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21.
Michael Wand Alexander Berner Martin Bokeloh Philipp Jenke Arno Fleck Mark Hoffmann Benjamin Maier Dirk Staneker Andreas Schilling Hans-Peter Seidel 《Computers & Graphics》2008,32(2):204-220
This paper describes a new out-of-core multi-resolution data structure for real-time visualization, interactive editing and externally efficient processing of large point clouds. We describe an editing system that makes use of the novel data structure to provide interactive editing and preprocessing tools for large scanner data sets. Using the new data structure, we provide a complete tool chain for 3D scanner data processing, from data preprocessing and filtering to manual touch-up and real-time visualization. In particular, we describe an out-of-core outlier removal and bilateral geometry filtering algorithm, a toolset for interactive selection, painting, transformation, and filtering of huge out-of-core point-cloud data sets and a real-time rendering algorithm, which all use the same data structure as storage backend. The interactive tools work in real-time for small model modifications. For large scale editing operations, we employ a two-resolution approach where editing is planned in real-time and executed in an externally efficient offline computation afterwards. We evaluate our implementation on example data sets of sizes up to 63 GB, demonstrating that the proposed technique can be used effectively in real-world applications. 相似文献
22.
The Formation of Calcified Nanospherites during Micropetrosis Represents a Unique Mineralization Mechanism in Aged Human Bone 下载免费PDF全文
Petar Milovanovic Elizabeth A. Zimmermann Annika vom Scheidt Björn Hoffmann George Sarau Timur Yorgan Michaela Schweizer Michael Amling Silke Christiansen Björn Busse 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(3)
Osteocytes—the central regulators of bone remodeling—are enclosed in a network of microcavities (lacunae) and nanocanals (canaliculi) pervading the mineralized bone. In a hitherto obscure process related to aging and disease, local plugs in the lacuno‐canalicular network disrupt cellular communication and impede bone homeostasis. By utilizing a suite of high‐resolution imaging and physics‐based techniques, it is shown here that the local plugs develop by accumulation and fusion of calcified nanospherites in lacunae and canaliculi (micropetrosis). Two distinctive nanospherites phenotypes are found to originate from different osteocytic elements. A substantial deviation in the spherites' composition in comparison to mineralized bone further suggests a mineralization process unlike regular bone mineralization. Clearly, mineralization of osteocyte lacunae qualifies as a strong marker for degrading bone material quality in skeletal aging. The understanding of micropetrosis may guide future therapeutics toward preserving osteocyte viability to maintain mechanical competence and fracture resistance of bone in elderly individuals. 相似文献
23.
Protecting and preserving clear barrier layers for flexible packaging materials In‐line thermal evaporation of organic topcoat layer 下载免费PDF全文
The end market for transparent flexible barrier films is larger than for metallized films. Presently, the market is still dominated by polymeric barrier layers but the used chemicals may be harmful for the environment. An alternative would be transparent thin layers deposited by vacuum deposition techniques using reactive processes. Ceramic materials like silicon oxide or aluminum oxide are used having a film thickness of just ~10 nm, a coating uniformity of +/?5% across and along the film at a barrier performance below 2.0 sccm/m2d for oxygen transmission rate (OTR) and below 1.0 g/m2d for water vapor transmission rate (WVTR) on PET substrates. In this paper, details will be provided about the deposition processes for these barrier layers using thermal evaporation, plasma‐assisted thermal evaporation as well as deposition by electron beam evaporation. An important factor for these high barrier transparent coatings is also to withstand the downstream processes in the whole packaging stream like slitting, lamination, printing etc. One solution is to protect the barrier layers by a Topcoat. For example, off‐line deposition of lacquers is used in field but the market penetration is low due to high process and material costs. An in‐situ Topcoat deposition is a smart solution to overcome this issue saving time and costs. Such an approach will be also described in the presentation and the impact on the performance of the final package will be discussed. 相似文献
24.
25.
Nils Hasler Carsten Stoll Bodo Rosenhahn Thorsten Thormhlen Hans-Peter Seidel 《Computers & Graphics》2009,33(3):211
The paper presents a method to estimate the detailed 3D body shape of a person even if heavy or loose clothing is worn. The approach is based on a space of human shapes, learned from a large database of registered body scans. Together with this database we use as input a 3D scan or model of the person wearing clothes and apply a fitting method, based on ICP (iterated closest point) registration and Laplacian mesh deformation. The statistical model of human body shapes enforces that the model stays within the space of human shapes. The method therefore allows us to compute the most likely shape and pose of the subject, even if it is heavily occluded or body parts are not visible. Several experiments demonstrate the applicability and accuracy of our approach to recover occluded or missing body parts from 3D laser scans. 相似文献
26.
