High availability using virtualization

International Nuclear Information System (INIS)

Calzolari, Federico; Arezzini, Silvia; Ciampa, Alberto; Mazzoni, Enrico; Domenici, Andrea; Vaglini, Gigliola

2010-01-01

High availability has always been one of the main problems for a data center. Till now high availability was achieved by host per host redundancy, a highly expensive method in terms of hardware and human costs. A new approach to the problem can be offered by virtualization. Using virtualization, it is possible to achieve a redundancy system for all the services running on a data center. This new approach to high availability allows the running virtual machines to be distributed over a small number of servers, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The 3RC system is based on a finite state machine, providing the possibility to restart each virtual machine over any physical host, or reinstall it from scratch. A complete infrastructure has been developed to install operating system and middleware in a few minutes. To virtualize the main servers of a data center, a new procedure has been developed to migrate physical to virtual hosts. The whole Grid data center SNS-PISA is running at the moment in virtual environment under the high availability system.

Virtual reality - aesthetic consequences

OpenAIRE

Benda, Lubor

2014-01-01

In the present work we study aesthetic consequences of virtual reality. Exploring the fringe between fictional and virtual is one of the key goals, that will be achieved through etymologic and technologic definition of both fiction and virtual reality, fictional and virtual worlds. Both fiction and virtual reality will be then studied from aesthetic distance and aesthetic pleasure point of view. At the end, we will see the main difference as well as an common grounds between fiction and virtu...

Super-virtual Interferometric Separation and Enhancement of Back-scattered Surface Waves

KAUST Repository

Guo, Bowen

2015-08-19

Back-scattered surface waves can be migrated to detect near-surface reflectors with steep dips. A robust surface-wave migration requires the prior separation of the back-scattered surface-wave events from the data. This separation is often difficult to implement because the back-scattered surface waves are masked by the incident surface waves. We mitigate this problem by using a super-virtual interferometric method to enhance and separate the back-scattered surface waves. The key idea is to calculate the virtual back-scattered surface waves by stacking the resulting virtual correlated and convolved traces associated with the incident and back-scattered waves. Stacking the virtual back-scattered surface waves improves their signal-to-noise ratio and separates the back-scattered surface-waves from the incident field. Both synthetic and field data results validate the robustness of this method.

Leader competencies in virtual organization

OpenAIRE

Bulinska-Stangrecka, Helena

2018-01-01

This paper discusses the competence required in the leadership of virtual organization. The specics of virtual organization presents a challenge to traditional managerial styles. In order to achieve success in virtual environment, a leader must develop specic abilities. This analysis examines the uniqueness of the virtual organization, including team work and management. The last part presents ndings and summaries regarding e€ective e-leadership requirement. A virtual leader ma...

Virtual Campus Hub technical evaluation report

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future.......This report describes and discusses the technical achievements of the Virtual Campus Hub project and formulates a brief agenda for the future....

The Effect of Virtual versus Traditional Learning in Achieving Competency-Based Skills

Science.gov (United States)

Mosalanejad, Leili; Shahsavari, Sakine; Sobhanian, Saeed; Dastpak, Mehdi

2012-01-01

Background: By rapid developing of the network technology, the internet-based learning methods are substituting the traditional classrooms making them expand to the virtual network learning environment. The purpose of this study was to determine the effectiveness of virtual systems on competency-based skills of first-year nursing students.…

Virtual photon spectra for finite nuclei

International Nuclear Information System (INIS)

Wolynec, E.; Martins, M.N.

1988-01-01

The experimental results of an isochromat of the virtual photon spectrum, obtained by measuring the number of ground-state protons emitted by the 16.28 MeV isobaric analogue state in 90 Zr as a function of electron incident energy in the range 17-105 MeV, are compared with the values predicted by a calculation of the E1 DWBA virtual photon spectra for finite nuclei. It is found that the calculations are in excellent agreement with the experimental results. The DWBA virtual photon spectra for finite nuclei for E2 and M1 multipoles are also assessed. (author) [pt

Thermal processes identification using virtual instrumentation

Directory of Open Access Journals (Sweden)

Iosif OLAH

2007-12-01

Full Text Available In this paper the experimental identification problem of thermal processes is presented, in order to establish their mathematical models which permit the adoption of the automation solutions, respectively the specification of a suitable control law. With this aim in view, the authors resorted to use Virtual Instrumentation with the aid of the LabVIEW development medium. In order to solve the problem of acquisition and processing data from physical real processes, Virtual Instruments which provide at the end a mathematical model which is basis of choosing the automation equipment of the aim followed was designed and achieved. The achieved Virtual Instruments get the opportunity to be used either in student instruction field with the virtual processes identification techniques or to put the identification of some real processes to good use of diverse beneficiaries. The results of some experimental attempts which were achieved during different thermal processes, illustrate the utility of the demarches performed in this paper.

Virtual Reality Design: How Head-Mounted Displays Change Design Paradigms of Virtual Reality Worlds

Directory of Open Access Journals (Sweden)

Christian Stein

2016-09-01

Full Text Available With the upcoming generation of virtual reality HMDs, new virtual worlds, scenarios, and games are created especially for them. These are no longer bound to a remote screen or a relatively static user, but to an HMD as a more immersive device. This article discusses requirements for virtual scenarios implemented in new-generation HMDs to achieve a comfortable user experience. Furthermore, the effects of positional tracking are introduced and the relation between the user’s virtual and physical body is analyzed. The observations made are exemplified by existing software prototypes. They indicate how the term “virtual reality,” with all its loaded connotations, may be reconceptualized to express the peculiarities of HMDs in the context of gaming, entertainment, and virtual experiences.

Effect of a Virtual Chemistry Laboratory on Students' Achievement

Science.gov (United States)

Tatli, Zeynep; Ayas, Alipasa

2013-01-01

It is well known that laboratory applications are of significant importance in chemistry education. However, laboratory applications have generally been neglected in recent educational environments for a variety of reasons. In order to address this gap, this study examined the effect of a virtual chemistry laboratory (VCL) on student achievement…

Has your greenhouse gone virtual?

Science.gov (United States)

Virtual Grower is a free decision-support software program available from USDA-ARS that allows growers to build a virtual greenhouse. It was initially designed to help greenhouse growers estimate heating costs and conduct simple simulations to figure out where heat savings could be achieved. Featu...

A Further Characterization of Empirical Research Related to Learning Outcome Achievement in Remote and Virtual Science Labs

Science.gov (United States)

Brinson, James R.

2017-10-01

This paper further characterizes recently reviewed literature related to student learning outcome achievement in non-traditional (virtual and remote) versus traditional (hands-on) science labs, as well as factors to consider when evaluating the state and progress of research in this field as a whole. Current research is characterized according to (1) participant nationality and culture, (2) participant education level, (3) participant demography, (4) scientific discipline, and (5) research methodology, which could provide avenues for further research and useful dialog regarding the measurement and interpretation of data related to student learning outcome achievement in, and thus the efficacy of, non-traditional versus traditional science labs. Current research is also characterized by (6) research publication media and (7) availability of non-traditional labs used, which demonstrate some of the obstacles to progress and consensus in this research field.

Designing presence for real locomotion in immersive virtual environments

DEFF Research Database (Denmark)

Turchet, Luca

2015-01-01

This paper describes a framework for designing systems for real locomotion in virtual environments (VEs) in order to achieve an intense sense of presence. The main outcome of the present research is a list of design features that the virtual reality technology should have in order to achieve...

How to Achieve Better Results Using PASS-Based Virtual Screening: Case Study for Kinase Inhibitors

Directory of Open Access Journals (Sweden)

Pavel V. Pogodin

2018-04-01

Full Text Available Discovery of new pharmaceutical substances is currently boosted by the possibility of utilization of the Synthetically Accessible Virtual Inventory (SAVI library, which includes about 283 million molecules, each annotated with a proposed synthetic one-step route from commercially available starting materials. The SAVI database is well-suited for ligand-based methods of virtual screening to select molecules for experimental testing. In this study, we compare the performance of three approaches for the analysis of structure-activity relationships that differ in their criteria for selecting of “active” and “inactive” compounds included in the training sets. PASS (Prediction of Activity Spectra for Substances, which is based on a modified Naïve Bayes algorithm, was applied since it had been shown to be robust and to provide good predictions of many biological activities based on just the structural formula of a compound even if the information in the training set is incomplete. We used different subsets of kinase inhibitors for this case study because many data are currently available on this important class of drug-like molecules. Based on the subsets of kinase inhibitors extracted from the ChEMBL 20 database we performed the PASS training, and then applied the model to ChEMBL 23 compounds not yet present in ChEMBL 20 to identify novel kinase inhibitors. As one may expect, the best prediction accuracy was obtained if only the experimentally confirmed active and inactive compounds for distinct kinases in the training procedure were used. However, for some kinases, reasonable results were obtained even if we used merged training sets, in which we designated as inactives the compounds not tested against the particular kinase. Thus, depending on the availability of data for a particular biological activity, one may choose the first or the second approach for creating ligand-based computational tools to achieve the best possible results in

Can Virtual Schools Thrive in the Real World?

Science.gov (United States)

Wang, Yinying; Decker, Janet R.

2014-01-01

Despite the relatively large number of students enrolled in Ohio's virtual schools, it is unclear how virtual schools compare to their traditional school counterparts on measures of student achievement. To provide some insight, we compared the school performance from 2007-2011 at Ohio's virtual and traditional schools. The results suggest that…

Applied virtual reality

International Nuclear Information System (INIS)

Yule, I.Y.; Lee, D.J.

1996-01-01

To reduce plant down time during irradiated fuel cell dismantling at Torness Power Station, a new visualisation technique has been used for the manipulator. Complex computer graphics packages were used to provide a ''Virtual Reality'' environment which allowed the Irradiated Fuel Dismantling Cell to be simulated. Significant cost savings have been achieved due to reductions in lost output. The virtual reality environment is at present being extended to the design and deployment of a new manipulator for in-vessel inspection of the boiler. (UK)

Worldwide R&D of Virtual Observatory

Science.gov (United States)

Cui, C. Z.; Zhao, Y. H.

2008-07-01

Virtual Observatory (VO) is a data intensive online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless and uniform access to astronomical information. The concept of VO was introduced in the late 1990s to meet the challenges brought up with data avalanche in astronomy. In the paper, current status of International Virtual Observatory Alliance, technical highlights from world wide VO projects are reviewed, a brief introduction of Chinese Virtual Observatory is given.

Bystander responses to a violent incident in an immersive virtual environment.

Science.gov (United States)

Slater, Mel; Rovira, Aitor; Southern, Richard; Swapp, David; Zhang, Jian J; Campbell, Claire; Levine, Mark

2013-01-01

Under what conditions will a bystander intervene to try to stop a violent attack by one person on another? It is generally believed that the greater the size of the crowd of bystanders, the less the chance that any of them will intervene. A complementary model is that social identity is critical as an explanatory variable. For example, when the bystander shares common social identity with the victim the probability of intervention is enhanced, other things being equal. However, it is generally not possible to study such hypotheses experimentally for practical and ethical reasons. Here we show that an experiment that depicts a violent incident at life-size in immersive virtual reality lends support to the social identity explanation. 40 male supporters of Arsenal Football Club in England were recruited for a two-factor between-groups experiment: the victim was either an Arsenal supporter or not (in-group/out-group), and looked towards the participant for help or not during the confrontation. The response variables were the numbers of verbal and physical interventions by the participant during the violent argument. The number of physical interventions had a significantly greater mean in the in-group condition compared to the out-group. The more that participants perceived that the Victim was looking to them for help the greater the number of interventions in the in-group but not in the out-group. These results are supported by standard statistical analysis of variance, with more detailed findings obtained by a symbolic regression procedure based on genetic programming. Verbal interventions made during their experience, and analysis of post-experiment interview data suggest that in-group members were more prone to confrontational intervention compared to the out-group who were more prone to make statements to try to diffuse the situation.

Bystander responses to a violent incident in an immersive virtual environment.

Directory of Open Access Journals (Sweden)

Mel Slater

Full Text Available Under what conditions will a bystander intervene to try to stop a violent attack by one person on another? It is generally believed that the greater the size of the crowd of bystanders, the less the chance that any of them will intervene. A complementary model is that social identity is critical as an explanatory variable. For example, when the bystander shares common social identity with the victim the probability of intervention is enhanced, other things being equal. However, it is generally not possible to study such hypotheses experimentally for practical and ethical reasons. Here we show that an experiment that depicts a violent incident at life-size in immersive virtual reality lends support to the social identity explanation. 40 male supporters of Arsenal Football Club in England were recruited for a two-factor between-groups experiment: the victim was either an Arsenal supporter or not (in-group/out-group, and looked towards the participant for help or not during the confrontation. The response variables were the numbers of verbal and physical interventions by the participant during the violent argument. The number of physical interventions had a significantly greater mean in the in-group condition compared to the out-group. The more that participants perceived that the Victim was looking to them for help the greater the number of interventions in the in-group but not in the out-group. These results are supported by standard statistical analysis of variance, with more detailed findings obtained by a symbolic regression procedure based on genetic programming. Verbal interventions made during their experience, and analysis of post-experiment interview data suggest that in-group members were more prone to confrontational intervention compared to the out-group who were more prone to make statements to try to diffuse the situation.

Radiation incidents in dentistry

International Nuclear Information System (INIS)

Lovelock, D.J.

1996-01-01

Most dental practitioners act as their own radiographer and radiologist, unlike their medical colleagues. Virtually all dental surgeons have a dental X-ray machine for intraoral radiography available to them and 40% of dental practices have equipment for dental panoramic tomography. Because of the low energy of X-ray equipment used in dentistry, radiation incidents tend to be less serious than those associated with other aspects of patient care. Details of 47 known incidents are given. The advent of the 1985 and 1988 Ionising Radiation Regulations has made dental surgeons more aware of the hazards of radiation. These regulations, and general health and safety legislation, have led to a few dental surgeons facing legal action. Because of the publicity associated with these court cases, it is expected that there will be a decrease in radiation incidents arising from the practice of dentistry. (author)

Virtual Telescope Alignment System

Data.gov (United States)

National Aeronautics and Space Administration — Next-generation space telescopes require two spacecraft to fly in a coordinated fashion in space forming a virtual telescope. Achieving and maintaining this precise...

Realistic Visualization of Virtual Views

DEFF Research Database (Denmark)

Livatino, Salvatore

2005-01-01

that can be impractical and sometime impossible. In addition, the artificial nature of data often makes visualized virtual scenarios not realistic enough. Not realistic in the sense that a synthetic scene is easy to discriminate visually from a natural scene. A new field of research has consequently...... developed and received much attention in recent years: Realistic Virtual View Synthesis. The main goal is a high fidelity representation of virtual scenarios while easing modeling and physical phenomena simulation. In particular, realism is achieved by the transfer to the novel view of all the physical...... phenomena captured in the reference photographs, (i.e. the transfer of photographic-realism). An overview of most prominent approaches in realistic virtual view synthesis will be presented and briefly discussed. Applications of proposed methods to visual survey, virtual cinematography, as well as mobile...

Managing virtual machines with Vac and Vcycle

Science.gov (United States)

McNab, A.; Love, P.; MacMahon, E.

2015-12-01

We compare the Vac and Vcycle virtual machine lifecycle managers and our experiences in providing production job execution services for ATLAS, CMS, LHCb, and the GridPP VO at sites in the UK, France and at CERN. In both the Vac and Vcycle systems, the virtual machines are created outside of the experiment's job submission and pilot framework. In the case of Vac, a daemon runs on each physical host which manages a pool of virtual machines on that host, and a peer-to-peer UDP protocol is used to achieve the desired target shares between experiments across the site. In the case of Vcycle, a daemon manages a pool of virtual machines on an Infrastructure-as-a-Service cloud system such as OpenStack, and has within itself enough information to create the types of virtual machines to achieve the desired target shares. Both systems allow unused shares for one experiment to temporarily taken up by other experiements with work to be done. The virtual machine lifecycle is managed with a minimum of information, gathered from the virtual machine creation mechanism (such as libvirt or OpenStack) and using the proposed Machine/Job Features API from WLCG. We demonstrate that the same virtual machine designs can be used to run production jobs on Vac and Vcycle/OpenStack sites for ATLAS, CMS, LHCb, and GridPP, and that these technologies allow sites to be operated in a reliable and robust way.

Rationalizing virtual reality based on manufacturing paradigms

NARCIS (Netherlands)

Damgrave, Roy Gerhardus Johannes; Lutters, Diederick; Drukker, J. W.

2014-01-01

Comparing the evolvement of the manufacturing industry of the last century to the way virtual reality is used nowadays some remarkable similarities come to light. Current virtual reality equipment requires a high level of craftsmanship to achieve the maximum results, and often equipment is specially

Virtual Machine Replication on Achieving Energy-Efficiency in a Cloud

Directory of Open Access Journals (Sweden)

Subrota K. Mondal

2016-07-01

Full Text Available The rapid growth in cloud service demand has led to the establishment of large-scale virtualized data centers in which virtual machines (VMs are used to handle user requests for service. A user’s request cannot be completed if the VM fails. Replication mechanisms can be used to mitigate the impact of failures. Further, data centers consume a large amount of energy resulting in high operating costs and contributing to significant greenhouse gas (GHG emissions. In this paper, we focus on Infrastructure as a Service (IaaS cloud where user job requests are processed by VMs and analyze the effectiveness of VM replications in terms of job completion time performance as well as energy consumption. Three different schemes: cold, warm, and hot replications are considered. The trade-offs between job completion time and energy consumption in different replication schemes are characterized through comprehensive analytical models which capture VM state transitions and associated power consumption patterns. The effectiveness of replication schemes are demonstrated through experimental results. To verify the validity of the proposed analytical models, we extend the widely used cloud simulator CloudSim and compare the simulation results with analytical solutions.

Virtual instrument automation of ion channeling setup for 1.7 MV tandetron accelerator

International Nuclear Information System (INIS)

Suresh, K.; Sundaravel, B.; Panigrahi, B.K.; Nair, K.G.M.; Viswanathan, B.

2004-01-01

A virtual instrument based automated ion channeling experimental setup has been developed and implemented in a 1.7 MV tandetron accelerator. Automation of the PC based setup is done using a windows based virtual instrument software allowing the setup to be easily ported between different computer operating systems. The virtual instrument software has been chosen to achieve quick and easy development of versatile, multi-purpose user friendly graphical interface for carrying out channeling experiments. The software has been modular designed to provide independent control of the stepper motors for fixing the sample at any user defined orientation, running and on-line display of azimuthal and tilt angular scans, auto storage of the angular scan data. Using this automated setup, the crystallographic axis of the sample can be aligned with the incident ion beam rapidly minimizing the beam damages to the sample. A standard single crystalline GaAs(100) has been characterized with this set up using 2 MeV He ++ ion beam. The crystalline quality (χ min ) and channeling half angle (ψ 1sol2 ) are measured to be 3.7% and 0.48 deg., respectively, which are close to the theoretical values. Salient features, working principles and design details of the automated setup are discussed in this paper

Survey on the virtual commissioning of manufacturing systems

Directory of Open Access Journals (Sweden)

Chi G. Lee

2014-07-01

Full Text Available This paper reviews and identifies issues in the application of virtual commissioning technology for automated manufacturing systems. While the real commissioning of a manufacturing system involves a real plant system and a real controller, the virtual commissioning deals with a virtual plant model and a real controller. The expected benefits of virtual commissioning are the reduction of debugging and correction efforts during the subsequent real commissioning stage. However, it requires a virtual plant model and hence still requires significant amount time and efforts. Two main issues are identified, the physical model construction of a virtual device, and the logical model construction of a virtual device. This paper reviews the current literature related to the two issues and proposes future research directions to achieve the full utilization of virtual commissioning technology.

Virtual Reality as Innovative Approach to the Interior Designing

Science.gov (United States)

Kaleja, Pavol; Kozlovská, Mária

2017-06-01

We can observe significant potential of information and communication technologies (ICT) in interior designing field, by development of software and hardware virtual reality tools. Using ICT tools offer realistic perception of proposal in its initial idea (the study). A group of real-time visualization, supported by hardware tools like Oculus Rift HTC Vive, provides free walkthrough and movement in virtual interior with the possibility of virtual designing. By improving of ICT software tools for designing in virtual reality we can achieve still more realistic virtual environment. The contribution presented proposal of an innovative approach of interior designing in virtual reality, using the latest software and hardware ICT virtual reality technologies

Virtual gap dielectric wall accelerator

Science.gov (United States)

Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

2013-11-05

A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

ENHANCING SPIRITUALISM IN VIRTUAL WORLD

Directory of Open Access Journals (Sweden)

Kiran Lata DANGWAL

2012-04-01

Full Text Available Spiritualism is one word which puts man on the highest plinth of life. Spirituality is the way we find meaning, hope, comfort and inner peace in life. Spirituality in the virtual World is generally known as Virtual Spirituality. A goldmine of wisdom from all kinds of religious and spiritual philosophies, traditions and practices can be found in virtual World now. Technology and Spirituality together forms the material to which man can incline on to and work for the development of a globe in which war will be considered a taboo and violence a rejected dogma. Therefore there is an urgent nee to made the world a safe place to live in and the spiritual reconstruction can help us in achieving this.Spiritualism, Virtual World, Online Technology.

Photo-Realistic Image Synthesis and Virtual Cinematography

DEFF Research Database (Denmark)

Livatino, Salvatore

2005-01-01

Realistic Virtual View Synthesis is a new field of research that has received increasing attention in recent years. It is strictly related to the grown popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer generated...... characters, "virtual actors", in the motion picture production increases every day. While the most known computer graphics techniques have largely been adopted successfully in nowadays fictions, it still remains very challenging to implement virtual actors which would resemble, visually, human beings....... Interestingly, film directors have been looking at the recent progress achieved by the research community in the field of realistic visualization of virtual views, and they have successfully implemented state of the art research approaches in their productions. An innovative concept is then gaining consensus...

Collaborative Educational Systems in the Virtual Environment

Directory of Open Access Journals (Sweden)

Cristian CIUREA

2012-01-01

Full Text Available The work leads to an original approach to the construction of collaborative systems metrics. The approach is based both on research already conducted by the author, on the experimental results obtained, and the foundation taken from the specific literature. The collaborative systems in knowledge-based economy are formalized and their characteristics are identified. The virtual campus structure is described and a comparison with the classical university is achieved. The architecture of virtual is designed and the categories of agents in virtual campus are analyzed.

Effectiveness of Collaborative Learning with 3D Virtual Worlds

Science.gov (United States)

Cho, Young Hoan; Lim, Kenneth Y. T.

2017-01-01

Virtual worlds have affordances to enhance collaborative learning in authentic contexts. Despite the potential of collaborative learning with a virtual world, few studies investigated whether it is more effective in student achievements than teacher-directed instruction. This study investigated the effectiveness of collaborative problem solving…

Dynamic management of geographic data in a virtual environment

NARCIS (Netherlands)

Jense, G.J.; Donkers, K.

1996-01-01

In order to achieve true 3D user interaction with geographic information, an interface between a virtual environment system and a geographic information system has been designed and implemented. This VE/GIS interface is based on a loose coupling of the underlying geographic database and the virtual

Effect of Virtual Analytical Chemistry Laboratory on Enhancing Student Research Skills and Practices

Science.gov (United States)

Bortnik, Boris; Stozhko, Natalia; Pervukhina, Irina; Tchernysheva, Albina; Belysheva, Galina

2017-01-01

This article aims to determine the effect of a virtual chemistry laboratory on university student achievement. The article describes a model of a laboratory course that includes a virtual component. This virtual component is viewed as a tool of student pre-lab autonomous learning. It presents electronic resources designed for a virtual laboratory…

Robust hopping based on virtual pendulum posture control

International Nuclear Information System (INIS)

Sharbafi, Maziar A; Ahmadabadi, Majid Nili; Yazdanpanah, Mohammad J; Maufroy, Christophe; Seyfarth, Andre

2013-01-01

A new control approach to achieve robust hopping against perturbations in the sagittal plane is presented in this paper. In perturbed hopping, vertical body alignment has a significant role for stability. Our approach is based on the virtual pendulum concept, recently proposed, based on experimental findings in human and animal locomotion. In this concept, the ground reaction forces are pointed to a virtual support point, named virtual pivot point (VPP), during motion. This concept is employed in designing the controller to balance the trunk during the stance phase. New strategies for leg angle and length adjustment besides the virtual pendulum posture control are proposed as a unified controller. This method is investigated by applying it on an extension of the spring loaded inverted pendulum (SLIP) model. Trunk, leg mass and damping are added to the SLIP model in order to make the model more realistic. The stability is analyzed by Poincaré map analysis. With fixed VPP position, stability, disturbance rejection and moderate robustness are achieved, but with a low convergence speed. To improve the performance and attain higher robustness, an event-based control of the VPP position is introduced, using feedback of the system states at apexes. Discrete linear quartic regulator is used to design the feedback controller. Considerable enhancements with respect to stability, convergence speed and robustness against perturbations and parameter changes are achieved. (paper)

High-power microwave generation from a frequency-stabilized virtual cathode source

International Nuclear Information System (INIS)

Fazio, M.V.; Hoeberling, R.F.; Kinross-Wright, J.

1988-01-01

The evolution of virtual cathode based high-power microwave-source technology has been directed primarily toward achieving higher peak-power levels. As peak powers in excess of 10 GW have been reported, attention has begun to focus on techniques for producing a more frequency- and phase-stable virtual cathode source. Free-running virtual cathode microwave sources characteristically exhibit bandwidths in a single pulse of tens of percent, which makes them unsuitable for many applications such as power sources for phased array antennas and microwave linear accelerators. Presented here are results of an experimental approach utilizing a high-Q, resonant cavity surrounding the oscillating virtual cathode to achieve frequency stabilization and repeatable narrow-band operation. A cylindrical cavity resonator is used with the microwave power being extracted radially through circumferential slot apertures into L-band waveguide

La Biblioteca Virtual en Equidad, Salud y Desarrollo Humano The Virtual Library in Equity, Health, and Human Development

Directory of Open Access Journals (Sweden)

América Valdés

2002-06-01

Full Text Available This article attempts to describe the rationale that has led to the development of information sources dealing with equity, health, and human development in countries of Latin America and the Caribbean within the context of the Virtual Health Library (Biblioteca Virtual en Salud, BVS. Such information sources include the scientific literature, databases in printed and electronic format, institutional directories and lists of specialists, lists of events and courses, distance education programs, specialty journals and bulletins, as well as other means of disseminating health information. The pages that follow deal with the development of a Virtual Library in Equity, Health, and Human Development, an effort rooted in the conviction that decision-making and policy geared toward achieving greater equity in health must, of necessity, be based on coherent, well-organized, and readily accessible first-rate scientific information. Information is useless unless it is converted into knowledge that benefits society. The Virtual Library in Equity, Health, and Human Development is a coordinated effort to develop a decentralized regional network of scientific information sources, with strict quality control, from which public officials can draw data and practical examples that can help them set health and development policies geared toward achieving greater equity for all.

Implementation of 3D virtual learning environment to improve students’ cognitive achievement

Science.gov (United States)

Rasim; Langi, A. Z. R.; Rosmansyah, Y.; Munir

2018-05-01

Virtual Learning Environment (VLE) has been widely used in assisting learning. This study aims to implement VLE-based learning in software engineering course. VLE provides many facilities for learning. In this research, VLE components used were presenter and quiz chair components. Evaluation results showed a significant difference from classical learning.

Virtualization for the LHCb Online system

International Nuclear Information System (INIS)

Bonaccorsi, Enrico; Brarda, Loic; Moine, Gary; Neufeld, Niko

2011-01-01

Virtualization has long been advertised by the IT-industry as a way to cut down cost, optimise resource usage and manage the complexity in large data-centers. The great number and the huge heterogeneity of hardware, both industrial and custom-made, has up to now led to reluctance in the adoption of virtualization in the IT infrastructure of large experiment installations. Our experience in the LHCb experiment has shown that virtualization improves the availability and the manageability of the whole system. We have done an evaluation of available hypervisors / virtualization solutions and find that the Microsoft HV technology provides a high level of maturity and flexibility for our purpose. We present the results of these comparison tests, describing in detail, the architecture of our virtualization infrastructure with a special emphasis on the security for services visible to the outside world. Security is achieved by a sophisticated combination of VLANs, firewalls and virtual routing - the cost and benefits of this solution are analysed. We have adapted our cluster management tools, notably Quattor, for the needs of virtual machines and this allows us to migrate smoothly services on physical machines to the virtualized infrastructure. The procedures for migration will also be described. In the final part of the document we describe our recent R and D activities aiming to replacing the SAN-backend for the virtualization by a cheaper iSCSI solution - this will allow to move all servers and related services to the virtualized infrastructure, excepting the ones doing hardware control via non-commodity PCI plugin cards.

Virtual and Augmented Reality on the 5G Highway

OpenAIRE

Orlosky, Jason; Kiyokawa, Kiyoshi; Takemura, Haruo

2017-01-01

In recent years, virtual and augmented reality have begun to take advantage of the high speed capabilities of data streaming technologies and wireless networks. However, limitations like bandwidth and latency still prevent us from achieving high fidelity telepresence and collaborative virtual and augmented reality applications. Fortunately, both researchers and engineers are aware of these problems and have set out to design 5G networks to help us to move to the next generation of virtual int...

Perspectives on the Viable Mobile Virtual Community for Telemedicine

OpenAIRE

van 't Klooster, J.W.J.R.; Pawar, P.; van Beijnum, Bernhard J.F.; Dulawan, Chariz; Hermens, Hermanus J.

2010-01-01

A virtual community is an electronically supported social network: it can be seen as a group of people who have regular social interaction, independent of time and space, because of a common interest such as a problem, task, or feeling exchange (Eysenbach, Powell, Englesakis, Rizo, & Stern, 2004; Rheingold, 1993). When independence of time and space is achieved through the use of mobile devices and wireless communication technologies, such a virtual community is called a Mobile Virtual Commun...

Integration Between SCORM Learning Objects and the CIEMAT Virtual Elearning Platform; Integracion de Objetos de Aprendizaje SCORM con la Plataforma de Ensenanza Virtual del CIEMAT

Energy Technology Data Exchange (ETDEWEB)

Bailador Ferreras, M A; Troiani, S; Gonzalez Giralda, C; Llorente Herranz, C; Marco Arboli, M L

2010-08-06

New information and communications technologies have made a major contribution in the way of understanding the training needs, which have been involved in the change from the traditional teaching to the use of virtual learning platforms. Thus, Ciemat, has installed a virtual platform for education, in particular MOODLE in which have been installed some virtual contents developed with Flash. The next necessary step has been how to integrate the contents with the MOODLE virtual platform, following the aim to know the assessment for learning tracking of the learners. This document provides the technological facts for the integration of the flash virtual contents and the virtual platform in order to achieve the training process is efficiently evaluated. (Author) 5 refs.

Virtually teaching virtual leadership

DEFF Research Database (Denmark)

Henriksen, Thomas Duus; Nielsen, Rikke Kristine; Børgesen, Kenneth

2017-01-01

This paper seeks to investigate the challenges to virtual collaboration and leadership on basis of findings from a virtual course on collaboration and leadership. The course used for this experiment was designed as a practical approach, which allowed participants to experience curriculum phenomena....... This experimental course provided insights into the challenges involved in virtual processes, and those experiences where used for addressing the challenges that virtual leadership is confronted with. Emphasis was placed on the reduction of undesired virtual distance and its consequences through affinity building....... We found that student scepticism appeared when a breakdown resulted in increasing virtual distance, and raises questions on how leaders might translate or upgrade their understandings of leadership to handling such increased distance through affinity building....

Exploring 3-D Virtual Reality Technology for Spatial Ability and Chemistry Achievement

Science.gov (United States)

Merchant, Z.; Goetz, E. T.; Keeney-Kennicutt, W.; Cifuentes, L.; Kwok, O.; Davis, T. J.

2013-01-01

We investigated the potential of Second Life® (SL), a three-dimensional (3-D) virtual world, to enhance undergraduate students' learning of a vital chemistry concept. A quasi-experimental pre-posttest control group design was used to conduct the study. A total of 387 participants completed three assignment activities either in SL or using…

Virtual-anode formation by an intense pulsed ion beam incident upon a magnetic barrier

International Nuclear Information System (INIS)

Robertson, S.; Wessel, F.

1980-01-01

An intense, pulsed, initially space-charge-neutral ion beam (100 kV, 1 kA, 600 nsec) has been propagated into a transversely oriented magnetic barrier. When the magnetic field is adjusted so that (rho/sub i/rho/sub e/)/sup 1/2/ very-much-less-than a < rho/sub i/, a virtual anode is formed whose potential oscillates at approx.ω/sub p/i about a value near the ion accelerating potential, where a is the transverse beam dimension, ω/sub tsp/i is the ion plasma frequency, and rho/sub e/ and rho/sub i/ are the electron and ion gyroradii. This behavior is similar to that predicted by Poukey and Rostoker for virtual cathodes

Collaborative Educational Systems in the Virtual Environment

OpenAIRE

Cristian CIUREA; Paul POCATILU

2012-01-01

The work leads to an original approach to the construction of collaborative systems metrics. The approach is based both on research already conducted by the author, on the experimental results obtained, and the foundation taken from the specific literature. The collaborative systems in knowledge-based economy are formalized and their characteristics are identified. The virtual campus structure is described and a comparison with the classical university is achieved. The architecture of virtual...

Virtual automation.

Science.gov (United States)

Casis, E; Garrido, A; Uranga, B; Vives, A; Zufiaurre, C

2001-01-01

Total laboratory automation (TLA) can be substituted in mid-size laboratories by a computer sample workflow control (virtual automation). Such a solution has been implemented in our laboratory using PSM, software developed in cooperation with Roche Diagnostics (Barcelona, Spain), to this purpose. This software is connected to the online analyzers and to the laboratory information system and is able to control and direct the samples working as an intermediate station. The only difference with TLA is the replacement of transport belts by personnel of the laboratory. The implementation of this virtual automation system has allowed us the achievement of the main advantages of TLA: workload increase (64%) with reduction in the cost per test (43%), significant reduction in the number of biochemistry primary tubes (from 8 to 2), less aliquoting (from 600 to 100 samples/day), automation of functional testing, drastic reduction of preanalytical errors (from 11.7 to 0.4% of the tubes) and better total response time for both inpatients (from up to 48 hours to up to 4 hours) and outpatients (from up to 10 days to up to 48 hours). As an additional advantage, virtual automation could be implemented without hardware investment and significant headcount reduction (15% in our lab).

Information literacy experiencies inside virtual learning environments

Directory of Open Access Journals (Sweden)

Patricia Hernández Salazar

2016-03-01

Full Text Available Objective. Suggest the use of virtual learning environments as an Information Literacy (IL alternative. Method. Analysis of the main elements of web sites. To achieve this purpose the article includes the relationship between IL and the learning virtual environment (by defining both phrases; phases to create virtual IL programs; processes to elaborate didactic media; the applications that may support this plan; and the description of eleven examples of learning virtual environments IL experiences from four countries (Mexico, United States of America, Spain and United Kingdom these examples fulfill the conditions expressed. Results. We obtained four comparative tables examining five elements of each experience: objectives; target community; institution; country; and platform used. Conclusions. Any IL proposal should have a clear definition; IL experiences have to follow a didactic systematic process; described experiences are based on IL definition; the experiences analyzed are similar; virtual learning environments can be used as alternatives of IL.

Research on virtual actor action editing and movement control

Institute of Scientific and Technical Information of China (English)

Wenhu QIN; Yuhui WU; Zhengxu ZHAO

2008-01-01

To directly use a virtual surface model for action editing and movement control, a general method for creating virtual actor skeleton models and controlling movement is presented. The method includes judging borderlines of the block virtual surface model, calculat-ing the joints, confirming the above block, and using the block hierarchical layout to create the skeleton model. Then, according to the virtual actor model and move-ment restriction, the study focuses on the generation of movement animation using the key frame technique and smoothing movement technique by automatically adding animation and adjusting the actor's pose by different weights on movement amplitude. Finally, movement control of the actor in the virtual environment is implemented by real-time control and path point control, which achieve a good result.

Modelling Virtual Environments for Geovisualization

DEFF Research Database (Denmark)

Bodum, Lars

2005-01-01

The use of virtual environments in geovisualization has become a major topic within the last few years. The main reason for this interest in the growing use of 3D models and visual realizations in a wide range of applications concerned with the geographic element of information. The implementation...... within the geographic domain. A categorization of the virtual environments is offered through which the differences between them are highlighted. It is possible to achieve this categorization in many ways from many perspectives since this is not and will not be research of a purely positive nature...

Virtual Reality in Engineering Education: The Future of Creative Learning

OpenAIRE

Abdul-Hadi Ghazi Abulrub; Alex Attridge; Mark A Williams

2011-01-01

Virtual reality has achieved an adequate level of development for it to be considered in innovative applications such as education, training, and research in higher education. Virtual reality offers both opportunities and challenges for the educational sector. One of the challenges of virtual reality technology is the costs associated which have been unaffordable for educational institutes. However, in recent years, computer hardware and software development has made it more feasible to incor...

Virtual Quantum Subsystems

International Nuclear Information System (INIS)

Zanardi, Paolo

2001-01-01

The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set A of operationally relevant observables. The algebraic structure of A selects a preferred tensor product structure, i.e., a partition into subsystems. The notion of compoundness for quantum systems is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies

Virtual Reality in Education: Defining Researchable Issues.

Science.gov (United States)

Hedburg, John; Alexander, Shirley

1994-01-01

Discusses situated learning and virtual reality, focusing on the pedagogical aspects of the technology and its importance in achieving a learning environment which challenges and supports effective learning. (AEF)

Virtual vitreoretinal surgery

DEFF Research Database (Denmark)

Vergmann, Anna Stage; Vestergaard, Anders Højslet; Grauslund, Jakob

2017-01-01

PURPOSE: To test the validity of the eyesi surgical simulator as an assessment tool in a virtual reality vitreoretinal training programme. METHODS: In collaboration with an experienced vitreoretinal surgeon, a virtual vitreoretinal training programme was composed on the eyesi surgical simulator......, software version 2.9.2 (VRmagic GmbH, Manheim, Germany). It was completed twice by three groups: 20 medical students, ten residents of ophthalmology and five trained vitreoretinal surgeons. The programme contained six training modules: navigation level 2 (Nav2), forceps training level 5 (ForT5), bimanual...... and microscope handling), and it was possible to achieve 100 points in each module. RESULTS: At the final training session, the highest overall median score was found for the vitreoretinal surgeons (vitreoretinal surgeons: 434 points, residents: 394.5 points, medical students: 272.5 points, p

Virtual Reality in Engineering Education: The Future of Creative Learning

Directory of Open Access Journals (Sweden)

Abdul-Hadi Ghazi Abulrub

2011-12-01

Full Text Available Virtual reality has achieved an adequate level of development for it to be considered in innovative applications such as education, training, and research in higher education. Virtual reality offers both opportunities and challenges for the educational sector. One of the challenges of virtual reality technology is the costs associated which have been unaffordable for educational institutes. However, in recent years, computer hardware and software development has made it more feasible to incorporate virtual reality technology into future teaching strategies. Despite the cost challenges, educational benefits of implementing virtual reality remain compelling. This paper explains virtual reality principle and describes the interactive educational environment developed at WMG, the University of Warwick. It also discusses the benefits of using state-of-the-art 3D photorealistic interactive and immersive virtual environment for engineering undergraduates and postgraduate teaching, learning and training.

Virtual Proprioception for eccentric training.

Science.gov (United States)

LeMoyne, Robert; Mastroianni, Timothy

2017-07-01

Wireless inertial sensors enable quantified feedback, which can be applied to evaluate the efficacy of therapy and rehabilitation. In particular eccentric training promotes a beneficial rehabilitation and strength training strategy. Virtual Proprioception for eccentric training applies real-time feedback from a wireless gyroscope platform enabled through a software application for a smartphone. Virtual Proprioception for eccentric training is applied to the eccentric phase of a biceps brachii strength training and contrasted to a biceps brachii strength training scenario without feedback. During the operation of Virtual Proprioception for eccentric training the intent is to not exceed a prescribed gyroscope signal threshold based on the real-time presentation of the gyroscope signal, in order to promote the eccentric aspect of the strength training endeavor. The experimental trial data is transmitted wireless through connectivity to the Internet as an email attachment for remote post-processing. A feature set is derived from the gyroscope signal for machine learning classification of the two scenarios of Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback. Considerable classification accuracy is achieved through the application of a multilayer perceptron neural network for distinguishing between the Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback.

The green and virtual data center

CERN Document Server

Schulz, Greg

2009-01-01

The Green and Virtual Data Center sets aside the political aspects of what is or is not considered green to instead focus on the opportunities for organizations that want to sustain environmentally-friendly economical growth. If you are willing to believe that IT infrastructure resources deployed in a highly virtualized manner can be combined with other technologies to achieve simplified and cost-effective delivery of services in a  green, profitable manner, this book is for you. Savvy industry veteran Greg Schulz provides real-world insight, addressing best practices, server, software, storag

Performance Comparison for Virtual Impedance Techniques Used in Droop Controlled Islanded Microgrids

DEFF Research Database (Denmark)

Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

2016-01-01

). Virtual impedance loops were proposed in literature to improve the current sharing between the inverters by normalizing the output impedance of the inverters. However, virtual impedance loops have constraints in this respect since the improvement in the current sharing occurs through redistribution...... for a single phase microgrid setup to achieve a fair performance comparison of the different virtual impedance techniques....

Untyped Memory in the Java Virtual Machine

DEFF Research Database (Denmark)

Gal, Andreas; Probst, Christian; Franz, Michael

2005-01-01

We have implemented a virtual execution environment that executes legacy binary code on top of the type-safe Java Virtual Machine by recompiling native code instructions to type-safe bytecode. As it is essentially impossible to infer static typing into untyped machine code, our system emulates...... untyped memory on top of Java’s type system. While this approach allows to execute native code on any off-the-shelf JVM, the resulting runtime performance is poor. We propose a set of virtual machine extensions that add type-unsafe memory objects to JVM. We contend that these JVM extensions do not relax...... Java’s type system as the same functionality can be achieved in pure Java, albeit much less efficiently....

Time multiplexing for increased FOV and resolution in virtual reality

Science.gov (United States)

Miñano, Juan C.; Benitez, Pablo; Grabovičkić, Dejan; Zamora, Pablo; Buljan, Marina; Narasimhan, Bharathwaj

2017-06-01

We introduce a time multiplexing strategy to increase the total pixel count of the virtual image seen in a VR headset. This translates into an improvement of the pixel density or the Field of View FOV (or both) A given virtual image is displayed by generating a succession of partial real images, each representing part of the virtual image and together representing the virtual image. Each partial real image uses the full set of physical pixels available in the display. The partial real images are successively formed and combine spatially and temporally to form a virtual image viewable from the eye position. Partial real images are imaged through different optical channels depending of its time slot. Shutters or other schemes are used to avoid that a partial real image be imaged through the wrong optical channels or at the wrong time slot. This time multiplexing strategy needs real images be shown at high frame rates (>120fps). Available display and shutters technologies are discussed. Several optical designs for achieving this time multiplexing scheme in a compact format are shown. This time multiplexing scheme allows increasing the resolution/FOV of the virtual image not only by increasing the physical pixel density but also by decreasing the pixels switching time, a feature that may be simpler to achieve in certain circumstances.

Virtual goods recommendations in virtual worlds.

Science.gov (United States)

Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

2015-01-01

Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

Primary and Secondary Virtual Learning in New Zealand: Examining Barriers to Achieving Maturity

Science.gov (United States)

Barbour, Michael; Davis, Niki; Wenmoth, Derek

2016-01-01

This paper describes the organisational development of virtual learning in networked rural schools in New Zealand, specifically the obstacles that e-learning clusters of rural schools face in their journey to sustainability and maturity through the lens of the Ministry's Learning Communities Online Handbook. Analysis of a nationwide purposeful…

Realistic terrain visualization based on 3D virtual world technology

Science.gov (United States)

Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

2010-11-01

The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

Astronomical Research Using Virtual Observatories

Directory of Open Access Journals (Sweden)

M Tanaka

2010-01-01

Full Text Available The Virtual Observatory (VO for Astronomy is a framework that empowers astronomical research by providing standard methods to find, access, and utilize astronomical data archives distributed around the world. VO projects in the world have been strenuously developing VO software tools and/or portal systems. Interoperability among VO projects has been achieved with the VO standard protocols defined by the International Virtual Observatory Alliance (IVOA. As a result, VO technologies are now used in obtaining astronomical research results from a huge amount of data. We describe typical examples of astronomical research enabled by the astronomical VO, and describe how the VO technologies are used in the research.

Applied virtual reality

International Nuclear Information System (INIS)

Yule, I.Y.; Lee, D.J.

1996-01-01

An early experience in deploying a manipulator to the Irradiated Fuel Dismantling Cell at Torness Power Station, quickly highlighted that special visualisation techniques were required to achieve a successful deployment and reduce plant system down time. This visualisation was later realised through the IGRIP software pakcage operating on a Silicon Graphics computing engine, which provides a 'Non-Immersive' Virtual Reality environment. Within this environment, models of the Irradiated Fuel Dismantling cell were generated along with a model of the manipulator, allowing manipulator deployment to the Irradiated Fuel Dismantling Cell be modelled. It is estimated that the first use of this new environment provided a significant saving to Scottish Nuclear in potential lost output. The use of this virtual reality environment is currently being extended into the design and deployment of a new manipulator for Torness in vessel inspection, the Boiler Inspection Manipulator. (author)

Virtual Grower 3: A powerful decision support tool for greenhouse systems

Science.gov (United States)

Several years ago, Virtual Grower software was released to the public. Initially designed to help greenhouse growers determine heating costs and do simple simulations to figure out where heat savings could be achieved, it has slowly added features. Now, Virtual Grower can help not only identify he...

Human factors consideration in clinical applications of virtual reality.

