浅析基于MongoDB的云数据管理技术的研究与应用

云计算概念的提出引起了数据存储和管理方式的巨大变革。本文以MongoDB数据库为基础对云数据管理技术进行了研究,最后通过实例检验了设计的可行性。     

Development and evaluation of BCI for operating VR flight simulator based on desktop VR equipment

Advancement of brain-computer interface (BCI) has shown its applications in various scenarios, including flight control. Flight simulator is a crucial part for aircraft design or experiment. Desktop virtual reality (VR)-based flight is a perfect choice for overcoming existing problems in head-mounted VR flight simulations, such as dizziness and isolation, which make interaction and sharing very difficult. In this paper, a BCI based on the steady-state visual evoked potential paradigm and a VR flight simulator were developed and integrated. The performance of the developed system was evaluated quantitatively for comparative studies. Experimental results show that the developed system is very convenient and suitable for VR flight simulations. The average operating accuracies with plane and VR visual stimuli are 81.6% and 86.8%, respectively. The VR visual stimuli can improve the average operating accuracy by 5.2% compared with the plane visual stimuli.     

Developing an integrated platform to enable hardware-in-the-loop for synchronous VR,traffic simulation and sensor interactions

Hardware-in-the-loop (HIL) is a testing paradigm where physical sensors (e.g., monitoring sensors such as cameras and proximity sensors, and alarm sensors such as screaming traffic cones) are connected to a virtual test system that simulates reality (e.g., virtual work zone with simulated dangerous situations). This paradigm is well-suited for conducting user studies for work zone safety because virtual test systems can be implemented using virtual reality (VR), which allows for safe and realistic testing of a sensing system without putting workers in danger along with avoiding high upfront costs needed to generate physical research testbeds. However, when recreating physical work zones in VR, researchers face various challenges while representing traffic patterns in VR, such as the lack of bi-directional communication between traffic simulation platforms and user behaviors in VR, hardware compatibility and integration issues, and customization inflexibility during implementation. Researchers, who need to develop such platforms for research studies that involve high-risk exposure to participants, are in need of evaluating the options available for bringing together the components of such platforms. This study provides an overview of alternative ways to integrate components of platforms that enable hardware-in-the-loop for synchronous VR, traffic simulation, and sensor interactions to position researchers to make decisions based on the pros and cons of each alternative. This paper also presents the implementation of such an integrated platform that allows a two-way interface between traffic simulation and VR environments for work zone safety analysis. Outcomes of this work will lay out the steps in implementing the integrated and immersive platform to be used in work zone safety studies based on the guidance presented.     

基于云计算的在线学习平台的设计与应用

本文将云计算的概念引入到在线学习平台的建设中,提出设计基于云计算的在线学习平台。首先介绍云计算的概念和特点,然后提出一种基于云计算在线学习平台的设计框架,最后实现了一个在线讨论的云计算教育服务平台。     

基于VR技术的防震安全教育软件的设计与实现

本文分析了虚拟现实技术应用于防震安全教育的优势,设计了虚拟场景的开发方案,利用3DS MAX,Virtools等软件工具设计开发出了防震安全教育软件。为了验证虚拟现实技术在防震安全教育中的有效应用,还对该软件作了测试与评价。     

Evaluation of quality and personalisation of VR/AR/MR learning systems

ABSTRACT

The paper aims to analyse the problem of quality evaluation and personalisation of virtual reality/augmented reality/mixed reality (VR/AR/MR). First of all, systematic review of relevant scientific literature on the research topic was conducted. After that, findings of the systematic review concerning evaluation of quality and personalisation of VR/AR/MR learning environments are presented. The author’s VR/AR/MR learning systems/environments quality evaluation and personalisation framework is also presented in the paper. Evaluation of quality of VR/AR/MR platforms/environments should be based on (a) applying both expert-centred (top-down) and user-centred (bottom-up) quality evaluation methods and (b) separating ‘internal quality’ criteria, and ‘quality in use’ criteria in the set of quality criteria (model). Personalisation of VR/AR/MR platforms/environments should be based on learners’ models/profiles using students’ learning styles, intelligent technologies, and Semantic Web applications.     

