137 research outputs found
Measuring Sociality in Driving Interaction
Interacting with other human road users is one of the most challenging tasks
for autonomous vehicles. For congruent driving behaviors, it is essential to
recognize and comprehend sociality, encompassing both implicit social norms and
individualized social preferences of human drivers. To understand and quantify
the complex sociality in driving interactions, we propose a Virtual-Game-based
Interaction Model (VGIM) that is parameterized by a social preference
measurement, Interaction Preference Value (IPV). The IPV is designed to capture
the driver's relative inclination towards individual rewards over group
rewards. A method for identifying IPV from observed driving trajectory is also
developed, with which we assessed human drivers' IPV using driving data
recorded in a typical interactive driving scenario, the unprotected left turn.
Our findings reveal that (1) human drivers exhibit particular social preference
patterns while undertaking specific tasks, such as turning left or proceeding
straight; (2) competitive actions could be strategically conducted by human
drivers in order to coordinate with others. Finally, we discuss the potential
of learning sociality-aware navigation from human demonstrations by
incorporating a rule-based humanlike IPV expressing strategy into VGIM and
optimization-based motion planners. Simulation experiments demonstrate that (1)
IPV identification improves the motion prediction performance in interactive
driving scenarios and (2) the dynamic IPV expressing strategy extracted from
human driving data makes it possible to reproduce humanlike coordination
patterns in the driving interaction
DDM-Lag : A Diffusion-based Decision-making Model for Autonomous Vehicles with Lagrangian Safety Enhancement
Decision-making stands as a pivotal component in the realm of autonomous
vehicles (AVs), playing a crucial role in navigating the intricacies of
autonomous driving. Amidst the evolving landscape of data-driven methodologies,
enhancing decision-making performance in complex scenarios has emerged as a
prominent research focus. Despite considerable advancements, current
learning-based decision-making approaches exhibit potential for refinement,
particularly in aspects of policy articulation and safety assurance. To address
these challenges, we introduce DDM-Lag, a Diffusion Decision Model, augmented
with Lagrangian-based safety enhancements. This work conceptualizes the
sequential decision-making challenge inherent in autonomous driving as a
problem of generative modeling, adopting diffusion models as the medium for
assimilating patterns of decision-making. We introduce a hybrid policy update
strategy for diffusion models, amalgamating the principles of behavior cloning
and Q-learning, alongside the formulation of an Actor-Critic architecture for
the facilitation of updates. To augment the model's exploration process with a
layer of safety, we incorporate additional safety constraints, employing a
sophisticated policy optimization technique predicated on Lagrangian relaxation
to refine the policy learning endeavor comprehensively. Empirical evaluation of
our proposed decision-making methodology was conducted across a spectrum of
driving tasks, distinguished by their varying degrees of complexity and
environmental contexts. The comparative analysis with established baseline
methodologies elucidates our model's superior performance, particularly in
dimensions of safety and holistic efficacy
Initial pore distribution characteristics and crack failure development of cemented tailings backfill under low impact amplitude
The stability of the cemented paste backfill is threatened by the dynamic disturbance during the excavation of the surrounding ore body. In this paper, the computerized tomography (CT) and Split Hopkinson Pressure Bar (SHPB) tests were conducted to explore the initial pore distribution characteristics of the cemented tailings backfill (CTB) and the development of the crack under low impact amplitude. SHPB tests were conducted with impact amplitudes of 34, 37, and 39 mV, respectively. Results show that the initial pores of CTB were steadily distributed with the height of CTB. The CTB contained many initial pores with similar pore size distribution characteristics, and the largest number of pores is between 0.1 and 0.3 mm. Most of the cracks in CTB after low impact amplitude develop and expand along the initial pores, and the damage of CTB mainly exists in shear cracks. A dependence has been established that the dynamic uniaxial compressive strength of the CTB increases, the total crack volume first increases and then decreases, and the number of cracks increases as the impact amplitude increases. The research results can provide a valuable reference for the dynamic performance of CTB under low impact amplitude and the design of mining backfill
