272 research outputs found

    Multi-View 3D Object Detection Network for Autonomous Driving

    Full text link
    This paper aims at high-accuracy 3D object detection in autonomous driving scenario. We propose Multi-View 3D networks (MV3D), a sensory-fusion framework that takes both LIDAR point cloud and RGB images as input and predicts oriented 3D bounding boxes. We encode the sparse 3D point cloud with a compact multi-view representation. The network is composed of two subnetworks: one for 3D object proposal generation and another for multi-view feature fusion. The proposal network generates 3D candidate boxes efficiently from the bird's eye view representation of 3D point cloud. We design a deep fusion scheme to combine region-wise features from multiple views and enable interactions between intermediate layers of different paths. Experiments on the challenging KITTI benchmark show that our approach outperforms the state-of-the-art by around 25% and 30% AP on the tasks of 3D localization and 3D detection. In addition, for 2D detection, our approach obtains 10.3% higher AP than the state-of-the-art on the hard data among the LIDAR-based methods.Comment: To appear in IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 201

    Exploring the factors influencing business model innovation using grounded theory: the case of a Chinese high-end equipment manufacturer

    Get PDF
    Business model innovation is vitally important for firms to gain competitive advantages and improve their performance. While it has attracted much attention recently, considerable work is still needed to properly understand business model innovation. This study aims to examine the factors influencing business model innovation through a case study of Shaanxi Blower, a high-end equipment manufacturer in China. Using grounded theory in terms of open coding, axial coding and selective coding, this case study found seven main factors that influenced business model innovation, namely, market pressure, government policy, entrepreneurship, culture and strategy, technology, human resources, and organizational capabilities. Market pressure, government policy and information technology are external factors, whereas, entrepreneurship and technological innovation are internal factors. Culture and strategy, human resources, and organizational capabilities are the guarantee factors. This study’s findings add to the growing literature by developing a more holistic understanding of the factors that influence business model innovation in the Chinese context, which indicates a possibility for Chinese high-end equipment manufacturers to improve their competitiveness and performance through better management of their business model innovation. View Full-Tex

    Modeling and Algorithms of the Crew Rostering Problem with Given Cycle on High-Speed Railway Lines

    Get PDF
    This paper studies the modeling and algorithms of crew roster problem with given cycle on highspeed railway lines. Two feasible compilation strategies for work out the crew rostering plan are discussed, and then an integrated compilation method is proposed in this paper to obtain a plan with relatively higher regularity in execution and lower crew members arranged. The process of plan making is divided into two subproblems which are decomposition of crew legs and adjustment of nonmaximum crew roster scheme. The decomposition subproblem is transformed to finding a Hamilton chain with the best objective function in network which was solved by an improved ant colony algorithm, whereas the adjustment of nonmaximum crew rostering scheme is finally presented as a set covering problem and solved by a two-stage algorithm. The effectiveness of the proposed models and algorithms are testified by a numerical example

    The Role of Alfalfa and Forage Resources in Crop-Livestock Systems in a Rain-Fed Region of North-Western China

    Get PDF
    Western China has been facing the challenges of both environmental sustainability and economic development. Current government policies and interventions support the development of integrated crop-livestock production systems for enhancing food security and environment sustainability. Compared with traditional grain-based faming systems, integrated systems have better resource utilisation, however annual forage supply deficits estimated at 1.37 t DM forage/farm are experienced in the region, especially in late winter and early spring. Accordingly, optimising the use of available forage resources is a priority for regional researchers and extension officers, with research seeking pathways for better fodder conservation and greater and more effective use of fodder sources to close the spring feed gap. This paper presents relevant research activities relating to alfalfa (Medicago sativa L.) and winter wheat (Triticum aestivum L.) management in integrated crop-livestock production systems. As the planting of alfalfa is strongly encouraged in northern China, alfalfa species selection and optimised harvesting management are essential to ensure the full benefits of alfalfa are available for livestock intensification. The capacity for a prevalent grain crop, winter wheat to be managed as a dual-purpose fodder and grain source shows potential as a means to alleviate deficits of animal feed supply. The present information expands our understanding of integrated forage-livestock production in rain-fed areas, exploring options that can improve productivity in small-farm households leading to income generation

