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This paper explores the impact of self-representation (full body Self Avatar vs. Just Controllers) in a Collaborate Virtual Environment (CVE) and the consistency of self-representation between the users. We conducted two studies: Study 1 between a confederate and a participant, Study 2 between two participants. In both studies, participants were asked to play a collaborative game, and we investigated the effect on trust with a questionnaire, money invested in a trust game, and performance data. Study 1 suggested that having a Self Avatar made the participant give more positive marks to the confederate and that when the confederate was without an avatar, they received more trust (measured by money). Study 2 showed that consistency led to more trust and better productivity. Overall, results imply consistency improves trust only when in an equal social dynamic in CVE, and that the use of confederate could shift the social dynamics.

Augmented and virtual reality have the potential to improve various aspects of everyday life such as tourism. An elementary part of tourism is the organization and execution of guided city tours. In case of tours for virtual cities, such as in the case of no longer existing ancient settlements, a combination of augmented and virtual reality may render high benefit for collaboration between guide and visitors. Immersive technology has been shown suitable for collaborative systems by previous research, as they can provide a better experience than other technologies. However, recent literature analyses showed that there is a lack of research regarding the role of augmented reality supporting the active/leading user role in such scenarios. Usually, augmented reality is used for the users who are passively experiencing the virtual environment and not for the one controlling it. However, we think that augmented reality has a large potential to improve the workflow of such a primary user. To investigate this research question, we present a collaborative system in this work, which implements a virtual city tour. In this system, the guide is using augmented reality and the visitor is immersed in the virtual city using virtual reality glasses. To implement a valid research prototype, the system has been developed in close feedback with experts in the field of guided city tours.

This paper presents an immersive virtual reality environment that can be used to develop collaborative educational applications. Multiple users can collaborate within the virtual shared space and communicate with each other through voice. To asses the feasibility of the collaborative environment a novel case-study concerned the education of a geography was developed and evaluated. The geovisualization experiment scenario explores the possibility of learning geography in a collaborative virtual environment. A user-study with 30 participants was performed. Participants evaluated and commented on the usability and interaction methods used within the virtual environment., 4 pages, 7 figures

Virtual reality (VR) enables immersive applications that make rich content available independent of time and space. By replacing or supplementing physical face-to-face meetings, VR could also radically change how we socially interact with others. Despite this potential, the effect of transferring physical collaborative experience into a virtual one is unclear. Therefore, we investigated the experience differences between a collaborative virtual environment (CVE) and a physical environment. We used a museum visit as a task since it is a typical social experience and a promising use case for VR. 48 participants experienced the task in real and virtual environments, either alone or with a partner. Despite the potential of CVEs, we found that being in a virtual environment has adverse effects on the experience which is reinforced by being in the environment with another person. Based on quantitative and qualitative results, we provide recommendations for the design of future multi-user virtual environments.

Purpose The paper aims to present the processing pipeline of an assembly immersive simulation application which can manage the interaction between the virtual scene and user using stereoscopic display and haptic devices. A new set of elements are integrated in a Collaborative Virtual Environment (CVE) and validated using an approach based on subjective and objective users’ performance criteria. The developed application is intended for Assembly/Disassembly (A/D) analysis, planning and training. Design/methodology/approach A mobility module based on contact information is used to handle the assembly components’ movements through real-time management of collision detection and kinematically constraint guidance. Information on CVE architecture, modules and application configuration process are presented. Impact of device type (3 degrees of freedom (DoFs) vs 6 DoFs) over user’s experience is evaluated. Parameters (number of assembled components and components assembly time) are measured for each user and each haptic device, and results are compared and discussed. Findings Test results proved the efficiency of using a mobility module based on predefined kinematic constraints for reducing the complexity of collision detection algorithms in real-time assembly haptic simulations. Also, experiments showed that, generally, users performed better with 3 DoFs haptic device compared to 6 DoFs haptic equipment. Originality/value The proposed immersive application automates the kinematical joints inference from 3D computer-aided design (CAD) assembly models and integrates it within a haptic-based virtual environment, for increasing the efficiency of A/D process simulations.

Many organizational analysis tasks are solved by collaborating teams. In technology-mediated collaborations, enabling relevant visual cues is a core issue with existing technology. We explore whether avatars can provide relevant cues in collaborative virtual environments. To do so, we develop a research prototype for a collaborative virtual environment that utilises avatars to improve workspace awareness in collaborative tasks. We test this solution through two studies, qualitative and quantitative, in which participants have to collaborate to jointly validate and correct a diagrammatic model of operational procedures.Our evaluations provide both positive and negative results about the proposed prototype. Collaboration patterns changed and became significantly easier, but, task performance was only slightly improved. Together, these findings inform both the ongoing development of collaborative 3D virtual environments and the role of technology-mediated collaboration for validating and fixing models of processes. We present design principles for 3D virtual environment collaboration technology for process diagram creation and validation.We present a proof-of-concept implementation of the technology.We present findings from two studies of collaborative validation of a process diagram, qualitative and quantitative.

