Interacting with virtual reconstructions in museums: The etruscanning project

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

Tactile sensing chips with POSFET array and integrated interface electronics

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

POSFET tactile sensing arrays using CMOS technology

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

BIM: An Integrated Model for Planned and Preventive Maintenance of Architectural Heritage

Modern digital technologies give us great possibilities to organize knowledge about constructions, regarding multidisciplinary fields like preservation, conservation and valorization of our architectural heritage, in order to suggest restoration projects and related work, or to suppose a planned preventive maintenance. New procedures to archive, analyze and manage architectural information find a natural support in 3D model, thanks to the development of capacities of new modeling software. Moreover, if the model contains or interfaces with a heterogeneous archive of information, as it is for BIM, this model can be considered as the bases of critical studies, projects of restoration, heritage maintenance, integrated management, protection, and valorization, and evaluation of economic aspects, management and planning, that can flow into a planned preventive maintenance [1]. The aspect that limit the use of BIM technology is the set up parametric object library inside programs: the standardized level of these objects deals difficulty with survey and restoration issues, where each single element has its own historical and architectural characterization [2]. From this foreword, the goal of this research is more evident: the possibilities of using BIM modeling to the existing constructions and cultural heritage, as a support for the construction and management of a Plan for planned preventive maintenance

3D survey technologies: Investigations on accuracy and usability in archaeology. The case study of the new "Municipio" underground station in Naples

Advanced 3D survey technologies, such as Digital Photogrammetry (imaged based) and Laser Scanner, are nowadays widely used in Cultural Heritage and Archaeological fields. The present paper describes the investigations realized by the Laboratory Hesutech of the Polytechnic of Milan in cooperation with the Superintendence Archaeology Campania in order to examine the potentiality of Image Based Modeling (IBM) systems applied to the archaeological field for advanced documentation purposes. Besides the 3D model production workflow in an uncommon excavation environment, a special consideration about the reached accuracy will be discussed. In the first part of the research, a comparison between photogrammetric camera parameters obtained with IBM systems and the ones provided with the calibration certificate by the manufacturer of the camera is performed. In the second part of the research, the operational phases of the application of such advanced 3D survey technologies are shown. The test field is the archaeological excavation area for the construction of the new "Municipio" underground station in Naples. Due to its position in one of the historical area of the city, its construction coexists with the archaeological excavations and it is strictly tied to their evolution. In such conditions, the need to reduce as much as possible the time to build the public infrastructure is a very relevant feature together with the ability to produce accurate documentation of what is considered archaeologically important

Wave equation with concentrated nonlinearities

In this paper we address the problem of wave dynamics in presence of concentrated nonlinearities. Given a vector field $V$ on an open subset of \CO^n and a discrete set Y\subset\RE^3 with $n$ elements, we define a nonlinear operator $\Delta_{V,Y}$ on L^2(\RE^3) which coincides with the free Laplacian when restricted to regular functions vanishing at $Y$, and which reduces to the usual Laplacian with point interactions placed at $Y$ when $V$ is linear and is represented by an Hermitean matrix. We then consider the nonlinear wave equation $\ddot \phi=\Delta_{V,Y}\phi$ and study the corresponding Cauchy problem, giving an existence and uniqueness result in the case $V$ is Lipschitz. The solution of such a problem is explicitly expressed in terms of the solutions of two Cauchy problem: one relative to a free wave equation and the other relative to an inhomogeneous ordinary differential equation with delay and principal part $\dot\zeta+V(\zeta)$. Main properties of the solution are given and, when $Y$ is a singleton, the mechanism and details of blow-up are studied.Comment: Revised version. To appear in Journal of Physics A: Mathematical and General, special issue on Singular Interactions in Quantum Mechanics: Solvable Model

Nonlinear Schroedinger equation with two symmetric point interactions in one dimension

We consider a time-dependent one-dimensional nonlinear Schroedinger equation with a symmetric potential double well represented by two delta interactions. Among our results we give an explicit formula for the integral kernel of the unitary semigroup associated with the linear part of the Hamiltonian. Then we establish the corresponding Strichartz-type estimate and we prove local existence and uniqueness of the solution to the original nonlinear problem

