用于脑网络连接加权图比较的可视分析系统设计与实现

人脑功能网络的研究是近十年生物学领域的重要课题,可视化工具作为数据分析的重要手段,在脑科学研究中有着举足轻重的地位;然而现有的脑功能网络可视化工具存在信息获取效率低、功能单一等问题;针对以上问题,设计并实现了一款用于脑网络连接加权图比较的可视分析系统,帮助研究人员探索不同群组间的差异;首次提出并使用一种用于脑网络连接加权图比较的新可视化方法,针对该方法的用户评估表明,改进后的可视方法在做对比分析任务时更有效;此外,系统将数据挖掘与可视化相结合,增强了群组间差异的表现形式;并且提供了多视图协同等一系列交互方式供研究人员自主探索;最后使用了两组公开数据集进行案例分析,验证了系统的有用性和高效性.     

基于X3D的交互式变电站信息可视化管理系统

针对三维信息系统并未在虚拟制造上得到广泛应用的现状，通过结合Extensible-3D(X3D)和Java程序语言，构建出一个具有人机交互效果的3D变电站信息可视化管理系统。系统的特点是可以在三维场景上直接进行信息管理操作，同时系统会将修改信息自动存入数据库中，再次运行系统时会自动重建三维场景。应用实例表明，所提出的系统架构具有交互性、可视化的管理特性，改变了过去单纯通过文字或二维文件进行信息管理的模式，对企业的虚拟化制造有着很好的借鉴作用。     

音乐可视化及其研究进展

随着计算机技术的发展,音乐的形象化出现了新的手段,这就是音乐可视化技术.作为听觉艺术与视觉艺术的结合体,音乐可视化已经得到了广泛关注.文章介绍了音乐可视化的概念与研究内容,从可视化音乐模型、可视化视觉模型、可视化系统、可视化的交互性四个层次着重分析和评述了目前国内外音乐可视化技术的研究进展,并分析了当前亟待解决的问题,展望了其未来的发展趋势.音乐可视化作为一种新型的可视化技术,仍存在许多问题需要解决,其研究具有很强的理论意义和实用价值.     

3DIVE: An Immersive Environment for Interactive Volume Data Exploration

This paper describes an immersive system,called 3DIVE,for interactive volume data visualization and exploration inside the CAVE virtual environment.Combining interactive volume rendering and virtual reality provides a netural immersive environment for volumetric data visualization.More advanced data exploration operations,such as object level data manipulation,simulation and analysis ,are supported in 3DIVE by several new techniques,In particular,volume primitives and texture regions ae used for the rendering,manipulation,and collision detection of volumetric objects;and the region-based rendering pipeline is integrated with 3D image filters to provide an image-based mechanism for interactive transfer function design.The system has been recently released as public domain software for CAVE/ImmersaDesk users,and is currently being actively used by various scientific and biomedical visualization projects.     

A survey of visualization systems for network security

Security Visualization is a very young term. It expresses the idea that common visualization techniques have been designed for use cases that are not supportive of security-related data, demanding novel techniques fine tuned for the purpose of thorough analysis. Significant amount of work has been published in this area, but little work has been done to study this emerging visualization discipline. We offer a comprehensive review of network security visualization and provide a taxonomy in the form of five use-case classes encompassing nearly all recent works in this area. We outline the incorporated visualization techniques and data sources and provide an informative table to display our findings. From the analysis of these systems, we examine issues and concerns regarding network security visualization and provide guidelines and directions for future researchers and visual system developers.     

Llun—a high‐level debugger for generated parsers

Parser generators such as yacc have been used in a large number of applications, not just those that involve compiler writing. This has meant that these tools are being used increasingly by nonspecialist developers. A consequence of this is that good support is required for debugging a grammar and its generated parser(s). This paper describes Llun, a debugging tool that visualizes the operation of a generated parser at both a high‐level and a low‐level. Llun is superior to other parser visualization products by virtue of the high‐level facilities it offers. The paper describes some of the problems encountered using parser generators, outlines a visualization system which addresses a number of the problems and uses a taxonomy developed by Price to categorize the system. Copyright © 2001 John Wiley & Sons, Ltd.     