This paper describes a design of a collaborative virtual environment (CVE) for training security agents in big events. The CVE was modelled with Autodesk 3ds Max, while Unity 3D was used to create the terrain and implement the features that make up a virtual environment. The Brazilian soccer stadium known as Maracana and its surroundings were chosen as the real counterparts of the CVE. The usability of the CVE was evaluated through simulations involving security agents dealing with threats related to suspects carrying radioactive material in big events. In order to perform these simulations, we use the same procedures used during 2014 FIFA World Cup and planned to be used in Rio 2016 Olympic Games. The main objective of this work is to verify the feasibility of designing a CVE and its usability for training security agents involved in big events issues. Results indicated that the proposed CVE has been successful concerning both, design and usability, besides of helping to improve the ability of each member of the security team on performing his duty.

This paper reflects on a Virtual Learning Environment (VLE) in the context of architecture, urban planning and design. The paper aims to critically assess the ability of virtual environments to support experiential online learning. It contributes to the literature by providing the experimental results of implementing the TERF virtual world for undergraduate and graduate Built Environment courses. TERF virtual world provides videos and other communication tools to support collaboration among students. Feedback on the usage and functionality of this 3D virtual platform was collected from students through post evaluation surveys. This experiment provided opportunities to facilitate team communication and a route to more collaborative leaning. It is also discussed the strengths and limitations of the 3D collaborative virtual environment to support deeper learning environment.

paper we evaluate Collaborative Virtual Environments (CVEs) in terms of network latency. Network Latency main requirements, given in the literature for CVEs, have been summarized. We also discuss effects of network latency on users" performance in the CVEs. Different factors can improve, by minimizing overall network latency, the performance of users in the CVEs. This review provides a comprehensive inside look to network latency in the CVEs and will help the researchers to adopt a network, with minimum latency, for their CVEs. The algorithms and ideas, suggested by the researchers, to be adopted by the CVEs to minimize network latency in virtual environment, are also discussed critically. Reducing network latency will ultimately improve the overall efficiency of CVEs.

Avatar facial expression and animation in 3D Collaborative Virtual Environment (CVE) systems are reconstructed through a complex manipulation of all details that compose it like muscles, bones and wrinkles in 3D space. The need for a fast and easy reconstruction approach has emerged out in the recent years due to its application in various domains; 3D disaster management and military training etc. These details simulation must be as realistic as possible to convey different emotions according to the constantly changing situations in CVE during the runtime. For example, in 3D disaster management, it is important to use dynamic avatar emotions; firefighters should be frightened when dealing with a fire disaster and smiling when treating injures and evacuating habitants. However, the solution of facial animation remains a challenge that restricts the rapid and ease development of facial animation systems. In this work, the author presents extensible game engine architecture to easily produce real-time facial animations using a script atomic action without having to deal with control structures and 3D programing language. The proposed architecture defines various controllers, object behaviors, tactical and graphics rendering, and collision effects to quickly design 3D virtual environment. Firstly, the author gives the concept of atomic expression, and the method to build a parametrized script file according to the atomic expression. Then the author shows the validity of the generated expressions based on the MPEG-4 facial animation framework. Finally, the feasibility of the proposed architecture is tested via a firefighter scenario. The author's approach has the advantages over previous techniques of fitting directly an easy and faster technology with a high degree of programming independence. The author also minimizes the interaction with the game engine during the runtime by injecting dynamically the XML file into the game engine without stopping or restarting the engine.

In this research, we aim to address the problem of combining the benefits of using eLearning environments and let students work together in groups in a collaborative virtual learning environments. In this paper, we explain the development of an establishment of a collaborative model for deaf people to support collaborative learning. The created model is an extension of traditional collaborative learning models in class rooms; it allows multiple deaf students to work together in a virtual environment to discuss the learning materials, solve problems, transfer knowledge, etc. We start by extending the collaborative learning model, by introducing explicit roles for each member in the group. The model provides a social space for deaf people to communicate using sign language. Moreover, it is implemented in a collaborative virtual environment that provides different types of features to support learning over distance. It allows deaf students to communicate and share knowledge easily. Bilingual chatting (text and sign language), video conference, and avatar feature are the main three features in the proposed model.

Virtual Reality (VR) is a computer-generated experience that can simulate physical presence in real or imagined environments [7]. A social VR system is an application that allows multiple users to join a collaborative Virtual Environment (VE), such as a computer-generated 3D scene or a 360-degree natural scene captured by an omnidirectional camera, and communicate with each other, usually by means of visual and audio cues. Each user is represented in the VE as a computer-generated avatar [3] or, in recently proposed systems, with a virtual representation based on live captures [1]. Depending on the system, the user’ virtual representation can also interact with the virtual environment, for example by manipulating virtual objects, controlling the appearance of the VE, or controlling the playout of additional media in the VE. The interest for social Virtual Reality (VR) systems dates back to the late 90s [4, 8] but has recently increased [2, 5, 6] due to the availability of affordable head-mounted displays on the consumer market and to the appearance of new applications, such as Facebook Spaces, YouTube VR, Hulu VR, which explicitly aim at including social features in existing VR platforms for multimedia delivery. In this talk, we will address the problem of measuring user Quality of Experience (QoE) in social VR systems. We will review the studies that have analysed how different features of a social VR system design, such as avatar appearance and behavioural realism, can affect user’s experience, and propose a comparison of the objective and subjective measures used in the literature to quantify user QoE in social VR. Finally, we will discuss the use case of watching movies together in VR and present the results of one of our recent studies focusing on this scenario, designed and performed in the framework of the European project VRTogether (http://vrtogether.eu). Particularly, we show an analysis of correlation between the objective and subjective measurements collected during our study, to provide guidelines toward the design of a unified methodology to monitor and quantify users’ QoE in social VR systems. The open questions to be addressed in the future in order to achieve such goal are also discussed.

