Elastic positron scattering by C{sub 2}H{sub 2}: Differential cross sections and virtual state formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carvalho, Claudia R.C. de; Varella, Marcio T. do N; Lima, Marco A.P.

2003-12-01

We present calculated elastic differential cross sections for positron-acetylene scattering, obtained by using the Schwinger multichannel method. Our results are in very good agreement with quasielastic experimental data of Kauppila et al. [Nucl. Instrum. Meth. Phys. Res. B 192, 162 (2002)]. We also discuss the existence of a virtual state (zero-energy resonance) in e{sup +}-C{sub 2}H{sub 2} collisions, based on the behavior of the integral cross section and of the s-wave phase shift. As expected the fixed-nuclei cross section and annihilation parameter (Z{sub eff}) present the same energy dependence at very low impact energies. As the virtual state energy approachesmore » zero, the magnitude of both cross section and Z{sub eff} are extremely enhanced (at zero impact energy). The possibility of shifting from a low-lying virtual state to a shallow bound state is not expected to significantly affect room-temperature annihilation rates.« less

Managing Global Virtual Teams across Classrooms, Students and Faculty

ERIC Educational Resources Information Center

Shea, Timothy P.; Sherer, Pamela D.; Quilling, Rosemary D.; Blewett, Craig N.

2011-01-01

Virtual teams are becoming commonplace in business today so our business school students should have experience in effectively working in virtual teams. Based on a month-long virtual team project conducted by the authors between classes in South Africa and the United States, this paper discusses the opportunities and challenges of using global…

Moving beyond Assumptions: The Use of Virtual Reference Data in an Academic Library

ERIC Educational Resources Information Center

Nolen, David S.; Powers, Amanda Clay; Zhang, Li; Xu, Yue; Cannady, Rachel E.; Li, Judy

2012-01-01

The Mississippi State University Libraries' Virtual Reference Service collected statistics about virtual reference usage. Analysis of the data collected by an entry survey from chat and e-mail transactions provided librarians with concrete information about what patron groups were the highest and lowest users of virtual reference services. These…

Hirarchical emotion calculation model for virtual human modellin - biomed 2010.

PubMed

Zhao, Yue; Wright, David

2010-01-01

This paper introduces a new emotion generation method for virtual human modelling. The method includes a novel hierarchical emotion structure, a group of emotion calculation equations and a simple heuristics decision making mechanism, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. A simple heuristics theory is introduced and integrated into decision making process in order to make the virtual humans decision making more like a real human. A data interface which connects the emotion calculation and the decision making structure together has also been designed and simulated to test the method in Virtools environment.

Motion of a virtual cathode in a cylindrical channel with electron beam transport in the “compressed” state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belomyttsev, S. Ya.; Grishkov, A. A.; Tsygankov, R. V.

2014-03-15

This paper studies the motion of a virtual cathode in a two-section drift tube with the formation and breakup of the “compressed” state of an electron beam. Experimental arrangements to intercept part of the injected current during the voltage pulse and to provide virtual cathode motion toward the collector are proposed. The arrangements were implemented on the SINUS-7 high-current electron accelerator. Theoretical and experimental dependences of the virtual cathode velocity on the injected current and cathode voltage are presented. The experimental data on virtual cathode motion agree with its theoretical model based on analytical solutions of equations assisted by computermore » simulation with the PIC code KARAT. The results of the work demonstrate the feasibility of controlling the virtual cathode motion which can be used in collective ion acceleration and microwave generation.« less

Value-Added in a Virtual Learning Environment: An Evaluation of a Virtual Charter School

ERIC Educational Resources Information Center

Lueken, Martin; Ritter, Gary; Beck, Dennis

2015-01-01

This paper evaluates an online charter school that serves children in grades K-8 in a southern state in the United States. We compare growth in math and literacy learning on state standardized assessments between students enrolled in this school and "matched twin" students enrolled in traditional public school students statewide each…

K-8 Virtual Schools: A Glimpse into the Future

ERIC Educational Resources Information Center

Revenaugh, Mickey

2006-01-01

Virtual courses and schools--in which the student and the teacher are in different locations--have become commonplace at the university and high school level. Public, full-time virtual schooling for younger students, however, is still on the frontier of education. About a dozen states now offer full-time virtual schools among their public school…

Developing a Novel Measure of Body Satisfaction Using Virtual Reality

PubMed Central

Purvis, Clare K.; Jones, Megan; Bailey, Jakki O.; Bailenson, Jeremy; Taylor, C. Barr

2015-01-01

Body image disturbance (BID), considered a key feature in eating disorders, is a pervasive issue among young women. Accurate assessment of BID is critical, but the field is currently limited to self-report assessment methods. In the present study, we build upon existing research, and explore the utility of virtual reality (VR) to elicit and detect changes in BID across various immersive virtual environments. College-aged women with elevated weight and shape concerns (n = 38) and a non-weight and shape concerned control group (n = 40) were randomly exposed to four distinct virtual environments with high or low levels of body salience and social presence (i.e., presence of virtual others). Participants interacted with avatars of thin, normal weight, and overweight body size (BMI of approximately 18, 22, and 27 respectively) in virtual social settings (i.e., beach, party). We measured state-level body satisfaction (state BD) immediately after exposure to each environment. In addition, we measured participants’ minimum interpersonal distance, visual attention, and approach preference toward avatars of each size. Women with higher baseline BID reported significantly higher state BD in all settings compared to controls. Both groups reported significantly higher state BD in a beach with avatars as compared to other environments. In addition, women with elevated BID approached closer to normal weight avatars and looked longer at thin avatars compared to women in the control group. Our findings indicate that VR may serve as a novel tool for measuring state-level BID, with applications for measuring treatment outcomes. Implications for future research and clinical interventions are discussed. PMID:26469860

Virtual imaging in sports broadcasting: an overview

NASA Astrophysics Data System (ADS)

Tan, Yi

2003-04-01

Virtual imaging technology is being used to augment television broadcasts -- virtual objects are seamlessly inserted into the video stream to appear as real entities to TV audiences. Virtual advertisements, the main application of this technology, are providing opportunities to improve the commercial value of television programming while enhancing the contents and the entertainment aspect of these programs. State-of-the-art technologies, such as image recognition, motion tracking and chroma keying, are central to a virtual imaging system. This paper reviews the general framework, the key techniques, and the sports broadcasting applications of virtual imaging technology.

The Comparative Effectiveness of Physical, Virtual, and Virtual-Physical Manipulatives on Third-Grade Students' Science Achievement and Conceptual Understanding of Evaporation and Condensation

ERIC Educational Resources Information Center

Wang, Tzu-Ling; Tseng, Yi-Kuan

2018-01-01

The purpose of this study was to investigate the relative effectiveness of experimenting with physical manipulatives alone, virtual manipulatives alone, and virtual preceding physical manipulatives (combination environment) on third-grade students' science achievement and conceptual understanding in the domain of state changes of water, focusing…

The Reality of Virtual Schools: A Review of the Literature

ERIC Educational Resources Information Center

Barbour, Michael K.; Reeves, Thomas C.

2009-01-01

Virtual schooling was first employed in the mid-1990s and has become a common method of distance education used in K-12 jurisdictions. The most accepted definition of a virtual school is an entity approved by a state or governing body that offers courses through distance delivery--most commonly using the Internet. While virtual schools can be…

The War Next Time: Countering Rogue States and Terrorists Armed with Chemical and Biological Weapons. Second Edition

DTIC Science & Technology

2004-04-01

Washington in 1814. 20 Woolsey Virtually all of our infrastructure has been put together with this spirit of transparency and ease of access. About...containers that cross U.S. borders every day and we decide that U.S. customs has to start inspecting virtually all of the containers at ports, instead of the...flexibility by giving the United States a virtually unlimited range of response options. While ambiguity gives flexibility to policymakers, it also

Ontological implications of being in immersive virtual environments

NASA Astrophysics Data System (ADS)

Morie, Jacquelyn F.

2008-02-01

The idea of Virtual Reality once conjured up visions of new territories to explore, and expectations of awaiting worlds of wonder. VR has matured to become a practical tool for therapy, medicine and commercial interests, yet artists, in particular, continue to expand the possibilities for the medium. Artistic virtual environments created over the past two decades probe the phenomenological nature of these virtual environments. When we inhabit a fully immersive virtual environment, we have entered into a new form of Being. Not only does our body continue to exist in the real, physical world, we are also embodied within the virtual by means of technology that translates our bodied actions into interactions with the virtual environment. Very few states in human existence allow this bifurcation of our Being, where we can exist simultaneously in two spaces at once, with the possible exception of meta-physical states such as shamanistic trance and out-of-body experiences. This paper discusses the nature of this simultaneous Being, how we enter the virtual space, what forms of persona we can don there, what forms of spaces we can inhabit, and what type of wondrous experiences we can both hope for and expect.

Framing the magic

NASA Astrophysics Data System (ADS)

Tsoupikova, Daria

2006-02-01

This paper will explore how the aesthetics of the virtual world affects, transforms, and enhances the immersive emotional experience of the user. What we see and what we do upon entering the virtual environment influences our feelings, mental state, physiological changes and sensibility. To create a unique virtual experience the important component to design is the beauty of the virtual world based on the aesthetics of the graphical objects such as textures, models, animation, and special effects. The aesthetic potency of the images that comprise the virtual environment can make the immersive experience much stronger and more compelling. The aesthetic qualities of the virtual world as born out through images and graphics can influence the user's state of mind. Particular changes and effects on the user can be induced through the application of techniques derived from the research fields of psychology, anthropology, biology, color theory, education, art therapy, music, and art history. Many contemporary artists and developers derive much inspiration for their work from their experience with traditional arts such as painting, sculpture, design, architecture and music. This knowledge helps them create a higher quality of images and stereo graphics in the virtual world. The understanding of the close relation between the aesthetic quality of the virtual environment and the resulting human perception is the key to developing an impressive virtual experience.

The Geography of Virtual Questioning

ERIC Educational Resources Information Center

Mon, Lorri; Bishop, Bradley Wade; McClure, Charles R.; McGilvray, Jessica; Most, Linda; Milas, Theodore Patrick; Snead, John T.

2009-01-01

This article explores the geography of virtual questioning by using geographic information systems to study activity within the Florida Electronic Library "Ask a Librarian" collaborative chat service. Researchers mapped participating libraries throughout the state of Florida that served as virtual "entry portals" for users as…

"Failure" Irrelevant: Virtual Schools and Accountability-Immunity

ERIC Educational Resources Information Center

Nespor, Jan; Voithofer, Rick

2016-01-01

Background: Virtual schools--free, state-funded, credit-awarding elementary and secondary schools offering curricula and programs exclusively online--are a rapidly expanding sector of U.S. education. Some of the largest of these schools have low graduation rates and receive "failing" rankings on state accountability metrics. They…

Virtual Cities--A Regional Discovery Project.

ERIC Educational Resources Information Center

Stanfel, Julie

1993-01-01

Describes the "Virtual Cities" project, a virtual reality satellite teleconference with students age 12 to 17 from Canada, Italy, and the United States held during the International Council for Educational Media 1992 conference. A visual database overlaid with instructional gaming strategies provided students with the opportunity to…

Magnetic Polarizability of Virtual (s\\bar{s}) and (c\\bar{c}) Pairs in the Nucleon

NASA Astrophysics Data System (ADS)

Filip, Peter

2017-12-01

We suggest 3 P 0 quantum state of virtual (s\\bar{s}) pairs in the nucleon can be polarised by the internal fields permeating the volume of the nucleon (proton or neutron). Due to the quadratic Zeeman interaction, 3 P 0 wavefunction of virtual (q\\bar{q}) pairs acquires the admixture of 1 P 10 quantum state in the magnetic field, which generates the antiparallel polarization of s and \\bar{s} quarks (in the nucleon). Considering the internal magnetic fields of neutron and proton (originating from their measured magnetic dipole moments), we suggest the induced s-quark polarization in the neutron to be of the oposite direction compared to the proton case. We mention the influence of the internal chromo-magnetic fields on the quantum state of (q\\bar{q}) pairs in the nucleon and we discuss also the expected behaviour of virtual (c\\bar{c}) pairs.

Fano-Agarwal couplings and non-rotating wave approximation in single-photon timed Dicke subradiance

NASA Astrophysics Data System (ADS)

Mirza, Imran M.; Begzjav, Tuguldur

2016-04-01

Recently a new class of single-photon timed Dicke (TD) subradiant states has been introduced with possible applications in single-photon-based quantum information storage and on demand ultrafast retrieval (Scully M. O., Phys. Rev. Lett., 115 (2015) 243602). However, the influence of any kind of virtual processes on the decay of these new kind of subradiant states has been left as an open question. In the present paper, we focus on this problem in detail. In particular, we investigate how pure Fano-Agarwal couplings and other virtual processes arising from non-rotating wave approximation impact the decay of otherwise sub- and superradiant states. In addition to the overall virtual couplings among all TD states, we also focus on the dominant role played by the couplings between specific TD states.

Entangled Biphoton Virtual-State Spectroscopy of the A(exp 2)Sigma(sup +)-X(exp 2)Pi System of OH

NASA Technical Reports Server (NTRS)

Kojima, Jun; Nguyen, Quang-Viet

2004-01-01

This Letter describes the first application of entanglement-induced virtual-state spectroscopy to a molecular system. Non-classical, non-monotonic behavior in a two-photon absorption cross section of the OH A-X system, induced by an entangled biphoton state is theoretically demonstrated. A Fourier transform analysis of the biphoton cross section permits access to the energy eigenvalues of intermediate rovibronic states with a fixed excitation photon energy. The dependence of the Fourier spectrum on the tuning range of the entanglement time (T(sub e)) and the relative path delay (tau(sub e)) is discussed. Our analysis reveals that the implementation of molecular virtual-state spectroscopy for the OH A-X system requires the tuning of tau(sub e) over a pico-second range with femto-second resolution.

Entangled Biphoton Virtual-State Spectroscopy of the A(exp 2)Sigma(+) - X(exp 2)Pi System of OH

NASA Technical Reports Server (NTRS)

Kojima, Jun; Nguyen, Quang-Viet

2004-01-01

This Letter describes the first application of entanglement-induced virtual-state spectroscopy to a molecular system. Non-classical, non-monotonic behavior in a two-photon absorption cross section of the OH A-X system, induced by an entangled biphoton state is theoretically demonstrated. A Fourier transform analysis of the biphoton cross section permits access to the energy eigenvalues of intermediate rovibronic states with a fixed excitation photon energy. The dependence of the Fourier spectrum on the tuning range of the entanglement time T(sub e), and the relative path delay tau(sub e) is discussed. Our analysis reveals that the implementation of molecular virtual-state spectroscopy for the OH A-X system requires the tuning of tau(sub e) over a pico-second range with femto-second resolution.

Experts Debate Cost Savings of Virtual Education

ERIC Educational Resources Information Center

Ash, Katie

2009-01-01

This article reports that a group of superintendents and secondary school educators in Massachusetts gathered to discuss how online courses might help offset budget cuts. Maryland state officials say their virtual Advanced Placement classes are a cost-effective way to get high-quality coursework to more students. And the largest state-sponsored…

A Cross-Country Comparison of Virtual Discussion Board Use in United States and Costa Rican Education Settings

ERIC Educational Resources Information Center

Hodge, Kari; Saxon, Terrill F.; Trumble, Jason

2013-01-01

The purpose of the current study was to compare the use of virtual discussion boards in various educational settings in the United States and Costa Rica. Participants included professors of education, in-service and pre-service teachers in the United States and Costa Rica where a survey was used that included demographic, knowledge, attitude, and…

Webinars at Louisiana Virtual School

ERIC Educational Resources Information Center

Grant, Allen

2009-01-01

Delivering meaningful professional development, engaging students in exciting yet practical curricula, and effectively communicating with faculty and staff members are challenges in any school setting. At the Louisiana Virtual School, a state-funded virtual school run by the Louisiana Department of Education, the 6,000 students, 115 instructors,…

An Overview of Evaluative Instrumentation for Virtual High Schools

ERIC Educational Resources Information Center

Black, Erik W.; Ferdig, Richard E.; DiPietro, Meredith

2008-01-01

With an increasing prevalence of virtual high school programs in the United States, a better understanding of evaluative tools available for distance educators and administrators is needed. These evaluative tools would provide opportunities for assessment and a determination of success within virtual schools. This article seeks to provide an…

Avoiding the Pitfalls of Virtual Schooling

ERIC Educational Resources Information Center

Schachter, Ron

2012-01-01

Virtual school programs--especially online high school courses--are gaining traction in school districts around the country. While offering online courses was once the exclusive province of large state, nonprofit and for-profit organizations and companies, districts and even individual schools are now starting virtual schools of their own. Not…

A Description of Exotic Nuclei by the Aid of Virtual States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vertse, T.; University of Debrecen, Faculty of Information Science, H-4010 Debrecen, Pf. 12; Id Betan, R.

2005-11-21

A new unified shell model scheme is introduced in which the single particle basis is a generalization of the Berggren representation. This repesentation includes virtual i.e. antibound basis states as well. We apply the new scheme to the ground state of the exotic nucleus 11Li. Here the antibound pole and the complex continuum both have large contributions and neither of them can be neglected.

Photorealistic virtual anatomy based on Chinese Visible Human data.

PubMed

Heng, P A; Zhang, S X; Xie, Y M; Wong, T T; Chui, Y P; Cheng, C Y

2006-04-01

Virtual reality based learning of human anatomy is feasible when a database of 3D organ models is available for the learner to explore, visualize, and dissect in virtual space interactively. In this article, we present our latest work on photorealistic virtual anatomy applications based on the Chinese Visible Human (CVH) data. We have focused on the development of state-of-the-art virtual environments that feature interactive photo-realistic visualization and dissection of virtual anatomical models constructed from ultra-high resolution CVH datasets. We also outline our latest progress in applying these highly accurate virtual and functional organ models to generate realistic look and feel to advanced surgical simulators. (c) 2006 Wiley-Liss, Inc.

Now It's Necessary: Virtual Reference Services at Washington State University, Pullman

ERIC Educational Resources Information Center

Nicol, Erica Carlson; Crook, Linda

2013-01-01

While virtual reference services (VRS) are becoming more and more common in academic libraries, implementing and maintaining well-used and effective VRS can be a challenge in the face of competing demands on time, staffing, and funding. Between 2011 and 2012, librarians at Washington State University, Pullman (WSU) have overhauled and reorganized…

A Virtual University for Small States of the Commonwealth

ERIC Educational Resources Information Center

Commonwealth of Learning, 2003

2003-01-01

Prepared for presentation at the 15th Conference of Commonwealth Education Ministers, in Edinburgh, Scotland, this report describes a proposal, created by the Commonwealth of Learning at the request by the Commonwealth Ministers of Education, to explore the creation of a virtual university to support higher education in small states. A Technical…

The Virtual University for Small States of the Commonwealth

ERIC Educational Resources Information Center

West, Paul; Daniel, John

2009-01-01

The Virtual University for Small States of the Commonwealth (VUSSC) was conceived by ministers at their triennial Conference of Commonwealth Ministers of Education in 2000. The Commonwealth of Learning was asked to investigate possible models, and presented a proposal to ministers at their next conference in 2003. The concept of a virtual…

The Future of Virtual Reality in the Classroom

ERIC Educational Resources Information Center

Vance, Amelia

2016-01-01

As state boards of education and other state policymakers consider the future of schools, sorting fad technology from technology that accelerates learning is key. Virtual reality (VR) is one such technology with promise that seems unlikely to fizzle. Hailed as potentially transformative for education and still in the early stages of application,…

Recent history and geography of virtual water trade.

PubMed

Carr, Joel A; D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

2013-01-01

The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.

Recent History and Geography of Virtual Water Trade

PubMed Central

Carr, Joel A.; D’Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

2013-01-01

The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products. PMID:23457481

Effects of Desktop Virtual Reality Environment Training on State Anxiety and Vocational Identity Scores among Persons with Disabilities during Job Placement

ERIC Educational Resources Information Center

Washington, Andre Lamont

2013-01-01

This study examined how desktop virtual reality environment training (DVRET) affected state anxiety and vocational identity of vocational rehabilitation services consumers during job placement/job readiness activities. It utilized a quantitative research model with a quasi-experimental pretest-posttest design plus some qualitative descriptive…

Doing Virtual Reference along with Everything Else

ERIC Educational Resources Information Center

Garlish, Betsy Harper

2009-01-01

Virtual reference is a service that makes particular sense in a state like Montana. The fourth-largest state by geographic area but 44th by population in the U.S., it has about one library per 11,392 residents. Montana's libraries, including the libraries of Montana Tech of the University of Montana, where the author currently serves as a…

Flow in E-learning: What Drives It and Why It Matters

ERIC Educational Resources Information Center

Rodríguez-Ardura, Inma; Meseguer-Artola, Antoni

2017-01-01

This paper seeks to explain why some individuals sink further into states of flow than others, and what effects flow has in the context of a virtual education environment. Our findings--gathered from both questionnaire and behavioural data--reveal that flow states are elicited by the e-learners' senses of controlling the virtual education…

Virtual Violence.

PubMed

2016-08-01

In the United States, exposure to media violence is becoming an inescapable component of children's lives. With the rise in new technologies, such as tablets and new gaming platforms, children and adolescents increasingly are exposed to what is known as "virtual violence." This form of violence is not experienced physically; rather, it is experienced in realistic ways via new technology and ever more intense and realistic games. The American Academy of Pediatrics continues to be concerned about children's exposure to virtual violence and the effect it has on their overall health and well-being. This policy statement aims to summarize the current state of scientific knowledge regarding the effects of virtual violence on children's attitudes and behaviors and to make specific recommendations for pediatricians, parents, industry, and policy makers. Copyright © 2016 by the American Academy of Pediatrics.

Empowering Teachers? An Exploratory Study of Personnel Practices in Virtual Charter Schools in the United States

ERIC Educational Resources Information Center

Beck, Dennis; Maranto, Robert

2014-01-01

Virtual charter schools have the potential to transform teacher personnel management. However, there is currently little evidence that they are doing so. This study examined how 89 teachers at two virtual charter schools perceived school personnel practices and leadership. Survey analysis indicated that teachers perceived personnel practices as…

Comparing the Performance and Preference of Students Experiencing a Reading Aloud Accommodation to Those Who Do Not on a Virtual Science Assessment

ERIC Educational Resources Information Center

Shelton, Angela

2012-01-01

Many United States secondary students perform poorly on standardized summative science assessments. Situated Assessments using Virtual Environments (SAVE) Science is an innovative assessment project that seeks to capture students' science knowledge and understanding by contextualizing problems in a game-based virtual environment called…

An Evaluative Case Study of Nine Virtual High School Programs

ERIC Educational Resources Information Center

Bannister, Clara M.

2009-01-01

The purpose of this study was to conduct a program evaluation of nine virtual high school programs in the states of Alabama, California, Florida, Idaho, Colorado, Illinois, Michigan, North Carolina and Massachusetts. In order to assess the quality and effectiveness of the virtual high school programs in the study in terms of overall quality and…

Virtual groundwater transfers from overexploited aquifers in the United States

PubMed Central

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J.

2015-01-01

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use. PMID:26124137

Virtual groundwater transfers from overexploited aquifers in the United States.

PubMed

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J

2015-07-14

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.

"Language Is a Costly and Complicating Factor": A Diachronic Study of Language Policy in the Virtual Public Sector

ERIC Educational Resources Information Center

Berezkina, Maimu

2018-01-01

This article examines language policy in the virtual linguistic landscape (VLL) in Norway and its development over time. The analysis is based on diachronic website data and interviews with state employees concerning the presence or absence of different languages on the websites of three central state institutions. The article reveals a linguistic…

A Preliminary Investigation of Maine Virtual Charter School Costs Relative to the Essential Programs and Services Funding Model

ERIC Educational Resources Information Center

Johnson, Amy F.; Hopper, Fleur; Sloan, James E.

2016-01-01

In 2015, the Maine State Legislature's Joint Standing Committee on Education and Cultural Affairs commissioned the Maine Education Policy Research Institute (MEPRI) to study the state's Essential Program and Services (EPS) K-12 education funding model in relationship to the funding for Maine's two virtual charter schools. The study was initiated…

National Security Implications of Virtual Currency: Examining the Potential for Non-state Actor Deployment

DTIC Science & Technology

2015-02-01

Centralization . . . . . . . . . . . . . . . . . . . . . . 43 “Anonymity”: A Bitcoin Case Study...been a case of x National Security Implications of Virtual Currency such a non-state actor deployment; in this report, we aim to high- light...development of VCs may advance, including a gen- eral increased sophistication in cryptographic applications. More gen- erally, we make the case that the main

Legal Protections and Advocacy for Contingent or "Casual" Workers in the United States: A Case Study in Day Labor

ERIC Educational Resources Information Center

Smith, Rebecca

2008-01-01

Contingent, non-standard or "casual" work is present in large numbers in virtually every sector of the United States economy. Staffing strategies that use subcontracted or contingent work--strategies that once characterized only some low-wage workers such as garment and agriculture--have now spread to virtually every area of industry, including…

Non-polynomial extensions of solvable potentials à la Abraham-Moses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odake, Satoru; Sasaki, Ryu; Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan

2013-10-15

Abraham-Moses transformations, besides Darboux transformations, are well-known procedures to generate extensions of solvable potentials in one-dimensional quantum mechanics. Here we present the explicit forms of infinitely many seed solutions for adding eigenstates at arbitrary real energy through the Abraham-Moses transformations for typical solvable potentials, e.g., the radial oscillator, the Darboux-Pöschl-Teller, and some others. These seed solutions are simple generalisations of the virtual state wavefunctions, which are obtained from the eigenfunctions by discrete symmetries of the potentials. The virtual state wavefunctions have been an essential ingredient for constructing multi-indexed Laguerre and Jacobi polynomials through multiple Darboux-Crum transformations. In contrast to themore » Darboux transformations, the virtual state wavefunctions generate non-polynomial extensions of solvable potentials through the Abraham-Moses transformations.« less

Pennsylvania | Midmarket Solar Policies in the United States | Solar

Science.gov Websites

ownership of renewable energy certificates (RECs). Meter aggregation: Virtual meter aggregation is allowed agreements are allowed in Pennsylvania. Community Solar Virtual net metering is allowed, enabling community

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Electronic Communications: Education Via a Virtual Workshop.

ERIC Educational Resources Information Center

Leibensperger, Roslyn; Mehringer, Susan; Trefethen, Anne; Kalos, Malvin

1997-01-01

Describes a virtual workshop where participants across the United States learn by interacting with their own computers. Highlights the program's goals, audience activity, goals versus accomplishments, CPU usage, consulting, and effectiveness. (Author/VWL)

Academic Library Consortia in Transition.

ERIC Educational Resources Information Center

Alberico, Ralph

2002-01-01

Using the example of the Virtual Library of Virginia, describes how library consortia are in a state of transformation as technology enables the development of virtual libraries while expanding opportunities for sharing printed works. (EV)

Towards incorporating affective computing to virtual rehabilitation; surrogating attributed attention from posture for boosting therapy adaptation

NASA Astrophysics Data System (ADS)

Rivas, Jesús J.; Heyer, Patrick; Orihuela-Espina, Felipe; Sucar, Luis Enrique

2015-01-01

Virtual rehabilitation (VR) is a novel motor rehabilitation therapy in which the rehabilitation exercises occurs through interaction with bespoken virtual environments. These virtual environments dynamically adapt their activity to match the therapy progress. Adaptation should be guided by the cognitive and emotional state of the patient, none of which are directly observable. Here, we present our first steps towards inferring non-observable attentional state from unobtrusively observable seated posture, so that this knowledge can later be exploited by a VR platform to modulate its behaviour. The space of seated postures was discretized and 648 pictures of acted representations were exposed to crowd-evaluation to determine attributed state of attention. A semi-supervised classifier based on Na¨ıve Bayes with structural improvement was learnt to unfold a predictive relation between posture and attributed attention. Internal validity was established following a 2×5 cross-fold strategy. Following 4959 votes from crowd, classification accuracy reached a promissory 96.29% (µ±σ = 87.59±6.59) and F-measure reached 82.35% (µ ± σ = 69.72 ± 10.50). With the afforded rate of classification, we believe it is safe to claim posture as a reliable proxy for attributed attentional state. It follows that unobtrusively monitoring posture can be exploited for guiding an intelligent adaptation in a virtual rehabilitation platform. This study further helps to identify critical aspects of posture permitting inference of attention.

Virtual Schools in the U.S. 2015: Politics, Performance, Policy, and Research Evidence

ERIC Educational Resources Information Center

Huerta, Luis; Shafer, Sheryl Rankin; Barbour, Michael K.; Miron, Gary; Gulosino, Charisse

2015-01-01

This 2015 report is third in a series of annual reports on virtual education in the U.S. It is organized in three major sections: Section I examines the policy and political landscape associated with virtual schooling and describes the current state of affairs related to finance and governance, instructional program quality, and teacher quality.…

Virtual Instrument Systems in Reality (VISIR) for Remote Wiring and Measurement of Electronic Circuits on Breadboard

ERIC Educational Resources Information Center

Tawfik, M.; Sancristobal, E.; Martin, S.; Gil, R.; Diaz, G.; Colmenar, A.; Peire, J.; Castro, M.; Nilsson, K.; Zackrisson, J.; Hakansson, L.; Gustavsson, I.

2013-01-01

This paper reports on a state-of-the-art remote laboratory project called Virtual Instrument Systems in Reality (VISIR). VISIR allows wiring and measuring of electronic circuits remotely on a virtual workbench that replicates physical circuit breadboards. The wiring mechanism is developed by means of a relay switching matrix connected to a PCI…

Virtual Reality Exposure Training for Musicians: Its Effect on Performance Anxiety and Quality.

PubMed

Bissonnette, Josiane; Dubé, Francis; Provencher, Martin D; Moreno Sala, Maria T

2015-09-01

Music performance anxiety affects numerous musicians, with many of them reporting impairment of performance due to this problem. This exploratory study investigated the effects of virtual reality exposure training on students with music performance anxiety. Seventeen music students were randomly assigned to a control group (n=8) or a virtual training group (n=9). Participants were asked to play a musical piece by memory in two separate recitals within a 3-week interval. Anxiety was then measured with the Personal Report of Confidence as a Performer Scale and the S-Anxiety scale from the State-Trait Anxiety Inventory (STAI-Y). Between pre- and post-tests, the virtual training group took part in virtual reality exposure training consisting of six 1-hour long sessions of virtual exposure. The results indicate a significant decrease in performance anxiety for musicians in the treatment group for those with a high level of state anxiety, for those with a high level of trait anxiety, for women, and for musicians with high immersive tendencies. Finally, between the pre- and post-tests, we observed a significant increase in performance quality for the experimental group, but not for the control group.

Spiritual and Affective Responses to a Physical Church and Corresponding Virtual Model.

PubMed

Murdoch, Matt; Davies, Jim

2017-11-01

Architectural and psychological theories posit that built environments have the potential to elicit complex psychological responses. However, few researchers have seriously explored this potential. Given the increasing importance and fidelity of virtual worlds, such research should explore whether virtual models of built environments are also capable of eliciting complex psychological responses. The goal of this study was to test these hypotheses, using a church, a corresponding virtual model, and an inclusive measure of state spirituality ("spiritual feelings"). Participants (n = 33) explored a physical church and corresponding virtual model, completing a measure of spiritual feelings after exploring the outside and inside of each version of the church. Using spiritual feelings after exploring the outside of the church as a baseline measure, change in state spirituality was assessed by taking the difference between spiritual feelings after exploring the inside and outside of the church (inside-outside) for both models. Although this change was greater in response to the physical church, there was no significant difference between the two models in eliciting such change in spiritual feelings. Despite the limitations of this exploratory study, these findings indicate that both built environments and corresponding virtual models are capable of evoking complex psychological responses.

Analysis of the social network development of a virtual community for Australian intensive care professionals.

PubMed

Rolls, Kaye Denise; Hansen, Margaret; Jackson, Debra; Elliott, Doug

2014-11-01

Social media platforms can create virtual communities, enabling healthcare professionals to network with a broad range of colleagues and facilitate knowledge exchange. In 2003, an Australian state health department established an intensive care mailing list to address the professional isolation experienced by senior intensive care nurses. This article describes the social network created within this virtual community by examining how the membership profile evolved from 2003 to 2009. A retrospective descriptive design was used. The data source was a deidentified member database. Since 2003, 1340 healthcare professionals subscribed to the virtual community with 78% of these (n = 1042) still members at the end of 2009. The membership profile has evolved from a single-state nurse-specific network to an Australia-wide multidisciplinary and multiorganizational intensive care network. The uptake and retention of membership by intensive care clinicians indicated that they appeared to value involvement in this virtual community. For healthcare organizations, a virtual community may be a communications option for minimizing professional and organizational barriers and promoting knowledge flow. Further research is, however, required to demonstrate a link between these broader social networks, enabling the exchange of knowledge and improved patient outcomes.

Neuro-parity pattern recognition system and method

DOEpatents

Gross, Kenneth C.; Singer, Ralph M.; Van Alstine, Rollin G.; Wegerich, Stephan W.; Yue, Yong

2000-01-01

A method and system for monitoring a process and determining its condition. Initial data is sensed, a first set of virtual data is produced by applying a system state analyzation to the initial data, a second set of virtual data is produced by applying a neural network analyzation to the initial data and a parity space analyzation is applied to the first and second set of virtual data and also to the initial data to provide a parity space decision about the condition of the process. A logic test can further be applied to produce a further system decision about the state of the process.

A Call to Action: To Improve the Quality of Full-Time Virtual Charter Public Schools

ERIC Educational Resources Information Center

National Alliance for Public Charter Schools, 2016

2016-01-01

Currently, more than 180,000 students attend 135 full-time virtual charter schools in 23 states and the District of Columbia. While some students do well in a full-time virtual charter school environment, too many of these schools are not providing a quality educational program to the vast majority of their students, while enrolling too many who…

Evaluation of South Carolina's virtual transit enterprise

DOT National Transportation Integrated Search

2005-09-09

The evaluation presents an assessment of South Carolina's Virtual Transit Enterprise (VTE) project up to February 2005. The VTE is a shared technology solution to bring the state's public transit providers together to solve mutual problems. The corne...

Asymptotic behavior and interpretation of virtual states: The effects of confinement and of basis sets

NASA Astrophysics Data System (ADS)

Boffi, Nicholas M.; Jain, Manish; Natan, Amir

2016-02-01

A real-space high order finite difference method is used to analyze the effect of spherical domain size on the Hartree-Fock (and density functional theory) virtual eigenstates. We show the domain size dependence of both positive and negative virtual eigenvalues of the Hartree-Fock equations for small molecules. We demonstrate that positive states behave like a particle in spherical well and show how they approach zero. For the negative eigenstates, we show that large domains are needed to get the correct eigenvalues. We compare our results to those of Gaussian basis sets and draw some conclusions for real-space, basis-sets, and plane-waves calculations.

Understanding virtual water flows: A multiregion input-output case study of Victoria

NASA Astrophysics Data System (ADS)

Lenzen, Manfred

2009-09-01

This article explains and interprets virtual water flows from the well-established perspective of input-output analysis. Using a case study of the Australian state of Victoria, it demonstrates that input-output analysis can enumerate virtual water flows without systematic and unknown truncation errors, an issue which has been largely absent from the virtual water literature. Whereas a simplified flow analysis from a producer perspective would portray Victoria as a net virtual water importer, enumerating the water embodiments across the full supply chain using input-output analysis shows Victoria as a significant net virtual water exporter. This study has succeeded in informing government policy in Australia, which is an encouraging sign that input-output analysis will be able to contribute much value to other national and international applications.

Ames Lab 101: C6: Virtual Engineering

ScienceCinema

McCorkle, Doug

2018-01-01

Ames Laboratory scientist Doug McCorkle explains the importance of virtual engineering and talks about the C6. The C6 is a three-dimensional, fully-immersive synthetic environment residing in the center atrium of Iowa State University's Howe Hall.

The Impact of Virtual Reality Distraction on Pain and Anxiety during Dental Treatment in 4-6 Year-Old Children: a Randomized Controlled Clinical Trial.

PubMed

Asl Aminabadi, Naser; Erfanparast, Leila; Sohrabi, Azin; Ghertasi Oskouei, Sina; Naghili, Armaghan

2012-01-01

Dental practitioners have numerous methods to control anxiety and pain in children, and distracting the child appears to be the most common technique used for behavior management during dental procedures. The aim of the present study was to evaluate the influence of using virtual reality eyeglasses on severity of pain and anxiety during dental procedures in pediatric patients. This study included 120 healthy children aged 4-6 years. Children with no previous anxiety disorder were randomly divided into two groups, each consisting of 60 children. The study consisted of 3 consecutive treatment sessions. During the first visit fluoride therapy was carried out in both groups. In the next sessions, the groups received restorative treatment with and without virtual reality eyeglasses in a randomized single-blind-controlled crossover fashion. Then at the end of each session the subjects' pain severity was assessed using Wong Baker FACES Pain Rating Scale and state anxiety was measured by Faces version of the Modified Child Dental Anxiety Scale [MCDAS (f)]. There was a significant decrease in pain perception (P < 0.001) and state anxiety scores (P < 0.001) with the use of virtual reality eyeglasses during dental treatment. Results of this study showed that virtual reality eyeglasses can successfully decrease pain perception and state anxiety during dental treatment. 201103126036N1.

Who Networks? The Social Psychology of Virtual Communities

DTIC Science & Technology

2004-06-01

virtual life: the open side - characterized by communities of interest, civil society movements, virtual “states,” and 4 online gaming communities...network of people hailing from Sicily. Sometimes the offline/ online similari- ties mesh even more, as when a gaming society in a small Swedish town...Commercially owned and regulated graphics-based Massively Multi- Player Gaming Communities (EverQuest, The Matrix Online ®, etc.) • UseNET

Compendium of Arms Control Verification Proposals.

DTIC Science & Technology

1982-03-01

proposals. This appears to be the case for virtually all kinds of prospective arms control topics from general and complete disarmament to control of specific... virtually anywhere. Unrestricted access would be particularly necessary in the case of states which previously had nuclear weapons. Practically speaking...been transferred out of the area, it would be harder to check on remaining stocks without some intrusive inspection and it would be virtually impossible

The virtual slice setup.

PubMed

Lytton, William W; Neymotin, Samuel A; Hines, Michael L

2008-06-30

In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

Shared virtual environments for aerospace training

NASA Technical Reports Server (NTRS)

Loftin, R. Bowen; Voss, Mark

1994-01-01

Virtual environments have the potential to significantly enhance the training of NASA astronauts and ground-based personnel for a variety of activities. A critical requirement is the need to share virtual environments, in real or near real time, between remote sites. It has been hypothesized that the training of international astronaut crews could be done more cheaply and effectively by utilizing such shared virtual environments in the early stages of mission preparation. The Software Technology Branch at NASA's Johnson Space Center has developed the capability for multiple users to simultaneously share the same virtual environment. Each user generates the graphics needed to create the virtual environment. All changes of object position and state are communicated to all users so that each virtual environment maintains its 'currency.' Examples of these shared environments will be discussed and plans for the utilization of the Department of Defense's Distributed Interactive Simulation (DIS) protocols for shared virtual environments will be presented. Finally, the impact of this technology on training and education in general will be explored.

Community-based pedestrian safety training in virtual reality : a pragmatic trial.

DOT National Transportation Integrated Search

2015-06-01

Child pedestrian injuries are a leading cause of mortality and morbidity across the United States : and the world. Repeated practice at the cognitive-perceptual task of crossing a street may lead to : safer pedestrian behavior. Virtual reality offers...

Virtual Reality.

ERIC Educational Resources Information Center

Newby, Gregory B.

1993-01-01

Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

Human Behavior Representation in Constructive Simulation (La representation du comportement humain dans la simulation constructive)

DTIC Science & Technology

2009-09-01

Environmental Medicine USN United States Navy VAE Virtual Air Environment VACP Visual, Auditory, Cognitive, Psychomotor (demand) VR Virtual Reality ...0 .5 m/s. Another useful approach to capturing leg, trunk, whole body, or movement tasks comes from virtual reality - based training research and...referred to as semi-automated forces (SAF). From: http://www.sedris.org/glossary.htm#C_grp. Constructive Models Abstractions from the reality to

The Role of a Multidimensional Concept of Trust in the Performance of Global Virtual Teams

NASA Technical Reports Server (NTRS)

Bodensteiner, Nan Muir; Stecklein, Jonette M.

2002-01-01

This paper focuses on the concept of trust as an important ingredient of effective global virtual team performance. Definitions of trust and virtual teams are presented. The concept of trust is developed from its unilateral application (trust, absence of trust) to a multidimensional concept including cognitive and affective components. The special challenges of a virtual team are then discussed with particular emphasis on how a multidimensional concept of trust impacts these challenges. Propositions suggesting the multidimensional concept of trust moderates the negative impacts of distance, cross cultural and organizational differences, the effects of electronically mediated communication, reluctance to share information and a lack of hi story/future on the performance of virtual teams are stated. The paper concludes with recommendations and a set of techniques to build both cognitive and affective trust in virtual teams.

VIRTUAL SYMPOSIUM: STATE OF THE SCIENCE--PPCPS AS ENVIRONMENTAL POLLUTANTS

EPA Science Inventory

This document provides a brief summary of how this pioneering meeting for the ACS was conducted, as well as some perspective and insights that could prove useful for those who might beinterested in organizing and hosting their own "virtual" meeting.

Effects of simulation fidelity on user experience in virtual fear of public speaking training - an experimental study.

PubMed

Poeschl, Sandra; Doering, Nicola

2014-01-01

Realistic models in virtual reality training applications are considered to positively influence presence and performance. The experimental study presented, analyzed the effect of simulation fidelity (static vs. animated audience) on presence as a prerequisite for performance in a prototype virtual fear of public speaking application with a sample of N = 40 academic non-phobic users. Contrary to the state of research, no influence was shown on virtual presence and perceived realism, but an animated audience led to significantly higher effects in anxiety during giving a talk. Although these findings could be explained by an application that might not have been realistic enough, they still question the role of presence as a mediating factor in virtual exposure applications.

Assessment of emotional reactivity produced by exposure to virtual environments in patients with eating disorders.

PubMed

Gutiérrez-Maldonado, José; Ferrer-García, Marta; Caqueo-Urízar, Alejandra; Letosa-Porta, Alex

2006-10-01

The aim of this study was to assess the usefulness of virtual environments representing situations that are emotionally significant to subjects with eating disorders (ED). These environments may be applied with both evaluative and therapeutic aims and in simulation procedures to carry out a range of experimental studies. This paper is part of a wider research project analyzing the influence of the situation to which subjects are exposed on their performance on body image estimation tasks. Thirty female patients with eating disorders were exposed to six virtual environments: a living-room (neutral situation), a kitchen with high-calorie food, a kitchen with low-calorie food, a restaurant with high-calorie food, a restaurant with low-calorie food, and a swimming-pool. After exposure to each environment the STAI-S (a measurement of state anxiety) and the CDB (a measurement of depression) were administered to all subjects. The results show that virtual reality instruments are particularly useful for simulating everyday situations that may provoke emotional reactions such as anxiety and depression, in patients with ED. Virtual environments in which subjects are obliged to ingest high-calorie food provoke the highest levels of state anxiety and depression.

Challenges of Virtual School Leadership

ERIC Educational Resources Information Center

Richardson, Jayson W.; LaFrance, Jason; Beck, Dennis

2015-01-01

The purpose of this case study was to examine challenges faced by virtual school leaders in the United States. Through semistructured interviews, the researchers explored challenges faced by eighteen leaders of fully online or blended online programs. Analysis revealed six main challenges: funding, staff, accountability, time, parents, and…

Curriculum Orientations of Virtual Teachers

ERIC Educational Resources Information Center

Singleton, Nicole Y.

2013-01-01

This study explored the curriculum orientation preferences of K-12 public school teachers who provided instruction in virtual settings (n = 47) in a midwestern state. Curriculum orientations were explored using a mixed-methods design. Quantitative assessments data revealed a pattern of curriculum orientations similar to teachers working in…

Virtually Usable: A Test of the Information Gardens

ERIC Educational Resources Information Center

Johnson, Megan; Ochoa, Louise; Purpur, Geraldine

2007-01-01

This paper presents the results of a usability study conducted to determine the functionality of a desktop, three-dimensional virtual library designed and supported by the Appalachian State University Distance Learning Library Services team. Formative evaluations were performed with representative students utilizing Morae software. Results…

E-Government Attempts in Small Island Developing States: The Rate of Corruption with Virtualization.

PubMed

Sari, Arif

2017-12-01

In recent years, many Small Island Developing State (SIDS) governments have worked to increase openness and transparency of their transactions as a means to enhance efficiency and reduce corruption in their economies. In order to achieve a cost-effective and efficient strategy to implement a transparent government, Information Communication Technologies offer an opportunity of virtualization by deploying e-government services to promote transparency, accountability and consistency in the public sector and to minimize corruption. This paper explores the potential impact of government virtualization by SIDS and against corruption by comparing the corruption perception index (CPI) rates of 15 SIDS countries. The CPI relates to the degree by which corruption is perceived to exist among public officials and politicians by business people and country analysts. In order to reveal the long-term impact of virtual deployment and its consequences on corruption, an in-depth case analysis based on the CPI index rates was conducted on the deployment of the e-government system in Cyprus.

Environmental Social Stress, Paranoia and Psychosis Liability: A Virtual Reality Study

PubMed Central

Veling, Wim; Pot-Kolder, Roos; Counotte, Jacqueline; van Os, Jim; van der Gaag, Mark

2016-01-01

The impact of social environments on mental states is difficult to assess, limiting the understanding of which aspects of the social environment contribute to the onset of psychotic symptoms and how individual characteristics moderate this outcome. This study aimed to test sensitivity to environmental social stress as a mechanism of psychosis using Virtual Reality (VR) experiments. Fifty-five patients with recent onset psychotic disorder, 20 patients at ultra high risk for psychosis, 42 siblings of patients with psychosis, and 53 controls walked 5 times in a virtual bar with different levels of environmental social stress. Virtual social stressors were population density, ethnic density and hostility. Paranoia about virtual humans and subjective distress in response to virtual social stress exposures were measured with State Social Paranoia Scale (SSPS) and self-rated momentary subjective distress (SUD), respectively. Pre-existing (subclinical) symptoms were assessed with the Community Assessment of Psychic Experiences (CAPE), Green Paranoid Thoughts Scale (GPTS) and the Social Interaction Anxiety Scale (SIAS). Paranoia and subjective distress increased with degree of social stress in the environment. Psychosis liability and pre-existing symptoms, in particular negative affect, positively impacted the level of paranoia and distress in response to social stress. These results provide experimental evidence that heightened sensitivity to environmental social stress may play an important role in the onset and course of psychosis. PMID:27038469

Interpretations of virtual reality.

PubMed

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.

Introduction of Virtualization Technology to Multi-Process Model Checking

NASA Technical Reports Server (NTRS)

Leungwattanakit, Watcharin; Artho, Cyrille; Hagiya, Masami; Tanabe, Yoshinori; Yamamoto, Mitsuharu

2009-01-01

Model checkers find failures in software by exploring every possible execution schedule. Java PathFinder (JPF), a Java model checker, has been extended recently to cover networked applications by caching data transferred in a communication channel. A target process is executed by JPF, whereas its peer process runs on a regular virtual machine outside. However, non-deterministic target programs may produce different output data in each schedule, causing the cache to restart the peer process to handle the different set of data. Virtualization tools could help us restore previous states of peers, eliminating peer restart. This paper proposes the application of virtualization technology to networked model checking, concentrating on JPF.

New perspectives and limitations in the use of virtual reality in the rehabilitation of motor disorders

NASA Astrophysics Data System (ADS)

De Mauro, Alessandro; Ardanza, Aitor; Monge, Esther; Molina Rueda, Francisco

2013-03-01

Several studies have shown that both virtual and augmented reality are technologies suitable for rehabilitation therapy due to the inherent ability of simulating real daily life activities while improving patient motivation. In this paper we will first present the state of the art in the use of virtual and augmented reality applications for rehabilitation of motor disorders and second we will focus on the analysis of the results of our project. In particular, requirements of patients with cerebrovascular accidents, spinal cord injuries and cerebral palsy to the use of virtual and augmented reality systems will be detailed.

Virtual screening of compound libraries.

PubMed

Cerqueira, Nuno M F S A; Sousa, Sérgio F; Fernandes, Pedro A; Ramos, Maria João

2009-01-01

During the last decade, Virtual Screening (VS) has definitively established itself as an important part of the drug discovery and development process. VS involves the selection of likely drug candidates from large libraries of chemical structures by using computational methodologies, but the generic definition of VS encompasses many different methodologies. This chapter provides an introduction to the field by reviewing a variety of important aspects, including the different types of virtual screening methods, and the several steps required for a successful virtual screening campaign within a state-of-the-art approach, from target selection to postfilter application. This analysis is further complemented with a small collection important VS success stories.

Comparative study of state-of-the-art myoelectric controllers for multigrasp prosthetic hands.

PubMed

Segil, Jacob L; Controzzi, Marco; Weir, Richard F ff; Cipriani, Christian

2014-01-01

A myoelectric controller should provide an intuitive and effective human-machine interface that deciphers user intent in real-time and is robust enough to operate in daily life. Many myoelectric control architectures have been developed, including pattern recognition systems, finite state machines, and more recently, postural control schemes. Here, we present a comparative study of two types of finite state machines and a postural control scheme using both virtual and physical assessment procedures with seven nondisabled subjects. The Southampton Hand Assessment Procedure (SHAP) was used in order to compare the effectiveness of the controllers during activities of daily living using a multigrasp artificial hand. Also, a virtual hand posture matching task was used to compare the controllers when reproducing six target postures. The performance when using the postural control scheme was significantly better (p < 0.05) than the finite state machines during the physical assessment when comparing within-subject averages using the SHAP percent difference metric. The virtual assessment results described significantly greater completion rates (97% and 99%) for the finite state machines, but the movement time tended to be faster (2.7 s) for the postural control scheme. Our results substantiate that postural control schemes rival other state-of-the-art myoelectric controllers.

Technology for performing ocular self-examination: comparison between printed and virtual booklets.

PubMed

Nascimento, Jennara Candido; Lima, Maria Alzete; Barros, Lívia Moreira; Galindo Neto, Nelson Miguel; Pagliuca, Lorita Marlena Freitag; Caetano, Joselany Áfio

2018-01-01

Comparing the results of the ocular self-examination performed with the aid of printed and virtual versions of an educational booklet. A quasi-experimental study carried out in a state (public) school of a capital in northeast Brazil, with 100 students equally divided into control and intervention groups according to age, gender, schooling and economic status. Pearson's Chi-square test and Fisher's exact test were applied with a significance level of 5%. The results of the self-examination obtained by the virtual and printed booklets were statistically similar, except for the item 'Alterations of the pupillary reflex', in which the virtual booklet was more effective for its identification (p=0.049). The printed and virtual versions of the ocular educational booklet have similar efficacy for performing ocular self-examination.