3D integrated photonic circuit for astrophotonic applications

LAUREA MAGISTRALELa fotonica integrata ha permesso enormi progressi in molti campi della fisica, dalle telecomunicazioni all'ottica quantistica. Una recente applicazione è da trovare in astronomia dove le piccole dimensioni e l'elevata stabilità termica e meccanica dei circuiti integrati hanno permesso di migliorare notevolmente le osservazioni astronomiche. In questo lavoro presentiamo l'implementazione di un dispositivo chiamato discrete beam combiner. Esso è un interferometro integrato capace di combinare la luce proveniente da otto punti dell'apertura di un telescopio, in modo da aumentarne la risoluzione angolare. Per fabbricare il dispositivo, abbiamo usato la tecnica di microfabbricazione con laser a femtosecondi in un substrato di vetro. Siccome la luce proveniente da un corpo celeste è non polarizzata, è richiesto che il dispositivo abbia un comportamento indipendente dalla polarizzazione della luce in ingresso. Dopo la scrittura del circuito è stato dunque necessario operare un processo di annealing che ha permesso di ridurre la birifrangenza delle guide d'onda. Il dispositivo è stato analizzato con luce classica, per validarne le funzionalità. Per tutti gli otto ingressi, le perdite di inserzione sono state ridotte sotto la soglia di 2.5 dB, un valore mai raggiunto prima per un chip con 6 cm di lunghezza. Inoltre, il dispositivo si comporta in maniera indipendente dalla polarizzazione, come richiesto. Un numero di condizionamento pari a 8 è stato misurato nella banda astronomica H. Infine, è presentato uno studio preliminare sull'aumento della banda operativa del dispositivo. A causa della complessa geometria di quest'ultimo, abbiamo deciso di considerare un accoppiatore direzionale e studiarne in tal caso l'aumento di banda. Ciò può essere realizzato con un accoppiatore detunato, ottenuto variando la costante di propagazione delle due guide d'onda. Siamo stati così in grado di fabbricare un accoppiatore con una riflessione di 50 +- 5% su più di 100 nm.The implementation of integrated photonic technologies can be beneficial in many fields of physics, ranging from telecommunications to quantum optics. In this respect, a novel application of photonics is related to the field of astronomy, where the small dimension and the high thermo-mechanical stability of the integrated circuits allow to improve the performances of the sky observation. In this work, we present the implementation of a discrete beam combiner, an integrated interferometer capable of combining light of up to eight points of a telescope aperture, in order to increase the angular resolution. To fabricate the circuit, we exploited the Femtosecond Laser Micromachining technique in a glass substrate. Since celestial light is unpolarized, one of the main requirements of stellar interferometry is the polarization insensitivity of the beam combiner. For this reason, after the inscription process, we performed a thermal annealing step, which allowed us to reduce the waveguide birefringence by releasing the internal stresses of glass. The integrated interferometer was tested with classical light in order to validate its functioning. In particular, the device showed insertion losses below 2.5 dB for all the eight different inputs, which can be considered a state-of-the-art result for an 6 cm long chip. Moreover, the device showed a polarization insensitive behavior and, from its interferometrical analysis, a minimum condition number of 8 was measured in the astronomical H band. The last part of this work is devoted to a preliminary study for increasing the operation bandwidth of the device. Due to the complex geometry of the beam combiner, we decided to focus on achieving a broadband directional coupler, obtained by detuning two coupled waveguides. With this technique, we were able to fabricate a directional coupler with a reflectivity of 50 +- 5% in more than 100 nm

Antibacterial-Nanocomposite Bone Filler Based on Silver Nanoparticles and Polysaccharides

Injectable bone fillers represent an attractive strategy for the treatment of bone defects. These injectable materials should be biocompatible, capable of supporting cell growth and possibly able to exert antibacterial effects. In this work, nanocomposite microbeads based on alginate, chitlac, hydroxyapatite and silver nanoparticles were prepared and characterized. The dried microbeads displayed a rapid swelling in contact with simulated body fluid and maintained their integrity for more than 30\ua0days. The evaluation of silver leakage from the microbeads showed that the antibacterial metal is slowly released in saline solution, with less than 6% of silver released after 1\ua0week. Antibacterial tests proved that the microbeads displayed bactericidal effects toward S. aureus, P. aeruginosa and S. epidermidis and were also able to damage pre-formed bacterial biofilms. On the other hand, the microbeads did not exert any cytotoxic effect towards osteoblast-like cells. After characterization of the bioactive microbeads, a possible means to embed them in a fluid medium was explored in order to obtain an injectable paste. Upon suspension of the particles in alginate solution or alginate/hyaluronic acid mixtures, a homogenous and time-stable paste was obtained. Mechanical tests enabled to quantify the extrusion forces from surgical syringes, pointing out the proper injectability of the material. This novel antibacterial bone-filler appears as a promising material for the treatment of bone defects, in particular when possible infections could compromise the bone-healing process

NEWPERS PECTIVES FOR MAPPING ALTERATIONS IN HBIMIN CONSERVATION PROJECTS

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