基于虚拟现实的装甲装备维修性定量指标验证方法研究

对维修性定量指标验证的研究现状进行分析,提出构建基于虚拟现实的产品维修性定量指标验证系统;首先,根据系统需求构建出系统的总体框架;其次,对系统搭建过程和仿真过程中的关键技术进行阐述;再者,对国军标中维修性定量参数估计模型进行改进,构建适用于复杂装备的虚拟仿真MTTR估计模型;最后,在验证系统中对某型车辆传动装置进行MTTR虚拟仿真试验,并运用MTTR估计模型进行MTTR验证;对比得到,通过虚拟仿真试验得到的验证结果与实车试验数据得到的结果基本一致,具有较高的可信性;该方法为在产品研制设计阶段并行维修性定量指标的验证工作提供了非常重要的参考价值。     

军事仿真与作战模拟的新方法

２１世纪是信息的时代,武器和军队必将也是信息化的。如何建设一支面向２１世纪的部队,发展武器装备,各国提出了利用分布式交互仿真技术的手段进行武器装备的先期技术演示和军事训练方法的改革。从武器装备体系的总体质量和效能去发展武器装备,而不是单靠发展单元武器系统来提高技术优势,这是体现“顶层设计”的思想方法和投资战略最佳选择。作者对美军分布式交互仿真进行了历史回顾,并对当前的现状作了分析。     

动漫衍生品数字展厅的设计与实现

该文阐述了构建动漫衍生品数字展厅的基础理论与研究思路,并在设计实践的基础上提出将视觉要素与数字技术相结合的设计流程与实现方法,开发出一个动漫衍生品的多功能网络展示平台,以此作为虚拟现实技术在动漫领域应用的初步尝试,并提出其潜在应用对象与发展前景。     

Augmented AVI video file for road surveying

This paper presents a novel video augmentation approach: a video recording of a real entity augmented by structured data. This augmented video is a self-contained entity integrating values of perceptible and non-perceptible attributes of the same real entity. It simplifies data search, storage and management. Streaming, sharing, collaboration and synchronization are also simplified by the fact that the structured data (so-called augmented data) are integrated in the video file and therefore only one file needs to be manipulated. Our approach was applied to address the issues which road engineers experience while using the ROad Measurement and Data Acquisition System (ROMDAS). The ROMDAS system collects and analyses the road-condition state through video recordings and the data corresponding acquired by specific measuring devices. Currently, however, road engineers have to search the videos manually in order to find details of interest provided by the analysis of the data measured due to the separation of the video from the data. The ROMDAS system manages a large collection of road-condition data. It does not offer history management of video recordings of the same road captured at different time. We present this hybrid video augmentation system: the Augmented Video stream Framework (AVF). It allows creation, search, history management and playback of such augmented video files for effective road surveying based on the discrete data recorded in parallel to the video recordings. The AVF provides road engineers with effective and more comfortable perceptible and non-perceptible data search, storage and history management to be used for (collaborative) road inspection and maintenance.     

船舶工程虚拟现实应用平台建设及研究

基于船舶工程虚拟现实平台建设过程中的技术与应用问题提出相应的解决办法.介绍了作为船舶工程虚拟现实系统所应达到的功能要求,以及与船舶设计、制造的相关问题.对虚拟现实应用和船舶工程仿真有一定的参考价值.     

Using a Visual Attention Model to Improve Gaze Tracking Systems in Interactive 3D Applications

This paper introduces the use of a visual attention model to improve the accuracy of gaze tracking systems. Visual attention models simulate the selective attention part of the human visual system. For instance, in a bottom‐up approach, a saliency map is defined for the image and gives an attention weight to every pixel of the image as a function of its colour, edge or intensity. Our algorithm uses an uncertainty window, defined by the gaze tracker accuracy, and located around the gaze point given by the tracker. Then, using a visual attention model, it searches for the most salient points, or objects, located inside this uncertainty window, and determines a novel, and hopefully, better gaze point. This combination of a gaze tracker together with a visual attention model is considered as the main contribution of the paper. We demonstrate the promising results of our method by presenting two experiments conducted in two different contexts: (1) a free exploration of a visually rich 3D virtual environment without a specific task, and (2) a video game based on gaze tracking involving a selection task. Our approach can be used to improve real‐time gaze tracking systems in many interactive 3D applications such as video games or virtual reality applications. The use of a visual attention model can be adapted to any gaze tracker and the visual attention model can also be adapted to the application in which it is used.     

