Sample records for virtual work principle

  1. On the Development of Multi-Step Inverse FEM with Shell Model

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Du, R.

    2005-08-01

    The inverse or one-step finite element approach is increasingly used in the sheet metal stamping industry to predict strain distribution and the initial blank shape in the preliminary design stage. Based on the existing theory, there are two types of method: one is based on the principle of virtual work and the other is based on the principle of extreme work. Much research has been conducted to improve the accuracy of simulation results. For example, based on the virtual work principle, Batoz et al. developed a new method using triangular DKT shell elements. In this new method, the bending and unbending effects are considered. Based on the principle of extreme work, Majlessi and et al. proposed the multi-step inverse approach with membrane elements and applied it to an axis-symmetric part. Lee and et al. presented an axis-symmetric shell element model to solve the similar problem. In this paper, a new multi-step inverse method is introduced with no limitation on the workpiece shape. It is a shell element model based on the virtual work principle. The new method is validated by means of comparing to the commercial software system (PAMSTAMP®). The comparison results indicate that the accuracy is good.

  2. Virtual data

    NASA Astrophysics Data System (ADS)

    Bjorklund, E.

    1994-12-01

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

  3. Post-Fisherian Experimentation: From Physical to Virtual

    DOE PAGES

    Jeff Wu, C. F.

    2014-04-24

    Fisher's pioneering work in design of experiments has inspired further work with broader applications, especially in industrial experimentation. Three topics in physical experiments are discussed: principles of effect hierarchy, sparsity, and heredity for factorial designs, a new method called CME for de-aliasing aliased effects, and robust parameter design. The recent emergence of virtual experiments on a computer is reviewed. Here, some major challenges in computer experiments, which must go beyond Fisherian principles, are outlined.

  4. International E-Benchmarking: Flexible Peer Development of Authentic Learning Principles in Higher Education

    ERIC Educational Resources Information Center

    Leppisaari, Irja; Vainio, Leena; Herrington, Jan; Im, Yeonwook

    2011-01-01

    More and more, social technologies and virtual work methods are facilitating new ways of crossing boundaries in professional development and international collaborations. This paper examines the peer development of higher education teachers through the experiences of the IVBM project (International Virtual Benchmarking, 2009-2010). The…

  5. The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial.

    PubMed

    Andersen, Steven Arild Wuyts; Mikkelsen, Peter Trier; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

    2016-01-01

    Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy. Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances. Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p  = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p  < 0.005). Initial instruction using worked examples followed by a problem completion exercise did not reduce the cognitive load or improve the performance of the following procedures in novices. Increased cognitive load when part tasks needed to be integrated in the post-training procedures could be a possible explanation for this. Other instructional designs and methods are needed to lower the cognitive load and improve the performance in virtual reality surgical simulation training of novices.

  6. The virtual-casing principle and Helmholtz's theorem

    DOE PAGES

    Hanson, J. D.

    2015-09-10

    The virtual-casing principle is used in plasma physics to convert a Biot–Savart integration over a current distribution into a surface integral over a surface that encloses the current. In many circumstances, use of virtual casing can significantly speed up the computation of magnetic fields. In this paper, a virtual-casing principle is derived for a general vector field with arbitrary divergence and curl. This form of the virtual-casing principle is thus applicable to both magnetostatic fields and electrostatic fields. The result is then related to Helmholtz's theorem.

  7. The virtual-casing principle and Helmholtz’s theorem

    DOE PAGES

    Hanson, J. D.

    2015-09-10

    The virtual-casing principle is used in plasma physics to convert a Biot–Savart integration over a current distribution into a surface integral over a surface that encloses the current. In many circumstances, use of virtual casing can significantly speed up the computation of magnetic fields. In this paper, a virtual-casing principle is derived for a general vector field with arbitrary divergence and curl. This form of the virtual-casing principle is thus applicable to both magnetostatic fields and electrostatic fields. The result is then related to Helmholtz’s theorem.

  8. Organizational Design Drivers to Enable Emergent Creativity in Web-Based Communities

    ERIC Educational Resources Information Center

    De Toni, Alberto F.; Biotto, Gianluca; Battistella, Cinzia

    2012-01-01

    Purpose: In the stream of works studying complexity from an organizational viewpoint, literature is focused mainly on describing new organizational forms (holonic organization, circular organization, virtual corporation, ...) and on conceptual works identifying new managerial principles to manage emergence (job enrichment, de-regulation, ...). But…

  9. Developing design principles for a Virtual Hospice: improving access to care.

    PubMed

    Taylor, Andrea; French, Tara; Raman, Sneha

    2018-03-01

    Providing access to hospice services will become increasingly difficult due to the pressures of an ageing population and limited resources. To help address this challenge, a small number of services called Virtual Hospice have been established. This paper presents early-stage design work on a Virtual Hospice to improve access to services provided by a hospice (Highland Hospice) serving a largely remote and rural population in Scotland, UK. The study was structured as a series of Experience Labs with Highland Hospice staff, healthcare professionals and patients. Experience Labs employ a participatory design approach where participants are placed at the centre of the design process, helping to ensure that the resultant service meets their needs. Data from the Experience Labs were analysed using qualitative thematic analysis and design analysis. A number of themes and barriers to accessing Highland Hospice services were identified. In response, an initial set of seven design principles was developed. Design principles are high-level guidelines that are used to improve prioritisation and decision making during the design process by ensuring alignment with research insights. The design principles were piloted with a group of stakeholders and gained positive feedback. The design principles are intended to guide the ongoing development of the Highland Hospice Virtual Hospice. However, the challenges faced by Highland Hospice in delivering services in a largely remote and rural setting are not unique. The design principles, encompassing digital and non-digital guidelines, or the design approach could be applied by other hospices in the UK or overseas. © 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.

  10. Social Work Continuing Education: Current Issues and Future Direction

    ERIC Educational Resources Information Center

    Kurzman, Paul A.

    2016-01-01

    Continuing education is arising as an area of rapid growth and increased attention in the social work profession. Conceptually, the impetus and focus are on the promotion of the principles of lifelong learning and professional replenishment; but pragmatically, the driving force has been the virtually universal requirement of continuing education…

  11. The maximum work principle regarded as a consequence of an optimization problem based on mechanical virtual power principle and application of constructal theory

    NASA Astrophysics Data System (ADS)

    Gavrus, Adinel

    2017-10-01

    This scientific paper proposes to prove that the maximum work principle used by theory of continuum media plasticity can be regarded as a consequence of an optimization problem based on constructal theory (prof. Adrian BEJAN). It is known that the thermodynamics define the conservation of energy and the irreversibility of natural systems evolution. From mechanical point of view the first one permits to define the momentum balance equation, respectively the virtual power principle while the second one explains the tendency of all currents to flow from high to low values. According to the constructal law all finite-size system searches to evolve in such configurations that flow more and more easily over time distributing the imperfections in order to maximize entropy and to minimize the losses or dissipations. During a material forming process the application of constructal theory principles leads to the conclusion that under external loads the material flow is that which all dissipated mechanical power (deformation and friction) become minimal. On a mechanical point of view it is then possible to formulate the real state of all mechanical variables (stress, strain, strain rate) as those that minimize the total dissipated power. So between all other virtual non-equilibrium states, the real state minimizes the total dissipated power. It can be then obtained a variational minimization problem and this paper proof in a mathematical sense that starting from this formulation can be finding in a more general form the maximum work principle together with an equivalent form for the friction term. An application in the case of a plane compression of a plastic material shows the feasibility of the proposed minimization problem formulation to find analytical solution for both cases: one without friction influence and a second which take into account Tresca friction law. To valid the proposed formulation, a comparison with a classical analytical analysis based on slices, upper/lower bound methods and numerical Finite Element simulation is also presented.

  12. Virtualization Technology for System of Systems Test and Evaluation

    DTIC Science & Technology

    2012-06-01

    Peterson , Tillman, & Hatfield (1972) outlined the capabilities of virtualization in the early days of VM with some guiding principles. The following...Sheikh, based on the work of Balci (1994, 1995), and Balci et al. ( 1996 ), seeks to organize types of tests and to align requirements to the appropriate...Verification, validation, and testing in software engineering (pp. 155–184). Hershey , PA: Idea Group. Adair, R. J., Bayles, R. U., Comeau, L. W

  13. Thermal stresses in composite tubes using complementary virtual work

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Cooper, D. E.

    1988-01-01

    This paper addresses the computation of thermally induced stresses in layered, fiber-reinforced composite tubes subjected to a circumferential gradient. The paper focuses on using the principle of complementary virtual work, in conjunction with a Ritz approximation to the stress field, to study the influence on the predicted stresses of including temperature-dependent material properties. Results indicate that the computed values of stress are sensitive to the temperature dependence of the matrix-direction compliance and matrix-direction thermal expansion in the plane of the lamina. There is less sensitivity to the temperature dependence of the other material properties.

  14. Implementation of utaut model to understand the use of virtual classroom principle in higher education

    NASA Astrophysics Data System (ADS)

    Aditya, B. R.; Permadi, A.

    2018-03-01

    This paper describes implementation of Unified Theory of Acceptance and User of Technology (UTAUT) model to assess the use of virtual classroom in support of teaching and learning in higher education. The purpose of this research is how virtual classroom that has fulfilled the basic principle can be accepted and used by students positively. This research methodology uses the quantitative and descriptive approach with a questionnaire as a tool for measuring the height of virtual classroom principle acception. This research uses a sample of 105 students in D3 Informatics Management at Telkom University. The result of this research is that the use of classroom virtual principle are positive and relevant to the students in higher education.

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

    Hanson, J. D.

    The virtual-casing principle is used in plasma physics to convert a Biot–Savart integration over a current distribution into a surface integral over a surface that encloses the current. In many circumstances, use of virtual casing can significantly speed up the computation of magnetic fields. In this paper, a virtual-casing principle is derived for a general vector field with arbitrary divergence and curl. This form of the virtual-casing principle is thus applicable to both magnetostatic fields and electrostatic fields. The result is then related to Helmholtz's theorem.

  16. Building intuitive 3D interfaces for virtual reality systems

    NASA Astrophysics Data System (ADS)

    Vaidya, Vivek; Suryanarayanan, Srikanth; Seitel, Mathias; Mullick, Rakesh

    2007-03-01

    An exploration of techniques for developing intuitive, and efficient user interfaces for virtual reality systems. Work seeks to understand which paradigms from the better-understood world of 2D user interfaces remain viable within 3D environments. In order to establish this a new user interface was created that applied various understood principles of interface design. A user study was then performed where it was compared with an earlier interface for a series of medical visualization tasks.

  17. 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

  18. The highly intelligent virtual agents for modeling financial markets

    NASA Astrophysics Data System (ADS)

    Yang, G.; Chen, Y.; Huang, J. P.

    2016-02-01

    Researchers have borrowed many theories from statistical physics, like ensemble, Ising model, etc., to study complex adaptive systems through agent-based modeling. However, one fundamental difference between entities (such as spins) in physics and micro-units in complex adaptive systems is that the latter are usually with high intelligence, such as investors in financial markets. Although highly intelligent virtual agents are essential for agent-based modeling to play a full role in the study of complex adaptive systems, how to create such agents is still an open question. Hence, we propose three principles for designing high artificial intelligence in financial markets and then build a specific class of agents called iAgents based on these three principles. Finally, we evaluate the intelligence of iAgents through virtual index trading in two different stock markets. For comparison, we also include three other types of agents in this contest, namely, random traders, agents from the wealth game (modified on the famous minority game), and agents from an upgraded wealth game. As a result, iAgents perform the best, which gives a well support for the three principles. This work offers a general framework for the further development of agent-based modeling for various kinds of complex adaptive systems.

  19. Angular motion equations for a satellite with hinged flexible solar panel

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, M. Yu.; Tkachev, S. S.; Roldugin, D. S.; Nuralieva, A. B.; Mashtakov, Y. V.

    2016-11-01

    Non-linear mathematical model for the satellite with hinged flexible solar panel is presented. Normal modes of flexible elements are used for motion description. Motion equations are derived using virtual work principle. A comparison of normal modes calculation between finite element method and developed model is presented.

  20. Closed-form dynamics of a hexarot parallel manipulator by means of the principle of virtual work

    NASA Astrophysics Data System (ADS)

    Pedrammehr, Siamak; Nahavandi, Saeid; Abdi, Hamid

    2018-04-01

    In this research, a systematic approach to solving the inverse dynamics of hexarot manipulators is addressed using the methodology of virtual work. For the first time, a closed form of the mathematical formulation of the standard dynamic model is presented for this class of mechanisms. An efficient algorithm for solving this closed-form dynamic model of the mechanism is developed and it is used to simulate the dynamics of the system for different trajectories. Validation of the proposed model is performed using SimMechanics and it is shown that the results of the proposed mathematical model match with the results obtained by the SimMechanics model.

  1. Full-Field Strain Measurement On Titanium Welds And Local Elasto-Plastic Identification With The Virtual Fields Method

    NASA Astrophysics Data System (ADS)

    Tattoli, F.; Pierron, F.; Rotinat, R.; Casavola, C.; Pappalettere, C.

    2011-01-01

    One of the main problems in welding is the microstructural transformation within the area affected by the thermal history. The resulting heterogeneous microstructure within the weld nugget and the heat affected zones is often associated with changes in local material properties. The present work deals with the identification of material parameters governing the elasto—plastic behaviour of the fused and heat affected zones as well as the base material for titanium hybrid welded joints (Ti6Al4V alloy). The material parameters are identified from heterogeneous strain fields with the Virtual Fields Method. This method is based on a relevant use of the principle of virtual work and it has been shown to be useful and much less time consuming than classical finite element model updating approaches applied to similar problems. The paper will present results and discuss the problem of selection of the weld zones for the identification.

  2. Implementation of a Virtual Microphone Array to Obtain High Resolution Acoustic Images

    PubMed Central

    Izquierdo, Alberto; Suárez, Luis; Suárez, David

    2017-01-01

    Using arrays with digital MEMS (Micro-Electro-Mechanical System) microphones and FPGA-based (Field Programmable Gate Array) acquisition/processing systems allows building systems with hundreds of sensors at a reduced cost. The problem arises when systems with thousands of sensors are needed. This work analyzes the implementation and performance of a virtual array with 6400 (80 × 80) MEMS microphones. This virtual array is implemented by changing the position of a physical array of 64 (8 × 8) microphones in a grid with 10 × 10 positions, using a 2D positioning system. This virtual array obtains an array spatial aperture of 1 × 1 m2. Based on the SODAR (SOund Detection And Ranging) principle, the measured beampattern and the focusing capacity of the virtual array have been analyzed, since beamforming algorithms assume to be working with spherical waves, due to the large dimensions of the array in comparison with the distance between the target (a mannequin) and the array. Finally, the acoustic images of the mannequin, obtained for different frequency and range values, have been obtained, showing high angular resolutions and the possibility to identify different parts of the body of the mannequin. PMID:29295485

  3. Virtual Worlds; Real Learning: Design Principles for Engaging Immersive Environments

    NASA Technical Reports Server (NTRS)

    Wu (u. Sjarpm)

    2012-01-01

    The EMDT master's program at Full Sail University embarked on a small project to use a virtual environment to teach graduate students. The property used for this project has evolved our several iterations and has yielded some basic design principles and pedagogy for virtual spaces. As a result, students are emerging from the program with a better grasp of future possibilities.

  4. Interactive Screen Experiments--Innovative Virtual Laboratories for Distance Learners

    ERIC Educational Resources Information Center

    Hatherly, P. A.; Jordan, S. E.; Cayless, A.

    2009-01-01

    The desirability and value of laboratory work for physics students is a well-established principle and issues arise where students are inherently remote from their host institution, as is the case for the UK's Open University. In this paper, we present developments from the Physics Innovations Centre for Excellence in Teaching and Learning…

  5. Internet virtual studio: low-cost augmented reality system for WebTV

    NASA Astrophysics Data System (ADS)

    Sitnik, Robert; Pasko, Slawomir; Karaszewski, Maciej; Witkowski, Marcin

    2008-02-01

    In this paper a concept of a Internet Virtual Studio as a modern system for production of news, entertainment, educational and training material is proposed. This system is based on virtual studio technology and integrated with multimedia data base. Its was developed for web television content production. In successive subentries the general system architecture, as well as the architecture of modules one by one is discussed. The authors describe each module by presentation of a brief information about work principles and technical limitations. The presentation of modules is strictly connected with a presentation of their capabilities. Results produced by each of them are shown in the form of exemplary images. Finally, exemplary short production is presented and discussed.

  6. Utah Virtual Lab: JAVA interactivity for teaching science and statistics on line.

    PubMed

    Malloy, T E; Jensen, G C

    2001-05-01

    The Utah on-line Virtual Lab is a JAVA program run dynamically off a database. It is embedded in StatCenter (www.psych.utah.edu/learn/statsampler.html), an on-line collection of tools and text for teaching and learning statistics. Instructors author a statistical virtual reality that simulates theories and data in a specific research focus area by defining independent, predictor, and dependent variables and the relations among them. Students work in an on-line virtual environment to discover the principles of this simulated reality: They go to a library, read theoretical overviews and scientific puzzles, and then go to a lab, design a study, collect and analyze data, and write a report. Each student's design and data analysis decisions are computer-graded and recorded in a database; the written research report can be read by the instructor or by other students in peer groups simulating scientific conventions.

  7. Design Principles of an Open Agent Architecture for Web-Based Learning Community.

    ERIC Educational Resources Information Center

    Jin, Qun; Ma, Jianhua; Huang, Runhe; Shih, Timothy K.

    A Web-based learning community involves much more than putting learning materials into a Web site. It can be seen as a complex virtual organization involved with people, facilities, and cyber-environment. Tremendous work and manpower for maintaining, upgrading, and managing facilities and the cyber-environment are required. There is presented an…

  8. Design of virtual SCADA simulation system for pressurized water reactor

    NASA Astrophysics Data System (ADS)

    Wijaksono, Umar; Abdullah, Ade Gafar; Hakim, Dadang Lukman

    2016-02-01

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles of energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor.

  9. Colonic transit time and pressure based on Bernoulli's principle.

    PubMed

    Uno, Yoshiharu

    2018-01-01

    Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli's principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli's principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli's principle. A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified. The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC. The CTT and HAPC can be explained by Bernoulli's principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics.

  10. Design of virtual SCADA simulation system for pressurized water reactor

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

    Wijaksono, Umar, E-mail: umar.wijaksono@student.upi.edu; Abdullah, Ade Gafar; Hakim, Dadang Lukman

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles ofmore » energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor.« less

  11. The Uncertainty Principle, Virtual Particles and Real Forces

    ERIC Educational Resources Information Center

    Jones, Goronwy Tudor

    2002-01-01

    This article provides a simple practical introduction to wave-particle duality, including the energy-time version of the Heisenberg Uncertainty Principle. It has been successful in leading students to an intuitive appreciation of "virtual particles" and the role they play in describing the way ordinary particles, like electrons and protons, exert…

  12. Nebula observations. Catalogues and archive of photoplates

    NASA Astrophysics Data System (ADS)

    Shlyapnikov, A. A.; Smirnova, M. A.; Elizarova, N. V.

    2017-12-01

    A process of data systematization based on "Academician G.A. Shajn's Plan" for studying the Galaxy structure related to nebula observations is considered. The creation of digital versions of catalogues of observations and publications is described, as well as their presentation in HTML, VOTable and AJS formats and basic principles of work in the interactive application of International Virtual Observatory the Aladin Sky Atlas.

  13. Utilizing Virtual Teams in a Management Principles Course

    ERIC Educational Resources Information Center

    Olson-Buchanan, Julie B.; Rechner, Paula L.; Sanchez, Rudolph J.; Schmidtke, James M.

    2007-01-01

    Purpose: The purpose of this paper is to describe development of a component in a management principles course to develop university students' virtual team skills. There were several challenges in creating and implementing this new component. The paper aims to describe how these challenges were addressed and discusses outcomes associated with this…

  14. Applying Virtual Rehearsal Principle in Developing a Persuasive Multimedia Learning Environment (PMLE)

    NASA Astrophysics Data System (ADS)

    Jaafar, Wan Ahmad; Nur, Sobihatun

    This paper is outlining the potential use of virtual environment in persuading through computer simulation. The main focus of the paper is to apply an attempt of how virtual rehearsal principle can be designed into educational material using CD ROM based multimedia application to persuade as well as to reduce children dental anxiety particularly in Malaysian children context. This paper divided in three stages. Firstly, we provide a conceptual background of virtual rehearsal principle and how the principle has been applied in designing the information interfaces and presentation of a persuasive multimedia learning environment (PMLE). Secondly, the research design was administered to measure the effects of the PMLE in reducing children dental anxiety. Primary school children age between seven and nine years old are selected as respondents. Thirdly, the result of the study has revealed the feedback from children regarding baseline test and children dental anxiety test. The results on presenting this PMLE to primary school children show how it was able to reduce children dental anxiety and could let the children have a "mentally-prepared" condition for dental visit in the future.

  15. Colonic transit time and pressure based on Bernoulli’s principle

    PubMed Central

    Uno, Yoshiharu

    2018-01-01

    Purpose Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli’s principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli’s principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli’s principle. Methods A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified. Results The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC. Conclusion The CTT and HAPC can be explained by Bernoulli’s principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics. PMID:29670388

  16. Managing Cognitive Load in Educational Multi-User Virtual Environments: Reflection on Design Practice

    ERIC Educational Resources Information Center

    Nelson, Brian C.; Erlandson, Benjamin E.

    2008-01-01

    In this paper, we explore how the application of multimedia design principles may inform the development of educational multi-user virtual environments (MUVEs). We look at design principles that have been shown to help learners manage cognitive load within multimedia environments and conduct a conjectural analysis of the extent to which such…

  17. The dynamic Virtual Fields Method on rubbers at medium and high strain rates

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-Ho; Siviour, Clive R.

