| Performance evaluation of compromised synchronization control mechanism for distributed virtual environment (DVE) | | BIBAK | Full-Text | 1-16 | |
| Olarn Wongwirat; Shigeyuki Ohara | |||
| Synchronization in a distributed virtual environment (DVE) involves
mechanisms to ensure a consistent view of a virtual world for all participants.
Most applications in the DVE are related to collaborative activities that
include non-contention and contention cases. Using transmission of update
messages is suitable enough to support synchronization for only non-contention
activity. The contention activity requires an additional mechanism to control
accessing a common object for synchronization. In this paper, we present the
compromised synchronization control mechanism to support both non-contention
and contention activities. The mechanism employs frequent update event and
multiple-lock checking to control the synchronization. Frequent update event is
used to support a dynamic virtual world for non-contention activity.
Multiple-lock checking is embedded to ensure consistency when accessing the
common object is required simultaneously for the contention event. Performance
measurement of the compromised synchronization is provided by simulation in
terms of locking time, sampling event, number of logical processes, and traffic
tolerance. Prototype application is also implemented to compare the result in a
small scale level. Based on the simulation and experimental results, the
compromised sychronization control mechanism is capable to support up to 100
participants for the non-contention activity. It provides a good performance of
supporting the contention activity in a small scale. The mechanism is
considered suitable for collaborative application where contention is
considered a critical event. Keywords: Performance evaluation; Compromised synchronization; Dynamic shared state;
Frequent update event; Multiple-lock checking; Distributed virtual environment | |||
| A hybrid reality environment and its application to the study of earthquake engineering | | BIBAK | Full-Text | 17-33 | |
| Tara C. Hutchinson; Falko Kuester; Tung-Ju Hsieh; Rebecca Chadwick | |||
| Visualization can provide the much needed computer-assisted design and
analysis environment to foster problem-based learning, while Virtual Reality
(VR) can provide the environment for hands-on manipulation, stimulating
interactive learning in engineering and the sciences. In this paper, an
interactive 2D and 3D (hybrid) environment is described, which facilitates
collaborative learning and research and utilizes techniques in visualization
and VR, therefore enhancing the interpretation of physical problems within
these fields. The environment described, termed VizClass, incorporates a
specially designed lecture room and laboratory integrating both 2-D and 3-D
spatial activities by coupling a series of interactive projection display
boards (touch-sensitive whiteboards) and a semi-immersive 3D wall display. The
environment is particularly appealing for studying critical, complex
engineering problems, for example, where time-varying feature modifications and
coupling between multiple modes of movement are occurring. This paper describes
the hardware architecture designed for this new hybrid environment as well as
an initial application within the environment to the study of a real case
history building subjected to a variety of earthquakes. The example simulation
uses field measured seismic data sources, and illustrations of simple visual
paradigms to provide an enhanced understanding of the physical model, the
damage accumulated by the model, and the association between the measured and
observed data. A detailed evaluation survey was also conducted to determine the
merits of the presented environment and the techniques implemented. Results
substantiate the plausibility of using these techniques for more general,
everyday users. Over 70% of the survey participants believed that the
techniques implemented were valuable for engineers. Keywords: Virtual reality; Visualization; Multimodal interaction; Human-computer
interaction; Display technologies | |||
| Tell Me a Story | | BIBAK | Full-Text | 34-48 | |
| Isabel Machado; Paul Brna; Ana Paiva | |||
| For the past few years, the storytelling research domain has raised the
interest of several researchers from different areas (such as interactive
drama, computer games, intelligent learning environment etc.), mainly because
stories are an important vehicle to structure the human knowledge and past
experience, and even to help people to behave in a social context. In this
paper, we present a storytelling approach, which is based on the premise that
story and narrative may emerge from characters' interactions during the
creation activity, but such characters may either act autonomously or be
controlled by children. Since we position our research in an educational
context, we argue that in such creation activities children's thoughts and
needs must be respected and contribute directly to the achievement of the
story. Therefore, children should be provided with some support and guidance
directives to help them to better understand and reflect on the role-taking
situations they experience during such activity. To prove the validity of our
approach we developed a generic architecture -- Support And Guidance
Architecture (SAGA). SAGA aims not only to provide support and guidance to
children during the story telling activities, by combining the roles of a
dynamic script writer and a drama manager, but also to provide such services to
already existing story creation applications. To illustrate this, we have
integrated SAGA with Teatrix, a collaborative virtual environment for story