电子证据的归属及证明力研究

笔者结合电子证据其自身的显著特征,探讨应将电子证据列为一种独立的证据类型,并且着重就电子证据的证明力等问题展开讨论。     

Lower bounds for sense of direction in regular graphs

A graph G with n vertices and maximum degree cannot be given weak sense of direction using less than colours. It is known that n colours are always sufficient, and it was conjectured that just are really needed, that is, one more colour is sufficient. Nonetheless, it has been shown [3] that for sufficiently large n there are graphs requiring more colours than . In this paper, using recent results in asymptotic graph enumeration, we show that (surprisingly) the same bound holds for regular graphs. We also show that colours are necessary, where d _G is the degree of G.Received: April 2002, Accepted: April 2003, Sebastiano Vigna: Partially supported by the Italian MURST (Finanziamento di iniziative di ricerca diffusa condotte da parte di giovani ricercatori).The results of this paper appeared in a preliminary form in Distributed Computing. 14th International Conference, DISC 2000, Springer-Verlag, 2000.     

基于云计算的校园教学云平台建设

随着教育信息化和互联网的高速发展,校园里面的教育信息化建设已经成为众多行业关注的重点。为了适应当前彳言,息化的发展,提高学生的学习质量和效率,文章重点结合云计算的特点以及我国目前校园信息化建设的现状,研究探讨了基于云计算的校园教育云平台的新模型建设。     

Journey from cloud of things to fog of things: Survey,new trends,and research directions

With the advent of the Internet of Things (IoT) paradigm, the cloud model is unable to offer satisfactory services for latency-sensitive and real-time applications due to high latency and scalability issues. Hence, an emerging computing paradigm named as fog/edge computing was evolved, to offer services close to the data source and optimize the quality of services (QoS) parameters such as latency, scalability, reliability, energy, privacy, and security of data. This article presents the evolution in the computing paradigm from the client-server model to edge computing along with their objectives and limitations. A state-of-the-art review of Cloud Computing and Cloud of Things (CoT) is presented that addressed the techniques, constraints, limitations, and research challenges. Further, we have discussed the role and mechanism of fog/edge computing and Fog of Things (FoT), along with necessitating amalgamation with CoT. We reviewed the several architecture, features, applications, and existing research challenges of fog/edge computing. The comprehensive survey of these computing paradigms offers the depth knowledge about the various aspects, trends, motivation, vision, and integrated architectures. In the end, experimental tools and future research directions are discussed with the hope that this study will work as a stepping-stone in the field of emerging computing paradigms.     

CodeCloud: A platform to enable execution of programming models on the Clouds

This paper presents a platform that supports the execution of scientific applications covering different programming models (such as Master/Slave, Parallel/MPI, MapReduce and Workflows) on Cloud infrastructures. The platform includes (i) a high-level declarative language to express the requirements of the applications featuring software customization at runtime, (ii) an approach based on virtual containers to encapsulate the logic of the different programming models, (iii) an infrastructure manager to interact with different IaaS backends, (iv) a configuration software to dynamically configure the provisioned resources and (v) a catalog and repository of virtual machine images. By using this platform, an application developer can adapt, deploy and execute parallel applications agnostic to the Cloud backend.     

智能社区云服务平台及服务模式研究

为满足人们对家居系统智能化的要求,提出将云服务应用于智能家居系统,以实现智能家居物联网系统和外部云计算平台的对接,从而形成高度智能化的云枉区,最终达到一站式服务于用户的目的。文中结合云计算技术给出了一种云服务平台的构建方法,该方法可提供不同用户的多种云服务模式,达到用最少的资源提供最多的服务这一目标。     

关于阳光政务平台建设的分析研究

如何推进电子政务建设,构建权力阳光机制,对新时期政府信息化工作是个严峻的挑战。文章主要阐明了切实打造阳光政务平台是解决当前电子政务建设问题的有效途径,指出打造阳光政务的关键是建设全省统一的网上办事大厅,分析了网上办事大厅的主要建设内容,探讨了如何构建统一的政务云计算平台等。只有按照规范建好阳光政务平台,才能真正实现政务公开,切实提高政府部门的行政效能和公共服务水平。     