Science.gov (United States)

Lewis, C H; Griffin, M J

1997-01-01

Virtual reality environments have many potential applications in medicine, including surgical training, tele-operated robotic surgery, assessment and rehabilitation of behavioural and neurological disorders and diagnosis, therapy and rehabilitation of physical disabilities. Although there is much potential for the use of immersive virtual reality environments in clinical applications, there are problems which could limit their ultimate usability. Some users have experienced side-effects during and after exposure to virtual reality environments. The symptoms include ocular problems, disorientation and balance disturbances, and nausea. Susceptibility to side-effects can be affected by age, ethnicity, experience, gender and physical fitness, as well as the characteristics of the display, the virtual environment and the tasks. The characteristics of the virtual reality system have also been shown to affect the ability of users to perform tasks in a virtual environment. Many of these effects can be attributed to delays between the sampling of head and limb positions and the presentation of an appropriate image on the display. The introduction of patients to virtual reality environments, for assessment, therapy or rehabilitation, raises particular safety and ethical issues. Patients exposed to virtual reality environments for assessment and rehabilitation may have disabilities which increase their susceptibility to certain side-effects. Special precautions therefore need to be taken to ensure the safety and effectiveness of such virtual reality applications. These precautions include minimisation of possible side-effects at the design stage. Factors are identified which are likely to affect the incidence of side-effects during and after exposures, and which need to be understood in order to minimise undesirable consequences. There is also a need for the establishment of protocols for monitoring and controlling exposures of patients to virtual reality environments. Issues

Pulse Wave Velocity Measuring System using Virtual Instrumentation on Mobile Device

Directory of Open Access Journals (Sweden)

Razvan Alin Ciobotariu

2013-03-01

Full Text Available Virtual instrumentation is a concept that permits customizable modular software measurement and the development of the user-defined tools for control, process and visualization of data, creating versatile systems, using modular programming, intuitive and easy to use. In this paper we investigate a possibility of using virtual instrumentation in the development of two physiological parameters monitoring system, in order to assess a cardiovascular parameter, the Pulse Wave Velocity (PWV. We choose to monitor this parameter due to major incidence and impact of cardiovascular diseases (CVD.

E-virtual reality exposure therapy in acrophobia: A pilot study.

Science.gov (United States)

Levy, Fanny; Leboucher, Pierre; Rautureau, Gilles; Jouvent, Roland

2016-06-01

Virtual reality therapy is already used for anxiety disorders as an alternative to in vivo and in imagino exposure. To our knowledge, however, no one has yet proposed using remote virtual reality (e-virtual reality). The aim of the present study was to assess e-virtual reality in an acrophobic population. Six individuals with acrophobia each underwent six sessions (two sessions per week) of virtual reality exposure therapy. The first three were remote sessions, while the last three were traditional sessions in the physical presence of the therapist. Anxiety (STAI form Y-A, visual analog scale, heart rate), presence, technical difficulties and therapeutic alliance (Working Alliance Inventory) were measured. In order to control the conditions in which these measures were made, all the sessions were conducted in hospital. None of the participants dropped out. The remote sessions were well accepted. None of the participants verbalized reluctance. No major technical problems were reported. None of the sessions were cancelled or interrupted because of software incidents. Measures (anxiety, presence, therapeutic alliance) were comparable across the two conditions. e-Virtual reality can therefore be used to treat acrophobic disorders. However, control studies are needed to assess online feasibility, therapeutic effects and the mechanisms behind online presence. © The Author(s) 2015.

Virtual marketing in virtual enterprises

OpenAIRE

Ale Ebrahim, Nader; Fattahi, Hamaid Ali; Golnam, Arash

2008-01-01

Virtualization caused tremendous evolution in the economics of marketing channels, patterns of physical distribution and the structure of distributors and developed a new concept that is known as virtual marketing (VM). VM combines the powerful technologies of interactive marketing and virtual reality. Virtual enterprise (VE) refers to an organization not having a clear physical locus. In other words, VE is an organization distributed geographically and whose work is coordinated through e...

VirtualSpace: A vision of a machine-learned virtual space environment

Science.gov (United States)

Bortnik, J.; Sarno-Smith, L. K.; Chu, X.; Li, W.; Ma, Q.; Angelopoulos, V.; Thorne, R. M.

2017-12-01

Space borne instrumentation tends to come and go. A typical instrument will go through a phase of design and construction, be deployed on a spacecraft for several years while it collects data, and then be decommissioned and fade into obscurity. The data collected from that instrument will typically receive much attention while it is being collected, perhaps in the form of event studies, conjunctions with other instruments, or a few statistical surveys, but once the instrument or spacecraft is decommissioned, the data will be archived and receive progressively less attention with every passing year. This is the fate of all historical data, and will be the fate of data being collected by instruments even at the present time. But what if those instruments could come alive, and all be simultaneously present at any and every point in time and space? Imagine the scientific insights, and societal gains that could be achieved with a grand (virtual) heliophysical observatory that consists of every current and historical mission ever deployed? We propose that this is not just fantasy but is imminently doable with the data currently available, with the present computational resources, and with currently available algorithms. This project revitalizes existing data resources and lays the groundwork for incorporating data from every future mission to expand the scope and refine the resolution of the virtual observatory. We call this project VirtualSpace: a machine-learned virtual space environment.

Incidence of ascariasis in gastric carcinoma

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Woo; Rhee, Hak Song; Bahk, Yong Whee [St Mary' s Hospital Catholic Medical College, Seoul (Korea, Republic of)

1972-09-15

Prompted by the finding that the radiological incidence of small bowel ascariasis in the patient with gastric carcinoma was unexpectedly lower than the incidence in the normal population, a clinical study was performed to investigate possible relationship between gastric carcinoma and intestinal ascariasis. As a preliminary survey, we reviewed the radiological incidence of ascariasis in a total of 2,446 cases of upper GI series performed at the Department of Radiology, St Mary's Hospital Catholic Medical College. These included 1,573 normal subjects, 146 gastric carcinoma patients, 100 benign gastric ulcer and 249 duodenal ulcer patients and 378 other upper GI diseases. Following the preliminary study, a more accurate parasitologic study was conducted in another 578 normal subjects and 51 gastric carcinoma patients. The radiological incidences of ascaiasis in normal subjects and gastric carcinoma patients were 15.1% and 28.1%, respectively. The incidence of overall helminthiasis including ascaris lumbricoides, trichocephalus trichiurus and trichostrongyloides orientalis in normal subjects of the present series was 73.5%. This figure is virtually the same with 69.1% of the general population incidence reported by Kim, et al. (1971), but the incidence in gastric carcinoma patients was 94.1%. The high incidence pattern of overall helminthiasis in gastric carcinoma patients is, however, reversed as for as ascariasis is concerned. Thus, the incidence of ascariasis of gastric carcinoma patients was much lower than that of normal subjects (9.8% vs 19.4%). From the present observation, it is postulated that there can be some possible antagonistic relationship between evolution of gastric carcinoma and small bowel infestation of ascaris lumbricoides.

Incidence of ascariasis in gastric carcinoma

International Nuclear Information System (INIS)

Kim, Jong Woo; Rhee, Hak Song; Bahk, Yong Whee

1972-01-01

Prompted by the finding that the radiological incidence of small bowel ascariasis in the patient with gastric carcinoma was unexpectedly lower than the incidence in the normal population, a clinical study was performed to investigate possible relationship between gastric carcinoma and intestinal ascariasis. As a preliminary survey, we reviewed the radiological incidence of ascariasis in a total of 2,446 cases of upper GI series performed at the Department of Radiology, St Mary's Hospital Catholic Medical College. These included 1,573 normal subjects, 146 gastric carcinoma patients, 100 benign gastric ulcer and 249 duodenal ulcer patients and 378 other upper GI diseases. Following the preliminary study, a more accurate parasitologic study was conducted in another 578 normal subjects and 51 gastric carcinoma patients. The radiological incidences of ascaiasis in normal subjects and gastric carcinoma patients were 15.1% and 28.1%, respectively. The incidence of overall helminthiasis including ascaris lumbricoides, trichocephalus trichiurus and trichostrongyloides orientalis in normal subjects of the present series was 73.5%. This figure is virtually the same with 69.1% of the general population incidence reported by Kim, et al. (1971), but the incidence in gastric carcinoma patients was 94.1%. The high incidence pattern of overall helminthiasis in gastric carcinoma patients is, however, reversed as for as ascariasis is concerned. Thus, the incidence of ascariasis of gastric carcinoma patients was much lower than that of normal subjects (9.8% vs 19.4%). From the present observation, it is postulated that there can be some possible antagonistic relationship between evolution of gastric carcinoma and small bowel infestation of ascaris lumbricoides

Architectural design and simulation of a virtual memory

Science.gov (United States)

Kwok, G.; Chu, Y.

1971-01-01

Virtual memory is an imaginary main memory with a very large capacity which the programmer has at his disposal. It greatly contributes to the solution of the dynamic storage allocation problem. The architectural design of a virtual memory is presented which implements by hardware the idea of queuing and scheduling the page requests to a paging drum in such a way that the access of the paging drum is increased many times. With the design, an increase of up to 16 times in page transfer rate is achievable when the virtual memory is heavily loaded. This in turn makes feasible a great increase in the system throughput.

Occupational emerging risks affecting international virtual project Team Results

Directory of Open Access Journals (Sweden)

Dumitraşcu-Băldău Iulia

2017-01-01

Full Text Available The expansion of internet access, high-speed connection services, collaborative work platforms and tools, allowed employees to interact virtually offering companies the possibility to develop projects around the world, reducing operational costs and gain competitive advantage. Realizing the advantages and disadvantages of developing a project team in an international virtual work environment, requires adopting specific strategies to construct an effective team and ensure the project success. One of the most important disadvantages that we identified is that the new work environment brings new risks for both team members and managers. So, it becomes mandatory to identify and analyze the occupational emerging risks and their impact on the productivity of virtual team members, in order to prevent them efficiently and to ensure the safety and health of employees in a virtual working environment. This paper aims to highlight the necessity for project managers and organizations, to include in their specific project strategies, an efficient occupational risks management in the virtual workplace, to obtain a continuously improved virtual working environment, so to achieve a high performance from virtual employees.

Virtual Presenters: Towards Interactive Virtual Presentations

NARCIS (Netherlands)

Nijholt, Antinus; Cappellini, V.; Hemsley, J.

2005-01-01

We discuss having virtual presenters in virtual environments that present information to visitors of these environments. Some current research is surveyed and we will look in particular to our research in the context of a virtual meeting room where a virtual presenter uses speech, gestures, pointing

Virtual Worlds for Virtual Organizing

Science.gov (United States)

Rhoten, Diana; Lutters, Wayne

The members and resources of a virtual organization are dispersed across time and space, yet they function as a coherent entity through the use of technologies, networks, and alliances. As virtual organizations proliferate and become increasingly important in society, many may exploit the technical architecture s of virtual worlds, which are the confluence of computer-mediated communication, telepresence, and virtual reality originally created for gaming. A brief socio-technical history describes their early origins and the waves of progress followed by stasis that brought us to the current period of renewed enthusiasm. Examination of contemporary examples demonstrates how three genres of virtual worlds have enabled new arenas for virtual organizing: developer-defined closed worlds, user-modifiable quasi-open worlds, and user-generated open worlds. Among expected future trends are an increase in collaboration born virtually rather than imported from existing organizations, a tension between high-fidelity recreations of the physical world and hyper-stylized imaginations of fantasy worlds, and the growth of specialized worlds optimized for particular sectors, companies, or cultures.

VirtualizeMe: Real-time avatar creation for Tele-Immersion environments

KAUST Repository

Knoblauch, Daniel

2010-03-01

VirtualizeMe introduces a new design for a fully immersive Tele-Immersion system for remote collaboration and virtual world interaction. This system introduces a new avatar creation approach full-filling four main attributes: high resolution, scalability, flexibility and affordability. This is achieved by a total separation of reconstruction and rendering and exploiting the capabilities of modern graphic cards. The high resolution is achieved by using as much of the input information as possible through lossless compression of the input data and introducing a focused volumetric visual hull reconstruction. The resulting avatar allows eye-to-eye collaboration for remote users. The interaction with the virtual world is facilitated by the volumetric avatar model and allows a fully immersive system. This paper shows a proof of concept based on publicly available pre-recorded data to allow easier comparison. ©2010 IEEE.

Analysis of a virtual memory model for maintaining database views

Science.gov (United States)

Kinsley, Kathryn C.; Hughes, Charles E.

1992-01-01

This paper presents an analytical model for predicting the performance of a new support strategy for database views. This strategy, called the virtual method, is compared with traditional methods for supporting views. The analytical model's predictions of improved performance by the virtual method are then validated by comparing these results with those achieved in an experimental implementation.

Reconfigurable virtual electrowetting channels.

Science.gov (United States)

Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

2012-02-21

Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

Beam steering for virtual/augmented reality displays with a cycloidal diffractive waveplate.

Science.gov (United States)

Chen, Haiwei; Weng, Yishi; Xu, Daming; Tabiryan, Nelson V; Wu, Shin-Tson

2016-04-04

We proposed a switchable beam steering device with cycloidal diffractive waveplate (CDW) for eye tracking in a virtual reality (VR) or augmented reality (AR) display system. Such a CDW diffracts the incident circularly polarized light to the first order with over 95% efficiency. To convert the input linearly polarized light to right-handed or left-handed circular polarization, we developed a broadband polarization switch consisting of a twisted nematic liquid crystal cell and an achromatic quarter-wave retardation film. By cascading 2-3 CDWs together, multiple diffraction angles can be achieved. To suppress the color dispersion, we proposed two approaches to obtain the same diffraction angle for red, green, and blue LEDs-based full color displays. Our device exhibits several advantages, such as high diffraction efficiency, fast response time, low power consumption, and low cost. It holds promise for the emerging VR/AR displays.

A VM-shared desktop virtualization system based on OpenStack

Science.gov (United States)

Liu, Xi; Zhu, Mingfa; Xiao, Limin; Jiang, Yuanjie

2018-04-01

With the increasing popularity of cloud computing, desktop virtualization is rising in recent years as a branch of virtualization technology. However, existing desktop virtualization systems are mostly designed as a one-to-one mode, which one VM can only be accessed by one user. Meanwhile, previous desktop virtualization systems perform weakly in terms of response time and cost saving. This paper proposes a novel VM-Shared desktop virtualization system based on OpenStack platform. The paper modified the connecting process and the display data transmission process of the remote display protocol SPICE to support VM-Shared function. On the other hand, we propose a server-push display mode to improve user interactive experience. The experimental results show that our system performs well in response time and achieves a low CPU consumption.

Teaching strategies in web technologies for virtual learning environments

Directory of Open Access Journals (Sweden)

Ilber Dario Saza-Garzón

2016-12-01

Full Text Available The virtual learning environments (AVAs have been a subject of discussion and questions mainly on finding the best teaching practices, which tools you can use them and how to achieve optimum utilization have better results in virtual education, for Therefore in this paper some elements about the characteristics, history, teaching, studies have virtual environments and web applications as tools to support teaching and learning, are set for a virtual tutor note the when planning, designing, creating and implementing online courses. Thus the reader will find concepts, explanations and different evolutionary processes that wins ICT and how are you have been involved in the educational context, spotting potential applications from mediation of teaching, plus some suggestions of how to carry out exposed use thereof in virtual learning environments to strengthen the different processes of teaching and learning.

Effect of virtual analytical chemistry laboratory on enhancing student research skills and practices

Directory of Open Access Journals (Sweden)

Boris Bortnik

2017-12-01

Full Text Available This article aims to determine the effect of a virtual chemistry laboratory on university student achievement. The article describes a model of a laboratory course that includes a virtual component. This virtual component is viewed as a tool of student pre-lab autonomous learning. It presents electronic resources designed for a virtual laboratory and outlines the methodology of e-resource application. To find out how virtual chemistry laboratory affects student scientific literacy, research skills and practices, a pedagogical experiment has been conducted. Student achievement was compared in two learning environments: traditional – in-class hands-on – learning (control group and blended learning – online learning combined with in-person learning (experimental group. The effectiveness of integrating an e-lab in the laboratory study was measured by comparing student lab reports of the two groups. For that purpose, a set of 10 criteria was developed. The experimental and control student groups were also compared in terms of test results and student portfolios. The study showed that the adopted approach blending both virtual and hands-on learning environments has the potential to enhance student research skills and practices in analytical chemistry studies.

Assessing the Impact of a Virtual Lab in an Allied Health Program.

Science.gov (United States)

Kay, Robin; Goulding, Helene; Li, Jia

2018-01-01

Competency-based education in health care requires rigorous standards to ensure professional proficiency. Demonstrating competency in hands-on laboratories calls for effective preparation, knowledge, and experience, all of which can be difficult to achieve using traditional teaching methods. Virtual laboratories are an alternative, cost-effective approach to providing students with sufficient preparatory information. Research on the use of virtual labs in allied health education is limited. The current study investigated the benefits, challenges, and perceived impact of a virtual lab in an allied health program. The sample consisted of 64 students (55 females, 9 males) enrolled in a university medical laboratory science program. A convergent mixed-methods approach (Likert survey, open-ended questions, think-aloud protocol data) revealed that students had positive attitudes towards visual learning, authenticity, learner control, organization, and scaffolding afforded by the virtual lab. Challenges reported included navigational difficulties, an absence of control over content selection, and lack of understanding for certain concepts. Over 90% of students agreed that the virtual lab helped them prepare for hands-on laboratory sessions and that they would use this format of instruction again. Overall, 84% of the students agreed that the virtual lab helped them to achieve greater success in learning.

Use of virtual sets in the broadcasting of major events

Directory of Open Access Journals (Sweden)

Cesáreo Fernández Fernández, PhD.

2011-01-01

Full Text Available In 2000, the BBC virtual studios expert, Danny Popkin, criticised the television industry for making a poor use of virtual technology. Ten years later the situation has not improved significantly. So far, virtual studios are seen just as good technological tools to save money and time in the production of news, children’s programming, commercials and elections coverage. However, the virtual studio must also enhance realism, improve the presentation of information, and increase entertainment. In order to help broadcasters achieving these goals, this article describes six examples of special television programmes, from 1996 to 2009, which presented some ideas to improve the quality and richness of the audiovisual language.

Sensorial Virtualization: Coupling Gaming and Virtual Environment

NARCIS (Netherlands)

Garbaya, S.; Miraoui, C.; Wendrich, Robert E.; Lim, T.; Stanescu, I.A.; Hauge, J.B.

2014-01-01

Virtual reality and virtualization are currently used to design complex systems and demonstrate that they represent the functionalities of real systems. However, the design refinement of the virtual environment (VE) and distributed virtual environment (DVE) are still time consuming and costly, as it

Virtualization of work in global supply chains

Directory of Open Access Journals (Sweden)

Sabina Wyrwich-Płotka

2016-12-01

Full Text Available Background: The paper is devoted to the notion and benefits of implementing virtual work in global supply chains. Virtual work must be understood as an intentional activity of a human being, aimed at rendering services (tangible and intangible, by means of ITC tools, performed in a distance from the traditional place of work, in a mobile manner. The empirical research were conducted on the basis of 4 case studies of global leaders of supply chains, which in accordance with M. Fisher's classification, represent two types. The case studies confirmed the positive influence of virtual work both in effective and flexible supply chains. Favourable market and technological conditions and increasing awareness of benefits of virtual work will make it more and more widespread in companies comprising global supply chains. The aim of the study is to demonstrate the cause and effect relationships between virtual work and competitiveness of efficient and flexible supply chain. Methods: The paper is based on the available recent scientific-theoretical research and publication.  The authors analyzed 4 enterprises in Poland. The enterprises representing a flexible or an effective supply chain, either using or not a virtual work. The study carried out the authors had the form of individual interviews. The authors used case studies to show that virtual work brings notable benefits in an effective and flexible supply chain.  Results: Based on these case studies, the authors demonstrated reasons to implement virtual work in selected enterprises. The reasons to implement virtual work are determinants of possible achieve economies in effective and flexible supply chain Conclusions: The examined case studies show that virtual work brings different benefits. In the effective supply chain, virtual workers enable to increase effectiveness and financial results for example. In the flexible supply chain the virtual work can be a way to maintain and build long

Topological Embedding Feature Based Resource Allocation in Network Virtualization

Directory of Open Access Journals (Sweden)

Hongyan Cui

2014-01-01

Full Text Available Virtualization provides a powerful way to run multiple virtual networks on a shared substrate network, which needs accurate and efficient mathematical models. Virtual network embedding is a challenge in network virtualization. In this paper, considering the degree of convergence when mapping a virtual network onto substrate network, we propose a new embedding algorithm based on topology mapping convergence-degree. Convergence-degree means the adjacent degree of virtual network’s nodes when they are mapped onto a substrate network. The contributions of our method are as below. Firstly, we map virtual nodes onto the substrate nodes with the maximum convergence-degree. The simulation results show that our proposed algorithm largely enhances the network utilization efficiency and decreases the complexity of the embedding problem. Secondly, we define the load balance rate to reflect the load balance of substrate links. The simulation results show our proposed algorithm achieves better load balance. Finally, based on the feature of star topology, we further improve our embedding algorithm and make it suitable for application in the star topology. The test result shows it gets better performance than previous works.

[The virtual library in equity, health, and human development].

Science.gov (United States)

Valdés, América

2002-01-01

This article attempts to describe the rationale that has led to the development of information sources dealing with equity, health, and human development in countries of Latin America and the Caribbean within the context of the Virtual Health Library (Biblioteca Virtual en Salud, BVS). Such information sources include the scientific literature, databases in printed and electronic format, institutional directories and lists of specialists, lists of events and courses, distance education programs, specialty journals and bulletins, as well as other means of disseminating health information. The pages that follow deal with the development of a Virtual Library in Equity, Health, and Human Development, an effort rooted in the conviction that decision-making and policy geared toward achieving greater equity in health must, of necessity, be based on coherent, well-organized, and readily accessible first-rate scientific information. Information is useless unless it is converted into knowledge that benefits society. The Virtual Library in Equity, Health, and Human Development is a coordinated effort to develop a decentralized regional network of scientific information sources, with strict quality control, from which public officials can draw data and practical examples that can help them set health and development policies geared toward achieving greater equity for all.

Open-Ended Behavioral Complexity for Evolved Virtual Creatures

DEFF Research Database (Denmark)

Lessin, Dan; Fussell, Don; Miikkulainen, Risto

2013-01-01

notable exception to this progress. Despite the potential benefits, there has been no clear increase in the behavioral complexity of evolved virtual creatures (EVCs) beyond the light following demonstrated in Sims' original work. This paper presents an open-ended method to move beyond this limit, making...... creature with behavioral complexity that clearly exceeds previously achieved levels. ESP thus demonstrates that EVCs may indeed have the potential to one day rival the behavioral complexity--and therefore the entertainment value--of their non-virtual counterparts....

Virtual Class Support at the Virtual Machine Level

DEFF Research Database (Denmark)

Nielsen, Anders Bach; Ernst, Erik

2009-01-01

This paper describes how virtual classes can be supported in a virtual machine.  Main-stream virtual machines such as the Java Virtual Machine and the .NET platform dominate the world today, and many languages are being executed on these virtual machines even though their embodied design choices...... conflict with the design choices of the virtual machine.  For instance, there is a non-trivial mismatch between the main-stream virtual machines mentioned above and dynamically typed languages.  One language concept that creates an even greater mismatch is virtual classes, in particular because fully...... general support for virtual classes requires generation of new classes at run-time by mixin composition.  Languages like CaesarJ and ObjectTeams can express virtual classes restricted to the subset that does not require run-time generation of classes, because of the restrictions imposed by the Java...

Asphyxia Neonatorum-Incidence In Cape Town

African Journals Online (AJOL)

task of all concerned with the process of human repro- duction. In order to achieve this, a study of the incidence and risk factors of asphyxia neonatorum was undertaken in the Groote Schuur Maternity Hospital. TABLE I. INCIDENCE OF ASPHYXIA NEONATORUM. Source of. Hospital. Apgar score 0 - 3% information.

Effects of decades of physical driving on body movement and motion sickness during virtual driving.

Directory of Open Access Journals (Sweden)

Thomas A Stoffregen

Full Text Available We investigated relations between experience driving physical automobiles and motion sickness during the driving of virtual automobiles. Middle-aged individuals drove a virtual automobile in a driving video game. Drivers were individuals who had possessed a driver's license for approximately 30 years, and who drove regularly, while non-drivers were individuals who had never held a driver's license, or who had not driven for more than 15 years. During virtual driving, we monitored movement of the head and torso. During virtual driving, drivers became motion sick more rapidly than non-drivers, but the incidence and severity of motion sickness did not differ as a function of driving experience. Patterns of movement during virtual driving differed as a function of driving experience. Separately, movement differed between participants who later became motion sick and those who did not. Most importantly, physical driving experience influenced patterns of postural activity that preceded motion sickness during virtual driving. The results are consistent with the postural instability theory of motion sickness, and help to illuminate relations between the control of physical and virtual vehicles.

Phenomenological model of an electron flow with a virtual cathode

International Nuclear Information System (INIS)

Koronovskij, A.A.; Khramov, A.E.; Anfinogenov, V.G.

1999-01-01

A phenomenological model of electron flow with a virtual cathode in diode space, which is a modification of cellular automation, is suggested. The type of models, called cellular conveyer, permits making allowance for distribution and delay in a beam with a virtual cathode. A good agreement between results of numerical study of electron flow dynamics and results obtained using the phenomenological model described has been achieved [ru

Microsoft Virtualization Master Microsoft Server, Desktop, Application, and Presentation Virtualization

CERN Document Server

Olzak, Thomas; Boomer, Jason; Keefer, Robert M

2010-01-01

Microsoft Virtualization helps you understand and implement the latest virtualization strategies available with Microsoft products. This book focuses on: Server Virtualization, Desktop Virtualization, Application Virtualization, and Presentation Virtualization. Whether you are managing Hyper-V, implementing desktop virtualization, or even migrating virtual machines, this book is packed with coverage on all aspects of these processes. Written by a talented team of Microsoft MVPs, Microsoft Virtualization is the leading resource for a full installation, migration, or integration of virtual syste

Virtual endoscopy in neurosurgery: a review.

Science.gov (United States)

Neubauer, André; Wolfsberger, Stefan

2013-01-01

Virtual endoscopy is the computerized creation of images depicting the inside of patient anatomy reconstructed in a virtual reality environment. It permits interactive, noninvasive, 3-dimensional visual inspection of anatomical cavities or vessels. This can aid in diagnostics, potentially replacing an actual endoscopic procedure, and help in the preparation of a surgical intervention by bridging the gap between plain 2-dimensional radiologic images and the 3-dimensional depiction of anatomy during actual endoscopy. If not only the endoscopic vision but also endoscopic handling, including realistic haptic feedback, is simulated, virtual endoscopy can be an effective training tool for novice surgeons. In neurosurgery, the main fields of the application of virtual endoscopy are third ventriculostomy, endonasal surgery, and the evaluation of pathologies in cerebral blood vessels. Progress in this very active field of research is achieved through cooperation between the technical and the medical communities. While the technology advances and new methods for modeling, reconstruction, and simulation are being developed, clinicians evaluate existing simulators, steer the development of new ones, and explore new fields of application. This review introduces some of the most interesting virtual reality systems for endoscopic neurosurgery developed in recent years and presents clinical studies conducted either on areas of application or specific systems. In addition, benefits and limitations of single products and simulated neuroendoscopy in general are pointed out.

Research and Application of Virtual Simulation Technology in the Aerospace Bearing Design and Manufacture

Directory of Open Access Journals (Sweden)

Jiangshan Liu

2018-01-01

Full Text Available Bearings are widely used in aerospace and other fields, its performance directly affects the production efficiency and safety. Nowadays, virtual simulation technology has become an indispensable part of intelligent manufacturing field. As a virtual simulation technology, FEA has been widely used in bearing design. China needs to import many aerospace bearings every year in aerospace area, Chinese national defense and other high precision technology is limited because the blockade of advanced bearing technology. We can use dynamics modeling and virtual simulation technology to achieve the predictive design, and strive to achieve foreign level. In this paper, the author proposed a method of bearing design based on virtual simulation technology. The factors of bearing which affect the dynamic characteristics are considered, the process of design bearing based on virtual simulation is also considered. According to the different design parameters, the simulation results are used to verify the rationality, these can reduce the cost and improve the reliability. The virtual simulation technology is applied to design the 7016C angular contact ball bearing which used in aerospace area, and supported decision-making in structure design and data analyze. Finally, The feasibility of this method is verified by experiments..

Virtual Library: An essential component of virtual education

Directory of Open Access Journals (Sweden)

M zarghani

2015-06-01

Full Text Available Abstract Introduction: Library is one of the essential elements of universities which provide some important educational needs of students. Virtual education can not be exempted and virtual libraries are important support for virtual training programs. The purpose of this study is to evaluate the viewpoint of administrators and students in virtual education centers about the virtual library, its role and resources. Methods: This study was a descriptive survey. The research instrument was a researcher made questionnaire that its validity and reliability was confirmed. The study population consisted of 19 virtual training centers in Tehran city. Out of 19 centers, simple randomized sampling was done in five Centers. The sample size was 360 students. Data collection was conducted online and descriptive statistics using SPSS 18 and Excel software were used. Results: The results showed that viewpoints of administrators and students about the mission and services of virtual libraries in some cases were similar and in some cases were different. One of the administrators’ reasons for setting up a virtual learning system was lifelong learning, and lack of knowledge about virtual libraries was the reason for inadequate use of virtual libraries. The best format of virtual library from the administrators’ and students’ viewpoint, was portal document format (PDF. Conclusion: One of the most important function of a virtual library, is lifelong learning and empowering users to provide information and educational needs. The main reason for not setting up a virtual library is t lack of knowledge about it.

Virtual Reality and the Virtual Library.

Science.gov (United States)

Oppenheim, Charles

1993-01-01

Explains virtual reality, including proper and improper uses of the term, and suggests ways that libraries might be affected by it. Highlights include elements of virtual reality systems; possible virtual reality applications, including architecture, the chemical industry, transport planning, armed forces, and entertainment; and the virtual…

From virtual environment to virtual community

NARCIS (Netherlands)

Nijholt, Antinus; Terano, Takao; Nishida, Toyoaki; Namatame, Akira; Tsumoto, Syusaku; Ohsawa, Yukido; Washio, Takashi

2001-01-01

We discuss a virtual reality theater environment and its transition to a virtual community by adding domain agents and by allowing multiple users to visit this environment. The environment has been built using VRML (Virtual Reality Modeling Language). We discuss how our ideas about this environment

Education Free Virtual Massfor the Prevention of Road Accidents in Ambato

Directory of Open Access Journals (Sweden)

Fredy Maximiliano Jordán Cordones

2016-08-01

Full Text Available Traffic accidents is a problem of a global nature, the World Health Organization in its 2009 report notes that are 1.2 million deaths a year from this cause, also indicates that the prevention of traffic accidents involves a wide range of measures where education is a fundamental pillar. In Ecuador the situation is the same, by 2014 more than 35000 traffic incidents were reported This project proposes a process of massive virtual training on issues related to traffic laws, signs and statistics in order to achieve an awareness among drivers, and based on this reduce accident rates. Is taken as a case study, driving schools Trade Union of Professional Drivers of Tungurahua, a population had to investigate comprising students of these training centers, this population is 1600 people, we worked with a sample that arrived 350 people. The study based on surveys, it was concluded that there are several factors to traffic accidents, but the most common are: speeding, driving inebriated, little caution and fatigue, it was also concluded that all people are willing to receive training processes in person or virtual. After the study, the MOOC was implemented located in the http://cursos.cedia.org.ec/ direction, around 500 people enrolled and trained them. The project was supplemented by various accesses to the platform and mobile applications, promotional posters with QR codes and more.

Content Management for the Virtual Library

Directory of Open Access Journals (Sweden)

Ed Salazar

2006-09-01

Full Text Available Traditional, larger libraries can rely on their physical collection, coffee shops, and study rooms as ways to entice patrons into their library. Yet virtual libraries merely have their online presence to attract students to resources. This can only be achieved by providing a fully functional site that is well designed and organized, allowing patrons to navigate and locate information easily. One such technology significantly improving the overall usefulness of Web sites is a content management system (CMS. Although the CMS is not a novel technology per se, it is a technology smaller libraries cannot afford to ignore. In the fall of 2004, the Northcentral University Electronic Learning Resources Center (ELRC, a small, virtual library, moved from a static to a database-driven Web site. This article explains the importance of a CMS for the virtual or smaller library and describes the methodology used by ELRC to complete the project.

Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

Science.gov (United States)

Bean, Jacob; Fuller, Chris; Schiller, Noah

2016-01-01

Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.

Experience in Education Environment Virtualization within the Automated Information System "Platonus" (Kazakhstan)

Science.gov (United States)

Abeldina, Zhaidary; Moldumarova, Zhibek; Abeldina, Rauza; Makysh, Gulmira; Moldumarova, Zhuldyz Ilibaevna

2016-01-01

This work reports on the use of virtual tools as means of learning process activation. A good result can be achieved by combining the classical learning with modern computer technology. By creating a virtual learning environment and using multimedia learning tools one can obtain a significant result while facilitating the development of students'…

Control of a virtual ambulation influences body movement and motion sickness

Directory of Open Access Journals (Sweden)

Hagstrom Jens

2011-12-01

Full Text Available Drivers typically are less susceptible to motion sickness than passengers. The influence of vehicle control has theoretical implications for the etiology of motion sickness, and has practical implications for the design of virtual environments. In the present study, participants either controlled or did not control a nonvehicular virtual avatar (i.e., an ambulatory character in a console video game. We examined the incidence of motion sickness and patterns of movement of the head and torso as participants either played or watched the game. Motion sickness incidence was lower when controlling the virutal avatar than when watching an avatar that was controlled by someone else. Patterns of head and torso movement differed between particpants who did and did not control the avatar. Indepenently, patterns of movement differed between participants who reported motion sickness and those who did not. The results suggest that motion sickness is influenced by control of stimulus motion, whether that motion arises from a vehicle or from any other source. We consider implications for the design of humancomputer interfaces.

Therapeutic Media: Treating PTSD with Virtual Reality Exposure Therapy

Directory of Open Access Journals (Sweden)

Kathrin Friedrich

2016-09-01

Full Text Available Applying head-mounted displays (HMDs and virtual reality scenarios in virtual reality exposure therapy (VRET promises to alleviate combat-related post-traumatic stress disorders (among others. Its basic premise is that, through virtual scenarios, patients may re-engage immersively with situations that provoke anxiety, thereby reducing fear and psychosomatic stress. In this context, HMDs and visualizations should be considered not merely as devices for entertainment purposes or tools for achieving pragmatic objectives but also as a means to instruct and guide patients’ imagination and visual perception in triggering traumatic experiences. Under what perceptual and therapeutic conditions is virtual therapy to be considered effective? Who is the “ideal” patient for such therapy regimes, both in terms of his/her therapeutic indications and his/her perceptual readiness to engage with VR scenarios? In short, how are “treatable” patients conceptualized by and within virtual therapy? From a media-theory perspective, this essay critically explores various aspects of the VRET application Bravemind in order to shed light on conditions of virtual exposure therapy and conceptions of subjectivity and traumatic experience that are embodied and replicated by such HMD-based technology.

Controlled interaction: strategies for using virtual reality to study perception.

Science.gov (United States)

Durgin, Frank H; Li, Zhi

2010-05-01

Immersive virtual reality systems employing head-mounted displays offer great promise for the investigation of perception and action, but there are well-documented limitations to most virtual reality systems. In the present article, we suggest strategies for studying perception/action interactions that try to depend on both scale-invariant metrics (such as power function exponents) and careful consideration of the requirements of the interactions under investigation. New data concerning the effect of pincushion distortion on the perception of surface orientation are presented, as well as data documenting the perception of dynamic distortions associated with head movements with uncorrected optics. A review of several successful uses of virtual reality to study the interaction of perception and action emphasizes scale-free analysis strategies that can achieve theoretical goals while minimizing assumptions about the accuracy of virtual simulations.

Possibilities and Determinants of Using Low-Cost Devices in Virtual Education Applications

Science.gov (United States)

Bun, Pawel Kazimierz; Wichniarek, Radoslaw; Górski, Filip; Grajewski, Damian; Zawadzki, Przemyslaw; Hamrol, Adam

2017-01-01

Virtual reality (VR) may be used as an innovative educational tool. However, in order to fully exploit its potential, it is essential to achieve the effect of immersion. To more completely submerge the user in a virtual environment, it is necessary to ensure that the user's actions are directly translated into the image generated by the…

Do "Virtual" and "Outpatient" Public Health Tuberculosis Clinics Perform Equally Well? A Program-Wide Evaluation in Alberta, Canada.

Directory of Open Access Journals (Sweden)

Richard Long

Full Text Available Meeting the challenge of tuberculosis (TB elimination will require adopting new models of delivering patient-centered care customized to diverse settings and contexts. In areas of low incidence with cases spread out across jurisdictions and large geographic areas, a "virtual" model is attractive. However, whether "virtual" clinics and telemedicine deliver the same outcomes as face-to-face encounters in general and within the sphere of public health in particular, is unknown. This evidence is generated here by analyzing outcomes between the "virtual" and "outpatient" public health TB clinics in Alberta, a province of Western Canada with a large geographic area and relatively small population.In response to the challenge of delivering equitable TB services over long distances and to hard to reach communities, Alberta established three public health clinics for the delivery of its program: two outpatient serving major metropolitan areas, and one virtual serving mainly rural areas. The virtual clinic receives paper-based or electronic referrals and generates directives which are acted upon by local providers. Clinics are staffed by dedicated public health nurses and university-based TB physicians. Performance of the two types of clinics is compared between the years 2008 and 2012 using 16 case management and treatment outcome indicators and 12 contact management indicators.In the outpatient and virtual clinics, respectively, 691 and 150 cases and their contacts were managed. Individually and together both types of clinics met most performance targets. Compared to outpatient clinics, virtual clinic performance was comparable, superior and inferior in 22, 3, and 3 indicators, respectively.Outpatient and virtual public health TB clinics perform equally well. In low incidence settings a combination of the two clinic types has the potential to address issues around equitable service delivery and declining expertise.

The role of virtual reality and 3D modelling in built environment education

OpenAIRE

Horne, Margaret; Thompson, Emine Mine

2007-01-01

This study builds upon previous research on the integration of Virtual Reality (VR) within the built environment curriculum and aims to investigate the role of Virtual Reality and three-dimensional (3D) computer modelling on learning and teaching in a school of the built environment. In order to achieve this aim a number of academic experiences were analysed to explore the applicability and viability of 3D computer modelling and Virtual Reality (VR) into built environment subject areas. Altho...

Holistic virtual machine scheduling in cloud datacenters towards minimizing total energy

OpenAIRE

Li, Xiang; Garraghan, Peter; Jiang, Xiaohong; Wu, Zhaohui; Xu, Jie

2018-01-01

Energy consumed by Cloud datacenters has dramatically increased, driven by rapid uptake of applications and services globally provisioned through virtualization. By applying energy-aware virtual machine scheduling, Cloud providers are able to achieve enhanced energy efficiency and reduced operation cost. Energy consumption of datacenters consists of computing energy and cooling energy. However, due to the complexity of energy and thermal modeling of realistic Cloud datacenter operation, tradi...

Developing a Measure of Virtual Community Citizenship Behavior

Directory of Open Access Journals (Sweden)

Luman Yong

2011-12-01

Full Text Available This study examines the kinds of behaviors that constitute virtual community citizenship behaviors (VCCB and tests three factors that may influence community members’ willingness to engage in VCCB. More specifically, the authors propose a multi-dimensional VCCB construct (altruism, civic virtue, consciousness, courtesy, and sportsmanship and three antecedents of VCCB (affective commitment, structural embeddedness and membership tenure. Four dimensions including altruism, civic virtue, courtesy and loyalty emerged as a result of behavioral examples collection from SMEs using critical incident technique and a VCCB survey with 19 Likert type items reflecting the behavioral examples within each dimension was created. Data was collected from an online discussion forum (The Grad Cafe to address the research questions of this study. Results indicate that affective commitment was a significant predictor of the virtual community citizenship behaviors. A research agenda for studying VCCB is presented.

Virtual environment simulation as a tool to support evacuation planning

International Nuclear Information System (INIS)

Mol, Antonio C.; Grecco, Claudio H.S.; Santos, Isaac J.A.L.; Carvalho, Paulo V.R.; Jorge, Carlos A.F.; Sales, Douglas S.; Couto, Pedro M.; Botelho, Felipe M.; Bastos, Felipe R.

2007-01-01

This work is a preliminary study of the use of a free game-engine as a tool to build and to navigate in virtual environments, with a good degree of realism, for virtual simulations of evacuation from building and risk zones. To achieve this goal, some adjustments in the game engine have been implemented. A real building with four floors, consisting of some rooms with furniture and people, has been virtually implemented. Simulations of simple different evacuation scenarios have been performed, measuring the total time spent in each case. The measured times have been compared with their corresponding real evacuation times, measured in the real building. The first results have demonstrated that the virtual environment building with the free game engine is capable to reproduce the real situation with a satisfactory level. However, it is important to emphasize that such virtual simulations serve only as an aid in the planning of real evacuation simulations, and as such must never substitute the later. (author)

The virtual mass of a growing and collapsing bubble

International Nuclear Information System (INIS)

Abdullah Abbas Kendoush

2005-01-01

Full text of publication follows: The acceleration of bubbles are encountered in flash evaporation, that results form the hypothetical sudden depressurization of the primary cooling circuit of light water nuclear reactors. Bubble growth during flash evaporation is a transient phenomenon, leads to a virtual mass force that should be introduced into the equation of motion. The importance of the virtual mass concept was appreciated by many investigators. They demonstrated that the inclusion of the virtual mass effect into the numerical solution of the transient two-phase flow appears to improve numerical stability and efficiency, and to achieve accurate results in many cases of practical concern. Analytical solutions were obtained for the virtual mass coefficient of a growing and collapsing bubble at high and low Jakob numbers. The method of solution was similar to that used previously by the author [Physics of Fluids 15(2782- 2785)2003]. The present solution is valid by its asymptotic approach to the limit of the virtual mass coefficient of the constant volume bubble. (author)

Virtual planning of complex head and neck reconstruction results in satisfactory match between real outcomes and virtual models.

Science.gov (United States)

Hanken, Henning; Schablowsky, Clemens; Smeets, Ralf; Heiland, Max; Sehner, Susanne; Riecke, Björn; Nourwali, Ibrahim; Vorwig, Oliver; Gröbe, Alexander; Al-Dam, Ahmed

2015-04-01

The reconstruction of large facial bony defects using microvascular transplants requires extensive surgery to achieve full rehabilitation of form and function. The purpose of this study is to measure the agreement between virtual plans and the actual results of maxillofacial reconstruction. This retrospective cohort study included 30 subjects receiving maxillofacial reconstruction with a preoperative virtual planning. Parameters including defect size, position, angle and volume of the transplanted segments were compared between the virtual plan and the real outcome using paired t test. A total of 63 bone segments were transplanted. The mean differences between the virtual planning and the postoperative situation were for the defect sizes 1.17 mm (95 % confidence interval (CI) (-.21 to 2.56 mm); p = 0.094), for the resection planes 1.69 mm (95 % CI (1.26-2.11); p = 0.033) and 10.16° (95 % CI (8.36°-11.96°); p satisfactory postoperative results are the basis for an optimal functional and aesthetic reconstruction in a single surgical procedure. The technique should be further investigated in larger study populations and should be further improved.

NASA Virtual Glovebox: An Immersive Virtual Desktop Environment for Training Astronauts in Life Science Experiments

Science.gov (United States)

Twombly, I. Alexander; Smith, Jeffrey; Bruyns, Cynthia; Montgomery, Kevin; Boyle, Richard

2003-01-01

The International Space Station will soon provide an unparalleled research facility for studying the near- and longer-term effects of microgravity on living systems. Using the Space Station Glovebox Facility - a compact, fully contained reach-in environment - astronauts will conduct technically challenging life sciences experiments. Virtual environment technologies are being developed at NASA Ames Research Center to help realize the scientific potential of this unique resource by facilitating the experimental hardware and protocol designs and by assisting the astronauts in training. The Virtual GloveboX (VGX) integrates high-fidelity graphics, force-feedback devices and real- time computer simulation engines to achieve an immersive training environment. Here, we describe the prototype VGX system, the distributed processing architecture used in the simulation environment, and modifications to the visualization pipeline required to accommodate the display configuration.

Immersive Learning Environment Using 3D Virtual Worlds and Integrated Remote Experimentation

Directory of Open Access Journals (Sweden)

Roderval Marcelino

2013-01-01

Full Text Available This project seeks to demonstrate the use of remote experimentation and 3D virtual environments applied to the teaching-learning in the areas of exact sciences-physics. In proposing the combination of remote experimentation and 3D virtual worlds in teaching-learning process, we intend to achieve greater geographic coverage, contributing to the construction of new methodologies of teaching support, speed of access and foremost motivation for students to continue in scientific study of the technology areas. The proposed architecture is based on a model implemented fully featured open source and open hardware. The virtual world was built in OpenSim software and integrated it a remote physics experiment called "electrical panel". Accessing the virtual world the user has total control of the experiment within the 3D virtual world.

Virtual colonoscopy - changes for screening examination?

International Nuclear Information System (INIS)

Rust, G.F.; Reiser, M.

2002-01-01

In principle, virtual colonoscopy is capable to be used as method for early detection of colorectal cancer (CRC), even if the accuracy of the method and radiation exposure are matters discussion in the radiological community. Virtual colonoscopy is able to detect any pathology which is relevant for early detection of CRC especially when using multislice CT, but also with single slice CT. The diagnosis of small lesions, less than 7 mm in diameter (polyps and flat lesions) is still problematic as it is in conventional colonoscopy. The exposure to x-rays in asymptomatic patients, without any increased risk of developing cancer is highly problematic and should be reduced to a minimum. Using special post processing filters on the volume dataset it can be shown that a tube current of 20 mAs is sufficient without any loss in accuracy. Measurements on the Alderson-phantom showed, that an effective dose exposure of 1.2 mSv is obtained using these reduced mAs values. It has to be differentiated between virtual colonoscopy for early detection of polyps and CRC in individual patients or as a screening examination of a large population. Virtual colonoscopy as a screening examination necessitates reduction of radiation dose, a high degree of automatisation in 3D reconstructions as well as the assessment of the entire mucosa. High risk patients, whom refuse fibreoptic colonoscopy should undergo virtual colonoscopy. Virtual colonoscopy has a good chance to become an accepted tool for general screening, if efficient dose reduction, complete visualization of the colon mucosa and automatisation of the post processing procedures can be achieved. (orig.) [de

Best-effort Support for a Virtual Seminar Room

DEFF Research Database (Denmark)

Sharp, Robin; Todirica, Edward Alexandru

2002-01-01

This paper describes the RTMM Virtual Seminar Room, an interactive distributed multimedia application based on a platform with a simple middleware architecture, using best effort scheduling and a best effort network service. Emphasis has been placed on achieving low latency in all parts...

