Strumenti e metodi per la documentazione digitale degli scavi archeologici: La Blanca (Petén - Guatemala)

[EN] In the context of the Mayan architectural heritage documentation, the use of devices that make extensive use of electronics and informatics has for several years supported traditional survey methods. Thanks to 3D models that are obtained by employing digital techniques and instruments, the description of an object is no longer relegated to just the conventional systems of representation, that, while remaining the irreplaceable drawings to exhaustively describe an artefact, can be accompanied with profit with other ¿products¿ that the world of computer graphics and reverse engineering allow, nowadays, to create. The most evident results are found, for example, in the dissemination of research results, with irrefutable and effective impact on the intelligibility of the analysis carried out, as well as on morphological, material and perceptual aspects of the artefacts. The paper illustrates the results of survey campaigns and operations of data restitution, that have been realized, between 2015 and 2016, in the sites of La Blanca and El Chilonché (Departamento de Petén, Guatemala) by the research group of DIDA committed to ¿Proyecto La Blanca.Merlo, A.; Aliperta, A.; Montuori, R. (2017). Strumenti e metodi per la documentazione digitale degli scavi archeologici: La Blanca (Petén - Guatemala). Restauro Archeologico. 26-47. doi:10.13128/RA-20525S264

La mappatura dei modelli digitali ottenuti mediante sensori attivi: verso nuove e più ampie prospettive di utilizzo

Il problema della mappatura del colore sui modelli digitali 3D ottenuti da sensori attivi apre numerose opportunità di ricerca e di riflessione dal momento in cui gli attuali sistemi di rilevamento laser scanner presentano limitazioni circa l’acquisizione del colore apparente, sia dovute alle condizioni logistiche del rilevamento, sia imputabili alle caratteristiche delle fotocamere montate su tali apparecchi. Il caso di studio qui trattato riguarda il progetto pilota per la valorizzazione e la salvaguardia delle chiese barocche in stile Ispano-americano facenti parte del patrimonio architettonico della città di Antigua Guatemala (Guatemala) fortemente danneggiato nel corso del secolo XVIII da un sisma di grande entità. L’obiettivo del progetto è quello di costruire modelli digitali 3D in grado di rappresentare accuratamente l’attuale stato di conservazione delle strutture e delle superfici esterne che presentano in molti casi un ricco apparato decorativo caratterizzato da affreschi policromi. Il rilevamento della Chiesa della Compagnia di Gesù eseguito attraverso scanner laser a variazione di fase non è però in grado di produrre texture del colore apparente a risoluzioni sufficientemente alte ed in condizioni favorevoli da consentire una adeguata mappatura sotto il profilo radiometrico; pertanto si è provveduto ad eseguire una apposita campagna fotografica finalizzata all’ottenimento di mappe di alta qualità corrette grazie a strumenti di editing bitmap che fanno largo uso dei vantaggi tipici dei formati .HDR e .RAW. Le texture del colore, integrate da mappe di normali e di scostamento, hanno permesso di realizzare modelli ottimizzati e multifunzione capaci cioè di fornire rappresentazioni interattive di alta qualità (fruibili via web attraverso applicazioni real-time), così come elaborati finalizzati alle pratiche di manutenzione e restauro attraverso disegni 2D. Il binomio costituito dalla sinergia di applicativi fotogrammetrici e di editing evoluto di immagini a 32 bit conferisce alla mappatura dei modelli digitali una affidabilità ad ampio raggio, tale da renderli congrui con le più elevate esigenze di conservazione e diffusione

Functional mimicry of Ruffini receptors with fibre Bragg gratings and deep neural networks enables a bio-inspired large-area tactile-sensitive skin