Generating Color Palettes using Intuitive Parameters

Color is widely used in data visualization to show data values. The proper selection of colors is critical to convey information correctly. In this paper, we present a technique for generating univariate lightness ordered palettes. These are specified via intuitive input parameters that are used define the appearance of the palette: number of colors, hue, lightness, saturation, contrast and hue range. The settings of the parameters are used to generate curves through CIELUV color space. This color space is used in order to correctly translate the requirements in terms of perceptual properties to a set of colors. The presented palette generation method enables users to specify palettes that have these perceptual properties, such as perceived order, equal perceived distance and equal importance. The technique has been integrated in Magna View, a system for multivariate data visualization.     

GPU-based interactive cut-surface extraction from high-order finite element fields

We present a GPU-based ray-tracing system for the accurate and interactive visualization of cut-surfaces through 3D simulations of physical processes created from spectral/hp high-order finite element methods. When used by the numerical analyst to debug the solver, the ability for the imagery to precisely reflect the data is critical. In practice, the investigator interactively selects from a palette of visualization tools to construct a scene that can answer a query of the data. This is effective as long as the implicit contract of image quality between the individual and the visualization system is upheld. OpenGL rendering of scientific visualizations has worked remarkably well for exploratory visualization for most solver results. This is due to the consistency between the use of first-order representations in the simulation and the linear assumptions inherent in OpenGL (planar fragments and color-space interpolation). Unfortunately, the contract is broken when the solver discretization is of higher-order. There have been attempts to mitigate this through the use of spatial adaptation and/or texture mapping. These methods do a better job of approximating what the imagery should be but are not exact and tend to be view-dependent. This paper introduces new rendering mechanisms that specifically deal with the kinds of native data generated by high-order finite element solvers. The exploratory visualization tools are reassessed and cast in this system with the focus on image accuracy. This is accomplished in a GPU setting to ensure interactivity.     

A Survey of Radial Methods for Information Visualization

Radial visualization, or the practice of displaying data in a circular or elliptical pattern, is an increasingly common technique in information visualization research. In spite of its prevalence, little work has been done to study this visualization paradigm as a methodology in its own right. We provide a historical review of radial visualization, tracing it to its roots in centuries-old statistical graphics. We then identify the types of problem domains to which modern radial visualization techniques have been applied. A taxonomy for radial visualization is proposed in the form of seven design patterns encompassing nearly all recent works in this area. From an analysis of these patterns, we distill a series of design considerations that system builders can use to create new visualizations that address aspects of the design space that have not yet been explored. It is hoped that our taxonomy will provide a framework for facilitating discourse among researchers and stimulate the development of additional theories and systems involving radial visualization as a distinct design metaphor.     

Provenance and annotation for visual exploration systems

Exploring data using visualization systems has been shown to be an extremely powerful technique. However, one of the challenges with such systems is an inability to completely support the knowledge discovery process. More than simply looking at data, users will make a semipermanent record of their visualizations by printing out a hard copy. Subsequently, users will mark and annotate these static representations, either for dissemination purposes or to augment their personal memory of what was witnessed. In this paper, we present a model for recording the history of user explorations in visualization environments, augmented with the capability for users to annotate their explorations. A prototype system is used to demonstrate how this provenance information can be recalled and shared. The prototype system generates interactive visualizations of the provenance data using a spatio-temporal technique. Beyond the technical details of our model and prototype, results from a controlled experiment that explores how different history mechanisms impact problem solving in visualization environments are presented     

Using hypermedia in computer-aided instruction

The previous article in this issue (see ibid., 1996) described the Discover distributed interactive visualization system, which has been running at National Cheng-Kung University Hospital since 1993. Shortly after Discover was implemented, we observed that physicians were having trouble understanding and navigating through Discover processes for image analysis and generation. To address this problem, we developed a computer aided instruction mechanism based on hypermedia technology-multimedia with hypertext navigation. Hints (Hypermedia Information Network System) is built around the concept of hypercontrol-the use of a multimedia document to control hardware or software systems. It is currently being used with Discover at the university hospital. Physicians use this hypermedia network system to learn the processes of the discover visualization system and to help them standardize the way they examine images     

