In this paper a new technique for computing and ray tracing point based geometry is presented. It uses a novel point primitive that is called "Spherical Patch Point" (SPP) to approximate the vicinity of a su...
详细信息
In this paper a new technique for computing and ray tracing point based geometry is presented. It uses a novel point primitive that is called "Spherical Patch Point" (SPP) to approximate the vicinity of a surface point. Due to property of curvature, SPP can achieve similar visual quality compared with previous methods with much fewer primitives for the cost of a few additional bytes per point and thus makes a significant reduction in rendering time. During pre-process,important attributes are added to each SPP for the purpose of ray tracing. During rendering, an intersection algorithm different from previous ones has been demonstrated to get satisfied results. The proposed technique makes it possible to render high quality ray traced images with global illumination using SPPs. It offers a higher ray tracing speed in comparison with previous methods.
In this paper a new point-based rendering method for ray tracing is presented. An oriented spherical patch that passes a surface point is used to approximate the vicinity of that *** this paper the spherical patch tog...
详细信息
In this paper a new point-based rendering method for ray tracing is presented. An oriented spherical patch that passes a surface point is used to approximate the vicinity of that *** this paper the spherical patch together with the surface point is called "Spherical Patch Point" (SPP). Due to property of curvature, SPP can achieve similar visual quality compared with previous methods with much fewer points. This paper defines new point attributes for the purpose of efficiently locating the intersection between incoming ray and ***, an algorithm of intersecting a ray with point geometry is proposed. The algorithm can achieve a higher rendering speed in comparison with previous methods. The presented technique deals well with shadow, reflection and refraction.
A dynamic growing neural network (DGNN) for supervised learning of pattern recognition or unsupervised learning of clustering is presented. The main ideas included in DGNN are growing, resonance, and post-prune. DGNN ...
详细信息
A dynamic growing neural network (DGNN) for supervised learning of pattern recognition or unsupervised learning of clustering is presented. The main ideas included in DGNN are growing, resonance, and post-prune. DGNN is called dynamic growing because it is based on the Hebbian learning rule and adds new neurons under certain conditions. When DGNN performs supervised learning, resonance will happen if the winner can't match the training example; this rule combines the ART/ARTMAP neural network and WTA learning rule. When DGNN performs unsupervised learning, post-prune is carried out to prevent over fitting the training data just like decision tree learning. DGNN's prune rule is based on the distance threshold. DGNN has some advantages: learning not only is stable because it grows under certain conditions; but also it is faster than back-propagation rules and favorable learned predictive accuracy in small, noisy, online or offline data sets. Three classes of simulations are performed on the primary benchmarks: circle-in-the-square and two-spirals-apart benchmarks are used to check DGNN's supervised learning and compare it with ARTMAP and BP neural networks; DGNN's unsupervised learning ability is checked on UCI Machine Learning Archive's Synthetic Control Chart Time Series data set
In recently years there has been plenty of interest in Random Constraint Satisfaction Problem, both from an experimental and a theoretical point of view. In this paper we study and analyze the four popular problem ins...
详细信息
In recently years there has been plenty of interest in Random Constraint Satisfaction Problem, both from an experimental and a theoretical point of view. In this paper we study and analyze the four popular problem instance generating models, and present the extended model B+ based on the most used model B, which has the different domains and constraint tightness meeting some probability distribution function. In the subsequent section we give the relation matrix version of backtracking integrated forward checking algorithms, and introduce the implementation of instances generator and solver based on the new model. Finally we show the experiment results and conclude the paper, point that our extended model B+ has the common phase transition region with the transitional models and it has the advantage of being suited to the testing of heuristic based constraint solving algorithms, such as variables selection heuristic algorithms.
In Containing Order Rough Set Methodology (CORS),terminologies on rules or rules set, such as robust, minimality,completeness, mutuality degree, and conflict are discussed. The rules generation algorithm IGRs is given...