    2015-09-01

    Elastomeric materials are widely used for energy absorption applications, often experiencing high strain rate deformations. The mechanical characterization of rubbers at high strain rates presents several experimental difficulties, especially associated with achieving adequate signal to noise ratio and static stress equilibrium, when using a conventional technique such as the split Hopkinson pressure bar. In the present study, these problems are avoided by using the dynamic Virtual Fields Method (VFM) in which acceleration fields, clearly generated by the non-equilibrium state, are utilized as a force measurement with in the frame work of the principle of virtual work equation. In this paper, two dynamic VFM based techniques are used to characterise an EPDM rubber. These are denoted as the linear and nonlinear VFM and are developed for (respectively) medium (drop-weight) and high (gas-gun) strain-rate experiments. The use of the two VFMs combined with high-speed imaging analysed by digital imaging correlation allows the identification of the parameters of a given rubber mechanical model; in this case the Ogden model is used.

  18. VIH-TAVIE.

    PubMed

    Rouleau, Geneviève; Richard, Lauralie; Côté, José

    2016-01-01

    The use of information and communication technologies for designing web-based nursing interventions is growing exponentially. Despite the interest devoted to such approaches, little is known about their foundational principles and the way they translate into virtual nursing practice to generate meaningful engagement with patients. VIH-TAVIETM is a virtual nursing intervention aiming to empower people living with HIV to help them in managing their antiretroviral therapy. Here we present VIH-TAVIETM relational model of engagement - its core components informed by interview data with patients and a virtual nurse: building a virtual presence founded on caring relational principles and values; creating a caring environment where patients feel safe, supported and respected; stimulating patients' engagement by offering supportive and tailored messages; transposing nursing communication skills into a virtual practice to build trust and reciprocal relationships. This study suggests that empowering connections can develop between a nurse and a patient within a caring virtual environment.

  19. Application of the Virtual Fields Method to a relaxation behaviour of rubbers

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-ho; Siviour, Clive R.

    2018-07-01

    This paper presents the application of the Virtual Fields Method (VFM) for the characterization of viscoelastic behaviour of rubbers. The relaxation behaviour of the rubbers following a dynamic loading event is characterized using the dynamic VFM in which full-field (two dimensional) strain and acceleration data, obtained from high-speed imaging, are analysed by the principle of virtual work without traction force data, instead using the acceleration fields in the specimen to provide stress information. Two (silicone and nitrile) rubbers were tested in tension using a drop-weight apparatus. It is assumed that the dynamic behaviour is described by the combination of hyperelastic and Prony series models. A VFM based procedure is designed and used to produce the identification of the modulus term of a hyperelastic model and the Prony series parameters within a time scale determined by two experimental factors: imaging speed and loading duration. Then, the time range of the data is extended using experiments at different temperatures combined with the time-temperature superposition principle. Prior to these experimental analyses, finite element simulations were performed to validate the application of the proposed VFM analysis. Therefore, for the first time, it has been possible to identify relaxation behaviour of a material following dynamic loading, using a technique that can be applied to both small and large deformations.

  20. Incremental analysis of large elastic deformation of a rotating cylinder

    NASA Technical Reports Server (NTRS)

    Buchanan, G. R.

    1976-01-01

    The effect of finite deformation upon a rotating, orthotropic cylinder was investigated using a general incremental theory. The incremental equations of motion are developed using the variational principle. The governing equations are derived using the principle of virtual work for a body with initial stress. The governing equations are reduced to those for the title problem and a numerical solution is obtained using finite difference approximations. Since the problem is defined in terms of one independent space coordinate, the finite difference grid can be modified as the incremental deformation occurs without serious numerical difficulties. The nonlinear problem is solved incrementally by totaling a series of linear solutions.

  1. Quantum probability ranking principle for ligand-based virtual screening.

    PubMed

    Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

    2017-04-01

    Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

  2. Quantum probability ranking principle for ligand-based virtual screening

    NASA Astrophysics Data System (ADS)

    Al-Dabbagh, Mohammed Mumtaz; Salim, Naomie; Himmat, Mubarak; Ahmed, Ali; Saeed, Faisal

    2017-04-01

    Chemical libraries contain thousands of compounds that need screening, which increases the need for computational methods that can rank or prioritize compounds. The tools of virtual screening are widely exploited to enhance the cost effectiveness of lead drug discovery programs by ranking chemical compounds databases in decreasing probability of biological activity based upon probability ranking principle (PRP). In this paper, we developed a novel ranking approach for molecular compounds inspired by quantum mechanics, called quantum probability ranking principle (QPRP). The QPRP ranking criteria would make an attempt to draw an analogy between the physical experiment and molecular structure ranking process for 2D fingerprints in ligand based virtual screening (LBVS). The development of QPRP criteria in LBVS has employed the concepts of quantum at three different levels, firstly at representation level, this model makes an effort to develop a new framework of molecular representation by connecting the molecular compounds with mathematical quantum space. Secondly, estimate the similarity between chemical libraries and references based on quantum-based similarity searching method. Finally, rank the molecules using QPRP approach. Simulated virtual screening experiments with MDL drug data report (MDDR) data sets showed that QPRP outperformed the classical ranking principle (PRP) for molecular chemical compounds.

  3. MHD Equilibrium with Reversed Current Density and Magnetic Islands Revisited: the Vacuum Vector Potential Calculus

    NASA Astrophysics Data System (ADS)

    L. Braga, F.

    2013-10-01

    The solution of Grad-Shafranov equation determines the stationary behavior of fusion plasma inside a tokamak. To solve the equation it is necessary to know the toroidal current density profile. Recent works show that it is possible to determine a magnetohydrodynamic (MHD) equilibrium with reversed current density (RCD) profiles that presents magnetic islands. In this work we show analytical MHD equilibrium with a RCD profile and analyze the structure of the vacuum vector potential associated with these equilibria using the virtual casing principle.

  4. Sulfonylureas and Glinides as New PPARγ Agonists:. Virtual Screening and Biological Assays

    NASA Astrophysics Data System (ADS)

    Scarsi, Marco; Podvinec, Michael; Roth, Adrian; Hug, Hubert; Kersten, Sander; Albrecht, Hugo; Schwede, Torsten; Meyer, Urs A.; Rücker, Christoph

    2007-12-01

    This work combines the predictive power of computational drug discovery with experimental validation by means of biological assays. In this way, a new mode of action for type 2 diabetes drugs has been unvealed. Most drugs currently employed in the treatment of type 2 diabetes either target the sulfonylurea receptor stimulating insulin release (sulfonylureas, glinides), or target PPARγ improving insulin resistance (thiazolidinediones). Our work shows that sulfonylureas and glinides bind to PPARγ and exhibit PPARγ agonistic activity. This result was predicted in silico by virtual screening and confirmed in vitro by three biological assays. This dual mode of action of sulfonylureas and glinides may open new perspectives for the molecular pharmacology of antidiabetic drugs, since it provides evidence that drugs can be designed which target both the sulfonylurea receptor and PPARγ. Targeting both receptors could in principle allow to increase pancreatic insulin secretion, as well as to improve insulin resistance.

  5. Second Life for Distance Language Learning: A Framework for Native/Non-Native Speaker Interactions in a Virtual World

    ERIC Educational Resources Information Center

    Tusing, Jennifer; Berge, Zane L.

    2010-01-01

    This paper examines a number of theoretical principles governing second language teaching and learning and the ways in which these principles are being applied in 3D virtual worlds such as Second Life. Also examined are the benefits to language learning afforded by the Second Life interface, including access, the availability of native speakers of…

  6. Curricular Implications of Virtual World Technology: A Review of Business Applications

    ERIC Educational Resources Information Center

    Cyphert, Dale; Wurtz, M. Susan; Duclos, Leslie K.

    2013-01-01

    As business organizations grow increasingly virtual, traditional principles of organizational communication require examination and modification. This article considers the curricular implications of the growing business uses of virtual world technology through three different lenses--students as employee-users, students as strategic designers and…

  7. Variational theorems for superimposed motions in elasticity, with application to beams

    NASA Technical Reports Server (NTRS)

    Doekmeci, M. C.

    1976-01-01

    Variational theorems are presented for a theory of small motions superimposed on large static deformations and governing equations for prestressed beams on the basis of 3-D theory of elastodynamics. First, the principle of virtual work is modified through Friedrichs's transformation so as to describe the initial stress problem of elastodynamics. Next, the modified principle together with a chosen displacement field is used to derive a set of 1-D macroscopic governing equations of prestressed beams. The resulting equations describe all the types of superimposed motions in elastic beams, and they include all the effects of transverse shear and normal strains, and the rotatory inertia. The instability of the governing equations is discussed briefly.

  8. Multiple Fingers - One Gestalt.

    PubMed

    Lezkan, Alexandra; Manuel, Steven G; Colgate, J Edward; Klatzky, Roberta L; Peshkin, Michael A; Drewing, Knut

    2016-01-01

    The Gestalt theory of perception offered principles by which distributed visual sensations are combined into a structured experience ("Gestalt"). We demonstrate conditions whereby haptic sensations at two fingertips are integrated in the perception of a single object. When virtual bumps were presented simultaneously to the right hand's thumb and index finger during lateral arm movements, participants reported perceiving a single bump. A discrimination task measured the bump's perceived location and perceptual reliability (assessed by differential thresholds) for four finger configurations, which varied in their adherence to the Gestalt principles of proximity (small versus large finger separation) and synchrony (virtual spring to link movements of the two fingers versus no spring). According to models of integration, reliability should increase with the degree to which multi-finger cues integrate into a unified percept. Differential thresholds were smaller in the virtual-spring condition (synchrony) than when fingers were unlinked. Additionally, in the condition with reduced synchrony, greater proximity led to lower differential thresholds. Thus, with greater adherence to Gestalt principles, thresholds approached values predicted for optimal integration. We conclude that the Gestalt principles of synchrony and proximity apply to haptic perception of surface properties and that these principles can interact to promote multi-finger integration.

  9. Theoretical Bases for Using Virtual Reality in Education

    ERIC Educational Resources Information Center

    Chen, Chwen Jen

    2009-01-01

    This article elaborates on how the technical capabilities of virtual reality support the constructivist learning principles. It introduces VRID, a model for instructional design and development that offers explicit guidance on how to produce an educational virtual environment. The define phase of VRID consists of three main tasks: forming a…

  10. Thermal analysis of smart composite laminated angle-ply using higher order shear deformation theory with zig zag function

    NASA Astrophysics Data System (ADS)

    YagnaSri, P.; Siddiqui, Maimuna; Vijaya Nirmala, M.

    2018-03-01

    The objective of the work is to develop the higher order theory for piezoelectric composite laminated plates with zigzag function and to determine the thermal characteristics of piezoelectric laminated plate with zig zag function for different aspect ratios (a/h), thickness ratios (z/h) and voltage and also to evaluate electric potential function by solving second order differential equation satisfying electric boundary conditions along the thickness direction of piezoelectric layer. The related functions and derivations for equation of motion are obtained using the dynamic version of the principle of virtual work or Hamilton’s principle. The solutions are obtained by using Navier’s stokes method for anti-symmetric angle-ply with specific type of simply supported boundary conditions. Computer programs have been developed for realistic prediction of stresses and deflections for various sides to thickness ratios (a/h) and voltages.

  11. Intelligent virtual reality in the setting of fuzzy sets

    NASA Technical Reports Server (NTRS)

    Dockery, John; Littman, David

    1992-01-01

    The authors have previously introduced the concept of virtual reality worlds governed by artificial intelligence. Creation of an intelligent virtual reality was further proposed as a universal interface for the handicapped. This paper extends consideration of intelligent virtual realty to a context in which fuzzy set principles are explored as a major tool for implementing theory in the domain of applications to the disabled.

  12. Mechanics

    NASA Astrophysics Data System (ADS)

    Cox, John

    2014-05-01

    Part 1. The Winning of the Principles: 1. Introduction; 2. The beginnings of statics. Archimedes. Problem of the lever and of the centre of gravity; 2. Experimental verification and applications of the principle of the lever; 3. The centre of gravity; 4. The balance; 5. Stevinus of Bruges. The principle of the inclined plane; 6. The parallelogram of forces; 7. The principle of virtual work; 8. Review of the principles of statics; 9. The beginnings of dynamics. Galileo. The problem of falling bodies; 10. Huyghens. The problem of uniform motion in a circle. 'Centrifugal force'; 11. Final statement of the principles of dynamics. Extension to the motions of the heavenly bodies. The law of universal gravitation. Newton; Part II. Mathematical Statement of the Principles: Introduction; 12. Kinematics; 13. Kinetics of a particle moving in a straight line. The laws of motion; 14. Experimental verification of the laws of motion. Atwood's machine; 15. Work and energy; 16. The parallelogram law; 17. The composition and resolution of forces. Resultant. Component. Equilibrium; 18. Forces in one plane; 19. Friction; Part III. Application to Various Problems: 20. Motion on an inclined plane. Brachistochrones; 21. Projectiles; 22. Simple harmonic motion; 23. The simple pendulum; 24. Central forces. The law of gravitation; 25. Impact and impulsive forces; Part IV. The Elements of Rigid Dynamics: 26. The compound pendulum. Huyghens' solution; 27. D'alembert's principle; 28. Moment of inertia; 29. Experimental determination of moments of inertia; 30. Determination of the value of gravity by Kater's pendulum; 31. The constant of gravitation, or weighing the Earth. The Cavendish experiment; Answers to the examples; Index.

  13. Hologram-reconstruction signal enhancement

    NASA Technical Reports Server (NTRS)

    Mezrich, R. S.

    1977-01-01

    Principle of heterodyne detection is used to combine object beam and reconstructed virtual image beam. All light valves in page composer are opened, and virtual-image beam is allowed to interfere with light from valves.

  14. Electromagnetic stress tensor for an amorphous metamaterial medium

    NASA Astrophysics Data System (ADS)

    Wang, Neng; Wang, Shubo; Ng, Jack

    2018-03-01

    We analytically and numerically investigated the internal optical forces exerted by an electromagnetic wave inside an amorphous metamaterial medium. We derived, by using the principle of virtual work, the Helmholtz stress tensor, which takes into account the electrostriction effect. Several examples of amorphous media are considered, and different electromagnetic stress tensors, such as the Einstein-Laub tensor and Minkowski tensor, are also compared. It is concluded that the Helmholtz stress tensor is the appropriate tensor for such systems.

  15. Modeling Pedagogy for Teachers Transitioning to the Virtual Classroom

    ERIC Educational Resources Information Center

    Canuel, Michael J.; White, Beverley J.

    2014-01-01

    This study is a review of the creation and evolution of a professional development program modeled on social constructivist principles and designed for online educators in a virtual high school who transitioned from the conventional classroom to the virtual educational environment. The narrative inquiry focuses on the critical events within the…

  16. A Virtual World Workshop Environment for Learning Agile Software Development Techniques

    ERIC Educational Resources Information Center

    Parsons, David; Stockdale, Rosemary

    2012-01-01

    Multi-User Virtual Environments (MUVEs) are the subject of increasing interest for educators and trainers. This article reports on a longitudinal project that seeks to establish a virtual agile software development workshop hosted in the Open Wonderland MUVE, designed to help learners to understand the basic principles of some core agile software…

  17. Evolving virtual creatures and catapults.

    PubMed

    Chaumont, Nicolas; Egli, Richard; Adami, Christoph

    2007-01-01

    We present a system that can evolve the morphology and the controller of virtual walking and block-throwing creatures (catapults) using a genetic algorithm. The system is based on Sims' work, implemented as a flexible platform with an off-the-shelf dynamics engine. Experiments aimed at evolving Sims-type walkers resulted in the emergence of various realistic gaits while using fairly simple objective functions. Due to the flexibility of the system, drastically different morphologies and functions evolved with only minor modifications to the system and objective function. For example, various throwing techniques evolved when selecting for catapults that propel a block as far as possible. Among the strategies and morphologies evolved, we find the drop-kick strategy, as well as the systematic invention of the principle behind the wheel, when allowing mutations to the projectile.

  18. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1989-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  19. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1990-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  20. Weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1991-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  1. A Desktop Virtual Reality Earth Motion System in Astronomy Education

    ERIC Educational Resources Information Center

    Chen, Chih Hung; Yang, Jie Chi; Shen, Sarah; Jeng, Ming Chang

    2007-01-01

    In this study, a desktop virtual reality earth motion system (DVREMS) is designed and developed to be applied in the classroom. The system is implemented to assist elementary school students to clarify earth motion concepts using virtual reality principles. A study was conducted to observe the influences of the proposed system in learning.…

  2. A study of navigation in virtual space

    NASA Technical Reports Server (NTRS)

    Darken, Rudy; Sibert, John L.; Shumaker, Randy

    1994-01-01

    In the physical world, man has developed efficient methods for navigation and orientation. These methods are dependent on the high-fidelity stimuli presented by the environment. When placed in a virtual world which cannot offer stimuli of the same quality due to computing constraints and immature technology, tasks requiring the maintenance of position and orientation knowledge become laborious. In this paper, we present a representative set of techniques based on principles of navigation derived from real world analogs including human and avian navigation behavior and cartography. A preliminary classification of virtual worlds is presented based on the size of the world, the density of objects in the world, and the level of activity taking place in the world. We also summarize an informal study we performed to determine how the tools influenced the subjects' navigation strategies and behavior. We conclude that principles extracted from real world navigation aids such as maps can be seen to apply in virtual environments.

  3. Human Machine Interfaces for Teleoperators and Virtual Environments

    NASA Technical Reports Server (NTRS)

    Durlach, Nathaniel I. (Compiler); Sheridan, Thomas B. (Compiler); Ellis, Stephen R. (Compiler)

    1991-01-01

    In Mar. 1990, a meeting organized around the general theme of teleoperation research into virtual environment display technology was conducted. This is a collection of conference-related fragments that will give a glimpse of the potential of the following fields and how they interplay: sensorimotor performance; human-machine interfaces; teleoperation; virtual environments; performance measurement and evaluation methods; and design principles and predictive models.

  4. Virtual Golden Foods Corporation: Generic Skills in a Virtual Crisis Environment (A Pilot Study)

    ERIC Educational Resources Information Center

    Godat, Meredith

    2007-01-01

    Workplace learning in a crisis-rich environment is often difficult if not impossible to integrate into programs so that students are able to experience and apply crisis management practices and principles. This study presents the results of a pilot project that examined the effective use of a virtual reality (VR) environment as a tool to teach…

  5. Updates in Head and Neck Reconstruction.

    PubMed

    Largo, Rene D; Garvey, Patrick B

    2018-02-01

    After reading this article, the participant should be able to: 1. Have a basic understanding of virtual planning, rapid prototype modeling, three-dimensional printing, and computer-assisted design and manufacture. 2. Understand the principles of combining virtual planning and vascular mapping. 3. Understand principles of flap choice and design in preoperative planning of free osteocutaneous flaps in mandible and midface reconstruction. 4. Discuss advantages and disadvantages of computer-assisted design and manufacture in reconstruction of advanced oncologic mandible and midface defects. Virtual planning and rapid prototype modeling are increasingly used in head and neck reconstruction with the aim of achieving superior surgical outcomes in functionally and aesthetically critical areas of the head and neck compared with conventional reconstruction. The reconstructive surgeon must be able to understand this rapidly-advancing technology, along with its advantages and disadvantages. There is no limit to the degree to which patient-specific data may be integrated into the virtual planning process. For example, vascular mapping can be incorporated into virtual planning of mandible or midface reconstruction. Representative mandible and midface cases are presented to illustrate the process of virtual planning. Although virtual planning has become helpful in head and neck reconstruction, its routine use may be limited by logistic challenges, increased acquisition costs, and limited flexibility for intraoperative modifications. Nevertheless, the authors believe that the superior functional and aesthetic results realized with virtual planning outweigh the limitations.

  6. Application of the "see one, do one, teach one" concept in surgical training.

    PubMed

    Kotsis, Sandra V; Chung, Kevin C

    2013-05-01

    The traditional method of teaching in surgery is known as "see one, do one, teach one." However, many have argued that this method is no longer applicable, mainly because of concerns for patient safety. The purpose of this article is to show that the basis of the traditional teaching method is still valid in surgical training if it is combined with various adult learning principles. The authors reviewed literature regarding the history of the formation of the surgical residency program, adult learning principles, mentoring, and medical simulation. The authors provide examples for how these learning techniques can be incorporated into a surgical resident training program. The surgical residency program created by Dr. William Halsted remained virtually unchanged until recently with reductions in resident work hours and changes to a competency-based training system. Such changes have reduced the teaching time between attending physicians and residents. Learning principles such as experience, observation, thinking, and action and deliberate practice can be used to train residents. Mentoring is also an important aspect in teaching surgical technique. The authors review the different types of simulators-standardized patients, virtual reality applications, and high-fidelity mannequin simulators-and the advantages and disadvantages of using them. The traditional teaching method of "see one, do one, teach one" in surgical residency programs is simple but still applicable. It needs to evolve with current changes in the medical system to adequately train surgical residents and also provide patients with safe, evidence-based care.

