In-situ three-dimensional visualization of dynamic tension deformation in ferrite stainless steels

An improved three-dimensional （3-D） experimental visualization methodology is presented tor evaluating the fracture mechanisms of ferritic stainless steels by in-situ tensile testing with an environmental scanning electron microscope （ESEM）. The samples were machined with a radial notched shape and a sloped surface. Both planar surface deformation and sloping surface deformation-induced microvoids were observed during dynamic tension experiments, where a greater amount of information could be obtained from the sloping surface. The results showed that microvoids formed at the grain boundaries of highly elongated large grains. The microvoids nucleated in the severely deformed regions grew nearly parallel to the tensile axis, predominantly along the grain boundaries. The microvoids nucleated at the interface of particles and the matrix did not propagate due to the high plasticity of the matrix. The large microvoids propagated and showed a zigzag shape along the grain boundaries,seemingly a consequence of the fracture of the slip bands caused by dislocation pile-ups. The final failure took place due to the reduction of the load-beating area.

Visualization analysis of the capability of weapon system of systems for multi-dimensional indicators

In the field of weapon system of systems (WSOS) simulation, various indicators are widely used to describe the capability of WSOS, but it is always difficult to describe the comprehensive capability of WSOS quickly and intuitively by visualization of multi-dimensional indicators. A method of machine learning and visualization is proposed, which can display and analyze the capabilities of different WSOS in a two-dimensional plane. The analysis and comparison of the comprehensive capability of different components of WSOS is realized by the method, which consists of six parts: multiple simulations, key indicators mining, three spatial distance calculation, fusion project calculation, calculation of individual capability density, and calculation of multiple capability ranges overlay. Binding a simulation experiment, the collaborative analysis of six indicators and 100 possible kinds of red WSOS are achieved. The experimental results show that this method can effectively improve the quality and speed of capabilities analysis, reveal a large number of potential information, and provide a visual support for the qualitative and quantitative analysis model.

Dynamic Terrain Visualization Based on ROAM and OGRE

Terrain Visualization is an important part of visualization systems of battlefield,and the visualization of dynamic terrain is also important for dynamic battle environment.In this paper,special attention has been paid on real-time optimally adapting meshes (ROAM) algorithm,which is a candidate for dynamic terrain,and its mesh representation,mesh continuity algorithm and error metrics are discussed.The DEXTER-ROAM algorithm is discussed and analyzed.By revising the mesh representation of ROAM,a dynamic ROAM algorithm based on partial-regular grid is established.By introducing transition region,mesh discontinuity of dynamic partial-regular grid is resolved.Error metric blocks are removed for computation complexity and culling blocks are introduced to accelerate view frustum culling.The algorithm is implemented in a 3D rendering engine called OGRE.In the end,an example of dynamic crater is given to examine the dynamic ROAM algorithm.

Dynamic Visual Image Modeling Based on Mobile RobotSelf- Organizing Network in Internetof Things Perception Layer

The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular visual system, the real visual images of the object will be obtained. Then through the mobile self-organizing network, a three-dimensional model is rebuilt by synthesizing the returned images. On this basis, we formalize a novel algorithm for multichannel binocular visual three-dimensional images based on fast three-dimensional modeling. Compared with the method based on single binocular visual system, the new algorithm can improve the Integrity and accuracy of the dynamic three-dimensional object modeling. The simulation results show that the new method can effectively accelerate the modeling speed, improve the similarity and not increase the data size.

Researches on Cartographic Database-Based Interactive Three-Dimensional Topographic Map

With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this technological revolution, and the applications of topographic 3D-map are spread rapidly to other relevant fields due to its incomparable advantage. The researches on digital map and the construction of map database offer strong technical support and abundant data source for this new technology, so the research and development of topographic 3D-map will receive greater concern. The basic data of the topographic 3D-map are rooted mainly in digital map and its basic model is derived from digital elevation model (DEM) and 3D-models of other DEM-based geographic features. In view of the potential enormous data and the complexity of geographic features, the dynamic representation of geographic information becomes the focus of the research of topographic 3D-map and also the prerequisite condition of 3D query and analysis. In addition to the equipment of hardware that are restraining, to a certain extent, the 3D representation, the data organization structure of geographic information will be the core problem of research on 3D-map. Level of detail (LOD), space partitioning, dynamic object loading (DOL) and object culling are core technologies of the dynamic 3D representation. The object- selection, attribute-query and model-editing are important functions and interaction tools for users with 3D-maps provided by topographic 3D-map system, all of which are based on the data structure of the 3D-model. This paper discusses the basic theories, concepts and cardinal principles of topographic 3D-map, expounds the basic way to organize the scene hierarchy of topographic 3D-map based on the node mechanism and studies the dynamic representation technologies of topographic 3D-map based on LOD, space partitioning, DOL and object culling. Moreover, such interactive operation functions are explored, in this paper, as spatial query, scene editing and management of topographic 3D-map. Finally, this paper describes briefly the applications of topographic 3D-map in its related fields.