Investigation of pesticide residues in commercialized fruits and risk assessment of dietary intake in Shaanxi Province from 2018 to 2021
ObjectiveTo assess human exposure risk from pesticide residues through ingestion of fruit in Shaanxi Province, pesticide residues in fruits were investigated and analyzed.MethodsFour hundred eighty-six commercialized fruit samples from 6 categories were collected from 10 cities in Shaanxi Province from 2018 to 2021. Two standard procedures, including “National Risk Monitoring Manual Standard Operating Procedure for the Determination of Multi-Component Pesticide Residues in Vegetal Samples by Gas Chromatography-Tandem Mass Spectrometry (GC-MS)” as well as “Standard Operating Procedure for the Determination of Multi-Component Pesticide Residues in Vegetal Samples (including Edible Fungi) by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS)” were used to analyze the residues of 13 kinds of insecticides and 15 kinds of bactericides. Furthermore, the detection rate and over-standard rate of multi-component pesticide residues in fruits were evaluated according to the GB 2763—2021 “National Food Safety Standard-Maximum Residue Limits of Pesticides in Food”. The point assessment method was used to assess the acute and chronic dietary exposure risks of all pesticide residues, and a food safety index model was used to determine the overall risk assessment of the detected pesticides.ResultsIn addition to four bactericides (pyraclostrobin, oxadixyl, myclobutanil and iprodione) and three insecticides ( ethoprophos, cyromazine and cyfluthrin), the remaining 21 pesticides, including some banned, highly toxic pesticides, were detected to different degrees with detection rates ranging from 0.77% to 21.54%. Four pesticide residues in seven samples exceeded the standard, with detection rates ranging from 0.28% to 1.27%. The detection rate of pesticide residues was highest in stone fruits (39.24%), tropical and subtropical fruits (28.33%), citrus fruits (26.47%), and kernel fruits (25.96%). The over-standard rate was highest in berry fruits (2.54%), and combined utilization of multiple pesticides was found. The values for acute and chronic dietary exposure to all pesticide types were lower than the health guidelines. The food safety index for a single pesticide is < 1. The overall food safety index of the fruits was less than 1.ConclusionAlthough the detection rate of pesticide residues in fruits from Shaanxi Province was relatively high, the over-standard rate was low. The risk from dietary intake of fruits monitored in this study was within an acceptable range; therefore, the safety and quality of the commercialized fruits collected from 2018 to 2020 met the requirements
NGC 5252: a pair of radio-emitting active galactic nuclei?
The X-ray source CXO J133815.6+043255 has counterparts in the UV, optical, and radio bands. Based on the multiband investigations, it has been recently proposed by Kim et al. as a rarely seen off-nucleus ultraluminous X-ray (ULX) source with a black hole mass of ≥104 M⊙ in the nearby Seyfert galaxy NGC 5252. To explore its radio properties at very high angular resolution, we performed very long-baseline interferometry (VLBI) observations with the European VLBI Network (EVN) at 1.7 GHz. We find that the radio counterpart is remarkably compact among the known ULXs. It does not show a resolved structure with a resolution of a few milliarcsecond (mas), and the total recovered flux density is comparable to that measured in earlier sub-arcsecond-resolution images. The compact radio structure, the relatively flat spectrum, and the high radio luminosity are consistent with a weakly accreting supermassive black hole in a low-luminosity active galactic nucleus. The nucleus of NGC 5252 itself has similar radio properties. We argue that the system represents a relatively rare pair of active galactic nuclei, where both components emit in the radio
Mechanical overloading induces GPX4-regulated chondrocyte ferroptosis in osteoarthritis via Piezo1 channel facilitated calcium influx
