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Static Scene Illumination Estimation from Videos with Applications

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Journal of Computer Science & Technology 2017年第3期32卷 430-442页

作者： Bin Liu Nun Xu ralph R. Martin Department of Computer Science and Technology Tsinghua University Beijing 100084 China School of Computer Science and Informatics Cardiff University Cardiff CF243AA U.K.

We present a system that automatically recovers scene geometry and illumination from a video, providing a basis for various applications. Previous image based illumination estimation methods require either user interaction or external information in the form of a database. We adopt structure-from-motion and multi-view stereo for initial scene reconstruction, and then estimate an environment map represented by spherical harmonics （as these perform better than other bases）. We also demonstrate several video editing applications that exploit the recovered geometry and illumination, including object insertion （e.g., for augmented reality）, shadow detection, and video relighting.

关键词： video processing augmented reality illumination recovery

因非ST段抬高型或ST段抬高型急性冠状动脉综合征行急诊冠状动脉搭桥术的患者中术前心肌肌钙蛋白I的预后价值

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世界核心医学期刊文摘（心脏病学分册） 2007年第1期3卷 32-33页

作者： Thielmann M. Massoudy P. neuhuser M. 刘少伟 Department of Thoracic and Cardiovascular Surgery West-German Heart Center Essen University of Duisburg-Essen Hufelandstrasse 55 45122 Essen GermanyDr

背景:心肌肌钙蛋白I(cTnI)已被证实可预测行择期冠状动脉搭桥术(CABG)术前和术后患者的预后,是一种具有高敏感性和特异性的生物标记物。目前尚不清楚术前cTnI水平升高是否也能同样预测因急性心肌梗死(AMI)而行急诊CABG的患者的预后。方... 详细信息

背景:心肌肌钙蛋白I(cTnI)已被证实可预测行择期冠状动脉搭桥术(CABG)术前和术后患者的预后,是一种具有高敏感性和特异性的生物标记物。目前尚不清楚术前cTnI水平升高是否也能同样预测因急性心肌梗死(AMI)而行急诊CABG的患者的预后。方法和结果:在症状出现24h内即行手术的57例ST段抬高型AM I(STEMI)患者(组1)和197例非ST段抬高型AM I(NSTEMI)患者(组2)中,研究术前cTnI水平与院内死亡及主要不良心脏事件(MACE)之间可能的相关性。主要研究终点是全因院内死亡。

关键词：心肌肌钙蛋白 ST段抬高冠状动脉搭桥术不良心脏事件预后价值急性心肌梗死次要终点生物标记物

As-Rigid-As-Possible Surface Morphing

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Journal of Computer Science & Technology 2011年第3期26卷 548-557页

作者：刘亚姝严寒冰 ralph R.Martin Department of Computer Science Beijing University of Civil Engineering and Architecture National Computer Network Emergency Response Technical Team/Coordination Center of China School of Computer Science Cardiff University

This paper presents a new morphing method based on the ＂as-rigid-as-possible＂ approach. Unlike the original as-rigid-as-possible method, we avoid the need to construct a consistent tetrahedral mesh, but instead require a consistent triangle surface mesh and from it create a tetrahedron for each surface triangle. Our new approach has several significant advantages. It is much easier to create a consistent triangle mesh than to create a consistent tetrahedral mesh. Secondly, the equations arising from our approach can be solved much more efficiently than the corresponding equations for a tetrahedral mesh. Finally, by incorporating the translation vector in the energy functional controlling interpolation, our new method does not need the user to arbitrarily fix any vertex to obtain a solution, allowing artists automatic control of interpolated mesh positions.

关键词： morphing simplex transformation interpolation

Approaches and tools for user-driven provenance and data quality information in spatial data infrastructures

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International Journal of Digital Earth 2023年第1期16卷 1510-1529页

作者： Julia Fischer Lukas Egli Juliane Groth Caterina Barrasso Steffen Ehrmann Heiko Figgemeier Christin Henzen Carsten Meyer ralph Müller-Pfefferkorn Arne Rümmler Michael Wagner Lars Bernard Ralf Seppelt Department of Computational Landscape Ecology UFZ—Helmholtz Centre for Environmental ResearchLeipzigGermany Macroecology and Society Group German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-LeipzigLeipzigGermany Chair of Geoinformatics Technische Universität DresdenDresdenGermany Institute of Biology Leipzig UniversityLeipzigGermany Institute of Geoscience&Geography Martin Luther University Halle-WittenbergHalle(Saale)Germany Center for Information Services and High Performance Computing Technische Universität DresdenDresdenGermany

Geospatial data are fundamental in most global-change and sustainability-related ***,readily accessible information on data quality and provenance is often missing or hardly accessible for users due to technical or perceptual barriers,for example,due to unstructured metadata information or missing *** an interdisciplinary process encompassing perspectives of data users,data producers,and software developers,we identified major needs to facilitate effectivefitness-for-use assessments by data users and developed approaches to address *** provided a stylized analysis of large-scale land use data to showcase selected *** support data users,interoperable quality and provenance information need to be meaningfully *** producers need efficient workflows and tools supporting them in creating high-quality,structured and detailed quality and provenance *** newly developed approaches to increase the availability of structured metadata synthesize new and existing tools to extract metadata or to generate provenance data during *** our approaches to improve interoperability and accessibility we present novel tools to support(i)the creation of curated and linked registers of data quality indicators and thematic terms,and(ii)linked visualization of data quality and provenance *** our approaches increases transparency,facilitatesfitness-for-use assessments,and ultimately improves research quality.

