403 research outputs found

    POSFET tactile sensing arrays using CMOS technology

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    This work presents fabrication and evaluation of novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing chip. In the newer version presented here, the tactile sensing chip has been fabricated using CMOS (Complementary Metal Oxide Semiconductor) technology. The chip consists of 4 x 4 POSFET touch sensing devices (or taxels) and both, the individual taxels and the array are designed to match spatio–temporal performance of the human fingertips. To detect contact events, the taxels utilize the contact forces induced change in the polarization level of piezoelectric polymer (and hence change in the induced channel current of MOS). The POSFET device on the chip have linear response in the tested dynamic contact forces range of 0.01–3 N and the sensitivity (without amplification) is 102.4 mV/N

    Interacting with virtual reconstructions in museums: The etruscanning project

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    Starting from our experience in this domain, we discuss some fundamental concepts about the potentialities of the virtual reconstructions of cultural sites inside museums, with a specific focus on the communication needs, the design, the combination of media, the interaction interfaces, and the embodiment. We conceive a virtual reconstruction as a digital ecosystem, whose main peculiarities are (1) 3D reconstruction, (2) inclusivity, and (3) interactivity. A virtual reconstruction, in a wide sense, should integrate different levels of visualization, both realistic and symbolic; 3D models; metadata; storytelling; behaviors; and tools of visualization and interaction, in order to "reconstruct" and communicate a cultural context, an ecosystem where all the information is integrated. Despite the great advancements of the last years in the digitization process, computer graphics techniques, and archiving strategies, a basic limit of most of virtual museums is that they do not fire up the attention and the involvement of the public: they lack stimulating activities for visitors, narratives metaphors, and emotional impact. The interaction interfaces are not always simple to understand and to control in a few minutes, and they can generate a sense of frustration that causes users to abandon the application after a short and superficial approach. No gap should exist between knowledge and communication. But how can we translate the complexity of the knowledge in appealing to users and into simple applications that fit with the public's need? This article focuses on some communication rules and criteria that are often considered of minor importance by the researchers working in the field of digital cultural heritage but that are really essential to cultural transmission, especially inside museums. We believe that a stronger collaboration between research institutions and museums and among different disciplines would be recommended. Given this premise, we present the Etruscanning EU project, developed in 2011- 2013, focused on the virtual reconstruction of two important Etruscan tombs of the Orientalizing period: the Regolini-Galassi tomb in Cerveteri and the tomb n.5 of Monte Michele in Veii. © 2014 ACM

    NEWPERS PECTIVES FOR MAPPING ALTERATIONS IN HBIMIN CONSERVATION PROJECTS

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    Historic Building Information Modelling (HBIM) finds one of its most interesting applications in conservation design. The HBIMapproachdid not originate as a simple data archive method but as an information tool to help the designer at all stages of the building process. Turning to the field of preservation, a lot of information about the building is represented by thematic maps. They makeit possible to get a graphic representation of the state of conservation of a facade or to understand the structural situation of a building. This research, experimented on the Arch of Augustus in Aosta, starts from the large amount of data acquired by the RAVA Laboratory of the Superintendence of Aosta over a long period. These data allowed for testing different approaches to thematic mapping, depending on the specific themes to be represented. In any case, even this experimentation required theoretical reasoning that preceded the operational phases. The question, which this article wants only to start to address, concerns the role of thematic mappings in the preservation project carried out with an HBIM approach, their necessity, and their implementation towards truly threedimensional data, which therefore maintains all the information that is directly acquired in three dimensions

    NEW PERSPECTIVES FOR MAPPING ALTERATIONS IN HBIM IN CONSERVATION PROJECTS

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    Historic Building Information Modelling (HBIM) finds one of its most interesting applications in conservation design. The HBIM approach did not originate as a simple data archive method but as an information tool to help the designer at all stages of the building process. Turning to the field of preservation, a lot of information about the building is represented by thematic maps. They make it possible to get a graphic representation of the state of conservation of a facade or to understand the structural situation of a building. This research, experimented on the Arch of Augustus in Aosta, starts from the large amount of data acquired by the RAVA Laboratory of the Superintendence of Aosta over a long period. These data allowed for testing different approaches to thematic mapping, depending on the specific themes to be represented. In any case, even this experimentation required theoretical reasoning that preceded the operational phases. The question, which this article wants only to start to address, concerns the role of thematic mappings in the preservation project carried out with an HBIM approach, their necessity, and their implementation towards truly threedimensional data, which therefore maintains all the information that is directly acquired in three dimensions

