Enabling Human–Machine Interaction in Projected Virtual Environments Through Camera Tracking of Imperceptible Markers

Existing tracking methods designed for interacting with projection-based displays generally require visible artifacts to be introduced in the environment in order to guarantee effective stability and accuracy. For instance, in optical-oriented approaches, either the camera sensor or the reference pattern used for tracking are often located within the user's sight (or interfere with it), thus occluding portions of the scene or altering the perception of the virtual environment. Several ways to tackle these issues have been recently explored. Proposed approaches basically aim at making the presence of tracking references in the virtual space transparent to the user. However, such solutions introduce possibly critical constraints on required hardware or environment configuration. In this work, a novel tracking approach based on imperceptible fiducial markers is proposed. The approach relies on a hiding technique that allows digital images to be embedded in (and retrieved from) a projected scene by exploiting the properties of light polarization and additive color mixing. In particular, the virtual scene is obtained by overlapping the light beams of two projectors and by dealing with markers’ hiding via color compensation. A prototype setup has been deployed, where interaction with a flat surface projection environment has been evaluated in terms of tracking accuracy and artifacts avoidance performance by using a consumer camera equipped with a polarizing filter. Although the performed tests presented in this article represent only a preliminary and a partial evaluation of the proposed approach, they provided encouraging results indicating that the proposed technique could be possibly applied in more complex interaction scenarios still with limited hardware requirements.     

Mycotoxin occurrence in beer produced in several European countries

The occurrence of ochratoxin A, trichothecenes, fumonisins and aflatoxins in a sample of 106 beers produced in several European countries, was investigated. The analyses were conducted using high-performance liquid chromatography with fluorimetric detection for ochratoxin A and aflatoxins, gas-chromatography and high-performance liquid chromatography, both coupled with mass spectrometer, for trichothecenes and fumonisins, respectively. Aflatoxins were not detected in any samples, whereas ochratoxin A, deoxynivalenol and fumonisins were found in a relatively high number of samples. Their presence was at low levels in all samples; however, some differences were observed between the European countries. As regards ochratoxin A, beer samples from southern Europe showed levels always lower than 0.040 μg l^?1, while the samples from other European countries showed significantly higher values, up to 0.189 μg l^?1 (P < 0.001). For fumonisins, the levels of Italian beers were significantly higher compared to the samples from other countries (P = 0.006).     

Identification of concrete fracture parameters through size effect experiments

This paper deals with the identification of concrete fracture parameters through indirect methods based on size effect experiments. These methods utilize the size effect curve (structural strength versus structural size), associated with a certain specimen geometry, to identify the tensile strength and the initial fracture energy. These two parameters, in turn, are typically used to characterize the peak and the initial post-peak slope of the cohesive crack law. In the literature, two different approaches can be found for the calculation of the size effect curve: (a) an approach based on the polynomial interpolation of numerically calculated structural strengths of geometrically similar specimens of different sizes, and (b) the classical approach based on equivalent elastic fracture mechanics, which gives rise to the well-known Bažant’s size effect law (SEL). In this paper, the two approaches are first reviewed, the relationship between them is investigated, and a new procedure to identify the tensile strength using the SEL is proposed. Then several sets of experimental results, recently performed at the Politecnico di Milano, are analyzed with both approaches in order to assess their range of applicability and accuracy in the identification of the two fracture parameters specified above.     

Evaluation of gamma rays influence on some biochemical and microbiological aspects in black truffles

The effects of two gamma-ray doses (1.5 kGy and 2.0 kGy) on some biochemical aspects and on the microbiological profile of black truffles was monitored, immediately after treatment and after 30 days of storage at 4 °C. Electrophoretic and chromatographic analyses of proteins and peptides, just like monitoring of polyphenol content, peroxides formation and microbial profile, allowed for the first time a better understanding of the mechanisms responsible for biochemical alterations and bacterial pattern in black truffles during their storage. Treatment at 1.5 kGy appeared to better preserve the characteristics of the fresh product. In 2.0 kGy-samples, the protein profile was characterised by a 20 kDa-polypeptide, which could be considered as an useful marker of the irradiation treatment and of the storage time of the product. MALDI-TOF mass spectrometry analysis did not permit a correct identification from tryptic peptides in databases, although the nano-ES/MS/MS analyses performed on the 10 kDa tryptic digest peptides showed an amino acidic sequence entirely contained in a protein of filamentous fungus Neurospora crassa.     