creation, and an evaluation study was conducted in order to find the impact of
SAGA in children's storytelling activities. Keywords: Virtual storytelling; Intelligent agents; Narrative; Intelligent learning
environments; Story generation | |||
| A multi-user desktop virtual environment for teaching shop-keeping to children | | BIBAK | Full-Text | 49-56 | |
| Brian M. Slator; Harold Chaput; Robert Cosmano; Ben Dischinger | |||
| Virtual role-playing environments can be a powerful mechanism of
instruction, provided they are constructed such that learning how to play and
win the game contributes to a player's understanding of real-world concepts and
procedures. North Dakota State University (NDSU) provides students with
environments to enhance their understanding of geology (Planet Oit), cellular
biology (Virtual Cell), programming languages (ProgrammingLand), retailing
(Dollar Bay), and history (Blackwood). These systems present a number of
opportunities and an equal number of challenges. Players are afforded a
role-based, multi-user, 'learn-by-doing' experience, with software agents
acting as both environmental effects and tutors and the possibilities of
multi-user cooperation and collaboration. However, technical issues and one
important cultural issue present a range of difficulties. The Dollar Bay
environment, its particular challenges, and the solutions to these are
presented. Keywords: Role-based learning systems; Multi-user learning systems; Software agents;
Intelligent software tutoring agents; Agent-based economic simulation | |||
| Efficient virtual reality design of quiet underwater shells | | BIBAK | Full-Text | 57-69 | |
| W. Akl; A. Baz | |||
| Abstract
Efficient computational tools are developed to model, visualize, and feel the structural-acoustics of shells in a virtual reality environment. These tools aim at building the structural-acoustic models of shells from an array of basic building blocks including: beams, shells, and stiffeners. The concepts of finite element analysis, sub-structuring, model reduction, meta-modeling, and parallel computations form the main steps to be followed for building simplified computational models of complex shell systems. The resulting models are particularly suitable for the efficient application of multi-criteria optimization techniques in order to select the optimal design parameters of these complex shell systems. The developed integrated analysis tools enable the engineers to design complex systems in a cost effective and a timely manner. Furthermore, engineers will be immersed in an audio-visually coupled tele-operated environment whereby direct interaction and control of the design process can be achieved. In this manner, the behavior of synthetic models of shells can be monitored by literally walking through the shell and adjusting its design parameters as needed to ensure optimal performance while satisfying design and operational requirements. For example, engineers can move electronic wands to vary the number, size, type, and location of stiffeners in the shell, monitor the resulting structural-acoustic visually or by haptic feedback and simultaneously listen to the radiated sound pressure field. Such manipulations of the virtual shells in the scene are carried out while the engineer is navigating through and around the shell to ensure that the vibration and sound levels, at any critical locations, are within the acceptable limits. The developed integrated approach also serves as a means for virtual training of students and engineers on designing and operating complex smart structures on the site as well as through collaborative efforts with other virtual reality sites. Such unique capability will enable engineers to design prototypes of expensive vehicles without building them. Examples of these vehicles include aircraft, submersibles, torpedoes, and others that can share this virtual experience and can be profoundly impacted upon by the proposed approach. The presented optimal design approach is implemented in the Virtual Reality CAVE Laboratory at the University of Maryland that is controlled by an eight parallel processor Silicon Graphics Infinite Reality (ONYX2) computer. Keywords: Finite element analysis; Sub-structural analysis; Reduced order models;
Meta-models; Multi-criteria design optimization; Design in virtual reality
environment | |||
| Neural network-based calibration of electromagnetic tracking systems | | BIBAK | Full-Text | 70-78 | |
| Volodymyr V. Kindratenko; William R. Sherman | |||
| Electromagnetic tracking systems are a common component of many virtual
reality installations. Their accuracy, however, suffers from the distortions of
the electromagnetic field used in calculating the tracker sensor's position. We
have developed a tracker calibration technique based on a neural network that
effectively compensates for the errors in both tracked location and
orientation. This case study discusses our implementation of the calibration
algorithm and compares the results with traditional calibration methods. Keywords: Tracker calibration; Electromagnetic tracker; Neural network; Virtual
reality | |||
| OpenTracker: A flexible software design for three-dimensional interaction | | BIBA | Full-Text | 79-92 | |
| Gerhard Reitmayr; Dieter Schmalstieg | |||
