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Rolling bearing fault diagnosis fusion model based on gene expression programming

Journal of Information and Computational science 2010年第12期7卷 2437-2442页

作者： Huang, Jiangtao Wang, Minghui Xu, Kaikuo Institute of Image and Graphics Sichuan University Chengdu 610064 China School of Computer Science Sichuan University Chengdu 610064 China College of Computer Science and Technology Chengdu University of Information Technology Chengdu 610225 China

Traditionally, a single sensor is always used to provide several machine components operating condition for fault diagnosis. Fault diagnosis based on this approach is difficult to obtain satisfactory results, especially in the severe operating environment. This paper proposes a new feature-level fusion model based on gene expression programming. And the new fusion model fuses machine component operating features from more than one sensor in parallel. Firstly, calculate time-domain feature parameters of each sensor signal. Secondly, construct multi-sensor feature-level fusion model by using gene expression programming. Finally, identify the integration information and make decisions for machine components fault diagnosis. Experiments show that the new approach can achieve better performance than single sensor approach, and it is able to further improve the accuracy of fault diagnosis. © 2010 Binary Information Press.

关键词： Failure analysis

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Towards the extraction of hierarchical building descriptions from 3D indoor scans 7

Towards the extraction of hierarchical building descriptions...

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7th Eurographics Workshop on 3D Object Retrieval, 3DOR 2014

作者： Ochmann, S. Vock, R. Wessel, R. Klein, R. Institute of Computer Science II University of Bonn Germany

ISBN: (纸本)9783905674583

We present a new method for the hierarchical decomposition of 3D indoor scans and the subsequent generation of an according hierarchical graph-based building descriptor. The hierarchy consists of four basic levels with according entities, building - storey - room - object. All entities are represented as attributed nodes in a graph and are linked to the upper level entity they are located in. Additionally, nodes of the same level are linked depending on their spatial and topological relationship. The hierarchical description enables easy navigation in the formerly unstructured data, measurement takings, as well as carrying out retrieval tasks that incorporate geometric, topological, and also functional building properties describing e.g. the designated use of single rooms according to the objects it contains. In contrast to previous methods which either focus on the segmentation into rooms or on the recognition of indoor objects, our holistic approach incorporates a rather large spectrum of entities on different semantic levels that are inherent to 3D building representations. In our evaluation we show the feasibility of our method for extraction of hierarchical building descriptions for various tasks using synthetic as well as real world data. © The Eurographics Association 2014.

关键词： Buildings

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Towards efficient online compression of incrementally acquired point clouds 19

Towards efficient online compression of incrementally acquir...

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19th International Workshop on Vision, Modeling and Visualization, VMV 2014

作者： Golla, Tim Schwartz, Christophe Klein, Reinhard Institute of Computer Science II University of Bonn Germany

We present a framework for the online compression of incrementally acquired point cloud data. For this, we extend an existing vector quantization-based offline point cloud compression algorithm to handle the challenges that arise from the envisioned online scenario. In particular, we learn a codebook in advance from training data and replace a computationally demanding part of the algorithm with a faster alternative. We show that the compression ratios and reconstruction quality are comparable to the offline version while the speed is sufficiently improved. Further-more, we investigate how well codebooks that are generated from different amounts of training data generalize to larger sets of point cloud data. © The Eurographics Association 2014.

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Efficient unsupervised temporal segmentation of human motion

Efficient unsupervised temporal segmentation of human motion

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2014 ACM SIGGRAPH/Eurographics Symposium on computer Animation, SCA 2014

作者： Vögele, Anna Krüger, Björn Klein, Reinhard Bonn University Institute for Computer Science II Germany

This work introduces an efficient method for fully automatic temporal segmentation of human motion sequences and similar time series. The method relies on a neighborhood graph to partition a given data sequence into distinct activities and motion primitives according to self-similar structures given in that input sequence. In particular, the fast detection of repetitions within the discovered activity segments is a crucial problem of any motion processing pipeline directed at motion analysis and synthesis. The same similarity information in the neighborhood graph is further exploited to cluster these primitives into larger entities of semantic significance. The elements subject to this classification are then used as prior for estimating the same target values for entirely unknown streams of data. The technique makes no assumptions about the motion sequences at hand and no user interaction is required for the segmentation or clustering. Tests of our techniques are conducted on the CMU and HDM05 motion capture databases demonstrating the capability of our system handling motion segmentation, clustering, motion synthesis and transfer-of-label problems in practice -the latter being an optional step which relies on the preexistence of a small set of labeled data. © The Eurographics Association 2014.

