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Fast Multi-Operator Image Resizing and Evaluation

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Journal of Computer Science & Technology 2012年第1期27卷 121-134页

作者： Wei-Ming Dong Guan-Bo Bao Xiao-Peng Zhang jean-claude paul Sino-French Laboratory for Computer Science Automation and Applied Mathematics/National Laboratory of Pattern RecognitionInstitute of AutomationChinese Academy of SciencesBeijing 100190China National Institute for Research in Computer Science and Control Domaine de Voluceau Rocquencourt Le Chesnay 78153France

Current multi-operator image resizing methods succeed in generating impressive results by using image similarity measure to guide the resizing process. An optimal operation path is found in the resizing space. However, their slow resizing speed caused by inefficient computation strategy of the bidirectional patch matching becomes a drawback in practical use. In this paper, we present a novel method to address this problem. By combining seam carving with scaling and cropping, our method can realize content-aware image resizing very fast. We define cost functions combing image energy and dominant color descriptor for all the operators to evaluate the damage to both local image content and global visual effect. Therefore our algorithm can automatically find an optimal sequence of operations to resize the image by using dynamic programming or greedy algorithm. We also extend our algorithm to indirect image resizing which can protect the aspect ratio of the dominant object in an image.

关键词： image resizing multi-operator operator cost indirect resizing

B-spline surface fitting to mesh vertices

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Science China(Information Sciences) 2017年第7期60卷 259-261页

作者： Yang LU Junhai YONG Kanle SHI Hejin GU Ping ZHENG jean-claude paul School of Software Tsinghua University Department of Computer Science and Technology Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Department of Research & Development Jiangxi Academy of Science Department of Mathematics and Computer Science Nanchang Normal University

Here we propose a novel method of fitting B-spline surfaces to input mesh *** a mesh model that is difficult to fit with one B-spline surface,we divide it into several patches that form a tree structure(which is called hierarchical splines[1]),and for each patch,we use one B-spline surface for ***,only a few patches are required,and G2continuity can be achieved between the adjacent surfaces.

关键词： B-spline surface fitting to mesh vertices

基于周期B样条曲面的环状N边洞G^n连续性过渡

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中国科学：信息科学 2011年第9期41卷 1112-1125页

作者：施侃乐雍俊海孙家广 jean-claude paul 清华大学软件学院北京100084 清华大学计算机科学与技术系北京100084 信息系统安全教育部重点实验室北京100084 清华大学信息科学与技术国家重点实验室北京100084 Institute National de Recherche en Informatique et en Automatique France

环状N边洞经常产生于零件端部的大半径过渡或光滑填充操作中,现有的基于四边形分割或约束求解的方法对此难以得到法向或更高阶连续的过渡曲面.本文首先对环状N边洞的边界进行保持Gn连续的重新参数化,以确保相邻边界跨越切矢曲线在连接... 详细信息

环状N边洞经常产生于零件端部的大半径过渡或光滑填充操作中,现有的基于四边形分割或约束求解的方法对此难以得到法向或更高阶连续的过渡曲面.本文首先对环状N边洞的边界进行保持Gn连续的重新参数化,以确保相邻边界跨越切矢曲线在连接处的相容性.然后根据极点处的Gn连续充分条件和通过参数连续曲面延伸,分别得到周期B样条曲面的内外两侧控制顶点.该方法仅生成单个填充曲面,控制顶点少,可直接通过插节点转化为标准B样条曲面,次数仅相对原边界曲线升n次.其构造方法简单快速,不涉及大方程求解和迭代,在几何相容条件下曲面连续性可达到Gn.本文提供了过渡实例来说明其有效性和实用性.

关键词：计算机辅助设计周期B样条曲面极坐标 N边洞填充 G^n连续

G~n filling orbicular N-sided holes using periodic B-spline surfaces

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Science China(Information Sciences) 2011年第7期54卷 1383-1394页

作者： paul jean-claude School of Software Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology Institute National de Recherche en Informatique et en Automatique

The orbicular N -sided hole filling problem is usually introduced by filleting an end-point of a part with large *** existing methods based on quadrilateral partition or constrained-optimization can rarely generate high-order continuous blending surfaces under these *** paper first reparameterizes the boundary of the specified orbicular N -sided hole to ensure the compatibility of neighboring cross-boundary derivatives on the connecting points,preserving their G n *** we compute the control points of the periodic B-spline surface using the sufficient G n continuity condition on the pole and the algorithm of extending parametric *** method generates single blending surface,which can be converted into standard Bspline surface by adding knots without introducing *** only elevates the degree of the boundary by *** construction method is simple and efficient,without iteration nor large-scale matrix *** achieves G n continuity under compatible *** blending examples underline its feasibility and practicability.

