数字化变电站信息流的智能分析与可视化

数字化变电站技术使用工业以太网技术代替传统二次接线传递数字和模拟信号,使得原有相互解耦、具象的二次接线被相互高度耦合、抽象的网络数据流所替代,给运行、调度、检修等相关专业带来了严峻的挑战.针对该问题,提出了一种数字化变电站信息流智能分析与可视化系统构架,将网络数据流以更为直观的图形方式显示给运行和检修人员.研究结果表明...     

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.     

Hadamard编码红外光谱成像系统设计

在空间调制型哈达玛变换光谱成像仪(Space Hadamard Transforms Spectral Imager,SHTSI)中采用数字微镜阵列(Digital Mirror Devices,DMD)作为编码器件,能够使系统实现小型化、轻量化、高分辨率、高帧频成像.但由于DMD的翻转特性,经过DMD编码后的光学成像...     

XML-based assembly visualization for a multi-CAD digital mock-up system

Using a virtual assembly tool, engineers are able to design accurate and interference free parts without making physical mock-ups. Instead of a single CAD source, several CAD systems are used to design a complex product in a distributed design environment. In this paper, a multi-CAD assembly method is proposed through an XML and the lightweight CAD file. XML data contains a hierarchy of the multi-CAD assembly. The lightweight CAD file produced from various CAD files through the ACIS kemel and InterOp includes not only mesh and B-Rep data, but also topological data. It is used to visualize CAD data and to verify dimensions of the parts. The developed system is executed on desktop computers. It does not require commercial CAD systems to visualize 3D assembly data. Multi-CAD models have been assembled to verify the effectiveness of the developed DMU system on the Internet.     

气阀对压缩机容积流量的影响

以实例说明气阀对压缩机容积流量存在影响，并分析了气阀对压缩机容积流量产生影响的原因。指出当气阀总的有效通流面积过小，气阀弹簧力严重不匹配时，会导致压缩机的容积流量下降幅度较大。压缩机气阀设计或改造时，应保证气阀有足够的总的有效通流面积及合适的弹簧力。     

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.     

超声彩色血流成像中基于动态区域划分抑制杂波的方法

为提高超声彩色血流成像质量,提出了一种基于动态区域划分的杂波抑制方法。先根据超声回波信号的幅度对血流与组织区域作出初步的划分,再根据杂波运动的非平稳性对组织区域作进一步的调整,最后对各区域用特征向量滤波器进行杂波抑制。将本方法用于计算机仿真血流信号和人体实测血流数据,结果表明:本方法在有效抑制非平稳杂波的同时,能较好地保持血流流速剖面的完整性,解决了传统均匀分段特征向量滤波器选取区间长度时的矛盾,有望成为超声彩色血流成像中一种有效的杂波抑制方法。     

Intact corneal stroma visualization of GFP mouse revealed by multiphoton imaging

The aim of this work is to demonstrate that multiphoton microscopy is a preferred technique to investigate intact cornea structure without slicing and staining. At the micron resolution, multiphoton imaging can provide both large morphological features and detailed structure of epithelium, corneal collagen fibril bundles and keratocytes. A large area multiphoton cross-section across an intact eye excised from a GFP mouse was obtained by a homebuilt multiphoton microscope. The broadband multiphoton fluorescence (435-700 nm) and second harmonic generation (SHG, 360-400 nm) signals were generated by the 760 nm output of a femtosecond titanium-sapphire laser. A water immersion objective (Fluor, 40X, NA 0.8; Nikon) was used to facilitate imaging the curve ocular surface. The multiphoton image over entire cornea provides morphological information of epithelial cells, keratocytes, and global collagen orientation. Specifically, our planar, large area multiphoton image reveals a concentric pattern of the stroma collagen, indicative of the laminar collagen organization throughout the stroma. In addition, the green fluorescence protein (GFP) labeling contributed to fluorescence contrast of cellular area and facilitated visualizing of inactive keratocytes. Our results show that multiphoton imaging of GFP labeled mouse cornea manifests both morphological significance and structural details. The second harmonic generation imaging reveals the collagen orientation, while the multiphoton fluorescence imaging indicates morphology and distribution of cells in cornea. Our results support that multiphoton microscopy is an appropriate technology for further in vivo investigation and diagnosis of cornea.     