多维动态网络的密钥认证数学建模与仿真

多维动态网络在密钥认证过程中,若加密的密钥安全程度较低,则会被量子计算机解码,使传输的隐私数据出现泄露。为有效提升密钥的安全认证效果,提出量子攻击下多维动态网络密钥认证数学建模方法。方法建立用于多维动态网络的密钥认证模型,在建立的认证模型中,对网络中待传输数据实施冗余清洗,并使用高级加密标准(Advanced Encryption Standard,AES)算法生成密钥对待传输数据初次加密;添加一串噪声数据在加密数据中,并对其二次加密,进一步提升数据的抗量子攻击性能,建立多维动态网络的安全密钥传输模型,完成密钥的安全传输。根据解密方法结合密钥对数据安全解密,完成多维动态网络密钥的安全认证。实验结果表明,利用上述方法开展网络密钥认证时,加解密时间短,认证准确率在85%以上,且抗量子攻击能力强。

基于多维投影时空事件帧的动态视觉传感手势识别

基于视觉的手势识别是虚拟现实、游戏仿真等领域常用的人机交互手段。在实际应用中,手势动作快速变化将导致传统RGB相机或深度相机成像模糊,给手势识别带来巨大挑战。针对上述问题,利用动态视觉传感器捕捉高速手势运动信息,提出一种基于多维投影时空事件帧(spatiotemporal event frame,STEF)的动态视觉数据手势识别方法。将时空信息嵌入到数据投影面融合形成多维投影时空事件帧,克服现有动态视觉信息事件帧表达方法时域信息丢失的局限性,提升动态视觉传感数据的特征表达能力。在此基础上,采用先进的脉冲神经网络对时空事件帧进行分类实现手势识别。在公开数据集上的识别精度达到96.67%,性能优于同类方法,表明该方法可显著提升动态视觉传感数据手势识别准确率。

多维互动在“视觉传达设计”混合教学中的应用效果分析

在“视觉传达设计”教学中,传统的教学模式难以满足学生日益增长的个性化学习需求。文章通过时间、主体、空间及理念4个维度的实践分析,结合“视觉传达设计”课程,探讨多维互动模式的创新应用,促进课程与新媒体技术的有效融合,为培养具有综合实践能力的设计人才提供参考,为提升教学效果提供新的思路和方法。

BioMGE——一个用于采集和分析生物医用材料和多组学数据的数据库

随着机器学习技术的发展,生物医用材料的科学研究也逐渐走向数据驱动,利用生物测序技术来测试生物医用材料的生物功能,需要对生物医用材料进行进一步优化.因此,一个开放、共享的基础设施来存储来自不同研究领域的异构科学数据是多学科交叉联合分析的基石.本文介绍了BioMGE,一个基于灵活的自定义平台NMDMS(国家材料数据管理与服务平台)实现的数据库建设案例,用于收集生物医用材料和多组学测序数据.NMDMS的动态容器框架允许用户定义个性化的数据提交模式,存储来自生物医用材料和多组学研究领域的数据.自2019年以来,BioMGE已收集了1547100个生物医用材料和多组学数据集.BioMGE提供了数据导出接口,方便用户直接导出数据以进行数据分析.以组学数据可视化为例,提供BioMGE-viewer模块以实现对生物染色质结构数据从一维到三维的数据可视化.该数据库可为其他跨领域研究的数据共享提供了新的思路和平台.

基于平行全维动态注意力机制的视觉地点识别方法

针对天气、季节、光线等环境变化导致的视觉地点识别鲁棒性低的问题,提出了一种提升视觉地点识别特征描述子环境稳健性的多维度注意力机制——平行全维动态注意力机制(POD-Attention)。为实现卷积核在全维度上的动态精细探索,增强特征提取网络对建筑物等不变性特征的提取与学习能力,采用全维动态卷积块在卷积核全维度(输入输出通道、卷积空间和卷积核数量)上添加互补性注意力。将1×1卷积、Skip Squeeze-and-Excitation(SSE)模块与全维动态卷积块平行融合,不仅有效提高了特征提取速率,还扩大了视觉地点识别网络的感受野,进一步提升了视觉地点的识别准确率。在公开数据集上进行的实验表明,基于VGG16及Patch-NetVLAD特征聚合的视觉地点识别方法经POD注意力机制改进后,在Nordland与Mapillary Street-Level Sequences数据集上的Recall@1指标提升了9.7%与1.8%,充分证明了本文POD注意力机制对于网络性能的提升效果,也证明了基于本文POD注意力机制的视觉地点识别方法的有效性。