From the ganglioside GQ1balpha to glycomimetic antagonists of the myelin-associated glycoprotein (MAG)

The tetrasaccharide 4, a substructure of ganglioside GQ1balpha, shows a remarkable affinity for the myelin-associated glycoprotein (MAG) and was therefore selected as starting point for a lead optimization program. In our search for structurally simplified and pharmacokinetically improved mimics of 4, antagonists with modifications of the core disaccharide Galbeta(1-3)GalNAc, as well as the terminal alpha(2-3)- and the internal alpha(2-6)-linked neuraminic acid were synthesized and tested in target-based binding assays. Compared to the reference tetrasaccharide 4, the most potent antagonist 17 exhibits a 360-fold improved affinity. Furthermore, pharmacokinetic parameters such as stability in the cerebrospinal fluid, logD and permeation through the BBB indicate the drug-like properties of antagonist 17.     

Reduction of the surface colour variability of thermally modified <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> wood by colour pre-grading and homogeneity thermal treatment

A new method that consists of combining wood pre-grading by surface colour followed by the application of homogeneity thermal treatments is proposed to reduce the surface colour variability of the thermally modified blue gum wood. To identify the conditions of the homogeneity thermal treatment for two pre-graded groups with different initial surface colours (pinkish and yellowish), the effects of applying 25 different thermal treatment intensities to such groups were analysed. The effects of this method on mass loss and volumetric swelling were also analysed. Results show that an optical pre-grading of the wood samples and treatments under different conditions can reduce the colour variability of the blue gum wood samples, as well as the volumetric swelling. Mass loss was not homogenised after the treatment, but the difference of masses between the two groups was similar to their untreated state. The application of this new methodology may be of interest for the sawn timber industry to bring more uniform boards on the markets and to promote Eucalyptus globulus as a price-competitive and sustainable alternative timber.     

IBA analyses and lead concentration measurements of AMS-C dated bones from two medieval sites in Italy

AMS (accelerator mass spectrometry) radiocarbon dated human bone samples recovered in the deserted medieval village of Quattro Macine, Lecce, in Southern Italy, were analyzed by PIXE (particle induced X-ray emission) and PIGE (particle induced gamma ray emission). The optimization of the PIXE-PIGE experimental set-up in term of beam energy and detection geometry resulted in the possibility to obtain information about major, minor and trace elements of the samples. Unexpectedly, all the analyzed samples showed a Pb concentration higher than 50 ppm. Two possible explanations of the measured high Pb concentration are discussed in the paper: the pre-mortem intake associated with the use of Pb-rich glazed pottery and the post-mortem intake from soil as the result of diagenetic processes.     

Thermodynamic modeling of hydrogen refueling for heavy-duty fuel cell buses and comparison with aggregated real data

The foreseen uptake of hydrogen mobility is a fundamental step towards the decarbonization of the transport sector. Under such premises, both refueling infrastructure and vehicles should be deployed together with improved refueling protocols. Several studies focus on refueling the light-duty vehicles with 10 kg_H2 up to 700 bar, however less known effort is reported for refueling heavy-duty vehicles with 30–40 kg_H2 at 350 bar. The present study illustrates the application of a lumped model to a fuel cell bus tank-to-tank refueling event, tailored upon the real data acquired in the 3Emotion Project. The evolution of the main refueling quantities, such as pressure, temperature, and mass flow, are predicted dynamically throughout the refueling process, as a function of the operating parameters, within the safety limits imposed by SAE J2601/2 technical standard. The results show to refuel the vehicle tank from half to full capacity with an Average Pressure Ramp Rate (APRR) equal to 0.03 MPa/s are needed about 10 min. Furthermore, it is found that the effect of varying the initial vehicle tank pressure is more significant than changing the ambient temperature on the refueling performances. In conclusion, the analysis of the effect of different APRR, from 0.03 to 0.1 MPa/s, indicate that is possible to safely reduce the duration of half-to-full refueling by 62% increasing the APRR value from 0.03 to 0.08 MPa/s.     

A framework for formal analysis and simulative evaluation of security attacks in wireless sensor networks

Journal of Computer Virology and Hacking Techniques - When designing Wireless Sensor Networks it is important to analyze their security risks and provide adequate solutions for protecting them from...