数显便携式测色仪设计

为了使牙齿健康美容领域中牙齿的配色更加精确,设计出一款以色度学原理为基础,应用白平衡调节手段,采用集成数字化电路及掌上结构设计的牙齿测色仪器。设备以正白光高亮LED为光源、mega128单片机为核心,采用TCS230可编程颜色传感器采集颜色信号,通过C语言编程来实现颜色数据的采集、显示以及存储。通过比色卡对比实验,分析了几种影响测量精确度的因素。仪器具有测量精度高、稳定度好、功耗低、便于携带等优点,具有广泛的应用前景及市场空间。     

Surface profile estimation by digital filtering for wear volume calculation

A new technique has been suggested for estimating the profile of an original unworn surface. Using digital filtering the profile signals from the profilometer are divided into two types: waviness—low frequency signals and roughness—high frequency signals. The original profile of a wear track was estimated by combining the waviness and the roughness taken from the surface before the wear test. The results of the study show that this technique results in an accurate estimate of the original profile.     

LDV measurement,flow visualization and numerical analysis of flow distribution in a close-coupled catalytic converter

Results from an experimental study of flow distribution in a close-coupled catalytic converter (CCC) are presented. The experiments were carried out with a flow measurement system specially designed for this study under steady and transient flow conditions. A pitot tube was a tool for measuring flow distribution at the exit of the first monolith. The flow distribution of the CCC was also measured by LDV system and flow visualization. Results from numerical analysis are also presented. Experimental results showed that the flow uniformity index decreases as flow Reynolds number increases. In steady flow conditions, the flow through each exhaust pipe made some flow concentrations on a specific region of the CCC inlet. The transient test results showed that the flow through each exhaust pipe in the engine firing order, interacted with each other to ensure that the flow distribution was uniform. The results of numerical analysis were quali-tatively accepted with experimental results. They supported and helped explain the flow in the entry region of CCC.     

基于数字孪生的数控设备互联互通及可视化

全球制造业正在向着智能化、规模化的方向快速发展,但是数控设备之间存在数据接口不统一、设备数据交互困难、现场设备状态监测成本较高等难题.现提出一种基于数字孪生的数控设备互联互通及可视化技术,首先利用三维激光扫描技术构建车间数控设备数字孪生模型,通过OPCUA通讯构架读取数控设备的实时运行数据,并转化格式后存入数据库作为指...     

A neural network to correct mass flow errors caused by two-phase flow in a digital coriolis mass flowmeter

Coriolis mass flow meters provide accurate measurement of single-phase flows, typically to 0.2%. However gas–liquid two-phase flow regimes may cause severe operating difficulties as well as measurement errors in these flow meters. As part of the Sensor Validation (SEVA) research at Oxford University a new fully digital coriolis transmitter has been developed which can operate with highly aerated fluids. This paper describes how a neural network has been used to correct the mass flow measurement for two-phase flow effects, based entirely on internally observed parameters, keeping errors to within 2%. The correction strategy has been successfully implemented on-line in the coriolis transmitter. As required by the SEVA philosophy, the quality of the corrected measurement is indicated by the on-line uncertainty provided with each measurement value.     

体三维成像的螺旋扫描系统设计

提出了一种可产生稳定、均匀的投影空间,并由伺服电机驱动阶梯轴,带动屏旋转的双螺旋屏扫描系统,以实现体三维实时、高清晰成像。对比分析了扫描屏结构的成像特点,设计了屏结构的加工方案。采用半透明高强度的光敏树脂材料和缕空支撑墙体快速成型直接制造。通过Solidworks软件进行螺旋扫描屏的三维建模,并利用COSMOSWorks模块进行稳定运行的可行性分析。仿真结果显示,屏在600r/min恒速旋转时产生的最大位移数据为0.013mm,远小于人眼视觉可分辨的范围,可以满足成像空间设计需求。最后,结合现有的工程技术与工艺水平,建立了双螺旋屏扫描系统的物理平台。实验结果表明,该螺旋屏扫描系统形成的25cm×Ф50cm的柱型成像空间,可以呈现出清晰的体三维图像。     

Detection and color correction of artifacts in digital images

A problem of automated retouching of point artifacts in the pre-press process is considered. A new algorithm of detection and localization of multiple point flares is proposed. The algorithm is based on using the so-called conjugate indicator. A scheme for constructing learning rules for tuning the system for different types of artifacts is developed. An example illustrating the proposed algorithm performance on a real image is given.     

