科学计算可视化映射研究及智能映射

映射是可视化过程中最关键的一步。本文探讨了当前的可视化软件工具在映射阶段存在的问题，介绍了可视化智能映射的研究现状，同时提出了自动映射、半自动映射、基于实例的推理等三种智能映射的理论模型。     

基于半监督聚元自组织映射的齿轮早期故障检测

自组织特征映射应用于齿轮早期故障检测时,常常导致训练时间长、检测精度低、故障分类结果不直观等问题.提出了基于LDA(线性判别分析)与半监督聚元自组织映射的故障检测方法,首先利用LDA对故障特征集进行降维处理,然后再利用半监督聚元自组织网络对降维后的特征子集进行分类并将结果可视化,Iris数据集的仿真结果验证了该方法的有...     

基于异构网格耦合的产品多物理场有限元数据集成与可视化仿真

在产品虚拟样机多物理场的性能分析和仿真过程中,由于分析目的和分析工具各不相同,各种物理场的有限元网格模型和仿真结果数据都是异构的。如何将异构有限元网格模型的几何和物理信息进行耦合,集成到虚拟环境中进行网格图形显示与结果数据可视化仿真是亟待解决的问题。提出产品多物理场异构有限元网格的几何特征映射与仿真结果插值方法,分别提取各异构网格模型的拓扑信息,建立过渡网格模型,根据空间相对位置将各异构网格节点与过渡网格模型节点进行耦合映射,实现异构网格模型物理属性到几何特征的映射。开发基于异构网格耦合的机械产品虚拟样机多物理场可视化仿真系统。     

基于OSG的风场三维数据可视化研究

为了研究三维流场数据的可视化方法,本文应用fluent软件对三维流体模型进行网格划分、网格数据求解分析,然后基于OpenSenceGraph（简称OSG）图形系统在C＋＋平台上,对分析的三维流场网格数据进行科学存储、可视化映射、绘制,完成可视化的后处理,最终实现了三维流场数据的可视化。本文应用了矢量线的方法,并在实际风场三维数据上也得到了验证,研究对三维流场特征等有效信息的获取及可视化实际应用有着重要的意义。     

功能梯度材料打印路径体素化的信息融合方法研究

目前，功能梯度材料模型的构建方法尚未成熟，仍需要建立一种新的算法，将功能梯度材料的材料组分信息附加到路径规划中，以实现材料空间到几何空间的映射。以Visual Studio 2019为开发平台，利用OpenGL进行可视化分析；将打印路径体素化，对材料组分进行设计与计算，并映射至几何坐标中，构建出有连续梯度变化的目标模型；生成具有几何信息和材料信息的新型G代码，并用于功能梯度材料精准3D打印。结果表明：利用路径体素化的方法，可以精准控制材料模型的梯度变化。     

基于粒子系统与纹理映射的空气分离可视化模拟

空气分离工艺流程复杂,导致流体在机械装备内的流动难以模拟与表达。为实现空气分离系统吸附、换热与精馏等工艺过程的可视化,提出了一种基于粒子流源与纹理映射的空气分离可视化模拟方法：采用关键帧间坐标系递推变换,描述运动部件位置及运动的变化;采用自定义粒子流源,模拟流体的传热传质属性;采用多尺度纹理映射,描述流体的流动迹线。开发了基于虚拟现实技术的可视化系统,实现了空气分离的性能模拟与可视化。     

基于模糊自组织映射网络聚类的案例库维护

针对CBR系统案例库的冗余问题,提出了一个基于自组织映射网络(Self-Organizing Map,SOM)聚类技术的案例库维护方法,首先利用自组织映射网络的可视化特性显示输入数据的大致分布,预估聚类个数,然后利用模糊自组织映射聚类算法对案例库案例进行聚类,最后在聚类基础上构建准案例库。并将该方法应用于水平定向钻产品的案例库维护,结果表明,准案例库规模比原案例库小,同时可以代表原案例库,达到案例库维护目的。     