[Virtual reality therapy in anxiety disorders].

Science.gov (United States)

Mitrousia, V; Giotakos, O

2016-01-01

During the last decade a number of studies have been conducted in order to examine if virtual reality exposure therapy can be an alternative form of therapy for the treatment of mental disorders and particularly for the treatment of anxiety disorders. Imaginal exposure therapy, which is one of the components of Cognitive Behavioral Therapy, cannot be easily applied to all patients and in cases like those virtual reality can be used as an alternative or a supportive psychotherapeutic technique. Most studies using virtual reality have focused on anxiety disorders, mainly in specific phobias, but some extend to other disorders such as eating disorders, drug dependence, pain control and palliative care and rehabilitation. Main characteristics of virtual reality therapy are: "interaction", "immersion", and "presence". High levels of "immersion" and "presence" are associated with increased response to exposure therapy in virtual environments, as well as better therapeutic outcomes and sustained therapeutic gains. Typical devices that are used in order patient's immersion to be achieved are the Head-Mounted Displays (HMD), which are only for individual use, and the computer automatic virtual environment (CAVE), which is a multiuser. Virtual reality therapy's disadvantages lie in the difficulties that arise due to the demanded specialized technology skills, devices' cost and side effects. Therapists' training is necessary in order for them to be able to manipulate the software and the hardware and to adjust it to each case's needs. Devices' cost is high but as technology continuously improves it constantly decreases. Immersion during virtual reality therapy can induce mild and temporary side effects such as nausea, dizziness or headache. Until today, however, experience shows that virtual reality offers several advantages. Patient's avoidance to be exposed in phobic stimuli is reduced via the use of virtual reality since the patient is exposed to them as many times as he

Virtual Team Governance: Addressing the Governance Mechanisms and Virtual Team Performance

Science.gov (United States)

Zhan, Yihong; Bai, Yu; Liu, Ziheng

As technology has improved and collaborative software has been developed, virtual teams with geographically dispersed members spread across diverse physical locations have become increasingly prominent. Virtual team is supported by advancing communication technologies, which makes virtual teams able to largely transcend time and space. Virtual teams have changed the corporate landscape, which are more complex and dynamic than traditional teams since the members of virtual teams are spread on diverse geographical locations and their roles in the virtual team are different. Therefore, how to realize good governance of virtual team and arrive at good virtual team performance is becoming critical and challenging. Good virtual team governance is essential for a high-performance virtual team. This paper explores the performance and the governance mechanism of virtual team. It establishes a model to explain the relationship between the performance and the governance mechanisms in virtual teams. This paper is focusing on managing virtual teams. It aims to find the strategies to help business organizations to improve the performance of their virtual teams and arrive at the objectives of good virtual team management.

ENGEMBANGAN VIRTUAL CLASS UNTUK PEMBELAJARAN AUGMENTED REALITY BERBASIS ANDROID

Directory of Open Access Journals (Sweden)

Rifiana Arief

2015-02-01

Full Text Available ABSTRACT Augmanted Reality for android handphone has been a trend among collage students of computer department who join New Media course. To develop this application, the knowladge about visual presentation theory and case study of Augmanted Reality on android phoneneed to be conducted. Learning media through virtual class can facilitate the students’ needs in learning and developing Augmanted Reality. The method of this study in developing virtual class for Augmented Reality learning were: a having preparation to arrange learning unit, b analyzing and developing the content of learning materials, c designing storyboard or scenario of the virtual class, d making website of virtual class, e implementing the website as facility of online learning for Augmanted Reality. The available facilities in virtual class were to check learning units, to choose and download the material in the forms of e-book and presentation slides, to open the relevant website link for material enrichment as well as students’ practice with pre-test and post-test for measuring students’ understanding. By implementing virtual class for Augmanted Reality learning based Android, it is expected to provide alternative learning strategies for students that are interesting and easy to understand. The students are expected to be able to utilize this facility optimally in order to achieve the purposes of learning process and graduates’ competence. Keywords: VirtualClass, Augmented Reality (AR

Virtual obstacle crossing: Reliability and differences in stroke survivors who prospectively experienced falls or no falls.

Science.gov (United States)

Punt, Michiel; Bruijn, Sjoerd M; Wittink, Harriet; van de Port, Ingrid G; Wubbels, Gijs; van Dieën, Jaap H

2017-10-01

Stroke survivors often fall during walking. To reduce fall risk, gait testing and training with avoidance of virtual obstacles is gaining popularity. However, it is unknown whether and how virtual obstacle crossing is associated with fall risk. The present study assessed whether obstacle crossing characteristics are reliable and assessed differences in stroke survivors who prospectively experienced falls or no falls. We recruited twenty-nine community dwelling chronic stroke survivors. Participants crossed five virtual obstacles with increasing lengths. After a break, the test was repeated to assess test-retest reliability. For each obstacle length and trial, we determined; success rate, leading limb preference, pre and post obstacle distance, margins of stability, toe clearance, and crossing step length and speed. Subsequently, fall incidence was monitored using a fall calendar and monthly phone calls over a six-month period. Test-retest reliability was poor, but improved with increasing obstacle-length. Twelve participants reported at least one fall. No association of fall incidence with any of the obstacle crossing characteristics was found. Given the absence of height of the virtual obstacles, obstacle avoidance may have been relatively easy, allowing participants to cross obstacles in multiple ways, increasing variability of crossing characteristics and reducing the association with fall risk. These finding cast some doubt on current protocols for testing and training of obstacle avoidance in stroke rehabilitation. Copyright © 2017 Elsevier B.V. All rights reserved.

A Security Monitoring Framework For Virtualization Based HEP Infrastructures

Science.gov (United States)

Gomez Ramirez, A.; Martinez Pedreira, M.; Grigoras, C.; Betev, L.; Lara, C.; Kebschull, U.; ALICE Collaboration

2017-10-01

High Energy Physics (HEP) distributed computing infrastructures require automatic tools to monitor, analyze and react to potential security incidents. These tools should collect and inspect data such as resource consumption, logs and sequence of system calls for detecting anomalies that indicate the presence of a malicious agent. They should also be able to perform automated reactions to attacks without administrator intervention. We describe a novel framework that accomplishes these requirements, with a proof of concept implementation for the ALICE experiment at CERN. We show how we achieve a fully virtualized environment that improves the security by isolating services and Jobs without a significant performance impact. We also describe a collected dataset for Machine Learning based Intrusion Prevention and Detection Systems on Grid computing. This dataset is composed of resource consumption measurements (such as CPU, RAM and network traffic), logfiles from operating system services, and system call data collected from production Jobs running in an ALICE Grid test site and a big set of malware samples. This malware set was collected from security research sites. Based on this dataset, we will proceed to develop Machine Learning algorithms able to detect malicious Jobs.

Utilization of virtual reality for reading the superheated emulsion detector

International Nuclear Information System (INIS)

Santos Sobrinho, Jose C.; Santo, Andre C.E.; Pereira, Claudio M.N.A.; Mol, Antonio C.A.

2013-01-01

This paper presents a method based on Virtual Reality for reading the Superheated Emulsion Detector (Bubble Detector). The proposed method is an alternative to: automatic counters offered by the manufacturers of detectors, since they have a relatively high cost (acquisition, maintenance and periodic calibration), and visual counting of detectors, since it only has an advantage when there are a small number of bubbles. The method starts with the collection of detector's digital images in order to obtain a sequence of images to create an animation that is displayed with the help of Virtual Reality. To this end, it is modeled, using OpenGL graphics library, a virtual environment for visualizing and manipulating virtual detector. It is made, then a calibration of this virtual environment thus ensuring the correspondence of the model with reality. The reading of the detector (bubbles count) is made visually by the user with the assistance of stereo vision and a 3D cursor to navigation, marking and counting the bubbles. The user views a further auxiliary display that shows the three-dimensional cursor position, the labeled amount of bubbles and the measured dose. After testing, the following results were achieved: better precision in counting the bubbles compared with the 10% reported by the manufacturer of the automatic reader; achieving a low cost tool that requires no calibration constant in the process of maintenance and/or lifetime; minimizing the problem of manual counting for large number of bubbles and ease of use, because can be operated by a common user. (author)

Utilization of virtual reality for reading the superheated emulsion detector

Energy Technology Data Exchange (ETDEWEB)

Santos Sobrinho, Jose C.; Santo, Andre C.E.; Pereira, Claudio M.N.A.; Mol, Antonio C.A., E-mail: volksparati@hotmail.com, E-mail: cotelli.andre@gmail.com, E-mail: cmnap@ien.gov.br, E-mail: mol@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

This paper presents a method based on Virtual Reality for reading the Superheated Emulsion Detector (Bubble Detector). The proposed method is an alternative to: automatic counters offered by the manufacturers of detectors, since they have a relatively high cost (acquisition, maintenance and periodic calibration), and visual counting of detectors, since it only has an advantage when there are a small number of bubbles. The method starts with the collection of detector's digital images in order to obtain a sequence of images to create an animation that is displayed with the help of Virtual Reality. To this end, it is modeled, using OpenGL graphics library, a virtual environment for visualizing and manipulating virtual detector. It is made, then a calibration of this virtual environment thus ensuring the correspondence of the model with reality. The reading of the detector (bubbles count) is made visually by the user with the assistance of stereo vision and a 3D cursor to navigation, marking and counting the bubbles. The user views a further auxiliary display that shows the three-dimensional cursor position, the labeled amount of bubbles and the measured dose. After testing, the following results were achieved: better precision in counting the bubbles compared with the 10% reported by the manufacturer of the automatic reader; achieving a low cost tool that requires no calibration constant in the process of maintenance and/or lifetime; minimizing the problem of manual counting for large number of bubbles and ease of use, because can be operated by a common user. (author)

Checking the virtual treatment modality Wedge from Siemens; Verificacion de la modalidad de tratamiento virtual WEDGE de SIEMENS

Energy Technology Data Exchange (ETDEWEB)

Suero Rodrigo, M. A.; Marques Fraguela, E.

2011-07-01

The treatment modality Virtual Wedge (VW) or implemented by Siemens virtual wedge in electron linear accelerators achieved dose distributions are similar but not identical, to those obtained with physical wedges. Among the advantages against the latter is the greater ease of use, wedge factor close to one, and lower peripheral dose. However, these benefits are to be effective requires a through quality control dependence because a larger number of parameters that control the generation of the beam, the dose monitor system and the movement of the jaws of the collimator. We performed a study of the wedge taking into account different configurations that can affect their behavior from the dosimetric point of view.

THE EFFECTIVENESS OF A VIRTUAL FIELD TRIP (VFT MODULE IN LEARNING BIOLOGY

Directory of Open Access Journals (Sweden)

Norbaizura HARIS

2015-07-01

Full Text Available Virtual Field Trip is a computer aided module of science developed to study the Colonisation and Succession in Mangrove Swamps, as an alternative to the real field trip in Form for Biology. This study is to identify the effectiveness of the Virtual Field Trip (VFT module towards the level of achievement in the formative test for this topic. This study was conducted to 60 students employing a quasi-experimental design involving a treatment group taught using the VFT module and a control group who were taught using conventional methods. Analysis into the effectiveness of the virtual module was done descriptively, followed by inferential analysis involving the two-way ANOVA. The results showed significant differences in the mean scores of pre and post achievement between students taught using VFT and students who were taught using conventional methods for objective, structure and essay type questions. The study concluded that teaching and learning by using the VFT module, integrated with ICT, has a positive impact on student achievement whencompared to conventional methods. This study focuses on the use of the VFT recognizing that teachers are often unable to conduct a real field trip on location.

Innovative application of virtual display technique in virtual museum

Science.gov (United States)

Zhang, Jiankang

2017-09-01

Virtual museum refers to display and simulate the functions of real museum on the Internet in the form of 3 Dimensions virtual reality by applying interactive programs. Based on Virtual Reality Modeling Language, virtual museum building and its effective interaction with the offline museum lie in making full use of 3 Dimensions panorama technique, virtual reality technique and augmented reality technique, and innovatively taking advantages of dynamic environment modeling technique, real-time 3 Dimensions graphics generating technique, system integration technique and other key virtual reality techniques to make sure the overall design of virtual museum.3 Dimensions panorama technique, also known as panoramic photography or virtual reality, is a technique based on static images of the reality. Virtual reality technique is a kind of computer simulation system which can create and experience the interactive 3 Dimensions dynamic visual world. Augmented reality, also known as mixed reality, is a technique which simulates and mixes the information (visual, sound, taste, touch, etc.) that is difficult for human to experience in reality. These technologies make virtual museum come true. It will not only bring better experience and convenience to the public, but also be conducive to improve the influence and cultural functions of the real museum.

What Happens in a Virtual World Has a Real-World Impact, a Scholar Finds

Science.gov (United States)

Foster, Andrea L.

2008-01-01

Forget the pills, hypnosis, and meditation. Losing weight or boosting self-confidence can be achieved by adopting an avatar and living in virtual reality, says Jeremy N. Bailenson, an assistant professor of communications at Stanford University. As the director of Stanford's Virtual Human Interaction Lab, Mr. Bailenson has explored ways that…

Virtual Trondheim: A Virtual Environment for Tourism and Education

OpenAIRE

Jose, Dawn Alphonse

2015-01-01

The purpose of this study is to investigate whether educational activities in tourism can be supported by virtual reality technologies, using virtual world frameworks. Settings of virtual world of SecondLife and a recent Virtual Reality technology known as Oculus Rift were used in the thesis work with the city of Trondheim as the main context. Theoretical studies on Virtual Reality systems were conducted and data for the research were obtained through empirical studies condu...

Second Life: A Virtual Learning Center for the Study of Sharks

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Tryfonas Papadamou

2011-06-01

Full Text Available In this work the educational capabilities of the virtual world Second Life are researched and tested. A virtual world is constructed to support education for sustainable development. The life and characteristics of the shark is studied as this fish has received a lot of negative publicity and is in the danger of extinction. A virtual museum was developed for this purpose. The research question is focused on whether it can be used effectively in a modern classroom and how difficult is for an educator to develop such an application. To achieve that, a number of learning activities were developed, a number of on line questionnaires were issued and a series of virtual meetings were held. Teachers used the application and answered the questionnaires. The entire effort was attempted through Internet exclusively.

Virtual Trackballs Revisited

DEFF Research Database (Denmark)

Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

2004-01-01

reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENCE]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual...... trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [CHECK END OF SENTENCE], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake......'s virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell's virtual trackball [CHECK END OF SENTENCE] and discuss studies of the usability of virtual trackballs....

Personal Virtual Libraries

Science.gov (United States)

Pappas, Marjorie L.

2004-01-01

Virtual libraries are becoming more and more common. Most states have a virtual library. A growing number of public libraries have a virtual presence on the Web. Virtual libraries are a growing addition to school library media collections. The next logical step would be personal virtual libraries. A personal virtual library (PVL) is a collection…

Dissemination of medical applications of nuclear energy with virtual reality technology

International Nuclear Information System (INIS)

Botelho, Felipe M.; Oliveira, Beatriz A.R.

2007-01-01

This work makes use of Virtual Reality technology to disseminate medical applications of nuclear energy, with educational purposes. Virtual Reality is an effective learning tool, since navigation and interaction in virtual worlds can improve motivation in the learning process. With this technology, learning can be achieved in a clearer, joyful and more objective way. Among the existing medical applications of nuclear energy, this work focuses on the use of radiopharmaceuticals. The goal is to simulate this application in a virtual environment, for educational purposes, and to show the absorption of a radiopharmaceutical by the human body, during a diagnostics or treatment procedure. An example has been chosen, for Iodine radiopharmaceutical, which has affinity with the thyroid, and then concentrates in this organ. During the simulation, the concentration of the radioactive Iodine in the thyroid can be emphasized, and in the sequence, the virtual patient can be shown during the imaging procedure. (author)

Wireless virtualization

CERN Document Server

Wen, Heming; Le-Ngoc, Tho

2013-01-01

This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

Typology on Leadership toward Creativity in Virtual Work

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Iris A Humala

2017-07-01

Full Text Available Aim/Purpose: This study aims to develop a descriptive typology to better identify leadership toward creativity in virtual work in different types of companies. Background: The study empirically explores how leadership toward creativity occurs in virtual work and uses the theoretical lenses of creativity-conducive leadership and heterarchy to generate a typology. Methodology\t: A multiple qualitative case study design, interpretivist approach, and abductive analysis are applied. Data is collected by interviewing 21 leaders and employees face-to-face in four companies in the ICT sector and one business advisor company. Contribution: The empirical evidence of this study enriches the understanding of leadership toward creativity in virtual work and contributes to the limited empirical knowledge on leadership that stimulates a virtual workforce to achieve creativity. Findings: The four different types of companies in the typology utilize various transitions toward leadership creativity in virtual work. The trend in leadership in the existing virtually networked business environment is toward the “collective mind” company, which is characterized by shared values, meaningful work, collective intelligence, conscious reflection, transparency, coaching, empowering leadership by example, effective multichannel interaction, and assertiveness. The findings empirically support applying a heterarchy perspective to lead a virtual workforce toward creativity and promote leaders who are genuinely interested in people, their development, collaboration, and technology. Recommendations for Practitioners: The typology helps professionals realize the need to develop leadership, communication, interaction, learning, and growth to foster creative interaction and improve productivity and competitiveness. Recommendation for Researchers: This study enables researchers to more rigorously and creatively conceptualize the conditions and relationships in leadership that

LivePhantom: Retrieving Virtual World Light Data to Real Environments.

Directory of Open Access Journals (Sweden)

Hoshang Kolivand

Full Text Available To achieve realistic Augmented Reality (AR, shadows play an important role in creating a 3D impression of a scene. Casting virtual shadows on real and virtual objects is one of the topics of research being conducted in this area. In this paper, we propose a new method for creating complex AR indoor scenes using real time depth detection to exert virtual shadows on virtual and real environments. A Kinect camera was used to produce a depth map for the physical scene mixing into a single real-time transparent tacit surface. Once this is created, the camera's position can be tracked from the reconstructed 3D scene. Real objects are represented by virtual object phantoms in the AR scene enabling users holding a webcam and a standard Kinect camera to capture and reconstruct environments simultaneously. The tracking capability of the algorithm is shown and the findings are assessed drawing upon qualitative and quantitative methods making comparisons with previous AR phantom generation applications. The results demonstrate the robustness of the technique for realistic indoor rendering in AR systems.

An Islanding Microgrid Power Sharing Approach Using Enhanced Virtual Impedance Control Scheme

DEFF Research Database (Denmark)

He, Jinwei; Li, Yun Wei; Guerrero, Josep M.

2013-01-01

In order to address the load sharing problem in islanding microgrids, this paper proposes an enhanced distributed generation (DG) unit virtual impedance control approach. The proposed method can realize accurate regulation of DG unit equivalent impedance at both fundamental and selected harmonic...... and PCC harmonic voltage compensation are achieved without using any fundamental and harmonic components extractions. Experimental results from a scaled single-phase microgrid prototype are provided to validate the feasibility of the proposed virtual impedance control approach....... frequencies. In contrast to conventional virtual impedance control methods, where only a line current feed-forward term is added to the DG voltage reference, the proposed virtual impedance at fundamental and harmonic frequencies is regulated using DG line current and point of common coupling (PCC) voltage...

Distributed continuous energy scheduling for dynamic virtual power plants

International Nuclear Information System (INIS)

Niesse, Astrid

2015-01-01

This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

3D virtual human rapid modeling method based on top-down modeling mechanism

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LI Taotao

2017-01-01

Full Text Available Aiming to satisfy the vast custom-made character demand of 3D virtual human and the rapid modeling in the field of 3D virtual reality, a new virtual human top-down rapid modeling method is put for-ward in this paper based on the systematic analysis of the current situation and shortage of the virtual hu-man modeling technology. After the top-level realization of virtual human hierarchical structure frame de-sign, modular expression of the virtual human and parameter design for each module is achieved gradu-al-level downwards. While the relationship of connectors and mapping restraints among different modules is established, the definition of the size and texture parameter is also completed. Standardized process is meanwhile produced to support and adapt the virtual human top-down rapid modeling practice operation. Finally, the modeling application, which takes a Chinese captain character as an example, is carried out to validate the virtual human rapid modeling method based on top-down modeling mechanism. The result demonstrates high modelling efficiency and provides one new concept for 3D virtual human geometric mod-eling and texture modeling.

Virtual colonoscopy

Science.gov (United States)

Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

Virtual Exploratories

DEFF Research Database (Denmark)

Jensen, Sisse Siggaard

2006-01-01

-systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...... the design and activity of the advanced virtual worlds and role-playing games, then the empirical research on the actors’ activity, while they are acting, is an important precondition to it. A step towards the conception of such a designing strategy for virtual exploratories is currently pursued....... [1] The research project: Actors and Avatars Communicating in Virtual Worlds – an Empirical Analysis of Actors’ Sense-making Strategies When Based on a Communication Theoretical Approach’ (2006-2007) is supported...

Immersive virtual walk-through development for tokamak using active head mounted display

International Nuclear Information System (INIS)

Dutta, Pramit

2015-01-01

A fully immersive virtual walk-through of the SST-1 tokamak has been developed. The virtual walkthrough renders the virtual model of SST-1 tokamak through a active stereoscopic head mounted display to visualize the virtual environment. All locations inside and outside of the reactor can be accessed and reviewed. Such a virtual walkthrough provides a 1:1 scale visualization of all components of the tokamak. To achieve such a virtual model, the graphical details of the tokamak CAD model are enhanced. Such enhancements are provided to improve lighting conditions at various locations, texturing of components to have a realistic visual effect and 360° rendering for ease of access. The graphical enhancements also include the redefinition of the facets to optimize the surface triangles to remove lags in display during visual rendering. Two separate algorithms are developed to interact with the virtual model. A fly-by algorithm, developed using C#, uses inputs from a commercial joystick to navigate within the virtual environment. The second algorithm uses the IR and gyroscopic tracking system of the head mounted display to render view as per the current pose of the user within the virtual environment and the direction of view. Such a virtual walk-thorough can be used extensively for design review and integration, review of new components, operator training for remote handling, operations, upgrades of tokamak, etc. (author)

A Computerized Procedure linked to Virtual Equipment

International Nuclear Information System (INIS)

Jung, Yeon Sub; Song, Tae Young

2011-01-01

Digital, information, and communication technologies have change human's behavior. This is because human has limitation to memorize and process information. Human has to access other information and real time information for important decisions. Those technologies are playing important roles. Nuclear power plants cannot be exception. Many accidents in nuclear power plants result from absent or incorrect information. The information for nuclear personnel is context sensitive. They don't have enough time to verify the context sensitive information. Therefore they skip the information, as resulting in incident. Nuclear personnel are usually carrying static paper procedures during local task performance. The procedure guides them steps to follow. There is, however, no dynamic and context sensitive information in the paper. The effect of the work is evaluated once while getting permission of the work. Afterward they are not informed. The static paper is generally simplified, so that it does not show detail of equipment being manipulated. Particularly novice workers feel difficult to understand the procedure due to lack of detail. Pictures of equipment inserted in the procedure are not enough for comprehension. A computerized procedure linked with virtual equipment is one of the best solutions to increase the detail of procedure. Virtual equipment, however, has still limitation not to provide real time information, because the virtual equipment is not synchronized with real plants

Sensitivity-based virtual fields for the non-linear virtual fields method

Science.gov (United States)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2017-09-01

The virtual fields method is an approach to inversely identify material parameters using full-field deformation data. In this manuscript, a new set of automatically-defined virtual fields for non-linear constitutive models has been proposed. These new sensitivity-based virtual fields reduce the influence of noise on the parameter identification. The sensitivity-based virtual fields were applied to a numerical example involving small strain plasticity; however, the general formulation derived for these virtual fields is applicable to any non-linear constitutive model. To quantify the improvement offered by these new virtual fields, they were compared with stiffness-based and manually defined virtual fields. The proposed sensitivity-based virtual fields were consistently able to identify plastic model parameters and outperform the stiffness-based and manually defined virtual fields when the data was corrupted by noise.

Virtual Inertia: Current Trends and Future Directions

Directory of Open Access Journals (Sweden)

Ujjwol Tamrakar

2017-06-01

Full Text Available The modern power system is progressing from a synchronous machine-based system towards an inverter-dominated system, with large-scale penetration of renewable energy sources (RESs like wind and photovoltaics. RES units today represent a major share of the generation, and the traditional approach of integrating them as grid following units can lead to frequency instability. Many researchers have pointed towards using inverters with virtual inertia control algorithms so that they appear as synchronous generators to the grid, maintaining and enhancing system stability. This paper presents a literature review of the current state-of-the-art of virtual inertia implementation techniques, and explores potential research directions and challenges. The major virtual inertia topologies are compared and classified. Through literature review and simulations of some selected topologies it has been shown that similar inertial response can be achieved by relating the parameters of these topologies through time constants and inertia constants, although the exact frequency dynamics may vary slightly. The suitability of a topology depends on system control architecture and desired level of detail in replication of the dynamics of synchronous generators. A discussion on the challenges and research directions points out several research needs, especially for systems level integration of virtual inertia systems.

Green Virtualization for Multiple Collaborative Cellular Operators

KAUST Repository

Farooq, Muhammad Junaid

2017-06-05

This paper proposes and investigates a green virtualization framework for infrastructure sharing among multiple cellular operators whose networks are powered by a combination of conventional and renewable sources of energy. Under the proposed framework, the virtual network formed by unifying radio access infrastructures of all operators is optimized for minimum energy consumption by deactivating base stations (BSs) with low traffic loads. The users initially associated to those BSs are off-loaded to neighboring active ones. A fairness criterion for collaboration based on roaming prices is introduced to cover the additional energy costs incurred by host operators. The framework also ensures that any collaborating operator is not negatively affected by its participation in the proposed virtualization. A multi-objective linear programming problem is formulated to achieve energy and cost efficiency of the networks\\' operation by identifying the set of inter-operator roaming prices. For the case when collaboration among all operators is infeasible due to profitability, capacity, or power constraints, an iterative algorithm is proposed to determine the groups of operators that can viably collaborate. Results show significant energy savings using the proposed virtualization as compared to the standalone case. Moreover, collaborative operators exploiting locally generated renewable energy are rewarded more than traditional ones.

On virtual displacement and virtual work in Lagrangian dynamics

International Nuclear Information System (INIS)

Ray, Subhankar; Shamanna, J

2006-01-01

The confusion and ambiguity encountered by students in understanding virtual displacement and virtual work is discussed in this paper. A definition of virtual displacement is presented that allows one to express them explicitly for holonomic (velocity independent), non-holonomic (velocity dependent), scleronomous (time independent) and rheonomous (time dependent) constraints. It is observed that for holonomic, scleronomous constraints, the virtual displacements are the displacements allowed by the constraints. However, this is not so for a general class of constraints. For simple physical systems, it is shown that the work done by the constraint forces on virtual displacements is zero. This motivates Lagrange's extension of d'Alembert's principle to a system of particles in constrained motion. However, a similar zero work principle does not hold for the allowed displacements. It is also demonstrated that d'Alembert's principle of zero virtual work is necessary for the solvability of a constrained mechanical problem. We identify this special class of constraints, physically realized and solvable, as the ideal constraints. The concept of virtual displacement and the principle of zero virtual work by constraint forces are central to both Lagrange's method of undetermined multipliers and Lagrange's equations in generalized coordinates

Coherent virtual absorption for discretized light

Science.gov (United States)

Longhi, S.

2018-05-01

Coherent virtual absorption (CVA) is a recently-introduced phenomenon for which exponentially growing waves incident onto a conservative optical medium are neither reflected nor transmitted, at least transiently. CVA has been associated to complex zeros of the scattering matrix and can be regarded as the time reversal of the decay process of a quasi-mode sustained by the optical medium. Here we consider CVA for discretized light transport in coupled resonator optical waveguides or waveguide arrays and show that a distinct kind of CVA, which is not related to complex zero excitation of quasi-modes, can be observed. This result suggests that scattering matrix analysis can not fully capture CVA phenomena.

The emergence of internet-based virtual private networks in international safeguards

International Nuclear Information System (INIS)

Smartt, Heidi Anne

2001-01-01

Full text: The costs associated with secure data transmission can be an obstacle to International Safeguards. Typical communication methods are priced by distance and may include telephone lines, frame relay, and ISDN. It is therefore costly to communicate globally. The growth of the Internet has provided an extensive backbone for global communications; however, the Internet does not provide intrinsic security measures. Combining the Internet with Virtual Private Network technology, which encrypts and authenticates data, creates a secure and potentially cost-effective data transmission path, as well as achieving other benefits such as reliability and scalability. Access to the Internet can be achieved by connecting to a local Internet Service Provider, which can be preferable to installing a static link between two distant points. The cost-effectiveness of the Internet-based Virtual Private Network is dependent on such factors as data amount, current operational costs, and the specifics of the Internet connection, such as user proximity to an Internet Service Provider or existing access to the Internet. This paper will introduce Virtual Private Network technology, the benefits of Internet communication, and the emergence of Internet-based Virtual Private Networks throughout the International Safeguards community. Specific projects to be discussed include: The completed demonstration of secure remote monitoring data transfer via the Internet between STUK in Helsinki, Finland, and the IAEA in Vienna, Austria; The demonstration of secure remote access to IAEA resources by traveling inspectors with Virtual Private Network software loaded on laptops; The proposed Action Sheets between ABACC/DOE and ARN/DOE, which will provide a link between Rio de Janeiro and Buenos Aires; The proposed use at the HIFAR research reactor, located in Australia, to provide remote monitoring data to the IAEA; The use of Virtual Private Networks by JRC, Ispra, Italy. (author)

Virtual Reality

Science.gov (United States)

1993-04-01

until exhausted. SECURITY CLASSIFICATION OF THIS PAGE All other editions are obsolete. UNCLASSIFIED " VIRTUAL REALITY JAMES F. DAILEY, LIEUTENANT COLONEL...US" This paper reviews the exciting field of virtual reality . The author describes the basic concepts of virtual reality and finds that its numerous...potential benefits to society could revolutionize everyday life. The various components that make up a virtual reality system are described in detail

Framework for Virtual Cognitive Experiment in Virtual Geographic Environments

Directory of Open Access Journals (Sweden)

Fan Zhang

2018-01-01

Full Text Available Virtual Geographic Environment Cognition is the attempt to understand the human cognition of surface features, geographic processes, and human behaviour, as well as their relationships in the real world. From the perspective of human cognition behaviour analysis and simulation, previous work in Virtual Geographic Environments (VGEs has focused mostly on representing and simulating the real world to create an ‘interpretive’ virtual world and improve an individual’s active cognition. In terms of reactive cognition, building a user ‘evaluative’ environment in a complex virtual experiment is a necessary yet challenging task. This paper discusses the outlook of VGEs and proposes a framework for virtual cognitive experiments. The framework not only employs immersive virtual environment technology to create a realistic virtual world but also involves a responsive mechanism to record the user’s cognitive activities during the experiment. Based on the framework, this paper presents two potential implementation methods: first, training a deep learning model with several hundred thousand street view images scored by online volunteers, with further analysis of which visual factors produce a sense of safety for the individual, and second, creating an immersive virtual environment and Electroencephalogram (EEG-based experimental paradigm to both record and analyse the brain activity of a user and explore what type of virtual environment is more suitable and comfortable. Finally, we present some preliminary findings based on the first method.

[Application of virtual reality in surgical treatment of complex head and neck carcinoma].

Science.gov (United States)

Zhou, Y Q; Li, C; Shui, C Y; Cai, Y C; Sun, R H; Zeng, D F; Wang, W; Li, Q L; Huang, L; Tu, J; Jiang, J

2018-01-07

Objective: To investigate the application of virtual reality technology in the preoperative evaluation of complex head and neck carcinoma and he value of virtual reality technology in surgical treatment of head and neck carcinoma. Methods: The image data of eight patients with complex head and neck carcinoma treated from December 2016 to May 2017 was acquired. The data were put into virtual reality system to built the three-dimensional anatomical model of carcinoma and to created the surgical scene. The process of surgery was stimulated by recognizing the relationship between tumor and surrounding important structures. Finally all patients were treated with surgery. And two typical cases were reported. Results: With the help of virtual reality, surgeons could adequately assess the condition of carcinoma and the security of operation and ensured the safety of operations. Conclusions: Virtual reality can provide the surgeons with the sensory experience in virtual surgery scenes and achieve the man-computer cooperation and stereoscopic assessment, which will ensure the safety of surgery. Virtual reality has a huge impact on guiding the traditional surgical procedure of head and neck carcinoma.

La comunicación didáctica en la tutoría virtual / Didactic communication in virtual tutoring / Comunicação didática

Directory of Open Access Journals (Sweden)

Antonio Medina Rivilla

2011-04-01

Full Text Available La comunicación didáctica en la tutoría virtual es la base para el desarrollo de contenidos formativos en el diseño de los nuevos planes de estudio. La comunicación virtual se ha convertido en el eje de la formación a distancia y en la herramienta clave del proceso de aprendizaje de los estudiantes. La flexibilidad de los procesos de enseñanza-aprendizaje en los medios virtuales incide en el diseño e implementación de los contenidos didácticos de las asignaturas en escenarios educativos, destacando la influencia de la función tutorial en los procesos formativos. La capacidad de adaptación de los estudiantes, docentes y docentes-tutores a éste medio ha de partir de la adquisición de las siguientes competencias claves para el desarrollo de la tarea educativa: la competencia didáctico-formativa y la competencia tecnológica-digital. A continuación presentamos una investigación de innovación docente en el que la comunicación didáctica virtual es la clave para el desarrollo de los procesos formativos.AbstractDidactic communication in virtual mentoring is the basis for the development of training content in the design of new curricula. Virtual communication has become the hub of distance learning and the key tool of the process d of student learning. The flexibility on the teaching and learning in virtual media affects the design and implementation of educational content of the educational course, emphasizing the influence of the tutorial role in the formative process. The resilience of students, teachers and teacher-tutors to this medium has to start from the acquisition of the following key competencies for the development of educational work, teaching-training competition and competition-digital technology. Here is an investigation of educational innovation in which the virtual didactic communication is the key to the development of educational processes.

Data center virtualization and its economic implications for the companies

Directory of Open Access Journals (Sweden)

Cristian STEFAN

2009-05-01

Full Text Available In the current situation of the economic crisis, when companies target budgetcuttings in a context of an explosive data growth, the IT community must evaluate potentialtechnology developments not only on their technical advantages, but on their economiceffects as well. More then ever, the old cliché “doing more things with fewer resources” istrue today. Many IT companies started building very large facilities, called data centers(DCs or Internet DC (IDCs, which provide businesses a wide range of solutions forsystems deployment and operation. In recent years, the IT departments around the worldhave moved from data center and infrastructure consolidation to virtualization.Data center virtualization is the process of aligning available resources with the actualneeds of the offered services, moving from physical servers to virtual servers, sharing andprovisioning servers, networks, storage, and applications. By taking advantage of threebasic innovations — virtualization, tiered storage architectures and dynamic provisioningsoftware — an organization can achieve greater efficiencies in their current computingenvironment.Such a unified computing architecture offers end-to-end virtualization; all structures areoptimized for virtualized environments, from the CPU to the aggregation layer. Incombination with embedded management, this new approach increases responsiveness andreduces the opportunities for human error, improving consistency and reducing server andnetwork deployment times.

The Integration of Virtual Public-Private Partnerships into Local Law Enforcement to Achieve Enhanced Intelligence-Led Policing

National Research Council Canada - National Science Library

Simeone, Jr, Matthew J

2007-01-01

.... Virtual public-private partnerships (VP3s) offer local law enforcement agencies an effective and efficient way to leverage a vast and resourceful private sector for the purpose of enhancing ILP...

Designing 3 Dimensional Virtual Reality Using Panoramic Image

Science.gov (United States)

Wan Abd Arif, Wan Norazlinawati; Wan Ahmad, Wan Fatimah; Nordin, Shahrina Md.; Abdullah, Azrai; Sivapalan, Subarna

The high demand to improve the quality of the presentation in the knowledge sharing field is to compete with rapidly growing technology. The needs for development of technology based learning and training lead to an idea to develop an Oil and Gas Plant Virtual Environment (OGPVE) for the benefit of our future. Panoramic Virtual Reality learning based environment is essential in order to help educators overcome the limitations in traditional technical writing lesson. Virtual reality will help users to understand better by providing the simulations of real-world and hard to reach environment with high degree of realistic experience and interactivity. Thus, in order to create a courseware which will achieve the objective, accurate images of intended scenarios must be acquired. The panorama shows the OGPVE and helps to generate ideas to users on what they have learnt. This paper discusses part of the development in panoramic virtual reality. The important phases for developing successful panoramic image are image acquisition and image stitching or mosaicing. In this paper, the combination of wide field-of-view (FOV) and close up image used in this panoramic development are also discussed.

Novel Data Mining Methods for Virtual Screening of Biological Active Chemical Compounds

KAUST Repository

Soufan, Othman M.

2016-11-23

Drug discovery is a process that takes many years and hundreds of millions of dollars to reveal a confident conclusion about a specific treatment. Part of this sophisticated process is based on preliminary investigations to suggest a set of chemical compounds as candidate drugs for the treatment. Computational resources have been playing a significant role in this part through a step known as virtual screening. From a data mining perspective, availability of rich data resources is key in training prediction models. Yet, the difficulties imposed by big expansion in data and its dimensionality are inevitable. In this thesis, I address the main challenges that come when data mining techniques are used for virtual screening. In order to achieve an efficient virtual screening using data mining, I start by addressing the problem of feature selection and provide analysis of best ways to describe a chemical compound for an enhanced screening performance. High-throughput screening (HTS) assays data used for virtual screening are characterized by a great class imbalance. To handle this problem of class imbalance, I suggest using a novel algorithm called DRAMOTE to narrow down promising candidate chemicals aimed at interaction with specific molecular targets before they are experimentally evaluated. Existing works are mostly proposed for small-scale virtual screening based on making use of few thousands of interactions. Thus, I propose enabling large-scale (or big) virtual screening through learning millions of interaction while exploiting any relevant dependency for a better accuracy. A novel solution called DRABAL that incorporates structure learning of a Bayesian Network as a step to model dependency between the HTS assays, is showed to achieve significant improvements over existing state-of-the-art approaches.

Simulation Of Assembly Processes With Technical Of Virtual Reality

Science.gov (United States)

García García, Manuel; Arenas Reina, José Manuel; Lite, Alberto Sánchez; Sebastián Pérez, Miguel Ángel

2009-11-01

Virtual reality techniques use at industrial processes provides a real approach to product life cycle. For components manual assembly, the use of virtual surroundings facilitates a simultaneous engineering in which variables such as human factors and productivity take a real act. On the other hand, in the actual phase of industrial competition it is required a rapid adjustment to client needs and to market situation. In this work it is analyzed the assembly of the front components of a vehicle using virtual reality tools and following up a product-process design methodology which includes every life service stage. This study is based on workstations design, taking into account productive and human factors from the ergonomic point of view implementing a postural study of every assembly operation, leaving the rest of stages for a later study. Design is optimized applying this methodology together with the use of virtual reality tools. It is also achieved a 15% reduction on time assembly and of 90% reduction in muscle—skeletal diseases at every assembly operation.

Virtualization Security Combining Mandatory Access Control and Virtual Machine Introspection

OpenAIRE

Win, Thu Yein; Tianfield, Huaglory; Mair, Quentin

2014-01-01

Virtualization has become a target for attacks in cloud computing environments. Existing approaches to protecting the virtualization environment against the attacks are limited in protection scope and are with high overheads. This paper proposes a novel virtualization security solution which aims to provide comprehensive protection of the virtualization environment.

Measurements of diamond-turned copper mirrors at glancing incidence

International Nuclear Information System (INIS)

Kimura, W.D.; Saito, T.T.

1987-01-01

The results of glancing incidence absorptance measurements performed on diamond-turned copper mirrors are presented. A photoacoustic calorimetry technique is used in which the output from a low power, chopped cw Nd:YAG laser (1.06 μm) is incident upon the mirror at angles of incidence from 0 to 87 0 , for both s and p-polarizations. Measurements are obtained as a function of the diamond turning groove orientation with respect to the plane of incidence. Minimum absorptance, at high angles of incidence, is achieved with s-polarized light and with the grooves aligned parallel to the plane of incidence. The affects on the absorptance of a large scratch at glancing incidence are also described

Measurements of diamond turned copper mirrors at glancing incidence

International Nuclear Information System (INIS)

Kimura, W.D.; Saito, T.T.

1987-01-01

The results of glancing incidence absorptance measurements performed on diamond turned copper mirrors are presented. A photoacoustic calorimetry technique is used in which the output from a low power, chopped cw Nd:YAG laser (1.06 μm) is incident upon the mirror at angles of incidence from 0 to 87 0 , for both s and p-polarizations. Measurements are obtained as a function of the diamond turning groove orientation with respect to the plane of incidence. Minimum absorptance at high angles of incidence is achieved with s-polarized light and with the grooves aligned parallel to the plane of incidence. The effects on the absorptance of a large scratch at glancing incidence are also described

Virtual reality simulation in endovascular surgical training.

LENUS (Irish Health Repository)

Tsang, J S

2008-08-01

Shortened trainingtimes duetothe European Working Time Directive (EWTD) and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. Virtual reality (VR) simulation is a fascinating innovation allowing surgeons to develop without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period.

Virtual Box

DEFF Research Database (Denmark)

Davis, Hilary; Skov, Mikael B.; Stougaard, Malthe

2007-01-01

. This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

Achievement of Virtual and Real Objects Using a Short-Term Motor Learning Protocol in People with Duchenne Muscular Dystrophy: A Crossover Randomized Controlled Trial.

Science.gov (United States)

Massetti, Thais; Fávero, Francis Meire; Menezes, Lilian Del Ciello de; Alvarez, Mayra Priscila Boscolo; Crocetta, Tânia Brusque; Guarnieri, Regiani; Nunes, Fátima L S; Monteiro, Carlos Bandeira de Mello; Silva, Talita Dias da

2018-04-01

To evaluate whether people with Duchenne muscular dystrophy (DMD) practicing a task in a virtual environment could improve performance given a similar task in a real environment, as well as distinguishing whether there is transference between performing the practice in virtual environment and then a real environment and vice versa. Twenty-two people with DMD were evaluated and divided into two groups. The goal was to reach out and touch a red cube. Group A began with the real task and had to touch a real object, and Group B began with the virtual task and had to reach a virtual object using the Kinect system. ANOVA showed that all participants decreased the movement time from the first (M = 973 ms) to the last block of acquisition (M = 783 ms) in both virtual and real tasks and motor learning could be inferred by the short-term retention and transfer task (with increasing distance of the target). However, the evaluation of task performance demonstrated that the virtual task provided an inferior performance when compared to the real task in all phases of the study, and there was no effect for sequence. Both virtual and real tasks promoted improvement of performance in the acquisition phase, short-term retention, and transfer. However, there was no transference of learning between environments. In conclusion, it is recommended that the use of virtual environments for individuals with DMD needs to be considered carefully.

THE INTEGRATION OF CREATIVITY MANAGEMENT MODELS INTO UNIVERSITIES’VIRTUAL LEARNING COMMUNITIES

Directory of Open Access Journals (Sweden)

Alexandru STRUNGĂ

2014-12-01

Full Text Available Given the access of an increasingly higher number of individuals to virtual learning networks, the issue of creativity management becomes extremely important, especially for schools and universities. In the specialized literature, participating in virtual learning communities has several advantages, including: permanent access to information, high educational performance and increased creativity, and also better-developed professional identity (North and Kumta, 2014; Boulay and van Raalte, 2014. In the Romanian literature, there are few studies that aim directly at the relationship between the participation in virtual learning networks and creativity and innovation management models, especially in higher education institutions. This paper aims to study the ways in which creativity and innovation management models can be used in virtual learning networks in order to achieve better productivity at both individual and organizational levels, taking into account several best practices from this field and their possible implementation in Romanian educational institutions.

A Layered Component-Based Architecture of a Virtual Learning Environment

NARCIS (Netherlands)

Avgeriou, Paris; Retalis, Simos; Skordalakis, Manolis; Psaromiligos, Yiannis

2001-01-01

There exists an urgent demand on defining architectures for Virtual Learning Environments (VLEs), so that high-level frameworks for understanding these systems can be discovered, portability, interoperability and reusability can be achieved and adaptability over time can be accomplished. In this

The Virtual GloveboX (VGX: a Semi-immersive Virtual Environment for Training Astronauts in Life Sciences Experiments

Directory of Open Access Journals (Sweden)

I. Alexander Twombly

2004-06-01

Full Text Available The International Space Station will soon provide an unparalleled research facility for studying the near- and longer-term effects of microgravity on living systems. Using the Space Station Glovebox Facility - a compact, fully contained reach-in environment - astronauts will conduct technically challenging life sciences experiments. Virtual environment technologies are being developed at NASA Ames Research Center to help realize the scientific potential of this unique resource by facilitating the experimental hardware and protocol designs and by assisting the astronauts in training. The "Virtual GloveboX" (VGX integrates high-fidelity graphics, force-feedback devices and real-time computer simulation engines to achieve an immersive training environment. Here, we describe the prototype VGX system, the distributed processing architecture used in the simulation environment, and modifications to the visualization pipeline required to accommodate the display configuration.