Collaborative virtual environments (CVEs), which allow naturalistic communication between two or more individuals in a shared virtual environment, hold promise as a tool for measuring and promoting social communication between peers. In this work, a CVE platform and a set of CVE-based collaborative games are designed for children with autism spectrum disorder (ASD). Two groups (7 ASD/TD pairs; 7 TD/TD pairs) participated in a pilot study to establish system feasibility and tolerability. We also designed a methodology for capturing meaningful metrics of social communication. Based on these metrics, we found improved game performance and trends in communication of these participants over time. Although preliminary, these results provide important insights on CVE-based interaction for ASD intervention.

In a co-located collaborative virtual environment, multiple users share the same physical tracked space and the same virtual workspace. When the virtual workspace is larger than the real workspace, navigation interaction techniques must be deployed to let the users explore the entire virtual environment. When a user navigates in the virtual space while remaining static in the real space, his/her position in the physical workspace and in the virtual workspace are no longer the same. Thus, in the context where each user is immersed in the virtual environment with a Head-Mounted-Display, a user can still perceive where his/her collaborators are in the virtual environment but not where they are in real world. In this paper, we propose and compare three methods to warn users about the position of collaborators in the shared physical workspace to ensure a proper cohabitation and safety of the collaborators. The frst one is based on a virtual grid shaped as a cylinder, the second one is based on a ghost representation of the user and the last one displays the physical safe-navigation space on the foor of the virtual environment. We conducted a user-study with two users wearing a Head-Mounted-Display in the context of a collaborative First-Person-Shooter game. Our three methods were compared with a condition where the physical tracked space was separated into two zones, one per user, to evaluate the impact of each condition on safety, displacement freedom and global satisfaction of users. Results suggest that the ghost avatar and the cylinder grid can be good alternatives to the separation of the tracked space.

In virtual environments most pedagogical virtual tutors or facilitators supervise or guide the learning activity; they are task-oriented. In contrast, the here proposed facilitator is strictly about monitoring some aspects of collaboration and offering advice in this regard. In a multiuser virtual environment, that is, a Collaborative Virtual Environment, oral communication is chosen over written communication in order to enhance the feelings of presence, co-presence, and immersion for the user; but oral communication analysis presents a high resource overhead. As an alternative, the monitoring activity of this facilitator is based on two nonverbal cues of interaction: talking-turn patterns and object manipulation. An empirical study to validate this approach was conducted based on the participants' perception regarding the suitability of the facilitator's messages; the results showed that the students' accepted a significant number of generated advice.

e-Technology has enabled users from remote locations to collaborate together virtually and involve in e-activities to reach their common goals. The virtual environment is commonly known as Networked Collaborative Virtual Environment. It is a challenge to manage these remote located users since they are diverse in term of language, culture, and skill. Most of the managements are performed by external entity such as administrator. As a result, the external handling is hardly matched or coped. Thus, this paper investigates the possibility of having a method called role behavior to manage users both internally and externally. The initial finding shows that roles are dynamic and their dynamic behaviors are further analyzed through a collaborative monopoly game. As a result, a set of role behaviors has been extracted from the game. Each behavior is analyzed and mapped to a real-life application as an abstraction of user management. Finally, a mathematical model has been proposed to represent a comprehensive collection of roles which has to be used in managing dynamic environment.

In order to integrate with an upcoming ecosystem of interconnected products and services, adaptive, intelligent and autonomous material handling systems (MHS) are being deployed in modern logistics facilities, enabling them to cope with requirements for high flexibility, configurability and reusability. Recent advances in virtual engineering and virtual reality (VR) technologies offer new possibilities for remote collaboration between companies regarding the design process of MHS, which involves several stakeholders. In this paper, we present a 3D collaborative virtual environment (3DCVE) as part of distributed multi-platform software for supporting MHS design tasks in logistics facilities. We describe how an in-memory data grid technology can be used for the distribution of data and the enabling of consistent user access to the virtual environment (VE). The main focus is put on the use-case of facility layout planning presenting the implementation of approaches regarding user interaction and collaboration.

Avatar facial expression and animation in 3D collaborative virtual environment (CVE) systems are reconstructed through a complex manipulation of muscles, bones, and wrinkles in 3D space. The need for a fast and easy reconstruction approach has emerged in the recent years due to its application in various domains: 3D disaster management, virtual shopping, and military training. In this work we proposed a new script language based on atomic parametric action to easily produce real-time facial animation. To minimize use of the game engine, we introduced script-based component where the user introduces simple short script fragments to feed the engine with a new animation on the fly. During runtime, when an embedded animation is required, an xml file is created and injected into the game engine without stopping or restarting the engine. The resulting animation method preserves the real-time performance because the modification occurs not through the modification of the 3D code that describes the CVE and its objects but rather through modification of the action scenario that rules when an animation happens or might happen in that specific situation.