  7. Computer Assisted REhabilitation (CARE) Lab: A novel approach towards Pediatric Rehabilitation 2.0.

    PubMed

    Olivieri, Ivana; Meriggi, Paolo; Fedeli, Cristina; Brazzoli, Elena; Castagna, Anna; Roidi, Marina Luisa Rodocanachi; Angelini, Lucia

    2018-01-01

    Pediatric Rehabilitation therapists have always worked using a variety of off-the-shelf or custom-made objects and devices, more recently including computer based systems. These Information and Communication Technology (ICT) solutions vary widely in complexity, from easy-to-use interactive videogame consoles originally intended for entertainment purposes to sophisticated systems specifically developed for rehabilitation.This paper describes the principles underlying an innovative "Pediatric Rehabilitation 2.0" approach, based on the combination of suitable ICT solutions and traditional rehabilitation, which has been progressively refined while building up and using a computer-assisted rehabilitation laboratory. These principles are thus summarized in the acronym EPIQ, to account for the terms Ecological, Personalized, Interactive and Quantitative. The paper also presents the laboratory, which has been designed to meet the children's rehabilitation needs and to empower therapists in their work. The laboratory is equipped with commercial hardware and specially developed software called VITAMIN: a virtual reality platform for motor and cognitive rehabilitation.

  8. The VIRTUAL EMBRYO. A Computational Framework for Developmental Toxicity

    EPA Science Inventory

    EPA’s ‘Virtual Embryo Project’ (v-Embryo™) is focused on the predictive toxicology of children’s health and developmental defects following prenatal exposure to environmental chemicals. The research is motivated by scientific principles in systems biology as a framework for the g...

  9. Equations of motion of a space station with emphasis on the effects of the gravity gradient

    NASA Technical Reports Server (NTRS)

    Tuell, L. P.

    1987-01-01

    The derivation of the equations of motion is based upon the principle of virtual work. As developed, these equations apply only to a space vehicle whose physical model consists of a rigid central carrier supporting several flexible appendages (not interconnected), smaller rigid bodies, and point masses. Clearly evident in the equations is the respect paid to the influence of the Earth's gravity field, considerably more than has been the custom in simulating vehicle motion. The effect of unpredictable crew motion is ignored.

  10. Design and optimization of the micro-engine turbine rotor manufacturing using the rapid prototyping technology

    NASA Astrophysics Data System (ADS)

    Vdovin, R. A.; Smelov, V. G.

    2017-02-01

    This work describes the experience in manufacturing the turbine rotor for the micro-engine. It demonstrates the design principles for the complex investment casting process combining the use of the ProCast software and the rapid prototyping techniques. At the virtual modelling stage, in addition to optimized process parameters, the casting structure was improved to obtain the defect-free section. The real production stage allowed demonstrating the performance and fitness of rapid prototyping techniques for the manufacture of geometrically-complex engine-building parts.

  11. Blended learning in paediatric emergency medicine: preliminary analysis of a virtual learning environment.

    PubMed

    Spedding, Ruth; Jenner, Rachel; Potier, Katherine; Mackway-Jones, Kevin; Carley, Simon

    2013-04-01

    Paediatric emergency medicine (PEM) currently faces many competing educational challenges. Recent changes to the working patterns have made the delivery of effective teaching to trainees extremely difficult. We developed a virtual learning environment, on the basis of socioconstructivist principles, which allows learning to take place regardless of time or location. The aim was to evaluate the effectiveness of a blended e-learning approach for PEM training. We evaluated the experiences of ST3 trainees in PEM using a multimodal approach. We classified and analysed message board discussions over a 6-month period to look for evidence of practice change and learning. We conducted semistructured qualitative interviews with trainees approximately 5 months after they completed the course. Trainees embraced the virtual learning environment and had positive experiences of the blended approach to learning. Socioconstructivist learning did take place through the use of message boards on the virtual learning environment. Despite their initial unfamiliarity with the online learning system, the participants found it easy to access and use. The participants found the learning relevant and there was an overlap between shop floor learning and the online content. Clinical discussion was often led by trainees on the forums and these were described as enjoyable and informative. A blended approach to e-learning in basic PEM is effective and enjoyable to trainees.

  12. Virtual Immunology: Software for Teaching Basic Immunology

    ERIC Educational Resources Information Center

    Berçot, Filipe Faria; Fidalgo-Neto, Antônio Augusto; Lopes, Renato Matos; Faggioni, Thais; Alves, Luiz Anastácio

    2013-01-01

    As immunology continues to evolve, many educational methods have found difficulty in conveying the degree of complexity inherent in its basic principles. Today, the teaching-learning process in such areas has been improved with tools such as educational software. This article introduces "Virtual Immunology," a software program available…

  13. Advanced training in emergency medicine: a pedagogical journey from didactic teachers to virtual problems

    PubMed Central

    Mackway‐Jones, Kevin; Carley, Simon; Kilroy, Darren

    2007-01-01

    Background As trainee numbers and the geographical spread of training departments have increased, the model of weekly face‐to‐face teaching has come under strain because of long travel times. This has been compounded by a reduction in the total number of hours worked by trainees. Furthermore the traditional teacher centred educational programme has been challenged as unfit for purpose on grounds of both content and style. Objective This article describes two shifts in the delivery of the programme. The first involved migration from a didactic delivery to a problem‐based model; the second a gradual shift to the internet culminating in implementation of a web based virtual learning environment. Conclusion The principles outlined in this paper are widely applicable and will be of interest to all clinical educators within the specialty, both within the UK and overseas. PMID:17901268

  14. Custom-made prefabricated titanium miniplates in Le Fort I osteotomies: principles, procedure and clinical insights.

    PubMed

    Philippe, B

    2013-08-01

    This paper describes a new type of miniplate system that is designed and custom made during virtual surgery planning based on an individual patient's osteotomy. These miniplates are prefabricated with commercially pure porous titanium using direct metal laser sintering. The principles that guide the conception and production of this new miniplate are presented. The surgical procedure from the stage of virtual surgery planning until the final Le Fort I osteotomy and bone fixation are described using a case example. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Virtual manufacturing in reality

    NASA Astrophysics Data System (ADS)

    Papstel, Jyri; Saks, Alo

    2000-10-01

    SMEs play an important role in manufacturing industry. But from time to time there is a shortage in resources to complete the particular order in time. Number of systems is introduced to produce digital information in order to support product and process development activities. Main problem is lack of opportunity for direct data transition within design system modules when needed temporary extension of design capacity (virtuality) or to implement integrated concurrent product development principles. The planning experience in the field is weakly used as well. The concept of virtual manufacturing is a supporting idea to solve this problem. At the same time a number of practical problems should be solved like information conformity, data transfer, unified technological concepts acceptation etc. In the present paper the proposed ways to solve the practical problems of virtual manufacturing are described. General objective is to introduce the knowledge-based CAPP system as missing module for Virtual Manufacturing in the selected product domain. Surface-centered planning concept based on STEP- based modeling principles, and knowledge-based process planning methodology will be used to gain the objectives. As a result the planning module supplied by design data with direct access, and supporting advising environment is expected. Mould producing SME would be as test basis.

  16. Teaching Marketing through a Micro-Economy in Virtual Reality

    ERIC Educational Resources Information Center

    Drake-Bridges, Erin; Strelzoff, Andrew; Sulbaran, Tulio

    2011-01-01

    Teaching retailing principles to students is a challenge because although real-world wholesale and retail decision making very heavily depends on dynamic conditions, classroom exercises are limited to abstract discussions and role-playing. This article describes two interlocking class projects taught using the virtual reality of secondlife.com,…

  17. The ethics of Google Earth: crossing thresholds from spatial data to landscape visualisation.

    PubMed

    Sheppard, Stephen R J; Cizek, Petr

    2009-05-01

    'Virtual globe' software systems such as Google Earth are growing rapidly in popularity as a way to visualise and share 3D environmental data. Scientists and environmental professionals, many of whom are new to 3D modeling and visual communications, are beginning routinely to use such techniques in their work. While the appeal of these techniques is evident, with unprecedented opportunities for public access to data and collaborative engagement over the web, are there nonetheless risks in their widespread usage when applied in areas of the public interest such as planning and policy-making? This paper argues that the Google Earth phenomenon, which features realistic imagery of places, cannot be dealt with only as a question of spatial data and geographic information science. The virtual globe type of visualisation crosses several key thresholds in communicating scientific and environmental information, taking it well beyond the realm of conventional spatial data and geographic information science, and engaging more complex dimensions of human perception and aesthetic preference. The realism, perspective views, and social meanings of the landscape visualisations embedded in virtual globes invoke not only cognition but also emotional and intuitive responses, with associated issues of uncertainty, credibility, and bias in interpreting the imagery. This paper considers the types of risks as well as benefits that may exist with participatory uses of virtual globes by experts and lay-people. It is illustrated with early examples from practice and relevant themes from the literature in landscape visualisation and related disciplines such as environmental psychology and landscape planning. Existing frameworks and principles for the appropriate use of environmental visualisation methods are applied to the special case of widely accessible, realistic 3D and 4D visualisation systems such as Google Earth, in the context of public awareness-building and agency decision-making on environmental issues. Relevant principles are suggested which lend themselves to much-needed evaluation of risks and benefits of virtual globe systems. Possible approaches for balancing these benefits and risks include codes of ethics, software design, and metadata templates.

  18. A virtual environment for medical radiation collaborative learning.

    PubMed

    Bridge, Pete; Trapp, Jamie V; Kastanis, Lazaros; Pack, Darren; Parker, Jacqui C

    2015-06-01

    A software-based environment was developed to provide practical training in medical radiation principles and safety. The Virtual Radiation Laboratory application allowed students to conduct virtual experiments using simulated diagnostic and radiotherapy X-ray generators. The experiments were designed to teach students about the inverse square law, half value layer and radiation protection measures and utilised genuine clinical and experimental data. Evaluation of the application was conducted in order to ascertain the impact of the software on students' understanding, satisfaction and collaborative learning skills and also to determine potential further improvements to the software and guidelines for its continued use. Feedback was gathered via an anonymous online survey consisting of a mixture of Likert-style questions and short answer open questions. Student feedback was highly positive with 80 % of students reporting increased understanding of radiation protection principles. Furthermore 72 % enjoyed using the software and 87 % of students felt that the project facilitated collaboration within small groups. The main themes arising in the qualitative feedback comments related to efficiency and effectiveness of teaching, safety of environment, collaboration and realism. Staff and students both report gains in efficiency and effectiveness associated with the virtual experiments. In addition students particularly value the visualisation of "invisible" physical principles and increased opportunity for experimentation and collaborative problem-based learning. Similar ventures will benefit from adopting an approach that allows for individual experimentation while visualizing challenging concepts.

  19. NASA Virtual Institutes: International Bridges for Space Exploration

    NASA Technical Reports Server (NTRS)

    Schmidt, Gregory K.

    2016-01-01

    NASA created the first virtual institute, the NASA Astrobiology Institute (NAI), in 2009 with an aim toward bringing together geographically disparate and multidisciplinary teams toward the goal of answering broad questions in the then-new discipline of astrobiology. With the success of the virtual institute model, NASA then created the NASA Lunar Science Institute (NLSI) in 2008 to address questions of science and human exploration of the Moon, and then the NASA Aeronautics Research Institute (NARI) in 2012 which addresses key questions in the development of aeronautics technologies. With the broadening of NASA's human exploration targets to include Near Earth Asteroids and the moons of Mars as well as the Moon, the NLSI morphed into the Solar System Exploration Research Virtual Institute (SSERVI) in 2012. SSERVI funds domestic research teams to address broad questions at the intersection of science and human exploration, with the underlying principle that science enables human exploration, and human exploration enables science. Nine domestic teams were funded in 2014 for a five-year period to address a variety of different topics, and nine international partners (with more to come) also work with the U.S. teams on a variety of topics of mutual interest. The result is a robust and productive research infrastructure that is not only scientifically productive but can respond to strategic topics of domestic and international interest, and which develops a new generation of researchers. This is all accomplished with the aid of virtual collaboration technologies which enable scientific research at a distance. The virtual institute model is widely applicable to a range of space science and exploration problems.

  20. Structural response of existing spatial truss roof construction based on Cosserat rod theory

    NASA Astrophysics Data System (ADS)

    Miśkiewicz, Mikołaj

    2018-04-01

    Paper presents the application of the Cosserat rod theory and newly developed associated finite elements code as the tools that support in the expert-designing engineering practice. Mechanical principles of the 3D spatially curved rods, dynamics (statics) laws, principle of virtual work are discussed. Corresponding FEM approach with interpolation and accumulation techniques of state variables are shown that enable the formulation of the C0 Lagrangian rod elements with 6-degrees of freedom per node. Two test examples are shown proving the correctness and suitability of the proposed formulation. Next, the developed FEM code is applied to assess the structural response of the spatial truss roof of the "Olivia" Sports Arena Gdansk, Poland. The numerical results are compared with load test results. It is shown that the proposed FEM approach yields correct results.

  1. Tools for Teaching Virtual Teams: A Comparative Resource Review

    ERIC Educational Resources Information Center

    Larson, Barbara; Leung, Opal; Mullane, Kenneth

    2017-01-01

    As the ubiquity of virtual work--and particularly virtual project teams--increases in the professional environment, management and other professional programs are increasingly teaching students skills related to virtual work. One of the most common forms of teaching virtual work skills is a virtual team project, in which students collaborate with…

  2. Application of See One, Do One, Teach One Concept in Surgical Training

    PubMed Central

    Kotsis, Sandra V.; Chung, Kevin C.

    2016-01-01

    Background The traditional method of teaching in Surgery is known as “See One, Do One, Teach One.” However, many have argued that this method is no longer applicable mainly because of concerns for patient safety. The purpose of this paper is to show that the basis of the traditional teaching method is still valid in surgical training if it is combined with various adult learning principles. Methods We reviewed literature regarding the history of the formation of the surgical residency program, adult learning principles, mentoring, and medical simulation. We provide examples for how these learning techniques can be incorporated into a surgical resident training program. Results The surgical residency program created by Dr. William Halsted remained virtually unchanged until recently with reductions in resident work hours and changes to a competency-based training system. Such changes have reduced the teaching time between attending physicians and residents. Learning principles such as “Experience, Observation, Thinking and Action” as well as deliberate practice can be used to train residents. Mentoring is also an important aspect in teaching surgical technique. We review the different types of simulators: standardized patients, virtual reality applications, and high-fidelity mannequin simulators and the advantages and disadvantages of using them. Conclusions The traditional teaching method of “see one, do one, teach one” in surgical residency programs is simple but still applicable. It needs to evolve with current changes in the medical system to adequately train surgical residents and also provide patients with safe, evidence-based care. PMID:23629100

  3. Architectural Principles and Experimentation of Distributed High Performance Virtual Clusters

    ERIC Educational Resources Information Center

    Younge, Andrew J.

    2016-01-01

    With the advent of virtualization and Infrastructure-as-a-Service (IaaS), the broader scientific computing community is considering the use of clouds for their scientific computing needs. This is due to the relative scalability, ease of use, advanced user environment customization abilities, and the many novel computing paradigms available for…

  4. Creative Writing, Problem-Based Learning, and Game-Based Learning Principles

    ERIC Educational Resources Information Center

    Trekles, Anastasia M.

    2012-01-01

    This paper examines how virtual worlds and other advanced social media can be married with problem-based learning to encourage creativity and critical thinking in the English/Language Arts classroom, particularly for middle school, high school, and undergraduate college education. Virtual world experiences such as "Second Life," Jumpstart.com, and…

  5. Visual-Spatial Thinking in Hypertexts.

    ERIC Educational Resources Information Center

    Johnson-Sheehan, Richard; Baehr, Craig

    2001-01-01

    Explores what it means to think visually and spatially in hypertexts and how users react and maneuver in real and virtual three-dimensional spaces. Offers four principles of visual thinking that can be applied when developing hypertexts. Applies these principles to actual hypertexts, demonstrating how selectivity, fixation, depth discernment, and…

  6. A radial time projection chamber for α detection in CLAS at JLab

    DOE PAGES

    Dupre, R.; Stepanyan, S.; Hattawy, M.; ...

    2018-08-01

    A new Radial Time Projection Chamber (RTPC) was developed at the Jefferson Laboratory to track low-energy nuclear recoils to measure exclusive nuclear reactions, such as coherent deeply virtual Compton scattering and coherent meson production off 4He. In 2009, we carried out these measurements using the CEBAF Large Acceptance Spectrometer (CLAS) supplemented by the RTPC positioned directly around a gaseous 4He target, allowing a detection threshold as low as 12 MeV for 4He. This work discusses the design, principle of operation, calibration methods and performances of this RTPC.

  7. An Approximate Solution to the Plastic Indentation of Circular Sandwich Panels

    NASA Astrophysics Data System (ADS)

    Xie, Z.

    2018-05-01

    The plastic indentation response of circular sandwich panels loaded by the flat end of a cylinder is investigated employing a velocity field model. Using the principles of virtual velocities and minimum work, an expression for the indenter load in relation to the indenter displacement and displacement field of the deformed face sheet is derived. The analytical solutions obtained are in good agreement with those found by simulations using the ABAQUS code. The radial tensile strain of the deformed face sheet and the ratio of energy absorption rate of the core to that of the face sheet are discussed.

  8. Identification of stars and digital version of the catalogue of 1958 by Brodskaya and Shajn

    NASA Astrophysics Data System (ADS)

    Gorbunov, M. A.; Shlyapnikov, A. A.

    2017-12-01

    The following topics are considered: the identification of objects on search maps, the determination of their coordinates at the epoch of 2000, and converting the published version of the catalogue of 1958 by Brodskaya and Shajn into a machine-readable format. The statistics for photometric and spectral data from the original catalogue is presented. A digital version of the catalogue is described, as well as its presentation in HTML, VOTable and AJS formats and the basic principles of work in the interactive application of International Virtual Observatory - the Aladin Sky Atlas.

  9. A radial time projection chamber for α detection in CLAS at JLab

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

    Dupre, R.; Stepanyan, S.; Hattawy, M.

    A new Radial Time Projection Chamber (RTPC) was developed at the Jefferson Laboratory to track low-energy nuclear recoils to measure exclusive nuclear reactions, such as coherent deeply virtual Compton scattering and coherent meson production off 4He. In 2009, we carried out these measurements using the CEBAF Large Acceptance Spectrometer (CLAS) supplemented by the RTPC positioned directly around a gaseous 4He target, allowing a detection threshold as low as 12 MeV for 4He. This work discusses the design, principle of operation, calibration methods and performances of this RTPC.

  10. Finite Elements, Design Optimization, and Nondestructive Evaluation: A Review in Magnetics, and Future Directions in GPU-based, Element-by-Element Coupled Optimization and NDE

    DTIC Science & Technology

    2013-07-18

    Nationale Supérieure d’Ingénieurs Electriciens de Grenoble (ENSIEG) group led by J.C. Sabonnadiere, J.L. Coulomb and G. Meunier would bring mathematical...1985. [11] J.L. Coulomb , “Analyse tridimensionnelle des champs électriques et magnétiques par la méthode des éléments finis,” These de Doctorat...computations by the virtual work principle [10]. However Coulomb [11-13] of the ENSIEG group identified a one-step solution for the computation of

  11. Exploring Pedagogical Foundations of Existing Virtual Reality Educational Applications: A Content Analysis Study

    ERIC Educational Resources Information Center

    Johnston, Elizabeth; Olivas, Gerald; Steele, Patricia; Smith, Cassandra; Bailey, Liston

    2018-01-01

    New virtual reality (VR) applications for education appear frequently in the marketplace but rarely contain explicit pedagogies. The research objective of this study was to identify and categorize principles and practices of pedagogy that are evident but not articulated in selected VR applications for education. Analysis of public content for the…

  12. Practicing Learner-Centered Teaching: Pedagogical Design and Assessment of a Second Life Project

    ERIC Educational Resources Information Center

    Schiller, Shu Z.

    2009-01-01

    Guided by the principles of learner-centered teaching methodology, a Second Life project is designed to engage students in active learning of virtual commerce through hands-on experiences and teamwork in a virtual environment. More importantly, an assessment framework is proposed to evaluate the learning objectives and learning process of the…

  13. University Teacher Competencies in a Virtual Teaching/Learning Environment: Analysis of a Teacher Training Experience

    ERIC Educational Resources Information Center

    Guasch, Teresa; Alvarez, Ibis; Espasa, Anna

    2010-01-01

    This paper attempts to shed light on the competencies a university teacher must have in order to teach in virtual learning environments. A teacher training experience was designed by taking into account the methodological criteria established in line with previous theoretical principles. The main objective of our analysis was to identify the…

  14. Effects of the Virtual Environment on Online Faculty Perceptions of Leadership: A Grounded Theory Study

    ERIC Educational Resources Information Center

    Curry, Steven P.