    A dehazing method for flight view images based on transformer and physical priori

    Get PDF
    Aiming at the problems of local dehazing distortion and incomplete global dehazing of existing algorithms in real airborne cockpit environments, a two-stage dehazing method PhysiFormer combining physical a priori with a Transformer oriented flight perspective was proposed. The first stage used synthetic pairwise data to pre-train the dehazing model. First, a pyramid pooling module (PPM) was introduced in the Transformer for multiscale feature extraction to solve the problem of poor recovery of local details, then a global context fusion mechanism was used to enable the model to better perceive global information. Finally, considering that combining the physical a priori needs to rely on the estimation of the atmosphere light, an encoding-decoding structure based on the residual blocks was used to estimate the atmosphere light, which was then used for dehazing through the atmospheric scattering model for dehazing. The second stage used real images combined with physical priori to optimize the model to better fit the real airborne environment. The experimental results show that the proposed method has better naturalness image quality evaluator (NIQE) and blind/referenceless image spatial quality evaluator (BRISQUE) indexes and exhibits the best dehazing visual effect in the tests of dense haze, non-uniform haze and real haze images, which effectively improves the problems of color distortion and haze residue

    Increase in grain production potential of China under climate change

    Get PDF
    The rapid growth of China’s demand for grains is expected to continue in the coming decades, largely as a result of the increasing feed demand to produce protein-rich food. This leads to a great concern on future supply potentials of Chinese agriculture under climate change and the extent of China’s dependence on world food markets. While the existing literature in both agronomy and climate economics indicates a dominance of the adverse impacts of climate change on rice, wheat, and maize yields, there is a lack of study to assess changes in multi-cropping opportunities induced by climate change. Multi-cropping benefits crop production by harvesting more than once per year from a given plot. To address this important gap, we established a procedure within the Agro-ecological Zones (AEZ) modeling framework to assess future spatial shifts of multi-cropping conditions. The assessment was based on an ensemble of five General Circulation Models under four Representative Concentration Pathway scenarios in the Phase Five of Coupled Model Inter-comparison Project and accounted for the water scarcity constraints. The results show significant northward extensions of single-, double- and triple-cropping zones in the future which would provide good opportunities for crop-rotation based adaptation. The increasing multi-cropping opportunities would be able to boost the annual grain production potential by an average scale of 89(±49) Mt at the current irrigation efficiency and 143(±46) Mt at the modernized irrigation efficiency with improvement between the baseline (1981-2010) and the mid-21st century (2041-2070)

    Declining Walking Impairment Questionnaire Scores Are Associated With Subsequent Increased Mortality in Peripheral Artery Disease

    Get PDF
    ObjectivesThis study determined whether greater 2-year declines in Walking Impairment Questionnaire (WIQ) stair climbing, distance, or speed scores were associated with higher all-cause and cardiovascular disease (CVD) mortality among men and women with lower extremity peripheral artery disease (PAD).BackgroundAssociations of decline in the WIQ with mortality among people with PAD are unknown.MethodsParticipants were 442 men and women with PAD identified from Chicago area medical centers. The WIQ was completed at baseline and at 2-year follow-up. Cox proportional hazard models were used to assess associations across categories of 2-year changes in WIQ stair climbing, WIQ distance, and WIQ speed scores with subsequent all-cause and CVD mortality, adjusting for age, sex, race, ankle-brachial index, body mass index, smoking, comorbidities, and other covariates.ResultsOne hundred twenty-three participants (27.8%) died during a median follow-up of 4.7 years after the 2-year change in WIQ score measurements. Forty-five participants died from CVD. Adjusting for covariates, participants with WIQ score declines ≥20.0 points had higher all-cause mortality (hazard ratio [HR]: 1.93, 95% confidence interval [CI]: 1.01 to 3.68 for WIQ stair climbing; HR: 2.34, 95% CI: 1.15 to 4.75 for WIQ distance; and HR: 3.55, 95% CI: 1.57 to 8.04 for WIQ speed, respectively) compared with participants with ≥20.0 point improvement in each of the corresponding WIQ categories. Participants with ≥20.0 point declines in the WIQ distance score had higher CVD mortality (HR: 4.56, 95% CI: 1.30 to 16.01) compared with those with ≥20.0 point improvement in the WIQ distance score.ConclusionsPatients with PAD who experienced ≥20.0 point declines in the WIQ stair climbing, distance, and speed scores had a higher rate of all-cause mortality compared with those with less declines in each WIQ score