Connecticut | Midmarket Solar Policies in the United States | Solar

Science.gov Websites

(RECs) Meter aggregation: Virtual net metering allowed for state, municipal, and agricultural customers " under a state, municipal, or agricultural host under certain conditions. Net excess generation

Virtual Reality and Cyberspace: From Science Fiction to Science Fact.

ERIC Educational Resources Information Center

Stone, Robert J.

1991-01-01

Traces the history of virtual reality (VR), or cyberspace, and describes some of the research and development efforts currently being carried out in the United Kingdom, Europe, and the United States. Applications of VR in interactive computer-aided design (CAD), the military, leisure activities, spaceflight, teleconferencing, and medicine are…

Portals for Undergraduate Subject Searching: Are They Worth It?

ERIC Educational Resources Information Center

Nichols, Jane; Mellinger, Margaret

2007-01-01

In spring 2005, a task force of Oregon State University librarians investigated whether undergraduates would gravitate toward subject portals tentatively named "virtual college libraries." A literature review and Web site inventory shaped our definition of a virtual college library. A preliminary needs assessment consisting of an online…

A Virtual World for Collaboration: The AETZone

ERIC Educational Resources Information Center

Cheney, Amelia W.; Sanders, Robert L.; Matzen, Nita J.; Bronack, Stephen C.; Riedl, Richard E.; Tashner, John H.

2009-01-01

Participation in learning communities, and the construction of knowledge in communities of practice, are important considerations in the use of 3D immersive worlds. This article describes the creation of this type of learning environment in AETZone, an immersive virtual environment in use within graduate programs at Appalachian State University…

Are You Ready for Knowledge Sharing? An Empirical Study of Virtual Communities

ERIC Educational Resources Information Center

Hung, Shiu-Wan; Cheng, Min-Jhih

2013-01-01

This study aimed to explore the relationship between knowledge sharing intentions and the perceptions of individual technology users who are members of virtual communities. We characterized learners' perceptions of new technological products or services by including both an individual's psychological state of readiness to accept technology and…

The Reality of Virtual Learning.

ERIC Educational Resources Information Center

Berman, Sheldon

1999-01-01

Through a $7.5 million U.S. Department of Education grant, students at the Hudson (Massachusetts) Public Schools "attend" Virtual High School--a network of 30 schools in 10 states. Kids attend classes any time, work collaboratively, and choose among innovative, timely, technologically rich course offerings. Other sites are described.…

Virtual Labs vs. Remote Labs: Between Myth & Reality.

ERIC Educational Resources Information Center

Alhalabi, Bassem; Hamza, M. Khalid; Hsu, Sam; Romance, Nancy

Many United States institutions of higher education have established Web-based educational environments that provide higher education curricula via the Internet and diverse modalities. Success has been limited primarily to virtual classrooms (real audio/video transmission) and/or test taking (online form filing). An extensive survey was carried…

Building a Collaborative Online Literary Experience

ERIC Educational Resources Information Center

Essid, Joe; Wilde, Fran

2011-01-01

Effective virtual simulations can embed participants in imaginary worlds. Researchers working in virtual worlds and gaming often refer to "immersion," a state in which a participant or player loses track of time and becomes one with the simulation. Immersive settings have been shown to deepen learning. Ken Hudson's work with students…

Data-driven model reference control of MIMO vertical tank systems with model-free VRFT and Q-Learning.

PubMed

Radac, Mircea-Bogdan; Precup, Radu-Emil; Roman, Raul-Cristian

2018-02-01

This paper proposes a combined Virtual Reference Feedback Tuning-Q-learning model-free control approach, which tunes nonlinear static state feedback controllers to achieve output model reference tracking in an optimal control framework. The novel iterative Batch Fitted Q-learning strategy uses two neural networks to represent the value function (critic) and the controller (actor), and it is referred to as a mixed Virtual Reference Feedback Tuning-Batch Fitted Q-learning approach. Learning convergence of the Q-learning schemes generally depends, among other settings, on the efficient exploration of the state-action space. Handcrafting test signals for efficient exploration is difficult even for input-output stable unknown processes. Virtual Reference Feedback Tuning can ensure an initial stabilizing controller to be learned from few input-output data and it can be next used to collect substantially more input-state data in a controlled mode, in a constrained environment, by compensating the process dynamics. This data is used to learn significantly superior nonlinear state feedback neural networks controllers for model reference tracking, using the proposed Batch Fitted Q-learning iterative tuning strategy, motivating the original combination of the two techniques. The mixed Virtual Reference Feedback Tuning-Batch Fitted Q-learning approach is experimentally validated for water level control of a multi input-multi output nonlinear constrained coupled two-tank system. Discussions on the observed control behavior are offered. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

A real signal and its states

NASA Astrophysics Data System (ADS)

Basiladze, S. G.

2017-05-01

The paper describes the general physical theory of signals, carriers of information, which supplements Shannon's abstract classical theory and is applicable in much broader fields, including nuclear physics. It is shown that in the absence of classical noise its place should be taken by the physical threshold of signal perception for objects of both macrocosm and microcosm. The signal perception threshold allows the presence of subthreshold (virtual) signal states. For these states, Boolean algebra of logic ( A = 0/1) is transformed into the "algebraic logic" of probabilities (0 ≤ a ≤ 1). The similarity and difference of virtual states of macroand microsignals are elucidated. "Real" and "quantum" information for computers is considered briefly. The maximum information transmission rate is estimated based on physical constants.

Environmental Social Stress, Paranoia and Psychosis Liability: A Virtual Reality Study.

PubMed

Veling, Wim; Pot-Kolder, Roos; Counotte, Jacqueline; van Os, Jim; van der Gaag, Mark

2016-11-01

The impact of social environments on mental states is difficult to assess, limiting the understanding of which aspects of the social environment contribute to the onset of psychotic symptoms and how individual characteristics moderate this outcome. This study aimed to test sensitivity to environmental social stress as a mechanism of psychosis using Virtual Reality (VR) experiments. Fifty-five patients with recent onset psychotic disorder, 20 patients at ultra high risk for psychosis, 42 siblings of patients with psychosis, and 53 controls walked 5 times in a virtual bar with different levels of environmental social stress. Virtual social stressors were population density, ethnic density and hostility. Paranoia about virtual humans and subjective distress in response to virtual social stress exposures were measured with State Social Paranoia Scale (SSPS) and self-rated momentary subjective distress (SUD), respectively. Pre-existing (subclinical) symptoms were assessed with the Community Assessment of Psychic Experiences (CAPE), Green Paranoid Thoughts Scale (GPTS) and the Social Interaction Anxiety Scale (SIAS). Paranoia and subjective distress increased with degree of social stress in the environment. Psychosis liability and pre-existing symptoms, in particular negative affect, positively impacted the level of paranoia and distress in response to social stress. These results provide experimental evidence that heightened sensitivity to environmental social stress may play an important role in the onset and course of psychosis. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Virtual Estimator for Piecewise Linear Systems Based on Observability Analysis

PubMed Central

Morales-Morales, Cornelio; Adam-Medina, Manuel; Cervantes, Ilse; Vela-Valdés and, Luis G.; García Beltrán, Carlos Daniel

2013-01-01

This article proposes a virtual sensor for piecewise linear systems based on observability analysis that is in function of a commutation law related with the system's outpu. This virtual sensor is also known as a state estimator. Besides, it presents a detector of active mode when the commutation sequences of each linear subsystem are arbitrary and unknown. For the previous, this article proposes a set of virtual estimators that discern the commutation paths of the system and allow estimating their output. In this work a methodology in order to test the observability for piecewise linear systems with discrete time is proposed. An academic example is presented to show the obtained results. PMID:23447007

Handheld Micromanipulation with Vision-Based Virtual Fixtures

PubMed Central

Becker, Brian C.; MacLachlan, Robert A.; Hager, Gregory D.; Riviere, Cameron N.

2011-01-01

Precise movement during micromanipulation becomes difficult in submillimeter workspaces, largely due to the destabilizing influence of tremor. Robotic aid combined with filtering techniques that suppress tremor frequency bands increases performance; however, if knowledge of the operator's goals is available, virtual fixtures have been shown to greatly improve micromanipulator precision. In this paper, we derive a control law for position-based virtual fixtures within the framework of an active handheld micromanipulator, where the fixtures are generated in real-time from microscope video. Additionally, we develop motion scaling behavior centered on virtual fixtures as a simple and direct extension to our formulation. We demonstrate that hard and soft (motion-scaled) virtual fixtures outperform state-of-the-art tremor cancellation performance on a set of artificial but medically relevant tasks: holding, move-and-hold, curve tracing, and volume restriction. PMID:23275860

Virtual Tutoring and Student Support Systems

ERIC Educational Resources Information Center

Geary, Jennifer Lee

2005-01-01

Virtual tutoring and student support systems may be pivotal in developing opportunities of equality and of outcome for students who study at a distance. Cookson (2002) mentions that it is important to assist students to have access to study programs. Cookson (2002) elaborates upon this and states, "If access is to be equitable, once they are…

The Participatory Design of a (Today and) Future Digital Entomology Lab

ERIC Educational Resources Information Center

Hai-Jew, Shalin

2011-01-01

This article showcases a virtual interactive participatory design activity for building a digital entomology lab. Conceptualized as a virtual complement to a general entomology course at Kansas State University, the lab would allow learners to explore morphological aspects of insects--their various forms and functions--in order to understand…

Pre-Service Teachers' Preconceptions, Misconceptions, and Concerns about Virtual Schooling

ERIC Educational Resources Information Center

Compton, Lily; Davis, Niki; Correia, Ana-Paula

2010-01-01

Over the last decade, online distance education has become a common mode of study in most states in the USA, where it is known as virtual schooling (VS), but many people have misconceptions about it. Pre-service teachers' personal histories as students and their preconceptions, misconceptions, and concerns influence pre-service teacher training…

Growth and Performance of Fully Online and Blended K-12 Public Schools

ERIC Educational Resources Information Center

Gulosino, Charisse; Miron, Gary

2017-01-01

This study provides a census of full-time virtual schools and blended schools from 35 states. Specifically, it utilizes data visualization and exploratory data analysis to examine student demographics and school performance measures of virtual schools and blended schools operating in the 2014-15 school year. The school achievement measures for…

Leadership Trust in Virtual Teams Using Communication Tools: A Quantitative Correlational Study

ERIC Educational Resources Information Center

Clark, Robert Lynn

2014-01-01

The purpose of this quantitative correlational study was to address leadership trust in virtual teams using communication tools in a small south-central, family-owned pharmaceutical organization, with multiple dispersed locations located in the United States. The results of the current research study could assist leaders to develop a communication…

Virtual Counseling for Students Enrolled in Online Educational Programs

ERIC Educational Resources Information Center

Currie, Nikki S.

2010-01-01

Virtual schools are increasing in popularity as a method of providing formal education for a growing number of students in the United States. The economy, coupled with technological advances and parental demand for a more personalized, innovative, individually tailored, and high quality education alternative for their children has led to the…

Visual Perspectives within Educational Computer Games: Effects on Presence and Flow within Virtual Immersive Learning Environments

ERIC Educational Resources Information Center

Scoresby, Jon; Shelton, Brett E.

2011-01-01

The mis-categorizing of cognitive states involved in learning within virtual environments has complicated instructional technology research. Further, most educational computer game research does not account for how learning activity is influenced by factors of game content and differences in viewing perspectives. This study is a qualitative…

Pursuing the Panderer: An Analysis of "United States v. Williams"

ERIC Educational Resources Information Center

McGrain, Patrick N.; Moore, Jennifer L.

2010-01-01

In May 2008, the Supreme Court addressed whether the government can regulate the ownership and distribution of virtual child pornography. "U.S. v. Williams" marked the first time the Court directly addressed the concept of pandering virtual child pornography. This article examines the Court's decision in "U.S. v. Williams" and…

Objective and subjective quality assessment of geometry compression of reconstructed 3D humans in a 3D virtual room

NASA Astrophysics Data System (ADS)

Mekuria, Rufael; Cesar, Pablo; Doumanis, Ioannis; Frisiello, Antonella

2015-09-01

Compression of 3D object based video is relevant for 3D Immersive applications. Nevertheless, the perceptual aspects of the degradation introduced by codecs for meshes and point clouds are not well understood. In this paper we evaluate the subjective and objective degradations introduced by such codecs in a state of art 3D immersive virtual room. In the 3D immersive virtual room, users are captured with multiple cameras, and their surfaces are reconstructed as photorealistic colored/textured 3D meshes or point clouds. To test the perceptual effect of compression and transmission, we render degraded versions with different frame rates in different contexts (near/far) in the scene. A quantitative subjective study with 16 users shows that negligible distortion of decoded surfaces compared to the original reconstructions can be achieved in the 3D virtual room. In addition, a qualitative task based analysis in a full prototype field trial shows increased presence, emotion, user and state recognition of the reconstructed 3D Human representation compared to animated computer avatars.

Cosmology of Universe Particles and Beyond

NASA Astrophysics Data System (ADS)

Xu, Wei

2016-06-01

For the first time in history, all properties of cosmology particles are uncovered and described concisely and systematically, known as the elementary particles in contemporary physics.Aligning with the synthesis of the virtual and physical worlds in a hierarchical taxonomy of the universe, this theory refines the topology framework of cosmology, and presents a new perspective of the Yin Yang natural laws that, through the processes of creation and reproduction, the fundamental elements generate an infinite series of circular objects and a Yin Yang duality of dynamic fields that are sequenced and transformed states of matter between the virtual and physical worlds.Once virtual objects are transformed, they embody various enclaves of energy states, known as dark energy, quarks, leptons, bosons, protons, and neutrons, characterized by their incentive oscillations of timestate variables in a duality of virtual realities: energy and time, spin and charge, mass and space, symmetry and antisymmetry.As a consequence, it derives the fully-scaled quantum properties of physical particles in accordance with numerous historical experiments, and has overcome the limitations of uncertainty principle and the Standard Model, towards concisely exploring physical nature and beyond...

Inter-City Virtual Water Transfers Within a Large Metropolitan Area: A Case Study of the Phoenix Metropolitan Area in the United States

NASA Astrophysics Data System (ADS)

Rushforth, R.; Ruddell, B. L.

2014-12-01

Water footprints have been proposed as potential sustainability indicators, but these analyses have thus far focused at the country-level or regional scale. However, for many countries, especially the United States, the most relevant level of water decision-making is the city. For water footprinting to inform urban sustainability, the boundaries for analysis must match the relevant boundaries for decision-making and economic development. Initial studies into city-level water footprints have provided insight into how large cities across the globe—Delhi, Lagos, Berlin, Beijing, York—create virtual water trade linkages with distant hinterlands. This study hypothesizes that for large cities the most direct and manageable virtual water flows exist at the metropolitan area scale and thus should provide the most policy-relevant information. This study represents an initial attempt at quantifying intra-metropolitan area virtual water flows. A modified commodity-by-industry input-output model was used to determine virtual water flows destined to, occurring within, and emanating from the Phoenix metropolitan area (PMA). Virtual water flows to and from the PMA were calculated for each PMA city using water consumption data as well as economic and industry statistics. Intra-PMA virtual water trade was determined using county-level traffic flow data, water consumption data, and economic and industry statistics. The findings show that there are archetypal cities within metropolitan areas and that each type of city has a distinct water footprint profile that is related to the value added economic processes occuring within their boundaries. These findings can be used to inform local water managers about the resilience of outsourced water supplies.

[Virtual reality in medical education].

PubMed

Edvardsen, O; Steensrud, T

1998-02-28

Virtual reality technology has found new applications in industry over the last few years. Medical literature has for several years predicted a break-through in this technology for medical education. Although there is a great potential for this technology in medical education, there seems to be a wide gap between expectations and actual possibilities at present. State of the technology was explored by participation at the conference "Medicine meets virtual reality V" (San Diego Jan. 22-25 1997) and a visit to one of the leading laboratories on virtual reality in medical education. In this paper we introduce some of the basic terminology and technology, review some of the topics covered by the conference, and describe projects running in one of the leading laboratories on virtual reality technology for medical education. With this information in mind, we discuss potential applications of the current technology in medical education. Current virtual reality systems are judged to be too costly and their usefulness in education too limited for routine use in medical education.

A Comprehensive Availability Modeling and Analysis of a Virtualized Servers System Using Stochastic Reward Nets

PubMed Central

Kim, Dong Seong; Park, Jong Sou

2014-01-01

It is important to assess availability of virtualized systems in IT business infrastructures. Previous work on availability modeling and analysis of the virtualized systems used a simplified configuration and assumption in which only one virtual machine (VM) runs on a virtual machine monitor (VMM) hosted on a physical server. In this paper, we show a comprehensive availability model using stochastic reward nets (SRN). The model takes into account (i) the detailed failures and recovery behaviors of multiple VMs, (ii) various other failure modes and corresponding recovery behaviors (e.g., hardware faults, failure and recovery due to Mandelbugs and aging-related bugs), and (iii) dependency between different subcomponents (e.g., between physical host failure and VMM, etc.) in a virtualized servers system. We also show numerical analysis on steady state availability, downtime in hours per year, transaction loss, and sensitivity analysis. This model provides a new finding on how to increase system availability by combining both software rejuvenations at VM and VMM in a wise manner. PMID:25165732

Producing coherent excitations in pumped Mott antiferromagnetic insulators

NASA Astrophysics Data System (ADS)

Wang, Yao; Claassen, Martin; Moritz, B.; Devereaux, T. P.

2017-12-01

Nonequilibrium dynamics in correlated materials has attracted attention due to the possibility of characterizing, tuning, and creating complex ordered states. To understand the photoinduced microscopic dynamics, especially the linkage under realistic pump conditions between transient states and remnant elementary excitations, we performed nonperturbative simulations of various time-resolved spectroscopies. We used the Mott antiferromagnetic insulator as a model platform. The transient dynamics of multiparticle excitations can be attributed to the interplay between Floquet virtual states and a modification of the density of states, in which interactions induce a spectral weight transfer. Using an autocorrelation of the time-dependent spectral function, we show that resonance of the virtual states with the upper Hubbard band in the Mott insulator provides the route towards manipulating the electronic distribution and modifying charge and spin excitations. Our results link transient dynamics to the nature of many-body excitations and provide an opportunity to design nonequilibrium states of matter via tuned laser pulses.

Entanglement entropy between real and virtual particles in ϕ4 quantum field theory

NASA Astrophysics Data System (ADS)

Ardenghi, Juan Sebastián

2015-04-01

The aim of this work is to compute the entanglement entropy of real and virtual particles by rewriting the generating functional of ϕ4 theory as a mean value between states and observables defined through the correlation functions. Then the von Neumann definition of entropy can be applied to these quantum states and in particular, for the partial traces taken over the internal or external degrees of freedom. This procedure can be done for each order in the perturbation expansion showing that the entanglement entropy for real and virtual particles behaves as ln (m0). In particular, entanglement entropy is computed at first order for the correlation function of two external points showing that mutual information is identical to the external entropy and that conditional entropies are negative for all the domain of m0. In turn, from the definition of the quantum states, it is possible to obtain general relations between total traces between different quantum states of a ϕr theory. Finally, discussion about the possibility of taking partial traces over external degrees of freedom is considered, which implies the introduction of some observables that measure space-time points where an interaction occurs.

Human Activity Behavior and Gesture Generation in Virtual Worlds for Long- Duration Space Missions. Chapter 8

NASA Technical Reports Server (NTRS)

Sierhuis, Maarten; Clancey, William J.; Damer, Bruce; Brodsky, Boris; vanHoff, Ron

2007-01-01

A virtual worlds presentation technique with embodied, intelligent agents is being developed as an instructional medium suitable to present in situ training on long term space flight. The system combines a behavioral element based on finite state automata, a behavior based reactive architecture also described as subsumption architecture, and a belief-desire-intention agent structure. These three features are being integrated to describe a Brahms virtual environment model of extravehicular crew activity which could become a basis for procedure training during extended space flight.

Virtual water trade and bilateral conflicts

NASA Astrophysics Data System (ADS)

De Angelis, Enrico; Metulini, Rodolfo; Bove, Vincenzo; Riccaboni, Massimo

2017-12-01

In light of growing water scarcity, virtual water, or the water embedded in key water-intensive commodities, has been an active area of debate among practitioners and academics alike. As of yet, however, there is no consensus on whether water scarcity affects conflict behavior and we still lack empirical research intending to account for the role of virtual water in affecting the odds of militarized disputes between states. Using quantitative methods and data on virtual water trade, we find that bilateral and multilateral trade openness reduce the probability of war between any given pair of countries, which is consistent with the strategic role of this important commodity and the opportunity cost associated with the loss of trade gains. We also find that the substantive effect of virtual water trade is comparable to that of oil and gas, the archetypal natural resources, in determining interstate conflicts' probability.

VTAC: virtual terrain assisted impact assessment for cyber attacks

NASA Astrophysics Data System (ADS)

Argauer, Brian J.; Yang, Shanchieh J.

2008-03-01

Overwhelming intrusion alerts have made timely response to network security breaches a difficult task. Correlating alerts to produce a higher level view of intrusion state of a network, thus, becomes an essential element in network defense. This work proposes to analyze correlated or grouped alerts and determine their 'impact' to services and users of the network. A network is modeled as 'virtual terrain' where cyber attacks maneuver. Overlaying correlated attack tracks on virtual terrain exhibits the vulnerabilities exploited by each track and the relationships between them and different network entities. The proposed impact assessment algorithm utilizes the graph-based virtual terrain model and combines assessments of damages caused by the attacks. The combined impact scores allow to identify severely damaged network services and affected users. Several scenarios are examined to demonstrate the uses of the proposed Virtual Terrain Assisted Impact Assessment for Cyber Attacks (VTAC).

Improvement of two-way continuous-variable quantum key distribution with virtual photon subtraction

NASA Astrophysics Data System (ADS)

Zhao, Yijia; Zhang, Yichen; Li, Zhengyu; Yu, Song; Guo, Hong

2017-08-01

We propose a method to improve the performance of two-way continuous-variable quantum key distribution protocol by virtual photon subtraction. The virtual photon subtraction implemented via non-Gaussian post-selection not only enhances the entanglement of two-mode squeezed vacuum state but also has advantages in simplifying physical operation and promoting efficiency. In two-way protocol, virtual photon subtraction could be applied on two sources independently. Numerical simulations show that the optimal performance of renovated two-way protocol is obtained with photon subtraction only used by Alice. The transmission distance and tolerable excess noise are improved by using the virtual photon subtraction with appropriate parameters. Moreover, the tolerable excess noise maintains a high value with the increase in distance so that the robustness of two-way continuous-variable quantum key distribution system is significantly improved, especially at long transmission distance.

Schools Open Doors to New E-Learning Rules, Ideas

ERIC Educational Resources Information Center

Education Week, 2012

2012-01-01

The world of virtual schooling is experiencing a host of major policy shifts that are opening doors for its expansion, but at the same time holding it up to greater scrutiny. This special report, the first in a three-part 2012-2013 series on virtual education, examines how state policymakers, educators, and schools are rethinking and changing the…

Investigating Student Attitudes toward a Synchronous, Online Graduate Course in a Multi-User Virtual Learning Environment

ERIC Educational Resources Information Center

Annetta, Leonard; Murray, Marshall; Gull Laird, Shelby; Bohr, Stephanie; Park, John

2008-01-01

This article describes a graduate distance education course at North Carolina State University, which combined science content and pedagogy with video game design. The course was conducted entirely in a synchronous, online, Virtual Learning Environment (VLE) through the ActiveWorlds[TM] platform. Inservice teachers enrolled as graduate students in…

Localising Content for an XMOOC in the UAE

ERIC Educational Resources Information Center

Eppard, Jenny; Reddy, Preeya

2017-01-01

Universities in the UAE are entering the age of virtual and open access education. This paper describes the evolution of a MOOC at a state-funded university in Dubai. We will describe the challenges as well as a reflection of our experiences as creating virtual learning spaces in this culture differs somewhat from Western models. [For the complete…

Virtual K-12 Public School Programs and Students with Disabilities: Issues and Recommendations

ERIC Educational Resources Information Center

Muller, Eve

2010-01-01

This policy forum proceedings document contains a short introduction section that describes the current status of virtual public school programs in general and special education programs in particular. Next, this document provides a state-of-the-nation report that describes the exponential growth these programs and the evolving policy issues for…

An Exploration of Leadership in Virtual Communities of Practice

ERIC Educational Resources Information Center

Chrisentary, John

2013-01-01

Virtual community of practice (VCoP) teams are becoming a typical function in many knowledge-based organizations. VCoP teams can consist of team members located in various cities, states, and countries. The main characteristic of the VCoP is team members' sense of community that allows individuals to share knowledge. Knowledge sharing in a VCoP…

The "Virtual Face" of Distance Learning at Public Colleges and Universities: What Do Websites Reveal about Administrative Student Support Services?

ERIC Educational Resources Information Center

Jones, Stephanie J.; Meyer, Katrina A.

2012-01-01

This study investigated how higher education institutions support their distance learning initiatives through their institutional websites--their "virtual face." The population was 40 institutions, of which 10 each were doctoral/research, master, baccalaureate, and community college, located in 40 different states. Using a researcher-developed…

Enhancing Adaptability of U.S. Military Forces. Part A: Main Report

DTIC Science & Technology

2011-01-01

virtual ...Research   and  Engineering,  Rapid  Capability  Fielding  Toolbox  Study,  stated  that   virtual  environment  tools  can...the   “approved”  basis   for   requirements   is   divorced   from   reality ,   and   setting   system  

Determinants of Presence in 3D Virtual Worlds: A Structural Equation Modelling Analysis

ERIC Educational Resources Information Center

Chow, Meyrick

2016-01-01

There is a growing body of evidence that feeling present in virtual environments contributes to effective learning. Presence is a psychological state of the user; hence, it is generally agreed that individual differences in user characteristics can lead to different experiences of presence. Despite the fact that user characteristics can play a…

Improving the Virtual Reference Experience: How Closely Do Academic Libraries Adhere to RUSA Guidelines?

ERIC Educational Resources Information Center

Platt, Jessica; Benson, Pete

2010-01-01

The purpose of this study was to measure the degree to which academic libraries or library staff members throughout the United States adhere to the Guidelines for Virtual Reference Services provided by the Reference & User Services Association (RUSA). The results of the study were analyzed to identify specific areas where improvement is needed…

Virtual vs. Concrete Manipulatives in Mathematics Teacher Education: Is One Type More Effective than the Other?

ERIC Educational Resources Information Center

Hunt, Annita W.; Nipper, Kelli L.; Nash, Linda E.

2011-01-01

Are virtual manipulatives as effective as concrete (hands-on) manipulatives in building conceptual understanding of number concepts and relationships in pre-service middle grades teachers? In the past, the use of concrete manipulatives in mathematics courses for Clayton State University's pre-service middle grades teachers has been effective in…

Communication, Community, and Disconnection: Pre-Service Teachers in Virtual School Field Experiences

ERIC Educational Resources Information Center

Wilkens, Christian; Eckdahl, Kelli; Morone, Mike; Cook, Vicki; Giblin, Thomas; Coon, Joshua

2014-01-01

This study examined the experiences of 11 graduate-level pre-service teachers completing Virtual School Field Experiences (VSFEs) with cooperating teachers in fully online, asynchronous high school courses in New York State. The VSFEs included a 7-week online teacher training course, and a 7-week online field experience. Pre-service teachers…

The Role of Multi-Institutional Partnerships in Supply Chain Management Course Design and Improvement

ERIC Educational Resources Information Center

Long, Suzanna; Moos, J. Chris; Radic, Anne Bartel

2012-01-01

The authors examined the skills achieved through a multicultural, virtual student project environment among 3 supply chain management courses. The partnership included 2 universities in the United States and 1 in France and created virtual teams of students across university lines and is presented as a case study. The case includes detailed…

The Virtual Classroom and Catholic School Leadership Preparation: The LMU Certificate in Catholic School Administration (CCSA) Program

ERIC Educational Resources Information Center

Sabatino, Anthony

2016-01-01

Catholic Extension and Loyola Marymount University (LMU) have engaged in a partnership to offer a graduate level, virtual classroom-based Certificate in Catholic School Administration (CCSA) program for novice and prospective leaders in Catholic schools in mission dioceses throughout the United States. This synchronous online Catholic School…

Teaching Energy Metabolism Using Scientific Articles: Implementation of a Virtual Learning Environment for Medical Students

ERIC Educational Resources Information Center

de Espindola, Marina Bazzo; El-Bacha, Tatiana; Giannella, Tais Rabetti; Struchiner, Miriam; da Silva, Wagner S.; Da Poian, Andrea T.

2010-01-01

This work describes the use of a virtual learning environment (VLE) applied to the biochemistry class for undergraduate, first-year medical students at the Federal University of Rio de Janeiro. The course focused on the integration of energy metabolism, exploring metabolic adaptations in different physiological or pathological states such as…

The development of a virtual science museum for the public understanding of science in eastern China and in the United States

NASA Astrophysics Data System (ADS)

Delello, Julie Anne

2009-12-01

In 1999, the Chinese Academy of Sciences realized that there was a need for a better public understanding of science. For the public to have better accessibility and comprehension of China's significance to the world, the Computer Network Information Center (CNIC), under the direction of the Chinese Academy of Sciences, combined resources from thousands of experts across the world to develop online science exhibits housed within the Virtual Science Museum of China. Through an analysis of historical documents, this descriptive dissertation presents a research project that explores a dimension of the development of the Giant Panda Exhibit. This study takes the reader on a journey, first to China and then to a classroom within the United States, in order to answer the following questions: (1) What is the process of the development of a virtual science exhibit; and, (2) What role do public audiences play in the design and implementation of virtual science museums? The creation of a virtual science museum exhibition is a process that is not completed with just the building and design, but must incorporate feedback from public audiences who utilize the exhibit. To meet the needs of the museum visitors, the designers at CNIC took a user-centered approach and solicited feedback from six survey groups. To design a museum that would facilitate a cultural exchange of scientific information, the CNIC looked at the following categories: visitor insights, the usability of the technology, the educational effectiveness of the museum exhibit, and the cultural nuances that existed between students in China and in the United States. The findings of this study illustrate that the objectives of museum designers may not necessarily reflect the needs of the visitors and confirm previous research studies which indicate that museum exhibits need a more constructivist approach that fully engages the visitor in an interactive, media-rich environment. Even though the world has moved forwards with digital technology, classroom instruction in both China and in the United States continues to reflect traditional teaching methods. Students were shown to have a lack of experience with the Internet in classrooms and difficulty in scientific comprehension when using the virtual science museum---showing a separation between classroom technology and learning. Students showed a greater interest level in learning science with technology through online gaming and rich multimedia suggesting that virtual science museums can be educationally valuable and support an alternative to traditional teaching methods if designed with the end user in mind.

The effectiveness of using non-traditional teaching methods to prepare student health care professionals for the delivery of mental state examination: a systematic review.

PubMed

Xie, Huiting; Liu, Lei; Wang, Jia; Joon, Kum Eng; Parasuram, Rajni; Gunasekaran, Jamuna; Poh, Chee Lien

2015-08-14

With the evolution of education, there has been a shift from the use of traditional teaching methods, such as didactic or rote teaching, towards non-traditional teaching methods, such as viewing of role plays, simulation, live interviews and the use of virtual environments. Mental state examination is an essential competency for all student healthcare professionals. If mental state examination is not taught in the most effective manner so learners can comprehend its concepts and interpret the findings correctly, it could lead to serious repercussions and subsequently impact on clinical care provided for patients with mental health conditions, such as incorrect assessment of suicidal ideation. However, the methods for teaching mental state examination vary widely between countries, academic institutions and clinical settings. This systematic review aimed to identify and synthesize the best available evidence of effective teaching methods used to prepare student health care professionals for the delivery of mental state examination. This review considered evidence from primary quantitative studies which address the effectiveness of a chosen method used for the teaching of mental state examination published in English, including studies that measure learner outcomes, i.e. improved knowledge and skills, self-confidence and learners' satisfaction. A three-step search strategy was undertaken in this review to search for articles published in English from the inception of the database to December 2014. An initial search of MEDLINE and CINAHL was undertaken to identify keywords. Secondly, the keywords identified were used to search electronic databases, namely, CINAHL, Medline, Cochrane Central Register of Controlled Trials, Ovid, PsycINFO and, ProQuest Dissertations & Theses. Thirdly, reference lists of the articles identified in the second stage were searched for other relevant studies. Studies selected were assessed by two independent reviewers for methodological validity prior to inclusion in the review using the standardized critical appraisal instruments from the Joanna Briggs Institute's Meta-Analysis of Statistics Assessment and Review Instrument embedded within the System for the Unified Management, Assessment and Review of Information. Any disagreements that arose between the reviewers were resolved through discussion between the reviewers. Data was extracted using data extraction tools developed by the Joanna Briggs Institute Quantitative data was extracted from papers using standardized data extraction tools from the Joanna Briggs Institute's Meta-Analysis of Statistics Assessment and Review Instrument. The included studies were found to be heterogeneous in terms of participants and teaching methods. Moreover, a wide variety of instruments were used to determine impact and outcomes of the teaching methods. Hence, findings of the included articles were presented in a narrative summary. A total of 12 articles were included in this review with consensus from all reviewers. The evidence retrieved in this study suggests that non-traditional teaching methods, such as videotapes, virtual simulation, standardized patients and reflection, improve learners' understanding and skills of mental state examination as opposed to traditional teaching methods like lectures and provision of reading materials. However, studies that specifically compared the effectiveness of one method over another were limited to comparison between lectures with videotaped interviews and virtual simulations. It was shown that both videotaped interviews and virtual simulations were superior to lectures. In videotaped teaching, interactions between patients and learners performing mental state examination were shown for the learner’s discussion while virtual simulations mimicked patient symptoms in computer applications. Virtual simulation was notably a unique learning opportunity for the learners as it allowed learning to take place without the use of diminishing real life resources. However, in view of the high cost and learners’ difficulty in negotiating the virtual environment, videotaped teaching remained as the more commonly used method of teaching mental state examination. This systematic review study identified teaching strategies utilized in the teaching of mental state examination and their effectiveness. Videotapes was the most widely used and effective approach, that is, until the issue of high cost and ease of maneuver in virtual simulation could be overcome. There were also potential benefits of other teaching, such as reflection and use of standardized patients, and educators could consider these in the teaching of mental state examination. Future research could focus more on the comparison of various teaching methods to offer more evidence on the use of one teaching method over another. The Joanna Briggs Institute.

A virtual-system coupled multicanonical molecular dynamics simulation: Principles and applications to free-energy landscape of protein-protein interaction with an all-atom model in explicit solvent

NASA Astrophysics Data System (ADS)

Higo, Junichi; Umezawa, Koji; Nakamura, Haruki

2013-05-01

We propose a novel generalized ensemble method, a virtual-system coupled multicanonical molecular dynamics (V-McMD), to enhance conformational sampling of biomolecules expressed by an all-atom model in an explicit solvent. In this method, a virtual system, of which physical quantities can be set arbitrarily, is coupled with the biomolecular system, which is the target to be studied. This method was applied to a system of an Endothelin-1 derivative, KR-CSH-ET1, known to form an antisymmetric homodimer at room temperature. V-McMD was performed starting from a configuration in which two KR-CSH-ET1 molecules were mutually distant in an explicit solvent. The lowest free-energy state (the most thermally stable state) at room temperature coincides with the experimentally determined native complex structure. This state was separated to other non-native minor clusters by a free-energy barrier, although the barrier disappeared with elevated temperature. V-McMD produced a canonical ensemble faster than a conventional McMD method.

Planar maneuvering control of underwater snake robots using virtual holonomic constraints.

PubMed

Kohl, Anna M; Kelasidi, Eleni; Mohammadi, Alireza; Maggiore, Manfredi; Pettersen, Kristin Y

2016-11-24

This paper investigates the problem of planar maneuvering control for bio-inspired underwater snake robots that are exposed to unknown ocean currents. The control objective is to make a neutrally buoyant snake robot which is subject to hydrodynamic forces and ocean currents converge to a desired planar path and traverse the path with a desired velocity. The proposed feedback control strategy enforces virtual constraints which encode biologically inspired gaits on the snake robot configuration. The virtual constraints, parametrized by states of dynamic compensators, are used to regulate the orientation and forward speed of the snake robot. A two-state ocean current observer based on relative velocity sensors is proposed. It enables the robot to follow the path in the presence of unknown constant ocean currents. The efficacy of the proposed control algorithm for several biologically inspired gaits is verified both in simulations for different path geometries and in experiments.

Multi-indexed Meixner and little q-Jacobi (Laguerre) polynomials

NASA Astrophysics Data System (ADS)

Odake, Satoru; Sasaki, Ryu

2017-04-01

As the fourth stage of the project multi-indexed orthogonal polynomials, we present the multi-indexed Meixner and little q-Jacobi (Laguerre) polynomials in the framework of ‘discrete quantum mechanics’ with real shifts defined on the semi-infinite lattice in one dimension. They are obtained, in a similar way to the multi-indexed Laguerre and Jacobi polynomials reported earlier, from the quantum mechanical systems corresponding to the original orthogonal polynomials by multiple application of the discrete analogue of the Darboux transformations or the Crum-Krein-Adler deletion of virtual state vectors. The virtual state vectors are the solutions of the matrix Schrödinger equation on all the lattice points having negative energies and infinite norm. This is in good contrast to the (q-)Racah systems defined on a finite lattice, in which the ‘virtual state’ vectors satisfy the matrix Schrödinger equation except for one of the two boundary points.

Staghorn: An Automated Large-Scale Distributed System Analysis Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabert, Kasimir; Burns, Ian; Elliott, Steven

2016-09-01

Conducting experiments on large-scale distributed computing systems is becoming significantly easier with the assistance of emulation. Researchers can now create a model of a distributed computing environment and then generate a virtual, laboratory copy of the entire system composed of potentially thousands of virtual machines, switches, and software. The use of real software, running at clock rate in full virtual machines, allows experiments to produce meaningful results without necessitating a full understanding of all model components. However, the ability to inspect and modify elements within these models is bound by the limitation that such modifications must compete with the model,more » either running in or alongside it. This inhibits entire classes of analyses from being conducted upon these models. We developed a mechanism to snapshot an entire emulation-based model as it is running. This allows us to \\freeze time" and subsequently fork execution, replay execution, modify arbitrary parts of the model, or deeply explore the model. This snapshot includes capturing packets in transit and other input/output state along with the running virtual machines. We were able to build this system in Linux using Open vSwitch and Kernel Virtual Machines on top of Sandia's emulation platform Firewheel. This primitive opens the door to numerous subsequent analyses on models, including state space exploration, debugging distributed systems, performance optimizations, improved training environments, and improved experiment repeatability.« less

Virtual water flows and trade liberalization.

PubMed

Ramirez-Vallejo, J; Rogers, P

2004-01-01

The linkages between agricultural trade and water resources need to be identified and analyzed to better understand the potential impacts that a full liberalization, or lack thereof, will have on water resources. This paper examines trade of virtual water embodied in agricultural products for most countries of the world. The main purpose of the paper, however, is to examine the impact of trade liberalization on virtual-water trade in the future. Based on a simulation of global agricultural trade, a scenario of full liberalization of agriculture was used to assess the net effect of virtual water flows from the relocation of meat and cereals' trade. The paper also identifies the main reasons behind the changes in the magnitude and direction of the net virtual water trade over time, and shows that virtual water trade flows are independent of water resource endowments, contrary to what the Heckscher-Ohlin Theorem states. Finally, based on a formal model, some input demand functions at the country level are estimated. The estimates of the income and agricultural support elasticities of demand for import of virtual water have the expected sign, and are statistically significant. Variables found to have some explanatory power of the variance of virtual water imports are average income; population; agriculture as value added; irrigated area, and exports of goods and services.

Training in virtual environments: putting theory into practice.

PubMed

Moskaliuk, Johannes; Bertram, Johanna; Cress, Ulrike

2013-01-01

Virtual training environments are used when training in reality is challenging because of the high costs, danger, time or effort involved. In this paper we argue for a theory-driven development of such environments, with the aim of connecting theory to practice and ensuring that the training provided fits the needs of the trained persons and their organisations. As an example, we describe the development of VirtualPolice (ViPOL), a training environment for police officers in a federal state of Germany. We provided the theoretical foundation for ViPOL concerning the feeling of being present, social context, learning motivation and perspective-taking. We developed a framework to put theory into practice. To evaluate our framework we interviewed the stakeholders of ViPOL and surveyed current challenges and limitations of virtual training. The results led to a review of a theory-into-practice framework which is presented in the conclusion. Feeling of presence, social context, learning motivation and perspective-taking are relevant for training in virtual environments. The theory-into-practice framework presented here supports developers and trainers in implementing virtual training tools. The framework was validated with an interview study of stakeholders of a virtual training project. We identified limitations, opportunities and challenges.

Trends in State Charter School Laws: Authorizers, Caps, Performance-Based Closures and Virtual Schools

ERIC Educational Resources Information Center

Christie, Kathy; Millard, Maria; Thomsen, Jennifer; Wixom, Micah

2014-01-01

Forty-two states and the District of Columbia have enacted charter school legislation. The Education Commission of the States (ECS) analysts reviewed laws in the 50 states in creating an online database that highlights how state charter school laws vary, particularly in how states establish standards and accountability for charter school…

Equivalences of the multi-indexed orthogonal polynomials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odake, Satoru

2014-01-15

Multi-indexed orthogonal polynomials describe eigenfunctions of exactly solvable shape-invariant quantum mechanical systems in one dimension obtained by the method of virtual states deletion. Multi-indexed orthogonal polynomials are labeled by a set of degrees of polynomial parts of virtual state wavefunctions. For multi-indexed orthogonal polynomials of Laguerre, Jacobi, Wilson, and Askey-Wilson types, two different index sets may give equivalent multi-indexed orthogonal polynomials. We clarify these equivalences. Multi-indexed orthogonal polynomials with both type I and II indices are proportional to those of type I indices only (or type II indices only) with shifted parameters.

Changing State Digital Libraries

ERIC Educational Resources Information Center

Pappas, Marjorie L.

2006-01-01

Research has shown that state virtual or digital libraries are evolving into websites that are loaded with free resources, subscription databases, and instructional tools. In this article, the author explores these evolving libraries based on the following questions: (1) How user-friendly are the state digital libraries?; (2) How do state digital…

State-of-the-Art of Virtual Reality Technologies for Children on the Autism Spectrum

ERIC Educational Resources Information Center

Parsons, Sarah; Cobb, Sue

2011-01-01

In the past decade there has been a rapid advance in the use of virtual reality (VR) technologies for leisure, training and education. VR is argued to offer particular benefits for children on the autism spectrum, chiefly because it can offer simulations of authentic real-world situations in a carefully controlled and safe environment. Given the…

Assessing Library Automation and Virtual Library Development in Four Academic Libraries in Oyo, Oyo State, Nigeria

ERIC Educational Resources Information Center

Gbadamosi, Belau Olatunde

2011-01-01

The paper examines the level of library automation and virtual library development in four academic libraries. A validated questionnaire was used to capture the responses from academic librarians of the libraries under study. The paper discovers that none of the four academic libraries is fully automated. The libraries make use of librarians with…

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

ERIC Educational Resources Information Center

Brinson, James R.

2017-01-01

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…

75 FR 79394 - United States v. L.B. Foster Company and Portec Rail Products, Inc.; Proposed Final Judgment and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... Foster and Portec will create a virtual monopoly in the U.S. market for bonded joints. (2) Poly Joints 29... Class 1 railroads, insist that new bonded joints undergo laboratory testing plus several years of in... would have a virtual monopoly in that market. Using a measure called the Herfindahl/Hirschman Index...

Credit Recovery in a Virtual School: Affordances of Online Learning for the At-Risk Student

ERIC Educational Resources Information Center

Oliver, Kevin; Kellogg, Shaun

2015-01-01

This paper summarizes evaluation findings about a high school credit recovery (CR) program as solicited by a statesponsored virtual school in the United States. Student and teacher surveys explained why CR students failed previous instances of face-to-face courses and defined how the online CR model helped these learners overcome both internal…

Development of an Innovative Interactive Virtual Classroom System for K-12 Education Using Google App Engine

ERIC Educational Resources Information Center

Mumba, Frackson; Zhu, Mengxia

2013-01-01

This paper presents a Simulation-based interactive Virtual ClassRoom web system (SVCR: www.vclasie.com) powered by the state-of-the-art cloud computing technology from Google SVCR integrates popular free open-source math, science and engineering simulations and provides functions such as secure user access control and management of courses,…

Revising the 2001 Revised Recommendation Concerning Technical and Vocational Education. Report of the UNESCO-UNEVOC Special Virtual Conference, 1-14 April 2014

ERIC Educational Resources Information Center

UNESCO-UNEVOC International Centre for Technical and Vocational Education and Training, 2014

2014-01-01

This virtual conference is part of a larger consultation process through which UNESCO will consult with practitioners and researchers; representatives of key stakeholder groupings such as employers' federations, trade unions and youth organizations; other international agencies and Member States in order to draft a new Revised Recommendation that…

Affordability, Accessibility and Accountability in Higher Education: Proceedings of the Community College Virtual Summit, June 28, 2007

ERIC Educational Resources Information Center

US Department of Education, 2008

2008-01-01

The main intention of the Community College Virtual Summit, as stated by Troy Justesen, assistant secretary for vocational and adult education, was to explore four critical issues facing community colleges: (1) Two- to four-year transitions; (2) Adult and nontraditional students; (3) Accountability; and (4) Leadership. These were selected as the…

End of Course Grades and End of Course Tests in the Virtual Environment: A Study of Correlation

ERIC Educational Resources Information Center

Philipp, Jamie Gilbert

2014-01-01

The purpose of this correlational study is to understand the relationship between end-of-course grades as assigned by teachers and standardized end-of-course scores earned by students in Algebra, Geometry, Biology, Physical Science, and U.S. History courses at one virtual charter school in the State of Georgia. Pearson Product-Moment Correlation…

Surface matching for correlation of virtual models: Theory and application

NASA Technical Reports Server (NTRS)

Caracciolo, Roberto; Fanton, Francesco; Gasparetto, Alessandro

1994-01-01

Virtual reality can enable a robot user to off line generate and test in a virtual environment a sequence of operations to be executed by the robot in an assembly cell. Virtual models of objects are to be correlated to the real entities they represent by means of a suitable transformation. A solution to the correlation problem, which is basically a problem of 3-dimensional adjusting, has been found exploiting the surface matching theory. An iterative algorithm has been developed, which matches the geometric surface representing the shape of the virtual model of an object, with a set of points measured on the surface in the real world. A peculiar feature of the algorithm is to work also if there is no one-to-one correspondence between the measured points and those representing the surface model. Furthermore the problem of avoiding convergence to local minima is solved, by defining a starting point of states ensuring convergence to the global minimum. The developed algorithm has been tested by simulation. Finally, this paper proposes a specific application, i.e., correlating a robot cell, equipped for biomedical use with its virtual representation.

Producing coherent excitations in pumped Mott antiferromagnetic insulators

DOE PAGES

Wang, Yao; Claassen, Martin; Moritz, B.; ...

2017-12-15

Nonequilibrium dynamics in correlated materials has attracted attention due to the possibility of characterizing, tuning, and creating complex ordered states. To understand the photoinduced microscopic dynamics, especially the linkage under realistic pump conditions between transient states and remnant elementary excitations, we performed nonperturbative simulations of various time-resolved spectroscopies. We used the Mott antiferromagnetic insulator as a model platform. The transient dynamics of multi-particle excitations can be attributed to the interplay between Floquet virtual states and a modification of the density of states, in which interactions induce a spectral weight transfer. Using an autocorrelation of the time-dependent spectral function, we showmore » that resonance of the virtual states with the upper Hubbard band in the Mott insulator provides the route towards manipulating the electronic distribution and modifying charge and spin excitations. In conclusion, our results link transient dynamics to the nature of many-body excitations and provide an opportunity to design nonequilibrium states of matter via tuned laser pulses.« less

Virtual screening of mandelate racemase mutants with enhanced activity based on binding energy in the transition state.

PubMed

Gu, Jiali; Liu, Min; Guo, Fei; Xie, Wenping; Lu, Wenqiang; Ye, Lidan; Chen, Zhirong; Yuan, Shenfeng; Yu, Hongwei

2014-02-05

Mandelate racemase (MR) is a promising candidate for the dynamic kinetic resolution of racemates. However, the poor activity of MR towards most of its non-natural substrates limits its widespread application. In this work, a virtual screening method based on the binding energy in the transition state was established to assist in the screening of MR mutants with enhanced catalytic efficiency. Using R-3-chloromandelic acid as a model substrate, a total of 53 mutants were constructed based on rational design in the two rounds of screening. The number of mutants for experimental validation was brought down to 17 by the virtual screening method, among which 14 variants turned out to possess improved catalytic efficiency. The variant V26I/Y54V showed 5.2-fold higher catalytic efficiency (k(cat)/K(m)) towards R-3-chloromandelic acid than that observed for the wild-type enzyme. Using this strategy, mutants were successfully obtained for two other substrates, R-mandelamide and R-2-naphthylglycolate (V26I and V29L, respectively), both with a 2-fold improvement in catalytic efficiency. These results demonstrated that this method could effectively predict the trend of mutational effects on catalysis. Analysis from the energetic and structural assays indicated that the enhanced interactions between the active sites and the substrate in the transition state led to improved catalytic efficiency. It was concluded that this virtual screening method based on the binding energy in the transition state was beneficial in enzyme rational redesign and helped to better understand the catalytic properties of the enzyme. Copyright © 2013 Elsevier Inc. All rights reserved.

Monitoring the englacial fracture state using virtual-reflector seismology

NASA Astrophysics Data System (ADS)

Lindner, F.; Weemstra, C.; Walter, F.; Hadziioannou, C.

2017-12-01

Fracturing and changes in the englacial macroscopic water content change the elastic bulk properties of ice bodies. Small seismic velocity variations, resulting from such changes, can be measured using a technique called coda-wave interferometry. Here, coda refers to the later-arriving, multiply scattered waves. Often, this technique is applied to so-called virtual-source responses, which can be obtained using seismic interferometry (a simple crosscorrelation process). Compared to other media (e.g., the Earth's crust), however, ice bodies exhibit relatively little scattering. This complicates the application of coda-wave interferometry to the retrieved virtual-source responses. In this work, we therefore investigate the applicability of coda-wave interferometry to virtual-source responses obtained using two alternative seismic interferometric techniques, namely, seismic interferometry by multidimensional deconvolution (SI by MDD), and virtual-reflector seismology (VRS). To that end, we use synthetic data, as well as active-source glacier data acquired on Glacier de la Plaine Morte, Switzerland. Both SI by MDD and VRS allow the retrieval of more accurate virtual-source responses. In particular, the dependence of the retrieved virtual-source responses on the illumination pattern is reduced. We find that this results in more accurate glacial phase-velocity estimates. In addition, VRS introduces virtual reflections from a receiver contour (partly) enclosing the medium of interest. By acting as a sort of virtual reverberation, the coda resulting from the application of VRS significantly increases seismic monitoring capabilities, in particular in cases where natural scattering coda is not available.