详细信息
In Containing Order Rough Set Methodology (CORS),terminologies on rules or rules set, such as robust, minimality,completeness, mutuality degree, and conflict are discussed. The rules generation algorithm IGRs is given and the details of algorithm IGRs are studied. Heuristic knowledge, which is mutuality degree of a condition item with a decision part, is used to choose condition item when generating rules. In primary and modified IGRs, two kinds of mutuality degree,simple and weighted mutuality are introduced respectively. In addition, the variable precision method is used to solve the conflict problem in modified IGRs. By experiments, the effects of two kinds heuristic knowledge and different weight values in synthetic mutuality on algorithms properties are shown,such as time consumption, calculation precision etc. The performances of IGRs with the primary and new conflict solution are compared by experiments.
The conclusion is that the weighted mutuality degree is more sound and the choice of appropriate weight values in it are important to optimize the quality of rules set. The variable precision method for dealing with conflict when generating rules is more reasonable. Both two modifications to primary IGRs make the performance of IGRs enhanced and the quality of rules set better. Algorithm IGRs still need further improvement.
In Containing Order Rough Set Methodology (CORS), ordered attribute 'criterion' is introduced. Criterion is related semantically with decision attributes, which results in producing more rational and significa...
详细信息
ISBN:
(纸本)1424404754
In Containing Order Rough Set Methodology (CORS), ordered attribute 'criterion' is introduced. Criterion is related semantically with decision attributes, which results in producing more rational and significant rules utilizing dominance relations. In this paper, some terminologies and properties on rules or rules set, such as robust, minimal, complete are discussed, the state of art in algorithms on rules generation are analyzed, and algorithms GRs and IGRs are proposed. We compare these two algorithms by experiments in time complexity, rules count and accuracy. We find that GRs can generate all minimal rules, but time complexity is high and IGRs' efficiency is better, but quality of rules are inferior to that of GRs. We also discuss the completeness of rules set and present a viewpoint that there are three hierarchies for completeness. In accuracy calculation, three formulas for accuracy calculation and two approaches for experimental test are given.
A hybrid discrete particle swarm algorithm is presented in this paper to solve open-shop problems. The operations are redefined in the discrete particle swarm algorithm. To improve the performance the simulated anneal...
详细信息
A technique for performing collision detection between complex deformable objects by using PSO optimizer is demonstrated. This approach provides a more comprehensive way to trade-off accuracy for computation time. Alt...
详细信息
A technique for performing collision detection between complex deformable objects by using PSO optimizer is demonstrated. This approach provides a more comprehensive way to trade-off accuracy for computation time. Although the swarm can handle temporal coherence and efficiently search through the highly large primitive pair solution space, we combine it with hierarchies to achieve higher culling efficiency and significantly reduce the size of solution space. At last, we give the precision and efficiency evaluation about the algorithm and find it might be a reasonable choice for deformable models in collision detection systems.
In this paper, we introduce the condition of distributed computing at present firstly. On this foundation, according to the analysis of particular case of distributed computing network, we implement a distributed netw...
详细信息
In this paper, we introduce the condition of distributed computing at present firstly. On this foundation, according to the analysis of particular case of distributed computing network, we implement a distributed network environment of P2P whose bottom layer frame is based on JXTA. It improves issuing method of message based on pipeline decomposition mechanism of task based on usage ratio of processor and distributed mechanism of object based on serialization. We build an improved distributed computing network platform on the platform of Linux and Windows and simulate a distributed computing environment. The simulated experiment proves the feasibility and the validity of the distributed network computing platform that is constructed in this paper
Fuzziness modeling for spatial data is currently an important problem in geographic information systems and spatial databases. In many geographical applications, spatial regions do not always have sharply defined boun...
详细信息
Fuzziness modeling for spatial data is currently an important problem in geographic information systems and spatial databases. In many geographical applications, spatial regions do not always have sharply defined boundaries but frequently their interiors and boundaries are fuzzy. A fuzzy spatial region model was proposed based on pleat set and the property of fuzzy regions was analyzed. The calculation method of relative membership of point in fuzzy region was given, and visualization model based on absolute membership value was proposed. The practical case shows that the model based on pleat set is valuable in the fields such as GIS, geography and spatial database.
暂无评论