期刊文献+
共找到61篇文章
< 1 2 4 >
每页显示 20 50 100
Advances in Studies and Applications of Centroidal Voronoi Tessellations 被引量:6
1
作者 Qiang Du Max Gunzburger Lili Ju 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期119-142,共24页
Centroidal Voronoi tessellations(CVTs) have become a useful tool in many applications ranging from geometric modeling,image and data analysis,and numerical partial differential equations,to problems in physics,astroph... Centroidal Voronoi tessellations(CVTs) have become a useful tool in many applications ranging from geometric modeling,image and data analysis,and numerical partial differential equations,to problems in physics,astrophysics,chemistry,and biology. In this paper,we briefly review the CVT concept and a few of its generalizations and well-known properties.We then present an overview of recent advances in both mathematical and computational studies and in practical applications of CVTs.Whenever possible,we point out some outstanding issues that still need investigating. 展开更多
关键词 Voronoi tessellations CENTROIDS CLUSTERING mesh generation and optimization IMAGEPROCESSING model reduction point sampling.
下载PDF
Edge-Weighted Centroidal Voronoi Tessellations 被引量:2
2
作者 Jie Wang Xiaoqiang Wang 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期223-244,共22页
Most existing applications of centroidal Voronoi tessellations(CVTs) lack consideration of the length of the cluster boundaries.In this paper we propose a new model and algorithms to produce segmentations which would ... Most existing applications of centroidal Voronoi tessellations(CVTs) lack consideration of the length of the cluster boundaries.In this paper we propose a new model and algorithms to produce segmentations which would minimize the total energy—a sum of the classic CVT energy and the weighted length of cluster boundaries.To distinguish it with the classic CVTs,we call it an Edge-Weighted CVT(EWCVT).The concept of EWCVT is expected to build a mathematical base for all CVT related data classifications with requirement of smoothness of the cluster boundaries.The EWCVT method is easy in implementation,fast in computation,and natural for any number of clusters. 展开更多
关键词 Centroidal Voronoi tessellations cluster boundaD edge detection clustering image processing.
下载PDF
Cooperative Sensing and Distributed Control of a Diffusion Process Using Centroidal Voronoi Tessellations
3
作者 Haiyang Chao Yang-Quan Chen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期162-177,共16页
This paper considers how to use a group of robots to sense and control a diffusion process.The diffusion process is modeled by a partial differential equation (PDE),which is a both spatially and temporally variant sys... This paper considers how to use a group of robots to sense and control a diffusion process.The diffusion process is modeled by a partial differential equation (PDE),which is a both spatially and temporally variant system.The robots can serve as mobile sensors,actuators,or both.Centroidal Voronoi Tessellations based coverage control algorithm is proposed for the cooperative sensing task.For the diffusion control problem,this paper considers spraying control via a group of networked mobile robots equipped with chemical neutralizers,known as smart mobile sprayers or actuators,in a domain of interest having static mesh sensor network for concentration sensing.This paper also introduces the information sharing and consensus strategy when using centroidal Voronoi tessellations algorithm to control a diffusion process.The information is shared not only on where to spray but also on how much to spray among the mobile actuators.Benefits from using CVT and information consensus seeking for sensing and control of a diffusion process are demonstrated in simulation results. 展开更多
关键词 CONSENSUS centroidal Voronoi tessellations diffusion process distributed control mobile actuator and sensor networks.
