Influences of haptic communication on a shared manual task

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.     

Design and evaluation of virtual environments mechanisms to support remote collaboration on complex process diagrams

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.     

Tree-Based Concurrency Control in Distributed Groupware

We present a novel algorithm, called dARB, forsolving the concurrency control problem indistributed collaborative applications. Themain issue of concurrency control is resolvingthe conflicts resulting from simultaneousactions of multiple users. The algorithmreduces the need for manual conflict resolutionby using a distributed arbitration scheme. Themain advantages of our approach are thesimplicity of use and good responsiveness, asthere are no lock mechanisms. Our algorithmrequires the applications to use a tree as theinternal data structure. This makes itapplication independent and suitable forgeneral collaborative applications. The treerequirement is reasonable since many newapplications use XML (extensible MarkupLanguage) for data representation and exchange,and parsing XML documents results in treestructures. Example applications of thealgorithm, a group text editor and acollaborative 3D virtual environment calledcWorld, are implemented and evaluated in theDISCIPLE collaboration framework. We alsointroduce awareness widgets that users avoidgenerating the conflicting events and help inmanual conflict resolution.     

基于Internet的多用户共享虚拟环境框架的研究

多用户共享虚拟环境是指网络化的协同虚拟现实系统，在该环境中多个用户之间通过各自的三维图形表示实现在虚拟环境中的多人感知，用户之间的交互以及对虚拟对象的协同操纵，在综合分析现有系统以及Internet的开放性标准化需求基础上，提出了一种基于Internet的多用户共享虚拟环境解决方案，即多用户共享虚拟环境框架（multi-user shared virtual envitonment framework,MSVEF)，该框架描述了多用户虚拟环境的体系结构，定义了基于XML的相关交互协议，通过在原型系统中的初步应用，证明该框架可以支持不同网络平台的用户在同一个虚拟场景中的再现与交互。     

Co-located collaborative visual analytics around a tabletop display

Co-located collaboration can be extremely valuable during complex visual analytics tasks. We present an exploratory study of a system designed to support collaborative visual analysis tasks on a digital tabletop display. Fifteen participant pairs employed Cambiera, a visual analytics system, to solve a problem involving 240 digital documents. Our analysis, supported by observations, system logs, questionnaires, and interview data, explores how pairs approached the problem around the table. We contribute a unique, rich understanding of how users worked together around the table and identify eight types of collaboration styles that can be used to identify how closely people work together while problem solving. We show how the closeness of teams’ collaboration and communication influenced how they performed on the task overall. We further discuss the role of the tabletop for visual analytics tasks and derive design implications for future co-located collaborative tabletop problem solving systems.     

Influence of contextual objects on spatial interactions and viewpoints sharing in virtual environments

Collaborative virtual environments (CVEs) are 3D spaces in which users share virtual objects, communicate, and work together. To collaborate efficiently, users must develop a common representation of their shared virtual space. In this work, we investigated spatial communication in virtual environments. In order to perform an object co-manipulation task, the users must be able to communicate and exchange spatial information, such as object position, in a virtual environment. We conducted an experiment in which we manipulated the contents of the shared virtual space to understand how users verbally construct a common spatial representation of their environment. Forty-four students participated in the experiment to assess the influence of contextual objects on spatial communication and sharing of viewpoints. The participants were asked to perform in dyads an object co-manipulation task. The results show that the presence of a contextual object such as fixed and lateralized visual landmarks in the virtual environment positively influences the way male operators collaborate to perform this task. These results allow us to provide some design recommendations for CVEs for object manipulation tasks.     

A Multi-User 3-D Virtual Environment with Interactive Collaboration and Shared Whiteboard Technologies

A multi-user 3-D virtual environment allows remote participants to have a transparent communication as if they are communicating face-to-face. The sense of presence in such an environment can be established by representing each participant with a vivid human-like character called an avatar. We review several immersive technologies, including directional sound, eye gaze, hand gestures, lip synchronization and facial expressions, that facilitates multimodal interaction among participants in the virtual environment using speech processing and animation techniques. Interactive collaboration can be further encouraged with the ability to share and manipulate 3-D objects in the virtual environment. A shared whiteboard makes it easy for participants in the virtual environment to convey their ideas graphically. We survey various kinds of capture devices used for providing the input for the shared whiteboard. Efficient storage of the whiteboard session and precise archival at a later time bring up interesting research topics in information retrieval.     

