1,485 research outputs found
Driver distraction detection using experimental methods and machine learning algorithms.
Driver distraction causes numerous road accidents, which is
approximately equal to 25% of the total crashes according to the
reports by the National Highway Traffic Safety Administration.
Warnings can be helpful to mitigate the risks caused by driver
distraction. Previous studies on driver distraction detection have not
sufficiently found relevant input features to filter insignificant
information, thus limiting the improvement of efficiency. Moreover, the
disadvantages of driving simulators and public roads pose a
challenge in collecting suitable data for feature identification and
comparisons of performance among driver distraction detection
algorithms. While the previous research focuses on improving
prediction accuracy, shortening the prediction time is critical in giving
timely warnings to drivers.
This thesis aims at detecting driver distraction, which could provide
faster and accurate warnings to drivers. The developed method is
implemented by cutting the redundancy and irrelevant information fed
to the algorithms and instead selecting suitable algorithms that
achieve the balance between the prediction accuracy and prediction
time. Moreover, a closed testing field supplies an environment for
collecting more accurate information to identify the relevant features
and to determine suitable algorithms.
In this study, open-source data and experimental data are used. The
results show that a balance between the prediction accuracy and the
prediction time is achieved by feeding the relevant features and using
suitable machine learning algorithms (e.g. Decision Tree). Compared
with existing state-of-the-art methods, the prediction accuracy of the
method proposed in this study has reached approximately the same
level. More importantly, the efficiency has improved, including
reduced prediction time and fewer input features. Consequently, less
computer storage is used.PhD in Transport System
CORE: Cooperative Reconstruction for Multi-Agent Perception
This paper presents CORE, a conceptually simple, effective and
communication-efficient model for multi-agent cooperative perception. It
addresses the task from a novel perspective of cooperative reconstruction,
based on two key insights: 1) cooperating agents together provide a more
holistic observation of the environment, and 2) the holistic observation can
serve as valuable supervision to explicitly guide the model learning how to
reconstruct the ideal observation based on collaboration. CORE instantiates the
idea with three major components: a compressor for each agent to create more
compact feature representation for efficient broadcasting, a lightweight
attentive collaboration component for cross-agent message aggregation, and a
reconstruction module to reconstruct the observation based on aggregated
feature representations. This learning-to-reconstruct idea is task-agnostic,
and offers clear and reasonable supervision to inspire more effective
collaboration, eventually promoting perception tasks. We validate CORE on
OPV2V, a large-scale multi-agent percetion dataset, in two tasks, i.e., 3D
object detection and semantic segmentation. Results demonstrate that the model
achieves state-of-the-art performance on both tasks, and is more
communication-efficient.Comment: Accepted to ICCV 2023; Code: https://github.com/zllxot/COR
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Genome Composition and Divergence of the Novel Coronavirus (2019-nCoV) Originating in China.
An in-depth annotation of the newly discovered coronavirus (2019-nCoV) genome has revealed differences between 2019-nCoV and severe acute respiratory syndrome (SARS) or SARS-like coronaviruses. A systematic comparison identified 380 amino acid substitutions between these coronaviruses, which may have caused functional and pathogenic divergence of 2019-nCoV
Stock Volatility Prediction Based on Transformer Model Using Mixed-Frequency Data
With the increasing volume of high-frequency data in the information age,
both challenges and opportunities arise in the prediction of stock volatility.