Behavioral Monitoring of Sexual Offenders Against Children in Virtual Risk Situations: A Feasibility Study.

PubMed

Fromberger, Peter; Meyer, Sabrina; Jordan, Kirsten; Müller, Jürgen L

2018-01-01

The decision about unsupervised privileges for sexual offenders against children (SOC) is one of the most difficult decisions for practitioners in forensic high-security hospitals. Facing the possible consequences of the decision for the society, a valid and reliable risk management of SOCs is essential. Some risk management approaches provide frameworks for the construction of relevant future risk situations. Due to ethical reasons, it is not possible to evaluate the validity of constructed risk situations in reality. The aim of the study was to test if behavioral monitoring of SOCs in high-immersive virtual risk situations provides additional information for risk management. Six SOCs and seven non-offender controls (NOC) walked through three virtual risk situations, confronting the participant with a virtual child character. The participant had to choose between predefined answers representing approach or avoidance behavior. Frequency of chosen answers were analyzed in regards to knowledge of the participants about coping skills and coping skills focused during therapy. SOCs and NOCs behavior differed only in one risk scenario. Furthermore, SOCs showed in 89% of all cases a behavior not corresponding to their own belief about adequate behavior in comparable risk situations. In 62% of all cases, SOCs behaved not corresponding to coping skills they stated that therapists focused on during therapy. In 50% of all cases, SOCs behaved in correspondence to coping skills therapists stated that they focused on during therapy. Therapists predicted the behavior of SOCs in virtual risk situations incorrect in 25% of all cases. Thus, virtual risk scenarios provide the possibility for practitioners to monitor the behavior of SOCs and to test their decisions on unsupervised privileges without endangering the community. This may provide additional information for therapy progress. Further studies are necessary to evaluate the predictive and ecological validity of behavioral monitoring in virtual risk situations for real life situations.

Behavioral Monitoring of Sexual Offenders Against Children in Virtual Risk Situations: A Feasibility Study

PubMed Central

Fromberger, Peter; Meyer, Sabrina; Jordan, Kirsten; Müller, Jürgen L.

2018-01-01

The decision about unsupervised privileges for sexual offenders against children (SOC) is one of the most difficult decisions for practitioners in forensic high-security hospitals. Facing the possible consequences of the decision for the society, a valid and reliable risk management of SOCs is essential. Some risk management approaches provide frameworks for the construction of relevant future risk situations. Due to ethical reasons, it is not possible to evaluate the validity of constructed risk situations in reality. The aim of the study was to test if behavioral monitoring of SOCs in high-immersive virtual risk situations provides additional information for risk management. Six SOCs and seven non-offender controls (NOC) walked through three virtual risk situations, confronting the participant with a virtual child character. The participant had to choose between predefined answers representing approach or avoidance behavior. Frequency of chosen answers were analyzed in regards to knowledge of the participants about coping skills and coping skills focused during therapy. SOCs and NOCs behavior differed only in one risk scenario. Furthermore, SOCs showed in 89% of all cases a behavior not corresponding to their own belief about adequate behavior in comparable risk situations. In 62% of all cases, SOCs behaved not corresponding to coping skills they stated that therapists focused on during therapy. In 50% of all cases, SOCs behaved in correspondence to coping skills therapists stated that they focused on during therapy. Therapists predicted the behavior of SOCs in virtual risk situations incorrect in 25% of all cases. Thus, virtual risk scenarios provide the possibility for practitioners to monitor the behavior of SOCs and to test their decisions on unsupervised privileges without endangering the community. This may provide additional information for therapy progress. Further studies are necessary to evaluate the predictive and ecological validity of behavioral monitoring in virtual risk situations for real life situations. PMID:29559934

The Impact of a Virtual Public Charter School Program on the Learning Outcomes of Students with Disabilities: A Quantitative Study

ERIC Educational Resources Information Center

Epps, Sucari

2017-01-01

This quantitative study investigated the learning outcomes of students with disabilities in comparison to their non-disabled peers in a TK-12th grade school that offers a sixth-twelfth grade virtual public charter school program that currently serves students in the state of California. No differences were found between groups indicating…

Beyond Minimum Technology Requirements: Course Characteristics for the Instructional Design of Virtual Programs at the Elementary Grade Levels

ERIC Educational Resources Information Center

Vytlacil, Kerrie A.

2013-01-01

With virtual public school initiatives in each of the 50 states, there is an impetus to develop and implement online programs for the elementary grades (Cavanaugh, 2004, pp. 262-266; Oliver et al., p. 56). Yet, learner usability characteristics for successful online schooling for the elementary grades are unknown and/or unspecified. The purpose of…

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCaskey, Alexander J.

There is a lack of state-of-the-art HPC simulation tools for simulating general quantum computing. Furthermore, there are no real software tools that integrate current quantum computers into existing classical HPC workflows. This product, the Quantum Virtual Machine (QVM), solves this problem by providing an extensible framework for pluggable virtual, or physical, quantum processing units (QPUs). It enables the execution of low level quantum assembly codes and returns the results of such executions.

Computing Accurate Grammatical Feedback in a Virtual Writing Conference for German-Speaking Elementary-School Children: An Approach Based on Natural Language Generation

ERIC Educational Resources Information Center

Harbusch, Karin; Itsova, Gergana; Koch, Ulrich; Kuhner, Christine

2009-01-01

We built a natural language processing (NLP) system implementing a "virtual writing conference" for elementary-school children, with German as the target language. Currently, state-of-the-art computer support for writing tasks is restricted to multiple-choice questions or quizzes because automatic parsing of the often ambiguous and fragmentary…

Building a Virtual Learning Environment to Foster Blended Learning Experiences in an Institute of Application in Brazil

ERIC Educational Resources Information Center

da Silva Marques Ribeiro, Andrea; Rodrigues Oliveira, Esequiel; Fortes Mello, Rodrigo

2017-01-01

Blended learning, the combination of face-to-face teaching with a virtual learning environment (VLE), is the theme of this study that aims at describing and analyzing the implementation of a VLE in the Institute of Application Fernando Rodrigues da Silveira, an academic unit of the State University of Rio de Janeiro. This study's main contribution…

Towards photorealistic and immersive virtual-reality environments for simulated prosthetic vision: integrating recent breakthroughs in consumer hardware and software.

PubMed

Zapf, Marc P; Matteucci, Paul B; Lovell, Nigel H; Zheng, Steven; Suaning, Gregg J

2014-01-01

Simulated prosthetic vision (SPV) in normally sighted subjects is an established way of investigating the prospective efficacy of visual prosthesis designs in visually guided tasks such as mobility. To perform meaningful SPV mobility studies in computer-based environments, a credible representation of both the virtual scene to navigate and the experienced artificial vision has to be established. It is therefore prudent to make optimal use of existing hardware and software solutions when establishing a testing framework. The authors aimed at improving the realism and immersion of SPV by integrating state-of-the-art yet low-cost consumer technology. The feasibility of body motion tracking to control movement in photo-realistic virtual environments was evaluated in a pilot study. Five subjects were recruited and performed an obstacle avoidance and wayfinding task using either keyboard and mouse, gamepad or Kinect motion tracking. Walking speed and collisions were analyzed as basic measures for task performance. Kinect motion tracking resulted in lower performance as compared to classical input methods, yet results were more uniform across vision conditions. The chosen framework was successfully applied in a basic virtual task and is suited to realistically simulate real-world scenes under SPV in mobility research. Classical input peripherals remain a feasible and effective way of controlling the virtual movement. Motion tracking, despite its limitations and early state of implementation, is intuitive and can eliminate between-subject differences due to familiarity to established input methods.

Creating state of the art, next-generation Virtual Reality exposure therapies for anxiety disorders using consumer hardware platforms: design considerations and future directions.

PubMed

Lindner, Philip; Miloff, Alexander; Hamilton, William; Reuterskiöld, Lena; Andersson, Gerhard; Powers, Mark B; Carlbring, Per

2017-09-01

Decades of research and more than 20 randomized controlled trials show that Virtual Reality exposure therapy (VRET) is effective in reducing fear and anxiety. Unfortunately, few providers or patients have had access to the costly and technical equipment previously required. Recent technological advances in the form of consumer Virtual Reality (VR) systems (e.g. Oculus Rift and Samsung Gear), however, now make widespread use of VRET in clinical settings and as self-help applications possible. In this literature review, we detail the current state of VR technology and discuss important therapeutic considerations in designing self-help and clinician-led VRETs, such as platform choice, exposure progression design, inhibitory learning strategies, stimuli tailoring, gamification, virtual social learning and more. We illustrate how these therapeutic components can be incorporated and utilized in VRET applications, taking full advantage of the unique capabilities of virtual environments, and showcase some of these features by describing the development of a consumer-ready, gamified self-help VRET application for low-cost commercially available VR hardware. We also raise and discuss challenges in the planning, development, evaluation, and dissemination of VRET applications, including the need for more high-quality research. We conclude by discussing how new technology (e.g. eye-tracking) can be incorporated into future VRETs and how widespread use of VRET self-help applications will enable collection of naturalistic "Big Data" that promises to inform learning theory and behavioral therapy in general.

BIM based virtual environment for fire emergency evacuation.

PubMed

Wang, Bin; Li, Haijiang; Rezgui, Yacine; Bradley, Alex; Ong, Hoang N

2014-01-01

Recent building emergency management research has highlighted the need for the effective utilization of dynamically changing building information. BIM (building information modelling) can play a significant role in this process due to its comprehensive and standardized data format and integrated process. This paper introduces a BIM based virtual environment supported by virtual reality (VR) and a serious game engine to address several key issues for building emergency management, for example, timely two-way information updating and better emergency awareness training. The focus of this paper lies on how to utilize BIM as a comprehensive building information provider to work with virtual reality technologies to build an adaptable immersive serious game environment to provide real-time fire evacuation guidance. The innovation lies on the seamless integration between BIM and a serious game based virtual reality (VR) environment aiming at practical problem solving by leveraging state-of-the-art computing technologies. The system has been tested for its robustness and functionality against the development requirements, and the results showed promising potential to support more effective emergency management.

Four-state virtual research peer exchange 2015 : final report.

DOT National Transportation Integrated Search

2016-01-01

The transportation research programs in Idaho, Nevada, South Dakota, and Wyoming each hosted a multi-state : online webinar-based peer exchange consisting of a series of four webinars addressing four topics: : - Research Quality: optimizing the value...

Decoherence induced deformation of the ground state in adiabatic quantum computation.

PubMed

Deng, Qiang; Averin, Dmitri V; Amin, Mohammad H; Smith, Peter

2013-01-01

Despite more than a decade of research on adiabatic quantum computation (AQC), its decoherence properties are still poorly understood. Many theoretical works have suggested that AQC is more robust against decoherence, but a quantitative relation between its performance and the qubits' coherence properties, such as decoherence time, is still lacking. While the thermal excitations are known to be important sources of errors, they are predominantly dependent on temperature but rather insensitive to the qubits' coherence. Less understood is the role of virtual excitations, which can also reduce the ground state probability even at zero temperature. Here, we introduce normalized ground state fidelity as a measure of the decoherence-induced deformation of the ground state due to virtual transitions. We calculate the normalized fidelity perturbatively at finite temperatures and discuss its relation to the qubits' relaxation and dephasing times, as well as its projected scaling properties.

Decoherence induced deformation of the ground state in adiabatic quantum computation

PubMed Central

Deng, Qiang; Averin, Dmitri V.; Amin, Mohammad H.; Smith, Peter

2013-01-01

Despite more than a decade of research on adiabatic quantum computation (AQC), its decoherence properties are still poorly understood. Many theoretical works have suggested that AQC is more robust against decoherence, but a quantitative relation between its performance and the qubits' coherence properties, such as decoherence time, is still lacking. While the thermal excitations are known to be important sources of errors, they are predominantly dependent on temperature but rather insensitive to the qubits' coherence. Less understood is the role of virtual excitations, which can also reduce the ground state probability even at zero temperature. Here, we introduce normalized ground state fidelity as a measure of the decoherence-induced deformation of the ground state due to virtual transitions. We calculate the normalized fidelity perturbatively at finite temperatures and discuss its relation to the qubits' relaxation and dephasing times, as well as its projected scaling properties. PMID:23528821

Estimation of the state of solar activity type stars by virtual observations of CrAVO

NASA Astrophysics Data System (ADS)

Dolgov, A. A.; Shlyapnikov, A. A.

2012-05-01

The results of precosseing of negatives with direct images of the sky from CrAO glass library are presented in this work, which became a part of on-line archive of the Crimean Astronomical Virtual Observatory (CrAVO). Based on the obtained data, the parameters of dwarf stars have been estimated, included in the catalog "Stars with solar-type activity" (GTSh10). The following matters are considered: searching methodology of negatives with positions of studied stars and with calculated limited magnitude; image viewing and reduction with the facilities of the International Virtual Observatory; the preliminary results of the photometry of studied objects.

Accelerating Virtual High-Throughput Ligand Docking: current technology and case study on a petascale supercomputer.

PubMed

Ellingson, Sally R; Dakshanamurthy, Sivanesan; Brown, Milton; Smith, Jeremy C; Baudry, Jerome

2014-04-25

In this paper we give the current state of high-throughput virtual screening. We describe a case study of using a task-parallel MPI (Message Passing Interface) version of Autodock4 [1], [2] to run a virtual high-throughput screen of one-million compounds on the Jaguar Cray XK6 Supercomputer at Oak Ridge National Laboratory. We include a description of scripts developed to increase the efficiency of the predocking file preparation and postdocking analysis. A detailed tutorial, scripts, and source code for this MPI version of Autodock4 are available online at http://www.bio.utk.edu/baudrylab/autodockmpi.htm.

Unbound states in quantum heterostructures

PubMed Central

Bastard, G

2006-01-01

We report in this review on the electronic continuum states of semiconductor Quantum Wells and Quantum Dots and highlight the decisive part played by the virtual bound states in the optical properties of these structures. The two particles continuum states of Quantum Dots control the decoherence of the excited electron – hole states. The part played by Auger scattering in Quantum Dots is also discussed.

First-Principle Construction of U(1) Symmetric Matrix Product States

NASA Astrophysics Data System (ADS)

Rakov, Mykhailo V.

2018-07-01

The algorithm to calculate the sets of symmetry sectors for virtual indices of U(1) symmetric matrix product states (MPS) is described. The principal differences between open (OBC) and periodic (PBC) boundary conditions are stressed, and the extension of PBC MPS algorithm to projected entangled pair states is outlined.

Reduced order modeling of head related transfer functions for virtual acoustic displays

NASA Astrophysics Data System (ADS)

Willhite, Joel A.; Frampton, Kenneth D.; Grantham, D. Wesley

2003-04-01

The purpose of this work is to improve the computational efficiency in acoustic virtual applications by creating and testing reduced order models of the head related transfer functions used in localizing sound sources. State space models of varying order were generated from zero-elevation Head Related Impulse Responses (HRIRs) using Kungs Single Value Decomposition (SVD) technique. The inputs to the models are the desired azimuths of the virtual sound sources (from minus 90 deg to plus 90 deg, in 10 deg increments) and the outputs are the left and right ear impulse responses. Trials were conducted in an anechoic chamber in which subjects were exposed to real sounds that were emitted by individual speakers across a numbered speaker array, phantom sources generated from the original HRIRs, and phantom sound sources generated with the different reduced order state space models. The error in the perceived direction of the phantom sources generated from the reduced order models was compared to errors in localization using the original HRIRs.

Virtual water flows in the international trade of agricultural products of China.

PubMed

Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

2016-07-01

With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

Trait and State Craving as Indicators of Validity of VR-based Software for Binge Eating Treatment.

PubMed

Pla-Sanjuanelo, Joana; Ferrer-Garcia, Marta; Gutiérrez-Maldonado, José; Vilalta-Abella, Ferran; Andreu-Gracia, Alexis; Dakanalis, Antonios; Fernandez-Aranda, Fernando; Fusté-Escolano, Adela; Ribas-Sabaté, Joan; Riva, Giuseppe; Saldaña, Carmina; Sánchez, Isabel

2015-01-01

The aim of this study was to establish whether virtual reality (VR) exposure to food cues is able to produce craving levels consistent with state-craving and trait-craving as assessed by the Spanish and Italian versions of the State and Trait Food Craving Questionnaires (FCQ-T/S). The results were compared in 40 patients with eating disorders (17 with binge eating disorder, 23 with bulimia nervosa) and 78 healthy control subjects without eating disorders. Controls and patients with higher levels of trait-craving and state-craving both showed a greater desire to eat during VR exposure. Results also showed that trait and state craving assessed by FCQ-T/S were able to predict the total mean craving experienced during exposure to the VR software in both clinical and control samples. These findings present preliminary evidence about the validity of a new virtual reality-based application for cue-exposure treatment in patients with eating disorders.

Cyber Therapy II, Virtual Healing, Designing Reality

DTIC Science & Technology

2006-08-01

exposures. The initial, prototype model goal was to see if the subjects were able to use the addresses smallpox and uses chicken pox and system, and to...Barcelona, Spain training for schizophrenia as well as cognitive Autonomous University of State of Mexico therapy for autism. This study developed a system...Toluca, Mexico for measuring schizophrenia patients’ behavioral E-mail: claudia.liliana.hardy@estudiant.upc.edu characteristics in a Virtual

Human-Computer Interaction and Virtual Environments

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Compiler)

1995-01-01

The proceedings of the Workshop on Human-Computer Interaction and Virtual Environments are presented along with a list of attendees. The objectives of the workshop were to assess the state-of-technology and level of maturity of several areas in human-computer interaction and to provide guidelines for focused future research leading to effective use of these facilities in the design/fabrication and operation of future high-performance engineering systems.

Free Energy-Based Virtual Screening and Optimization of RNase H Inhibitors of HIV-1 Reverse Transcriptase.

PubMed

Zhang, Baofeng; D'Erasmo, Michael P; Murelli, Ryan P; Gallicchio, Emilio

2016-09-30

We report the results of a binding free energy-based virtual screening campaign of a library of 77 α-hydroxytropolone derivatives against the challenging RNase H active site of the reverse transcriptase (RT) enzyme of human immunodeficiency virus-1. Multiple protonation states, rotamer states, and binding modalities of each compound were individually evaluated. The work involved more than 300 individual absolute alchemical binding free energy parallel molecular dynamics calculations and over 1 million CPU hours on national computing clusters and a local campus computational grid. The thermodynamic and structural measures obtained in this work rationalize a series of characteristics of this system useful for guiding future synthetic and biochemical efforts. The free energy model identified key ligand-dependent entropic and conformational reorganization processes difficult to capture using standard docking and scoring approaches. Binding free energy-based optimization of the lead compounds emerging from the virtual screen has yielded four compounds with very favorable binding properties, which will be the subject of further experimental investigations. This work is one of the few reported applications of advanced-binding free energy models to large-scale virtual screening and optimization projects. It further demonstrates that, with suitable algorithms and automation, advanced-binding free energy models can have a useful role in early-stage drug-discovery programs.

Role of Chemical Reactivity and Transition State Modeling for Virtual Screening.

PubMed

Karthikeyan, Muthukumarasamy; Vyas, Renu; Tambe, Sanjeev S; Radhamohan, Deepthi; Kulkarni, Bhaskar D

2015-01-01

Every drug discovery research program involves synthesis of a novel and potential drug molecule utilizing atom efficient, economical and environment friendly synthetic strategies. The current work focuses on the role of the reactivity based fingerprints of compounds as filters for virtual screening using a tool ChemScore. A reactant-like (RLS) and a product- like (PLS) score can be predicted for a given compound using the binary fingerprints derived from the numerous known organic reactions which capture the molecule-molecule interactions in the form of addition, substitution, rearrangement, elimination and isomerization reactions. The reaction fingerprints were applied to large databases in biology and chemistry, namely ChEMBL, KEGG, HMDB, DSSTox, and the Drug Bank database. A large network of 1113 synthetic reactions was constructed to visualize and ascertain the reactant product mappings in the chemical reaction space. The cumulative reaction fingerprints were computed for 4000 molecules belonging to 29 therapeutic classes of compounds, and these were found capable of discriminating between the cognition disorder related and anti-allergy compounds with reasonable accuracy of 75% and AUC 0.8. In this study, the transition state based fingerprints were also developed and used effectively for virtual screening in drug related databases. The methodology presented here provides an efficient handle for the rapid scoring of molecular libraries for virtual screening.

Using Virtual Reality to Distract Overweight Children from Bodily Sensations During Exercise.

PubMed

Baños, Rosa M; Escobar, Patricia; Cebolla, Ausias; Guixeres, Jaime; Alvarez Pitti, Julio; Lisón, Juan Francisco; Botella, Cristina

2016-02-01

This study analyzes the potential of virtual reality (VR) to enhance attentional distraction in overweight children as they experience bodily sensations during exercise. It has been suggested that one reason why obese children stop exercising is the perception of bodily sensations. In a counterbalanced design, a total of 109 children (33 overweight, 10-15 years old) were asked to walk twice for 6 minutes on a treadmill under one of two conditions: (a) traditional condition (TC)-focusing their attention on their physical feelings and sensations or (b) distraction condition (DC)-focusing their attention on a virtual environment. Attentional focus during exercise, bad-good feeling states (pre- and postexperimental), perceived exertion (3 minutes and post), heart rate, and enjoyment were assessed. Results indicated that overweight children focused on internal information under the TC, but they significantly shifted their attention to regard the external environment in the DC. This attentional distraction effect of VR was more intense in overweight than in normal-weight children. No differences between groups were found when examining changes in feeling states and perceived exertion. VR increased enjoyment during exercise, and children preferred exercise using virtual environments. VR is useful to promote distraction and may help overweight and obese children to enjoy exercise.

LVC interaction within a mixed-reality training system

NASA Astrophysics Data System (ADS)

Pollock, Brice; Winer, Eliot; Gilbert, Stephen; de la Cruz, Julio

2012-03-01

The United States military is increasingly pursuing advanced live, virtual, and constructive (LVC) training systems for reduced cost, greater training flexibility, and decreased training times. Combining the advantages of realistic training environments and virtual worlds, mixed reality LVC training systems can enable live and virtual trainee interaction as if co-located. However, LVC interaction in these systems often requires constructing immersive environments, developing hardware for live-virtual interaction, tracking in occluded environments, and an architecture that supports real-time transfer of entity information across many systems. This paper discusses a system that overcomes these challenges to empower LVC interaction in a reconfigurable, mixed reality environment. This system was developed and tested in an immersive, reconfigurable, and mixed reality LVC training system for the dismounted warfighter at ISU, known as the Veldt, to overcome LVC interaction challenges and as a test bed for cuttingedge technology to meet future U.S. Army battlefield requirements. Trainees interact physically in the Veldt and virtually through commercial and developed game engines. Evaluation involving military trained personnel found this system to be effective, immersive, and useful for developing the critical decision-making skills necessary for the battlefield. Procedural terrain modeling, model-matching database techniques, and a central communication server process all live and virtual entity data from system components to create a cohesive virtual world across all distributed simulators and game engines in real-time. This system achieves rare LVC interaction within multiple physical and virtual immersive environments for training in real-time across many distributed systems.

Measuring Co-Presence and Social Presence in Virtual Environments - Psychometric Construction of a German Scale for a Fear of Public Speaking Scenario.

PubMed

Poeschl, Sandra; Doering, Nicola

2015-01-01

Virtual reality exposure therapy (VRET) applications use high levels of fidelity in order to produce high levels of presence and thereby elicit an emotional response for the user (like fear for phobia treatment). State of research shows mixed results for the correlation between anxiety and presence in virtual reality exposure, with differing results depending on specific anxiety disorders. A positive correlation for anxiety and presence for social anxiety disorder is not proven up to now. One reason might be that plausibility of the simulation, namely including key triggers for social anxiety (for example verbal and non-verbal behavior of virtual agents that reflects potentially negative human evaluation) might not be acknowledged in current presence questionnaires. A German scale for measuring co-presence and social presence for virtual reality (VR) fear of public speaking scenarios was developed based on a translation and adaption of existing co-presence and social presence questionnaires. A sample of N = 151 students rated co-presence and social presence after using a fear of public speaking application. Four correlated factors were derived by item- and principle axis factor analysis (Promax rotation), representing the presenter's reaction to virtual agents, the reactions of the virtual agents as perceived by the presenter, impression of interaction possibilities, and (co-)presence of other people in the virtual environment. The scale developed can be used as a starting point for future research and test construction for VR applications with a social context.

Development of a cognitive function test using virtual reality technology: examination in healthy participants.

PubMed

Sakai, Hiromi; Nagano, Akinori; Seki, Keiko; Okahashi, Sayaka; Kojima, Maki; Luo, Zhiwei

2018-07-01

We developed a virtual reality test to assess the cognitive function of Japanese people in near-daily-life environment, namely, a virtual shopping test (VST). In this test, participants were asked to execute shopping tasks using touch panel operations in a "virtual shopping mall." We examined differences in VST performances among healthy participants of different ages and correlations between VST and screening tests, such as the Mini-Mental State Examination (MMSE) and Everyday Memory Checklist (EMC). We included 285 healthy participants between 20 and 86 years of age in seven age groups. Therefore, each VST index tended to decrease with advancing age; differences among age groups were significant. Most VST indices had a significantly negative correlation with MMSE and significantly positive correlation with EMC. VST may be useful for assessing general cognitive decline; effects of age must be considered for proper interpretation of the VST scores.

Pulse!!: a model for research and development of virtual-reality learning in military medical education and training.

PubMed

Dunne, James R; McDonald, Claudia L

2010-07-01

Pulse!! The Virtual Clinical Learning Lab at Texas A&M University-Corpus Christi, in collaboration with the United States Navy, has developed a model for research and technological development that they believe is an essential element in the future of military and civilian medical education. The Pulse!! project models a strategy for providing cross-disciplinary expertise and resources to educational, governmental, and business entities challenged with meeting looming health care crises. It includes a three-dimensional virtual learning platform that provides unlimited, repeatable, immersive clinical experiences without risk to patients, and is available anywhere there is a computer. Pulse!! utilizes expertise in the fields of medicine, medical education, computer science, software engineering, physics, computer animation, art, and architecture. Lab scientists collaborate with the commercial virtual-reality simulation industry to produce research-based learning platforms based on cutting-edge computer technology.

Sheet metals characterization using the virtual fields method

NASA Astrophysics Data System (ADS)

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

2018-05-01

In this work, a characterisation method involving a deep-notched specimen subjected to a tensile loading is introduced. This specimen leads to heterogeneous states of stress and strain, the latter being measured using a stereo DIC system (MatchID). This heterogeneity enables the identification of multiple material parameters in a single test. In order to identify material parameters from the DIC data, an inverse method called the Virtual Fields Method is employed. The method combined with recently developed sensitivity-based virtual fields allows to optimally locate areas in the test where information about each material parameter is encoded, improving accuracy of the identification over the traditional user-defined virtual fields. It is shown that a single test performed at 45° to the rolling direction is sufficient to obtain all anisotropic plastic parameters, thus reducing experimental effort involved in characterisation. The paper presents the methodology and some numerical validation.

A weak Hamiltonian finite element method for optimal guidance of an advanced launch vehicle

NASA Technical Reports Server (NTRS)

Hodges, Dewey H.; Calise, Anthony J.; Bless, Robert R.; Leung, Martin

1989-01-01

A temporal finite-element method based on a mixed form of the Hamiltonian weak principle is presented for optimal control problems. The mixed form of this principle contains both states and costates as primary variables, which are expanded in terms of nodal values and simple shape functions. Time derivatives of the states and costates do not appear in the governing variational equation; the only quantities whose time derivatives appear therein are virtual states and virtual costates. Numerical results are presented for an elementary trajectory optimization problem; they show very good agreement with the exact solution along with excellent computational efficiency and self-starting capability. The feasibility of this approach for real-time guidance applications is evaluated. A simplified model for an advanced launch vehicle application that is suitable for finite-element solution is presented.

What makes virtual agents believable?

NASA Astrophysics Data System (ADS)

Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

2016-01-01

In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

The State of Integration of the Virtual Learning Environment and ICT into the Pedagogy of the Royal University of Bhutan: A Descriptive Study

ERIC Educational Resources Information Center

Choeda; Penjor, Tandin; Dupka, Dorji; Zander, Pär-Ola

2016-01-01

This paper reports a descriptive research study on the integration of ICT and pedagogy in the colleges of the Royal University of Bhutan. It investigates whether ICT is integrated into the pedagogy and, if so, in what way. The study identifies the use of a Virtual Learning Environment (VLE) as the key technology, which is used as part of…

Peacetime Reprisals Under Article 51: An Argument for Legal Legitimacy in Cases of Terrorism

DTIC Science & Technology

1997-04-01

legitimize virtually any international use of force under the law, it is more difficult to justify the morality of an action under the application of...lawlessness and barbarism." 149 SIR PAUL VINOGRADOFF, HISTORICAL TYPES OF INTERNATIONAL LAW, IN 1 BIBLIOTECA ViSSERIANA DiSSERTATIONUM Ius... virtually unchallenged, there is basis in state practice for giving Article 51 a broader interpretation, or possibly for the further development of customary

A Legal Reasoning Component of a Network Security Command and Control System

DTIC Science & Technology

2010-03-01

United States Code VA Vulnerability Assessment VLC Virtual Legal Cell xv ACKNOWLEDGMENTS The authors would like to humbly thank Professor Bret...cyberspace environment. In this thesis, the authors address the information warrior’s challenge of obtaining just-in-time legal advice. They...PROPOSED VIRTUAL DYNAMIC LEGAL CELL One of the challenges in cyberspace is to define and detect a hostile act or the use of force. Another major

Simulation-Based Learning: Workshops for Researchers and Educators in the Western United States, and the Pacific Rim

DTIC Science & Technology

2007-03-01

Artificial Intelligence Walter Greenleaf, Greenleaf Medical Applications in Rehabilitation Medicine Workshop 4: 12/14-5/07 SUMMIT/TATRC...Applications in Medicine; 1-day Long Beach, CA – MMVR 118 people 1/25/05 2 MEDICAL-SURGICAL TRAINING WITH VIDEOGAMES ; ½-day Portland, OR...for Modeling Virtual Patients Parvati Dev " Intelligent " characters in Virtual World Lou Halamek, Stanford Debriefing- After Action Review

Virtual Reality for Sensorimotor Rehabilitation Post-Stroke: The Promise and Current State of the Field.

PubMed

Fluet, Gerard G; Deutsch, Judith E

2013-03-01

Developments over the past 2 years in virtual reality (VR) augmented sensorimotor rehabilitation of upper limb use and gait post-stroke were reviewed. Studies were included if they evaluated comparative efficacy between VR and standard of care, and or differences in VR delivery methods; and were CEBM (center for evidence based medicine) level 2 or higher. Eight upper limb and two gait studies were included and described using the following categories hardware (input and output), software (virtual task and feedback and presentation) intervention (progression and dose), and outcomes. Trends in the field were commented on, gaps in knowledge identified, and areas of future research and translation of VR to practice were suggested.

The Virtual Space Telescope: A New Class of Science Missions

NASA Technical Reports Server (NTRS)

Shah, Neerav; Calhoun, Philip

2016-01-01

Many science investigations proposed by GSFC require two spacecraft alignment across a long distance to form a virtual space telescope. Forming a Virtual Space telescope requires advances in Guidance, Navigation, and Control (GNC) enabling the distribution of monolithic telescopes across multiple space platforms. The capability to align multiple spacecraft to an intertial target is at a low maturity state and we present a roadmap to advance the system-level capability to be flight ready in preparation of various science applications. An engineering proof of concept, called the CANYVAL-X CubeSat MIssion is presented. CANYVAL-X's advancement will decrease risk for a potential starshade mission that would fly with WFIRST.

BIM Based Virtual Environment for Fire Emergency Evacuation

PubMed Central

Rezgui, Yacine; Ong, Hoang N.

2014-01-01

Recent building emergency management research has highlighted the need for the effective utilization of dynamically changing building information. BIM (building information modelling) can play a significant role in this process due to its comprehensive and standardized data format and integrated process. This paper introduces a BIM based virtual environment supported by virtual reality (VR) and a serious game engine to address several key issues for building emergency management, for example, timely two-way information updating and better emergency awareness training. The focus of this paper lies on how to utilize BIM as a comprehensive building information provider to work with virtual reality technologies to build an adaptable immersive serious game environment to provide real-time fire evacuation guidance. The innovation lies on the seamless integration between BIM and a serious game based virtual reality (VR) environment aiming at practical problem solving by leveraging state-of-the-art computing technologies. The system has been tested for its robustness and functionality against the development requirements, and the results showed promising potential to support more effective emergency management. PMID:25197704

A Survey on Virtualization of Wireless Sensor Networks

PubMed Central

Islam, Md. Motaharul; Hassan, Mohammad Mehedi; Lee, Ga-Won; Huh, Eui-Nam

2012-01-01

Wireless Sensor Networks (WSNs) are gaining tremendous importance thanks to their broad range of commercial applications such as in smart home automation, health-care and industrial automation. In these applications multi-vendor and heterogeneous sensor nodes are deployed. Due to strict administrative control over the specific WSN domains, communication barriers, conflicting goals and the economic interests of different WSN sensor node vendors, it is difficult to introduce a large scale federated WSN. By allowing heterogeneous sensor nodes in WSNs to coexist on a shared physical sensor substrate, virtualization in sensor network may provide flexibility, cost effective solutions, promote diversity, ensure security and increase manageability. This paper surveys the novel approach of using the large scale federated WSN resources in a sensor virtualization environment. Our focus in this paper is to introduce a few design goals, the challenges and opportunities of research in the field of sensor network virtualization as well as to illustrate a current status of research in this field. This paper also presents a wide array of state-of-the art projects related to sensor network virtualization. PMID:22438759

A survey on virtualization of Wireless Sensor Networks.

PubMed

Islam, Md Motaharul; Hassan, Mohammad Mehedi; Lee, Ga-Won; Huh, Eui-Nam

2012-01-01

Wireless Sensor Networks (WSNs) are gaining tremendous importance thanks to their broad range of commercial applications such as in smart home automation, health-care and industrial automation. In these applications multi-vendor and heterogeneous sensor nodes are deployed. Due to strict administrative control over the specific WSN domains, communication barriers, conflicting goals and the economic interests of different WSN sensor node vendors, it is difficult to introduce a large scale federated WSN. By allowing heterogeneous sensor nodes in WSNs to coexist on a shared physical sensor substrate, virtualization in sensor network may provide flexibility, cost effective solutions, promote diversity, ensure security and increase manageability. This paper surveys the novel approach of using the large scale federated WSN resources in a sensor virtualization environment. Our focus in this paper is to introduce a few design goals, the challenges and opportunities of research in the field of sensor network virtualization as well as to illustrate a current status of research in this field. This paper also presents a wide array of state-of-the art projects related to sensor network virtualization.

The digital library: an oxymoron?

PubMed Central

Guédon, J C

1999-01-01

"Virtual libraries" and "digital libraries" have become stock phrases of our times. But what do they really mean? While digital refers to a new form of document encoding and must be approached from that perspective, virtual resonates with aspects that modern philosophy treats with benign neglect at best. The word virtual harbors the notion of potential, and therein lies its hidden strength. Although strong commercial interests try to use the shift to a digital environment to redefine the political economy of knowledge, and thus virtualize libraries into a state of almost complete impotence, all hope is not lost. Librarians of virtualized libraries may well discover that they have re-empowered institutions if they place human interaction at the heart of their operations. In other words, rather than envisioning themselves as knowledge bankers sitting on treasure vaults of knowledge, they should see themselves as "hearts" dynamizing human communities. They should also see themselves as an essential part of these communities, and not as external repositories of knowledge. In this fashion, they will avoid the fate of becoming an oxymoron. PMID:9934524

Virtual continuity of measurable functions and its applications

NASA Astrophysics Data System (ADS)

Vershik, A. M.; Zatitskii, P. B.; Petrov, F. V.

2014-12-01

A classical theorem of Luzin states that a measurable function of one real variable is `almost' continuous. For measurable functions of several variables the analogous statement (continuity on a product of sets having almost full measure) does not hold in general. The search for a correct analogue of Luzin's theorem leads to a notion of virtually continuous functions of several variables. This apparently new notion implicitly appears in the statements of embedding theorems and trace theorems for Sobolev spaces. In fact it reveals the nature of such theorems as statements about virtual continuity. The authors' results imply that under the conditions of Sobolev theorems there is a well-defined integration of a function with respect to a wide class of singular measures, including measures concentrated on submanifolds. The notion of virtual continuity is also used for the classification of measurable functions of several variables and in some questions on dynamical systems, the theory of polymorphisms, and bistochastic measures. In this paper the necessary definitions and properties of admissible metrics are recalled, several definitions of virtual continuity are given, and some applications are discussed. Bibliography: 24 titles.

Virtual reality simulators for gastrointestinal endoscopy training

PubMed Central

Triantafyllou, Konstantinos; Lazaridis, Lazaros Dimitrios; Dimitriadis, George D

2014-01-01

The use of simulators as educational tools for medical procedures is spreading rapidly and many efforts have been made for their implementation in gastrointestinal endoscopy training. Endoscopy simulation training has been suggested for ascertaining patient safety while positively influencing the trainees’ learning curve. Virtual simulators are the most promising tool among all available types of simulators. These integrated modalities offer a human-like endoscopy experience by combining virtual images of the gastrointestinal tract and haptic realism with using a customized endoscope. From their first steps in the 1980s until today, research involving virtual endoscopic simulators can be divided in two categories: investigation of the impact of virtual simulator training in acquiring endoscopy skills and measuring competence. Emphasis should also be given to the financial impact of their implementation in endoscopy, including the cost of these state-of-the-art simulators and the potential economic benefits from their usage. Advances in technology will contribute to the upgrade of existing models and the development of new ones; while further research should be carried out to discover new fields of application. PMID:24527175

State of the practice on data access, sharing, and integration.

DOT National Transportation Integrated Search

2016-12-01

The purpose of this state-of-the-practice review was to lay both technical and institutional foundation for all aspects of the development of the Virtual Data Access Framework. The review focused on current data sharing and integration practices amon...

A compendium of existing HOV lane facilities in the United States

DOT National Transportation Integrated Search

2008-12-01

The compendium provides an assembly of available information on existing HOV lane facilities in the United States. While it is comprehensive and thought to include virtually all existing facilities at this time, it is possible that there are isolated...

Human agency beliefs influence behaviour during virtual social interactions.

PubMed

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.

DJINNI: A Novel Technology Supported Exposure Therapy Paradigm for SAD Combining Virtual Reality and Augmented Reality.

PubMed

Ben-Moussa, Maher; Rubo, Marius; Debracque, Coralie; Lange, Wolf-Gero

2017-01-01

The present paper explores the benefits and the capabilities of various emerging state-of-the-art interactive 3D and Internet of Things technologies and investigates how these technologies can be exploited to develop a more effective technology supported exposure therapy solution for social anxiety disorder. "DJINNI" is a conceptual design of an in vivo augmented reality (AR) exposure therapy mobile support system that exploits several capturing technologies and integrates the patient's state and situation by vision-based, audio-based, and physiology-based analysis as well as by indoor/outdoor localization techniques. DJINNI also comprises an innovative virtual reality exposure therapy system that is adaptive and customizable to the demands of the in vivo experience and therapeutic progress. DJINNI follows a gamification approach where rewards and achievements are utilized to motivate the patient to progress in her/his treatment. The current paper reviews the state of the art of technologies needed for such a solution and recommends how these technologies could be integrated in the development of an individually tailored and yet feasible and effective AR/virtual reality-based exposure therapy. Finally, the paper outlines how DJINNI could be part of classical cognitive behavioral treatment and how to validate such a setup.

DJINNI: A Novel Technology Supported Exposure Therapy Paradigm for SAD Combining Virtual Reality and Augmented Reality

PubMed Central

Ben-Moussa, Maher; Rubo, Marius; Debracque, Coralie; Lange, Wolf-Gero

2017-01-01

The present paper explores the benefits and the capabilities of various emerging state-of-the-art interactive 3D and Internet of Things technologies and investigates how these technologies can be exploited to develop a more effective technology supported exposure therapy solution for social anxiety disorder. “DJINNI” is a conceptual design of an in vivo augmented reality (AR) exposure therapy mobile support system that exploits several capturing technologies and integrates the patient’s state and situation by vision-based, audio-based, and physiology-based analysis as well as by indoor/outdoor localization techniques. DJINNI also comprises an innovative virtual reality exposure therapy system that is adaptive and customizable to the demands of the in vivo experience and therapeutic progress. DJINNI follows a gamification approach where rewards and achievements are utilized to motivate the patient to progress in her/his treatment. The current paper reviews the state of the art of technologies needed for such a solution and recommends how these technologies could be integrated in the development of an individually tailored and yet feasible and effective AR/virtual reality-based exposure therapy. Finally, the paper outlines how DJINNI could be part of classical cognitive behavioral treatment and how to validate such a setup. PMID:28503155

Flatness-based control in successive loops for stabilization of heart's electrical activity

NASA Astrophysics Data System (ADS)

Rigatos, Gerasimos; Melkikh, Alexey

2016-12-01

The article proposes a new flatness-based control method implemented in successive loops which allows for stabilization of the heart's electrical activity. Heart's pacemaking function is modeled as a set of coupled oscillators which potentially can exhibit chaotic behavior. It is shown that this model satisfies differential flatness properties. Next, the control and stabilization of this model is performed with the use of flatness-based control implemented in cascading loops. By applying a per-row decomposition of the state-space model of the coupled oscillators a set of nonlinear differential equations is obtained. Differential flatness properties are shown to hold for the subsystems associated with the each one of the aforementioned differential equations and next a local flatness-based controller is designed for each subsystem. For the i-th subsystem, state variable xi is chosen to be the flat output and state variable xi+1 is taken to be a virtual control input. Then the value of the virtual control input which eliminates the output tracking error for the i-th subsystem becomes reference setpoint for the i + 1-th subsystem. In this manner the control of the entire state-space model is performed by successive flatness-based control loops. By arriving at the n-th row of the state-space model one computes the control input that can be actually exerted on the aforementioned biosystem. This real control input of the coupled oscillators' system, contains recursively all virtual control inputs associated with the previous n - 1 rows of the state-space model. This control approach achieves asymptotically the elimination of the chaotic oscillation effects and the stabilization of the heart's pulsation rhythm. The stability of the proposed control scheme is proven with the use of Lyapunov analysis.

Meditation experts try Virtual Reality Mindfulness: A pilot study evaluation of the feasibility and acceptability of Virtual Reality to facilitate mindfulness practice in people attending a Mindfulness conference.

PubMed

Navarro-Haro, María V; López-Del-Hoyo, Yolanda; Campos, Daniel; Linehan, Marsha M; Hoffman, Hunter G; García-Palacios, Azucena; Modrego-Alarcón, Marta; Borao, Luis; García-Campayo, Javier

2017-01-01

Regular mindfulness practice benefits people both mentally and physically, but many populations who could benefit do not practice mindfulness. Virtual Reality (VR) is a new technology that helps capture participants' attention and gives users the illusion of "being there" in the 3D computer generated environment, facilitating sense of presence. By limiting distractions from the real world, increasing sense of presence and giving people an interesting place to go to practice mindfulness, Virtual Reality may facilitate mindfulness practice. Traditional Dialectical Behavioral Therapy (DBT®) mindfulness skills training was specifically designed for clinical treatment of people who have trouble focusing attention, however severe patients often show difficulties or lack of motivation to practice mindfulness during the training. The present pilot study explored whether a sample of mindfulness experts would find useful and recommend a new VR Dialectical Behavioral Therapy (DBT®) mindfulness skills training technique and whether they would show any benefit. Forty four participants attending a mindfulness conference put on an Oculus Rift DK2 Virtual Reality helmet and floated down a calm 3D computer generated virtual river while listening to digitized DBT® mindfulness skills training instructions. On subjective questionnaires completed by the participants before and after the VR DBT® mindfulness skills training session, participants reported increases/improvements in state of mindfulness, and reductions in negative emotional states. After VR, participants reported significantly less sadness, anger, and anxiety, and reported being significantly more relaxed. Participants reported a moderate to strong illusion of going inside the 3D computer generated world (i.e., moderate to high "presence" in VR) and showed high acceptance of VR as a technique to practice mindfulness. These results show encouraging preliminary evidence of the feasibility and acceptability of using VR to practice mindfulness based on clinical expert feedback. VR is a technology with potential to increase computerized dissemination of DBT® skills training modules. Future research is warranted.

Meditation experts try Virtual Reality Mindfulness: A pilot study evaluation of the feasibility and acceptability of Virtual Reality to facilitate mindfulness practice in people attending a Mindfulness conference.

PubMed Central

Navarro-Haro, María V.; López-del-Hoyo, Yolanda; Campos, Daniel; Linehan, Marsha M.; Hoffman, Hunter G.; García-Palacios, Azucena; Modrego-Alarcón, Marta; Borao, Luis; García-Campayo, Javier

2017-01-01

Regular mindfulness practice benefits people both mentally and physically, but many populations who could benefit do not practice mindfulness. Virtual Reality (VR) is a new technology that helps capture participants’ attention and gives users the illusion of “being there” in the 3D computer generated environment, facilitating sense of presence. By limiting distractions from the real world, increasing sense of presence and giving people an interesting place to go to practice mindfulness, Virtual Reality may facilitate mindfulness practice. Traditional Dialectical Behavioral Therapy (DBT®) mindfulness skills training was specifically designed for clinical treatment of people who have trouble focusing attention, however severe patients often show difficulties or lack of motivation to practice mindfulness during the training. The present pilot study explored whether a sample of mindfulness experts would find useful and recommend a new VR Dialectical Behavioral Therapy (DBT®) mindfulness skills training technique and whether they would show any benefit. Forty four participants attending a mindfulness conference put on an Oculus Rift DK2 Virtual Reality helmet and floated down a calm 3D computer generated virtual river while listening to digitized DBT® mindfulness skills training instructions. On subjective questionnaires completed by the participants before and after the VR DBT® mindfulness skills training session, participants reported increases/improvements in state of mindfulness, and reductions in negative emotional states. After VR, participants reported significantly less sadness, anger, and anxiety, and reported being significantly more relaxed. Participants reported a moderate to strong illusion of going inside the 3D computer generated world (i.e., moderate to high “presence” in VR) and showed high acceptance of VR as a technique to practice mindfulness. These results show encouraging preliminary evidence of the feasibility and acceptability of using VR to practice mindfulness based on clinical expert feedback. VR is a technology with potential to increase computerized dissemination of DBT® skills training modules. Future research is warranted. PMID:29166665

Quality of experience in real and virtual environments: some suggestions for the development of positive technologies.

PubMed

Gaggioli, Andrea

2012-01-01

What does one feel when one uses virtual reality? How does this experience differ from the experience associated with "real life" activities and situations? To answer these questions, we used the Experience Sampling Method (ESM), a procedure that allows researchers to investigate the daily fluctuations in the quality of experience through on-line self reports that participants fill out during daily life. The investigation consisted in one-week ESM observation (N = 42). During this week, participants underwent two virtual reality sessions: Immediately after the exposure to virtual environments, they were asked to complete a ESM report. For data analysis, experiential variables were aggregated into four dimensions: Mood, Engagement, Confidence, and Intrinsic Motivation Intrinsic Motivation. Findings showed that virtual experience is characterized by a specific configuration, which comprises significantly positive values for affective and cognitive components. In particular, positive scores of Mood suggest that participants perceived VR as an intrinsically pleasurable activity, while positive values of Engagement indicate that the use of VR and the experimental task provided valid opportunities for action and high skill investment. Furthermore, results showed that virtual experience is associated with Flow, a state of consciousness characterized by narrowed focus of attention, deep concentration, positive affect and intrinsic reward. Implications for VR research and practice are discussed.

Agency and Gender Influence Older Adults' Presence-Related Experiences in an Interactive Virtual Environment.

PubMed

Kothgassner, Oswald D; Goreis, Andreas; Kafka, Johanna X; Hlavacs, Helmut; Beutl, Leon; Kryspin-Exner, Ilse; Felnhofer, Anna

2018-05-01

While virtual humans are increasingly used to benefit the elderly, considerably little is still known about older adults' virtual experiences. However, due to age-related changes, older adults' perceptions of virtual environments (VEs) may be unique. Hence, our objective was to examine possible gender differences in immersion, flow, and emotional states as well as physical and social presence in elderly males and females interacting either with a computer-controlled agent or a human-controlled avatar. Seventy-eight German-speaking older adults were randomly assigned to an avatar or an agent condition and were exposed to a brief social encounter in a virtual café. Results indicate no overall gender differences, but a significant effect of agency on social presence, physical presence, immersion, and flow. Participants in the avatar condition reported higher levels in all measures, except for involvement. Furthermore, significant gender × agency interactions were found, with females showing more social presence, spatial presence, and flow when interacting with a human-controlled avatar and more realism when conversing with an agent. Also, all participants showed significant changes in their affect post exposure. In sum, older adults' virtual experiences seem to follow unique patterns, yet, they do not preclude the elderly from successfully participating in VEs.

Recent drought conditions in the Conterminous United States

Treesearch

Frank H. Koch; William D. Smith; John W. Coulston

2013-01-01

Droughts are common in virtually all U.S. forests, but their frequency and intensity vary widely both between and within forest ecosystems (Hanson and Weltzin 2000). Forests in the Western United States generally exhibit a pattern of annual seasonal droughts. Forests in the Eastern United States tend to exhibit one of two prevailing patterns: random occasional droughts...

Analysis of pure maple syrup consumers

Treesearch

Paul E. Sendak

1974-01-01

Virtually all of the pure maple syrup productim in the United States is in the northern states of Maine, Massachusetts, Michigan, New Hampshire, New York, Ohio, Pennsylvania, Vermont, and Wisconsin. Pure maple syrup users living in the maple production area and users living in other areas of the United States were asked a series of questions about their use of pure...

Vibrons in finite size molecular lattices: a route for high-fidelity quantum state transfer at room temperature.