一种基于颜色分量的数字水印嵌入方法

本文提出了一种在彩色图像中嵌入水印的新方法,该算法利用Chebyshev映射生成一个随机序列,利用该随机序列对二值水印图像进行加密调制,最后利用人类视觉系统的特点选择图像的某一颜色分量信息将水印嵌入到原始图像中去.仿真试验结果表明,实现的水印具有较好不可见性,而且对于常见的噪声、裁剪、JPEG压缩具有较好的健壮性.     

体绘制技术在剂量三维可视化中的应用

本文基于光线投射方法的体绘制三维可视化用技术,在光线投射采样过程中,对阻光度分别基于CT值自动分类和手动自定义分类,基于感兴趣区进行自定义分类,对颜色值分量分别基于剂量值进行自动分类,基于处方剂量进行自定义分类.这些分类方式及不同组合,使医生可以根据临床需要对阻光度及颜色进行定义,从而使得剂量分布可以基于需要进行三维可视化显示,从而使医生能更直观地判断相关组织的剂量分布情况.此外,由于基于光线投射理论的体绘制技术无需构造中间几何图元,使得基于患者CT图像体数据的三维可视化细节更加清晰.     

海洋无隔水管修井的数字孪生框架与可视化交互

为保障海洋无隔水管修井作业安全,构建了修井数字孪生系统.设计了海洋修井数字孪生系统五维模型框架,包括修井系统物理实体、虚拟实体、虚实数据交互、人工智能数据分析、作业决策服务.通过SolidWorks构建三维模型,将其导入U nity 3D来建立场景,构建修井系统的虚拟实体,利用虚拟现实技术提升交互性;基于OPC UA协...     

磁光成像使亚表面缺陷探测可视化的研究

根据间歇式脉冲激励电涡流,以及法拉第磁光效应使反射光的偏振面发生偏转的原理,提出了一种磁光／涡流显微成像技术,目标是实现对亚表面细小缺陷的可视化无损检测。介绍了基本原理和新型传感器的设计,并通过实验与传统涡流传感器进行了比较。     

Pre-compression volume on flow ripple reduction of a piston pump

Axial piston pump with pre-compression volume（PCV） has lower flow ripple in large scale of operating condition than the traditional one. However, there is lack of precise simulation model of the axial piston pump with PCV, so the parameters of PCV are difticult to be determined. A finite element simulation model for piston pump with PCV is built by considering the piston movement, the fluid characteristic（including fluid compressibility and viscosity） and the leakage flow rate. Then a test of the pump flow ripple called the secondary source method is implemented to validate the simulation model. Thirdly, by comparing results among the simulation results, test results and results from other publications at the same operating condition, the simulation model is validated and used in optimizing the axial piston pump with PCV. According to the pump flow ripples obtained by the simulation model with different PCV parameters, the flow ripple is the smallest when the PCV angle is 13~, the PCV volume is 1.3 ~ I0-4 m3 at such operating condition that the pump suction pressure is 2 MPa, the pump delivery pressure 15 MPa, the pump speed 1 000 r/min, the swash plate angle 13~. At the same time, the flow ripple can be reduced when the pump suction pressure is 2 MPa, the pump delivery pressure is 5 MPa,15 MPa, 22 MPa, pump speed is 400 r/min, 1 000 r/rain, 1 500 r/rain, the swash plate angle is ll~, 13~, 15~ and 17~, respectively. The finite element simulation model proposed provides a method for optimizing the PCV structure and guiding for designing a quieter axial piston pump.