Análisis de cursos de Educación Social en entornos virtuales de aprendizaje y su influencia en la calidad

Directory of Open Access Journals (Sweden)

Sonia María SANTOVEÑA CASAL

2009-05-01

Full Text Available RESUMEN: El presente artículo muestra una síntesis de los resultados obtenidos en la tesis doctoral «Análisis de cursos de Educación Social: Los entornos virtuales de aprendizaje y su incidencia en la calidad». Analizar los cursos de Educación Social en entornos virtuales de aprendizaje y su incidencia en la calidad constituye el objetivo principal de la tesis. Se pretende estudiar la participación (accesos, mensajes leídos y enviados a los foros y la calidad (entorno, metodología didáctica y técnica que ofrecen los cursos virtuales. Además, se busca conocer la relación entre la participación y la calidad, analizar cómo influye el uso de los medios tecnológicos en la calidad del aprendizaje y, por último, presentar una propuesta de mejora de los cursos. La fundamentación teórica de la investigación está contextualizada en la Educación Social, la calidad en la enseñanza universitaria y en Internet, el Espacio Europeo de Educación Superior y los entornos virtuales de aprendizaje. Se utilizó un diseño mixto de investigación (cualitativo y cuantitativo por medio de diferentes técnicas e instrumentos de evaluación. El análisis de datos se ha desarrollado por medio de un análisis descriptivo y un análisis relacional. Se llevó a cabo una discusión de resultados de cada uno de los cursos virtuales por separado y una discusión de los resultados de toda la muestra. Para finalizar el artículo se presentan conclusiones, limitaciones del estudio y prospectiva de la investigación.ABSTRACT: This article presents a resume of the results obtained in the investigation made in the doctoral Thesis «Analysis of courses of Social Education: The virtual surroundings of learning and their incidence in the quality». The main objective of this Thesis is to analyze the courses of Social Education in virtual environment of learning and its incidence in the quality. In order to achieve this aim, the study has focused on two aspects of

Realidad virtual y materialidad

OpenAIRE

Pérez Herranz, Fernando Miguel

2009-01-01

1. Fenomenología de partida: Real / Simbólico / Imaginario 2. Realidad 3. Virtual 3.1. Virtual / real / posible / probable 3.2. Los contextos de la realidad virtual A) REALIDAD VIRTUAL INMERSIVA B) REALIDAD VIRTUAL NO INMERSIVA C) REALIDAD VIRTUAL Y DIGITALIZACIÓN 3.3. Cruce virtual / real 3.4. Cuestiones filosóficas 4. Materialidad 5. Materialidad y descentramiento 5.1. Ejemplos de descentramiento en los contextos de Realidad Virtual A’) DUALISMO CARTESIANO, CUERPO Y «CIBORG » B’) EL ESPÍRIT...

Human agency beliefs influence behaviour during virtual social interactions.

Science.gov (United States)

Caruana, Nathan; Spirou, Dean; Brock, Jon

2017-01-01

In recent years, with the emergence of relatively inexpensive and accessible virtual reality technologies, it is now possible to deliver compelling and realistic simulations of human-to-human interaction. Neuroimaging studies have shown that, when participants believe they are interacting via a virtual interface with another human agent, they show different patterns of brain activity compared to when they know that their virtual partner is computer-controlled. The suggestion is that users adopt an "intentional stance" by attributing mental states to their virtual partner. However, it remains unclear how beliefs in the agency of a virtual partner influence participants' behaviour and subjective experience of the interaction. We investigated this issue in the context of a cooperative "joint attention" game in which participants interacted via an eye tracker with a virtual onscreen partner, directing each other's eye gaze to different screen locations. Half of the participants were correctly informed that their partner was controlled by a computer algorithm ("Computer" condition). The other half were misled into believing that the virtual character was controlled by a second participant in another room ("Human" condition). Those in the "Human" condition were slower to make eye contact with their partner and more likely to try and guide their partner before they had established mutual eye contact than participants in the "Computer" condition. They also responded more rapidly when their partner was guiding them, although the same effect was also found for a control condition in which they responded to an arrow cue. Results confirm the influence of human agency beliefs on behaviour in this virtual social interaction context. They further suggest that researchers and developers attempting to simulate social interactions should consider the impact of agency beliefs on user experience in other social contexts, and their effect on the achievement of the application's goals.

Human agency beliefs influence behaviour during virtual social interactions

Directory of Open Access Journals (Sweden)

Nathan Caruana

2017-09-01

Full Text Available In recent years, with the emergence of relatively inexpensive and accessible virtual reality technologies, it is now possible to deliver compelling and realistic simulations of human-to-human interaction. Neuroimaging studies have shown that, when participants believe they are interacting via a virtual interface with another human agent, they show different patterns of brain activity compared to when they know that their virtual partner is computer-controlled. The suggestion is that users adopt an “intentional stance” by attributing mental states to their virtual partner. However, it remains unclear how beliefs in the agency of a virtual partner influence participants’ behaviour and subjective experience of the interaction. We investigated this issue in the context of a cooperative “joint attention” game in which participants interacted via an eye tracker with a virtual onscreen partner, directing each other’s eye gaze to different screen locations. Half of the participants were correctly informed that their partner was controlled by a computer algorithm (“Computer” condition. The other half were misled into believing that the virtual character was controlled by a second participant in another room (“Human” condition. Those in the “Human” condition were slower to make eye contact with their partner and more likely to try and guide their partner before they had established mutual eye contact than participants in the “Computer” condition. They also responded more rapidly when their partner was guiding them, although the same effect was also found for a control condition in which they responded to an arrow cue. Results confirm the influence of human agency beliefs on behaviour in this virtual social interaction context. They further suggest that researchers and developers attempting to simulate social interactions should consider the impact of agency beliefs on user experience in other social contexts, and their effect

A virtual network computer's optical storage virtualization scheme

Science.gov (United States)

Wang, Jianzong; Hu, Huaixiang; Wan, Jiguang; Wang, Peng

2008-12-01

In this paper, we present the architecture and implementation of a virtual network computers' (VNC) optical storage virtualization scheme called VOSV. Its task is to manage the mapping of virtual optical storage to physical optical storage, a technique known as optical storage virtualization. The design of VOSV aims at the optical storage resources of different clients and servers that have high read-sharing patterns. VOSV uses several schemes such as a two-level Cache mechanism, a VNC server embedded module and the iSCSI protocols to improve the performance. The results measured on the prototype are encouraging, and indicating that VOSV provides the high I/O performance.

Virtual bronchoscopy

International Nuclear Information System (INIS)

Rogalla, P.; Meiri, N.; Hamm, B.; Rueckert, J.C.; Schmidt, B.; Witt, C.

2001-01-01

Flexible bronchoscopy represents a clinically well-established invasive diagnostic tool. Virtual bronchoscopies, calculated from thin-slice CT sections, allow astonishing immitations of reality although principal differences exist between both technologies: the Fact that colour representation is artificial and concommitant interventions are impossible limits the clinical use of virtual bronchoscopy. However, its value increases when calculations can be attained within minutes due to technological advancements, and when virtually any chest CT is suitable for further postprocessing. Indications, findings and the clinical role of virtual bronchoscopy are discussed. (orig.) [de

Virtual button interface

Science.gov (United States)

Jones, J.S.

1999-01-12

An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment are disclosed. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch. 4 figs.

Pneumoperitoneum after virtual colonoscopy: causes, risk factors, and management.

Science.gov (United States)

Baccaro, Leopoldo M; Markelov, Alexey; Wilhelm, Jakub; Bloch, Robert

2014-06-01

Computed tomographic virtual colonoscopy (CTVC) is a safe and minimally invasive modality when compared with fiberoptic colonoscopy for evaluating the colon and rectum. We have reviewed the risks for colonic perforation by investigating the relevant literature. The objectives of this study were to assess the risk of colonic perforation during CTVC, describe risk factors, evaluate ways to reduce the incidence complications, and to review management and treatment options. A formal search of indexed publications was performed through PubMed. Search queries using keywords "CT colonography," "CT virtual colonoscopy," "virtual colonoscopy," and "perforation" yielded a total of 133 articles. A total of eight case reports and four review articles were selected. Combining case reports and review articles, a total of 25 cases of colonic perforation after CTVC have been reported. Causes include, but are not limited to, diverticular disease, irritable bowel diseases, obstructive processes, malignancies, and iatrogenic injury. Both operative and nonoperative management has been described. Nonoperative management has been proven safe and successful in minimally symptomatic and stable patients. Colonic perforation after CTVC is a rare complication and very few cases have been reported. Several risk factors are recurrent in the literature and must be acknowledged at the time of the study. Management options vary and should be tailored to each individual patient.

Virtual Web Services

OpenAIRE

Rykowski, Jarogniew

2007-01-01

In this paper we propose an application of software agents to provide Virtual Web Services. A Virtual Web Service is a linked collection of several real and/or virtual Web Services, and public and private agents, accessed by the user in the same way as a single real Web Service. A Virtual Web Service allows unrestricted comparison, information merging, pipelining, etc., of data coming from different sources and in different forms. Detailed architecture and functionality of a single Virtual We...

Virtual MR arthroscopy of the wrist joint: a new intraarticular perspective

International Nuclear Information System (INIS)

Sahin, Guelden; Dogan, Basak Erguvan; Demirtas, Mehmet

2004-01-01

The aim of this study is to investigate whether virtual MR arthroscopy could be used to visualize the internal architecture of the radiocarpal compartment of the wrist joint in comparison to surgical arthroscopy. Diluted paramagnetic contrast material was injected into the radiocarpal compartment prior to MR examination in all patients. A fat-suppressed T1-weighted three-dimensional fast spoiled gradient echo sequence was acquired in addition to our standard MR imaging protocol in each patient. Three-dimensional data sets were then transferred to an independent workstation and were postprocessed using navigator software to generate surface rendered virtual MR arthroscopic images. Nineteen patients referred for chronic ulnar-sided wrist pain were evaluated with conventional MR arthrography prospectively. Virtual MR arthroscopic images demonstrating the triangular fibrocartilage complex (TFCC) in an intraarticular perspective were achieved in 12 out of 19 patients. Our preliminary investigation suggests that although it has several limitations, virtual MR arthroscopy shows promise in visualizing the TFCC from an intraarticular perspective. (orig.)

Experimental evaluation of the objective virtual mass coefficient; Avaliacao experimental do coeficiente de massa virtual apoiada em uma formulacao objetiva

Energy Technology Data Exchange (ETDEWEB)

Heilbron Filho, Paulo Fernando Lavalle

1984-04-15

This work is a continuation of many others studies that have been made in the field of two-phase flow, concerning the influence of the void fraction in a parameter known as 'induced mass' that appears in the constitutive equation of the inter-phase force called 'virtual mass force'. The determination of the influence of the void fraction in the induced mass is done using experiment involving a bubble flow in a vertical tube filled with water. Using the two-phase flow model together with some hypothesis concerning the bubble flow experience and the constitutive equation for the virtual mass force, we achieve through the analysis of the filming of the experiment our purpose in determining the influence of the void fraction on the induced mass. (author)

76 FR 61371 - All-Hazard Position Task Books for Type 3 Incident Management Teams

Science.gov (United States)

2011-10-04

...-Hazard Position Task Books for Type 3 Incident Management Teams AGENCY: Federal Emergency Management... Books for Type 3 Incident Management Teams were developed to assist personnel achieve qualifications in... Management Teams were developed to assist personnel achieve qualifications in the All-Hazard ICS positions...

Motion in Human and Machine: A Virtual Fatigue Approach

NARCIS (Netherlands)

Potkonjak, V.; Kostic, D.; Rasic, M.; Djordjevic, G.

2002-01-01

Achieving human-like behavior of a robot is a key issue of the paper. Redundancy in the inverse kinematics problem is resolved using a biological analogue. It is shown that by means of "virtual fatigue" functions, it is possible to generate robot movements similar to movements of a human arm subject

Improving Performance to Engineering Students through Virtual Labs and its Monitoring in Cockpit

Directory of Open Access Journals (Sweden)

Leandro Rosniak Tibola

2014-10-01

Full Text Available Modern education needs use all resources to improve teaching-learning process. To achieve this goal, technology can be a sharp allied. Especially to the engineering education, which seeks the balance among theoretical and practice lessons. Thus, many universities are using the virtual labs and virtual worlds 3D like way to support the student's learning and enrich the teaching methods. High tech classes, broadband communication, mobility and ubiquity aren't enough if the student's engagement can't be measured. This work presents a proposal to monitor the virtual lab use by students, showing the educational parameters in a graphical interface, following the suitable pedagogical concepts.

Virtual reality training improves students' knowledge structures of medical concepts.

Science.gov (United States)

Stevens, Susan M; Goldsmith, Timothy E; Summers, Kenneth L; Sherstyuk, Andrei; Kihmm, Kathleen; Holten, James R; Davis, Christopher; Speitel, Daniel; Maris, Christina; Stewart, Randall; Wilks, David; Saland, Linda; Wax, Diane; Panaiotis; Saiki, Stanley; Alverson, Dale; Caudell, Thomas P

2005-01-01

Virtual environments can provide training that is difficult to achieve under normal circumstances. Medical students can work on high-risk cases in a realistic, time-critical environment, where students practice skills in a cognitively demanding and emotionally compelling situation. Research from cognitive science has shown that as students acquire domain expertise, their semantic organization of core domain concepts become more similar to those of an expert's. In the current study, we hypothesized that students' knowledge structures would become more expert-like as a result of their diagnosing and treating a patient experiencing a hematoma within a virtual environment. Forty-eight medical students diagnosed and treated a hematoma case within a fully immersed virtual environment. Student's semantic organization of 25 case-related concepts was assessed prior to and after training. Students' knowledge structures became more integrated and similar to an expert knowledge structure of the concepts as a result of the learning experience. The methods used here for eliciting, representing, and evaluating knowledge structures offer a sensitive and objective means for evaluating student learning in virtual environments and medical simulations.

Structure functions of longitudinal virtual photons at low virtualities

International Nuclear Information System (INIS)

Ioffe, B.L.; Shushpanov, I.A.

1996-01-01

The structure functions F L 1 and F L 2 of longitudinal virtual photons at low virtualities are calculated in the framework of chiral perturbation theory (ChPT) in the zero and first order of ChPT. It is assumed that the virtuality of a target longitudinal photon p 2 is much less than the virtuality of the hard projectile photon Q 2 and both are less than the characteristic ChPT scale. In this approximation the structure functions are determined by the production of two pions in γγ collisions. The numerical results for F L 2 and F L 1 are presented (the upper index refers to the longitudinal polarization of the virtual target photon). The possibilities of measurements of these structure functions are briefly discussed. copyright 1996 The American Physical Society

On the transverse momentum in Z-boson production in a virtually ordered parton shower

Energy Technology Data Exchange (ETDEWEB)

Nagy, Zoltan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Soper, Davison E. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science

2009-12-15

Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using parton showers is to sum these large logarithms. We ask whether this goal is achieved for the transverse momentum distribution of a Z-boson produced in hadron-hadron collisions when the shower is organized with higher virtuality parton splittings coming first, followed successively by lower virtuality parton splittings. We find that the virtuality ordered shower works well in reproducing the known QCD result. (orig.)

On the transverse momentum in Z-boson production in a virtually ordered parton shower

International Nuclear Information System (INIS)

Nagy, Zoltan; Soper, Davison E.

2009-12-01

Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using parton showers is to sum these large logarithms. We ask whether this goal is achieved for the transverse momentum distribution of a Z-boson produced in hadron-hadron collisions when the shower is organized with higher virtuality parton splittings coming first, followed successively by lower virtuality parton splittings. We find that the virtuality ordered shower works well in reproducing the known QCD result. (orig.)

Virtual hand: a 3D tactile interface to virtual environments

Science.gov (United States)

Rogowitz, Bernice E.; Borrel, Paul

2008-02-01

We introduce a novel system that allows users to experience the sensation of touch in a computer graphics environment. In this system, the user places his/her hand on an array of pins, which is moved about space on a 6 degree-of-freedom robot arm. The surface of the pins defines a surface in the virtual world. This "virtual hand" can move about the virtual world. When the virtual hand encounters an object in the virtual world, the heights of the pins are adjusted so that they represent the object's shape, surface, and texture. A control system integrates pin and robot arm motions to transmit information about objects in the computer graphics world to the user. It also allows the user to edit, change and move the virtual objects, shapes and textures. This system provides a general framework for touching, manipulating, and modifying objects in a 3-D computer graphics environment, which may be useful in a wide range of applications, including computer games, computer aided design systems, and immersive virtual worlds.

Ensinar e aprender no meio virtual: rompendo paradigmas Teaching and learning in the virtual environment: shifting paradigms

Directory of Open Access Journals (Sweden)

Gilberto Lacerda dos Santos

2011-08-01

precisely, the text aims at outlining the paradigm crisis around the rupture between the presence classroom and the virtual classroom, in view of the emergence of the information society, through empirical data gathered by the 13 Master students that took part in this longitudinal study sponsored by CNPq, FAPDF, and FENADESP. In its first part, there is a general introduction to the theme and to the research problem that gave origin to the meta-analytic or synthesis study described here, which is defined by four questions: 1 what are the new formats for the virtual classroom?; 2 what pedagogical strategies are more adequate to guide the teaching work in the virtual classroom?; 3 what innovative didactic materials are consistent with the teaching work in the virtual classroom?; 4 what new teacher roles emerge in the context of the virtual classroom? There follows a succinct description of the methodological approach adopted to give support to our investigation effort in search of answers to the questions posed above. The third part of the article consists of an equally brief theoretical picture of the concept of virtual classroom. The next section brings a discussion of each of those issues in the light of the results achieved in the 13 Master dissertations analyzed. Lastly, conclusions are put forward, which point out and discuss some of the defining elements of the virtual classroom that give shape to the paradigm crisis alluded to here.

Dynamic virtual AliEn Grid sites on Nimbus with CernVM

International Nuclear Information System (INIS)

Harutyunyan, A; Buncic, P; Freeman, T; Keahey, K

2010-01-01

We describe the work on enabling one click deployment of Grid sites of AliEn Grid framework on the Nimbus 'science cloud' at the University of Chicago. The integration of computing resources of the cloud with the resource pool of AliEn Grid is achieved by leveraging two mechanisms: the Nimbus Context Broker developed at Argonne National Laboratory and the University of Chicago, and CernVM - a baseline virtual software appliance for LHC experiments developed at CERN. Two approaches of dynamic virtual AliEn Grid site deployment are presented.

The Gender Confidence Gap in Fractions Knowledge: Gender Differences in Student Belief-Achievement Relationships

Science.gov (United States)

Ross, John A.; Scott, Garth; Bruce, Catherine D.

2012-01-01

Recent research demonstrates that in many countries gender differences in mathematics achievement have virtually disappeared. Expectancy-value theory and social cognition theory both predict that if gender differences in achievement have declined there should be a similar decline in gender differences in self-beliefs. Extant literature is…

Advanced server virtualization VMware and Microsoft platforms in the virtual data center

CERN Document Server

Marshall, David; McCrory, Dave

2006-01-01

Executives of IT organizations are compelled to quickly implement server virtualization solutions because of significant cost savings. However, most IT professionals tasked with deploying virtualization solutions have little or no experience with the technology. This creates a high demand for information on virtualization and how to properly implement it in a datacenter. Advanced Server Virtualization: VMware® and Microsoft® Platforms in the Virtual Data Center focuses on the core knowledge needed to evaluate, implement, and maintain an environment that is using server virtualization. This boo

A Virtual Class Calculus

DEFF Research Database (Denmark)

Ernst, Erik; Ostermann, Klaus; Cook, William Randall

2006-01-01

Virtual classes are class-valued attributes of objects. Like virtual methods, virtual classes are defined in an object's class and may be redefined within subclasses. They resemble inner classes, which are also defined within a class, but virtual classes are accessed through object instances...... model for virtual classes has been a long-standing open question. This paper presents a virtual class calculus, vc, that captures the essence of virtual classes in these full-fledged programming languages. The key contributions of the paper are a formalization of the dynamic and static semantics of vc...

The Virtual Tablet: Virtual Reality as a Control System

Science.gov (United States)

Chronister, Andrew

2016-01-01

In the field of human-computer interaction, Augmented Reality (AR) and Virtual Reality (VR) have been rapidly growing areas of interest and concerted development effort thanks to both private and public research. At NASA, a number of groups have explored the possibilities afforded by AR and VR technology, among which is the IT Advanced Concepts Lab (ITACL). Within ITACL, the AVR (Augmented/Virtual Reality) Lab focuses on VR technology specifically for its use in command and control. Previous work in the AVR lab includes the Natural User Interface (NUI) project and the Virtual Control Panel (VCP) project, which created virtual three-dimensional interfaces that users could interact with while wearing a VR headset thanks to body- and hand-tracking technology. The Virtual Tablet (VT) project attempts to improve on these previous efforts by incorporating a physical surrogate which is mirrored in the virtual environment, mitigating issues with difficulty of visually determining the interface location and lack of tactile feedback discovered in the development of previous efforts. The physical surrogate takes the form of a handheld sheet of acrylic glass with several infrared-range reflective markers and a sensor package attached. Using the sensor package to track orientation and a motion-capture system to track the marker positions, a model of the surrogate is placed in the virtual environment at a position which corresponds with the real-world location relative to the user's VR Head Mounted Display (HMD). A set of control mechanisms is then projected onto the surface of the surrogate such that to the user, immersed in VR, the control interface appears to be attached to the object they are holding. The VT project was taken from an early stage where the sensor package, motion-capture system, and physical surrogate had been constructed or tested individually but not yet combined or incorporated into the virtual environment. My contribution was to combine the pieces of

Virtual haptic system for intuitive planning of bone fixation plate placement

Directory of Open Access Journals (Sweden)

Kup-Sze Choi

2017-01-01

Full Text Available Placement of pre-contoured fixation plate is a common treatment for bone fracture. Fitting of fixation plates on fractured bone can be preoperatively planned and evaluated in 3D virtual environment using virtual reality technology. However, conventional systems usually employ 2D mouse and virtual trackball as the user interface, which makes the process inconvenient and inefficient. In the paper, a preoperative planning system equipped with 3D haptic user interface is proposed to allow users to manipulate the virtual fixation plate intuitively to determine the optimal position for placement on distal medial tibia. The system provides interactive feedback forces and visual guidance based on the geometric requirements. Creation of 3D models from medical imaging data, collision detection, dynamics simulation and haptic rendering are discussed. The system was evaluated by 22 subjects. Results show that the time to achieve optimal placement using the proposed system was shorter than that by using 2D mouse and virtual trackball, and the satisfaction rating was also higher. The system shows potential to facilitate the process of fitting fixation plates on fractured bones as well as interactive fixation plate design.

The Tale of Two Virtual Teacher Professional Development Modules

Science.gov (United States)

Keown, Paul

2009-01-01

Virtual communities of practice (VCoP) have been advocated for some time as a promising means of taking professional development to teachers in widely distributed locations. However, geography, and indeed education literature as a whole, contains very few examples where this has been achieved. This paper reports on two VCoP professional…

Experimental evaluation of the objective virtual mass coefficient

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle

1984-04-01

This work is a continuation of many others studies that have been made in the field of two-phase flow, concerning the influence of the void fraction in a parameter known as 'induced mass' that appears in the constitutive equation of the inter-phase force called 'virtual mass force'. The determination of the influence of the void fraction in the induced mass is done using experiment involving a bubble flow in a vertical tube filled with water. Using the two-phase flow model together with some hypothesis concerning the bubble flow experience and the constitutive equation for the virtual mass force, we achieve through the analysis of the filming of the experiment our purpose in determining the influence of the void fraction on the induced mass. (author)

Virtual projects

DEFF Research Database (Denmark)

Svejvig, Per; Commisso, Trine Hald

2012-01-01

that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects....... The overall implications for research and practice are to acknowledge virtual project management as very different to traditional project management and to address this difference.......Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...

Alfabetización informacional en la educación superior virtual: logros y desafíos Informational Literacy in Virtual Higher Education: Achievements and Challenges

Directory of Open Access Journals (Sweden)

Clelia Pineda Báez

2012-06-01

Full Text Available La educación virtual se constituye en una alternativa para el acceso de un mayor número de estudiantes al sistema de educación superior. En Colombia se ha incrementado el número de programas de pregrado en esta modalidad, pero la documentación sobre el trabajo pedagógico desarrollado en la implementación de estas propuestas educativas es insuficiente para examinar su calidad. Esta investigación propuso como una de sus categorías de análisis indagar las percepciones y experiencias de agentes educativos acerca del desarrollo de la alfabetización informacional en los programas que se ofrecen en esa modalidad para especificar transformaciones, avances, rupturas, entre otros aspectos. El estudio empleó técnicas cuantitativas y cualitativas para la recolección de información de profesores, coordinadores, tutores y estudiantes de nueve instituciones de educación superior que contaban con programas con un alto componente virtual. Los resultados muestran que se ha dado inicio al fortalecimiento de las competencias informacionales de los estudiantes, pero que aún se requiere del trabajo colectivo entre profesores, tutores y estudiantes para refinar los criterios de búsqueda, valoración y aplicación de la información. Se evidencia también la necesidad de capacitación para expertos temáticos y la necesidad de reflexionar sobre estrategias para combatir el plagio.Abstract: Virtual education has become an alternative for students to access the higher education system. In Colombia, there has been an increase in the number of undergraduate programs in this form of education. However, information about the pedagogical work undertaken in those programs is scarce, and it is needed to examine their quality. This research project examined the education community's perception of undergraduate virtual education programs in Colombian higher education institutions. One of the key elements in the analysis was the development of students

Transforming Virtual Teams

DEFF Research Database (Denmark)

Bjørn, Pernille

2005-01-01

Investigating virtual team collaboration in industry using grounded theory this paper presents the in-dept analysis of empirical work conducted in a global organization of 100.000 employees where a global virtual team with participants from Sweden, United Kingdom, Canada, and North America were...... studied. The research question investigated is how collaboration is negotiated within virtual teams? This paper presents findings concerning how collaboration is negotiated within a virtual team and elaborate the difficulties due to invisible articulation work and managing multiple communities...... in transforming the virtual team into a community. It is argued that translucence in communication structures within the virtual team and between team and management is essential for engaging in a positive transformation process of trustworthiness supporting the team becoming a community, managing the immanent...

Trust and virtual worlds

DEFF Research Database (Denmark)

Ess, Charles; Thorseth, May

2011-01-01

We collect diverse philosophical analyses of the issues and problems clustering around trust online with specific attention to establishing trust in virtual environments. The book moves forward important discussions of how virtual worlds and virtuality are to be defined and understood; the role o...... by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....

Virtual water: Virtuous impact? : the unsteady state of virtual water

NARCIS (Netherlands)

Roth, D.; Warner, J.F.

2008-01-01

“Virtual water,” water needed for crop production, is now being mainstreamed in the water policy world. Relying on virtual water in the form of food imports is increasingly recommended as good policy for water-scarce areas. Virtual water globalizes discussions on water scarcity, ecological

Evolution-based Virtual Content Insertion with Visually Virtual Interactions in Videos

Science.gov (United States)

Chang, Chia-Hu; Wu, Ja-Ling

With the development of content-based multimedia analysis, virtual content insertion has been widely used and studied for video enrichment and multimedia advertising. However, how to automatically insert a user-selected virtual content into personal videos in a less-intrusive manner, with an attractive representation, is a challenging problem. In this chapter, we present an evolution-based virtual content insertion system which can insert virtual contents into videos with evolved animations according to predefined behaviors emulating the characteristics of evolutionary biology. The videos are considered not only as carriers of message conveyed by the virtual content but also as the environment in which the lifelike virtual contents live. Thus, the inserted virtual content will be affected by the videos to trigger a series of artificial evolutions and evolve its appearances and behaviors while interacting with video contents. By inserting virtual contents into videos through the system, users can easily create entertaining storylines and turn their personal videos into visually appealing ones. In addition, it would bring a new opportunity to increase the advertising revenue for video assets of the media industry and online video-sharing websites.

Theft of Virtual Property — Towards Security Requirements for Virtual Worlds

Science.gov (United States)

Beyer, Anja

The article is focused to introduce the topic of information technology security for Virtual Worlds to a security experts’ audience. Virtual Worlds are Web 2.0 applications where the users cruise through the world with their individually shaped avatars to find either amusement, challenges or the next best business deal. People do invest a lot of time but beyond they invest in buying virtual assets like fantasy witcheries, wepaons, armour, houses, clothes,...etc with the power of real world money. Although it is called “virtual” (which is often put on the same level as “not existent”) there is a real value behind it. In November 2007 dutch police arrested a seventeen years old teenager who was suspicted to have stolen virtual items in a Virtual World called Habbo Hotel [Reuters07]. In order to successfully provide security mechanisms into Virtual Worlds it is necessarry to fully understand the domain for which the security mechansims are defined. As Virtual Worlds must be clasified into the domain of Social Software the article starts with an overview of how to understand Web 2.0 and gives a short introduction to Virtual Worlds. The article then provides a consideration of assets of Virtual Worlds participants, describes how these assets can be threatened and gives an overview of appopriate security requirements and completes with an outlook of possible countermeasures.

Interaction with virtual crowd in Immersive and semi‐Immersive Virtual Reality systems

OpenAIRE

Kyriakou, Marios; Pan, Xueni; Chrysanthou, Yiorgos

2016-01-01

This study examines attributes of virtual human behavior that may increase the plausibility of a simulated crowd and affect the user's experience in Virtual Reality. Purpose-developed experiments in both Immersive and semi-Immersive Virtual Reality systems queried the impact of collision and basic interaction between real-users and the virtual crowd and their effect on the apparent realism and ease of navigation within Virtual Reality (VR). Participants' behavior and subjective measurements i...

Experimental evaluation of the objective virtual mass coefficient; Avaliacao experimental do coeficiente de massa virtual apoiada em uma formulacao objetiva

Energy Technology Data Exchange (ETDEWEB)

Heilbron Filho, Paulo Fernando Lavalle

1984-04-15

This work is a continuation of many others studies that have been made in the field of two-phase flow, concerning the influence of the void fraction in a parameter known as 'induced mass' that appears in the constitutive equation of the inter-phase force called 'virtual mass force'. The determination of the influence of the void fraction in the induced mass is done using experiment involving a bubble flow in a vertical tube filled with water. Using the two-phase flow model together with some hypothesis concerning the bubble flow experience and the constitutive equation for the virtual mass force, we achieve through the analysis of the filming of the experiment our purpose in determining the influence of the void fraction on the induced mass. (author)

Designing Virtual Worlds

DEFF Research Database (Denmark)

Gürsimsek, Remzi Ates

2014-01-01

The online social platforms known as virtual worlds present their users various affordances for avatar based co-presence, social interaction and provide tools for collaborative content creation, including objects, textures and animations. The users of these worlds navigate their avatars as personal...... the audio-visual characteristics of designing in multi-user virtual environments generate experiential, interpersonal and textual meaning potentials....... mediators in 3D virtual space to collaborate and co-design the digital content. These co-designers are also the residents of these worlds, as they socialize by building inworld friendships. This article presents a social semiotic analysis of the three-dimensional virtual places and artifacts in the virtual...

Classification of EMG signals using artificial neural networks for virtual hand prosthesis control.

Science.gov (United States)

Mattioli, Fernando E R; Lamounier, Edgard A; Cardoso, Alexandre; Soares, Alcimar B; Andrade, Adriano O

2011-01-01

Computer-based training systems have been widely studied in the field of human rehabilitation. In health applications, Virtual Reality presents itself as an appropriate tool to simulate training environments without exposing the patients to risks. In particular, virtual prosthetic devices have been used to reduce the great mental effort needed by patients fitted with myoelectric prosthesis, during the training stage. In this paper, the application of Virtual Reality in a hand prosthesis training system is presented. To achieve this, the possibility of exploring Neural Networks in a real-time classification system is discussed. The classification technique used in this work resulted in a 95% success rate when discriminating 4 different hand movements.

Energy-efficient virtual optical network mapping approaches over converged flexible bandwidth optical networks and data centers.

Science.gov (United States)

Chen, Bowen; Zhao, Yongli; Zhang, Jie

2015-09-21

In this paper, we develop a virtual link priority mapping (LPM) approach and a virtual node priority mapping (NPM) approach to improve the energy efficiency and to reduce the spectrum usage over the converged flexible bandwidth optical networks and data centers. For comparison, the lower bound of the virtual optical network mapping is used for the benchmark solutions. Simulation results show that the LPM approach achieves the better performance in terms of power consumption, energy efficiency, spectrum usage, and the number of regenerators compared to the NPM approach.

PENERAPAN VIRTUAL EXPERIMENT BERBASIS INKUIRI UNTUK MENGEMBANGKAN KEMANDIRIAN MAHASISWA

Directory of Open Access Journals (Sweden)

D. Yulianti

2012-07-01

Full Text Available Mahasiswa sebagai calon guru fisika bertugas sebagi pilar bagi perkembangan fisika di masyarakat, oleh karena itu dituntut menguasai fisika dan kemandirian di dalam mempelajari fisika. Kemandirian mahasiswa yang rendah perlu dilatih melalui penelitian tindakan kelas yang bersiklus. Penelitian Tindakan Kelas ini bertujuan mengembangkan kemandirian mahasiswa prodi Pendidikan Fisika melalui penerapan virtual experiment berbasis inkuiri pada pembelajaran Mekanika I Tujuan yang lain meningkatkan hasil belajar melalui pembelajaran inkuiri menggunakan virtual experiment  Penelitian  berlangsung tiga siklus, tiga pertemuan pada bahasan gerak parabola. Setiap siklus terdiri dari perencanaan, pelaksanaan, pengamatan dan refleksi. Data hasil belajar kognitif   diperoleh melalui, tes dan lembar pengamatan untuk mengukur hasil belajar afektif dan psikomotorik. Hasil yang diperoleh kemandirian mahasiswa dapat berkembang dan terjadi pe-ningkatan hasil belajar kognitif, afektif, dan psikomotorik mahasiswa prodi Pendidikan Fisika FMIPA Unnes semester III tahun 2011/2012This three-cycle classroom action research was aimed to develop physics education student autonomy and to increase students’ cognitive, afective and psychomotoric achievements by applying inquiry virtual experiment on Mechanics I lecture. Each cycle consists of planning, action, observing and reflection activity. The cognitive data was collected by using test, while the affective and psychomotoric ones were collected by using observation sheet. The result showed an increase of student autonomy and students’ cognitive, affective and psycomotoric achievements of third semester students of physics education of FMIPA Unnes year 2011/2012.

Remote inspection through a virtual world

Energy Technology Data Exchange (ETDEWEB)

Lee, D.J.

1996-05-01

Virtual Reality (VR) is an expression that is most often associated with the entertainment industry. At Torness Power Station however, VR technology has been successfully applied to recovery operations with significant time and cost benefits. This paper describes the nature of the VR applications at Torness and its proposed development for remote reactor inspection. The present programme has provided several challenges to the VR system capabilities which are described together with details of how these are being overcome. Efficient computer model development and user-friendly operator interfaces are established as essential ingredients. These factors are being achieved in a progressive manner and there is confidence that significant operational improvements will be achieved through the application of this rapidly developing technology. (author).

Remote inspection through a virtual world

International Nuclear Information System (INIS)

Lee, D.J.

1996-01-01

Virtual Reality (VR) is an expression that is most often associated with the entertainment industry. At Torness Power Station however, VR technology has been successfully applied to recovery operations with significant time and cost benefits. This paper describes the nature of the VR applications at Torness and its proposed development for remote reactor inspection. The present programme has provided several challenges to the VR system capabilities which are described together with details of how these are being overcome. Efficient computer model development and user-friendly operator interfaces are established as essential ingredients. These factors are being achieved in a progressive manner and there is confidence that significant operational improvements will be achieved through the application of this rapidly developing technology. (author)

Server virtualization solutions

OpenAIRE

Jonasts, Gusts

2012-01-01

Currently in the information technology sector that is responsible for a server infrastructure is a huge development in the field of server virtualization on x86 computer architecture. As a prerequisite for such a virtualization development is growth in server productivity and underutilization of available computing power. Several companies in the market are working on two virtualization architectures – hypervizor and hosting. In this paper several of virtualization products that use host...

Virtual Trackballs Revisited

OpenAIRE

Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

2004-01-01

Udgivelsesdato: March/April Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENC...

Interactive Virtual Cinematography

OpenAIRE

Burelli, Paolo

2012-01-01

A virtual camera represents the point-of-view of the player through which sheperceives the game world and gets feedback on her actions. Thus, the virtualcamera plays a vital role in 3D computer games and aects player experienceand enjoyability in games. Interactive virtual cinematography is the process ofvisualising the content of a virtual environment by positioning and animatingthe virtual camera in the context of interactive applications such as a computergame.Camera placement and animatio...

Proposal of a Model for effective Management and Development of virtual Teams

Directory of Open Access Journals (Sweden)

Petr Skyrik

2010-10-01

Full Text Available The main aim of this paper is to present a pilot proposal of a model of “Virtual Development Management System” (ViDeMaS which will facilitate more effective management and development of virtual teams. Management and development of virtual teams is not a simple concept. It comprises a body of knowledge from a number of fields and scientific disciplines. The complexity of the concept may not be simplified as it is absolutely essential for full understanding of its nature. In order to gain better orientation in the concept, different perspectives will be used in the description of the model, which will enable us to achieve the goal of the work and to present the main results of the work (creation of a model for Virtual Development Management System. The present paper thus describes from different perspectives the proposal of a sufficiently detailed and complex model that may be utilized both on theoretical and application level.

Scheme for achieving coherent perfect absorption by anisotropic metamaterials

KAUST Repository

Zhang, Xiujuan

2017-02-22

We propose a unified scheme to achieve coherent perfect absorption of electromagnetic waves by anisotropic metamaterials. The scheme describes the condition on perfect absorption and offers an inverse design route based on effective medium theory in conjunction with retrieval method to determine practical metamaterial absorbers. The scheme is scalable to frequencies and applicable to various incident angles. Numerical simulations show that perfect absorption is achieved in the designed absorbers over a wide range of incident angles, verifying the scheme. By integrating these absorbers, we further propose an absorber to absorb energy from two coherent point sources.

Virtual Presence and the Mind's Eye in 3-D Online Communities

Science.gov (United States)

Beacham, R. C.; Denard, H.; Baker, D.

2011-09-01

Digital technologies have introduced fundamental changes in the forms, content, and media of communication. Indeed, some have suggested we are in the early stages of a seismic shift comparable to that in antiquity with the transition from a primarily oral culture to one based upon writing. The digital transformation is rapidly displacing the long-standing hegemony of text, and restoring in part social, bodily, oral and spatial elements, but in radically reconfigured forms and formats. Contributing to and drawing upon such changes and possibilities, scholars and those responsible for sites preserving or displaying cultural heritage, have undertaken projects to explore the properties and potential of the online communities enabled by "Virtual Worlds" and related platforms for teaching, collaboration, publication, and new modes of disciplinary research. Others, keenly observing and evaluating such work, are poised to contribute to it. It is crucial that leadership be provided to ensure that serious and sustained investigation be undertaken by scholars who have experience, and achievements, in more traditional forms of research, and who perceive the emerging potential of Virtual World work to advance their investigations. The Virtual Museums Transnational Network will seek to engage such scholars and provide leadership in this emerging and immensely attractive new area of cultural heritage exploration and experience. This presentation reviews examples of the current "state of the art" in heritage based Virtual World initiatives, looking at the new modes of social interaction and experience enabled by such online communities, and some of the achievements and future aspirations of this work.

Virtual Reflexes

OpenAIRE

Jonker, Catholijn; Broekens, Joost; Plaat, Aske

2014-01-01

Virtual Reality is used successfully to treat people for regular phobias. A new challenge is to develop Virtual Reality Exposure Training for social skills. Virtual actors in such systems have to show appropriate social behavior including emotions, gaze, and keeping distance. The behavior must be realistic and real-time. Current approaches consist of four steps: 1) trainee social signal detection, 2) cognitive-affective interpretation, 3) determination of the appropriate bodily responses, and...

Evaluating the Effects of Virtual Pair Programming on Students’ Achievement and Satisfaction

Directory of Open Access Journals (Sweden)

Nick Zacharis

2009-09-01

Full Text Available Pair programming is a lightweight software development technique in which two programmers work together at one computer. In literature, many benefits of pair programming have been proposed, such as increased productivity, improved code quality, enhanced job satisfaction and confidence. Although pair programming provides clear pedagogical benefits, its collocation requirement and the limited time during a lab session are serious barriers in the full deployment and evaluation of this programming technique. This paper reports on a study that investigated the effectiveness of Virtual Pair Programming (VPP on student performance and satisfaction in an introductory Java course where students worked collaboratively in pairs on homework programming assignments, using online tools that integrated desktop sharing and real time communication. The results of this study support previous research findings and suggest that VPP is an effective pedagogical tool for flexible collaboration and an acceptable alternative to individual/solo programming experience, regarding productivity, code quality, academic performance and student satisfaction.

VIRTUAL COMPETITIVENESS: YOUTHS’ VIEWS

Directory of Open Access Journals (Sweden)

M. Yu. Semenov

2018-01-01

Full Text Available Introduction. Nowadays, the use of information and communication technologies (ICT has become an integral part both of every individual’s life and of the society in general. It is no longer possible to deny the impact of virtual environment on socialisation and development of the identity of young people. In this regard, the investigation of young people’s view on virtual social networks, and the possibility of students’ own competitiveness realization through various web services. The aim of the research presented in the article is to study the factors of students’ assessment of virtual social networks as a tool of personal fulfillment. Methodology and research methods. Content analysis and synthesis of scientific publications studies were carried out at a theoretical stage of the research; secondary sampling analysis of sociologic data material sources was conducted. The empirical research stage involved the instrument of questionnaire surveys, statistical data processing and interpretation of the results. Results and scientific novelty. The social survey conducted in 2017 with the participation of 1087 high school students and 1196 college students of the Tyumen Region shown that the more competitive students consider themselves, the more competitive they perceive the people having great popularity on the Internet. At that, compared to girls, young people are more inclined to consider the people having great popularity on the Internet competitive. It is determined that having a popular virtual media account for the young person is less worthwhile than for female respondents. The author explains this fact: male representatives regard it as “social capital” which can contribute to growth of their competitiveness in society as well as to achieve some profit. The author concludes that youth views on competitiveness are not directly related to the activity in virtual social networks. Frequent use by respondents of the Internet and

Design of focused and restrained subsets from extremely large virtual libraries.

Science.gov (United States)

Jamois, Eric A; Lin, Chien T; Waldman, Marvin

2003-11-01

With the current and ever-growing offering of reagents along with the vast palette of organic reactions, virtual libraries accessible to combinatorial chemists can reach sizes of billions of compounds or more. Extracting practical size subsets for experimentation has remained an essential step in the design of combinatorial libraries. A typical approach to computational library design involves enumeration of structures and properties for the entire virtual library, which may be unpractical for such large libraries. This study describes a new approach termed as on the fly optimization (OTFO) where descriptors are computed as needed within the subset optimization cycle and without intermediate enumeration of structures. Results reported herein highlight the advantages of coupling an ultra-fast descriptor calculation engine to subset optimization capabilities. We also show that enumeration of properties for the entire virtual library may not only be unpractical but also wasteful. Successful design of focused and restrained subsets can be achieved while sampling only a small fraction of the virtual library. We also investigate the stability of the method and compare results obtained from simulated annealing (SA) and genetic algorithms (GA).

USB port compatible virtual instrument based automation for x-ray diffractometer setup

International Nuclear Information System (INIS)

Jayapandian, J.; Sheela, O.K.; Mallika, R.; Thiruarul, A.; Purniah, B.

2004-01-01

Windows based virtual instrument (VI) programs in graphic language simplify the design automation in R and D laboratories. With minimal hardware and maximum support of software, the automation becomes easier and user friendly. A novel design approach for the automation of SIEMENS make x-ray diffractometer setup is described in this paper. The automation is achieved with an indigenously developed virtual instrument program in labVIEW ver.6.0 and with a simple hardware design using 89C2051 micro-controller compatible with PC's USB port for the total automation of the experiment. (author)

Virtual hand illusion induced by visuomotor correlations.

Directory of Open Access Journals (Sweden)

Maria V Sanchez-Vives

Full Text Available BACKGROUND: Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation. METHODOLOGY/PRINCIPAL FINDINGS: To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant. CONCLUSIONS/SIGNIFICANCE: We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation.

Virtual microscopy and digital pathology in training and education.

Science.gov (United States)

Hamilton, Peter W; Wang, Yinhai; McCullough, Stephen J

2012-04-01

Traditionally, education and training in pathology has been delivered using textbooks, glass slides and conventional microscopy. Over the last two decades, the number of web-based pathology resources has expanded dramatically with centralized pathological resources being delivered to many students simultaneously. Recently, whole slide imaging technology allows glass slides to be scanned and viewed on a computer screen via dedicated software. This technology is referred to as virtual microscopy and has created enormous opportunities in pathological training and education. Students are able to learn key histopathological skills, e.g. to identify areas of diagnostic relevance from an entire slide, via a web-based computer environment. Students no longer need to be in the same room as the slides. New human-computer interfaces are also being developed using more natural touch technology to enhance the manipulation of digitized slides. Several major initiatives are also underway introducing online competency and diagnostic decision analysis using virtual microscopy and have important future roles in accreditation and recertification. Finally, researchers are investigating how pathological decision-making is achieved using virtual microscopy and modern eye-tracking devices. Virtual microscopy and digital pathology will continue to improve how pathology training and education is delivered. © 2012 The Authors APMIS © 2012 APMIS.

[Virtual + 1] * Reality

Science.gov (United States)

Beckhaus, Steffi

Virtual Reality aims at creating an artificial environment that can be perceived as a substitute to a real setting. Much effort in research and development goes into the creation of virtual environments that in their majority are perceivable only by eyes and hands. The multisensory nature of our perception, however, allows and, arguably, also expects more than that. As long as we are not able to simulate and deliver a fully sensory believable virtual environment to a user, we could make use of the fully sensory, multi-modal nature of real objects to fill in for this deficiency. The idea is to purposefully integrate real artifacts into the application and interaction, instead of dismissing anything real as hindering the virtual experience. The term virtual reality - denoting the goal, not the technology - shifts from a core virtual reality to an “enriched” reality, technologically encompassing both the computer generated and the real, physical artifacts. Together, either simultaneously or in a hybrid way, real and virtual jointly provide stimuli that are perceived by users through their senses and are later formed into an experience by the user's mind.

Virtual Vision

Science.gov (United States)

Terzopoulos, Demetri; Qureshi, Faisal Z.

Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

Tangible interfaces in virtual environments, case study: Instituto de Engenharia Nuclear Virtual

Energy Technology Data Exchange (ETDEWEB)

Santo, Andre Cotelli do E.; Mol, Antonio Carlos A.; Pinto, Emanuele Oliveira; Melo, Joao Victor da C.; Paula, Vanessa Marcia de; Freitas, Victor Goncalves Gloria [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Machado, Daniel Mol [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto Alberto Luiz Coimbra

2015-07-01

Virtual Reality (VR) techniques allow the creation of realistic representations of an individual. These technologies are being applied in several fields such as training, simulations, virtual experiments and new applications are constantly being found. This work aims to present an interactive system in virtual environments without the use of peripherals typically found in computers such as mouse and keyboard. Through the movement of head and hands it is possible to control and navigate the virtual character (avatar) in a virtual environment, an improvement in the man-machine integration. The head movements are recognized using a virtual helmet with a tracking system. An infrared camera detects the position of infrared LEDs located in the operator's head and places the vision of the virtual character in accordance with the operator's vision. The avatar control is performed by a system that detects the movement of the hands, using infrared sensors, allowing the user to move it in the virtual environment. This interaction system was implemented in the virtual model of the Instituto de Engenharia Nuclear (IEN), which is located on the Ilha do Fundao - Rio de Janeiro - Brazil. This three-dimensional environment, in which avatars can move and interact according to the user movements, gives a feeling of realism to the operator. The results show an interface that allows a higher degree of immersion of the operator in the virtual environment, promoting a more engaging and dynamic way of working. (author)

Tangible interfaces in virtual environments, case study: Instituto de Engenharia Nuclear Virtual

International Nuclear Information System (INIS)

Santo, Andre Cotelli do E.; Mol, Antonio Carlos A.; Pinto, Emanuele Oliveira; Melo, Joao Victor da C.; Paula, Vanessa Marcia de; Freitas, Victor Goncalves Gloria; Machado, Daniel Mol

2015-01-01

Virtual Reality (VR) techniques allow the creation of realistic representations of an individual. These technologies are being applied in several fields such as training, simulations, virtual experiments and new applications are constantly being found. This work aims to present an interactive system in virtual environments without the use of peripherals typically found in computers such as mouse and keyboard. Through the movement of head and hands it is possible to control and navigate the virtual character (avatar) in a virtual environment, an improvement in the man-machine integration. The head movements are recognized using a virtual helmet with a tracking system. An infrared camera detects the position of infrared LEDs located in the operator's head and places the vision of the virtual character in accordance with the operator's vision. The avatar control is performed by a system that detects the movement of the hands, using infrared sensors, allowing the user to move it in the virtual environment. This interaction system was implemented in the virtual model of the Instituto de Engenharia Nuclear (IEN), which is located on the Ilha do Fundao - Rio de Janeiro - Brazil. This three-dimensional environment, in which avatars can move and interact according to the user movements, gives a feeling of realism to the operator. The results show an interface that allows a higher degree of immersion of the operator in the virtual environment, promoting a more engaging and dynamic way of working. (author)

Origami-inspired metamaterial absorbers for improving the larger-incident angle absorption

International Nuclear Information System (INIS)

Shen, Yang; Pang, Yongqiang; Wang, Jiafu; Ma, Hua; Pei, Zhibin; Qu, Shaobo

2015-01-01

When a folded resistive patch array stands up on a metallic plane, it can exhibit more outstanding absorption performance. Our theoretical investigations and simulations demonstrated that the folded resistive patch arrays can enhance the absorption bandwidth progressively with the increase of the incident angle for the oblique transverse magnetic incidence, which is contrary to the conventional resistive frequency selective surface absorber. On illumination, we achieved a 3D structure metamaterial absorber with the folded resistive patches. The proposed absorber is obtained from the inspiration of the origami, and it has broadband and lager-incident angle absorption. Both the simulations and the measurements indicate that the proposed absorber achieves the larger-incident angle absorption until 75° in the frequency band of 3.6–11.4 GHz. In addition, the absorber is extremely lightweight. The areal density of the fabricated sample is about 0.023 g cm −2 . Due to the broadband and lager-incident angle absorption, it is expected that the absorbers may find potential applications such as stealth technologies and electromagnetic interference. (paper)

Studies of the field-of-view resolution tradeoff in virtual-reality systems

Science.gov (United States)

Piantanida, Thomas P.; Boman, Duane; Larimer, James; Gille, Jennifer; Reed, Charles

1992-01-01

Most virtual-reality systems use LCD-based displays that achieve a large field-of-view at the expense of resolution. A typical display will consist of approximately 86,000 pixels uniformly distributed over an 80-degree by 60-degree image. Thus, each pixel subtends about 13 minutes of arc at the retina; about the same as the resolvable features of the 20/200 line of a Snellen Eye Chart. The low resolution of LCD-based systems limits task performance in some applications. We have examined target-detection performance in a low-resolution virtual world. Our synthesized three-dimensional virtual worlds consisted of target objects that could be positioned at a fixed distance from the viewer, but at random azimuth and constrained elevation. A virtual world could be bounded by chromatic walls or by wire-frame, or it could be unbounded. Viewers scanned these worlds and indicated by appropriate gestures when they had detected the target object. By manipulating the viewer's field size and the chromatic and luminance contrast of annuli surrounding the field-of-view, we were able to assess the effect of field size on the detection of virtual objects in low-resolution synthetic worlds.

PROVISIONING RESTORABLE VIRTUAL PRIVATE NETWORKS USING BARABASI AND WAXMAN TOPOLOGY GENERATION MODEL

Directory of Open Access Journals (Sweden)

R. Ravi

2010-12-01

Full Text Available As internet usage grows exponentially, network security issues become increasingly important. Network security measures are needed to protect data during transmission. Various security controls are used to prevent the access of hackers in networks. They are firewall, virtual private networks and encryption algorithms. Out of these, the virtual private network plays a vital role in preventing hackers from accessing the networks. A Virtual Private Network (VPN provides end users with a way to privately access information on their network over a public network infrastructure such as the internet. Using a technique called “Tunneling”, data packets are transmitted across a public routed network, such as the internet that simulates a point-to-point connection. Virtual private networks provide customers with a secure and low-cost communication environment. The basic structure of the virtual circuit is to create a logical path from the source port to the destination port. This path may incorporate many hops between routers for the formation of the circuit. The final, logical path or virtual circuit acts in the same way as a direct connection between the two ports. Our proposed Provisioning Restorable Virtual Private Networks Algorithm (PRA is used to combine the provisioning and restoration algorithms to achieve better results than the ones obtained by independent restoration and provisioning. In order to ensure service quality and availability in Virtual Private Networks, seamless recovery from failures is essential. The quality of service of the Virtual Private Networks is also improved due to the combination of provisioning and restoration. The bandwidth sharing concept is also applied in link to improve the quality of service in the Virtual Private Network. The performance analysis of the proposed algorithm is carried out in terms of cost, the number of nodes, the number of VPN nodes, delay, asymmetric ratio and delay with constraints with

Virtual volatility

Science.gov (United States)

Silva, A. Christian; Prange, Richard E.

2007-03-01

We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

Virtual laboratories : comparability of real and virtual environments for environmental psychology

NARCIS (Netherlands)

Kort, de Y.A.W.; IJsselsteijn, W.A.; Kooijman, J.M.A.; Schuurmans, Y.

2003-01-01

Virtual environments have the potential to become important new research tools in environment behavior research. They could even become the future (virtual) laboratories, if reactions of people to virtual environments are similar to those in real environments. The present study is an exploration of

Modelling Ecological Cognitive Rehabilitation Therapies for Building Virtual Environments in Brain Injury.

Science.gov (United States)

Martínez-Moreno, J M; Sánchez-González, P; Luna, M; Roig, T; Tormos, J M; Gómez, E J

2016-01-01

Brain Injury (BI) has become one of the most common causes of neurological disability in developed countries. Cognitive disorders result in a loss of independence and patients' quality of life. Cognitive rehabilitation aims to promote patients' skills to achieve their highest degree of personal autonomy. New technologies such as virtual reality or interactive video allow developing rehabilitation therapies based on reproducible Activities of Daily Living (ADLs), increasing the ecological validity of the therapy. However, the lack of frameworks to formalize and represent the definition of this kind of therapies can be a barrier for widespread use of interactive virtual environments in clinical routine. To provide neuropsychologists with a methodology and an instrument to design and evaluate cognitive rehabilitation therapeutic interventions strategies based on ADLs performed in interactive virtual environments. The proposed methodology is used to model therapeutic interventions during virtual ADLs considering cognitive deficit, expected abnormal interactions and therapeutic hypotheses. It allows identifying abnormal behavioural patterns and designing interventions strategies in order to achieve errorless-based rehabilitation. An ADL case study ('buying bread') is defined according to the guidelines established by the ADL intervention model. This case study is developed, as a proof of principle, using interactive video technology and is used to assess the feasibility of the proposed methodology in the definition of therapeutic intervention procedures. The proposed methodology provides neuropsychologists with an instrument to design and evaluate ADL-based therapeutic intervention strategies, attending to solve actual limitation of virtual scenarios, to be use for ecological rehabilitation of cognitive deficit in daily clinical practice. The developed case study proves the potential of the methodology to design therapeutic interventions strategies; however our current

Virtual reality in education

OpenAIRE

Minocha, Shailey; Tudor, Ana-Despina

2017-01-01

In this workshop-presentation, we described the evolution of virtual reality technologies and our research from 3D virtual worlds, 3D virtual environments built in gaming environments such as Unity 3D, 360-degree videos, and mobile virtual reality via Google Expeditions. For each of these four technologies, we discussed the affordances of the technologies and how they contribute towards learning and teaching. We outlined the significance of students being aware of the different virtual realit...

Virtual Reality: Principles and Applications

OpenAIRE

MÉRIENNE , Frédéric

2017-01-01

Virtual reality aims at immersing a user in a virtual environment. Dedicated virtual reality technologies of human–computer interaction enable to make the link between the user and a virtual environment in capturing the user’s motion, acting on his senses as well as computing the virtual experience in real-time. The immersion in virtual environment is evaluated through the user’s perception and reaction. Virtual reality is used in a large variety of application domains which need multisensory...

Virtual Organizations: Beyond Network Organization

Directory of Open Access Journals (Sweden)

Liviu Gabriel CRETU

2006-01-01

Full Text Available One of the most used buzz-words in (e-business literature of the last decade is virtual organization. The term "virtual" can be identified in all sorts of combinations regarding the business world. From virtual products to virtual processes or virtual teams, everything that is “touched” by the computer’s processing power instantly becomes virtual. Moreover, most of the literature treats virtual and network organizations as being synonyms. This paper aims to draw a much more distinctive line between the two concepts. Providing a more coherent description of what virtual organization might be is also one of our intentions.

Virtual Reference Services.

Science.gov (United States)

Brewer, Sally

2003-01-01

As the need to access information increases, school librarians must create virtual libraries. Linked to reliable reference resources, the virtual library extends the physical collection and library hours and lets students learn to use Web-based resources in a protected learning environment. The growing number of virtual schools increases the need…

Security incidents on the Internet, 1989--1995

Energy Technology Data Exchange (ETDEWEB)

Howard, J.D.

1995-12-31

This paper presents an analysis of trends in Internet security based on an investigation of 4,299 Internet security-related incidents reported to the CERT{reg_sign} Coordination Center (CERT{reg_sign}/CC) from 1989 through 1995. Prior to this research, knowledge of actual Internet security incidents was limited and primarily anecdotal. This research: (1) developed a taxonomy to classify Internet attacks and incidents, (2) organized, classified, and analyzed CERT{reg_sign}/CC incident records, (3) summarized the relative frequency of the use of tools and vulnerabilities, success in achieving access, and results of attacks, (4) estimated total Internet incident activity, (5) developed recommendations for Internet users and suppliers, and (6) developed recommendations for future research. With the exception of denial-of-service attacks, security incidents were found to be increasing at a rate less than Internet growth. Estimates showed that most, if not all, severe incidents were reported to the CERT{reg_sign}/CC, and that more than one out of three above average incidents (in terms of duration and number of sites) were reported. Estimates also indicated that a typical Internet site was involved in, at most, around one incident (of any kind) per year, and a typical Internet host in, at most, around one incident in 45 years. The probability of unauthorized privileged access was around an order of magnitude less likely. As a result, simple and reasonable security precautions should be sufficient for most Internet users.

Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

Science.gov (United States)

Scacchi, Walt

There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

Virtual patient care: an interprofessional education approach for physician assistant, physical therapy and occupational therapy students.

Science.gov (United States)

Shoemaker, Michael J; Platko, Christina M; Cleghorn, Susan M; Booth, Andrew

2014-07-01

The purpose of this retrospective qualitative case report is to describe how a case-based, virtual patient interprofessional education (IPE) simulation activity was utilized to achieve physician assistant (PA), physical therapy (PT) and occupational therapy (OT) student IPE learning outcomes. Following completion of a virtual patient case, 30 PA, 46 PT and 24 OT students were required to develop a comprehensive, written treatment plan and respond to reflective questions. A qualitative analysis of the submitted written assignment was used to determine whether IPE learning objectives were met. Student responses revealed three themes that supported the learning objectives of the IPE experience: benefits of collaborative care, role clarification and relevance of the IPE experience for future practice. A case-based, IPE simulation activity for physician assistant and rehabilitation students using a computerized virtual patient software program effectively facilitated achievement of the IPE learning objectives, including development of greater student awareness of other professions and ways in which collaborative patient care can be provided.

Virtual commissioning of automated micro-optical assembly

Science.gov (United States)

Schlette, Christian; Losch, Daniel; Haag, Sebastian; Zontar, Daniel; Roßmann, Jürgen; Brecher, Christian

2015-02-01

In this contribution, we present a novel approach to enable virtual commissioning for process developers in micro-optical assembly. Our approach aims at supporting micro-optics experts to effectively develop assisted or fully automated assembly solutions without detailed prior experience in programming while at the same time enabling them to easily implement their own libraries of expert schemes and algorithms for handling optical components. Virtual commissioning is enabled by a 3D simulation and visualization system in which the functionalities and properties of automated systems are modeled, simulated and controlled based on multi-agent systems. For process development, our approach supports event-, state- and time-based visual programming techniques for the agents and allows for their kinematic motion simulation in combination with looped-in simulation results for the optical components. First results have been achieved for simply switching the agents to command the real hardware setup after successful process implementation and validation in the virtual environment. We evaluated and adapted our system to meet the requirements set by industrial partners-- laser manufacturers as well as hardware suppliers of assembly platforms. The concept is applied to the automated assembly of optical components for optically pumped semiconductor lasers and positioning of optical components for beam-shaping

Virtualization A Manager's Guide

CERN Document Server

Kusnetzky, Dan

2011-01-01

What exactly is virtualization? As this concise book explains, virtualization is a smorgasbord of technologies that offer organizations many advantages, whether you're managing extremely large stores of rapidly changing data, scaling out an application, or harnessing huge amounts of computational power. With this guide, you get an overview of the five main types of virtualization technology, along with information on security, management, and modern use cases. Topics include: Access virtualization-Allows access to any application from any deviceApplication virtualization-Enables applications

Tools virtualization for command and control systems

Science.gov (United States)

Piszczek, Marek; Maciejewski, Marcin; Pomianek, Mateusz; Szustakowski, Mieczysław

2017-10-01

Information management is an inseparable part of the command process. The result is that the person making decisions at the command post interacts with data providing devices in various ways. Tools virtualization process can introduce a number of significant modifications in the design of solutions for management and command. The general idea involves replacing physical devices user interface with their digital representation (so-called Virtual instruments). A more advanced level of the systems "digitalization" is to use the mixed reality environments. In solutions using Augmented reality (AR) customized HMI is displayed to the operator when he approaches to each device. Identification of device is done by image recognition of photo codes. Visualization is achieved by (optical) see-through head mounted display (HMD). Control can be done for example by means of a handheld touch panel. Using the immersive virtual environment, the command center can be digitally reconstructed. Workstation requires only VR system (HMD) and access to information network. Operator can interact with devices in such a way as it would perform in real world (for example with the virtual hands). Because of their procedures (an analysis of central vision, eye tracking) MR systems offers another useful feature of reducing requirements for system data throughput. Due to the fact that at the moment we focus on the single device. Experiments carried out using Moverio BT-200 and SteamVR systems and the results of experimental application testing clearly indicate the ability to create a fully functional information system with the use of mixed reality technology.

Using virtual reality technology for decommissioning and outage planning

International Nuclear Information System (INIS)

Lirvall, Peter

1998-01-01

The VR Decom. Tool is a decommissioning, planning, and training tool. It is not yet in use, but appropriate technology has been identified to develop such a tool The tool is intended to be used as an interactive virtual mock-up of a process plant to plan and practice decommissioning activities. The tool will be able to create or import existing CAD drawing to be visualised in an interactive Virtual Reality (VR) environment, with links to data bases containing useful information about all the process components for planning the decommissioning. The most use of the tool is foreseen to be in areas that have limited access, such as, radioactive or hazardous. The main advantages are summarised below: (1) virtual mock-up for visualisation of non-accessible areas to plan and provide training for decommissioning procedures, (2) visualisation of three dimensional radiation maps for As Low As Reasonably Achievable (A.L.A.R.A.) staff dose management, (3) raining of special tele-operations procedures, (4) special tools prototyping and testing, (5) information access and team vision sharing. (author)

User-centered virtual environment design for virtual rehabilitation

Directory of Open Access Journals (Sweden)

Rizzo Albert A

2010-02-01

Full Text Available Abstract Background As physical and cognitive rehabilitation protocols utilizing virtual environments transition from single applications to comprehensive rehabilitation programs there is a need for a new design cycle methodology. Current human-computer interaction designs focus on usability without benchmarking technology within a user-in-the-loop design cycle. The field of virtual rehabilitation is unique in that determining the efficacy of this genre of computer-aided therapies requires prior knowledge of technology issues that may confound patient outcome measures. Benchmarking the technology (e.g., displays or data gloves using healthy controls may provide a means of characterizing the "normal" performance range of the virtual rehabilitation system. This standard not only allows therapists to select appropriate technology for use with their patient populations, it also allows them to account for technology limitations when assessing treatment efficacy. Methods An overview of the proposed user-centered design cycle is given. Comparisons of two optical see-through head-worn displays provide an example of benchmarking techniques. Benchmarks were obtained using a novel vision test capable of measuring a user's stereoacuity while wearing different types of head-worn displays. Results from healthy participants who performed both virtual and real-world versions of the stereoacuity test are discussed with respect to virtual rehabilitation design. Results The user-centered design cycle argues for benchmarking to precede virtual environment construction, especially for therapeutic applications. Results from real-world testing illustrate the general limitations in stereoacuity attained when viewing content using a head-worn display. Further, the stereoacuity vision benchmark test highlights differences in user performance when utilizing a similar style of head-worn display. These results support the need for including benchmarks as a means of better

User-centered virtual environment design for virtual rehabilitation.

Science.gov (United States)

Fidopiastis, Cali M; Rizzo, Albert A; Rolland, Jannick P

2010-02-19

As physical and cognitive rehabilitation protocols utilizing virtual environments transition from single applications to comprehensive rehabilitation programs there is a need for a new design cycle methodology. Current human-computer interaction designs focus on usability without benchmarking technology within a user-in-the-loop design cycle. The field of virtual rehabilitation is unique in that determining the efficacy of this genre of computer-aided therapies requires prior knowledge of technology issues that may confound patient outcome measures. Benchmarking the technology (e.g., displays or data gloves) using healthy controls may provide a means of characterizing the "normal" performance range of the virtual rehabilitation system. This standard not only allows therapists to select appropriate technology for use with their patient populations, it also allows them to account for technology limitations when assessing treatment efficacy. An overview of the proposed user-centered design cycle is given. Comparisons of two optical see-through head-worn displays provide an example of benchmarking techniques. Benchmarks were obtained using a novel vision test capable of measuring a user's stereoacuity while wearing different types of head-worn displays. Results from healthy participants who performed both virtual and real-world versions of the stereoacuity test are discussed with respect to virtual rehabilitation design. The user-centered design cycle argues for benchmarking to precede virtual environment construction, especially for therapeutic applications. Results from real-world testing illustrate the general limitations in stereoacuity attained when viewing content using a head-worn display. Further, the stereoacuity vision benchmark test highlights differences in user performance when utilizing a similar style of head-worn display. These results support the need for including benchmarks as a means of better understanding user outcomes, especially for patient

Improper Signaling for Virtual Full-Duplex Relay Systems

KAUST Repository

Gaafar, Mohamed; Amin, Osama; Schaefer, Rafael F.; Alouini, Mohamed-Slim

2017-01-01

Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.

Improper Signaling for Virtual Full-Duplex Relay Systems

KAUST Repository

Gaafar, Mohamed

2017-02-14

Virtual full-duplex (VFD) is a powerful solution to compensate the rate loss of half-duplex relaying without the need to full-duplex capable nodes. Inter-relay interference (IRI) challenges the operation of VFD relaying systems. Recently, improper signaling is employed at both relays of the VFD to mitigate the IRI by imposing the same signal characteristics for both relays. To further boost the achievable rate performance, asymmetric time sharing VFD relaying system is adopted with different improper signals at the half-duplex relays. The joint tuning of the three design parameters improves the achievable rate performance at different ranges of IRI and different relays locations. Extensive simulation results are presented and analyzed to show the achievable rate gain of the proposed system and understand the system behavior.

Trends in Virtualized User Environments

Directory of Open Access Journals (Sweden)

Diane Barrett

2008-06-01

Full Text Available Virtualized environments can make forensics investigation more difficult. Technological advances in virtualization tools essentially make removable media a PC that can be carried around in a pocket or around a neck. Running operating systems and applications this way leaves very little trace on the host system. This paper will explore all the newest methods for virtualized environments and the implications they have on the world of forensics. It will begin by describing and differentiating between software and hardware virtualization. It will then move on to explain the various methods used for server and desktop virtualization. Next, it will explain how virtualization affects the basic forensic process. Finally, it will describe the common methods to find virtualization artifacts and identify virtual activities that affect the examination process of certain virtualized user environments.

A VIRTUAL GLOBE-BASED MULTI-RESOLUTION TIN SURFACE MODELING AND VISUALIZETION METHOD

Directory of Open Access Journals (Sweden)

X. Zheng

2016-06-01

Full Text Available The integration and visualization of geospatial data on a virtual globe play an significant role in understanding and analysis of the Earth surface processes. However, the current virtual globes always sacrifice the accuracy to ensure the efficiency for global data processing and visualization, which devalue their functionality for scientific applications. In this article, we propose a high-accuracy multi-resolution TIN pyramid construction and visualization method for virtual globe. Firstly, we introduce the cartographic principles to formulize the level of detail (LOD generation so that the TIN model in each layer is controlled with a data quality standard. A maximum z-tolerance algorithm is then used to iteratively construct the multi-resolution TIN pyramid. Moreover, the extracted landscape features are incorporated into each-layer TIN, thus preserving the topological structure of terrain surface at different levels. In the proposed framework, a virtual node (VN-based approach is developed to seamlessly partition and discretize each triangulation layer into tiles, which can be organized and stored with a global quad-tree index. Finally, the real time out-of-core spherical terrain rendering is realized on a virtual globe system VirtualWorld1.0. The experimental results showed that the proposed method can achieve an high-fidelity terrain representation, while produce a high quality underlying data that satisfies the demand for scientific analysis.

[Virtual Campus of Public Health: six years of human resources education in Mexico].

Science.gov (United States)

Ramos Herrera, Igor; Alfaro Alfaro, Noé; Fonseca León, Joel; García Sandoval, Cristóbal; González Castañeda, Miguel; López Zermeño, María Del Carmen; Benítez Morales, Ricardo

2014-11-01

This paper discusses the gestation process, implementation methodology, and results obtained from the initiative to use e-learning to train human resources for health, six years after the launch of the Virtual Campus of Public Health of the University of Guadalajara (Mexico); the discussion is framed by Pan American Health Organization (PAHO) standards and practices. This is a special report on the work done by the institutional committee of the Virtual Campus in western Mexico to create an Internet portal that follows the guidelines of the strategic model established by Nodo México and PAHO for the Region of the Americas. This Virtual Campus began its activities in 2007, on the basis of the use of free software and institutional collaboration. Since the initial year of implementation of the node, over 500 health professionals have been trained using virtual courses, the node's educational platform, and a repository of virtual learning resources that are interoperable with other repositories in Mexico and the Region of the Americas. The University of Guadalajara Virtual Campus committee has followed the proposed model as much as possible, thereby achieving most of the goals set in the initial work plan, despite a number of administrative challenges and the difficulty of motivating committee members.

Short Term Motor-Skill Acquisition Improves with Size of Self-Controlled Virtual Hands.

Science.gov (United States)

Ossmy, Ori; Mukamel, Roy

2017-01-01

Visual feedback in general, and from the body in particular, is known to influence the performance of motor skills in humans. However, it is unclear how the acquisition of motor skills depends on specific visual feedback parameters such as the size of performing effector. Here, 21 healthy subjects physically trained to perform sequences of finger movements with their right hand. Through the use of 3D Virtual Reality devices, visual feedback during training consisted of virtual hands presented on the screen, tracking subject's hand movements in real time. Importantly, the setup allowed us to manipulate the size of the displayed virtual hands across experimental conditions. We found that performance gains increase with the size of virtual hands. In contrast, when subjects trained by mere observation (i.e., in the absence of physical movement), manipulating the size of the virtual hand did not significantly affect subsequent performance gains. These results demonstrate that when it comes to short-term motor skill learning, the size of visual feedback matters. Furthermore, these results suggest that highest performance gains in individual subjects are achieved when the size of the virtual hand matches their real hand size. These results may have implications for optimizing motor training schemes.

Short Term Motor-Skill Acquisition Improves with Size of Self-Controlled Virtual Hands.

Directory of Open Access Journals (Sweden)

Ori Ossmy

Full Text Available Visual feedback in general, and from the body in particular, is known to influence the performance of motor skills in humans. However, it is unclear how the acquisition of motor skills depends on specific visual feedback parameters such as the size of performing effector. Here, 21 healthy subjects physically trained to perform sequences of finger movements with their right hand. Through the use of 3D Virtual Reality devices, visual feedback during training consisted of virtual hands presented on the screen, tracking subject's hand movements in real time. Importantly, the setup allowed us to manipulate the size of the displayed virtual hands across experimental conditions. We found that performance gains increase with the size of virtual hands. In contrast, when subjects trained by mere observation (i.e., in the absence of physical movement, manipulating the size of the virtual hand did not significantly affect subsequent performance gains. These results demonstrate that when it comes to short-term motor skill learning, the size of visual feedback matters. Furthermore, these results suggest that highest performance gains in individual subjects are achieved when the size of the virtual hand matches their real hand size. These results may have implications for optimizing motor training schemes.

Prospects for HIV control in South Africa: a model-based analysis

Directory of Open Access Journals (Sweden)

Leigh F. Johnson

2016-06-01

Full Text Available Background: The goal of virtual elimination of horizontal and mother-to-child HIV transmission in South Africa (SA has been proposed, but there have been few systematic investigations of which interventions are likely to be most critical to reducing HIV incidence. Objective: This study aims to evaluate SA's potential to achieve virtual elimination targets and to identify which interventions will be most critical to achieving HIV incidence reductions. Design: A mathematical model was developed to simulate the population-level impact of different HIV interventions in SA. Probability distributions were specified to represent uncertainty around 32 epidemiological parameters that could be influenced by interventions, and correlation coefficients (r were calculated to assess the sensitivity of the adult HIV incidence rates and mother-to-child transmission rates (2015–2035 to each epidemiological parameter. Results: HIV incidence in SA adults (ages 15–49 is expected to decline from 1.4% in 2011–2012 to 0.29% by 2035 (95% CI: 0.10–0.62%. The parameters most strongly correlated with future adult HIV incidence are the rate of viral suppression after initiating antiretroviral treatment (ART (r=−0.56, the level of condom use in non-marital relationships (r=−0.40, the phase-in of intensified risk-reduction counselling for HIV-positive adults (r=0.29, the uptake of medical male circumcision (r=−0.24 and the phase-in of universal ART eligibility (r=0.22. The paediatric HIV parameters most strongly associated with mother-to-child transmission rates are the relative risk of transmission through breastfeeding when the mother is receiving ART (r=0.70 and the rate of ART initiation during pregnancy (r=−0.16. Conclusions: The virtual elimination target of a 0.1% incidence rate in adults will be difficult to achieve. Interventions that address the infectiousness of patients after ART initiation will be particularly critical to achieving long-term HIV

Training multitasking in a virtual supermarket: a novel intervention after stroke.

Science.gov (United States)

Rand, Debbie; Weiss, Patrice L Tamar; Katz, Noomi

2009-01-01

To explore the potential of the VMall, a virtual supermarket running on a video-capture virtual reality system, as an intervention tool for people who have multitasking deficits after stroke. Poststroke, 4 participants received ten 60-min sessions over 3 weeks using the VMall. The intervention focused on improving multitasking while the participant was engaged in a virtual shopping task. Instruments included the Multiple Errands Test-Hospital Version (MET-HV) in a real mall and in the VMall. Participants achieved improvements ranging from 20.5% to 51.2% for most of the MET-HV measures performed in a real shopping mall and in the VMall. The data support the VMall's potential as a motivating and effective intervention tool for the rehabilitation of people poststroke who have multitasking deficits during the performance of daily tasks. However, because the sample was small, additional intervention studies with the VMall should be conducted.

Virtual reality training for improving the skills needed for performing surgery of the ear, nose or throat.

Science.gov (United States)

Piromchai, Patorn; Avery, Alex; Laopaiboon, Malinee; Kennedy, Gregor; O'Leary, Stephen

2015-09-09

Virtual reality simulation uses computer-generated imagery to present a simulated training environment for learners. This review seeks to examine whether there is evidence to support the introduction of virtual reality surgical simulation into ear, nose and throat surgical training programmes. 1. To assess whether surgeons undertaking virtual reality simulation-based training achieve surgical ('patient') outcomes that are at least as good as, or better than, those achieved through conventional training methods.2. To assess whether there is evidence from either the operating theatre, or from controlled (simulation centre-based) environments, that virtual reality-based surgical training leads to surgical skills that are comparable to, or better than, those achieved through conventional training. The Cochrane Ear, Nose and Throat Disorders Group (CENTDG) Trials Search Co-ordinator searched the CENTDG Trials Register; Central Register of Controlled Trials (CENTRAL 2015, Issue 6); PubMed; EMBASE; ERIC; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 27 July 2015. We included all randomised controlled trials and controlled trials comparing virtual reality training and any other method of training in ear, nose or throat surgery. We used the standard methodological procedures expected by The Cochrane Collaboration. We evaluated both technical and non-technical aspects of skill competency. We included nine studies involving 210 participants. Out of these, four studies (involving 61 residents) assessed technical skills in the operating theatre (primary outcomes). Five studies (comprising 149 residents and medical students) assessed technical skills in controlled environments (secondary outcomes). The majority of the trials were at high risk of bias. We assessed the GRADE quality of evidence for most outcomes across studies as 'low'. Operating theatre environment (primary outcomes) In

Fuzzy Pheromone Potential Fields for Virtual Pedestrian Simulation

Directory of Open Access Journals (Sweden)

Meriem Mandar

2016-01-01

Full Text Available The study of collective movement of pedestrians is crucial in various situations, such as evacuation of buildings, stadiums, or external events like concerts or public events. In such situations and under panic conditions, several incidents and disasters may arise, resulting in loss of human lives. Hence, the study and modeling of the pedestrians behavior are imperative in both normal and panic situations. In a previous work, we developed a microscopic model for pedestrian movement based on the algorithm of Ant Colonies and the principles of cellular automata. We took advantage of a fuzzy model to better reflect the uncertainty and vagueness of the perception of space to pedestrians, especially to represent the desirability or blurred visibility of virtual pedestrians. This paper uses the mechanism of artificial potential fields. Said fields provide virtual pedestrians with better visibility of their surroundings and its various components (goals and obstacles. The predictions provided by the first-order traffic flow theory are confirmed by the results of the simulation. The advantage of this model lies in the combination of benefits provided by the model of ants and artificial potential fields in a fuzzy modeling, to better understand the perceptions of pedestrians.

Multi Agent Systems to Set Up Virtual Enterprises

Directory of Open Access Journals (Sweden)

Catalin Lupu

2008-01-01

Full Text Available This work presents a model of organizing moreenterprises into a virtual or a web enterprise. To constitutevirtual enterprises multiagent systems are utilized.In this sense the following are to be considered:elaborating a model to constitute the virtual enterprise, theimplementation of a multiagent system based on this modeland the testing and evaluation of the system performances,comparing them with more classic types of realization.In this paper, we describe how the multi-agentarchitecture can be used to support Virtual Enterprises(VE. We have focused on understanding how aVE is formedand, in particular, how the partners of a VE are selected. Wetryto analyse this scenario in the form of an AgentInteraction Protocol (AIP and then discuss how the multiagentarchitecrure can be used to support this process.Our working definition of a VE is: a team of partners thatcollaborate to achieve a specific goal. The partners may behuman beings, organisations or software agents. We believethat software agents, hereafter referred to as agents, are asuitable means of representing the partners of a VE. Oneimportant reason is that by representing the partners of aVE as agents and by delegating agents to look for the nextVE and conduct the negotiation on behalf of the partners, thepartners would then have the time to do the actual workrequired in the current VE.At the end of the paper we will present an experimentalsystem for the architecture of a virtual enterprise.

Research on Collaborative Technology in Distributed Virtual Reality System

Science.gov (United States)

Lei, ZhenJiang; Huang, JiJie; Li, Zhao; Wang, Lei; Cui, JiSheng; Tang, Zhi

2018-01-01

Distributed virtual reality technology applied to the joint training simulation needs the CSCW (Computer Supported Cooperative Work) terminal multicast technology to display and the HLA (high-level architecture) technology to ensure the temporal and spatial consistency of the simulation, in order to achieve collaborative display and collaborative computing. In this paper, the CSCW’s terminal multicast technology has been used to modify and expand the implementation framework of HLA. During the simulation initialization period, this paper has used the HLA statement and object management service interface to establish and manage the CSCW network topology, and used the HLA data filtering mechanism for each federal member to establish the corresponding Mesh tree. During the simulation running period, this paper has added a new thread for the RTI and the CSCW real-time multicast interactive technology into the RTI, so that the RTI can also use the window message mechanism to notify the application update the display screen. Through many applications of submerged simulation training in substation under the operation of large power grid, it is shown that this paper has achieved satisfactory training effect on the collaborative technology used in distributed virtual reality simulation.

Effects of Reviewing Annotations and Homework Solutions on Math Learning Achievement

Science.gov (United States)

Hwang, Wu-Yuin; Chen, Nian-Shing; Shadiev, Rustam; Li, Jin-Sing

2011-01-01

Previous studies have demonstrated that making annotations can be a meaningful and useful learning method that promote metacognition and enhance learning achievement. A web-based annotation system, Virtual Pen (VPEN), which provides for the creation and review of annotations and homework solutions, has been developed to foster learning process…

A Virtual Sensor for Online Fault Detection of Multitooth-Tools

Directory of Open Access Journals (Sweden)

Andres Bustillo

2011-03-01

Full Text Available The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a Bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases.

A Virtual Sensor for Online Fault Detection of Multitooth-Tools

Science.gov (United States)

Bustillo, Andres; Correa, Maritza; Reñones, Anibal

2011-01-01

The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a Bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases. PMID:22163766

Virtual Workshop

DEFF Research Database (Denmark)

Buus, Lillian; Bygholm, Ann

In relation to the Tutor course in the Mediterranean Virtual University (MVU) project, a virtual workshop “Getting experiences with different synchronous communication media, collaboration, and group work” was held with all partner institutions in January 2006. More than 25 key-tutors within MVU...

Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation.

Science.gov (United States)

Ma, Ke; Lippelt, Dominique P; Hommel, Bernhard

2017-03-01

Studies investigating how people represent themselves and their own body often use variants of "ownership illusions", such as the traditional rubber-hand illusion or the more recently discovered enfacement illusion. However, these examples require rather artificial experimental setups, in which the artificial effector needs to be stroked in synchrony with the participants' real hand or face-a situation in which participants have no control over the stroking or the movements of their real or artificial effector. Here, we describe a technique to establish ownership illusions in a setup that is more realistic, more intuitive, and of presumably higher ecological validity. It allows creating the virtual-hand illusion by having participants control the movements of a virtual hand presented on a screen or in virtual space in front of them. If the virtual hand moves in synchrony with the participants' own real hand, they tend to perceive the virtual hand as part of their own body. The technique also creates the virtual-face illusion by having participants control the movements of a virtual face in front of them, again with the effect that they tend to perceive the face as their own if it moves in synchrony with their real face. Studying the circumstances that illusions of this sort can be created, increased, or reduced provides important information about how people create and maintain representations of themselves.

Virtually fabricated guide for placement of the C-tube miniplate.

Science.gov (United States)

Paek, Janghyun; Jeong, Do-Min; Kim, Yong; Kim, Seong-Hun; Chung, Kyu-Rhim; Nelson, Gerald

2014-05-01

This paper introduces a virtually planned and stereolithographically fabricated guiding system that will allow the clinician to plan carefully for the best location of the device and to achieve an accurate position without complications. The scanned data from preoperative dental casts were edited to obtain preoperative 3-dimensional (3D) virtual models of the dentition. After the 3D virtual models were repositioned, the 3D virtual surgical guide was fabricated. A surgical guide was created onscreen, and then these virtual guides were materialized into real ones using the stereolithographic technique. Whereas the previously described guide required laboratory work to be performed by the orthodontist, our technique is more convenient because the laboratory work is done remotely by computer-aided design/computer-aided manufacturing technology. Because the miniplate is firmly held in place as the patient holds his or her mandibular teeth against the occlusal pad of the surgical guide, there is no risk that the miniscrews can slide on the bone surface during placement. The software program (2.5-dimensional software) in this study combines 2-dimensional cephalograms with 3D virtual dental models. This software is an effective and efficient alternative to 3D software when 3D computed tomography data are not available. To confidently and safely place a miniplate with screw fixation, a simple customized guide for an orthodontic miniplate was introduced. The use of a custom-made, rigid guide when placing miniplates will minimize complications such as vertical mislocation or slippage of the miniplate during placement. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Virtual data in CMS production

International Nuclear Information System (INIS)

Arbree, A. et al.

2004-01-01

Initial applications of the GriPhyN Chimera Virtual Data System have been performed within the context of CMS Production of Monte Carlo Simulated Data. The GriPhyN Chimera system consists of four primary components: (1) a Virtual Data Language, which is used to describe virtual data products, (2) a Virtual Data Catalog, which is used to store virtual data entries, (3) an Abstract Planner, which resolves all dependencies of a particular virtual data product and forms a location and existence independent plan, (4) a Concrete Planner, which maps an abstract, logical plan onto concrete, physical grid resources accounting for staging in/out files and publishing results to a replica location service. A CMS Workflow Planner, MCRunJob, is used to generate virtual data products using the Virtual Data Language. Subsequently, a prototype workflow manager, known as WorkRunner, is used to schedule the instantiation of virtual data products across a grid

Virtual Data in CMS Production

CERN Document Server

Arbree, A; Bourilkov, D; Cavanaugh, R J; Graham, G; Katageri, S; Rodríguez, J; Voeckler, J; Wilde, M

2003-01-01

Initial applications of the GriPhyN Chimera Virtual Data System have been performed within the context of CMS Production of Monte Carlo Simulated Data. The GriPhyN Chimera system consists of four primary components: 1) a Virtual Data Language, which is used to describe virtual data products, 2) a Virtual Data Catalog, which is used to store virtual data entries, 3) an Abstract Planner, which resolves all dependencies of a particular virtual data product and forms a location and existence independent plan, 4) a Concrete Planner, which maps an abstract, logical plan onto concrete, physical grid resources accounting for staging in/out files and publishing results to a replica location service. A CMS Workflow Planner, MCRunJob, is used to generate virtual data products using the Virtual Data Language. Subsequently, a prototype workflow manager, known as WorkRunner, is used to schedule the instantiation of virtual data products across a grid.

Virtual reality exposure therapy

OpenAIRE

Rothbaum, BO; Hodges, L; Kooper, R

1997-01-01

It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

Building interactive virtual environments for simulated training in medicine using VRML and Java/JavaScript.

Science.gov (United States)

Korocsec, D; Holobar, A; Divjak, M; Zazula, D

2005-12-01

Medicine is a difficult thing to learn. Experimenting with real patients should not be the only option; simulation deserves a special attention here. Virtual Reality Modelling Language (VRML) as a tool for building virtual objects and scenes has a good record of educational applications in medicine, especially for static and animated visualisations of body parts and organs. However, to create computer simulations resembling situations in real environments the required level of interactivity and dynamics is difficult to achieve. In the present paper we describe some approaches and techniques which we used to push the limits of the current VRML technology further toward dynamic 3D representation of virtual environments (VEs). Our demonstration is based on the implementation of a virtual baby model, whose vital signs can be controlled from an external Java application. The main contributions of this work are: (a) outline and evaluation of the three-level VRML/Java implementation of the dynamic virtual environment, (b) proposal for a modified VRML Timesensor node, which greatly improves the overall control of system performance, and (c) architecture of the prototype distributed virtual environment for training in neonatal resuscitation comprising the interactive virtual newborn, active bedside monitor for vital signs and full 3D representation of the surgery room.

Virtual data

International Nuclear Information System (INIS)

Bjorklund, E.

1993-01-01

In the 1970's, when computers were memory limited, operating system designers created the concept of ''virtual memory'' which gave users the ability to address more memory than physically existed. In the 1990s, many large control systems have the potential for becoming data limited. We propose that many of the principles behind virtual memory systems (working sets, locality, caching, and clustering) can also be applied to data-limited systems - creating, in effect, ''virtual data systems.'' At the Los Alamos National Laboratory's Clinton P. Anderson Meson Physics Facility (LAMPF), we have applied these principles to a moderately sized (10,000 data points) data acquisition and control system. To test the principles, we measured the system's performance during tune-up, production, and maintenance periods. In this paper, we present a general discussion of the principles of a virtual data system along with some discussion of our own implementation and the results of our performance measurements

Universidades virtuales: ¿aprendizaje real?

OpenAIRE

Valenzuela González, Jaime R.

2015-01-01

1. Introducción; 2. Modalidades educativas; 3. Concepto y características de las universidades virtuales; 4. Un modelo de universidad virtual; 5. Universidades virtuales ¿aprendizaje real?; 6. Tensiones de las universidades virtuales; 7. Referencias

MULTIMEDIA EDITOR OF VIRTUAL PHYSICAL LABORATORY IN DISTANCE LEARNING SYSTEM «KHERSON VIRTUAL UNIVERSITY»

Directory of Open Access Journals (Sweden)

Kravtsov H.

2017-12-01

Full Text Available The questions of modeling the structure of the objects of the system, the design of software modules and technologies for creating the editor of a virtual laboratory are considered. The relevance of the study is due to the lack in existing distance learning systems of support for the creation and use of virtual laboratory work on disciplines of the natural-science profile. The subject of the study is a software module for creating and using virtual laboratory work in a distance learning system. The purpose of the study is the development of a system model and a description of the software development technology of a virtual laboratory for physics for a distance learning system. The information technologies of designing the structure of the virtual laboratory and the main modes of the program module of the editor of the virtual laboratory work are described. At the heart of the structure of the software module "Virtual Laboratory" is the multimedia Web-editor of virtual laboratory works, which is created using object-oriented design technology. The program library of multimedia 3D objects created in the development environment of interactive graphic objects Unity3D. It unifies the process of creation and processing of virtual laboratory works. The basic mathematical package for supporting calculations is the mathematical processor Waterloo Maple. The application of the developed software interface will allow teachers to create laboratory works and use them in their distance courses. Students, in turn, will be able to conduct research, performing virtual laboratory work. As an example, the editor of the virtual laboratory for physics in the distance learning system "Kherson Virtual University" is considered.

The Learner Characteristics, Features of Desktop 3D Virtual Reality Environments, and College Chemistry Instruction: A Structural Equation Modeling Analysis

Science.gov (United States)

Merchant, Zahira; Goetz, Ernest T.; Keeney-Kennicutt, Wendy; Kwok, Oi-man; Cifuentes, Lauren; Davis, Trina J.

2012-01-01

We examined a model of the impact of a 3D desktop virtual reality environment on the learner characteristics (i.e. perceptual and psychological variables) that can enhance chemistry-related learning achievements in an introductory college chemistry class. The relationships between the 3D virtual reality features and the chemistry learning test as…

Virtualized Networks and Virtualized Optical Line Terminal (vOLT)

Science.gov (United States)

Ma, Jonathan; Israel, Stephen

2017-03-01

The success of the Internet and the proliferation of the Internet of Things (IoT) devices is forcing telecommunications carriers to re-architecture a central office as a datacenter (CORD) so as to bring the datacenter economics and cloud agility to a central office (CO). The Open Network Operating System (ONOS) is the first open-source software-defined network (SDN) operating system which is capable of managing and controlling network, computing, and storage resources to support CORD infrastructure and network virtualization. The virtualized Optical Line Termination (vOLT) is one of the key components in such virtualized networks.

A study on development of virtual panel and virtual collaboration system

International Nuclear Information System (INIS)

Yoo, H. J.; Park, S. Y.; Lee, M. S.; Hong, J. H.

2001-01-01

The Nuclear I and C group of KEPRI has been peforming research and development on the VRCATS, Virtual Reality based Computer Assisted Training System. For the past two years, we have developed the first VRCATS for Youngkwang 1 nuclear power plant. Currently, we are developing an advanced VRCATS for Uljin 3 nuclear power plant. In this paepr, we will describe virtual panel system and VR based collaborate training system (VRCATS) of the Uljin VRCATS. Since Virtual Panel provides the same environment as the real MCR, trainees can expect the same training effect with Virtual Panel as they do with full scope simulator. i.e., trainees can check key variables and operate the plants and get responses with Virtual Panel. VRCTS provides another realistic training environment for trainees. In VRCATS, for example, operators in a group can work together t handle LOCA (Loss of Coolant Accident) according to emergency operation procedures

Using virtual machine monitors to overcome the challenges of monitoring and managing virtualized cloud infrastructures

Science.gov (United States)

Bamiah, Mervat Adib; Brohi, Sarfraz Nawaz; Chuprat, Suriayati

2012-01-01

Virtualization is one of the hottest research topics nowadays. Several academic researchers and developers from IT industry are designing approaches for solving security and manageability issues of Virtual Machines (VMs) residing on virtualized cloud infrastructures. Moving the application from a physical to a virtual platform increases the efficiency, flexibility and reduces management cost as well as effort. Cloud computing is adopting the paradigm of virtualization, using this technique, memory, CPU and computational power is provided to clients' VMs by utilizing the underlying physical hardware. Beside these advantages there are few challenges faced by adopting virtualization such as management of VMs and network traffic, unexpected additional cost and resource allocation. Virtual Machine Monitor (VMM) or hypervisor is the tool used by cloud providers to manage the VMs on cloud. There are several heterogeneous hypervisors provided by various vendors that include VMware, Hyper-V, Xen and Kernel Virtual Machine (KVM). Considering the challenge of VM management, this paper describes several techniques to monitor and manage virtualized cloud infrastructures.