On one hand, the outcome of prediction using tradition method combining stock
technical and macroeconomic indicators still leaves room for improvement; on
the other hand, macroeconomic indicators and peoples' search record on those
search engines affecting their interested topics will intuitively have an
impact on the stock volatility. For the convenience of assessment of the
influence of these indicators, macroeconomic indicators and stock technical
indicators are then grouped into objective factors, while Baidu search indices
implying people's interested topics are defined as subjective factors. To align
different frequency data, we introduce GARCH-MIDAS model. After mixing all the
above data, we then feed them into Transformer model as part of the training
data. Our experiments show that this model outperforms the baselines in terms
of mean square error. The adaption of both types of data under Transformer
model significantly reduces the mean square error from 1.00 to 0.86.Comment: Accepted by the 7th APWeb-WAIM International Joint Conference on Web
and Big Data. (APWeb 2023
Urban consumer trust and food certifications in China
China has experienced frequent food safety incidents that have undermined consumer trust in the food supply chain. To overcome this problem, China requalified the legislative framework and adopted a comprehensive food certification system over the years. Here, we investigated the influences of food traceability and Chinese certifications (QS/SC—food quality safety market access/production system, hazard-free, green, and organic) on Chinese consumer trust of food safety for different types of products: fish, meat, milk, eggs, and rice. Data were collected through face-to-face surveys conducted in rural and urban Chinese areas. With a sample of 757 questionnaires, we ran a logit model. The results show consumers’ uncertainty and skepticism of certifications guaranteeing food safety attributes, especially for animal-based products. We found that price is used as a cue of safety by Chinese consumers. Individuals with higher education seem less influenced by certifications and other cues included in the analysis. The findings demonstrate that Chinese policy makers should implement new strategies to enhance consumer food safety trust, and design policies by considering different categories (e.g., vegetables, meat, fish, etc.) of food
Addressing China's grand challenge of achieving food security while ensuring environmental sustainability
China’s increasingly urbanized and wealthy population is driving a growing and changing demand for food, which might not be met without significant increase in agricultural productivity and sustainable use of natural resources. Given the past relationship between lack of access to affordable food and political instability, food security has to be given a high priority on national political agendas in the context of globalization. The drive for increased food production has had a significant impact on the environment, and the deterioration in ecosystem quality due to historic and current levels of pollution will potentially compromise the food production system in China. We discuss the grand challenges of not only producing more food but also producing it sustainably and without environmental degradation. In addressing these challenges, food production should be considered as part of an environmental system (soil, air, water, and biodiversity) and not independent from it. It is imperative that new ways of meeting the demand for food are developed while safeguarding the natural resources upon which food production is based. We present a holistic approach to both science and policy to ensure future food security while embracing the ambition of achieving environmental sustainability in China. It is a unique opportunity for China to be a role model as a new global player, especially for other emerging economies
Study on coal seam physical characteristics and influence on stimulation: A case study of coal seams in zhengzhuang block
Coalbed Methane (CBM) is an unconventional form of natural gas which is self-generated and self-stored in coal seams. In order to realize the effective exploitation of CBM in Zhengzhuang block, microstructure, wettability, permeability, rock mechanics and in-situ stress of coal were studied in this research. It is found that high rank anthracite characterized by high vitrinite content and low inorganic mineral content, is abundant in CBM. More than 96% of inorganic minerals are clays dominated by kaolinite and illite. Various types of pores are developed on the coal. The wettability of coal differs from high to low to surface water, active water, and foam fracturing fluid; and contact angles of coal with active water and foam fracturing fluid decrease with the increase of burial depth. Gradients of fracture pressure and closure pressure in No.3 coal seam are higher than that of No.15 coal seam. The elastic modulus of coal is lower than that of sandstone. The construction curve of hydraulic fracturing shows that, when the construction flow rate and sand quantity are similar, the construction pressure of prepad in No.3 coal seam is lower than the pumping pressure of No.15 coal seam, but the propagated pressure is higher than that of No.15 coal seam. The drainage effect of No.3 coal seam with large pore volume, shallow burial depth and obvious fracture pressure is better than that of No.15 coal seam. The comprehensive understanding of coal physical properties and engineering practice in the block provide certain guiding significance to the CBM exploitation in Qinshui Basin
