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.     

虚拟现实--一种新媒体

作中新媒体，ＶＲ技术与将来的艺术、社会、娱乐尤其是通讯网络有密切的关系，沉浸感、交互性与安全投入这三个思想组合在一起构成了ＶＲ的实质，这些概念并不仅在ＶＲ中存在，其它媒体也同了同样的思想。ＶＲ独特之处在于这三个思想可同时实现。     

Using a serious game to communicate risk and minimize psychological distance regarding environmental pollution

Persuading individuals to engage in pro-environmental behavior is challenging. Interactive media, such as virtual environments and video games, present opportunities to minimize psychological distance and bolster perceived risks associated with environmental threats. In this experiment, we tested the effects of a serious game that allowed users to engage in environmental cleanup. In the virtual environment, participants (N = 190) navigated down a polluted river that was described as geographically and temporally close or distant. The affordance of interactivity, specifically contingency, was also manipulated. Results revealed that feeling psychologically close to the environment led to greater risk perception, which in turn led to more environmental behavior and greater support for environmental policy in the days following the experiment. In terms of interactivity, higher perceptions of contingency led to greater self-efficacy, which also led to more environmental behavior and greater support for environmental policy after the experiment. We discuss implications for environmental communication, science communication, and other prosocial persuasion efforts using interactive media such as serious games and virtual reality.     

Relevant and rich interactivity under uncertainty: Guest reviews,host responses,and guest purchase intention on Airbnb

Online commerce, increasingly running on digital platforms, is subject to higher uncertainty and risk in transactions (e.g., fraud, opportunism) than offline commerce. To cope with this challenge, online commerce companies often use information systems to promote interactive communication between sellers and buyers. This study examines how such seller-buyer interactivity affects buyers’ purchase intention in an online commerce context of accommodation sharing. In particular, we use text mining techniques to analyze guest reviews and host responses on Airbnb. Our analysis suggests that not only the quantity but also the quality of the response messages matter: potential guests’ purchase intention increases with the relevance and richness of the host’s responses as well as their volume. Further, we find a notable nonlinearity in the quantity effect that the volume of host responses significantly affects guest purchase intention only when it is large enough. Making sufficient responses, the hosts could enjoy complementarity between the quantity and quality effects of their responses; otherwise, the relative richness of their responses becomes more important.     

How Does Interactivity Persuade? An Experimental Test of Interactivity on Cognitive Absorption,Elaboration, and Attitudes

We explore theoretical mechanisms by which the interactivity of a medium enhances the persuasive potential of messages, by investigating the effects of 2 different types of website interactivity—modality interactivity and message interactivity—on the nature of user engagement with messages. In a 3 (Message Interactivity: High/Medium/Low) × 2 (Modality Interactivity: Slider/Control) factorial experiment (N = 167), we discovered that modality interactivity led to more positive assessment of the interface and greater cognitive absorption, contributing to more favorable attitudes toward the website and even toward the antismoking messages. However, it reduced the amount of message‐related thoughts. In contrast, message interactivity enhanced message elaboration, leading to more positive attitudes among those with low involvement in the message topic.     

What Creates Interactivity in Online News Discussions? An Exploratory Analysis of Discussion Factors in User Comments on News Items

While the social, political, and journalistic relevance of user comments on online news items has been discussed intensively, no study has tried to examine why some online news discussions are more interactive than others. Based on the rationale of news value theory, this study argues that so‐called discussion factors in user comments indicate general relevance to later users to respond to them. Qualitative interviews with users who comment on news stories online and a quantitative content analysis of 1,580 user comments showed that the discussion factors uncertainty, controversy, comprehensibility, negativity, and personalization can explain interactivity in news discussions. Further, different technological implementations of the comment function seem to have a limited influence on the effects of these discussion factors.     

Who finds value in news comment communities? An analysis of the influence of individual user,perceived news site quality,and site type factors

User commenting forums are a ubiquitous interactive feature offered by news organizations. Despite their popularity, research has generally failed to investigate extent to which news readers themselves find any redeeming value in news comment communities and, therein, the factors that serve as antecedents to such value perceptions. In light of this gap in the literature, this study set out to determine the factors associated with news community value. Using a sample of over 500 news consumers, we explored the impact of individual user, site quality, and site type factors. The results suggested that perceived news community value was highest among those with high levels of self-efficacy and those who use the Internet for civic purposes. The data indicated also that value perceptions were highest for those news sites that were understood to be interactive and aesthetically pleasing. Finally, perceived news community value was highest on sites that were both non-traditional and non-partisan in nature.     

Changing user roles in ICT developments; the case of digital television

This paper focuses on the question: what active user roles concerning digital television can be distinguished and how can these be classified in a way they can be related to business models? It will look at the value chain for digital television and try to show where users are enabled to be more active and value adding. The paper will continue with an exploratory look at current interactive television practices. But since interactive television is still in its infancy, to look beyond what is happening in digital and interactive television at this moment, may provide useful insights.     

新一代音视频编码标准MPEG-4

本文介绍了多媒体通信音视频编码新标准ＭＰＥＧ－４,重点介绍了其两大特点：对音视频对象的编码及基于内容的交互。同时介绍了ＭＰＥＧ－４的组成及功能。     

Designing Modular Software: A Case Study in Introductory Statistics

Modular programming is a development paradigm that emphasizes self-contained, flexible, and independent pieces of functionality. This practice allows new features to be seamlessly added when desired, and unwanted features to be removed, thus simplifying the software's user interface. The recent rise of web-based software applications has presented new challenges for designing an extensible, modular software system. In this article, we outline a framework for designing such a system, with a focus on reproducibility of the results. We present as a case study a Shiny-based web application called intRo, that allows the user to perform basic data analyses and statistical routines. Finally, we highlight some challenges we encountered, and how to address them, when combining modular programming concepts with reactive programming as used by Shiny. Supplementary material for this article is available online.