PubMed

Pouthier, Vincent

2012-11-07

A communication protocol is proposed in which vibron-mediated quantum state transfer takes place in a molecular lattice. We consider two distant molecular groups grafted on each side of the lattice. These groups form two quantum computers where vibrational qubits are implemented and received. The lattice defines the communication channel along which a vibron delocalizes and interacts with a phonon bath. Using quasi-degenerate perturbation theory, vibron-phonon entanglement is taken into account through the effective Hamiltonian concept. A vibron is thus dressed by a virtual phonon cloud whereas a phonon is clothed by virtual vibronic transitions. It is shown that three quasi-degenerate dressed states define the relevant paths followed by a vibron to tunnel between the computers. When the coupling between the computers and the lattice is judiciously chosen, constructive interference takes place between these paths. Phonon-induced decoherence is minimized and a high-fidelity quantum state transfer occurs over a broad temperature range.

Perceived Parent Involvement and a Technology-Enabled Workbook Intervention Effect Analysis on Summer Learning Loss for 6th and 7th Grade Students Attending a Pennsylvania K-12 Virtual School

ERIC Educational Resources Information Center

Boyd, Amy Cronin

2018-01-01

The literature suggests that while the number of students attending virtual charter schools continues to grow in Pennsylvania, math student academic performance in 6th and 7th-grade math in students attending cyber charter schools falls well below the state average. Although it is tempting to assume that the concern of summer slide would be…

Performance Analysis of Live-Virtual-Constructive and Distributed Virtual Simulations: Defining Requirements in Terms of Temporal Consistency

DTIC Science & Technology

2009-12-01

events. Work associated with aperiodic tasks have the same statistical behavior and the same timing requirements. The timing deadlines are soft. • Sporadic...answers, but it is possible to calculate how precise the estimates are. Simulation-based performance analysis of a model includes a statistical ...to evaluate all pos- sible states in a timely manner. This is the principle reason for resorting to simulation and statistical analysis to evaluate

Practical Issues in Delivery of Clinician-to-Patient Telemental Health in an Academic Medical Center.

PubMed

Abrams, Jessica; Sossong, Sarah; Schwamm, Lee H; Barsanti, Lauren; Carter, Michael; Kling, Naomi; Kotarski, Meghan; Leddy, Jaclyn; Meller, Benjamin; Simoni, Marcy; Sullivan, Michael; Wozniak, Janet

In the age of online communication, psychiatric care can now be provided via videoconferencing technologies. While virtual visits as a part of telepsychiatry and telemental health provide a highly efficient and beneficial modality of care, the implementation of virtual visits requires attention to quality and safety issues. As practitioners continue to utilize this technology, issues of clinician licensing, treatment outcomes of virtual visits versus in-person visits, and cost offset require ongoing study. This review provides an overview of the topics of technology, legal and regulatory issues, clinical issues, and cost savings as they relate to practicing psychiatry and psychology via virtual visits in an academic medical center. We review the telepsychiatry/telemental health effectiveness literature from 2013 to the present. Our literature searches used the following terms: telemental health effective, telepsychiatry effective, telepsychiatry efficacy, and telemental health efficacy. These searches produced 58 articles, reduced to 16 when including only articles that address effectiveness of clinician-to-patient services. The technological, legal, and regulatory issues vary from state to state and over time. The emerging research addressing diverse populations and disorders provides strong evidence for the effectiveness of telepsychiatry. Cost savings are difficult to precisely determine and depend on the scope of the cost and benefit measured. Establishing a telepsychiatry program requires a comprehensive approach with up-to-date legal and technological considerations.

Virtual water exported from Californian agriculture

NASA Astrophysics Data System (ADS)

Nicholas, K. A.; Johansson, E. L.

2015-12-01

In an increasingly teleconnected world, international trade drives the exchange of virtual land and water as crops produced in one region are consumed in another. In theory, this can be an optimal use of scarce resources if crops are grown where they can most efficiently be produced. Several recent analyses examine the export of land and water from food production in developing countries where these resources may be more abundant. Here we focus on a developed region and examine the virtual export of land and water from California, the leading agricultural state in the US and the leading global producer of a wide range of fruit, nut, and other specialty crops. As the region faces a serious, ongoing drought, water use is being questioned, and water policy governance re-examined, particularly in the agricultural sector which uses over three-quarters of water appropriations in the state. We look at the blue water embodied in the most widely grown crops in California and use network analysis to examine the trading patterns for flows of virtual land and water. We identify the main crops and export partners representing the majority of water exports. Considered in the context of tradeoffs for land and water resources, we highlight the challenges and opportunities for food production systems to play a sustainable role in meeting human needs while protecting the life-support systems of the planet.

Distributed virtual environment for emergency medical training

NASA Astrophysics Data System (ADS)

Stytz, Martin R.; Banks, Sheila B.; Garcia, Brian W.; Godsell-Stytz, Gayl M.

1997-07-01

In many professions where individuals must work in a team in a high stress environment to accomplish a time-critical task, individual and team performance can benefit from joint training using distributed virtual environments (DVEs). One professional field that lacks but needs a high-fidelity team training environment is the field of emergency medicine. Currently, emergency department (ED) medical personnel train by using words to create a metal picture of a situation for the physician and staff, who then cooperate to solve the problems portrayed by the word picture. The need in emergency medicine for realistic virtual team training is critical because ED staff typically encounter rarely occurring but life threatening situations only once in their careers and because ED teams currently have no realistic environment in which to practice their team skills. The resulting lack of experience and teamwork makes diagnosis and treatment more difficult. Virtual environment based training has the potential to redress these shortfalls. The objective of our research is to develop a state-of-the-art virtual environment for emergency medicine team training. The virtual emergency room (VER) allows ED physicians and medical staff to realistically prepare for emergency medical situations by performing triage, diagnosis, and treatment on virtual patients within an environment that provides them with the tools they require and the team environment they need to realistically perform these three tasks. There are several issues that must be addressed before this vision is realized. The key issues deal with distribution of computations; the doctor and staff interface to the virtual patient and ED equipment; the accurate simulation of individual patient organs' response to injury, medication, and treatment; and an accurate modeling of the symptoms and appearance of the patient while maintaining a real-time interaction capability. Our ongoing work addresses all of these issues. In this paper we report on our prototype VER system and its distributed system architecture for an emergency department distributed virtual environment for emergency medical staff training. The virtual environment enables emergency department physicians and staff to develop their diagnostic and treatment skills using the virtual tools they need to perform diagnostic and treatment tasks. Virtual human imagery, and real-time virtual human response are used to create the virtual patient and present a scenario. Patient vital signs are available to the emergency department team as they manage the virtual case. The work reported here consists of the system architectures we developed for the distributed components of the virtual emergency room. The architectures we describe consist of the network level architecture as well as the software architecture for each actor within the virtual emergency room. We describe the role of distributed interactive simulation and other enabling technologies within the virtual emergency room project.

Virtual Reality for Enhanced Ecological Validity and Experimental Control in the Clinical, Affective and Social Neurosciences

PubMed Central

Parsons, Thomas D.

2015-01-01

An essential tension can be found between researchers interested in ecological validity and those concerned with maintaining experimental control. Research in the human neurosciences often involves the use of simple and static stimuli lacking many of the potentially important aspects of real world activities and interactions. While this research is valuable, there is a growing interest in the human neurosciences to use cues about target states in the real world via multimodal scenarios that involve visual, semantic, and prosodic information. These scenarios should include dynamic stimuli presented concurrently or serially in a manner that allows researchers to assess the integrative processes carried out by perceivers over time. Furthermore, there is growing interest in contextually embedded stimuli that can constrain participant interpretations of cues about a target’s internal states. Virtual reality environments proffer assessment paradigms that combine the experimental control of laboratory measures with emotionally engaging background narratives to enhance affective experience and social interactions. The present review highlights the potential of virtual reality environments for enhanced ecological validity in the clinical, affective, and social neurosciences. PMID:26696869

Virtual Reality for Enhanced Ecological Validity and Experimental Control in the Clinical, Affective and Social Neurosciences.

PubMed

Parsons, Thomas D

2015-01-01

An essential tension can be found between researchers interested in ecological validity and those concerned with maintaining experimental control. Research in the human neurosciences often involves the use of simple and static stimuli lacking many of the potentially important aspects of real world activities and interactions. While this research is valuable, there is a growing interest in the human neurosciences to use cues about target states in the real world via multimodal scenarios that involve visual, semantic, and prosodic information. These scenarios should include dynamic stimuli presented concurrently or serially in a manner that allows researchers to assess the integrative processes carried out by perceivers over time. Furthermore, there is growing interest in contextually embedded stimuli that can constrain participant interpretations of cues about a target's internal states. Virtual reality environments proffer assessment paradigms that combine the experimental control of laboratory measures with emotionally engaging background narratives to enhance affective experience and social interactions. The present review highlights the potential of virtual reality environments for enhanced ecological validity in the clinical, affective, and social neurosciences.

Afraid to be there? Evaluating the relation between presence, self-reported anxiety, and heart rate in a virtual public speaking task.

PubMed

Felnhofer, Anna; Kothgassner, Oswald D; Hetterle, Thomas; Beutl, Leon; Hlavacs, Helmut; Kryspin-Exner, Ilse

2014-05-01

The link between anxiety and presence in a virtual environment (VE) is still a subject of an unresolved debate, with little empirical research to support theoretical claims. Thus, the current study analyzed presence, self-reported anxiety, and a physiological parameter (heart rate [HR]) in a sample of 30 high anxious and 35 low anxious participants. Both groups delivered a 5 minute speech in a virtual lecture hall. Results indicate no mediating influences of presence on group differences in self-reported state anxiety during the speech, but point toward negative correlations between state anxiety and the iGroup Presence Questionnaire (IPQ) scales "sense of being there" and "realism." Furthermore, HR was found to be unrelated to self-reported presence. Only the IPQ scale "spatial presence" showed a marginally significant influence on group differences in state anxiety. The present results support the assumption that presence and anxiety are logically distinct, meaning that presence does not directly influence the intensity of an emotion felt in a VE. Rather, it constitutes a precondition for an emotion to be at all elicited by a VE. Also, HR has proven to be no adequate substitute measure for presence, since it only assesses anxiety not presence. It may, however, mediate the interplay between trait anxiety and state anxiety. Possible implications of the current findings are discussed alongside the problem of using presence questionnaires that seem to be prone to subjective bias (i.e., participants confusing presence and emotion).

Self-replicating machines in continuous space with virtual physics.

PubMed

Smith, Arnold; Turney, Peter; Ewaschuk, Robert

2003-01-01

JohnnyVon is an implementation of self-replicating machines in continuous two-dimensional space. Two types of particles drift about in a virtual liquid. The particles are automata with discrete internal states but continuous external relationships. Their internal states are governed by finite state machines, but their external relationships are governed by a simulated physics that includes Brownian motion, viscosity, and springlike attractive and repulsive forces. The particles can be assembled into patterns that can encode arbitrary strings of bits. We demonstrate that, if an arbitrary seed pattern is put in a soup of separate individual particles, the pattern will replicate by assembling the individual particles into copies of itself. We also show that, given sufficient time, a soup of separate individual particles will eventually spontaneously form self-replicating patterns. We discuss the implications of JohnnyVon for research in nanotechnology, theoretical biology, and artificial life.

Event shape analysis of deep inelastic scattering events with a large rapidity gap at HERA

NASA Astrophysics Data System (ADS)

ZEUS Collaboration; Breitweg, J.; Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Repond, J.; Stanek, R.; Talaga, R. L.; Yoshida, R.; Zhang, H.; Mattingly, M. C. K.; Anselmo, F.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Castellini, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; Pesci, A.; Polini, A.; Ricci, F.; Sartorelli, G.; Zamora Garcia, Y.; Zichichi, A.; Amelung, C.; Bornheim, A.; Brock, I.; Coböken, K.; Crittenden, J.; Deffner, R.; Eckert, M.; Grothe, M.; Hartmann, H.; Heinloth, K.; Heinz, L.; Hilger, E.; Jakob, H.-P.; Katz, U. F.; Kerger, R.; Paul, E.; Pfeiffer, M.; Rembser, Ch.; Stamm, J.; Wedemeyer, R.; Wieber, H.; Bailey, D. S.; Campbell-Robson, S.; Cottingham, W. N.; Foster, B.; Hall-Wilton, R.; Hayes, M. E.; Heath, G. P.; Heath, H. F.; McFall, J. D.; Piccioni, D.; Roff, D. G.; Tapper, R. J.; Arneodo, M.; Ayad, R.; Capua, M.; Garfagnini, A.; Iannotti, L.; Schioppa, M.; Susinno, G.; Kim, J. Y.; Lee, J. H.; Lim, I. T.; Pac, M. Y.; Caldwell, A.; Cartiglia, N.; Jing, Z.; Liu, W.; Mellado, B.; Parsons, J. A.; Ritz, S.; Sampson, S.; Sciulli, F.; Straub, P. B.; Zhu, Q.; Borzemski, P.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Klimek, K.; Przybycień , M. B.; Zawiejski, L.; Adamczyk, L.; Bednarek, B.; Bukowy, M.; Jeleń , K.; Kisielewska, D.; Kowalski, T.; Przybycień , M.; Rulikowska-Zarȩ Bska, E.; Suszycki, L.; Zaja C, J.; Duliń Ski, Z.; Kotań Ski, A.; Abbiendi, G.; Bauerdick, L. A. T.; Behrens, U.; Beier, H.; Bienlein, J. K.; Cases, G.; Deppe, O.; Desler, K.; Drews, G.; Fricke, U.; Gilkinson, D. J.; Glasman, C.; Göttlicher, P.; Haas, T.; Hain, W.; Hasell, D.; Johnson, K. F.; Kasemann, M.; Koch, W.; Kötz, U.; Kowalski, H.; Labs, J.; Lindemann, L.; Löhr, B.; Löwe, M.; Mań Czak, O.; Milewski, J.; Monteiro, T.; Ng, J. S. T.; Notz, D.; Ohrenberg, K.; Park, I. H.; Pellegrino, A.; Pelucchi, F.; Piotrzkowski, K.; Roco, M.; Rohde, M.; Roldán, J.; Ryan, J. J.; Savin, A. A.; Schneekloth, U.; Selonke, F.; Surrow, B.; Tassi, E.; Voß, T.; Westphal, D.; Wolf, G.; Wollmer, U.; Youngman, C.; Zsolararnecki, A. F.; Zeuner, W.; Burow, B. D.; Grabosch, H. J.; Meyer, A.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P.; Maccarrone, G.; Votano, L.; Bamberger, A.; Eisenhardt, S.; Markun, P.; Trefzger, T.; Wölfle, S.; Bromley, J. T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; MacDonald, N.; Saxon, D. H.; Sinclair, L. E.; Strickland, E.; Waugh, R.; Bohnet, I.; Gendner, N.; Holm, U.; Meyer-Larsen, A.; Salehi, H.; Wick, K.; Gladilin, L. K.; Horstmann, D.; Kçira, D.; Klanner, R.; Lohrmann, E.; Poelz, G.; Schott, W.; Zetsche, F.; Bacon, T. C.; Butterworth, I.; Cole, J. E.; Howell, G.; Hung, B. H. Y.; Lamberti, L.; Long, K. R.; Miller, D. B.; Pavel, N.; Prinias, A.; Sedgbeer, J. K.; Sideris, D.; Walker, R.; Mallik, U.; Wang, S. M.; Wu, J. T.; Cloth, P.; Filges, D.; Fleck, J. I.; Ishii, T.; Kuze, M.; Suzuki, I.; Tokushuku, K.; Yamada, S.; Yamauchi, K.; Yamazaki, Y.; Hong, S. J.; Lee, S. B.; Nam, S. W.; Park, S. K.; Barreiro, F.; Fernández, J. P.; García, G.; Graciani, R.; Hernández, J. M.; Hervás, L.; Labarga, L.; Martínez, M.; del Peso, J.; Puga, J.; Terrón, J.; de Trocóniz, J. F.; Corriveau, F.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Murray, W. N.; Ochs, A.; Riveline, M.; Stairs, D. G.; St-Laurent, M.; Ullmann, R.; Tsurugai, T.; Bashkirov, V.; Dolgoshein, B. A.; Stifutkin, A.; Bashindzhagyan, G. L.; Ermolov, P. F.; Golubkov, Yu. A.; Khein, L. A.; Korotkova, N. A.; Korzhavina, I. A.; Kuzmin, V. A.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Solomin, A. N.; Zotkin, S. A.; Bokel, C.; Botje, M.; Brümmer, N.; Chlebana, F.; Engelen, J.; Koffeman, E.; Kooijman, P.; van Sighem, A.; Tiecke, H.; Tuning, N.; Verkerke, W.; Vossebeld, J.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; Acosta, D.; Bylsma, B.; Durkin, L. S.; Gilmore, J.; Ginsburg, C. M.; Kim, C. L.; Ling, T. Y.; Nylander, P.; Romanowski, T. A.; Blaikley, H. E.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Edmonds, J. K.; Große-Knetter, J.; Harnew, N.; Nath, C.; Noyes, V. A.; Quadt, A.; Ruske, O.; Tickner, J. R.; Uijterwaal, H.; Walczak, R.; Waters, D. S.; Bertolin, A.; Brugnera, R.; Carlin, R.; dal Corso, F.; Dosselli, U.; Limentani, S.; Morandin, M.; Posocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Bulmahn, J.; Oh, B. Y.; Okrasiń Ski, J. R.; Toothacker, W. S.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Raso, M.; Hart, J. C.; McCubbin, N. A.; Shah, T. P.; Epperson, D.; Heusch, C.; Rahn, J. T.; Sadrozinski, H. F.-W.; Seiden, A.; Wichmann, R.; Williams, D. C.; Schwarzer, O.; Walenta, A. H.; Abramowicz, H.; Briskin, G.; Dagan, S.; Kananov, S.; Levy, A.; Abe, T.; Fusayasu, T.; Inuzuka, M.; Nagano, K.; Umemori, K.; Yamashita, T.; Hamatsu, R.; Hirose, T.; Homma, K.; Kitamura, S.; Matsushita, T.; Cirio, R.; Costa, M.; Ferrero, M. I.; Maselli, S.; Monaco, V.; Peroni, C.; Petrucci, M. C.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Fagerstroem, C.-P.; Galea, R.; Hartner, G. F.; Joo, K. K.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Polenz, S.; Sabetfakhri, A.; Simmons, D.; Teuscher, R. J.; Butterworth, J. M.; Catterall, C. D.; Jones, T. W.; Lane, J. B.; Saunders, R. L.; Sutton, M. R.; Wing, M.; Ciborowski, J.; Grzelak, G.; Kasprzak, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Pawlak, R.; Tymieniecka, T.; Wróblewski, A. K.; Zakrzewski, J. A.; Adamus, M.; Coldewey, C.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Badgett, W. F.; Chapin, D.; Cross, R.; Dasu, S.; Foudas, C.; Loveless, R. J.; Mattingly, S.; Reeder, D. D.; Smith, W. H.; Vaiciulis, A.; Wodarczyk, M.; Deshpande, A.; Dhawan, S.; Hughes, V. W.; Bhadra, S.; Frisken, W. R.; Khakzad, M.; Schmidke, W. B.

1998-03-01

A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range 5<=Q2<=185 GeV2 and 160<=W<=250 GeV, where Q2 is the virtuality of the photon and W is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the γ*-pomeron rest frame, on the mass of the hadronic final state, MX. With increasing MX the multihadronic final state becomes more collimated and planar. The experimental results are compared with several models which attempt to describe diffractive events. The broadening effects exhibited by the data require in these models a significant gluon component of the pomeron.

Ambient Intelligence in Multimeda and Virtual Reality Environments for the rehabilitation

NASA Astrophysics Data System (ADS)

Benko, Attila; Cecilia, Sik Lanyi

This chapter presents a general overview about the use of multimedia and virtual reality in rehabilitation and assistive and preventive healthcare. This chapter deals with multimedia, virtual reality applications based AI intended for use by medical doctors, nurses, special teachers and further interested persons. It describes methods how multimedia and virtual reality is able to assist their work. These include the areas how multimedia and virtual reality can help the patients everyday life and their rehabilitation. In the second part of the chapter we present the Virtual Therapy Room (VTR) a realized application for aphasic patients that was created for practicing communication and expressing emotions in a group therapy setting. The VTR shows a room that contains a virtual therapist and four virtual patients (avatars). The avatars are utilizing their knowledge base in order to answer the questions of the user providing an AI environment for the rehabilitation. The user of the VTR is the aphasic patient who has to solve the exercises. The picture that is relevant for the actual task appears on the virtual blackboard. Patient answers questions of the virtual therapist. Questions are about pictures describing an activity or an object in different levels. Patient can ask an avatar for answer. If the avatar knows the answer the avatars emotion changes to happy instead of sad. The avatar expresses its emotions in different dimensions. Its behavior, face-mimic, voice-tone and response also changes. The emotion system can be described as a deterministic finite automaton where places are emotion-states and the transition function of the automaton is derived from the input-response reaction of an avatar. Natural language processing techniques were also implemented in order to establish highquality human-computer interface windows for each of the avatars. Aphasic patients are able to interact with avatars via these interfaces. At the end of the chapter we visualize the possible future research field.

Virtual Reality for Sensorimotor Rehabilitation Post-Stroke: The Promise and Current State of the Field

PubMed Central

Fluet, Gerard G.

2013-01-01

Developments over the past 2 years in virtual reality (VR) augmented sensorimotor rehabilitation of upper limb use and gait post-stroke were reviewed. Studies were included if they evaluated comparative efficacy between VR and standard of care, and or differences in VR delivery methods; and were CEBM (center for evidence based medicine) level 2 or higher. Eight upper limb and two gait studies were included and described using the following categories hardware (input and output), software (virtual task and feedback and presentation) intervention (progression and dose), and outcomes. Trends in the field were commented on, gaps in knowledge identified, and areas of future research and translation of VR to practice were suggested. PMID:24579058

Immersive virtual reality for visualization of abdominal CT

NASA Astrophysics Data System (ADS)

Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A.; Bodenheimer, Robert E.

2013-03-01

Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

English Language Arts and Science Courses in a Virtual School: A Comparative Case Study

NASA Astrophysics Data System (ADS)

Tustin, Rachel Sarah

Virtual K-12 schools have rapidly become a popular choice for parents and students in the last decade. However, little research has been done on the instructional practices used in virtual courses. As reflected in the central research question, the purpose of this study was to explore how teachers provided instruction for Grade 7-10 students in both English language arts and science courses in a virtual school in a southern state. The conceptual framework was based on Piaget's theory of cognitive development and Garrison, Anderson, and Siemens' research on instructional design. The units of analysis in this qualitative, comparative case study were four virtual courses; the data were collected from teacher and student questionnaires, threaded student discussions, student work samples, and archival records. The first level of data analysis involved coding and categorization using the constant comparative method, and the second level involved examining the data for patterns, themes, and relationships to determine key findings. Results indicated that a standardized virtual course design supported teacher use of direct instruction and summative assessments and some individualized instruction to deliver course content, including adjusting the course pace, conducting individual telephone conferences, and providing small group instruction using Blackboard Elluminate. Opportunities for student interaction and inquiry learning were limited. This study is expected to contribute to positive social change by providing educators and policymakers with an awareness of the critical need for further study of research-based instructional practices in K-12 virtual courses that would improve student learning.

The Virtual Observatory: I

NASA Astrophysics Data System (ADS)

Hanisch, R. J.

2014-11-01

The concept of the Virtual Observatory arose more-or-less simultaneously in the United States and Europe circa 2000. Ten pages of Astronomy and Astrophysics in the New Millennium: Panel Reports (National Academy Press, Washington, 2001), that is, the detailed recommendations of the Panel on Theory, Computation, and Data Exploration of the 2000 Decadal Survey in Astronomy, are dedicated to describing the motivation for, scientific value of, and major components required in implementing the National Virtual Observatory. European initiatives included the Astrophysical Virtual Observatory at the European Southern Observatory, the AstroGrid project in the United Kingdom, and the Euro-VO (sponsored by the European Union). Organizational/conceptual meetings were held in the US at the California Institute of Technology (Virtual Observatories of the Future, June 13-16, 2000) and at ESO Headquarters in Garching, Germany (Mining the Sky, July 31-August 4, 2000; Toward an International Virtual Observatory, June 10-14, 2002). The nascent US, UK, and European VO projects formed the International Virtual Observatory Alliance (IVOA) at the June 2002 meeting in Garching, with yours truly as the first chair. The IVOA has grown to a membership of twenty-one national projects and programs on six continents, and has developed a broad suite of data access protocols and standards that have been widely implemented. Astronomers can now discover, access, and compare data from hundreds of telescopes and facilities, hosted at hundreds of organizations worldwide, stored in thousands of databases, all with a single query.

Immersive Virtual Reality for Visualization of Abdominal CT.

PubMed

Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A; Bodenheimer, Robert E

2013-03-28

Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two-dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

An interactive VR system based on full-body tracking and gesture recognition

NASA Astrophysics Data System (ADS)

Zeng, Xia; Sang, Xinzhu; Chen, Duo; Wang, Peng; Guo, Nan; Yan, Binbin; Wang, Kuiru

2016-10-01

Most current virtual reality (VR) interactions are realized with the hand-held input device which leads to a low degree of presence. There is other solutions using sensors like Leap Motion to recognize the gestures of users in order to interact in a more natural way, but the navigation in these systems is still a problem, because they fail to map the actual walking to virtual walking only with a partial body of the user represented in the synthetic environment. Therefore, we propose a system in which users can walk around in the virtual environment as a humanoid model, selecting menu items and manipulating with the virtual objects using natural hand gestures. With a Kinect depth camera, the system tracks the joints of the user, mapping them to a full virtual body which follows the move of the tracked user. The movements of the feet can be detected to determine whether the user is in walking state, so that the walking of model in the virtual world can be activated and stopped by means of animation control in Unity engine. This method frees the hands of users comparing to traditional navigation way using hand-held device. We use the point cloud data getting from Kinect depth camera to recognize the gestures of users, such as swiping, pressing and manipulating virtual objects. Combining the full body tracking and gestures recognition using Kinect, we achieve our interactive VR system in Unity engine with a high degree of presence.

3D multiplayer virtual pets game using Google Card Board

NASA Astrophysics Data System (ADS)

Herumurti, Darlis; Riskahadi, Dimas; Kuswardayan, Imam

2017-08-01

Virtual Reality (VR) is a technology which allows user to interact with the virtual environment. This virtual environment is generated and simulated by computer. This technology can make user feel the sensation when they are in the virtual environment. The VR technology provides real virtual environment view for user and it is not viewed from screen. But it needs another additional device to show the view of virtual environment. This device is known as Head Mounted Device (HMD). Oculust Rift and Microsoft Hololens are the most famous HMD devices used in VR. And in 2014, Google Card Board was introduced at Google I/O developers conference. Google Card Board is VR platform which allows user to enjoy the VR with simple and cheap way. In this research, we explore Google Card Board to develop simulation game of raising pet. The Google Card Board is used to create view for the VR environment. The view and control in VR environment is built using Unity game engine. And the simulation process is designed using Finite State Machine (FSM). This FSM can help to design the process clearly. So the simulation process can describe the simulation of raising pet well. Raising pet is fun activity. But sometimes, there are many conditions which cause raising pet become difficult to do, i.e. environment condition, disease, high cost, etc. this research aims to explore and implement Google Card Board in simulation of raising pet.

M-MRAC Backstepping for Systems with Unknown Virtual Control Coefficients

NASA Technical Reports Server (NTRS)

Stepanyan, Vahram; Krishnakumar, Kalmanje

2015-01-01

The paper presents an over-parametrization free certainty equivalence state feedback backstepping adaptive control design method for systems of any relative degree with unmatched uncertainties and unknown virtual control coefficients. It uses a fast prediction model to estimate the unknown parameters, which is independent of the control design. It is shown that the system's input and output tracking errors can be systematically decreased by the proper choice of the design parameters. The benefits of the approach are demonstrated in numerical simulations.

Simulation of eye disease in virtual reality.

PubMed

Jin, Bei; Ai, Zhuming; Rasmussen, Mary

2005-01-01

It is difficult to understand verbal descriptions of visual phenomenon if one has no such experience. Virtual Reality offers a unique opportunity to "experience" diminished vision and the problems it causes in daily life. We have developed an application to simulate age-related macular degeneration, glaucoma, protanopia, and diabetic retinopathy in a familiar setting. The application also includes the introduction of eye anatomy representing both normal and pathologic states. It is designed for patient education, health care practitioner training, and eye care specialist education.

[Virtual Patients and Medical Teaching].

PubMed

Gómez-Restrepo, Carlos; Narváez, Yamile Reveiz

2012-01-01

Biomedical advancements have evolved to the point where teaching software may be implemented to represent real-life scenarios. Virtual Patients or VPs are software programs that simulate clinical scenarios allowing students to generate a diagnosis and make treatment decisions. In this article, advantages and disadvantages regarding the use of this state-of-the-art technology are discussed. VP is a useful technique for psychiatry students. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Chapter4 - Drought patterns in the conterminous United States and Hawaii.

Treesearch

Frank H. Koch; William D. Smith; John W. Coulston

2014-01-01

Droughts are common in virtually all U.S. forests, but their frequency and intensity vary widely both between and within forest ecosystems (Hanson and Weltzin 2000). Forests in the Western United States generally exhibit a pattern of annual seasonal droughts. Forests in the Eastern United States tend to exhibit one of two prevailing patterns: random occasional droughts...

Virtual reality training for surgical trainees in laparoscopic surgery.

PubMed

Nagendran, Myura; Gurusamy, Kurinchi Selvan; Aggarwal, Rajesh; Loizidou, Marilena; Davidson, Brian R

2013-08-27

Standard surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time-consuming, costly, and of variable effectiveness. Training using a virtual reality simulator is an option to supplement standard training. Virtual reality training improves the technical skills of surgical trainees such as decreased time for suturing and improved accuracy. The clinical impact of virtual reality training is not known. To assess the benefits (increased surgical proficiency and improved patient outcomes) and harms (potentially worse patient outcomes) of supplementary virtual reality training of surgical trainees with limited laparoscopic experience. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and Science Citation Index Expanded until July 2012. We included all randomised clinical trials comparing virtual reality training versus other forms of training including box-trainer training, no training, or standard laparoscopic training in surgical trainees with little laparoscopic experience. We also planned to include trials comparing different methods of virtual reality training. We included only trials that assessed the outcomes in people undergoing laparoscopic surgery. Two authors independently identified trials and collected data. We analysed the data with both the fixed-effect and the random-effects models using Review Manager 5 analysis. For each outcome we calculated the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals based on intention-to-treat analysis. We included eight trials covering 109 surgical trainees with limited laparoscopic experience. Of the eight trials, six compared virtual reality versus no supplementary training. One trial compared virtual reality training versus box-trainer training and versus no supplementary training, and one trial compared virtual reality training versus box-trainer training. There were no trials that compared different forms of virtual reality training. All the trials were at high risk of bias. Operating time and operative performance were the only outcomes reported in the trials. The remaining outcomes such as mortality, morbidity, quality of life (the primary outcomes of this review) and hospital stay (a secondary outcome) were not reported. Virtual reality training versus no supplementary training: The operating time was significantly shorter in the virtual reality group than in the no supplementary training group (3 trials; 49 participants; MD -11.76 minutes; 95% CI -15.23 to -8.30). Two trials that could not be included in the meta-analysis also showed a reduction in operating time (statistically significant in one trial). The numerical values for operating time were not reported in these two trials. The operative performance was significantly better in the virtual reality group than the no supplementary training group using the fixed-effect model (2 trials; 33 participants; SMD 1.65; 95% CI 0.72 to 2.58). The results became non-significant when the random-effects model was used (2 trials; 33 participants; SMD 2.14; 95% CI -1.29 to 5.57). One trial could not be included in the meta-analysis as it did not report the numerical values. The authors stated that the operative performance of virtual reality group was significantly better than the control group. Virtual reality training versus box-trainer training: The only trial that reported operating time did not report the numerical values. In this trial, the operating time in the virtual reality group was significantly shorter than in the box-trainer group. Of the two trials that reported operative performance, only one trial reported the numerical values. The operative performance was significantly better in the virtual reality group than in the box-trainer group (1 trial; 19 participants; SMD 1.46; 95% CI 0.42 to 2.50). In the other trial that did not report the numerical values, the authors stated that the operative performance in the virtual reality group was significantly better than the box-trainer group. Virtual reality training appears to decrease the operating time and improve the operative performance of surgical trainees with limited laparoscopic experience when compared with no training or with box-trainer training. However, the impact of this decreased operating time and improvement in operative performance on patients and healthcare funders in terms of improved outcomes or decreased costs is not known. Further well-designed trials at low risk of bias and random errors are necessary. Such trials should assess the impact of virtual reality training on clinical outcomes.

A 3D visualization and simulation of the individual human jaw.

PubMed

Muftić, Osman; Keros, Jadranka; Baksa, Sarajko; Carek, Vlado; Matković, Ivo

2003-01-01

A new biomechanical three-dimensional (3D) model for the human mandible based on computer-generated virtual model is proposed. Using maps obtained from the special kinds of photos of the face of the real subject, it is possible to attribute personality to the virtual character, while computer animation offers movements and characteristics within the confines of space and time of the virtual world. A simple two-dimensional model of the jaw cannot explain the biomechanics, where the muscular forces through occlusion and condylar surfaces are in the state of 3D equilibrium. In the model all forces are resolved into components according to a selected coordinate system. The muscular forces act on the jaw, along with the necessary force level for chewing as some kind of mandible balance, preventing dislocation and loading of nonarticular tissues. In the work is used new approach to computer-generated animation of virtual 3D characters (called "Body SABA"), using in one object package of minimal costs and easy for operation.

Sensing and Virtual Worlds - A Survey of Research Opportunities

NASA Technical Reports Server (NTRS)

Moore, Dana

2012-01-01

Virtual Worlds (VWs) have been used effectively in live and constructive military training. An area that remains fertile ground for exploration and a new vision involves integrating various traditional and now non-traditional sensors into virtual worlds. In this paper, we will assert that the benefits of this integration are several. First, we maintain that virtual worlds offer improved sensor deployment planning through improved visualization and stimulation of the model, using geo-specific terrain and structure. Secondly, we assert that VWs enhance the mission rehearsal process, and that using a mix of live avatars, non-player characters, and live sensor feeds (e.g. real time meteorology) can help visualization of the area of operations. Finally, tactical operations are improved via better collaboration and integration of real world sensing capabilities, and in most situations, 30 VWs improve the state of the art over current "dots on a map" 20 geospatial visualization. However, several capability gaps preclude a fuller realization of this vision. In this paper, we identify many of these gaps and suggest research directions

Rendezvous with the World: Missouri Southern State University's Themed Semesters

ERIC Educational Resources Information Center

Stebbins, Chad

2011-01-01

Although most universities emphasize study abroad as the primary vehicle to internationalize the campus, in reality only a small percentage of students actually participate in this endeavor. The internationally themed semesters at Missouri Southern State University (MSSU) reach virtually every student, and provide a global perspective and cultural…

Perceived Social Support and Subjective States in Urban Adolescent Girls.

ERIC Educational Resources Information Center

Procidano, Mary E.; And Others

While prospective investigations of social support, coping, and stress are accumulating, there is relatively little empirical knowledge regarding how these variables are related to each other among adolescents, and virtually no empirical knowledge regarding their relationship to subjective states in that population. This study examined the…

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Fla. Budget Threatens Online Ed. Mandate

ERIC Educational Resources Information Center

Manzo, Kathleen Kennedy

2009-01-01

As Florida school districts scramble to meet a looming state mandate to offer full-time online instruction for K-8 students, and as high school enrollments in such courses continue to climb, lawmakers are mulling restrictions and budget cuts for the state's nationally known virtual school. Together, online-learning advocates say, the growing…

The NASA Augmented/Virtual Reality Lab: The State of the Art at KSC

NASA Technical Reports Server (NTRS)

Little, William

2017-01-01

The NASA Augmented Virtual Reality (AVR) Lab at Kennedy Space Center is dedicated to the investigation of Augmented Reality (AR) and Virtual Reality (VR) technologies, with the goal of determining potential uses of these technologies as human-computer interaction (HCI) devices in an aerospace engineering context. Begun in 2012, the AVR Lab has concentrated on commercially available AR and VR devices that are gaining in popularity and use in a number of fields such as gaming, training, and telepresence. We are working with such devices as the Microsoft Kinect, the Oculus Rift, the Leap Motion, the HTC Vive, motion capture systems, and the Microsoft Hololens. The focus of our work has been on human interaction with the virtual environment, which in turn acts as a communications bridge to remote physical devices and environments which the operator cannot or should not control or experience directly. Particularly in reference to dealing with spacecraft and the oftentimes hazardous environments they inhabit, it is our hope that AR and VR technologies can be utilized to increase human safety and mission success by physically removing humans from those hazardous environments while virtually putting them right in the middle of those environments.

Teachers' Perspectives on Online Virtual Labs vs. Hands-On Labs in High School Science

NASA Astrophysics Data System (ADS)

Bohr, Teresa M.

This study of online science teachers' opinions addressed the use of virtual labs in online courses. A growing number of schools use virtual labs that must meet mandated laboratory standards to ensure they provide learning experiences comparable to hands-on labs, which are an integral part of science curricula. The purpose of this qualitative case study was to examine teachers' perceptions of the quality and effectiveness of high school virtual labs. The theoretical foundation was constructivism, as labs provide student-centered activities for problem solving, inquiry, and exploration of phenomena. The research questions focused on experienced teachers' perceptions of the quality of virtual vs. hands-on labs. Data were collected through survey questions derived from the lab objectives of The Next Generation Science Standards . Eighteen teachers rated the degree of importance of each objective and also rated how they felt virtual labs met these objectives; these ratings were reported using descriptive statistics. Responses to open-ended questions were few and served to illustrate the numerical results. Many teachers stated that virtual labs are valuable supplements but could not completely replace hands-on experiences. Studies on the quality and effectiveness of high school virtual labs are limited despite widespread use. Comprehensive studies will ensure that online students have equal access to quality labs. School districts need to define lab requirements, and colleges need to specify the lab experience they require. This study has potential to inspire positive social change by assisting science educators, including those in the local school district, in evaluating and selecting courseware designed to promote higher order thinking skills, real-world problem solving, and development of strong inquiry skills, thereby improving science instruction for all high school students.

Design Considerations for Attitude State Awareness and Prevention of Entry into Unusual Attitudes

NASA Technical Reports Server (NTRS)

Ellis, Kyle K. E.; Prinzel, Lawrence J., III; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel; Verstynen, Harry; Hubbs, Clay; Wilkerson, James

2017-01-01

Loss of control - inflight (LOC-I) has historically represented the largest category of commercial aviation fatal accidents. A review of the worldwide transport airplane accidents (2001-2010) evinced that loss of attitude or energy state awareness was responsible for a large majority of the LOC-I events. A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that flight crew loss of attitude awareness or energy state awareness due to lack of external visual reference cues was a significant causal factor in 17 of the 18 reviewed flights. CAST recommended that "Virtual Day-Visual Meteorological Condition" (Virtual Day-VMC) displays be developed to provide the visual cues necessary to prevent loss-of-control resulting from flight crew spatial disorientation and loss of energy state awareness. Synthetic vision or equivalent systems (SVS) were identified for a design "safety enhancement" (SE-200). Part of this SE involves the conduct of research for developing minimum aviation system performance standards (MASPS) for these flight deck display technologies to aid flight crew attitude and energy state awareness similar to that of a virtual day-VMC-like environment. This paper will describe a novel experimental approach to evaluating a flight crew's ability to maintain attitude awareness and to prevent entry into unusual attitudes across several SVS optical flow design considerations. Flight crews were subjected to compound-event scenarios designed to elicit channelized attention and startle/surprise within the crew. These high-fidelity scenarios, designed from real-world events, enable evaluation of the efficacy of SVS at improving flight crew attitude awareness to reduce the occurrence of LOC-I incidents in commercial flight operations.

Two-Electron Transfer Pathways.

PubMed

Lin, Jiaxing; Balamurugan, D; Zhang, Peng; Skourtis, Spiros S; Beratan, David N

2015-06-18

The frontiers of electron-transfer chemistry demand that we develop theoretical frameworks to describe the delivery of multiple electrons, atoms, and ions in molecular systems. When electrons move over long distances through high barriers, where the probability for thermal population of oxidized or reduced bridge-localized states is very small, the electrons will tunnel from the donor (D) to acceptor (A), facilitated by bridge-mediated superexchange interactions. If the stable donor and acceptor redox states on D and A differ by two electrons, it is possible that the electrons will propagate coherently from D to A. While structure-function relations for single-electron superexchange in molecules are well established, strategies to manipulate the coherent flow of multiple electrons are largely unknown. In contrast to one-electron superexchange, two-electron superexchange involves both one- and two-electron virtual intermediate states, the number of virtual intermediates increases very rapidly with system size, and multiple classes of pathways interfere with one another. In the study described here, we developed simple superexchange models for two-electron transfer. We explored how the bridge structure and energetics influence multielectron superexchange, and we compared two-electron superexchange interactions to single-electron superexchange. Multielectron superexchange introduces interference between singly and doubly oxidized (or reduced) bridge virtual states, so that even simple linear donor-bridge-acceptor systems have pathway topologies that resemble those seen for one-electron superexchange through bridges with multiple parallel pathways. The simple model systems studied here exhibit a richness that is amenable to experimental exploration by manipulating the multiple pathways, pathway crosstalk, and changes in the number of donor and acceptor species. The features that emerge from these studies may assist in developing new strategies to deliver multiple electrons in condensed-phase redox systems, including multiple-electron redox species, multimetallic/multielectron redox catalysts, and multiexciton excited states.

Distributed Drug Discovery, Part 2: Global Rehearsal of Alkylating Agents for the Synthesis of Resin-Bound Unnatural Amino Acids and Virtual D3 Catalog Construction

PubMed Central

2008-01-01

Distributed Drug Discovery (D3) proposes solving large drug discovery problems by breaking them into smaller units for processing at multiple sites. A key component of the synthetic and computational stages of D3 is the global rehearsal of prospective reagents and their subsequent use in the creation of virtual catalogs of molecules accessible by simple, inexpensive combinatorial chemistry. The first section of this article documents the feasibility of the synthetic component of Distributed Drug Discovery. Twenty-four alkylating agents were rehearsed in the United States, Poland, Russia, and Spain, for their utility in the synthesis of resin-bound unnatural amino acids 1, key intermediates in many combinatorial chemistry procedures. This global reagent rehearsal, coupled to virtual library generation, increases the likelihood that any member of that virtual library can be made. It facilitates the realistic integration of worldwide virtual D3 catalog computational analysis with synthesis. The second part of this article describes the creation of the first virtual D3 catalog. It reports the enumeration of 24 416 acylated unnatural amino acids 5, assembled from lists of either rehearsed or well-precedented alkylating and acylating reagents, and describes how the resulting catalog can be freely accessed, searched, and downloaded by the scientific community. PMID:19105725

[Use of virtual reality in forensic psychiatry. A new paradigm?].

PubMed

Fromberger, P; Jordan, K; Müller, J L

2014-03-01

For more than 20 years virtual realities (VR) have been successfully used in the assessment and treatment of psychiatric disorders. The most important advantages of VR are the high ecological validity of virtual environments, the entire controllability of virtual stimuli in the virtual environment and the capability to induce the sensation of being in the virtual environment instead of the physical environment. VRs provide the opportunity to face the user with stimuli and situations which are not available or too risky in reality. Despite these advantages VR-based applications have not yet been applied in forensic psychiatry. On the basis of an overview of the recent state-of-the-art in VR-based applications in general psychiatry, the article demonstrates the advantages and possibilities of VR-based applications in forensic psychiatry. Up to now only preliminary studies regarding the VR-based assessment of pedophilic interests exist. These studies demonstrate the potential of ecologically valid VR-based applications for the assessment of forensically relevant disorders. One of the most important advantages is the possibility of VR to assess the behavior of forensic inpatients in crime-related situations without endangering others. This provides completely new possibilities not only regarding the assessment but also for the treatment of forensic inpatients. Before utilizing these possibilities in the clinical practice exhaustive research and development will be necessary. Given the high potential of VR-based applications, this effort would be worth it.

A Pipeline To Enhance Ligand Virtual Screening: Integrating Molecular Dynamics and Fingerprints for Ligand and Proteins.

PubMed

Spyrakis, Francesca; Benedetti, Paolo; Decherchi, Sergio; Rocchia, Walter; Cavalli, Andrea; Alcaro, Stefano; Ortuso, Francesco; Baroni, Massimo; Cruciani, Gabriele

2015-10-26

The importance of taking into account protein flexibility in drug design and virtual ligand screening (VS) has been widely debated in the literature, and molecular dynamics (MD) has been recognized as one of the most powerful tools for investigating intrinsic protein dynamics. Nevertheless, deciphering the amount of information hidden in MD simulations and recognizing a significant minimal set of states to be used in virtual screening experiments can be quite complicated. Here we present an integrated MD-FLAP (molecular dynamics-fingerprints for ligand and proteins) approach, comprising a pipeline of molecular dynamics, clustering and linear discriminant analysis, for enhancing accuracy and efficacy in VS campaigns. We first extracted a limited number of representative structures from tens of nanoseconds of MD trajectories by means of the k-medoids clustering algorithm as implemented in the BiKi Life Science Suite ( http://www.bikitech.com [accessed July 21, 2015]). Then, instead of applying arbitrary selection criteria, that is, RMSD, pharmacophore properties, or enrichment performances, we allowed the linear discriminant analysis algorithm implemented in FLAP ( http://www.moldiscovery.com [accessed July 21, 2015]) to automatically choose the best performing conformational states among medoids and X-ray structures. Retrospective virtual screenings confirmed that ensemble receptor protocols outperform single rigid receptor approaches, proved that computationally generated conformations comprise the same quantity/quality of information included in X-ray structures, and pointed to the MD-FLAP approach as a valuable tool for improving VS performances.

ACStor: Optimizing Access Performance of Virtual Disk Images in Clouds

DOE PAGES

Wu, Song; Wang, Yihong; Luo, Wei; ...

2017-03-02

In virtualized data centers, virtual disk images (VDIs) serve as the containers in virtual environment, so their access performance is critical for the overall system performance. Some distributed VDI chunk storage systems have been proposed in order to alleviate the I/O bottleneck for VM management. As the system scales up to a large number of running VMs, however, the overall network traffic would become unbalanced with hot spots on some VMs inevitably, leading to I/O performance degradation when accessing the VMs. Here, we propose an adaptive and collaborative VDI storage system (ACStor) to resolve the above performance issue. In comparisonmore » with the existing research, our solution is able to dynamically balance the traffic workloads in accessing VDI chunks, based on the run-time network state. Specifically, compute nodes with lightly loaded traffic will be adaptively assigned more chunk access requests from remote VMs and vice versa, which can effectively eliminate the above problem and thus improves the I/O performance of VMs. We also implement a prototype based on our ACStor design, and evaluate it by various benchmarks on a real cluster with 32 nodes and a simulated platform with 256 nodes. Experiments show that under different network traffic patterns of data centers, our solution achieves up to 2-8 performance gain on VM booting time and VM’s I/O throughput, in comparison with the other state-of-the-art approaches.« less

Virtual Modeling for Cities of the Future. State-Of Art and Virtual Modeling for Cities of the Future. State-Of Art AN

NASA Astrophysics Data System (ADS)

Valencia, J.; Muñoz-Nieto, A.; Rodriguez-Gonzalvez, P.

2015-02-01

3D virtual modeling, visualization, dissemination and management of urban areas is one of the most exciting challenges that must face geomatics in the coming years. This paper aims to review, compare and analyze the new technologies, policies and software tools that are in progress to manage urban 3D information. It is assumed that the third dimension increases the quality of the model provided, allowing new approaches to urban planning, conservation and management of architectural and archaeological areas. Despite the fact that displaying 3D urban environments is an issue nowadays solved, there are some challenges to be faced by geomatics in the coming future. Displaying georeferenced linked information would be considered the first challenge. Another challenge to face is to improve the technical requirements if this georeferenced information must be shown in real time. Are there available software tools ready for this challenge? Are they useful to provide services required in smart cities? Throughout this paper, many practical examples that require 3D georeferenced information and linked data will be shown. Computer advances related to 3D spatial databases and software that are being developed to convert rendering virtual environment to a new enriched environment with linked information will be also analyzed. Finally, different standards that Open Geospatial Consortium has assumed and developed regarding the three-dimensional geographic information will be reviewed. Particular emphasis will be devoted on KML, LandXML, CityGML and the new IndoorGML.

The Virtual Mouse Brain: A Computational Neuroinformatics Platform to Study Whole Mouse Brain Dynamics.

PubMed

Melozzi, Francesca; Woodman, Marmaduke M; Jirsa, Viktor K; Bernard, Christophe

2017-01-01

Connectome-based modeling of large-scale brain network dynamics enables causal in silico interrogation of the brain's structure-function relationship, necessitating the close integration of diverse neuroinformatics fields. Here we extend the open-source simulation software The Virtual Brain (TVB) to whole mouse brain network modeling based on individual diffusion magnetic resonance imaging (dMRI)-based or tracer-based detailed mouse connectomes. We provide practical examples on how to use The Virtual Mouse Brain (TVMB) to simulate brain activity, such as seizure propagation and the switching behavior of the resting state dynamics in health and disease. TVMB enables theoretically driven experimental planning and ways to test predictions in the numerous strains of mice available to study brain function in normal and pathological conditions.

Who commits virtual identity suicide? Differences in privacy concerns, Internet addiction, and personality between Facebook users and quitters.

PubMed

Stieger, Stefan; Burger, Christoph; Bohn, Manuel; Voracek, Martin

2013-09-01

Social networking sites such as Facebook attract millions of users by offering highly interactive social communications. Recently, a counter movement of users has formed, deciding to leave social networks by quitting their accounts (i.e., virtual identity suicide). To investigate whether Facebook quitters (n=310) differ from Facebook users (n=321), we examined privacy concerns, Internet addiction scores, and personality. We found Facebook quitters to be significantly more cautious about their privacy, having higher Internet addiction scores, and being more conscientious than Facebook users. The main self-stated reason for committing virtual identity suicide was privacy concerns (48 percent). Although the adequacy of privacy in online communication has been questioned, privacy is still an important issue in online social communications.

Virtual Long Baseline (VLBL) Autonomous Underwater Vehicle Navigation Using a Single Transponder

DTIC Science & Technology

2006-06-01

is needed from the lbl structure for the % indicated time range lbl_sb = sext (lbl,find(lbl.t > Start_Time & lbl.t < End_Time...Take only the lbl data points from the chosen transponder which % correspond to status 5, which means good data lbl_SB = sext (lbl_sb,find...i)); L = length(Time); % Extract the data which is needed from the state structure state_SB = sext (state,find(state.t

Human agency beliefs influence behaviour during virtual social interactions

PubMed Central

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. PMID:28948104

Fast Virtual Fractional Flow Reserve Based Upon Steady-State Computational Fluid Dynamics Analysis: Results From the VIRTU-Fast Study.