基于物联网的大学信息化教学辅助实验平台应用

在大学教学过程中,实验是一种必不可少的辅助手段。但是,面对日益增长的实验科研需求,一方面是设备使用紧张,另一方面是昂贵的实验器材不能够充分被利用,因此,如何实现实验设备的充分利用是大学信息化建设面临的一个主要问题。文章采用物联网技术将仪器设备布置于网络中,并允许用户通过远程访问使用仪器设备进行科研,同时通过一个具体实例来阐述物联网实验平台构造,从而提高设备使用率。     

卫星遥感及图像处理平台发展

航天科技是国家综合国力和科技实力的重要体现,而卫星遥感则是航天科技转化为生产力最直接、最现实的途径之一。遥感数据获取与分发、数据处理与信息提取是卫星遥感应用的两个基本步骤。随着国家民用空间基础设施规划中的遥感卫星体系稳步推进,以及商业卫星遥感的蓬勃发展,我国的卫星遥感数据获取能力呈现质量齐升之势。但同时,作为卫星遥感应用的基础设施和关键工具,遥感图像处理系统平台逐渐成为制约自主卫星数据应用和空间信息业务发展的重要因素之一。本文围绕卫星遥感对地观测主题,从卫星遥感数据获取能力、卫星遥感数据处理系统平台两方面,对国内外现状进行综述,在此基础上分析了卫星遥感的发展趋势。     

Hadoop平台的多队列作业调度优化方法研究

对Hadoop平台的作业调度算法进行了研究, 提出了支持作业类型区分的多队列调度优化算法。优化算法支持根据节点当前的负载情况分配不同类型的作业, 以提高节点的资源利用率; 允许作业队列的资源在闲置时被其他作业队列占用; 在原作业队列需要时可以被即时回收, 即回收过程支持任务抢占; 采用共享队列列表和非共享队列列表的逻辑划分来防止乒乓效应。Hadoop平台的性能测试结果表明, 优化算法相比系统默认算法在作业调度的执行效率、执行平稳性等方面都有了显著的提升。     

Effects of speed,complexity and stereoscopic VR cues on cybersickness examined via EEG and self-reported measures

This study evaluated the interplay between environmental cues in virtual reality (VR) and cybersickness as experienced by users of head-mounted displays (HMDs). Utilizing electroencephalogram (EEG) data and self-reported discomfort measures, the effects of three major VR cues – speed, scene complexity, and stereoscopic rendering – on cybersickness were examined, with the latter being of particular interest as it had not previously been studied explicitly in the context of VR-HMDs. Self-reported discomfort was assessed through in-VR single-item queries and post-VR simulator sickness questionnaires, accounting for both immediate and persistent cybersickness, respectively, and over three experiment sessions, accounting for the effects of accumulation. Analysis revealed connections that indicate a relationship between EEG data and the presence of cybersickness for all three cue types. Significant differences were observed in EEG relative power changes between the trials where cybersickness was and was not reported. EEG relative power changes were also linked to both immediate and persistent cybersickness, especially in the theta and gamma frequency bands. The increase in immediate discomfort with the stereoscopic rendering cues over successive sessions suggests a decrease in tolerance to these effects over time.     

感兴趣区域遥感图像分类与支持向量机应用研究

提出了基于SVM的遥感图像分类方法并构建了分类模型,该方法以唐山1∶50 000 TM局部图为分类数据来源,由用户选择感兴趣的区域,分别提取该区域绿地、公共用地和房屋的图像特征,并以此为训练样本进行训练,采取交叉校验的方法获得SVM的最优惩罚因子C和间隔γ参数进行图像分类。实验结果表明,此分类方法准确率高、稳定快捷,是SVM在遥感图像分类中的一个很好的应用。     

计算机虚拟现实技术的教学应用与软件的开发研究

提出了利用虚拟现实技术开发的"模拟法庭教学软件",建设<模拟法庭>虚拟实验室,以解决"模拟法庭"数量不足的问题,使每一个学生都参与到实践教学中去,教学效果良好.     

云计算在高校信息化建设中的应用研究

作为新兴技术,云计算的诞生对互联网已经产生了深远的影响。本文主要分析云计算在高校信息化建设中的需求和应用,以及如何才能保证云计算数据中心安全可靠的运行。