下载PDF
Noneuclidean Tessellations and Their Relation to Regge Trajectories
4
作者 B. H. Lavenda 《Journal of Modern Physics》 2013年第7期950-962,共13页
The coefficients in the confluent hypergeometric equation specify the Regge trajectories and the degeneracy of the angular momentum states. Bound states are associated with real angular momenta while resonances are ch... The coefficients in the confluent hypergeometric equation specify the Regge trajectories and the degeneracy of the angular momentum states. Bound states are associated with real angular momenta while resonances are characterized by complex angular momenta. With a centrifugal potential, the half-plane is tessellated by crescents. The addition of an electrostatic potential converts it into a hydrogen atom, and the crescents into triangles which may have complex conjugate angles;the angle through which a rotation takes place is accompanied by a stretching. Rather than studying the properties of the wave functions themselves, we study their symmetry groups. A complex angle indicates that the group contains loxodromic elements. Since the domain of such groups is not the disc, hyperbolic plane geometry cannot be used. Rather, the theory of the isometric circle is adapted since it treats all groups symmetrically. The pairing of circles and their inverses is likened to pairing particles with their antiparticles which then go on to produce nested circles, or a proliferation of particles. A corollary to Laguerre’s theorem, which states that the euclidean angle is represented by a pure imaginary projective invariant, represents the imaginary angle in the form of a real projective invariant. 展开更多
关键词 tessellations Reggie Trajectories
下载PDF
2D Centroidal Voronoi Tessellations with Constraints
5
作者 Jane Tournois Pierre Alliez Olivier Devillers 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期212-222,共11页
We tackle the problem of constructing 2D centroidal Voronoi tessellations with constraints through an efficient and robust construction of bounded Voronoi diagrams, the pseudo-dual of the constrained Delaunay triangul... We tackle the problem of constructing 2D centroidal Voronoi tessellations with constraints through an efficient and robust construction of bounded Voronoi diagrams, the pseudo-dual of the constrained Delaunay triangulation.We exploit the fact that the cells of the bounded Voronoi diagram can be obtained by clipping the ordinary ones against the constrained Delaunay edges.The clipping itself is efficiently computed by identifying for each constrained edge the(connected) set of triangles whose dual Voronoi vertices are hidden by the constraint.The resulting construction is amenable to Lloyd relaxation so as to obtain a centroidal tessellation with constraints. 展开更多
关键词 Centroidal Voronoi tessellation bounded Voronoi diagram constrained Delaunay triangulation.
下载PDF
Reactor field reconstruction from sparse and movable sensors using Voronoi tessellation-assisted convolutional neural networks 被引量:1
6
作者 He-Lin Gong Han Li +1 位作者 Dunhui Xiao Sibo Cheng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期173-185,共13页
The aging of operational reactors leads to increased mechanical vibrations in the reactor interior.The vibration of the incore sensors near their nominal locations is a new problem for neutronic field reconstruction.C... The aging of operational reactors leads to increased mechanical vibrations in the reactor interior.The vibration of the incore sensors near their nominal locations is a new problem for neutronic field reconstruction.Current field-reconstruction methods fail to handle spatially moving sensors.In this study,we propose a Voronoi tessellation technique in combination with convolutional neural networks to handle this challenge.Observations from movable in-core sensors were projected onto the same global field structure using Voronoi tessellation,holding the magnitude and location information of the sensors.General convolutional neural networks were used to learn maps from observations to the global field.The proposed method reconstructed multi-physics fields(including fast flux,thermal flux,and power rate)using observations from a single field(such as thermal flux).Numerical tests based on the IAEA benchmark demonstrated the potential of the proposed method in practical engineering applications,particularly within an amplitude of 5 cm around the nominal locations,which led to average relative errors below 5% and 10% in the L_(2) and L_(∞)norms,respectively. 展开更多
