Individual differences in embodied distance estimation in virtual reality

There are important individual differences when experiencing VR setups. We ran a study with 20 participants who got a scale-matched avatar and were asked to blind-walk to a VR target placed 2.5 meters away. In such setups, people typically underestimate distances by approximately 10% when virtual environments are viewed through head mounted displays. Consistent with previous studies we found that the underestimation was significantly reduced the more embodied the participants were. However, not all participants developed the same level of embodiment when exposed to the exact same conditions

A mechatronic shape display based on auxetic materials

Shape displays enable people to touch simulated surfaces. A common architecture of such devices uses a mechatronic pin-matrix. Besides their complexity and high cost, these matrix displays suffer from sharp edges due to the discreet representation which reduces their ability to render a large continuous surface when sliding the hand. We propose using an engineered auxetic material actuated by a smaller number of motors. The material bends in multiple directions, feeling smooth and rigid to touch. A prototype implementation uses nine actuators on a 220 mm square section of material. It can display a range of surface curvatures under the palm of a user without aliased edges. In this work we use an auxetic skeleton to provide rigidity on a soft material and demonstrate the potential of this class of surface through user experiments

A silicon-based single-electron interferometer coupled to a fermionic sea

We study Landau-Zener-Stueckelberg-Majorana (LZSM) interferometry under the influence of projective readout using a charge qubit tunnel-coupled to a fermionic sea. This allows us to characterise the coherent charge qubit dynamics in the strong-driving regime. The device is realised within a silicon complementary metal-oxide-semiconductor (CMOS) transistor. We first read out the charge state of the system in a continuous non-demolition manner by measuring the dispersive response of a high-frequency electrical resonator coupled to the quantum system via the gate. By performing multiple fast passages around the qubit avoided crossing, we observe a multi-passage LZSM interferometry pattern. At larger driving amplitudes, a projective measurement to an even-parity charge state is realised, showing a strong enhancement of the dispersive readout signal. At even larger driving amplitudes, two projective measurements are realised within the coherent evolution resulting in the disappearance of the interference pattern. Our results demonstrate a way to increase the state readout signal of coherent quantum systems and replicate single-electron analogues of optical interferometry within a CMOS transistor

Using Facial Animation to Increase the Enfacement Illusion and Avatar Self-Identification

Through avatar embodiment in Virtual Reality (VR) we can achieve the illusion that an avatar is substituting our body: the avatar moves as we move and we see it from a first person perspective. However, self-identification, the process of identifying a representation as being oneself, poses new challenges because a key determinant is that we see and have agency in our own face. Providing control over the face is hard with current HMD technologies because face tracking is either cumbersome or error prone. However, limited animation is easily achieved based on speaking. We investigate the level of avatar enfacement, that is believing that a picture of a face is one's own face, with three levels of facial animation: (i) one in which the facial expressions of the avatars are static, (ii) one in which we implement lip-sync motion and (iii) one in which the avatar presents lip-sync plus additional facial animations, with blinks, designed by a professional animator. We measure self-identification using a face morphing tool that morphs from the face of the participant to the face of a gender matched avatar. We find that self-identification on avatars can be increased through pre-baked animations even when these are not photorealistic nor look like the participant

A review of the current use of commercial wearable technology and smartphone apps with application in monitoring individuals following total hip replacement surgery

The advent of commercially available wearable activity monitors and smartphone apps allows objective digital monitoring of daily activities of patients before and after THR surgery. A wide variety of wearable activity monitors and smartphone apps are being marketed to assist with enhancing physical activity following surgery. A systematic review of commercial wearable tech- nology and smartphone apps was undertaken to assess the evidence supporting their efficacy in assisting rehabilitation and patient monitoring following THR. A search was conducted using the electronic databases including Medline, CINAHL, Cochrane, PsycARTICLES and PubMed of studies from January 2000 to January 2019. Five studies met the eligibility criteria. A review of the studies found very little evidence to support long term efficacy of the technology in enhancing rehabilitation and patient monitoring post THR. Future work is required to establish which commercially available monitoring technology is most valuable to patients, which ones improve clinical outcomes post THR, and what are the best economical models for their deployment

The Neurological Traces of Look-Alike Avatars

We designed an observational study where participants (n = 17) were exposed to pictures and look-alike avatars pictures of themselves, a familiar friend or an unfamiliar person. By measuring participants’ brain activity with electroencephalography (EEG), we found face-recognition event related potentials (ERPs) in the visual cortex, around 200–250 ms, to be prominent for the different familiarity levels. A less positive component was found for self-recognized pictures (P200) than pictures of others, showing similar effects in both real faces and look-alike avatars. A rapid adaptation in the same component was found when comparing the neural processing of avatar faces vs. real faces, as if avatars in general were assimilated as real face representations over time. ERP results also showed that in the case of the self-avatar, the P200 component correlated with more complex conscious encodings of self-representation, i.e., the difference in voltage in the P200 between the self-avatar and the self-picture was reduced in participants that felt the avatar looked like them. This study is put into context within the literature of self-recognition and face recognition in the visual cortex. Additionally, the implications of these results on look-alike avatars are discussed both for future virtual reality (VR) and neuroscience studies

Using Factorial Design Methodology to Assess PLA-g-Ma and Henequen Microfibrillated Cellulose Content on the Mechanical Properties of Poly(lactic acid) Composites

