Curve-skeletons of 3-D objects are medial axes shrunk to a single line. There are several applications for curve-skeletons. For example, animation of 3-D objects, such as an animal or a human, as well as planning of f...
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ISBN:
(纸本)9783540886051
Curve-skeletons of 3-D objects are medial axes shrunk to a single line. There are several applications for curve-skeletons. For example, animation of 3-D objects, such as an animal or a human, as well as planning of flight paths for virtual colonoscopy. Other applications are the extraction of center lines within blood vessels where center lines are used to quantitatively measure vessel length, vessel diameter, and angles between vessels. The described method computes curve-skeletons based on a vector field that is orthogonal to the object's boundary surface. A topological analysis of this field then yields the center lines of the curve-skeletons. In contrast to previous methods, the vector field does not need to be computed for every sampled point of the entire volume. Instead, the vector field is determined only on the sample points on the boundary surface of the objects. Since most of the computational time was spent on calculating the force Held in previous methods, the proposed approach requires significantly less time compared to previous vector-based techniques while still achieving a better accuracy and robustness compared to methods based on Voronoi tessellations.
Visualizing vector fields using streamlines or some derived applications is still one of the most popular flow visualization methods in use today. Besides the known trade-off between sufficient coverage in the field a...
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ISBN:
(纸本)9783540886051
Visualizing vector fields using streamlines or some derived applications is still one of the most popular flow visualization methods in use today. Besides the known trade-off between sufficient coverage in the field and cluttering of streamlines, the typical user question is: Where should I start my streamlines to see all important behavior? In previous work, we define flow structures as an extension of flow topology that permits a, partition of the whole flow tailored to the users needs. Based on the skeletal representation of the topology of flow structures, we propose a 3D streamline placement generating a minimal set of streamlines, that on the one hand exactly illustrates the desired property of the flow and on the other hand takes the topology of the specific flow structure into account. We present a heuristic and a deterministic approach and discuss their advantages and disadvantages.
If one wants to study the global dynamics of a, given system, key components are the stable or unstable manifolds of invariant sets, such as equilibria and periodic orbits. Even in the simplest examples, these global ...
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ISBN:
(纸本)9783540886051
If one wants to study the global dynamics of a, given system, key components are the stable or unstable manifolds of invariant sets, such as equilibria and periodic orbits. Even in the simplest examples, these global manifolds must be approximated by means of numerical computations. We discuss an algorithm for computing global manifolds of vector fields that is decidedly geometric in nature. A two-dimensional manifold is built up as a collection of approximate geodesic level sets, i.e. topological smooth circles. Our method allows to visualize the resulting surface by making use of the geodesic parametrization. As we show with the example of the Lorenz system, this is a big advantage when one wants to understand the geometry of complicated two-dimensional global manifolds. More precisely, for the standard system parameters, the origin of the Lorenz system has a two-dimensional stable manifold - called the Lorenz manifold - and the other two equilibria each have a two-dimensional unstable manifold. The intersections of these manifolds in the three-dimensional phase space form heteroclinic connections from the nontrivial equilibria to the origin. A parameter-dependent visualization of these manifolds clarifies the transition to chaos in the Lorenz system.
Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. One method to counteracting this cyber threat is to provide security analysts with better tools to discover patterns, detect anomalies,...
ISBN:
(数字)9783540782438
ISBN:
(纸本)9783540782421
Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. One method to counteracting this cyber threat is to provide security analysts with better tools to discover patterns, detect anomalies, identify correlations, and communicate their findings. visualization for computer security (VizSec) researchers and developers are doing just that. VizSec is about putting robust information visualization tools into the hands of human analysts to take advantage of the power of the human perceptual and cognitive processes in solving computer security problems. This volume collects the papers presented at the 4th International Workshop on Computer Security - VizSec 2007.
A high level analysis too] was developed for aiding in the analysis of large volumes of network telescope traffic, and in particular the comparisons of data collected from multiple telescope sources. Providing a visua...
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ISBN:
(数字)9783540782438
ISBN:
(纸本)9783540782421
A high level analysis too] was developed for aiding in the analysis of large volumes of network telescope traffic, and in particular the comparisons of data collected from multiple telescope sources. Providing a visual means for the evaluation of worm propagation algorithms has also been achieved. By using a Hilbert curve as a means of ordering points within the visualization space, the concept of nearness between numerically sequential network blocks was preserved. The design premise and initial results obtained using the tool developed are discussed, and a number of future extensions proposed.
The development of security visualization applications must involve the user in the design process in order to create usable systems. However, it is all too easy to lose track of the user during the design and develop...
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ISBN:
(数字)9783540782438
ISBN:
(纸本)9783540782421
The development of security visualization applications must involve the user in the design process in order to create usable systems. However, it is all too easy to lose track of the user during the design and development process, even though upfront investment in extensive user requirements gathering has proven benefits. To address this challenge, we adapt a user-centered design method called personas that enables effective requirements capture for varying scopes of requirements-gathering efforts, and, when used properly, keeps the user involved at every step of the process from design to evaluation.
Monitoring host behavior in a network is one of the most essential tasks in the fields of network monitoring and security since more and more malicious code in the wild internet constantly threatens the network infras...
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ISBN:
(数字)9783540782438
ISBN:
(纸本)9783540782421
Monitoring host behavior in a network is one of the most essential tasks in the fields of network monitoring and security since more and more malicious code in the wild internet constantly threatens the network infrastructure. In this paper, we present a visual analytics tool that visualizes network host behavior through positional changes in a two-dimensional space using a force-directed graph layout algorithm. The tool's interaction capabilities allow for visual exploration of network traffic over time and are demonstrated using netflow data as well as IDS alerts. Automatic accentuation of hosts with highly variable traffic results in fast hypothesis generation and confirmation of suspicious host behavior. By triggering the behavior graph from the HNMap tool, we were able to monitor more abstract network entities.
Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. Automated systems to combat this threat are one potential solution, but most automated systems require vigilant human oversight. This a...
详细信息
ISBN:
(数字)9783540782438
ISBN:
(纸本)9783540782421
Networked computers are ubiquitous, and are subject to attack, misuse, and abuse. Automated systems to combat this threat are one potential solution, but most automated systems require vigilant human oversight. This automated approach under-values the strong analytic capabilities of humans. While automation affords opportunities for increased scalability, humans provide the ability to handle exceptions and novel patterns. One method to counteracting the ever increasing cyber threat is to provide the human security analysts with better tools to discover pattems, detect anomalies, identify correlations, and communicate their findings. This is what visualization for computer security (VizSec) researchers and developers are doing. VizSec is about putting robust information visualization tools into the hands of humans to take advantage of the power of the human perceptual and cognitive processes in solving computer security problems. This chapter is an introduction to the VizSec research community and the papers in this volume.
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