用户认知驱动的VR自然交互认知负荷研究

针对目前虚拟现实自然交互系统中用户认知负荷难以量化问题,以量化认知负荷为目的,提出一种基于概率神经网络的多通道信息融合模型。首先根据认知理论建立“认知—行为—环境”框架,并在此基础上研究用户认知的数学表征（方法,过程,机理）,构建多通道认知模型;然后将多通道信息融合方法引入虚拟现实自然交互系统,建立一种面向虚拟现实自然交互系统的认知负荷模型;通过VR隧道应急救援系统实验对系统中用户认知进行验证。验证结果表明,具体提出的认知负荷模型具有一定的可行性。     

基于分类挖掘的网格资源分配研究

根据用户访问网格资源的历史信息,采用分类算法对此信息进行挖掘,得出用户使用集群资源的访问规则和模式,在此基础上构造一种基于分类挖掘的资源调度模型、用户调度UA算法以及资源调度CDMRA算法,分别将用户请求调度到各个集群中闲置的CPU资源.实验证明,采用基于分类挖掘的资源分配策略相比其他算法可以减少资源分配过程中对资源的重新分配次数,可以提高网格资源的利用率.     

虚拟环境的用户意图捕获

目的虚拟制造环境中需要复杂精确的3D人机交互。目前的虚拟环境(VE)的主要问题是人在交互过程中的认知和操作负荷太重,交互效率亟需提高。解决此问题的重要途径是提高机器的认知能力。方法本文研究了用户意图的分析和抽取,并建立多通道用户意图理解的算法,以此来提高交互效率。结果结合虚拟装配应用给出了典型意图的实验结果并给予分析。通过实验对多通道意图的可用性和可靠性,以及基于意图系统的实时性进行了评估。实验是虚拟装配空间中用户拾取对象意图的实验。当3维鼠标和对象距离为5 000 mm时,传统系统中操作平均耗时5.344 7 s,而基于意图的系统中平均耗时2.326 6 s。基于意图的系统极大地降低了操作的时间和复杂度。结论采用意图驱动的系统情景转换能在虚拟环境工作中有效地降低人的认知负荷,并能很好地帮助系统开发者进行混成系统的建模和分析,降低开发的复杂度。实践结果表明用户意图理解的多通道模型和算法能极大地提高交互式系统的交互自然性和交互效率。该方法不仅适用于本文所用的虚拟装配系统,对于所有的虚拟环境应用场景都有同样的有效性。     

可视化资源网格化方法

为提高可视化资源的使用效率,提出一种可视化资源网格化方法。研究网格环境下可视化资源共享的体系结构和工作模式以及可视化资源服务化封装方法。可视化服务利用帧缓存捕捉可视化程序运行屏幕并保存为图像文件,通过Web服务器传送至远程的客户端显示。用户通过客户端向可视化服务提出请求,该请求被封装为XML格式文件,包含可视化任务执行所需参数描述信息。以虚拟样机可视化虚拟环境的网格化为例,验证了该方法的有效性。     

Internet资源动态分配的分布计算模型及其系统支撑技术

Internet资源的动态性使得资源分配问题已成为阻碍Internet资源获得充分利用的一大难题.为方便用户进行Internet应用开发,提出了一个资源动态分配的分布计算模型以及相关的分布处理算法.首先,通过分析Internet资源的动态性,分别从资源申请者和资源提供者的角度给出了资源分配过程中哪些特性是不变的;然后,基于资源分配过程中的不变特性,定义了资源使用时的接口描述,提出了适应资源动态变化的分布资源的组织模型和动态资源分配计算模型;研究了支持上述模型的系统支撑技术,提出了相应的分布式资源分配算法;另外,定义了优质服务节点并给出了优质服务节点选择算法,并且通过实验证明优质节点选择算法可以有效地降低服务请求被拒绝的比例;基于上述模型和系统支撑技术实现了两类Internet应用,验证了模型和算法的有效性.     

基于动态性有效资源分配的云计算效益学习模型研究

为了将有限的资源合理地分配给用户,并尽可能地提高云系统的资源和能量利用效率,提出了一种改进的面向动态性有效资源分配的云计算效益学习模型算法,在动态性有效资源分配上提出了服务质量准则框架(QSSF)来得出云服务的计费管理机制;采用资源竞拍策略和动态双向博弈策略更好地权衡用户和云计算提供商之间的利益关系,并将资源分配给资源需求量大的用户;在云系统的运算和存储任务的资源和能量分配上,采用了基于云计算的效益学习模型,通过权衡任务对资源和能量的需求量来实现系统效益的最优化;实验仿真结果表明,该算法能够更加合理地为系统的运算和存储任务分配资源和能量,在资源和能量的利用率上优于其他对比算法.     

