An MPEG‐4 Compliant Interactive Multimedia Streaming Platform Using Overlay Networks

This paper presents a multimedia streaming platform for efficiently transmitting MPEG‐4 content over IP networks. The platform includes an MPEG‐4 compliant streaming server and client, supporting object‐based representation of multimedia scenes, interactivity, and advanced encoding profiles defined by the ISO standard. For scalability purposes, we employ an application‐layer multicast scheme for media transmission using overlay networks. The overlay network, governed by the central entity of the network distribution manager, is dynamically deployed according to a set of pre‐defined criteria. The overlay network supports both broadcast delivery and video‐on‐demand content. The multimedia streaming platform is standards‐compliant and utilizes widespread multimedia protocols such as MPEG‐4, real‐time transport protocol, real‐time transport control protocol, and real‐time streaming protocol. The design of the overlay network was architected with the goal of transparency to both the streaming server and the client. As a result, many commercial implementations that use industry‐standard protocols can be plugged into the architecture relatively painlessly and can enjoy the benefits of the platform.     

巧用PowerPoint触发器设计交互性测试题

交互式测试题是优秀多媒体课件中不可或缺的部分,其灵活性、交互性能使课程教学更加丰富生动,有效提高学生的学习兴趣。本文通过实例讲解的方法,介绍使用PowerPoint触发器制作各种类型的交互式测试题。     

一种基于智能体的游戏消息公平处理方法

首先分析了现有网络游戏相关的消息处理方法,然后给出了分布式游戏服务器中一种基于智能体的消息处理结构,在此结构中,智能体处理游戏消息的算法可以实现一种公平的消息处理效果.通过选择离用户较近的服务器创建与用户直接通信的智能体,使得用户与该智能体间的网络时延抖动较小,不需要同步用户和服务器之间的时间就能够从游戏中获得一个相对公平的游戏效果.最后在模拟环境中给出了该算法的实验结果.     

Knowledge search and people with high epistemic curiosity

Porter sites have tried to increase their business potentials by helping users easily engage in diverse online activities such as search, entertainment, online communities, and others. Knowledge search engine is one of the most successful killer applications increasing user loyalty. However, most studies have independently focused on search engine technology such as search keyword algorithm, presentation of information and user characteristics such as cognitive style, search experiences, and skill levels. However, these previous studies lack an integrated understanding of causal links among critical factors predicting user motives and intention involving more situation-specific user characteristics. To fill these gaps in the literature, the present study focuses on whether knowledge characteristics such as specialization, preciseness, and diversity, and system characteristics such as interactivity, responsiveness, and communication richness are important in forming user motives and intention. The present study also identifies a moderating role of epistemic curiosity in the links between motives and intention. Two hundred and fifty-five data from Korean university students confirmed that knowledge and services characteristics such as specialty, preciseness, diversity, communication richness improve user motives, which have a positive impact on intention. Epistemic curiosity has a moderating effect on the links between motives and intention. Theoretical and practical implications are discussed in conclusion.     

Rule cubes for causal investigations

With the complexity of modern vehicles tremendously increasing, quality engineers play a key role within today’s automotive industry. Field data analysis supports corrective actions in development, production and after sales support. We decompose the requirements and show that association rules, being a popular approach to generating explanative models, still exhibit shortcomings. Interactive rule cubes, which have been proposed recently, are a promising alternative. We extend this work by introducing a way of intuitively visualizing and meaningfully ranking them. Moreover, we present methods to interactively factorize a problem and validate hypotheses by ranking patterns based on expectations, and by browsing a cube-based network of related influences. All this is currently in use as an interactive tool for warranty data analysis in the automotive industry. A real-world case study shows how engineers successfully use it in identifying root causes of quality issues.

Unobtrusive vehicle motion prediction cues reduced simulator sickness during passive travel in a driving simulator

This study investigated cues that permit prediction of turns during passive movement through a virtual environment. Effects on simulator sickness (SS), presence and enjoyment were examined. Subjects were exposed to complex visual motion through a cartoon-like simulated environment in a driving simulator. Forward velocity remained constant and the motion path was the same across all experimental conditions. Using a within-subject design, we examined visual paths that provided different levels of cue salience – detailed, simplified and no cues – for the upcoming simulated vehicle motion. Following each trial, participants completed questionnaires on SS, presence and enjoyment. After all of the trials were completed, a debriefing determined participants' perceptions of vehicle motion attributes and their awareness of the prediction cues. The results showed that SS in the no-cue condition was significantly greater than that in the conditions that provided vehicle motion cues. Presence and enjoyment responses were not different across the conditions. No participants reported differences between prediction cue conditions or recognized that the vehicle motion followed the same path across trials. However, participants tended to report that the motion was smoother for the detailed-cue than the no-cue condition. Participants ranked turn predictability as higher in conditions with prediction cues. The results support the hypothesis that unobtrusive and unreported motion cues may alleviate SS in a virtual environment.     

Paradise Lost: Children,multimedia and the myth of interactivity

Abstract The dramatic expansion of IT use in the primary schools of South-West Scotland, in the mid-1980s, centred on highly interactive and pupil-empowering forms such as LOGO or database management software. While later forms of IT in education which have come to dominate computer-use in the same area, such as multimedia encyclopaedias and ‘living books’, are worthwhile, their surface sophistication and information richness does not compensate for reduced interactivity levels and the consequent loss of learner engagement and control. The uncritical adoption of technological advances combined with reduced local authority resources to drive curriculum development have resulted in failure to embed one of the most radical educational initiatives of the late twentieth-century.     

When and why is perceived congruity important for in-game advertising in fantasy games?

The present study investigates how the perceived congruity (the perceived level of fit between the execution of the in-game ad and the game environment) of in-game advertising (IGA) in fantasy games affects both players' attitude towards the IGA and their play intention of the fantasy game in which it is embedded, and how these effects are moderated by perceived IGA interactivity. An experimental study with actual fantasy game players (N = 619) following a 2 (Congruent IGA − Incongruent IGA) × 2 (Interactive IGA – Non-interactive IGA) between-subjects design was conducted. The results indicate that the perceived congruity of IGA reduces the perceived intrusiveness of the IGA and positively contributes to the perceived realism of the fantasy game. Intrusiveness and realism, in turn, influence players’ attitude towards the IGA and their play intention of the fantasy game. Whilst the positive effect of perceived congruity through intrusiveness is reinforced by the perceived interactivity of the IGA, the effect of perceived congruity through realism is attenuated by perceived interactivity.     

Interactivity and memory: Information processing of interactive versus non-interactive content

Existing research on the effects of interactivity tends to treat it as a global characteristic of the interface. However, not all content on an interface is endowed with interactive features. Therefore, it is important to explore how interactivity affects the cognitive processing of those particular content that is presented with interactive features and the surrounding content without these features. With this objective, a between-subjects experiment was conducted to understand how levels of interactivity affect information processing among users of an e-commerce website. The major findings of the study are: 1) Higher interactivity enhances recognition as well as recall memory of interactive content, but diminishes recognition and recall memory of non-interactive content; 2) Individuals spend the least amount of time on the interface with high interactivity, while most of this time is spent on interactive part rather than non-interactive part of the interface; 3) A moderate level of interactivity attracts most user attention to product information. The findings about interactivity’s effect have implications for cue-summation theory and limited capacity theory. The experiment’s results also hold practical implications for e-tailers.