Study on the influence of smoke and exit signs on fire evacuation - Analysis of evacuation experiments in a real and virtual hotel

NARCIS (Netherlands)

Kobes, M.; Helsloot, I.; Vries, de B.; Post, J.G.; Oberije, N.; Groenewegen, K.

2010-01-01

Human behaviour in fires is mainly studied by incident evaluations and real-life experiments, such as unannounced evacuation drills. The possibilities of virtual reality for studying human behaviour in fires are so far hardly adopted by researchers. Nevertheless, the application of a behavioural

Organization Virtual or Networked?

Directory of Open Access Journals (Sweden)

Rūta Tamošiūnaitė

2013-08-01

Full Text Available Purpose—to present distinction between “virtual organization” and “networked organization”; giving their definitions.Design/methodology/approach—review of previous researches, systemic analyses of their findings and synthesis of distinctive characteristics of ”virtual organization” and “networked organization.”Findings—the main result of the research is key diverse features separating ”virtual organization” and ”networked organization.” Definitions of “virtual organization” and “networked organization” are presented.Originality/Value—distinction between “virtual organization” and “networked organization” creates possibilities to use all advantages of those types of organizations and gives foundation for deeper researches in this field.Research type: general review.

Perception of Virtual Audiences.

Science.gov (United States)

Chollet, Mathieu; Scherer, Stefan

2017-01-01

A growing body of evidence shows that virtual audiences are a valuable tool in the treatment of social anxiety, and recent works show that it also a useful in public-speaking training programs. However, little research has focused on how such audiences are perceived and on how the behavior of virtual audiences can be manipulated to create various types of stimuli. The authors used a crowdsourcing methodology to create a virtual audience nonverbal behavior model and, with it, created a dataset of videos with virtual audiences containing varying behaviors. Using this dataset, they investigated how virtual audiences are perceived and which factors affect this perception.

Virtual School Startups: Founder Processes in American K-12 Public Virtual Schools

Science.gov (United States)

Taylor, Brett D.; McNair, Delores E.

2018-01-01

Traditional school districts do not have a lot of experience with virtual schools and have lost students to state and charter virtual schools. To retain students and offer alternative learning opportunities, more public districts are starting their own virtual schools. This study was an examination of foundational processes at three California…

Virtual Reality: An Overview.

Science.gov (United States)

Franchi, Jorge

1994-01-01

Highlights of this overview of virtual reality include optics; interface devices; virtual worlds; potential applications, including medicine and archaeology; problems, including costs; current research and development; future possibilities; and a listing of vendors and suppliers of virtual reality products. (Contains 11 references.) (LRW)

Generation and Application of Virtual Dynamic Learning Environments

Directory of Open Access Journals (Sweden)

Esther Zaretsky

2009-04-01

Full Text Available The generation of virtual dynamic learning environments by mental imagery improved physical education of student teachers. Up-to-date studies showed that training computerized simulations improved spatial abilities, especially visualization of the body's movements in space, and enhanced academic achievements. The main program of the research concentrated on creating teaching units focusing on a variety of physical skills through computerized dynamic presentations. The findings showed that as the student teachers practiced the creation of simulations through the PowerPoint Software, it became clear to them how the computer is related to physical activities. Consequently their presentations became highly animated, and applied to the natural environment. The student teachers applied their presentations in their practical classroom and reported about their pupils' progress in physical skills. Moreover the motivation of the student teachers and pupils to both modes of learning, manipulating virtually and physically, was enhanced.

Development and Reliability Evaluation of the Movement Rating Instrument for Virtual Reality Video Game Play.

Science.gov (United States)

Levac, Danielle; Nawrotek, Joanna; Deschenes, Emilie; Giguere, Tia; Serafin, Julie; Bilodeau, Martin; Sveistrup, Heidi

2016-06-01

Virtual reality active video games are increasingly popular physical therapy interventions for children with cerebral palsy. However, physical therapists require educational resources to support decision making about game selection to match individual patient goals. Quantifying the movements elicited during virtual reality active video game play can inform individualized game selection in pediatric rehabilitation. The objectives of this study were to develop and evaluate the feasibility and reliability of the Movement Rating Instrument for Virtual Reality Game Play (MRI-VRGP). Item generation occurred through an iterative process of literature review and sample videotape viewing. The MRI-VRGP includes 25 items quantifying upper extremity, lower extremity, and total body movements. A total of 176 videotaped 90-second game play sessions involving 7 typically developing children and 4 children with cerebral palsy were rated by 3 raters trained in MRI-VRGP use. Children played 8 games on 2 virtual reality and active video game systems. Intraclass correlation coefficients (ICCs) determined intra-rater and interrater reliability. Excellent intrarater reliability was evidenced by ICCs of >0.75 for 17 of the 25 items across the 3 raters. Interrater reliability estimates were less precise. Excellent interrater reliability was achieved for far reach upper extremity movements (ICC=0.92 [for right and ICC=0.90 for left) and for squat (ICC=0.80) and jump items (ICC=0.99), with 9 items achieving ICCs of >0.70, 12 items achieving ICCs of between 0.40 and 0.70, and 4 items achieving poor reliability (close-reach upper extremity-ICC=0.14 for right and ICC=0.07 for left) and single-leg stance (ICC=0.55 for right and ICC=0.27 for left). Poor video quality, differing item interpretations between raters, and difficulty quantifying the high-speed movements involved in game play affected reliability. With item definition clarification and further psychometric property evaluation, the MRI

Virtual currencies- Real opportunities?

OpenAIRE

Selldahl, Sara

2013-01-01

The European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community.” (European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last few years as they become increasingly prevalent in our society across many different industries. Up until now, the field of virtual currencies has been mainly uncharted ...

Agreements in Virtual Organizations

Science.gov (United States)

Pankowska, Malgorzata

This chapter is an attempt to explain the important impact that contract theory delivers with respect to the concept of virtual organization. The author believes that not enough research has been conducted in order to transfer theoretical foundations for networking to the phenomena of virtual organizations and open autonomic computing environment to ensure the controllability and management of them. The main research problem of this chapter is to explain the significance of agreements for virtual organizations governance. The first part of this chapter comprises explanations of differences among virtual machines and virtual organizations for further descriptions of the significance of the first ones to the development of the second. Next, the virtual organization development tendencies are presented and problems of IT governance in highly distributed organizational environment are discussed. The last part of this chapter covers analysis of contracts and agreements management for governance in open computing environments.

Use of virtual reality to estimate radiation dose rates in nuclear plants

International Nuclear Information System (INIS)

Augusto, Silas C.; Mol, Antonio C.A.; Jorge, Carlos A.F.; Couto, Pedro M.

2007-01-01

Operators in nuclear plants receive radiation doses during several different operation procedures. A training program capable of simulating these operation scenarios will be useful in several ways, helping the planning of operational procedures so as to reduce the doses received by workers, and to minimize operations' times. It can provide safe virtual operation training, visualization of radiation dose rates, and estimation of doses received by workers. Thus, a virtual reality application, a free game engine, has been adapted to achieve the goals of this project. Simulation results for Argonauta research reactor of Instituto de Engenharia Nuclear are shown in this paper. A database of dose rate measurements, previously performed by the radiological protection service, has been used to display the dose rate distribution in the region of interest. The application enables the user to walk in the virtual scenario, displaying at all times the dose accumulated by the avatar. (author)

Integration of virtualized worker nodes in standard batch systems

International Nuclear Information System (INIS)

Buege, Volker; Kunze, Marcel; Oberst, Oliver; Quast, Guenter; Scheurer, Armin; Hessling, Hermann; Kemp, Yves; Synge, Owen

2010-01-01

Current experiments in HEP only use a limited number of operating system flavours. Their software might only be validated on one single OS platform. Resource providers might have other operating systems of choice for the installation of the batch infrastructure. This is especially the case if a cluster is shared with other communities, or communities that have stricter security requirements. One solution would be to statically divide the cluster into separated sub-clusters. In such a scenario, no opportunistic distribution of the load can be achieved, resulting in a poor overall utilization efficiency. Another approach is to make the batch system aware of virtualization, and to provide each community with its favoured operating system in a virtual machine. Here, the scheduler has full flexibility, resulting in a better overall efficiency of the resources. In our contribution, we present a lightweight concept for the integration of virtual worker nodes into standard batch systems. The virtual machines are started on the worker nodes just before jobs are executed there. No meta-scheduling is introduced. We demonstrate two prototype implementations, one based on the Sun Grid Engine (SGE), the other using Maui/Torque as a batch system. Both solutions support local job as well as Grid job submission. The hypervisors currently used are Xen and KVM, a port to another system is easily envisageable. To better handle different virtual machines on the physical host, the management solution VmImageManager is developed. We will present first experience from running the two prototype implementations. In a last part, we will show the potential future use of this lightweight concept when integrated into high-level (i.e. Grid) work-flows.

Convenience of achieving a software platform leading to increased travel safety for disabled persons

Directory of Open Access Journals (Sweden)

Alina Simona TECĂU

2017-07-01

Full Text Available The paper presents the results of a qualitative marketing research, achieved by the focus group method, one of a series of marketing researches proposed with a view to determining the extent to which it is opportune to achieve a software platform containing a database with safe tourist routes and images, accessible for disabled persons, which may tested/ visualized by virtual reality.

Secure Hardware Performance Analysis in Virtualized Cloud Environment

Directory of Open Access Journals (Sweden)

Chee-Heng Tan

2013-01-01

Full Text Available The main obstacle in mass adoption of cloud computing for database operations is the data security issue. In this paper, it is shown that IT services particularly in hardware performance evaluation in virtual machine can be accomplished effectively without IT personnel gaining access to real data for diagnostic and remediation purposes. The proposed mechanisms utilized TPC-H benchmark to achieve 2 objectives. First, the underlying hardware performance and consistency is supervised via a control system, which is constructed using a combination of TPC-H queries, linear regression, and machine learning techniques. Second, linear programming techniques are employed to provide input to the algorithms that construct stress-testing scenarios in the virtual machine, using the combination of TPC-H queries. These stress-testing scenarios serve 2 purposes. They provide the boundary resource threshold verification to the first control system, so that periodic training of the synthetic data sets for performance evaluation is not constrained by hardware inadequacy, particularly when the resources in the virtual machine are scaled up or down which results in the change of the utilization threshold. Secondly, they provide a platform for response time verification on critical transactions, so that the expected Quality of Service (QoS from these transactions is assured.

Kinematic/Dynamic Characteristics for Visual and Kinesthetic Virtual Environments

Science.gov (United States)

Bortolussi, Michael R. (Compiler); Adelstein, B. D.; Gold, Miriam

1996-01-01

Work was carried out on two topics of principal importance to current progress in virtual environment research at NASA Ames and elsewhere. The first topic was directed at maximizing the temporal dynamic response of visually presented Virtual Environments (VEs) through reorganization and optimization of system hardware and software. The final results of this portion of the work was a VE system in the Advanced Display and Spatial Perception Laboratory at NASA Ames capable of updating at 60 Hz (the maximum hardware refresh rate) with latencies approaching 30 msec. In the course of achieving this system performance, specialized hardware and software tools for measurement of VE latency and analytic models correlating update rate and latency for different system configurations were developed. The second area of activity was the preliminary development and analysis of a novel kinematic architecture for three Degree Of Freedom (DOF) haptic interfaces--devices that provide force feedback for manipulative interaction with virtual and remote environments. An invention disclosure was filed on this work and a patent application is being pursued by NASA Ames. Activities in these two areas are expanded upon below.

Virtual Machine in Automation Projects

OpenAIRE

Xing, Xiaoyuan

2010-01-01

Virtual machine, as an engineering tool, has recently been introduced into automation projects in Tetra Pak Processing System AB. The goal of this paper is to examine how to better utilize virtual machine for the automation projects. This paper designs different project scenarios using virtual machine. It analyzes installability, performance and stability of virtual machine from the test results. Technical solutions concerning virtual machine are discussed such as the conversion with physical...

Educational Tutorial Video with Aspects of Psychological Sensation and Perception in Academic Achievement

Directory of Open Access Journals (Sweden)

Martha Jiménez García

2015-09-01

Full Text Available In Mexico 75.5% of children and young students in elementary and secondary school are at insufficient and elementary levels in mathematics. The purpose of this research is to join the UNESCO initiative by granting quality education, boosted by technology (Rose, 2013. Specifically, the objective is to analyze the impact of using a tutorial video on academic achievement, based on Gestalt psychology stimulating the sensation and perception cognitive capabilities. Using a 50 student sample was used, which was divided into two groups (experimental and control we test whether students that use a tutorial video based on sensation and perception increase their attention and interest to increase academic achievement. The experimental group was a virtual class with tutorial videos on the use of slopes, explanation of the equation, and a virtual graph generator. Both groups were a survey and an exam. The results show that a high impact on the grades and on the perception of knowledge in the experimental group; the average academic achievement of the experimental group was 9.31, against 2 in the control group. Thus, we conclude that the tutorial video presented stimulates cognitive capabilities and improves academic achievement with a 7.3 impact per additional unit of tutorial video, presented as reinforcement of the class.

Cancer incidence in an area contaminated with radionuclides near a nuclear installation

International Nuclear Information System (INIS)

Johnson, C.J.

1981-01-01

Exposures of a large population in the Denver area to plutonium and other radionuclides in the exhaust plumes from the Rocky Flats (nuclear weapons) plant date back to 1953. Anglo cancer incidence in 1969-1971 was evaluated in census tracts with and without contamination in the Denver area (1970 pop. 1 019 130). Cancer incidence in males was 24% higher, and in females, 10% higher in the suburban area(pop. 154 170) with most contamination nearest the plant, compared to the unexposed area (pop. 423 870), also predominantly suburban, which had virtually the same age-adjusted incidence rate for all cancer as the state. Excess cases of cancer were due to more cases than expected of leukemia, lymphoma and myeloma and cancer of the lung, thyroid, breast, esophagus, stomach and colon, a pattern similar to that obs- erved in the survivors of Hiroshima and Nagasaki. The ratio of these cancers to all other cancer was 17.6% higher in males and 11.9% higher in females in the area near the plant. Cancer of the gonads (especially the testes), liver, and, in females, pancreas and brain contributed to the higher incidence of all cancer in areas near the plant. (Auth.)

The Virtuality Continuum Revisited

NARCIS (Netherlands)

Nijholt, Antinus; Traum, D.; Zhai, Sh.; Kellogg, W.

2005-01-01

We survey the themes and the aims of a workshop devoted to the state-of-the-art virtuality continuum. In this continuum, ranging from fully virtual to real physical environments, allowing for mixed, augmented and desktop virtual reality, several perspectives can be taken. Originally, the emphasis

The virtual nose: a 3-dimensional virtual reality model of the human nose.

Science.gov (United States)

Vartanian, A John; Holcomb, Joi; Ai, Zhuming; Rasmussen, Mary; Tardy, M Eugene; Thomas, J Regan

2004-01-01

The 3-dimensionally complex interplay of soft tissue, cartilaginous, and bony elements makes the mastery of nasal anatomy difficult. Conventional methods of learning nasal anatomy exist, but they often involve a steep learning curve. Computerized models and virtual reality applications have been used to facilitate teaching in a number of other complex anatomical regions, such as the human temporal bone and pelvic floor. We present a 3-dimensional (3-D) virtual reality model of the human nose. Human cadaveric axial cross-sectional (0.33-mm cuts) photographic data of the head and neck were used. With 460 digitized images, individual structures were traced and programmed to create a computerized polygonal model of the nose. Further refinements to this model were made using a number of specialized computer programs. This 3-D computer model of the nose was then programmed to operate as a virtual reality model. Anatomically correct 3-D model of the nose was produced. High-resolution images of the "virtual nose" demonstrate the nasal septum, lower lateral cartilages, middle vault, bony dorsum, and other structural details of the nose. Also, the model can be combined with a separate virtual reality model of the face and its skin cover as well as the skull. The user can manipulate the model in space, examine 3-D anatomical relationships, and fade superficial structures to reveal deeper ones. The virtual nose is a 3-D virtual reality model of the nose that is accurate and easy to use. It can be run on a personal computer or in a specialized virtual reality environment. It can serve as an effective teaching tool. As the first virtual reality model of the nose, it establishes a virtual reality platform from which future applications can be launched.

Virtual Museums as Educational Tool

DEFF Research Database (Denmark)

2007-01-01

Virtual Museums as Educational Tool On this web site you will find a collection of resources on virtual museums. The web site is meant to be a knowledge base for people with interest in museums, virtuality and education, and how virtual museums may contribute to adult education and lifelong...

[Virtual reality in neurosurgery].

Science.gov (United States)

Tronnier, V M; Staubert, A; Bonsanto, M M; Wirtz, C R; Kunze, S

2000-03-01

Virtual reality enables users to immerse themselves in a virtual three-dimensional world and to interact in this world. The simulation is different from the kind in computer games, in which the viewer is active but acts in a nonrealistic world, or on the TV screen, where we are passively driven in an active world. In virtual reality elements look realistic, they change their characteristics and have almost real-world unpredictability. Virtual reality is not only implemented in gambling dens and the entertainment industry but also in manufacturing processes (cars, furniture etc.), military applications and medicine. Especially the last two areas are strongly correlated, because telemedicine or telesurgery was originated for military reasons to operate on war victims from a secure distance or to perform surgery on astronauts in an orbiting space station. In medicine and especially neurosurgery virtual-reality methods are used for education, surgical planning and simulation on a virtual patient.

Study on virtual instrument developing system based on intelligent virtual control

International Nuclear Information System (INIS)

Tang Baoping; Cheng Fabin; Qin Shuren

2005-01-01

The paper introduces a non-programming developing system of a virtual instrument (VI), i.e., a virtual measurement instrument developing system (VMIDS) based on intelligent virtual control (IVC). The background of the IVC-based VMIDS is described briefly, and the hierarchical message bus (HMB)-based software architecture of VMIDS is discussed in detail. The three parts and functions of VMIDS are introduced, and the process of non-programming developing VI is further described

Study on virtual instrument developing system based on intelligent virtual control

Energy Technology Data Exchange (ETDEWEB)

Tang Baoping; Cheng Fabin; Qin Shuren [Test Center, College of Mechanical Engineering, Chongqing University , Chongqing 400030 (China)

2005-01-01

The paper introduces a non-programming developing system of a virtual instrument (VI), i.e., a virtual measurement instrument developing system (VMIDS) based on intelligent virtual control (IVC). The background of the IVC-based VMIDS is described briefly, and the hierarchical message bus (HMB)-based software architecture of VMIDS is discussed in detail. The three parts and functions of VMIDS are introduced, and the process of non-programming developing VI is further described.

Virtualization Technologies for the Business

OpenAIRE

Sabina POPESCU

2011-01-01

There is a new trend of change in today's IT industry. It's called virtualization. In datacenter virtualization can occur on several levels, but the type of virtualization has created this trend change is the operating system offered or server virtualization. OS virtualization technologies come in two forms. First, there is a software component that is used to simulate a natural machine that has total control of an operating system operating on the host equipment. The second is a hypervisor, ...

Sobre objetos y experiencias virtuales

OpenAIRE

Pacho, Julián

2009-01-01

This paper analyses basic onto-epistemological properties of the virtual reality and suggests these theses. First, the virtual reality establishes a new nature; its essential feature is to be an organic world of emancipated techno-theories. Second, the virtual reality doesn’t substitutes the traditional book; it substitutes the world. Third, the experience of the world in the virtual reality excludes the natural world experience. Fourth, the ontology of virtual reality is build without an act...

Etnografía virtual Virtual ethnography: exploring a methodological option for the research on virtual learning environments.

Directory of Open Access Journals (Sweden)

Álvarez Cadavid Gloria María

2009-01-01

Full Text Available Este artículo pretende esbozar algunas de las consideraciones metodológicas que hoy confluyen en el estudio de los ambientes virtuales, desde la opción etnográfica. De manera específica se quiere observar la forma en que, algunos investigadores han abordado el aspecto metodológico para estudiar los ambientes virtuales, líneas de evolución y posible contribución al conocimiento y mejoramiento de los procesos de e-learning. This article aims to outline some methodological considerations that merge together on the study of virtual learning environments, especially from the ethnographic perspective. Specifically, what we want to observe, is the way some researchers have approached the methodological aspect in order to study virtual learning environments, the evolution lines and the possible contribution they’ve made to knowledge and improvement of e-learning processes.

Note on santi s-production in anti p-nucleus reactions at 607 MeV/c incident momentum

Energy Technology Data Exchange (ETDEWEB)

Balestra, F.; Bossolasco, S.; Bussa, M.P.; Busso, L.; Fava, L.; Ferrero, L.; Grasso, A.; Panzieri, D.; Piragino, G.; Piragino, R.; Tosello, F. (Ist. di Fisica Generale ' A. Avogadro' , Univ. of Turin, INFN (Italy)); Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Venaglioni, A.; Zenoni, A. (Dipt. di Fisica Nucleare e Teorica, Univ. of Pavia (Italy) INFN, Sezione di Pavia (Italy)); Batusov, Yu.; Bunyatov, S.A.; Falomkin, I.V.; Nichitiu, F.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I. (Joint Inst. of Nuclear Research, Dubna (USSR)); Guaraldo, C.; Maggiora, A. (Lab. Nazionali di Frascati dell' INFN (Italy)); Lodi Rizzini, E. (Dipt. di Automazione Industriale, Univ. of Brescia (Italy) INFN, Sezione di Pavia (Italy)); Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M. (Physics Dept., Univ. of Bergen (Norway)); Breivik, F.O.; Danielsen, K.M.; Jacobsen, T.; Soerensen, S.O. (Inst. of Physics, Univ. of Oslo (Norway)); CERN-Project PS-179 LEAR-Collaboration Bergen-Brescia-Dubna-Frascati-Oslo-Pavia-Torino

1990-09-01

The measured cross sections for K{sub s}{sup 0} and {Lambda}{sup 0} ({Sigma}{sup 0}) production in anti pA reactions at 607 MeV/c incident momentum and the number of quark recombinations give the cross section {sigma}(santi s) for strange particle production for target nuclei with A = 2, 4, 20 nucleons, respectively. The result favours the relation {sigma}(santi s) {proportional to} A{sup 1/3}. Scattering of an antiquark off a virtual santi s-pair, or gluon Bremsstrahlung emitted by scattering of an incident antiquark passing through nuclear matter, are possible processes consistent with this relation. Models inconsistent with this relation may be wrong. (orig.).

Note on santi s-production in anti p-nucleus reactions at 607 MeV/c incident momentum

International Nuclear Information System (INIS)

Balestra, F.; Bossolasco, S.; Bussa, M.P.; Busso, L.; Fava, L.; Ferrero, L.; Grasso, A.; Panzieri, D.; Piragino, G.; Piragino, R.; Tosello, F.; Bendiscioli, G.; Filippini, V.; Rotondi, A.; Salvini, P.; Venaglioni, A.; Zenoni, A.; Batusov, Yu.; Bunyatov, S.A.; Falomkin, I.V.; Nichitiu, F.; Pontecorvo, G.B.; Rozhdestvensky, A.M.; Sapozhnikov, M.G.; Tretyak, V.I.; Guaraldo, C.; Maggiora, A.; Lodi Rizzini, E.; Haatuft, A.; Halsteinslid, A.; Myklebost, K.; Olsen, J.M.; Breivik, F.O.; Danielsen, K.M.; Jacobsen, T.; Soerensen, S.O.

1990-01-01

The measured cross sections for K s 0 and Λ 0 (Σ 0 ) production in anti pA reactions at 607 MeV/c incident momentum and the number of quark recombinations give the cross section σ(santi s) for strange particle production for target nuclei with A = 2, 4, 20 nucleons, respectively. The result favours the relation σ(santi s) ∝ A 1/3 . Scattering of an antiquark off a virtual santi s-pair, or gluon Bremsstrahlung emitted by scattering of an incident antiquark passing through nuclear matter, are possible processes consistent with this relation. Models inconsistent with this relation may be wrong. (orig.)

Virtual reality: new method of teaching anorectal and pelvic floor anatomy.

Science.gov (United States)

Dobson, Howard D; Pearl, Russell K; Orsay, Charles P; Rasmussen, Mary; Evenhouse, Ray; Ai, Zhuming; Blew, Gregory; Dech, Fred; Edison, Marcia I; Silverstein, Jonathan C; Abcarian, Herand

2003-03-01

, teachers and students can interact from locations world-wide to manipulate the components of this model to achieve the educational goals of this project along with the potential for virtual surgery.

Photon virtual bound state

International Nuclear Information System (INIS)

Inoue, J.; Ohtaka, K.

2004-01-01

We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

[Research on the virtual water composition and virtual water trade for agriculture in Beijing].

Science.gov (United States)

Wang, Hong-rui; Wang, Yan; Wang, Jun-hong; Dong, Yan-yan; Han, Zhao-xing

2007-12-01

Based on the irrigation norm of typical district and county, and revised by the isoline map of Chinese crops water demand, the change of crops program was analyzed as well as the agricultural water use and its GDP benefits. Then the virtual water was calculated for years. At last, the input-output method was used to calculate the trade of virtual water in Beijing. As the results, the virtual water for cereal crops has been decreasing in Beijing, from 1.832 x 10(9) m3 in 1990 to 4.283 x 10(8) m3 in 2004. Otherwise the virtual water for technical crops has been increasing, which is from 9.06 x 10(8) m3 in 1990 to 1.492 x 10(9) m3 in 2004. On the whole, the virtual water for crops has been decreasing in Beijing. From the angle of primary products Beijing is a virtual water importing area. Virtual water importing of annual average is 2.37 x 10(8) m3, which is about 5.93% of the total water of Beijing. Virtual water has been an important supplement of local real water of Beijing.

A methodology to emulate and evaluate a productive virtual workstation

Science.gov (United States)

Krubsack, David; Haberman, David

1992-01-01

The Advanced Display and Computer Augmented Control (ADCACS) Program at ACT is sponsored by NASA Ames to investigate the broad field of technologies which must be combined to design a 'virtual' workstation for the Space Station Freedom. This program is progressing in several areas and resulted in the definition of requirements for a workstation. A unique combination of technologies at the ACT Laboratory have been networked to effectively create an experimental environment. This experimental environment allows the integration of nonconventional input devices with a high power graphics engine within the framework of an expert system shell which coordinates the heterogeneous inputs with the 'virtual' presentation. The flexibility of the workstation is evolved as experiments are designed and conducted to evaluate the condition descriptions and rule sets of the expert system shell and its effectiveness in driving the graphics engine. Workstation productivity has been defined by the achievable performance in the emulator of the calibrated 'sensitivity' of input devices, the graphics presentation, the possible optical enhancements to achieve a wide field of view color image and the flexibility of conditional descriptions in the expert system shell in adapting to prototype problems.

In vivo T-cell depletion using alemtuzumab in family and unrelated donor transplantation for pediatric non-malignant disease achieves engraftment with low incidence of graft vs. host disease.

Science.gov (United States)

Saif, M A; Borrill, R; Bigger, B W; Lee, H; Logan, A; Poulton, K; Hughes, S; Turner, A J; Bonney, D K; Wynn, R F

2015-03-01

In vivo T-cell depletion, using alemtuzumab therapy prior to SCT, can reduce the incidence of GVHD. This treatment has a potential to delay immune reconstitution resulting in increased morbidity due to viral illnesses. We retrospectively analyzed data on all pediatric patients with non-malignant disorders who received alemtuzumab-based conditioning regimens in our center over the last 10 yr (n = 91). Our data show an OS of 91.2%. The incidence of acute (grade 2-4) GVHD was 18.7% and that of chronic GVHD 5.5%. Viremia due to adenovirus, EBV and CMV was seen in 19.8%, 64.8% and 39.6% patients, respectively, with only two deaths attributed to viral infection (adenovirus). Chimerism level at three month was predictive of graft outcome. Nine patients, who had graft failure after first SCT, were salvaged with a second SCT using RIC and same donor (if available). Based on these results, we conclude that the use of in vivo T-cell depletion is safe, achieves good chimerism and does not lead to increased morbidity and mortality due to viral infections. It is associated with a reduced incidence of chronic GVHD. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Art in virtual reality 2010

Science.gov (United States)

Chang, Ben

2010-01-01

For decades, virtual reality artwork has existed in a small but highly influential niche in the world of electronic and new media art. Since the early 1990's, virtual reality installations have come to define an extreme boundary point of both aesthetic experience and technological sophistication. Classic virtual reality artworks have an almost mythological stature - powerful, exotic, and often rarely exhibited. Today, art in virtual environments continues to evolve and mature, encompassing everything from fully immersive CAVE experiences to performance art in Second Life to the use of augmented and mixed reality in public space. Art in Virtual Reality 2010 is a public exhibition of new artwork that showcases the diverse ways that contemporary artists use virtual environments to explore new aesthetic ground and investigate the continually evolving relationship between our selves and our virtual worlds.

Knowledge Acquisition and Job Training for Advanced Technical Skills Using Immersive Virtual Environment

Science.gov (United States)

Watanuki, Keiichi; Kojima, Kazuyuki

The environment in which Japanese industry has achieved great respect is changing tremendously due to the globalization of world economies, while Asian countries are undergoing economic and technical development as well as benefiting from the advances in information technology. For example, in the design of custom-made casting products, a designer who lacks knowledge of casting may not be able to produce a good design. In order to obtain a good design and manufacturing result, it is necessary to equip the designer and manufacturer with a support system related to casting design, or a so-called knowledge transfer and creation system. This paper proposes a new virtual reality based knowledge acquisition and job training system for casting design, which is composed of the explicit and tacit knowledge transfer systems using synchronized multimedia and the knowledge internalization system using portable virtual environment. In our proposed system, the education content is displayed in the immersive virtual environment, whereby a trainee may experience work in the virtual site operation. Provided that the trainee has gained explicit and tacit knowledge of casting through the multimedia-based knowledge transfer system, the immersive virtual environment catalyzes the internalization of knowledge and also enables the trainee to gain tacit knowledge before undergoing on-the-job training at a real-time operation site.

An Automatic Decision-Making Mechanism for Virtual Machine Live Migration in Private Clouds

Directory of Open Access Journals (Sweden)

Ming-Tsung Kao

2014-01-01

Full Text Available Due to the increasing number of computer hosts deployed in an enterprise, automatic management of electronic applications is inevitable. To provide diverse services, there will be increases in procurement, maintenance, and electricity costs. Virtualization technology is getting popular in cloud computing environment, which enables the efficient use of computing resources and reduces the operating cost. In this paper, we present an automatic mechanism to consolidate virtual servers and shut down the idle physical machines during the off-peak hours, while activating more machines at peak times. Through the monitoring of system resources, heavy system loads can be evenly distributed over physical machines to achieve load balancing. By integrating the feature of load balancing with virtual machine live migration, we successfully develop an automatic private cloud management system. Experimental results demonstrate that, during the off-peak hours, we can save power consumption of about 69 W by consolidating the idle virtual servers. And the load balancing implementation has shown that two machines with 80% and 40% CPU loads can be uniformly balanced to 60% each. And, through the use of preallocated virtual machine images, the proposed mechanism can be easily applied to a large amount of physical machines.

Virtual reality simulation for construction safety promotion.

Science.gov (United States)

Zhao, Dong; Lucas, Jason

2015-01-01

Safety is a critical issue for the construction industry. Literature argues that human error contributes to more than half of occupational incidents and could be directly impacted by effective training programs. This paper reviews the current safety training status in the US construction industry. Results from the review evidence the gap between the status and industry expectation on safety. To narrow this gap, this paper demonstrates the development and utilisation of a training program that is based on virtual reality (VR) simulation. The VR-based safety training program can offer a safe working environment where users can effectively rehearse tasks with electrical hazards and ultimately promote their abilities for electrical hazard cognition and intervention. Its visualisation and simulation can also remove the training barriers caused by electricity's features of invisibility and dangerousness.

Utilization of a virtual patient for advanced assessment of student performance in pain management.

Science.gov (United States)

Smith, Michael A; Waite, Laura H

2017-09-01

To assess student performance and achievement of course objectives following the integration of a virtual patient case designed to promote active, patient-centered learning in a required pharmacy course. DecisionSim™ (Kynectiv, Inc., Chadsford, PA), a dynamic virtual patient platform, was used to implement an interactive patient case to augment pain management material presented during a didactic session in a pharmacotherapy course. Simulation performance data were collected and analyzed. Student exam performance on pain management questions was compared to student exam performance on nearly identical questions from a prior year when a paper-based case was used instead of virtual patient technology. Students who performed well on the virtual patient case performed better on exam questions related to patient assessment (p = 0.0244), primary pharmacological therapy (p = 0.0001), and additional pharmacological therapy (p = 0.0001). Overall exam performance did not differ between the two groups. However, students with exposure to the virtual patient case demonstrated significantly better performance on higher level Bloom's Taxonomy questions that required them to create pharmacotherapy regimens (p=0.0005). Students in the previous year (exposed only to a paper patient case) performed better in calculating conversions of opioids for patients (p = 0.0001). Virtual patient technology may enhance student performance on high-level Bloom's Taxonomy examination questions. This study adds to the current literature demonstrating the value of virtual patient technology as an active-learning strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Setting up virtual private network

International Nuclear Information System (INIS)

Huang Hongmei; Zhang Chengjun

2003-01-01

Setting up virtual private network for business enterprise provides a low cost network foundation, increases enterprise's network function and enlarges its private scope. The text introduces virtual private network's principal, privileges and protocols that use in virtual private network. At last, this paper introduces several setting up virtual private network's technologies which based on LAN

Setting up virtual private network

International Nuclear Information System (INIS)

Huang Hongmei; Zhang Chengjun

2003-01-01

Setting up virtual private network for business enterprise provides a low cost network foundation, increases enterprise network function and enlarges its private scope. This text introduces virtual private network principal, privileges and protocols applied in virtual private network. At last, this paper introduces several setting up virtual private network technologies which is based on LAN

Exploiting the ALICE HLT for PROOF by scheduling of Virtual Machines

International Nuclear Information System (INIS)

Meoni, Marco; Boettger, Stefan; Zelnicek, Pierre; Kebschull, Udo; Lindenstruth, Volker

2011-01-01

The HLT (High-Level Trigger) group of the ALICE experiment at the LHC has prepared a virtual Parallel ROOT Facility (PROOF) enabled cluster (HAF - HLT Analysis Facility) for fast physics analysis, detector calibration and reconstruction of data samples. The HLT-Cluster currently consists of 2860 CPU cores and 175TB of storage. Its purpose is the online filtering of the relevant part of data produced by the particle detector. However, data taking is not running continuously and exploiting unused cluster resources for other applications is highly desirable and improves the usage-cost ratio of the HLT cluster. As such, unused computing resources are dedicated to a PROOF-enabled virtual cluster available to the entire collaboration. This setup is especially aimed at the prototyping phase of analyses that need a high number of development iterations and a short response time, e.g. tuning of analysis cuts, calibration and alignment. HAF machines are enabled and disabled upon user request to start or complete analysis tasks. This is achieved by a virtual machine scheduling framework which dynamically assigns and migrates virtual machines running PROOF workers to unused physical resources. Using this approach we extend the HLT usage scheme to running both online and offline computing, thereby optimizing the resource usage.

Virtual reality hardware and graphic display options for brain-machine interfaces.

Science.gov (United States)

Marathe, Amar R; Carey, Holle L; Taylor, Dawn M

2008-01-15

Virtual reality hardware and graphic displays are reviewed here as a development environment for brain-machine interfaces (BMIs). Two desktop stereoscopic monitors and one 2D monitor were compared in a visual depth discrimination task and in a 3D target-matching task where able-bodied individuals used actual hand movements to match a virtual hand to different target hands. Three graphic representations of the hand were compared: a plain sphere, a sphere attached to the fingertip of a realistic hand and arm, and a stylized pacman-like hand. Several subjects had great difficulty using either stereo monitor for depth perception when perspective size cues were removed. A mismatch in stereo and size cues generated inappropriate depth illusions. This phenomenon has implications for choosing target and virtual hand sizes in BMI experiments. Target-matching accuracy was about as good with the 2D monitor as with either 3D monitor. However, users achieved this accuracy by exploring the boundaries of the hand in the target with carefully controlled movements. This method of determining relative depth may not be possible in BMI experiments if movement control is more limited. Intuitive depth cues, such as including a virtual arm, can significantly improve depth perception accuracy with or without stereo viewing.

Virtuality and Reality in Science

International Nuclear Information System (INIS)

Cohen-Tannoudji, G.

1995-01-01

This book compiles eight contributions devoted to the topical question about the relation between virtuality and reality. In the theoretical frame of quantum and relativistic particle physics, the concept of virtuality is used according to its strict and precise meaning. In this context, particles are generally invented before their discovery. Some famous historical experiments which led to the postulation and then the discovery of new particles are mentioned. These examples are used to illustrate and to discuss the concept of virtuality as well as the physical reality of virtual processes. But, how can the concept of virtuality in other scientific fields be applied ? In order to answer this question, the concepts of virtuality and reality are discussed in other branches of physics as well as in other fields such as geophysics, cosmology and biology. Philosophical and sociological implications of virtual realities are also considered. Moreover, in relation to virtuality and reality, the connections between modeling, simulation and experimentation, their respective roles, the advantages and risks of their use are discussed (in relation to nuclear sciences and geophysical problems) (N.T.)

Comparative study of the effectiveness of three learning environments: Hyper-realistic virtual simulations, traditional schematic simulations and traditional laboratory

Directory of Open Access Journals (Sweden)

Maria Isabel Suero

2011-10-01

Full Text Available This study compared the educational effects of computer simulations developed in a hyper-realistic virtual environment with the educational effects of either traditional schematic simulations or a traditional optics laboratory. The virtual environment was constructed on the basis of Java applets complemented with a photorealistic visual output. This new virtual environment concept, which we call hyper-realistic, transcends basic schematic simulation; it provides the user with a more realistic perception of a physical phenomenon being simulated. We compared the learning achievements of three equivalent, homogeneous groups of undergraduates—an experimental group who used only the hyper-realistic virtual laboratory, a first control group who used a schematic simulation, and a second control group who used the traditional laboratory. The three groups received the same theoretical preparation and carried out equivalent practicals in their respective learning environments. The topic chosen for the experiment was optical aberrations. An analysis of variance applied to the data of the study demonstrated a statistically significant difference (p value <0.05 between the three groups. The learning achievements attained by the group using the hyper-realistic virtual environment were 6.1 percentage points higher than those for the group using the traditional schematic simulations and 9.5 percentage points higher than those for the group using the traditional laboratory.

Optimizing Virtual Network Functions Placement in Virtual Data Center Infrastructure Using Machine Learning

Science.gov (United States)

Bolodurina, I. P.; Parfenov, D. I.

2018-01-01

We have elaborated a neural network model of virtual network flow identification based on the statistical properties of flows circulating in the network of the data center and characteristics that describe the content of packets transmitted through network objects. This enabled us to establish the optimal set of attributes to identify virtual network functions. We have established an algorithm for optimizing the placement of virtual data functions using the data obtained in our research. Our approach uses a hybrid method of visualization using virtual machines and containers, which enables to reduce the infrastructure load and the response time in the network of the virtual data center. The algorithmic solution is based on neural networks, which enables to scale it at any number of the network function copies.

Incorporating Virtually Immersive Environments as a Collaborative Medium for Virtual Teaming

Directory of Open Access Journals (Sweden)

Charles J. Lesko, Jr.

2012-08-01

Full Text Available Virtually immersive environments incorporate the use of various computer modelling and simulation techniques enabling geographically dispersed virtual project teams to interact within an artificially projected three-dimensional space online. This study focused on adoption of virtually immersive technologies as a collaborative media to support virtual teaming of both graduate and undergraduate-level project management students. The data and information from this study has implications for educators using virtually immersive environments in the classroom. In this study, we specifically evaluated two key components in this paper: 1 students’ level of trust and; 2 students’ willingness to use the technology, along with their belief about the virtual environment’s ability to extend and improve knowledge sharing in their team work environment. We learned that while students did find the environment a positive add on for working collaboratively, there were students who were neither more nor less likely to use the technology for future collaborative ventures. Most of the students who were not very positive about the environment were “fence sitters” likely indicating needs related to additional training to improve communication skills. Finally, based on the full study results we have provided basic recommendations designed to support team trust building in the system along with interpersonal trust building to facilitate knowledge transfer and better strategic us of the technology.

Virtual Teaming and Collaboration Technology: A Study of Influences on Virtual Project Outcomes

Science.gov (United States)

Broils, Gary C.

2014-01-01

The purpose of this quantitative correlational study was to explore the relationships between the independent variables, contextual factors for virtual teams and collaboration technology, and the dependent variable, virtual project outcomes. The problem leading to the need for the study is a lower success rate for virtual projects compared to…

Characterizing first and third person viewpoints and their alternation for embodied interaction in virtual reality.

Science.gov (United States)

Galvan Debarba, Henrique; Bovet, Sidney; Salomon, Roy; Blanke, Olaf; Herbelin, Bruno; Boulic, Ronan

2017-01-01

Empirical research on the bodily self has shown that the body representation is malleable, and prone to manipulation when conflicting sensory stimuli are presented. Using Virtual Reality (VR) we assessed the effects of manipulating multisensory feedback (full body control and visuo-tactile congruence) and visual perspective (first and third person perspective) on the sense of embodying a virtual body that was exposed to a virtual threat. We also investigated how subjects behave when the possibility of alternating between first and third person perspective at will was presented. Our results support that illusory ownership of a virtual body can be achieved in both first and third person perspectives under congruent visuo-motor-tactile condition. However, subjective body ownership and reaction to threat were generally stronger for first person perspective and alternating condition than for third person perspective. This suggests that the possibility of alternating perspective is compatible with a strong sense of embodiment, which is meaningful for the design of new embodied VR experiences.

Monitoring and Control by Virtual Tools of an Educational Renewable Energy System

Directory of Open Access Journals (Sweden)

Gligor Adrian

2009-12-01

Full Text Available The scope of the present paper is to present the architecture and design of an effective tool useful for monitoring, maintenance and training of specialists in the field of photovoltaic renewable energy Among renewable energy resources, solar energy represents an easy to use, accessible and green source of energy. An important goal is the efficient use of solar energy which can only be achieved by the knowledge of solar datum and equipment characteristics from a studied area. Based on this idea, the paper presents a concept of virtual tools developed on web technologies and virtual instrumentation for monitoring and control of solar renewable energy. These tools are mainly designed as a base for a virtual laboratory that can be used for the study of photovoltaic and thermal solar energy parameters, representing, by didactical point of view, a handful way for students to study the phenomenology and also a training tool for specialists in the field of solar photovoltaic energy.

Interpretations of virtual reality.

Science.gov (United States)

Voiskounsky, Alexander

2011-01-01

University students were surveyed to learn what they know about virtual realities. The two studies were administered with a half-year interval in which the students (N=90, specializing either in mathematics and science, or in social science and humanities) were asked to name particular examples of virtual realities. The second, but not the first study, was administered after the participants had the chance to see the movie "Avatar" (no investigation was held into whether they really saw it). While the students in both studies widely believed that activities such as social networking and online gaming represent virtual realities, some other examples provided by the students in the two studies differ: in the second study the participants expressed a better understanding of the items related to virtual realities. At the same time, not a single participant reported particular psychological states (either regular or altered) as examples of virtual realities. Profound popularization efforts need to be done to acquaint the public, including college students, with virtual realities and let the public adequately understand how such systems work.

Avoiding radiation exposure while training to locate a radioactive source: a virtual reality exercise

International Nuclear Information System (INIS)

Marins, E.R.; Cotelli do Espírito Santo, A.; Abreu Mól, A. C. de; Cunha, G.; Landau, L.

2015-01-01

A technician undergoing radioprotection training must learn to use radiation detectors. Practical exercises involve being near to radiation sources. The work here presented reduces the exposure to individuals using a virtual environment to achieve preliminary apprenticeship prior using real radioactive sources. (authors)

Virtual Dance and Motion-Capture

Directory of Open Access Journals (Sweden)

Marc Boucher

2011-01-01

Full Text Available A general view of various ways in which virtual dance can be understood is presented in the first part of this article. It then appraises the uses of the term “virtual” in previous studies of digital dance. A more in-depth view of virtual dance as it relates to motion-capture is offered, and key issues are discussed regarding computer animation, digital imaging, motion signature, virtual reality and interactivity. The paper proposes that some forms of virtual dance be defined in relation to both digital technologies and contemporary theories of virtuality.

Developing Simulated Cyber Attack Scenarios Against Virtualized Adversary Networks

Science.gov (United States)

2017-03-01

enclave, as shown in Figure 11, is a common design for many secure networks. Different variations of a cyber-attack scenario can be rehearsed based...achieved a greater degree of success against multiple variations of an enemy network. E. ATTACK TYPES A primary goal of this thesis is to define and...2013. [33] R. Goldberg , “Architectural principles for virtual computer systems,” Ph.D. dissertation, Dept. of Comp. Sci., Harvard Univ., Cambridge

Sense of presence and anxiety during virtual social interactions between a human and virtual humans.