    Serum Helicobacter pylori NapA antibody as a potential biomarker for gastric cancer

    Get PDF
    Helicobacter pylori (H. pylori) infection is strongly associated with gastric cancer. However, only a minority of infected individuals ever develop gastric cancer. This risk stratification may be in part due to differences among strains. The relationship between neutrophil-activating protein (NapA) and gastric cancer is unclear. The purpose of this study is to evaluate the significance of NapA as a biomarker in gastric cancer. We used enzyme linked immunosorbent assay (ELISA) to determine the status of H. pylori infection. Indirect ELISA method was used for detection of NapA antibody titer in the serum of H. pyloriinfected individuals. Unconditional logistic regressions were adopted to analyze the variables and determine the association of NapA and gastric cancer. The results of study indicated serum H. pylori NapA antibody level were associated with a reduced risk for development of gastric cancer. It may be used in conjugation with other indicators for gastric cancer detection

    The various substrates of Usnea aurantiaco-atra and its algal sources in the Fildes Peninsula, Antarctica

    Get PDF
    The lichen species Usnea aurantiaco-atra (Jacq.) Bory is the most dominant vegetation on the Fildes Peninsula, Antarctica. Most individuals grow on rocks, and some are found with mosses. During the 27th and 28th Chinese National Antarctic Research expeditions of the Great Wall Station, U. aurantiaco-atra was observed growing on the lichen thallus of Umbilicaria antarctica Frey & I.M. Lamb, or on wood, which indicated that Usnea aurantiaco-atra could grow on various substrates. The diversities of the symbionts in U. aurantiaco-atra collected in the Fildes Peninsula were investigated using ITS rDNA sequences. The results showed that the sequences from mycobionts of U. aurantiaco-atra growing on various substrates did not exhibit significant differences. All photobionts in this lichen species were the green algae Trebouxia jamesii (Hildreth & Ahmadjian) Gärtner. The identical sequences from the photobionts of both Umbilicaria antarctica and Usnea aurantiaco-atra indicated there was an algae pool in this area and different mycobionts could obtain their algal partners from this pool. The variety of substrates for U. aurantiaco-atra suggested its photobiont could be obtained from a mature lichen thallus by vegetative propagation; from other lichen thalli (e.g. Umbilicaria antarctica); or from the surroundings. This study will promote understanding of the distribution of photobionts and the process of lichenization

    Detection of a superconducting phase in a two-atom layer of hexagonal Ga film grown on semiconducting GaN(0001)

    Get PDF
    The recent observation of superconducting state at atomic scale has motivated the pursuit of exotic condensed phases in two-dimensional (2D) systems. Here we report on a superconducting phase in two-monolayer crystalline Ga films epitaxially grown on wide band-gap semiconductor GaN(0001). This phase exhibits a hexagonal structure and only 0.552 nm in thickness, nevertheless, brings about a superconducting transition temperature Tc as high as 5.4 K, confirmed by in situ scanning tunneling spectroscopy, and ex situ electrical magneto-transport and magnetization measurements. The anisotropy of critical magnetic field and Berezinski-Kosterlitz-Thouless-like transition are observed, typical for the 2D superconductivity. Our results demonstrate a novel platform for exploring atomic-scale 2D superconductor, with great potential for understanding of the interface superconductivity
    corecore