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Performance evaluations of a cloud computing physical machine with task reneging and task resubmission (feedback) 27th

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Performance evaluations of a cloud computing physical machin...

27th International Conference on computer Networks, CN 2020

作者： Kuaban, Godlove Suila Soodan, Bhavneet Singh Kumar, Rakesh Czekalski, Piotr Institute of Theoretical and Applied Informatics Polish Academy of Sciences Baltycka 5 Gliwice44-100 Poland School of Mathematics Shri Mata Vaishno Devi University KatraJammu and Kashmir182320 India Department of Computer Graphics Vision and Digital Systems Faculty of Automatic Control Electronics and Computer Science Silesian University of Technology Akademicka 16 Gliwice44-100 Poland

ISBN: (纸本)9783030507183

Cloud service providers (CSP) provide on-demand cloud computing services, reduces the cost of setting-up and scaling-up IT infrastructure and services, and stimulates shorter establishment times for start-ups that offer or use cloud-based services. Task reneging or dropping sometimes occur when a task waits in the queue longer than its timeout or execution deadline, or it is compromised and must be dropped from the queue or as an active queue management strategy to avoid tail dropping of tasks when the queues are full. Reneged or dropped tasks could be resubmitted provided they were not dropped due to security reasons. In this paper, we present a simple M/M/c/N queueing model of a cloud computing physical machine, where the interarrival times and the services times are exponentially distributed, with N buffer size and c virtual machines running in parallel. We present numerical examples to illustrate the effect of task reneging and task resubmission on the queueing delay, probability of task rejection, and the probability of immediate service. © Springer Nature Switzerland AG 2020.

关键词： Cloud computing

Bayesian uncertainty estimation of learned variational MRI reconstruction

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arXiv 2021年

作者： Narnhofer, Dominik Effland, Alexander Kobler, Erich Hammernik, Kerstin Knoll, Florian Pock, Thomas Institute of Computer Graphics and Vision Graz University of Technology Graz Austria Graz Austria Institute of Applied Mathematics University of Bonn Bonn Germany Computer Science Department Johannes Kepler University Linz Austria Technical University of Munich Munich Germany Imperial College London London United Kingdom Nyu School of Medicine NY United States

Recent deep learning approaches focus on improving quantitative scores of dedicated benchmarks, and therefore only reduce the observation-related (aleatoric) uncertainty. However, the model-immanent (epistemic) uncertainty is less frequently systematically analyzed. In this work, we introduce a Bayesian variational framework to quantify the epistemic uncertainty. To this end, we solve the linear inverse problem of undersampled MRI reconstruction in a variational setting. The associated energy functional is composed of a data fidelity term and the total deep variation (TDV) as a learned parametric regularizer. To estimate the epistemic uncertainty we draw the parameters of the TDV regularizer from a multivariate Gaussian distribution, whose mean and covariance matrix are learned in a stochastic optimal control problem. In several numerical experiments, we demonstrate that our approach yields competitive results for undersampled MRI reconstruction. Moreover, we can accurately quantify the pixelwise epistemic uncertainty, which can serve radiologists as an additional resource to visualize reconstruction *** Codes 68T45, 65K10, 65D19 Copyright © 2021, The Authors. All rights reserved.

关键词： Uncertainty analysis

Comparative Analysis of Efficiency of the Machine Learning Methods for Gesture Recognition Using Double-Channel Electromyography

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Journal of Physics: Conference Series 2021年第1期2134卷

作者： Y V Ponomarchuk I V Kuznetsov Computer Science and Computer Graphics Department Far Eastern State Transport University Khabarovsk 680000 Russian Federation

The paper is devoted to the efficiency analysis of the machine learning methods for gesture recognition, which are applied to the surface double-channel electromyography data. The comparative analysis was conducted for recognition of eight types of palm movements. The results of the analysis lead to conclusion that it is necessary to consider the muscle groups' location for better recognition accuracy and the increase of the number of considered gestures.

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Sketch-aided retrieval of incomplete 3D cultural heritage objects 12

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Sketch-aided retrieval of incomplete 3D cultural heritage ob...