| Tracking is an indispensable part of any virtual reality and augmented reality application. While the need for quality of tracking, in particular for high performance and fidelity, has led to a large body of past and current research, little attention is typically paid to software engineering aspects of tracking software. To address this issue we describe a software design and implementation that applies the pipes-and-filter architectural pattern to provide a customizable and flexible way of dealing with tracking data and configurations. The contribution of this work cumulates in the development of a generic data flow network library called OpenTracker to deal specifically with tracking data. The flexibility of the data flow network approach is demonstrated in a set of development scenarios and prototype applications in the area of mobile augmented reality. | |||
| Analysis of composite gestures with a coherent probabilistic graphical model | | BIB | Full-Text | 93 | |
| Jason J. Corso; Guangqi Ye; Gregory D. Hager | |||
| Editorial: design of haptic user-interfaces and applications | | BIB | Full-Text | 95-96 | |
| Steven Wall; Stephen Brewster | |||
| Communication in a networked haptic virtual environment for temporal bone surgery training | | BIBAK | Full-Text | 97-107 | |
| Matthew A. Hutchins; Duncan R. Stevenson; Chris Gunn | |||
| Networked virtual environments using haptic interfaces can be used for
surgical training and support both a simulation component and a communication
component. We present such an environment for training in surgery of the
temporal bone, which emphasises communication between an instructor and a
student. We give an overview of the learning requirements for surgeons in this
area and present the details of our implementation with a focus on the way
communication is supported. We describe a training trial that was undertaken
with a group of surgical trainees and carry out a qualitative analysis of
transcripts from the teaching sessions. We conclude that the virtual
environment supports a rich dialogue between the instructor and student,
allowing them to ground their conversation in the shared model. Haptic
interfaces are an important enabling technology for the simulation and
communication and are used in conjunction with other modes and media to support
situated learning. Keywords: Haptic workbench; Networked virtual environments; Haptic surgical training;
Conversation analysis | |||
| Supporting visually impaired children with software agents in a multimodal learning environment | | BIBAK | Full-Text | 108-117 | |
| Rami Saarinen; Janne Järvi; Roope Raisamo; Eva Tuominen | |||
| Visually impaired children have a great disadvantage in the modern society
since their ability to use modern computer technology is limited due to
inappropriate user interfaces. The aim of the work presented in this paper was
to develop a multimodal software architecture and applications to support
learning of visually impaired children. The software architecture is based on
software agents, and has specific support for visual, auditory and haptic
interaction. It has been used successfully with different groups of 7-8
year-old and 12 year-old visually impaired children. In this paper we discuss
the enabling software technology and interaction techniques aimed to realize
our goal and our experiences in the actual use of the system. Keywords: Multimodal interaction; Software agent architecture; Visually impaired
children; Learning environments; Haptics; Auditory feedback | |||
| Stroke-based modeling and haptic skill display for Chinese calligraphy simulation system | | BIBA | Full-Text | 118-132 | |
| Daniel Wang; Yuru Zhang; Chong Yao | |||
| The goal of this paper is to study haptic skill representation and display in a Chinese calligraphy training system. The challenge is to model haptic skill during the writing of different strokes in Chinese characters and to achieve haptic rendering with high fidelity and stability. The planning of the writing process is organized at three levels: task, representation and device level to describe the haptic handwriting skill. State transition graph (STG) is proposed to describe switches between tasks during the handwriting. Chinese characters are modeled using 39 typical strokes, which are further grouped into basic and compound strokes. The compound stroke is considered to be sequential combination of the basic strokes. Straight and curve strokes are modeled using line segment and the Bezier curve, respectively. Information from STG is used for real-time collision detection and haptic rendering. Ambiguity of the collision detection at stroke-corner points is prevented using active stroke combined with local nearest point computation. A modified virtual fixture method is developed for haptic rendering. The approach is tested on a prototype training system using Phantom desktop. Initial experiments suggest that the proposed modeling and rendering method is effective. | |||
| A novel multimodal interface for improving visually impaired people's web accessibility | | BIBAK | Full-Text | 133-148 | |
| Wai Yu; Ravi Kuber; Emma Murphy; Philip Strain; Graham McAllister | |||
| This paper introduces a novel interface designed to help blind and visually
impaired people to explore and navigate on the Web. In contrast to
traditionally used assistive tools, such as screen readers and magnifiers, the
new interface employs a combination of both audio and haptic features to
provide spatial and navigational information to users. The haptic features are
presented via a low-cost force feedback mouse allowing blind people to interact
with the Web, in a similar fashion to their sighted counterparts. The audio
provides navigational and textual information through the use of non-speech
sounds and synthesised speech. Interacting with the multimodal interface offers
a novel experience to target users, especially to those with total blindness. A
series of experiments have been conducted to ascertain the usability of the
interface and compare its performance to that of a traditional screen reader.