关键词： CAD periodic B-spline surface polar coordinates N -sided hole filling G n continuity

Ontogeny of Drosophila melanogaster female sex-appeal and cuticular hydrocarbons

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Integrative Zoology 2010年第3期5卷 272-282页

作者： Marisa ARIENTI claude ANTONY claude WICKER-THOMAS jean-paul DELBECQUE jean-Marc JALLON University of Paris South 11 Center of Neurosciences of Paris SouthOrsayFrance Department of Biology Autonoma Metropolitan University-XochimilcoMexico DFMexico EMBL HeidelbergGermany LEGS CNRSGif sur YvetteFrance University of Bordeaux 1 Center of Integrative and Cognitive NeurosciencesTalenceFrance

The chemical communication system in Drosophila melanogaster Meigen,1830 plays a major role in courtship and consists of the male-specific cis-Vaccenyl acetate and sex-specific contact pheromones,cuticular hydrocarbons(CHC),which build up during ontogeny(first 4 days).They replace longer CHCs,common to both sexes and present only after the imaginal eclosion.A detailed quantitative description of the evolution of cuticular unsaturated hydrocarbons with age is presented here for males and females of different *** strains,which have been bred in well controlled *** appear in both sexes at around 12 h,before female *** present paper argues that this is likely linked to the switching on of a new set of ***,which is more abundant in females than in males during this critical period,might control this *** behavioral studies show that whereas female of all ages trigger early mature male courtship steps like wing vibration,only females older than 1 day trigger late courtship steps like attempted *** supports the hypothesis that late male courtship steps might be triggered by the CHCs,which build up after this age,especially female-specific(Z,Z)-7,11-and(Z,Z)-5,9-dienes.

关键词： contact pheromones Drosophila melanogaster ecdysone control ontogeny sex differences

An octree-based proxy for collision detection in large-scale particle systems

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Science China(Information Sciences) 2013年第1期56卷 55-64页

作者： FAN WenShan WANG Bin paul jean-claude SUN JiaGuang School of Software Tsinghua University Beijing Aerospace Control Center Department of Computer Science and Technology Tsinghua University Key Laboratory for Information System Security Ministry of Education of China Tsinghua National Laboratory for Information Science and Technology Institut National de Recherche en Informatique et en Automatique(INRIA)

Particle systems are important building block for simulating vivid and detail-rich effects in virtual *** of the most difficult aspects of particle systems has been detecting collisions between particles and mesh *** to the huge computation,a variety of proxy-based approaches have been proposed recently to perform visually correct ***,all either limit the complexity of the scene,fail to guarantee non-penetration,or are too slow for real-time use with many *** this paper,we propose a new octree-based proxy for colliding particles with meshes on the *** approach works by subdividing the scene mesh with an octree in which each leaf node associates with a representative normal corresponding to the normals of the triangles that intersect the *** present a view-visible method,which is suitable for both closed and non-closed models,to label the empty leaf nodes adjacent to nonempty ones with appropriate back/front property,allowing particles to collide with both sides of the scene *** show how collisions can be performed robustly on this proxy structure in place of the original mesh,and describe an extension that allows for fast traversal of the octree structure on the *** experiments show that the proposed method is fast enough for real-time performance with millions of particles interacting with complex scenes.

关键词： particle systems collision detection octree-based proxy GPU

Simulating Human Visual Perception in Nighttime Illumination

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Tsinghua Science and Technology 2009年第1期14卷 133-138页

作者：周宁董未名王家廞 paul jean-claude Department of Computer Science and Technology Tsinghua University INRIA Lorraine

This paper presents an image-based algorithm for simulating the visual adaptation of the human visual system to various illuminations, especially in dark nighttime conditions. The human visual system exhibits different characteristics depending on the illumination intensity, with photopic vision in bright conditions, scotopic vision in dark conditions, and mesopic vision between these two. A computational model is designed to simulate multiple features of mesopic vision and scotopic vision, including the chromaticity change, luminance change, and visual acuity loss. The system uses a source image under bright illumination as input. Then assuming that the viewer has already adapted to the new conditions, the color spectrum of the input image is reconstructed to replace the source with modifications of the chromaticity and the luminance of the relighted scene. A bilateral filter is used to simulate the visual acuity loss. The model parameters have clear physical meanings and can be obtained from experimental data to achieve realistic *** algorithm can be used not only for visual perception simulation, but also as a day-for-night tool to produce realistic nighttime images from daytime images.

关键词： Image enhancement

The synergy between the payloads on the ASO-S mission

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Research in Astronomy and Astrophysics 2019年第11期19卷 115-126页

作者： jean-claude Vial Institut d’Astrophysique Spatiale University Paris-Sud

This paper addresses the improved science resulting from joint observations performed by the different instruments onboard the Advanced Space-based Solar Observatory(ASO-S)mission along with ancillary instruments on missions flying at the same *** first describes the three major instruments along with their stated *** it presents some basic science issues concerning jointly observed flares,coronal mass ejections(CMEs)and eruptive prominences(EPs).Each physical candidate(magnetic reconnection,instability,hard X-ray emission and magnetic coronal field topology)is discussed in terms of its signature and identification with ASO-S *** importance of Lyαdetection and non-LTE modeling is *** instrumental and science challenges are briefly discussed.

关键词： techniques imagery,polarimetry-Sun eruptions,flares,coronal mass ejections

Lanthanide-doped nanoscintillators

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Light(Science & Applications) 2022年第10期11卷 2264-2266页

作者： jean-claude Georges Bünzli institute of Chemical Sciences and Engineering Swiss Federal Institute of TechnologyLausanne(EPFL)LausanneSwitzerland Department of Biomedical Engineering Southern University of Science and Technology(SUSTech)ShenzhenChina

Lanthanide-doped nanoscintillators are taking the lead in several important fields including radiation detection,biomedicine,both at the level of diagnosis and therapy,and information encoding.

关键词： diagnosis Lanthanide ill