12th Eurographics Workshop on 3D Object Retrieval, 3DOR 2019, in conjunction with the 40th Annual Conference of the European Association for computer graphics, EG 2019

作者： Lengauer, S. Komar, A. Labrada, A. Karl, S. Trinkl, E. Preiner, R. Bustos, B. Schreck, T. Institute of Computer Graphics and Knowledge Visualisation Graz University of Technology Austria Institute of Archaeology University of Graz Austria Millenium Institute for Foundational Research on Data Department of Computer Science University of Chile Chile

ISBN: (纸本)9783038680772

Due to advances in digitization technology, documentation efforts and digital library systems, increasingly large collections of visual Cultural Heritage (CH) object data becomes available, offering rich opportunities for domain analysis, e.g., for comparing, tracing and studying objects created over time. In principle, existing shape- and image-based similarity search methods can aid such domain analysis tasks. However, in practice, visual object data are given in different modalities, including 2D, 3D, sketches or conventional drawings like profile sections or unwrappings. In addition, collections may be distributed across different publications and repositories, posing a challenge for implementing encompassing search and analysis systems. We introduce a methodology and system for cross-modal visual search in CH object data. Specifically, we propose a new query modality based on 3D views enhanced by user sketches (3D+sketch). This allows for adding new context to the search, which is useful e.g., for searching based on incomplete query objects, or for testing hypotheses on existence of certain shapes in a collection. We present an appropriately designed workflow for constructing query views from incomplete 3D objects enhanced by a user sketch based on shape completion and texture inpainting. Visual cues additionally help users compare retrieved objects with the query. We apply our method on a set of relevant 3D and view-based CH object data, demonstrating the feasibility of our approach and its potential to support analysis of domain experts in Archaeology and the field of CH in general. © 2019 The Author(s)

关键词： Textures

Motif-Driven retrieval of greek painted pottery

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Motif-Driven retrieval of greek painted pottery

2019 Eurographics Workshop on graphics and Cultural Heritage, GCH 2019

ISBN: (纸本)9783038680826

The analysis of painted pottery is instrumental for understanding ancient Greek society and human behavior of past cultures in Archaeology. A key part of this analysis is the discovery of cross references to establish links and correspondences. However, due to the vast amount of documented images and 3D scans of pottery objects in today's domain repositories, manual search is very time consuming. computer aided retrieval methods are of increasing importance. Mostly, current retrieval systems for this kind of cultural heritage data only allow to search for pottery of similar vessel's shape. However, in many cases important similarity cues are given by motifs painted on these vessels. We present an interactive retrieval system that makes use of this information to allow for a motif-driven search in cultural heritage repositories. We address the problem of unsupervised motif extraction for preprocessing and the shape-based similarity search for Greek painted pottery. Our experimental evaluation on relevant repository data demonstrates effectiveness of our approach on examples of different motifs of interests. © 2019 Eurographics Association.

关键词： Behavioral research

Minimal Cases for Computing the Generalized Relative Pose using Affine Correspondences

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arXiv 2020年

作者： Guan, Banglei Zhao, Ji Barath, Daniel Fraundorfer, Friedrich College of Aerospace Science and Engineering National University of Defense Technology China Computer Vision and Geometry Group Department of Computer Science ETH Zürich Institute for Computer Graphics and Vision Graz University of Technology Austria Remote Sensing Technology Institute German Aerospace Center Germany

We propose three novel solvers for estimating the relative pose of a multi-camera system from affine correspondences (ACs). A new constraint is derived interpreting the relationship of ACs and the generalized camera model. Using the constraint, we demonstrate efficient solvers for two types of motions assumed. Considering that the cameras undergo planar motion, we propose a minimal solution using a single AC and a solver with two ACs to overcome the degenerate case. Also, we propose a minimal solution using two ACs with known vertical direction, e.g., from an IMU. Since the proposed methods require significantly fewer correspondences than state-of-the-art algorithms, they can be efficiently used within RANSAC for outlier removal and initial motion estimation. The solvers are tested both on synthetic data and on real-world scenes from the KITTI odometry benchmark. It is shown that the accuracy of the estimated poses is superior to the state-of-the-art techniques. Copyright © 2020, The Authors. All rights reserved.