Effects of elevated ozone on physiological, anatomical and ultrastructural characteristics of four common urban tree species in China
Fast urbanization has led to ozone (O3) being the main pollutant in summer in most of China. To assess future ground-level O3 effects on the service of urban greening species and clarify the underlying mechanism of O3 damage, four common urban greening species, Ailanthus altissima (AA), Fraxinus chinensis(FC), Platanus orientalis (PO) and Robinia pseudoacacia (RP) were exposed to non-filtered air (NF) and to elevated O3 (E-O3) in open-top chambers. E-O3 induced visible injury in all species as well as microscopic alterations such as collapse of the palisade parenchyma cells, callose accumulation, or chloroplast and mitochondrial accelerated senescence. E-O3 significantly reduced light-saturated CO2 assimilation (Asat),the maximum activity of Rubisco (Vcmax), the maximum electron transport rate (Jmax), and fluorescence parameters such as the quantum yield of noncyclic electron transport (�PSII), and the quenching of photochemical efficiency of PSII (qP). It also increased total antioxidant capacity, phenolics and ascorbate contents. No significant interaction between O3and species was found in photosynthetic performance and antioxidant systems, suggesting that the four species selected were sensitive to O3. Of all four species,AA was the most sensitive species due to a combination of earlier injury onset, anatomical features, lower antioxidant responses and higher stomatal conductance. The sensitivity of tree species to O3 is a factor to be considered for urban greening. Ozone may affect important urban forest ecosystem services by reducing CO2 assimilationThis study has been funded by the Hundred Talents Program, Chinese Academy of Sciences and State Key Laboratory of Urban and Regional Ecology. Collaboration between RCEES and Fundacion CEAM has been possible thanks to project AMIS (Fate and Impact of Atmospheric Pollutants, PIRSES-GA-2011-295132), and by the Chinese Academy of Sciences Visiting Professorships for Senior International Scientists (grant number: 2013T2Z0009). VC also acknowledges the support of PROMETEOII/2014/038 project (Generalitat Valenciana, G.V.), and FGB and JRA that of PROMETEOII2013/021 (G.V.), and CGL2012-40058-C02-01/02 (MINECO). We thank Mr. Yulong Zhang for the experimental management.Gao, F.; Calatayud Lorente, V.; GarcĂa-Breijo, F.; Reig Armiñana, J.; Feng, Z. (2016). Effects of elevated ozone on physiological, anatomical and ultrastructural characteristics of four common urban tree species in China. Ecological Indicators. 67:367-379. https://doi.org/10.1016/j.ecolind.2016.03.012S3673796
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Whole blood microRNA markers are associated with acute respiratory distress syndrome
Background: MicroRNAs (miRNAs) can play important roles in inflammation and infection, which are common manifestations of acute respiratory distress syndrome (ARDS). We assessed if whole blood miRNAs were potential diagnostic biomarkers for human ARDS. Methods: This nested case-control study (N = 530) examined a cohort of ARDS patients and critically ill at-risk controls. Whole blood miRNA profiles and logistic regression analyses identified miRNAs correlated with ARDS. Stratification analysis also assessed selected miRNA markers for their role in sepsis and pneumonia associated with ARDS. Receiver operating characteristic (ROC) analysis evaluated miRNA diagnostic performance, along with Lung Injury Prediction Score (LIPS). Results: Statistical analyses were performed on 294 miRNAs, selected from 754 miRNAs after quality control screening. Logistic regression identified 22 miRNAs from a 156-patient discovery cohort as potential risk or protective markers of ARDS. Three miRNAs—miR-181a, miR-92a, and miR-424—from the discovery cohort remained significantly associated with ARDS in a 373-patient independent validation cohort (FDR q < 0.05) and meta-analysis (p < 0.001). ROC analyses demonstrated a LIPS baseline area-under-the-curve (AUC) value of ARDS of 0.708 (95% CI 0.651–0.766). Addition of miR-181a, miR-92a, and miR-424 to LIPS increased baseline AUC to 0.723 (95% CI 0.667–0.778), with a relative integrated discrimination improvement of 2.40 (p = 0.005) and a category-free net reclassification index of 27.21% (p = 0.01). Conclusions: miR-181a and miR-92a are risk biomarkers for ARDS, whereas miR-424 is a protective biomarker. Addition of these miRNAs to LIPS can improve the risk estimate for ARDS. Electronic supplementary material The online version of this article (10.1186/s40635-017-0155-0) contains supplementary material, which is available to authorized users
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