45109672
Dynamic Terrain LOD with Region Preservation in 3D Game Engine
In the outdoor 3D game, the terrain can be modified because of interaction. This brings two new complexities to render terrain in 3D game. The first lies in the real-time visualization of dynamic terrain, and the second is that the modified terrain surface need to be preserved. We present an algorithm for dynamic terrain LOD(DT LOD) with preserving region in 3D game engine. The algorithm uses a DAG to represent dependency relationship of vertices which split triangles, and employs an active vertices set to update triangles in two consecutive frames for improving rendering performance. The region LOD can be constructed according to the view direction and the distance between the viewpoint and regions. The results of experiments show that our algorithm has a effective performance during rendering terrain.
34224506
Exploiting Frame-to-Frame Coherence for Rendering Terrain Using Continuous LOD
It is the key issue of the terrain real-time rendering to reduce the time-spending for the level-of-detail. The concept of triangle live frame is introduced in this paper. Using this live frame, the algorithm reuses per-vertex visibility computation from previously displayed frames efficiently during continuous view-dependent level-of-detail visualizations. This algorithm decreases to a certain extent computing the distance from the viewpoint to vertex at each frame. Experimental results show that the algorithm reduces the time effectively to produce the LOD terrain.
33127711
Real-Time Visualization of Tire Tracks in Dynamic Terrain with LOD
In off-road simulation, the terrain is being modified as a result of its interaction with the vehicles. Previous methods dealing with tire tracks are to animate tire tracks and have no interactivity. In this paper, we describe a method to render tire tracks in dynamic terrain. In the base of hierarchical structure for terrain LOD, hierarchical structure starts at a resolution sufficient to represent the initial terrain, and then increases the resolution wherever necessary at the modified terrain regions. To avoid the cracks at the boundary between terrain cells, which are modified and increased the resolution, an algorithm based on window-scanning avoids cracks between neighboring cells in the 2×2 window is given. This algorithm avoids the transfer of cracks effectively through guaranteeing the results after window scanning will not impact the edges processed previously. The results of experiments show that not only this algorithm avoids crack effectively, but also the cost of computing is very low.
17362173
A New Heuristic Reduct Algorithm Base on Rough Sets Theory
Real world data sets usually have many features, which increases the complexity of data mining task. Feature selection, as a preprocessing step to the data mining, has been shown very effective in reducing dimensionality, removing irrelevant data, increasing learning accuracy, and improving comprehensibility. To find the optimal feature subsets is the aim of feature selection. Rough sets theory provides a mathematical approach to find optimal feature subset, but this approach is time consuming. In this paper, we propose a novel heuristic algorithm based on rough sets theory to find out the feature subset. This algorithm employs appearing frequency of attribute as heuristic information. Experiment results show in most times our algorithm can find out optimal feature subset quickly and efficiently.
40653800
Coordination Research on Key Parameters in Generation Competition Based on Dynamic Simulation
Power generation adequacy is critical for the reliability of electricity supply service, and therefore its investment draws much attention. This paper builds a dynamic simulation model to solve the setting of two key parameters, the energy price cap and the capacity price in the generation market, and applies this model to various cases to analyze the generation capacity development. Based on the simulation results, this paper analyzes the sensitivity of generation capacity to the key parameters. Furthermore, this paper proposes an evaluation index system for the simulation model, and discusses the correlation between the two key parameters, from the views of reliability and economy. The research shows that there might be potential unmarked misunderstandings in the setting of key parameters, and suggests that under a certain electricity bill for customers, parameter combination of low energy price cap and high capacity price should be made, in order to curb the fluctuation of generation capacity and maintain the system reliability.
12801074
Studies on a Class of AWG-Based Node Architectures for Optical Burst-Switched Networks
We investigate a class of novel node architectures based on the static arrayed-waveguide gratings (AWGs) and tunable waveband converters (TWBCs) for optical burst-switched (OBS) networks. As compared to the other AWG-based architectures using tunable wavelength converters (TWCs) for switching, our design needs much fewer wavelength-converting devices, TWBCs, instead of a large number of TWCs (operating only on one wavelength at a time). Notwithstanding the inherent simplicity, AWG-based architectures, due to the static routing properties of AWGs, exhibit some internal blocking as compared to the strictly nonblocking OBS nodes employing SOA/TWC-based architectures. We address this issue in our design methodology to arrive at different candidate node architectures using multiple layers of AWGs. Our simulation results indicate that the proposed class of node architectures using TWBCs and multiple layers of AWG can offer acceptable blocking performance with a simple and cost-effective optical hardware for OBS networks.
2869397
Creditability Modeling of Distributed Embedded System Based on Real-Time Interaction Specification
Creditability modeling on real-time interaction specification for embedded systems on the distributed platform is a continuing challenge to developers. This paper presents a creditability modeling strategy that reduces complexity by separating data-related computational parts and time synchronization interaction among components. We introduce a notion of supervisor to discuss how to aggregate individual component’s computation into a well-defined composite computation from a view of causality interaction analysis. A prototyping system is implemented to prove the feasibility and flexibility of our methodology.
18278402
Hyperspectral images lossless compression by a novel three-dimensional wavelet coding
In this paper, we present a 3D hyperspectral images lossless compression algorithm, which is based on the asymmetric 3D quincunx structured wavelet transform (A3D-QWT) and the adaptive classification coding. A3D-QWT is a simpler 3D transform compared to the classical asymmetric 3D pyramidal wavelet structure (A3D-DWT) with nearly equal entropy; furthermore the spectral correlation after this quincunx structured transform is higher, which is useful to the adaptive classification coding. The adaptive classification coding can make full use of not only the spatial correlation but also the spectral correlation characteristics of hyperspectral images. Experiments show that our method is capable of providing a higher compression performance for hyperspectral images.