一种基于手绘草图的三维建模方法研究

研究一种基于手绘草图进行三维建模的方法。将用户界面分为手势区、轮廓区、控制区、信息提示区等。根据手势区输入的手势以及控制区输入的控制信息,对轮廓区输入的二维信息构建三维模型。采用模板匹配的方法识别用户手势,采用容差环的方法识别用户输入的物体轮廓,根据生成的三维数据之间的分层信息构建物体表面三角网格,对物体进行三维建模。     

支持概念设计的特征手势建模

给出了特征手势的概念并且建立了特征手势库，描述了基于特征手势的建模过程；进一步讨论了特征手势内部的约束建立和求解算法以及上下文感知技术，通过与传统建模和交互方式的对比，验证了特征手势建模的方便性．文中算法以用户为中心，给出了自然简便的设计工具，改善了人机交互方式．     

虚拟现实的建模技术

本文介绍了虚拟现实建模所涉及的一些基本概念、基本技术和开发工具，包括几何建模、运动建模、物理建模、对象特征、模型分割，以及ＯｐｅｎＩｎｖｅｎｔｏｒ和ＶＲＭＬ语言等建模工具。     

一种基于剖分与聚类的三维手势建模方法

针对有些建模方法需要设置复杂参数,或所建模型不够平滑、完整,以及出现多余网格等问题,提出了一种基于Delaunay三角剖分与K-Means聚类的三维手势静态建模方法。首先对点云进行半径滤波,再把点云投影在X0Y平面上,然后进行Delaunay三角剖分,对于剖分得到的三角网格中的长边与短边,使用K-Means算法聚为两类,最后删除含有长边的三角面片,得到完整手势的三维模型。实验结果表明,该方法有利于减少多余的网格面,形成的三维手势模型的网格面也较为平滑、完整。     

基于UML的CAPP系统建模与开发

简要介绍了利用UML语言进行CAPP系统的建模与开发，介绍了UML语言的基础知识、采用UML进行软件开发的过程以及一个CAPP系统建模实例，最后给出了UML模型与IDEF模型的比较。     

基于多尺度形状描述子的手势识别

随着计算机性能的提高和人机交互技术的发展,手势识别越来越受到人们的重视,尤其是基于视觉通道的手势识别,使人机交互变得更加便捷。但由于人手是复杂形变体,现有的方法对运动过程中手的形变的描述不够充分。该文从视觉角度提出了一种新的手势建模的方法-多尺度形状描述子。从分析手的基本形状入手,利用了圆形的轴对称和中心对称的几何特点,具有旋转和尺度不变性。该描述子从多个尺度对手势进行形状描述,在一定程度上解决了手势的精细区分问题。     

一种可描述系统功能的OO建模方法

本文介绍一种可描述系统的数据，行为，组织以及功能四种观战的建模技术，该建模技术保留原来ＯＯ建模技术的优点，具有更丰富的语义和更强的描述能力。     

OPNE7在罩事通信网络建模与仿真中的应用研究

在通信系统领域，出现了许多强大的商用建模仿真工具。本文主要探讨OPNET在现代军事通信网络建模与仿真申的应用，介绍了OPNET的主要特点和一般建模方法，讨论了军事通信网络建模仿真的主要发展趋势以及OPNE了提供的相应支持，最後得出结论：由于OPNET强大的表示和分析能力，以及其特有的灵活性与开放性，将其作为军事通信网络的核心仿真引擎是很合适的。     

连续动态手势的时空表观建模及识别

论述了复杂背景下连接动态手势的分割、建模及识别;融合手势运动信息和皮肤颜色信息,进行复杂背景下的手势分割;通过结合手势的时序信息、运动表观以及形状表观,提出动态手势的时空表观模型,并提出基于颜色、运动以及形状等多模式信息的分层次融合策略抽取时空表观模型的参数,最后,提出动态时空规整算法用于手势识别,实验表明,利用上述提出的手势分割、建模、特征参数抽取及识别方法识别１２种手势,平均识别率高达９７％。     