关键词 Voronoi tessellation Field reconstruction Nuclear reactors Reactor physics On-line monitoring
下载PDF
Adaptive triangular mesh coarsening with centroidal Voronoi tessellations 被引量:2
7
作者 Zhen-yu SHU Guo-zhao WANG Chen-shi DONG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第4期535-545,共11页
We present a novel algorithm for adaptive triangular mesh coarsening. The algorithm has two stages. First, the input triangular mesh is refined by iteratively applying the adaptive subdivision operator that performs a... We present a novel algorithm for adaptive triangular mesh coarsening. The algorithm has two stages. First, the input triangular mesh is refined by iteratively applying the adaptive subdivision operator that performs a so-called red-green split. Second, the refined mesh is simplified by a clustering algorithm based on centroidal Voronoi tessellations (CVTs). The accuracy and good quality of the output triangular mesh are achieved by combining adaptive subdivision and the CVTs technique. Test results showed the mesh coarsening scheme to be robust and effective. Examples are shown that validate the method. 展开更多
关键词 Triangular mesh Mesh coarsening Surface subdivision Centroidal Voronoi tessellations (CVTs)
原文传递
Investigation of stress-induced progressive failure of mine pillars using a Voronoi grain-based breakable block model
8
作者 Shili Qiu Shirui Zhang +3 位作者 Quan Jiang Shaojun Li Hao Zhang Qiankuan Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第5期713-729,共17页
The Voronoi grain-based breakable block model(VGBBM)based on the combined finite-discrete element method(FDEM)was proposed to explicitly characterize the failure mechanism and predict the deformation behavior of hard-... The Voronoi grain-based breakable block model(VGBBM)based on the combined finite-discrete element method(FDEM)was proposed to explicitly characterize the failure mechanism and predict the deformation behavior of hard-rock mine pillars.The influence of the microscopic parameters on the macroscopic mechanical behavior was investigated using laboratory-scale models.The field-scale pillar models(width-to-height,W/H=1,2 and 3)were calibrated based on the empirically predicted stress-strain curves of Creighton mine pillars.The results indicated that as the W/H ratios increased,the VGBBM effectively predicted the transition from strain-softening to pseudo-ductile behavior in pillars,and explicitly captured the separated rock slabs and the V-shaped damage zones on both sides of pillars and conjugate shear bands in core zones of pillars.The volumetric strain field revealed significant compressional deformation in core zones of pillars.While the peak strains of W/H=1 and 2 pillars were relatively consistent,there were significant differences in the strain energy storage and release mechanism.W/H was the primary factor influencing the deformation and strain energy in the pillar core.The friction coefficient of the structural plane was also an important factor affecting the pillar strength and the weakest discontinuity angle.The fracture surface was controlled by the discontinuity angle and the friction coefficient.This study demonstrated the capability of the VGBBM in predicting the strengths and deformation behavior of hard-rock pillars in deep mine design. 展开更多
关键词 Pillar strength FDEM Voronoi tessellation SPALLING BULKING
下载PDF
A typhoon-induced storm surge numerical model with GPU acceleration based on an unstructured spherical centroidal Voronoi tessellation grid
9
作者 Yuanyong Gao Fujiang Yu +2 位作者 Cifu Fu Jianxi Dong Qiuxing Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期40-47,共8页
Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal areas.Accurate and timely issuance of storm surge warnings to take appropriate countermeasures is an important me... Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal areas.Accurate and timely issuance of storm surge warnings to take appropriate countermeasures is an important means to reduce storm surge-related losses.Storm surge numerical models are important for storm surge forecasting.To further improve the performance of the storm surge forecast models,we developed a numerical storm surge forecast model based on an unstructured spherical centroidal Voronoi tessellation(SCVT)grid.The model is based on shallow water equations in vector-invariant form,and is discretized by Arakawa C grid.The SCVT grid can not only better describe the coastline information but also avoid rigid transitions,and it has a better global consistency by generating high-resolution grids in the key areas