See-through techniques for referential awareness in collaborative virtual reality

Multi-user virtual reality systems enable natural collaboration in shared virtual worlds. Users can talk to each other, gesture and point into the virtual scenery as if it were real. As in reality, referring to objects by pointing results often in a situation whereon objects are occluded from the other users' viewpoints. While in reality this problem can only be solved by adapting the viewing position, specialized individual views of the shared virtual scene enable various other solutions. As one such solution we propose show-through techniques to make sure that the objects one is pointing to can always be seen by others. We first study the impact of such augmented viewing techniques on the spatial understanding of the scene, the rapidity of mutual information exchange as well as the proxemic behavior of users. To this end we conducted a user study in a co-located stereoscopic multi-user setup. Our study revealed advantages for show-through techniques in terms of comfort, user acceptance and compliance to social protocols while spatial understanding and mutual information exchange is retained. Motivated by these results we further analyze whether show-through techniques may also be beneficial in distributed virtual environments. We investigated a distributed setup for two users, each participant having its own display screen and a minimalist avatar representation for each participant. In such a configuration there is a lack of mutual awareness, which hinders the understanding of each other's pointing gestures and decreases the relevance of social protocols in terms of proxemic behavior. Nevertheless, we found that show-through techniques can improve collaborative interaction tasks even in such situations.     

Resolving Conflicting Insights in Asynchronous Collaborative Visual Analysis

Analyzing large and complex datasets for critical decision making can benefit from a collective effort involving a team of analysts. However, insights and findings from different analysts are often incomplete, disconnected, or even conflicting. Most existing analysis tools lack proper support for examining and resolving the conflicts among the findings in order to consolidate the results of collaborative data analysis. In this paper, we present CoVA, a visual analytics system incorporating conflict detection and resolution for supporting asynchronous collaborative data analysis. By using a declarative visualization language and graph representation for managing insights and insight provenance, CoVA effectively leverages distributed revision control workflow from software engineering to automatically detect and properly resolve conflicts in collaborative analysis results. In addition, CoVA provides an effective visual interface for resolving conflicts as well as combining the analysis results. We conduct a user study to evaluate CoVA for collaborative data analysis. The results show that CoVA allows better understanding and use of the findings from different analysts.     

Conflict resolution in collaborative planning dialogs

In a collaborative planning environment in which the agents are autonomous and heterogeneous, it is inevitable that discrepancies in the agents' beliefs result in conflicts during the planning process. In such cases, it is important that the agents engage in collaborative negotiation to resolve the detected conflicts in order to determine what should constitute their shared plan of actions and shared beliefs. This paper presents a plan-based model for conflict detection and resolution in collaborative planning dialogs. Our model specifies how a collaborative system should detect conflicts that arise between the system and its user during the planning process. If the detected conflicts warrant resolution, our model initiates collaborative negotiation in an attempt to resolve the conflicts in the agent's beliefs. In addition, when multiple conflicts arise, our model identifies and addresses the most effective aspect in its pursuit of conflict resolution. Furthermore, by capturing the collaborative planning process in a recursive Propose–Evaluate–Modify cycle of actions, our model is capable of handling embedded negotiation during conflict resolution.     

Remote collaboration on desk‐sized displays

Work on remote collaboration has often focused on the person space created by a conventional videoconference where the participants see each other's faces, but we argue that a task space containing shared visual information is more important for most tasks. Trends in display technology mean that large visual task spaces can be created to maximize the shared context between collaborators. We have created a system called the Escritoire that presents users with a desk‐sized projected display with bimanual input that allows documents and images to be arranged and modified by multiple remote collaborators. We describe the software architecture, the protocol that is used between the client and server programs, and the pen traces we have added to allow participants to gesture to each other in the large visual space to enrich their communication. Our user trials have shown that participants were able to use the system with a minimum of training, and found the traces useful in the collaborative setting. In future we will be connecting three or more sites together to explore the issues that arise with multi‐party interaction on large shared desks. Copyright © 2005 John Wiley & Sons, Ltd.     