关键词： Motion analysis

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On feature extraction for fingerprinting grapevine leaves

On feature extraction for fingerprinting grapevine leaves

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2013 International Conference on Image Processing, computer Vision, and Pattern Recognition, IPCV 2013, at WORLDCOMP 2013

作者： Michels, Dominik L. Giesselbach, Sven A. Werner, Thomas Steinhage, Volker Institute of Computer Science II University of Bonn Germany

ISBN: (纸本)1601322526

Within the scope of ***, an interdisciplinary research network of Bonn University and the Jülich Research Centre, we work on a new model-based approach to the phenotyping of grapevine. Our algorithm performs a robust extraction of different features from a given leaf image, like specific points of the vein network, the vein network itself, and different distances respectively angles between special features. For that we present robust methods, like a template based method to extract the peduncle point, a detection strategy to determine end points of leaf veins, and a Gabor filter-based directional edge tracing procedure to extract the network. The extracted features are fed into a support vector machine in order to realize a full automatic sufficient variety identification. © 2013 CSREA Press. All rights reserved.

关键词： Support vector machines

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Simple and efficient compression of animation sequences 05

Simple and efficient compression of animation sequences

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Proceedings of the 2005 ACM SIGGRAPH/Eurographics symposium on computer animation

作者： Sattler, Mirko Sarlette, Ralf Klein, Reinhard Institute of Computer Science II University of Bonn Germany

ISBN: (纸本)9781595931986

We present a new geometry compression method for animations, which is based on the clustered principal component analysis (CPCA). Instead of analyzing the set of vertices for each frame, our method analyzes the set of paths for all vertices for a certain animation length. Thus, using a data-driven approach, it can identify mesh parts, that are "coherent" over time. This usually leads to a very efficient and robust segmentation of the mesh into meaningful clusters, e.g. the wings of a chicken. These parts are then compressed separately using standard principal component analysis (PCA). Each of this clusters can be compressed more efficiently with lesser PCA components compared to previous approaches. Results show, that the new method outperforms other compression schemes like pure PCA based compression or combinations with linear prediction coding, while maintaining a better reconstruction error. This is true, even if the components and weights are quantized before transmission. The reconstruction process is very simple and can be performed directly on the GPU. © 2010 ACM.

关键词： Principal component analysis

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Hairstyle construction from raw surface data

Hairstyle construction from raw surface data

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International Conference on computer graphics, Imaging and Visualisation, CGIV'06

作者： Sobottka, Gerrit Kusak, Michael Weber, Andreas Institute of Computer Science II University of Bonn Germany

ISBN: (纸本)0769526063

We present a novel approach to the problem of hairstyle construction from raw surface data such as the ones obtained from surface scans. Our approach is based on a shape matching algorithm that fits individual hair fibers into a given volume according to a set of boundary conditions and additional hair density information. Our method employs a mechanical rod model based on the special theory of Cosserat rods. Such models can efficiently be used to simulate the deformation of individual fibers in subsequent manipulation steps. © 2006 IEEE.

关键词： computer graphics

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Data driven surface reflectance from sparse and irregular samples

Data driven surface reflectance from sparse and irregular sa...

