18976777
Up to Face Extrusion Algorithm for Generating B-Rep Solid
Up to face extrusion (UTFE) is an effective operation to extrude the profile from a sketch plane to a selected face. An up to face extrusion algorithm is presented in this paper. The algorithm first generates the trimmed extrusion through a simple body-surface Boolean operation method, and then generates the resultant solid through a regularized Boolean operation between the original solid and the trimmed extrusion. The algorithm has been implemented in a commercial geometric modeling software system TiGems. Examples are given to illustrate the algorithm.
16104127
Bilateral Filter for Meshes Using New Predictor
A new predictor of bilateral filter for smoothing meshes is presented. It prevents shrinkage of corners. A major feature of mesh smoothing is to move every vertex along the direction determined by the mean curvature normal with speed defined by the predictor. It prevents unnatural deformation for irregular meshes. In order to remove thenormal noise, we use adaptive Gaussian filter to smooth triangle normals.
18261046
Shelling Algorithm in Solid Modeling
Shelling is a powerful modeling operation in current CAD /CAM systems. In this paper, we present a new shelling algorithm for regular B-Rep solids. We first generate an initial offset solid, then correct the self-intersecting offset solid if necessary. We obtain the resultant shelling solid through a regularized Boolean operation finally. The algorithm has been implemented in a solid modeling system, and some examples are given to illustrate it.
17170240
The Z-Transformation graph for an outerplane bipartite graph has a Hamilton path
The Z-transformation graph of perfect matchings of a plane bipartite graph G has the perfect matchings of G as vertices, two perfect matchings being adjacent if their symmetric difference forms a cycle that is the boundary of an interior face of G. In this note, we prove that the Z-transformation graph of perfect matchings of an outerplane bipartite graph has a Hamilton path.
14763506
Real-time voxelization for complex polygonal models
In this paper, we present an efficient voxelization algorithm for complex polygonal models by exploiting newest programmable graphics hardware. We first convert the model into three discrete voxel spaces according to its surface orientation. The resultant voxels are encoded as 2D textures and stored in three intermediate sheet buffers called directional sheet buffers. These buffers are finally synthesized into one worksheet, which records the volumetric representation of the target. The whole algorithm traverses the geometric model only once and is accomplished entirely in GPU (graphics processing unit), achieving real-time frame rate for models with up to 2 million triangles.
32668520
2D DGT induced fluxes in sediments and soils (2D DIFS)
Diffusive gradients in thin films (DGT) is an emerging, dynamic, measuring technique that can provide diverse information on the concentrations and behaviour of solutes, including chemical speciation and partitioning between solid phase and solution in waters, sediments and soils. The DGT device, which accumulates solute in a binding layer after transport through a well-defined diffusion layer, is simple to construct and use. However, complete interpretation of the dependence of mass accumulation with time requires a numerical model of the transport and reactions occurring within the device and its deployment medium. We have developed a software tool that models the temporal dependence of DGT induced fluxes from soils or sediments by considering diffusion of solutes in two dimensions (2D) and incorporating first order exchange of solute between solid phase and solution. Microniches of elevated concentrations, that emulate zones of high microbial activity, can be created in the soil or sediment. The solver uses an advanced 2D FEM method and a flexible and user-friendly Graphical User Interface, which incorporates essential model calibration tools, is provided. This solution in 2D is shown to substantially increase the accuracy of the simulation, compared to that achieved with the established DIFS software that provides only a 1D solution, and yet it still has short calculation times on modern PCs. The 2D model is shown to provide a good approximation to the full 3D solution, obtained using FEMLAB, when the supply from the solid phase is larger than supply by diffusion. Example simulations are provided for the three major solute supply situations, namely diffusion only, very rapid and sustained supply from the solid phase and two intermediate cases of partial resupply.
5415099
Face Annotation for Family Photo Album Management
In this paper, we propose a framework to semi-automatically annotate faces in family photo albums. The core of the framework is the features used to define face similarity and this results in the learning algorithm used to refine automatic face annotation. We have adopted similarity based search and relevance feedback ideas developed for content-based image retrieval and a set of simple yet effective color and texture based features, in addition to the traditional face recognition features, in performing candidate annotation search. The experimental evaluation of the proposed approach has been conducted with a family album of 1707 photos and the results show that the proposed approach is an effective and efficient one for semi-automatic family photo album annotation.
37845872
The complexity of learning in PLN networks
Abstract In this paper, the complexity of learning in the feedforward PLN network is investigated by using Markov chain theory, when its training samples are incomplete (i.e., a network with hidden nodes). We present a learning algorithm. A formula for computing the average number of steps that the learning algorithm converges is obtained when the PLN network exists a solution. In the probabilistic sense, the completeness of the learning algorithm is proved. Some computer simulations are given to verify the analysis.