through transition refinement.In addition,the simulation speed of the model is accelerated by using the openACC-based GPU acceleration technology to meet the timeliness requirements of operational ensemble forecast.It only takes 37 s to simulate a day in the coastal waters of China.The newly developed storm surge model was applied to simulate typhoon-induced storm surges in the coastal waters of China.The hindcast experiments on the selected representative typhoon-induced storm surge processes indicate that the model can reasonably simulate the distribution characteristics of storm surges.The simulated maximum storm surges and their occurrence times are consistent with the observed data at the representative tide gauge stations,and the mean absolute errors are 3.5 cm and 0.6 h respectively,showing high accuracy and application prospects. 展开更多
关键词 typhoon-induced storm surge numerical model GPU acceleration unstructured grid spherical centroidal Voronoi tessellation(SCVT)
下载PDF
Convergent Adaptive Finite Element Method Based on Centroidal Voronoi Tessellations and Superconvergence 被引量:2
10
作者 Yunqing Huang Hengfeng Qin +1 位作者 Desheng Wang Qiang Du 《Communications in Computational Physics》 SCIE 2011年第7期339-370,共32页
We present a novel adaptive finite element method(AFEM)for elliptic equations which is based upon the Centroidal Voronoi Tessellation(CVT)and superconvergent gradient recovery.The constructions of CVT and its dual Cen... We present a novel adaptive finite element method(AFEM)for elliptic equations which is based upon the Centroidal Voronoi Tessellation(CVT)and superconvergent gradient recovery.The constructions of CVT and its dual Centroidal Voronoi Delaunay Triangulation(CVDT)are facilitated by a localized Lloyd iteration to produce almost equilateral two dimensional meshes.Working with finite element solutions on such high quality triangulations,superconvergent recovery methods become particularly effective so that asymptotically exact a posteriori error estimations can be obtained.Through a seamless integration of these techniques,a convergent adaptive procedure is developed.As demonstrated by the numerical examples,the new AFEM is capable of solving a variety of model problems and has great potential in practical applications. 展开更多
关键词 Finite element methods superconvergent gradient recovery Centroidal Voronoi Tessellation adaptive methods.
原文传递
Tessellations in GIS:Part I—putting it all together
11
作者 Christopher Gold 《Geo-Spatial Information Science》 SCIE EI CSCD 2016年第1期9-25,共17页
This article attempts to describe the role of tessellated models of space within the discipline of geographic information systems(GIS)—a speciality coming largely out of geography and land surveying,where there was a... This article attempts to describe the role of tessellated models of space within the discipline of geographic information systems(GIS)—a speciality coming largely out of geography and land surveying,where there was a strong need to represent information about the land’s surface within a computer system rather than on the original paper maps.We look at some of the basic operations in GIS,including dynamic and kinetic applications.We examine issues of topology and data structures and produce a tessellation model that may be widely applied both to traditional“object”and“field”data types.Based on this framework,it can be argued that tessellation models are fundamental to our understanding and processing of geographical space,and provide a coherent framework for understanding the“space”in which we exist.This first article examines static structures,and a subsequent article looks at“change”—what happens when things move. 展开更多
关键词 GIS tessellation model static structure TOPOLOGY data structure object and field Voronoi diagram
原文传递
Tessellations in GIS: Part Ⅱ-making changes
12
《Geo-Spatial Information Science》 CSCD 2016年第2期中插7-中插7,157-167,共12页
