79 research outputs found

    AffordPose: A Large-scale Dataset of Hand-Object Interactions with Affordance-driven Hand Pose

    Full text link
    How human interact with objects depends on the functional roles of the target objects, which introduces the problem of affordance-aware hand-object interaction. It requires a large number of human demonstrations for the learning and understanding of plausible and appropriate hand-object interactions. In this work, we present AffordPose, a large-scale dataset of hand-object interactions with affordance-driven hand pose. We first annotate the specific part-level affordance labels for each object, e.g. twist, pull, handle-grasp, etc, instead of the general intents such as use or handover, to indicate the purpose and guide the localization of the hand-object interactions. The fine-grained hand-object interactions reveal the influence of hand-centered affordances on the detailed arrangement of the hand poses, yet also exhibit a certain degree of diversity. We collect a total of 26.7K hand-object interactions, each including the 3D object shape, the part-level affordance label, and the manually adjusted hand poses. The comprehensive data analysis shows the common characteristics and diversity of hand-object interactions per affordance via the parameter statistics and contacting computation. We also conduct experiments on the tasks of hand-object affordance understanding and affordance-oriented hand-object interaction generation, to validate the effectiveness of our dataset in learning the fine-grained hand-object interactions. Project page: https://github.com/GentlesJan/AffordPose.Comment: Accepted by ICCV 202

    Two-Dimensional Far Field Source Locating Method with Nonprior Velocity

    Get PDF
    Relative position of seismic source and sensors has great influence on locating accuracy, particularly in far field conditions, and the accuracy will decrease seriously due to limited calculation precision and prior velocity error. In order to improve the locating accuracy of far field sources by isometric placed sensors in a straight line, a new locating method with nonprior velocity is proposed. After exhaustive research, this paper states that the hyperbola which is used for locating will be very close to its asymptote when seismic source locates in far field of sensors; therefore, the locating problem with prior velocity is equivalent to solving linear equations and the problem with nonprior velocity is equivalent to a nonlinear optimization problem with respect to the unknown velocity. And then, this paper proposed a new locating method based on a one-variable objective function with respect to the unknown velocity. Numerical experiments show that the proposed method has faster convergence speed, higher accuracy, and better stability

    Intercropping with Trifolium repens contributes disease suppression of banana Fusarium wilt by reshaping soil protistan communities

    Get PDF
    Fusarium wilt disease of bananas, caused by the soil-borne pathogen Fusarium oxysporum, threatens banana production. Intercropping, cultivation of more than one crop simultaneously on the same field, has emerged as efficient and sustainable land management for suppressing Fusarium wilt disease. Although previous studies have proven the changes in soil microbial communities including bacteria and fungi under intercropping contributed to disease suppression, little is known about the role of protistan communities in driving this effect. In a field experiment, we assessed microbiome shifts with a focus on protists under intercropping of banana with the legume Trifolium repens. Our results showed that the reduced Fusarium wilt disease incidence and the decreased Fusarium pathogen density under intercropping could be attributed to the changes in protistan community compositions. Specially, we observed a significant negative correlation between the relative abundance of phagotrophic protists and Fusarium oxysporum. We further conducted a pot experiment to examine the impacts of the legume crop on phagotrophic protists across different spatial distances, which showing that intercropping enriched the relative abundance of phagotrophic protists, especially Cercomonas, with members of this group showing the capacity to directly inhibit the growth of Fusarium pathogen in vitro. We highlight that predatory protists are important agents underlying disease suppression in intercropping system, which can offer new venues to promote plant health in sustainable agriculture

    A BAHD acyltransferase contributes to the biosynthesis of both ethyl benzoate and methyl benzoate in the flowers of Lilium oriental hybrid ‘Siberia’

