Information spaces such the WWW are the most challenging type of space that many people navigate during everyday life. Unlike the real world, there are no effective maps of information spaces, so people are forced to ...
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ISBN:
(纸本)9780769541655
Information spaces such the WWW are the most challenging type of space that many people navigate during everyday life. Unlike the real world, there are no effective maps of information spaces, so people are forced to rely on search engines which are only suited to some types of retrieval task. This paper describes a new method for creating maps of information spaces, called INSPIRE. The INSPIRE engine is a tree drawing algorithm that uses a city metaphor, comprised of streets and buildings, and generates maps entirely automatically from webcrawl data. A technical evaluation was carried out using data from 112 universities, which had up to 485,775 pages on their websites. Although they take longer to compute than radial layouts (e.g., the Bubble Tree), INSPIRE maps are much more compact. INSPIRE maps also have desirable aesthetic properties of being orthogonal, preserving symmetry between identical subtrees and being planar.
Real-time tessellation methods offer the ability to upsample 3D surface meshes on the fly during rendering. This upsampling relies on 3 major steps. First, it requires a tessellation kernel which can be implemented on...
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ISBN:
(纸本)9781424479948
Real-time tessellation methods offer the ability to upsample 3D surface meshes on the fly during rendering. This upsampling relies on 3 major steps. First, it requires a tessellation kernel which can be implemented on GPU or may be already available as a hardware unit. Second, the surface model defines the positions of the newly inserted vertices - we focus on recent visually smooth models. And third the adaptive sampling tailors the spatially varying distribution of newly inserted vertices on the input surface. We study the last component and introduce a new view-dependent adaptivity metric which builds upon both intrinsic and extrinsic criteria of the input mesh. As a result, we obtain a better vertex distribution around important features in the tessellated mesh.
The rapid advancement of digital scanner, digital camera and digital video recorder technologies has created a huge market for digital multi-media, such as documents, photos and videos, storage, retrieval and reproduc...
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ISBN:
(纸本)9781424453092
The rapid advancement of digital scanner, digital camera and digital video recorder technologies has created a huge market for digital multi-media, such as documents, photos and videos, storage, retrieval and reproduction market. The ease of modifications using editing tools makes the identification of original masterpiece difficult and these forgeries sometimes become an important issue for identification, authentication and law enforcement. The demand of a security protection chip increases as digital documents in form of digital video became popular and forensic approaches for detecting forgery evident became vital. In this paper, a real time forensic chip is designed and implemented. This Chip captures real time video frames and encodes forensic mark into the video frame. The video frame with forensic mark embedded is then transmitted to remote host through TCP/IP. On the remote host, the same Chip can be used to decode the stored forensic mark from the received video frame. Any modifications to the original captured video can immediately be detected by the chip in real time.
A tool to deform non-planar parametric surfaces based on B-splines is presented. This tool is based on an energy functional and its variational formulation. The deformation of the non-planar surface is made moving the...
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ISBN:
(纸本)9789077381571
A tool to deform non-planar parametric surfaces based on B-splines is presented. This tool is based on an energy functional and its variational formulation. The deformation of the non-planar surface is made moving the control points of the surface. In order to do that, the space will be discretized and an ordinary differential equation has to be solved. To do it, an analytical solution will be used taking into account the features of B-splines as a finite elements. Our method will be fast because only a reduced number of control points will be moved instead of all the surface points. So, our method can be used to make simulations.
A discrete collision detection algorithm to detect self-collisions between deformable objects is presented, this is built up using a Bounding Volume Hierarchy (BVH) and a Feature-based method. The deformations are rep...
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ISBN:
(纸本)9780769539577
A discrete collision detection algorithm to detect self-collisions between deformable objects is presented, this is built up using a Bounding Volume Hierarchy (BVH) and a Feature-based method. The deformations are represented by the features of the mesh, which are within the bounding volumes and consequently the updating time for the BVH is reduced. The algorithm compares the minimum bounded geometry, the 1-ring, with the other spheres of the hierarchy in order to cull away Bounding Volumes (BV) that are far apart. The 3D objects utilised are surface-based and are deformed by warping, control points of splines, and a mass-spring model.
We propose a method of downsizing technique for point sampled data which reduces information amount of three dimensional point cloud data. Our method generates clusters and spiral chain lists. Each chain is consists o...