基于深度学习的智能电表数据挖掘分析与研究

人口的指数增长和电子电气设备的使用增加了对能源生产管理的需求。从而使得更加需要精确的能源管理系统，可以预测消费者的使用，以供未来的政策制定。提出了一种基于集群算法的用电功耗水平预测技术，用于智能传感器数据的分析。提出的框架基于深度自动编码器和自适应组织映射。安装在电表和家电上的智能传感器可以有效地分析能源使用情况，根据居民的能源消费水平来生产和分配电力。提出的能耗分析集群算法，将消费者用电量划分为不同层次。提出的深度自动编码器将低维能耗数据输入自适应组织映射集群算法。然后，对集群算法得到的数据进行统计分析，确定电能消耗水平。最后，将结果可视化到图形中，并在城市地图上绘制出能源消耗的预测水平，为能源利用分析提供了一个有效的解决方法。     

面向工艺规划重用的复杂曲面精加工知识图谱构建及可视化研究

针对复杂曲面精加工中普遍存在的工艺规划效率低、以往的加工实例数据难以有效重用的问题,构建了复杂曲面精加工工艺规划知识图谱。以UG软件中的CAM模块和相关知识为背景,首先进行类、对象属性和数据属性三方面的抽象,完成知识图谱模式层的交互式构建,其次按照模式层需要将复杂曲面精加工实例数据存入关系型数据库,然后运用R2RML语言映射工具Ontop调用数据库中的加工实例数据与预设模式层映射,构建出完整的复杂曲面精加工知识图谱,最终实现基于图数据库Neo4j的数据存储及可视化展示。该研究成果可用于知识图谱的精加工工艺规划及智能问答。     

基于自组织映射的齿轮箱状态监测可视化研究

提出了一种自组织映射网络训练结果的可视化方法——距离映射法,该方法通过计算出竞争层神经元权矢量与输入模式的相似度,并综合考虑神经元的网格分布,把输入矢量降维映射到二维平面。结合该方法研究了自组织映射网络在齿轮箱故障识别和状态监测中的应用。与U－矩阵法相比,该方法能更加清楚地将齿轮正常、裂纹和断齿状态的特征数据映射到二维平面的不同区域,将齿轮箱状态聚类分开,特征数据在平面上的映像点轨迹变化趋势直观反映了齿轮箱工作状态的变化,便于及时监测识别出齿轮的早期故障及其变化趋势。     

Three-dimensional microscopy data exploration by interactive volume visualization

This paper presents a new volume visualization approach for three-dimensional (3-D) interactive microscopy data exploration. Because of their unique image characteristics, 3-D microscopy data are often not able to be visualized effectively by conventional volume visualization techniques. In our approach, microscopy visualization is carried out in an interactive data exploration environment, based on a combination of interactive volume rendering techniques and image-based transfer function design methods. Interactive volume rendering is achieved by using two-dimensional (2-D) texture mapping in a Shear-Warp volume rendering algorithm. Image processing techniques are employed and integrated into the rendering pipeline for the definition and searching of appropriate transfer functions that best reflect the user's visualization intentions. These techniques have been implemented successfully in a prototype visualization system on low-end and middle-range SGI desktop workstations. Since only 2-D texture mapping is required, the system can also be easily ported to PC platforms.     

Three‐dimensional microscopy data exploration by interactive volume visualization

This paper presents a new volume visualization approach for three‐dimensional (3‐D) interactive microscopy data exploration. Because of their unique image characteristics, 3‐D microscopy data are often not able to be visualized effectively by conventional volume visualization techniques. In our approach, microscopy visualization is carried out in an interactive data exploration environment, based on a combination of interactive volume rendering techniques and image‐based transfer function design methods. Interactive volume rendering is achieved by using two‐dimensional (2‐D) texture mapping in a Shear‐Warp volume rendering algorithm. Image processing techniques are employed and integrated into the rendering pipeline for the definition and searching of appropriate transfer functions that best reflect the user's visualization intentions. These techniques have been implemented successfully in a prototype visualization system on low‐end and middle‐range SGI desktop workstations. Since only 2‐D texture mapping is required, the system can also be easily ported to PC platforms.     

