基于X3D的网络虚拟实验系统的研究

提出了基于X3D的网络虚拟实验系统设计方案,该方案采用B/S结构、3DMAX建模、X3D及Java编程,并以虚拟示波器为例,给出了虚拟实验系统中关键技术的设计实现方案。实验证明,该系统满足虚拟现实的沉浸性和交互性要求,并且通过对XML文件的压缩,提高了系统的实时性。     

单片机虚拟实验系统构建的研究

通过分析传统单片机教学中遇到的问题,提出了建立单片机虚拟实验系统的方案,该方案主要配置为PRO-TEUS KEIL/WAVE,文章通过一个具体实例揭示该虚拟实验系统开发流程。最后给总结该虚拟实验系统应用于科研和教学所带来的益处,其特别适合于远程网络教学。     

虚拟实验技术在微机接口实验中的应用研究

本文根据虚拟实验的特点,针对现有的几种虚拟实验技术在微机原理与接口技术课程中的优缺点,提出一种基于虚拟器件的WEB虚拟实验方案用于该课程的实验教学。     

数字逻辑虚拟实验系统的研究与设计

建立虚拟实验系统是非常有意义的，它是对现代多媒体教学和远程教育的重要补充。在对计算机虚拟实验系统的研究与设计中，电子仪器的软件仿真和虚拟电子实验平台的实现是关键。本文对高校数字电路与逻辑设计(数字逻辑)课程的虚拟实验系统进行了分析与设计，并给出了数字逻辑虚拟实验系统的实现方案。该方案已成功应用于实际系统中。     

基于WEB和原型技术的混合虚拟网络工程实验体系的实现

在研究传统虚拟网络工程实验体系的基础上,提出基于WEB和原型技术的混合虚拟网络工程实验体系,阐述其硬件架构方案、软件体系结构和实现技术。     

移动通信虚拟仿真实验课程建设和实践

为了改进传统《移动通信》实验课程中存在一些实验不具备或难以完成的教学功能,拓展学生的创新思维,引入虚拟仿真技术建设改革《移动通信》实验课程是十分必要的.本文提出了LTE移动通信系统四个实验建设的方案和内容,强调了利用虚拟仿真技术进行实验课程建设的意义.实践结果表明,采用该建设方案的虚拟仿真实验课程取得了良好的教学效果,...     

远程虚拟实验的构建

给出远程虚拟实验的技术原理与实现方法，按照基于虚拟原型的虚拟实验的一般原理，提出概率统计原理的虚拟实验方法以实现方案，基于Java语言，设计了一个远程虚拟实验系统并给出了几个实验实例。     

远程教育中虚拟实验与虚拟仪器及技术的运用与前景

本文介绍虚拟实验与虚拟仪器技术的发展和应用前景,并探讨了将虚拟实验与虚拟仪器技术、仿真技术和网络技术结合,开展更具有交互性和可操作性的计算机模拟仿真实验和小组远程协作实验的前景,探讨虚拟实验在学校教学、科研和实验中的运用及前景,为远程教育的实验教学提供一种新的可行的方案。     

虚拟实验指导系统的交互设计研究

本文通过对虚拟实验的概念、特点及虚拟实验学习者、虚拟实验指导系统进行分析,在产品界面交互设计基本原则的基础上,提出了虚拟实验指导系统应当遵循的两个原则。在此基础上以开放式实验教学与实验室管理系统的虚拟实验指导系统为例,分析了该指导系统的优缺点及改进方案。     

电路远程虚拟实验室的设计与应用

讨论了基于LabVIEW的电路远程虚拟实验室的设计与应用,提出了实现原理及构成方案,设计了硬件系统和软件系统,并利用设计好的电路虚拟实验室进行实验,结果证明此电路远程虚拟实验室具有良好的实验效果。     

Comparing effects of 2-D and 3-D visual cues during aurally aided target acquisition

The aim of the present study was to investigate interactions between vision and audition during a visual target acquisition task performed in a virtual environment. In two experiments, participants were required to perform an acquisition task guided by auditory and/or visual cues. In both experiments the auditory cues were constructed using virtual 3-D sound techniques based on nonindividualized head-related transfer functions. In Experiment 1 the visual cue was constructed in the form of a continuously updated 2-D arrow. In Experiment 2 the visual cue was a nonstereoscopic, perspective-based 3-D arrow. The results suggested that virtual spatial auditory cues reduced acquisition time but were not as effective as the virtual visual cues. Experiencing the 3-D perspective-based arrow rather than the 2-D arrow produced a faster acquisition time not only in the visually aided conditions but also when the auditory cues were presented in isolation. Suggested novel applications include providing 3-D nonstereoscopic, perspective-based visual information on radar displays, which may lead to a better integration with spatial virtual auditory information.     