PubMed

Morris, Paul D; Silva Soto, Daniel Alejandro; Feher, Jeroen F A; Rafiroiu, Dan; Lungu, Angela; Varma, Susheel; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

2017-08-01

Fractional flow reserve (FFR)-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel "pseudotransient" analysis protocol for computing virtual fractional flow reserve (vFFR) based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis) using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis. Sensitivity analysis demonstrated that physiological lesion significance was influenced less by coronary or lesion anatomy (33%) and more by microvascular physiology (59%). If coronary microvascular resistance can be estimated, vFFR can be accurately computed in less time than it takes to make invasive measurements.

Sign of the Singlet ( np)-Scattering Length, Neutron Radiative Capture by the Proton and Problem of the Virtual Level of the ( np) System

NASA Astrophysics Data System (ADS)

Lyuboshitz, V. L.; Lyuboshitz, V. V.

2011-05-01

It is shown that, taking into account the process of neutron radiative capture by the proton and the negative sign of the length of singlet ( np)-scattering ( a s = - f s (0) < 0), the singlet ( np)-scattering amplitude f s has a pole at a complex energy {widetilde{E}_s}, the real part of which is negative ({Re widetilde{E}_s < 0}) and the imaginary part is positive ({Im widetilde{E}_s > 0}). This means that a singlet state of the ( np) system, which would decay into the deuteron in the ground state and the γ quantum ("singlet deuteron") does not exist, and the pole {widetilde{E}_s} corresponds to the virtual but not true quasistationary level.

Border Security: A Journey Without a Destination

DTIC Science & Technology

2013-12-01

states and the federal government are, to a significant extent, defined by the United States Constitution and relevant case law .”77 Historically...government can invoke the “supremacy clause” of the Constitution , which can preempt state law . The federal government cited the supremacy clause in their...local governments have all defined what constitutes a secure border differently, which makes the measurement of success or failure virtually

Visualisation and Gamification of e-Learning and Programming Education

ERIC Educational Resources Information Center

Olsson, Marie; Mozelius, Peter; Collin, Jonas

2015-01-01

Courses in virtual learning environments can leave recently enrolled participants in a state of loneliness, confusion and boredom. What course content is essential in the course, where can more information be found and which assignments are mandatory? Research has stated that learner control and motivation are crucial issues for successful online…

Dealing with Budget Cuts. Research Brief

ERIC Educational Resources Information Center

Williamson, Ronald

2011-01-01

Virtually every school district in the country is dealing with the need to reduce their budget. The process used to make those decisions varies from state to state but almost always includes a combination of short and long-term approaches. In many school districts the emphasis is on reducing individual budget line items and not filling vacant…

Fire Ground Decision-Making: Transferring Virtual Knowledge to the Physical Environment

ERIC Educational Resources Information Center

Gillespie, Steven

2013-01-01

The primary purpose of this quantitative study was to examine if simulation training correlated with the decision-making abilities of firefighters from two departments (one in a mountain state and one in a southwest state). The other purposes were to determine if firefighter demographics were correlated with the completion of the simulation…

Continuous-variable measurement-device-independent quantum key distribution with virtual photon subtraction

NASA Astrophysics Data System (ADS)

Zhao, Yijia; Zhang, Yichen; Xu, Bingjie; Yu, Song; Guo, Hong

2018-04-01

The method of improving the performance of continuous-variable quantum key distribution protocols by postselection has been recently proposed and verified. In continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocols, the measurement results are obtained from untrusted third party Charlie. There is still not an effective method of improving CV-MDI QKD by the postselection with untrusted measurement. We propose a method to improve the performance of coherent-state CV-MDI QKD protocol by virtual photon subtraction via non-Gaussian postselection. The non-Gaussian postselection of transmitted data is equivalent to an ideal photon subtraction on the two-mode squeezed vacuum state, which is favorable to enhance the performance of CV-MDI QKD. In CV-MDI QKD protocol with non-Gaussian postselection, two users select their own data independently. We demonstrate that the optimal performance of the renovated CV-MDI QKD protocol is obtained with the transmitted data only selected by Alice. By setting appropriate parameters of the virtual photon subtraction, the secret key rate and tolerable excess noise are both improved at long transmission distance. The method provides an effective optimization scheme for the application of CV-MDI QKD protocols.

Virtual Water Trade: Revisiting the Assessments to Incorporate Regional Water Stress

NASA Astrophysics Data System (ADS)

Perveen, S.; Puma, M. J.; Troy, T. J.; Browne, M.; Ghosh, M.

2011-12-01

Virtual water (VW) refers to the volume of freshwater embedded in the production and shipment of a commodity, which can include agricultural or industrial products, and the trade of commodities can then be viewed as the trade of one region's water resources to another. The premise behind this trade is that countries with a comparative water advantage may choose to export crops, and countries with scarce water resources may focus economic activity on non-water intensive sectors. However, this assumption is not always true given food self-sufficiency policies; water scarce regions often choose to unsustainably mine aquifers for irrigation. Recent studies have shown no correlation between dependency on VW imports and water scarcity for nations, suggesting that politico-economic considerations rather than resource scarcity considerations may dominate the current VW dynamics. Existing VW computations do not take into account water-scarcity value or the full-cost pricing of commodities. This study aims to fill in this gap by focusing on three countries - the United States, India, and Japan - and their production, imports and exports of crop, livestock and industrial commodities. These countries offer three different perspectives on virtual water, with Japan as a net importer of agriculture virtual water and a major industrial nation. The United States, on the other hand, exports significant quantities of grain. India is a developing country with a strong focus on food self-sufficiency. We first quantify the amount of water used in the production of each commodity and then examine the virtual water trade balance for each country, examining the tradeoffs each country has made between agriculture and industrial water use; given that water resources are finite. To examine the interplay between virtual water trade and water scarcity, we focus on two sub-regions, the Ogallala Aquifer in the US and the Punjab region in India, both of which have significant agricultural economies and are knowingly depleting their groundwater resources. We estimate the direct and indirect cost of water in each region and evaluate the economic trade-offs these regions are making.

[Virtual reality therapy in anxiety disorders].

PubMed

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 wishes and under the supervision of the therapist. The technique takes place in the therapist's office which ensures confidentiality and privacy. The therapist is able to control unpredicted events that can occur during patient's exposure in real environments. Mainly the therapist can control the intensity of exposure and adapt it to the patient's needs. Virtual reality can be proven particularly useful in some specific psychological states. For instance, patients with post-traumatic stress disorder (PTSD) who prone to avoid the reminders of the traumatic events. Exposure in virtual reality can solve this problem providing to the patient a large number of stimuli that activate the senses causing the necessary physiological and psychological anxiety reactions, regardless of his willingness or ability to recall in his imagination the traumatic event.

Termite testing continues

Treesearch

Terence L. Wagner; Joe Mulrooney; Chris Petereson

2002-01-01

The United States Department of Agriculture Forest Service's termiticide testing program provides unbiased efficacy data for product registration using standardized tests, sites and evaluation procedures. Virtually all termiticides undergo Forest Service tests prior to registration.

The Virtual Cell Animation Collection: Tools for Teaching Molecular and Cellular Biology

PubMed Central

Reindl, Katie M.; White, Alan R.; Johnson, Christina; Vender, Bradley; Slator, Brian M.; McClean, Phillip

2015-01-01

A cell is a minifactory in which structures and molecules are assembled, rearranged, disassembled, packaged, sorted, and transported. Because cellular structures and molecules are invisible to the human eye, students often have difficulty conceptualizing the dynamic nature of cells that function at multiple scales across time and space. To represent these dynamic cellular processes, the Virtual Cell Productions team at North Dakota State University develops freely available multimedia materials to support molecular and cellular biology learning inside and outside the high school and university classroom. PMID:25856580

Virtual photon polarization and dilepton anisotropy in relativistic nucleus-nucleus collisions

NASA Astrophysics Data System (ADS)

Speranza, Enrico; Jaiswal, Amaresh; Friman, Bengt

2018-07-01

The polarization of virtual photons produced in relativistic nucleus-nucleus collisions provides information on the conditions in the emitting medium. In a hydrodynamic framework, the resulting angular anisotropy of the dilepton final state depends on the flow as well as on the transverse momentum and invariant mass of the photon. We illustrate these effects in dilepton production from quark-antiquark annihilation in the QGP phase and π+π- annihilation in the hadronic phase for a static medium in global equilibrium and for a longitudinally expanding system.

Virtual reality in autism: state of the art.

PubMed

Bellani, M; Fornasari, L; Chittaro, L; Brambilla, P

2011-09-01

Autism spectrum disorders are characterized by core deficits with regard to three domains, i.e. social interaction, communication and repetitive or stereotypic behaviour. It is crucial to develop intervention strategies helping individuals with autism, their caregivers and educators in daily life. For this purpose, virtual reality (VR), i.e. a simulation of the real world based on computer graphics, can be useful as it allows instructors and therapists to offer a safe, repeatable and diversifiable environment during learning. This mini review examines studies that have investigated the use of VR in autism.

Determination of balloon gas mass and revised estimates of drag and virtual mass coefficients

NASA Technical Reports Server (NTRS)

Robbins, E.; Martone, M.

1993-01-01

In support of the NASA Balloon Program, small-scale balloons were flown with varying lifting gas and total system mass. Instrument packages were developed to measure and record acceleration and temperature data during these tests. Top fitting and instrument payload accelerations were measured from launch to steady state ascent and through ballast drop transients. The development of the small lightweight self-powered Stowaway Special instrument packages is discussed along with mathematical models developed to determine gas mass, drag and virtual mass coefficients.

California's state oral health infrastructure: opportunities for improvement and funding.

PubMed

Diringer, Joel; Phipps, Kathy R

2012-01-01

California has virtually no statewide dental public health infrastructure leaving the state without leadership, a surveillance program, an oral health plan, oral health promotion and disease prevention programs, and federal funding. Based on a literature review and interviews with 15 oral health officials nationally, the paper recommends hiring a state dental director with public health experience, developing a state oral health plan, and seeking federal and private funding to support an office of oral health.

Welfare Impact of Virtual Trading on Wholesale Electricity Markets

NASA Astrophysics Data System (ADS)

Giraldo, Juan S.

Virtual bidding has become a standard feature of multi-settlement wholesale electricity markets in the United States. Virtual bids are financial instruments that allow market participants to take financial positions in the Day-Ahead (DA) market that are automatically reversed/closed in the Real-Time (RT) market. Most U.S. wholesale electricity markets only have two types of virtual bids: a decrement bid (DEC), which is virtual load, and an increment offer (INC), which is virtual generation. In theory, financial participants create benefits by seeking out profitable bidding opportunities through arbitrage or speculation. Benefits have been argued to take the form of increased competition, price convergence, increased market liquidity, and a more efficient dispatch of generation resources. Studies have found that price convergence between the DA and RT markets improved following the introduction of virtual bidding into wholesale electricity markets. The improvement in price convergence was taken as evidence that market efficiency had increased and many of the theoretical benefits realized. Persistent price differences between the DA and RT markets have led to calls to further expand virtual bidding as a means to address remaining market inefficiencies. However, the argument that price convergence is beneficial is extrapolated from the study of commodity and financial markets and the role of futures for increasing market efficiency in that context. This viewpoint largely ignores details that differentiate wholesale electricity markets from other commodity markets. This dissertation advances the understanding of virtual bidding by evaluating the impact of virtual bidding based on the standard definition of economic efficiency which is social welfare. In addition, an examination of the impacts of another type of virtual bid, up-to-congestion (UTC) transactions is presented. This virtual product significantly increased virtual bidding activity in the PJM interconnection market since it became available to be used by financial traders in September 2010. Stylized models are used to determine the optimal bidding strategy for the different virtual bids under different scenarios. The welfare analysis shows that the main impact of virtual bidding is surplus reallocation and that the impact on market efficiency is small by comparison. The market structure is such that it is more likely to see surplus transfers from consumers to producers. The results also show that outcomes with greater price convergence as a result of virtual bidding activity were not necessarily more efficient, nor do they always correct surplus distribution distortions that result from bias in the DA expectation of RT load. Compared to INCs and DECs, the UTC analysis showed that UTCs do not have the same self-corrective incentives towards price convergence and are less likely to lead to nodal price convergence or correct for surplus distribution distortions caused by uncertainty and bias in the DA expectation of RT load. Additionally, the analysis showed that UTCs allow financial traders to engage in low risk high volume trading strategies that, while profitable, may have little to no impact on price convergence or market efficiency.

Virtual Inertia: Current Trends and Future Directions

DOE PAGES

Tamrakar, Ujjwol; Shrestha, Dipesh; Maharjan, Manisha; ...

2017-06-26

The modern power system is progressing from a synchronous machine-based system towards an inverter-dominated system, with a 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 themas 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. Our paper presents a literature review of the current state-of-the-art of virtual inertia implementation techniques, and explores potential research directionsmore » 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. We present a discussion on the challenges and research directions which points out several research needs, especially for systems level integration of virtual inertia systems.« less

Virtual Inertia: Current Trends and Future Directions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamrakar, Ujjwol; Shrestha, Dipesh; Maharjan, Manisha

The modern power system is progressing from a synchronous machine-based system towards an inverter-dominated system, with a 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 themas 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. Our paper presents a literature review of the current state-of-the-art of virtual inertia implementation techniques, and explores potential research directionsmore » 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. We present a discussion on the challenges and research directions which points out several research needs, especially for systems level integration of virtual inertia systems.« less

50 CFR 648.21 - Procedures for determining initial annual amounts.

Code of Federal Regulations, 2010 CFR

2010-10-01

...; virtual population analysis results; levels of noncompliance by harvesters or individual states; impact of...: (A) Total world export potential of mackerel producing countries. (B) Total world import demand of...

A pseudoenergy wave-activity relation for ageostrophic and non-hydrostatic moist atmosphere

NASA Astrophysics Data System (ADS)

Ran, Ling-Kun; Ping, Fan

2015-05-01

By employing the energy-Casimir method, a three-dimensional virtual pseudoenergy wave-activity relation for a moist atmosphere is derived from a complete system of nonhydrostatic equations in Cartesian coordinates. Since this system of equations includes the effects of water substance, mass forcing, diabatic heating, and dissipations, the derived wave-activity relation generalizes the previous result for a dry atmosphere. The Casimir function used in the derivation is a monotonous function of virtual potential vorticity and virtual potential temperature. A virtual energy equation is employed (in place of the previous zonal momentum equation) in the derivation, and the basic state is stationary but can be three-dimensional or, at least, not necessarily zonally symmetric. The derived wave-activity relation is further used for the diagnosis of the evolution and propagation of meso-scale weather systems leading to heavy rainfall. Our diagnosis of two real cases of heavy precipitation shows that positive anomalies of the virtual pseudoenergy wave-activity density correspond well with the strong precipitation and are capable of indicating the movement of the precipitation region. This is largely due to the cyclonic vorticity perturbation and the vertically increasing virtual potential temperature over the precipitation region. Project supported by the National Basic Research Program of China (Grant No. 2013CB430105), the Key Program of the Chinese Academy of Sciences (Grant No. KZZD-EW-05), the National Natural Science Foundation of China (Grant No. 41175060), and the Project of CAMS, China (Grant No. 2011LASW-B15).

Robust kernel collaborative representation for face recognition

NASA Astrophysics Data System (ADS)

Huang, Wei; Wang, Xiaohui; Ma, Yanbo; Jiang, Yuzheng; Zhu, Yinghui; Jin, Zhong

2015-05-01

One of the greatest challenges of representation-based face recognition is that the training samples are usually insufficient. In other words, the training set usually does not include enough samples to show varieties of high-dimensional face images caused by illuminations, facial expressions, and postures. When the test sample is significantly different from the training samples of the same subject, the recognition performance will be sharply reduced. We propose a robust kernel collaborative representation based on virtual samples for face recognition. We think that the virtual training set conveys some reasonable and possible variations of the original training samples. Hence, we design a new object function to more closely match the representation coefficients generated from the original and virtual training sets. In order to further improve the robustness, we implement the corresponding representation-based face recognition in kernel space. It is noteworthy that any kind of virtual training samples can be used in our method. We use noised face images to obtain virtual face samples. The noise can be approximately viewed as a reflection of the varieties of illuminations, facial expressions, and postures. Our work is a simple and feasible way to obtain virtual face samples to impose Gaussian noise (and other types of noise) specifically to the original training samples to obtain possible variations of the original samples. Experimental results on the FERET, Georgia Tech, and ORL face databases show that the proposed method is more robust than two state-of-the-art face recognition methods, such as CRC and Kernel CRC.

Virtual reality for health care: a survey.

PubMed

Moline, J

1997-01-01

This report surveys the state of the art in applications of virtual environments and related technologies for health care. Applications of these technologies are being developed for health care in the following areas: surgical procedures (remote surgery or telepresence, augmented or enhanced surgery, and planning and simulation of procedures before surgery); medical therapy; preventive medicine and patient education; medical education and training; visualization of massive medical databases; skill enhancement and rehabilitation; and architectural design for health-care facilities. To date, such applications have improved the quality of health care, and in the future they will result in substantial cost savings. Tools that respond to the needs of present virtual environment systems are being refined or developed. However, additional large-scale research is necessary in the following areas: user studies, use of robots for telepresence procedures, enhanced system reality, and improved system functionality.

Interactive 3D visualization for theoretical virtual observatories

NASA Astrophysics Data System (ADS)

Dykes, T.; Hassan, A.; Gheller, C.; Croton, D.; Krokos, M.

2018-06-01

Virtual observatories (VOs) are online hubs of scientific knowledge. They encompass a collection of platforms dedicated to the storage and dissemination of astronomical data, from simple data archives to e-research platforms offering advanced tools for data exploration and analysis. Whilst the more mature platforms within VOs primarily serve the observational community, there are also services fulfilling a similar role for theoretical data. Scientific visualization can be an effective tool for analysis and exploration of data sets made accessible through web platforms for theoretical data, which often contain spatial dimensions and properties inherently suitable for visualization via e.g. mock imaging in 2D or volume rendering in 3D. We analyse the current state of 3D visualization for big theoretical astronomical data sets through scientific web portals and virtual observatory services. We discuss some of the challenges for interactive 3D visualization and how it can augment the workflow of users in a virtual observatory context. Finally we showcase a lightweight client-server visualization tool for particle-based data sets, allowing quantitative visualization via data filtering, highlighting two example use cases within the Theoretical Astrophysical Observatory.

Defense applications of the CAVE (CAVE automatic virtual environment)

NASA Astrophysics Data System (ADS)

Isabelle, Scott K.; Gilkey, Robert H.; Kenyon, Robert V.; Valentino, George; Flach, John M.; Spenny, Curtis H.; Anderson, Timothy R.

1997-07-01

The CAVE is a multi-person, room-sized, high-resolution, 3D video and auditory environment, which can be used to present very immersive virtual environment experiences. This paper describes the CAVE technology and the capability of the CAVE system as originally developed at the Electronics Visualization Laboratory of the University of Illinois- Chicago and as more recently implemented by Wright State University (WSU) in the Armstrong Laboratory at Wright- Patterson Air Force Base (WPAFB). One planned use of the WSU/WPAFB CAVE is research addressing the appropriate design of display and control interfaces for controlling uninhabited aerial vehicles. The WSU/WPAFB CAVE has a number of features that make it well-suited to this work: (1) 360 degrees surround, plus floor, high resolution visual displays, (2) virtual spatialized audio, (3) the ability to integrate real and virtual objects, and (4) rapid and flexible reconfiguration. However, even though the CAVE is likely to have broad utility for military applications, it does have certain limitations that may make it less well- suited to applications that require 'natural' haptic feedback, vestibular stimulation, or an ability to interact with close detailed objects.

Studying and Treating Schizophrenia Using Virtual Reality: A New Paradigm

PubMed Central

Freeman, Daniel

2008-01-01

Understanding schizophrenia requires consideration of patients’ interactions in the social world. Misinterpretation of other peoples’ behavior is a key feature of persecutory ideation. The occurrence and intensity of hallucinations is affected by the social context. Negative symptoms such as anhedonia, asociality, and blunted affect reflect difficulties in social interactions. Withdrawal and avoidance of other people is frequent in schizophrenia, leading to isolation and rumination. The use of virtual reality (VR)—interactive immersive computer environments—allows one of the key variables in understanding psychosis, social environments, to be controlled, providing exciting applications to research and treatment. Seven applications of virtual social environments to schizophrenia are set out: symptom assessment, identification of symptom markers, establishment of predictive factors, tests of putative causal factors, investigation of the differential prediction of symptoms, determination of toxic elements in the environment, and development of treatment. The initial VR studies of persecutory ideation, which illustrate the ascription of personalities and mental states to virtual people, are highlighted. VR, suitably applied, holds great promise in furthering the understanding and treatment of psychosis. PMID:18375568

Proof-of-principle demonstration of a virtual flow meter-based transducer for gaseous helium monitoring in particle accelerator cryogenics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arpaia, P.; Technology Department, European Organization for Nuclear Research; Blanco, E.

2015-07-15

A transducer based on a virtual flow meter is proposed for monitoring helium distribution and consumption in cryogenic systems for particle accelerators. The virtual flow meter allows technical and economical constraints, preventing installation of physical instruments in all the needed measurement points, to be overcome. Virtual flow meter performance for the alternative models of Samson [ http://www.samson.de (2015)] and Sereg-Schlumberger [ http://www.slb.com/ (2015)] is compared with the standard IEC 60534-2-1 [Industrial-process control valves—Part 2-1: Flow capacity—sizing equations for fluid flow under installed conditions (2011), https://webstore.iec.ch/publication/2461], for a large temperature range, for both gaseous and liquid helium phases, and for differentmore » pressure drops. Then, the calibration function of the transducer is derived. Finally, the experimental validation for the helium gaseous state on the test station for superconducting magnets in the laboratory SM18 [Pirotte et al., AIP Conf. Proc. 1573, 187 (2014)] at CERN is reported.« less

A Novel Approach for Efficient Pharmacophore-based Virtual Screening: Method and Applications

PubMed Central

Dror, Oranit; Schneidman-Duhovny, Dina; Inbar, Yuval; Nussinov, Ruth; Wolfson, Haim J.

2009-01-01

Virtual screening is emerging as a productive and cost-effective technology in rational drug design for the identification of novel lead compounds. An important model for virtual screening is the pharmacophore. Pharmacophore is the spatial configuration of essential features that enable a ligand molecule to interact with a specific target receptor. In the absence of a known receptor structure, a pharmacophore can be identified from a set of ligands that have been observed to interact with the target receptor. Here, we present a novel computational method for pharmacophore detection and virtual screening. The pharmacophore detection module is able to: (i) align multiple flexible ligands in a deterministic manner without exhaustive enumeration of the conformational space, (ii) detect subsets of input ligands that may bind to different binding sites or have different binding modes, (iii) address cases where the input ligands have different affinities by defining weighted pharmacophores based on the number of ligands that share them, and (iv) automatically select the most appropriate pharmacophore candidates for virtual screening. The algorithm is highly efficient, allowing a fast exploration of the chemical space by virtual screening of huge compound databases. The performance of PharmaGist was successfully evaluated on a commonly used dataset of G-Protein Coupled Receptor alpha1A. Additionally, a large-scale evaluation using the DUD (directory of useful decoys) dataset was performed. DUD contains 2950 active ligands for 40 different receptors, with 36 decoy compounds for each active ligand. PharmaGist enrichment rates are comparable with other state-of-the-art tools for virtual screening. Availability The software is available for download. A user-friendly web interface for pharmacophore detection is available at http://bioinfo3d.cs.tau.ac.il/PharmaGist. PMID:19803502

Virtual Reality Applications for Stress Management Training in the Military.

PubMed

Pallavicini, Federica; Argenton, Luca; Toniazzi, Nicola; Aceti, Luciana; Mantovani, Fabrizia

2016-12-01

Stress Management Training programs are increasingly being adopted in the military field for resilience empowerment and primary stress prevention. In the last several years, advanced technologies (virtual reality in particular) have been integrated in order to develop more innovative and effective stress training programs for military personnel, including soldiers, pilots, and other aircrew professionals. This systematic review describes experimental studies that have been conducted in recent years to test the effectiveness of virtual reality-based Stress Management Training programs developed for military personnel. This promising state-of-the-art technology has the potential to be a successful new approach in empowering soldiers and increasing their resilience to stress. To provide an overview from 2001 to 2016 of the application of virtual reality for Stress Management Training programs developed for the military, a computer-based search for relevant publications was performed in several databases. Databases used in the search were PsycINFO, Web of Science (Web of Knowledge), PubMed, and Medline. The search string was: ("Virtual Reality") AND ("Military") AND ["Stress Training" OR ("Stress Management")]. There were 14 studies that met the inclusion criteria and were included in the review. The main observation to be drawn from this review is that virtual reality can provide interactive Stress Management Training to decrease levels of perceived stress and negative affect in military personnel. This technology appears to be a promising tool for assessing individuals' resilience to stress and for identifying the impact that stress can have on physiological reactivity and performance.Pallavicini F, Argenton L, Toniazzi N, Aceti L, Mantovani F. Virtual realtiy applications for stress management training in the military. Aerosp Med Hum Perform. 2016; 87(12):1021-1030.

Virtual water and water self-sufficiency in agricultural and livestock products in Brazil.

PubMed

da Silva, Vicente de Paulo R; de Oliveira, Sonaly D; Braga, Célia C; Brito, José Ivaldo B; de Sousa, Francisco de Assis S; de Holanda, Romildo M; Campos, João Hugo B C; de Souza, Enio P; Braga, Armando César R; Rodrigues Almeida, Rafaela S; de Araújo, Lincoln E

2016-12-15

Virtual water trade is often considered a solution for restricted water availability in many regions of the world. Brazil is the world leader in the production and export of various agricultural and livestock products. The country is either a strong net importer or a strong net exporter of these products. The objective of this study is to determine the volume of virtual water contained in agricultural and livestock products imported/exported by Brazil from 1997 to 2012, and to define the water self-sufficiency index of agricultural and livestock products in Brazil. The indexes of water scarcity (WSI), water dependency (WDI) and water self-sufficiency (WSSI) were calculated for each Brazilian state. These indexes and the virtual water balance were calculated following the methodology developed by Chapagain and Hoekstra (2008) and Hoekstra and Hung (2005). The total water exports and imports embedded in agricultural and livestock products were 5.28 × 10 10 and 1.22 × 10 10  Gm 3  yr -1 , respectively, which results in positive virtual water balance of 4.05 × 10 10  Gm 3  yr -1 . Brazil is either a strong net importer or a strong net exporter of agricultural and livestock products among the Mercosur countries. Brazil has a positive virtual water balance of 1.85 × 10 10  Gm 3  yr -1 . The indexes used in this study reveal that Brazil is self-sufficient in food production, except for a few products such as wheat and rice. Horticultural products (tomato, onion, potato, cassava and garlic) make up a unique product group with negative virtual water balance in Brazil. Copyright © 2016 Elsevier Ltd. All rights reserved.

CB4-03: An Eye on the Future: A Review of Data Virtualization Techniques to Improve Research Analytics

PubMed Central

Richter, Jack; McFarland, Lela; Bredfeldt, Christine

2012-01-01

Background/Aims Integrating data across systems can be a daunting process. The traditional method of moving data to a common location, mapping fields with different formats and meanings, and performing data cleaning activities to ensure valid and reliable integration across systems can be both expensive and extremely time consuming. As the scope of needed research data increases, the traditional methodology may not be sustainable. Data Virtualization provides an alternative to traditional methods that may reduce the effort required to integrate data across disparate systems. Objective Our goal was to survey new methods in data integration, cloud computing, enterprise data management and virtual data management for opportunities to increase the efficiency of producing VDW and similar data sets. Methods Kaiser Permanente Information Technology (KPIT), in collaboration with the Mid-Atlantic Permanente Research Institute (MAPRI) reviewed methodologies in the burgeoning field of Data Virtualization. We identified potential strengths and weaknesses of new approaches to data integration. For each method, we evaluated its potential application for producing effective research data sets. Results Data Virtualization provides opportunities to reduce the amount of data movement required to integrate data sources on different platforms in order to produce research data sets. Additionally, Data Virtualization also includes methods for managing “fuzzy” matching used to match fields known to have poor reliability such as names, addresses and social security numbers. These methods could improve the efficiency of integrating state and federal data such as patient race, death, and tumors with internal electronic health record data. Discussion The emerging field of Data Virtualization has considerable potential for increasing the efficiency of producing research data sets. An important next step will be to develop a proof of concept project that will help us understand to benefits and drawbacks of these techniques.

Part-to-itself model inversion in process compensated resonance testing

NASA Astrophysics Data System (ADS)

Mayes, Alexander; Jauriqui, Leanne; Biedermann, Eric; Heffernan, Julieanne; Livings, Richard; Aldrin, John C.; Goodlet, Brent; Mazdiyasni, Siamack

2018-04-01

Process Compensated Resonance Testing (PCRT) is a non-destructive evaluation (NDE) method involving the collection and analysis of a part's resonance spectrum to characterize its material or damage state. Prior work used the finite element method (FEM) to develop forward modeling and model inversion techniques. In many cases, the inversion problem can become confounded by multiple parameters having similar effects on a part's resonance frequencies. To reduce the influence of confounding parameters and isolate the change in a part (e.g., creep), a part-to-itself (PTI) approach can be taken. A PTI approach involves inverting only the change in resonance frequencies from the before and after states of a part. This approach reduces the possible inversion parameters to only those that change in response to in-service loads and damage mechanisms. To evaluate the effectiveness of using a PTI inversion approach, creep strain and material properties were estimated in virtual and real samples using FEM inversion. Virtual and real dog bone samples composed of nickel-based superalloy Mar-M-247 were examined. Virtual samples were modeled with typically observed variations in material properties and dimensions. Creep modeling was verified with the collected resonance spectra from an incrementally crept physical sample. All samples were inverted against a model space that allowed for change in the creep damage state and the material properties but was blind to initial part dimensions. Results quantified the capabilities of PTI inversion in evaluating creep strain and material properties, as well as its sensitivity to confounding initial dimensions.

Quality Authorizing for Online and Blended-Learning Charter Schools. NACSA Monograph

ERIC Educational Resources Information Center

Watson, John; Rapp, Chris

2011-01-01

Online charter schools are one key subset of the K-12 online education landscape, which also includes state virtual schools, district-level online programs, private providers of both individual courses and entire schools, and others. As of late 2010, online and blended charter schools existed in more than 20 states, serving more than 100,000…

Background: What the States Created

ERIC Educational Resources Information Center

Cox, James C.

2009-01-01

Prior to 2003, virtual universities were being created at a rate that would question the usual perception that higher education rarely changed, or changed (if at all) at a glacial speed. No comprehensive study of what was actually being created had been done; nor had anyone tapped the experiences of the developers in the states to see what was…

North Carolina State University, Department of Adult and Community College Education Revised Compact Plan for 2003-2005.

ERIC Educational Resources Information Center

North Carolina State Univ., Raleigh.

This article contends that the Department of Adult and Community College Education at North Carolina State University faces a significant challenge over the next 5 years, due to current Department faculty retirements and increasing competition from traditional, nontraditional, and virtual distance learning programs for prospective students. This…

An improved method for standardized mapping of drought conditions

Treesearch

Frank H. Koch; William D. Smith; John W. Coulston

2013-01-01

Virtually all U.S. forests experience droughts, although the intensity and frequency of the droughts vary widely between, as well as, within forest ecosystems (Hanson and Weltzin 2000). Generally, forests throughout the Western United States are subject to annual seasonal droughts, while forests in the Eastern United States can be characterized by one of two...

E-Learning 2010: Assessing the Agenda for Change

ERIC Educational Resources Information Center

Education Week, 2010

2010-01-01

Virginia Gov. Bob McDonnell signed legislation this month promoting the growth of virtual schools. The new law requires the state to develop policies for approving and monitoring a wide array of private and nonprofit online education providers. The legislative action in Virginia is the most recent major policy move by a state to expand the…

Virtual Water Transfers in U.S. Cities from Domestic Commodity Flows

NASA Astrophysics Data System (ADS)

Ahams, I. C.; Mejia, A.; Paterson, W.

2015-12-01

Cities have imported water into their boundaries for centuries but understanding how cities indirectly affect watersheds through the commodities which they import is fairly unknown. Thus, we present and discuss here a methodology for determining the virtual water transfers to and from U.S. cities associated with domestic commodity flows. For our methodology, we only consider agricultural and industrial commodities and, to represent the commodity flows, we use the Freight Analysis Framework (FAF) dataset from the U.S. Department of Transportation. Accordingly, we determine virtual water transfers for the 123 geographic regions in the FAF, which consists of 17 states, 73 metropolitan statistical areas (MSAs), and 33 remainders of states. Out of the 41 sectors that comprise the FAF data, we consider only the 29 sectors that account for the agricultural and industrial commodities. Using both water use data for macro-sectors and national water use coefficients for different industries, we determine a weighted water use coefficient for each of the 29 sectors considered. Ultimately, we use these weighted coefficients to estimate virtual water transfers and the water footprint for each city. Preliminary comparisons with other water footprint estimates indicate that our methodology yields reasonable results. In terms of the water footprint, we find that cities (i.e. MSAs) are net consumers, can consume a large proportion of their own production, and can have a large agricultural production. We also find that the per capita water footprint of industrial consumption decreases with increasing population in cities, suggesting that large cities may be more efficient.

Detecting navigational deficits in cognitive aging and Alzheimer disease using virtual reality

PubMed Central

Cushman, Laura A.; Stein, Karen; Duffy, Charles J.

2008-01-01

Background: Older adults get lost, in many cases because of recognized or incipient Alzheimer disease (AD). In either case, getting lost can be a threat to individual and public safety, as well as to personal autonomy and quality of life. Here we compare our previously described real-world navigation test with a virtual reality (VR) version simulating the same navigational environment. Methods: Quantifying real-world navigational performance is difficult and time-consuming. VR testing is a promising alternative, but it has not been compared with closely corresponding real-world testing in aging and AD. We have studied navigation using both real-world and virtual environments in the same subjects: young normal controls (YNCs, n = 35), older normal controls (ONCs, n = 26), patients with mild cognitive impairment (MCI, n = 12), and patients with early AD (EAD, n = 14). Results: We found close correlations between real-world and virtual navigational deficits that increased across groups from YNC to ONC, to MCI, and to EAD. Analyses of subtest performance showed similar profiles of impairment in real-world and virtual testing in all four subject groups. The ONC, MCI, and EAD subjects all showed greatest difficulty in self-orientation and scene localization tests. MCI and EAD patients also showed impaired verbal recall about both test environments. Conclusions: Virtual environment testing provides a valid assessment of navigational skills. Aging and Alzheimer disease (AD) share the same patterns of difficulty in associating visual scenes and locations, which is complicated in AD by the accompanying loss of verbally mediated navigational capacities. We conclude that virtual navigation testing reveals deficits in aging and AD that are associated with potentially grave risks to our patients and the community. GLOSSARY AD = Alzheimer disease; EAD = early Alzheimer disease; MCI = mild cognitive impairment; MMSE = Mini-Mental State Examination; ONC = older normal control; std. wt. = standardized weight; THSD = Tukey honestly significant difference; VR = virtual reality; YNC = young normal control. PMID:18794491

Distillation of Greenberger-Horne-Zeilinger states by selective information manipulation.

PubMed

Cohen, O; Brun, T A

2000-06-19

Methods for distilling Greenberger-Horne-Zeilinger (GHZ) states from arbitrary entangled tripartite pure states are described. These techniques work for virtually any input state. Each technique has two stages which we call primary and secondary distillations. Primary distillation produces a GHZ state with some probability, so that when applied to an ensemble of systems a certain percentage is discarded. Secondary distillation produces further GHZs from the discarded systems. These protocols are developed with the help of an approach to quantum information theory based on absolutely selective information, which has other potential applications.

JPRS Report, Soviet Union, World Economy & International Relations, No. 5, May 1988

DTIC Science & Technology

1988-10-06

here: playing on the feelings of national pride and patriotism, the incitement of jingoism, chauvinism and hostility toward other peoples and so...state, which brought states of an opposite nature in the class respect into direct conflict. However, this argument does not, we are convinced...sometimes serves as virtually the main argument designed to explain the foreign policy unity of this group of states or the other. Such characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumpower, J.L.

There are strong structural similarities between risks from technological hazards and big-purse state lottery games. Risks from technological hazards are often described as low-probability, high-consequence negative events. State lotteries could be equally well characterized as low-probability, high-consequence positive events. Typical communications about state lotteries provide a virtual strategic textbook for opponents of risky technologies. The same techniques can be used to sell lottery tickets or sell opposition to risky technologies. Eight basic principles are enumerated.

75 FR 63509 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

.... Products LLC. 74,606 Watson Laboratories, Inc., Carmel, NY September 3, 2009. Watson Pharmaceuticals...--Enterprise Services), Virtual Workers Across the United States. 74,343 JohnsonDiversey Santa Cruz, CA...

Lewy Body Dementia Association

MedlinePlus

... Services Local LBD Support Groups Caregiver Link Caregiving Materials Virtual Groups Caregiver Resources Related Organizations LBD stories submit a caregiver story forums Research Research News LBD: State of the Science Learn About Clinical Trials Participate in Research Funding ...

Can virtual autopsy with postmortem CT improve clinical diagnosis of cause of death? A retrospective observational cohort study in a Dutch tertiary referral centre.

PubMed

Sonnemans, Lianne J P; Kubat, Bela; Prokop, Mathias; Klein, Willemijn M

2018-03-16

To investigate whether virtual autopsy with postmortem CT (PMCT) improves clinical diagnosis of the immediate cause of death. Retrospective observational cohort study. inhospital and out-of-hospital deaths over the age of 1 year in whom virtual autopsy with PMCT and conventional autopsy were performed. forensic cases, postmortal organ donors and cases with incomplete scanning procedures. Cadavers were examined by virtual autopsy with PMCT prior to conventional autopsy. The clinically determined cause of death was recorded before virtual autopsy and was then adjusted with the findings of virtual autopsy. Using conventional autopsy as reference standard, we investigated the increase in sensitivity for immediate cause of death, type of pathology and anatomical system involved before and after virtual autopsy. Tertiary referral centre. 86 cadavers that underwent conventional and virtual autopsy between July 2012 and June 2016. PMCT consisted of brain, cervical spine and chest-abdomen-pelvis imaging. Conventional autopsy consisted of thoracoabdominal examination with/without brain autopsy. Increase in sensitivity for the immediate cause of death, type of pathology (infection, haemorrhage, perfusion disorder, other or not assigned) and anatomical system (pulmonary, cardiovascular, gastrointestinal, other or not assigned) involved, before and after virtual autopsy. Using PMCT, the sensitivity for immediate cause of death increased with 12% (95% CI 2% to 22%) from 53% (41% to 64%) to 64% (53% to 75%), with 18% (9% to 27%) from 65% (54% to 76%) to 83% (73% to 91%) for type of pathology and with 19% (9% to 30%) from 65% (54% to 76%) to 85% (75% to 92%) for anatomical system. While unenhanced PMCT is an insufficient substitute for conventional autopsy, it can improve diagnosis of cause of death over clinical diagnosis alone and should therefore be considered whenever autopsy is not performed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Can virtual science foster real skills? A study of inquiry skills in a virtual world

NASA Astrophysics Data System (ADS)

Dodds, Heather E.

Online education has grown into a part of the educational market answering the demand for learning at the learner's choice of time and place. Inquiry skills such as observing, questioning, collecting data, and devising fair experiments are an essential element of 21st-century online science coursework. Virtual immersive worlds such as Second Life are being used as new frontiers in science education. There have been few studies looking specifically at science education in virtual worlds that foster inquiry skills. This quantitative quasi-experimental nonrandomized control group pretest and posttest study explored what affect a virtual world experience had on inquiry skills as measured by the TIPS (Test of Integrated Process Skills) and TIPS II (Integrated Process Skills Test II) instruments. Participants between the ages of 18 and 65 were recruited from educator mailing lists and Second Life discussion boards and then sorted into the experimental group, which received instructions to utilize several displays in Mendelian genetics at the Genome Island location within Second Life, or the control group, which received text-based PDF documents of the same genetics course content. All participants, in the form of avatars, were experienced Second Life residents to reduce any novelty effect. This study found a greater increase in inquiry skills in the experimental group interacting using a virtual world to learn science content (0.90 points) than a control group that is presented only with online text-based content (0.87 points). Using a mixed between-within ANOVA (analysis of variance), with an alpha level of 0.05, there was no significant interaction between the control or experimental groups and inquiry skills, F (1, 58) = .783, p = .380, partial eta squared = .013, at the specified .05 alpha level suggesting no significant difference as a result of the virtual world exercise. However, there is not enough evidence to state that there was no effect because there was a greater increase in scores for the group that experienced a virtual world exercise. This study adds to the increasing body of knowledge about virtual worlds and inquiry skills, particularly with adult learners.

Three-Dimensional User Interfaces for Immersive Virtual Reality

NASA Technical Reports Server (NTRS)

vanDam, Andries

1997-01-01

The focus of this grant was to experiment with novel user interfaces for immersive Virtual Reality (VR) systems, and thus to advance the state of the art of user interface technology for this domain. Our primary test application was a scientific visualization application for viewing Computational Fluid Dynamics (CFD) datasets. This technology has been transferred to NASA via periodic status reports and papers relating to this grant that have been published in conference proceedings. This final report summarizes the research completed over the past year, and extends last year's final report of the first three years of the grant.

Virtual Rover Takes its First Turn

NASA Image and Video Library

2004-01-13

This image shows a screenshot from the software used by engineers to drive the Mars Exploration Rover Spirit. The software simulates the rover's movements across the martian terrain, helping to plot a safe course for the rover. The virtual 3-D world around the rover is built from images taken by Spirit's stereo navigation cameras. Regions for which the rover has not yet acquired 3-D data are represented in beige. This image depicts the state of the rover before it backed up and turned 45 degrees on Sol 11 (01-13-04). http://photojournal.jpl.nasa.gov/catalog/PIA05063

Emotional recognition from the speech signal for a virtual education agent

NASA Astrophysics Data System (ADS)

Tickle, A.; Raghu, S.; Elshaw, M.

2013-06-01

This paper explores the extraction of features from the speech wave to perform intelligent emotion recognition. A feature extract tool (openSmile) was used to obtain a baseline set of 998 acoustic features from a set of emotional speech recordings from a microphone. The initial features were reduced to the most important ones so recognition of emotions using a supervised neural network could be performed. Given that the future use of virtual education agents lies with making the agents more interactive, developing agents with the capability to recognise and adapt to the emotional state of humans is an important step.

Multi-indexed (q-)Racah polynomials

NASA Astrophysics Data System (ADS)

Odake, Satoru; Sasaki, Ryu

2012-09-01

As the second stage of the project multi-indexed orthogonal polynomials, we present, in the framework of ‘discrete quantum mechanics’ with real shifts in one dimension, the multi-indexed (q-)Racah polynomials. They are obtained from the (q-)Racah polynomials by the multiple application of the discrete analogue of the Darboux transformations or the Crum-Krein-Adler deletion of ‘virtual state’ vectors, in a similar way to the multi-indexed Laguerre and Jacobi polynomials reported earlier. The virtual state vectors are the ‘solutions’ of the matrix Schrödinger equation with negative ‘eigenvalues’, except for one of the two boundary points.

Katja — the 24th week of virtual pregnancy for dosimetric calculations

NASA Astrophysics Data System (ADS)

Becker, Janine; Zankl, Maria; Fill, Ute; Hoeschen, Christoph

2008-01-01

Virtual human models, a.k.a. voxel models, are currently the state of the art in radiation protection for computing organ irradiation doses without difficult or morally unfeasible experiments. They are based on medical image data of human patients and offer a realistic, three dimensional representation of human anatomy. We present our newest voxel model Katja, a virtual woman in the 24th week of pregnancy. Katja integrates two previous voxel models, one obtained from the abdominal MRI scan of a pregnant patient and an already segmented model of a non-pregnant woman. The latter is the ICRP-AF, fitting the reference values for standard height, weight and organ masses given by the Internationals Committee of Radiological Protection (ICRP). The dataset was altered in order to fit the segmented foetus taken from the abdominal MRI scan. The resulting pregnant woman model, Katja, complies with the ICRP reference values for the adult female.

Distributed computing environments for future space control systems

NASA Technical Reports Server (NTRS)

Viallefont, Pierre

1993-01-01

The aim of this paper is to present the results of a CNES research project on distributed computing systems. The purpose of this research was to study the impact of the use of new computer technologies in the design and development of future space applications. The first part of this study was a state-of-the-art review of distributed computing systems. One of the interesting ideas arising from this review is the concept of a 'virtual computer' allowing the distributed hardware architecture to be hidden from a software application. The 'virtual computer' can improve system performance by adapting the best architecture (addition of computers) to the software application without having to modify its source code. This concept can also decrease the cost and obsolescence of the hardware architecture. In order to verify the feasibility of the 'virtual computer' concept, a prototype representative of a distributed space application is being developed independently of the hardware architecture.

Content and structure of knowledge base used for virtual control of android arm motion in specified environment

NASA Astrophysics Data System (ADS)

Pritykin, F. N.; Nebritov, V. I.

2018-01-01

The paper presents the configuration of knowledge base necessary for intelligent control of android arm mechanism motion with different positions of certain forbidden regions taken into account. The present structure of the knowledge base characterizes the past experience of arm motion synthesis in the vector of velocities with due regard for the known obstacles. This structure also specifies its intrinsic properties. Knowledge base generation is based on the study of the arm mechanism instantaneous states implementations. Computational experiments connected with the virtual control of android arm motion with known forbidden regions using the developed knowledge base are introduced. Using the developed knowledge base to control virtually the arm motion reduces the time of test assignments calculation. The results of the research can be used in developing control systems of autonomous android robots in the known in advance environment.

3-D Imaging In Virtual Environment: A Scientific Clinical and Teaching Tool

NASA Technical Reports Server (NTRS)

Ross, Muriel D.; DeVincenzi, Donald L. (Technical Monitor)

1996-01-01

The advent of powerful graphics workstations and computers has led to the advancement of scientific knowledge through three-dimensional (3-D) reconstruction and imaging of biological cells and tissues. The Biocomputation Center at NASA Ames Research Center pioneered the effort to produce an entirely computerized method for reconstruction of objects from serial sections studied in a transmission electron microscope (TEM). The software developed, ROSS (Reconstruction of Serial Sections), is now being distributed to users across the United States through Space Act Agreements. The software is in widely disparate fields such as geology, botany, biology and medicine. In the Biocomputation Center, ROSS serves as the basis for development of virtual environment technologies for scientific and medical use. This report will describe the Virtual Surgery Workstation Project that is ongoing with clinicians at Stanford University Medical Center, and the role of the Visible Human data in the project.

Dynamic virtual machine allocation policy in cloud computing complying with service level agreement using CloudSim

NASA Astrophysics Data System (ADS)

Aneri, Parikh; Sumathy, S.

2017-11-01

Cloud computing provides services over the internet and provides application resources and data to the users based on their demand. Base of the Cloud Computing is consumer provider model. Cloud provider provides resources which consumer can access using cloud computing model in order to build their application based on their demand. Cloud data center is a bulk of resources on shared pool architecture for cloud user to access. Virtualization is the heart of the Cloud computing model, it provides virtual machine as per application specific configuration and those applications are free to choose their own configuration. On one hand, there is huge number of resources and on other hand it has to serve huge number of requests effectively. Therefore, resource allocation policy and scheduling policy play very important role in allocation and managing resources in this cloud computing model. This paper proposes the load balancing policy using Hungarian algorithm. Hungarian Algorithm provides dynamic load balancing policy with a monitor component. Monitor component helps to increase cloud resource utilization by managing the Hungarian algorithm by monitoring its state and altering its state based on artificial intelligent. CloudSim used in this proposal is an extensible toolkit and it simulates cloud computing environment.

Behavior believability in virtual worlds: agents acting when they need to.

PubMed

Avradinis, Nikos; Panayiotopoulos, Themis; Anastassakis, George

2013-12-01

Believability has been a perennial goal for the intelligent virtual agent community. One important aspect of believability largely consists in demonstrating autonomous behavior, consistent with the agent's personality and motivational state, as well as the world conditions. Autonomy, on behalf of the agent, implies the existence of an internal structure and mechanism that allows the agent to have its own needs and interests, based on which the agent will dynamically select and generate goals that will in turn lead to self-determined behavior. Intrinsic motivation allows the agent to function and demonstrate behavior, even when no external stimulus is present, due to the constant change of its internal emotional and physiological state. The concept of motivation has already been investigated by research works on intelligent agents, trying to achieve autonomy. The current work presents an architecture and model to represent and manage internal driving factors in intelligent virtual agents, using the concept of motivations. Based on Maslow and Alderfer's bio-psychological needs theories, we present a motivational approach to represent human needs and produce emergent behavior through motivation synthesis. Particular attention is given to basic, physiological level needs, which are the basis of behavior and can produce tendency to action even when there is no other interaction with the environment.

Using multimedia virtual patients to enhance the clinical curriculum for medical students.

PubMed

McGee, J B; Neill, J; Goldman, L; Casey, E

1998-01-01

Changes in the environment in which clinical medical education takes place in the United States has profoundly affected the quality of the learning experience. A shift to out-patient based care, minimization of hospitalization time, and shrinking clinical revenues has changed the teaching hospital or "classroom" to a degree that we must develop innovative approaches to medical education. One solution is the Virtual Patient Project. Utilizing state-of-the-art computer-based multimedia technology, we are building a library of simulated patient encounters that will serve to fill some of the educational gaps that the current health care system has created. This project is part of a newly formed and unique organization, the Harvard Medical School-Beth Israel Deaconess Mount Auburn Institute for Education and Research (the Institute), which supports in-house educational design, production, and faculty time to create Virtual Patients. These problem-based clinical cases allow the medical student to evaluate a patient at initial presentation, order diagnostic tests, observe the outcome and obtain context-sensitive feedback through a computer program designed at the Institute. Multimedia technology and authoring programs have reached a level of sophistication to allow content experts (the teaching faculty) to design and create the majority of the program themselves and to allow students to adapt the program to their individual learning needs.

Use of a virtual human performance laboratory to improve integration of mathematics and biology in sports science curricula in Sweden and the United States.