    Tactile sensing chips with POSFET array and integrated interface electronics

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    This work presents the advanced version of novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing chip. The new version of the tactile sensing chip presented here comprises of a 4 x 4 array of POSFET touch sensing devices and integrated interface electronics (i.e. multiplexers, high compliance current sinks and voltage output buffers). The chip also includes four temperature diodes for the measurement of contact temperature. Various components on the chip have been characterized systematically and the overall operation of the tactile sensing system has been evaluated. With new design the POSFET devices have improved performance (i.e. linear response in the dynamic contact forces range of 0.01–3N and sensitivity (without amplification) of 102.4 mV/N), which is more than twice the performance of their previous implementations. The integrated interface electronics result in reduced interconnections which otherwise would be needed to connect the POSFET array with off-chip interface electronic circuitry. This research paves the way for CMOS (Complementary Metal Oxide Semiconductor) implementation of full on-chip tactile sensing systems based on POSFETs

    The Significance of Porches in Urban Applications: A Method for Automated Modeling and Integration

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    Porches, as defined by the Art & Architecture Thesaurus, serve as vital transitional spaces linking indoor and outdoor environments. Despite their historical and contemporary significance, porches lack explicit representation in prevalent standards like CityGML and IndoorGML, posing challenges for comprehensive spatial modeling and its application. This paper proposes a method for modeling porches that aligns with the existing OGC standard CityGML 3.0, ensuring accuracy and compatibility. Drawing upon geomatics techniques, the method aims to bridge the gap in representing these spaces, critical for applications such as navigation systems, urban planning, and energy simulations. By integrating geometric, machine learning, and informative modeling approaches, this method seeks to provide a robust foundation for various practical applications. The paper outlines a comprehensive state-of-the-art review, describes the proposed method from digitalization to random forest (RF)-based point cloud classification and vectorization, presents case studies and results, and offers critical discussions and conclusions. Through this endeavor, the paper contributes to enhancing the representation and understanding of porches within the digital spatial landscape

    THE ARCH OF AUGUSTUS IN AOSTA: DATA AND ANALYSIS REUSE FOR A CONSERVATION PROJECT

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    The paper proposes a path for the management of the Arch of Augustus in Aosta to exploit the potential of Historic Building Information Modelling (HBIM). The HBIM system acts both as a place where to georeference the available data and as a tool for the elaboration of the conservation project in all its aspects. The system deals with different data from the survey of geometries to that of materials and alterations, up to the conservation project (mainly focused on the surfaces, with the aim of traceability of the events that the monument has lived, lives, and will live). The challenges in this research concern several aspects. First, it will be necessary to adapt the regular geometry of the BIM approach to the complex shapes necessary for the reproduction of surface alterations in the Puddinga stone. In addition, even more important, the ability to manage the monitoring data distributed at different times, comparing and making them available to current and future restorers (and other operators involved in the preservation). These tasks will be fixed by drawing up a dynamic conservation project, i.e. one that can make use of the available data at any time and all those that will become available during the work. Attempts of data digitization to give a shared value to the conservation activities had already been proposed in the past. The new research now starts from the reconnaissance of the weaknesses of the previous proposals, mainly related to the use of tailor-made systems (software) that are difficult to maintain, to implement and use in a very heterogeneous team of operators (architects, archaeologists, engineers, topographers, chemists, historians…

    Drones and Real-Time Kinematic Base Station Integration for Documenting Inaccessible Ruins: A Case Study Approach