    Get PDF
    Lily is a popular flower worldwide due to its elegant appearance and pleasant fragrance. Floral volatiles of lily are predominated by monoterpenes and benzenoids. While a number of genes for monoterpene biosynthesis have been characterized, the molecular mechanism underlying floral benzenoid formation in lily remains unclear. Here, we report on the identification and characterization of a novel BAHD acyltransferase gene that contributes to the biosynthesis of two related floral scent benzoate esters, ethyl benzoate and methyl benzoate, in the scented Lilium oriental hybrid ‘Siberia’. The emission of both methyl benzoate and ethyl benzoate in L. ‘Siberia’ was found to be tepal-specific, floral development-regulated and rhythmic. Through transcriptome profiling and bioinformatic analysis, a BAHD acyltransferase gene designated LoAAT1 was identified as the top candidate gene for the production of ethyl benzoate. In vitro enzyme assays and substrate feeding assays provide substantial evidence that LoAAT1 is responsible for the biosynthesis of ethyl benzoate. It was interesting to note that in in vitro enzyme assay, LoAAT1 can also catalyze the formation of methyl benzoate, which is typically formed by the action of benzoic acid methyltransferase (BAMT). The lack of an expressed putative BAMT gene in the flower transcriptome of L. ‘Siberia’, together with biochemical and expression evidence, led us to conclude that LoAAT1 is also responsible for, or at least contributes to, the biosynthesis of the floral scent compound methyl benzoate. This is the first report that a member of the plant BAHD acyltransferase family contributes to the production of both ethyl benzoate and methyl benzoate, presenting a new mechanism for the biosynthesis of benzoate esters

    The Impact of Government Governance on Regional Public Health and Development Measures from the Perspective of Ecological Environment

    No full text
    In order to further improve the satisfaction of public health safety, this paper discusses the impact of government governance on the satisfaction of regional public health safety and discusses the effectiveness of government public health governance and development countermeasures. From the perspective of ecological environment protection, combined with the survey data of national urban public health safety satisfaction in the last two years, this paper performs an in-depth empirical analysis on the relationship between government governance, public health governance efficiency, public credibility and regional public health safety satisfaction, as well as the impact mechanism. Through the analysis, it is found that the efficiency of government governance directly affects the satisfaction of regional residents with public health safety. With the help of the intermediary effect test, the significant level standard error of the indirect effect is greater than 1.96, and the confidence interval does not include 0, which proves that the intermediary effect exists. On this basis, the strategy of improving the satisfaction of regional public health security is further analyzed

    Spatio-temporal variation and prediction of land use and carbon storage in high groundwater level mining area

    No full text
    Mining activities and urbanisation in high dive mining areas can lead to significant changes in land use types, which in turn affect the carbon sequestration capacity of mining areas. Based on the land use data of Panxie mining area from 2002 to 2021, and used the FLUS (Future Land Use Simulation) model to predict land use changes in 2028 under two scenarios: natural development and ecological conservation, using mining, socio-economic and climatic data as drivers, and then The historical carbon stocks in the Panshet mine area from 2002 to 2021 and the future carbon stocks in 2028 under different scenarios were calculated by combining the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) model, and the spatial and temporal characteristics of the carbon stocks in the Panxie mine area were analysed. The spatial and temporal variability of carbon stocks in the Panxie mine was also analysed. The results show that: ① from 2002 to 2021, land use changes in the Panxai mining area show a continuous decrease in arable land and a continuous increase in wetland and building land, with a decrease of 147.93 km2 in arable land and an increase of 71.01 km2 and 75.76 km2 in wetland and building land, respectively. during this period, the carbon stock in the Panxai mining area decreases from 1.62×105 t, a decrease of 3.83%, with the fastest decrease in carbon reserves from 2018 to 2021. ② The predicted results show that the land use changes in the study area under both scenarios in 2028 are a continuous increase in wetlands and building land, and a continuous decrease in arable land. However, compared to the natural development scenario, the ecological conservation scenario protects and increases the area of arable land in the mine area, while the growth of wetlands and building land slows down. Compared with 2021, the carbon stock in the natural development scenario decreases by 0.74×105 t and the ecological conservation scenario decreases by 0.53×105 t. The results of the study indicate that the decrease in arable land due to sinking water and the expansion of construction land is the main reason for the decrease in carbon stock due to the influence of coal mining subsidence and urban development, and that the adoption of ecological conservation measures can slow down the decrease in carbon stock to a certain extent. Ecological conservation measures can slow down the decline of carbon stocks to a certain extent

    Non-Structural Damage Verification of the High Pressure Pump Assembly Ball Valve in the Gasoline Direct Injection Vehicle System

