Adaptive Hypermedia Techniques for 3D Educational Virtual Environments

Based on a well-known adaptive hypermedia framework, the proposed system creates a 3D educational virtual environment that selects and personalizes interactive learning content for users. In EVEs, users not only see concepts visualized, but they can perform tasks in a suitable fictional world or a real-world reproduction. Moreover, compared to 2D multimedia, using interactive 3D graphics lets developers create representations of subjects or phenomena that are more informative and make it possible for users to analyze a single subject from different viewpoints. In EVEs, adaptivity can play an important role in increasing both learning-process effectiveness and interface usability.     

How Web Technology can Facilitate Learning

A challenging task for information systems management is to provide users with more flexible training methodologies to meet their needs, and one way to meet this challenge is to adopt Web-based training. in showing how Web technology can facilitate end-user learning, this article discusses how users can benefit from Web-based training, some issues to consider when developing Web-based training, and different stages of Web-based training.     

From real cities to virtual worlds using an open modular architecture

The technologies for the Web and virtual worlds are currently converging, but although there are some efforts made to integrate them with each other, they typically rely on technologies foreign to most Web developers. In this paper, we present a new open architecture that combines several emerging and established technologies to provide convenient tools for developing virtual worlds directly in the Web. These technologies are easy to learn and understand by the Web community and allow for quick prototyping. Overall the modular architecture allows virtual worlds to be developed more quickly and more widely deployed. Additionally, we demonstrate that creating an adequate virtual environment can be an easy task when applying the principles of crowd-sourcing. We present an application that uses one of the largest available open data sources of geospatial information to bring 3D cities from the real world into the virtual environment.     

基于Web的装备虚拟训练系统通用体系结构

分析了装备虚拟训练的现状,比较了Web3D技术和单机3D图形技术的优缺点,提出了装备虚拟训练的一种通用体系结构--基于Web浏览器的体系结构,建立了一个小型基于Cult3D技术的装备虚拟训练系统.这种基于Web的装备虚拟训练系统通用体系结构不仅具有良好的保真度和交互性,而且能够实现多个虚拟训练系统无缝集成及已有Web3D对象的复用,为不同装备的虚拟训练系统提供了统一的标准和访问平台.为装备虚拟训练在Web浏览器中的实现提供了借鉴.     

Adaptable visual presentation of 2D and 3D learning materials in web-based cyberworlds

Educational cyberworlds allow one to circumvent physical, safety, and cost constraints that often affect real-world training and learning scenarios, allowing students to study the learning content flexibly and individually. However, this does not eliminate the need for presenting the educational materials in an effective way, using visualization, interaction and presentation techniques that are better suited to the learner’s preferences, abilities, and the available devices. The system that we present in this paper is capable, starting from a set of available educational resources (e.g., text, pictures, movies and 3D models) and lesson structures (e.g., suitable ordering of topics), to automatically build a set of alternative web-based educational cyberworlds characterized by different visualization (2D and 3D), interaction and presentation techniques, including virtual humans as instructors. The learner (or her instructor) can then choose the cyberworld that best fits her preferences and needs.     

Reusable,lifelike virtual humans for mentoring and role-playing

Lifelike, interactive digital characters, serving as mentors and role-playing actors, have been shown to significantly improve learner motivation and retention. However, the cost of modeling such characters, authoring and editing their interactions, and delivering them over limited-bandwidth connections can be prohibitive. This paper describes a framework, authoring tools, and Web-based run-time environment that support the creation of training scenarios using digital virtual humans and other reusable 3D components. By conforming to the Humanoid Animation (H-Anim), Extensible 3D, and ADL Shareable Content Object Reference Model specifications, these 3D components are designed to promote reuse and interoperability at several levels. Recently, these software tools were used to develop prototype lessons in foreign language and cultural familiarization for use at the Defense Language Institute Foreign Language Center. These lessons include simulations in which the student, taking the role of a US soldier, interacts with the local population of a foreign culture in authentic situations, using both English and the local dialect. Digital virtual humans are used to represent not only the soldier, and the role-playing actors; but also a mentor who reviews language and cultural learning points, and provides remediation. Using these prototype lessons as examples, we review the potential advantages of the technology in other training applications.     