Mediating Media Studies – Stimulating critical awareness in a virtual environment

Second Life has become increasingly popular with educators and educational institutions, because of the educational possibilities it seems to offer. While there has been a lot of hype and academic publications about educational design or the theoretical framing of teaching in virtual environments, there have been few publications focussing on actual teaching and learning experiences of lecturers and students in Higher Education institutions. This article uses practical examples from an introductory course on Media studies taught at the Hong Kong Polytechnic University to demonstrate that even simple tasks in Second Life can be used to great effect if properly contextualised into the course being taught. High levels of technical skills, or extraordinary educational designs are less important to employing Second Life successfully in a Higher Education environment, than a proper evaluation of student learning outcomes, and teaching goals.     

The effects of practice teaching sessions in second life on the change in pre-service teachers’ teaching efficacy

The purpose of this research was to investigate the effect of practice teaching in Second Life on the change of preservice teachers’ teaching efficacy, and the difference of changes between individual teaching practice and collaborative teaching practice in their teaching efficacy. Participants were placed into the individual teaching practice or collaborative teaching practice group as a part of a teaching methods and educational technology course. Both groups completed practice teaching sessions twice in Second Life and an instrument adopted for measuring of pre-service teachers’ teaching efficacy beliefs was administered after each of three stages. The researcher collected data from both groups before the first practice teaching, after the first practice teaching session, and after the second session. Results from a Repeated Measure ANOVA indicated that the practice sessions influenced changes in participants’ personal teaching efficacy but not teaching outcome expectancy. In addition, the results indicated significant difference between groups on their personal teaching efficacy after the second practice session, but not on teaching outcome expectancy. The difference between the two groups is attributed to the different methods in preparing for the practice session, practicing the teaching, and the reflection methods posed to each group of participants. This research suggests that pre-service teachers can gain valuable teaching practice in Second Life, and furthermore that collaborative practice teaching is more effective way than individual approaches to practicing teaching.     

Learning science in a virtual reality application: The impacts of animated-virtual actors’ visual complexity

As the technology in computer graphics advances, Animated-Virtual Actors (AVAs) in Virtual Reality (VR) applications become increasingly rich and complex. Cognitive Theory of Multimedia Learning (CTML) suggests that complex visual materials could hinder novice learners from attending to the lesson properly. On the other hand, previous studies have shown that visual complexity correlates with presence and may increase the perceived affective quality of the virtual world, towards an optimal experience or flow. Increasing these in VR applications may promote enjoyment and higher cognitive engagement for better learning outcomes. While visually complex materials could be motivating and pleasing to attend to, would they affect learning adversely? We developed a series of VR presentations to teach second-year psychology students about the navigational behaviour of Cataglyphis ants with flat, cartoon, or lifelike AVAs. To assess learning outcomes, we used Program Ratings, which measured perception of learning and perceived difficulty, and retention and transfer tests. The results from 200 students did not reveal any significant differences in presence, perceived affective quality, or learning outcomes as a function of the AVA’s visual complexity. While the results showed positive correlations between presence, perceived affective quality and perception of learning, none of these correlates with perceived difficulty, retention, or transfer scores. Nevertheless, our simulation produced significant improvements on retention and transfer scores in all conditions. We discuss possible explanations and future research directions.     

Cognitive,social and teaching presence in a virtual world and a text chat

Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed.