微机接口虚拟中断实验的研究和实现

虚拟实验是随着现代计算机技术的进步而产生和发展的一种实验模式。分析目前微机接口实验模式存在的问题和不足,并根据该课程的具体特点,对微机接口虚拟实验的设计思想和实现原理进行了深入研究,以截获用户实验程序I/O指令的VDD虚拟设备驱动技术为基础来设计和实现虚拟实验。中断系统是微机系统的重要组成部分,重点阐述了虚拟中断实验的具体实现方法。实验结果表明,微机接口虚拟中断实验能较好地满足教学的要求,不占用系统硬件资源,具有实验容易、灵活等特点。     

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.     

Virtual Mechatronic/Robotic laboratory – A step further in distance learning

The implementation of the distance learning and e-learning in technical disciplines (like Mechanical and Electrical Engineering) is still far behind the grown practice in narrative disciplines (like Economy, management, etc.). This comes out from the fact that education in technical disciplines inevitably involves laboratory exercises and this fact drastically increases the complexity of a potential e-learning system. New approach and new specific knowledge are needed to develop such a system. We expect to meet the requirements of distance learning by developing the software-based laboratory exercises, i.e., a virtual laboratory. To fully substitute a physical system like laboratory equipment, one must emulate its full dynamics. The mathematical model in the form of differential equations will be applied to calculate dynamics and provide the data that would otherwise be measured on a physical system – this means simulation.     

Change detection in desktop virtual environments: An eye-tracking study

It is common knowledge that attention is important for learning. We need to utilize attention in order to learn something efficiently and effectively. Similarly, we may also need to acquire familiarity with (i.e., learn) our surroundings in order to utilize our attention. In this study, learning is defined as a product of one’s exposure to natural visual stimuli. Using a virtual model of a natural scene, we investigate both attention and its relationship to learning, according to this definition. Specifically, our focus is the effect of environment familiarity on gaze direction. Our findings reveal that the factor of familiarity with one’s surroundings in virtual reality environments exerts a significant influence on peoples’ ability to detect a variety of specific changes that occur within scenes under their observation.     

User goals in social virtual worlds: A means-end chain approach

The purpose of this study is twofold: first, to investigate user goals in social virtual worlds; second, to introduce a methodological alternative (i.e., a means-end chain approach) for analyzing user goals in cyberspaces. The data were acquired from a web survey, and were analyzed by means-end chain analysis (MECA), which produces users’ goal structure in reference to a hierarchical system of interrelated goals (Olson & Reynolds, 1983). The results show that people come to social virtual worlds to satisfy their social and hedonic needs, and to escape from real world constraints, as do virtual community members and virtual gamers; they also pursue unique activities, such as creating virtual objects and selling them. On the other hand, by clarifying relations among users’ goals, MECA provides a richer explanation for user goals than prior research which only offers separate user goals for cyberspace users without explanation of relationship among goals.     

The effects of incorporating a virtual agent in a computer-aided test designed for stress management education: The mediating role of enjoyment

Drawing upon the Entertainment–Education paradigm, this study evaluated the effectiveness of a computer-aided interactive test designed for stress management education targeting college students. The presence (vs. absence) of a virtual agent incorporated into the interactive test was proposed as the key factor that induces enjoyment and educational outcomes. The interactive test consisted of scenarios describing stressful situations that could occur in college students’ everyday lives. Furthermore, college students could relate the concerns raised by these hypothetical situations to the ways they manage their stress and mental health. After the student’s choice behavior in each scenario, a virtual agent conveyed health-related educational messages via a text-modal dialogue box. Participants who took the interactive test in which there was a virtual agent perceived the test as more educational and entertaining than those who took the test without a virtual agent. Results of a path analysis also revealed a significant mediating role of enjoyment on educational outcomes (i.e., students’ enjoyment of the interactive test mediated the effects of the presence of a virtual agent on their perceived educational value of health information), thus confirming the Entertainment–Education link. In addition, engaging in the interactive test resulted in stress management self-efficacy improvement. Theoretical and practical implications are discussed.