Collaborative Virtual Environment (CVE) system supports a large number of users to explore a virtual world and interact with each other through networks, so one of the key issues in the design of scalable CVE systems is the partitioning problem. Existing partitioning algorithms in CVE systems based on multiple-server architecture, in our opinion, hardly consider the communication character of virtual environment. In this paper, we propose a new partitioning method based on area of interest (AOI) model matching to improve the quality of partitioning. The experimental results show preliminarily that our partitioning approach based on AOI model matching does decrease the traffic among the servers in the system and improve the partitioning performance.

With the advent of new haptic feedback devices, researchers are giving serious consideration to the incorporation of haptic communication in collaborative virtual environments. For instance, haptic interactions based tools can be used for medical and related education whereby students can train in minimal invasive surgery using virtual reality before approaching human subjects. To design virtual environments that support haptic communication, a deeper understanding of humans′ haptic interactions is required. In this paper, human′s haptic collaboration is investigated. A collaborative virtual environment was designed to support performing a shared manual task. To evaluate this system, 60 medical students participated to an experimental study. Participants were asked to perform in dyads a needle insertion task after a training period. Results show that compared to conventional training methods, a visual-haptic training improves user′s collaborative performance. In addition, we found that haptic interaction influences the partners′ verbal communication when sharing haptic information. This indicates that the haptic communication training changes the nature of the users′ mental representations. Finally, we found that haptic interactions increased the sense of copresence in the virtual environment: haptic communication facilitates users′ collaboration in a shared manual task within a shared virtual environment. Design implications for including haptic communication in virtual environments are outlined.

Existing client/server architecture with a multiple server has the capacity constraint of users due to the fixed number of servers. A hierarchical architecture based on the tailoring tree model for improving scalability and consistency in the collaborative virtual environment (CVE) is described. In our architecture, the main server, region servers and clients maintain the state of the CVE together. In order to improve the scalability and consistency, computing resources and communication resources should be effectively assigned. Two algorithms are proposed to solve the resource assignment problem in the hierarchical architecture: a dynamic clustering algorithm partitions the virtual environment according to the current load, which can effectively assign computing resources; a time-bounding-box-based filtering scheme is used to reduce the traffic, which can effectively assign communication resources. Experimental results show that the hierarchical architecture with our algorithms has a reasonable assignment of computing resources and communication resources at the same time, and, indeed, improves the scalability and consistency.

The destruction caused by wildfires has led to the development of various models that try to predict the effects of this phenomenon. However, as the computational complexity of these models increases, their utility for real-time applications diminishes. Fortunately, the burgeoning processing power of the graphics processing unit can not only mitigate these concerns but also allow for high-fidelity visualization. We present VFire, an immersive wildfire simulation and visualization system. Users are placed in a virtual environment generated from real-world data regarding topology and vegetation. There they can simulate wildfires in real-time under various conditions. They can then experiment with various suppression techniques, such as fire breaks and water drops. The simulation is performed on the graphics card, which then provides visualization of the results. The system is intended to train fire chiefs in planning containment efforts and to educate firefighters, policymakers, and the general public about wildfire behavior and the effects of preventative measures.

Collaborative Virtual Environments (CVEs) such as military training programs, emergency preparedness simulations, and online games place strict requirements on network performance when participating users share the 3D virtual environment through their mobile devices in an ad hoc network. However, most support systems for existing CVEs are confined to a desktop setting, thus preventing collaboration while users are mobile. In this work, we propose and evaluate a Gnutella peer-to-peer network over mobile ad hoc networks (MANETs) to support Mobile Collaborative Virtual Environment (MCVE) applications. Both architectures share some common features such as decentralization, self-reorganization, and self-healing. However, peer-to-peer networks and MANETs operate on different network layers, and thus, cause poor performance. To address this problem, we explore a novel cross-layer approach to improve the overall performance of CVEs over MANETs. The network layer should be aware of the user's physical position in the virtual environment (VE) in order to minimize network traffic and cope with a moderate workload between nodes. In this paper, we present a cross-layer approach model for collaborative virtual environment over MANET. We describe its implementation and evaluate its performance using NS2 simulator.

The design of the virtual environment (VE) has to take into account several factors including the input and output devices, the design of the interaction metaphor and the application domain. In addition to these considerations, the design of collaborative virtual environment (CVE) needs to take into account the collaborative aspect of the interaction metaphor. in one hand, the interaction metaphor must be designed to produce the most possible task performance. In the other hand, the influence of the interaction metaphor on the user’s experience (in terms of psychological and social considerations) constitutes an important research question. To address this research question, we presented a new user-centred method for Collaborative Virtual Environments in taking into account human factors. Our goal is to study the effect of 3D interaction metaphors in CVE on copresence, involvement, awareness and collaborative effort.