    2016-01-01

    The purpose of this qualitative study was to explore how faculty members, teaching in the virtual environment of higher education, perceived the effectiveness of leader actions to understand how principles of existing leadership theory in critical areas such as communication effectiveness, development of trust, and ability to motivate faculty…

  15. Computer Associates International, CA-ACF2/VM Release 3.1

    DTIC Science & Technology

    1987-09-09

    Associates CA-ACF2/VM Bibliography International Business Machines Corporation, IBM Virtual Machine/Directory Maintenance Program Logic Manual...publication number LY20-0889 International Business Machines International Business Machines Corporation, IBM System/370 Principles of Operation...publication number GA22-7000 International Business Machines Corporation, IBM Virtual Machine/Directory Maintenance Installation and System Administrator’s

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

    PubMed

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

    2016-01-01

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

  17. Design, development, and evaluation of an online virtual emergency department for training trauma teams.

    PubMed

    Youngblood, Patricia; Harter, Phillip M; Srivastava, Sakti; Moffett, Shannon; Heinrichs, Wm LeRoy; Dev, Parvati

    2008-01-01

    Training interdisciplinary trauma teams to work effectively together using simulation technology has led to a reduction in medical errors in emergency department, operating room, and delivery room contexts. High-fidelity patient simulators (PSs)-the predominant method for training healthcare teams-are expensive to develop and implement and require that trainees be present in the same place at the same time. In contrast, online computer-based simulators are more cost effective and allow simultaneous participation by students in different locations and time zones. In this pilot study, the researchers created an online virtual emergency department (Virtual ED) for team training in crisis management, and compared the effectiveness of the Virtual ED with the PS. We hypothesized that there would be no difference in learning outcomes for graduating medical students trained with each method. In this pilot study, we used a pretest-posttest control group, experimental design in which 30 subjects were randomly assigned to either the Virtual ED or the PS system. In the Virtual ED each subject logged into the online environment and took the role of a team member. Four-person teams worked together in the Virtual ED, communicating in real time with live voice over Internet protocol, to manage computer-controlled patients who exhibited signs and symptoms of physical trauma. Each subject had the opportunity to be the team leader. The subjects' leadership behavior as demonstrated in both a pretest case and a posttest case was assessed by 3 raters, using a behaviorally anchored scale. In the PS environment, 4-person teams followed the same research protocol, using the same clinical scenarios in a Simulation Center. Guided by the Emergency Medicine Crisis Resource Management curriculum, both the Virtual ED and the PS groups applied the basic principles of team leadership and trauma management (Advanced Trauma Life Support) to manage 6 trauma cases-a pretest case, 4 training cases, and a posttest case. The subjects in each group were assessed individually with the same simulation method that they used for the training cases. Subjects who used either the Virtual ED or the PS showed significant improvement in performance between pretest and posttest cases (P < 0.05). In addition, there was no significant difference in subjects' performance between the 2 types of simulation, suggesting that the online Virtual ED may be as effective for learning team skills as the PS, the method widely used in Simulation Centers. Data on usability and attitudes toward both simulation methods as learning tools were equally positive. This study shows the potential value of using virtual learning environments for developing medical students' and resident physicians' team leadership and crisis management skills.

  18. Identification of material parameters for plasticity models: A comparative study on the finite element model updating and the virtual fields method

    NASA Astrophysics Data System (ADS)

    Martins, J. M. P.; Thuillier, S.; Andrade-Campos, A.

    2018-05-01

    The identification of material parameters, for a given constitutive model, can be seen as the first step before any practical application. In the last years, the field of material parameters identification received an important boost with the development of full-field measurement techniques, such as Digital Image Correlation. These techniques enable the use of heterogeneous displacement/strain fields, which contain more information than the classical homogeneous tests. Consequently, different techniques have been developed to extract material parameters from full-field measurements. In this study, two of these techniques are addressed, the Finite Element Model Updating (FEMU) and the Virtual Fields Method (VFM). The main idea behind FEMU is to update the parameters of a constitutive model implemented in a finite element model until both numerical and experimental results match, whereas VFM makes use of the Principle of Virtual Work and does not require any finite element simulation. Though both techniques proved their feasibility in linear and non-linear constitutive models, it is rather difficult to rank their robustness in plasticity. The purpose of this work is to perform a comparative study in the case of elasto-plastic models. Details concerning the implementation of each strategy are presented. Moreover, a dedicated code for VFM within a large strain framework is developed. The reconstruction of the stress field is performed through a user subroutine. A heterogeneous tensile test is considered to compare FEMU and VFM strategies.

  19. Analyzing Virtual Physics Simulations with Tracker

    NASA Astrophysics Data System (ADS)

    Claessens, Tom

    2017-12-01

    In the physics teaching community, Tracker is well known as a user-friendly open source video analysis software, authored by Douglas Brown. With this tool, the user can trace markers indicated on a video or on stroboscopic photos and perform kinematic analyses. Tracker also includes a data modeling tool that allows one to fit some theoretical equations of motion onto experimentally obtained data. In the field of particle mechanics, Tracker has been effectively used for learning and teaching about projectile motion, "toss up" and free-fall vertical motion, and to explain the principle of mechanical energy conservation. Also, Tracker has been successfully used in rigid body mechanics to interpret the results of experiments with rolling/slipping cylinders and moving rods. In this work, I propose an original method in which Tracker is used to analyze virtual computer simulations created with a physics-based motion solver, instead of analyzing video recording or stroboscopic photos. This could be an interesting approach to study kinematics and dynamics problems in physics education, in particular when there is no or limited access to physical labs. I demonstrate the working method with a typical (but quite challenging) problem in classical mechanics: a slipping/rolling cylinder on a rough surface.

  20. A virtual work space for both hands manipulation with coherency between kinesthetic and visual sensation

    NASA Technical Reports Server (NTRS)

    Ishii, Masahiro; Sukanya, P.; Sato, Makoto

    1994-01-01

    This paper describes the construction of a virtual work space for tasks performed by two handed manipulation. We intend to provide a virtual environment that encourages users to accomplish tasks as they usually act in a real environment. Our approach uses a three dimensional spatial interface device that allows the user to handle virtual objects by hand and be able to feel some physical properties such as contact, weight, etc. We investigated suitable conditions for constructing our virtual work space by simulating some basic assembly work, a face and fit task. We then selected the conditions under which the subjects felt most comfortable in performing this task and set up our virtual work space. Finally, we verified the possibility of performing more complex tasks in this virtual work space by providing simple virtual models and then let the subjects create new models by assembling these components. The subjects can naturally perform assembly operations and accomplish the task. Our evaluation shows that this virtual work space has the potential to be used for performing tasks that require two-handed manipulation or cooperation between both hands in a natural manner.

  1. An Educational Development Tool Based on Principles of Formal Ontology

    ERIC Educational Resources Information Center

    Guzzi, Rodolfo; Scarpanti, Stefano; Ballista, Giovanni; Di Nicolantonio, Walter

    2005-01-01

    Computer science provides with virtual laboratories, places where one can merge real experiments with the formalism of algorithms and mathematics and where, with the advent of multimedia, sounds and movies can also be added. In this paper we present a method, based on principles of formal ontology, allowing one to develop interactive educational…

  2. The Avenor Virtual Trainer Project--A 3D Interactive Training Module on Energy Control Procedures: Development and First Validation Results.

    ERIC Educational Resources Information Center

    Giardina, Max

    This paper examines the implementation of 3D simulation through the development of the Avenor Virtual Trainer and how situated learning and fidelity of model representation become the basis for more effective Interactive Multimedia Training Situations. The discussion will focus of some principles concerned with situated training, simulation,…

  3. Group-multicast capable optical virtual private ring with contention avoidance

    NASA Astrophysics Data System (ADS)

    Peng, Yunfeng; Du, Shu; Long, Keping

    2008-11-01

    A ring based optical virtual private network (OVPN) employing contention sensing and avoidance is proposed to deliver multiple-to-multiple group-multicast traffic. The network architecture is presented and its operation principles as well as performance are investigated. The main contribution of this article is the presentation of an innovative group-multicast capable OVPN architecture with technologies available today.

  4. Validation of Virtual Environments Incorporating Virtual Operators for Procedural Learning

    DTIC Science & Technology

    2012-09-01

    according to Hierarchical Task Analysis principles (Annett, 2003; Annett & Duncan, 1967; Annett, Duncan, Stammers & Gray, 1971; Annett & Stanton, 2000...the literature (Anderson, 2001; Haider & Grensch, 2002; Heathcote et al., 2000; Suzuki & Ohnishi, 2007 ). Nevertheless, the analysis of the regression...analysis and training design. Occupational Psychology, 41. Annett, J., Duncan, K. D., Stammers , R. B. & Gray, M. J. (1971). Task Analysis. London

  5. Gesture therapy: an upper limb virtual reality-based motor rehabilitation platform.

    PubMed

    Sucar, Luis Enrique; Orihuela-Espina, Felipe; Velazquez, Roger Luis; Reinkensmeyer, David J; Leder, Ronald; Hernández-Franco, Jorge

    2014-05-01

    Virtual reality platforms capable of assisting rehabilitation must provide support for rehabilitation principles: promote repetition, task oriented training, appropriate feedback, and a motivating environment. As such, development of these platforms is a complex process which has not yet reached maturity. This paper presents our efforts to contribute to this field, presenting Gesture Therapy, a virtual reality-based platform for rehabilitation of the upper limb. We describe the system architecture and main features of the platform and provide preliminary evidence of the feasibility of the platform in its current status.

  6. Dementia-friendly design resource.

    PubMed

    Baillie, Jonathan

    2014-02-01

    Although estimates suggest that, on average, some 30 per cent of all patients in general acute medical wards may have some form of dementia, Stirling University's Dementia Services Development Centre (DSDC), one of the leading international knowledge centres working to improve the lives of dementia sufferers, says progress in designing healthcare facilities that address such patients' needs has been 'patchy at best'. With the number of individuals living with dementia expected to double in the next 25 years, the DSDC has recently worked with Edinburgh-based architects, Burnett Pollock Associates, to develop an online resource that clearly illustrates, via 15 simulated 'dementia-friendly' healthcare 'spaces', some of the key principles to consider when designing effectively for this fast-growing group. HEJ editor, Jonathan Baillie, attended the launch of the so-called 'Virtual Hospital'.

  7. Simulation modelling for new gas turbine fuel controller creation.

    NASA Astrophysics Data System (ADS)

    Vendland, L. E.; Pribylov, V. G.; Borisov, Yu A.; Arzamastsev, M. A.; Kosoy, A. A.

    2017-11-01

    State of the art gas turbine fuel flow control systems are based on throttle principle. Major disadvantage of such systems is that they require high pressure fuel intake. Different approach to fuel flow control is to use regulating compressor. And for this approach because of controller and gas turbine interaction a specific regulating compressor is required. Difficulties emerge as early as the requirement definition stage. To define requirements for new object, his properties must be known. Simulation modelling helps to overcome these difficulties. At the requirement definition stage the most simplified mathematical model is used. Mathematical models will get more complex and detailed as we advance in planned work. If future adjusting of regulating compressor physical model to work with virtual gas turbine and physical control system is planned.

  8. Virtual immunology: software for teaching basic immunology.

    PubMed

    Berçot, Filipe Faria; Fidalgo-Neto, Antônio Augusto; Lopes, Renato Matos; Faggioni, Thais; Alves, Luiz Anastácio

    2013-01-01

    As immunology continues to evolve, many educational methods have found difficulty in conveying the degree of complexity inherent in its basic principles. Today, the teaching-learning process in such areas has been improved with tools such as educational software. This article introduces "Virtual Immunology," a software program available free of charge in Portuguese and English, which can be used by teachers and students in physiology, immunology, and cellular biology classes. We discuss the development of the initial two modules: "Organs and Lymphoid Tissues" and "Inflammation" and the use of interactive activities to provide microscopic and macroscopic understanding in immunology. Students, both graduate and undergraduate, were questioned along with university level professors about the quality of the software and intuitiveness of use, facility of navigation, and aesthetic organization using a Likert scale. An overwhelmingly satisfactory result was obtained with both students and immunology teachers. Programs such as "Virtual Immunology" are offering more interactive, multimedia approaches to complex scientific principles that increase student motivation, interest, and comprehension. © 2013 by The International Union of Biochemistry and Molecular Biology.

  9. Intersecting Virtual Patients and Microbiology: Fostering a culture of learning.

    PubMed

    McCarthy, David; O'Gorman, Ciaran; Gormley, Gerard

    2015-10-01

    The use and integration of Technology Enhanced Learning (TEL) resources in medical education has attracted considerable commentary and support. "Virtual Patients" are one such resource. Whilst evidence exists supporting the benefits of these resources, there has not been specific consideration of their implications for teaching microbiology; nor attention paid to both the internal and external factors that influence learner engagement with virtual patients. The principle aims of this study are to identify factors that explicitly and implicitly influence the student's interaction with a microbiology virtual patient resource and how these interactions reflect upon the use of the resource. A mixed method quantitative (online questionnaire; n=161) and qualitative (student focus groups; N=11) study was undertaken amongst third year medical students enrolled at Queen's University Belfast in the academic year 2012-2013. The results supported prior evidence that virtual patients are a useful learning tool (mean score of 5.09 out of 7) that helped them to integrate microbiology principles with clinical experiences. How students used the virtual patients and the depth of the subsequent benefits was dependent upon their perception of the importance of the resource. This was influenced by a number of factors including how the resources were presented and positioned within the curriculum, whether they were formally examined or timetabled and the importance attributed by peers who had already completed the examinations. Integration of virtual patients into the microbiology curriculum is widely endorsed and may even be considered superior to other methods of teaching. How students use these resources is dependent upon a positive perception of their importance. Educators should be aware of the factors that shape this perception when integrating TEL resources into curricula.

  10. 3D simulation as a tool for improving the safety culture during remediation work at Andreeva Bay.

    PubMed

    Chizhov, K; Sneve, M K; Szőke, I; Mazur, I; Mark, N K; Kudrin, I; Shandala, N; Simakov, A; Smith, G M; Krasnoschekov, A; Kosnikov, A; Kemsky, I; Kryuchkov, V

    2014-12-01

    Andreeva Bay in northwest Russia hosts one of the former coastal technical bases of the Northern Fleet. Currently, this base is designated as the Andreeva Bay branch of Northwest Center for Radioactive Waste Management (SevRAO) and is a site of temporary storage (STS) for spent nuclear fuel (SNF) and other radiological waste generated during the operation and decommissioning of nuclear submarines and ships. According to an integrated expert evaluation, this site is the most dangerous nuclear facility in northwest Russia. Environmental rehabilitation of the site is currently in progress and is supported by strong international collaboration. This paper describes how the optimization principle (ALARA) has been adopted during the planning of remediation work at the Andreeva Bay STS and how Russian-Norwegian collaboration greatly contributed to ensuring the development and maintenance of a high level safety culture during this process. More specifically, this paper describes how integration of a system, specifically designed for improving the radiological safety of workers during the remediation work at Andreeva Bay, was developed in Russia. It also outlines the 3D radiological simulation and virtual reality based systems developed in Norway that have greatly facilitated effective implementation of the ALARA principle, through supporting radiological characterisation, work planning and optimization, decision making, communication between teams and with the authorities and training of field operators.

  11. Thermally induced stresses in cross-ply composite tubes

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Cooper, D. E.; Tompkins, S. S.

    1986-01-01

    An approximate solution for determining stresses in cross-ply composite tubes subjected to a circumferential temperature gradient is presented. The solution is based on the principle of complementary virtual work (PCVW) in conjunction with a Ritz approximation on the stress field and accounts for the temperature dependence of material properties. The PCVW method is compared with a planar elasticity solution using temperature-independent material properties and a Navier approach. The net effect of including temperature-dependent material properties is that the peak absolute values of the stresses are reduced. The dependence of the stresses on the circumferential location is also reduced in comparison with the case of temperature-independent properties.

  12. Evaluating Students' Perspectives about Virtual Classrooms with Regard to Seven Principles of Good Practice

    ERIC Educational Resources Information Center

    Çakýroðlu, Ünal

    2014-01-01

    This study assesses the quality of distance learning (DL) in higher education assessed by considering the Seven Principles of Good Practice (SPGP). The participants were 77 second-year students from the Computer and Instructional Technologies Program (CEIT) of a Faculty of Education in Turkey. A questionnaire was developed in line with the SPGP…

  13. [Computerization and robotics in medical practice].

    PubMed

    Dervaderics, J

    1997-10-26

    The article gives the outlines of all principles used in computing included the non-electrical and analog computers and the artifical intelligence followed by citing examples as well. The principles and medical utilization of virtual reality are also mentioned. There are discussed: surgical planning, image guided surgery, robotic surgery, telepresence and telesurgery, and telemedicine implemented partially via Internet.

  14. The 'Sydney Principles' for reducing the commercial promotion of foods and beverages to children.

    PubMed

    Swinburn, Boyd; Sacks, Gary; Lobstein, Tim; Rigby, Neville; Baur, Louise A; Brownell, Kelly D; Gill, Tim; Seidell, Jaap; Kumanyika, Shiriki

    2008-09-01

    A set of seven principles (the 'Sydney Principles') was developed by an International Obesity Taskforce (IOTF) Working Group to guide action on changing food and beverage marketing practices that target children. The aim of the present communication is to present the Sydney Principles and report on feedback received from a global consultation (November 2006 to April 2007) on the Principles. The Principles state that actions to reduce marketing to children should: (i) support the rights of children; (ii) afford substantial protection to children; (iii) be statutory in nature; (iv) take a wide definition of commercial promotions; (v) guarantee commercial-free childhood settings; (vi) include cross-border media; and (vii) be evaluated, monitored and enforced. The draft principles were widely disseminated and 220 responses were received from professional and scientific associations, consumer bodies, industry bodies, health professionals and others. There was virtually universal agreement on the need to have a set of principles to guide action in this contentious area of marketing to children. Apart from industry opposition to the third principle calling for a statutory approach and several comments about the implementation challenges, there was strong support for each of the Sydney Principles. Feedback on two specific issues of contention related to the age range to which restrictions should apply (most nominating age 16 or 18 years) and the types of products to be included (31% nominating all products, 24% all food and beverages, and 45% energy-dense, nutrient-poor foods and beverages). The Sydney Principles, which took a children's rights-based approach, should be used to benchmark action to reduce marketing to children. The age definition for a child and the types of products which should have marketing restrictions may better suit a risk-based approach at this stage. The Sydney Principles should guide the formation of an International Code on Food and Beverage Marketing to Children.

  15. Casuistry and principlism: the convergence of method in biomedical ethics.

    PubMed

    Kuczewski, M

    1998-12-01

    Casuistry and principlism are two of the leading contenders to be considered the methodology of bioethics. These methods may be incommensurable since the former emphasizes the examination of cases while the latter focuses on moral principles. Conversely, since both analyze cases in terms of mid-level principles, there is hope that these methods may be reconcilable or complementary. I analyze the role of principles in each and thereby show that these theories are virtually identical when interpreted in a certain light. That is, if the gaps in each method are filled by a concept of judgment or Aristotelian practical wisdom, these methods converge.

  16. Software system design for the non-null digital Moiré interferometer

    NASA Astrophysics Data System (ADS)

    Chen, Meng; Hao, Qun; Hu, Yao; Wang, Shaopu; Li, Tengfei; Li, Lin

    2016-11-01

    Aspheric optical components are an indispensable part of modern optics systems. With the development of aspheric optical elements fabrication technique, high-precision figure error test method of aspheric surfaces is a quite urgent issue now. We proposed a digital Moiré interferometer technique (DMIT) based on partial compensation principle for aspheric and freeform surface measurement. Different from traditional interferometer, DMIT consists of a real and a virtual interferometer. The virtual interferometer is simulated with Zemax software to perform phase-shifting and alignment. We can get the results by a series of calculation with the real interferogram and virtual interferograms generated by computer. DMIT requires a specific, reliable software system to ensure its normal work. Image acquisition and data processing are two important parts in this system. And it is also a challenge to realize the connection between the real and virtual interferometer. In this paper, we present a software system design for DMIT with friendly user interface and robust data processing features, enabling us to acquire the figure error of the measured asphere. We choose Visual C++ as the software development platform and control the ideal interferometer by using hybrid programming with Zemax. After image acquisition and data transmission, the system calls image processing algorithms written with Matlab to calculate the figure error of the measured asphere. We test the software system experimentally. In the experiment, we realize the measurement of an aspheric surface and prove the feasibility of the software system.

  17. Open web system of Virtual labs for nuclear and applied physics

    NASA Astrophysics Data System (ADS)

    Saldikov, I. S.; Afanasyev, V. V.; Petrov, V. I.; Ternovykh, M. Yu

    2017-01-01

    An example of virtual lab work on unique experimental equipment is presented. The virtual lab work is software based on a model of real equipment. Virtual labs can be used for educational process in nuclear safety and analysis field. As an example it includes the virtual lab called “Experimental determination of the material parameter depending on the pitch of a uranium-water lattice”. This paper included general description of this lab. A description of a database on the support of laboratory work on unique experimental equipment which is included this work, its concept development are also presented.

  18. The Application of Virtual Intensive Care Unit Principles in the Aeromedical Evacuation Environment Can Improve Patient Safety, Lead to Better Patient Outcomes and Deliver Integrated Medical Care

    DTIC Science & Technology

    2016-02-01

    not reflect the official policy or position of the US government, the Department of Defense , or Air University. In accordance with Air Force...capability in the AE environment. Utilizing current civilian and Department of Defense (DoD) vICU research, an analysis of the principles demonstrates...deliver integrated medical care. This paper provides a historical narrative of telemedicine and vICU principles and highlights the utility of this

  19. Virtual Teams and Human Work Interaction Design - Learning to Work in and Designing for Virtual Teams

    NASA Astrophysics Data System (ADS)

    Orngreen, Rikke; Clemmensen, Torkil; Pejtersen, Annelise Mark

    The boundaries and work processes for how virtual teams interact are undergoing changes, from a tool and stand-alone application orientation, to the use of multiple generic platforms chosen and redesigned to the specific context. These are often at the same time designed both by professional software developers and the individual members of the virtual teams, rather than determined on a single organizational level. There may be no impact of the technology per se on individuals, groups or organizations, as the technology for virtual teams rather enhance situation ambiguity and disrupt existing task-artifact cycles. This ambiguous situation calls for new methods for empirical work analysis and interaction design that can help us understand how organizations, teams and individuals learn to organize, design and work in virtual teams in various networked contexts.

  20. The Ames Virtual Environment Workstation: Implementation issues and requirements

    NASA Technical Reports Server (NTRS)

    Fisher, Scott S.; Jacoby, R.; Bryson, S.; Stone, P.; Mcdowall, I.; Bolas, M.; Dasaro, D.; Wenzel, Elizabeth M.; Coler, C.; Kerr, D.

    1991-01-01

    This presentation describes recent developments in the implementation of a virtual environment workstation in the Aerospace Human Factors Research Division of NASA's Ames Research Center. Introductory discussions are presented on the primary research objectives and applications of the system and on the system's current hardware and software configuration. Principle attention is then focused on unique issues and problems encountered in the workstation's development with emphasis on its ability to meet original design specifications for computational graphics performance and for associated human factors requirements necessary to provide compelling sense of presence and efficient interaction in the virtual environment.