Science.gov (United States)

Morina, Nexhmedin; Brinkman, Willem-Paul; Hartanto, Dwi; Emmelkamp, Paul M G

2014-01-01

Virtual reality exposure therapy (VRET) has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using different virtual reality displays. A non-clinical sample of 38 participants was randomly assigned to either a head-mounted display (HMD) with motion tracker and sterescopic view condition or a one-screen projection-based virtual reality display condition. Participants in both conditions engaged in free speech dialogues with virtual humans controlled by research assistants. It was hypothesized that exposure to virtual social interactions will elicit moderate levels of sense of presence and anxiety in both groups. Further it was expected that participants in the HMD condition will report higher scores of sense of presence and anxiety than participants in the one-screen projection-based display condition. Results revealed that in both conditions virtual social interactions were associated with moderate levels of sense of presence and anxiety. Additionally, participants in the HMD condition reported significantly higher levels of presence than those in the one-screen projection-based display condition (p = .001). However, contrary to the expectations neither the average level of anxiety nor the highest level of anxiety during exposure to social virtual environments differed between the groups (p = .97 and p = .75, respectively). The findings suggest that virtual social interactions can be successfully applied in VRET to enhance sense of presence and anxiety. Furthermore, our results indicate that one-screen projection-based displays can successfully activate levels of anxiety in

Sense of presence and anxiety during virtual social interactions between a human and virtual humans

Directory of Open Access Journals (Sweden)

Nexhmedin Morina

2014-04-01

Full Text Available Virtual reality exposure therapy (VRET has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using different virtual reality displays. A non-clinical sample of 38 participants was randomly assigned to either a head-mounted display (HMD with motion tracker and sterescopic view condition or a one-screen projection-based virtual reality display condition. Participants in both conditions engaged in free speech dialogues with virtual humans controlled by research assistants. It was hypothesized that exposure to virtual social interactions will elicit moderate levels of sense of presence and anxiety in both groups. Further it was expected that participants in the HMD condition will report higher scores of sense of presence and anxiety than participants in the one-screen projection-based display condition. Results revealed that in both conditions virtual social interactions were associated with moderate levels of sense of presence and anxiety. Additionally, participants in the HMD condition reported significantly higher levels of presence than those in the one-screen projection-based display condition (p = .001. However, contrary to the expectations neither the average level of anxiety nor the highest level of anxiety during exposure to social virtual environments differed between the groups (p = .97 and p = .75, respectively. The findings suggest that virtual social interactions can be successfully applied in VRET to enhance sense of presence and anxiety. Furthermore, our results indicate that one-screen projection-based displays can successfully activate levels

Innovation and Virtual Environments: Towards Virtual Knowledge Brokers

OpenAIRE

VERONA G; PRANDELLI E.; SAWHNEY M.

2006-01-01

The authors examine the implications of virtual customer environments for supporting the innovation process. By building on the literature of knowledge brokers, they introduce the concept of virtual knowledge brokers — actors who leverage the internet to support third parties’ innovation activities. These actors enable firms to extend their reach in engaging with customers and they also allow firms to have a richer dialogue with customers because of their perceived neutrality. Consequently...

Virtual Pediatric Hospital

Science.gov (United States)

... Thoracopaedia - An Imaging Encyclopedia of Pediatric Thoracic Disease Virtual Pediatric Hospital is the Apprentice's Assistant™ Last revised ... pediatric resources: GeneralPediatrics.com | PediatricEducation.org | SearchingPediatrics.com Virtual Pediatric Hospital is curated by Donna M. D' ...

Virtual Surgical Planning for Correction of Delayed Presentation Scaphocephaly Using a Modified Melbourne Technique.

Science.gov (United States)

Macmillan, Alexandra; Lopez, Joseph; Mundinger, Gerhard S; Major, Melanie; Medina, Miguel A; Dorafshar, Amir H

2018-02-23

Late treatment of scaphocephaly presents challenges including need for more complex surgery to achieve desired head shape. Virtual surgical planning for total vault reconstruction may mitigate some of these challenges, but has not been studied in this unique and complex clinical setting. A retrospective chart review was conducted for patients with scaphocephaly who presented to our institution between 2000 and 2014. Patients presenting aged 12 months or older who underwent virtual surgical planning-assisted cranial vault reconstruction were included. Patient demographic, intraoperative data, and postoperative outcomes were recorded. Pre- and postoperative anthropometric measurements were obtained to document the fronto-occipital (FO) and biparietal (BP) distance and calculate cephalic index (CI). Virtual surgical planning predicted, and actual postoperative anthropometric measurements were compared. Five patients were identified who fulfilled inclusion criteria. The mean age was 50.6 months. One patient demonstrated signs of elevated intracranial pressure preoperatively. Postoperatively, all but one needed no revisional surgery (Whitaker score of 1). No patient demonstrated postoperative evidence of bony defects, bossing, or suture restenosis. The mean preoperative, simulated, and actual postoperative FO length was 190.3, 182, and 184.3 mm, respectively. The mean preoperative, simulated, and actual postoperative BP length was 129, 130.7, and 131 mm, respectively. The mean preoperative, simulated, and actual postoperative CI was 66, 72, and 71.3, respectively. Based on our early experience, virtual surgical planning using a modified Melbourne technique for total vault remodeling achieves good results in the management of late presenting scaphocephaly.

Virtual Project Teams

DEFF Research Database (Denmark)

Bjørn, Pernille

technology in six real-life virtual teams, two in industry and four in education, applying interpretative research and action research methods. Two main lines of investigation are pursued: the first involves an examination of the organisational issues related to groupware adaptation in virtual project teams......, professional disciplines, time differences and technology. This thesis comprises a general introduction, referred to as the summary report, and seven research papers, which deal in detail with the results and findings of the empirical cases. The summary report provides a general introduction to the research......, while the second looks at the social context and practices of virtual project teams. Two of the key findings are 1) that the process of groupware adaptation by virtual project teams can be viewed as a process of expanding and aligning the technological frames of the participants, which includes mutual...

A Low-Cost Immersive Virtual Reality System for Teaching Robotic Manipulators Programming

Directory of Open Access Journals (Sweden)

Vicente Román-Ibáñez

2018-04-01

Full Text Available Laboratory tasks are a powerful pedagogical strategy for developing competences in science and engineering degrees, making students understand in a practical way the theoretical topics explained in the classroom. However, performing experiments in real conditions is usually expensive in terms of time, money and energy, as it requires expensive infrastructures that are generally difficult to maintain in good conditions. To overcome this problem, virtual reality has proven to be a powerful tool to achieve sustainability, making it easy to update laboratories without the need to acquire new equipment. Moreover, the ability to introduce practical knowledge into classrooms without leaving them, makes virtual laboratories capable of simulating typical operating environments as well as extreme situations in the operation of different devices. A typical subject in which students can benefit from the use of virtual laboratories is robotics. In this work we will develop an immersive virtual reality (VR pedagogical simulator of industrial robotic arms for engineering students. With the proposed system, students will know the effects of their own designed trajectories on several different robotic arms and cell environments without having to buy all of them and being safe of damaging the cell components. The simulation will be checking for collisions of the elements in the scene and alert the student when they happen. This can be achieved with a robotic simulator, but the integration with immersive VR is intended to help students better understand robotics. Moreover, even having a real robotic arm available for students, with this proposed VR method, all the students have the opportunity to manage and learn his own version of the robotic cell, without waiting times generated by having less robotic arms than students in classroom.

Using Virtual Pets to Promote Physical Activity in Children: An Application of the Youth Physical Activity Promotion Model.

Science.gov (United States)

Ahn, Sun Joo Grace; Johnsen, Kyle; Robertson, Tom; Moore, James; Brown, Scott; Marable, Amanda; Basu, Aryabrata

2015-01-01

A virtual pet was developed based on the framework of the youth physical activity promotion model and tested as a vehicle for promoting physical activity in children. Children in the treatment group interacted with the virtual pet for three days, setting physical activity goals and teaching tricks to the virtual pet when their goals were met. The virtual pet became more fit and learned more sophisticated tricks as the children achieved activity goals. Children in the control group interacted with a computer system presenting equivalent features but without the virtual pet. Physical activity and goal attainment were evaluated using activity monitors. Results indicated that children in the treatment group engaged in 1.09 more hours of daily physical activity (156% more) than did those in the control group. Physical activity self-efficacy and beliefs served as mediators driving this increase in activity. Children that interacted with the virtual pet also expressed higher intentions than children in the control group to continue physical activity in the future. Theoretical and practical potentials of using a virtual pet to systematically promote physical activity in children are discussed.

Virtual Exploration of Earth's Evolution

Science.gov (United States)

Anbar, A. D.; Bruce, G.; Semken, S. C.; Summons, R. E.; Buxner, S.; Horodyskyj, L.; Kotrc, B.; Swann, J.; Klug Boonstra, S. L.; Oliver, C.

2014-12-01

Traditional introductory STEM courses often reinforce misconceptions because the large scale of many classes forces a structured, lecture-centric model of teaching that emphasizes delivery of facts rather than exploration, inquiry, and scientific reasoning. This problem is especially acute in teaching about the co-evolution of Earth and life, where classroom learning and textbook teaching are far removed from the immersive and affective aspects of field-based science, and where the challenges of taking large numbers of students into the field make it difficult to expose them to the complex context of the geologic record. We are exploring the potential of digital technologies and online delivery to address this challenge, using immersive and engaging virtual environments that are more like games than like lectures, grounded in active learning, and deliverable at scale via the internet. The goal is to invert the traditional lecture-centric paradigm by placing lectures at the periphery and inquiry-driven, integrative virtual investigations at the center, and to do so at scale. To this end, we are applying a technology platform we devised, supported by NASA and the NSF, that integrates a variety of digital media in a format that we call an immersive virtual field trip (iVFT). In iVFTs, students engage directly with virtual representations of real field sites, with which they interact non-linearly at a variety of scales via game-like exploration while guided by an adaptive tutoring system. This platform has already been used to develop pilot iVFTs useful in teaching anthropology, archeology, ecology, and geoscience. With support the Howard Hughes Medical Institute, we are now developing and evaluating a coherent suite of ~ 12 iVFTs that span the sweep of life's history on Earth, from the 3.8 Ga metasediments of West Greenland to ancient hominid sites in East Africa. These iVFTs will teach fundamental principles of geology and practices of scientific inquiry, and expose

Using Avatars and Virtual Environments in Learning: What Do They Have to Offer?

Science.gov (United States)

Falloon, Garry

2010-01-01

This paper explores and discusses arguments for the use of virtual environments and interactive avatars in supporting the achievement of student learning goals within conventional educational contexts. It describes and evaluates arguments promoted by some authors (eg, van den Brekel, 2007; Deuchar & Nodder, 2003; Dickey, 2003; Facer, 2004; de…

Technology in the Aid of Delivering Economic Content to Teachers: Virtual Economics v. 3

OpenAIRE

John R. Swinton; Benjamin Scafidi

2012-01-01

We examine the impact on student achievement of a face-to-face teacher workshop that also provides economics instructors with access to an electronic library of instructional and reference material for their economics classroom—Virtual Economics v. 3 (VE3), offered by the Council for Economic Education. Based on evidence using student and teacher-level administrative data from the Georgia Department of Education and controlling for students’ prior achievement in mathematics, we find evidence ...

Exploring Virtual Reality for Classroom Use: The Virtual Reality and Education Lab at East Carolina University.

Science.gov (United States)

Auld, Lawrence W. S.; Pantelidis, Veronica S.

1994-01-01

Describes the Virtual Reality and Education Lab (VREL) established at East Carolina University to study the implications of virtual reality for elementary and secondary education. Highlights include virtual reality software evaluation; hardware evaluation; computer-based curriculum objectives which could use virtual reality; and keeping current…

Virtual Machine Logbook - Enabling virtualization for ATLAS

International Nuclear Information System (INIS)

Yao Yushu; Calafiura, Paolo; Leggett, Charles; Poffet, Julien; Cavalli, Andrea; Frederic, Bapst

2010-01-01

ATLAS software has been developed mostly on CERN linux cluster lxplus or on similar facilities at the experiment Tier 1 centers. The fast rise of virtualization technology has the potential to change this model, turning every laptop or desktop into an ATLAS analysis platform. In the context of the CernVM project we are developing a suite of tools and CernVM plug-in extensions to promote the use of virtualization for ATLAS analysis and software development. The Virtual Machine Logbook (VML), in particular, is an application to organize work of physicists on multiple projects, logging their progress, and speeding up ''context switches'' from one project to another. An important feature of VML is the ability to share with a single 'click' the status of a given project with other colleagues. VML builds upon the save and restore capabilities of mainstream virtualization software like VMware, and provides a technology-independent client interface to them. A lot of emphasis in the design and implementation has gone into optimizing the save and restore process to makepractical to store many VML entries on a typical laptop disk or to share a VML entry over the network. At the same time, taking advantage of CernVM's plugin capabilities, we are extending the CernVM platform to help increase the usability of ATLAS software. For example, we added the ability to start the ATLAS event display on any computer running CernVM simply by clicking a button in a web browser. We want to integrate seamlessly VML with CernVM unique file system design to distribute efficiently ATLAS software on every physicist computer. The CernVM File System (CVMFS) download files on-demand via HTTP, and cache it locally for future use. This reduces by one order of magnitude the download sizes, making practical for a developer to work with multiple software releases on a virtual machine.

Virtual Seminar Room

DEFF Research Database (Denmark)

Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

1999-01-01

The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

A Virtual Commissioning Learning Platform

DEFF Research Database (Denmark)

Mortensen, Steffen; Madsen, Ole

2018-01-01

The introduction of reconfigurable manufacturing systems (RMS), Industry 4.0 and the associated technologies requires the establishment of new competencies. Towards that goal, Aalborg University (AAU) has developed an Industry 4.0 learning factory, the AAU Smart Production Lab. The AAU Smart...... Production Lab integrates a number of Industry 4.0 technologies for learning and research purposes. One of the many techniques is virtual commissioning. Virtual commissioning uses a virtual plant model and real controllers (PLCs) enabling a full emulation of the manufacturing system for verification. Virtual...... commissioning can lower the commissioning time up to 63%, allowing faster time to market. However, virtual commission is still missing industrial impact one of the reasons being lack of competencies and integration experiences. The paper presents the setup of the virtual commissioning learning platform...

Virtual toolbox

Science.gov (United States)

Jacobus, Charles J.; Jacobus, Heidi N.; Mitchell, Brian T.; Riggs, A. J.; Taylor, Mark J.

1993-04-01

At least three of the five senses must be fully addressed in a successful virtual reality (VR) system. Sight, sound, and touch are the most critical elements for the creation of the illusion of presence. Since humans depend so much on sight to collect information about their environment, this area has been the focus of much of the prior art in virtual reality, however, it is also crucial that we provide facilities for force, torque, and touch reflection, and sound replay and 3-D localization. In this paper we present a sampling of hardware and software in the virtual environment maker's `toolbox' which can support rapidly building up of customized VR systems. We provide demonstrative examples of how some of the tools work and we speculate about VR applications and future technology needs.

A Virtual History of Mauritius

African Journals Online (AJOL)

admpather

University of Mauritius, Réduit, Mauritius. 116. A Virtual History ... out will be presented. Keywords: Virtual Heritage, Virtual Reality, Archaeology, Mauritius ... money would better be spent on other major education and IT development projects ...

Effects of VIrtualIty on Employee Performance and CommItment: A Research

OpenAIRE

Baysal, Zeynep; Baraz, Barış

2017-01-01

In the modern business world, due to the impact of technological advancements and globalisation,organisations are obliged to keep up with the change in order to seize new opportunities they encounterand overcome the obstacles in their way. Concepts of virtuality and virtual organisations are amongthese concepts which surfaced as a result of these changes. All white-collar employees have a certaindegree of virtuality and the fact that organisations are taking rapid steps towards virtualisation...

A model for the development of virtual communities for people with long-term, severe physical disabilities

Directory of Open Access Journals (Sweden)

C.M. Tilley

2006-01-01

Full Text Available Introduction. This paper reports results of an investigation into the needs of persons with disabilities wanting to participate in the use of virtual communities. The aim was to investigate 'how virtual communities for persons with long-term, severe physical disabilities can best be facilitated'? Method. A Grounded Theory approach was adopted to inform the investigation. In- depth interviews were conducted with twelve persons with paraplegia, quadriplegia or other severe, long-term physical or mobility disabilities and six health care professionals, service providers, information personnel and policy advisers who were involved in their well-being. Analysis. Rich explanations were derived about the information and communication technology (ICT usage and the technologies' contributions towards restoration of sense of control over their lives. Results. The primary outcome of the investigation is a theory regarding the character of virtual communities for the disabled. The theory is represented as a Virtual Community Model. The model identifies: the need for 'a sense of control' as the foundation element of virtual communities for the disabled; the key domains in which disabled people participate in virtual communities; and the barriers and enablers to their participation. Conclusion. The model provides a framework which can be used by interest groups and other organizations to facilitate the development of virtual communities for persons with severe physical disabilities. The six key types of community need to be represented in such virtual communities if a full 'sense of control' is to be achieved by disabled persons.

Virtual reality for employability skills

OpenAIRE

Minocha, Shailey; Tudor, Ana-Despina

2017-01-01

We showed a variety of virtual reality technologies, and through examples, we discussed how virtual reality technology is transforming work styles and workplaces. Virtual reality is becoming pervasive in almost all domains starting from arts, environmental causes to medical education and disaster management training, and to supporting patients with Dementia. Thus, an awareness of the virtual reality technology and its integration in curriculum design will provide and enhance employability ski...

Comparing 3-dimensional virtual methods for reconstruction in craniomaxillofacial surgery.

Science.gov (United States)

Benazzi, Stefano; Senck, Sascha

2011-04-01

In the present project, the virtual reconstruction of digital osteomized zygomatic bones was simulated using different methods. A total of 15 skulls were scanned using computed tomography, and a virtual osteotomy of the left zygomatic bone was performed. Next, virtual reconstructions of the missing part using mirror imaging (with and without best fit registration) and thin plate spline interpolation functions were compared with the original left zygomatic bone. In general, reconstructions using thin plate spline warping showed better results than the mirroring approaches. Nevertheless, when dealing with skulls characterized by a low degree of asymmetry, mirror imaging and subsequent registration can be considered a valid and easy solution for zygomatic bone reconstruction. The mirroring tool is one of the possible alternatives in reconstruction, but it might not always be the optimal solution (ie, when the hemifaces are asymmetrical). In the present pilot study, we have verified that best fit registration of the mirrored unaffected hemiface and thin plate spline warping achieved better results in terms of fitting accuracy, overcoming the evident limits of the mirroring approach. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Finite Element Methods for real-time Haptic Feedback of Soft-Tissue Models in Virtual Reality Simulators

Science.gov (United States)

Frank, Andreas O.; Twombly, I. Alexander; Barth, Timothy J.; Smith, Jeffrey D.; Dalton, Bonnie P. (Technical Monitor)

2001-01-01

We have applied the linear elastic finite element method to compute haptic force feedback and domain deformations of soft tissue models for use in virtual reality simulators. Our results show that, for virtual object models of high-resolution 3D data (>10,000 nodes), haptic real time computations (>500 Hz) are not currently possible using traditional methods. Current research efforts are focused in the following areas: 1) efficient implementation of fully adaptive multi-resolution methods and 2) multi-resolution methods with specialized basis functions to capture the singularity at the haptic interface (point loading). To achieve real time computations, we propose parallel processing of a Jacobi preconditioned conjugate gradient method applied to a reduced system of equations resulting from surface domain decomposition. This can effectively be achieved using reconfigurable computing systems such as field programmable gate arrays (FPGA), thereby providing a flexible solution that allows for new FPGA implementations as improved algorithms become available. The resulting soft tissue simulation system would meet NASA Virtual Glovebox requirements and, at the same time, provide a generalized simulation engine for any immersive environment application, such as biomedical/surgical procedures or interactive scientific applications.

Integrating virtual manipulative with the use of iPad in the teaching and learning of fractions

Directory of Open Access Journals (Sweden)

Hajah Nadzirah Fatin Mohammad Malik Finti

2016-12-01

Full Text Available Several reports have suggested that students have difficulties in understanding the concepts of fraction, particularly on fraction equivalence and addition of fractions that involved unlike denominators. It is envisaged that the implementation of Virtual Manipulative using iPad would enhance students’ conceptual understanding. The purpose of this study is to examine the effectiveness of Virtual Manipulative with the use of iPads in teaching equivalence and addition of fractions. The target groups were two Year 7 classes in one of the secondary schools in Brunei, one class comprising high-achieving students, while the other consist of low-achieving students. An action research design that included quantitative and qualitative data analyses was conducted. The findings revealed that the implementation of Virtual Manipulative using iPad has significant effect on students’ performance in-group activities, and it has significant effect for students with low abilities. The study also revealed that students’ motivation to learn fractions increased as they found the use of iPads to be fun and interesting. However, the results also revealed that the use of iPads as a teaching tool appeared to be challenging for teachers.

Scheme for achieving coherent perfect absorption by anisotropic metamaterials

KAUST Repository

Zhang, Xiujuan; Wu, Ying

2017-01-01

in conjunction with retrieval method to determine practical metamaterial absorbers. The scheme is scalable to frequencies and applicable to various incident angles. Numerical simulations show that perfect absorption is achieved in the designed absorbers over a

Virtual Campus Hub technology

DEFF Research Database (Denmark)

Vercoulen, Frank; Badger, Merete; Monaco, Lucio

This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

Real and virtual radiation

International Nuclear Information System (INIS)

Wolynec, E.

1988-01-01

Electrodisintegration cross sections related to the corresponding photonuclear process through virtual-photon spectra. A brief review of virtual-photon theory is presented. Calculations of DWBA virtual-photon spectra for finite nuclei are compared with experimental results. The multipole decomposition of electrodisintegration cross sections using these spectra is discussed and several experimental results are presented. A brief review for the bremsstrahlung cross section is also presented. (author) [pt

Virtual reality: A new track in psychological research.

Science.gov (United States)

de la Rosa, Stephan; Breidt, Martin

2018-05-10

One major challenge of social interaction research is to achieve high experimental control over social interactions to allow for rigorous scientific reasoning. Virtual reality (VR) promises this level of control. Pan and Hamilton guide us with a detailed review on existing and future possibilities and challenges of using VR for social interaction research. Here, we extend the discussion to methodological and practical implications when using VR. © 2018 The Authors. British Journal of Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Traditional microscopy instruction versus process-oriented virtual microscopy instruction: a naturalistic experiment with control group.

Science.gov (United States)

Helle, Laura; Nivala, Markus; Kronqvist, Pauliina; Gegenfurtner, Andreas; Björk, Pasi; Säljö, Roger

2011-03-30

Virtual microscopy is being introduced in medical education as an approach for learning how to interpret information in microscopic specimens. It is, however, far from evident how to incorporate its use into existing teaching practice. The aim of the study was to explore the consequences of introducing virtual microscopy tasks into an undergraduate pathology course in an attempt to render the instruction more process-oriented. The research questions were: 1) How is virtual microscopy perceived by students? 2) Does work on virtual microscopy tasks contribute to improvement in performance in microscopic pathology in comparison with attending assistant-led demonstrations only? During a one-week period, an experimental group completed three sets of virtual microscopy homework assignments in addition to attending demonstrations. A control group attended the demonstrations only. Performance in microscopic pathology was measured by a pre-test and a post-test. Student perceptions of regular instruction and virtual microscopy were collected one month later by administering the Inventory of Intrinsic Motivation and open-ended questions. The students voiced an appreciation for virtual microscopy for the purposes of the course and for self-study. As for learning gains, the results indicated that learning was speeded up in a subgroup of students consisting of conscientious high achievers. The enriched instruction model may be suited as such for elective courses following the basic course. However, the instructional model needs further development to be suited for basic courses.

Interreality in practice: bridging virtual and real worlds in the treatment of posttraumatic stress disorders.

Science.gov (United States)

Riva, Giuseppe; Raspelli, Simona; Algeri, Davide; Pallavicini, Federica; Gorini, Alessandra; Wiederhold, Brenda K; Gaggioli, Andrea

2010-02-01

The use of new technologies, particularly virtual reality, is not new in the treatment of posttraumatic stress disorders (PTSD): VR is used to facilitate the activation of the traumatic event during exposure therapy. However, during the therapy, VR is a new and distinct realm, separate from the emotions and behaviors experienced by the patient in the real world: the behavior of the patient in VR has no direct effects on the real-life experience; the emotions and problems experienced by the patient in the real world are not directly addressed in the VR exposure. In this article, we suggest that the use of a new technological paradigm, Interreality, may improve the clinical outcome of PTSD. The main feature of Interreality is a twofold link between the virtual and real worlds: (a) behavior in the physical world influences the experience in the virtual one; (b) behavior in the virtual world influences the experience in the real one. This is achieved through 3D shared virtual worlds; biosensors and activity sensors (from the real to the virtual world); and personal digital assistants and/or mobile phones (from the virtual world to the real one). We describe different technologies that are involved in the Interreality vision and its clinical rationale. To illustrate the concept of Interreality in practice, a clinical scenario is also presented and discussed: Rosa, a 55-year-old nurse, involved in a major car accident.

The use of strain gauge platform and virtual reality tool for patient stability examination

Science.gov (United States)

Walendziuk, Wojciech; Wysk, Lukasz; Skoczylas, Marcin

2016-09-01

Virtual reality is one of the fastest growing information technologies. This paper is only a prelude to a larger study on the use of virtual reality tools in analysing bony labyrinth and sense of balance. Problems with the functioning of these areas of the body are a controversial topic in debate among specialists. The result of still unresolved imbalance treatments is a constant number of people reporting this type of ailment. Considering above, authors created a system and application that contains a model of virtual environment, and a tool for the modification of the obstacles in 3D space. Preliminary studies of patients from a test group aged 22-49 years were also carried out, in which behaviour and sense of balance in relation to the horizontal curvature of the virtual world around patient has been analysed. Experiments carried out on a test group showed that the shape of the curve and the virtual world space and age of patient has a major impact on a sense of balance. The data obtained can be linked with actual disorders of bony labyrinth and human behaviour at the time of their occurrence. Another important achievement that will be the subject of further work is possible use a modified version of the software for rehabilitation purposes.

Evaluating the Effects of Immersive Embodied Interaction on Cognition in Virtual Reality

Science.gov (United States)

Parmar, Dhaval

Virtual reality is on its advent of becoming mainstream household technology, as technologies such as head-mounted displays, trackers, and interaction devices are becoming affordable and easily available. Virtual reality (VR) has immense potential in enhancing the fields of education and training, and its power can be used to spark interest and enthusiasm among learners. It is, therefore, imperative to evaluate the risks and benefits that immersive virtual reality poses to the field of education. Research suggests that learning is an embodied process. Learning depends on grounded aspects of the body including action, perception, and interactions with the environment. This research aims to study if immersive embodiment through the means of virtual reality facilitates embodied cognition. A pedagogical VR solution which takes advantage of embodied cognition can lead to enhanced learning benefits. Towards achieving this goal, this research presents a linear continuum for immersive embodied interaction within virtual reality. This research evaluates the effects of three levels of immersive embodied interactions on cognitive thinking, presence, usability, and satisfaction among users in the fields of science, technology, engineering, and mathematics (STEM) education. Results from the presented experiments show that immersive virtual reality is greatly effective in knowledge acquisition and retention, and highly enhances user satisfaction, interest and enthusiasm. Users experience high levels of presence and are profoundly engaged in the learning activities within the immersive virtual environments. The studies presented in this research evaluate pedagogical VR software to train and motivate students in STEM education, and provide an empirical analysis comparing desktop VR (DVR), immersive VR (IVR), and immersive embodied VR (IEVR) conditions for learning. This research also proposes a fully immersive embodied interaction metaphor (IEIVR) for learning of computational

Virtual reality in assessment and treatment of schizophrenia: a systematic review

Directory of Open Access Journals (Sweden)

Mônica Macedo

2015-03-01

Full Text Available Objective To conduct a systematic review about the use of virtual reality (VR for evaluation, treatment and/or rehabilitation of patients with schizophrenia, focused on: areas, fields and objectives; methodological issues; features of the VR used; viability and efficiency of this resource. Methods Searches were performed about schizophrenia and virtual reality in PsycINFO, Academic Search Complete, MEDLINE Complete, CINAHL with Full Text, Web of Science and Business Source Premier databases, using the following keywords: [“schizophrenia”] AND [“virtual reality” OR “serious game”] AND [“treatment” OR “therapy” OR “rehabilitation”]. The search was carried out between November 2013 and June 2014 without using any search limiters. Results A total of 101 papers were identified, and after the application of exclusion criteria, 33 papers remained. The studies analysed focused on the use of VR for the evaluation of cognitive, social, perceptual and sensory skills, and the vast majority were experimental studies, with virtual reality specifically created for them. All the reviewed papers point towards a reliable and safe use of VR for evaluating and treating cognitive and social deficits in patients with schizophrenia, with different results in terms of generalisation, motivation, assertiveness and task participation rate. Some problems were highlighted, such as its high cost and a constant need for software maintenance. Conclusion The studies show that using the virtual reality may streamline traditional evaluation/rehabilitation programmes, allowing to enhance the results achieved, both in the cognitive and in the social field, helping for the legitimisation of this population’s psycho-social inclusion.

Varieties of virtualization

Science.gov (United States)

Ellis, Stephen R.

1991-01-01

Natural environments have a content, i.e., the objects in them; a geometry, i.e., a pattern of rules for positioning and displacing the objects; and a dynamics, i.e., a system of rules describing the effects of forces acting on the objects. Human interaction with most common natural environments has been optimized by centuries of evolution. Virtual environments created through the human-computer interface similarly have a content, geometry, and dynamics, but the arbitrary character of the computer simulation creating them does not insure that human interaction with these virtual environments will be natural. The interaction, indeed, could be supernatural but it also could be impossible. An important determinant of the comprehensibility of a virtual environment is the correspondence between the environmental frames of reference and those associated with the control of environmental objects. The effects of rotation and displacement of control frames of reference with respect to corresponding environmental references differ depending upon whether perceptual judgement or manual tracking performance is measured. The perceptual effects of frame of reference displacement may be analyzed in terms of distortions in the process of virtualizing the synthetic environment space. The effects of frame of reference displacement and rotation have been studied by asking subjects to estimate exocentric direction in a virtual space.

Multi-viewpoint Image Array Virtual Viewpoint Rapid Generation Algorithm Based on Image Layering

Science.gov (United States)

Jiang, Lu; Piao, Yan

2018-04-01

The use of multi-view image array combined with virtual viewpoint generation technology to record 3D scene information in large scenes has become one of the key technologies for the development of integrated imaging. This paper presents a virtual viewpoint rendering method based on image layering algorithm. Firstly, the depth information of reference viewpoint image is quickly obtained. During this process, SAD is chosen as the similarity measure function. Then layer the reference image and calculate the parallax based on the depth information. Through the relative distance between the virtual viewpoint and the reference viewpoint, the image layers are weighted and panned. Finally the virtual viewpoint image is rendered layer by layer according to the distance between the image layers and the viewer. This method avoids the disadvantages of the algorithm DIBR, such as high-precision requirements of depth map and complex mapping operations. Experiments show that, this algorithm can achieve the synthesis of virtual viewpoints in any position within 2×2 viewpoints range, and the rendering speed is also very impressive. The average result proved that this method can get satisfactory image quality. The average SSIM value of the results relative to real viewpoint images can reaches 0.9525, the PSNR value can reaches 38.353 and the image histogram similarity can reaches 93.77%.

Cooperation, Coordination, and Trust in Virtual Teams: Insights from Virtual Games

Science.gov (United States)

Korsgaard, M. Audrey; Picot, Arnold; Wigand, Rolf T.; Welpe, Isabelle M.; Assmann, Jakob J.

This chapter considers fundamental concepts of effective virtual teams, illustrated by research on Travian, a massively multiplayer online strategy game wherein players seek to build empires. Team inputs are the resources that enable individuals to work interdependently toward a common goal, including individual and collective capabilities, shared knowledge structures, and leadership style. Team processes, notably coordination and cooperation, transform team inputs to desired collective outcomes. Because the members of virtual teams are geographically dispersed, relying on information and communication technology, three theories are especially relevant for understanding how they can function effectively: social presence theory, media richness theory, and media synchronicity theory. Research in settings like Travian can inform our understanding of structures, processes, and performance of virtual teams. Such research could provide valuable insight into the emergence and persistence of trust and cooperation, as well as the impact of different communication media for coordination and information management in virtual organizations.

Virtual reality exposure therapy for social anxiety disorder: a randomized controlled trial.

Science.gov (United States)

Anderson, Page L; Price, Matthew; Edwards, Shannan M; Obasaju, Mayowa A; Schmertz, Stefan K; Zimand, Elana; Calamaras, Martha R

2013-10-01

This is the first randomized trial comparing virtual reality exposure therapy to in vivo exposure for social anxiety disorder. Participants with a principal diagnosis of social anxiety disorder who identified public speaking as their primary fear (N = 97) were recruited from the community, resulting in an ethnically diverse sample (M age = 39 years) of mostly women (62%). Participants were randomly assigned to and completed 8 sessions of manualized virtual reality exposure therapy, exposure group therapy, or wait list. Standardized self-report measures were collected at pretreatment, posttreatment, and 12-month follow-up, and process measures were collected during treatment. A standardized speech task was delivered at pre- and posttreatment, and diagnostic status was reassessed at 3-month follow-up. Analysis of covariance showed that, relative to wait list, people completing either active treatment significantly improved on all but one measure (length of speech for exposure group therapy and self-reported fear of negative evaluation for virtual reality exposure therapy). At 12-month follow-up, people showed significant improvement from pretreatment on all measures. There were no differences between the active treatments on any process or outcome measure at any time, nor differences on achieving partial or full remission. Virtual reality exposure therapy is effective for treating social fears, and improvement is maintained for 1 year. Virtual reality exposure therapy is equally effective as exposure group therapy; further research with a larger sample is needed, however, to better control and statistically test differences between the treatments.

ROLE OF VIRTUALIZATION IN CLOUD COMPUTING

OpenAIRE

Avneet kaur; Dr. Gaurav Gupta; Dr. Gurjit Singh Bhathal

2017-01-01

Cloud Computing is the fundamental change happening in the field of Information Technology.. Virtualization is the key component of cloud computing. With the use of virtualization, cloud computing brings about not only convenience and efficiency benefits, but also great challenges in the field of data security and privacy protection. .In this paper, we are discussing about virtualization, architecture of virtualization technology as well as Virtual Machine Monitor (VMM). Further discussing ab...

Virtual care

DEFF Research Database (Denmark)

Kamp, Annette; Aaløkke Ballegaard, Stinne

of retrenchment, promising better quality, empowerment of citizens and work that is smarter and more qualified. Through ethnographic field studies we study the introduction of virtual home care in Danish elderly care, focusing on the implications for relational work and care relations. Virtual home care entails...... the performance of specific home care services by means of video conversations rather than physical visits in the citizens’ homes. As scholars within the STS tradition maintain, technologies do not simply replace a human function; they rather transform care work, redistributing tasks between citizens, technology...... point out how issues of trust and surveillance, which are always negotiated in care relations, are in fact accentuated in this kind of virtual care work. Moreover, we stress that the contemporary institutional context, organization and time schedules have a vast impact on the practices developed....

Directional virtual backbone based data aggregation scheme for Wireless Visual Sensor Networks.

Science.gov (United States)

Zhang, Jing; Liu, Shi-Jian; Tsai, Pei-Wei; Zou, Fu-Min; Ji, Xiao-Rong

2018-01-01

Data gathering is a fundamental task in Wireless Visual Sensor Networks (WVSNs). Features of directional antennas and the visual data make WVSNs more complex than the conventional Wireless Sensor Network (WSN). The virtual backbone is a technique, which is capable of constructing clusters. The version associating with the aggregation operation is also referred to as the virtual backbone tree. In most of the existing literature, the main focus is on the efficiency brought by the construction of clusters that the existing methods neglect local-balance problems in general. To fill up this gap, Directional Virtual Backbone based Data Aggregation Scheme (DVBDAS) for the WVSNs is proposed in this paper. In addition, a measurement called the energy consumption density is proposed for evaluating the adequacy of results in the cluster-based construction problems. Moreover, the directional virtual backbone construction scheme is proposed by considering the local-balanced factor. Furthermore, the associated network coding mechanism is utilized to construct DVBDAS. Finally, both the theoretical analysis of the proposed DVBDAS and the simulations are given for evaluating the performance. The experimental results prove that the proposed DVBDAS achieves higher performance in terms of both the energy preservation and the network lifetime extension than the existing methods.

VR-Cluster: Dynamic Migration for Resource Fragmentation Problem in Virtual Router Platform

Directory of Open Access Journals (Sweden)

Xianming Gao

2016-01-01

Full Text Available Network virtualization technology is regarded as one of gradual schemes to network architecture evolution. With the development of network functions virtualization, operators make lots of effort to achieve router virtualization by using general servers. In order to ensure high performance, virtual router platform usually adopts a cluster of general servers, which can be also regarded as a special cloud computing environment. However, due to frequent creation and deletion of router instances, it may generate lots of resource fragmentation to prevent platform from establishing new router instances. In order to solve “resource fragmentation problem,” we firstly propose VR-Cluster, which introduces two extra function planes including switching plane and resource management plane. Switching plane is mainly used to support seamless migration of router instances without packet loss; resource management plane can dynamically move router instances from one server to another server by using VR-mapping algorithms. Besides, three VR-mapping algorithms including first-fit mapping algorithm, best-fit mapping algorithm, and worst-fit mapping algorithm are proposed based on VR-Cluster. At last, we establish VR-Cluster protosystem by using general X86 servers, evaluate its migration time, and further analyze advantages and disadvantages of our proposed VR-mapping algorithms to solve resource fragmentation problem.

Virtual classroom design for Blended Learning: Human Development and Quality of Life

Directory of Open Access Journals (Sweden)

Juan Carlos Morales Intriago

2017-03-01

Full Text Available The explosive development in all areas of knowledge has evolved the scenarios of generation and transfer of knowledge, in terms of media, channels and supports, parallel to this appear new resources that optimize the processes of vocational training, whether formal, non-formal and informal. The EVA or Virtual Learning Environments evolve the traditional way of teaching a Blended environment, which is, combining classroom education with online training processes. The present work designs a training process set in Blended Learning for the subject Human Development and Quality of Life, summarizing in 8 steps the construction of the virtual and face-to-face environment, where starting from the common to the specific, the system is described systemically. The methodology applied in the present work was of Bibliographic and documentary type. To achieve the proposed objective, a systemic design was designed that divided the research into two stages: the exploration stage and the design stage. In the exploration stage, a large bibliographical collection was revised and in the design stage the virtual classroom model of the subject was constructed. Product of the investigation is a guide that guides step by step in the construction of virtual environments set in the Blended Learning.

Internet-delivered multi-patient virtual reality exposure therapy system for the treatment of anxiety disorders

NARCIS (Netherlands)

Kang, N.; Brinkman, W.P.; Riemsdijk, M.B. van; Neerincx, M.A.

2011-01-01

Motivation - The project is to reduce the therapist's workload in virtual reality exposure therapy (VRET) for anxiety disorders and explore cognitive ergonomic factors in the design of an internet-delivered multi-patient treatment system. Research questions - The aim can be achieved by system

vSphere virtual machine management

CERN Document Server

Fitzhugh, Rebecca

2014-01-01

This book follows a step-by-step tutorial approach with some real-world scenarios that vSphere businesses will be required to overcome every day. This book also discusses creating and configuring virtual machines and also covers monitoring virtual machine performance and resource allocation options. This book is for VMware administrators who want to build their knowledge of virtual machine administration and configuration. It's assumed that you have some experience with virtualization administration and vSphere.

Clinical Virtual Reality tools to advance the prevention, assessment, and treatment of PTSD

Science.gov (United States)

Rizzo, Albert ‘Skip’; Shilling, Russell

2017-01-01

ABSTRACT Numerous reports indicate that the incidence of posttraumatic stress disorder (PTSD) in Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) military personnel has created a significant behavioural healthcare challenge. These findings have served to motivate research on how to better develop and disseminate evidence-based treatments for PTSD. The current article presents the use of Virtual Reality (VR) as a clinical tool to address the assessment, prevention, and treatment of PTSD, based on the VR projects that were evolved at the University of Southern California Institute for Creative Technologies since 2004. A brief discussion of the definition and rationale for the clinical use of VR is followed by a description of a VR application designed for the delivery of prolonged exposure (PE) for treating Service Members (SMs) and Veterans with combat- and sexual assault-related PTSD. The expansion of the virtual treatment simulations of Iraq and Afghanistan for PTSD assessment and prevention is then presented. This is followed by a forward-looking discussion that details early efforts to develop virtual human agent systems that serve the role of virtual patients for training the next generation of clinical providers, as healthcare guides that can be used to support anonymous access to trauma-relevant behavioural healthcare information, and as clinical interviewers capable of automated behaviour analysis of users to infer psychological state. The paper will conclude with a discussion of VR as a tool for breaking down barriers to care in addition to its direct application in assessment and intervention. PMID:29372007

Clinical Virtual Reality tools to advance the prevention, assessment, and treatment of PTSD.

Science.gov (United States)

Rizzo, Albert 'Skip'; Shilling, Russell

2017-01-01

Numerous reports indicate that the incidence of posttraumatic stress disorder (PTSD) in Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) military personnel has created a significant behavioural healthcare challenge. These findings have served to motivate research on how to better develop and disseminate evidence-based treatments for PTSD. The current article presents the use of Virtual Reality (VR) as a clinical tool to address the assessment, prevention, and treatment of PTSD, based on the VR projects that were evolved at the University of Southern California Institute for Creative Technologies since 2004. A brief discussion of the definition and rationale for the clinical use of VR is followed by a description of a VR application designed for the delivery of prolonged exposure (PE) for treating Service Members (SMs) and Veterans with combat- and sexual assault-related PTSD. The expansion of the virtual treatment simulations of Iraq and Afghanistan for PTSD assessment and prevention is then presented. This is followed by a forward-looking discussion that details early efforts to develop virtual human agent systems that serve the role of virtual patients for training the next generation of clinical providers, as healthcare guides that can be used to support anonymous access to trauma-relevant behavioural healthcare information, and as clinical interviewers capable of automated behaviour analysis of users to infer psychological state. The paper will conclude with a discussion of VR as a tool for breaking down barriers to care in addition to its direct application in assessment and intervention.

APLIKASI SERVER VIRTUAL IP UNTUK MIKROKONTROLER

OpenAIRE

Ashari, Ahmad

2008-01-01

Selama ini mikrokontroler yang terhubung ke satu komputer hanya dapat diakses melalui satu IP saja, padahal kebanyakan sistem operasi sekarang dapat memperjanjikan lebih dari satu IP untuk setiap komputer dalam bentuk virtual IP. Penelitian ini mengkaji pemanfaatan virtual IP dari IP aliasing pada sistem operasi Linux sebagai Server Virtual IP untuk mikrokontroler. Prinsip dasar Server Virtual IP adalah pembuatan Virtual Host pada masing-masing IP untuk memproses paket-paket data dan menerjem...

Do Nonverbal Emotional Cues Matter? Effects of Video Casting in Synchronous Virtual Classrooms

Science.gov (United States)

Han, Heeyoung

2013-01-01

This study examined the effects of an instructor's use of video casting as a nonverbal emotional cue in synchronous discussion sessions on students' social presence, satisfaction, and learning achievement. A quasi-experimental design was used to evaluate the effect of video casting in a synchronous virtual classroom. The research setting was a…

Security challenges for virtualization in cloud

International Nuclear Information System (INIS)

Tayab, A.

2015-01-01

Virtualization is a model that is vastly growing in IT industry. Virtualization provides more than one logical resource in one single physical machine. Infrastructure use cloud services and on behalf of virtualization, cloud computing is also a rapidly growing model of IT industry. Cloud provider and cloud user, both remain ignorant of each other's security. Since virtualization and cloud computing are rapidly expanding and becoming more and more complex in infrastructure, more security is required to protect them from potential attacks and security threats. Virtualization provides various benefits in terms of hardware utilization, resources protection, remote access and other resources. This paper intends to discuss the common exploits of security uses in the virtualized environment and focuses on the security threats from the attacker's perspective. This paper discuss the major areas of virtualized model environment and also address the security concerns. And finally presents a solution for secure valorization in IT infrastructure and to protect inter communication of virtual machines. (author)

Virtual vitreoretinal surgery: validation of a training programme.

Science.gov (United States)

Vergmann, Anna Stage; Vestergaard, Anders Højslet; Grauslund, Jakob

2017-02-01

To test the validity of the eyesi surgical simulator as an assessment tool in a virtual reality vitreoretinal training programme. In collaboration with an experienced vitreoretinal surgeon, a virtual vitreoretinal training programme was composed on the eyesi surgical simulator, software version 2.9.2 (VRmagic GmbH, Manheim, Germany). It was completed twice by three groups: 20 medical students, ten residents of ophthalmology and five trained vitreoretinal surgeons. The programme contained six training modules: navigation level 2 (Nav2), forceps training level 5 (ForT5), bimanual training level 3 (BimT3), laser coagulation level 3 (LasC3), posterior hyaloid level 3 (PostH3) and internal limiting membrane peeling level 3 (ILMP3). The scores in each module were assessed from two to five different factors (tissue treatment, efficiency, target achievement, instrument handling and microscope handling), and it was possible to achieve 100 points in each module. At the final training session, the highest overall median score was found for the vitreoretinal surgeons (vitreoretinal surgeons: 434 points, residents: 394.5 points, medical students: 272.5 points, p training programme with validity for the eyesi surgical simulator as an assessment tool for overall score and for four of six vitreoretinal modules. These findings could potentially make the programme a useful tool in the training of future vitreoretinal surgeons. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Talking with a Virtual Human : Controlling the Human Experience and Behavior in a Virtual Conversation

NARCIS (Netherlands)

Qu, C.

2014-01-01

Virtual humans are often designed to replace real humans in virtual reality applications for e.g., psychotherapy, education and entertainment. In general, applications with virtual humans are created for modifying a person's knowledge, beliefs, attitudes, emotions or behaviors. Reaching these

Multi-objective stochastic scheduling optimization model for connecting a virtual power plant to wind-photovoltaic-electric vehicles considering uncertainties and demand response

International Nuclear Information System (INIS)

Ju, Liwei; Li, Huanhuan; Zhao, Junwei; Chen, Kangting; Tan, Qingkun; Tan, Zhongfu

2016-01-01

optimize customers’ power consumption behaviors and improve the grid connection space of the virtual power plant. The electric vehicle group and demand response could achieve a linkage optimization effect between the generation side and demand side, achieving optimal system scheduling objectives.

Diagnostic accuracy in virtual dermatopathology

DEFF Research Database (Denmark)

Mooney, E.; Kempf, W.; Jemec, G.B.E.

2012-01-01

Background Virtual microscopy is used for teaching medical students and residents and for in-training and certification examinations in the United States. However, no existing studies compare diagnostic accuracy using virtual slides and photomicrographs. The objective of this study was to compare...... diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...... slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology...