基于SOA的虚拟仪器共享平台

针对目前各高校间虚拟仪器实验教学系统集成度不足,实验资源难以共享的问题,提出了利用SOA与Web服务的技术优势,结合网络化虚拟仪器的技术特点,在.NET环境下设计实现了校际虚拟仪器实验教学共享平台和虚拟仪器实验教学系统的资源共享。     

基于X3D的虚拟场景建模技术

Web3D联盟发布的X3D标准作为下一代面向互联网的三维图形描述规范,已经被ISO批准成为国际标准,越来越广泛地应用于教育、训练、模拟等方面。该文从介绍虚拟现实技术的发展情况入手,深入分析了X3D规范的文件结构和语法结构。提出了利用X3D规范进行虚拟现实场景建模和系统优化的方法,对于提高景物建模的真实感和降低景物建模的复杂度都有重要的现实意义。     

Fast and learnable behavioral and cognitive modeling for virtual character animation

Behavioral and cognitive modeling for virtual characters is a promising field. It significantly reduces the workload on the animator, allowing characters to act autonomously in a believable fashion. It also makes interactivity between humans and virtual characters more practical than ever before. In this paper we present a novel technique where an artificial neural network is used to approximate a cognitive model. This allows us to execute the model much more quickly, making cognitively empowered characters more practical for interactive applications. Through this approach, we can animate several thousand intelligent characters in real time on a PC. We also present a novel technique for how a virtual character, instead of using an explicit model supplied by the user, can automatically learn an unknown behavioral/cognitive model by itself through reinforcement learning. The ability to learn without an explicit model appears promising for helping behavioral and cognitive modeling become more broadly accepted and used in the computer graphics community, as it can further reduce the workload on the animator. Further, it provides solutions for problems that cannot easily be modeled explicitly. Copyright © 2004 John Wiley & Sons, Ltd.     

基于网络的手机定制系统的实现方法研究

首先分析了基于网络的手机定制特点和现状,并从用户个性化在线配置角度分析了目前主要基于文本和二维图形的网络化定制系统中存在的问题,进而对其系统结构、三维模型构建、系统集成等关键问题进行了研究并分析了其中的关键技术。结合典型手机产品开发了原型系统,该系统用一种比VRML更加优越的新的Web3D实现技术——Cult3D实现了网络三维产品的虚拟展示。经实际应用证明,该系统可有效地提高定制产品的客户满意度,进而提高企业的竞争力。     

A Semantic web approach to handling soft constraints in virtual organisations

In this paper we present a proposal for representing soft constraint satisfaction problems (CSPs) within the Semantic Web architecture. The proposal is motivated by the need for a service-providing agent in a virtual organisation to reason about its commitments as soft constraints. The three essential requirements addressed are: (1) the need to have constraints express commitments in terms of Semantic Web services, (2) the need to associate utility values with constraints, to reflect the relative importance of satisfying them, and (3) the need to make statements about which constraints are satisfied and violated by a given solution. The proposal builds upon previous work in defining a Semantic Web constraint interchange format (CIF), which itself builds on the proposed Semantic Web rule language (SWRL). The paper describes an ontology for representing soft CSPs and their solutions, allowing an agent’s set of commitments to be expressed as a collection of soft constraints. The ontology is an open interchange format for soft CSPs, allowing commitment to be communicated and exchanged among the members of a virtual organisation.     

“网站开发与网页制作”网络课程设计

网络课程是基于网络平台能够在网上进行自主学习、研究性学习和协作学习的一种教学模式。对“网站开发与网页制作”网络课程的教学和系统结构设计进行了研究,给出了一个较为合理的网络课程理论构架。     

基于X3D的虚拟场景建模技术

Web3D联盟发布的X3D标准作为下一代面向互联网的三维图形描述规范,已经被ISO批准成为国际标准,越来越广泛地应用于教育、训练、模拟等方面。该文从介绍虚拟现实技术的发展情况入手,深入分析了X3D规范的文件结构和语法结构。提出了利用X3D规范进行虚拟现实场景建模和系统优化的方法,对于提高景物建模的真实感和降低景物建模的复杂度都有重要的现实意义。     

Using a cognition-motivation-control view to assess the adoption intention for Web-based learning

People expect Web technology to facilitate learning, particularly in higher education. A key issue involves the factors motivating the adoption of the Web for learning. Drawing upon social cognitive theory (SCT) and the theory of planned behavior (TPB), this study adopts a cognition-motivation-control view to assess learner adoption intentions for Web-based learning. The proposed model is validated by surveying 319 undergraduate students who had enrolled in Web-based courses and attended a 12-hour training program on using a Web-based system for academic learning. The empirical findings identified that efficacy control and efficacy expectations can be used to guide learner adaptation learning behaviors on the Web. The limitations of this study are discussed and future research directions suggested.     

