关于一类扩压器的几何建模技术研究

为开展管式扩压器设计技术的初步研究，本章中，通过对管式扩压器的三维几何造型进行程序化设计来发展管式扩压器的几何建模技术。造型的关键技术包括管道中心线的设计，管道截面形状的设计，管间相贯前缘的生成，以及所有管道在空间的排布设计。通过一系列设计参数与调控参数可以按不同的要求设计不同样式的管式扩压器，以满足与离心叶轮相匹配的不同管式扩压器的结构。     

基于满意度函数的新型逃生管道多目标稳健性设计

新型逃生管道参数具有不确定性且单目标优化存在局限性，为了实现新型逃生管道多目标稳健性设计，结合田口稳健性设计方法与满意度函数，提出了一种基于满意度函数的多目标稳健性设计方法。该方法将产品质量特性的信噪比转换为具有田口稳健性设计的望大特性的满意度，然后通过加权几何均值实现结构的多目标稳健性设计。通过使用Hypermesh和LS-DYNA建立新型逃生管道的有限元模型，并对该有限元模型进行验证，然后运用所提出的方法对新型逃生管道进行多目标稳健性设计。结果表明，稳健性设计后新型逃生管道的信噪比提升了5.3%，说明管道抵抗噪声因子的干扰能力增强，结构更稳健；新型逃生管道质量降低了9.6%，实现了管道轻量化的目的。研究结果对提高新型逃生管道的稳健性具有一定的理论和工程意义。     

基于三维数字技术的建筑给排水消防管道安装

BIM技术通过对建筑信息的参数化整合与三维可视化模型应用,使得三维模型技术在建筑领域展现出区别于传统建筑设计方法的独特优势.本文主要阐述了三维技术在建筑给排水工程及消防管道设计中的参数化应用以及管线综合优化设计,总结了三维技术在消防管道安装中的应用技术优势.     

三维激光扫描技术在管道维抢修作业中的应用

该文在对大口径长输管道换管维抢修作业技术深入分析的基础上,引入了三维激光扫描技术,并设计开发了激光点云扫描管道换管参数计算软件。利用三维激光扫描仪对管道进行数据采集,通过计算软件对数据进行分析、筛选和计算,得出管道测量、下料尺寸信息以及管端椭圆、偏移等信息,不但解决了人工测量计算精度低、效率慢的问题,而且还为焊口组对提供了更多的信息,实现了管道换管维抢修作业测量计算的自动化、数字化。经过1 016 mm管道测试平台的验证,其测量精度和效率均满足现场作业测量计算的需求。     

水电站引水管道系统的三维重构

利用引水发电系统的平面布置与纵剖面CAD图,探讨了如何从平面图形中提取所隐含的三维信息.提出了图形分层、分色处理的基本思想与处理方法,包括对管道中心线及管道断面图层的命名规定、管道中心线交替颜色设置等.详细阐述了管道的编码规则、断面数据获取方法,以及经数据匹配生成三维构造所需几何与拓扑信息的基本原理.在KerenCAD图形系统中实现了水电站引水管道的三维重构.     

BIM技术在综合医院医疗气体专项深化设计建模排布中的应用

本文通过建立综合医院的三维模型，利用BIM软件进行设计建模，可以有效优化医疗气体系统的设计和排布，提高施工效率和设备运行安全性。详细介绍了BIM技术在医疗气体系统设计中的应用流程和关键要素，包括气体管道网络走向确定、设备选型与安装以及管道连接方式的确定等，可为综合医院医疗气体系统的设计提供科学、高效的方法和技术支持。     

空分冷箱内管路配置新技术的应用

介绍了低温配管在工艺上所要注意的问题,着重强调低温管道应仔细进行应力分析。最后阐述了传统应力分析存在的不足,并详细分析了应用计算机软件实现空分设备配管三维设计的优点。图2。     