This article presents a method for classifying color points for automotive applications in the Hue Saturation Intensity (HSI)
Space based on the distances between their projections onto the SI plane. Firstly the HSI Space is analyzed in detail. Secondly
the projection of image points from a typical automotive scene onto the SI plane is shown. The minimal classes relevant for
driver assistance applications are derived. The requirements for the classification of the points into those classes are obtained.
Several weighting functions are proposed and a fast form of an euclidean metric is investigated in detail. In order to improve
the sensitivity of the weighting function, dynamic coefficients are introduced. It is shown how to compute them automatically
in order to get optimal results for the classification. Finally some results of applying the metric to the sample images are
shown and the conclusions are drawn.
Calin Rotaru is a PhD candidate at the Department of Computer Science, University of Hamburg, Germany. His PhD work focuses on the topic color machine vision for driver assistance systems and is supported by Volkswagen AG, Group Research Electronics. He graduated (2002) with the topic “Stereo Camera Based Object Recognition” for Driver Assistance Systems from the Faculty of Automation and Computer Science of the Technical University of Cluj-Napoca, Romania. His research interests include color machine vision, smart vision systems, multisensorial data fusion and vision in driver assistance systems. Thorsten Graf received the diploma (M.Sc.) degree in computer science and the Ph.D. degree (his thesis was on “Flexible Object Recognition Based on Invariant Theory and Agent Technology”) from the University of Bielefeld, Bielefeld, Germany, in 1997 and 2000, respectively. In 1997 he became a Member of the “Task Oriented Communication” graduate program, University of Bielefeld, funded by the German research foundation DFG. In June 2001 he joined Volkswagen Group Research, Wolfsburg, Germany. Since then, he has worked on different projects in the area of driver assistance systems as a Researcher and Project Leader. He is the author or coauthor of more than 40 publications and owns several patents. His research interests include image processing and analysis dedicated to advanced comfort/safety automotive applications. Dr. Jianwei Zhang is full professor and director of the Institute of Technical Aspects of Multimodal Systems, Department of Computer Science, University of Hamburg, Germany. He is one of the Chair Professors “Human-Computer Interaction” of the Department of Computer Science of Tsinghua University. He received his Bachelor (1986) and Master degree (1989) from the Department of Computer Science of Tsinghua University, and his PhD (1994) from the Department of Computer Science, University of Karlsruhe, Germany. His research interests include multimodal information processing, robot learning, service robots, smart vision systems and Embodied Intelligence. In these areas he has published over 120 journal and conference papers, six book chapters and two research monographs. He leads numerous basic research and application projects, including the EU basic research programs and the Collaborative Research Centre supported by the German Research Council. Dr. Zhang has received multiple awards including the IEEE ROMAN Best Paper 2002. 相似文献
Jianwei ZhangEmail: |
Calin Rotaru is a PhD candidate at the Department of Computer Science, University of Hamburg, Germany. His PhD work focuses on the topic color machine vision for driver assistance systems and is supported by Volkswagen AG, Group Research Electronics. He graduated (2002) with the topic “Stereo Camera Based Object Recognition” for Driver Assistance Systems from the Faculty of Automation and Computer Science of the Technical University of Cluj-Napoca, Romania. His research interests include color machine vision, smart vision systems, multisensorial data fusion and vision in driver assistance systems. Thorsten Graf received the diploma (M.Sc.) degree in computer science and the Ph.D. degree (his thesis was on “Flexible Object Recognition Based on Invariant Theory and Agent Technology”) from the University of Bielefeld, Bielefeld, Germany, in 1997 and 2000, respectively. In 1997 he became a Member of the “Task Oriented Communication” graduate program, University of Bielefeld, funded by the German research foundation DFG. In June 2001 he joined Volkswagen Group Research, Wolfsburg, Germany. Since then, he has worked on different projects in the area of driver assistance systems as a Researcher and Project Leader. He is the author or coauthor of more than 40 publications and owns several patents. His research interests include image processing and analysis dedicated to advanced comfort/safety automotive applications. Dr. Jianwei Zhang is full professor and director of the Institute of Technical Aspects of Multimodal Systems, Department of Computer Science, University of Hamburg, Germany. He is one of the Chair Professors “Human-Computer Interaction” of the Department of Computer Science of Tsinghua University. He received his Bachelor (1986) and Master degree (1989) from the Department of Computer Science of Tsinghua University, and his PhD (1994) from the Department of Computer Science, University of Karlsruhe, Germany. His research interests include multimodal information processing, robot learning, service robots, smart vision systems and Embodied Intelligence. In these areas he has published over 120 journal and conference papers, six book chapters and two research monographs. He leads numerous basic research and application projects, including the EU basic research programs and the Collaborative Research Centre supported by the German Research Council. Dr. Zhang has received multiple awards including the IEEE ROMAN Best Paper 2002. 相似文献
27.