We attempt to describe the role of tessellated models of space within the discipline of Geographic Information Systems (GIS) - a speciality coming largely out of Geography and Land Surveying, where there was a strong ... We attempt to describe the role of tessellated models of space within the discipline of Geographic Information Systems (GIS) - a speciality coming largely out of Geography and Land Surveying, where there was a strong need to represent information about the land's surface within a computer system rather than on the original paper maps. We look at some of the basic operations in GIS, including dynamic and kinetic applications. We examine issues of topology and data structures, and produced a tessellation model that may be widely applied both to traditional'object'and'field'data types.The Part Ⅰ of this study examined object and field spatial models, the Voronoi extension of objects, and the graphs that express the resulting adjacencies. The required data structures were also briefly described, along with 2D and 3D structures and hierarchical indexing. The importance of graph duality was emphasized. Here, this second paper builds on the structures described in the first, and examines how these may be modified:change may often be associated with either viewpoint or time. Incremental algorithms permit additional point insertion, and applications involving the addition of skeleton points, for map scanning, contour enrichment or watershed delineation and simulation. Dynamic algorithms permit skeleton smoothing, and higher order Voronoi diagram applications, including Sibson interpolation. Kinetic algorithms allow collision detection applications, free-Lagrange flow modeling, and pen movement simulation for map drawing. If desired these methods may be extended to 3D. Based on this framework, it can be argued that tessellation models are fundamental to our understanding and processing of geographical space, and provide a coherent framework for understanding the'space'in which we exist. 展开更多
关键词 GIS TESSELLATION model dynamic STRUCTURE topology data STRUCTURE object and field VORONOI DIAGRAM KINETIC algorithm
全文增补中
On the calibration and verification of Voronoi-based discontinuous deformation analysis for modeling rock fracture 被引量:2
13
作者 Kaiyu Zhang Feng Liu +3 位作者 Kaiwen Xia Ying Xu Peng Dong Changyi Yu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第8期2025-2038,共14页
Since its introduction,discontinuous deformation analysis(DDA)has been widely used in different areas of rock mechanics.By dividing large blocks into subblocks and introducing artificial joints,DDA can be applied to r... Since its introduction,discontinuous deformation analysis(DDA)has been widely used in different areas of rock mechanics.By dividing large blocks into subblocks and introducing artificial joints,DDA can be applied to rock fracture simulation.However,parameter calibration,a fundamental issue in discontinuum methods,has not received enough attention in DDA.In this study,the parameter calibration of DDA for intact rock is carefully studied.To this end,a subblock DDA with Voronoi tessellation is presented first.Then,a modified contact constitutive law is introduced,in which the tensile and shear meso-strengths are modified to be independent of the bond lengths.This improvement can prevent the unjustified preferential failure of short edges.A method for imposing confining pressure is also introduced.Thereafter,sensitivity analysis is performed to investigate the influence of the calculated parameters and meso-parameters on the mechanical properties of modeled rock.Based on the sensitivity analysis,a unified calibration procedure is suggested for both cases with and without confining pressure.Finally,the calibration procedure is applied to two examples,including a biaxial compression test.The results show that the proposed Voronoi-based DDA can simulate rock fracture with and without confining pressure very well after careful parameter calibration. 展开更多
关键词 Discontinuous deformation analysis(DDA) Voronoi tessellation Parameter calibration Confining pressure Rock fracture
下载PDF
Role of grain boundary networks in vortex motion in superconducting films 被引量:1
14
作者 刘宇 薛峰 苟晓凡 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期528-533,共6页
We study the vortex dynamics of the polycrystalline superconductors in the presence of both random point defects and the generated grain boundary(GB) networks with Voronoi diagram. The synergistic effect of adjacent G... We study the vortex dynamics of the polycrystalline superconductors in the presence of both random point defects and the generated grain boundary(GB) networks with Voronoi diagram. The synergistic effect of adjacent GBs on restricting the vortex motion in intragranular region is proposed and the corresponding intensity factor of the synergistic effect which characterizes the strength of the synergistic restriction of adjacent grain boundaries is also determined in the present work.The interconnected GBs offer easy-flow channels for vortices in addition to pinning effects on the vortices. The combined channels and the vortex flow patterns in the superconducting film are analyzed in detail from molecular dynamics simulations. Furthermore, it is discovered that the critical current increases with the decrease of magnetic field intensity,temperature, and the average grain size. The large number of vortices results in the enhanced repulsive interaction forcing the vortices to move out from the GBs. The thermal depinning from GBs leads to the lower Lorentz force range. The increase of the grain size causes the number of GBs to decrease. In summary, these effects leads the critical current to become a decreasing function of magnetic field, temperature, and grain size. 展开更多