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33rd Annual Conference on European Association for computer graphics, EUROgraphics 2012

作者： Ruiters, Roland Schwartz, Christopher Klein, Reinhard Institute for Computer Science II University of Bonn Germany

In recent years, measuring surface reflectance has become an established method for high quality renderings. In this context, especially non-parametric representations got a lot of attention as they allow for a very accurate representation of complex reflectance behavior. However, the acquisition of this data is a challenging task especially if complex object geometry is involved. Capturing images of the object under varying illumination and view conditions results in irregular angular samplings of the reflectance function with a limited angular resolution. Classical data-driven techniques, like tensor factorization, are not well suited for such data sets as they require a resampling of the high dimensional measurement data to a regular grid. This grid has to be on a much higher angular resolution to avoid resampling artifacts which in turn would lead to data sets of enormous size. To overcome these problems we introduce a novel, compact data-driven representation of reflectance functions based on a sum of separable functions which are fitted directly to the irregular set of data without any further resampling. The representation allows for efficient rendering and is also well suited for GPU applications. By exploiting spatial coherence of the reflectance function over the object a very precise reconstruction even of specular materials becomes possible already with a sparse input sampling. This would be impossible using standard data interpolation techniques. Since our algorithm exclusively operates on the compressed representation, it is both efficient in terms of memory use and computational complexity, depending only sub-linearly on the size of the fully tabulated data. The quality of the reflectance function is evaluated on synthetic data sets as ground truth as well as on real world measurements. © 2012 The Author(s).

关键词： Reflection

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Influence of the substrate's shape complexity on the coating properties produced by HVOF spraying of fine WC-12Co (2-10 μm) powders

Influence of the substrate's shape complexity on the coating...

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International Thermal Spray Conference and Exposition: Innovative Coating Solutions for the Global Economy, ITSC 2013

作者： Tillmann, W. Hollingsworth, P. Baumann, I. Flossbach, S. Müller, H. Wiederkehr, T. Institute of Materials Engineering TU Dortmund Germany Computer Science VII - Computer Graphics TU Dortmund Germany

ISBN: (纸本)9781632666819

Thermal spraying has emerged as a viable solution to produce wear and corrosion protective coatings on planar or large radial symmetric parts. However, in the field of industrial applications there is an increasing demand for parts with more complex shape. This, in turn, leads to the challenge to produce near-net-shape coatings with constant coating properties along the parts entire contour. The present study investigates the influence of the outer radius size on the deposition rate, the properties (hardness and porosity) and morphology of HVOF sprayed fine structured WC-12Co coatings. As feedstock material an agglomerated and sintered WC-12Co powder with a size distribution of 2-10 μm was used. For the spray experiments the process parameters were held constant, while the radii were varied between 5-40 mm. It has been generally shown that HVOF spraying of fine powders is more robust against the alteration of the curvature than other spray processes. However the deposition rate decreases compared to planar substrates.

关键词： Powders

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Augmentation techniques for efficient exploration in head-mounted display environments 10

Augmentation techniques for efficient exploration in head-mo...

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Proceedings of the 17th ACM Symposium on Virtual Reality Software and Technology

作者： Bolte, Benjamin Bruder, Gerd Steinicke, Frank Hinrichs, Klaus Lappe, Markus Visualization and Computer Graphics Group Department of Computer Science University of Münster Germany Psychology Department II University of Münster Germany

ISBN: (纸本)9781450304412

Physical characteristics and constraints of today's head-mounted displays (HMDs) often impair interaction in immersive virtual environments (VEs). For instance, due to the limited field of view (FOV) subtended by the display units in front of the user's eyes more effort is required to explore a VE by head rotations than for exploration in the real world. In this paper we propose a combination of two augmentation techniques that have the potential to make exploration of VEs more efficient: (1) augmenting the geometric FOV (GFOV) used for rendering the VE, and (2) amplifying head rotations while the user changes her head orientation. In order to identify how much manipulation can be applied without users noticing, we conducted two psychophysical experiments in which we analyzed subjects' ability to discriminate between virtual and real head pitch and roll rotations while three different geometric FOVs were used. Our results show that the combination of both techniques has great potential to support efficient exploration of VEs. We found that virtual pitch and roll rotations can be amplified by 30% and 44% respectively, when the GFOV matches the subject's estimation of the most natural FOV. This leads to a possible reduction of the user's effort required to explore the VE using a combination of both techniques by approximately 25%. Copyright © 2010 by the Association for Computing Machinery, Inc.

关键词： Virtual reality

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