Verification and validation of automated driving systems' safety are some of the biggest challenges for the introduction of automated vehicles into the market. Scenario-based safety assessment is an ...efficient and repeatable method to test the systems' safety before their deployment in the real world. However, even with limited traffic situations identified as critical to the system behavior, there is still an open range of parameters to describe each situation. Thus, defining specific parameter ranges is crucial to realize the scenario-based safety assessment approach. This study proposes a method to parameterize scenarios extracted from real-world traffic data, analyze their distribution and correlation, and incorporate them into the definition of reasonably foreseeable parameter ranges through the contextualization of resulting ranges with reasonable risk acceptance thresholds from different fields and international environments. Representative values can be selected from these specific parameter ranges to extract specific concrete scenarios applicable for the systems safety assessment. The applicability of the proposed method is demonstrated using parameter ranges obtained to define two sets of 960 cut-in and 6,442 deceleration scenarios extracted from a new set of traffic data collected from Japanese highways under the SAKURA initiative. The outcomes will enable comparisons with traffic data from other countries and inform automated driving system developers, standardization bodies, and policymakers to develop automated vehicle safety assessments applicable internationally.
The total cross sections were measured for coherent double neutral-pion photoproduction on the deuteron at incident energies below 0.9 GeV for the first time. No clear resonance-like behavior is ...observed in the excitation function for Wγd=2.38–2.61 GeV, where the d⁎(2380) dibaryon resonance observed at COSY is expected to appear. The measured excitation function is consistent with the existing theoretical calculation for this reaction. The upper limit of the total cross section is found to be 0.034 μb for the dibaryon resonance at Wγd=2.37 GeV (90% confidence level) in the γd→π0π0d reaction.
This study aims to generate test cases for scenario-based assessment of automated driving systems (ADS) when encounter a cut-out maneuver where the lead vehicle having changed lanes, revealing a new ...lead vehicle that, in some cases, is slower than the original lead (the cutting-out) vehicle. We extracted the cut-out scenarios from an established real-world traffic dataset recorded by instrumented vehicles on Japanese highways and then defined them using vehicle kinematic parameters (velocities and distances). The extracted scenarios were analyzed based on the direct correlation between every two consecutive vehicles: a rear part that describes the correlation between the following vehicle and the cutting-out vehicle; and a frontal part that describes the correlation between the cutting-out vehicle and the preceding vehicle. Parameter ranges were quantified with a regression model and determined based on the risk acceptance threshold applied in the field of Japanese high-speed trains and annual exposure by professional highway drivers to produce a scenario space with a reasonably foreseeable range in which ADS may not produce crashes lest it performs worse than human drivers. A multi-dimensional distribution analytical approach was used to derive a correlation between the following and preceding vehicles considering the initial longitudinal velocities. Results suggest that when the time headway between the following vehicle and the cutting-out vehicle is equal to or more than 2 s, there should not have collision risks between the following vehicle and the preceding vehicle. These findings can help to understand normative driver behavior during cut-out scenarios and to generate accident-free scenario space for which ADS must perform flawlessly.
We have constructed a new laser-Compton-scattering facility, called the LEPS2 beamline, at the 8 GeV electron storage ring, SPring-8. This facility provides a linearly polarized photon beam in a ...tagged energy range of 1.3–2.4 GeV. Thanks to a small divergence of the low-emittance storage-ring electrons, the tagged photon beam has a size (σ) suppressed to about 4 mm even after it travels about 130 m to the experimental building that is independent of the storage ring building and contains large detector systems. This beamline is designed to achieve a photon beam intensity higher than that of the first laser-Compton-scattering beamline at SPring-8 by adopting the simultaneous injection of up to four high-power laser beams and increasing a transmittance for the long photon-beam path up to about 77%. The new beamline is under operation for hadron photoproduction experiments.
A yellow N-doped TiO2 powder was prepared by the sol-gel method using titanium tetra-isopropoxide and hydrazine monohydrate. An EPR signal was induced by the irradiation of light with hv ≥ 2.2 eV to ...the yellow TiO2 powder and the signal intensity gradually decreased in the dark. The EPR signal was due to thermally trapped carriers interacting with the doped N. The thermal activation energy of the trapped carriers was estimated to be 0.22 eV. XPS measurement was performed on the yellow powder as well as colorless and blue N-doped powders obtained by oxidation and reduction, respectively. The N1s bands at 399.5 eV can be assigned to nitrogen adsorbed on the surface. The atomic valence of nitrogen in the colorless, yellow and blue powders was positive, neutral and negative, respectively. The atomic valence of nitrogen in doped TiO2 depends on the oxidation-reduction procedure.
Multiple myeloma (MM) is incurable, mainly because of cell adhesion-mediated drug resistance (CAM-DR). In this study, we performed functional screening using short hairpin RNA (shRNA) to define the ...molecule(s) responsible for CAM-DR of MM. Using four bona fide myeloma cell lines (KHM-1B, KMS12-BM, RPMI8226 and U266) and primary myeloma cells, we identified CD29 (beta1-integrin), CD44, CD49d (alpha4-integrin, a subunit of VLA-4), CD54 (intercellular adhesion molecule-1 (ICAM-1)), CD138 (syndecan-1) and CD184 (CXC chemokine receptor-4 (CXCR4)) as major adhesion molecules expressed on MM. shRNA-mediated knockdown of CD49d but not CD44, CD54, CD138 and CD184 significantly reversed CAM-DR of myeloma cells to bortezomib, vincristine, doxorubicin and dexamethasone. Experiments using blocking antibodies yielded almost identical results. Bortezomib was relatively resistant to CAM-DR because of its ability to specifically downregulate CD49d expression. This property was unique to bortezomib and was not observed in other anti-myeloma drugs. Pretreatment with bortezomib was able to ameliorate CAM-DR of myeloma cells to vincristine and dexamethasone. These results suggest that VLA-4 plays a critical role in CAM-DR of MM cells. The combination of bortezomib with conventional anti-myeloma drugs may be effective in overcoming CAM-DR of MM.
•This study aims to constrain the composition of the lunar magma ocean.•We focus on the geophysical and geochemical conditions for lunar crust formation.•An incremental polybaric fractionation model ...is developed for lunar differentiation.•FeO must be ∼1.3–1.8times the Earth unless Al2O3 is extremely higher than the Earth.•Oxidized lunar formation disk or oxidized impactor of the giant impact is suggested.
The present study aims to constrain the composition of the initial lunar magma ocean (LMO) with fluid dynamic and thermodynamic consideration. A plausible range of the initial LMO composition is investigated by developing an incremental polybaric fractional crystallization model with variable fractionation efficiency to satisfy three conditions for the anorthosite crust formation: (1) the amount of anorthite crystallized from the LMO is abundant enough to form the crust with the observed thickness, (2) the Mg# (=Mg/(Mg+Fe)) of orthopyroxene crystallized with anorthite in the cooling LMO is consistent with that observed in the lunar highland rocks, ferroan anorthosite, and (3) crystallized anorthite separated to float in the turbulent LMO. A plausible range of FeO and Al2O3 contents of the bulk LMO is successfully constrained as a crescent region tight for FeO and loose for Al2O3. The FeO content must be higher than 1.3 times the bulk silicate Earth (BSE) and lower than 1.8×BSE unless the Al2O3 content of the Moon is extremely higher than the Earth. These upper and lower limits for FeO are positively correlated with the initial Al2O3 content and fractionation efficiency. The FeO–rich LMO composition may suggest that the circum-Earth disk just after the giant impact of the Earth–Moon system formation was more oxidizing or the impactor was richer in FeO than the Earth’s mantle.
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