2-D frictionless dynamic contact analysis of large deformable bodies by Petrov–Galerkin natural element method

This paper presents a Petrov–Galerkin natural element method for the nonlinear analysis of 2-D dynamic contact problems without friction. The frictionless dynamic contact problem is formulated according to the linearized total Lagrangian method incorporated with the linearized penalty method. The displacement increment is approximated with Laplace interpolation functions defined with the help of Voronoi polygons, while the admissible virtual displacement is expanded with constant strain functions which are supported on Delaunay triangles. The spatial numerical integration is carried out by applying the conventional Gauss quadrature rule to Delaunay triangles and the temporal time integration is performed by the implicit Newmark method. The validity of the proposed method is examined through the illustrating numerical experiments.     

Shared understanding for collaborative control

This paper presents results from three experiments in which human operators were teamed with a mixed-initiative robot control system to accomplish various indoor search and exploration tasks. By assessing human workload and error together with overall performance, these experiments provide an objective means to contrast different modes of robot autonomy and to evaluate both the usability of the interface and the effectiveness of autonomous robot behavior. The first experiment compares the performance achieved when the robot takes initiative to support human driving with the opposite case when the human takes initiative to support autonomous robot driving. The utility of robot autonomy is shown through achievement of better performance when the robot is in the driver's seat. The second experiment introduces a virtual three-dimensional (3-D) map representation that supports collaborative understanding of the task and environment. When used in place of video, the 3-D map reduced operator workload and navigational error. By lowering bandwidth requirements, use of the virtual 3-D interface enables long-range, nonline-of-sight communication. Results from the third experiment extend the findings of experiment 1 by showing that collaborative control can increase performance and reduce error even when the complexity of the environment is increased and workload is distributed amongst multiple operators.     

一种圆柱形全景图生成新算法及其实现

利用基于图象的绘制(IBR)技术来建立具有真实感的虚拟环境是当前计算机图形学研究领域中的一项热门课题，也是虚拟现实技术中的关键技术。它以简单的图象合成代替基于三维几何的建模和渲染，加快了画面的显示速度，是建立特定三维场景的一种高效率的方法。基于这种方法，我们提出了一种生成圆柱形全景图的新算法，它通过快速查找
相邻两幅图象的匹配区域而实现图象的无缝拼接，建立圆柱形全景图。本算法计算速度快，效率高，能生成逼真的全景图。文章的最后给出了基于这种算法生成的部分全景图图实例。     

Performance of a skilled motor task in virtual and real environments

Three experiments compared the performances of adult participants (three groups of 10) on a perceptuo-motor task in both real world (RW) and virtual environments (VEs). The task involved passing a hoop over a bent wire course, and three versions of the task were used: a 3-D wire course with no background, a flattened version of the 3-D course (2½-D course) with no background, and the 2½-D course with added background to provide spatial context. In all three experiments the participants had to prevent the hoop from touching the wire as they moved it. In the first experiment, the VE condition produced about 18 times more errors than the RW task. The VE 2½-D task was found to be as difficult as the 3-D, and the 2½-D with the added background produced more errors than the other two experiments. Taken together, the experiments demonstrate the difficulty of performing fine motor tasks in VEs, a phenomenon that has not been given due attention in many previous studies of motor control in VEs.     