PubMed

Garza, D; Besier, T; Johnston, T; Rolston, B; Schorsch, A; Matheson, G; Annerstedt, C; Lindh, J; Rydmark, M

2007-01-01

New fields such as bioengineering are exploring the role of the physical sciences in traditional biological approaches to problems, with exciting results in device innovation, medicine, and research biology. The integration of mathematics, biomechanics, and material sciences into the undergraduate biology curriculum will better prepare students for these opportunities and enhance cooperation among faculty and students at the university level. We propose the study of sports science as the basis for introduction of this interdisciplinary program. This novel integrated approach will require a virtual human performance laboratory dual-hosted in Sweden and the United States. We have designed a course model that involves cooperative learning between students at Göteborg University and Stanford University, utilizes new technologies, encourages development of original research and will rely on frequent self-assessment and reflective learning. We will compare outcomes between this course and a more traditional didactic format as well as assess the effectiveness of multiple web-hosted virtual environments. We anticipate the grant will result in a network of original faculty and student research in exercise science and pedagogy as well as provide the opportunity for implementation of the model in more advance training levels and K-12 programs.

"Social, technological, and research responses to potential erosion and sediment disasters in the western United States, with examples from California"

Treesearch

R. M. Rice

1985-01-01

Synopsis - Examples from California are used to illustrate typical responses to erosion and debris flow disasters the United States. Political institutions leave virtually all responsibility for disaster prevention to the lowest levels of government or to individuals. Three circumstances in which disasters occur are discussed: urbanized debris cones, urbanized unstable...

Social, technological, and research responses to potential erosion and sediment disasters in the western United States, with examples from California

Treesearch

R. M. Rice

1985-01-01

Examples from California are used to illustrate typical responses to erosion and debris flow disasters in the United States. Political institutions leave virtually all responsibility for disaster prevention to the lowest levels of government or to individuals. Three circumstances in which disasters occur are discussed: urbanized debris cones, urbanized unstable...

A finite element based method for solution of optimal control problems

NASA Technical Reports Server (NTRS)

Bless, Robert R.; Hodges, Dewey H.; Calise, Anthony J.

1989-01-01

A temporal finite element based on a mixed form of the Hamiltonian weak principle is presented for optimal control problems. The mixed form of this principle contains both states and costates as primary variables that are expanded in terms of elemental values and simple shape functions. Unlike other variational approaches to optimal control problems, however, time derivatives of the states and costates do not appear in the governing variational equation. Instead, the only quantities whose time derivatives appear therein are virtual states and virtual costates. Also noteworthy among characteristics of the finite element formulation is the fact that in the algebraic equations which contain costates, they appear linearly. Thus, the remaining equations can be solved iteratively without initial guesses for the costates; this reduces the size of the problem by about a factor of two. Numerical results are presented herein for an elementary trajectory optimization problem which show very good agreement with the exact solution along with excellent computational efficiency and self-starting capability. The goal is to evaluate the feasibility of this approach for real-time guidance applications. To this end, a simplified two-stage, four-state model for an advanced launch vehicle application is presented which is suitable for finite element solution.

Using mixed methods to evaluate efficacy and user expectations of a virtual reality-based training system for upper-limb recovery in patients after stroke: a study protocol for a randomised controlled trial.

PubMed

Schuster-Amft, Corina; Eng, Kynan; Lehmann, Isabelle; Schmid, Ludwig; Kobashi, Nagisa; Thaler, Irène; Verra, Martin L; Henneke, Andrea; Signer, Sandra; McCaskey, Michael; Kiper, Daniel

2014-09-06

In recent years, virtual reality has been introduced to neurorehabilitation, in particular with the intention of improving upper-limb training options and facilitating motor function recovery. The proposed study incorporates a quantitative part and a qualitative part, termed a mixed-methods approach: (1) a quantitative investigation of the efficacy of virtual reality training compared to conventional therapy in upper-limb motor function are investigated, (2a) a qualitative investigation of patients' experiences and expectations of virtual reality training and (2b) a qualitative investigation of therapists' experiences using the virtual reality training system in the therapy setting. At three participating clinics, 60 patients at least 6 months after stroke onset will be randomly allocated to an experimental virtual reality group (EG) or to a control group that will receive conventional physiotherapy or occupational therapy (16 sessions, 45 minutes each, over the course of 4 weeks). Using custom data gloves, patients' finger and arm movements will be displayed in real time on a monitor, and they will move and manipulate objects in various virtual environments. A blinded assessor will test patients' motor and cognitive performance twice before, once during, and twice after the 4-week intervention. The primary outcome measure is the Box and Block Test. Secondary outcome measures are the Chedoke-McMaster Stroke Assessments (hand, arm and shoulder pain subscales), the Chedoke-McMaster Arm and Hand Activity Inventory, the Line Bisection Test, the Stroke Impact Scale, the MiniMentalState Examination and the Extended Barthel Index. Semistructured face-to-face interviews will be conducted with patients in the EG after intervention finalization with a focus on the patients' expectations and experiences regarding the virtual reality training. Therapists' perspectives on virtual reality training will be reviewed in three focus groups comprising four to six occupational therapists and physiotherapists. The interviews will help to gain a deeper understanding of the phenomena under investigation to provide sound recommendations for the implementation of the virtual reality training system for routine use in neurorehabilitation complementing the quantitative clinical assessments. Cliniclatrials.gov Identifier: NCT01774669 (15 January 2013).

Web-Based Virtual Patients in Nursing Education: Development and Validation of Theory-Anchored Design and Activity Models

PubMed Central

2014-01-01

Background Research has shown that nursing students find it difficult to translate and apply their theoretical knowledge in a clinical context. Virtual patients (VPs) have been proposed as a learning activity that can support nursing students in their learning of scientific knowledge and help them integrate theory and practice. Although VPs are increasingly used in health care education, they still lack a systematic consistency that would allow their reuse outside of their original context. There is therefore a need to develop a model for the development and implementation of VPs in nursing education. Objective The aim of this study was to develop and evaluate a virtual patient model optimized to the learning and assessment needs in nursing education. Methods The process of modeling started by reviewing theoretical frameworks reported in the literature and used by practitioners when designing learning and assessment activities. The Outcome-Present State Test (OPT) model was chosen as the theoretical framework. The model was then, in an iterative manner, developed and optimized to the affordances of virtual patients. Content validation was performed with faculty both in terms of the relevance of the chosen theories but also its applicability in nursing education. The virtual patient nursing model was then instantiated in two VPs. The students’ perceived usefulness of the VPs was investigated using a questionnaire. The result was analyzed using descriptive statistics. Results A virtual patient Nursing Design Model (vpNDM) composed of three layers was developed. Layer 1 contains the patient story and ways of interacting with the data, Layer 2 includes aspects of the iterative process of clinical reasoning, and finally Layer 3 includes measurable outcomes. A virtual patient Nursing Activity Model (vpNAM) was also developed as a guide when creating VP-centric learning activities. The students perceived the global linear VPs as a relevant learning activity for the integration of theory and practice. Conclusions Virtual patients that are adapted to the nursing paradigm can support nursing students’ development of clinical reasoning skills. The proposed virtual patient nursing design and activity models will allow the systematic development of different types of virtual patients from a common model and thereby create opportunities for sharing pedagogical designs across technical solutions. PMID:24727709

Analysis of Thermal Track Buckling in the Lateral Plane

DOT National Transportation Integrated Search

1976-09-01

The post-buckling equilibrium states are determined analytically. To obtain a consistent formulation of the problem, use is made of the principle of virtual displacements and the variational calculus for variable matching points. The obtained formula...

[A new concept in digestive surgery: the computer assisted surgical procedure, from virtual reality to telemanipulation].

PubMed

Marescaux, J; Clément, J M; Nord, M; Russier, Y; Tassetti, V; Mutter, D; Cotin, S; Ayache, N

1997-11-01

Surgical simulation increasingly appears to be an essential aspect of tomorrow's surgery. The development of a hepatic surgery simulator is an advanced concept calling for a new writing system which will transform the medical world: virtual reality. Virtual reality extends the perception of our five senses by representing more than the real state of things by the means of computer sciences and robotics. It consists of three concepts: immersion, navigation and interaction. Three reasons have led us to develop this simulator: the first is to provide the surgeon with a comprehensive visualisation of the organ. The second reason is to allow for planning and surgical simulation that could be compared with the detailed flight-plan for a commercial jet pilot. The third lies in the fact that virtual reality is an integrated part of the concept of computer assisted surgical procedure. The project consists of a sophisticated simulator which has to include five requirements: visual fidelity, interactivity, physical properties, physiological properties, sensory input and output. In this report we will describe how to get a realistic 3D model of the liver from bi-dimensional 2D medical images for anatomical and surgical training. The introduction of a tumor and the consequent planning and virtual resection is also described, as are force feedback and real-time interaction.

Robust hopping based on virtual pendulum posture control.

PubMed

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

2013-09-01

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.

Community-based pedestrian safety training in virtual reality: A pragmatic trial.

PubMed

Schwebel, David C; Combs, Tabitha; Rodriguez, Daniel; Severson, Joan; Sisiopiku, Virginia

2016-01-01

Child pedestrian injuries are a leading cause of mortality and morbidity across the United States and the world. Repeated practice at the cognitive-perceptual task of crossing a street may lead to safer pedestrian behavior. Virtual reality offers a unique opportunity for repeated practice without the risk of actual injury. This study conducted a pre-post within-subjects trial of training children in pedestrian safety using a semi-mobile, semi-immersive virtual pedestrian environment placed at schools and community centers. Pedestrian safety skills among a group of 44 seven- and eight-year-old children were assessed in a laboratory, and then children completed six 15-minute training sessions in the virtual pedestrian environment at their school or community center following pragmatic trial strategies over the course of three weeks. Following training, pedestrian safety skills were re-assessed. Results indicate improvement in delay entering traffic following training. Safe crossings did not demonstrate change. Attention to traffic and time to contact with oncoming vehicles both decreased somewhat, perhaps an indication that training was incomplete and children were in the process of actively learning to be safer pedestrians. The findings suggest virtual reality environments placed in community centers hold promise for teaching children to be safer pedestrians, but future research is needed to determine the optimal training dosage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cognitive evaluation for the diagnosis of Alzheimer's disease based on Turing Test and Virtual Environments.

PubMed

Fernandez Montenegro, Juan Manuel; Argyriou, Vasileios

2017-05-01

Alzheimer's screening tests are commonly used by doctors to diagnose the patient's condition and stage as early as possible. Most of these tests are based on pen-paper interaction and do not embrace the advantages provided by new technologies. This paper proposes novel Alzheimer's screening tests based on virtual environments and game principles using new immersive technologies combined with advanced Human Computer Interaction (HCI) systems. These new tests are focused on the immersion of the patient in a virtual room, in order to mislead and deceive the patient's mind. In addition, we propose two novel variations of Turing Test proposed by Alan Turing as a method to detect dementia. As a result, four tests are introduced demonstrating the wide range of screening mechanisms that could be designed using virtual environments and game concepts. The proposed tests are focused on the evaluation of memory loss related to common objects, recent conversations and events; the diagnosis of problems in expressing and understanding language; the ability to recognize abnormalities; and to differentiate between virtual worlds and reality, or humans and machines. The proposed screening tests were evaluated and tested using both patients and healthy adults in a comparative study with state-of-the-art Alzheimer's screening tests. The results show the capacity of the new tests to distinguish healthy people from Alzheimer's patients. Copyright © 2017. Published by Elsevier Inc.

A virtual clean room to teach USP 797 regulations for intravenous medications.

PubMed

Patel, Sheetal; Vincent, Ashley H; Abel, Steven R; Jacobs, Carolyn M; Dunlop, Steven R; Seibert, Megan

2011-02-10

To provide a virtual environment for pharmacy students to learn United States Pharmacopeia Chapter 797 (USP 797) requirements, while recognizing the role of pharmacists in the safe use of intravenous (IV) medications. A virtual laboratory was created that included stations for IV medications, product verification, medication safety, and patient cases pertaining to high-alert medications. Pharmacy students used 3-D glasses and a wireless controller to navigate through the session and identify violations of USP 797 regulations. Pre-assessments and post-assessments were administered to students who completed the session in each of the 2 years it was offered. In the first year, 88% of students strongly agreed or agreed that the sessions met their expectation. Following their APPE clerkship, 92% of these students felt the virtual IV room prepared them for the IV clean room experience. In the second year, 88% of students felt the experience enhanced their understanding of clean room procedures. After session completion, 75% of participants perceived medication errors to be more significant. Written examinations also were administered and students' mean scores improved significantly compared to those of students' prior to implementation of the session (89.6% in year 0; 91.2% in year 1; and 96.1% in year 2). The immersive virtual environment is a contemporary and effective way to teach USP 797 requirements and enhance the awareness of medication errors.

A Virtual Clean Room to Teach USP 797 Regulations for Intravenous Medications

PubMed Central

Patel, Sheetal; Abel, Steven R.; Jacobs, Carolyn M.; Dunlop, Steven R.; Seibert, Megan

2011-01-01

Objective To provide a virtual environment for pharmacy students to learn United States Pharmacopeia Chapter 797 (USP 797) requirements, while recognizing the role of pharmacists in the safe use of intravenous (IV) medications. Design A virtual laboratory was created that included stations for IV medications, product verification, medication safety, and patient cases pertaining to high-alert medications. Pharmacy students used 3-D glasses and a wireless controller to navigate through the session and identify violations of USP 797 regulations. Assessment Preassessments and postassessments were administered to students who completed the session in each of the 2 years it was offered. In the first year, 88% of students strongly agreed or agreed that the sessions met their expectation. Following their APPE clerkship, 92% of these students felt the virtual IV room prepared them for the IV clean room experience. In the second year, 88% of students felt the experience enhanced their understanding of clean room procedures. After session completion, 75% of participants perceived medication errors to be more significant. Written examinations also were administered and students' mean scores improved significantly compared to those of students' prior to implementation of the session (89.6% in year 0; 91.2% in year 1; and 96.1% in year 2). Conclusion The immersive virtual environment is a contemporary and effective way to teach USP 797 requirements and enhance the awareness of medication errors. PMID:21451759

Virtual microscopy and digital cytology: state of the art.

PubMed

Giansanti, Daniele; Grigioni, Mauro; D'Avenio, Giuseppe; Morelli, Sandra; Maccioni, Giovanni; Bondi, Arrigo; Giovagnoli, Maria Rosaria

2010-01-01

The paper approaches a new technological scenario relevant for the introduction of the digital cytology (D-CYT) in the health service. A detailed analysis of the state of the art on the status of the introduction of D-CYT in the hospital and more in general in the dispersed territory has been conducted. The analysis was conducted in a form of review and was arranged into two parts: the first part focused on the technological tools needed to carry out a successful service (client server architectures, e-learning, quality assurance issues); the second part focused on issues oriented to help the introduction and evaluation of the technology (specific training in D-CYT, health technology assessment in-routine application, data format standards and picture archiving computerized systems (PACS) implementation, image quality assessment, strategies of navigation, 3D-virtual-reality potentialities). The work enlightens future scenarios of actions relevant for the introduction of the technology.

Synthetic Vision System Commercial Aircraft Flight Deck Display Technologies for Unusual Attitude Recovery

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Ellis, Kyle E.; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel

2017-01-01

A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that the lack of external visual references was associated with a flight crew's loss of attitude awareness or energy state awareness in 17 of these events. Therefore, CAST recommended development and implementation of virtual day-Visual Meteorological Condition (VMC) display systems, such as synthetic vision systems, which can promote flight crew attitude awareness similar to a day-VMC environment. This paper describes the results of a high-fidelity, large transport aircraft simulation experiment that evaluated virtual day-VMC displays and a "background attitude indicator" concept as an aid to pilots in recovery from unusual attitudes. Twelve commercial airline pilots performed multiple unusual attitude recoveries and both quantitative and qualitative dependent measures were collected. Experimental results and future research directions under this CAST initiative and the NASA "Technologies for Airplane State Awareness" research project are described.

Understanding the Influence of the Pakistani Government in South Asia

DTIC Science & Technology

2010-11-01

that, “Jinnah, virtually alone, became the exponent of constitution making along secular lines. His vision involved the blending of multiple traditions...Hindu nor Sikh, but citizens of an all-embracing secular state, had little meaning for the vast majority who were now expected to adapt the Pakistani...to maintain ties to the United States Ayub Kahn began to move towards friendlier relations with China, a move that the United States would view as

Along the Virtuality Continuum - Two Showcases on how xR Technologies Transform Geoscience Research and Education

NASA Astrophysics Data System (ADS)

Klippel, A.; Zhao, J.; Masrur, A.; Wallgruen, J. O.; La Femina, P. C.

2017-12-01

We present work along the virtuality continuum showcasing both AR and VR environments for geoscience applications and research. The AR/VR project focusses on one of the most prominent landmarks on the Penn State campus which, at the same time, is a representation of the geology of Pennsylvania. The Penn State Obelisk is a 32" high, 51 ton monument composed of 281 rocks collected from across Pennsylvania. While information about its origins and composition are scattered in articles and some web databases, we compiled all the available data from the web and archives and curated them as a basis for an immersive xR experience. Tabular data was amended by xR data such as 360° photos, videos, and 3D models (e.g., the Obelisk). Our xR (both AR and VR) prototype provides an immersive analytical environment that supports interactive data visualization and virtual navigation in a natural environment (a campus model of today and of 1896, the year of the Obelisk's installation). This work-in-progress project can provide an interactive immersive learning platform (specifically, for K-12 and introductory level geosciences students) where learning process is enhanced through seamless navigation between 3D data space and physical space. The, second, VR focused application is creating and empirically evaluating virtual reality (VR) experiences for geosciences research, specifically, an interactive volcano experience based on LiDAR and image data of Iceland's Thrihnukar volcano. The prototype addresses the lack of content and tools for immersive virtual reality (iVR) in geoscientific education and research and how to make it easier to integrate iVR into research and classroom experiences. It makes use of environmentally sensed data such that interaction and linked content can be integrated into a single experience. We discuss our workflows as well as methods and authoring tools for iVR analysis and creation of virtual experiences. These methods and tools aim to enhance the utility of geospatial data from repositories such as OpenTopography.org through unlocking treasure-troves of geospatial data for VR applications. Their enhanced accessibility in education and research for the geosciences and beyond will benefit geoscientists and educators who cannot be expected to be VR and 3D application experts.

iRODS: A Distributed Data Management Cyberinfrastructure for Observatories

NASA Astrophysics Data System (ADS)

Rajasekar, A.; Moore, R.; Vernon, F.

2007-12-01

Large-scale and long-term preservation of both observational and synthesized data requires a system that virtualizes data management concepts. A methodology is needed that can work across long distances in space (distribution) and long-periods in time (preservation). The system needs to manage data stored on multiple types of storage systems including new systems that become available in the future. This concept is called infrastructure independence, and is typically implemented through virtualization mechanisms. Data grids are built upon concepts of data and trust virtualization. These concepts enable the management of collections of data that are distributed across multiple institutions, stored on multiple types of storage systems, and accessed by multiple types of clients. Data virtualization ensures that the name spaces used to identify files, users, and storage systems are persistent, even when files are migrated onto future technology. This is required to preserve authenticity, the link between the record and descriptive and provenance metadata. Trust virtualization ensures that access controls remain invariant as files are moved within the data grid. This is required to track the chain of custody of records over time. The Storage Resource Broker (http://www.sdsc.edu/srb) is one such data grid used in a wide variety of applications in earth and space sciences such as ROADNet (roadnet.ucsd.edu), SEEK (seek.ecoinformatics.org), GEON (www.geongrid.org) and NOAO (www.noao.edu). Recent extensions to data grids provide one more level of virtualization - policy or management virtualization. Management virtualization ensures that execution of management policies can be automated, and that rules can be created that verify assertions about the shared collections of data. When dealing with distributed large-scale data over long periods of time, the policies used to manage the data and provide assurances about the authenticity of the data become paramount. The integrated Rule-Oriented Data System (iRODS) (http://irods.sdsc.edu) provides the mechanisms needed to describe not only management policies, but also to track how the policies are applied and their execution results. The iRODS data grid maps management policies to rules that control the execution of the remote micro-services. As an example, a rule can be created that automatically creates a replica whenever a file is added to a specific collection, or extracts its metadata automatically and registers it in a searchable catalog. For the replication operation, the persistent state information consists of the replica location, the creation date, the owner, the replica size, etc. The mechanism used by iRODS for providing policy virtualization is based on well-defined functions, called micro-services, which are chained into alternative workflows using rules. A rule engine, based on the event-condition-action paradigm executes the rule-based workflows after an event. Rules can be deferred to a pre-determined time or executed on a periodic basis. As the data management policies evolve, the iRODS system can implement new rules, new micro-services, and new state information (metadata content) needed to manage the new policies. Each sub- collection can be managed using a different set of policies. The discussion of the concepts in rule-based policy virtualization and its application to long-term and large-scale data management for observatories such as ORION and NEON will be the basis of the paper.

Analytical transition-matrix treatment of electric multipole polarizabilities of hydrogen-like atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kharchenko, V.F., E-mail: vkharchenko@bitp.kiev.ua

2015-04-15

The direct transition-matrix approach to the description of the electric polarization of the quantum bound system of particles is used to determine the electric multipole polarizabilities of the hydrogen-like atoms. It is shown that in the case of the bound system formed by the Coulomb interaction the corresponding inhomogeneous integral equation determining an off-shell scattering function, which consistently describes virtual multiple scattering, can be solved exactly analytically for all electric multipole polarizabilities. Our method allows to reproduce the known Dalgarno–Lewis formula for electric multipole polarizabilities of the hydrogen atom in the ground state and can also be applied to determinemore » the polarizability of the atom in excited bound states. - Highlights: • A new description for electric polarization of hydrogen-like atoms. • Expression for multipole polarizabilities in terms of off-shell scattering functions. • Derivation of integral equation determining the off-shell scattering function. • Rigorous analytic solving the integral equations both for ground and excited states. • Study of contributions of virtual multiple scattering to electric polarizabilities.« less

Simulating and stimulating performance: introducing distributed simulation to enhance musical learning and performance.

PubMed

Williamon, Aaron; Aufegger, Lisa; Eiholzer, Hubert

2014-01-01

Musicians typically rehearse far away from their audiences and in practice rooms that differ significantly from the concert venues in which they aspire to perform. Due to the high costs and inaccessibility of such venues, much current international music training lacks repeated exposure to realistic performance situations, with students learning all too late (or not at all) how to manage performance stress and the demands of their audiences. Virtual environments have been shown to be an effective training tool in the fields of medicine and sport, offering practitioners access to real-life performance scenarios but with lower risk of negative evaluation and outcomes. The aim of this research was to design and test the efficacy of simulated performance environments in which conditions of "real" performance could be recreated. Advanced violin students (n = 11) were recruited to perform in two simulations: a solo recital with a small virtual audience and an audition situation with three "expert" virtual judges. Each simulation contained back-stage and on-stage areas, life-sized interactive virtual observers, and pre- and post-performance protocols designed to match those found at leading international performance venues. Participants completed a questionnaire on their experiences of using the simulations. Results show that both simulated environments offered realistic experience of performance contexts and were rated particularly useful for developing performance skills. For a subset of 7 violinists, state anxiety and electrocardiographic data were collected during the simulated audition and an actual audition with real judges. Results display comparable levels of reported state anxiety and patterns of heart rate variability in both situations, suggesting that responses to the simulated audition closely approximate those of a real audition. The findings are discussed in relation to their implications, both generalizable and individual-specific, for performance training.

NASA Virtual Conferences and Instruction Over the Internet

NASA Technical Reports Server (NTRS)

Leon, Mark; McCurdy, Andrea; Wood, Charles

1997-01-01

Distance learning is not new. Since the time that radio has embellished our culture distance learning has taken on may forms. With the onset of television, video tape and satellite link ups the world of multimedia has taken a presence in our remote learning environment. Now in the information age new models for bring the best education to people through out the world is in its early stages. Recent "Information Age" technological developments have made key advancements to distance learning through the greater bandwidths now available over the Internet and a broader communications infrastructure that extends to classrooms throughout the country and the world. Further, new software compression technology allows audio and video to be communicated over the Internet much more efficiently. Larger amounts of data can be transferred to remote sites at less cost. The purpose of this paper is to demonstrate the use of state-of-art technology in the educational community. The focus will be on virtual conferences, virtual instruction and remote education. The techniques herein have been developed by NASA and the University of North Dakota(UND) through the use of existing software and hardware purchased in the United States. NASA has awarded UND a grant for continued research in this area based on their pioneering effort to date. NASA has been conducting "Virtual Conferences" from Ames Research Center in order to make unique educational opportunities available to participants across the country and internationally. Through the use of this technical approach, hundreds of teachers have been able to attend events where physical or financial barriers traditionally prevented their attendance. This technique is currently being adopted by industry due to its scaleable merit.

Simulating and stimulating performance: introducing distributed simulation to enhance musical learning and performance

PubMed Central

Williamon, Aaron; Aufegger, Lisa; Eiholzer, Hubert

2014-01-01

Musicians typically rehearse far away from their audiences and in practice rooms that differ significantly from the concert venues in which they aspire to perform. Due to the high costs and inaccessibility of such venues, much current international music training lacks repeated exposure to realistic performance situations, with students learning all too late (or not at all) how to manage performance stress and the demands of their audiences. Virtual environments have been shown to be an effective training tool in the fields of medicine and sport, offering practitioners access to real-life performance scenarios but with lower risk of negative evaluation and outcomes. The aim of this research was to design and test the efficacy of simulated performance environments in which conditions of “real” performance could be recreated. Advanced violin students (n = 11) were recruited to perform in two simulations: a solo recital with a small virtual audience and an audition situation with three “expert” virtual judges. Each simulation contained back-stage and on-stage areas, life-sized interactive virtual observers, and pre- and post-performance protocols designed to match those found at leading international performance venues. Participants completed a questionnaire on their experiences of using the simulations. Results show that both simulated environments offered realistic experience of performance contexts and were rated particularly useful for developing performance skills. For a subset of 7 violinists, state anxiety and electrocardiographic data were collected during the simulated audition and an actual audition with real judges. Results display comparable levels of reported state anxiety and patterns of heart rate variability in both situations, suggesting that responses to the simulated audition closely approximate those of a real audition. The findings are discussed in relation to their implications, both generalizable and individual-specific, for performance training. PMID:24550856

Virtual reality exposure therapy for fear of driving: analysis of clinical characteristics, physiological response, and sense of presence.

PubMed

Costa, Rafael T da; Carvalho, Marcele R de; Ribeiro, Pedro; Nardi, Antonio E

2018-01-01

To investigate the reactions of women with driving phobia to a therapeutic program of scheduled virtual reality exposure treatment (VRET) sessions. The study intervention consisted of a computer game with car-driving scenarios that included several traffic situations. We investigated the participants' sense of presence, subjective distress, and physiological responses during eight virtual-reality exposures. We also evaluated clinical characteristics, driving cognitions, and quality of life in the participants. Thirteen women were selected. Eight were able to complete the protocol. After VRET, there was a decrease in the frequency of distorted thoughts and state anxiety scores, as well as a slight improvement in quality of life. Subjective discomfort scores, heart rate variation, and sense of presence scores confirmed that there was sense of presence in the virtual reality environment. All patients showed some degree of improvement and demonstrated different levels of anxiety in subsequent in vivo driving experiences. Our findings suggest that VRET could be used to facilitate in vivo exposure, because it can induce presence/immersion and reduce anxiety in patients with specific phobia. Furthermore, VRET is not associated with any type of risk.

[The technology of virtual reality resource for formation in public health in the distance: an application for the learning of anthropometric procedures].

PubMed

Barilli, Elomar Christina Vieira Castilho; Ebecken, Nelson Francisco Favilla; Cunha, Gerson Gomes

2011-01-01

This article presents the research developed in the Laboratory of Computational Methods in Engineering of the Federal University of Rio de Janeiro in partnership with the Program of Distance Education of the National School of Public Health Sergio Arouca (ENSP), approaching the integration between Distance Education and Virtual Reality (VR) technology as reply to the public health educative demands that require the development of motor abilities. The application field was the formation of the professionals of the Food and Nutritional Surveillance, as is the base of one of the Brazilian public policies targeting the monitoring of lacks of nutrients. The prototype consists of a complementary virtual environment, supported in VR for the Monitoring of Food and Nutritional specialization course, that is part of the regulate courses of the Distance Education of ENSP approaching the anthropometric procedures for being the most used in the survey of the nutritional state of the population. A total of 189 participants visited the Virtual Environment and it could be evidenced that the VR can be used as a pedagogical resource to collaborate with the processes of professional distance education, that demand the development of motor abilities.

Dynamic-Stark-effect-induced coherent mixture of virtual paths in laser-dressed helium: energetic electron impact excitation

NASA Astrophysics Data System (ADS)

Agueny, Hicham; Makhoute, Abdelkader; Dubois, Alain

2017-06-01

We theoretically investigate quantum virtual path interference caused by the dynamic Stark effect in bound-bound electronic transitions. The effect is studied in an intermediate resonant region and in connection with the energetic electron impact excitation of a helium atom embedded in a weak low-frequency laser field. The process under investigation is dealt with via a Born-Floquet approach. Numerical calculations show a resonant feature in laser-assisted cross sections. The latter is found to be sensitive to the intensity of the laser field dressing. We show that this feature is a signature of quantum beats which result from the coherent mixture of different quantum virtual pathways, and that excitation may follow in order to end up with a common final channel. This mixture arises from the dynamic Stark effect, which produces a set of avoided crossings in laser-dressed states. The effect allows one to coherently control quantum virtual path interference by varying the intensity of the laser field dressing. Our findings suggest that the combination of an energetic electron and a weak laser field is a useful tool for the coherent control of nonadiabatic transitions in an intermediate resonant region.

Virtual commissioning of automated micro-optical assembly

NASA Astrophysics Data System (ADS)

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

Facilitating learning through an international virtual collaborative practice: A case study.

PubMed

Wihlborg, Monne; Friberg, Elizabeth E; Rose, Karen M; Eastham, Linda

2018-02-01

Internationalisation of higher education involving information and communication technology such as e-learning opens opportunities for innovative learning approaches across nations and cultures. Describe a case in practice of collaborative and transformative learning in relation to 'internationalisation on home grounds' with the broader learning objective of 'becoming aware and knowledgeable'. A mutually developed project established a virtual international collaborative exchange for faculty and students using a course management software (MOODLE) and open access technology (Adobe CONNECT). Two research universities in Sweden and the United States. Approximately 90 nursing students from each university per semester over several semesters. A collaborative process to develop a joint learning community to construct a virtual module and learning activity involving academics and nursing students in two countries using principles of meaning construction and negotiated learning. Developed possibilities for dealing with the challenges and finding strategies for a future higher education system that opens dialogues worldwide. Virtual international exchanges open innovative communication and learning contexts across nations and cultures. Internationalisation is so much more than students and teachers' mobility. 'Internationalisation on home grounds' (internationalisation for all) should receive more attention to support faculty and student collaboration, learning, and professional development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fire training in a virtual-reality environment

NASA Astrophysics Data System (ADS)

Freund, Eckhard; Rossmann, Jurgen; Bucken, Arno

2005-03-01

Although fire is very common in our daily environment - as a source of energy at home or as a tool in industry - most people cannot estimate the danger of a conflagration. Therefore it is important to train people in combating fire. Beneath training with propane simulators or real fires and real extinguishers, fire training can be performed in virtual reality, which means a pollution-free and fast way of training. In this paper we describe how to enhance a virtual-reality environment with a real-time fire simulation and visualisation in order to establish a realistic emergency-training system. The presented approach supports extinguishing of the virtual fire including recordable performance data as needed in teletraining environments. We will show how to get realistic impressions of fire using advanced particle-simulation and how to use the advantages of particles to trigger states in a modified cellular automata used for the simulation of fire-behaviour. Using particle systems that interact with cellular automata it is possible to simulate a developing, spreading fire and its reaction on different extinguishing agents like water, CO2 or oxygen. The methods proposed in this paper have been implemented and successfully tested on Cosimir, a commercial robot-and VR-simulation-system.

Two-Time Scale Virtual Sensor Design for Vibration Observation of a Translational Flexible-Link Manipulator Based on Singular Perturbation and Differential Games

PubMed Central

Ju, Jinyong; Li, Wei; Wang, Yuqiao; Fan, Mengbao; Yang, Xuefeng

2016-01-01

Effective feedback control requires all state variable information of the system. However, in the translational flexible-link manipulator (TFM) system, it is unrealistic to measure the vibration signals and their time derivative of any points of the TFM by infinite sensors. With the rigid-flexible coupling between the global motion of the rigid base and the elastic vibration of the flexible-link manipulator considered, a two-time scale virtual sensor, which includes the speed observer and the vibration observer, is designed to achieve the estimation for the vibration signals and their time derivative of the TFM, as well as the speed observer and the vibration observer are separately designed for the slow and fast subsystems, which are decomposed from the dynamic model of the TFM by the singular perturbation. Additionally, based on the linear-quadratic differential games, the observer gains of the two-time scale virtual sensor are optimized, which aims to minimize the estimation error while keeping the observer stable. Finally, the numerical calculation and experiment verify the efficiency of the designed two-time scale virtual sensor. PMID:27801840

Amplitude analysis and the nature of the Z c(3900)

DOE PAGES

Pilloni, A.; Fernandez-Ramirez, C.; Jackura, A.; ...

2017-06-21

The microscopic nature of the XYZ states remains an unsettled topic. We show how a thorough amplitude analysis of the data can help constraining models of these states. Specifically, we consider the case of the Z c(3900) peak and discuss possible scenarios of a QCD state, virtual state, or a kinematical enhancement. Here, we conclude that current data are not precise enough to distinguish between these hypotheses, however, the method we propose, when applied to the forthcoming high-statistics measurements should shed light on the nature of these exotic enhancements.

Amplitude analysis and the nature of the Z c(3900)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilloni, A.; Fernandez-Ramirez, C.; Jackura, A.

The microscopic nature of the XYZ states remains an unsettled topic. We show how a thorough amplitude analysis of the data can help constraining models of these states. Specifically, we consider the case of the Z c(3900) peak and discuss possible scenarios of a QCD state, virtual state, or a kinematical enhancement. Here, we conclude that current data are not precise enough to distinguish between these hypotheses, however, the method we propose, when applied to the forthcoming high-statistics measurements should shed light on the nature of these exotic enhancements.

Agent-Based Modleing of Power Plants Placement to Evaluate the Clean Energy Standard Goal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Omitaomu, Olufemi A

2014-01-01

There is a political push for utilities to supply a specified share of their electricity sales from clean energy resources under the clean energy standard (CES). The goal is to achieve 80% clean energy by 2035. However, there are uncertainties about the ability of the utility industry to ramp up quickly even with the incentives that will be provided. Water availability from the streams is one of the major factors. The contiguous United States is divided into eighteen water regions, and multiple states share water from a single water region. Consequently, water usage decisions made in one state (located upstreammore » of a water region that crosses multiple states) will greatly impact what is available downstream in another state. In this paper, an agent-based modeling approach is proposed to evaluate the clean energy standard goal for water-dependent energy resources. Specifically, using a water region rather than a state boundary as a bounding envelope for the modeling and starting at the headwaters, virtual power plants are placed based on the conditions that there is: (i) suitable land to site a particular power plant, (ii) enough water that meet regulatory guidelines within 20 miles of the suitable land, and (iii) a 20-mile buffer zone from an existing or a virtual power plant. The results obtained are discussed in the context of the proposed clean energy standard goal for states that overlap with one water region.« less

The (virtual) conceptual necessity of quantum probabilities in cognitive psychology.

PubMed

Blutner, Reinhard; beim Graben, Peter

2013-06-01

We propose a way in which Pothos & Busemeyer (P&B) could strengthen their position. Taking a dynamic stance, we consider cognitive tests as functions that transfer a given input state into the state after testing. Under very general conditions, it can be shown that testable properties in cognition form an orthomodular lattice. Gleason's theorem then yields the conceptual necessity of quantum probabilities (QP).

Countering Violent Extremism (CVE) Literature Review

DTIC Science & Technology

2011-03-01

state similar to hypnosis , and this state enables them to relinquish their general reality orientation and have their conscious, critical faculties...terrorist beliefs and perceptions or appreciate the adversary’s construction of reality . He also argues that research should focus on how governments...modern’ style of Islam and its objectives. In many cases this newly aspired form of Islam is communicated virtually and is shaped through the

State Efforts to Promote Reading and Literary Activities in Communities. NGA Center for Best Practices Issue Brief

ERIC Educational Resources Information Center

National Governors Association, 2006

2006-01-01

Rates of reading in the United States have been declining for at least two decades, with the steepest decline occurring among young adults. Fewer than half of adults read literature--poetry, plays, short stories or novels--in their leisure time. At the current rate of decline, literary reading will virtually disappear in the next half-century. Few…

Networking in 2005: Its only Limitations May Be the Boundaries of Imagination.

ERIC Educational Resources Information Center

Butters, Gerry

1998-01-01

Presents insights into the state of networking of the near future. Discusses the promotion of virtual reality in every-day society; the unlimited bandwidth of optical networking; and terrestrial wireless links tethered to optical tools. (AEF)

BACTERIA, BEACHES AND SWIMMABLE WATERS: INTRODUCING VIRTUAL BEACH

EPA Science Inventory

Safe beaches meet water quality standards and are valued for their aesthetics and the recreational opportunities that they afford. In the United States recreational water quality assessments and beach closure decisions are presently based on samples of enterococci or Escherichia ...

Linking Immersive Virtual Field Trips with an Adaptive Learning Platform

NASA Astrophysics Data System (ADS)

Bruce, G.; Taylor, W.; Anbar, A. D.; Semken, S. C.; Buxner, S.; Mead, C.; El-Moujaber, E.; Summons, R. E.; Oliver, C.

2016-12-01

The use of virtual environments in science education has been constrained by the difficulty of guiding a learner's actions within the those environments. In this work, we demonstrate how advances in education software technology allow educators to create interactive learning experiences that respond and adapt intelligently to learner input within the virtual environment. This innovative technology provides a far greater capacity for delivering authentic inquiry-driven educational experiences in unique settings from around the world. Our immersive virtual field trips (iVFT) bring students virtually to geologically significant but inaccessible environments, where they learn through authentic practices of scientific inquiry. In one recent example, students explore the fossil beds in Nilpena, South Australia to learn about the Ediacaran fauna. Students interactively engage in 360° recreations of the environment, uncover the nature of the historical ecosystem by identifying fossils with a dichotomous key, explore actual fossil beds in high resolution imagery, and reconstruct what an ecosystem might have looked like millions of years ago in an interactive simulation. With the new capacity to connect actions within the iVFT to an intelligent tutoring system, these learning experiences can be tracked, guided, and tailored individually to the immediate actions of the student. This new capacity also has great potential for learning designers to take a data-driven approach to lesson improvement and for education researchers to study learning in virtual environments. Thus, we expect iVFT will be fertile ground for novel research. Such iVFT are currently in use in several introductory classes offered online at Arizona State University in anthropology, introductory biology, and astrobiology, reaching thousands of students to date. Drawing from these experiences, we are designing a curriculum for historical geology that will be built around iVFT-based exploration of Earth history.

Virtual in-service training from the librarians' point of view in libraries of medical sciences universities in Tehran.

PubMed

Mohaghegh, Niloofar; Raiesi Dehkordi, Puran; Alibeik, MohammadReza; Ghashghaee, Ahmad; Janbozorgi, Mojgan

2016-01-01

Background: In-service training courses are one of the most available programs that are used to improve the quantity and quality level of the staff services in various organizations, including libraries and information centers. With the advent of new technologies in the field of education, the problems and shortcomings of traditional in-service training courses were replaced with virtual ones. This study aimed to evaluate the virtual in-service training courses from the librarians' point of view in libraries of state universities of medical sciences in Tehran. Methods: This was a descriptive- analytical study. The statistical population consisted of all librarians at libraries of universities of medical sciences in Tehran. Out of 103 librarians working in the libraries under the study, 93 (90%) participated in this study. Data were collected, using a questionnaire. Results: The results revealed that 94/6% of librarians were satisfied to participate in virtual in-service training courses. In this study, only 45 out of 93 participants said that the virtual in-service courses were held in their libraries. Of the participants, 75.6% were satisfied with the length of training courses, and one month seemed to be adequate time duration for the librarians to be more satisfied. The satisfaction level of the individuals who participated in in-service courses of the National Library was moderate to high. A total of 84.4% participants announced that the productivity level of the training courses was moderate to high. The most important problem with which the librarians were confronted in virtual in-service training was the "low speed of the internet and inadequate computer substructures". Conclusion: Effectiveness of in-service training courses from librarians' point of view was at an optimal level in the studied libraries.

Virtual in-service training from the librarians' point of view in libraries of medical sciences universities in Tehran

PubMed Central

Mohaghegh, Niloofar; Raiesi Dehkordi, Puran; Alibeik, MohammadReza; Ghashghaee, Ahmad; Janbozorgi, Mojgan

2016-01-01

Background: In-service training courses are one of the most available programs that are used to improve the quantity and quality level of the staff services in various organizations, including libraries and information centers. With the advent of new technologies in the field of education, the problems and shortcomings of traditional in-service training courses were replaced with virtual ones. This study aimed to evaluate the virtual in-service training courses from the librarians' point of view in libraries of state universities of medical sciences in Tehran. Methods: This was a descriptive- analytical study. The statistical population consisted of all librarians at libraries of universities of medical sciences in Tehran. Out of 103 librarians working in the libraries under the study, 93 (90%) participated in this study. Data were collected, using a questionnaire. Results: The results revealed that 94/6% of librarians were satisfied to participate in virtual in-service training courses. In this study, only 45 out of 93 participants said that the virtual in-service courses were held in their libraries. Of the participants, 75.6% were satisfied with the length of training courses, and one month seemed to be adequate time duration for the librarians to be more satisfied. The satisfaction level of the individuals who participated in in-service courses of the National Library was moderate to high. A total of 84.4% participants announced that the productivity level of the training courses was moderate to high. The most important problem with which the librarians were confronted in virtual in-service training was the "low speed of the internet and inadequate computer substructures". Conclusion: Effectiveness of in-service training courses from librarians’ point of view was at an optimal level in the studied libraries. PMID:28491833

Virtual Reality and Augmented Reality in Plastic Surgery: A Review.

PubMed

Kim, Youngjun; Kim, Hannah; Kim, Yong Oock

2017-05-01

Recently, virtual reality (VR) and augmented reality (AR) have received increasing attention, with the development of VR/AR devices such as head-mounted displays, haptic devices, and AR glasses. Medicine is considered to be one of the most effective applications of VR/AR. In this article, we describe a systematic literature review conducted to investigate the state-of-the-art VR/AR technology relevant to plastic surgery. The 35 studies that were ultimately selected were categorized into 3 representative topics: VR/AR-based preoperative planning, navigation, and training. In addition, future trends of VR/AR technology associated with plastic surgery and related fields are discussed.

One's Colonies: a virtual reality environment of oriental residences

NASA Astrophysics Data System (ADS)

Chi, Catherine

2013-03-01

This paper is a statement about my virtual reality environment project, One's Colonies, and a description of the creative process of the project. I was inspired by the buildings in my hometown-Taiwan, which is really different from the architectural style in the United States. By analyzing the unique style of dwellings in Taiwan, I want to demonstrate how the difference between geography, weather and culture change the appearance of the living space. Through this project I want to express the relationship between architectural style and cultural difference, and how the emotional condition or characteristics of the residents are affected by their residencies.

Virtual Reality and Augmented Reality in Plastic Surgery: A Review

PubMed Central

Kim, Youngjun; Kim, Hannah

2017-01-01

Recently, virtual reality (VR) and augmented reality (AR) have received increasing attention, with the development of VR/AR devices such as head-mounted displays, haptic devices, and AR glasses. Medicine is considered to be one of the most effective applications of VR/AR. In this article, we describe a systematic literature review conducted to investigate the state-of-the-art VR/AR technology relevant to plastic surgery. The 35 studies that were ultimately selected were categorized into 3 representative topics: VR/AR-based preoperative planning, navigation, and training. In addition, future trends of VR/AR technology associated with plastic surgery and related fields are discussed. PMID:28573091

Computer-assisted virtual autopsy using surgical navigation techniques.

PubMed

Ebert, Lars Christian; Ruder, Thomas D; Martinez, Rosa Maria; Flach, Patricia M; Schweitzer, Wolf; Thali, Michael J; Ampanozi, Garyfalia

2015-01-01

OBJECTIVE; Virtual autopsy methods, such as postmortem CT and MRI, are increasingly being used in forensic medicine. Forensic investigators with little to no training in diagnostic radiology and medical laypeople such as state's attorneys often find it difficult to understand the anatomic orientation of axial postmortem CT images. We present a computer-assisted system that permits postmortem CT datasets to be quickly and intuitively resliced in real time at the body to narrow the gap between radiologic imaging and autopsy. Our system is a potentially valuable tool for planning autopsies, showing findings to medical laypeople, and teaching CT anatomy, thus further closing the gap between radiology and forensic pathology.

VERDEX: A virtual environment demonstrator for remote driving applications

NASA Technical Reports Server (NTRS)

Stone, Robert J.

1991-01-01

One of the key areas of the National Advanced Robotics Centre's enabling technologies research program is that of the human system interface, phase 1 of which started in July 1989 and is currently addressing the potential of virtual environments to permit intuitive and natural interactions between a human operator and a remote robotic vehicle. The aim of the first 12 months of this program (to September, 1990) is to develop a virtual human-interface demonstrator for use later as a test bed for human factors experimentation. This presentation will describe the current state of development of the test bed, and will outline some human factors issues and problems for more general discussion. In brief, the virtual telepresence system for remote driving has been designed to take the following form. The human operator will be provided with a helmet-mounted stereo display assembly, facilities for speech recognition and synthesis (using the Marconi Macrospeak system), and a VPL DataGlove Model 2 unit. The vehicle to be used for the purposes of remote driving is a Cybermotion Navmaster K2A system, which will be equipped with a stereo camera and microphone pair, mounted on a motorized high-speed pan-and-tilt head incorporating a closed-loop laser ranging sensor for camera convergence control (currently under contractual development). It will be possible to relay information to and from the vehicle and sensory system via an umbilical or RF link. The aim is to develop an interactive audio-visual display system capable of presenting combined stereo TV pictures and virtual graphics windows, the latter featuring control representations appropriate for vehicle driving and interaction using a graphical 'hand,' slaved to the flex and tracking sensors of the DataGlove and an additional helmet-mounted Polhemus IsoTrack sensor. Developments planned for the virtual environment test bed include transfer of operator control between remote driving and remote manipulation, dexterous end effector integration, virtual force and tactile sensing (also the focus of a current ARRL contract, initially employing a 14-pneumatic bladder glove attachment), and sensor-driven world modeling for total virtual environment generation and operator-assistance in remote scene interrogation.

Assessing students' learning outcomes, self-efficacy and attitudes toward the integration of virtual science laboratory in general physics

NASA Astrophysics Data System (ADS)

Ghatty, Sundara L.

Over the past decade, there has been a dramatic rise in online delivery of higher education in the United States. Recent developments in web technology and access to the internet have led to a vast increase in online courses. For people who work during the day and whose complicated lives prevent them from taking courses on campus, online courses are the only alternatives by which they may achieve their goals in education. The laboratory courses are the major requirements for college and university students who want to pursue degree and certification programs in science. It is noted that there is a lack of laboratory courses in online physics courses. The present study addressed the effectiveness of a virtual science laboratory in physics instruction in terms of learning outcomes, attitudes, and self-efficacy of students in a Historically Black University College. The study included fifty-eight students (36 male and 22 female) of different science majors who were enrolled in a general physics laboratory course. They were divided into virtual and traditional groups. Three experiments were selected from the syllabus. The traditional group performed one experiment in a traditional laboratory, while the virtual group performed the same experiment in a virtual laboratory. For the second experiment, the use of laboratories by both groups was exchanged. Learner's Assessment Test (LAT), Attitudes Toward Physics Laboratories (ATPL), and Self-Efficacy Survey (SES) instruments were used. Additionally, quantitative methods such as an independent t-test, a paired t-test, and correlation statistics were used to analyze the data. The results of the first experiment indicated the learning outcomes were higher in the Virtual Laboratory than in the traditional laboratory, whereas there was no significant difference in learning outcomes with either type of lab instruction. However, significant self-efficacy gains were observed. Students expressed positive attitudes in terms of liking as well as interests in performing experiments in virtual laboratories. No gender differences were observed in learning outcomes or self-efficacy. The results of the study indicated that virtual laboratories may be a substitute for traditional laboratories to some extent, and may play a vital role in online science courses.

Mathematical Analysis of Vehicle Delivery Scale of Bike-Sharing Rental Nodes

NASA Astrophysics Data System (ADS)

Zhai, Y.; Liu, J.; Liu, L.

2018-04-01

Aiming at the lack of scientific and reasonable judgment of vehicles delivery scale and insufficient optimization of scheduling decision, based on features of the bike-sharing usage, this paper analyses the applicability of the discrete time and state of the Markov chain, and proves its properties to be irreducible, aperiodic and positive recurrent. Based on above analysis, the paper has reached to the conclusion that limit state (steady state) probability of the bike-sharing Markov chain only exists and is independent of the initial probability distribution. Then this paper analyses the difficulty of the transition probability matrix parameter statistics and the linear equations group solution in the traditional solving algorithm of the bike-sharing Markov chain. In order to improve the feasibility, this paper proposes a "virtual two-node vehicle scale solution" algorithm which considered the all the nodes beside the node to be solved as a virtual node, offered the transition probability matrix, steady state linear equations group and the computational methods related to the steady state scale, steady state arrival time and scheduling decision of the node to be solved. Finally, the paper evaluates the rationality and accuracy of the steady state probability of the proposed algorithm by comparing with the traditional algorithm. By solving the steady state scale of the nodes one by one, the proposed algorithm is proved to have strong feasibility because it lowers the level of computational difficulty and reduces the number of statistic, which will help the bike-sharing companies to optimize the scale and scheduling of nodes.

Time evolution, Lamb shift, and emission spectra of spontaneous emission of two identical atoms

NASA Astrophysics Data System (ADS)

Wang, Da-Wei; Li, Zheng-Hong; Zheng, Hang; Zhu, Shi-Yao

2010-04-01

A unitary transformation method is used to investigate the dynamic evolution of two multilevel atoms, in the basis of symmetric and antisymmetric states, with one atom being initially prepared in the first excited state and the other in the ground state. The unitary transformation guarantees that our calculations are based on the ground state of the atom-field system and the self-energy is subtracted at the beginning. The total Lamb shifts of the symmetric and antisymmetric states are divided into transformed shift and dynamic shift. The transformed shift is due to emitting and reabsorbing of virtual photons, by a single atom (nondynamic single atomic shift) and between the two atoms (quasi-static shift). The dynamic shift is due to the emitting and reabsorbing of real photons, by a single atom (dynamic single atomic shift) and between the two atoms (dynamic interatomic shift). The emitting and reabsorbing of virtual and real photons between the two atoms result in the interatomic shift, which does not exist for the one-atom case. The spectra at the long-time limit are calculated. If the distance between the two atoms is shorter than or comparable to the wavelength, the strong coupling between the two atoms splits the spectrum into two peaks, one from the symmetric state and the other from the antisymmetric state. The origin of the red or blue shifts for the symmetric and antisymmetric states mainly lies in the negative or positive interaction energy between the two atoms. In the investigation of the short time evolution, we find the modification of the effective density of states by the interaction between two atoms can modulate the quantum Zeno and quantum anti-Zeno effects in the decays of the symmetric and antisymmetric states.