A Collaborative Virtual Environment or CVE extends stand alone virtual environment to include real-time collaboration, interaction and sharing of the same virtual space among users across the network. We utilize the Torque Game Engine Advanced to develop a CVE application that was customized to support architectural students' design activities in a virtual environment. This application allows multiple users across the local area network and the internet to collaborate, interact, and share information within the same virtual space. Included in the application is an automated data-mining system to record the various users' activities during the collaborative design sessions in the virtual environment. In this paper, we present findings from our pilot study where we evaluate performance when designing and working collaboratively in a virtual environment. Subjects were divided into four groups; Group 1: experts working as individuals, Group 2: non-experts working as individuals, Group 3: experts working in pairs, and Group 4: non-experts working in pairs. Subjects were to assemble a building structure in the virtual environment using the CVE application. Several dependent measures were computed while performing the experimental tasks. The measures included: time taken when moving objects, the movement frequency, and the average pitch angle where subject's gaze was oriented. The results show that the overall performance of experts working in pairs in a CVE is better than that of the individuals working alone.

In collaborative product design situations, enabling effective communication between participants and managing related knowledge are two key elements in the collaboration process. In this paper, we propose an enhancement to communication and knowledge management through the use of 3D-annotations directly in the collaborative virtual environment. We present our 3D-annotation model, which is based on three components: form, spatialization, and metadata. To facilitate the manipulation of 3D-annotations, we introduce a knowledge model, which is used to index and filter the annotations in the virtual environment. Experiments examining the influence of this knowledge model on the annotation-reading task show that users find the pertinent information more easily and with a greater level of confidence.

A Collaborative Virtual Environment (CVE) extends a standalone Virtual Environment to include real-time collaboration, interaction and sharing of the same virtual space among users across the network. A CVE presents a positive learning environment for students where they can learn to work collaboratively. Architectural students could benefit from the use of a CVE because it provides the opportunity for them to work interactively in a virtual workplace, and collaborate directly on a design project. In this study, we utilize a 3D game engine to develop a CVE prototype software application; the Collaborative World Design Tool (CWDT). The CWDT software application allows for real-time collaboration and interaction among multiple users across the network. The CWDT is customized to support architectural design activities in a CVE. An automated data logging system is also developed to record activities during collaborative design sessions. We conducted an experiment with architectural students as the subjects, to determine the effects of working collaboratively within a CVE, as opposed to working individually in a standalone VE. The results and observations obtained suggest the benefits of working collaboratively within a CVE outweighed working individually in a standalone VE. Our findings indicate that collaboration within a CVE has great potential to increase the productivity at which designs are assembled, reduce the number of errors in design, provides a constructive learning environment, reduces the overall stress levels, and increases positive thinking and a group mindset for subjects. These findings also have allowed us to identify areas of focus for future research.

The present work was motivated by the increasing importance in the competences of the entrepreneurial spirit and initiative (ESI) at all levels of education, as well as the need to expand into competence-based education. This paper studies entrepreneurship education in two different environments: virtual and classroom training. It specifically addresses teamwork competence, which supports the development of ESI competences. Thus, there is a particular interest in investigating how to better contribute to the development of ESI. However, little or nothing is known about the matter in collaborative virtual environments. This research analyses 51 group dynamics in educational environments -20 virtual groups and 31 classroom groups. It offers interesting conclusions in relation to reducing team conflict, monitoring individual and collective group performances, and facilitating cohesion. It also analyses the results of collaborative work. These conclusions are useful for both the teaching and development of entrepreneurial teams that are involved in the development of new projects. This is particularly the case for entrepreneurial teams that work in a multinational and decentralized environment.

With the rapid development and popularity of cloud computing technology, more and more Collaborative Virtual Environment (CVE) systems are migrated to cloud computing environment to improve the effectiveness of resource usage. Virtual Machine (VM) placement in cloud data center is a key issue of providing high-efficient cloud platform for CVE system. However, most existing VM placement algorithms ignore the following characteristics of actual cloud environment: (1) VMs deployment requests arrive and leave dynamically, (2) Cloud data center usually consists of many heterogeneous Physical Machines (PMs). Ignoring these two characteristics result in an inefficient and unbalanced use of multiple resources of PMs. Thus using these algorithms directly will lead to a poor resource utilization. In this article, we propose a two-phase online VM placement algorithm, which helps the cloud data center to minimize different resource usages and aims at a more efficient use of multiple resources. Our algorithm selects the most suitable PM type for VM based on Cosine Similarity, and adaptively maps VMs to PMs by using an approximation algorithm. The proposed algorithm is evaluated by simulations. Experimental results show our proposed algorithm ensures a more efficient use of multiple resources over the existing approaches.

In this paper, we describe the enactment of autonomous agents and avatars in the web-based social collaborative virtual environment of REVERIE that supports natural, human-like behavior, physical interaction and engagement. Represented by avatars, users feel immersed in this virtual world in which they can meet and share experiences as in real life. Like the avatars, autonomous agents that may act in this world are capable of demonstrating human-like non-verbal behavior and facilitate social interaction. We describe how reasoning components of the REVERIE system connect and cooperatively control autonomous agents and avatars representing a user.

Individuals with Autism Spectrum Disorders (ASD) evidence core impairments regarding social interaction and communication. These impairments can inhibit the ability of individuals with ASD from effectively engaging with peers and collaborating on goal-oriented tasks. Recently collaborative virtual environment (CVE) in which individuals with ASD can interact with one another or with a therapist to achieve some common goal has been proposed for social competence interventions (SCI) for these individuals. In this paper, we present the design of a distributed CVE for playing the classic video game pong to be used for SCI. This collaborative game can be played at several different modes ranging from one player against an artificial agent in one computer to two players against each other in two different computers. The system functionality and robustness were validated through a small user study. In the future, this CVE will be evaluated with children and adolescents with ASD.