认知无线网络中基于信誉度管理的动态频谱接入研究

随着无线服务和相关设备的飞速发展,认知无线网络中特有频谱稀缺问题越来越引起研究者的重视。在集中式认知无线网络中,次级用户基站SUBS作为融合中心,通过收到周围的次级用户的感知信息来分配频谱资源。然而,环境的易变性使次级用户容易受到攻击从而影响次级用户感知信息,导致网络频谱资源分配错误。引入信誉度模型来表现次级用户在认知循环中的行为规范,在分配频谱阶段将信誉度作为评定标准,鼓励次级用户积极感知及规范运行。在感知阶段,次级用户感知信道数越多,感知信息越正确,其信誉度越高。在运行阶段,次级用户行为越符合网络规范,则信誉度越高。仿真结果表明,论文模型可以很好地减少次级用户基站的错误决策次数,提高其抗攻击性,同时使得网络在很好地分配资源的同时鼓励整个网络行为积极化。     

语义虚拟环境本体可视化模型的研究

当前信息可视化所面临的一个瓶颈就是,需要一种模型来把场景图形内容和特定领域的语义信息进行有效集成,使用户可以有效地解释个性化可视化信息。基于X3D标准以及本体用本体描述语言OWL描述X3D标准,构建了一个X3D标准本体和一个映射本体来实现X3D标准本体和其他具体领域本体之间类和属性的映射,以达到丰富虚拟场景语义的目的。基于X3D标准本体和映射本体设计了语义虚拟环境本体可视化模型,从而为具体领域本体实现可视化提供了一种方法。实验结果证明了该模型的可行性。     

多维信息空间的动画设计与实现

在研究和探讨虚拟环境之下构造以人为中心的多维信息空间的基础上,提出了虚拟环境下的多维信息空间动画模型.该模型综合了空间、时间以及知识处理的优点,很好地表达了动画系统中各个对象的行为、智能性及场景转换过程.根据这一模型构造了动画引擎的核心模块,并且在实验教学软件中实现了物质微观状态的可视化模拟,实验结果验证了该模型的有效性.     

基于博弈理论的经济网格资源配置研究

针对经济网格中,由于网格系统的复杂性和用户的私利性,使得网格用户在资源竞价过程中往往因相关信息的匮乏而导致资源竞价的盲目性问题,根据重复博弈分阶段执行的特点,将网格用户间对网格资源的竞争看作多阶段的重复博弈过程.用户依据前一阶段博弈的竞价值及竞价结果对当前阶段的竞价策略进行调整,通过有限次的阶段博弈达到均衡出价策略组合,实现用户最大效用下的资源分配.仿真表明,在不完全信息的网格环境中,该竞价模型可逐步改善网格用户的资源竞价策略,实现优化目标最大化下的网格资源分配.     

Consumer processing of virtual experience in e-commerce: A test of an integrated framework

This study combined discursive and imagery processing streams of research to propose an integrated model of virtual experience as it relates to the strength of brand attitude. The model assumes that both cognitive elaboration (representing the discursive process) and imagery vividness (reflecting the imagery process) are responsible for the effectiveness of virtual experience in the form of 3-D product visualization regarding attitude accessibility and attitude confidence. The results indicate that a brand attitude formed via an interactive 3-D product interface was more accessible and confident than via a static 2-D presentation. Imagery vividness contributed to creating a strong brand attitude. However, effects transmitted via cognitive elaboration were either negative (for accessibility) or nonsignificant (for confidence). Findings suggest that although the two processes are compensatory rather than complementary in the context of virtual experience, the imagery process dominates the discursive process. Theoretical and practical implications are discussed.     

The virtual wind tunnel

The design and implementation of a virtual environment linked to a graphics workstation for the visualization of complex fluid flows are described. The system user wears a stereo head-tracked display, which effectively displays 3-D information, and an instrumented glove to intuitively position flow-visualization tools. The visualization structures and their interfaces in the virtual environment and the implementation hardware and software are described. The performance of the virtual wind tunnel is reviewed using the flow past a tapered cylinder as an example. Performance issues and future directions for the system are discussed     

云计算中虚拟资源的智能多代理设计

针对随着网络数据传输速度和复杂性的不断增加,网络管理变得更加困难的现状,提出了一种虚拟资源的智能多代理模型。描述了虚拟资源的智能多代理的处理过程,讨论了不同代理的处理机制。通过分析用户上下文和系统状态,可实时地分析社会媒体资源。根据虚拟资源的使用类型,对用户上下信息的需求进行分析和推断,自动地给用户分配资源。采用云计算中虚拟资源动态调度方法及MovieLens系统评估该模型,结果证明所提出的模型具有较好的性能,可实现虚拟资源的动态调度,动态地实现负载均衡,使云计算中的虚拟资源得到高效的利用。     

Design and application of real-time visual attention model for the exploration of 3D virtual environments