A Systematic Review to Uncover a Universal Protocol for Accuracy Assessment of 3-Dimensional Virtually Planned Orthognathic Surgery.

PubMed

Gaber, Ramy M; Shaheen, Eman; Falter, Bart; Araya, Sebastian; Politis, Constantinus; Swennen, Gwen R J; Jacobs, Reinhilde

2017-11-01

The aim of this study was to systematically review methods used for assessing the accuracy of 3-dimensional virtually planned orthognathic surgery in an attempt to reach an objective assessment protocol that could be universally used. A systematic review of the currently available literature, published until September 12, 2016, was conducted using PubMed as the primary search engine. We performed secondary searches using the Cochrane Database, clinical trial registries, Google Scholar, and Embase, as well as a bibliography search. Included articles were required to have stated clearly that 3-dimensional virtual planning was used and accuracy assessment performed, along with validation of the planning and/or assessment method. Descriptive statistics and quality assessment of included articles were performed. The initial search yielded 1,461 studies. Only 7 studies were included in our review. An important variability was found regarding methods used for 1) accuracy assessment of virtually planned orthognathic surgery or 2) validation of the tools used. Included studies were of moderate quality; reviewers' agreement regarding quality was calculated to be 0.5 using the Cohen κ test. On the basis of the findings of this review, it is evident that the literature lacks consensus regarding accuracy assessment. Hence, a protocol is suggested for accuracy assessment of virtually planned orthognathic surgery with the lowest margin of error. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

Non-resonant excitation of rare-earth ions via virtual Auger process

NASA Astrophysics Data System (ADS)

Yassievich, I. N.

2011-05-01

The luminescence of rare-earth ions (REI) is often intensified by defects associated with REIs or excitons bound to these defects. In this paper we show that the presence of such a state opens the possibility of non-resonance optical pumping via the process involving virtual Auger transition. It is the second order perturbation process when an electron arrives in an virtual intermediate state due to the optical transition (the first step) and the Auger transition is the second one. We have calculated the cross-section of such an excitation process when the optical transition is accompanied by creation of the exciton bound to the defect associated with REI and obtained a simple analytical expression for the cross-section. The excess energy of the excitation quanta is taken away by multiphonon emission. The electron-phonon interaction with local phonon vibrations of the bound exciton is assumed to determine the multiphonon process. It is shown that the probability of the process under study exceeds considerably the probability of direct optical 4f-4f absorption even in the case when the energy distance between the excitation quantum energy and the exciton energy is about 0.1 of the exciton energy. The excitation mechanism considered leads to the appearance of a broad unsymmetrical band in the excitation spectrum with the red side much wider and flatter than the blue one.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Song; Wang, Yihong; Luo, Wei

In virtualized data centers, virtual disk images (VDIs) serve as the containers in virtual environment, so their access performance is critical for the overall system performance. Some distributed VDI chunk storage systems have been proposed in order to alleviate the I/O bottleneck for VM management. As the system scales up to a large number of running VMs, however, the overall network traffic would become unbalanced with hot spots on some VMs inevitably, leading to I/O performance degradation when accessing the VMs. Here, we propose an adaptive and collaborative VDI storage system (ACStor) to resolve the above performance issue. In comparisonmore » with the existing research, our solution is able to dynamically balance the traffic workloads in accessing VDI chunks, based on the run-time network state. Specifically, compute nodes with lightly loaded traffic will be adaptively assigned more chunk access requests from remote VMs and vice versa, which can effectively eliminate the above problem and thus improves the I/O performance of VMs. We also implement a prototype based on our ACStor design, and evaluate it by various benchmarks on a real cluster with 32 nodes and a simulated platform with 256 nodes. Experiments show that under different network traffic patterns of data centers, our solution achieves up to 2-8 performance gain on VM booting time and VM’s I/O throughput, in comparison with the other state-of-the-art approaches.« less

Application of virtual reality for crew mental health in extended-duration space missions

NASA Astrophysics Data System (ADS)

Salamon, Nick; Grimm, Jonathan M.; Horack, John M.; Newton, Elizabeth K.

2018-05-01

Human exploration of the solar system brings a host of environmental and engineering challenges. Among the most important factors in crew health and human performance is the preservation of mental health. The mental well-being of astronaut crews is a significant issue affecting the success of long-duration space missions, such as habitation on or around the Moon, Mars exploration, and eventual colonization of the solar system. If mental health is not properly addressed, these missions will be at risk. Upkeep of mental health will be especially difficult on long duration missions because many of the support systems available to crews on shorter missions will not be available. In this paper, we examine the use of immersive virtual reality (VR) simulations to maintain healthy mental states in astronaut crews who are removed from the essential comforts typically associated with terrestrial life. Various methods of simulations and their administration are analyzed in the context of current research and knowledge in the fields of psychology, medicine, and space sciences, with a specific focus on the environment faced by astronauts on long-term missions. The results of this investigation show that virtual reality should be considered a plausible measure in preventing mental state deterioration in astronauts, though more work is needed to provide a comprehensive view of the effectiveness and administration of VR methods.

Virtual containment system for composite flywheels

NASA Astrophysics Data System (ADS)

Shiue, Fuh-Wen

2001-07-01

There is much interest in advanced composite flywheel systems for use on satellites mainly because of the potential for considerable weight savings associated with combined energy and momentum management. The additional weight of a containment system needed to protect the satellite in the event of a flywheel failure, however, could negate the potential savings. Therefore, the development of a condition monitoring and virtual containment system is essential to ensure the wide acceptance of flywheel batteries for spacecraft applications. A virtual containment system is a near real-time condition monitoring system, plus additional logic to adjust the operating conditions (maximum rotational speed) accordingly when a flaw or fault is detected. Flaws of primary interest in this study are those unique to composite flywheels, such as delamination and debonding of interfaces. Such flaws change the balance state of a flywheel through small, but detectable, motion of the mass center and principal axes of inertia. A proposed monitoring technique determines the existence and the extent of such flaws by a method similar to the influence-coefficient rotor balancing method. Because of the speed-dependence of the imbalance caused by elastic flaws, a normalized imbalance change, which is a direct measure of the flaw size, was defined. To account for the possibility that flaw growth could actually improve the balance state of a rotor, a new concept of accumulated imbalance change was also introduced. Laboratory tests showed the proposed method was able to detect small simulated flaws that result in as little as 2--3 microns of mass center movement. Fracture mechanics concepts were used to evaluate the severity and growth rate of the detected flaw. An interesting discovery that coincided with some experimental observations reported in the literature was the energy release rate reduction with a large crack. This finding indicates a possible stress relief and crack arrest when a circumferential crack grows over certain size. This phenomenon is largely due to crack curvature unique to filament-wound composite flywheels. Several virtual containment strategies were investigated numerically to demonstrate the feasibility of virtual containment systems. Once a flaw is detected during flywheel operation, the maximum operating speed can be reduced to prevent catastrophic failure, achieve a specific design life, and maximize energy storage capacity over the remaining life. A numerical example showed 4--5 times of improvement in cumulative energy storage through lifetime with a virtual containment. A closed-loop speed controller using condition monitoring sensor feedback was investigated numerically to account for possible imperfection of the fracture mechanics model. Finally, an integrated virtual containment system without any complex fracture mechanics analysis was also developed and successfully demonstrated experimentally.

The effect of visual and interaction fidelity on spatial cognition in immersive virtual environments.

PubMed

Mania, Katerina; Wooldridge, Dave; Coxon, Matthew; Robinson, Andrew

2006-01-01

Accuracy of memory performance per se is an imperfect reflection of the cognitive activity (awareness states) that underlies performance in memory tasks. The aim of this research is to investigate the effect of varied visual and interaction fidelity of immersive virtual environments on memory awareness states. A between groups experiment was carried out to explore the effect of rendering quality on location-based recognition memory for objects and associated states of awareness. The experimental space, consisting of two interconnected rooms, was rendered either flat-shaded or using radiosity rendering. The computer graphics simulations were displayed on a stereo head-tracked Head Mounted Display. Participants completed a recognition memory task after exposure to the experimental space and reported one of four states of awareness following object recognition. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection, and also included guesses. Experimental results revealed variations in the distribution of participants' awareness states across conditions while memory performance failed to reveal any. Interestingly, results revealed a higher proportion of recollections associated with mental imagery in the flat-shaded condition. These findings comply with similar effects revealed in two earlier studies summarized here, which demonstrated that the less "naturalistic" interaction interface or interface of low interaction fidelity provoked a higher proportion of recognitions based on visual mental images.

Resting-State fMRI Activity Predicts Unsupervised Learning and Memory in an Immersive Virtual Reality Environment

PubMed Central

Wong, Chi Wah; Olafsson, Valur; Plank, Markus; Snider, Joseph; Halgren, Eric; Poizner, Howard; Liu, Thomas T.

2014-01-01

In the real world, learning often proceeds in an unsupervised manner without explicit instructions or feedback. In this study, we employed an experimental paradigm in which subjects explored an immersive virtual reality environment on each of two days. On day 1, subjects implicitly learned the location of 39 objects in an unsupervised fashion. On day 2, the locations of some of the objects were changed, and object location recall performance was assessed and found to vary across subjects. As prior work had shown that functional magnetic resonance imaging (fMRI) measures of resting-state brain activity can predict various measures of brain performance across individuals, we examined whether resting-state fMRI measures could be used to predict object location recall performance. We found a significant correlation between performance and the variability of the resting-state fMRI signal in the basal ganglia, hippocampus, amygdala, thalamus, insula, and regions in the frontal and temporal lobes, regions important for spatial exploration, learning, memory, and decision making. In addition, performance was significantly correlated with resting-state fMRI connectivity between the left caudate and the right fusiform gyrus, lateral occipital complex, and superior temporal gyrus. Given the basal ganglia's role in exploration, these findings suggest that tighter integration of the brain systems responsible for exploration and visuospatial processing may be critical for learning in a complex environment. PMID:25286145

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newton, Marshall D.

Extension of the Förster analogue for the ET rate constant (based on virtual intermediate electron detachment or attachment states) with inclusion of site–site correlation due to coulomb terms associated with solvent reorganization energy and the driving force, has been developed and illustrated for a simple three-state, two-mode model. Furthermore, the model is applicable to charge separation (CS), recombination (CR), and shift (CSh) ET processes, with or without an intervening bridge. The model provides a unified perspective on the role of virtual intermediate states in accounting for the thermal Franck–Condon weighted density of states (FCWD), the gaps controlling superexchange coupling, andmore » mean absolute redox potentials, with full accommodation of site–site coulomb interactions. We analyzed two types of correlation: aside from the site–site correlation due to coulomb interactions, we have emphasized the intrinsic “nonorthogonality” which generally pertains to reaction coordinates (RCs) for different ET processes involving multiple electronic states, as may be expressed by suitably defined direction cosines (cos(θ)). A pair of RCs may be nonorthogonal even when the site–site coulomb correlations are absent. While different RCs are linearly independent in the mathematical sense for all θ ≠ 0°, they are independent in the sense of being “uncorrelated” only in the limit of orthogonality (θ = 90°). There is application to more than two coordinates is straightforward and may include both discrete and continuum contributions.« less

Virtual reality for treatment compliance for people with serious mental illness.

PubMed

Välimäki, Maritta; Hätönen, Heli M; Lahti, Mari E; Kurki, Marjo; Hottinen, Anja; Metsäranta, Kiki; Riihimäki, Tanja; Adams, Clive E

2014-10-08

Virtual reality (VR) is computerised real-time technology, which can be used an alternative assessment and treatment tool in the mental health field. Virtual reality may take different forms to simulate real-life activities and support treatment. To investigate the effects of virtual reality to support treatment compliance in people with serious mental illness. We searched the Cochrane Schizophrenia Group Trials Register (most recent, 17th September 2013) and relevant reference lists. All relevant randomised studies comparing virtual reality with standard care for those with serious mental illnesses. We defined virtual reality as a computerised real-time technology using graphics, sound and other sensory input, which creates the interactive computer-mediated world as a therapeutic tool. All review authors independently selected studies and extracted data. For homogeneous dichotomous data the risk difference (RD) and the 95% confidence intervals (CI) were calculated on an intention-to-treat basis. For continuous data, we calculated mean differences (MD). We assessed risk of bias and created a 'Summary of findings' table using the GRADE approach. We identified three short-term trials (total of 156 participants, duration five to 12 weeks). Outcomes were prone to at least a moderate risk of overestimating positive effects. We found that virtual reality had little effects regarding compliance (3 RCTs, n = 156, RD loss to follow-up 0.02 CI -0.08 to 0.12, low quality evidence), cognitive functioning (1 RCT, n = 27, MD average score on Cognistat 4.67 CI -1.76 to 11.10, low quality evidence), social skills (1 RCT, n = 64, MD average score on social problem solving SPSI-R (Social Problem Solving Inventory - Revised) -2.30 CI -8.13 to 3.53, low quality evidence), or acceptability of intervention (2 RCTs, n = 92, RD 0.05 CI -0.09 to 0.19, low quality evidence). There were no data reported on mental state, insight, behaviour, quality of life, costs, service utilisation, or adverse effects. Satisfaction with treatment - measured using an un-referenced scale - and reported as "interest in training" was better for the virtual reality group (1 RCT, n = 64, MD 6.00 CI 1.39 to 10.61,low quality evidence). There is no clear good quality evidence for or against using virtual reality for treatment compliance among people with serious mental illness. If virtual reality is used, the experimental nature of the intervention should be clearly explained. High-quality studies should be undertaken in this area to explore any effects of this novel intervention and variations of approach.

Virtual reality in surgery and medicine.

PubMed

Chinnock, C

1994-01-01

This report documents the state of development of enhanced and virtual reality-based systems in medicine. Virtual reality systems seek to simulate a surgical procedure in a computer-generated world in order to improve training. Enhanced reality systems seek to augment or enhance reality by providing improved imaging alternatives for specific patient data. Virtual reality represents a paradigm shift in the way we teach and evaluate the skills of medical personnel. Driving the development of virtual reality-based simulators is laparoscopic abdominal surgery, where there is a perceived need for better training techniques; within a year, systems will be fielded for second-year residency students. Further refinements over perhaps the next five years should allow surgeons to evaluate and practice new techniques in a simulator before using them on patients. Technical developments are rapidly improving the realism of these machines to an amazing degree, as well as bringing the price down to affordable levels. In the next five years, many new anatomical models, procedures, and skills are likely to become available on simulators. Enhanced reality systems are generally being developed to improve visualization of specific patient data. Three-dimensional (3-D) stereovision systems for endoscopic applications, head-mounted displays, and stereotactic image navigation systems are being fielded now, with neurosurgery and laparoscopic surgery being major driving influences. Over perhaps the next five years, enhanced and virtual reality systems are likely to merge. This will permit patient-specific images to be used on virtual reality simulators or computer-generated landscapes to be input into surgical visualization instruments. Percolating all around these activities are developments in robotics and telesurgery. An advanced information infrastructure eventually will permit remote physicians to share video, audio, medical records, and imaging data with local physicians in real time. Surgical robots are likely to be deployed for specific tasks in the operating room (OR) and to support telesurgery applications. Technical developments in robotics and motion control are key components of many virtual reality systems. Since almost all of the virtual reality and enhanced reality systems will be digitally based, they are also capable of being put "on-line" for tele-training, consulting, and even surgery. Advancements in virtual and enhanced reality systems will be driven in part by consumer applications of this technology. Many of the companies that will supply systems for medical applications are also working on commercial products. A big consumer hit can benefit the entire industry by increasing volumes and bringing down costs.(ABSTRACT TRUNCATED AT 400 WORDS)

Astronomical virtual observatory and the place and role of Bulgarian one

NASA Astrophysics Data System (ADS)

Petrov, Georgi; Dechev, Momchil; Slavcheva-Mihova, Luba; Duchlev, Peter; Mihov, Bojko; Kochev, Valentin; Bachev, Rumen

2009-07-01

Virtual observatory could be defined as a collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. Several countries have initiated national virtual observatory programs that combine existing databases from ground-based and orbiting observatories, scientific facility especially equipped to detect and record naturally occurring scientific phenomena. As a result, data from all the world's major observatories will be available to all users and to the public. This is significant not only because of the immense volume of astronomical data but also because the data on stars and galaxies has been compiled from observations in a variety of wavelengths-optical, radio, infrared, gamma ray, X-ray and more. In a virtual observatory environment, all of this data is integrated so that it can be synthesized and used in a given study. During the autumn of the 2001 (26.09.2001) six organizations from Europe put the establishment of the Astronomical Virtual Observatory (AVO)-ESO, ESA, Astrogrid, CDS, CNRS, Jodrell Bank (Dolensky et al., 2003). Its aims have been outlined as follows: - To provide comparative analysis of large sets of multiwavelength data; - To reuse data collected by a single source; - To provide uniform access to data; - To make data available to less-advantaged communities; - To be an educational tool. The Virtual observatory includes: - Tools that make it easy to locate and retrieve data from catalogues, archives, and databases worldwide; - Tools for data analysis, simulation, and visualization; - Tools to compare observations with results obtained from models, simulations and theory; - Interoperability: services that can be used regardless of the clients computing platform, operating system and software capabilities; - Access to data in near real-time, archived data and historical data; - Additional information - documentation, user-guides, reports, publications, news and so on. This large growth of astronomical data and the necessity of an easy access to those data led to the foundation of the International Virtual Observatory Alliance (IVOA). IVOA was formed in June 2002. By January 2005, the IVOA has grown to include 15 funded VO projects from Australia, Canada, China, Europe, France, Germany, Hungary, India, Italy, Japan, Korea, Russia, Spain, the United Kingdom, and the United States. At the time being Bulgaria is not a member of European Astronomical Virtual Observatory and as the Bulgarian Virtual Observatory is not a legal entity, we are not members of IVOA. The main purpose of the project is Bulgarian Virtual Observatory to join the leading virtual astronomical institutions in the world. Initially the Bulgarian Virtual Observatory will include: - BG Galaxian virtual observatory; - BG Solar virtual observatory; - Department Star clusters of IA, BAS; - WFPDB group of IA, BAS. All available data will be integrated in the Bulgarian centers of astronomical data, conducted by the Wide Field Plate Archive data centre. For the above purpose POSTGRESQL or/and MySQL will be installed on the server of BG-VO and SAADA tools, ESO-MEX or/and DAL ToolKit to transform our FITS files in standard format for VO-tools. A part of the participants was acquainted with the principles of these products during the "Days of virtual observatory in Sofia" January, 2008.

Online Course Use in Iowa and Wisconsin Public Schools: The Results of Two Statewide Surveys. Stated Briefly. REL 2015-090

ERIC Educational Resources Information Center

Clements, Margaret; Pazzaglia, Angela M.; Stafford, Erin

2015-01-01

This "Stated Briefly" report is a companion piece that summarizes the results of another report of the same name. The purpose of the study conducted by REL Midwest in partnership with the Midwest Virtual Education Research Alliance was to develop and administer a survey to describe online course use in Iowa and Wisconsin brick-and-mortar…

A Comparison of the Effects of Classroom and Multi-User Virtual Environments on the Perceived Speaking Anxiety of Adult Post-Secondary English Language Learners

ERIC Educational Resources Information Center

Abal, Abdulaziz

2013-01-01

The population of English Language Learners (ELLs) globally has been increasing substantially every year. In the United States alone, adult ELLs are the fastest growing portion of learners in adult education programs (Yang, 2005). There is a significant need to improve the teaching of English to ELLs in the United States and other English-speaking…

Teaching about Global Human Rights for Global Citizenship: Action Research in the Social Studies Curriculum

ERIC Educational Resources Information Center

Gaudelli, William; Fernekes, William R.

2004-01-01

What are my rights? What can I do if my rights are violated? Who has the right to do that?Questions like these are easily articulated by most students in the United States because from an early age they frequently receive socially diffused rights messages in virtually every aspect of their lives. The United States has been described as a highly…

Vital Interests, Virtual Threats: Reconciling International Law with Information Warfare and United States Security

DTIC Science & Technology

1999-05-01

and status. Previously, natural resources and physical labor were broad measurements of the wealth of a business , a corporation , or a state.19 With...30 5 Global Grid......................................................................................................32 6 Components of ...John D. Jones and Marc F. Griesbach, eds., Just War Theory in the Nuclear Age (New York, N.Y.: University Press of America, 1985), 3-34; see also A.J

Vital Interests, Virtual Threats: Reconciling International Law with Information Warfare and United States Security

DTIC Science & Technology

2001-03-01

natural resources and physical labor were broad meas­ urements of the wealth of a business , a corporation , or a state.18 With the globalization of ...5 Global Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6 Components of Information Superiority...point where the source of attacks can be verified. 6 Notes 1. John D. Jones and Marc F. Griesbach, eds., Just War Theory in the Nuclear Age (Lanham

Web-Based Army Repeatable Lesson in Operational Combat (WARLOC)

DTIC Science & Technology

2014-06-01

United States Army B.A., St. John’s University, 1996 Austin T. Starken Captain, United States Army B.S., Florida Institute of Technology, 2005 Submitted...Simulation Games. New York, NY: Continuum International Publishing Group, 2012. [25] J. Peterson , Playing at the World: A History of Simulating Wars, People...Serious Games and Virtual Worlds in Education, Professional Development, and Healthcare. Ed. Hershey , PA: IGI Global, 2013. [Online]. Available

Virtual reality walking and dopamine: opening new doorways to understanding freezing of gait in Parkinson's disease.

PubMed

Matar, E; Shine, J M; Naismith, S L; Lewis, S J G

2014-09-15

Freezing of gait (FOG) is a disabling form of gait disturbance that is common in the advanced stages of Parkinson's disease (PD). Despite its prevalence, methods of studying and assessing FOG are limited. We have previously shown that a virtual reality paradigm was able to distinguish between those who report FOG ("freezers") and those who do not report FOG ("non-freezers"). In this paradigm, 'freezers' were found to have prolonged footstep latency in response to known triggers of FOG including doorways, sliding doors and dual-tasking. In this study, we employed the same paradigm to assess performance of 27 freezers and 14 non-freezers in their clinical 'on' and 'off' medication states. In this study, only participants in the freezing group demonstrated statistically significant increases in latencies experienced in the 'off' state compared to the 'on' state in response to wide and narrow doorways and the opening of a sliding door. By contrast, these behavioral differences were not apparent in non-freezers. Furthermore the delay was specific to environmental cues and was not due to generalized slowing in the 'off' state. The findings suggest that this motor delay when processing environmentally salient cues is specific to freezers and is partially mediated by dopamine-dependent neurocircuitry. Copyright © 2014 Elsevier B.V. All rights reserved.

Testing helicity-dependent γγ → γγ scattering in the region of MeV

NASA Astrophysics Data System (ADS)

Homma, K.; Matsuura, K.; Nakajima, K.

2016-01-01

Light-by-light scatterings contain rich information on photon coupling to virtual and real particle states. In the context of quantum electrodynamics (QED), photons can couple to a virtual e^+e^- pair. Photons may also couple to known resonance states in the context of quantum chromodyanmics and electroweak dynamics in higher energy domains and possibly couple to unknown resonance states beyond the standard model. The perturbative QED calculations manifestly predict a maximized cross section at the MeV scale; however, no example of exact real-photon-real-photon scattering has yet been observed. Hence, we propose direct measurement with the maximized cross section at the center-of-mass system energy of 1-2 MeV to establish a firm footing at the MeV scale. Given current state of the art high power lasers, helicity-dependent elastic scattering may be observed at a reasonable rate, if a photon-photon collider exploiting γ -rays generated by the inverse nonlinear Compton process with electrons delivered from laser-plasma accelerators (LPA) are properly designed. We show that such verification is feasible in a table-top scale collider, which may be an unprecedented breakthrough in particle accelerators for basic physics research in contrast to energy frontier colliders.

Are the effects of Unreal violent video games pronounced when playing with a virtual reality system?

PubMed

Arriaga, Patrícia; Esteves, Francisco; Carneiro, Paula; Monteiro, Maria Benedicta

2008-01-01

This study was conducted to analyze the short-term effects of violent electronic games, played with or without a virtual reality (VR) device, on the instigation of aggressive behavior. Physiological arousal (heart rate (HR)), priming of aggressive thoughts, and state hostility were also measured to test their possible mediation on the relationship between playing the violent game (VG) and aggression. The participants--148 undergraduate students--were randomly assigned to four treatment conditions: two groups played a violent computer game (Unreal Tournament), and the other two a non-violent game (Motocross Madness), half with a VR device and the remaining participants on the computer screen. In order to assess the game effects the following instruments were used: a BIOPAC System MP100 to measure HR, an Emotional Stroop task to analyze the priming of aggressive and fear thoughts, a self-report State Hostility Scale to measure hostility, and a competitive reaction-time task to assess aggressive behavior. The main results indicated that the violent computer game had effects on state hostility and aggression. Although no significant mediation effect could be detected, regression analyses showed an indirect effect of state hostility between playing a VG and aggression. Copyright 2008 Wiley-Liss, Inc.

Characteristics of social anxiety from virtual interpersonal interactions in patients with schizophrenia.

PubMed

Park, Il Ho; Kim, Jae-Jin; Ku, Jeonghun; Jang, Hee Jeong; Park, Sung-Hyouk; Kim, Chan-Hyung; Kim, In Young; Kim, Sun I

2009-01-01

Dysfunctional emotional processing affects social functioning in patients with schizophrenia. However, the relationship between emotional perception and response in social interaction has not been elucidated. Twenty-seven patients with schizophrenia and 27 normal controls performed a virtual reality social encounter task in which they introduced themselves to avatars expressing happy, neutral, or angry emotions while verbal response duration and onset time were measured and perception of emotional valence and arousal, and state anxiety were rated afterwards. Self-reported trait-affective scale scores and the Positive and Negative Syndrome Scale (PANSS) ratings were also obtained. Patient group significantly underestimated the valence and arousal of angry emotions expressed by an avatar. While valence and arousal ratings of happy avatars were comparable between groups, patient group reported significantly higher state anxiety in response to happy avatars. State anxiety ratings significantly decreased from encounters with neutral to happy avatars in normal controls while no significant decrease was observed in the patient group. The Social Anhedonia Scale and PANSS negative symptom subscale scores (blunted affect, emotional withdrawal, and passive/ apathetic social withdrawal items) were significantly correlated with state anxiety ratings of the encounters with happy avatars. These results suggest that patients with schizophrenia have interference with the experience of pleasure in social interactions which may be associated with negative symptoms.

Anemometer performance at fire-weather stations.

Treesearch

Donald A. Haines; John S. Frost

1984-01-01

A survey of 142 fire-weather stations in the Northeastern United States showed that, although maintenance was generally satisfactory, calibration or testing of anemometers was virtually nonexistent. We tested these anemometers using portable equipment that we designed and found the deviations from true wind speed.

FPI Cohort Reports: Canada/CAUBO

ERIC Educational Resources Information Center

Dew, George

2013-01-01

CAUBO--the Canadian Association of University Business Officers--is a volunteer-driven organization that represents the administrative function of virtually all Canadian universities (CAUBO is the Canadian counterpart to NACUBO in the United States). Member committees provide direction and subject matter expertise, with each committee typically…

75 FR 25113 - High-Cost Universal Service Support, Federal-State Joint Board on Universal Service, Lifeline and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-07

... is a virtual reality,'' because 92.8 percent of households surveyed in Puerto Rico had wireline or... providing service,'' so ``[i]t need not reflect physical reality in all aspects if it produces `reasonably...

The route of the Three Notch'd Road : a preliminary report.

DOT National Transportation Integrated Search

1975-01-01

Of the many colonial roads constructed during the eighteenth century as settlement moved across Piedmont and Southside Virginia, a few have remained virtually intact and in service as state roads over most of their length. One of the most significant...

Low-cost warning device industry assessment : research results.

DOT National Transportation Integrated Search

2011-12-01

Virtually all of the grade crossing train detection and warning systems in the United States use a variant of the track circuit technology developed over a century ago. Track circuits have evolved through the years, but the design and principles of o...

Fast mental states decoding in mixed reality.

PubMed

De Massari, Daniele; Pacheco, Daniel; Malekshahi, Rahim; Betella, Alberto; Verschure, Paul F M J; Birbaumer, Niels; Caria, Andrea

2014-01-01

The combination of Brain-Computer Interface (BCI) technology, allowing online monitoring and decoding of brain activity, with virtual and mixed reality (MR) systems may help to shape and guide implicit and explicit learning using ecological scenarios. Real-time information of ongoing brain states acquired through BCI might be exploited for controlling data presentation in virtual environments. Brain states discrimination during mixed reality experience is thus critical for adapting specific data features to contingent brain activity. In this study we recorded electroencephalographic (EEG) data while participants experienced MR scenarios implemented through the eXperience Induction Machine (XIM). The XIM is a novel framework modeling the integration of a sensing system that evaluates and measures physiological and psychological states with a number of actuators and effectors that coherently reacts to the user's actions. We then assessed continuous EEG-based discrimination of spatial navigation, reading and calculation performed in MR, using linear discriminant analysis (LDA) and support vector machine (SVM) classifiers. Dynamic single trial classification showed high accuracy of LDA and SVM classifiers in detecting multiple brain states as well as in differentiating between high and low mental workload, using a 5 s time-window shifting every 200 ms. Our results indicate overall better performance of LDA with respect to SVM and suggest applicability of our approach in a BCI-controlled MR scenario. Ultimately, successful prediction of brain states might be used to drive adaptation of data representation in order to boost information processing in MR.

Fast mental states decoding in mixed reality

PubMed Central

De Massari, Daniele; Pacheco, Daniel; Malekshahi, Rahim; Betella, Alberto; Verschure, Paul F. M. J.; Birbaumer, Niels; Caria, Andrea

2014-01-01

The combination of Brain-Computer Interface (BCI) technology, allowing online monitoring and decoding of brain activity, with virtual and mixed reality (MR) systems may help to shape and guide implicit and explicit learning using ecological scenarios. Real-time information of ongoing brain states acquired through BCI might be exploited for controlling data presentation in virtual environments. Brain states discrimination during mixed reality experience is thus critical for adapting specific data features to contingent brain activity. In this study we recorded electroencephalographic (EEG) data while participants experienced MR scenarios implemented through the eXperience Induction Machine (XIM). The XIM is a novel framework modeling the integration of a sensing system that evaluates and measures physiological and psychological states with a number of actuators and effectors that coherently reacts to the user's actions. We then assessed continuous EEG-based discrimination of spatial navigation, reading and calculation performed in MR, using linear discriminant analysis (LDA) and support vector machine (SVM) classifiers. Dynamic single trial classification showed high accuracy of LDA and SVM classifiers in detecting multiple brain states as well as in differentiating between high and low mental workload, using a 5 s time-window shifting every 200 ms. Our results indicate overall better performance of LDA with respect to SVM and suggest applicability of our approach in a BCI-controlled MR scenario. Ultimately, successful prediction of brain states might be used to drive adaptation of data representation in order to boost information processing in MR. PMID:25505878

Large-Scale Land Acquisition and Its Effects on the Water Balance in Investor and Host Countries

PubMed Central

Breu, Thomas; Bader, Christoph; Messerli, Peter; Heinimann, Andreas; Rist, Stephan; Eckert, Sandra

2016-01-01

This study examines the validity of the assumption that international large-scale land acquisition (LSLA) is motivated by the desire to secure control over water resources, which is commonly referred to as ‘water grabbing’. This assumption was repeatedly expressed in recent years, ascribing the said motivation to the Gulf States in particular. However, it must be considered of hypothetical nature, as the few global studies conducted so far focused primarily on the effects of LSLA on host countries or on trade in virtual water. In this study, we analyse the effects of 475 intended or concluded land deals recorded in the Land Matrix database on the water balance in both host and investor countries. We also examine how these effects relate to water stress and how they contribute to global trade in virtual water. The analysis shows that implementation of the LSLAs in our sample would result in global water savings based on virtual water trade. At the level of individual LSLA host countries, however, water use intensity would increase, particularly in 15 sub-Saharan states. From an investor country perspective, the analysis reveals that countries often suspected of using LSLA to relieve pressure on their domestic water resources—such as China, India, and all Gulf States except Saudi Arabia—invest in agricultural activities abroad that are less water-intensive compared to their average domestic crop production. Conversely, large investor countries such as the United States, Saudi Arabia, Singapore, and Japan are disproportionately externalizing crop water consumption through their international land investments. Statistical analyses also show that host countries with abundant water resources are not per se favoured targets of LSLA. Indeed, further analysis reveals that land investments originating in water-stressed countries have only a weak tendency to target areas with a smaller water risk. PMID:26943794

Large-Scale Land Acquisition and Its Effects on the Water Balance in Investor and Host Countries.

PubMed

Breu, Thomas; Bader, Christoph; Messerli, Peter; Heinimann, Andreas; Rist, Stephan; Eckert, Sandra

2016-01-01

This study examines the validity of the assumption that international large-scale land acquisition (LSLA) is motivated by the desire to secure control over water resources, which is commonly referred to as 'water grabbing'. This assumption was repeatedly expressed in recent years, ascribing the said motivation to the Gulf States in particular. However, it must be considered of hypothetical nature, as the few global studies conducted so far focused primarily on the effects of LSLA on host countries or on trade in virtual water. In this study, we analyse the effects of 475 intended or concluded land deals recorded in the Land Matrix database on the water balance in both host and investor countries. We also examine how these effects relate to water stress and how they contribute to global trade in virtual water. The analysis shows that implementation of the LSLAs in our sample would result in global water savings based on virtual water trade. At the level of individual LSLA host countries, however, water use intensity would increase, particularly in 15 sub-Saharan states. From an investor country perspective, the analysis reveals that countries often suspected of using LSLA to relieve pressure on their domestic water resources--such as China, India, and all Gulf States except Saudi Arabia--invest in agricultural activities abroad that are less water-intensive compared to their average domestic crop production. Conversely, large investor countries such as the United States, Saudi Arabia, Singapore, and Japan are disproportionately externalizing crop water consumption through their international land investments. Statistical analyses also show that host countries with abundant water resources are not per se favoured targets of LSLA. Indeed, further analysis reveals that land investments originating in water-stressed countries have only a weak tendency to target areas with a smaller water risk.

The presence of field geologists in Mars-like terrain

NASA Technical Reports Server (NTRS)

Mcgreevy, Michael W.

1992-01-01

Methods of ethnographic observation and analysis have been coupled with object-oriented analysis and design concepts to begin the development of a clear path from observations in the field to the design of virtual presence systems. The existence of redundancies in field geology and presence allowed for the application of methods for understanding complex systems. As a result of this study, some of these redundancies have been characterized. Those described are all classes of continuity relations, including the continuities of continuous existence, context-constituent continuities, and state-process continuities. The discussion of each includes statements of general relationships, logical consequences of these, and hypothetical situations in which the relationships would apply. These are meant to aid in the development of a theory of presence. The discussion also includes design considerations, providing guidance for the design of virtual planetary exploration systems and other virtual presence systems. Converging evidence regarding continuity in presence is found in the nature of psychological dissociation. Specific methodological refinements should enhance ecological validity in subsequent field studies, which are in progress.

A Context-Aware Method for Authentically Simulating Outdoors Shadows for Mobile Augmented Reality.

PubMed

Barreira, Joao; Bessa, Maximino; Barbosa, Luis; Magalhaes, Luis

2018-03-01

Visual coherence between virtual and real objects is a major issue in creating convincing augmented reality (AR) applications. To achieve this seamless integration, actual light conditions must be determined in real time to ensure that virtual objects are correctly illuminated and cast consistent shadows. In this paper, we propose a novel method to estimate daylight illumination and use this information in outdoor AR applications to render virtual objects with coherent shadows. The illumination parameters are acquired in real time from context-aware live sensor data. The method works under unprepared natural conditions. We also present a novel and rapid implementation of a state-of-the-art skylight model, from which the illumination parameters are derived. The Sun's position is calculated based on the user location and time of day, with the relative rotational differences estimated from a gyroscope, compass and accelerometer. The results illustrated that our method can generate visually credible AR scenes with consistent shadows rendered from recovered illumination.

Augmented Reality to Preserve Hidden Vestiges in Historical Cities. a Case Study

NASA Astrophysics Data System (ADS)

Martínez, J. L.; Álvareza, S.; Finat, J.; Delgado, F. J.; Finat, J.

2015-02-01

Mobile devices provide an increasingly sophisticated support to enhanced experiences and understanding the remote past in an interactive way. The use of augmented reality technologies allows to develop mobile applications for indoor exploration of virtually reconstructed archaeological places. In our work we have built a virtual reconstruction of a Roman Villa with data arising from an urgent partial excavation which were performed in order to build a car parking in the historical city of Valladolid (Spain). In its current state, the archaeological site is covered by an urban garden. Localization and tracking are performed using a combination of GPS and inertial sensors of the mobile device. In this work we prove how to perform an interactive navigation around the 3D virtual model showing an interpretation of the way it was. The user experience is enhanced by answering some simple questions, performing minor tasks and puzzles which are presented with multimedia contents linked to key features of the archaeological site.

Virtual substrate method for nanomaterials characterization

PubMed Central

Da, Bo; Liu, Jiangwei; Yamamoto, Mahito; Ueda, Yoshihiro; Watanabe, Kazuyuki; Cuong, Nguyen Thanh; Li, Songlin; Tsukagoshi, Kazuhito; Yoshikawa, Hideki; Iwai, Hideo; Tanuma, Shigeo; Guo, Hongxuan; Gao, Zhaoshun; Sun, Xia; Ding, Zejun

2017-01-01

Characterization techniques available for bulk or thin-film solid-state materials have been extended to substrate-supported nanomaterials, but generally non-quantitatively. This is because the nanomaterial signals are inevitably buried in the signals from the underlying substrate in common reflection-configuration techniques. Here, we propose a virtual substrate method, inspired by the four-point probe technique for resistance measurement as well as the chop-nod method in infrared astronomy, to characterize nanomaterials without the influence of underlying substrate signals from four interrelated measurements. By implementing this method in secondary electron (SE) microscopy, a SE spectrum (white electrons) associated with the reflectivity difference between two different substrates can be tracked and controlled. The SE spectrum is used to quantitatively investigate the covering nanomaterial based on subtle changes in the transmission of the nanomaterial with high efficiency rivalling that of conventional core-level electrons. The virtual substrate method represents a benchmark for surface analysis to provide ‘free-standing' information about supported nanomaterials. PMID:28548114

Virtual-system-coupled adaptive umbrella sampling to compute free-energy landscape for flexible molecular docking.

PubMed

Higo, Junichi; Dasgupta, Bhaskar; Mashimo, Tadaaki; Kasahara, Kota; Fukunishi, Yoshifumi; Nakamura, Haruki

2015-07-30

A novel enhanced conformational sampling method, virtual-system-coupled adaptive umbrella sampling (V-AUS), was proposed to compute 300-K free-energy landscape for flexible molecular docking, where a virtual degrees of freedom was introduced to control the sampling. This degree of freedom interacts with the biomolecular system. V-AUS was applied to complex formation of two disordered amyloid-β (Aβ30-35 ) peptides in a periodic box filled by an explicit solvent. An interpeptide distance was defined as the reaction coordinate, along which sampling was enhanced. A uniform conformational distribution was obtained covering a wide interpeptide distance ranging from the bound to unbound states. The 300-K free-energy landscape was characterized by thermodynamically stable basins of antiparallel and parallel β-sheet complexes and some other complex forms. Helices were frequently observed, when the two peptides contacted loosely or fluctuated freely without interpeptide contacts. We observed that V-AUS converged to uniform distribution more effectively than conventional AUS sampling did. © 2015 Wiley Periodicals, Inc.

Virtual TeamSTEPPS(®) Simulations Produce Teamwork Attitude Changes Among Health Professions Students.

PubMed

Sweigart, Linda I; Umoren, Rachel A; Scott, Patrician J; Carlton, Kay Hodson; Jones, James A; Truman, Barbara; Gossett, Evalyn J

2016-01-01

The majority of the estimated 400,000 or more patient deaths per year in the United States are from preventable medical errors due to poor communication. Team training programs have been established to teach teamwork skills to health professions students. However, it is often challenging to provide this training at a physical site. A brief intervention using a virtual learning environment with TeamSTEPPS(®)-based scenarios is described. Using a pretest-posttest design, the effects on teamwork attitudes in 109 health professional students from two institutions and multiple disciplines were measured using the TeamSTEPPS Teamwork Attitudes questionnaire. Participants showed significant attitude changes in the categories of leadership, situation monitoring, mutual support, and communication (p ⩽ .05), with significance in four of the six indicator attitudes in the communication section at the p ⩽ .001 level. These findings indicate the potential impact that virtual learning experiences may have on teamwork attitudes in learners across professions on multiple campuses. Copyright 2016, SLACK Incorporated.

The interplays among technology and content, immersant and VE

NASA Astrophysics Data System (ADS)

Song, Meehae; Gromala, Diane; Shaw, Chris; Barnes, Steven J.

2010-01-01

The research program aims to explore and examine the fine balance necessary for maintaining the interplays between technology and the immersant, including identifying qualities that contribute to creating and maintaining a sense of "presence" and "immersion" in an immersive virtual reality (IVR) experience. Building upon and extending previous work, we compare sitting meditation with walking meditation in a virtual environment (VE). The Virtual Meditative Walk, a new work-in-progress, integrates VR and biofeedback technologies with a self-directed, uni-directional treadmill. As immersants learn how to meditate while walking, robust, real-time biofeedback technology continuously measures breathing, skin conductance and heart rate. The physiological states of the immersant will in turn affect the audio and stereoscopic visual media through shutter glasses. We plan to test the potential benefits and limitations of this physically active form of meditation with data from a sitting form of meditation. A mixed-methods approach to testing user outcomes parallels the knowledge bases of the collaborative team: a physician, computer scientists and artists.

Planning and Management of Real-Time Geospatialuas Missions Within a Virtual Globe Environment

NASA Astrophysics Data System (ADS)

Nebiker, S.; Eugster, H.; Flückiger, K.; Christen, M.

2011-09-01

This paper presents the design and development of a hardware and software framework supporting all phases of typical monitoring and mapping missions with mini and micro UAVs (unmanned aerial vehicles). The developed solution combines state-of-the art collaborative virtual globe technologies with advanced geospatial imaging techniques and wireless data link technologies supporting the combined and highly reliable transmission of digital video, high-resolution still imagery and mission control data over extended operational ranges. The framework enables the planning, simulation, control and real-time monitoring of UAS missions in application areas such as monitoring of forest fires, agronomical research, border patrol or pipeline inspection. The geospatial components of the project are based on the Virtual Globe Technology i3D OpenWebGlobe of the Institute of Geomatics Engineering at the University of Applied Sciences Northwestern Switzerland (FHNW). i3D OpenWebGlobe is a high-performance 3D geovisualisation engine supporting the web-based streaming of very large amounts of terrain and POI data.

Interactions with Virtual People: Do Avatars Dream of Digital Sheep?. Chapter 6

NASA Technical Reports Server (NTRS)

Slater, Mel; Sanchez-Vives, Maria V.

2007-01-01

This paper explores another form of artificial entity, ones without physical embodiment. We refer to virtual characters as the name for a type of interactive object that have become familiar in computer games and within virtual reality applications. We refer to these as avatars: three-dimensional graphical objects that are in more-or-less human form which can interact with humans. Sometimes such avatars will be representations of real-humans who are interacting together within a shared networked virtual environment, other times the representations will be of entirely computer generated characters. Unlike other authors, who reserve the term agent for entirely computer generated characters and avatars for virtual embodiments of real people; the same term here is used for both. This is because avatars and agents are on a continuum. The question is where does their behaviour originate? At the extremes the behaviour is either completely computer generated or comes only from tracking of a real person. However, not every aspect of a real person can be tracked every eyebrow move, every blink, every breath rather real tracking data would be supplemented by inferred behaviours which are programmed based on the available information as to what the real human is doing and her/his underlying emotional and psychological state. Hence there is always some programmed behaviour it is only a matter of how much. In any case the same underlying problem remains how can the human character be portrayed in such a manner that its actions are believable and have an impact on the real people with whom it interacts? This paper has three main parts. In the first part we will review some evidence that suggests that humans react with appropriate affect in their interactions with virtual human characters, or with other humans who are represented as avatars. This is so in spite of the fact that the representational fidelity is relatively low. Our evidence will be from the realm of psychotherapy, where virtual social situations are created that do test whether people react appropriately within these situations. We will also consider some experiments on face-to-face virtual communications between people in the same shared virtual environments. The second part will try to give some clues about why this might happen, taking into account modern theories of perception from neuroscience. The third part will include some speculations about the future developments of the relationship between people and virtual people. We will suggest that a more likely scenario than the world becoming populated by physically embodied virtual people (robots, androids) is that in the relatively near future we will interact more and more in our everyday lives with virtual people- bank managers, shop assistants, instructors, and so on. What is happening in the movies with computer graphic generated individuals and entire crowds may move into the space of everyday life.

Of nannies and nudges: the current state of U.S. obesity policymaking.

PubMed

Kersh, R

2015-08-01

In the sprawling American political debates over obesity, which date back a decade and a half, 'nanny state' has been a rhetorical cudgel used to oppose those seeking even modest state action to address rising obesity rates. This essay explores obesity policy through the prism of state involvement, focusing on four possible types of response to what virtually all those involved--physicians and nutritional scientists, public-health advocacy groups, even food industry executives--agree is a serious threat to individual and collective health. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Modeling virtual organizations with Latent Dirichlet Allocation: a case for natural language processing.

PubMed

Gross, Alexander; Murthy, Dhiraj

2014-10-01

This paper explores a variety of methods for applying the Latent Dirichlet Allocation (LDA) automated topic modeling algorithm to the modeling of the structure and behavior of virtual organizations found within modern social media and social networking environments. As the field of Big Data reveals, an increase in the scale of social data available presents new challenges which are not tackled by merely scaling up hardware and software. Rather, they necessitate new methods and, indeed, new areas of expertise. Natural language processing provides one such method. This paper applies LDA to the study of scientific virtual organizations whose members employ social technologies. Because of the vast data footprint in these virtual platforms, we found that natural language processing was needed to 'unlock' and render visible latent, previously unseen conversational connections across large textual corpora (spanning profiles, discussion threads, forums, and other social media incarnations). We introduce variants of LDA and ultimately make the argument that natural language processing is a critical interdisciplinary methodology to make better sense of social 'Big Data' and we were able to successfully model nested discussion topics from forums and blog posts using LDA. Importantly, we found that LDA can move us beyond the state-of-the-art in conventional Social Network Analysis techniques. Copyright © 2014 Elsevier Ltd. All rights reserved.

The validity of virtual environments for eliciting emotional responses in patients with eating disorders and in controls.

PubMed

Ferrer-García, Marta; Gutiérrez-Maldonado, José; Caqueo-Urízar, Alejandra; Moreno, Elena

2009-11-01

This article explores the efficacy of virtual environments representing situations that are emotionally significant to patients with eating disorders (ED) to modify depression and anxiety levels both in these patients and in controls. Eighty-five ED patients and 108 students were randomly exposed to five experimental virtual environments (a kitchen with low-calorie food, a kitchen with high-calorie food, a restaurant with high-calorie food, a restaurant with low-calorie food, and a swimming-pool) and to one neutral environment. In the interval between the presentation of each situation, anxiety and depressed mood were assessed. Results of several repeated measures analyses demonstrated that patients show higher levels of anxiety and a more depressed mood after eating, especially high-calorie food, and after visiting the swimming pool than in the neutral room. In contrast, controls only show higher levels of anxiety in the swimming pool. In the rest of the situations they presented a similar mood state as in the neutral room. We concluded that virtual reality is a useful vehicle for eliciting similar emotional reactions to those one would expect in real life situations. Thus, this technology seems well suited for use in experimental studies as well as in evaluative and therapeutic contexts.

Virtual environments for motor rehabilitation: review.

PubMed

Holden, Maureen K

2005-06-01

In this paper, the current "state of the art" for virtual reality (VR) applications in the field of motor rehabilitation is reviewed. The paper begins with a brief overview of available equipment options. Next, a discussion of the scientific rationale for use of VR in motor rehabilitation is provided. Finally, the major portion of the paper describes the various VR systems that have been developed for use with patients, and the results of clinical studies reported to date in the literature. Areas covered include stroke rehabilitation (upper and lower extremity training, spatial and perceptual-motor training), acquired brain injury, Parkinson's disease, orthopedic rehabilitation, balance training, wheelchair mobility and functional activities of daily living training, and the newly developing field of telerehabilitation. Four major findings emerge from these studies: (1) people with disabilities appear capable of motor learning within virtual environments; (2) movements learned by people with disabilities in VR transfer to real world equivalent motor tasks in most cases, and in some cases even generalize to other untrained tasks; (3) in the few studies (n = 5) that have compared motor learning in real versus virtual environments, some advantage for VR training has been found in all cases; and (4) no occurrences of cybersickness in impaired populations have been reported to date in experiments where VR has been used to train motor abilities.

Visualizing Mars Using Virtual Reality: A State of the Art Mapping Technique Used on Mars Pathfinder

NASA Technical Reports Server (NTRS)

Stoker, C.; Zbinden, E.; Blackmon, T.; Nguyen, L.

1999-01-01

We describe an interactive terrain visualization system which rapidly generates and interactively displays photorealistic three-dimensional (3-D) models produced from stereo images. This product, first demonstrated in Mars Pathfinder, is interactive, 3-D, and can be viewed in an immersive display which qualifies it for the name Virtual Reality (VR). The use of this technology on Mars Pathfinder was the first use of VR for geologic analysis. A primary benefit of using VR to display geologic information is that it provides an improved perception of depth and spatial layout of the remote site. The VR aspect of the display allows an operator to move freely in the environment, unconstrained by the physical limitations of the perspective from which the data were acquired. Virtual Reality offers a way to archive and retrieve information in a way that is intuitively obvious. Combining VR models with stereo display systems can give the user a sense of presence at the remote location. The capability, to interactively perform measurements from within the VR model offers unprecedented ease in performing operations that are normally time consuming and difficult using other techniques. Thus, Virtual Reality can be a powerful a cartographic tool. Additional information is contained in the original extended abstract.

Flexing the Faculty. Lumina Foundation Focus[TM]. Summer 2011

ERIC Educational Resources Information Center

Lumina Foundation for Education, 2011

2011-01-01

The lingering economic downturn has affected virtually every American institution--perhaps none more significantly than the nation's higher education system. These days, facing significant revenue shortfalls that are widely recognized as the "new normal," state-supported colleges and universities are looking, sometimes desperately, for…

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCaskey, Alexander J.