Collaborative robots are expected to physically interact with humans in daily living and the workplace, including industrial and healthcare settings. A key related enabling technology is tactile sensing, which currently requires addressing the outstanding scientific challenge to simultaneously detect contact location and intensity by means of soft conformable artificial skins adapting over large areas to the complex curved geometries of robot embodiments. In this work, the development of a large-area sensitive soft skin with a curved geometry is presented, allowing for robot total-body coverage through modular patches. The biomimetic skin consists of a soft polymeric matrix, resembling a human forearm, embedded with photonic fibre Bragg grating transducers, which partially mimics Ruffini mechanoreceptor functionality with diffuse, overlapping receptive fields. A convolutional neural network deep learning algorithm and a multigrid neuron integration process were implemented to decode the fibre Bragg grating sensor outputs for inference of contact force magnitude and localization through the skin surface. Results of 35 mN (interquartile range 56 mN) and 3.2 mm (interquartile range 2.3 mm) median errors were achieved for force and localization predictions, respectively. Demonstrations with an anthropomorphic arm pave the way towards artificial intelligence based integrated skins enabling safe human–robot cooperation via machine intelligence

A meta-learning algorithm for respiratory flow prediction from FBG-based wearables in unrestrained conditions

The continuous monitoring of an individual's breathing can be an instrument for the assessment and enhancement of human wellness. Specific respiratory features are unique markers of the deterioration of a health condition, the onset of a disease, fatigue and stressful circumstances. The early and reliable prediction of high-risk situations can result in the implementation of appropriate intervention strategies that might be lifesaving. Hence, smart wearables for the monitoring of continuous breathing have recently been attracting the interest of many researchers and companies. However, most of the existing approaches do not provide comprehensive respiratory information. For this reason, a meta-learning algorithm based on LSTM neural networks for inferring the respiratory flow from a wearable system embedding FBG sensors and inertial units is herein proposed. Different conventional machine learning approaches were implemented as well to ultimately compare the results. The meta-learning algorithm turned out to be the most accurate in predicting respiratory flow when new subjects are considered. Furthermore, the LSTM model memory capability has been proven to be advantageous for capturing relevant aspects of the breathing pattern. The algorithms were tested under different conditions, both static and dynamic, and with more unobtrusive device configurations. The meta-learning results demonstrated that a short one-time calibration may provide subject-specific models which predict the respiratory flow with high accuracy, even when the number of sensors is reduced. Flow RMS errors on the test set ranged from 22.03 L/min, when the minimum number of sensors was considered, to 9.97 L/min for the complete setting (target flow range: 69.231 ± 21.477 L/min). The correlation coefficient r between the target and the predicted flow changed accordingly, being higher (r = 0.9) for the most comprehensive and heterogeneous wearable device configuration. Similar results were achieved even with simpler settings which included the thoracic sensors (r ranging from 0.84 to 0.88; test flow RMSE = 10.99 L/min, when exclusively using the thoracic FBGs). The further estimation of respiratory parameters, i.e., rate and volume, with low errors across different breathing behaviors and postures proved the potential of such approach. These findings lay the foundation for the implementation of reliable custom solutions and more sophisticated artificial intelligence-based algorithms for daily life health-related applications

L'architettura palaziale maya del periodo clásico tardío: Geometria e misura nell'Acópolis di La Blanca (Petén, Guatemala)La arquitectura palaciega maya del periodo cásico tardío: Geometría y medidas en la Acrópolis de La Blanca (Petén, Guatemala)

