面向海量层次信息可视化的嵌套圆鱼眼视图

针对海量层次信息可视化问题,提出嵌套圆鱼眼视图及实现方法.首先分析了相关工作;然后构造了针对同层兄弟节点的变形函数,给出了针对焦点节点同层兄弟节点的外切圆变形排列算法、变形后节点的子节点的嵌套圆递归排列算法及将二维鱼眼视图映射为三维鱼眼视图的方法;最后将该方法应用于计算机文件系统可视化.实验结果表明:该方法在相对小的显示空间内,既能显示海量信息的整体视图,又能突出局部焦点细节信息,具有较高的任务完成效率与用户满意度.     

基于Venn图的层次信息可视化

为解决具有层次结构的大量信息的可视化问题,文中给出了用嵌套圆表达树型结构信息的可视化方法,即用相切的圆表示兄弟节点,嵌套的圆表示父子节点,圆的位置、大小和颜色分别表示树节点的不同属性信息.同层的兄弟节点并排排列,圆的排列算法快速、稳定、紧密且不相互重叠,排列圆的个数与时间呈线性关系,该排列算法适于大量信息的可视化,既能快速显示大数据集的整体视图,又方便查看细节信息;既能清楚地表达复杂信息间的层次关系,又能显示树节点的属性.该方法可用于文件系统的可视化,实例表明该方法简单、实用、高效、可靠.     

关于树形Focus+Context信息可视化技术的探讨

层次信息的可视化结构最直观的方式是树形结构.针对目前信息浏览中的用户迷路和认知超负荷等问题所提出的相关树形Focus+Context信息可视化技术进行初步探讨,分析比较了各种树形Focus+Context信息可视化技术的优缺点,并对树形信息可视化技术的发展做了展望.     

巨量挖掘结果的Focus + Context展现

针对数据挖掘结果集数量巨大的特点,基于Focus+Context人机交互可视化技术实现结果集的B roadV iew and D etail on D em and导航可以有效帮助对挖掘结果的聚焦与探询,进而帮助用户快速找到所需要的信息。给出了基于规则层次凝聚类与Focus+Context技术的可视化系统方法与原形系统,有效地解决了巨量规则的有效浏览与可视化问题,避免了直接对规则元素图形显示效果不佳的问题,从而有利于挖掘的应用。     

基于内容的Focus+Context可视化技术

尽管一些研究通过可视化技术较好地解决了大数据量信息在相对较小的屏幕上的显示问题,但很少有方法可以给用户提供一种直观灵活可控的交互方式。提出一种允许用户随意指定Focus区域的方法,并设计了一个巧妙的能量模型来保持Focus区域的细节。为了减少Context 区域的扭曲,用户可以指定一个Glue区域。通过变形能量的光滑扩散,Focus区域的扭曲被分布到其他区域。大量实验结果证明,所提出的方法能极大地改善可视化效果,帮助用户在较小的屏幕上了解更多信息。     

面向网状信息的Radial+Focus可视化*

针对当前网状信息可视化技术忽略了网状信息节点的可视信息的问题,提出一种面向网状信息的Radial+Focus可视化技术。首先介绍网状信息节点的信息详细度与先验重要度,并研究通过节点的交互历史计算节点的先验重要度的方法;然后研究了基于节点先验重要度的Radial+Focus布局算法;最后,给出了Radial+Focus可视化技术的应用实例和实验评估。实验评估表明,该技术能自然、高效地可视化网状信息,为用户对网状信息关系及网状信息节点的可视信息的分析提供有力的支持。     

面向层次化数据的变分圆形树图

圆形树图(circular treemap)是面向层次化数据的一种信息可视化方法.提出一种圆形树图构造方法,将圆形树图的布局问题与组合优化中的圆排列(disk packing)问题相结合,以一种基于变分连续优化的算法求解多个半径不同圆的优化布局,由此提高圆形树图的空间利用率,并支持层次下行、层次上行与焦点+上下文等自然交互方式.实验结果表明了该方法的有效性.     