关键词 grain boundary network Voronoi tessellation synergistic effect intensity factor of synergistic effect vortex motion combined channels
下载PDF
移动渲染的网格细化方法 被引量:1
15
作者 徐爱莉 马骋 周鹏 《石油矿场机械》 2009年第10期30-34,共5页
随着移动设备性能的逐渐提高,越来越多的图形渲染技术由普通PC移植到了移动平台,但移动设备的计算能力与PC相比依然存在较大差距。对于PC上能够渲染的复杂网格模型,需要进行简化后才能够在移动设备上渲染,而网格简化必然会导致模型的走... 随着移动设备性能的逐渐提高,越来越多的图形渲染技术由普通PC移植到了移动平台,但移动设备的计算能力与PC相比依然存在较大差距。对于PC上能够渲染的复杂网格模型,需要进行简化后才能够在移动设备上渲染,而网格简化必然会导致模型的走样。虽然Phong着色可以实现大部分正向面的平滑效果,但是未能解决轮廓部分的不连续性。为了解决这个问题,利用一种基于顶点着色器的实时细化方法,在移动设备上实现了Phong Tessellation,达到了模型轮廓部分细化的目的。 展开更多
关键词 Phong TESSELLATION 实时细化 移动渲染 顶点着色器 网格细化
下载PDF
A Novel Voronoi Based Particle Filter for Multi-Sensor Data Fusion 被引量:1
16
作者 Vani Cheruvu Priyanka Aggarwal Vijay Devabhaktuni 《Applied Mathematics》 2012年第11期1787-1794,共8页
Seamless and reliable navigation for civilian/military application is possible by fusing prominent Global Positioning System (GPS) with Inertial Navigation System (INS). This integrated GPS/INS unit exhibits a continu... Seamless and reliable navigation for civilian/military application is possible by fusing prominent Global Positioning System (GPS) with Inertial Navigation System (INS). This integrated GPS/INS unit exhibits a continuous navigation solution with increased accuracy and reduced uncertainty or ambiguity. In this paper, we propose a novel approach of dynamically creating a Voronoi based Particle Filter (VPF) for integrating INS and GPS data. This filter is based on redistribution of the proposal distribution such that the redistributed particles lie in high likelihood region;thereby increasing the filter accuracy. The usual limitations like degeneracy, sample impoverishment that are seen in conventional particle filter are overcome using our VPF with minimum feasible particles. The small particle size in our methodology reduces the computational load of the filter and makes real-time implementation feasible. Our field test results clearly indicate that the proposed VPF algorithm effectively compensated and reduced positional inaccuracies when GPS data is available. We also present the preliminary results for cases with short GPS outages that occur for low-cost inertial sensors. 展开更多
关键词 Sensor Fusion Global POSITIONING SYSTEM INERTIAL NAVIGATION SYSTEM VORONOI tessellations Particle Filter
下载PDF
An Improved Cooperative Team Spraying Control of a Diffusion Process With a Moving or Static Pollution Source 被引量:1
17
作者 Juan Chen Baotong Cui +1 位作者 Yang Quan Chen Bo Zhuang 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第2期494-504,共11页
This paper is concerned with a control problem of a diffusion process with the help of static mesh sensor networks in a certain region of interest and a team of networked mobile actuators carrying chemical neutralizer... This paper is concerned with a control problem of a diffusion process with the help of static mesh sensor networks in a certain region of interest and a team of networked mobile actuators carrying chemical neutralizers.The major contribution of this paper can be divided into three parts:the first is the construction of a cyber-physical system framework based on centroidal Voronoi tessellations(CVTs),the second is the convergence analysis of the actuators location,and the last is a novel proportional integral(PI)control method for actuator motion planning and neutralizing control(e.g.,spraying)of a diffusion process with a moving or static pollution source,which is more effective than a proportional(P)control method.An optimal spraying control cost function is constructed.Then,the minimization problem of the spraying amount is addressed.Moreover,a new CVT algorithm based on the novel PI control method,henceforth called PI-CVT algorithm,is introduced together with the convergence analysis of the actuators location via a PI control law.Finally,a modified simulation platform called diffusion-mobile-actuators-sensors-2-dimension-proportional integral derivative(Diff-MAS2D-PID)is illustrated.In addition,a numerical simulation example for the diffusion process is presented to verify the effectiveness of our proposed controllers. 展开更多