Results have shown the advantages that the new multimodal interface offers
blind and visually impaired people. This includes the enhanced perception of
the spatial layout of Web pages, and navigation towards elements on a page.
Certain issues regarding the design of the haptic and audio features raised in
the evaluation are discussed and presented in terms of recommendations for
future work. Keywords: Multimodal interface; Haptics; Audio; Assistive technology; Web
accessibility; Web navigation | |||
| Mediated social touch: a review of current research and future directions | | BIBAK | Full-Text | 149-159 | |
| Antal Haans; Wijnand IJsselsteijn | |||
| In this paper, we review research and applications in the area of mediated
or remote social touch. Whereas current communication media rely predominately
on vision and hearing, mediated social touch allows people to touch each other
over a distance by means of haptic feedback technology. Overall, the reviewed
applications have interesting potential, such as the communication of simple
ideas (e.g., through Hapticons), establishing a feeling of connectedness
between distant lovers, or the recovery from stress. However, the beneficial
effects of mediated social touch are usually only assumed and have not yet been
submitted to empirical scrutiny. Based on social psychological literature on
touch, communication, and the effects of media, we assess the current research
and design efforts and propose future directions for the field of mediated
social touch. Keywords: Physical contact; Social touch; Interpersonal interaction; Literature
review; Computer mediated communication; Haptic feedback | |||
| A haptic interface for computer-integrated endoscopic surgery and training | | BIBAK | Full-Text | 160-176 | |
| M. Tavakoli; R. V. Patel; M. Moallem | |||
| Haptic feedback has the potential to provide superior performance in
computer-integrated surgery and training. This paper discusses the design of a
user interface that is capable of providing force feedback in all the degrees
of freedom (DOFs) available during endoscopic surgery. Using the Jacobian
matrix of the haptic interface and its singular values, methods are proposed
for analysis and optimization of the interface performance with regard to the
accuracy of force feedback, the range of applicable forces, and the accuracy of
control. The haptic user interface is used with a sensorized slave robot to
form a master-slave test-bed for studying haptic interaction in a minimally
invasive environment. Using the master-slave test-bed, teleoperation
experiments involving a single degree of freedom surgical task (palpation) are
conducted. Different bilateral control methods are compared based on the
transparency of the master-slave system in terms of transmitting the critical
task-related information to the user in the context of soft-tissue surgical
applications. Keywords: Endoscopic surgery; Robot-assisted surgery; Haptic interface; Force
observer; Master-slave teleoperation; VRPN; Bilateral control; Transparency;
Soft tissue | |||
| Guidelines for haptic interpersonal communication applications: an exploration of foot interaction styles | | BIBAK | Full-Text | 177-191 | |
| A. F. Rovers; H. A. van Essen | |||
| A new method for researching haptic interaction styles is presented, based
on a layered interaction model and a classification of existing devices. The
method is illustrated by designing a new foot interaction device. The aim of
which is to enhance non-verbal communication over a computer network. A layered
protocols interaction model allows to consider all aspects of the haptic
communication process: the intention to perform an action, limitations of the
human body, and specifications of the communication device and the network. We
demonstrate how this model can be used to derive design-guidelines by analyzing
and classifying existing communication devices. By designing and evaluating a
foot interaction device, we not only demonstrate that feet are suited for
personal, concealed communication over a network, but also show the added value
of the design-guidelines. Results of user tests provide clues for designing
stimuli for foot interaction and indicate applications of foot communication
devices. Keywords: Haptic interaction; Foot interaction; Layered protocols; Communication;
Hapticons | |||
| Haptic modeling in the conceptual phases of product design | | BIBAK | Full-Text | 192-202 | |
| M. Bordegoni; U. Cugini | |||
| The paper presents the results of a research project aimed at developing an
innovative system for modeling industrial products based on haptic technology.