This paper introduces an integrated validation system that consists of the following modular components: kinematic/dynamic analysis module, kinetostatic model, CAD module, FEM module, CAM module, optimization module and virtual environment for remote control. In this paper, authors focus mainly on the modules of kinetostatic modeling, dynamic modeling, PKM design optimization and remote control realization. The prototype of a 3-dof Parallel Kinematic Machine (PKM) developed at the Integrated Manufacturing Technologies Institute of National Research Council of Canada (NRC-IMTI) is used as an example throughout this paper.

A collaborative virtual environment (CVE) allows geographically dispersed users to interact with each other and objects in a common virtual environment via network connections. One of the successful applications of CVE is multiplayer on-line role-playing game. To support massive interactions among virtual entities in a large-scale CVE and maintain consistent status of the interaction among users with the constraint of limited network bandwidth, an efficient collaborative interaction management method is required. In this paper, we propose a behaviour-based interaction management framework for supporting multiplayer role-playing CVE applications. It incorporates a two-tiered architecture which includes high-level role behaviour-based interaction management and low-level message routing. In the high level, interaction management is achieved by enabling interactions based on collaborative behaviour definitions. In the low level, message routing controls interactions according to the run-time status of the interactive entities. Collaborative Behaviour Description Language is designed as a scripting interface for application developers to define collaborative behaviours of interactive entities and simulation logics/game rules in a CVE. We demonstrate and evaluate the performance of the proposed framework through a prototype system and simulations. Copyright © 2006 John Wiley & Sons, Ltd.

Virtual Reality leads Digital Product Development technology to a more effective and convenient way by presenting the product model in an immersive real 3D environment. Distributed VR even enables partners to discuss the design of the product independent of their locations. This paper introduces our work with a Digital Product Development System with Virtually Cooperating Teams Using High Bandwidth Networks — ProViT, which aims at building up immersive telepresence systems for design review across high-bandwidth networks. Video and audio streaming are integrated in the virtual environment to support immersive teleconference aspects of the distributed design review sessions. A network management system has been developed for the supervision, maintenance and processing of distributed setups, and network security.

Virtual reality technology is increasingly being applied to globally distributed teams engaged in collaborative product design. Observations of product design teams have suggested four distinct patterns of collaboration—complementary, competitive, peer-to-peer, and leader-follower. Another insight from observation is that collaboration consists of fluid transitions between these patterns in the accomplishment of the design task, driven by a flexible process of subgrouping and regrouping which reflects the structure and progress of the task. Yet most collaborative virtual environment systems support only one pattern of collaboration—peer-to-peer—and those that do explicitly support multiple patterns or roles do not allow fluid transitions between them in the context of the same task. In addition, no explicit support is provided to allow subgroups to be formed and dissolved. A collaborative virtual environment that supports multiple collaboration patterns and fluid transitions was developed using the Shared Simple Virtual Environment (SSVE) application framework. A novel user interface widget, the collaboration tree, was created to drive the subgrouping and regrouping process. Group experiments were performed to test the operating hypothesis that support for group collaboration patterns led to higher performance. The result was that the operating hypothesis was confirmed; however, the conceptual approach to problem solving, suggested by the presence of support for collaboration patterns, may have been more significant than the actual mechanism provided.

One of the challenges for 3D multiuser virtual simulation environments (3DMUVEs) developers is to keep the shared virtual simulation environment synchronized among all the participating users' terminals. Support to 3DMUVEs through traditional client-server communication model offers simpler management but can lead to bottlenecks and higher latencies. Peer-to-peer communication model, on the other hand, offers no central coordination but are more complex to manage. Current peer-to-peer networks, such as KaZaA and Gnutella, provide multimedia sharing services but do not support multiuser 3D virtual environment (VE) applications. This paper describes a solution to support 3DMUVEs in a hybrid peer-to-peer Gnutella network, which provides session control and distributed shared VE synchronization. As a result of this work, two components specified by the ongoing multiuser extension to the MPEG-4 standard were implemented and integrated to the Gnutella network for control and synchronization. This solution minimizes the disadvantages of client-server and pure peer-to-peer models. The results show that this approach can be a feasible solution, specially for spontaneous 3DMUVEs that can emerge from any user, with no investment needed (apart from his own computer). The use of peer-to-peer networks such as the Gnutella could be used as a test environment for companies wishing to check both their multiuser 3DMUVEs software for correctness and their acceptance by the users community before making heavy investments.

Collaborative virtual environments (CVEs) hold great potential for people With autism. An exploratory empirical study Was conducted to determine if children and youth With autism could understand basic emotions as represented by a humanoid avatar. Thirty-four participants (ages 7.8—16 years) reported to have autism interacted With a softWare program designed to evaluate their ability to identify and make inferences from facial expressions. Over 90% of the participants accurately recognized emotions displayed by avatar representations. These findings support the optimism that CVEs can be used effectively as an assistive technology, as an educational technology, and as a means of helping address potential theory-of-mind impairments.