In this work, a 22 factorial design was used to study the effect of microfibrillated henequen cellulose fibers (HENCEL) and PLA-g-MA coupling agent contents on the tensile, flexural, and impact mechanical properties and the heat deflection temperature (HDT) of biodegradable PLA composites. The results show that the principal effects of HENCEL and MA are statistically significant for the tensile, flexural, HDT, and impact strength properties of PLA composites. Regarding the interactions between the principle effects, MA-HENCEL, there are differences with respect to the mechanical property; for example, for tensile and flexural mechanical properties, there is a synergistic effect between MA and HENCEL, whereas for HDT and impact strength there is not any. The micromechanical analysis shows an excellent agreement between the measured and the estimated values for both the composite tensile strength and the elastic modulus and only slight deviations were noticed for high microfibrillated cellulose fibers content. The morphological analysis via SEM indicated that the addition of PLA-g-MA improved the fiber-matrix adhesion because of the HENCEL unbounding and pull-out decreases from the PLA matrix. The use of appropriate values of matrix strength and stiffness and considering the improved fiber-matrix adhesion of the coupling agent yield a good agreement between experimental and estimated values

Semi-inclusive charged-current neutrino-nucleus cross sections in the relativistic plane wave impulse approximation

Neutrino-nucleus quasielastic scattering is studied in the plane wave impulse approximation for three nuclear models: the relativistic Fermi gas (RFG), the independent-particle shell model (IPSM) and the natural orbitals (NO) model with Lorentzian dependence of the excitation energy. A complete study of the kinematics of the semi-inclusive process and the associated cross sections are presented and discussed for 40 Ar and 12 C. Inclusive cross sections are also obtained by integrating the semi-inclusive expressions over the outgoing hadron. Results are consistent with previous studies restricted to the inclusive channel. In particular, a comparison with the analytical results for the RFG model is performed. Explicit expressions for the hadronic tensor and the 10 semi-inclusive nuclear responses are given. Theoretical predictions are compared with semi-inclusive experimental data from T2K experiment.Comment: 55 pages, 22 figures, submitted to Physical Review

Caracterización preliminar de frutos de granada china (Passiflora ligularis Juss.) en Hueyapan y Teziutlán, Puebla

En la Sierra Nororiental de Puebla, México, los frutos de granada china son muy apreciados por la población local, pero existen pocos datos sobre su calidad hortofrutícola. Con el fin de iniciar la selección de individuos productores de frutos de buena calidad, se tomaron como muestra diez frutos de 20 plantas, cinco de cada localidad, Talzinta, Nexpan, Tanamacoyan y Mexcalcuautla, para analizarlos física (peso, diámetro, color, porcentaje de los componentes del fruto) y bioquímicamente (sólidos solubles totales, pH, acidez titulable, densidad del jugo). El valor medio para peso de frutos varió de 85 a 57 g; el porcentaje de pulpa de 81 a 51%; y el contenido de sólidos solubles totales (SST) fue de 17.5 a 12.2 ºB. El análisis de conglomerados, a una distancia euclidiana de 12.6, formó cinco grupos; en los grupos 2, 3 y 4 se observaron frutos de mayor tamaño (+ 75 g), con altos porcentajes de pulpa (60%) y valores aceptables de SST (14 ºB); éstos fueron los colectados en Talzinta y Nexpan. El análisis de componentes principales (CP) indicó que los primeros cinco CP explicaron el 75% de la variabilidad observada; siendo 25 y 18% la variabilidad que explican los CP 1 y CP 2, respectivamente. CP 1 estuvo altamente influenciado por el diámetro polar (0.900), luminosidad (-0.767) y el peso fresco del fruto (0.750); el CP 2 se relacionó con porcentaje de pulpa (0.866), porcentaje de cáscara (-0.866) y porcentaje de semillas (0.857). Esta información permitirá iniciar la selección de individuos productores de fruto de buena calidad, en la región de Teziutlán, PueblaEn la Sierra Nororiental de Puebla, MÈxico, los frutos de granada china son muy apreciados por la poblaciÛn local, pero existen pocos datos sobre su calidad hortofrutÌcola. Con el fin de iniciar la selecciÛn de individuos productores de frutos de buena calidad, se tomaron como muestra diez frutos de 20 plantas, cinco de cada localidad, Talzinta, Nexpan, Tanamacoyan y Mexcalcuautla, para analizarlos fÌsica (peso, di·metro, color, porcentaje de los componentes del fruto) y bioquÌmicamente (sÛlidos solubles totales, pH, acidez titulable, densidad del jugo). El valor medio para peso de frutos variÛ de 85 a 57 g; el porcentaje de pulpa de 81 a 51%; y el contenido de sÛlidos solubles totales (SST) fue de 17.5 a 12.2 ºB. El an·lisis de conglomerados, a una distancia euclidiana de 12.6, formÛ cinco grupos; en los grupos 2, 3 y 4 se observaron frutos de mayor tamaÒo (+ 75 g), con altos porcentajes de pulpa (60%) y valores aceptables de SST (14 ºB); Èstos fueron los colectados en Talzinta y Nexpan. El an·lisis de componentes principales (CP) indicÛ que los primeros cinco CP explicaron el 75% de la variabilidad observada; siendo 25 y 18% la variabilidad que explican los CP 1 y CP 2, respectivamente. CP 1 estuvo altamente influenciado por el di·metro polar (0.900), luminosidad ( 0.767) y el peso fresco del fruto (0.750); el CP 2 se relacionÛ con porcentaje de pulpa (0.866), porcentaje de c·scara ( 0.866) y porcentaje de semillas (0.857). Esta informaciÛn permitir· iniciar la selecciÛn de individuos productores de fruto de buena calidad, en la regiÛn de Teziutl·n, Puebla