17252867
Efficient radiosity rendering using textures and bicubic reconstruction
Wepresenta method to speed up walkthmttghs of static scenes. It involves the cmatiort of acmttimsous C1 radiosity reconstruction for adaptively sampled tegiotts. This mpmaentation is a unitied solution to handle usuestricted quadtrees and T-vertices, and allows for the generation of multiple different levels-of-detail of the radiosity function, which are represented as texture maps. The method also involves the use of hardwase bicublc filtering for the mdiosity shading. Both techniques allow improvenmts in performance and memory usage while preserving visual appearance. CR CMegories and Subject Deaeriptom: L3.3 [Computer Graphics]: Pictusdmage Generation Viewing Algorithm, 1.3.6 [Computer Graphics]: Methodology and Techniques Integration Techniques. Additioatsl
686393
Accelerated walkthrough of large spline models
CAD and rmimation applications. In this pa-per, we present algorithms for interactive walkthrough ofcomplex NURBS models composed of tens of thousands ofpatches on current graphics systems. Given a spline model,the algorithm precomputes simplification of a collection ofpatches and represents them hierarchically. Given a chang-ing viewpoint, the algorithm combines these simplificationswith dynamic tessellations to generate appropriate levels ofdetail. We also propose a system pipeline for parallel im-plementation on multi-processor configurations. Diiferentcomponents,
8107037
Forward Shadow Mapping
Forward shadow mapping is a new approach to real-time shadow generation. The traditional shadow map algorithm maps the pixels in the eye’s view backward into the depth buffers of light sources (i.e. shadow maps), which is similiar to and often implemented as an extension to texture mapping. Our algorithm reverses this process by using 3-D image warping techniques to transform shadow map pixels forward into the eye’s view to directly indicate which pixels are lit; it does not interfere with normal texture mapping and easily supports antialiased shadow edges and projective textures. Access to shadow maps and projective textures is in pixel-sequential order. This algorithm has advantages when speed of texture mapping becomes the performance bottleneck, which is often the case in visual simulation and game applications.
35208191
Pattern generation with color map gouraud shading
Abstract This paper introduces a simple and fast method for generating intricate and aesthetically pleasing patterns. The essence of the method is rendering color map Gouraud-shaded polygons. In color map Gouraud shading, the interpolated values are not the RGB color components but the indices of entries in a color map. The method can produce a great variety of complex patterns, and the generation time depends almost solely on the speed of rendering Gouraud-shaded polygons.
2157887
Concurrent subspaces analysis
A representative subspace is significant for image analysis, while the corresponding techniques often suffer from the curse of dimensionality dilemma. In this paper, we propose a new algorithm, called concurrent subspaces analysis (CSA), to derive representative subspaces by encoding image objects as 2/sup nd/ or even higher order tensors. In CSA, an original higher dimensional tensor is transformed into a lower dimensional one using multiple concurrent subspaces that characterize the most representative information of different dimensions, respectively. Moreover, an efficient procedure is provided to learn these subspaces in an iterative manner. As analyzed in this paper, each sub-step of CSA takes the column vectors of the matrices, which are acquired from the k-mode unfolding of the tensors, as the new objects to be analyzed, thus the curse of dimensionality dilemma can be effectively avoided. The extensive experiments on the 3/sup rd/ order tensor data, simulated video sequences and Gabor filtered digital number image database show that CSA outperforms principal component analysis in terms of both reconstruction and classification capability.
13620764
Multi-level differential surface representation based on local transformations
One crucial issue of multi-resolution surface representations is how to effectively record and reconstruct geometric details among surface levels. Standard multi-resolution techniques encode details directly as local displacements in the vertices, and may produce unplausible results when the base level endures large deformations. In this paper we propose an alternative detail representation and reconstruction scheme, based on local transformations on a per-triangle basis. While more storage is required, recording details as local transformations favors global coupling of geometric details and allows for large-scale surface manipulations. By modeling the scale components of the surface modifications as a set of deforming factors, we achieved detail-preserving reconstruction results naturally under very large deformations. Comprehensive experimental results verify the efficiency and robustness of our approach.
5976625
Augmenting naive Bayes for ranking
Naive Bayes is an effective and efficient learning algorithm in classification. In many applications, however, an accurate ranking of instances based on the class probability is more desirable. Unfortunately, naive Bayes has been found to produce poor probability estimates. Numerous techniques have been proposed to extend naive Bayes for better classification accuracy, of which selective Bayesian classifiers (SBC) (Langley & Sage, 1994), tree-augmented naive Bayes (TAN) (Friedman et al., 1997), NBTree (Kohavi, 1996), boosted naive Bayes (Elkan, 1997), and AODE (Webb et al., 2005) achieve remarkable improvement over naive Bayes in terms of classification accuracy. An interesting question is: Do these techniques also produce accurate ranking? In this paper, we first conduct a systematic experimental study on their efficacy for ranking. Then, we propose a new approach to augmenting naive Bayes for generating accurate ranking, called hidden naive Bayes (HNB). In an HNB, a hidden parent is created for each attribute to represent the influences from all other attributes, and thus a more accurate ranking is expected. HNB inherits the structural simplicity of naive Bayes and can be easily learned without structure learning. Our experiments show that HNB outperforms naive Bayes, SBC, boosted naive Bayes, NBTree, and TAN significantly, and performs slightly better than AODE in ranking.
7692801
Semi-quantitative Simulation Modeling of Software Engineering Process
Software process simulation models hold out the promise of improving project planning and control. However, purely quantitative models require a very detailed understanding of the software process, i.e. process knowledge represented quantitatively. When such data is lacking, quantitative models impose severe constraints, restricting the model's value. In contrast, qualitative models display all possible behaviors but only in qualitative terms. This paper illustrates the value and flexibility of semi-quantitative modeling by developing a model of the software staffing process and comparing it with other quantitative staffing models. We show that the semi-quantitative model provides more insights into the staffing process and more confidence in the outcomes than the quantitative models by achieving a tradeoff between quantitative and qualitative simulation. In particular, the semi-quantitative simulation produces a set of possible outcomes with the ranges of real numeric values. The semi-quantitative model allows us to determine the solution boundaries for specific scenarios under the conditions of limited knowledge.
13233829
6 DOF long-range precision tracking system
A novel design of a 6 DOF tracking system intended for large-scale dynamic robot measurement is presented. By integrating data from three-laser tracking systems and an inertial measurement unit, the system provides high frequency, precision position and attitude data. The drifting convergence problem of the inertial measurement method is corrected by using the laser tracking systems. And the integration of laser tracking systems and inertial measurement unit also increase the overall precision of the combined measurement system. Even if the measurements of laser tracker are intermittent and are obtained at a low frequency, the experimental result indicates the method proposed in this paper is able to reach an accuracy of a few hundred micron. Finally, real experiments performed with a parallel robot are presented and analyzed.