541 research outputs found

    What Is the Gaze Behavior of Pedestrians in Interactions with an Automated Vehicle When They Do Not Understand Its Intentions?

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    Interactions between pedestrians and automated vehicles (AVs) will increase significantly with the popularity of AV. However, pedestrians often have not enough trust on the AVs , particularly when they are confused about an AV's intention in a interaction. This study seeks to evaluate if pedestrians clearly understand the driving intentions of AVs in interactions and presents experimental research on the relationship between gaze behaviors of pedestrians and their understanding of the intentions of the AV. The hypothesis investigated in this study was that the less the pedestrian understands the driving intentions of the AV, the longer the duration of their gazing behavior will be. A pedestrian--vehicle interaction experiment was designed to verify the proposed hypothesis. A robotic wheelchair was used as the manual driving vehicle (MV) and AV for interacting with pedestrians while pedestrians' gaze data and their subjective evaluation of the driving intentions were recorded. The experimental results supported our hypothesis as there was a negative correlation between the pedestrians' gaze duration on the AV and their understanding of the driving intentions of the AV. Moreover, the gaze duration of most of the pedestrians on the MV was shorter than that on an AV. Therefore, we conclude with two recommendations to designers of external human-machine interfaces (eHMI): (1) when a pedestrian is engaged in an interaction with an AV, the driving intentions of the AV should be provided; (2) if the pedestrian still gazes at the AV after the AV displays its driving intentions, the AV should provide clearer information about its driving intentions.Comment: 10 pages, 10 figure

    Superconducting Properties and Microstructure in Dilute Copper Alloys Containing Small Amounts of V_3Ga Particles(Metallurgy)

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    The superconducting properties (T_c and J_c) were investigated by the resistivity measurement, and the structure was observed by a transmission electron microscopy in the dilute copper alloys containing small amounts of V_3Ga particles prepared by quenching from the liquid state and aging. No superconductivity could be observed at 4.2 K in as-quenched and/or in overaged samples. The highest T_ (=12.5 K), T_ (=9.6 K), and J_c (=525 A/cm^2) were obtained by aging at 700℃ for 96 h and corresponded with the structure of fine V_3Ga precipitates dispersed homogeneously in the copper matrix. Therefore, it is concluded that superconductivity in these alloys results from the superconducting path due to the proximity effect of the superconducting V_3Ga particles

    Implementation of muon pair production in PHITS and verification by comparing with the muon shielding experiment at SLAC

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    We implemented a model of muon pair production through a real photon in PHITS and compared our calculations with data of the muon shielding experiment conducted at SLAC to verify the validity of the implemented model. Our predictions of the muon fluence induced by electrons are in good agreement with the experimental data. To understand the known differences between the calculations of the muon fluence, which have been determined using other Monte-Carlo codes, we quantitatively evaluate the fluctuations in the Monte-Carlo results due to systematic errors in multiple Coulomb scattering, differences in the approximation methods and energy loss models, and whether incoherent production is considered.Comment: 16 pages, 8 figure

    Effects of Surface Treatments and Cement Types on the Bond Strength of Porcelain‐to‐Porcelain Repair