Introductions: Excessive mechanical stress is closely associated with cell death in various conditions. Exposure of chondrocytes to excessive mechanical loading leads to a catabolic response as well as exaggerated cell death. Ferroptosis is a recently identified form of cell death during cell aging and degeneration. However, it's potential association with mechanical stress remains to be illustrated. Objectives: To identify whether excessive mechanical stress can cause ferroptosis. To explore the role of mechanical overloading in chondrocyte ferroptosis. Methods: Chondrocytes were collected from loading and unloading zones of cartilage in patients with osteoarthritis (OA), and the ferroptosis phenotype was analyzed through transmission electron microscope and microarray. Moreover, the relationship between ferroptosis and OA was analyzed by GPX4-conditional knockout (Col2a1-CreERT: GPX4flox/flox) mice OA model and chondrocytes cultured with high strain mechanical stress. Furthermore, the role of Piezo1 ion channel in chondrocyte ferroptosis and OA development was explored by using its inhibitor (GsMTx4) and agonist (Yoda1). Additionally, chondrocyte was cultured in calcium-free medium with mechanical stress, and ferroptosis phenotype was tested. Results: Human cartilage and mouse chondrocyte experiments revealed that mechanical overloading can induce GPX4-associated ferroptosis. Conditional knockout of GPX4 in cartilage aggravated experimental OA process, while additional treatment with ferroptosis suppressor protein (FSP-1) and coenzyme Q10 (CoQ10) abated OA development in GPX4-CKO mice. In mouse OA model and chondrocyte experiments, inhibition of Piezo1 channel activity increased GPX4 expression, attenuated ferroptosis phenotype and reduced the severity of osteoarthritis. Additionally, high strain mechanical stress induced ferroptosis damage in chondrocyte was largely abolished by blocking calcium influx through calcium-free medium. Conclusions: Our findings show that mechanical overloading induces ferroptosis through Piezo1 activation and subsequent calcium influx in chondrocytes, which might provide a potential target for OA treatment
BRI1 EMS SUPPRESSOR1 genes regulate abiotic stress and anther development in wheat (Triticum aestivum L.)
BRI1 EMS SUPPRESSOR1 (BES1) family members are crucial downstream regulators that positively mediate brassinosteroid signaling, playing vital roles in the regulation of plant stress responses and anther development in Arabidopsis. Importantly, the expression profiles of wheat (Triticum aestivum L.) BES1 genes have not been analyzed comprehensively and systematically in response to abiotic stress or during anther development. In this study, we identified 23 BES1-like genes in common wheat, which were unevenly distributed on 17 out of 21 wheat chromosomes. Phylogenetic analysis clustered the BES1 genes into four major clades; moreover, TaBES1-3A2, TaBES1-3B2 and TaBES1-3D2 belonged to the same clade as Arabidopsis BES1/BZR1 HOMOLOG3 (BEH3) and BEH4, which participate in anther development. The expression levels of 23 wheat BES1 genes were assessed using real-time quantitative PCR under various abiotic stress conditions (drought, salt, heat, and cold), and we found that most TaBES1-like genes were downregulated under abiotic stress, particularly during drought stress. We therefore used drought-tolerant and drought-sensitive wheat cultivars to explore TaBES1 expression patterns under drought stress. TaBES1-3B2 and TaBES1-3D2 expression was high in drought-tolerant cultivars but substantially repressed in drought-sensitive cultivars, while TaBES1-6D presented an opposite pattern. Among genes preferentially expressed in anthers, TaBES1-3B2 and TaBES1-3D2 expression was substantially downregulated in thermosensitive genic male-sterile wheat lines compared to common wheat cultivar under sterile conditions, while we detected no obvious differences under fertile conditions. This result suggests that TaBES1-3B2 and TaBES1-3D2 might not only play roles in regulating drought tolerance, but also participate in low temperature-induced male sterility
Simulation study of BESIII with stitched CMOS pixel detector using ACTS
Reconstruction of tracks of charged particles with high precision is very
crucial for HEP experiments to achieve their physics goals. As the tracking
detector of BESIII experiment, the BESIII drift chamber has suffered from aging
effects resulting in degraded tracking performance after operation for about 15
years. To preserve and enhance the tracking performance of BESIII, one of the
proposals is to add one layer of thin CMOS pixel sensor in cylindrical shape
based on the state-of-the-art stitching technology, between the beam pipe and
the drift chamber. The improvement of tracking performance of BESIII with such
an additional pixel detector compared to that with only the existing drift
chamber is studied using the modern common tracking software ACTS, which
provides a set of detector-agnostic and highly performant tracking algorithms
that have demonstrated promising performance for a few high energy physics and
nuclear physics experiments
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