Methods and framework for visualizing higher-order finite elements

The finite element method is an important, widely used numerical technique for solving partial differential equations. This technique utilizes basis functions for approximating the geometry and the variation of the solution field over finite regions, or elements, of the domain. These basis functions are generally formed by combinations of polynomials. In the past, the polynomial order of the basis has been low-typically of linear and quadratic order. However, in recent years so-called p and hp methods have been developed, which may elevate the order of the basis to arbitrary levels with the aim of accelerating the convergence of the numerical solution. The increasing complexity of numerical basis functions poses a significant challenge to visualization systems. In the past, such systems have been loosely coupled to simulation packages, exchanging data via file transfer, and internally reimplementing the basis functions in order to perform interpolation and implement visualization algorithms. However, as the basis functions become more complex and, in some cases, proprietary in nature, it becomes increasingly difficult if not impossible to reimplement them within the visualization system. Further, most visualization systems typically process linear primitives, in part to take advantage of graphics hardware and, in part, due to the inherent simplicity of the resulting algorithms. Thus, visualization of higher-order finite elements requires tessellating the basis to produce data compatible with existing visualization systems. In this paper, we describe adaptive methods that automatically tessellate complex finite element basis functions using a flexible and extensible software framework. These methods employ a recursive, edge-based subdivision algorithm driven by a set of error metrics including geometric error, solution error, and error in image space. Further, we describe advanced pretessellation techniques that guarantees capture of the critical points of the polynomial basis. The framework has been designed using the adaptor design pattern, meaning that the visualization system need not reimplement basis functions, rather it communicates with the simulation package via simple programmatic queries. We demonstrate our method on several examples, and have implemented the framework in the open-source visualization system VTK.     

Echarts在数据可视化课程中的应用

数据可视化作为一种数据展示和分析的工具已广泛应用各个领域。文章根据数据可视化课程的特点,有机结合了Echarts的基本功能、参数配置以及实现手段等内容,并把这些内容通过分阶段有效地运用到课堂教学的各个环节中。在课堂教学中展示了数据可视化的实现过程。文章表明了,通过一系列的训练,学生掌握了运用数据可视化工具的方法,同时学生的综合应用能力也得到了很大的提升。     

基于四叉树的多分辨率地形数据3维可视化

大场景的3维地形可视化模型是地理信息系统平台的重要组成部分。但至今大场景的3维地形数据可视化仍存在数据处理速度慢,显示滞后的问题,针对此问题提出了一种基于四叉树的多分辨率地形数据3维可视化算法,即首先以规则网格为基本处理单元,采用链式四叉树数据结构存储多分辨率地形数据;然后在此基础上,设计了动态LOD算法完成四叉树的高效遍历。在该算法中,采用了视景裁剪、三角扇形和内存池等优化显示技术,用以支持大场景3维地形数据的实时显示,并已在Windows平台上,用VC 6.0开发了大场景地形数据3维可视化演示软件。     

基于ArcGISEngine的电力规划数据可视化管理系统研究

设计并实现了插入式电力规划数据可视化管理系统,系统采用插入应用程序框架,并结合ArcGISEngine进行开发实现。数据录入采用主从表数据录人模式,融合了GIS的通用功能,建立图形工作站,实现数据的图形可视化管理;对数据引入双重关联验证机制保证空间和属性数据的一致性,而数据检验运用基于关联规则的校验方法,确保录入数据的准确性。运用该系统完成了对全国电力规划数据的收集整理,并且已经运用到全国电力规划系统中。     