There is a lack of state-of-the-art quantum computing simulation software that scales on heterogeneous systems like Titan. Tensor Network Quantum Virtual Machine (TNQVM) provides a quantum simulator that leverages a distributed network of GPUs to simulate quantum circuits in a manner that leverages recent results from tensor network theory.

Theme issue ;State-of-the-art in photogrammetry, remote sensing and spatial information science;

NASA Astrophysics Data System (ADS)

Heipke, Christian; Madden, Marguerite; Li, Zhilin; Dowman, Ian

2016-05-01

Over the past few years, photogrammetry, remote sensing and spatial information science have witnessed great changes in virtually every stage of information from imagery. Indeed, we have seen, for example, a sharply increased interest in unmanned aerial vehicles,

ANALYTICAL METHODS FOR FUEL OXYGENATES

EPA Science Inventory

MTBE (and potentially any other oxygenate) may be present at any petroleum UST site, whether the release is new or old, virtually anywhere in the United States. Consequently, it is prudent to analyze samples for the entire suite of oxygenates as identified in this protocol (i.e....

Regional cooperation and transportation planning in Alaska : a regional models of cooperation peer exchange summary report.

DOT National Transportation Integrated Search

2017-01-31

This report summarizes the proceedings of a Regional Models of Cooperation Virtual Peer Exchange Workshop held on March 9 10, 2016 for the State of Alaska. Participants discussed the benefits and challenges of cooperation across jurisdictions and...

Pulse!! The Virtual Clinical Learning Lab and Center of Excellence

DTIC Science & Technology

2011-08-01

environments, physiological assets and case-authoring tools using state- of-the art technologies common to the videogame industry but here appropriated...interior processes (e.g., fluid dynamics) are beyond the current reach of the videogame industry. c. Concise Accomplishments (limit 200 words/170

The rules implementing sections 201 and 210 of the Public Utility Regulatory Policies Act of 1978: A regulatory history

NASA Technical Reports Server (NTRS)

Danziger, R. N.

1980-01-01

The act provides that utilities must purchase power for qualifying producers of electricity at nondiscriminatory rates. It exempts private generators from virtually all state and federal utility regulation. Pertinent reference material is provided.

Learning without Borders

ERIC Educational Resources Information Center

Anderson, Sue

2013-01-01

In 2010, State College Area School District (SCASD) in Pennsylvania, USA, agreed to help develop a virtual international classroom exchange called the Schoolwires Greenleaf program. The program's project-based curriculum paired U.S. students with Chinese learners to collaborate, foster global citizenship, and prepare students for the digital work…

Predicting catastrophes of non-autonomous networks with visibility graphs and horizontal visibility

NASA Astrophysics Data System (ADS)

Zhang, Haicheng; Xu, Daolin; Wu, Yousheng

2018-05-01

Prediction of potential catastrophes in engineering systems is a challenging problem. We first attempt to construct a complex network to predict catastrophes of a multi-modular floating system in advance of their occurrences. Response time series of the system can be mapped into an virtual network by using visibility graph or horizontal visibility algorithm. The topology characteristics of the networks can be used to forecast catastrophes of the system. Numerical results show that there is an obvious corresponding relationship between the variation of topology characteristics and the onset of catastrophes. A Catastrophe Index (CI) is proposed as a numerical indicator to measure a qualitative change from a stable state to a catastrophic state. The two approaches, the visibility graph and horizontal visibility algorithms, are compared by using the index in the reliability analysis with different data lengths and sampling frequencies. The technique of virtual network method is potentially extendable to catastrophe predictions of other engineering systems.

Model-Free control performance improvement using virtual reference feedback tuning and reinforcement Q-learning

NASA Astrophysics Data System (ADS)

Radac, Mircea-Bogdan; Precup, Radu-Emil; Roman, Raul-Cristian

2017-04-01

This paper proposes the combination of two model-free controller tuning techniques, namely linear virtual reference feedback tuning (VRFT) and nonlinear state-feedback Q-learning, referred to as a new mixed VRFT-Q learning approach. VRFT is first used to find stabilising feedback controller using input-output experimental data from the process in a model reference tracking setting. Reinforcement Q-learning is next applied in the same setting using input-state experimental data collected under perturbed VRFT to ensure good exploration. The Q-learning controller learned with a batch fitted Q iteration algorithm uses two neural networks, one for the Q-function estimator and one for the controller, respectively. The VRFT-Q learning approach is validated on position control of a two-degrees-of-motion open-loop stable multi input-multi output (MIMO) aerodynamic system (AS). Extensive simulations for the two independent control channels of the MIMO AS show that the Q-learning controllers clearly improve performance over the VRFT controllers.

Choice-specific sequences in parietal cortex during a virtual-navigation decision task

PubMed Central

Harvey, Christopher D.; Coen, Philip; Tank, David W.

2012-01-01

The posterior parietal cortex (PPC) plays an important role in many cognitive behaviors; however, the neural circuit dynamics underlying PPC function are not well understood. Here we optically imaged the spatial and temporal activity patterns of neuronal populations in mice performing a PPC-dependent task that combined a perceptual decision and memory-guided navigation in a virtual environment. Individual neurons had transient activation staggered relative to one another in time, forming a sequence of neuronal activation spanning the entire length of a task trial. Distinct sequences of neurons were triggered on trials with opposite behavioral choices and defined divergent, choice-specific trajectories through a state space of neuronal population activity. Cells participating in the different sequences and at distinct time points in the task were anatomically intermixed over microcircuit length scales (< 100 micrometers). During working memory decision tasks the PPC may therefore perform computations through sequence-based circuit dynamics, rather than long-lived stable states, implemented using anatomically intermingled microcircuits. PMID:22419153

Design and analysis of a global sub-mesoscale and tidal dynamics admitting virtual ocean.

NASA Astrophysics Data System (ADS)

Menemenlis, D.; Hill, C. N.

2016-02-01

We will describe the techniques used to realize a global kilometerscale ocean model configuration that includes representation of sea-ice and tidal excitation, and spans scales from planetary gyres to internal tides. A simulation using this model configuration provides a virtual ocean that admits some sub-mesoscale dynamics and tidal energetics not normally represented in global calculations. This extends simulated ocean behavior beyond broadly quasi-geostrophic flows and provides a preliminary example of a next generation computational approach to explicitly probing the interactions between instabilities that are usually parameterized and dominant energetic scales in the ocean. From previous process studies we have ascertained that this can lead to a qualitative improvement in the realism of many significant processes including geostrophic eddy dynamics, shelf-break exchange and topographic mixing. Computationally we exploit high-degrees of parallelism in both numerical evaluation and in recording model state to persistent disk storage. Together this allows us to compute and record a full three-dimensional model trajectory at hourly frequency for a timeperiod of 5 months with less than 9 million core hours of parallel computer time, using the present generation NASA Ames Research Center facilities. We have used this capability to create a 5 month trajectory archive, sampled at high spatial and temporal frequency for an ocean configuration that is initialized from a realistic data-assimilated state and driven with reanalysis surface forcing from ECMWF. The resulting database of model state provides a novel virtual laboratory for exploring coupling across scales in the ocean, and for testing ideas on the relationship between small scale fluxes and large scale state. The computation is complemented by counterpart computations that are coarsened two and four times respectively. In this presentation we will review the computational and numerical technologies employed and show how the high spatio-temporal frequency archive of model state can provide a new and promising tool for researching richer ocean dynamics at scale. We will also outline how computations of this nature could be combined with next generation computer hardware plans to help inform important climate process questions.

One library's experience with review and selection of chat software for reference.

PubMed

Behm, Leslie M

2003-01-01

When Michigan State University (MSU) Libraries decided to make the foray into virtual reference, the first thing that needed to be done was to decide on the software to use. This article discusses the process used including the items considered essential (deal-breakers) for software to make the first cut, what other features needed to be included, and what features would be useful but were not critical. A literature review of some useful current articles on virtual reference is included. The vendor and software ultimately selected was not one of the original vendors; how MSU Libraries was able to evaluate and select Docutek is presented. A matrix for software comparison is included in the appendix.

Virtual reality systems for rodents

PubMed Central

Ayaz, Aslı

2017-01-01

Abstract Over the last decade virtual reality (VR) setups for rodents have been developed and utilized to investigate the neural foundations of behavior. Such VR systems became very popular since they allow the use of state-of-the-art techniques to measure neural activity in behaving rodents that cannot be easily used with classical behavior setups. Here, we provide an overview of rodent VR technologies and review recent results from related research. We discuss commonalities and differences as well as merits and issues of different approaches. A special focus is given to experimental (behavioral) paradigms in use. Finally we comment on possible use cases that may further exploit the potential of VR in rodent research and hence inspire future studies. PMID:29491968

Overview of theory and simulations in the Heavy Ion Fusion Science Virtual National Laboratory

NASA Astrophysics Data System (ADS)

Friedman, Alex

2007-07-01

The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is a collaboration of Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, and Princeton Plasma Physics Laboratory. These laboratories, in cooperation with researchers at other institutions, are carrying out a coordinated effort to apply intense ion beams as drivers for studies of the physics of matter at extreme conditions, and ultimately for inertial fusion energy. Progress on this endeavor depends upon coordinated application of experiments, theory, and simulations. This paper describes the state of the art, with an emphasis on the coordination of modeling and experiment; developments in the simulation tools, and in the methods that underly them, are also treated.

Synthesis of Virtual Environments for Aircraft Community Noise Impact Studies

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Sullivan, Brenda M.

2005-01-01

A new capability has been developed for the creation of virtual environments for the study of aircraft community noise. It is applicable for use with both recorded and synthesized aircraft noise. When using synthesized noise, a three-stage process is adopted involving non-real-time prediction and synthesis stages followed by a real-time rendering stage. Included in the prediction-based source noise synthesis are temporal variations associated with changes in operational state, and low frequency fluctuations that are present under all operating conditions. Included in the rendering stage are the effects of spreading loss, absolute delay, atmospheric absorption, ground reflections, and binaural filtering. Results of prediction, synthesis and rendering stages are presented.

Statistical analysis of EGFR structures' performance in virtual screening

NASA Astrophysics Data System (ADS)

Li, Yan; Li, Xiang; Dong, Zigang

2015-11-01

In this work the ability of EGFR structures to distinguish true inhibitors from decoys in docking and MM-PBSA is assessed by statistical procedures. The docking performance depends critically on the receptor conformation and bound state. The enrichment of known inhibitors is well correlated with the difference between EGFR structures rather than the bound-ligand property. The optimal structures for virtual screening can be selected based purely on the complex information. And the mixed combination of distinct EGFR conformations is recommended for ensemble docking. In MM-PBSA, a variety of EGFR structures have identically good performance in the scoring and ranking of known inhibitors, indicating that the choice of the receptor structure has little effect on the screening.

Virtual World Astrosociology

NASA Astrophysics Data System (ADS)

Bainbridge, William Sims

2010-01-01

This essay introduces the opportunity for theory development and even empirical research on some aspects of astrosociology through today's online virtual worlds. The examples covered present life on other planets or in space itself, in a manner that can be experienced by the user and where the user's reactions may simulate to some degree future human behavior in real extraterrestrial environments: Tabula Rasa, Anarchy Online, Entropia Universe, EVE Online, StarCraft and World of Warcraft. Ethnographic exploration of these computerized environments raises many questions about the social science both of space exploration and of direct contact with extraterrestrials. The views expressed in this essay do not necessarily represent the views of the National Science Foundation or the United States.

Virtual Control Policy for Binary Ordered Resources Petri Net Class.

PubMed

Rovetto, Carlos A; Concepción, Tomás J; Cano, Elia Esther

2016-08-18

Prevention and avoidance of deadlocks in sensor networks that use the wormhole routing algorithm is an active research domain. There are diverse control policies that will address this problem being our approach a new method. In this paper we present a virtual control policy for the new specialized Petri net subclass called Binary Ordered Resources Petri Net (BORPN). Essentially, it is an ordinary class constructed from various state machines that share unitary resources in a complex form, which allows branching and joining of processes. The reduced structure of this new class gives advantages that allow analysis of the entire system's behavior, which is a prohibitive task for large systems because of the complexity and routing algorithms.

Analyzing the first years of the click it or ticket mobilizations.

DOT National Transportation Integrated Search

2010-01-01

The Click It or Ticket seat belt enforcement programs conducted between 2000 and 2006 were an important factor in increasing seat belt use nationwide and in virtually all States. This was the case for observed belt use, belt use in fatalities, and se...

The New Three Rs: Research, Reading, and Results. Breakthrough to Literacy[TM].

ERIC Educational Resources Information Center

McGraw-Hill Companies, New York, NY. Educational and Professional Publishing Group.

Research in school districts throughout the United States shows that children who use "Breakthrough to Literacy" achieve significant and lasting improvement in their reading skills. At virtually every site studied where implementation criteria were met, children who participated in "Breakthrough" demonstrated marked increases…

Inquiring Minds

Science.gov Websites

-performance Computing Grid Computing Networking Mass Storage Plan for the Future State of the Laboratory to help decipher the language of high-energy physics. Virtual Ask-a-Scientist Read transcripts from past online chat sessions. last modified 1/04/2005 email Fermilab Fermi National Accelerator Laboratory

Teaching Surgery without a Patient.

ERIC Educational Resources Information Center

Mangan, Katherine A.

2000-01-01

Reports on the increasing use of virtual-reality devices at Pennsylvania State University's Milton S. Hershey Medical Center and other institutions that allow medical residents to practice their skills in simulated operations. Notes that both students and professors are enthusiastic about the simulations but that the necessary technology and…

International Competitiveness in Electronics.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

This assessment continues the Office of Technology Assessment's (OTA) exploration of the meaning of industrial policy in the United States context, while also examining the industrial policies of several U.S. economic rivals. The major focus is on electronics, an area which virtually defines "high technology" of the 1980's. The…

Creating a State-Wide Virtual Health Library: The Michigan Experience.

ERIC Educational Resources Information Center

Brenneise, Harvey

The AccessMichigan Electronic Community Health Information Initiative (AMECHII) is a response to a recommendation of the Michigan Information Technology Commission Report recommending improved access to high-quality health care information for all Michigan stakeholders. This project is multi-type, including public, general academic, academic…

Ethmoidectomy combined with superior meatus enlargement increases olfactory airflow

PubMed Central

Kondo, Kenji; Nomura, Tsutomu; Yamasoba, Tatsuya

2017-01-01

Objectives The relationship between a particular surgical technique in endoscopic sinus surgery (ESS) and airflow changes in the post‐operative olfactory region has not been assessed. The present study aimed to compare olfactory airflow after ESS between conventional ethmoidectomy and ethmoidectomy with superior meatus enlargement, using virtual ESS and computational fluid dynamics (CFD) analysis. Study Design Prospective computational study. Materials and Methods Nasal computed tomography images of four adult subjects were used to generate models of the nasal airway. The original preoperative model was digitally edited as virtual ESS by performing uncinectomy, ethmoidectomy, antrostomy, and frontal sinusotomy. The following two post‐operative models were prepared: conventional ethmoidectomy with normal superior meatus (ESS model) and ethmoidectomy with superior meatus enlargement (ESS‐SM model). The calculated three‐dimensional nasal geometries were confirmed using virtual endoscopy to ensure that they corresponded to the post‐operative anatomy observed in the clinical setting. Steady‐state, laminar, inspiratory airflow was simulated, and the velocity, streamline, and mass flow rate in the olfactory region were compared among the preoperative and two postoperative models. Results The mean velocity in the olfactory region, number of streamlines bound to the olfactory region, and mass flow rate were higher in the ESS‐SM model than in the other models. Conclusion We successfully used an innovative approach involving virtual ESS, virtual endoscopy, and CFD to assess postoperative outcomes after ESS. It is hypothesized that the increased airflow to the olfactory fossa achieved with ESS‐SM may lead to improved olfactory function; however, further studies are required. Level of Evidence NA. PMID:28894833

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

PubMed

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.

Social environments and interpersonal distance regulation in psychosis: A virtual reality study.

PubMed

Geraets, Chris N W; van Beilen, Marije; Pot-Kolder, Roos; Counotte, Jacqueline; van der Gaag, Mark; Veling, Wim

2018-02-01

Experimentally studying the influence of social environments on mental health and behavior is challenging, as social context is difficult to standardize in laboratory settings. Virtual Reality (VR) enables studying social interaction in terms of interpersonal distance in a more ecologically valid manner. Regulation of interpersonal distance may be abnormal in patients with psychotic disorders and influenced by environmental stress, symptoms or distress. To investigate interpersonal distance in people with a psychotic disorder and at ultrahigh risk for psychosis (UHR) compared to siblings and controls in virtual social environments, and explore the relationship between clinical characteristics and interpersonal distance. Nineteen UHR patients, 52 patients with psychotic disorders, 40 siblings of patients with a psychotic disorder and 47 controls were exposed to virtual cafés. In five virtual café visits, participants were exposed to different levels of social stress, in terms of crowdedness, ethnicity and hostility. Measures on interpersonal distance, distress and state paranoia were obtained. Baseline measures included trait paranoia, social anxiety, depressive, positive and negative symptoms. Interpersonal distance increased when social stressors were present in the environment. No difference in interpersonal distance regulation was found between the groups. Social anxiety and distress were positively associated with interpersonal distance in the total sample. This VR paradigm indicates that interpersonal distance regulation in response to environmental social stressors is unaltered in people with psychosis or UHR. Environmental stress, social anxiety and distress trigger both people with and without psychosis to maintain larger interpersonal distances in social situations. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed Central

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

Virtual reality in mental health : a review of the literature.

PubMed

Gregg, Lynsey; Tarrier, Nicholas

2007-05-01

Several virtual reality (VR) applications for the understanding, assessment and treatment of mental health problems have been developed in the last 10 years. The purpose of this review is to outline the current state of virtual reality research in the treatment of mental health problems. PubMed and PsycINFO were searched for all articles containing the words "virtual reality". In addition a manual search of the references contained in the papers resulting from this search was conducted and relevant periodicals were searched. Studies reporting the results of treatment utilizing VR in the mental health field and involving at least one patient were identified. More than 50 studies using VR were identified, the majority of which were case studies. Seventeen employed a between groups design: 4 involved patients with fear of flying; 3 involved patients with fear of heights; 3 involved patients with social phobia/public speaking anxiety; 2 involved people with spider phobia; 2 involved patients with agoraphobia; 2 involved patients with body image disturbance and 1 involved obese patients. There are both advantages in terms of delivery and disadvantages in terms of side effects to using VR. Although virtual reality based therapy appears to be superior to no treatment the effectiveness of VR therapy over traditional therapeutic approaches is not supported by the research currently available. There is a lack of good quality research on the effectiveness of VR therapy. Before clinicians will be able to make effective use of this emerging technology greater emphasis must be placed on controlled trials with clinically identified populations.

Influence of real and virtual heights on standing balance.

PubMed

Cleworth, Taylor W; Horslen, Brian C; Carpenter, Mark G

2012-06-01

Fear and anxiety induced by threatening scenarios, such as standing on elevated surfaces, have been shown to influence postural control in young adults. There is also a need to understand how postural threat influences postural control in populations with balance deficits and risk of falls. However, safety and feasibility issues limit opportunities to place such populations in physically threatening scenarios. Virtual reality (VR) has successfully been used to simulate threatening environments, although it is unclear whether the same postural changes can be elicited by changes in virtual and real threat conditions. Therefore, the purpose of this study was to compare the effects of real and virtual heights on changes to standing postural control, electrodermal activity (EDA) and psycho-social state. Seventeen subjects stood at low and high heights in both real and virtual environments matched in scale and visual detail. A repeated measures ANOVA revealed increases with height, independent of visual environment, in EDA, anxiety, fear, and center of pressure (COP) frequency, and decreases with height in perceived stability, balance confidence and COP amplitude. Interaction effects were seen for fear and COP mean position; where real elicited larger changes with height than VR. This study demonstrates the utility of VR, as simulated heights resulted in changes to postural, autonomic and psycho-social measures similar to those seen at real heights. As a result, VR may be a useful tool for studying threat related changes in postural control in populations at risk of falls, and to screen and rehabilitate balance deficits associated with fear and anxiety. Copyright © 2012 Elsevier B.V. All rights reserved.

Extension of Hopfield’s Electron Transfer Model To Accommodate Site–Site Correlation

DOE PAGES

Newton, Marshall D.

2015-10-26

Extension of the Förster analogue for the ET rate constant (based on virtual intermediate electron detachment or attachment states) with inclusion of site–site correlation due to coulomb terms associated with solvent reorganization energy and the driving force, has been developed and illustrated for a simple three-state, two-mode model. Furthermore, the model is applicable to charge separation (CS), recombination (CR), and shift (CSh) ET processes, with or without an intervening bridge. The model provides a unified perspective on the role of virtual intermediate states in accounting for the thermal Franck–Condon weighted density of states (FCWD), the gaps controlling superexchange coupling, andmore » mean absolute redox potentials, with full accommodation of site–site coulomb interactions. We analyzed two types of correlation: aside from the site–site correlation due to coulomb interactions, we have emphasized the intrinsic “nonorthogonality” which generally pertains to reaction coordinates (RCs) for different ET processes involving multiple electronic states, as may be expressed by suitably defined direction cosines (cos(θ)). A pair of RCs may be nonorthogonal even when the site–site coulomb correlations are absent. While different RCs are linearly independent in the mathematical sense for all θ ≠ 0°, they are independent in the sense of being “uncorrelated” only in the limit of orthogonality (θ = 90°). There is application to more than two coordinates is straightforward and may include both discrete and continuum contributions.« less

Outreach/education interface for Cryosphere models using the Virtual Ice Sheet Laboratory

NASA Astrophysics Data System (ADS)

Larour, E. Y.; Halkides, D. J.; Romero, V.; Cheng, D. L.; Perez, G.

2014-12-01

In the past decade, great strides have been made in the development of models capable of projecting the future evolution of glaciers and the polar ice sheets in a changing climate. These models are now capable of replicating some of the trends apparent in satellite observations. However, because this field is just now maturing, very few efforts have been dedicated to adapting these capabilities to education. Technologies that have been used in outreach efforts in Atmospheric and Oceanic sciences still have not been extended to Cryospheric Science. We present a cutting-edge, technologically driven virtual laboratory, geared towards outreach and k-12 education, dedicated to the polar ice sheets on Antarctica and Greenland, and their role as major contributors to sea level rise in coming decades. VISL (Virtual Ice Sheet Laboratory) relies on state-of-the art Web GL rendering of polar ice sheets, Android/iPhone and web portability using Javascript, as well as C++ simulations (back-end) based on the Ice Sheet System Model, the NASA model for simulating the evolution of polar ice sheets. Using VISL, educators and students can have an immersive experience into the world of polar ice sheets, while at the same exercising the capabilities of a state-of-the-art climate model, all of it embedded into an education experience that follows the new STEM standards for education.This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

A positive psychological intervention using virtual reality for patients with advanced cancer in a hospital setting: a pilot study to assess feasibility.

PubMed

Baños, Rosa M; Espinoza, Macarena; García-Palacios, Azucena; Cervera, José M; Esquerdo, Gaspar; Barrajón, Enrique; Botella, Cristina

2013-01-01

This study presents data on the feasibility and possible benefits of a psychological intervention that uses virtual reality to induce positive emotions on adult hospitalized patients with metastatic cancer. The patient's satisfaction and perceived utility was also examined. The sample was composed of 19 patients (53 % men, aged from 29 to 85 years old; x = 60.9; standard deviation = 14.54). The intervention consisted of four 30-min sessions during 1 week in which patients navigated through virtual environments designed to induce joy or relaxation. Mood was assessed before and after each session using the Visual Analog Scale. Patient satisfaction was assessed after each session and at the end of the intervention. Qualitative data were also collected with open-ended questions. There were no major difficulties with the use of devices, and any difficulties that did arise were solved through practice. There were adequate levels of pleasantness and perceived utility of the proposed intervention. The main perceived benefits were distraction, entertainment, and promotion of relaxation states. Regarding mood changes, an increase in positive emotions and a decrease in negative emotions were also detected. The intervention was positively assessed and rated as minimally uncomfortable. Future actions are discussed as well as the need to implement brief interventions that take into account the patients' medical state and physical discomfort level, especially with those in the advanced stages of disease.

The “Good Cop, Bad Cop” Effect in the RT-Based Concealed Information Test: Exploring the Effect of Emotional Expressions Displayed by a Virtual Investigator

PubMed Central

Varga, Mihai; Visu-Petra, George; Miclea, Mircea; Visu-Petra, Laura

2015-01-01

Concealing the possession of relevant information represents a complex cognitive process, shaped by contextual demands and individual differences in cognitive and socio-emotional functioning. The Reaction Time-based Concealed Information Test (RT-CIT) is used to detect concealed knowledge based on the difference in RTs between denying recognition of critical (probes) and newly encountered (irrelevant) information. Several research questions were addressed in this scenario implemented after a mock crime. First, we were interested whether the introduction of a social stimulus (facial identity) simulating a virtual investigator would facilitate the process of deception detection. Next, we explored whether his emotional displays (friendly, hostile or neutral) would have a differential impact on speed of responses to probe versus irrelevant items. We also compared the impact of introducing similar stimuli in a working memory (WM) updating context without requirements to conceal information. Finally, we explored the association between deceptive behavior and individual differences in WM updating proficiency or in internalizing problems (state / trait anxiety and depression). Results indicated that the mere presence of a neutral virtual investigator slowed down participants' responses, but not the appended lie-specific time (difference between probes and irrelevants). Emotional expression was shown to differentially affect speed of responses to critical items, with positive displays from the virtual examiner enhancing lie-specific time, compared to negative facial expressions, which had an opposite impact. This valence-specific effect was not visible in the WM updating context. Higher levels of trait / state anxiety were related to faster responses to probes in the negative condition (hostile facial expression) of the RT-CIT. These preliminary findings further emphasize the need to take into account motivational and emotional factors when considering the transfer of deception detection techniques from the laboratory to real-life settings. PMID:25699516

Global TIE: Developing a Virtual Network of Robotic Observatories for K-12 Education

NASA Astrophysics Data System (ADS)

Mayo, L. A.; Clark, G.

2001-11-01

Astronomy in grades K-12 is traditionally taught (if at all) using textbooks and a few simple hands-on activities. In addition, most students, by High School graduation, will never have even looked through the eyepiece of a telescope. The possibility now exists to establish a network of research grade telescopes, no longer useful to the professional astronomical community, that can be made accessible to schools all across the country through existing IT technologies and applications. These telescopes could provide unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns underutilized observatory facilities into valuable, state-of-the-art teaching centers. The NASA-sponsored Telescopes In Education (TIE, http://tie.jpl.nasa.gov) project has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. Global TIE integrates these telescopes seamlessly into one virtual observatory and provides the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J" for publication of results, and access to related educational materials provided by the TIE community. Global TIE provides unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns essentially unused observatory facilities into valuable, state-of-the-art teaching centers. This presentation describes the Global TIE Observatory data and organizational systems and details the technology, partnerships, operational capabilities, science applications, and learning opportunities that this powerful virtual observatory network will provide.

Using the virtual brain to reveal the role of oscillations and plasticity in shaping brain's dynamical landscape.

PubMed

Roy, Dipanjan; Sigala, Rodrigo; Breakspear, Michael; McIntosh, Anthony Randal; Jirsa, Viktor K; Deco, Gustavo; Ritter, Petra

2014-12-01

Spontaneous brain activity, that is, activity in the absence of controlled stimulus input or an explicit active task, is topologically organized in multiple functional networks (FNs) maintaining a high degree of coherence. These "resting state networks" are constrained by the underlying anatomical connectivity between brain areas. They are also influenced by the history of task-related activation. The precise rules that link plastic changes and ongoing dynamics of resting-state functional connectivity (rs-FC) remain unclear. Using the framework of the open source neuroinformatics platform "The Virtual Brain," we identify potential computational mechanisms that alter the dynamical landscape, leading to reconfigurations of FNs. Using a spiking neuron model, we first demonstrate that network activity in the absence of plasticity is characterized by irregular oscillations between low-amplitude asynchronous states and high-amplitude synchronous states. We then demonstrate the capability of spike-timing-dependent plasticity (STDP) combined with intrinsic alpha (8-12 Hz) oscillations to efficiently influence learning. Further, we show how alpha-state-dependent STDP alters the local area dynamics from an irregular to a highly periodic alpha-like state. This is an important finding, as the cortical input from the thalamus is at the rate of alpha. We demonstrate how resulting rhythmic cortical output in this frequency range acts as a neuronal tuner and, hence, leads to synchronization or de-synchronization between brain areas. Finally, we demonstrate that locally restricted structural connectivity changes influence local as well as global dynamics and lead to altered rs-FC.

An adaptive transmission protocol for managing dynamic shared states in collaborative surgical simulation.

PubMed

Qin, J; Choi, K S; Ho, Simon S M; Heng, P A

2008-01-01

A force prediction algorithm is proposed to facilitate virtual-reality (VR) based collaborative surgical simulation by reducing the effect of network latencies. State regeneration is used to correct the estimated prediction. This algorithm is incorporated into an adaptive transmission protocol in which auxiliary features such as view synchronization and coupling control are equipped to ensure the system consistency. We implemented this protocol using multi-threaded technique on a cluster-based network architecture.

CNA/The Institute for Statecraft Meeting on Evaluating and Countering the Threat from the Islamic State

DTIC Science & Technology

2015-08-10

Charlie Hebdo.  Mastery of social media enables IS to exist as a virtual global caliphate. Islamic State: From Jihadi Movement to Potential Global...military skills but also in classic terror methods , in propaganda techniques, and in deception. As a conventional military, IS has demonstrated...Salafism, a strict constructionist , originalist interpretation of the core texts of Islam. Their intention is to reform Islam and return to what they

STEM Interns Get Real-World Experience in NHRC's Virtual Reality Lab

Science.gov Websites

stated purpose of this DoD website. Comments Closed Comments are closed. You will not be able to post a comment in this post. Follow Us! Follow Us on Facebook Follow Us on Twitter Follow Us on YouTube Follow Us

Evaluation of knowledge transfer in an immersive virtual learning environment for the transportation community : research project capsule.

DOT National Transportation Integrated Search

2010-01-01

In 2008 alone, 720 individuals were killed in a : construction or maintenance work zone in the : United States. However, since 2003, the total : number of individuals killed in a construction or : maintenance work zone in the US reached a : staggerin...

A Configuration Framework and Implementation for the Least Privilege Separation Kernel

DTIC Science & Technology

2010-12-01

The Altova Web site states that virtualization software, Parallels for Mac and Wine , is required for running it on MacOS and RedHat Linux...University of Singapore Singapore 28. Tan Lai Poh National University of Singapore Singapore 29. Quek Chee Luan Defence Science & Technology Agency Singapore

Comparisons and Contrasts in Traditional versus On-Line Teaching in Management.

ERIC Educational Resources Information Center

Karber, David J.

2001-01-01

Based on the experience of the California State University/Dominguez Hills in offering an Internet master's of business administration, explores forces causing the shift toward online learning, unique characteristics of the virtual student, how the playing field is "leveled" in online education, the importance of communicating carefully…

76 FR 66125 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-25

..., as well as testing. BNSF states it created a Web-based software application that it characterizes as.... Specifically, BNSF is proposing to use Web-based software to satisfy the ``hands-on'' portion of training... scenario. The employee must maneuver the avatar in the virtual setting and perform all inspection tasks...

Proactive Recruitment Strategies at CSUS Increase FCS Majors

ERIC Educational Resources Information Center

Malroutu, Y. Lakshmi; Tripp, Paula J.

2008-01-01

The profile and needs of today's undergraduate students have changed, and family and consumer sciences (FCS) departments will benefit from taking a proactive approach to adjust their recruitment strategies to meet those needs. California State University, Sacramento, implemented successful efforts in the areas of virtual contact, direct contact,…

Virtual Coaching for Instructional Leaders: A Multi-Method Investigation of Technology-Enabled External Assistance

ERIC Educational Resources Information Center

Ermeling, Bradley; Tatsui, Timothy; Young, Kelly

2015-01-01

Background: Education reforms over the last several decades have relied heavily on external assistance to help schools increase capacity for improving outcomes, but investing in sustained outside coaching and support is increasingly difficult with diminishing federal, state, and district resources. One under-investigated possibility for…

Prague: The City Is the Museum.

ERIC Educational Resources Information Center

Meilach, Dona Z.

2001-01-01

States that Prague, the capital of the Czech-Republic, is a virtual art museum because of the number of architectural styles and other artworks throughout the city. Explores the various architectural styles that are present in the city from the Gothic monasteries and churches to examples of contemporary styles. (CMK)

Legal Aspects of the Brown Decision.

ERIC Educational Resources Information Center

Carter, Robert L.

In Brown v. Board of Education of Topeka, Kansas, the Supreme Court outlawed segregation in the nation's public schools. This decision has not eliminated racial segregation, but it fundamentally altered the psychological pattern of race relations in the United States. Brown concerned a form of racial discrimination that has virtually vanished from…

The Dilemma of the Tuition-Driven College

ERIC Educational Resources Information Center

Dehne, Gerald; Small, Christopher

2006-01-01

The term "tuition driven" no longer pertains only to private colleges. As state appropriations to public universities dwindle, more colleges are relying to a greater degree on keeping classes full in order to generate revenue. The fact is, virtually all institutions are essentially tuition driven. Although trustees generally understand what being…

Trends in Student Aid.

ERIC Educational Resources Information Center

College Board, Washington, DC. Washington Office.

This report presents annual data on the amount of financial assistance available to postsecondary students in the form of grants, loans, and work-study. The data cover virtually all federal aid and most state and institutional assistance; not included in the study is financial aid in the form of indirect subsidies, students' wages, employer-paid…

Semiconductor laser technology for remote sensing experiments

NASA Technical Reports Server (NTRS)

Katz, Joseph

1988-01-01

Semiconductor injection lasers are required for implementing virtually all spaceborne remote sensing systems. Their main advantages are high reliability and efficiency, and their main roles are envisioned in pumping and injection locking of solid state lasers. In some shorter range applications they may even be utilized directly as the sources.

Inferring the annual migration patterns of fall armyworm(Lepidoptera: Noctuidae) in the United States from mitochondrial haplotypes

USDA-ARS?s Scientific Manuscript database

1. Regions of southern Florida, USA and southern Texas, USA (extending into Mexico)provide the source populations for virtually all fall armyworm infestations affecting the continental USA. Understanding how these overwintering populations annually disperse is important to efforts to predict and con...

Our Experiment in Online, Real-Time Reference.

ERIC Educational Resources Information Center

Broughton, Kelly

2001-01-01

Describes experiences in providing real-time online reference services to users with remote Web access at the Bowling Green State University library. Discusses the decision making process first used to select HumanClick software to communicate via chat; and the selection of a fee-based customer service product, Virtual Reference Desk. (LRW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stein, R.L.

A procedure for the analysis of observed isotope effects on rates of complex reactions is outlined which can be applied to kinetic isotope effect data for any reaction having a virtual transition state whose structure can be varied by adjusting a reaction parameter. This procedure is applied to the basic hydrolysis of p-nitroacetanilide. 3 tables. (DLC)

Holiday Perspectives on Air Traffic Control

NASA Image and Video Library

2016-12-14

As America travels over the holidays, NASA’s FutureFlight Central (FFC) is working to help passengers get to their destinations on time. The 360-degree virtual air traffic control tower is capable of simulating traffic and weather conditions to include snow, sleet and rain at almost any airport in the United States.

Moving towards the Virtual University: A Vision of Technology in Higher Education.

ERIC Educational Resources Information Center

Baker, Warren J.; Gloster, Arthur S. II

1994-01-01

California Polytechnic State University at San Luis Obispo is exploring several cost-effective technological solutions to improve learning productivity, reduce labor intensity, and provide new ways to deliver education and better services to students while enhancing quality of instruction. Strategic planning and partnerships have been key…

Tennessee's High School Dropouts: Examining the Fiscal Consequences

ERIC Educational Resources Information Center

D'Andrea, Christian

2010-01-01

High school dropouts adversely impact the state of Tennessee each year--financially and socially. Dropouts' lower incomes, high unemployment rates, increased need for medical care, and higher propensity for incarceration create a virtual vortex that consumes Tennesseans' tax dollars at a vicious rate. Hundreds of millions of dollars are spent on…

Black Athletes; Educational, Economic, and Political Considerations

ERIC Educational Resources Information Center

Green, Robert L.; And Others

1974-01-01

This issue focuses on racial discrimination in athletic competition in the United States. Data supports the contention that the employment of Blacks in Big Ten universities in virtually nonexistent at every level of athletics. Articles document the unequal treatment and exploitation of Black athletes in the areas of education, academic advising,…

Story Lab: Student Data Privacy

ERIC Educational Resources Information Center

Herold, Benjamin

2015-01-01

Student data privacy is an increasingly high-profile--and controversial--issue that touches schools and families across the country. There are stories to tell in virtually every community. About three dozen states have passed legislation addressing student data privacy in the past two years, and eight different proposals were floating around…

MEETING IN MEXICO: NOWCASTING AND FORECASTING BEACH BACTERIA CONCENTRATION USING EPA'S VIRTUAL BEACH SOFTWARE

EPA Science Inventory

Beaches in the United States of (North) America are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on water samples that typically require at least 18 hours to analyze. This persistence approach, or model, often leads...

Growing Scientists: A Partnership between a University and a School District

ERIC Educational Resources Information Center

Woods, Teresa Marie

2012-01-01

Precollege science education in the United States has virtually always been influenced by university scientists to one degree or another. Partnership models for university scientist--school district collaborations are being advocated to replace outreach models. Although the challenges for such partnerships are well documented, the means of…

Summary and synthesis: Cumulative impacts

Treesearch

Raymond M. Rice; Neil H. Berg

1987-01-01

Although the title of our plenary session speaks generally of ""development"", virtually all of our discussion (and that in the other two plenary sessions) dealt with the effect of forest practices. That emphasis is appropriate. Seventy percent of the State's utilizable streamflow comes from commercial forest lands. An additional 25 percent...

The Argument Is Not Compulsory Law, but How Attendance Is Recorded

ERIC Educational Resources Information Center

Watson, Michael; Hemmer, Lynn

2015-01-01

This paper examines attendance accounting policies and practices for students enrolled in public schools in Texas and in alternative schools of choice (ASC) in particular. Technology advancement allows students to complete their coursework virtually anywhere they have internet access; however, conventional state attendance policies still require…

Delivered! A Mid-Sized Academic Library's Experience with Distance Education

ERIC Educational Resources Information Center

Bartnik, Linda

2010-01-01

Murray State University (Kentucky) has been experimenting with various means of document delivery and research instruction for its online only and satellite campuses. These include ILLiad-based document delivery, Camtasia-to-UTube tutorials, a discipline-based service called Library on Blackboard, Eluminate and other virtual instructional methods.…

Virtual Civic Engagement: Exploring Technology, Secondary Social Studies, and Problem Based Learning with TPACK

ERIC Educational Resources Information Center

Schneider, Brett

2017-01-01

Sociological and cultural analysts have noted the reticence of public secondary schooling to recognize and build academic activities around the participatory culture in which adolescents are so readily involved (Jenkins, Purushotma, Weigel, Clinton & Robison, 2009). Despite the Common Core State Standards having required students to…

Fifty Years of Predictive Testing for Human Developmental Toxicity: From Thalidomide to Virtual Embryos

EPA Science Inventory

The thalidomide tragedy of the early 1960s led to the three “Segment” tests promulgated by the United States Food and Drug Administration in 1966. The Segment II study involves exposing pregnant rodents or rabbits during organogenesis and examining fetuses prior to pa...

Alternative Options in State-University Relationships in a Regional Setting: The Case of Canada.

ERIC Educational Resources Information Center

Farquhar, Robin H.

This document highlights the special challenges that Canada's higher education system faces due to its organizational structure that is, the relationship between the federal government and the provincial governments. Virtually all Canadian universities are publicly supported, but because the constitution clearly assigns responsibility for…

Building Virtual Models by Postprocessing Radiology Images: A Guide for Anatomy Faculty

ERIC Educational Resources Information Center

Tam, Matthew D. B. S.

2010-01-01

Radiology and radiologists are recognized as increasingly valuable resources for the teaching and learning of anatomy. State-of-the-art radiology department workstations with industry-standard software applications can provide exquisite demonstrations of anatomy, pathology, and more recently, physiology. Similar advances in personal computers and…

The Interactive Virtual Earth Science Teaching (InVEST) project: preliminary results

NASA Astrophysics Data System (ADS)

Gallus, W.; Cervato, C.; Parham, T.; Larsen, M.; Cruz-Neira, C.; Boudreaux, H.

2009-04-01

The InVEST (Interactive Virtual Earth Science Teaching) project has as its goal the development of state-of-the-art virtual reality geoscience tools that can be used to correct student misunderstandings about some geoscience phenomena. One tool, originally developed several years ago, the virtual tornadic thunderstorm, was recently modified based on feedback from instructors given the opportunity to use the tool. The modified virtual storm will be demonstrated during the presentation. In addition, a virtual volcano application is currently under development. To steer the development of this application, a Volcanic Concept Survey was recently administered to over 600 students at six U.S. institutions with the goal of identifying areas of greatest misconception relating to volcanoes. Both mean and median scores on the instrument were exceptionally low, indicating that students generally possessed minimal understanding of volcanic systems. High scores were restricted to the simplest aspects of volcanism (terminology, basic volcano shape) while questions requiring higher thinking and deeper conceptual connections (analysis of patterns, eruptive controls, and hazards) saw much lower scores. Categorical analysis of response types revealed the extent of specific misconceptions, the most predominant of which demonstrated a failure to link tectonics to a global volcanic pattern. Eruptive catalysts and controls also appear poorly understood, as are volcanic impacts on the environment and human endeavors. The survey also included demographic information which has been analyzed. Analysis of student sources of knowledge found that over 41% of students said that they had acquired most of their understanding about volcanoes from non-traditional sources such as the popular media and Hollywood films. Application of a multiple linear regression model and an expanded model suggests that these students were much less likely to receive high scores on questions relating to understanding. In contrast, traditional sources of knowledge (in-class learning, learning from textbooks) were highly significant predictors of high score in both models.

Addressing security issues related to virtual institute distributed activities

NASA Astrophysics Data System (ADS)

Stytz, Martin R.; Banks, Sheila B.

2008-03-01

One issue confounding the development and experimentation of distributed modeling and simulation environments is the inability of the project team to identify and collaborate with resources, both human and technical, from outside the United States. This limitation is especially significant within the human behavior representation area where areas such as cultural effects research and joint command team behavior modeling require the participation of various cultural and national representatives. To address this limitation, as well as other human behavior representation research issues, NATO Research and Technology Organization initiated a project to develop a NATO virtual institute that enables more effective and more collaborative research into human behavior representation. However, in building and operating a virtual institute one of the chief concerns must be the cyber security of the institute. Because the institute "exists" in cyberspace, all of its activities are susceptible to cyberattacks, subterfuge, denial of service and all of the vulnerabilities that networked computers must face. In our opinion, for the concept of virtual institutes to be successful and useful, their operations and services must be protected from the threats in the cyber environment. A key to developing the required protection is the development and promulgation of standards for cyber security. In this paper, we discuss the types of cyber standards that are required, how new internet technologies can be exploited and can benefit the promulgation, development, maintenance, and robustness of the standards. This paper is organized as follows. Section One introduces the concept of the virtual institutes, the expected benefits, and the motivation for our research and for research in this area. Section Two presents background material and a discussion of topics related to VIs, uman behavior and cultural modeling, and network-centric warfare. Section Three contains a discussion of the security challenges that face the virtual institute and the characteristics of the standards that must be employed. Section Four contains our proposal for documentation of the cybersecurity standards. Section Five contains the conclusion and suggestions for further work.

Teleportation of atomic and photonic states in low-Q cavity QED

NASA Astrophysics Data System (ADS)

Peng, Zhao-Hui; Zou, Jian; Liu, Xiao-Juan; Kuang, Le-Man

2012-11-01

We propose two alternative teleportation protocols in low-Q cavity QED. Through the input-output process of photons, we can generate atom-photon entangled states as the quantum channel. Then we propose to teleport single-atom (two-atom entangled) state using coherent photonic states, and to teleport single photonic state with the assistance of three-level atom. The distinct feature of our protocols is that we can teleport both atomic and photonic states via the input-output process of photons in the low-Q cavity. Furthermore, as our protocols work in low-Q cavities and only involve virtual excitation of atoms, they are insensitive to both cavity decay and atomic spontaneous emission, and may be feasible with current technology.

Plasma effect on fast-electron-impact-ionization from 2p state of hydrogen-like ions

NASA Astrophysics Data System (ADS)

Qi, Y. Y.; Ning, L. N.; Wang, J. G.; Qu, Y. Z.

2013-12-01

Plasma effects on the high-energy electron-impact ionization process from 2p orbital of Hydrogen-like ions embedded in weakly coupled plasmas are investigated in the first Born approximation. The plasma screening of the Coulomb interaction between charged particles is represented by the Debye Hückel model. The screening of Coulomb interactions decreases the ionization energies and varies the wave functions for not only the bound orbital but also the continuum; the number of the summation for the angular-momentum states in the generalized oscillator strength densities is reduced with the plasma screening stronger when the ratio of ɛ /I2p (I2p is the ionization energy of 2p state and ɛ is the energy of the continuum electron) is kept, and then the contribution from the lower-angular-momentum states dominates the generalized oscillator strength densities, so the threshold phenomenon in the generalized oscillator strength densities and the double differential cross sections are remarkable: The accessional minima, the outstanding enhancement, and the resonance peaks emerge a certain energy region, whose energy position and width are related to the vicinity between δ and the critical value δnlc, corresponding to the special plasma condition when the bound state |nl⟩ just enters the continuum; the multiple virtual-state enhancement and the multiple shape resonances in a certain energy domain also appear in the single differential cross section whenever the plasma screening parameter passes through a critical value δnlc, which is similar to the photo-ionization process but different from it, where the dipole transition only happens, but multi-pole transition will occur in the electron-impact ionization process, so its multiple virtual-state enhancements and the multiple shape resonances appear more frequently than the photo-ionization process.

Overview of telepathology, virtual microscopy, and whole slide imaging: prospects for the future.

PubMed

Weinstein, Ronald S; Graham, Anna R; Richter, Lynne C; Barker, Gail P; Krupinski, Elizabeth A; Lopez, Ana Maria; Erps, Kristine A; Bhattacharyya, Achyut K; Yagi, Yukako; Gilbertson, John R

2009-08-01

Telepathology, the practice of pathology at a long distance, has advanced continuously since 1986. Today, fourth-generation telepathology systems, so-called virtual slide telepathology systems, are being used for education applications. Both conventional and innovative surgical pathology diagnostic services are being designed and implemented as well. The technology has been commercialized by more than 30 companies in Asia, the United States, and Europe. Early adopters of telepathology have been laboratories with special challenges in providing anatomic pathology services, ranging from the need to provide anatomic pathology services at great distances to the use of the technology to increase efficiency of services between hospitals less than a mile apart. As to what often happens in medicine, early adopters of new technologies are professionals who create model programs that are successful and then stimulate the creation of infrastructure (ie, reimbursement, telecommunications, information technologies, and so on) that forms the platforms for entry of later, mainstream, adopters. The trend at medical schools, in the United States, is to go entirely digital for their pathology courses, discarding their student light microscopes, and building virtual slide laboratories. This may create a generation of pathology trainees who prefer digital pathology imaging over the traditional hands-on light microscopy. The creation of standards for virtual slide telepathology is early in its development but accelerating. The field of telepathology has now reached a tipping point at which major corporations now investing in the technology will insist that standards be created for pathology digital imaging as a value added business proposition. A key to success in teleradiology, already a growth industry, has been the implementation of standards for digital radiology imaging. Telepathology is already the enabling technology for new, innovative laboratory services. Examples include STAT QA surgical pathology second opinions at a distance and a telehealth-enabled rapid breast care service. The innovative bundling of telemammography, telepathology, and teleoncology services may represent a new paradigm in breast care that helps address the serious issue of fragmentation of breast cancer care in the United States and elsewhere. Legal and regulatory issues in telepathology are being addressed and are regarded as a potential catalyst for the next wave of telepathology advances, applications, and implementations.

Experimental and numeric stress analysis of titanium and zirconia one-piece dental implants.

PubMed

Mobilio, Nicola; Stefanoni, Filippo; Contiero, Paolo; Mollica, Francesco; Catapano, Santo

2013-01-01

To compare the stress in bone around zirconia and titanium implants under loading. A one-piece zirconia implant and a replica of the same implant made of commercially pure titanium were embedded in two self-curing acrylic resin blocks. To measure strain, a strain gauge was applied on the surface of the two samples. Loads of 50, 100, and 150 N, with orientations of 30, 45, and 60 degrees with respect to the implant axis were applied on the implant. Strain under all loading conditions on both samples was measured. Three-dimensional virtual replicas of both the implants were reproduced using the finite element method and inserted into a virtual acrylic resin block. All the materials were considered isotropic, linear, and elastic. The same geometry and loading conditions of the experimental setup were used to realize two new models, with the implants embedded within a virtual bone block. Very close values of strain in the two implants embedded in acrylic resin were obtained both experimentally and numerically. The stress states generated by the implants embedded in virtual bone were also very similar, even if the two implants moved differently. Moreover, the stress levels were higher on cortical bone than on trabecular bone. The stress levels in bone, generated by the two implants, appeared to be very similar. From a mechanical point of view, zirconia is a feasible substitute for titanium.

Manipulating the fidelity of lower extremity visual feedback to identify obstacle negotiation strategies in immersive virtual reality.

PubMed

Kim, Aram; Zhou, Zixuan; Kretch, Kari S; Finley, James M

2017-07-01

The ability to successfully navigate obstacles in our environment requires integration of visual information about the environment with estimates of our body's state. Previous studies have used partial occlusion of the visual field to explore how information about the body and impending obstacles are integrated to mediate a successful clearance strategy. However, because these manipulations often remove information about both the body and obstacle, it remains to be seen how information about the lower extremities alone is utilized during obstacle crossing. Here, we used an immersive virtual reality (VR) interface to explore how visual feedback of the lower extremities influences obstacle crossing performance. Participants wore a head-mounted display while walking on treadmill and were instructed to step over obstacles in a virtual corridor in four different feedback trials. The trials involved: (1) No visual feedback of the lower extremities, (2) an endpoint-only model, (3) a link-segment model, and (4) a volumetric multi-segment model. We found that the volumetric model improved success rate, placed their trailing foot before crossing and leading foot after crossing more consistently, and placed their leading foot closer to the obstacle after crossing compared to no model. This knowledge is critical for the design of obstacle negotiation tasks in immersive virtual environments as it may provide information about the fidelity necessary to reproduce ecologically valid practice environments.