This paper studies the design and application of a novel visual attention model designed to compute user's gaze position automatically, i.e., without using a gaze-tracking system. The model we propose is specifically designed for real-time first-person exploration of 3D virtual environments. It is the first model adapted to this context which can compute in real time a continuous gaze point position instead of a set of 3D objects potentially observed by the user. To do so, contrary to previous models which use a mesh-based representation of visual objects, we introduce a representation based on surface-elements. Our model also simulates visual reflexes and the cognitive processes which take place in the brain such as the gaze behavior associated to first-person navigation in the virtual environment. Our visual attention model combines both bottom-up and top-down components to compute a continuous gaze point position on screen that hopefully matches the user's one. We conducted an experiment to study and compare the performance of our method with a state-of-the-art approach. Our results are found significantly better with sometimes more than 100 percent of accuracy gained. This suggests that computing a gaze point in a 3D virtual environment in real time is possible and is a valid approach, compared to object-based approaches. Finally, we expose different applications of our model when exploring virtual environments. We present different algorithms which can improve or adapt the visual feedback of virtual environments based on gaze information. We first propose a level-of-detail approach that heavily relies on multiple-texture sampling. We show that it is possible to use the gaze information of our visual attention model to increase visual quality where the user is looking, while maintaining a high-refresh rate. Second, we introduce the use of the visual attention model in three visual effects inspired by the human visual system namely: depth-of-field blur, camera- motions, and dynamic luminance. All these effects are computed based on the simulated gaze of the user, and are meant to improve user's sensations in future virtual reality applications.     

Research on environmental landscape design based on virtual reality technology and deep learning

Virtual Reality (VR) provides immersive visualization and intuitive interaction. The VR is used to enable any biomedical profession to develop a deep learning (DL) model for image classification. The Deep Neural Network (DNN) models can be used as a powerful tool for data analysis, but they are also challenging to understand and develop. To make deep learning more convenient and fast operation, it have established a landscape of DNN development environment based on virtual reality. In this environment, users can move concrete objects only to build neural networks with their own hands. It automatically transforms these configurations into a trainable model and reports on the real-time test dataset. In addition to realizing the insights users are developing into DNN models, it has also visually enriched the virtual environmental landscape objects with the parts of the model. In this way bridge the gap between professionals in different disciplines, providing a new perspective on the model analysis and data interaction. This system further demonstrates that learning and visualization technologies developed in Shenzhen can benefit from integrating virtual reality.     

A Network Scheduling Strategy of Android-Based Virtual Reality System

Mobile platform develops rapidly in recent years, with its performance and capacity increasing. A large number of virtual reality applications such as 3D simulation and visualization have appeared on mobile platform. However, due to restrictions, such as the lack of computing resources and the limited network bandwidth, the virtual reality systems on mobile platform could not have comparable performance as their peers on desktop platform. Taking resource restrictions into consideration, trade-offs have been made regarding the display of virtual reality systems. We propose a unified network scheduling strategy based on asynchronous multi-thread, database cache, prioritization and elimination of overdue requests. This strategy has been tested on the prototype system of virtual reality system on Android. The results demonstrate higher network resource utilization and better user experience.     

面向服务网格的虚拟环境部署运行管理系统

虚拟技术的最新进展为网格计算提供了封装资源的新方式,其封装性、隔离性和安全性能够有效屏蔽底层资源的异构性,根据用户应用需求定制执行环境,更好地适应于网格环境的复杂性和应用的多样性。为了满足当前服务网格的需求发展,基于新的虚拟机技术,研究适合于服务网格的虚拟环境部署运行管理系统,该系统为用户提供可视化、易操作的远程虚拟环境部署和运行管理功能;并实现一个标准的网格服务,结合服务网格平台CROWN,该服务可根据用户应用的特定需求动态透明地部署虚拟执行环境,并根据资源状态自适配调度执行用户任务。并对系统进行了实验分析,实验结果验证了系统的良好可用性和运行性能。     

A model supported interactive virtual environment for natural resource sharing in environmental education

This paper introduces a realistic 3D model supported virtual environment for environmental education, that highlights the importance of water resource sharing by focusing on the tragedy of the commons dilemma. The proposed virtual environment entails simulations that are controlled by a multi-agent simulation model of a real ecosystem consisting of a lake that is being drained by a community of farmers with different types of behaviours. This resembles real-life scenarios, where farmers operate under extreme economic pressure. The virtual environment provides realistic visualization of the elements of the multi-agent model in a comprehensible manner, while keeping the details and the complexity of the ecosystem hidden from the students. Extensive experiments were conducted using students divided in a control group, exposed to conventional teaching means, and an experimental group that used the proposed virtual environment. Both groups were administered questionnaires at pre-test and post-test intervals, and conclusions were drawn after qualitative and quantitative analysis of the results. It was revealed that the proposed virtual environment provided significant cognitive advancements for the students, especially for complex inter-related notions, thus constituting a valuable tool for environment education.