The system consists of a Computer Aided Design (CAD) system enhanced with
intuitive designer-oriented interaction tools and modalities. The system
integrates innovative six degrees of freedom (DOF) haptic tools for modeling
digital shapes, with sweep operators applied to class-A surfaces and force
computation models based on chip formation models. The system aims at
exploiting designers' existing skills in modeling products, improving the
products design process by reducing the necessity of building several physical
models for evaluating and testing the product designs. The system requirements
have been defined observing designers during their daily work and translating
the way they model shapes using hands and craft tools into specifications for
the modeling system and the haptic tool. The system prototype has been tested
by designers who have found it intuitive and effective to use. Keywords: Virtual prototyping; Product design; Haptics; Haptic modeling | |||
| Wearable vibrotactile systems for virtual contact and information display | | BIBAK | Full-Text | 203-213 | |
| Robert W. Lindeman; Yasuyuki Yanagida; Haruo Noma; Kenichi Hosaka | |||
| This paper presents a development history of a wearable, scalable
vibrotactile stimulus delivery system. This history has followed a path from
desktop-based, fully wired systems, through hybrid approaches consisting of a
wireless connection from the host computer to a body-worn control box and wires
to each tactor, to a completely wireless system employing Bluetooth technology
to connect directly from the host to each individual tactor unit. Applications
for such a system include delivering vibrotactile contact cues to users of
virtual environments, providing directional cues in order to increase
situational awareness in both real and virtual environments, and for general
information display in wearable contexts. Through empirical study, we show that
even a simple configuration, such as eight tactors arrayed around the torso,
can be effective in increasing situational awareness in a building-clearing
task, compared to users who perform the same task without the added cues. Keywords: Vibrotactile; Tactile; Wearable; Feedback; Human-computer interaction | |||
| Virtual reality design techniques for web-based historical reconstructions | | BIBAK | Full-Text | 215-225 | |
| Kevin Badni | |||
| Due to increases in personal computer power and available bandwidths, 3D
worlds are becoming increasingly accessible over the Internet, allowing viewers
to freely explore virtual constructed worlds. However, even with advances in
computing power and bandwidths, creating realistic 3D worlds which are fast
downloading and are pleasurable to navigate around requires a number of design
techniques to be employed. The aim of this paper is to describe the design
techniques used in a redesign of a web-based virtual reality reconstruction of
an historical site describing how different techniques can be used to optimise
download times yet retain historical realism. The techniques and processes can
be used as a guide by any designer to help create lightweight realistic virtual
models. Keywords: VRML; Design methodologies; Visualisation techniques; On-line constraints | |||
| Subjective performance | | BIBA | Full-Text | 226-233 | |
| Karsten Bormann | |||
| Much effort has gone into exploring the concept of presence in virtual environments. One of the reasons for this is the possible link between presence and performance, which has also received a fair amount of attention. However, the performance side of this equation has been largely ignored. That is, without much discussion, researchers tend to equate performance with measured performance on some specific task. But if presence is a measure of overall acceptance of the virtual experience can we get away with any less than assessing all aspects of user performance? This is a problem as we can neither measure everything subjects do nor determine the weights or importance of all subtasks carried out during task completion by any given user. The way around this may be to ask subjects to assess their own performance, call it subjective performance. This notion is explored in the context of an experiment that investigated the presence-performance relationship by decoupling the variation in spatial audio fidelity (the one independent variable) from its relevance to the search task at hand (the other independent variable). It was found that while presence showed no correlation with task time presence did exhibit a fairly strong correlation with subjective performance. | |||
| The contribution of virtual reality to research on sensory feedback in remote control | | BIBAK | Full-Text | 234-242 | |
| Barry Richardson; Mark Symmons; Dianne Wuillemin | |||
| Here we consider research on the kinds of sensory information most effective
as feedback during remote control of machines, and the role of virtual reality
and telepresence in that research. We argue that full automation is a distant
goal and that remote control deserves continued attention and improvement.
