Learning experiences from digital laboratory safety training

We present a digital laboratory safety training platform called AALTOLAB which we have developed to address the need for more flexible and engaging ways to teach laboratory safety for chemical engineers. AALTOLAB consists of an interactive, web-based 360° virtual laboratory, integrated with a Moodle-based digital exam with automatic assessment. The modular platform offers different modules from general comprehensive laboratory training to more specialised modules. Students and staff can freely navigate in the laboratory rooms at any time and interact with different action points including interactive videos, slideshows, and minigames. Our technical solution allows teachers even with limited technological skills to easily modify the training materials in real time. The relationship of students’ learning experiences and level of learning is also discussed. We believe that our safety training concept facilitates deep learning and students’ engagement, thus improving safety culture in our laboratories.     

用于虚拟现实的360度视频编码技术新进展*

随着虚拟现实技术不断发展,360度视频编码开始成为研究热点。应用于虚拟现实的360度视频与传统的视频相比分辨率更高,编码数据量更大,在实际应用中面临传输带宽有限的瓶颈,编码效率问题有待解决。归纳分析了国际标准组织联合视频研究组（joint video exploration team, JVET）正在制定的360度视频编码投影变换技术及其编码优化方法,综合对比了各变换技术的编码性能。根据当前最新研究成果,对下一步研究需要解决的问题进行了探讨总结,给出未来的研究方向和思路。     

采用主监视窗扩展技术的增强现实三维注册方法

在增强现实三维注册中,采用重新检测策略时顿卡现象严重。提出一种采用主监视窗扩展技术的增强现实三维注册方法。在检测阶段,引入特征点可信度和主监视窗,并设计主监视窗的分割、扩展和调控策略,大幅提升了计算速度;在跟踪阶段,采用基于图像金字塔的光流算法进行特征点跟踪。实验证明,该方法不仅有效缓解了顿卡现象,也提升了系统整体的实时性。     

Fisher discrimination based low rank matrix recovery for face recognition

In this paper, we consider the issue of computing low rank (LR) recovery of matrices with sparse errors. Based on the success of low rank matrix recovery in statistical learning, computer vision and signal processing, a novel low rank matrix recovery algorithm with Fisher discrimination regularization (FDLR) is proposed. Standard low rank matrix recovery algorithm decomposes the original matrix into a set of representative basis with a corresponding sparse error for modeling the raw data. Motivated by the Fisher criterion, the proposed FDLR executes low rank matrix recovery in a supervised manner, i.e., taking the with-class scatter and between-class scatter into account when the whole label information are available. The paper shows that the formulated model can be solved by the augmented Lagrange multipliers and provides additional discriminating power over the standard low rank recovery models. The representative bases learned by the proposed method are encouraged to be closer within the same class, and as far as possible between different classes. Meanwhile, the sparse error recovered by FDLR is not discarded as usual, but treated as a feedback in the following classification tasks. Numerical simulations demonstrate that the proposed algorithm achieves the state of the art results.     

Continuous Self‐Collision Detection for Deformable Surfaces Interacting with Solid Models

In this paper, we propose a new continuous self‐collision detection (CSCD) method for a deformable surface that interacts with a simple solid model. The method is developed based on the radial‐view‐based culling method. Our method is suitable for the deformable surface that has large contact region with the solid model. The deformable surface may consist of small round‐shaped holes. At the pre‐processing stage, the holes of the deformable surface are filled with ghost triangles so as to make the mesh of the deformable surface watertight. An observer primitive (i.e. a point or a line segment) is computed so that it lies inside the solid model. At the runtime stage, the orientations of triangles with respect to the observer primitive are evaluated. The collision status of the deformable surface is then determined. We evaluated our method for several animations including virtual garments. Experimental results show that our method improves the process of CSCD.     

