检索结果-内蒙古大学图书馆

Concrete crack detection through full-field displacement and curvature measurements by visual mark tracking: A proof-of-concept study

引用

STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL 2014年第2期13卷 205-218页

作者： Yin, Zhaozheng Wu, Chenglin Chen, Genda Missouri Univ Sci & Technol Dept Comp Sci Rolla MO 65409 USA Missouri Univ Sci & Technol Dept Civil Architectural & Environm Engn Rolla MO 65409 USA

In this study, a noncontact vision-based sensing method is proposed to measure surface displacements and curvatures and to detect cracks in a reinforced concrete slab. The proposed method includes five independent modules for structure boundary identification by a dynamic programming algorithm, boundary movement tracking by a contour tracking algorithm, distinguishable surface feature detection by speed-up-robust features, feature (visual mark) tracking by a three-stage data association algorithm, and displacement interpolation from those at visual marks by a Delaunay triangulation algorithm. The displacement field was used to evaluate the slab curvature that functioned as a crack indicator. The proposed data association algorithm for visual mark translation, linking, and connection was successfully applied for visual mark tracking of concrete slab images. The proposed algorithms used in five modules are computationally efficient, making them viable tools for real-time structural health monitoring. By persistently tracking the features and positions of spatially distributed visual marks in time-lapse videos, the displacement time histories at mark locations are successfully evaluated. The relative error of displacement measurements for the tested concrete slab is approximately 1.24%. The proposed method was applied to successfully detect cracks of a full-scale reinforced concrete slab from image analysis. Unlike contact measurements, the proposed noncontact measurement is not affected by concrete cracking.

关键词： Noncontact measurement visual marks feature detection and tracking data association algorithm displacement and curvature crack detection

来源：评论

学校读者我要写书评

暂无评论

Progressive Learning of Topic Modeling Parameters: A Visual Analytics Framework

引用

IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2018年第1期24卷 382-391页

作者： El-Assady, Mennatallah Sevastjanova, Rita Sperrle, Fabian Keim, Daniel Collins, Christopher Univ Konstanz Constance Germany Univ Ontario Inst Technol Oshawa ON Canada

Topic modeling algorithms are widely used to analyze the thematic composition of text corpora but remain difficult to interpret and adjust. Addressing these limitations, we present a modular visual analytics framework, tackling the understandability and adaptability of topic models through a user-driven reinforcement learning process which does not require a deep understanding of the underlying topic modeling algorithms. Given a document corpus, our approach initializes two algorithm configurations based on a parameter space analysis that enhances document separability. We abstract the model complexity in an interactive visual workspace for exploring the automatic matching results of two models, investigating topic summaries, analyzing parameter distributions, and reviewing documents. The main contribution of our work is an iterative decision-making technique in which users provide a document-based relevance feedback that allows the framework to converge to a user-endorsed topic distribution. We also report feedback from a two-stage study which shows that our technique results in topic model quality improvements on two independent measures.

关键词： Topic Model Configuration Reinforcement Learning feature detection and tracking Iterative Optimization

来源：评论

学校读者我要写书评

暂无评论

Analysis of the Near-Wall Flow in a Turbine Cascade by Splat Visualization

引用

IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2020年第1期26卷 719-728页

作者： Nsonga, Baldwin Scheuermann, Gerik Gumhold, Stefan Ventosa-Molina, Jordi Koschichow, Denis Froehlich, Jochen Univ Leipzig Leipzig Germany Tech Univ Dresden Inst Software & Multimedia Dresden Germany Tech Univ Dresden Inst Fluid Mech Dresden Germany

Turbines are essential components of jet planes and power plants. Therefore, their efficiency and service life are of central engineering interest. In the case of jet planes or thermal power plants, the heating of the turbines due to the hot gas flow is critical. Besides effective cooling, it is a major goal of engineers to minimize heat transfer between gas flow and turbine by design. Since it is known that splat events have a substantial impact on the heat transfer between flow and immersed surfaces, we adapt a splat detection and visualization method to a turbine cascade simulation in this case study. Because splat events are small phenomena, we use a direct numerical simulation resolving the turbulence in the flow as the base of our analysis. The outcome shows promising insights into splat formation and its relation to vortex structures. This may lead to better turbine design in the future.

关键词： Flow Visualization Visualization in Physical Sciences and Engineering feature detection and tracking Vector Field Data

来源：评论

学校读者我要写书评

暂无评论

Framework and algorithms for illustrative visualizations of time-varying flows on unstructured meshes

引用

ADVANCES IN ENGINEERING SOFTWARE 2016年 97卷 72-84页

作者： Rattner, Alexander S. Guillen, Donna Post Joshi, Alark Garimella, Srinivas Georgia Inst Technol Sustainable Thermal Syst Lab George W Woodruff Sch Mech Engn Atlanta GA 30332 USA Idaho Natl Lab Adv Proc & Decis Syst Dept Idaho Falls ID 83401 USA Univ San Francisco Dept Comp Sci Coll Arts & Sci San Francisco CA 94117 USA