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    Ruins, marked by decay and abandonment, present challenges for digital documentation due to their varied conditions and remote locations. Surveying inaccessible ruins demands innovative approaches for safety and accuracy. Drones with high-resolution cameras enable the detailed aerial inspection and imaging of these inaccessible areas. This study investigated how surveying technologies, particularly Unmanned Aerial Vehicles (UAVs), are used to document inaccessible ruins. Integration with Real-Time Kinematic (RTK) technologies allows direct georeferencing in photogrammetric processing. A case study of the Castle of Terracorpo in Italy was used to demonstrate UAV-only surveying feasibility in inaccessible environments, testing two different scenarios. The first scenario involved the use of a DJI Matrice 300 RTK coupled with the D-RTK2 base station to survey the Castle; both direct and indirect georeferencing were exploited and compared through the photogrammetric process. This first scenario confirmed that this approach can lead to a centimetre-level accuracy (about three times the GSD value for indirect georeferencing and seven times the GSD value for direct georeferencing exploting RTK). The second scenario testing the integration of data from drones at varying resolutions enabled the comprehensive coverage of ruinous structures. In this case, the photogrammetric survey performed with the dji Mavic 3 Cine drone (indirect georeferencing) was integrated with the photogrammetric survey performed with the dji Matrice 300 RTK drone (direct georeferencing). This scenario showed that GCPs extracted from a direct georeferencing photogrammetric survey could be successfully used to georeference and integrate other drone data. However, challenges persist in surveying underground or enclosed spaces that are inaccessible to UAVs. Future research will explore integrating robotic LiDAR survey systems and advanced data fusion techniques to enhance documentation