弧形管道的制作与安装技术

为了改进传统管道的安装方式,解决空间浪费,接缝过多不美观等问题,越来越多的建筑采用造型新颖的弧形结构设计形式,增加管道与建筑结构形式的匹配度。本文以东直门地区某一公建项目为例,借助BIM技术进行深化设计,建立高精度三维模型,形成管道预制加工数据及材料清单,实现模型指导工厂预制,高效精准完成弧形管道安装,可为类似工程提供借鉴参考。     

三维工厂设计在大型制氧工程中的应用

在首钢京唐钢2套75000m3/h空分设备工程的工厂设计中开发并应用了三维工厂设计软件,有效提高了设计的精准度和深度,达到了节约投资、提高设计效率的目的。文章介绍了利用三维工厂设计软件在气体压缩系统、分子筛纯化系统管路以及板翅式换热器冷箱外管道设计中的应用效果,以及对分子筛纯化系统、氮气增压机出口进行应力分析的结果和管道ISO图。     

PDMS配管数据库的建立以及在冷箱外围管道中的运用

PDMS是国内外常用的管道设计软件,其拥有独立数据库,可提供真实的1∶1彩色模型,还原工厂设计中的各个方面,在冷箱内配管已运用得十分成熟。随着空分设备的大型化发展,PDMS在冷箱外围管道配管中的应用也越来越广泛。结合国内常用标准,建立适应本土化的PDMS数据库,以更好地实现国内项目冷箱外配管的准确性与高效性。介绍PDMS在配管设计中的优点、数据库的建立、三维建模的内容和输出功能等。     

磁力泵（釜）中轴承材料的选择

介绍了磁力泵（釜）中用于不同工况条件下轴承材料的选择，介绍了轴承的设计要点。     

复杂环境下35 m高砖烟囱定向爆破拆除

在倒塌场地非常狭小的条件下,采用定向爆破的的方法成功地拆除了1座35 m高的砖烟囱。主要介绍了烟囱爆破的设计和施工要点,通过开设定向窗及采取防护措施,确保爆破定向准确及周边建筑物、设施的安全。     

基于颜色矩的改进尺度不变特征变换的移动机器人定位算法

针对基于图像外观的移动机器人定位中图像特征提取与匹配实时性和准确性差的问题,提出基于颜色矩的改进尺度不变特征变换分级图像匹配算法。该算法先由颜色矩来排序图像序列,再由改进尺度不变特征变换特征与排序后图像序列精确匹配实现定位。其中,改进的尺度不变特征变换算法以基于采样的迭代搜索算法检测极值点,由Sobel算子计算特征点的梯度方向和幅值,提高尺度不变特征变换算法速度及匹配精度。实验结果表明:改进的尺度不变特征变换算法降低误匹配率约9.2%,特征提取与匹配耗时减少约25.8%;分级图像匹配算法减少尺度不变特征变换特征计算代价约70%,减少总体耗时约43.3%。     

Automatic diagnosis of diabetic retinopathy with the aid of adaptive average filtering with optimized deep convolutional neural network

The most effective treatment for diabetic retinopathy (DR) is the early detection through regular screening, which is critical for a better prognosis. Automatic screening of the images would assist the physicians in diagnosing the condition of patients easily and accurately. This condition searches out for special importance of image processing technology in the way of processing the retinal fundus images. Accordingly, this article plans to develop an automatic DR detection model with the aid of three main stages like (a) image preprocessing, (b) blood vessel segmentation, and (c) classification. The preprocessing phase includes two steps: conversion of RGB to Lab, and contrast enhancement. The Histogram equalization process is done using the contrast enhancement of an image. To the next of preprocessing, the segmentation phase starts with a valuable procedure. It includes (a), thresholding the contrast-enhanced and filtered images, (b) thresholding the keypoints of contrast-enhanced and filtered images, and (c) adding both thresholded binary images. Here, the filtering process is performed by proposed adaptive average filtering, where the filter coefficients are tuned or optimized by an improved meta-heuristic algorithm called fitness probability-based CSO (FP-CSO). Finally, the classification part uses Deep CNN, where the improvement is exploited on the convolutional layer, which is optimized by the same improved FP-CSO. Since the conventional CSO depends on a fitness probability in the improved algorithm, the proposed algorithm termed as FP-CSO. Finally, valuable comparative and performance analysis has confirmed the effectiveness of the proposed model.     

