A Comparison of Three Different NeuroTag Visualization Media: Brain Visual Stimuli by Monitor, Augmented and Virtual Reality Devices

Brain-Computer Interfaces (BCIs) proved to overcome some limitations of other input modes (e.g., gestures, voice, haptic, etc.). BCIs are able to detect the brain activity, thus identifying searched patterns. When a specific brain activity is recognized, a well-defined action can be triggered, thus implementing a human-machine interaction paradigm. BCIs can be used in different domains ranging from industry to services for impaired people. This paper considers BCIs that can be designed and developed by the NextMind, which is a small and ergonomics device to capture the activity of the visual cortex. Objects called NeuroTags can be inserted in both 2D and 3D scenes; these objects act like switches when the user is able to focus on them. The aim of this work is to evaluate different NeuroTag configurations (varying in terms of size and distance) as well as different visualization devices: a monitor, a virtual reality head-mounted display, and an augmented reality head-mounted display. User tests outline that the best tradeoff between robustness and selection speed is obtained by medium-size and medium-spaced NeuroTags; on the other hand, monitor visualization outperforms the AR solution, whereas it is not possible to identify statistically significant differences between monitor-VR and AR-VR

SiN integrated photonic components in the Visible to Near-Infrared spectral region

Integrated photonics has emerged as one of the most promising platforms for quantum applications. The performances of quantum photonic integrated circuits (QPIC) necessitate a demanding optimization to achieve enhanced properties and tailored characteristics with more stringent requirements with respect to their classical counterparts. In this study, we report on the simulation, fabrication, and characterization of a series of fundamental components for photons manipulation in QPIC based on silicon nitride. These include crossing waveguides, multimode-interferometer-based integrated beam splitters (MMIs), asymmetric integrated Mach-Zehnder interferometers (MZIs) based on MMIs, and micro-ring resonators. Our investigation revolves primarily around the Visible to Near-Infrared spectral region, as these devices are meticulously designed and tailored for optimal operation within this wavelength range. By advancing the development of these elementary building blocks, we aim to pave the way for significant improvements in QPIC in a spectral region only little explored so far.Comment: 13 pages, 10 figure

Le basi neurologiche del rapporto tra il consumatore e la marca. Il contributo del neuro-imaging alle ricerche di marketing

Consumer develop very tight relationships with brands. In many cases, consumers develop positive relationships with their preferred brands and goods. In some of these cases true “love” relationship may occur. Sometimes, also negative relationships arise, often as a reaction toward unsatisfactory experiences, bad practices, etc. Companies aim at developing strong and positive emotional relationships between their brands and their customers. When they succeed, the brand is immediately recognized, it elicits positive affective responses, it is more difficult to be substituted for by competitors. The aim of the present study is to measure behavioral and emotional brain responses to covert visual recognition of brands. Functional magnetic resonance imaging (fMRI) was used to measure brain activity in 15 healthy subjects (7 females, 23-33 years) that were exposed to four stimulus types: coloured scrambled pictures, coloured squares, brand logos, and IAPS pictures with positive and negative valence scores. Sixty-three popular brands were selected among 8 different product categories. Two specific patterns of activation emerged for like (amygdale) and dislike brands (anterior medial cingulate, left inferior frontal gyrus, left middle temporal gyrus, medial cuneus). Implications for interpreting the role of brands in consumer mental processes are given, with special reference to the asymmetry between positive and negative evaluations

A Wireless Charging System Applying Phase-Shift and Amplitude Control to Maximize Efficiency and Extractable Power

Wireless power transfer (WPT) is an emerging technology with an increasing number of potential applications to transfer power from a transmitter to a mobile receiver over a relatively large air gap. However, its widespread application is hampered due to the relatively low efficiency of current Wireless power transfer (WPT) systems. This study presents a concept to maximize the efficiency as well as to increase the amount of extractable power of a WPT system operating in nonresonant operation. The proposed method is based on actively modifying the equivalent secondary-side load impedance by controlling the phase-shift of the active rectifier and its output voltage level. The presented hardware prototype represents a complete wireless charging system, including a dc-dc converter which is used to charge a battery at the output of the system. Experimental results are shown for the proposed concept in comparison to a conventional synchronous rectification approach. The presented optimization method clearly outperforms state-of-the-art solutions in terms of efficiency and extractable power

Diving response after a one-week diet and overnight fasting

Background: We hypothesized that overnight fasting after a short dietary period, especially with carbohydrates, could allow performing breath-hold diving with no restraint for diaphragm excursion and blood shift and without any increase of metabolism, and in turn improve the diving response. Methods: During two separate sessions, 8 divers carried out two trials: (A) a 30-m depth dive, three hours after a normal breakfast and (B) a dive to the same depth, but after following a diet and fasting overnight. Each test consisted of 3 apnea phases: descent, static and ascent whose durations were measured by a standard chronometer. An impedance cardiograph, housed in an underwater torch, provided data on trans-thoracic fluid index (TFI), stroke volume (SV), heart rate (HR) and cardiac output (CO). Mean blood pressure (MBP), arterial O-2 saturation (SaO(2)), blood glucose (Glu) and blood lactate (BLa) were also collected. Results: In condition B, duration of the static phase of the dive was longer than A (37.8 +/- 7.4 vs. 27.3 +/- 8.4 s respectively, P < 0.05). In static phases, mean Delta SV value (difference between basal and nadir values) during fasting was lower than breakfast one (-2.6 +/- 5.1 vs. 5.7 +/- 7.6 ml, P < 0.05). As a consequence, since mean. HR values were equally decreased in both metabolic conditions, mean. CO value during static after fasting was lower than the same phase after breakfast (-0.4 +/- 0.5 vs. 0.4 +/- 0.5 L . min(-1) respectively, P < 0.05). At emersion, despite the greater duration of dives during fasting, SaO(2) was higher than A (92.0 +/- 2.7 vs. 89.4 +/- 2.9 % respectively, P < 0.05) and BLa was lower in the same comparison (4.2 +/- 0.7 vs. 5.3 +/- 1.1 mmol L-1, P < 0.05). Conclusions: An adequate balance between metabolic and splancnic status may improve the diving response during a dive at a depth of 30 m, in safe conditions for the athlete's healt