一种特征点权重自适应优化的动态SLAM算法

针对传统的同步定位与地图构建(SLAM)在动态场景中位姿估计准确率低、鲁棒性差的问题,提出一种基于特征点权重自适应优化的动态视觉SLAM算法。首先,利用掩膜区域卷积神经网络(Mask R-CNN)对输入图像进行语义分割并获取动态特征点掩码,在此基础上对静态特征点进行帧间匹配得到位姿变换初值;然后利用运动一致性检测算法和多视图几何算法处理图像并分别得到对应的动态特征点掩码,进而依据得到的3种动态特征点掩码信息构建特征点权重函数,利用最小化重投影误差自适应调整特征点对位姿优化的影响程度,降低场景中的动态目标对SLAM精度的影响;最后使用慕尼黑工业大学动态数据集进行仿真测试,在室内高动态场景中,绝对轨迹误差(ATE)的均方根误差值(RMSE)仅为尺度不变特征变换同步定位与地图构建(ORB-SLAM2)的3.1%。与DS-SLAM、DynaSLAM等动态SLAM系统相比,绝对轨迹误差分别为DS-SLAM的52%、DynaSLAM的86.1%。结果表明,该算法可以显著提高SLAM系统在高动态环境下的定位精度和鲁棒性。

高带宽压电片变形镜的动力学仿真与优化方法研究

为进一步提高压电波前校正器的响应速度和轻量化程度,对面向高动态形状控制的压电片变形镜的动力学仿真与优化方法进行了研究。首先,基于压电片变形镜的参数化有限元模型,提出了高效、高精度的电-力耦合动力学仿真分析方法。然后,通过正交遍历多维设计参数(光学反射镜与压电陶瓷的材料类型、几何尺寸和固定方式等),探究了不同参数对压电片变形镜动态形状控制性能的影响规律。最后,优化得到具有预期响应带宽和驱动位移性能的压电片变形镜设计方案,并通过制备压电片变形镜的原理样件来验证其性能。实验结果表明,所研制的压电片变形镜的固有频率和镜面驱动位移幅值符合预期,验证了所提出的动力学仿真与优化方法的有效性,这可为高带宽压电片变形镜的高效研制提供科学的理论方法。

浮动式反应堆事故多舱室气溶胶扩散泳沉积与三维流动的耦合数值模拟

基于计算流体力学方法对浮动式反应堆破口事故在壁面冷却条件下水蒸气冷凝及壁面冷凝引起的气溶胶扩散泳沉降进行仿真分析,并与静态条件下气溶胶扩散泳沉积对比,发现:所采取的冷凝模型经实验对比能很好地预测水蒸气冷凝;静态条件下气溶胶扩散泳沉积速度与气溶胶粒径几乎无关,与集总参数法的规律一致,此外湍流沉积会使气溶胶衰减因子增大约3×10^(-4)。非均匀流场在冷凝环境下会产生大范围的回转流动。气流曳力会使衰减因子产生量级上的增加,同时曳力作用对于气溶胶粒径不敏感;冷凝使堆舱出现很大的湍流强度,会增强扩散泳的沉积效果,增强效果对小粒径颗粒更明显,使1μm颗粒衰减因子明显大于堆舱中的10μm颗粒衰减因子,最大可达0.035。

三维模型在建筑物不动产登记管理中的应用研究

不动产登记管理是城市管理的重要组成部分,对“智慧城市”的建设有重要意义。随着城市建筑群向着更加立体化和规模化发展,二维不动产登记管理在表达建筑空间和划分不动产权属空间范围等方面已经不能满足不动产登记管理的需求。利用实景三维模型动态单体化技术和基于BIM的房间信息三维可视化技术对不动产中的建筑物进行自然幢、户室单元、房间3级管理,实现了室内外一体化三维不动产场景构建和三维不动产登记管理。

鄱阳湖湿地生态过程3维动态可视化模拟方法

该文以鄱阳湖大湖池为研究区域,采用3维建模、在多源数据融合下的场景搭建技术和动态模拟技术,对湿地复杂的生态过程变化进行3维动态模拟.以3维动态可视化的方法呈现鄱阳湖湿地的植被四季生长演替变化、季节性水位变化和不同水位与植被群落相互作用机制以及候鸟对水位和植被提供生境的响应等生态过程变化.研究结果表明:多源数据的融合是虚拟场景集成的重要基础;采用数据-模型-场景-综合动态模拟的技术为创建动态仿真场景提供有效途径;3维动态模拟技术和可视化效率优化技术结合使用可以直观有效地模拟和呈现湿地生态过程的动态变化.

