spectral potential

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Connector theory for reusing model results to determine materials properties

International audienceAbstract The success of Density Functional Theory (DFT) is partly due to that of simple approximations, such as the Local Density Approximation (LDA), which uses results of a model, the homogeneous electron gas, to simulate exchange-correlation effects in real materials. We turn this intuitive approximation into a general and in principle exact theory by introducing the concept of a connector: a prescription how to use results of a model system in order to simulate a given quantity in a real system. In this framework, the LDA can be understood as one particular approximation for a connector that is designed to link the exchange-correlation potentials in the real material to that of the model. Formulating the in principle exact connector equations allows us to go beyond the LDA in a systematic way. Moreover, connector theory is not bound to DFT, and it suggests approximations also for other functionals and other observables. We explain why this very general approach is indeed a convenient starting point for approximations. We illustrate our purposes with simple but pertinent examples

Design of auxiliary systems for spectroscopy

International audienceThe Kohn-Sham system is the prototypical example of an auxiliary system that targets, in principle exactly, an observable like the electronic density without the need to calculate the complicated many-body wavefunction. Although the Kohn-Sham system does not describe excited-state properties directly, it represents a very successful strategy guideline also for many spectroscopy applications. Here we propose a generalization of the Kohn-Sham idea. In many situations one is interested only in limited answers to specific questions, whereas in state-of-the-art approaches a lot of information is generally calculated that is not needed for the interpretation of experimental spectra. For example, while the target is a spectrum S(ω) like the optical absorption of a solid, within time-dependent density-functional theory (TDDFT) one calculates the whole response function χ(r, r , ω). Analogously , within many-body perturbation theory (MBPT) one calculates the whole one-particle Green's function G(r, r , ω), while only the total spectral function A(ω) is needed for angle-integrated pho-toemission spectra. In this contribution, we advocate the possibility to design auxiliary systems with effective potentials or kernels that target only the specific spectral properties of interest and are simpler than the self-energy of MBPT or the exchange-correlation kernel of TDDFT. In particular, we discuss the fundamentals and prototypical applications of simplified effective kernels for optical absorption and spectral potentials for photoemission, and we discuss how to express these potentials or kernels as functionals of the density

Numerical analysis of the annual energy performance of timber buildings in Chile

The research focusses on the analysis of the annual energy performance of one reference building built according to different construction types: mass timber, timber frame and masonry. The buildings are simulated by means of the dynamic software Trnsys in three different cities of Chile (Concepción, Santiago and Osorno), distinguished by different climatic conditions. The developed dynamic models have been tuned on the energy performance of the real building, located in Northern Italy. The design of the HVAC system coupled to the simulated buildings involves a mechanical ventilation system, used for air change and dehumidification, and an air-to-air heat pump, used for thermal zones climatization. For each combination building-location considered in this work the overall energy performance is evaluated and compared one another, in terms of building envelope net energy demand, HVAC system primary energy consumption and heat pump seasonal performance factor (SPF). The analysis shows that, if the space heating energy demand is considered, the two wooden structures are characterized by a similar energy request, while the adoption of the masonry structure determines an increase of 26% for the heating energy consumption. The energy requirement for cooling is present only in Santiago, albeit in minimal quantities. Furthermore, taking into consideration the city of Santiago, it has been verified that the proposed air-to-air heat pump is characterized by a suitable efficiency, during both the heating and the cooling season: the calculated SCOP is around 4, while the value of SEER is approximately 3

Unraveling intrinsic correlation effects with angle-resolved photoemission spectroscopy

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