关键词： Dashboard earthsystem science fitness forpurpose ISO 19157 landuseandland cover data ontology

Improving Shape from Shading with Interactive Tabu Search

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Journal of Computer Science & Technology 2016年第3期31卷 450-462页

作者： Jing Wu Paul L. Rosin Xianfang Sun ralph R. Martin School of Computer Science and Informatics Cardiff University Cardiff CF24 3AA U.K.

Optimisation based shape from shading （SFS） is sensitive to initialization： errors in initialization are a signifi- cant cause of poor overall shape reconstruction. In this paper, we present a method to help overcome this problem by means of user interaction. There are two key elements in our method. Firstly, we extend SFS to consider a set of initializations, rather than to use a single one. Secondly, we efficiently explore this initialization space using a heuristic search method, tabu search, guided by user evaluation of the reconstruction quality. Reconstruction results on both synthetic and real images demonstrate the effectiveness of our method in providing more desirable shape reconstructions.

关键词： shape from shading user interaction tabu search

Sustainable Water Resources Management: River Basin Modelling and Decision Support Framework

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Wuhan University Journal of Natural Sciences 2009年第6期14卷 543-551页

作者： RAO Zhengfu POTTER Bob WEBB David PARKIN ralph Halcrow Group Ltd Swindon SN4 0QD United Kingdom Halcrow China Ltd Shanghai 200083 China

Sustainability is a key objective of water resources management and this paper describes a modelling and decision support framework that achieves this, illustrated by applications on the UK Thames and Mekong river basins. The decision support framework contains several modules, including an interactive user＇s interface linked to a GIS, a geo-database, knowledge base, simulation models and optimization procedures. Based on the analysis of scenarios and proposed interventions, efficient modelling and optimization tools form a comprehensive integrated decision support framework for the analysis and operational management of water resources in the river basin, our emphasis has been on a practical implementation through careful screening of alternatives, consideration of the institutional framework and direct involvement of stakeholders in the decision making process. Operating in this environment is transparent, reproducible and auditable, securing the trust of all interested parties. This paper discusses its applications to water utilisation on the Mekong river basin and drought management of the Lower Thames stored reservoir system.

关键词： decision support framework sustainable water resources management mathematical modelling optimization

Ubiquitous Computing in the Library:Indiana State University Library's Experience

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现代图书情报技术 2002年第S1期 161-167页

作者： ralph B.Gabbard Judith Tribble Paul Asay Chris Hayes Indiana State University and Indiana University IndianaIndiana State UniversityIndianaIndiana State UniversityIndianaIndiana State UniversityIndiana

1 Introduction New technologies and other developments haye changedthe information seeking behaviors of the academic communityand the general *** is this more evident than inthe exponential growth of the World Wide Web and cellularphone *** to these user needs and newtechnologies,libraries are moving from being InformationWarehouses to becoming Information ***-text。

关键词：年刊连续出版物 Ubiquitous Computing in the Library 《现代图书情报技术》 Access PDA Card USB

Expressive line drawings of human faces from range images

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Science in China(Series F) 2009年第2期52卷 295-307页

作者： HUANG YueZhu MARTIN ralph R. ROSIN Paul L. MENG XiangXu YANG ChengLei Department of Computer Science and Technology Shandong University Jinan 250101 China School of Computer Science Cardiff University Cardiff United Kingdom

We propose a novel technique to extract features from a range image and use them to produce a 3D pen-and-ink style portrait similar to a traditional artistic drawing. Unlike most previous template-based, component-based or example-based face sketching methods, which work from a frontal photograph as input, our system uses a range image as input. Our method runs in real-time for models of moderate complexity, allowing the pose and drawing style to be modified interactively. Portrait drawing in our system makes use of occluding contours and suggestive contours as the most important shape cues. However, current 3D feature line detection methods require a smooth mesh and cannot be reliably applied directly to noisy range images. We thus present an improved silhouette line detection algorithm. Feature edges related to the significant parts of a face are extracted from the range image, connected, and smoothed, allowing us to construct chains of line paths which can then be rendered as desired. We also incorporate various portrait-drawing principles to provide several simple yet effective non- photorealistic portrait renderers such as a pen-and-ink shader, a hatch shader and a sketch shader. These are able to generate various life-like impressions in different styles from a user-chosen viewpoint. To obtain satisfactory results, we refine rendered output by smoothing changes in line thickness and opacity. We are careful to provide appropriate visual cues to enhance the viewer＇s comprehension of the human face. Our experimental results demonstrate the robustness and effectiveness of our approach, and further suggest that our approach can be extended to other 3D geometric objects.

关键词： portrait drawing non-photorealistic rendering line drawing suggestive contour occluding contour feature line stylization

Video Structure Analysis

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Tsinghua Science and Technology 2007年第6期12卷 714-718页

作者：张松海张一飞陈韬 Peter M. Hall ralph Martin Department of Computer Science and Technology Tsinghua University Department of Computer Science University of Bath Bath BA2 7AY United Kingdom School of Computer Science Cardiff University Wales CF24 3AA United Kingdom

Video structure analysis is a basic requirement for most content-based video editing and processing systems. This paper presents a fast video structure analysis method based on image segmentation in each frame, with region matching between frames. The structure analysis decomposes the video into several moving objects, including information about their colors, positions, shapes, movements, and lifetimes. The method also supports user interactions to improve the results. The result shows that this method is fast and stable and can complete video analyzinq interactivelv.

关键词： video structure analysis video segmentation image segmentation region matching