线图解释研究综述

介绍了计算机解释线图研究的意义和问题。从线图定性分析和线图定量分析两个方面详细阐述了计算机解释线图的研究概况。线图的定性分析包括线图标记、面识别和不完整线图的完整；线图的定量分析按求解方法分成线性系统方法、优化方法、梯度空间方法、图元方法、模糊方法等。提出了计算机解释线图研究需要解决一些问题。     

地铁引起古建筑物振动三维数值分析

以南昌市八一广场地铁旁的一个古建筑物为研究对象,通过建立包含4孔隧道的轨道-隧道-大地-建筑物三维有限元模型,进行模态分析和瞬态动力学分析。计算1、2号线单独运行及1、2号线同时运行三种情况下的建筑物振动。结果表明：埋深较浅的2号线对建筑物振动影响较大;只有当1号线和2号线同时运行时,建筑物振动才会超过限值,但超标量不大;随楼层上升,建筑物水平振动呈减小趋势,但在顶层却有最大值。     

Two-dimensional line defects in anisotropic elastic solids

The Stroh formalism and analytic continuation approach are used to develop a systematic study for two-dimensional line defects in anisotropic elastic solids. The line defects are classified as either belonging to the craze type or line inhomogeneity type. A crack and rigid line are considered as two special cases of these categories. The governing equations, given in terms of the Stroh matrix notation, show many complementary features between these two line defects. In addition, a discussion is given showing why the line defect field cannot in general be developed from the Eshelby inclusion solution [1], except for the special cases of a crack and rigid line inhomogeneity.     

The effect of breakdowns on U-shaped production lines

Consider a synchronized line performing assembly or fabrication tasks. Tasks are grouped into stations and stations are positioned on a line that is U-shaped. Stations may break down and be repaired. Small buffer inventories may be placed between stations to lessen the effect of breakdowns at one station on production at other stations. This paper investigates the effect of the U-shape of the line on the line effectiveness. We find that effectiveness increases when the line is U-shaped, compared with the traditional straight line shape.     

Numerical simulations of dynamic interfacial crack growth allowing for crack growth away from the bond line

Dynamic crack growth is analyzed numerically for a plane strain bimaterial block with an initial central crack subject to impact tensile loading. The material on each side of the bond line is characterized by an isotropic hyperelastic constitutive relation. Potential surfaces of decohesion are interspersed in the material on either side of the bond line and along the bond line. The cohesive surface constitutive relation allows for the creation of new tree surface and dimensional considerations introduce a characteristic length into the formulation. Full transient analyses are carried out. The resistance to crack initiation, the crack speed history and the crack path are predicted without invoking any ad hoc failure criterion. Three calculations are carried out for a PMMA/Al bimaterial. The imposed loading and the properties of the adjacent materials are kept fixed, while the bond line strength is taken to be 1/4, 1/2, and 3/4 of the strength of PMMA. The nominal crack speed decreases with increasing bond line strength. When the bond line strength is 1/4 that of PMMA, the crack remains on the bond line although there is an attempt at branching off the bond line. For the intermediate case, a bond line strength 1/2 that of PMMA, repeated branching of the main crack off the bond line into the PMMA occurs, together with micro-crack nucleation on the bond line. The crack branches off the bond line into the PMMA when its strength is 3/4 that of PMMA, with the main direction of growth being parallel to the bond line, but with the crack progressively drifting further into the PMMA.