  1. Can Science Education Research Give an Answer to Questions Posed by History of Science and Technology? The Case of Steam Engine's Measurement

    ERIC Educational Resources Information Center

    Kanderakis, Nikos E.

    2009-01-01

    According to the principle of virtual velocities, if on a simple machine in equilibrium we suppose a slight virtual movement, then the ratio of weights or forces equals the inverse ratio of velocities or displacements. The product of the weight raised or force applied multiplied by the height or displacement plays a central role there. British…

  2. The cognitive apprenticeship theory for the teaching of mathematics in an online 3D virtual environment

    NASA Astrophysics Data System (ADS)

    Bouta, Hara; Paraskeva, Fotini

    2013-03-01

    Research spanning two decades shows that there is a continuing development of 3D virtual worlds and investment in such environments for educational purposes. Research stresses the need for these environments to be well-designed and for suitable pedagogies to be implemented in the teaching practice in order for these worlds to be fully effective. To this end, we propose a pedagogical framework based on the cognitive apprenticeship for deriving principles and guidelines to inform the design, development and use of a 3D virtual environment. This study examines how the use of a 3D virtual world facilitates the teaching of mathematics in primary education by combining design principles and guidelines based on the Cognitive Apprenticeship Theory and the teaching methods that this theory introduces. We focus specifically on 5th and 6th grade students' engagement (behavioral, affective and cognitive) while learning fractional concepts over a period of two class sessions. Quantitative and qualitative analyses indicate considerable improvement in the engagement of the students who participated in the experiment. This paper presents the findings regarding students' cognitive engagement in the process of comprehending basic fractional concepts - notoriously hard for students to master. The findings are encouraging and suggestions are made for further research.

  3. Emergence of Virtual Reality as a Tool for Upper Limb Rehabilitation: Incorporation of Motor Control and Motor Learning Principles

    PubMed Central

    Weiss, Patrice L.; Keshner, Emily A.

    2015-01-01

    The primary focus of rehabilitation for individuals with loss of upper limb movement as a result of acquired brain injury is the relearning of specific motor skills and daily tasks. This relearning is essential because the loss of upper limb movement often results in a reduced quality of life. Although rehabilitation strives to take advantage of neuroplastic processes during recovery, results of traditional approaches to upper limb rehabilitation have not entirely met this goal. In contrast, enriched training tasks, simulated with a wide range of low- to high-end virtual reality–based simulations, can be used to provide meaningful, repetitive practice together with salient feedback, thereby maximizing neuroplastic processes via motor learning and motor recovery. Such enriched virtual environments have the potential to optimize motor learning by manipulating practice conditions that explicitly engage motivational, cognitive, motor control, and sensory feedback–based learning mechanisms. The objectives of this article are to review motor control and motor learning principles, to discuss how they can be exploited by virtual reality training environments, and to provide evidence concerning current applications for upper limb motor recovery. The limitations of the current technologies with respect to their effectiveness and transfer of learning to daily life tasks also are discussed. PMID:25212522

  4. Working Virtually: Transforming the Mobile Workplace. 2nd Edition

    ERIC Educational Resources Information Center

    Hoefling, Trina

    2017-01-01

    Remote working is the new reality, and transactional work--provided by freelancers, contract employees or consultants--has increased exponentially. It is forecast that as much as half the labor force will be working independently and virtually by 2020. Most organizations are still grappling with how to effectively manage their virtual staff and…

  5. Aspects of skeletal muscle modelling.

    PubMed

    Epstein, Marcelo; Herzog, Walter

    2003-09-29

    The modelling of skeletal muscle raises a number of philosophical questions, particularly in the realm of the relationship between different possible levels of representation and explanation. After a brief incursion into this area, a list of desiderata is proposed as a guiding principle for the construction of a viable model, including: comprehensiveness, soundness, experimental consistency, predictive ability and refinability. Each of these principles is illustrated by means of simple examples. The presence of internal constraints, such as incompressibility, may lead to counterintuitive results. A one-panel example is exploited to advocate the use of the principle of virtual work as the ideal tool to deal with these situations. The question of stability in the descending limb of the force-length relation is addressed and a purely mechanical analogue is suggested. New experimental results confirm the assumption that fibre stiffness is positive even in the descending limb. The indeterminacy of the force-sharing problem is traditionally resolved by optimizing a, presumably, physically meaningful target function. After presenting some new results in this area, based on a separation theorem, it is suggested that a more fundamental approach to the problem is the abandoning of optimization criteria in favour of an explicit implementation of activation criteria.

  6. Modeling the Benchmark Active Control Technology Wind-Tunnel Model for Active Control Design Applications

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    1998-01-01

    This report describes the formulation of a model of the dynamic behavior of the Benchmark Active Controls Technology (BACT) wind tunnel model for active control design and analysis applications. The model is formed by combining the equations of motion for the BACT wind tunnel model with actuator models and a model of wind tunnel turbulence. The primary focus of this report is the development of the equations of motion from first principles by using Lagrange's equations and the principle of virtual work. A numerical form of the model is generated by making use of parameters obtained from both experiment and analysis. Comparisons between experimental and analytical data obtained from the numerical model show excellent agreement and suggest that simple coefficient-based aerodynamics are sufficient to accurately characterize the aeroelastic response of the BACT wind tunnel model. The equations of motion developed herein have been used to aid in the design and analysis of a number of flutter suppression controllers that have been successfully implemented.

  7. Virtual patients in the acquisition of clinical reasoning skills: does presentation mode matter? A quasi-randomized controlled trial.

    PubMed

    Schubach, Fabian; Goos, Matthias; Fabry, Götz; Vach, Werner; Boeker, Martin

    2017-09-15

    The objective of this study is to compare two different instructional methods in the curricular use of computerized virtual patients in undergraduate medical education. We aim to investigate whether using many short and focused cases - the key feature principle - is more effective for the learning of clinical reasoning skills than using few long and systematic cases. We conducted a quasi-randomized, non-blinded, controlled parallel-group intervention trial in a large medical school in Southwestern Germany. During two seminar sessions, fourth- and fifth-year medical students (n = 56) worked on the differential diagnosis of the acute abdomen. The educational tool - virtual patients - was the same, but the instructional method differed: In one trial arm, students worked on multiple short cases, with the instruction being focused only on important elements ("key feature arm", n = 30). In the other trial arm, students worked on few long cases, with the instruction being comprehensive and systematic ("systematic arm", n = 26). The overall training time was the same in both arms. The students' clinical reasoning capacity was measured by a specifically developed instrument, a script concordance test. Their motivation and the perceived effectiveness of the instruction were assessed using a structured evaluation questionnaire. Upon completion of the script concordance test with a reference score of 80 points and a standard deviation of 5 for experts, students in the key feature arm attained a mean of 57.4 points (95% confidence interval: 50.9-63.9), and in the systematic arm, 62.7 points (57.2-68.2), with Cohen's d at 0.337. The difference is statistically non-significant (p = 0.214). In the evaluation survey, students in the key feature arm indicated that they experienced more time pressure and perceived the material as more difficult. In this study powered for a medium effect, we could not provide empirical evidence for the hypothesis that a key feature-based instruction on multiple short cases is superior to a systematic instruction on few long cases in the curricular implementation of virtual patients. The results of the evaluation survey suggest that learners should be given enough time to work through case examples, and that caution should be taken to prevent cognitive overload.

  8. Dark Energy and Dark Matter as w = -1 Virtual Particles and the World Hologram Model

    NASA Astrophysics Data System (ADS)

    Sarfatti, Jack

    2011-04-01

    The elementary physics battle-tested principles of Lorentz invariance, Einstein equivalence principle and the boson commutation and fermion anti-commutation rules of quantum field theory explain gravitationally repulsive dark energy as virtual bosons and gravitationally attractive dark matter as virtual fermion-antifermion pairs. The small dark energy density in our past light cone is the reciprocal entropy-area of our future light cone's 2D future event horizon in a Novikov consistent loop in time in our accelerating universe. Yakir Aharonov's "back-from-the-future" post-selected final boundary condition is set at our observer-dependent future horizon that also explains why the irreversible thermodynamic arrow of time of is aligned with the accelerating dark energy expansion of the bulk 3D space interior to our future 2D horizon surrounding it as the hologram screen. Seth Lloyd has argued that all 2D horizon surrounding surfaces are pixelated quantum computers projecting interior bulk 3D quanta of volume (Planck area)Sqrt(area of future horizon) as their hologram images in 1-1 correspondence.

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

    NASA Astrophysics Data System (ADS)

    Herbuś, K.; Ociepka, P.

    2015-11-01

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

  10. Modular modelling with Physiome standards

    PubMed Central

    Nickerson, David P.; Nielsen, Poul M. F.; Hunter, Peter J.

    2016-01-01

    Key points The complexity of computational models is increasing, supported by research in modelling tools and frameworks. But relatively little thought has gone into design principles for complex models.We propose a set of design principles for complex model construction with the Physiome standard modelling protocol CellML.By following the principles, models are generated that are extensible and are themselves suitable for reuse in larger models of increasing complexity.We illustrate these principles with examples including an architectural prototype linking, for the first time, electrophysiology, thermodynamically compliant metabolism, signal transduction, gene regulation and synthetic biology.The design principles complement other Physiome research projects, facilitating the application of virtual experiment protocols and model analysis techniques to assist the modelling community in creating libraries of composable, characterised and simulatable quantitative descriptions of physiology. Abstract The ability to produce and customise complex computational models has great potential to have a positive impact on human health. As the field develops towards whole‐cell models and linking such models in multi‐scale frameworks to encompass tissue, organ, or organism levels, reuse of previous modelling efforts will become increasingly necessary. Any modelling group wishing to reuse existing computational models as modules for their own work faces many challenges in the context of construction, storage, retrieval, documentation and analysis of such modules. Physiome standards, frameworks and tools seek to address several of these challenges, especially for models expressed in the modular protocol CellML. Aside from providing a general ability to produce modules, there has been relatively little research work on architectural principles of CellML models that will enable reuse at larger scales. To complement and support the existing tools and frameworks, we develop a set of principles to address this consideration. The principles are illustrated with examples that couple electrophysiology, signalling, metabolism, gene regulation and synthetic biology, together forming an architectural prototype for whole‐cell modelling (including human intervention) in CellML. Such models illustrate how testable units of quantitative biophysical simulation can be constructed. Finally, future relationships between modular models so constructed and Physiome frameworks and tools are discussed, with particular reference to how such frameworks and tools can in turn be extended to complement and gain more benefit from the results of applying the principles. PMID:27353233

  11. Two-photon calcium imaging during fictive navigation in virtual environments

    PubMed Central

    Ahrens, Misha B.; Huang, Kuo Hua; Narayan, Sujatha; Mensh, Brett D.; Engert, Florian

    2013-01-01

    A full understanding of nervous system function requires recording from large populations of neurons during naturalistic behaviors. Here we enable paralyzed larval zebrafish to fictively navigate two-dimensional virtual environments while we record optically from many neurons with two-photon imaging. Electrical recordings from motor nerves in the tail are decoded into intended forward swims and turns, which are used to update a virtual environment displayed underneath the fish. Several behavioral features—such as turning responses to whole-field motion and dark avoidance—are well-replicated in this virtual setting. We readily observed neuronal populations in the hindbrain with laterally selective responses that correlated with right or left optomotor behavior. We also observed neurons in the habenula, pallium, and midbrain with response properties specific to environmental features. Beyond single-cell correlations, the classification of network activity in such virtual settings promises to reveal principles of brainwide neural dynamics during behavior. PMID:23761738

  12. Two-photon calcium imaging during fictive navigation in virtual environments.

    PubMed

    Ahrens, Misha B; Huang, Kuo Hua; Narayan, Sujatha; Mensh, Brett D; Engert, Florian

    2013-01-01

    A full understanding of nervous system function requires recording from large populations of neurons during naturalistic behaviors. Here we enable paralyzed larval zebrafish to fictively navigate two-dimensional virtual environments while we record optically from many neurons with two-photon imaging. Electrical recordings from motor nerves in the tail are decoded into intended forward swims and turns, which are used to update a virtual environment displayed underneath the fish. Several behavioral features-such as turning responses to whole-field motion and dark avoidance-are well-replicated in this virtual setting. We readily observed neuronal populations in the hindbrain with laterally selective responses that correlated with right or left optomotor behavior. We also observed neurons in the habenula, pallium, and midbrain with response properties specific to environmental features. Beyond single-cell correlations, the classification of network activity in such virtual settings promises to reveal principles of brainwide neural dynamics during behavior.

  13. Interaction Design and Usability of Learning Spaces in 3D Multi-user Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Minocha, Shailey; Reeves, Ahmad John

    Three-dimensional virtual worlds are multimedia, simulated environments, often managed over the Web, which users can 'inhabit' and interact via their own graphical, self-representations known as 'avatars'. 3D virtual worlds are being used in many applications: education/training, gaming, social networking, marketing and commerce. Second Life is the most widely used 3D virtual world in education. However, problems associated with usability, navigation and way finding in 3D virtual worlds may impact on student learning and engagement. Based on empirical investigations of learning spaces in Second Life, this paper presents design guidelines to improve the usability and ease of navigation in 3D spaces. Methods of data collection include semi-structured interviews with Second Life students, educators and designers. The findings have revealed that design principles from the fields of urban planning, Human- Computer Interaction, Web usability, geography and psychology can influence the design of spaces in 3D multi-user virtual environments.

  14. The use of the virtual source technique in computing scattering from periodic ocean surfaces.

    PubMed

    Abawi, Ahmad T

    2011-08-01

    In this paper the virtual source technique is used to compute scattering of a plane wave from a periodic ocean surface. The virtual source technique is a method of imposing boundary conditions using virtual sources, with initially unknown complex amplitudes. These amplitudes are then determined by applying the boundary conditions. The fields due to these virtual sources are given by the environment Green's function. In principle, satisfying boundary conditions on an infinite surface requires an infinite number of sources. In this paper, the periodic nature of the surface is employed to populate a single period of the surface with virtual sources and m surface periods are added to obtain scattering from the entire surface. The use of an accelerated sum formula makes it possible to obtain a convergent sum with relatively small number of terms (∼40). The accuracy of the technique is verified by comparing its results with those obtained using the integral equation technique.

  15. Hierarchic plate and shell models based on p-extension

    NASA Technical Reports Server (NTRS)

    Szabo, Barna A.; Sahrmann, Glenn J.

    1988-01-01

    Formulations of finite element models for beams, arches, plates and shells based on the principle of virtual work was studied. The focus is on computer implementation of hierarchic sequences of finite element models suitable for numerical solution of a large variety of practical problems which may concurrently contain thin and thick plates and shells, stiffeners, and regions where three dimensional representation is required. The approximate solutions corresponding to the hierarchic sequence of models converge to the exact solution of the fully three dimensional model. The stopping criterion is based on: (1) estimation of the relative error in energy norm; (2) equilibrium tests, and (3) observation of the convergence of quantities of interest.

  16. First- and second-order sensitivity analysis of linear and nonlinear structures

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Mroz, Z.

    1986-01-01

    This paper employs the principle of virtual work to derive sensitivity derivatives of structural response with respect to stiffness parameters using both direct and adjoint approaches. The computations required are based on additional load conditions characterized by imposed initial strains, body forces, or surface tractions. As such, they are equally applicable to numerical or analytical solution techniques. The relative efficiency of various approaches for calculating first and second derivatives is assessed. It is shown that for the evaluation of second derivatives the most efficient approach is one that makes use of both the first-order sensitivities and adjoint vectors. Two example problems are used for demonstrating the various approaches.

  17. Codec-on-Demand Based on User-Level Virtualization

    NASA Astrophysics Data System (ADS)

    Zhang, Youhui; Zheng, Weimin

    At work, at home, and in some public places, a desktop PC is usually available nowadays. Therefore, it is important for users to be able to play various videos on different PCs smoothly, but the diversity of codec types complicates the situation. Although some mainstream media players can try to download the needed codec automatically, this may fail for average users because installing the codec usually requires administrator privileges to complete, while the user may not be the owner of the PC. We believe an ideal solution should work without users' intervention, and need no special privileges. This paper proposes such a user-friendly, program-transparent solution for Windows-based media players. It runs the media player in a user-mode virtualization environment, and then downloads the needed codec on-the-fly. Because of API (Application Programming Interface) interception, some resource-accessing API calls from the player will be redirected to the downloaded codec resources. Then from the viewpoint of the player, the necessary codec exists locally and it can handle the video smoothly, although neither system registry nor system folders was modified during this process. Besides convenience, the principle of least privilege is maintained and the host system is left clean. This paper completely analyzes the technical issues and presents such a prototype which can work with DirectShow-compatible players. Performance tests show that the overhead is negligible. Moreover, our solution conforms to the Software-As-A-Service (SaaS) mode, which is very promising in the Internet era.

  18. RandomSpot: A web-based tool for systematic random sampling of virtual slides.

    PubMed

    Wright, Alexander I; Grabsch, Heike I; Treanor, Darren E

    2015-01-01

    This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Systematic random sampling (SRS) is a stereological tool, which provides a framework to quickly build an accurate estimation of the distribution of objects or classes within an image, whilst minimizing the number of observations required. RandomSpot is a web-based tool for SRS in stereology, which systematically places equidistant points within a given region of interest on a virtual slide. Each point can then be visually inspected by a pathologist in order to generate an unbiased sample of the distribution of classes within the tissue. Further measurements can then be derived from the distribution, such as the ratio of tumor to stroma. RandomSpot replicates the fundamental principle of traditional light microscope grid-shaped graticules, with the added benefits associated with virtual slides, such as facilitated collaboration and automated navigation between points. Once the sample points have been added to the region(s) of interest, users can download the annotations and view them locally using their virtual slide viewing software. Since its introduction, RandomSpot has been used extensively for international collaborative projects, clinical trials and independent research projects. So far, the system has been used to generate over 21,000 sample sets, and has been used to generate data for use in multiple publications, identifying significant new prognostic markers in colorectal, upper gastro-intestinal and breast cancer. Data generated using RandomSpot also has significant value for training image analysis algorithms using sample point coordinates and pathologist classifications.

  19. fVisiOn: glasses-free tabletop 3D display to provide virtual 3D media naturally alongside real media

    NASA Astrophysics Data System (ADS)

    Yoshida, Shunsuke

    2012-06-01

    A novel glasses-free tabletop 3D display, named fVisiOn, floats virtual 3D objects on an empty, flat, tabletop surface and enables multiple viewers to observe raised 3D images from any angle at 360° Our glasses-free 3D image reproduction method employs a combination of an optical device and an array of projectors and produces continuous horizontal parallax in the direction of a circular path located above the table. The optical device shapes a hollow cone and works as an anisotropic diffuser. The circularly arranged projectors cast numerous rays into the optical device. Each ray represents a particular ray that passes a corresponding point on a virtual object's surface and orients toward a viewing area around the table. At any viewpoint on the ring-shaped viewing area, both eyes collect fractional images from different projectors, and all the viewers around the table can perceive the scene as 3D from their perspectives because the images include binocular disparity. The entire principle is installed beneath the table, so the tabletop area remains clear. No ordinary tabletop activities are disturbed. Many people can naturally share the 3D images displayed together with real objects on the table. In our latest prototype, we employed a handmade optical device and an array of over 100 tiny projectors. This configuration reproduces static and animated 3D scenes for a 130° viewing area and allows 5-cm-tall virtual characters to play soccer and dance on the table.

  20. Models and algorithm of optimization launch and deployment of virtual network functions in the virtual data center

    NASA Astrophysics Data System (ADS)

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

    2017-10-01

    The goal of our investigation is optimization of network work in virtual data center. The advantage of modern infrastructure virtualization lies in the possibility to use software-defined networks. However, the existing optimization of algorithmic solutions does not take into account specific features working with multiple classes of virtual network functions. The current paper describes models characterizing the basic structures of object of virtual data center. They including: a level distribution model of software-defined infrastructure virtual data center, a generalized model of a virtual network function, a neural network model of the identification of virtual network functions. We also developed an efficient algorithm for the optimization technology of containerization of virtual network functions in virtual data center. We propose an efficient algorithm for placing virtual network functions. In our investigation we also generalize the well renowned heuristic and deterministic algorithms of Karmakar-Karp.

  1. Impact of Virtual Work Environment on Traditional Team Domains.

    ERIC Educational Resources Information Center

    Geroy, Gary D.; Olson, Joel; Hartman, Jackie

    2002-01-01

    Examines a virtual work team to determine the domains of the team and the effect the virtual work environment had on the domains. Discusses results of a literature review and a phenomenological heuristic case study, including the effects of post-modern philosophy and postindustrial society on changes in the marketplace. (Contains 79 references.)…

  2. Does It Matter Where You Work? A Comparison of How Three Work Venues (Traditional Office, Virtual Office, and Home Office) Influence Aspects of Work and Personal/Family Life.