International virtual teams engineering global success

CERN Document Server

Brewer, P

2015-01-01

As a complete guide to international virtual team communication with practical problem-solving strategies, this book is a must read for managers and engineers in all stages of their professional development This book provides essential information for creating and maintaining successful international virtual teams for those who manage, participate in, or train others in international virtual teaming. Based on new studies in engineering communication, this book presents processes and principles that can help managers and engineers establish global virtual teams that work, assess the virtual team climate, and maintain the effectiveness of virtual teams across cultural boundaries. It provides knowledge and tools necessary to understand the variable contexts of global virtual teams, so that organizations are able to respond to inevitable changes in technology and the global marketplace.

Distributed Virtual Reality: System Concepts for Cooperative Training and Commanding in Virtual Worlds

Directory of Open Access Journals (Sweden)

Eckhard Freund

2003-02-01

Full Text Available The general aim of the development of virtual reality technology for automation applications at the IRF is to provide the framework for Projective Virtual Reality which allows users to "project" their actions in the virtual world into the real world primarily by means of robots but also by other means of automation. The framework is based on a new task-oriented approach which builds on the "task deduction" capabilities of a newly developed virtual reality system and a task planning component. The advantage of this new approach is that robots which work at great distances from the control station can be controlled as easily and intuitively as robots that work right next to the control station. Robot control technology now provides the user in the virtual world with a "prolonged arm" into the physical environment, thus paving the way for a new quality of userfriendly man machine interfaces for automation applications. Lately, this work has been enhanced by a new structure that allows to distribute the virtual reality application over multiple computers. With this new step, it is now possible for multiple users to work together in the same virtual room, although they may physically be thousands of miles apart. They only need an Internet or ISDN connection to share this new experience. Last but not least, the distribution technology has been further developed to not just allow users to cooperate but to be able to run the virtual world on many synchronized PCs so that a panorama projection or even a cave can be run with 10 synchronized PCs instead of high-end workstations, thus cutting down the costs for such a visualization environment drastically and allowing for a new range of applications.

Software for virtual accelerator designing

International Nuclear Information System (INIS)

Kulabukhova, N.; Ivanov, A.; Korkhov, V.; Lazarev, A.

2012-01-01

The article discusses appropriate technologies for software implementation of the Virtual Accelerator. The Virtual Accelerator is considered as a set of services and tools enabling transparent execution of computational software for modeling beam dynamics in accelerators on distributed computing resources. Distributed storage and information processing facilities utilized by the Virtual Accelerator make use of the Service-Oriented Architecture (SOA) according to a cloud computing paradigm. Control system tool-kits (such as EPICS, TANGO), computing modules (including high-performance computing), realization of the GUI with existing frameworks and visualization of the data are discussed in the paper. The presented research consists of software analysis for realization of interaction between all levels of the Virtual Accelerator and some samples of middle-ware implementation. A set of the servers and clusters at St.-Petersburg State University form the infrastructure of the computing environment for Virtual Accelerator design. Usage of component-oriented technology for realization of Virtual Accelerator levels interaction is proposed. The article concludes with an overview and substantiation of a choice of technologies that will be used for design and implementation of the Virtual Accelerator. (authors)

Virtual currencies : Real opportunities?

OpenAIRE

Selldahl, Sara

2013-01-01

AbstractThe European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usuallycontrolled by its developers, and used and accepted among the members of a specific virtual community.”(European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last fewyears as they become increasingly prevalent in our society across many different industries. Up until now, the field ofvirtual currencies has been mainly uncharte...

Corporate Training in Virtual Worlds

Directory of Open Access Journals (Sweden)

Charles Nebolsky

2004-12-01

Full Text Available This paper presents virtual training worlds that are relatively low-cost distributed collaborative learning environments suitable for corporate training. A virtual training world allows a facilitator, experts and trainees communicating and acting in the virtual environment for practicing skills during collaborative problem solving. Using these environments is beneficial to both trainees and corporations. Two system prototypes – the sales training and the leadership training virtual worlds – are described. The leadership training course design is discussed in details.

Sense of presence and anxiety during virtual social interactions between a human and virtual humans

OpenAIRE

Morina, Nexhmedin; Brinkman, Willem-Paul; Hartanto, Dwi; Emmelkamp, Paul M.G.

2014-01-01

Virtual reality exposure therapy (VRET) has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using d...

Effects of Game-Based Learning in an Opensim-Supported Virtual Environment on Mathematical Performance

Science.gov (United States)

Kim, Heesung; Ke, Fengfeng

2017-01-01

This experimental study was intended to examine whether the integration of game characteristics in the OpenSimulator-supported virtual reality (VR) learning environment can improve mathematical achievement for elementary school students. In this pre- and posttest experimental comparison study, data were collected from 132 fourth graders through an…

State Virtual Libraries

Science.gov (United States)

Pappas, Marjorie L.

2003-01-01

Virtual library? Electronic library? Digital library? Online information network? These all apply to the growing number of Web-based resource collections managed by consortiums of state library entities. Some, like "INFOhio" and "KYVL" ("Kentucky Virtual Library"), have been available for a few years, but others are just starting. Searching for…

CEDS Addresses: Virtual and Blended Learning

Science.gov (United States)

US Department of Education, 2015

2015-01-01

The Common Education Data Standards (CEDS) common data vocabulary supports the collection and use of information about virtual and blended learning. The data element "Virtual Indicator", introduced in version 3 of CEDS, supports a range of virtual learning-related use cases. The Virtual Indicator element may be related to a Course…

Virtual Reality for Anxiety Disorders

Directory of Open Access Journals (Sweden)

Elif Uzumcu

2018-03-01

Full Text Available Virtual reality is a relatively new exposure tool that uses three-dimensional computer-graphics-based technologies which allow the individual to feel as if they are physically inside the virtual environment by misleading their senses. As virtual reality studies have become popular in the field of clinical psychology in recent years, it has been observed that virtual-reality-based therapies have a wide range of application areas, especially on anxiety disorders. Studies indicate that virtual reality can be more realistic than mental imagery and can create a stronger feeling of ԰resenceԻ that it is a safer starting point compared to in vivo exposure; and that it can be applied in a more practical and controlled manner. The aim of this review is to investigate exposure studies based on virtual reality in anxiety disorders (specific phobias, panic disorder and agoraphobias, generalized anxiety disorder, social phobia, posttraumatic stress disorder and obsessive compulsive disorder.

The ethnography of virtual reality

Directory of Open Access Journals (Sweden)

Gavrilović Ljiljana 1

2004-01-01

Full Text Available This paper discusses possible application of ethnographic research in the realm of virtual reality, especially in the relationship between cultures in virtual communities. This represents an entirely new area of ethnographic research and therefore many adjustments in the research design are needed for example, a development of a specific method of data gathering and tools for their verification. A virtual, cyber space is a version of social space more or less synchronous with it, but without the, "real", that is, physical presence of the people who create it. This virtual reality, defined and bounded by virtual space, is in fact real - and though we are not able to observe real, physical parameters of its existence, we can perceive its consequences. In sum, an innovative ethnographic research method is fully applicable for exploring the realm of virtual reality; in order to do so we need to expand, in addition to the new research design and methods, the field of science itself.

Virtual reality technology and applications

CERN Document Server

Mihelj, Matjaž; Beguš, Samo

2014-01-01

As virtual reality expands from the imaginary worlds of science fiction and pervades every corner of everyday life, it is becoming increasingly important for students and professionals alike to understand the diverse aspects of this technology. This book aims to provide a comprehensive guide to the theoretical and practical elements of virtual reality, from the mathematical and technological foundations of virtual worlds to the human factors and the applications that enrich our lives: in the fields of medicine, entertainment, education and others. After providing a brief introduction to the topic, the book describes the kinematic and dynamic mathematical models of virtual worlds. It explores the many ways a computer can track and interpret human movement, then progresses through the modalities that make up a virtual world: visual, acoustic and haptic. It explores the interaction between the actual and virtual environments, as well as design principles of the latter. The book closes with an examination of diff...

Surgery applications of virtual reality

Science.gov (United States)

Rosen, Joseph

1994-01-01

Virtual reality is a computer-generated technology which allows information to be displayed in a simulated, bus lifelike, environment. In this simulated 'world', users can move and interact as if they were actually a part of that world. This new technology will be useful in many different fields, including the field of surgery. Virtual reality systems can be used to teach surgical anatomy, diagnose surgical problems, plan operations, simulate and perform surgical procedures (telesurgery), and predict the outcomes of surgery. The authors of this paper describe the basic components of a virtual reality surgical system. These components include: the virtual world, the virtual tools, the anatomical model, the software platform, the host computer, the interface, and the head-coupled display. In the chapter they also review the progress towards using virtual reality for surgical training, planning, telesurgery, and predicting outcomes. Finally, the authors present a training system being developed for the practice of new procedures in abdominal surgery.

Virtual Sustainability

Directory of Open Access Journals (Sweden)

William Sims Bainbridge

2010-09-01

Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

Virtual Tower

International Nuclear Information System (INIS)

Wayne, R.A.

1997-01-01

The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems

Development of a Virtual Museum Including a 4d Presentation of Building History in Virtual Reality

Science.gov (United States)

Kersten, T. P.; Tschirschwitz, F.; Deggim, S.

2017-02-01

In the last two decades the definition of the term "virtual museum" changed due to rapid technological developments. Using today's available 3D technologies a virtual museum is no longer just a presentation of collections on the Internet or a virtual tour of an exhibition using panoramic photography. On one hand, a virtual museum should enhance a museum visitor's experience by providing access to additional materials for review and knowledge deepening either before or after the real visit. On the other hand, a virtual museum should also be used as teaching material in the context of museum education. The laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has developed a virtual museum (VM) of the museum "Alt-Segeberger Bürgerhaus", a historic town house. The VM offers two options for visitors wishing to explore the museum without travelling to the city of Bad Segeberg, Schleswig-Holstein, Germany. Option a, an interactive computer-based, tour for visitors to explore the exhibition and to collect information of interest or option b, to immerse into virtual reality in 3D with the HTC Vive Virtual Reality System.

Control of an ER haptic master in a virtual slave environment for minimally invasive surgery applications

International Nuclear Information System (INIS)

Han, Young-Min; Choi, Seung-Bok

2008-01-01

This paper presents the control performance of an electrorheological (ER) fluid-based haptic master device connected to a virtual slave environment that can be used for minimally invasive surgery (MIS). An already developed haptic joint featuring controllable ER fluid and a spherical joint mechanism is adopted for the master system. Medical forceps and an angular position measuring device are devised and integrated with the joint to establish the MIS master system. In order to embody a human organ in virtual space, a volumetric deformable object is used. The virtual object is then mathematically formulated by a shape-retaining chain-linked (S-chain) model. After evaluating the reflection force, computation time and compatibility with real-time control, the haptic architecture for MIS is established by incorporating the virtual slave with the master device so that the reflection force for the object of the virtual slave and the desired position for the master operator are transferred to each other. In order to achieve the desired force trajectories, a sliding mode controller is formulated and then experimentally realized. Tracking control performances for various force trajectories are evaluated and presented in the time domain

A rural virtual health sciences library project: research findings with implications for next generation library services.

Science.gov (United States)

Richwine, M P; McGowan, J J

2001-01-01

The Shared Hospital Electronic Library of Southern Indiana (SHELSI) research project was designed to determine whether access to a virtual health sciences library and training in its use would support medical decision making in rural southern Indiana and achieve the same level of impact seen by targeted information services provided by health sciences librarians in urban hospitals. Based on the results of a needs assessment, a virtual medical library was created; various levels of training were provided. Virtual library users were asked to complete a Likert-type survey, which included questions on intent of use and impact of use. At the conclusion of the project period, structured interviews were conducted. Impact of the virtual health sciences library showed a strong correlation with the impact of information provided by health sciences librarians. Both interventions resulted in avoidance of adverse health events. Data collected from the structured interviews confirmed the perceived value of the virtual library. While librarians continue to hold a strong position in supporting information access for health care providers, their roles in the information age must begin to move away from providing information toward selecting and organizing knowledge resources and instruction in their use.

Image Based Rendering and Virtual Reality

DEFF Research Database (Denmark)

Livatino, Salvatore

The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

Saving Money and Time with Virtual Server

CERN Document Server

Sanders, Chris

2006-01-01

Microsoft Virtual Server 2005 consistently proves to be worth its weight in gold, with new implementations thought up every day. With this product now a free download from Microsoft, scores of new users are able to experience what the power of virtualization can do for their networks. This guide is aimed at network administrators who are interested in ways that Virtual Server 2005 can be implemented in their organizations in order to save money and increase network productivity. It contains information on setting up a virtual network, virtual consolidation, virtual security, virtual honeypo

Management and Engineering of Virtual Enterprises

DEFF Research Database (Denmark)

Tølle, Martin

) Component layer: consists of reusable components and modules. - Each layer builds on the previous one, i.e. the VE concept is captured in VERA, and the VERA can be used to structure each of the VERAM components. * C) A methodology for virtual enterprise named VEM (Virtual Enterprise Methodology) - One...... to the set up of virtual enterprises. Types of work preparation include definitions (e.g. shared terminology), ICT support (e.g. infrastructure and applications), procedures (e.g. how to set up virtual enterprises, partner selection), reference models (e.g. contract models and product structure) and the like....... * B) A framework and a reference architecture for virtual enterprises named VERAM (Virtual Enterprise Reference Architecture and Methodology) and VERA (Virtual Enterprise Reference Architecture) respectively. - VERAM is a framework that structures the body of knowledge related to preparation, set up...

Web-based training in radiology - student course in the Virtual University of Bavaria

International Nuclear Information System (INIS)

Grunewald, M.; Jakob, C.; Wagner, M.; Bautz, W.A.; Geess, H.R.; Gebhard, H.; Hothorn, T.; Neuhuber, W.L.

2004-01-01

Purpose: The nint version of the licensing regulation for medical doctors (Approbation Regulation (AR)) sets a benchmark in terms of practical experience, interdigitation of preclinical and clinical studies, interdisciplinary approach, economic efficiency, independence of students, added new teaching and learning modalities, and ongoing evaluation of the progress of the medical students. It is the aim to implement these major points of the AR in a model course for diagnostic radiology and radiation protection within the scope of the Virtual University of Bavaria and test them in practice. Materials and Methods: In cooperation with residents and board certified radiologists, students developed the virtual course 'Web-Based Training (WBT) Radiology' in diagnostic radiology and radiation protection for students in the first clinical semester. A representative target group taken from the student body was asked about the options to get access to the World Wide Web (Internet), and the satisfaction concerning configuration and content of the newly developed program. A comparison was made between the results of the final examination taken by students who made use of the virtual course in addition to conventional lessons and taken by students who did not subscribe to the virtual course and exclusively relied on conventional lessons. In addition, a pilot study was conducted in the winter semester 2002/03, which compared students taking either the traditional lessons or the new virtual course on the Internet. Results: The virtual course-model had test results with a positive trend. All targeted students had Internet access. Constructive criticism was immediately implemented and contributed to rapid optimization. The learning success of the additive or alternative virtual course was in no way less than the learning success achieved with the conventional course. (orig.) [de

Virtual Reality in the Classroom.

Science.gov (United States)

Pantelidis, Veronica S.

1993-01-01

Considers the concept of virtual reality; reviews its history; describes general uses of virtual reality, including entertainment, medicine, and design applications; discusses classroom uses of virtual reality, including a software program called Virtus WalkThrough for use with a computer monitor; and suggests future possibilities. (34 references)…

Interacting with a Virtual Conductor

NARCIS (Netherlands)

Bos, Pieter; Reidsma, Dennis; Ruttkay, Zsófia; Nijholt, Anton; Harper, Richard; Rauterberg, Matthias; Combetto, Marco

This paper presents a virtual embodied agent that can conduct musicians in a live performance. The virtual conductor conducts music specified by a MIDI file and uses input from a microphone to react to the tempo of the musicians. The current implementation of the virtual conductor can interact with

Virtual reality in surgical training.

Science.gov (United States)

Lange, T; Indelicato, D J; Rosen, J M

2000-01-01

Virtual reality in surgery and, more specifically, in surgical training, faces a number of challenges in the future. These challenges are building realistic models of the human body, creating interface tools to view, hear, touch, feel, and manipulate these human body models, and integrating virtual reality systems into medical education and treatment. A final system would encompass simulators specifically for surgery, performance machines, telemedicine, and telesurgery. Each of these areas will need significant improvement for virtual reality to impact medicine successfully in the next century. This article gives an overview of, and the challenges faced by, current systems in the fast-changing field of virtual reality technology, and provides a set of specific milestones for a truly realistic virtual human body.

Virtual School Counseling

Science.gov (United States)

Osborn, Debra S.; Peterson, Gary W.; Hale, Rebecca R.

2015-01-01

The advent of virtual schools opens doors to opportunity for delivery of student services via the Internet. Through the use of structured interviews with four practicing Florida virtual school counselors, and a follow-up survey, the authors examined the experiences and reflections of school counselors who are employed full time in a statewide…

Radiation emission as a virtually exact realization of Heisenbergs microscope

Energy Technology Data Exchange (ETDEWEB)

Andersen, K.K., E-mail: kka@phys.au.dk [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C (Denmark); Brock, S. [Department of Culture and Society, Aarhus University, Jens Chr. Skous Vej 5, 8000 Aarhus C (Denmark); Esberg, J.; Thomsen, H.D.; Uggerhøj, U.I. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C (Denmark)

2013-11-15

Through the concept of ‘formation length’, recently observed directly in the radiation emission from ultrarelativistic electrons and an essential component in the interpretation of strong field radiation from electrons penetrating single crystals, we discuss the indeterminacy in the location of radiation emission. The analogy with the indeterminacy in the Heisenberg microscope Gedanken experiment is demonstrated from a number of viewpoints to be almost exact. The positive attitude regarding photon emission as a process that is somehow located in space and time is emphasized. We therefore interpret the measurements of formation lengths in radiation emission as a practically realizable version – using virtual incident photons instead of real – of the Heisenberg microscope Gedanken experiment.

Printed Three-dimensional Anatomic Templates for Virtual Preoperative Planning Before Reconstruction of Old Pelvic Injuries: Initial Results

Directory of Open Access Journals (Sweden)

Xin-Bao Wu

2015-01-01

Full Text Available Background: Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy, difficult-to-access surgical sites, and the relatively low incidence of such cases. Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture. The goal of this study was to assess the use of three-dimensional (3D printing techniques for surgical management of old pelvic fractures. Methods: First, 16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data. Next, nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models. The pelvic injuries were all type C, and the average time from injury to reconstruction was 11 weeks (range: 8-17 weeks. The workflow consisted of: (1 Printing patient-specific bone models based on preoperative computed tomography (CT scans, (2 virtual fracture reduction using the printed 3D anatomic template, (3 virtual fracture fixation using Kirschner wires, and (4 preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation. These models aided communication between surgical team members during the procedure. This technique was validated by comparing the preoperative planning to the intraoperative procedure. Results: The accuracy of the 3D printed models was within specification. Production of a model from standard CT DICOM data took 7 hours (range: 6-9 hours. Preoperative planning using the 3D printed models was feasible in all cases. Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases. The patients were followed for 3-29 months (median: 5 months. The fracture healing time was 9-17 weeks (mean: 10 weeks. No delayed incision healing, wound infection, or nonunions occurred. The

Analisis Gameplay Game Genre Virtual Pet

Directory of Open Access Journals (Sweden)

Abi Senoprabowo

2015-02-01

Full Text Available Game adalah struktur interaktif yang membuat pemain berjuang menuju sebuah tujuan. Game dapat memberikan emosi dan mood, menghubungkan dengan orang latihan, sarana latihan, serta dapat memberikan edukasi. Salah satu game yang berkembang saat ini adalah game bergenre Virtual pet. Game virtual pet merupakan game simulasi memelihara sesuatu. Virtual pet memiliki gameplay yang menarik dan menyenangkan yang membuat pemain seolah-olah benar-benar memiliki binatang peliharaan mereka sendiri. Virtual pet dianggap oleh sebagian besar penggunanya dapat memberikan kegembiraan serta rasa kasih sayang karena tingkat interaksinya yang baik. Banyak pengembang game pemula yang mengembangkan genre ini sebagai game yang mereka buat karena kemudahaan dan tingkat penggunanya yang banyak. Akan tetapi banyak dari pengembang game pemula tidak memperhatikan tingkat keberlanjutan game virtual pet yang mereka buat sehingga membuat pemain cepat bosan. Pada penelitian ini, analisis game bergenre virtual pet yang sudah sukses dibuat seperti Zombigotchi, Tamagotchi Unicorn, dan Bird Land, diharapkan dapat membantu para pengembang game pemula agar mengetahui cara merancang dan mengembangkan game virtual pet dengan baik. Kata Kunci: game, gameplay, virtual pet

Note on s anti s-production in anti p-nucleus reactions at 607 MeV/c incident momentum

International Nuclear Information System (INIS)

Breivik, F.O.; Haatuft, A.; Halsteinslid, A.

1990-01-01

The measured cross sections for K o s and Λ o (Σ o ) production in anti pA reactions at 607 MeV/c incident momentum, and the number of quark recombinations, give the cross section σ(s anti s) for strange particle production for target nuclei with A= 2, 4 and 20 nucleons, respectively. The result favours the relation σ(s anti s) ∝ A 1/3 . Scattering of an antiquark off a virtual s anti s-pair, or gluon Bremsstrahlung emitted by scattering of an incident antiquark passing through nuclear matter, are possible processes consistent with this relation. Models inconsistent with the relation may be wrong. 4 refs.; 2 tabs

Ethnography in a Virtual World

Science.gov (United States)

Shumar, Wesley; Madison, Nora

2013-01-01

This article situates the discussion of virtual ethnography within the larger political/economic changes of twenty-first century consumer capitalism and suggests that increasingly our entire social world is a virtual world and that there were very particular utopian and dystopian framings of virtual community growing out of that history. The…

Virtual superheroes: using superpowers in virtual reality to encourage prosocial behavior.

Directory of Open Access Journals (Sweden)

Robin S Rosenberg

Full Text Available BACKGROUND: Recent studies have shown that playing prosocial video games leads to greater subsequent prosocial behavior in the real world. However, immersive virtual reality allows people to occupy avatars that are different from them in a perceptually realistic manner. We examine how occupying an avatar with the superhero ability to fly increases helping behavior. PRINCIPAL FINDINGS: Using a two-by-two design, participants were either given the power of flight (their arm movements were tracked to control their flight akin to Superman's flying ability or rode as a passenger in a helicopter, and were assigned one of two tasks, either to help find a missing diabetic child in need of insulin or to tour a virtual city. Participants in the "super-flight" conditions helped the experimenter pick up spilled pens after their virtual experience significantly more than those who were virtual passengers in a helicopter. CONCLUSION: The results indicate that having the "superpower" of flight leads to greater helping behavior in the real world, regardless of how participants used that power. A possible mechanism for this result is that having the power of flight primed concepts and prototypes associated with superheroes (e.g., Superman. This research illustrates the potential of using experiences in virtual reality technology to increase prosocial behavior in the physical world.

Virtual Peace Education

Science.gov (United States)

Firer, Ruth

2008-01-01

This article is based on the convictions that peace education is the basis for any sustainable non-violent relations between parties in a conflict, and that virtual peace education is almost the only feasible way to practise peace education in an open violent conflict as is the current Israeli/Palestinians one. Moreover, virtual peace education…

Medication incidents reported to an online incident reporting system.

LENUS (Irish Health Repository)

Alrwisan, Adel

2011-01-15

AIMS: Approximately 20% of deaths from adverse events are related to medication incidents, costing the NHS an additional £500 million annually. Less than 5% of adverse events are reported. This study aims to assess the reporting rate of medication incidents in NHS facilities in the north east of Scotland, and to describe the types and outcomes of reported incidents among different services. Furthermore, we wished to quantify the proportion of reported incidents according to the reporters\\' profession. METHODS: A retrospective description was made of medication incidents reported to an online reporting system (DATIX) over a 46-month-period (July 2005 to April 2009). Reports originated from acute and community hospitals, mental health, and primary care facilities. RESULTS: Over the study period there were 2,666 incidents reported with a mean monthly reporting rate of 78.2\\/month (SD±16.9). 6.1% of all incidents resulted in harm, with insulin being the most commonly implicated medication. Nearly three-quarters (74.2%, n=1,978) of total incidents originated from acute hospitals. Administration incidents were implicated in the majority of the reported medication incidents (59%), followed by prescribing (10.8%) and dispensing (9.9%), while the nondescript "other medication incidents" accounted for 20.3% of total incidents. The majority of reports were made by nursing and midwifery staff (80%), with medical and dental professionals reporting the lowest number of incidents (n=56, 2%). CONCLUSIONS: The majority of medication incidents in this study were reported by nursing and midwifery staff, and were due to administration incidents. There is a clear need to elucidate the reasons for the limited contribution of the medical and dental professionals to reporting medication incidents.

Developing a Virtual Book - Material for Virtual Learning Environments

Directory of Open Access Journals (Sweden)

Anne Karin Larsen

2007-12-01

Full Text Available This article describes the process of, and considerations taken when Virtual Learning Materials were developed for an international study in Comparative Social Work arranged by the VIRCLASS project. The steps taken and the elements included in the Virtual Book – A Guide to Social Work in Europe are presented in details to inform others who are planning to make virtual learning materials. Students from 11 countries in Europe participated, and their reception of this material and learning outcomes from using it are analysed and presented. Furthermore; the article discuss how the learning material contributes to students’ learning, how a common understanding of practice enhances knowledge-building and in what way audio-visual learning material can contribute to good learning in e-learning courses. The results are discussed in relation to theories about composite texts and community of inquiry, and outlines some challenges for e-teachers’ competences.

A Descriptive Study of Wisconsin PK-12 Virtual Public School Program Operations and Management

Science.gov (United States)

Banker, Margaret M.

2012-01-01

E-Learning as it pertains to public education is in its infancy in America. There is limited research on what operational design, development, and management attributes of virtual school programs foster student achievement. The Wisconsin Department of Instruction has not developed or adopted program standards for E-Learning programs. The purpose…

A virtual tour of virtual reality

Science.gov (United States)

Harris, Margaret

2018-03-01

Virtual-reality glasses might still be on the starting blocks, but plenty of companies are working on the technology. Margaret Harris tries on some examples at the Photonics West show in San Francisco

Drawing Inspiration from Human Brain Networks: Construction of Interconnected Virtual Networks.

Science.gov (United States)

Murakami, Masaya; Kominami, Daichi; Leibnitz, Kenji; Murata, Masayuki

2018-04-08

Virtualization of wireless sensor networks (WSN) is widely considered as a foundational block of edge/fog computing, which is a key technology that can help realize next-generation Internet of things (IoT) networks. In such scenarios, multiple IoT devices and service modules will be virtually deployed and interconnected over the Internet. Moreover, application services are expected to be more sophisticated and complex, thereby increasing the number of modifications required for the construction of network topologies. Therefore, it is imperative to establish a method for constructing a virtualized WSN (VWSN) topology that achieves low latency on information transmission and high resilience against network failures, while keeping the topological construction cost low. In this study, we draw inspiration from inter-modular connectivity in human brain networks, which achieves high performance when dealing with large-scale networks composed of a large number of modules (i.e., regions) and nodes (i.e., neurons). We propose a method for assigning inter-modular links based on a connectivity model observed in the cerebral cortex of the brain, known as the exponential distance rule (EDR) model. We then choose endpoint nodes of these links by controlling inter-modular assortativity, which characterizes the topological connectivity of brain networks. We test our proposed methods using simulation experiments. The results show that the proposed method based on the EDR model can construct a VWSN topology with an optimal combination of communication efficiency, robustness, and construction cost. Regarding the selection of endpoint nodes for the inter-modular links, the results also show that high assortativity enhances the robustness and communication efficiency because of the existence of inter-modular links of two high-degree nodes.

Drawing Inspiration from Human Brain Networks: Construction of Interconnected Virtual Networks

Directory of Open Access Journals (Sweden)

Masaya Murakami

2018-04-01

Full Text Available Virtualization of wireless sensor networks (WSN is widely considered as a foundational block of edge/fog computing, which is a key technology that can help realize next-generation Internet of things (IoT networks. In such scenarios, multiple IoT devices and service modules will be virtually deployed and interconnected over the Internet. Moreover, application services are expected to be more sophisticated and complex, thereby increasing the number of modifications required for the construction of network topologies. Therefore, it is imperative to establish a method for constructing a virtualized WSN (VWSN topology that achieves low latency on information transmission and high resilience against network failures, while keeping the topological construction cost low. In this study, we draw inspiration from inter-modular connectivity in human brain networks, which achieves high performance when dealing with large-scale networks composed of a large number of modules (i.e., regions and nodes (i.e., neurons. We propose a method for assigning inter-modular links based on a connectivity model observed in the cerebral cortex of the brain, known as the exponential distance rule (EDR model. We then choose endpoint nodes of these links by controlling inter-modular assortativity, which characterizes the topological connectivity of brain networks. We test our proposed methods using simulation experiments. The results show that the proposed method based on the EDR model can construct a VWSN topology with an optimal combination of communication efficiency, robustness, and construction cost. Regarding the selection of endpoint nodes for the inter-modular links, the results also show that high assortativity enhances the robustness and communication efficiency because of the existence of inter-modular links of two high-degree nodes.

Learning Ethics through Virtual Fieldtrips: Teaching Ethical Theories through Virtual Experiences

Science.gov (United States)

Houser, Rick; Thoma, Steve; Coppock, Amanda; Mazer, Matthew; Midkiff, Lewis; Younanian, Marisa; Young, Sarah

2011-01-01

Teaching ethical reasoning is considered an important component of the undergraduate learning experience. A recent approach to teaching using experiential learning is through virtual worlds such as Second Life. We discuss how ethics may be taught using experiential learning in the virtual world of Second Life. Participants in the class in this…

Control over the virtual environment influences the presence and efficacy of a virtual reality intervention on pain.

Science.gov (United States)

Gutiérrez-Martínez, Olga; Gutiérrez-Maldonado, José; Loreto-Quijada, Desirée

2011-01-01

The main aim of this study is to investigate whether the control the user has over a virtual environment (VE) influences the sense of presence. A secondary purpose is to explore the relationship between Virtual Reality (VR) presence and pain tolerance during a cold-pressor experience. Ninety-four participants underwent two consecutive cold-pressor trials, one without VR exposure and the other providing a VR stereoscopic figure used as a symbolic representation of the sensation of pain. Participants were randomly assigned to an interactive condition in which they could actively manipulate the VR figure to achieve a pleasant, tranquil environment (analogous to no-pain situation) or to a passive intervention, in which they observed the changes in the VR figure. Results showed that the amount of VR presence reported was significantly higher in the interactive condition. Participants had a higher pain tolerance during both VR conditions than in the no-VR trial, with a greater increase in pain tolerance from the non-VR trial in the interactive condition. Presence scores correlated significantly and positively with pain tolerance scores. We discuss the importance of VR interaction and control over the VR environments used in VR pain interventions designed to increase cognitive control over pain.

Factors Influencing Virtual Patron Satisfaction with Online Library Resources and Services

Directory of Open Access Journals (Sweden)

Katherine Tyler

2011-07-01

Full Text Available College students are accessing virtual libraries whether they are on campus or learning from a distance. Academic institutions serving virtual patrons must remain focused on meeting the needs of those library users by continually examining their preferences, their searching behavior, and the information they seek. The purpose of this research was to determine if virtual patrons are satisfied with the resources and services being provided by a university’s online library. Following a web-based survey, demographic characteristics of students were analyzed to determine if any influenced students’ satisfaction. Using analysis of variance, correlation, and descriptive statistics, several demographic factors were found to influence student satisfaction with the library’s online resources: age, gender, achieved educational level, student status, and computer experience. One factor, computer experience, was found to influence student satisfaction with the library’s online services. Overall, students reported satisfaction with the university’s online library resources and services. Comments submitted to open-ended questions regarding areas for improvement to the online library provide library administrators with avenues for development to increase awareness of library services, focus improvement in navigation, and enhance student satisfaction.

Virtual Stationary Automata for Mobile Networks

National Research Council Canada - National Science Library

Dolev, Shlomi; Gilbert, Seth; Lahiani, Limor; Lynch, Nancy; Nolte, Tina

2005-01-01

We define a programming abstraction for mobile networks called the Virtual Stationary Automata programming layer, consisting of real mobile clients, virtual timed I/O automata called virtual stationary automata (VSAs...

CT virtual reality in the preoperative workup of malunited distal radius fractures: preliminary results

International Nuclear Information System (INIS)

Rieger, Michael; Gruber, Hannes; Jaschke, Werner R.; Gabl, Markus; Mallouhi, Ammar

2005-01-01

Our objective was to evaluate the usefulness of CT virtual preoperative planning in the surgical repositioning of malunited distal radius fracture. Eleven patients with malunited distal radius fracture underwent multislice CT of both wrists. A preoperative workup was performed in a virtual reality environment created from the CT data sets. Virtual planning comprised three main procedures, carrying out the virtual osteotomy of the radius, prediction of the final position of the distal radius after osteotomy and computer-assisted manufacturing of a repositioning device, which was later placed at the surgical osteotomy site to reposition objectively the distal radius fragment before fixation with the osteosynthesis. All patients tolerated the surgical procedure well. During surgery, the orthopedic surgeons were not required in any of the cases to alter the position of the distal radius that was determined by the repositioning device. At postoperative follow-up, the anatomic relationship of the distal radius was restored (radial inclination, 21.4 ; volar tilt, 10.3 ; ulnar variance, 0.5 mm). Clinically, a significant improvement of pronation (P=0.012), supination (P=0.01), flexion (P=0.001) and extension (P=0.006) was achieved. Pain decreased from 54 to 7 points. CT virtual reality is a valuable adjunct for the preoperative workup and surgical reposition of malunited distal radius fractures. (orig.)

Integration of the virtual 3D model of a control system with the virtual controller

Science.gov (United States)

Herbuś, K.; Ociepka, P.

2015-11-01

Nowadays the design process includes simulation analysis of different components of a constructed object. It involves the need for integration of different virtual object to simulate the whole investigated technical system. The paper presents the issues related to the integration of a virtual 3D model of a chosen control system of with a virtual controller. The goal of integration is to verify the operation of an adopted object of in accordance with the established control program. The object of the simulation work is the drive system of a tunneling machine for trenchless work. In the first stage of work was created an interactive visualization of functioning of the 3D virtual model of a tunneling machine. For this purpose, the software of the VR (Virtual Reality) class was applied. In the elaborated interactive application were created adequate procedures allowing controlling the drive system of a translatory motion, a rotary motion and the drive system of a manipulator. Additionally was created the procedure of turning on and off the output crushing head, mounted on the last element of the manipulator. In the elaborated interactive application have been established procedures for receiving input data from external software, on the basis of the dynamic data exchange (DDE), which allow controlling actuators of particular control systems of the considered machine. In the next stage of work, the program on a virtual driver, in the ladder diagram (LD) language, was created. The control program was developed on the basis of the adopted work cycle of the tunneling machine. The element integrating the virtual model of the tunneling machine for trenchless work with the virtual controller is the application written in a high level language (Visual Basic). In the developed application was created procedures responsible for collecting data from the running, in a simulation mode, virtual controller and transferring them to the interactive application, in which is verified the

Manually locating physical and virtual reality objects.

Science.gov (United States)

Chen, Karen B; Kimmel, Ryan A; Bartholomew, Aaron; Ponto, Kevin; Gleicher, Michael L; Radwin, Robert G

2014-09-01

In this study, we compared how users locate physical and equivalent three-dimensional images of virtual objects in a cave automatic virtual environment (CAVE) using the hand to examine how human performance (accuracy, time, and approach) is affected by object size, location, and distance. Virtual reality (VR) offers the promise to flexibly simulate arbitrary environments for studying human performance. Previously, VR researchers primarily considered differences between virtual and physical distance estimation rather than reaching for close-up objects. Fourteen participants completed manual targeting tasks that involved reaching for corners on equivalent physical and virtual boxes of three different sizes. Predicted errors were calculated from a geometric model based on user interpupillary distance, eye location, distance from the eyes to the projector screen, and object. Users were 1.64 times less accurate (p virtual versus physical box corners using the hands. Predicted virtual targeting errors were on average 1.53 times (p virtual targets but not significantly different for close-up virtual targets. Target size, location, and distance, in addition to binocular disparity, affected virtual object targeting inaccuracy. Observed virtual box inaccuracy was less than predicted for farther locations, suggesting possible influence of cues other than binocular vision. Human physical interaction with objects in VR for simulation, training, and prototyping involving reaching and manually handling virtual objects in a CAVE are more accurate than predicted when locating farther objects.

A Virtual Tomb for Kelvingrove: Virtual Reality, Archaeology and Education

Directory of Open Access Journals (Sweden)

Melissa M. Terras

1999-11-01

Full Text Available The use of computers as an educational resource in museums is becoming increasingly popular as more and more institutions realise that multimedia displays are very successful in imparting a broad variety of information. Although three-dimensional reconstructions of sites and structures have been used in archaeology for many years, the majority of museum computer installations have dealt with two-dimensional media because of the costs, equipment and labour involved in producing interactive 3D scenes. The birth of VRML (Virtual Reality Modeling Language has changed the way virtual reality is implemented and viewed. As an internet protocol, VRML can be used on most major platforms and implemented by anyone with a word-processing package, an internet browser, and the relevant plug-in. There is no reason why this new technology cannot be adopted by archaeologists and museums to produce virtual reality models of structures, sites and objects to aid the research of specialists and the education of the public. This project (undertaken at the Humanities Advanced Technology and Information Institute, University of Glasgow, Scotland, between May and October 1998 investigated the practicalities involved in using VRML to create a virtual reality model for use in a public space. A model of the Egyptian tomb of Sen-nedjem was developed for installation in the Egyptian Gallery of the Kelvingrove Museum and Art Gallery, Glasgow, in the hope that the introduction of this computer display would encourage the museum visitor's interest in the gallery's existing artefacts. Creation of the model would also investigate the possibility of using VRML to build accurate archaeological reconstructions cheaply and efficiently using publicly available software and existing archaeological resources. A fully functioning virtual reality model of the tomb of Sen-nedjem has been created, incorporating interactive elements, photorealistic representation, and animation, and this

A conceptualisation of the relationship between virtual experience and cybernauts' satisfaction with virtual communities

OpenAIRE

Bouattour , Dorra; Debos , Franck; Abdellatif , Tarek

2015-01-01

International audience; In this research, we developed and tested an integrated model relating individuals' satisfaction with their experiential values in virtual communities. Using a realised factorial analysis and regression, we identified the factors that influence member satisfaction in virtual communities. Adopting Mathwick et al.'s (2001) concept of experiential value, we proposed a conceptualisation of a virtual experience that fits closely with the original nomological framework advoc...

Control of grid integrated voltage source converters under unbalanced conditions: development of an on-line frequency-adaptive virtual flux-based approach

Energy Technology Data Exchange (ETDEWEB)

Suul, Jon Are

2012-03-15

Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor-less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly applied for operation during unbalanced conditions. Methods for voltage-sensor-less grid synchronization and control of VSCs under unbalanced grid voltage conditions will therefore be the main focus of this Thesis. Estimation methods based on the concept of Virtual Flux, considering the integral of the converter voltage in analogy to the flux of an electric machine, are among the simplest and most well known techniques for achieving voltage-sensor-less grid synchronization. Most of the established techniques for Virtual Flux estimation are, however, either sensitive to grid frequency variations or they are not easily adaptable for operation under unbalanced grid voltage conditions. This Thesis addresses both these issues by proposing a simple approach for Virtual Flux estimation by utilizing a frequency-adaptive filter based on a Second Order Generalized Integrator (SOGI). The proposed approach can be used to achieve on-line frequency-adaptive varieties of conventional strategies for Virtual Flux estimation. The main advantage is, however, that the SOGI-based Virtual Flux estimation can be arranged in a structure that achieves inherent symmetrical component sequence separation under unbalanced conditions. The proposed method for Virtual Flux estimation can be used as a general basis for voltage-sensor-less grid synchronization and control during unbalanced conditions. In this Thesis, the estimated Virtual Flux signals are used to develop a flexible strategy for control of active

A Virtual Hosting Environment for Distributed Online Gaming

Science.gov (United States)

Brossard, David; Prieto Martinez, Juan Luis

With enterprise boundaries becoming fuzzier, it’s become clear that businesses need to share resources, expose services, and interact in many different ways. In order to achieve such a distribution in a dynamic, flexible, and secure way, we have designed and implemented a virtual hosting environment (VHE) which aims at integrating business services across enterprise boundaries and virtualising the ICT environment within which these services operate in order to exploit economies of scale for the businesses as well as achieve shorter concept-to-market time scales. To illustrate the relevance of the VHE, we have applied it to the online gaming world. Online gaming is an early adopter of distributed computing and more than 30% of gaming developer companies, being aware of the shift, are focusing on developing high performance platforms for the new online trend.

Virtual environments simulation in research reactor

Science.gov (United States)

Muhamad, Shalina Bt. Sheik; Bahrin, Muhammad Hannan Bin

2017-01-01

Virtual reality based simulations are interactive and engaging. It has the useful potential in improving safety training. Virtual reality technology can be used to train workers who are unfamiliar with the physical layout of an area. In this study, a simulation program based on the virtual environment at research reactor was developed. The platform used for virtual simulation is 3DVia software for which it's rendering capabilities, physics for movement and collision and interactive navigation features have been taken advantage of. A real research reactor was virtually modelled and simulated with the model of avatars adopted to simulate walking. Collision detection algorithms were developed for various parts of the 3D building and avatars to restrain the avatars to certain regions of the virtual environment. A user can control the avatar to move around inside the virtual environment. Thus, this work can assist in the training of personnel, as in evaluating the radiological safety of the research reactor facility.

Virtually naked: virtual environment reveals sex-dependent nature of skin disclosure.

Directory of Open Access Journals (Sweden)

Anna M Lomanowska

Full Text Available The human tendency to reveal or cover naked skin reflects a competition between the individual propensity for social interactions related to sexual appeal and interpersonal touch versus climatic, environmental, physical, and cultural constraints. However, due to the ubiquitous nature of these constraints, isolating on a large scale the spontaneous human tendency to reveal naked skin has remained impossible. Using the online 3-dimensional virtual world of Second Life, we examined spontaneous human skin-covering behavior unhindered by real-world climatic, environmental, and physical variables. Analysis of hundreds of avatars revealed that virtual females disclose substantially more naked skin than virtual males. This phenomenon was not related to avatar hypersexualization as evaluated by measurement of sexually dimorphic body proportions. Furthermore, analysis of skin-covering behavior of a population of culturally homogeneous avatars indicated that the propensity of female avatars to reveal naked skin persisted despite explicit cultural norms promoting less revealing attire. These findings have implications for further understanding how sex-specific aspects of skin disclosure influence human social interactions in both virtual and real settings.

Applying a Virtual Economy Model in Mexico's Oil Sector

International Nuclear Information System (INIS)

Baker, G.

1994-01-01

The state of Mexico's oil industry, including the accomplishments of Pemex, Mexico's national oil company, was discussed, with particular reference to the progress made in the period of 1988-1994, and the outlook for innovations in the post-Salinas era. The concept of an evolutionary trend from a command economy (State as sole producer), towards market (State as regulator) or mixed economies (State as business partner) in developing countries, was introduced, placing Pemex within this evolutionary model as moving away from centralized control of oil production and distribution, while achieving international competitiveness. The concept of ''virtual market economy'' was also discussed. This model contains the legal basis of a command economy, while instituting modernization programs in order to stimulate market-economic conditions. This type of economy was considered particularly useful in this instance, sine it would allow Pemex units to operate within international performance and price benchmarks while maintaining state monopoly. Specific details of how Pemex could transform itself to a virtual market economy were outlined. It was recommended that Pemex experiment with the virtual mixed economy model; in essence, making the state a co-producer, co-transporter, and co-distributor of hydrocarbons. The effects of such a move would be to bring non-debt funding to oil and gas production, transmission, and associated industrial activities

Virtual worlds. Meta-analysis of educational experiences from its beginnings

Directory of Open Access Journals (Sweden)

Sergio Manuel DÍAZ FERNÁNDEZ

2016-12-01

Full Text Available Over a decade has passed since the specialized scientific literature presented in 2004 the first educational experience with virtual worlds. An evolutionary period that requires analysis to determine the adequacy of the developed experiences so far, enabling the formulation of guidelines and / or aspects to consider in future experiences to achieve better adjustment and adaptation to the specific framework.The investigation lies within the meta-analytic paradigm, with a quantitative and systematic review of the results of the 36 experiences that have been accessed, projecting an analysis and review of the same by using a form of observation, new and validated, in which a number of desirable compliance parameters are set, based on the current framework established by different experts.The results show a high degree of adaptation in didactic and pedagogical aspects, as well as communication and interaction, being lower in technical and support aspects, which can influence the work in virtual worlds. On the other hand, errors not meet the characteristics of the participants are detected. Failure to take into account their degree of socialization, their digital knowledge or communication skills in these environments, determines the validity of the designs and implementations, being important to consider in future experiences with virtual worlds.

Virtual organization of hospital medical imaging: a user satisfaction survey.

Science.gov (United States)

Sicotte, Claude; Paré, Guy; Bini, Kobena Kra; Moreault, Marie-Pierre; Laverdure, Guy

2010-12-01

A virtual medical imaging department is an innovative and demanding organizational model, to the extent that the underlying goal is to achieve a continuous and advanced organizational integration of human and physical resources, clinical data, and clienteles. To better understand the kind of benefits offered, we conducted a survey of three groups of users--radiologists, radiological technologists, and medical specialists--working in a five-site virtual organization. We received 127 valid questionnaires, for an overall response rate of 66%. The assessments vary according to the use made of the system. The scores for system quality and the quality of the data produced were markedly higher for intra-hospital use (respectively 7.9 and 8.7 out of 10) than for inter-hospital use (5.4 and 7.0). Despite the negative assessments they made of inter-hospital use, users maintained a positive attitude toward some type of virtual organization of medical imaging. Indeed, the score for Overall satisfaction with the system was very high, 8.9 out of 10. Moreover, the scores for Intended future use of the system were very high for both intra-hospital use (8.9) and inter-hospital use (8.7). We also found significant differences in perceptions among user groups.