Ordered binary decision diagrams are the state-of-the-art representation of switching functions. In order to keep the sizes of OBDDs tractable, heuristics and dynamic reordering algorithms are applied to optimize the underlying variable order. When finite state machines are represented by OBDDs the state encoding can be used as an additional optimization parameter. In this paper, we analyze local encoding transformations which can be applied dynamically. First, we investigate the potential of re-encoding techniques. We then propose the use of an XOR-transformation and show why this transformation is most suitable among the set of all encoding transformations. The presented theoretical framework establishes a new optimization technique for OBDDs. 相似文献
28.
Plate J Holtkaemper T Froehlich B 《IEEE transactions on visualization and computer graphics》2007,13(6):1584-1591
We present a powerful framework for 3D-texture-based rendering of multiple arbitrarily intersecting volumetric datasets. Each volume is represented by a multi-resolution octree-based structure and we use out-of-core techniques to support extremely large volumes. Users define a set of convex polyhedral volume lenses, which may be associated with one or more volumetric datasets. The volumes or the lenses can be interactively moved around while the region inside each lens is rendered using interactively defined multi-volume shaders. Our rendering pipeline splits each lens into multiple convex regions such that each region is homogenous and contains a fixed number of volumes. Each such region is further split by the brick boundaries of the associated octree representations. The resulting puzzle of lens fragments is sorted in front-to-back or back-to-front order using a combination of a view-dependent octree traversal and a GPU-based depth peeling technique. Our current implementation uses slice-based volume rendering and allows interactive roaming through multiple intersecting multi-gigabyte volumes. 相似文献
29.
P Kahane L Tassi S Francione D Hoffmann G Lo Russo C Munari 《Canadian Metallurgical Quarterly》1993,23(4):305-326
In patients with severe drug-resistant partial epilepsy, undergoing Stereo-EEG investigations, spatial definition of the "epileptogenic area" is mainly based on spontaneous seizures recordings, but also on seizures induced by intracerebral electrical stimulation (ES). Only "trains" ES (TES, 50 pps) are currently used with this aim; "shocks" ES (SES, 1 pps) are principally applied to localize motor pathways. We have shown, during a prospective study concerning 10 temporal lobe epileptic patients, that SES could frequently induce seizures, especially when stimulation is applied in the anterior part of the Ammon's horn. Even if its efficacy seems lower than by TES, this kind of stimulation, in the majority of the cases, does reproduce isolated ictal subjective symptomatology, allowing the visualization of the progressive organisation of ictal electrical discharges, and avoids "unexpected" ("false positive"?) clinical responses. 相似文献
30.
F Markwardt HP Kl?cking K Sedlarik J Perlewitz J Drawert J Hoffmann 《Canadian Metallurgical Quarterly》1976,35(2):193-203
The purpose of this investigation was to explore the feasibility of enhancing the electrochemical stability of dental amalgam restorations by a process of "selective interfacial amalgamation." If dental amalgam restorations can be selectively alloyed at the tooth-amalgam interface, to a minor thickness as compared with the dimensions of the bulk amalgam, so as to present a more electrochemically stable phase than psi2 to the oral environment, corrosion will be reduced and desirable qualities of existing amalgams can be utilized. It was found that selective interfacial amalgamation was indeed possible and that it could be readily accomplished using a silver suspension as a cavity liner. By then placing a conventional silver-tin amalgam according to ordinary dental techniques, mercury expressed during hand condensing reacted with the silver in the liner resulting in the formation of an integral amalgam restoration with the more noble psi1 phase adjacent to tooth structure. In vitro corrosion tests of samples so prepared exhibited corrosion resistance far superior to unlined control samples. 相似文献