402 research outputs found

    Sociable Robot ‘Lometh’: Exploring Interactive Regions of a Product-Promoting Robot in a Supermarket

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    The robot ‘Lometh’ is an information-presenting robot that naturally interacts with people in a supermarket environment. In recent years, considerable effort has been devoted to the implementation of robotic interfaces to identify effective behaviors of communication robots focusing only on the social and physical factors of the addresser and the hearer. As attention focus and attention target shifting of people differs based on the human visual focus and the spatiality, this study considered four interactive regions, considering the visual focus of attention as well as the interpersonal space between robot and human. The collected primary data revealed that 56% attention shifts occurred in near peripheral field of view regions and 44% attention shifts in far peripheral field of view regions. Using correspondence analysis, we identified that the bodily behaviors of the robot showed the highest success rate in the left near peripheral field of view region. The verbal behaviors of the robot captured human attention best in the right near peripheral field of view region. In this experiment of finding a socially acceptable way to accomplish the attention attracting goals of a communication robot, we observed that the robots’ affective behaviors were successful in shifting human attention towards itself in both left and right far- peripheral field of view regions, so we concluded that for far field of view regions, designing similar interaction interventions can be expected to be successful

    Sociable Robot ‘Lometh’: Exploring Interactive Regions of a Product-Promoting Robot in a Supermarket

    Get PDF
    The robot ‘Lometh’ is an information-presenting robot that naturally interacts with people in a supermarket environment. In recent years, considerable effort has been devoted to the implementation of robotic interfaces to identify effective behaviors of communication robots focusing only on the social and physical factors of the addresser and the hearer. As attention focus and attention target shifting of people differs based on the human visual focus and the spatiality, this study considered four interactive regions, considering the visual focus of attention as well as the interpersonal space between robot and human. The collected primary data revealed that 56% attention shifts occurred in near peripheral field of view regions and 44% attention shifts in far peripheral field of view regions. Using correspondence analysis, we identified that the bodily behaviors of the robot showed the highest success rate in the left near peripheral field of view region. The verbal behaviors of the robot captured human attention best in the right near peripheral field of view region. In this experiment of finding a socially acceptable way to accomplish the attention attracting goals of a communication robot, we observed that the robots’ affective behaviors were successful in shifting human attention towards itself in both left and right far- peripheral field of view regions, so we concluded that for far field of view regions, designing similar interaction interventions can be expected to be successful

    Correlation analysis between foveal avascular zone and near peripheral retinal hypoperfusion in multiple sclerosis: a wide field optical coherence tomography angiography study

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    The identification of non-invasive biomarkers to investigate and monitor retinal structural and vascular changes in multiple sclerosis (MS) represents an interesting source of debate. Until now optical coherence tomography angiography (OCTA) evaluated the foveal avascular zone (FAZ) and areas of retinal non-perfusion only in the macular region in MS patients. It could be interesting to identify possible biomarkers, useful in assessing the ischemic areas also in the near peripheral retina, since FAZ enlargement and the areas of peripheral retinal non-perfusions share common pathogenic processes. In this cross-sectional study, we investigated the correlation between the FAZ area and retinal vessel density (VD) in the near peripheral retina by new wide-field optical coherence tomography angiography (OCTA) in patients affected by relapsing-remitting multiple sclerosis (RR-MS). Moreover, we compared the FAZ area and the VD of superficial and deep capillary plexuses in the fovea region and in the near peripheral retina (6.4 x 6.4 mm) between RR-MS patients and healthy controls by means of a Solix full-range OCTA. Last, we also detected the changes in structural OCT parameters (ganglion cell complex and retinal nerve fiber layer). Thirty-three eyes of 33 RR-MS patients and 35 eyes of 35 healthy controls were enrolled. RR-MS patients showed a lower VD in the superficial capillary plexus and a significant increase in the FAZ area compared with controls. The deep capillary plexus revealed a reduced VD although not statistically significant in patients with respect to controls. In the patients' group, the FAZ area showed significantly negative correlations with VD of superficial capillary plexuses in the foveal and whole region, while the FAZ area did not negatively correlate with the VD of the deep capillary plexus. The significant correlations among OCTA parameters could demonstrate the FAZ area as a possible biomarker for assessing the perfusion status in the near peripheral retina, useful in RR-MS management. These findings could confirm the role of vascular dysfunction in the pathogenetic mechanisms of MS