    ERIC Educational Resources Information Center

    Hill, E. Jeffrey; Ferris, Maria; Martinson, Vjollca

    2003-01-01

    A comparison was made of IBM employees in traditional offices (n=4,316), virtual offices (n=767), and home offices (n=441). Home office teleworking helped balance work and family and enhanced business performance with cost savings. Virtual office teleworking was associated with less work-family balance and less successful personal/family life.…

  3. Developing interprofessional health competencies in a virtual world

    PubMed Central

    King, Sharla; Chodos, David; Stroulia, Eleni; Carbonaro, Mike; MacKenzie, Mark; Reid, Andrew; Torres, Lisa; Greidanus, Elaine

    2012-01-01

    Background Virtual worlds provide a promising means of delivering simulations for developing interprofessional health skills. However, developing and implementing a virtual world simulation is a challenging process, in part because of the novelty of virtual worlds as a simulation platform and also because of the degree of collaboration required among technical and subject experts. Thus, it can be difficult to ensure that the simulation is both technically satisfactory and educationally appropriate. Methods To address this challenge, we propose the use of de Freitas and Oliver's four-dimensional framework as a means of guiding the development process. We give an overview of the framework and describe how its principles can be applied to the development of virtual world simulations. Results We present two virtual world simulation pilot projects that adopted this approach, and describe our development experience in these projects. We directly connect this experience to the four-dimensional framework, thus validating the framework's applicability to the projects and to the context of virtual world simulations in general. Conclusions We present a series of recommendations for developing virtual world simulations for interprofessional health education. These recommendations are based on the four-dimensional framework and are also informed by our experience with the pilot projects. PMID:23195649

  4. Factors and Traits Attributed to the Success of Virtual Managers: A Delphi Study

    ERIC Educational Resources Information Center

    Garrett, Leslie A.

    2012-01-01

    This study explored the factors and traits impacting the success of virtual managers. It can be argued that given technology's role in working virtually, one would deem technology as the most important factor impacting one's work in a virtual environment, however, there are other factors "including support from the organization and one's personal…

  5. 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.

  6. Recurrent Network models of sequence generation and memory

    PubMed Central

    Rajan, Kanaka; Harvey, Christopher D; Tank, David W

    2016-01-01

    SUMMARY Sequential activation of neurons is a common feature of network activity during a variety of behaviors, including working memory and decision making. Previous network models for sequences and memory emphasized specialized architectures in which a principled mechanism is pre-wired into their connectivity. Here, we demonstrate that starting from random connectivity and modifying a small fraction of connections, a largely disordered recurrent network can produce sequences and implement working memory efficiently. We use this process, called Partial In-Network training (PINning), to model and match cellular-resolution imaging data from the posterior parietal cortex during a virtual memory-guided two-alternative forced choice task [Harvey, Coen and Tank, 2012]. Analysis of the connectivity reveals that sequences propagate by the cooperation between recurrent synaptic interactions and external inputs, rather than through feedforward or asymmetric connections. Together our results suggest that neural sequences may emerge through learning from largely unstructured network architectures. PMID:26971945

  7. Leadership toward Creativity in Virtual Work in a Start-Up Context

    ERIC Educational Resources Information Center

    Humala, Iris Annukka

    2015-01-01

    Purpose: This paper aims to better understand how to lead toward creativity in virtual work in a start-up context. Design/methodology/approach: The study investigates the participants' experiences about the learning challenges in leadership toward creativity in virtual work in a start-up company and the meanings attributed to their experiences,…

  8. The effectiveness of signaling principle in virtual reality courseware towards achievement of transfer learning among students with different spatial ability

    NASA Astrophysics Data System (ADS)

    Yahaya, Wan Ahmad Jaafar Wan; Ahmad, Awaatif

    2017-10-01

    Past research revealed that students and society, in general, are relatively under-skilled in performing the practice of Islamic funeral management which is one of the "ibadah fardu kifayah" (a legal obligation that must be discharged by the Muslim community as a whole) in Islam. Participation among youth in managing funerals is relatively low, partly due to the ineffectiveness of the instructional approach. This paper aims to examine the effectiveness of the signaling principle in virtual reality courseware pertaining to the topic of Islamic Funeral Management in the Islamic Education subject to ensure the accomplishment of transfer learning among students with different spatial abilities. The study comprises of two phases namely the courseware development phase and treatment phase. The courseware development employs the Instructional Design Model by Alessi and Trollip. Besides that, the courseware is integrated with components of CLE, principles in Theory of CATLM and signaling principle in multimedia learning. The sample consisted of 130 Form Two students who were selected randomly from four Malaysian secondary schools. They were divided into two experimental groups with 63 students in group one and 67 students in group two. The experimental group one used VR courseware without the signaling principle (VRTI) while experimental group two used the VR courseware with the signaling principle (VRDI). The experiment lasted for three weeks. ANOVA was utilised to analyse the data from this research. The findings showed significant differences between students who used VRDI in the transfer of learning compared to students who used VRTI.

  9. NASA Team Collaboration Pilot: Enabling NASA's Virtual Teams

    NASA Technical Reports Server (NTRS)

    Prahst, Steve

    2003-01-01

    Most NASA projects and work activities are accomplished by teams of people. These teams are often geographically distributed - across NASA centers and NASA external partners, both domestic and international. NASA "virtual" teams are stressed by the challenge of getting team work done - across geographic boundaries and time zones. To get distributed work done, teams rely on established methods - travel, telephones, Video Teleconferencing (NASA VITS), and email. Time is our most critical resource - and team members are hindered by the overhead of travel and the difficulties of coordinating work across their virtual teams. Modern, Internet based team collaboration tools offer the potential to dramatically improve the ability of virtual teams to get distributed work done.

  10. The Ecology of Collaborative Work. Workscape 21: The Ecology of New Ways of Working.

    ERIC Educational Resources Information Center

    Becker, Franklin; Quinn, Kristen L.; Tennessen, Carolyn M.

    A study examined Chiat/Day inc. Advertising's team-based virtual office in which work could occur at any location inside or outside the office at any time. Three sites used three workplace strategies: full virtual (FV), modified virtual (MV), and conventional (C). Interviews, observations, and archival data were used to assess project teams doing…

  11. The German VR Simulation Realism Scale--psychometric construction for virtual reality applications with virtual humans.

    PubMed

    Poeschl, Sandra; Doering, Nicola

    2013-01-01

    Virtual training applications with high levels of immersion or fidelity (for example for social phobia treatment) produce high levels of presence and therefore belong to the most successful Virtual Reality developments. Whereas display and interaction fidelity (as sub-dimensions of immersion) and their influence on presence are well researched, realism of the displayed simulation depends on the specific application and is therefore difficult to measure. We propose to measure simulation realism by using a self-report questionnaire. The German VR Simulation Realism Scale for VR training applications was developed based on a translation of scene realism items from the Witmer-Singer-Presence Questionnaire. Items for realism of virtual humans (for example for social phobia training applications) were supplemented. A sample of N = 151 students rated simulation realism of a Fear of Public Speaking application. Four factors were derived by item- and principle component analysis (Varimax rotation), representing Scene Realism, Audience Behavior, Audience Appearance and Sound Realism. The scale developed can be used as a starting point for future research and measurement of simulation realism for applications including virtual humans.

  12. An optimization method of VON mapping for energy efficiency and routing in elastic optical networks

    NASA Astrophysics Data System (ADS)

    Liu, Huanlin; Xiong, Cuilian; Chen, Yong; Li, Changping; Chen, Derun

    2018-03-01

    To improve resources utilization efficiency, network virtualization in elastic optical networks has been developed by sharing the same physical network for difference users and applications. In the process of virtual nodes mapping, longer paths between physical nodes will consume more spectrum resources and energy. To address the problem, we propose a virtual optical network mapping algorithm called genetic multi-objective optimize virtual optical network mapping algorithm (GM-OVONM-AL), which jointly optimizes the energy consumption and spectrum resources consumption in the process of virtual optical network mapping. Firstly, a vector function is proposed to balance the energy consumption and spectrum resources by optimizing population classification and crowding distance sorting. Then, an adaptive crossover operator based on hierarchical comparison is proposed to improve search ability and convergence speed. In addition, the principle of the survival of the fittest is introduced to select better individual according to the relationship of domination rank. Compared with the spectrum consecutiveness-opaque virtual optical network mapping-algorithm and baseline-opaque virtual optical network mapping algorithm, simulation results show the proposed GM-OVONM-AL can achieve the lowest bandwidth blocking probability and save the energy consumption.

  13. Approaches to the Successful Design and Implementation of VR Applications

    NASA Technical Reports Server (NTRS)

    Bryson, Steve; Cooper, D. M. (Technical Monitor)

    1994-01-01

    The successful design of virtual reality applications involves both "top-down" and "bottom-up" strategies. This talk will broadly outline these strategies: how bottom-up strategies are driven primarily by performance considerations; and how top-down strategies are driven primarily by the application task, the interaction metaphors, and the integration of the virtual environment. How to ensure these two approaches "meet in the middle" through Iterative design processes will be stressed. The discussion will be motivated by examples of both success and failure. The talk contains information bryson presented at SIGGRAPH '93 and Visualization '93, and is a high-level discussion of design principles for virtual reality. There will be essentially no discussion of virtual wind tunnel specific issues or any other matters relating to aerospace, the tutorial is a repeat of the tutorial Bryson and Steve Feiner presented at Visualization '93 In October 1993 in San Jose, CA, and will cite the virtual windtunnel only as an example.

  14. Verification of Emmert's law in actual and virtual environments.

    PubMed

    Nakamizo, Sachio; Imamura, Mariko

    2004-11-01

    We examined Emmert's law by measuring the perceived size of an afterimage and the perceived distance of the surface on which the afterimage was projected in actual and virtual environments. The actual environment consisted of a corridor with ample cues as to distance and depth. The virtual environment was made from the CAVE of a virtual reality system. The afterimage, disc-shaped and one degree in diameter, was produced by flashing with an electric photoflash. The observers were asked to estimate the perceived distance to surfaces located at various physical distances (1 to 24 m) by the magnitude estimation method and to estimate the perceived size of the afterimage projected on the surfaces by a matching method. The results show that the perceived size of the afterimage was directly proportional to the perceived distance in both environments; thus, Emmert's law holds in virtual as well as actual environments. We suggest that Emmert's law is a specific case of a functional principle of distance scaling by the visual system.

  15. Automated Protocol for Large-Scale Modeling of Gene Expression Data.

    PubMed

    Hall, Michelle Lynn; Calkins, David; Sherman, Woody

    2016-11-28

    With the continued rise of phenotypic- and genotypic-based screening projects, computational methods to analyze, process, and ultimately make predictions in this field take on growing importance. Here we show how automated machine learning workflows can produce models that are predictive of differential gene expression as a function of a compound structure using data from A673 cells as a proof of principle. In particular, we present predictive models with an average accuracy of greater than 70% across a highly diverse ∼1000 gene expression profile. In contrast to the usual in silico design paradigm, where one interrogates a particular target-based response, this work opens the opportunity for virtual screening and lead optimization for desired multitarget gene expression profiles.

  16. Implementation of Free-Formulation-Based Flat Shell Elements into NASA Comet Code and Development of Nonlinear Shallow Shell Element

    NASA Technical Reports Server (NTRS)

    Barut, A.; Madenci, Erdogan; Tessler, A.

    1997-01-01

    This study presents a transient nonlinear finite element analysis within the realm of a multi-body dynamics formulation for determining the dynamic response of a moderately thick laminated shell undergoing a rapid and large rotational motion and nonlinear elastic deformations. Nonlinear strain measure and rotation, as well as 'the transverse shear deformation, are explicitly included in the formulation in order to capture the proper motion-induced stiffness of the laminate. The equations of motion are derived from the virtual work principle. The analysis utilizes a shear deformable shallow shell element along with the co-rotational form of the updated Lagrangian formulation. The shallow shell element formulation is based on the Reissner-Mindlin and Marguerre theory.

  17. Rawls and the refusal of medical treatment to children.

    PubMed

    Macdougall, D Robert

    2010-04-01

    That Jehovah's Witnesses cannot refuse life-saving blood transfusions on behalf of their children has acquired the status of virtual "consensus" among bioethicists. However strong the consensus may be on this matter, this article explores whether this view can be plausibly defended on liberal principles by examining it in light of one particularly well worked-out liberal political theory, that of Rawls. It concludes that because of the extremely high priority Rawls attributes to "freedom of conscience," and the implication from the original position that parents must act paternalistically toward their children as their protectors, Jehovah's Witnesses cannot legitimately be barred from making decisions on behalf of their children, even when the consequences of such decisions are serious and irremediable.

  18. Virtual library

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    If you have a computer and a grasp of algebra, you can learn physics. That is one of the messages behind the release of Physics—The Root Science, a new full-text version of a physics textbook available at no cost on the World Wide Web.The interactive textbook is the work of the International Institute of Theoretical and Applied Physics (IITAP) at Iowa State University, which was established in 1993 as a partnership with the United Nations Education, Scientific, and Cultural Organization (UNESCO). With subject matter equivalent to that of a 400-page volume, the text is designed to be completed in one school year. The textbook also will eventually include video clips of experiments and interactive learning modules, as well as links to appropriate cross-references about fundamental principles of physics.

  19. Dynamic modeling of parallel robots for computed-torque control implementation

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

    Codourey, A.

    1998-12-01

    In recent years, increased interest in parallel robots has been observed. Their control with modern theory, such as the computed-torque method, has, however, been restrained, essentially due to the difficulty in establishing a simple dynamic model that can be calculated in real time. In this paper, a simple method based on the virtual work principle is proposed for modeling parallel robots. The mass matrix of the robot, needed for decoupling control strategies, does not explicitly appear in the formulation; however, it can be computed separately, based on kinetic energy considerations. The method is applied to the DELTA parallel robot, leadingmore » to a very efficient model that has been implemented in a real-time computed-torque control algorithm.« less

  20. Reduction of Free Edge Peeling Stress of Laminated Composites Using Active Piezoelectric Layers

    PubMed Central

    Huang, Bin; Kim, Heung Soo

    2014-01-01

    An analytical approach is proposed in the reduction of free edge peeling stresses of laminated composites using active piezoelectric layers. The approach is the extended Kantorovich method which is an iterative method. Multiterms of trial function are employed and governing equations are derived by taking the principle of complementary virtual work. The solutions are obtained by solving a generalized eigenvalue problem. By this approach, the stresses automatically satisfy not only the traction-free boundary conditions, but also the free edge boundary conditions. Through the iteration processes, the free edge stresses converge very quickly. It is found that the peeling stresses generated by mechanical loadings are significantly reduced by applying a proper electric field to the piezoelectric actuators. PMID:25025088

  1. Viscous Effects in the Elastodynamics of Thick Beams

    NASA Technical Reports Server (NTRS)

    Johnson, A. R.; Tessler, A.

    1997-01-01

    A viscoelastic higher-order thick beam finite element formulation is extended to include elastodynamic deformations. The material constitutive law is a special differential form of the Maxwell solid. In the constitutive model, the elastic strains and the conjugate viscous strains are coupled through a system of first- order ordinary differential equations. The total time-dependent stress is the superposition of its elastic and viscous components. The elastodynamic equations of motion are derived from the virtual work principle. Computational examples are carried out for a thick orthotropic cantilevered beam. A quasi-static relaxation problem is employed as a validation test for the elastodynamic algorithm. The elastodynamic code is demonstrated by analyzing the damped vibrations of the beam which is deformed and then released to freely vibrate.

  2. Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment.

    PubMed

    Kibria, Muhammad Golam; Ali, Sajjad; Jarwar, Muhammad Aslam; Kumar, Sunil; Chong, Ilyoung

    2017-09-22

    Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented.

  3. Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment

    PubMed Central

    Chong, Ilyoung

    2017-01-01

    Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented. PMID:28937590

  4. 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...

  5. A Strategic Approach to Network Defense: Framing the Cloud

    DTIC Science & Technology

    2011-03-10

    accepted network defensive principles, to reduce risks associated with emerging virtualization capabilities and scalability of cloud computing . This expanded...defensive framework can assist enterprise networking and cloud computing architects to better design more secure systems.

  6. Virtually-Enhanced Fluid Laboratories for Teaching Meteorology

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Illari, L.

    2015-12-01

    The Weather in a Tank (WIAT) project aims to offer instructors a repertoire of rotating tank experiments, and a curriculum in fluid dynamics, to better assist students in learning how to move between phenomena in the real world and basic principles of rotating fluid dynamics which play a central role in determining the climate of the planet. Despite the increasing use of laboratory experiments in teaching meteorology, however, we are aware that many teachers and students do not have access to suitable apparatus and so cannot benefit from them. Here we describe a 'virtually-enhanced' laboratory that we hope could be very effective in getting across a flavor of the experiments and bring them to a wider audience. In the pedagogical spirit of WIAT we focus on how simple underlying principles, illustrated through laboratory experiments, shape the observed structure of the large-scale atmospheric circulation.

  7. Research on inosculation between master of ceremonies or players and virtual scene in virtual studio

    NASA Astrophysics Data System (ADS)

    Li, Zili; Zhu, Guangxi; Zhu, Yaoting

    2003-04-01

    A technical principle about construction of virtual studio has been proposed where orientation tracker and telemeter has been used for improving conventional BETACAM pickup camera and connecting with the software module of the host. A model of virtual camera named Camera & Post-camera Coupling Pair has been put forward, which is different from the common model in computer graphics and has been bound to real BETACAM pickup camera for shooting. The formula has been educed to compute the foreground frame buffer image and the background frame buffer image of the virtual scene whose boundary is based on the depth information of target point of the real BETACAM pickup camera's projective ray. The effect of real-time consistency has been achieved between the video image sequences of the master of ceremonies or players and the CG video image sequences for the virtual scene in spatial position, perspective relationship and image object masking. The experimental result has shown that the technological scheme of construction of virtual studio submitted in this paper is feasible and more applicative and more effective than the existing technology to establish a virtual studio based on color-key and image synthesis with background using non-linear video editing technique.

  8. Modeling the Benchmark Active Control Technology Wind-Tunnel Model for Application to Flutter Suppression

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    1996-01-01

    This paper describes the formulation of a model of the dynamic behavior of the Benchmark Active Controls Technology (BACT) wind-tunnel model for application to design and analysis of flutter suppression controllers. The model is formed by combining the equations of motion for the BACT wind-tunnel model with actuator models and a model of wind-tunnel turbulence. The primary focus of this paper is the development of the equations of motion from first principles using Lagrange's equations and the principle of virtual work. A numerical form of the model is generated using values for parameters obtained from both experiment and analysis. A unique aspect of the BACT wind-tunnel model is that it has upper- and lower-surface spoilers for active control. Comparisons with experimental frequency responses and other data show excellent agreement and suggest that simple coefficient-based aerodynamics are sufficient to accurately characterize the aeroelastic response of the BACT wind-tunnel model. The equations of motion developed herein have been used to assist the design and analysis of a number of flutter suppression controllers that have been successfully implemented.

  9. Perfecting Scientists' Collaboration and Problem-Solving Skills in the Virtual Team Environment

    NASA Astrophysics Data System (ADS)

    Jabro, A.; Jabro, J.

    2012-04-01

    PPerfecting Scientists' Collaboration and Problem-Solving Skills in the Virtual Team Environment Numerous factors have contributed to the proliferation of conducting work in virtual teams at the domestic, national, and global levels: innovations in technology, critical developments in software, co-located research partners and diverse funding sources, dynamic economic and political environments, and a changing workforce. Today's scientists must be prepared to not only perform work in the virtual team environment, but to work effectively and efficiently despite physical and cultural barriers. Research supports that students who have been exposed to virtual team experiences are desirable in the professional and academic arenas. Research supports establishing and maintaining established protocols for communication behavior prior to task discussion provides for successful team outcomes. Research conducted on graduate and undergraduate virtual teams' behaviors led to the development of successful pedagogic practices and assessment strategies.

  10. HVS: an image-based approach for constructing virtual environments

    NASA Astrophysics Data System (ADS)

    Zhang, Maojun; Zhong, Li; Sun, Lifeng; Li, Yunhao

    1998-09-01

    Virtual Reality Systems can construct virtual environment which provide an interactive walkthrough experience. Traditionally, walkthrough is performed by modeling and rendering 3D computer graphics in real-time. Despite the rapid advance of computer graphics technique, the rendering engine usually places a limit on scene complexity and rendering quality. This paper presents a approach which uses the real-world image or synthesized image to comprise a virtual environment. The real-world image or synthesized image can be recorded by camera, or synthesized by off-line multispectral image processing for Landsat TM (Thematic Mapper) Imagery and SPOT HRV imagery. They are digitally warped on-the-fly to simulate walking forward/backward, to left/right and 360-degree watching around. We have developed a system HVS (Hyper Video System) based on these principles. HVS improves upon QuickTime VR and Surround Video in the walking forward/backward.

  11. A serious gaming/immersion environment to teach clinical cancer genetics.

    PubMed

    Nosek, Thomas M; Cohen, Mark; Matthews, Anne; Papp, Klara; Wolf, Nancy; Wrenn, Gregg; Sher, Andrew; Coulter, Kenneth; Martin, Jessica; Wiesner, Georgia L

    2007-01-01

    We are creating an interactive, simulated "Cancer Genetics Tower" for the self-paced learning of Clinical Cancer Genetics by medical students (go to: http://casemed.case.edu/cancergenetics). The environment uses gaming theory to engage the students into achieving specific learning objectives. The first few levels contain virtual laboratories where students achieve the basic underpinnings of Cancer Genetics. The next levels apply these principles to clinical practice. A virtual attending physician and four virtual patients, available for questioning through virtual video conferencing, enrich each floor. The pinnacle clinical simulation challenges the learner to integrate all information and demonstrate mastery, thus "winning" the game. A pilot test of the program by 17 medical students yielded very favorable feedback; the students found the Tower a "great way to teach", it held their attention, and it made learning fun. A majority of the students preferred the Tower over other resources to learn Cancer Genetics.