基于MQTT协议的分布式泵站物联网系统设计

为了解决自来水供水系统中分散的增压泵站运行状态的远程统一监控和数据可视化难题,设计了基于消息队列遥测传输(MQTT)协议的分布式泵站远程监测物联网(IoT)系统。系统子站点以ARM单片机为核心,实时采集现场各种传感器数据和设备运行状态(如压力、温度、变频器状态等参数),并采用PID算法自动调节变频泵运行参数,以实现恒压供水。子站点的触摸屏作为本地数据可视化和组态窗口。子站点通过4G无线传输模块和云平台进行数据通信,云平台采用B/S架构设计,方便维保人员远程通过计算机或手机等移动设备查看泵站运行状态,同时可以通过云端预留的API接口无缝接入其他智慧水务平台。该系统已经某自来水公司投入实际运行。从现场运行情况来看,该系统运行稳定、可靠,已经消除了多起设备故障隐患,极大地提升了泵站运维效率。该系统具有实施简单、便捷、成本低、可复制性高等特点,在智慧城市、智慧水务中具有广阔的应用前景。     

制导武器半实物仿真的可视化系统设计

可视化系统是某制导武器半实物仿真系统的重要组成部分,对制导武器的研制与评估具有重要意义.针对半实物仿真实时产生数据的特点,分析了组成该系统的各功能模块,提出了利用多线程技术和基于TCP/IP网络的双机仿真结构来实现数据驱动的设计方法,这两种设计方法将解决半实物仿真实时性要求与数据可视化系统占用计算机资源之间的矛盾,节省系统资源.在Windows平台下以MFC和OpenGL实现了该制导武器的二维飞行参数变化曲线显示和的三维视景显示,其中详细介绍了两种数据驱动方式的实现方法,及三维视景显示的实现技术.该可视化系统具有图像逼真,信息准确,实时性好的特点,已成功应用于某制导武器的半实物仿真.     

Selective refinement queries for volume visualization of unstructured tetrahedral meshes

We address the problem of the efficient visualization of large irregular volume data sets by exploiting a multiresolution model based on tetrahedral meshes. Multiresolution models, also called Level-Of-Detail (LOD) models, allow encoding the whole data set at a virtually continuous range of different resolutions. We have identified a set of queries for extracting meshes at variable resolution from a multiresolution model, based on field values, domain location, or opacity of the transfer function. Such queries allow trading off between resolution and speed in visualization. We define a new compact data structure for encoding a multiresolution tetrahedral mesh built through edge collapses to support selective refinement efficiently and show that such a structure has a storage cost from 3 to 5.5 times lower than standard data structures used for tetrahedral meshes. The data structures and variable resolution queries have been implemented together with state-of-the art visualization techniques in a system for the interactive visualization of three-dimensional scalar fields defined on tetrahedral meshes. Experimental results show that selective refinement queries can support interactive visualization of large data sets.     

ViStA: a visualization system for exploring Arabic text

Text visualization has become a significant tool that facilitates knowledge discovery and insightful presentation of large amounts of data. This paper presents a visualization system for exploring Arabic text called ViStA. We report about the design, the implementation and some of the experiments we conducted on the system. The development of such tools assists Arabic language analysts to effectively explore, understand, and discover interesting knowledge hidden in text data. We used statistical techniques from the field of Information Retrieval to identify the relevant documents coupled with sophisticated natural language processing (NLP) tools to process the text. For text visualization, the system used a hybrid approach combining latent semantic indexing for feature selection and multidimensional scaling for dimensionality reduction. Initial results confirm the viability of using this approach to tackle the problem of Arabic text visualization and other Arabic NLP applications.     

Logichart — Intelligible Program Diagram for Prolog and its Processing System

An intelligible program diagram called Logichart has been developed for Prolog visualization. Its syntax rules and layout rules are formalized in terms of an attribute graph grammar. This grammar is underlain by a context–free graph grammar whose productions are defined to formalize the graph–syntax rules of Logichart diagrams. Semantic rules attached to the productions are defined in such a way that they can extract the layout information needed to display a Logichart diagram as attributes. Our Prolog visualization system, which has been implemented based on the attribute graph grammar, can draw a Logichart diagram for any correct Prolog program (completeness), and any Logichart diagram displayed by the system is always valid for the grammar (soundness). The system can also display the execution of a Prolog program in real time; that is, the Logichart diagram is dynamically updated as the program runs.