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ISBN:
(纸本)9788086943862
We propose a method of downsizing technique for point sampled data which reduces information amount of three dimensional point cloud data. Our method generates clusters and spiral chain lists. Each chain is consists of three dimensional points. After that, we adopt a predictive encoding to compress these chain lists. In addition, we show the effectiveness of our method with same experimental results by comparison with one of conventional methods. From these experiments, our method can reduce the information amount coordinate data to 31.7% of original model.
In clinical routine of liver surgery there are a multitude of risks such as vessel injuries, blood loss, incomplete tumor resection, etc. In order to avoid these risks the surgeons perform a planning of a surgical int...
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ISBN:
(纸本)9781424441242
In clinical routine of liver surgery there are a multitude of risks such as vessel injuries, blood loss, incomplete tumor resection, etc. In order to avoid these risks the surgeons perform a planning of a surgical intervention. A good graphical representation of the liver and its inner structures is of great importance for a good planning. In this work we introduce a new planning system for liver surgery, which is meant for computer tomography (CT) data analysis and graphical representation. The system is based on automatic and semiautomatic segmentation techniques as well as on a simple and intuitive user interface and was developed with the intention to help surgeons by planning an operation and increasing the efficiency in open liver surgery.
This paper presents an approach to probabilistic active perception planning for scene modeling in cluttered and realistic environments. When dealing with complex, multi-object scenes with arbitrary object positions, t...
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ISBN:
(纸本)9781424466757
This paper presents an approach to probabilistic active perception planning for scene modeling in cluttered and realistic environments. When dealing with complex, multi-object scenes with arbitrary object positions, the estimation of 6D poses including their expected uncertainties is essential. The scene model keeps track of the probabilistic object hypotheses over several sequencing sensing actions to represent the real object constellation. To improve detection results and to tackle occlusion problems a method for active planning is proposed which reasons about model and state transition uncertainties in continuous and high-dimensional domains. Information theoretic quality criteria are used for sequential decision making to evaluate probability distributions. The probabilistic planner is realized as a partially observable Markov decision process (POMDP). The active perception system for autonomous service robots is evaluated in experiments in a kitchen environment. In 80 test runs the efficiency and satisfactory behavior of the proposed methodology is shown in comparison to a random and a step-aside action selection strategy. The objects are selected from a large database consisting of 100 different household items.
This paper introduces the Auto Terrain Generation System (ATGS), which is based on an Interactive Genetic Algorithm (IGA) that enables non-specialist users to rapidly generate terrains. The motivation for using an IGA...
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ISBN:
(纸本)9781424481262
This paper introduces the Auto Terrain Generation System (ATGS), which is based on an Interactive Genetic Algorithm (IGA) that enables non-specialist users to rapidly generate terrains. The motivation for using an IGA is discussed, existing terrain generation techniques are described and a new approach, based on a fractal terrain engine, is outlined. graphics engines allow terrains to be specified with over 800 floating point parameters, which can overwhelm non-specialist users. These parameters also create a vast search space for auto-terrain generation systems that can complicate procedural techniques. ATGS addresses these issues via interaction with the user, which is implemented in ATGS by a web based user interface that allows users to rapidly indicate terrain preferences. These user preferences are used by a genetic algorithm to explore a multi-dimensional parameter space that satisfies the user's intuition and aesthetics. Proof of concept experiments are outlined, results are presented and future research work is projected.
Fast instance generation is a key requirement in atlas-based registration and other problems that need a large number of atlas instances. This paper describes a new method to represent and construct intensity atlases....
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ISBN:
(纸本)9781424441242
Fast instance generation is a key requirement in atlas-based registration and other problems that need a large number of atlas instances. This paper describes a new method to represent and construct intensity atlases. Both geometry and intensity information are represented using B-spline deformation lattices;intensities are approximated using the multi-level B-spline approximation algorithm during model creation and the parallel computation capability of modern graphics processing units is used to accelerate the process of instance generation. Experiments with distal radius CTs show that, with a coefficients-to-voxels ratio of 0.16, intensities can be approximated up to an average accuracy of 2 +/- 17 grey-levels (out of 3072 total grey-levels), and instances of resolution 256 x 256 x 200 can be produced in a rate of 25 instances per second with a GeForce GTX 285 video card, which is about 500 times performance improvement over the traditional method that uses plain CPU.
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