  12. Probabilistic motor sequence learning in a virtual reality serial reaction time task.

    PubMed

    Sense, Florian; van Rijn, Hedderik

    2018-01-01

    The serial reaction time task is widely used to study learning and memory. The task is traditionally administered by showing target positions on a computer screen and collecting responses using a button box or keyboard. By comparing response times to random or sequenced items or by using different transition probabilities, various forms of learning can be studied. However, this traditional laboratory setting limits the number of possible experimental manipulations. Here, we present a virtual reality version of the serial reaction time task and show that learning effects emerge as expected despite the novel way in which responses are collected. We also show that response times are distributed as expected. The current experiment was conducted in a blank virtual reality room to verify these basic principles. For future applications, the technology can be used to modify the virtual reality environment in any conceivable way, permitting a wide range of previously impossible experimental manipulations.

  13. DHM simulation in virtual environments: a case-study on control room design.

    PubMed

    Zamberlan, M; Santos, V; Streit, P; Oliveira, J; Cury, R; Negri, T; Pastura, F; Guimarães, C; Cid, G

    2012-01-01

    This paper will present the workflow developed for the application of serious games in the design of complex cooperative work settings. The project was based on ergonomic studies and development of a control room among participative design process. Our main concerns were the 3D human virtual representation acquired from 3D scanning, human interaction, workspace layout and equipment designed considering ergonomics standards. Using Unity3D platform to design the virtual environment, the virtual human model can be controlled by users on dynamic scenario in order to evaluate the new work settings and simulate work activities. The results obtained showed that this virtual technology can drastically change the design process by improving the level of interaction between final users and, managers and human factors team.

  14. Quantum theory and Aquinas's doctrine on matter

    NASA Astrophysics Data System (ADS)

    Grove, Stanley F.

    The Aristotelian conception of the material principle, deepened by Aquinas, is today widely misunderstood and largely alien to modern mathematical physics, despite the latter's preoccupation with matter and the spatiotemporal. The present dissertation seeks to develop a coherent understanding of matter in the Aristotelian-Thomistic sense, and to apply it to some key interpretive issues in quantum physics. I begin with a brief historical analysis of the Aristotelian, Newtonian ("classical"), and modern (quantum) approaches to physics, in order to highlight their commonality as well as their differences. Next, matter---especially prime matter---is investigated, in an Aristotelian-Thomistic perspective, under several rationes: as principle of individuation, as principle of extension or spatiality, as principle of corruptibility, as related to essence and existence, and as ground of intelligibility. An attempt is made to order these different rationes according to primordiality. A number of topics concerning the formal structure of hylomorphic being are then addressed: elementarity, virtual presence, the "dispositions of matter," entia vialia, natural minima, atomism, the nature of local motion, the plenum and instantaneous action at a distance---all with a view to their incorporation in a unified account of formed matter at or near the elementary level. Finally I take up several interpretive problems in quantum physics which were introduced early in the dissertation, and show how the material and formal principles expounded in the central chapters can render these problems intelligible. Thus I propose that wave and particle aspects in the quantum realm are related substantially rather than accidentally, and that characteristics of substantial (prime) matter and substantial form are therefore being evidenced directly at this level---in the reversibility of the wave-particle transition, in the spatial and temporal instantaneity of quantum events, and in the probabilism encountered in such phenomena. I offer related hypotheses for Heisenberg uncertainty and for quantum nonlocality. In closing, I address some strengths and weaknesses in others' work on quantum interpretation in the light of Aristotelian principles. Three Appendices explore further aspects of matter as a cosmic principle.

  15. Promotion of self-directed learning using virtual patient cases.

    PubMed

    Benedict, Neal; Schonder, Kristine; McGee, James

    2013-09-12

    To assess the effectiveness of virtual patient cases to promote self-directed learning (SDL) in a required advanced therapeutics course. Virtual patient software based on a branched-narrative decision-making model was used to create complex patient case simulations to replace lecture-based instruction. Within each simulation, students used SDL principles to learn course objectives, apply their knowledge through clinical recommendations, and assess their progress through patient outcomes and faculty feedback linked to their individual decisions. Group discussions followed each virtual patient case to provide further interpretation, clarification, and clinical perspective. Students found the simulated patient cases to be organized (90%), enjoyable (82%), intellectually challenging (97%), and valuable to their understanding of course content (91%). Students further indicated that completion of the virtual patient cases prior to class permitted better use of class time (78%) and promoted SDL (84%). When assessment questions regarding material on postoperative nausea and vomiting were compared, no difference in scores were found between the students who attended the lecture on the material in 2011 (control group) and those who completed the virtual patient case on the material in 2012 (intervention group). Completion of virtual patient cases, designed to replace lectures and promote SDL, was overwhelmingly supported by students and proved to be as effective as traditional teaching methods.

  16. Promotion of Self-directed Learning Using Virtual Patient Cases

    PubMed Central

    Schonder, Kristine; McGee, James

    2013-01-01

    Objective. To assess the effectiveness of virtual patient cases to promote self-directed learning (SDL) in a required advanced therapeutics course. Design. Virtual patient software based on a branched-narrative decision-making model was used to create complex patient case simulations to replace lecture-based instruction. Within each simulation, students used SDL principles to learn course objectives, apply their knowledge through clinical recommendations, and assess their progress through patient outcomes and faculty feedback linked to their individual decisions. Group discussions followed each virtual patient case to provide further interpretation, clarification, and clinical perspective. Assessments. Students found the simulated patient cases to be organized (90%), enjoyable (82%), intellectually challenging (97%), and valuable to their understanding of course content (91%). Students further indicated that completion of the virtual patient cases prior to class permitted better use of class time (78%) and promoted SDL (84%). When assessment questions regarding material on postoperative nausea and vomiting were compared, no difference in scores were found between the students who attended the lecture on the material in 2011 (control group) and those who completed the virtual patient case on the material in 2012 (intervention group). Conclusion. Completion of virtual patient cases, designed to replace lectures and promote SDL, was overwhelmingly supported by students and proved to be as effective as traditional teaching methods. PMID:24052654

  17. Naming Collections of Solar Physics Data

    NASA Astrophysics Data System (ADS)

    Hourcle, Joseph

    2014-06-01

    To better deal with tracking cross-discipline data usage, a number of groups have come up with guidelines and principles for data citation. In 2012, the National Academy's Board on Research Data and Information released the report "For Attribution-Developing Data Attribution and Citation Practices and Standards" [1] and it was followed last year by the CODATA-ICSTI report "Out of Cite, Out of Mind".[2]Participants from a number of groups synthesized a single set of principles for data citation that could be endorsed by all groups involved in research.[3] Implementing these principles can help to improve the scientific ecosystem by giving proper attribution to all contributors to data, improving transparency and reproducability, and making data more easily reusable to both astronomers and other researchers.Unfortunately, to implement these principles, we first need to come up with appropriate groupings of data such that they can be easily cited.[4] From this, we can determine appropriate names/titles to unambiguously identify them. The Virtual Solar Observatory will need to work with PI teams to determine these groupings and document them using the DataCite schema.[5]We will present the Joint Declaration of Data Citation Principles and the DataCite schema, discuss the implication of them for solar physics data, and recommend steps towards implementation.References:[1] National Research Council, 2012. http://www.nap.edu/catalog.php?record_id=13564[2] CODATA, 2013. http://dx.doi.org/10.2481/dsj.OSOM13-043[3] FORCE11, 2014. http://www.force11.org/datacitation[4] Wynholds, 2011. http://dx.doi.org/10.2218/ijdc.v6i1.183[5] DataCite, 2013. http://dx.doi.org/10.5438/0008

  18. An ESS maximum principle for matrix games.

    PubMed

    Vincent, T L; Cressman, R

    2000-11-01

    Previous work has demonstrated that for games defined by differential or difference equations with a continuum of strategies, there exists a G-function, related to individual fitness, that must take on a maximum with respect to a virtual variable v whenever v is one of the vectors in the coalition of vectors which make up the evolutionarily stable strategy (ESS). This result, called the ESS maximum principle, is quite useful in determining candidates for an ESS. This principle is reformulated here, so that it may be conveniently applied to matrix games. In particular, we define a matrix game to be one in which fitness is expressed in terms of strategy frequencies and a matrix of expected payoffs. It is shown that the G-function in the matrix game setting must again take on a maximum value at all the strategies which make up the ESS coalition vector. The reformulated maximum principle is applicable to both bilinear and nonlinear matrix games. One advantage in employing this principle to solve the traditional bilinear matrix game is that the same G-function is used to find both pure and mixed strategy solutions by simply specifying an appropriate strategy space. Furthermore we show how the theory may be used to solve matrix games which are not in the usual bilinear form. We examine in detail two nonlinear matrix games: the game between relatives and the sex ratio game. In both of these games an ESS solution is determined. These examples not only illustrate the usefulness of this approach to finding solutions to an expanded class of matrix games, but aids in understanding the nature of the ESS as well.

  19. Scaling roads and wildlife: The Cinderella principle

    USGS Publications Warehouse

    Bissonette, J.A.

    2002-01-01

    It is clear that a reduction in both direct and indirect effects of roads and road networks must be the goal of management agencies. However, increased permeability of roaded landscapes can only be achieved by up-front planning and subsequent mitigative actions. The key is to understand that roads must be made permeable to the movement of animals. More profoundly, ecosystem services, i.e., clean water, clean air, uncontaminated soil, natural landscapes, recreation opportunities, abundant wildlife, and life sustaining ecological processes must not be seriously impacted. In other words, quality of life as measured by ecosystem services should be a major component of the planning process when roads are constructed or improved. Mitigative structures exist to increase permeability of roads. Wildlife overpasses and underpasses, often referred to as ecoducts or green bridges, with associated structures to enable larger animals to exit the road right of way, e.g., earthen escape ramps (BISSONETTE and HAMMER, 2001), various culvert designs for smaller animals including badger pipes and amphibian and reptile tunnels, and fish ladders are but a small sampling of the structures already in place around the world. What is needed is attention to the big picture. Landscapes need to be reconnected and made more permeable. Responsible agencies and organizations need to be aggressive about promoting mitigations and a conservation ethic into road planning. Only with a broad based effort between a concerned public, a database to work from, and a willingness of responsible agencies, will the now very large virtual footprint of roads and road networks be reduced to more closely approximate the physical footprint. By embracing the Cinderella Principle of making the virtual shoe fit more closely the actual physical footprint of roads, we will be able to achieve a closer connection with ecological harmony with its resultant effect of abundant wildlife.

  20. Safety in numbers 3: Authenticity, Building knowledge & skills and Competency development & assessment: the ABC of safe medication dosage calculation problem-solving pedagogy.

    PubMed

    Weeks, Keith W; Meriel Hutton, B; Coben, Diana; Clochesy, John M; Pontin, David

    2013-03-01

    When designing learning and assessment environments it is essential to articulate the underpinning education philosophy, theory, model and learning style support mechanisms that inform their structure and content. We elaborate on original PhD research that articulates the design rationale of authentic medication dosage calculation problem-solving (MDC-PS) learning and diagnostic assessment environments. These environments embody the principles of authenticity, building knowledge and skills and competency assessment and are designed to support development of competence and bridging of the theory-practice gap. Authentic learning and diagnostic assessment environments capture the features and expert practices that are located in real world practice cultures and recreate them in authentic virtual clinical environments. We explore how this provides students with a safe virtual authentic environment to actively experience, practice and undertake MDC-PS learning and assessment activities. We argue that this is integral to the construction and diagnostic assessment of schemata validity (mental constructions and frameworks that are an individual's internal representation of their world), bridging of the theory-practice gap and cognitive and functional competence development. We illustrate these principles through the underpinning pedagogical design of two online virtual authentic learning and diagnostic assessment environments (safeMedicate and eDose™). Copyright © 2012. Published by Elsevier Ltd.

  1. Cybersickness and Anxiety During Simulated Motion: Implications for VRET.

    PubMed

    Bruck, Susan; Watters, Paul

    2009-01-01

    Some clinicians have suggested using virtual reality environments to deliver psychological interventions to treat anxiety disorders. However, given a significant body of work on cybersickness symptoms which may arise in virtual environments - especially those involving simulated motion - we tested (a) whether being exposed to a virtual reality environment alone causes anxiety to increase, and (b) whether exposure to simulated motion in a virtual reality environment increases anxiety. Using a repeated measures design, we used Kim's Anxiety Scale questionnaire to compare baseline anxiety, anxiety after virtual environment exposure, and anxiety after simulated motion. While there was no significant effect on anxiety for being in a virtual environment with no simulated motion, the introduction of simulated motion caused anxiety to significantly increase, but not to a severe or extreme level. The implications of this work for virtual reality exposure therapy (VRET) are discussed.

  2. Accurate prediction of the refractive index of polymers using first principles and data modeling

    NASA Astrophysics Data System (ADS)

    Afzal, Mohammad Atif Faiz; Cheng, Chong; Hachmann, Johannes

    Organic polymers with a high refractive index (RI) have recently attracted considerable interest due to their potential application in optical and optoelectronic devices. The ability to tailor the molecular structure of polymers is the key to increasing the accessible RI values. Our work concerns the creation of predictive in silico models for the optical properties of organic polymers, the screening of large-scale candidate libraries, and the mining of the resulting data to extract the underlying design principles that govern their performance. This work was set up to guide our experimentalist partners and allow them to target the most promising candidates. Our model is based on the Lorentz-Lorenz equation and thus includes the polarizability and number density values for each candidate. For the former, we performed a detailed benchmark study of different density functionals, basis sets, and the extrapolation scheme towards the polymer limit. For the number density we devised an exceedingly efficient machine learning approach to correlate the polymer structure and the packing fraction in the bulk material. We validated the proposed RI model against the experimentally known RI values of 112 polymers. We could show that the proposed combination of physical and data modeling is both successful and highly economical to characterize a wide range of organic polymers, which is a prerequisite for virtual high-throughput screening.

  3. 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...

  4. Simulation and performance analysis of a novel high-accuracy sheathless microfluidic impedance cytometer with coplanar electrode layout.

    PubMed

    Caselli, Federica; Bisegna, Paolo

    2017-10-01

    The performance of a novel microfluidic impedance cytometer (MIC) with coplanar configuration is investigated in silico. The main feature of the device is the ability to provide accurate particle-sizing despite the well-known measurement sensitivity to particle trajectory. The working principle of the device is presented and validated by means of an original virtual laboratory providing close-to-experimental synthetic data streams. It is shown that a metric correlating with particle trajectory can be extracted from the signal traces and used to compensate the trajectory-induced error in the estimated particle size, thus reaching high-accuracy. An analysis of relevant parameters of the experimental setup is also presented. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  5. Finite element model of size, shape and blood pressure on rupture of intracranial saccular aneurysms

    NASA Astrophysics Data System (ADS)

    Rica Nabong, Jennica; David, Guido

    2017-10-01

    Rupture of intracranial saccular aneurysms is a primary concern for neurologists and patients because it leads to stroke and permanent disability. This paper examines the role of blood pressure, in connection with size of and wall thickness, in the rupture of saccular aneurysms. A bulb-shaped geometry of a saccular aneurysm is obtained from angiographic images of a patient and modeled using Finite Elements based on the principle of virtual work under the Fung stress-strain relationship. The numerical model is subjected to varying levels of systolic blood pressure. Rupture is assumed to occur when the wall stress exceeded its mechanical strength. The results show which sizes of this class of aneurysms are at high risk of rupture for varying levels of blood pressure.

  6. How cognitive theory guides neuroscience.

    PubMed

    Frank, Michael J; Badre, David

    2015-02-01

    The field of cognitive science studies latent, unobservable cognitive processes that generate observable behaviors. Similarly, cognitive neuroscience attempts to link latent cognitive processes with the neural mechanisms that generate them. Although neural processes are partially observable (with imaging and electrophysiology), it would be a mistake to 'skip' the cognitive level and pursue a purely neuroscientific enterprise to studying behavior. In fact, virtually all of the major advances in understanding the neural basis of behavior over the last century have relied fundamentally on principles of cognition for guiding the appropriate measurements, manipulations, tasks, and interpretations. We provide several examples from the domains of episodic memory, working memory and cognitive control, and decision making in which cognitive theorizing and prior experimentation has been essential in guiding neuroscientific investigations and discoveries. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Novel quadrilateral elements based on explicit Hermite polynomials for bending of Kirchhoff-Love plates

    NASA Astrophysics Data System (ADS)

    Beheshti, Alireza

    2018-03-01

    The contribution addresses the finite element analysis of bending of plates given the Kirchhoff-Love model. To analyze the static deformation of plates with different loadings and geometries, the principle of virtual work is used to extract the weak form. Following deriving the strain field, stresses and resultants may be obtained. For constructing four-node quadrilateral plate elements, the Hermite polynomials defined with respect to the variables in the parent space are applied explicitly. Based on the approximated field of displacement, the stiffness matrix and the load vector in the finite element method are obtained. To demonstrate the performance of the subparametric 4-node plate elements, some known, classical examples in structural mechanics are solved and there are comparisons with the analytical solutions available in the literature.

  8. SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics

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

    Laursen, T.A.; Attaway, S.W.; Zadoks, R.I.

    1999-03-01

    This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples ofmore » the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.« less

  9. Derivatives of buckling loads and vibration frequencies with respect to stiffness and initial strain parameters

    NASA Technical Reports Server (NTRS)

    Haftka, Raphael T.; Cohen, Gerald A.; Mroz, Zenon

    1990-01-01

    A uniform variational approach to sensitivity analysis of vibration frequencies and bifurcation loads of nonlinear structures is developed. Two methods of calculating the sensitivities of bifurcation buckling loads and vibration frequencies of nonlinear structures, with respect to stiffness and initial strain parameters, are presented. A direct method requires calculation of derivatives of the prebuckling state with respect to these parameters. An adjoint method bypasses the need for these derivatives by using instead the strain field associated with the second-order postbuckling state. An operator notation is used and the derivation is based on the principle of virtual work. The derivative computations are easily implemented in structural analysis programs. This is demonstrated by examples using a general purpose, finite element program and a shell-of-revolution program.

  10. Evaluation of the power consumption of a high-speed parallel robot

    NASA Astrophysics Data System (ADS)

    Han, Gang; Xie, Fugui; Liu, Xin-Jun

    2018-06-01

    An inverse dynamic model of a high-speed parallel robot is established based on the virtual work principle. With this dynamic model, a new evaluation method is proposed to measure the power consumption of the robot during pick-and-place tasks. The power vector is extended in this method and used to represent the collinear velocity and acceleration of the moving platform. Afterward, several dynamic performance indices, which are homogenous and possess obvious physical meanings, are proposed. These indices can evaluate the power input and output transmissibility of the robot in a workspace. The distributions of the power input and output transmissibility of the high-speed parallel robot are derived with these indices and clearly illustrated in atlases. Furtherly, a low-power-consumption workspace is selected for the robot.

  11. Design principles for engaging and retaining virtual citizen scientists.

    PubMed

    Wald, Dara M; Longo, Justin; Dobell, A R

    2016-06-01

    Citizen science initiatives encourage volunteer participants to collect and interpret data and contribute to formal scientific projects. The growth of virtual citizen science (VCS), facilitated through websites and mobile applications since the mid-2000s, has been driven by a combination of software innovations and mobile technologies, growing scientific data flows without commensurate increases in resources to handle them, and the desire of internet-connected participants to contribute to collective outputs. However, the increasing availability of internet-based activities requires individual VCS projects to compete for the attention of volunteers and promote their long-term retention. We examined program and platform design principles that might allow VCS initiatives to compete more effectively for volunteers, increase productivity of project participants, and retain contributors over time. We surveyed key personnel engaged in managing a sample of VCS projects to identify the principles and practices they pursued for these purposes and led a team in a heuristic evaluation of volunteer engagement, website or application usability, and participant retention. We received 40 completed survey responses (33% response rate) and completed a heuristic evaluation of 20 VCS program sites. The majority of the VCS programs focused on scientific outcomes, whereas the educational and social benefits of program participation, variables that are consistently ranked as important for volunteer engagement and retention, were incidental. Evaluators indicated usability, across most of the VCS program sites, was higher and less variable than the ratings for participant engagement and retention. In the context of growing competition for the attention of internet volunteers, increased attention to the motivations of virtual citizen scientists may help VCS programs sustain the necessary engagement and retention of their volunteers. © 2016 Society for Conservation Biology.

  12. Accelerated Discovery of High-Refractive-Index Polymers Using First-Principles Modeling, Virtual High-Throughput Screening, and Data Mining

    NASA Astrophysics Data System (ADS)

    Afzal, Mohammad Atif Faiz; Cheng, Chong; Hachmann, Johannes

    Organic materials with refractive index (RI) values higher than 1.7 have attracted considerable interest in recent years due to the tremendous potential for their application in optical, optometric, and optoelectronic devices, and thus for shaping technological innovation in numerous related areas. Our work is concerned with creating predictive models for the optical properties of organic polymers, which will guide our experimentalist partners and allow them to target the most promising candidates. The RI model is developed based on a synergistic combination of first-principles electronic structure theory and machine learning techniques. The RI values predicted for common polymers using this model are in very good agreement with the experimental values. We also benchmark different DFT approximations along with various basis sets for their predictive performance in this model. We demonstrate that this combination of first-principles and data modeling is both successful and highly economical in determining the RI values of a wide range of organic polymers. To accelerate the development process, we cast this modeling approach into the high-throughput screening, materials informatics, and rational design framework that is developed in the group. This framework is a powerful tool and has shown to be highly promising for rapidly identifying polymer candidates with exceptional RI values as well as discovering design rules for advanced materials.

  13. Virtual reality and gaming systems to improve walking and mobility for people with musculoskeletal and neuromuscular conditions.

    PubMed

    Deutsch, Judith E

    2009-01-01

    Improving walking for individuals with musculoskeletal and neuromuscular conditions is an important aspect of rehabilitation. The capabilities of clinicians who address these rehabilitation issues could be augmented with innovations such as virtual reality gaming based technologies. The chapter provides an overview of virtual reality gaming based technologies currently being developed and tested to improve motor and cognitive elements required for ambulation and mobility in different patient populations. Included as well is a detailed description of a single VR system, consisting of the rationale for development and iterative refinement of the system based on clinical science. These concepts include: neural plasticity, part-task training, whole task training, task specific training, principles of exercise and motor learning, sensorimotor integration, and visual spatial processing.