一种面向临床决策推理的可视诊疗技术

海量医学信息的快速增长已远远超出人类认知能力,医疗服务环境和用户人群的复杂多样性使得海量数据难以在现有能力和工具的支持下满足广大用户对于信息服务的需求.临床诊疗服务的可视化、智能化程度不高导致现有的医学知识服务水平难以保证海量资源信息的充分利用.在分析了临床诊疗环境下人机协同认知特性的基础上给出了一种基于语义层次的信息组织方式;分析了符合该数据组织模式的可视形态及自然的可视交互技术;在上述工作的基础上构建了一个面向临床决策推理的可视诊疗分析框架,并给出了原型系统实例加以验证.结果表明,通过结合交互式可视化和自动分析技术,可以有效地帮助人们从海量数据中获取到有用的信息模式,减轻人们对数据进行分析的负担,为医疗诊断过程提供决策支持服务.     

MCSM:一种基于移动设备的上下文感知中间件

提出一种针对移动设备的上下文感知中间件MCSM(Mobile Context Sensing Middleware).MCSM可以动态地感知当前移动设备的内外部计算环境及用户活动等上下文信息,并以统一的接口将感知到的上下文数据提供给上层应用程序.为了克服外部传感器数据的高异构性,MCSM采用了一种基于XML的上下文数据描述语言CDDL.基于MCSM的原型系统表明,MCSM具有良好的运行效率和可扩展性,并可显著提高上下文应用程序的开发效率.     

一种模型驱动的交互式信息可视化开发方法

设计与实现面向领域应用的交互式信息可视化软件十分困难.缺乏统一的开发方法与支撑工具箱,为非专家用户提供对层次、网络、多维等数据类型的统一支持,对各种可视化技术与交互技术的统一支持,以及对信息可视化任务的统一支持针对此问题,提出了一种模型驱动的交互式信息可视化开发方法Daisy.首先,提出了交互式信息可视化界面模型IIVM(interactive information visualization interface model);然后,提出了基于IIVM的交互式信息可视化开发方法Daisy,讨论了该方法的两个核心技术:IIVM建模与描述文件生成方法、系统自动生成方法.同时。给出了Daisy工具箱,包括Daisy建模工具、Daisy系统自动生成工具以及运行时框架与组件库.最后,给出了该开发方法与工具箱的应用实例.实例表明,该方法能够为交互式信息可视化开发的统一支撑方法问题提供一种有效的解决方案.     

Focus+Context Exploration of Hierarchical Embeddings

Hierarchical embeddings, such as HSNE, address critical visual and computational scalability issues of traditional techniques for dimensionality reduction. The improved scalability comes at the cost of the need for increased user interaction for exploration. In this paper, we provide a solution for the interactive visual Focus+Context exploration of such embeddings. We explain how to integrate embedding parts from different levels of detail, corresponding to focus and context groups, in a joint visualization. We devise an according interaction model that relates typical semantic operations on a Focus+Context visualization with the according changes in the level‐of‐detail‐hierarchy of the embedding, including also a mode for comparative Focus+Context exploration and extend HSNE to incorporate the presented interaction model. In order to demonstrate the effectiveness of our approach, we present a use case based on the visual exploration of multi‐dimensional images.     

Feature-preserving volume data reduction and focus+context visualization

The growing sizes of volumetric data sets pose a great challenge for interactive visualization. In this paper, we present a feature-preserving data reduction and focus+context visualization method based on transfer function driven, continuous voxel repositioning and resampling techniques. Rendering reduced data can enhance interactivity. Focus+context visualization can show details of selected features in context on display devices with limited resolution. Our method utilizes the input transfer function to assign importance values to regularly partitioned regions of the volume data. According to user interaction, it can then magnify regions corresponding to the features of interest while compressing the rest by deforming the 3D mesh. The level of data reduction achieved is significant enough to improve overall efficiency. By using continuous deformation, our method avoids the need to smooth the transition between low and high-resolution regions as often required by multiresolution methods. Furthermore, it is particularly attractive for focus+context visualization of multiple features. We demonstrate the effectiveness and efficiency of our method with several volume data sets from medical applications and scientific simulations.     