海运物流自动订舱系统的EFSM建模与实现

自动订舱系统是一类控制条件复杂的状态变化自动处理系统，精确的系统建模是系统成功的关键，文中首先介绍了海运物流自动订舱系统的特征及相关建模技术，提出了一种扩展有限状态机（EFSM）的建模方法，分析了该建模技术的方法，图素，语义以及模型到算法的一种映射关系。最后利用这种形式化建模技术实现了海运物流自动定舱系统，给出的系统建模和实现方法可以运用到各类电子化申请／答复的的系统设计中。     

基于用例的领域业务服务本体建模

业务服务本体的作用是规范化描述领域业务活动及其之间关系,形成领域业务的基本知识体系。如何让涉众参与本体的设计,是目前联合本体工程研究的热点问题。通过将概念建模时常用的用例图与迭代式本体构建方法相结合,一方面使用领域本体建立规范的业务模型,另一方面基于用例,从用户视角优化本体模型。该建模方法有助于对领域业务的全面理解,所得到的本体模型可满足不同涉众需求。     

Global Correspondence Optimization for Non‐Rigid Registration of Depth Scans

We present a registration algorithm for pairs of deforming and partial range scans that addresses the challenges of non‐rigid registration within a single non‐linear optimization. Our algorithm simultaneously solves for correspondences between points on source and target scans, confidence weights that measure the reliability of each correspondence and identify non‐overlapping areas, and a warping field that brings the source scan into alignment with the target geometry. The optimization maximizes the region of overlap and the spatial coherence of the deformation while minimizing registration error. All optimization parameters are chosen automatically; hand‐tuning is not necessary. Our method is not restricted to part‐in‐whole matching, but addresses the general problem of partial matching, and requires no explicit prior correspondences or feature points. We evaluate the performance and robustness of our method using scan data acquired by a structured light scanner and compare our method with existing non‐rigid registration algorithms.     

Digital Twin Enhanced Dynamic Job-Shop Scheduling

For dynamic scheduling, which is daily decision-making in a job-shop, machine availability prediction, disturbance detection and performance evaluation are always common bottlenecks. Previous research efforts on addressing the bottlenecks primarily emphasize on the analysis of data from the physical job-shop, but with little connection and convergence with its virtual models and simulated data. By introducing digital twin (DT), further convergence between physical and virtual spaces of the job-shop can be achieved, which greatly enables dynamic scheduling. DT fuses both real and simulated data to provide more information for the prediction of machine availability on one hand; and on the other hand, it helps to detect disturbances through comparing the physical machine with its continuously updated digital counterpart in real time, triggering timely rescheduling when needed. It also enables comprehensive performance evaluation for rescheduling using multiple-dimension models, which can describe geometric properties, physics parameters and behaviors of the machines. In the paper, a five-dimension DT for a machine in the job-shop is introduced first, then the DT-based machine availability prediction, disturbance detection and performance evaluation methods are explored. Based on this, a DT-enhanced dynamic scheduling methodology is proposed. A scheduling process of making hydraulic valves in a machining job-shop is taken as a case study to illustrate the effectiveness and advantages of the proposed method.     

Building a right digital twin with model engineering

In recent years, the concept of digital twin (DT) is attracting more and more attention from researchers and engineers. But there is still no consensus on what a right DT is. On one hand, some common models are renamed as DTs. On the other hand, some DTs extremely pursue ‘the same’ as physical objects, which bring unnecessary complexities to them. In this paper, we try to answer two questions from the point of view of model engineering: how to define a right digital twin, and how to build a right digital twin. The concept and related technologies of model engineering are introduced. Some basic principles and a set of metrics for a right DT are given. An evolutionary concurrent modeling method for DT (ECoM4DT) is proposed not only inheriting the theory from classic M&S methods but also highlighting the characteristics of DT compared with traditional models to systemically guide the DT modeling process.     

