We present a multiresolution trim structure for fast and accurate B-Rep model visualization. To get a good tradeoff between performance and visual accuracy, we propose to use a vectorial but approximated representation of the model that allows efficient, real-time GPU exploitation. Our structure, based on a quadtree, enables us to do shallow lookups for distant fragments. For closeups, we lever...

Solving the machine feature recognition problem has been widely recognized as a cornerstone for developing an automated process planning system directly linked to a CAD system. Various recognition techniques have been developed; however, they are in general deficient in robustness. That is, valid machined features may not be recognized and features which are recognized may not be valid in pract...

Adeno-associated virus type 2 (AAV-2), a human parvovirus which is apathogenic in adults, inhibits replication and gene expression of human immunodeficiency virus type 1 (HIV-1) in human cells. The rep gene of AAV-2, which was shown earlier to be sufficient for this negative interference, also down-regulated the expression of heterologous sequences driven by the long terminal repeat (LTR) of HI...

ABSTRACT Diversity in host range, pathogenicity, phenotypic characteristics, repetitive extragenic palindromic polymerase chain reaction (rep-PCR) profiles, and sequence of the 16S-23S rDNA spacer region was examined among 44 Xanthomonas strains isolated from lettuce. Forty-two of the strains were divided into two groups, designated A and B. Seventy percent were Group A, and most of the remaini...

We propose a versatile pipeline to render B-Rep models interactively, precisely and without rendering-related artifacts such as cracks. Our rendering method is based on dynamic surface evaluation using both tesselation and ray-casting, and direct GPU surface trimming. An initial rendering of the scene is performed using dynamic tesselation. The algorithm we propose reliably detects then fills u...

Sixty isolates of Pythium aphanidermatum as the causal agent of sugar beet root rot were selected on the basis of their geographical origins, morphological and genetic diversity studies. Pathogenicity test using the Kruskal-Wallis analysis showed significant differences between the pathogenic potential of isolates. Based on the growth rate, isolates were categorized in two groups with low and h...

As the number of models in 3D databases grows, an efficient 3D models indexing mechanism and a similarity measure to ease model retrieval are necessary. In this paper, we present a query-by-model framework for NURBS based B-Rep models retrieval that combines partial symmetry of the object and the Fourier shape descriptor of canonical 2D projections of the 3D models. In fact, most objects are co...

Currently, most of CAD/CAM systems are feature-based. Features are important to maintain geometric and non-geometric relations across product models. Often, during data translation some useful geometric and non-geometric information such as features and their associated semantics are stripped off. In this paper, we introduce a new method of feature-based modeling in product data exchange using ...

The current study was conducted to determine the usefulness of 2 molecular techniques, automated repetitive extragenic palindromic-PCR (REP-PCR) and denaturing gradient gel electrophoresis (DGGE), to identify Salmonella serotypes of poultry origin. Salmonella continues to be a foodborne pathogen of principal concern in the United States. The interspersed conserved repetitive sequence of the bac...