The Effect of Collaboration Styles and View Independence on Video-Mediated Remote Collaboration

This paper investigates how different collaboration styles and view independence affect remote collaboration. Our remote collaboration system shares a live video of a local user’s real-world task space with a remote user. The remote user can have an independent view or a dependent view of a shared real-world object manipulation task and can draw virtual annotations onto the real-world objects as a visual communication cue. With the system, we investigated two different collaboration styles; (1) remote expert collaboration where a remote user has the solution and gives instructions to a local partner and (2) mutual collaboration where neither user has a solution but both remote and local users share ideas and discuss ways to solve the real-world task. In the user study, the remote expert collaboration showed a number of benefits over the mutual collaboration. With the remote expert collaboration, participants had better communication from the remote user to the local user, more aligned focus between participants, and the remote participants’ feeling of enjoyment and togetherness. However, the benefits were not always apparent at the local participants’ end, especially with measures of enjoyment and togetherness. The independent view also had several benefits over the dependent view, such as allowing remote participants to freely navigate around the workspace while having a wider fully zoomed-out view. The benefits of the independent view were more prominent in the mutual collaboration than in the remote expert collaboration, especially in enabling the remote participants to see the workspace.     

Co-Insights framework for collaborative decision support and tacit knowledge transfer

Abundant software tools use visual analytics (VA) techniques to support various decisions with the aim of boosting better insights. Large organizations, however, lose efficiency in selecting the right tools to support the persons who apply the tools to various decision tasks. Consequently, the creation and sharing of insights are far from optimal, leading consistently to sub-optimal decisions. In this work, the Co-Insights framework is introduced with automated collaboration support features to enable effective creation and sharing of distributed insights. A collaboration network (Co-Net) is established to model the collaborative decision making process in an organization. Two important features of the Co-Insights framework are developed: collaborative agent allocation analysis (CA3) for task–participant matching; and a robust mechanism for the recommendation of selected VA tools, by participant–tool matching. Thus, by better matching of tasks and tools with participants, the creation and sharing of insights are improved in any collaborative team for better decision making, accompanied with the tacit knowledge transfer to sustain the entire organization. To validate the effectiveness of these two main features, two experiments built on the Co-Net model are performed to test the newly developed algorithms. It has been found that CA3 significantly improves the matching scores by up to 35%, compared with conventional task–participant matching methods. The neural network based participant–tool matching mechanism yields robust results with 4% mismatches for 10% noise levels, and with 16% mismatches for 30% noise levels. Real case applications and implications are described, and further plans to extend this new framework are also outlined based on the reported experiments and evaluations.     

An end-to-end communication architecture for collaborative virtual environments

Synchronous collaboration in virtual reality spaces has specific requirements that differ from those of other application data, leading to a different communication approach. Update messages corresponding to the change in the state of a shared object must be communicated both reliably and in a timely manner among users. While a lot of research has been done in terms of transmission of update messages representing the motion of avatars and objects, very few works focus on collaboration itself. Here, we present an architecture that supports tightly coupled collaborative tasks to be performed efficiently in virtual environments. The architecture consists of an application-general layer which is mapped into a communication protocol. An implementation is also presented as proof of concept.     

Immersive Whiteboard Collaborative System

An immersive whiteboard system is presented where users at multiple locations can communicate with each other. The system features a virtual environment with vivid avatars, stroke compression and streaming technology to effectively deliver stroke data across meeting participants, friendly human interaction and navigation, virtual and physical whiteboard. The whiteboard is both a physical platform for our input/output interfaces and a virtual screen for sharing common multimedia. It is this whiteboard correspondence that allows the user to physically write on the virtual whiteboard. In addition to drawing on the shared virtual board, the immersive whiteboard in our setup permits users to control the application menus, insert multimedia objects into the world, and navigate around the virtual environment. By integrating multimedia objects and avatar representations into an immersive environment, we provide the users with a more transparent medium so that they feel as if they are communicating and interacting face-to-face. The whiteboard efficiently pulls all the collaboration technologies together. The goal of this collaborative system is to provide a convenient environment for participants to interact with each other and support collaborative applications such as instant messaging, distance learning and conferencing.     