How does communication mode affect people's experience of social presence, presence, and performance, and how does it affect their actual collaboration in a virtual environment? In a first experiment, subjects communicated by text-chat, audio conference, or video conference in a desktop collaborative virtual environment (CVE). Both perceived social presence and presence were shown to be lower in the text-chat condition than in the audio- and video-conference conditions. People spent a longer time performing a decision-making task together, spoke fewer words in total, and also spoke fewer words per second in the text-chat environment. Finally, more words per second were spoken in the audio-conference than in the video-conference condition. In a second experiment, collaboration in a CVE audio- and a CVE video condition was compared to collaboration in a Web audio-conference and a Web video-conference condition. Results showed that presence was rated higher in the two video than in the two audio conditions and especially in the Web video condition. People spent more time in the video than in the audio conditions and more words per second were spoken in the Web than in the CVE conditions. In conclusion, it was found that both the communication media used and the environment in which collaboration takes place (CVE or Web) make a difference for how subjects experience interaction and for their communication behavior.

This paper discusses a study in supporting collaborative military planning in which groupware, video-conferencing and a desktop Collaborative Virtual Environment (CVE) were used. It discusses the design and implementation of the CVE and the setup and execution of the study using questionnaires and observation. The results of the study questionnaires showed that the CVE was not seen by users as the best of the ways offered to support collaborative planning; these results are discussed and their implication for the design of such a CVE are assessed.

This paper analyzes an online graduate course for teachers of English. The study is geared towards the theory of complexity. It focuses more on the relationships between various elements and the inter-agents in this process, and less on the results. In as far as the pedagogical design of this contextualized course, one of the challenges that were identified in the studies involved seeking a better understanding of the factors that facilitated the creation of an environment that was conducive to the learning of the course components. For this study, we adopted as a guiding principle some notions from chaos theory/complexity, which form the epistemological basis of the analyses and the discussions of this research. In addition, we researched the properties of complex systems such as emergence, attraction principles, self-organization, adaptability and sensitivity to initial conditions, as well as external factors that occurred during a complex system. To this end, the analysis focused on the relationship between the pedagogical aspects of the course (the project), and its instructional design, as well as online interactions and other factors and elements that could positively or negatively influence the creation of a favorable learning environment. The relationship between the educational project and the virtual environment led to other social dimensions such as reciprocity, collaboration (or lack thereof), learning strategies and learning environment. We conclude that the increased understanding of the characteristics, the functioning and the implementation of standards in distance education courses for teachers aids discussions about collaborative virtual environment practices in this field.

The efficient reconstruction of ancient cuneiform tablets has been a challenging problem over many decades, which if an approach is found to speed up the rate of potential fragment joins, will lead to a discovery of rich historical records of knowledge inscribed 5,000 years ago. This paper describes The Leverhulme Trust funded development of a crowd-sourcing collaborative virtual environment via the identification of cooperative personalities. We conducted experiments in which 12 groups of 3 participants collaborated to reconstruct fragments in a laboratory 3D puzzle virtual environment. Personality types were analysed together with NASA TLX workloads and task performance. We discovered that patterns exist for each of the virtual interaction modalities, demonstrating a potential for profiling systems to group personality types for maximising the effective reconstruction of cuneiform fragments.

Recently, new interactive devices such as hap tic devices became available for game development. 6DOF hap tic devices give the user an opportunity "to feel" the simulated virtual environment in the way similar to the real world. Hap tic-based interaction can add a new dimension to "serious games" development. The user can "feel" objects surfaces and complex objects interaction forces in a 3D virtual environment. In this paper, we propose two hap tic-based serious games. In the first "T Puzzle" game, the user can "feel" the weight of objects, rotate and move the 3D puzzle pieces in the virtual world. This game can be used to improve the user's spatial abilities. In the second "Mol Docking" game, the player can feel interaction forces between molecular systems and learn the process of molecular docking in collaborative virtual environment.

In networked collaborative virtual environment, users from dispersed locations can work as a group. Each user holds certain roles along with responsibilities and access to resources. However, the virtual environment is dynamic and users have to change their roles frequently. The process is called role transition and currently it is managed by users manually or handled by specific domain applications automatically. In manual management, users are burden with unnecessary workload and the role transitions are prone to errors, whereas the automatic handling is limited to its preset role transition capability. This research aims to explore the provision of role transition management. This exploration will uncover the vital patterns for structured and flexible role transition management. In order to achieve the objective, this research has chosen a call centre in a leading banking system to capture real-life scenarios via observation and interviews. For immerse and deep understanding of role transition, personas have been utilized as a mechanism of illustration to demonstrate the complex role transition in the call center. All factors gathered in the study will provide strong foundation in the design of an automated system for facilitating role transition management that will balance the workload of an authorized human and an automatic programmable technical element in a system.