关键词 Centroidal Voronoi tessellations(CVTs) diffusion processes mobile actuator-sensor networks(MAS-Net) PI control
下载PDF
Fast Multilevel CVT-Based Adaptive Data Visualization Algorithm
18
作者 M.Emelianenko 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期195-211,共17页
Efficient data visualization techniques are critical for many scientific applications. Centroidal Voronoi tessellation(CVT) based algorithms offer a convenient vehicle for performing image analysis,segmentation and co... Efficient data visualization techniques are critical for many scientific applications. Centroidal Voronoi tessellation(CVT) based algorithms offer a convenient vehicle for performing image analysis,segmentation and compression while allowing to optimize retained image quality with respect to a given metric.In experimental science with data counts following Poisson distributions,several CVT-based data tessellation algorithms have been recently developed.Although they surpass their predecessors in robustness and quality of reconstructed data,time consumption remains to be an issue due to heavy utilization of the slowly converging Lloyd iteration.This paper discusses one possible approach to accelerating data visualization algorithms.It relies on a multidimensional generalization of the optimization based multilevel algorithm for the numerical computation of the CVTs introduced in[1],where a rigorous proof of its uniform convergence has been presented in 1-dimensional setting.The multidimensional implementation employs barycentric coordinate based interpolation and maximal independent set coarsening procedures.It is shown that when coupled with bin accretion algorithm accounting for the discrete nature of the data,the algorithm outperforms Lloyd-based schemes and preserves uniform convergence with respect to the problem size.Although numerical demonstrations provided are limited to spectroscopy data analysis,the method has a context-independent setup and can potentially deliver significant speedup to other scientific and engineering applications. 展开更多
关键词 Centroidal Voronoi tessellations computational algorithms Lloyd's method acceleration schemes multilevel method BINNING image analysis VISUALIZATION signal-to-noise ratio.
下载PDF
Three-Dimensional Finite Element Superconvergent Gradient Recovery on Par6 Patterns
19
作者 Jie Chen Desheng Wang 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期178-194,共17页
In this paper, we present a theoretical analysis for linear finite element superconvergent gradient recovery on Par6 mesh, the dual of which is centroidal Voronoi tessellations with the lowest energy per unit volume a... In this paper, we present a theoretical analysis for linear finite element superconvergent gradient recovery on Par6 mesh, the dual of which is centroidal Voronoi tessellations with the lowest energy per unit volume and is the congruent cell predicted by the three-dimensional Gersho's conjecture. We show that the linear finite element solution uh and the linear interpolation uI have superclose gradient on Par6 meshes. Consequently, the gradient recovered from the finite element solution by using the superconvergence patch recovery method is superconvergent to Vu. A numerical example is presented to verify the theoretical result. 展开更多
关键词 SUPERCONVERGENCE Par6 finite element method centroidal Voronoi tessellations Gersho's conjecture.
下载PDF
Analysis of a Class of Symmetric Equilibrium Configurations for a Territorial Model
20
作者 Michael Busch Jeff Moehlis 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2010年第2期143-161,共19页
Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for... Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for a rectangular domain that exhibits interesting symmetry properties.We also demonstrate the procedure for performing a center manifold reduction on the system to extract a set of coordinates which capture the long term dynamics when the system is close to a bifurcation.Bifurcations of the system restricted to the center manifold are then classified and compared to numerical results.Although we analyze a specific set-up,these methods can in principle be applied to any bifurcation point of any equilibrium for any domain. 展开更多
关键词 Territorial behavior Voronoi tessellations BIFURCATION center manifold reduction.
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部