WEB工作流的访问控制研究与实现

由于WEB技术本身所具有的分布式、广域访问的特点以及企业现在普遍比以往更加重视自身的信息安全问题,在基于WEB的工作流的设计和实现过程中,访问控制问题成为一个至关重要的议题。文中从一个企业级的WEB工作流系统基础出发,探讨在一个典型的基于WEB的工作流应用系统中,如何对来自广域环境下的用户访问进行有效的控制并提供安全的授权机制。同时能提供与企业组织结构相适应的动态的角色权限分配管理机制。     

Learning Style Compatibility Between Objects in a Real‐World 3D Asset Database

Large 3D asset databases are critical for designing virtual worlds, and using them effectively requires techniques for efficient querying and navigation. One important form of query is search by style compatibility: given a query object, find others that would be visually compatible if used in the same scene. In this paper, we present a scalable, learning‐based approach for solving this problem which is designed for use with real‐world 3D asset databases; we conduct experiments on 121 3D asset packages containing around 4000 3D objects from the Unity Asset Store. By leveraging the structure of the object packages, we introduce a technique to synthesize training labels for metric learning that work as well as human labels. These labels can grow exponentially with the number of objects, allowing our approach to scale to large real‐world 3D asset databases without the need for expensive human training labels. We use these synthetic training labels in a metric learning model that analyzes the in‐engine rendered appearance of an object—combining geometry, material, and texture—whereas prior work considers only object geometry, or disjoint geometry and texture features. Through an ablation experiment, we find that using this representation yields better results than using renders which lack texture, materiality, or both.     

Sharing VLNET worlds on the Web

Virtual environments define a new interface for networked multimedia applications. The sense of “presence” in the virtual environment is an important requirement for collaborative activities involving multiple remote users working with social interactions. Using virtual actors within the shared environment is a supporting tool for presence. In this paper, we present a shared virtual life network with virtual humans that provides a natural interface for collaborative working and we describe the bridge we realized between this 3D shared world and the Web through a system of 3D snapshots.     

Web-based environment for mechanism simulation integrated with CAD system

The present work describes the architecture of a new approach addressing the sharing of virtual prototypes over the Web with standard programming tools. The usage of standard Web-based technologies leads to easier, effective and more general applications suitable for small and medium size companies with limited resources in that field of research. Designers not only exchange just geometry data, but also more information about design knowledge and design solutions, and collaboration is performed on remote locations. In this work the framework is proposed to model a mechanical product focusing on behavioural criteria. In order to avoid time-consuming virtual model preparation, product variety is defined in single configuration file. The configuration file is covering all the variations, with formalisation of the assembly structure and linking the parts and attributes in uniform way. It enables visualisation of the models from different modelling systems and allows interactive changes and evaluation of the virtual prototype.     

HTML5-based system for interoperable 3D digital home applications

Digital home application market shifts just about every month. This means risk for developers struggling to adapt their applications to several platforms and marketplaces while changing how people experience and use their TVs, smartphones and tablets. New ubiquitous and context-aware experiences through interactive 3D applications on these devices engage users to interact with virtual applications with complex 3D scenes. Interactive 3D applications are boosted by emerging standards such as HTML5 and WebGL removing limitations, and transforming the Web into a real application framework to tackle interoperability over the heterogeneous digital home platforms. Developers can apply their knowledge of web-based solutions to design digital home applications, removing learning curve barriers related to platform-specific APIs. However, constraints to render complex 3D environments are still present especially in home media devices. This paper provides a state-of-the-art survey of current capabilities and limitations of the digital home devices and describes a latency-driven system design based on hybrid remote and local rendering architecture, enhancing the interactive experience of 3D graphics on these thin devices. It supports interactive navigation of high complexity 3D scenes while provides an interoperable solution that can be deployed over the wide digital home device landscape.     

基于XML的虚拟法异构数据集成方法研究*

随着信息技术的发展,Web上的数据日趋成为当今数据的主流,但是Web上的数据多是异构的,而越来越多的人需要访问各种异构数据,为了满足这种需求,必须有一种系统能够支持异构数据集成。异构数据集成的方法有很多,给出一个基于XML的虚拟法异构数据集成系统体系结构,引入虚拟法,提出用虚拟法进行异构数据集成;最后引入数据清洗技术,能够较好地解决异构数据的集成。