融合多维注意力机制与动态尺度的数据校核算法

为实现对医疗机构中设备、药品及耗材等数据的智能监控与校核,文中提出了一种基于多维注意力机制的动态尺度数据校核算法。该算法引入了通道注意力和空间注意力两种机制来挖掘出数据的深度特征及空间位置,并将其送入主干网络Transformer中进行准确地数据校核。同时在算法模型中加入了动态尺度,且通过设置阈值来确定是否需要利用潜补偿来缓解不平衡网络。在自建数据集上进行的实验结果表明,所提算法模型的预测精确率可达96%,优于传统模型。证明了该算法的有效性,能够实现对数据的自动校核。

基于MATLAB和Visual C^(++)的风机流场分析的可视化研究

为提高风机可视化仿真系统可维护性和可移植性 ,采用MATLAB编写流场数据图形显示程序 ,并将其转换为动态链接库 ,作为其他程序调用图形显示程序的接口 ,使系统能独立运行。

YOLO-POD:基于多维注意力机制的高精度PCB微小缺陷检测算法

随着电子设备的广泛应用,印刷电路板(Printed Circuit Board,PCB)在电子制造行业中具有重要意义.然而,由于制造过程中的不完美和环境因素的干扰,PCB上可能存在微小的缺陷.因此,开发高效准确的缺陷检测算法对于确保产品质量至关重要.针对PCB微小缺陷检测问题,本文提出了一种基于多维注意力机制的高精度PCB微小缺陷检测算法.为降低网络的模型参数量和计算量,引入部分卷积(Partial Convolution,PConv),将ELAN(Efficient Layer Aggregation Network)模块设计为更加高效的P-ELAN,同时,为增强网络对微小缺陷的特征提取能力,引入多维注意力机制(Multi-Dimensional Attention Mechanism,MDAM)的全维动态卷积(Omni-dimensional Dynamic Convolution,ODConv)并结合部分卷积,设计了POD-CSP(Partial ODconv-Cross Stage Partial)和POD-MP(Partial ODconv-Max Pooling)跨阶段部分网络模块,提出了OD-Neck结构.最后,本文基于(Youo Only Look Once version 7,YOLOv7)提出了对小目标更加高效的YOLO-POD模型,并在训练阶段采用一种新颖的Alpha-SIoU损失函数对网络进行优化.实验结果表明,YOLO-POD的检测精确率和召回率分别达到了98.31%和97.09%,并在多个指标上取得了领先优势,尤其是对于更严格的(mean Average Precision at IoU threshold of 0.75,mAP75)指标,比原始的YOLOv7模型提高28%.验证了YOLO-POD在PCB缺陷检测性能中具有较高的准确性和鲁棒性,满足高精度的检测要求,可为PCB制造行业提供有效的检测解决方案.

基于Visual C＋＋和Pro^＊ C/C＋＋技术的油田动态分析系统设计新方法

针对传统的动态分析系统功能固定用户自由度小的问题,提出了一种改进方法。通过实现对辽河油田提出的动态分析系统的设计,采用了配置文件、多线程技术的观念,结合使用安全数组和Variants数据类型,设计出了一套新式的油藏动态分析的数据库数据管理及数据存取、显示方法。增加了用户的自由度,解决了常规动态分析中功能固定的局限性。

基于多维可视化的表贴式高速永磁电机转子护套设计

护套厚度和过盈量是影响表贴式高速永磁电机转子强度的主要因素。通过分析永磁转子的受力情况,把三维永磁电机转子的强度模型简化为平面应力问题,在极坐标下推导出考虑护套厚度、过盈量及转速影响的碳纤维护套永磁转子应力解析解。将永磁体和转子铁心接触面间的接触压强及碳纤维护套的最大环向应力作为优化目标,以永磁体和护套的应力极限强度为约束条件,选择碳纤维护套厚度以及永磁体与碳纤维护套之间的静态过盈量作为设计变量,通过多维可视化算法计算求解找到满足条件要求的护套厚度及静态过盈量的优解范围。通过有限元法和解析法的计算结果对比来验证转子的应力分布情况。仿真结果表明,所设计的转子护套能够满足高速下永磁体的强度保护要求,能够实现为高速永磁电机转子表面安装碳纤维护套的优化设计。