Photo- and physically realistic techniques are often insufficient for visualization of fluid flow simulations, especially for 3D and time-varying studies. Substantial research effort has been dedicated to the development of non-photorealistic and illustration-inspired visualization techniques for compact and intuitive presentation of such complex datasets. However, a great deal of work has been reproduced in this field, as many research groups have developed specialized visualization software. Additionally, interoperability between illustrative visualization software is limited due to diverse processing and rendering architectures employed in different studies. In this investigation, a framework for illustrative visualization is proposed, and implemented in MarmotViz, a ParaView plug-in, enabling its use on a variety of computing platforms with various data file formats and mesh geometries. Region-of-interest identification and feature-tracking algorithms incorporated into this tool are described. Implementations of multiple illustrative effect algorithms are also presented to demonstrate the use and flexibility of this framework. By providing an integrated framework for illustrative visualization of CFD data, MarmotViz can serve as a valuable asset for the interpretation of simulations of ever-growing scale. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Flow visualization Illustrative visualization feature detection and tracking Unstructured meshes Surface rendering Two-phase flow

来源：评论

学校读者我要写书评

暂无评论

Verifying Scientific Simulations via Comparative and Quantitative Visualization

引用

IEEE COMPUTER GRAPHICS AND APPLICATIONS 2010年第6期30卷 16-28页

作者： Ahrens, James P. Heitmann, Katrin Petersen, Mark Woodring, Jonathan Williams, Sean Fasel, Patricia Ahrens, Christine Hsu, Chung-Hsing Geveci, Berk Los Alamos Natl Lab Appl Comp Sci Grp Los Alamos NM 87545 USA Los Alamos Natl Lab Space Sci & Applicat Grp Los Alamos NM 87545 USA Los Alamos Natl Lab Comp Computat & Stat Sci Div Los Alamos NM 87545 USA Los Alamos Natl Lab Informat Sci Grp Los Alamos NM 87545 USA Los Alamos Natl Lab Sci Software Engn Grp Los Alamos NM 87545 USA Oak Ridge Natl Lab Applicat Performance Tools Grp Oak Ridge TN USA

This article presents a visualization-assisted process that verifies scientific-simulation codes. Code verification is necessary because scientists require accurate predictions to interpret data confidently. This verification process integrates iterative hypothesis verification with comparative, feature, and quantitative visualization. Following this process can help identify differences in cosmological and oceanographic simulations.

关键词： and environmental sciences computer graphics feature detection and tracking graphics and multimedia hypothesis testing space visual evidence visualization in earth

来源：评论

学校读者我要写书评

暂无评论

Analysis of micro-blog diffusion using a dynamic fluid model

引用

JOURNAL OF VISUALIZATION 2015年第2期18卷 201-219页

作者： Liu, Yuhua Wang, Changbo Ye, Peng Zhang, Kang E China Normal Univ Inst Software Engn Shanghai 200062 Peoples R China Soochow Univ Coll Comp Sci & Technol Suzhou 215006 Peoples R China Univ Texas Dallas Dept Comp Sci Richardson TX 75080 USA

Various methods on the display of dynamic information diffusion for social media have been proposed. Most of them use data mining approaches to explore the behaviors and interactions between users. Such approaches are unable to reveal the complex mechanism and the process of information diffusion. Lattice Boltzmann Method (LBM) models fluid behaviors at the microscopic scale, similar to the information diffusion in social media that is determined by the collective behavior of many personal retweeting of topics. We propose an information diffusion model inspired by the fundamental idea of LBM to analyze and simulate users' communicating behaviors and processes in Micro-blogging. The micro-blog space is regarded as an artificial physical system with social phenomena such as micro-blog bursting. The macroscopic properties of the information diffusion model are explored to simulate and predict the trend of information diffusion for any specific topic. A novel visualization style mimicking fluid dynamics is proposed to help understand the scale of information diffusion and the popularity of a topic. The flow visualization based on the speed of information diffusion is useful in discovering typical information diffusion patterns for different types of topics in social networks. Comparing with other approaches, our approach provides more effective yet intuitive simulation.

关键词： Knowledge discovery Visual analytics feature detection and tracking Graph/network data Social networks

来源：评论

学校读者我要写书评

暂无评论

Verification of the Time Evolution of Cosmological Simulations via Hypothesis-Driven Comparative and Quantitative Visualization

Verification of the Time Evolution of Cosmological Simulatio...

引用

IEEE Pacific Visualization Symposium

作者： Hsu, Chung-Hsing Ahrens, James P. Heitmann, Katrin

ISBN: (纸本)9781424466849

We describe a visualization-assisted process for the verification of cosmological simulation codes. The need for code verification stems from the requirement for very accurate predictions in order to interpret observational data confidently. We compare different simulation algorithms in order to reliably predict differences in simulation results and understand their dependence on input parameter settings. Our verification process consists of the integration of iterative hypothesis-verification with comparative, feature and quantitative visualization. We validate this process by verifying the time evolution results of three different cosmology simulation codes. The purpose of this verification is to study the accuracy of AMR methods versus other N-body simulation methods for cosmological simulations.