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    Purpose The purpose of this in vitro study was to evaluate the effects of four surface treatments and two resin cements on the repair bond strength of a ceramic primer. Materials and Methods Eighty‐eight pairs of disks (10 and 5 mm in diameter, 3 mm thickness) were prepared from heat‐pressed feldspar ceramics (GC Initial IQ). After being stored in mucin‐artificial saliva for 2 weeks, the 10‐mm disks were divided into four surface treatment groups (n = 22) and then treated as follows: (1) no treatment (control); (2) 40% phosphoric acid; (3) 5% hydrofluoric acid + acid neutralizer + 40% phosphoric acid; (4) silica coating (CoJet‐sand) + 40% phosphoric acid. The 5‐mm disks were treated with 5% hydrofluoric acid + 40% phosphoric acid. The two sizes of porcelain disks, excluding the control group, were primed with Clearfil Ceramic Primer. The specimens in each group were further divided into two subgroups of 11 each, and bonded with Clearfil Esthetic Cement (CEC) or Panavia F 2.0 Cement (PFC). The specimens were stored in distilled water at 37°C for 24 hours, thermocycled for 3000 cycles at 5 to 55°C, and stored at 37°C for an additional 7 days. Shear bond strength (SBS) was measured with a universal testing machine at a 0.5 mm/min crosshead speed until fracture. Statistical analysis of the results was carried out with a two‐way ANOVA and Tukey HSD test (α = 0.05). Debonded specimen surfaces were examined under an optical microscope to determine the mode of failure. Results The statistical analysis showed that the SBS was significantly affected by surface treatment and resin cement ( p < 0.05). For treatment groups bonded with CEC, the SBS (MPa) values were (1) 2.64 ± 1.1, (2) 13.31 ± 3.6, (3) 18.88 ± 2.6, (4) 14.27 ± 2.7, while for treatment groups cemented with PFC, the SBS (MPa) values were (1) 3.04 ± 1.1, (2) 16.44 ± 3.3, (3) 20.52 ± 2.2, and (4) 16.24 ± 2.9. All control specimens exhibited adhesive failures, while mixed types of failures were observed in phosphoric acid‐treated groups. The other groups revealed mainly cohesive and mixed failures. Conclusions Combined surface treatment of etching with hydrofluoric acid and phosphoric acid provides the highest bond strengths to porcelain. Also, PFC exhibited higher SBS than CEC did.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109888/1/jopr12194.pd

    Growth of Adsorbed Additive Layer for Further Friction Reduction

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    Special Issue:6th European Conference on Tribology (ECOTRIB 2017)Boundary lubrication is one of the most interesting topics in the field of tribology, and a lot of studies have been conducted from the past for understanding the behaviour of boundary lubrication films. General boundary lubrication films are formed by the adsorption of additives mixed into lubricant, and then the tribological performances are drastically improved in many cases. However, there is still room for discussion on the “actual” behaviour of adsorbed additive layer in the tribological condition, that is, under high pressure and/or with external forces. This paper showed the “growing” behaviour of an adsorbed additive layer onto metal surface due to high pressure by means of neutron reflectometry in conjunction with the result obtained through cross‐sectional imaging by frequency‐modulation atomic force microscopy. In addition, the nanotribological study using atomic force microscopy with a colloidal probe showed that the coefficient of friction in the pre‐scratched area was lower than that in the non‐scratched area and that the reduction ratio for lubricant with additive was higher than that for lubricant without additive. This result indicates that growth of the adsorbed additive layer contributed more greatly to a reduction in the coefficient of friction

    Interleukin 17A plays a role in lipopolysaccharide/d-galactosamine–induced fulminant hepatic injury in mice

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    AbstractBackgroundLipopolysaccharide/d-galactosamine (LPS/GalN)–induced hepatic injury is an experimental model of fulminant hepatic failure in which tumor necrosis factor alpha (TNF-α) plays a pivotal role. Moreover, it was reported from our laboratory that interleukin (IL) 17A enhanced production of TNF-α by the Kupffer cell.ObjectiveThe purpose of this study was to determine the role of IL-17A in LPS/GalN-induced hepatic injury in mice.MethodsLPS/GalN was injected into three mouse models: wild-type (WT) mice, IL-17A knockout (KO) mice, or IL-17A KO mice treated with recombinant mouse (rm) IL-17A homodimer (KO + rmIL-17A). Survival was assessed for 24 h after LPS/GalN injection, and histopathologic findings were evaluated at various time points after LPS/GalN injection for neutrophil and apoptosis markers. After LPS/GalN injection, expression of the inflammatory mediators TNF-α, IL-6, monocyte chemotactic protein 1, IL-17A, high-mobility group box 1, and soluble intercellular adhesion molecule 1 was assessed in serum by enzyme-linked immunosorbent assay.ResultsSurvival was higher in KO mice compared with WT mice after LPS/GalN injection. However, in KO + rmIL-17A mice, mortality was not significantly different compared to the other groups. Neutrophil infiltration and apoptosis were significantly greater in WT mice than KO mice. Furthermore, serum alanine aminotransferase, serum TNF-α, monocyte chemotactic protein 1, IL-17A, high-mobility group box 1, and soluble intercellular adhesion molecule 1 levels were also significantly greater in WT mice than KO mice. In KO + rmIL-17A mice, these levels were similar to those in WT mice.ConclusionsIL-17A is a key regulator in hepatic injury caused by neutrophil-induced inflammatory responses after LPS/GalN injection
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