Visual feedback to controllers has developed in various ways but
autostereoscopic displays have yet to be proven. Haptic force feedback, in both
real and virtual settings, has been demonstrated to offer much to the remote
control environment and has led to a greater understanding of the kinesthetic
and cutaneous components of haptics, and their role in multimodal processes,
such as sensory capture and integration. We suggest that many displays using
primarily visual feedback would benefit from the addition of haptic information
but that much is yet to be learned about optimizing such displays. Keywords: Haptic; Feedback; Active; Passive; Kinesthetic; Cutaneous; Virtual reality;
Perception | |||
| Identification of real objects under conditions similar to those in haptic displays: providing spatially distributed information at the contact areas is more important than increasing the number of areas | | BIBAK | Full-Text | 243-249 | |
| Gunnar Jansson; Linda Monaci | |||
| Present day haptic displays have one or a few contact areas, the information
being similar over the whole area. The aim of this investigation was to study
the relative importance of increasing the number of contact areas and providing
spatially distributed information at each contact area. Technical development
was "simulated" in experiments with real objects where the information was
constrained in ways similar to those in haptic displays. The results suggest
clearly that the largest improvement can be expected if spatially distributed
information is made available within each contact area. If that is made, an
improvement of performance can be expected also with an increased number of
contact areas. Increasing only the number of contact areas will not give the
same result. Keywords: Haptic displays; Technical development; Contact areas; Spatially distributed
cutaneous information | |||
| Freshly squeezed touch into bits: towards the development of a haptic design palette | | BIBAK | Full-Text | 250-259 | |
| Simone Gumtau | |||
| Haptic interfaces have the potential to enhance communication and
interaction via the computer-enabling affective expressive interpersonal
communication and enriching interaction by haptic feedback. Still, what exactly
their potential is and how we can design in order to fulfil it remains topic of
contemporary debate. My contribution to this debate shall be to place some of
the current developments into a philosophical and cultural context and to
introduce social science based methodologies, which will help broaden the
discussion and scope of input. Through semiotic analysis, we can predict
'meaning making' in haptic communication that goes beyond linguistic
description. Examples of Haptic interfaces shall be positioned as case studies
in this typology. Also, I describe the Haptic Box and PinKom as my way of
investigating a semiotic system of touch. In conclusion, this paper hopes to
inform and catalyse the development of a haptic design palette. Keywords: Haptic; Communication; Semiotics; Affect; Social; Culture | |||
| Linking GIS with real-time visualisation for exploration of landscape changes in rural community workshops | | BIBAK | Full-Text | 260-270 | |
| Christian Stock; Ian D. Bishop | |||
| To allow rural communities to evaluate possible future landscape scenarios,
we have created a portable environment for landscape simulation (envisioning
system). The goal of this system is to give communities the opportunity to plan
their desired futures. Our system is designed for workshop environments and
allows workshop attendees to explore and to interact with representations of
virtual landscapes. We are using virtual reality technology to visualise the
landscape representations, a geographic information system to allow
participants to change the current landscape configuration, and mobile
computing devices to allow the attendees to navigate in the virtual landscape,
and give feedback and opinions on the landscape changes. Here, we describe the
technology that implements the interaction between geographical information
systems and real-time rendering needed to achieve real-time visualisation of
landscape changes. To achieve this functionality we have programmed two
software clients (a renderer and an ESRI ArcMap extension) and a server that
handles message flow. The landscape has been divided into management units that
each supports one land use type. Using the GIS interface, users can change the
land uses associated to the units and the renderer will update the landscape
correspondingly in real time. Keywords: Envisioning systems; Virtual reality; Geographic information systems;
Community values | |||