关键词： Visualization in Earth Space and Environmental Sciences Hypothesis Testing Visual Evidence feature detection and tracking

来源：评论

学校读者我要写书评

暂无评论

Automatic Camera Pose Initialization, using Scale, Rotation and Luminance Invariant Natural feature tracking

Automatic Camera Pose Initialization, using Scale, Rotation ...

引用

16th International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision

作者： Bastos, Rafael Dias, Miguel Sales ADETTI ISCTE Ave Forcas ArmadasEdificio ISCTE P-1500 Lisbon Portugal Microsoft ISCTE P-1500 Lisbon Portugal

ISBN: (纸本)9788086943145

The solution to the camera registration and tracking problem serves Augmented Reality, in order to provide an enhancement to the user's cognitive perception of the real world and his/her situational awareness. By analyzing the five most representative tracking and feature detection techniques, we have concluded that the Camera Pose Initialization (CPI) problem, a relevant sub-problem in the overall camera tracking problem, is still far from being solved using straightforward and non-intrusive methods. The assessed techniques often use user inputs (i.e. mouse clicking) or auxiliary artifacts (i.e. fiducial markers) to solve the CPI problem. This paper presents a novel approach to real-time scale, rotation and luminance invariant natural feature tracking, in order to solve the CPI problem using totally automatic procedures. The technique is applicable for the case of planar objects with arbitrary topologies and natural textures, and can be used in Augmented Reality. We also present a heuristic method for feature clustering, which has revealed to be efficient and reliable. The presented work uses this novel feature detection technique as a baseline for a real-time and robust planar texture tracking algorithm, which combines optical flow, backprojection and template matching techniques. The paper presents also performance and precision results of the proposed technique.

关键词： Camera Pose Initialization feature detection and tracking Augmented Reality Texture tracking scale invariant rotation invariant luminance invariant

来源：评论

学校读者我要写书评

暂无评论

DRIFT CORRECTION FOR FLUORESCENCE LIVE CELL IMAGING THROUGH CORRELATED MOTION IDENTIFICATION

DRIFT CORRECTION FOR FLUORESCENCE LIVE CELL IMAGING THROUGH ...

引用

IEEE 10th International Symposium on Biomedical Imaging - From Nano to Macro (ISBI)

作者： Qiu, Minhua Yang, Ge Carnegie Mellon Univ Dept Biomed Engn Pittsburgh PA 15213 USA

ISBN: (纸本)9781467364553

Fluorescence live cell imaging is an important experimental technique for visualizing and recording dynamic cellular processes under physiological conditions. However, a problem commonly encountered during imaging is sample drift. Without correction, such drift will cause bias or even error in subsequent image analysis of intracellular movement. Traditional area-based and feature-based image registration techniques often fail to correct such drift because, in addition to whole cell drift, intracellular features of interest also undergo separate and complex motion. To address this problem, we developed an image registration technique based on identifying clusters of features that undergo highly correlated motion. Sample drift is determined from movement of these features and corrected. Experiments confirmed that this technique can effectively remove translational drift with sub-pixel accuracy. For drift that also involves rotation, an extension of the technique is developed to determine rotation angles both within and out of the image plane so that rotational drift can be corrected. The technique is general and can be used for drift correction in a broad range of biological studies.

关键词： drift correction image registration live cell imaging feature detection and tracking clustering

来源：评论

学校读者我要写书评

暂无评论

Autonomous Localisation of Rovers for Future Planetary Exploration

Autonomous Localisation of Rovers for Future Planetary Explo...

引用

作者： A. Bajpai University Of Surrey

学位级别：博士

Future Mars exploration missions will have increasingly ambitious goals compared to current rover and lander missions. There will be a need for extremely long distance traverses over shorter periods of time. This will allow more varied and complex scientific tasks to be performed and increase the overall value of the missions. The missions may also include a sample return component, where items collected on the surface will be returned to a cache in order to be returned to Earth, for further study. In order to make these missions feasible, future rover platforms will require increased levels of autonomy, allowing them to operate without heavy reliance on a terrestrial ground station. Being able to autonomously localise the rover is an important element in increasing the rover's capability to independently explore. This thesis develops a Planetary Monocular Simultaneous Localisation And Mapping (PM-SLAM) system aimed specifically at a planetary exploration context. The system uses a novel modular feature detection and tracking algorithm called hybrid-saliency in order to achieve robust tracking, while maintaining low computational complexity in the SLAM filter. The hybrid saliency technique uses a combination of cognitive inspired saliency features with point-based feature descriptors as input to the SLAM filter. The system was tested on simulated datasets generated using the Planetary, Asteroid and Natural scene Generation Utility (PANGU) as well as two real world datasets which closely approximated images from a planetary environment. The system was shown to provide a higher accuracy of localisation estimate than a state-of-the-art VO system tested on the same data set. In order to be able to localise the rover absolutely, further techniques are investig- ated which attempt to determine the rover's position in orbital maps. Orbiter Mask Matching uses point-based features detected by the rover to associate descriptors with large features extracted from orbital image

关键词： Simultaneous Localisation And Mapping Planetary Guidance Navigation and Control feature detection and tracking Autonomous Localisation Rover Autonomy

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：