Free radical polymerization in multilaminated microreactors: 2D and 3D multiphysics CFD modeling

This paper investigates the modeling of styrene free radical polymerization in two different types of microreactor. A multiphysics model which simultaneously takes into account the hydrodynamics, thermal and mass transfer (convection, diffusion and chemical reaction) is proposed. The set of partial differential equations resulting from the model is solved with the help of the finite elements method either in a 2D or a 3D approach. The different modeled microreactors are on one hand an interdigital multilamination microreactor with a large focusing section, and on the other hand a simple T-junction followed by a straight tube with three different radii. The results are expressed in terms of reactor temperature, polydispersity index, number-average degree of polymerization and monomer conversion for different values of the chemical species diffusion coefficient. It was found that the 2D approach gives the same results as the 3D approach but allows to dramatically reduce the computing time. Despite the heat released by the polymerization reaction, it was found that the thermal transfer in such microfluidic devices is high enough to ensure isothermal conditions. Concerning the polydispersity index, the range of diffusion coefficients over which the polydispersity index can be maintained close to the theoretical value for ideal conditions increases as the tube reactor radius decreases. The interdigital multilamination microreactor was found to act as a tubular reactor of 0.78 mm ID but with a shorter length. This underlines that the use of microfluidic devices can lead to a better control of polymerization reactions.     

基于UML的实验设备管理信息系统的分析和设计

该系统通过实现网上记录设备的详细信息及其维修、购买和报废的相关数据等功能,解决高校实验设备信息不能进行网上管理．而只能靠手工对设备信息进行维护的不便。系统的开发采用面向对象思想方法,并基于UML对该系统进行建模分析。     

Coupling climate and hydrological models: Interoperability through Web Services

Understanding regional-scale water resource systems requires understanding coupled hydrologic and climate interactions. The traditional approach in the hydrologic sciences and engineering fields has been to either treat the atmosphere as a forcing condition on the hydrologic model, or to adopt a specific hydrologic model design in order to be interoperable with a climate model. We propose here a different approach that follows a service-oriented architecture and uses standard interfaces and tools: the Earth System Modeling Framework (ESMF) from the weather and climate community and the Open Modeling Interface (OpenMI) from the hydrologic community. A novel technical challenge of this work is that the climate model runs on a high performance computer and the hydrologic model runs on a personal computer. In order to complete a two-way coupling, issues with security and job scheduling had to be overcome. The resulting application demonstrates interoperability across disciplinary boundaries and has the potential to address emerging questions about climate impacts on local water resource systems. The approach also has the potential to be adapted for other climate impacts applications that involve different communities, multiple frameworks, and models running on different computing platforms. We present along with the results of our coupled modeling system a scaling analysis that indicates how the system will behave as geographic extents and model resolutions are changed to address regional-scale water resources management problems.     

The long way toward multivariate predictive control of flotation processes

Flotation processes are very complex, and after more than one hundred years of history, there are few reports on applications of novel techniques in monitoring and control of flotation units, circuits and global plants. On the other hand, the successful application of multivariate predictive control on other processes is well known. In this paper, an analysis on how the characteristics of flotation processes, the quality of measurements of key variables, and the general lack of realistic dynamic models, are delaying the appropriate use of predictive control. In this context, the applications of multivariate statistics, such as PCA, to model the relationship between operating data for on-line diagnosis and fault detection and to build causal models are discussed. Also the use of PLS models to predict target variables for control purposes, is presented. Results, obtained at pilot and industrial scales, are discussed, introducing new ideas on how to obtain more valuable information from the usual available operating data of the plant, and particularly from froth images.     

Interactive Modeling of City Layouts using Layers of Procedural Content

In this paper, we present new solutions for the interactive modeling of city layouts that combine the power of procedural modeling with the flexibility of manual modeling. Procedural modeling enables us to quickly generate large city layouts, while manual modeling allows us to hand‐craft every aspect of a city. We introduce transformation and merging operators for both topology preserving and topology changing transformations based on graph cuts. In combination with a layering system, this allows intuitive manipulation of urban layouts using operations such as drag and drop, translation, rotation etc. In contrast to previous work, these operations always generate valid, i.e., intersection‐free layouts. Furthermore, we introduce anchored assignments to make sure that modifications are persistent even if the whole urban layout is regenerated.