海量STL文件的快速读取与显示

STL文件作为一种通用的三维数据文件格式,广泛应用于快速成型及其他领域。如何快速读取海量数据的STL文件并显示,是模型后续操作的一个首要环节。本文针对海量数据的特点,采用内存映射手段、基于哈希表结构的冗余顶点删除和OpenGL中显示列表技术等,对海量STL文件的快速读取和显示进行了研究,并和国外先进软件进行了比较,实验数据表明本文方法较Surfacer软件和Rap idForm软件提高效率25%~40%左右。     

逆向工程中离散曲率估算及其可视化的实现

采用Meyer离散曲率估算方法估算了三角网格模型的顶点曲率;在此基础上,通过图像处理中的直方图均衡化算法对曲率值进行处理,并用颜色索引表建立了曲率和颜色间的映射关系,以曲率的可视化来清晰地反映网格模型的曲率变化,进而验证曲率估算的准确性,突出凹凸特征显示;为逆向工程中的数据分割、特征识别以及模型优化等提供技术保证。     

RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY

Assembly sketch is not only the visualization of abstract function, but also the template of detail design. Two kinds of information are needed to create assembly sketch: structure and assembly constraint. Most researches are aimed at how to obtain structures from function, but the problem of how to obtain assembly constraint from function is ignored. Following the definition of assembly unit and the classification of function, a hierarchical mapping method from function to assembly constraint is put forward, and the mapping method includes two steps. The first step is the mapping from function to assembly semantics which is assembly expression and accordant with engineer's design habit. The second one is the mapping from assembly semantics to basic assembly constraints that are convenient for computer to handle. The mapping method is applied to DDMS (design, drafting and management system) successfully.     

Hyperspectral data influenced by sample matrix: the importance of building relevant reference spectral libraries to map materials of interest

Hyperspectral imaging (HSI) and mapping are increasingly used for visualization and identification of nanoparticles (NPs) in a variety of matrices, including aqueous suspensions and biological samples. Reference spectral libraries (RSLs) contain hyperspectral data collected from materials of known composition and are used to detect the known materials in experimental samples through a one‐to‐one pixel “mapping” process. In some HSI studies, RSLs created from raw NPs were used to map NPs in experimental samples in a different matrix; for example, RSLs created from NPs in suspension to map NPs in biological tissue. Others have utilized RSLs created from NPs in the same matrix. However, few studies have systematically compared hyperspectral data as a function of the matrix in which the NPs are found and its impact on mapping results. The objective of this study is to compare RSLs created from metal oxide NPs in aqueous suspensions to RSLs created from the same NPs in rat tissues following in vivo inhalation exposure, and to investigate the differences in mapping that result from the use of each RSL. Results demonstrate that the spectral profiles of these NPs are matrix dependent: RSLs created from NPs in positive control tissues mapped to experimental tissues more appropriately than RSLs created from NPs in suspension. Aqueous suspension RSLs mapped 0‐602 out of 500,424 pixels per tissue image while tissue RSLs mapped 689‐18,435 pixels for the same images. This study underscores the need for appropriate positive controls for the creation of RSLs for mapping NPs in experimental samples.     

基于符号演变的运动方案建模

针对目前计算机辅助设计系统对机械运动方案设计支持能力不足的问题,提出了运动功能-机构映射-机构组合的层次运动方案设计模型。运动功能层利用功能符号实现了运动方案设计过程和复杂机构运动关系的抽象表达,机构映射层通过运动功能到机构和运动关系到机构组合关系两个映射过程实现了功能符号到机构简图符号以及机构简图符号到机构装配符号的演化,机构组合层通过机构装配符号组合实现了运动方案设计结果的可视化。     

Representation of scanning probe images in virtual reality

The visualization of the data obtained with scanning probe microscopes can be improved by the use of virtual reality software which has recently become available commercially. One such software program was applied to images obtained with an atomic force microscope. The mapping capabilities of this new visualization technique as well as the images were quite striking when viewed in virtual reality.