    Near Peripheral Motion Contrast Threshold Predicts Older Drivers\u27 Driving Simulator Performance

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    The method of descending limits assessed motion contrast thresholds of 11 young participants (17–28), and 21 older drivers (63–86) for 0.4 cycle/degree drifting Gabor stimuli at 15 degrees eccentricity. Peripheral motion contrast thresholds (PMCT) of younger participants (M = –45.5 dB, SD = 1.66 dB) and older participants (M = –43.3 dB, SD = 3.79 dB) differed (t(29) = 2.295, p < .05 (all p-values one-tailed)). Older drivers performed UFOV® tests and a high-fidelity driving simulation. Between independent variables, significant correlations were PMCT with UFOV2 (r = .74, p < .001), PMCT with UFOV3 (r = .50, p < .01), PMCT with age (r =.73, p < .001), UFOV2 with age (r = .48, p < .05), and UFOV3 with age (r = .44, p < .05). Between vision and simulator measures, PMCT and UFOV2 significantly predicted rater’s simulator score (r = .66, p < .001; r = .58, p < .01 respectively), and simulator crashes ( r = .63, p < .001; r = .72, p < .001 respectively). Thus, PMCT and UFOV2 strongly predicted simulator performance. Partial correlations showed that: substantial association between PMCT and UFOV2 was not age–related; PMCT and UFOV2 tapped a common visual function; and PMCT assessed a component not captured by UFOV2. The descending limits procedure is as reliable and faster than forcedchoice. A practicable PMCT test that informs at-risk drivers about visual deficits may help them compensate effectively by learning voluntary scanning techniques and by otherwise modifying their driving techniques

    The effect of spatial frequency on peripheral collinear facilitation

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    The detection of a Gabor patch (target) can be decreased or improved by the presence of co-oriented Gabor patches (flankers) having the same spatial frequency as the target. These phenomena are thought to be mediated by lateral interactions. Depending on the distance between target and flankers, commonly defined as a multiple of the wavelength (λ) of the carrier, flankers can increase or decrease a target's detectability. Studies with foveal presentation showed that for target-to-flankers distances 3λ contrast thresholds decrease. Earlier studies on collinear facilitation at the near-periphery of the visual field (4° of eccentricity) showed inconsistent facilitation (Shani & Sagi, 2005, Vision Research, 45, 2009-2024) whereas more recent studies showed consistent facilitation for larger separations (7-8λ) (Maniglia et al., 2011, PLoS ONE, 6, e25568; Lev & Polat, 2011, Vision Research, 51, 2488-2498). However, all of these studies used medium-to-high spatial frequencies (3-8cpd). In this study we tested lower spatial frequencies (1, 2, and 3cpd) with different target-to-flankers distances. The rationale was that near-peripheral vision is tuned for lower spatial frequencies and this could be reflected in collinear facilitation. Results show consistent collinear facilitation at 8λ for all the spatial frequencies tested, but also show collinear facilitation at shorter target-to-flanker distance (6λ) for the lowest spatial frequencies tested (1cpd). Additionally, collinear facilitation decreases as spatial frequency increases; opposite to the findings of Polat (2009, Spatial Vision, 22, 179-193) in the fovea, indicating a different spatial frequency tuning between foveal and peripheral lateral interactions

    Near Peripheral Motion Detection Threshold Predicts Detection Failure Accident Risk in Younger and Older Drivers