基于无线网的农业虚拟现实技术的研究、

针对传统农业在作物生长过程中遇到技术问题只能在网上或书上查得文字解决方案的弊端,作者将无线网技术与农业虚拟现实技术相结合,采用虎拟现实技术设计了一套虚拟农业专家系统,该系统使用802．11g作为无线网传输标准．利用作物现场的终端设备对作物生长情况进行实进监测和分析,并及时调用专家系统中的虚拟解决方案进行针对性的处理,从而可将损失减到最小．     

基于虚拟现实技术的无人机转角控制仿真

无人机飞行状态具有较强的非线性特征,机体绕X轴的转动惯量较小,副翼的舵效相对较高,受到扰动后滚转角速率变化很快,使得无人机的横侧向控制成为转角控制的难点问题.传统采用转角跟踪器的无人机转角控制方法中,反馈线性化过程较为繁琐,对于模型精度要求较高,无法适应不断变化的无人机飞行状态.提出一种应用虚拟现实技术的无人机转角控制方法,用三维实景仿真塑造虚拟的无人机飞行区域实景,在无人机运动过程中,辅助操纵手在目视距离内,由增稳控制或人工遥控方式对飞机转角进行操作,并通过三维建模来对无人机机体模型和舵面模型进行构建,并导人到相应的环境中,再通过相应程序对无人机的运动和舵面的转角进行有效的控制,从而实现无人机转角的准确控制.仿真结果表明,相比传统控制方法,所提方法控制下的无人机转角的响应速度更快,具有高的控制效率,在各种扰动的情况下,均可以实现无差的控制跟踪.     

An integrated emotional and physiological assessment for VR-based active shooter incident experiments

Unfortunately, active shooter incidents are on the rise in the United States. With the recent technological advancements, virtual reality (VR) experiments could serve as an effective method to prepare civilians and law enforcement personnel for such scenarios. However, for VR experiments to be effective for active shooter training and research, such experiments must be able to evoke emotional and physiological responses as live active shooter drills and events do. The objective of this study is thus to test the effectiveness of an active shooter VR experiment on emotional and physiological responses. Additionally, we consider different locomotion techniques (i.e., walk-in-place and controller) and explore their impact on users’ sense of presence. The results suggest that the VR active shooter experiment in this study can induce emotional arousal and increase heart rate of the participants immersed in the virtual environment. Furthermore, compared to the controller, the walk-in-place technique resulted in a higher emotional arousal in terms of negative emotions and a stronger sense of presence. The study presents a foundation for future active shooter experiments as it supports the ecological validity using VR for active shooter incident related work for the purposes of training or research.     

The impact of CCT on driving safety in the normal and accident situation: A VR-based experimental study

Correlated color temperature (CCT) of the light source inside the road tunnel plays a crucial role in ensuring driving safety, which is demonstrated by previous studies that CCT influences not only visual effects but also non-visual effects. Although conventional laboratory experiments could simulate the CCT environment inside the tunnel to some extent, they fail to restore driving experience, let alone simulate driving behavior in the accident situation. It has largely remained unclear whether and how CCT would influence visual/non-visual performance of the subjects who are performing driving tasks, especially in the accident situation. Motivated by this gap, a virtual-reality-based framework for assessing the influence of CCT on the visual and non/visual performance in normal driving situation and in accident situation was proposed. In this study, tunnel models under seven different CCTs were created and a rear-end accident was designed in the tunnel. By integrating analog driving equipment, all participants were required to perform virtual driving tasks both in the normal situation and in the accident situation. The non-visual performance (driving fatigue) and the visual performance (reaction time) of the participants were collected and analyzed. Results show that the CCT of light source inside the tunnel was significant on the driving fatigue of the driver who was performing driving task, and it also had a significant impact on the visual performance when the driver was faced with a rear-end accident. Detailed experimental methodology, behavioral explanations underlying these findings, validity of results and practical implications are also discussed in the paper.     

虚拟现实全景流体绘画系统的可用性研究

虚拟现实环境给三维空间场景应用带来更强的真实感和身临其境的体验。在虚拟现实场景中经 常需要使用 360全景图像生成沉浸式环境背景,其中全景流体动力学绘画系统提供了一个新的全景图绘制方 法。在调研虚拟现实技术在流体绘画领域应用的适用性测试中,本文综合运用用户测试法、操作日志分析法、 事后问卷调查法和访谈法,对基于虚拟现实的全景式流体绘画创作系统进行可用性评估,并创意性地使用可视 化方法辅助日志分析。所有的受试者均认为系统的可用性不低于一般水平,利用该系统完成流体绘画的创作工 作不需要受试者具有专业绘画经验。受试者对系统的功能效果持积极肯定的意见,并期待尝试用其他交互形式 代替手柄类交互方式以促进艺术创作的表达。其研究方法和结果将为同类系统的开发和评估提供参考。