Sensible data analysis requires data quality control. An essential part of this is data profiling, which is the identification and assessment of data quality problems as a prerequisite for adequately handling these pr...
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ISBN:
(纸本)9781538614242
Sensible data analysis requires data quality control. An essential part of this is data profiling, which is the identification and assessment of data quality problems as a prerequisite for adequately handling these problems. Differentiating between actual quality problems and unusual, but valid data values requires the "human-in-the-loop" through the use of visual analytics. Unfortunately, existing approaches for data profiling do not adequately support the special characteristics of time, which is imperative to identify quality problems in time series data - a data type prevalent in a multitude of disciplines. In this design study paper, we outline the design, implementation, and evaluation of "Know Your Enemy" (KYE) - a visual analytics approach to assess the quality of time series data. KYE supports the task of data profiling with (1) predefined data quality checks, (2) user-definable, customized quality checks, (3) interactive visualization to explore and reason about automatically detected problems, and (4) the visual identification of hidden quality problems.
This article presents interactive visualizations to support the comprehension of spatial relationships between virtual and real-world objects for Augmented Reality (AR) applications. To enhance the clarity of such rel...
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This article presents interactive visualizations to support the comprehension of spatial relationships between virtual and real-world objects for Augmented Reality (AR) applications. To enhance the clarity of such relationships, we discuss visualization techniques and their suitability for AR. We apply them on different AR applications with different goals, e. g., in x-ray vision or in applications that draw a user's attention to an object of interest. We demonstrate how Focus and Context (F+C) visualizations are used to affect the user's perception of hidden or nearby objects by presenting contextual information in the area of augmentation. The organization and possible sources of data for visualizations in AR are presented, as well as cascaded multilevel F+C visualizations to address complex cluttered scenes that are inevitable in real environments. This article furthermore shows filter operations and tools to interactively control the amount of augmentation. It compares the impact of real-world context preservations to a pure virtual and uniform enhancement of occluding structures for augmentations of real-world imagery. Finally, this paper discusses the stylization of sparse object representations to improve the comprehension of x-ray visualizations in AR.
This paper describes a 3D tool machining simulation system. The initial tool and the grinding wheels are integrated with the machine tool. The application reads and interprets the CNC program code that controls the ma...
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This paper describes a 3D tool machining simulation system. The initial tool and the grinding wheels are integrated with the machine tool. The application reads and interprets the CNC program code that controls the machine, it computes the positions and the motion of components and it translates the sequence of machining operations into Boolean operations. The machining is computed for 2D sections and, later, a 3D model of the tool is reconstructed. The application is ready to yield tool visualization, it gives measurements on sections and it can show an interactive animation of the whole process. A novel aspect of the simulation is that it is able to deal with 6-axes machines, whereas most of previous work is limited to 3- and 4-axes machines. In addition, it allows to interrupt the machining process and to show partially machined tools. A major contribution is the fact that the Boolean operations are performed in 2D and the 3D model is reconstructed from the cross sections, which provides user control on the resolution of the operations at a low cost. (C) 2002 Elsevier Science Ltd. All rights reserved.
The language of geometric algebra can be used in the development of computer graphics applications. This paper proposes a method to describe a 3D polygonal mesh model using a representation technique based on geometri...
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The language of geometric algebra can be used in the development of computer graphics applications. This paper proposes a method to describe a 3D polygonal mesh model using a representation technique based on geometric algebra and the conformal model of the 3D Euclidean space. It describes also the stages necessary to develop an application that uses this formalism. The current application was used to validate the implementation of the main abstract operations characteristic to a geometric algebra computational environment (programming module GAP). The datastructures that characterize this geometric algebra based modeling approach as well as the implementation of geometric algebra based methods for model visualization/transformation are developed in detail. The paper emphasizes the elegance and generality of the geometric algebra approach referring also to the necessary computational resources. (C) 2004 Published by Elsevier Ltd.
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