基于内容的网格生成算法

在基于模型的编码技术中,选择合适的网络模型对提高模糊的运动估计精度、编码效率和得到高质量的解码图像都是至关重要的。本文提出的基于图像内容的自适应网络模型生成算法,首先利用数学形态学中的水线算法把编码图像分割成许多纹理一致的区域,所分割的区域反映了图像的结构、轮廓和边界;再对这些区域的边界进行多边形拟合,得到多边形各个边的端点作为网格模型的节点,以这些节点为基础就能生成一个Ｄｅｌａｕｎａｙ三角形网格     

Molecular dynamics-based unstructured grid generation method for aerodynamic applications

A new approach to triangular mesh generation based on the molecular dynamics method is proposed. Mesh nodes are considered as interacting particles. After the node placement by molecular dynamics simulation, well-shaped triangles or tetrahedra can be created after connecting the nodes by Delaunay triangulation or tetrahedrization. Some examples are considered in order to illustrate the method’s ability to generate a mesh for an aircraft with a complicated boundary. Mesh adaptation technology for molecular dynamics simulation is presented.     

Addressing and routing in hexagonal networks with applications for tracking mobile users and connection rerouting in cellular networks

Nodes in a hexagonal network are placed at the vertices of a regular triangular tessellation, so that each node has up to six neighbors. The network is proposed as an alternative interconnection network to a mesh connected computer (with nodes serving as processors) and is used also to model cellular networks where nodes are the base stations. In this paper, we propose a suitable addressing scheme for nodes (with two variants), derive a formula for distance between nodes, and present a very simple and elegant routing algorithm. This addressing scheme and corresponding routing algorithm for hexagonal interconnection are considerably simpler than previously proposed solutions. We then apply the addressing scheme for solving two problems in cellular networks. With the new scheme, the distance between the new and old cell to which a mobile phone user is connected can be easily determined and coded with three integers, one of them being zero. Further, in order to minimize the wireless cost of tracking mobile users, we propose hexagonal cell identification codes containing three, four, or six bits, respectively, to implement a distance based tracking strategy. These schemes do not have errors in determining cell distance in existing hexagonal based cellular networks. Another application is for connection rerouting in cellular networks during a path extension process.     

平面自动布点及Delaunay三角形网格生成

文中给出了一种区域内布点的自动生成算法,可从背景点云中逐个选出符合区域几何特征的内部节点,其疏密变化通过边界点上的节点间距函数进行控制。最终生成的内部点云和边界点既可以用来做无网格计算,也可以结合波前推进法生成Delaunay三角形网格。通过对网格生成算法的改进,算例表明该算法得到网格具有很好质量。     

用于视频编码的小波域三角形网格构造方法

在深入研究视频图像冗余离散变换特征的基础上,提出一种用于视频编码运动补偿技术的小波域不规则三角形网格构造方法．基于孔径问题的原理,使用冗余离散变换小波的水平和垂直子带构造三角形网格节点的选择判据,把节点的特征匹配度集成到节点前向追踪过程的判据中;通过获得的节点运动矢量和网格映射实现运动补偿功能．实验证明,该方法获得了较好运动补偿的效果．     

A consistent octree hanging node elimination algorithm for hexahedral mesh generation

A new algorithm for hanging node elimination in octree structures is developed. The proposed algorithm utilizes hanging node elimination by refinement templates and a new mesh conditioning technique based on decoupling templates. Refinement templates insert transition elements to eliminate hanging nodes. Decoupling templates insert circular loops in the dual mesh without introducing or removing hanging nodes. Decoupling templates are introduced to avoid full refinement in the cases that do not match any of the available refinement templates. The proposed algorithm eliminates hanging nodes for concavely refined regions without excessive refinement. Another advantage of the proposed algorithm lies in eliminating narrow gaps of coarse meshes between refined regions. This step has a positive effect on the mesh quality as it avoids introducing non-regular templates with a limited penalty of uniform refinement. The presented algorithm produces good quality meshes and provides a consistent and complete method for producing conformally refined octree structures.     

基于骨架关节点约束的交互式局部变形

利用广义元球变形技术,提出一种基于骨架关节点约束的交互式局部变形方法。该方法提取多边形网格模型的骨架关节点并结合模型骨架图结构确定骨架关节点对应的局部区域,计算三维网格点到骨架节点的欧式距离,将约束区域的最大欧氏距离作为约束半径,得到各骨架节点对应的势函数值,通过控制骨架节点的空间位置给出三角形面片点的新坐标位置。实验结果表明,该方法有效保持多边形网络模型的局部特征,并确保了模型变形的直观性和高效性。