A pesar de que se han realizado grandes avances sobre el conocimiento de esta antigua civilización maya, aún queda mucho por investigar sobre las proporciones y geometría de los espacios construidos, cuyos resultados nos permitiría comprender mejor el pensamiento arquitectónico de los antiguos mayas. Por ello esta investigación se centra en estudios morfológicos y métricos sobre la arquitectura maya. El objetivo principal de este trabajo es profundizar, a través de la investigación geométrico-métrica, en el conocimiento de la arquitectura maya palaciega del período Clásico Tardío. Como punto de partida se toma la Acrópolis de La Blanca, un asentamiento maya ubicado en la región del Petén guatemalteco La metodología de investigación propuesta se basa en el levantamiento arquitectónico realizado con ayuda de la tecnología digital actual, lo que permite alcanzar en la adquisición de datos un nivel de precisión muy elevado, proporcionando una documentación arquitectónica exacta de los edificios que son objeto de estudio. Cabe tener en cuenta que la mayoría de estos edificios están en riesgo o en mal estado de conservación, ya que se encuentran en un medio ambiente hostil. En este contexto, el levantamiento arquitectónico se combina con la investigación arqueológica, por lo que es necesario desarrollar una metodología de adquisición de datos válida y fiable, no sólo para los elementos ya visibles, sino también para aquellos que diariamente salen a la luz conforme avanza la excavación arqueológica. Los modelos tridimensionales, obtenidos a partir de los datos del levantamiento digital, se convierten en una herramienta eficaz para llevar a cabo, con el rigor científico apropiado, un análisis métrico-dimensional de los edificios a distintas escalas, cuyos resultados nos permitirá formular hipótesis sobre el pensamiento y criterios de diseño que emplearon los antiguos mayas para construir estos edificios dentro de este contexto cultural.Aquesta investigació forma part dels estudis morfomètrics dels edificis relacionats, en particular, a l'arquitectura maia. Tot i que la Civilització Maia ha estat i esta sent estudiada, el tema de les proporcions i la geometria necessària per traduïr el pensament arquitectònic en espais construïts, avui en dia encara està poc investigat. Aquest treball té com a objectiu aprofundir, a través de la investigació geométrica-mètrica, el coneixement de la arquitectura palatina maia del periode Clàsico Tardío, a partir de l'estudi de l'Acrópolis de La Blanca, un assentament maia ubicat en la regió del Petén guatemaltec. El mètode d'investigació proposat està basat en l'aixecament fet amb l'ajuda de les tecnologies digitals actuals, que, permitint obtenir un nivell de precisió molt alt en l'adquisició de les dades, proporcionen una documentació més precisa dels artefactes que, en l'actualitat, estàn majoritàriament en estat de ruïna i la seva conservació està en risc al trovar-se en un medi ambient hostil. En aquest context l'aixecament arquitectònic es combina amb l'aixecament arqueològic, pel que és necessari el desenvolupament d'una metodologia d'adquisició vàlida i fiable no només per als artefactes ja visibles, sinó també per a aquells que diàriament surten a la llum en el transcurs de tota la campanya d'excavació. Les elaboracions tridimensionals obtingudes mitjançant les dades de l'aixecament digital, gràcies a l'ajuda d'aplicacions específiques, representen una eficaç eina per a dur a terme, amb el rigor científic apropiat, anàlisi mètric-dimensionals de l'artefacte pertanyents a diferents escales, després dels quals formular hipòtesi sobre el pensament de disseny que va conduir a la seva realització dins el context cultural on es van construir. Aquesta investigació es desenvolupa en un context de cooperació internacional entre la Universitat de Florència i la Universitat Politècnica de València.The present research is part of the morphometric studies of the built environment related, in particular, to Mayan architecture. Despite the Mayan civilization has been and continues to be the subject of study, the theme of proportion and geometry, useful to translate the architectural thinking in built spaces, it is still little discussed. This work aims to deepen, through the metric and geometrical investigation, the knowledge of mayan palatial architecture of the Clásico Tardío period, starting from the study of the Acrópolis of La Blanca, a settlement located in the region of the Guatemalan Petén. The proposed research method is based on the survey carried out with the help of current digital technologies, which, allowing to achieve a very high precision in data acquisition, allow accurate documentation of the artifacts that are mostly in state of ruin and whose conservation in hostile environments is at risk. In this context, the architecture survey merges with the archaeological one making it necessary the develop of a valid and reliable acquisition methodology not only for the already visible artefacts, but also for those fragments that are brought to light every day over an entire excavation campaign. The three-dimensional models obtained starting from digital survey data, thanks to the help of proper software, represent an effective tool to perform, with the appropriate scientific rigor, geometric and dimensional analysis on artefacts at different scales as a result of which to formulate hypotheses on the design thinking that led to their realization in constant reference with the cultural context in which they were erected. The research was carried out within an international cooperation project between the University of Florence and the Universitat Politècnica de València.Aliperta, A. (2018). L'architettura palaziale maya del periodo clásico tardío: Geometria e misura nell'Acópolis di La Blanca (Petén, Guatemala)La arquitectura palaciega maya del periodo cásico tardío: Geometría y medidas en la Acrópolis de La Blanca (Petén, Guatemala) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/113179TESI