关键词： Motion estimation

Inferring the 3D Standing Spine Posture from 2D Radiographs

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arXiv 2020年

作者： Bayat, Amirhossein Sekuboyina, Anjany Paetzold, Johannes C. Payer, Christian Stern, Darko Urschler, Martin Kirschke, Jan S. Menze, Bjoern H. Department of Informatics Technical University of Munich Germany Department of Neuroradiology Klinikum rechts der Isar Germany Institute of Computer Graphics and Vision Graz University of Technology Austria School of Computer Science University of Auckland New Zealand

The treatment of degenerative spinal disorders requires an understanding of the individual spinal anatomy and curvature in 3D. An upright spinal pose (i.e. standing) under natural weight bearing is crucial for such bio-mechanical analysis. 3D volumetric imaging modalities (e.g. CT and MRI) are performed in patients lying down. On the other hand, radiographs are captured in an upright pose, but result in 2D projections. This work aims to integrate the two realms, i.e. it combines the upright spinal curvature from radiographs with the 3D vertebral shape from CT imaging for synthesizing an upright 3D model of spine, loaded naturally. Specifically, we propose a novel neural network architecture working vertebra-wise, termed TransVert, which takes orthogonal 2D radiographs and infers the spine’s 3D posture. We validate our architecture on digitally reconstructed radiographs, achieving a 3D reconstruction Dice of 95.52%, indicating an almost perfect 2D-to-3D domain translation. Deploying our model on clinical radiographs, we successfully synthesise full-3D, upright, patient-specific spine models for the first time. Copyright © 2020, The Authors. All rights reserved.

关键词： Magnetic resonance imaging

Testing the usability and accessibility of smart TV applications using an automated model-based approach

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arXiv 2020年

作者： Bures, Miroslav Macik, Miroslav Ahmed, Bestoun S. Rechtberger, Vaclav Slavik, Pavel Department of Computer Science Faculty of Electrical Engineering Czech Technical University Karlovo nam. 13 Prague Czech Republic Department of Computer Graphics and Interaction FEE Czech Technical University in Prague Karlovo nam. 13 Prague Czech Republic Department of Mathematics and Computer Science Karlstad University Sweden Department of Computer Science Czech Technical University Karlovo nam. 13 Prague Czech Republic

As the popularity of Smart Televisions (TVs) and interactive Smart TV applications (apps) has recently grown, the usability of these apps has become an important quality characteristic. Previous studies examined Smart TV apps from a usability perspective. However, these methods are mainly manual, and the potential of automated model-based testing methods for usability testing purposes has not yet been fully explored. In this paper, we propose an approach to test the usability of Smart TV apps based on the automated generation of a Smart TV user interaction model from an existing app by a specialized automated crawler. By means of this model, defined user tasks in the Smart TV app can be evaluated automatically in terms of their feasibility and estimated user effort, which reflects the usability of the analyzed app. This analysis can be applied in the context of regular users and users with various specific needs. The findings from this model-based automated analysis approach can be used to optimize the user interface of a Smart TV app to increase its usability, accessibility, and quality. Copyright © 2020, The Authors. All rights reserved.

关键词： Model checking

Identification of altitude profiles in 3D geovisualizations:the role of interaction and spatial abilities

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International Journal of Digital Earth 2019年第2期12卷 156-172页

作者： Petr Kubíček Čeněk Šašinka Zdeněk Stachoň Lukáš Herman Vojtěch Juřík Tomáš Urbánek Jiří Chmelík Department of Geography Faculty of ScienceMasaryk UniversityBrnoCzech Republic HUME Lab Faculty of ArtsMasaryk UniversityBrnoCzech Republic Department of Psychology Faculty of ArtsMasaryk UniversityBrnoCzech Republic Department of Computer Graphics and Design Faculty of InformaticsMasaryk UniversityBrnoCzech Republic

Three-dimensional geovisualizations are currently pushed both by technological development and by the demands of experts in various applied *** the presented empirical study,we compared the features of real 3D(stereoscopic)versus pseudo 3D(monoscopic)geovisualizations in static and interactive digital elevation *** tested 39 high-school students in their ability to identify the correct terrain profile from digital elevation ***’performance was recorded and further analysed with respect to their spatial abilities,which were measured by a psychological mental rotation test and think aloud *** results of the study indicated that the influence of the type of 3D visualization(monoscopic/stereoscopic)on the performance of the users is not clear,the level of navigational interactivity has significant influence on the usability of a particular 3D visualization,and finally no influences of the spatial abilities on the performance of the user within the 3D environment were identified.

关键词： 3D geovisualizations stereoscopic and monoscopic 3D vision spatial abilities level of navigational interactivity