Generation of quantum-certified random numbers using on-chip path-entangled single photons from an LED

Single-photon entanglement is a peculiar type of entanglement in which two or more degrees of freedom of a single photon are correlated quantum-mechanically. Here, we demonstrate a photonic integrated chip (PIC) able to generate and manipulate single-photon path-entangled states, using a commercial red LED as light source. A Bell test, in the Clauser, Horne, Shimony and Holt (CHSH) form, is performed to confirm the presence of entanglement, resulting in a maximum value of the CHSH correlation parameter equal to $2.605 \pm 0.004$. This allows us to use it as an integrated semi-device independent quantum random number generator able to produce certified random numbers. The certification scheme is based on a Bell's inequality violation and on a partial characterization of the experimental setup, without the need of introducing any further assumptions either on the input state or on the particular form of the measurement observables. In the end a min-entropy of $33\%$ is demonstrated.Comment: 22 pages, 8 figure

Have different kinds of photon-pair sources the same indistinguishability in quantum silicon photonics?

In the same silicon photonic integrated circuit, we compare two types of integrated degenerate photon-pair sources (microring resonators or waveguides) by means of Hong-Ou-Mandel (HOM) interference experiments. Two nominally identical microring resonators are coupled to two nominally identical waveguides which form the arms of a Mach-Zehnder interferometer. This is pumped by two lasers at two different wavelengths to generate by spontaneous four-wave mixing degenerate photon pairs. In particular, the microring resonators can be thermally tuned in or out of resonance with the pump wavelengths, thus choosing either the microring resonators or the waveguides as photon-pair sources, respectively. In this way, an on-chip HOM visibility of 94% with microring resonators and 99% with straight waveguides is measured. We compare our experimental results with theoretical simulations of the joint spectral intensity and the purity of the degenerate photon pairs. We verify that the visibility is connected to the sources' indistinguishability, which can be quantified by the overlap between the joint spectral amplitudes (JSA) of the photon pairs generated by the two sources. We estimate a JSA overlap of 98% with waveguides and 89% with microring resonators

Rilevamento metrico 3D e modellazione HBIM per la manutenzione programmata del patrimonio architettonico.

L’insieme dei Sacri Monti localizzati in aree alpine a cavallo tra il Piemonte e la Lombardia richiede numerose attività di gestione e manutenzione indispensabili per la conservazione e la valorizzazione di questi siti riconosciuti dall’UNESCO quale patrimonio dell’umanità. Uno degli esempi più significativi è il Sacro Monte di Varallo Sesia (VC) che, con il suo complesso sistema di cappelle, richiede l’utilizzo di complesse attività di manutenzione programmata e la definizione di nuove politiche di valorizzazione che possono trarre vigore dall’utilizzo delle più recenti tecniche della geomatica: il rilievo metrico integrato mediante LiDAR terrestre e fotogrammetria da drone per la generazione di un modello HBIM (Historical Building Information Model). La metodologia utilizzata sfrutta la geomatica come supporto per la rappresentazione tridimensionale di un modello HBIM e per la conseguente creazione di un database che agevoli la gestione dei dati per la manutenzione programmata di questo patrimonio. In questo contributo, gli autori hanno voluto indagare l’efficacia del rilievo integrato e della modellazione HBIM come validi strumenti per la conoscenza, la conservazione e la manutenzione dei beni architettonici, valutandone i punti di forza, le criticità e i limiti dell’approccio BIM applicato al patrimonio esistente

Magnetic properties of spin diluted iron pnictides from muSR and NMR in LaFe1-xRuxAsO

The effect of isoelectronic substitutions on the microscopic properties of LaFe1-xRuxAsO, for 0< x< 0.8, has been investigated by means of muSR and 139La NMR. It was found that Ru substitution causes a progressive reduction of the N\`eel temperature (T_N) and of the magnetic order parameter without leading to the onset of superconductivity. The temperature dependence of 139La nuclear spin-lattice relaxation rate 1/T_1 can be suitably described within a two-band model. One band giving rise to the spin density wave ground-state, while the other one is characterized by weakly correlated electrons. Fe for Ru substitution yields to a progressive decrease of the density of states at the Fermi level close to the one derived from band structure calculations. The reduction of T_N with doping follows the predictions of the J_1-J_2 model on a square lattice, which appears to be an effective framework to describe the magnetic properties of the spin density wave ground-state.Comment: 6 pages, 8 figure