    MEMS Piezoresistive Micro-Cantilever Arrays for Sensing Applications

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    In several application fields there is an increasing need for a diffused on-field control of parameters able to diagnosis potential risks or problems in advance or in early stages in order to reduce their impact. The timely recognition of specific parameters is often the key for a tighter control on production processes, for instance in food industry, or in the development of dangerous events such as pollution or the onset of diseases in humans. Diffused monitoring can be hardly performed with traditional instrumentation in specialised laboratories, due to the time required for sample collection and analysis. In all applications, one of the key-points for a successful solution of the problem is the availability of detectors with high-sensitivity and selectivity to the chemical or biochemical parameters of interest. Moreover, an increased diffused on-field control of parameters can be only achieved by replacing the traditional costly laboratory instrumentations with a larger number of low cost devices. In order to compete with well-known and established solution, one of main feature of new systems is the capability to perform specific tests on the field with fast response times; in this perspective, a fast measurement of reduced number of parameters is to be preferred to a straightforward “clone” of laboratory instrumentation. Moreover, the detector must also provide robustness and reliability for real-world applications, with low costs and easiness of use. In this paradigm, MEMS technologies are emerging as realisation of miniaturised and portable instrumentation for agro-food, biomedical and material science applications with high sensitivity and low cost. In fact, MEMS technologies can allow a reduction of the manufacturing cost of detectors, by taking advantage of the parallel manufacturing of large number of devices at the same time; furthermore, MEMS devices can be potentially expanded to systems with high level of measurement parallelism. Device costs are also a key issues when devices must be for “single use”, which is a must in application where cross-contamination between different measurement is a major cause of system failure and may cause severe consequences, such as in biomedical application. Among different options, cantilever micro-mechanical structures are one of the most promising technical solution for the realisation of MEMS detectors with high sensitivity. This thesis deals with the development of cantilever-based sensor arrays for chemical and biological sensing and material characterisation. In addiction to favourable sensing properties of single devices, an array configuration can be easily implemented with MEMS technologies, allowing the detection of multiple species at the same time, as well as the implementation of reference sensors to reject both physical and chemical interfering signals. In order to provide the capability to operate in the field, solution providing simple system integration and high robustness of readout have been preferred, even at the price of a lower sensitivity with respect to other possibilities requiring more complex setups. In particular, piezoresistive readout has been considered as the best trade-off between sensitivity and system complexity, due to the easy implementation of readout systems for resistive sensors and to their high potential for integration with standard CMOS technologies. The choice has been performed after an analysis of mechanical and sensing properties of microcantilever, also depending of technological options for their realisation. As case-studies for the development of cantilever devices, different approaches have been selected for gas sensing applications, DNA hybridisation sensing and material characterisation, based on two different technologies developed at the BioMEMS research unit of FBK (Fondazione Bruno Kessler - Center for Materials and Microsystems, Trento). The first process, based on wet-etching bulk micromachining techniques, has provided 10 µm-thick silicon microcantilevers while the second technology, based on Silicon-On-Insulator (SOI) wafer, has provided a reduction of device thickness, thus resulting in an increase of sensitivity. Performances of devices has been investigated by analytical and numerical modelling of both structures and readout elements, in order to optimise both fabrication technology and design. In particular, optimal implant parameters for the realisation of piezoresistors have been evaluated with process simulation with Athena Silvaco simulation software, while ANSYS has been used to analyse the best design for devices and the effect of some technology-related issues, such as the effect of underetch during the release of the beams or residual stresses. Static and modal analysis of cantilever bending in different conditions have been performed, in order to evaluate the mechanical performances of the device, and later results have been compared with the experimental characterisation. With regard to gas sensing applications, the development has been oriented to resonant sensors, where the adsorption of analytes on a adsorbent layer deposited on the cantilever leads to shift of resonance frequency of the structure, thus providing a gravimetric detection of analytes. The detection of amines, as markers of fish spoilage during transport, has been selected as a case-study for the analysis of these sensors. The sensitivity of devices has been measured, with results compatible with the models. Cantilever structures are also suitable for bioaffinity-based applications or genomic tests, such as the detection of specific Single Nucleotide Polymorphisms (SNPs) that can be used to analyse the predisposition of individuals to genetic-based diseases. In this case, measurements are usually performed in liquid phase, where viscous damping of structures results in a severe reduction of resonance quality factor, which is a key-parameter for the device detection limit. Then, cantilever working in “bending mode” are usually preferred for these applications. In this thesis, the design and technologies have been optimised for this approach, which has different requirements with respect to resonant detectors. In fact, the interaction of target analytes with properly functionalised surfaces results in a bending of the cantilever device, which is usually explained by a number of mechanism ranging from electrostatic and steric interaction of molecules to energy-based considerations. In the case of DNA hybridisation detection, the complexity of the molecule interactions and solid-liquid interfaces leads to a number of different phenomena concurring in the overall response. Main parameters involved in the cantilever bending during DNA hybridisation has been studied on the basis of physical explanations available in the literature, in order to identify the key issues for an efficient detection. Microcantilever devices can play a role also in thin film technologies, where residual stresses and material properties in general need to be accurately measured. Since cantilever sensors are highly sensitive to stress, their use is straightforward for this application. Moreover, apart from their sensitivity, they also have other advantages on other methods for stress measurements, such as the possibility to perform on-line measurements during the film deposition in an array configuration, which can be useful for combinatorial approaches for the development of thin film materials libraries. In collaboration with the Plasma Advanced Materials (PAM) group of the Bruno Kessler Foundation, the properties of TiO2 films deposited by sputtering has been measured as a case study for these applications. In addiction to residual stress, a method for measuring the Young’s modulus of the deposited films has been developed, based on the measurement by means of a stylus profilometer of beam stiffness increase due to TiO2 film. The optimal data analysis procedure has been evaluated in order to increase the efficiency of the measurement. In conclusion, this work has provided the development of MEMS-based microcantilever devices for a range of different applications by evaluating the technological solutions for their realisation, the optimisation of design and testing of realised devices. The results validate the use of this class of devices in applications where high sensitivity detectors are required for portable analysis systems

    GEOMETRY AND INFORMATION FOR THE PRESERVATION OF A ROMAN MOSAIC THROUGH A HBIM APPROACH

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    Abstract. The archaeological site is a mine of data and information that helps to deepen the knowledge of its origin, history, and structure. This virtuous approach becomes even more effective when these data, properly processed and structured, form the basis for a project of conservation and enhancement of the cultural asset.The Roman mosaics dug in Castiglione delle Stiviere in 1995 represent an interesting case in which all the archaeological information, made available by the Superintendence, was used through an HBIM (Historical Building Information Modeling) approach for the conservation project. The Stratigraphic Units (US) of the findings have identified the strategy for the geometric and informative modeling of the BIM (Building Information Modeling) model and have also been exploited in the design phase for the project of the new roof structure and especially for the cost analysis. The structuring of the data by stratigraphic units was also used in the drafting of the preventive and planned conservation, necessary to enhance and prolong the state of good health of the property.This work has been developed in the internship activity within a training course on HBIM, in collaboration with the Diocese of Mantua, owner of the property
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