Integrating communication formats: synchronous versus asynchronous and text-based versus visual

The present article describes activities undertaken in the virtual world called “Euroland” to promote collaborative knowledge building, using a variety of communication formats. The communication formats available in Euroland are text-based via a chat (synchronous) and a discussion forum (asynchronous); and visual in the form of virtual objects, pictures, and photos. Euroland has been designed, implemented, and evaluated by a Dutch-Italian community composed of students, teachers, and researchers performing educational, cross-cultural, and interdisciplinary tasks. The relevant theoretical perspectives concerning collaborative knowledge building, visualization within a three-dimensional environment, and the community of learners and the community of practices models are also reviewed. A qualitative evaluation of the activities performed in Euroland is then undertaken. It is concluded that the activities involving different communication formats within a virtual world are only appreciated and used when the community of users reaches a particular level of awareness with regard to the technical and cognitive functions of each format. When integrated, the communication formats are found to have a reciprocal influence on each other. The community is able to generate new activities not planned in advance, depending upon the specific situation, which gets defined during the interaction between the various participants in Euroland.     

Predicting Visual Focus of Attention From Intention in Remote Collaborative Tasks

While shared visual space plays a very important role in remote collaboration on physical tasks, it is challenging and expensive to track users' focus of attention (FOA) during these tasks. In this paper, we propose to identify a user's FOA from his/her intention based on task properties, people's actions in the workspace, and conversational content. We employ a conditional Markov model to characterize a subject's FOA. We demonstrate the feasibility of the proposed method using a collaborative laboratory task in which one partner (the helper) instructs another (the worker) on how to assemble online puzzles. We model a helper's FOA using task properties, workers' actions, and conversational content. The accuracy of the model ranged from 65.40% for puzzles with easy-to-name pieces to 74.25% for puzzles with more difficult-to-name pieces. The proposed model can be used to predicate a user's FOA in a remote collaborative task without tracking the user's eye gaze.      

Task-based and stable telenanomanipulation in a nanoscale virtual environment

In a haptic interface system with a nanoscale virtual environment (NVE) using an atomic force microscope, not only is stability important, but task-based performance (or fidelity) is crucial. In this paper, we introduce a nanoscale virtual coupling (NSVC) concept and explicitly derive the relationship between performance, stability, and scaling factors of velocity (or position) and force. An available scaling factor region is represented based on Llewellyn's absolute stability criteria and the physical limitation of the haptic device. For the stable haptic interface, the sampled time passivity controller is implemented in the NVE. Experiments have been performed for telenanomanipulation tasks, such as positioning, indenting, and nanolithography with guaranteed stability in the NVE. Note to Practitioners-This paper suggests methods and control schemes for the task-based and stable telenanomanipulation in the nanoscale virtual environment (NVE). The proposed task-based and stable telenanomanipulation in the NVE can be used for an augmented human machine interface for the manipulation of nanoscale objects with the atomic force microscope (AFM). In addition, it is beneficial for learning or performing nanoscale tasks, such as nanolithography, nanoindenting, nanofabrication, and cell manipulation. Also, the interaction with the NVE using haptic device provides a useful tool for researchers in a variety of disciplines, such as biology, chemistry, and physics. Moreover, it may even be applied to educational purposes. In future research, the developed stable haptic interface would be integrated with the AFM system as a slave manipulator for telenanomanipulation experiments, such as pushing a nanoparticle with precise positioning and nanoassembly.     

群组协作社交网络关系的分析及可视化

社交网络的研究应用领域广泛,大多数的研究主要关注于社交网络结构中节点和链接的变化,研究角度较为单一.而群组协作关系在社交网络中较为普遍,为更好地探索群组协作过程中群组级别网络结构的演变,首先将组级任务添加到用于图可视化的任务分类中,针对协作关系网络的特性,设置一个适用于群组协作关系分析的任务分类法,根据此任务分类法设置探究群组协作需完成的任务;然后设计相关可视化视图,以更直观的方式展示群组之间以及群组内部协作关系的特征以及随时间推进的演变模式;最后在学术协作文献数据集上进行具体案例分析,通过用户评估实验,采用李克特量表对调查问卷进行分析,验证了设计可视化视图的有效性和实用性,可为社交网络关系分析人员提供群组协作的可视化分析方法,更便于对群组协作网络关系的进一步探究和应用.