This paper deals with the behavior of virtual environments from the collaboration point-of-view, in which actors (human or virtual beings) interact and collaborate by means of interdependent tasks. In this sense, actors may realize tasks that are dependent on tasks performed by other actors, while the interdependencies between tasks (through resource management and temporal relations) delineate the overall behavior of a virtual environment. Our main goal is to propose an approach for the coordination of those behaviors. Initially a generic study of possible interdependencies between collaborative tasks is presented, followed by the formal modeling (using Petri Nets) of coordination mechanisms for those dependencies. In order to implement such mechanisms, an architecture of reusable and pluggable coordination components is also introduced. These components are used in an implementation of a multi-user videogame. The presented approach is a concrete step to create virtual societies of actors that collaborate to reach common goals without the risk of getting involved in conflicting or repetitive tasks. r 2001 Elsevier Science Ltd. All rights reserved.

A review of existing systems for performing manufacturing tasks in a collaborative virtual environment highlights the limitations for modeling object behavioral characteristics. It is difficult for users to describe the tasks to be performed in the environment. A behavioral layer architecture is presented to address these limitations. The layer consists of a virtual manufacturing lattice (VML) structure, an object library, and a virtual manufacturing script (VMS). The VML is a hierarchical structure to encapsulate object behavioral characteristics, which augments the scenegraph structure. The encapsulation is achieved by using a four-tuple structure (C,R,T,E), where C is the composition structure of the node which contains geometry, material, texture, and location data, R is the precedence relationship element, T is the trajectory relationship element, and E is the event control list used to describe the state information about the object. The VMS is implemented as a script and a parser that serves as an interface between the user and collaborative virtual reality software. The script is a grammar-like structure to describe manufacturing tasks. In the behavioral layer architecture, the script is parsed, and calls are issued to the underlying functions to initiate the tasks and to manipulate the lattice structure to perform the specified tasks. Availability of network bandwidth is a key ingredient for using our system for telecollaboration. As part of an example to demonstrate the implementation of VML-VMS, a study of network latency and saturation is performed for different network medium, packet sizes, sampling rate, and network protocols to explore ways of reducing network latency and display frame jitter.

Virtual environments have the potential of adding a new dimension to the concept of a community. In this paper, we describe our work on a text-based virtual environment. Although our focus is on work applications, the environment is equally suited for educational and recreational uses. The paper is presented in the context of the needs of a software development team but can be applied to other work teams as well. Two essential characteristics of successful work teams are good communication and efficient access to project information. Maintaining both of these becomes more and more difficult as the size of the team grows, and gets very difficult when the team is geographically dispersed. We describe a project that could be used to test the hypothesis that a collaborative environment using text-based virtual reality would alleviate these problems by relieving physical separation through virtual proximity. In the first phase of the project, we adapted and extended Jersey, a Smalltalk-based MOO (Multi-user domain Object Oriented) with collaborative virtual environment (CVE) features. On the basis of our experience, we then started designing and implementing MUM, a Multi-Universe MOO. When completed, the more extendable and customisable MUM will provide novel features and encourage developer experimentation. We describe some of MUM's features and our plans for it.

Collaborative virtual environments allow younger and older people to interact over long distances and stay in contact with their families and friends. Thus, these virtual environments are considered to be both, a crucial factor for active and healthy ageing and a great chance for future developments that may enhance and alter communication for specific age groups. Yet, to date there is a lack of studies examining differences between younger and older adults with special regards to technology usage factors, presence related factors as well as anxiety measures and psychophysiological arousal during social interactions in a collaborative virtual environment. Consequently, the objective of the current study was to evaluate the above mentioned factors in a group of 20 younger and 20 older adults using a slightly stressful collaborative virtual environment. The corresponding results indicate that virtual environments could indeed be beneficial tools for the communication of both, younger and older adults. Yet, older adults reported significantly lower levels of social presence during the interaction and were less able to handle the system than younger adults. Interestingly however, both groups did not differ in their technology related anxiety or regarding physiological measures of stress during the experience of the virtual environment.

Collaborative Virtual Environments are experiencing a large interest in cultural heritage field mostly due to the strong opportunity given by novel augmented reality applications. There are already several examples of collaborative augmented visit to museums or historical sites. Anyway the traditional and static approach to computer graphics is very limiting because it often requires the development of a Virtual Environment for every new application. In this paper, we propose a technique for model-driven generation of mixed reality virtual environments, where every modification in contents, visit path and in interactions with the physical surrounding environment don't require a great re-coding effort, enabling fast deployment of collaborative virtual environments for cultural explorations only providing new contents and a small set of parameters.

Numerous studies have explored the process of learning and its effectiveness in training and education. Collaborative virtual environment for studying aircraft evacuations in virtual reality environment can be used as an education and training tool. We believe that people learn best through real life experiences and that a sense of presence is developed in a virtual environment that can provide real world knowledge and experience. Our proposed multiuser environment consists of aircrafts, an airport, runways, and a control tower. Virtual reality experiments with virtual evacuation drills are necessary to study human behavior under panic or stressful situations that cannot be evaluated in the real world. The use of collaborative virtual environments to run virtual evacuation drills for an emergency evacuation eliminates risk of injury to participants and allows for the testing of scenarios that could not be tested in real life due to legal issues and possible health risks to participants. Our contribution lies in our approach to combine computer simulated agents and user controlled autonomous agents in a collaborative virtual environment to perform virtual evacuation drills. Results from this study can be used to measure the effectiveness of current procedures, protocols, and the effectiveness of training for airline and security personals.