基于开源场景图形的三维可视化与信息管理系统设计

对于产品虚拟装配的三维呈现过程中难以实现零件信息管理问题,结合电动车模型的拆装,提出三维可视化与信息管理技术融为一体的设计方案。首先,建立三维模型库,并根据电动车模型的拓扑结构和辅助信息,如零件的材质、型号等,建立信息库;其次,读取信息库中零件与子装配体间的父子关系信息建立目录树,根据子装配体与场景树均为“多叉树”组成结构的原理进行子装配体的三维呈现,再对子装配体的各个节点设置动画完成拆装呈现;最后,采用多线程方法将电动车配件信息管理与可视化有机结合,实现支持三维的拾取交互查询和检索定位查询等功能。系统以世纪鸟电动车进行验证,实现了三维可视化技术与信息系统相融合,能快速有效地为电动车的三维呈现和虚拟装配提供技术支持。实例验证表明,所设计系统可以有效地将零件的信息管理融入到虚拟装配的三维可视化中。     

一种三维燃烧和爆炸特殊效果的建模和管理方法

在现代虚拟现实应用中,为使三维虚拟环境更为逼真,各种虚拟环境下的三维特殊效果的表现是必不可少的,如风、雨、雪、雾等自然现象效果,爆炸、燃烧等由虚拟环境中的用户和环境间的交互产生的特殊效果。文章描述了爆炸、燃烧特殊效果的一种基于BillBoarding技术的简洁高效的建模方法,并经过分析,抽象出了此类由交互产生的特殊效果的共同特征,提出了一种对此类特殊效果统一进行存储和管理的方式,这种方式便于特殊效果在三维绘制引擎中的使用,并具有良好的扩展性。     

DLSLA 3-D SAR imaging algorithm for off-grid targets based on pseudo-polar formatting and atomic norm minimization基于伪极坐标变换和原子范数最小化的网格偏离目标DLSLA 3-D SAR成像方法

This paper concerns the imaging problem for downward looking sparse linear array three-dimensional synthetic aperture radar (DLSLA 3-D SAR) under the circumstance of sparse and non-uniform cross-track dimensional virtual phase centers configuration. Since the 3-D imaging scene behaves typical sparsity in a certain domain, sparse recovery approaches hold the potential to achieve a better reconstruction performance. However, most of the existing compressive sensing (CS) algorithms assume the scatterers located on the pre-discretized grids, which is often violated by the off-grid effect. By contrast, atomic norm minimization (ANM) deals with sparse recovery problem directly on continuous space instead of discrete grids. This paper firstly analyzes the off-grid effect in DLSLA 3-D SAR sparse image reconstruction, and then introduces an imaging method applied to off-gird targets reconstruction which combines 3-D pseudo-polar formatting algorithm (pseudo-PFA) with ANM. With the proposed method, wave propagation and along-track image reconstruction are operated with pseudo-PFA, then the cross-track reconstruction is implemented with semidefinite programming (SDP) based on the ANM model. The proposed method holds the advantage of avoiding the off-grid effect and managing to locate the off-grid targets to accurate locations in different imaging scenes. The performance of the proposed method is verified and evaluated by the 3-D image reconstruction of different scenes, i.e., point targets and distributed scene.     

Performance of a skilled motor task in virtual and real environments

Three experiments compared the performances of adult participants (three groups of 10) on a perceptuo-motor task in both real world (RW) and virtual environments (VEs). The task involved passing a hoop over a bent wire course, and three versions of the task were used: a 3-D wire course with no background, a flattened version of the 3-D course (2(1/2)-D course) with no background, and the 2(1/2)-D course with added background to provide spatial context. In all three experiments the participants had to prevent the hoop from touching the wire as they moved it. In the first experiment, the VE condition produced about 18 times more errors than the RW task. The VE 2(1/2)-D task was found to be as difficult as the 3-D, and the 2(1/2)-D with the added background produced more errors than the other two experiments. Taken together, the experiments demonstrate the difficulty of performing fine motor tasks in VEs, a phenomenon that has not been given due attention in many previous studies of motor control in VEs.     

三维动画技术与三维虚拟技术的研究

目前三维图形技术主要包括两大类：三维动画技术和三维虚拟技术。该文的目的是研究两种技术的开发原理，并通过对两种技术的对比，进一步说明了三维虚拟仿真技术在实时性、交互性方面的优势。该文首先介绍了三维动画技术的应用原理、开发步骤，重点阐述了三维虚拟技术中的实时显示技术和交互技术，给出了虚拟仿真应用的开发方法及基于两种技术的应用实例，并对两种技术在实时性、交互性、时间性和三维建模效果等方面作了比较，最后展望三维虚拟技术的发展方向。