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    Motion contrast thresholds for 0.4 cycle/degree drifting Gabor stimuli were assessed at 15-degrees eccentricity for 16 younger drivers (ages 24 to 42), and 15 older drivers (ages 65 to 84), using a temporal two-alternative forced choice staircase procedure. Two self-report questionnaires assessed detection failure accident risk—the Driver Perception Questionnaire (DPQ5), and an abridged Aging Driver Questionnaire (ADQ15). The UFOV® test battery was also administered. Mean peripheral motion contrast thresholds (PMCT) of younger and older participants were –39.3 dB and –33.8 dB, respectively. For younger drivers, the correlation between PMCT and DPQ5 scores was .62 (p\u3c.01), and between DPQ5 and ADQ16 (new and validated self-report measures, respectively) was .59 (p\u3c.01). For older drivers, correlation between PMCT and DPQ5 scores was .49 (p\u3c.01), between DPQ5 and ADQ16 was .73 (p\u3c.01), and between PMCT and age was .49 (p\u3c.05). For drivers overall, correlation was .48 (p\u3c.01) between PMCT and DPQ5 scores, .63 (p\u3c.0001) between DPQ5 and ADQ16, and .69 (p\u3c.0001) between PMCT and age. For drivers overall, correlation was .30 (p\u3c.05) between UFOV1 and age, .67 (p\u3c.0001) between UFOV2 and age, .56 (p\u3c.001) between UFOV2 and PMCT, .80 (p\u3c.0001) between UFOV3 and age, and .58 (p\u3c.001) between UFOV3 and PMCT. Holding age constant, partial correlation of PMCT with DPQ5 was .55 (p\u3c.001), and of PMCT with ADQ15 was .39 (p\u3c.05). PMCT significantly predicted self-reported driving performance in a laboratory setting, and worsened significantly with age. PMCT assessment should be made practicable. Informing high-risk drivers may encourage appropriate risk reduction countermeasures

    Protosymbols that integrate recognition and response

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    We explore two controversial hypotheses through robotic implementation: (1) Processes involved in recognition and response are tightly coupled both in their operation and epigenesis; and (2) processes involved in symbol emergence should respect the integrity of recognition and response while exploiting the periodicity of biological motion. To that end, this paper proposes a method of recognizing and generating motion patterns based on nonlinear principal component neural networks that are constrained to model both periodic and transitional movements. The method is evaluated by an examination of its ability to segment and generalize different kinds of soccer playing activity during a RoboCup match

    Liquid-gas phase transition in finite nuclei

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    In a finite temperature Thomas-Fermi framework, we calculate density distributions of hot nuclei enclosed in a freeze-out volume of few times the normal nuclear volume and then construct the caloric curve, with and without inclusion of radial collective flow. In both cases, the calculated specific heats CvC_v show a peaked structure signalling a liquid-gas phase transition. Without flow, the caloric curve indicates a continuous phase transition whereas with inclusion of flow, the transition is very sharp. In the latter case, the nucleus undergoes a shape change to a bubble from a diffuse sphere at the transition temperature.Comment: Proc. of 6th Int. Conf. on N-N Collisions (Gatlinburg); Nuclear Physics A (in press

    Mapping of periodically poled crystals via spontaneous parametric down-conversion

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    A new method for characterization of periodically poled crystals is developed based on spontaneous parametric down-conversion. The method is demonstrated on crystals of Y:LiNbO3, Mg:Y:LiNbO3 with non-uniform periodically poled structures, obtained directly under Czochralski growth procedure and designed for application of OPO in the mid infrared range. Infrared dispersion of refractive index, effective working periods and wavelengths of OPO were determined by special treatment of frequency-angular spectra of spontaneous parametric down-conversion in the visible range. Two-dimensional mapping via spontaneous parametric down-conversion is proposed for characterizing spatial distribution of bulk quasi-phase matching efficiency across the input window of a periodically poled sample.Comment: 19 pages, 6 figure
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