    No full text
    The injection pressure of the gasoline direct injection vehicle is currently developing from the low pressure to the high pressure, and the increase of the injection pressure has brought various damage problems to the high pressure pump structure. These problems should be solved urgently. In this paper, the damage problem of the high pressure pump unloading valve ball in a gasoline direct injection vehicle under high pressure conditions is studied. The theoretical calculation of the force of the pressure relief valve is carried out. Firstly, the equivalent friction coefficient is obtained by decoupling analysis of the statically indeterminate model. Based on this, a finite element model is established. The equivalent stress is obtained by numerical simulation. The equivalent stress is compared with the yield strength of the valve ball material to determine that the valve ball damage is a non-static damage. At the same time, the s-N curve of the probability of destruction of one-millionth of the material of the valve ball is given. Then, the fatigue numerical simulation is performed. A safety factor of 3.66 is obtained. In summary, the high pressure relief valve ball in the direct injection high pressure pump should not be a traditional structural damage under high pressure conditions. In the theoretical calculation, the tangential displacement and radial displacement of the ball are all on the micrometer level. It can be presumed that the surface damage of the valve ball is microscopic damage, such as fretting wear

    Understanding the Impact of Opinion Leaders’ Characteristics on Online Group Knowledge-Sharing Engagement from In-Group and Out-Group Perspectives: Evidence from a Chinese Online Knowledge-Sharing Community

    No full text
    Opinion leaders often play key roles in online knowledge-sharing communities, which has intrigued a lot of researchers and practitioners worldwide. However, it is not clear how various characteristics of opinion leaders may affect different online groups’ knowledge-sharing engagement. This paper aims to answer this question by building upon social capital theory to examine the differential influences of opinion leaders’ characteristics (interactivity, authority, and activity) on online groups. In-groups and out-groups were distinguished, and the study used the context of an investment-oriented online knowledge-sharing community. By leveraging a unique aggregated group-level secondhand dataset collected from Snowball.com, we conducted log-linear and Poisson regression models. The results revealed that the intensity of online group knowledge-sharing engagement was heavily contingent upon the types of characteristics of opinion leaders. We found that in-group knowledge-sharing engagement (generating new knowledge) was driven by an opinion leader’s interactivity and authority, whereas out-group knowledge-sharing engagement (developing new members) could not be facilitated by these types of characteristics. Instead, the opinion leader’s activity hindered out-group users from joining in-groups. The study also identified a “mutual promotion” issue, which was generated from the association between in-group and out-group knowledge-sharing engagement

    Rearrangement and domestication as drivers of Rosaceae mitogenome plasticity

    No full text
    Background The mitochondrion is an important cellular component in plants and that functions in producing vital energy for the cell. However, the evolution and structure of mitochondrial genomes (mitogenomes) remain unclear in the Rosaceae family. In this study, we assembled 34 Rosaceae mitogenomes and characterized genome variation, rearrangement rate, and selection signal variation within these mitogenomes. Results Comparative analysis of six genera from the Amygdaloideae and five from the Rosoideae subfamilies of Rosaceae revealed that three protein-coding genes were absent from the mitogenomes of five Rosoideae genera. Positive correlations between genome size and repeat content were identified in 38 Rosaceae mitogenomes. Twenty repeats with high recombination frequency (> 50%) provided evidence for predominant substoichiometric conformation of the mitogenomes. Variations in rearrangement rates were identified between eleven genera, and within the Pyrus, Malus, Prunus, and Fragaria genera. Based on population data, phylogenetic inferences from Pyrus mitogenomes supported two distinct maternal lineages of Asian cultivated pears. A Pyrus-specific deletion (DEL-D) in selective sweeps was identified based on the assembled genomes and population data. After the DEL-D sequence fragments originally arose, they may have experienced a subsequent doubling event via homologous recombination and sequence transfer in the Amygdaloideae; afterwards, this variant sequence may have significantly expanded to cultivated groups, thereby improving adaptation during the domestication process. Conclusions This study characterizes the variations in gene content, genome size, rearrangement rate, and the impact of domestication in Rosaceae mitogenomes and provides insights into their structural variation patterns and phylogenetic relationships
    • …
    corecore