1,784 research outputs found

    Research of Simulation in Character Animation Based on Physics Engine

    Get PDF
    Computer 3D character animation essentially is a product, which is combined with computer graphics and robotics, physics, mathematics, and the arts. It is based on computer hardware and graphics algorithms and related sciences rapidly developed new technologies. At present, the mainstream character animation technology is based on the artificial production of key technologies and capture frames based on the motion capture device technology. 3D character animation is widely used not only in the production of film, animation, and other commercial areas but also in virtual reality, computer-aided education, flight simulation, engineering simulation, military simulation, and other fields. In this paper, we try to study physics based character animation to solve these problems such as poor real-time interaction that appears in the character, low utilization rate, and complex production. The paper deeply studied the kinematics, dynamics technology, and production technology based on the motion data. At the same time, it analyzed ODE, PhysX, Bullet, and other variety of mainstream physics engines and studied OBB hierarchy bounding box tree, AABB hierarchical tree, and other collision detection algorithms. Finally, character animation based on ODE is implemented, which is simulation of the motion and collision process of a tricycle

    Influence of Secondary Hyperparathyroidism Induced by Low Dietary Calcium, Vitamin D Deficiency, and Renal Failure on Circulating Rat PTH Molecular Forms

    Get PDF
    Rats(r) with secondary hyperparathyroidism were studied to define the relationship between vitamin D metabolites and rPTH levels measured by 3 different rat ELISAs. Controls and renal failure (RF) rats were on a normal diet, while 2 groups on a low-calcium (-Ca) or a vitamin D-deficient (-D) diet. RF was induced surgically. Mild RF rats had normal calcium and 25(OH)D but reduced 1,25(OH)2D levels (P < .001) with a 2.5-fold increased in rPTH (P < .001). Severe RF rats and those on a -Ca or -D diet had reduced calcium (P < .01) and 25(OH)D levels (P < .05), with rPTH increased by 2 (-Ca diet; P < .05), 4 (-D diet; P < .001), and 20-folds (RF; P < .001) while 1,25(OH)2D was high (-Ca diet: P < .001) or low (-D diet, RF: P < .001). 25(OH)D and 1,25(OH)2D were positively and negatively related on the -Ca and -D diets, respectively. rPTH molecular forms behaved as expected in RF and on -Ca diet, but not on -D diet with more C-rPTH fragments when less were expected. This may be related to the short-time course of this study compared to prior studies

    SPM: Structured Pretraining and Matching Architectures for Relevance Modeling in Meituan Search

    Full text link
    In e-commerce search, relevance between query and documents is an essential requirement for satisfying user experience. Different from traditional e-commerce platforms that offer products, users search on life service platforms such as Meituan mainly for product providers, which usually have abundant structured information, e.g. name, address, category, thousands of products. Modeling search relevance with these rich structured contents is challenging due to the following issues: (1) there is language distribution discrepancy among different fields of structured document, making it difficult to directly adopt off-the-shelf pretrained language model based methods like BERT. (2) different fields usually have different importance and their length vary greatly, making it difficult to extract document information helpful for relevance matching. To tackle these issues, in this paper we propose a novel two-stage pretraining and matching architecture for relevance matching with rich structured documents. At pretraining stage, we propose an effective pretraining method that employs both query and multiple fields of document as inputs, including an effective information compression method for lengthy fields. At relevance matching stage, a novel matching method is proposed by leveraging domain knowledge in search query to generate more effective document representations for relevance scoring. Extensive offline experiments and online A/B tests on millions of users verify that the proposed architectures effectively improve the performance of relevance modeling. The model has already been deployed online, serving the search traffic of Meituan for over a year.Comment: Accepted by CIKM '2

    Damage Effects of Fluid filled Submunitions by High Velocity Projectile Impact

    Get PDF
    A series of tests investigating the damage effects of fluid-filled submunitions by high velocity projectile impact were conducted. An analytical model is presented, in which the yaw angle of the projectile was taken into account. Based on the analytical model, the influence of the strike angle, hit-point offset distance and projectile length to diameter ratio on submunition damage ratio were predicted. The analytical results showed a good agreement with the experiments. The submunition damage ratio strongly depends on the hit-point offset distance, showing a significant decrease with increasing hit-point offset distance. For large hit-point offset distance, increasing the length to diameter ratio of the projectile will effectively improve the submunition damage ratio. There is an appropriate yaw angle of the projectile in which the submunition damage ratio will be maximal

    Novel polymorphism of the bovine fat mass and obesity-associated (FTO) gene are related to backfat thickness and longissimus muscle area in five Chinese native cattle breeds

    Get PDF
    In this study, genetic variation of the fat mass and obesity-associated gene (FTO) was detected by PCRSSCP and DNA sequencing in 618 individuals from five Chinese indigenous cattle breeds, and their genetic effects on meat quality traits were evaluated. The results showed that a novel single nucleotide polymorphism C1071T was detected in exon 5 and the allelic frequencies for the C and T alleles of the five breeds were 0.666/0.334, 0.583/0.417, 0.631/0.369, 0.653/0.347 and 0.689/0.311, respectively. Animals with CT genotype had higher mean values for backfat thickness than those with CC or TT genotypes (P &lt; 0.01). Individuals with CC or CT genotypes had higher longissimus muscle area than those with TT genotype (P &lt; 0.05). The FTO gene may be a candidate gene for identifying differences in meat quality traits and therefore, could be applied to marker-assisted selection of native Chinese cattle breeds.Key words: Cattle, fat mass and obesity-associated (FTO) gene, single nucleotide polymorphism (SNP), meat quality traits

    Molecular characterization, polymorphism of growth differentiation factor 5 gene and association with ultrasound measurement traits in native Chinese cattle breeds

    Get PDF
    Growth differentiation factor 5 (GDF5), involved in the development and maintenance of bone andcartilage, is a n important candidate gene for growth and carcass traits selection through markerassisted selection (MAS). Genomic structural analysis showed that bovine GDF5 shares much similarity with human GDF5. The latest findings demonstrate that the single nucleotide polymorphism (SNP) T586C in exon 1 is significantly associated with ultrasound marbling score (UMAR) and ultrasound backfat thickness (UBF). Furthermore, the analysis of T586C SNP marker shows there are significant effects on the UBF (P = 0.0498) and on the UMAR (P = 0.0058) in 465 individuals. These results clearly suggest that the GDF5 gene is among target genes for carcass traits in bovine reproduction and breeding.Keywords: Cattle, GDF5 gene, ultrasound measurement, polymorphism, association analysisAfrican Journal of Biotechnology Vol. 9(33), pp. 5269-5273, 16 August, 201
    corecore