  14. A nonlocal strain gradient model for dynamic deformation of orthotropic viscoelastic graphene sheets under time harmonic thermal load

    NASA Astrophysics Data System (ADS)

    Radwan, Ahmed F.; Sobhy, Mohammed

    2018-06-01

    This work presents a nonlocal strain gradient theory for the dynamic deformation response of a single-layered graphene sheet (SLGS) on a viscoelastic foundation and subjected to a time harmonic thermal load for various boundary conditions. Material of graphene sheets is presumed to be orthotropic and viscoelastic. The viscoelastic foundation is modeled as Kelvin-Voigt's pattern. Based on the two-unknown plate theory, the motion equations are obtained from the dynamic version of the virtual work principle. The nonlocal strain gradient theory is established from Eringen nonlocal and strain gradient theories, therefore, it contains two material scale parameters, which are nonlocal parameter and gradient coefficient. These scale parameters have two different effects on the graphene sheets. The obtained deflection is compared with that predicted in the literature. Additional numerical examples are introduced to illustrate the influences of the two length scale coefficients and other parameters on the dynamic deformation of the viscoelastic graphene sheets.

  15. Translational mini-review series on vaccines: The Edward Jenner Museum and the history of vaccination.

    PubMed

    Morgan, A J; Parker, S

    2007-03-01

    Edward Jenner's discovery of vaccination must rank as one of the most important medical advances of all time and is a prominent example of the power of rational enquiry being brought to bear during the Age of Enlightenment in 18th century Europe. In the modern era many millions of lives are saved each year by vaccines that work essentially on the same principles that were established by Edward Jenner more than 200 years ago. His country home in Berkeley, Gloucestershire, is where he carried out his work and where he spent most of his life. The building is now a museum in which the life and times of Jenner are commemorated including not only the discovery of smallpox vaccination but also his other important scientific contributions to natural history and medicine. The trustees of the Edward Jenner museum are committed to promoting the museum as a real and "virtual" educational centre that is both entertaining and informative.

  16. Case-Based Learning in Virtual Groups--Collaborative Problem Solving Activities and Learning Outcomes in a Virtual Professional Training Course

    ERIC Educational Resources Information Center

    Kopp, Birgitta; Hasenbein, Melanie; Mandl, Heinz

    2014-01-01

    This article analyzes the collaborative problem solving activities and learning outcomes of five groups that worked on two different complex cases in a virtual professional training course. In this asynchronous virtual learning environment, all knowledge management content was delivered virtually and collaboration took place through forums. To…

  17. Runtime Performance and Virtual Network Control Alternatives in VM-Based High-Fidelity Network Simulations

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

    Yoginath, Srikanth B; Perumalla, Kalyan S; Henz, Brian J

    2012-01-01

    In prior work (Yoginath and Perumalla, 2011; Yoginath, Perumalla and Henz, 2012), the motivation, challenges and issues were articulated in favor of virtual time ordering of Virtual Machines (VMs) in network simulations hosted on multi-core machines. Two major components in the overall virtualization challenge are (1) virtual timeline establishment and scheduling of VMs, and (2) virtualization of inter-VM communication. Here, we extend prior work by presenting scaling results for the first component, with experiment results on up to 128 VMs scheduled in virtual time order on a single 12-core host. We also explore the solution space of design alternatives formore » the second component, and present performance results from a multi-threaded, multi-queue implementation of inter-VM network control for synchronized execution with VM scheduling, incorporated in our NetWarp simulation system.« less

  18. Whither Headship?

    ERIC Educational Resources Information Center

    Male, Trevor

    2006-01-01

    Headship in England was radically altered in nature in 1988 by the Education Reform Act which introduced the principle of local management of schools. Despite this legislative intervention, however, the model of headship in England remained virtually unchanged, rather it was headteacher behaviour that changed. The maintained school system is still…

  19. VERS: a virtual environment for reconstructive surgery planning

    NASA Astrophysics Data System (ADS)

    Montgomery, Kevin N.

    1997-05-01

    The virtual environment for reconstructive surgery (VERS) project at the NASA Ames Biocomputation Center is applying virtual reality technology to aid surgeons in planning surgeries. We are working with a craniofacial surgeon at Stanford to assemble and visualize the bone structure of patients requiring reconstructive surgery either through developmental abnormalities or trauma. This project is an extension of our previous work in 3D reconstruction, mesh generation, and immersive visualization. The current VR system, consisting of an SGI Onyx RE2, FakeSpace BOOM and ImmersiveWorkbench, Virtual Technologies CyberGlove and Ascension Technologies tracker, is currently in development and has already been used to visualize defects preoperatively. In the near future it will be used to more fully plan the surgery and compute the projected result to soft tissue structure. This paper presents the work in progress and details the production of a high-performance, collaborative, and networked virtual environment.

  20. Virtual collaboration in the online educational setting: a concept analysis.

    PubMed

    Breen, Henny

    2013-01-01

    This study was designed to explore the concept of virtual collaboration within the context of an online learning environment in an academic setting. Rodgers' method of evolutionary concept analysis was used to provide a contextual view of the concept to identify attributes, antecedents, and consequences of virtual collaboration. Commonly used terms to describe virtual collaboration are collaborative and cooperative learning, group work, group interaction, group learning, and teamwork. A constructivist pedagogy, group-based process with a shared purpose, support, and web-based technology is required for virtual collaboration to take place. Consequences of virtual collaboration are higher order thinking and learning to work with others. A comprehensive definition of virtual collaboration is offered as an outcome of this analysis. Clarification of virtual collaboration prior to using it as a pedagogical tool in the online learning environment will enhance nursing education with the changes in nursing curriculum being implemented today. Further research is recommended to describe the developmental stages of the collaborative process among nursing students in online education and how virtual collaboration facilitates collaboration in practice. © 2013 Wiley Periodicals, Inc.

  1. Prototyping Faithful Execution in a Java virtual machine.

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

    Tarman, Thomas David; Campbell, Philip LaRoche; Pierson, Lyndon George

    2003-09-01

    This report presents the implementation of a stateless scheme for Faithful Execution, the design for which is presented in a companion report, ''Principles of Faithful Execution in the Implementation of Trusted Objects'' (SAND 2003-2328). We added a simple cryptographic capability to an already simplified class loader and its associated Java Virtual Machine (JVM) to provide a byte-level implementation of Faithful Execution. The extended class loader and JVM we refer to collectively as the Sandia Faithfully Executing Java architecture (or JavaFE for short). This prototype is intended to enable exploration of more sophisticated techniques which we intend to implement in hardware.

  2. Application of virtual reality technology in clinical medicine

    PubMed Central

    Li, Lan; Yu, Fei; Shi, Dongquan; Shi, Jianping; Tian, Zongjun; Yang, Jiquan; Wang, Xingsong; Jiang, Qing

    2017-01-01

    The present review discusses the application of virtual reality (VR) technology in clinical medicine, especially in surgical training, pain management and therapeutic treatment of mental illness. We introduce the common types of VR simulators and their operational principles in aforementioned fields. The clinical effects are also discussed. In almost every study that dealt with VR simulators, researchers have arrived at the same conclusion that both doctors and patients could benefit from this novel technology. Moreover, advantages and disadvantages of the utilization of VR technology in each field were discussed, and the future research directions were proposed. PMID:28979666

  3. Application of virtual reality technology in clinical medicine.

    PubMed

    Li, Lan; Yu, Fei; Shi, Dongquan; Shi, Jianping; Tian, Zongjun; Yang, Jiquan; Wang, Xingsong; Jiang, Qing

    2017-01-01

    The present review discusses the application of virtual reality (VR) technology in clinical medicine, especially in surgical training, pain management and therapeutic treatment of mental illness. We introduce the common types of VR simulators and their operational principles in aforementioned fields. The clinical effects are also discussed. In almost every study that dealt with VR simulators, researchers have arrived at the same conclusion that both doctors and patients could benefit from this novel technology. Moreover, advantages and disadvantages of the utilization of VR technology in each field were discussed, and the future research directions were proposed.

  4. Virtual Reality and Computer-Enhanced Training Applied to Wheeled Mobility: An Overview of Work in Pittsburgh

    ERIC Educational Resources Information Center

    Cooper, Rory A.; Ding, Dan; Simpson, Richard; Fitzgerald, Shirley G.; Spaeth, Donald M.; Guo, Songfeng; Koontz, Alicia M.; Cooper, Rosemarie; Kim, Jongbae; Boninger, Michael L.

    2005-01-01

    Some aspects of assistive technology can be enhanced by the application of virtual reality. Although virtual simulation offers a range of new possibilities, learning to navigate in a virtual environment is not equivalent to learning to navigate in the real world. Therefore, virtual reality simulation is advocated as a useful preparation for…

  5. A virtual tour of virtual reality

    NASA Astrophysics Data System (ADS)

    Harris, Margaret

    2018-03-01

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

  6. Immersive Virtual Reality Therapy with Myoelectric Control for Treatment-resistant Phantom Limb Pain: Case Report.

    PubMed

    Chau, Brian; Phelan, Ivan; Ta, Phillip; Humbert, Sarah; Hata, Justin; Tran, Duc

    2017-01-01

    Objective: Phantom limb pain is a condition frequently experienced after amputation. One treatment for phantom limb pain is traditional mirror therapy, yet some patients do not respond to this intervention, and immersive virtual reality mirror therapy offers some potential advantages. We report the case of a patient with severe phantom limb pain following an upper limb amputation and successful treatment with therapy in a custom virtual reality environment. Methods: An interactive 3-D kitchen environment was developed based on the principles of mirror therapy to allow for control of virtual hands while wearing a motion-tracked, head-mounted virtual reality display. The patient used myoelectric control of a virtual hand as well as motion-tracking control in this setting for five therapy sessions. Pain scale measurements and subjective feedback was elicited at each session. Results: Analysis of the measured pain scales showed statistically significant decreases per session [Visual Analog Scale, Short Form McGill Pain Questionnaire, and Wong-Baker FACES pain scores decreased by 55 percent (p=0.0143), 60 percent (p=0.023), and 90 percent (p=0.0024), respectively]. Significant subjective pain relief persisting between sessions was also reported, as well as marked immersion within the virtual environments. On followup at six weeks, the patient noted continued decrease in phantom limb pain symptoms. Conclusions: Currently available immersive virtual reality technology with myolectric and motion tracking control may represent a possible therapy option for treatment-resistant phantom limb pain.

  7. Immersive Virtual Reality Therapy with Myoelectric Control for Treatment-resistant Phantom Limb Pain: Case Report

    PubMed Central

    Phelan, Ivan; Ta, Phillip; Humbert, Sarah; Hata, Justin; Tran, Duc

    2017-01-01

    Objective: Phantom limb pain is a condition frequently experienced after amputation. One treatment for phantom limb pain is traditional mirror therapy, yet some patients do not respond to this intervention, and immersive virtual reality mirror therapy offers some potential advantages. We report the case of a patient with severe phantom limb pain following an upper limb amputation and successful treatment with therapy in a custom virtual reality environment. Methods: An interactive 3-D kitchen environment was developed based on the principles of mirror therapy to allow for control of virtual hands while wearing a motion-tracked, head-mounted virtual reality display. The patient used myoelectric control of a virtual hand as well as motion-tracking control in this setting for five therapy sessions. Pain scale measurements and subjective feedback was elicited at each session. Results: Analysis of the measured pain scales showed statistically significant decreases per session [Visual Analog Scale, Short Form McGill Pain Questionnaire, and Wong-Baker FACES pain scores decreased by 55 percent (p=0.0143), 60 percent (p=0.023), and 90 percent (p=0.0024), respectively]. Significant subjective pain relief persisting between sessions was also reported, as well as marked immersion within the virtual environments. On followup at six weeks, the patient noted continued decrease in phantom limb pain symptoms. Conclusions: Currently available immersive virtual reality technology with myolectric and motion tracking control may represent a possible therapy option for treatment-resistant phantom limb pain. PMID:29616149

  8. 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.

  9. Web-Based Learning in the Computer-Aided Design Curriculum.

    ERIC Educational Resources Information Center

    Sung, Wen-Tsai; Ou, S. C.

    2002-01-01

    Applies principles of constructivism and virtual reality (VR) to computer-aided design (CAD) curriculum, particularly engineering, by integrating network, VR and CAD technologies into a Web-based learning environment that expands traditional two-dimensional computer graphics into a three-dimensional real-time simulation that enhances user…

  10. NREL, EPRI Validate Advanced Microgrid Controller with ESIF's Virtual

    Science.gov Websites

    Microgrid Controller with ESIF's Virtual Microgrid Model NREL, EPRI Validate Advanced Microgrid Controller with ESIF's Virtual Microgrid Model NREL is working with the Electric Power Research Institute (EPRI Energy Systems Integration Facility, by connecting it to a virtual model of a microgrid. NREL researchers

  11. Visualization of N-body Simulations in Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Knop, Robert A.; Ames, J.; Djorgovski, G.; Farr, W.; Hut, P.; Johnson, A.; McMillan, S.; Nakasone, A.; Vesperini, E.

    2010-01-01

    We report on work to use virtual worlds for visualizing the results of N-body calculations, on three levels. First, we have written a demonstration 3-body solver entirely in the scripting language of the popularly used virtual world Second Life. Second, we have written a physics module for the open source virtual world OpenSim that performs N-body calculations as the physics engine for the server, allowing natural 3-d visualization of the solution as the solution is being performed. Finally, we give an initial report on the potential use of virtual worlds to visualize calculations which have previously been performed, or which are being performed in other processes and reported to the virtual world server. This work has been performed as part of the Meta-Institute of Computational Astrophysics (MICA). http://www.mica-vw.org

  12. Incorporating haptic effects into three-dimensional virtual environments to train the hemiparetic upper extremity

    PubMed Central

    Adamovich, Sergei; Fluet, Gerard G.; Merians, Alma S.; Mathai, Abraham; Qiu, Qinyin

    2010-01-01

    Current neuroscience has identified several constructs to increase the effectiveness of upper extremity rehabilitation. One is the use of progressive, skill acquisition-oriented training. Another approach emphasizes the use of bilateral activities. Building on these principles, this paper describes the design and feasibility testing of a robotic / virtual environment system designed to train the arm of persons who have had strokes. The system provides a variety of assistance modes, scalable workspaces and hand-robot interfaces allowing persons with strokes to train multiple joints in three dimensions. The simulations utilize assistance algorithms that adjust task difficulty both online and offline in relation to subject performance. Several distinctive haptic effects have been incorporated into the simulations. An adaptive master-slave relationship between the unimpaired and impaired arm encourages active movement of the subject's hemiparetic arm during a bimanual task. Adaptive anti-gravity support and damping stabilize the arm during virtual reaching and placement tasks. An adaptive virtual spring provides assistance to complete the movement if the subject is unable to complete the task in time. Finally, haptically rendered virtual objects help to shape the movement trajectory during a virtual placement task. A proof of concept study demonstrated this system to be safe, feasible and worthy of further study. PMID:19666345

  13. Virtualization of System of Systems Test and Evaluation

    DTIC Science & Technology

    2012-06-04

    computers and is the primary enabler for virtualization. 2. Virtualization System Elements Parmalee, Peterson , Tillman, & Hatfield (1972) outlined the...The work of Abu-Taieh and El Sheikh, based on the work of Balci (1994, 1995), and Balci et al. ( 1996 ), seeks to organize types of tests and to...and testing. In A. Dasso & A. Funes (Eds.), Verification, validation, and testing in software engineering (pp. 155–184). Hershey , PA: Idea Group

  14. Supercritical fluid extraction. Principles and practice

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

    McHugh, M.A.; Krukonis, V.J.

    This book is a presentation of the fundamentals and application of super-critical fluid solvents (SCF). The authors cover virtually every facet of SCF technology: the history of SCF extraction, its underlying thermodynamic principles, process principles, industrial applications, and analysis of SCF research and development efforts. The thermodynamic principles governing SCF extraction are covered in depth. The often complex three-dimensional pressure-temperature composition (PTx) phase diagrams for SCF-solute mixtures are constructed in a coherent step-by-step manner using the more familiar two-dimensional Px diagrams. The experimental techniques used to obtain high pressure phase behavior information are described in detail and the advantages andmore » disadvantages of each technique are explained. Finally, the equations used to model SCF-solute mixtures are developed, and modeling results are presented to highlight the correlational strengths of a cubic equation of state.« less

  15. Principles of reasoning in historical epidemiology.

    PubMed

    Tulodziecki, Dana

    2012-10-01

    The case of John Snow has long been important to epidemiologists and public health officials. However, despite the fact that there have been many discussions about the various aspects of Snow's case, there has been virtually no discussion about what guided Snow's reasoning in his coming to believe his various conclusions about cholera. Here, I want to take up this question in some detail and show that there are a number of specific principles of reasoning that played a crucial role for Snow. Moreover, these principles were epistemologically important to Snow, a fact about which Snow is explicit in many places. An analysis of Snow's case suggests that, because of the epistemic role such principles of reasoning can play, health care practitioners ought to understand their practices to be theoretically informed in these ways, and not just data driven. © 2012 Blackwell Publishing Ltd.

  16. First-principles study of the effects of Silicon doping on the Schottky barrier of TiSi2/Si interfaces

    NASA Astrophysics Data System (ADS)

    Wang, Han; Silva, Eduardo; West, Damien; Sun, Yiyang; Restrepo, Oscar; Zhang, Shengbai; Kota, Murali

    As scaling of semiconductor devices is pursued in order to improve power efficiency, quantum effects due to the reduced dimensions on devices have become dominant factors in power, performance, and area scaling. In particular, source/drain contact resistance has become a limiting factor in the overall device power efficiency and performance. As a consequence, techniques such as heavy doping of source and drain have been explored to reduce the contact resistance, thereby shrinking the width of depletion region and lowering the Schottky barrier height. In this work, we study the relation between doping in Silicon and the Schottky barrier of a TiSi2/Si interface with first-principles calculation. Virtual Crystal Approximation (VCA) is used to calculate the average potential of the interface with varying doping concentration, while the I-V curve for the corresponding interface is calculated with a generalized one-dimensional transfer matrix method. The relation between substitutional and interstitial Boron and Phosphorus dopant near the interface, and their effect on tuning the Schottky barrier is studied. These studies provide insight to the type of doping and the effect of dopant segregation to optimize metal-semiconductor interface resistance.

  17. Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

    NASA Astrophysics Data System (ADS)

    Scacchi, Walt

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

  18. Solar-Terrestrial Ontology Development

    NASA Astrophysics Data System (ADS)

    McGuinness, D.; Fox, P.; Middleton, D.; Garcia, J.; Cinquni, L.; West, P.; Darnell, J. A.; Benedict, J.

    2005-12-01

    The development of an interdisciplinary virtual observatory (the Virtual Solar-Terrestrial Observatory; VSTO) as a scalable environment for searching, integrating, and analyzing databases distributed over the Internet requires a higher level of semantic interoperability than here-to-fore required by most (if not all) distributed data systems or discipline specific virtual observatories. The formalization of semantics using ontologies and their encodings for the internet (e.g. OWL - the Web Ontology Language), as well as the use of accompanying tools, such as reasoning, inference and explanation, open up both a substantial leap in options for interoperability and in the need for formal development principles to guide ontology development and use within modern, multi-tiered network data environments. In this presentation, we outline the formal methodologies we utilize in the VSTO project, the currently developed use-cases, ontologies and their relation to existing ontologies (such as SWEET).

  19. Synchronous E-Learning: Reflections and Design Considerations

    ERIC Educational Resources Information Center

    Tabak, Filiz; Rampal, Rohit

    2014-01-01

    This paper is a personal reflection on the design, development, and delivery of online synchronous conferencing as a pedagogical tool complementing traditional, face-to-face content delivery and learning. The purpose of the paper is to demonstrate how instructors can combine collaborative and virtual learning principles in course design. In…

  20. 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.

  1. Augmented Reflective Learning and Knowledge Retention Perceived among Students in Classrooms Involving Virtual Laboratories

    ERIC Educational Resources Information Center

    Achuthan, Krishnashree; Francis, Saneesh P.; Diwakar, Shyam

    2017-01-01

    Learning theories converge on the principles of reflective learning processes and perceive them as fundamental to effective learning. Traditional laboratory education in science and engineering often happens in highly resource-constrained environments that compromise some of the learning objectives. This paper focuses on characterizing three…

  2. Learning in Transformational Computer Games: Exploring Design Principles for a Nanotechnology Game

    ERIC Educational Resources Information Center

    Masek, Martin; Murcia, Karen; Morrison, Jason; Newhouse, Paul; Hackling, Mark

    2012-01-01

    Transformational games are digital computer and video applications purposefully designed to create engaging and immersive learning environments for delivering specified learning goals, outcomes and experiences. The virtual world of a transformational game becomes the social environment within which learning occurs as an outcome of the complex…

  3. Designing Creative User Interactions for Learning

    ERIC Educational Resources Information Center

    Hong, Yi-Chun; Clinton, Gregory; Rieber, Lloyd P.

    2014-01-01

    Profitable creative ideas can emerge from within virtually any phase of the instructional design and development process. However, the design of user interactions is perhaps where learners can most directly experience the benefits of such ideas. In this article, the authors discuss principles of learner interaction as found in the instructional…

  4. A Teaching Guide to Evolution

    ERIC Educational Resources Information Center

    Gregg, Thomas G.; Janssen, Gary R.; Bhattacharjee, J.K.

    2003-01-01

    Evolution is considered by virtually all biologists to be the central unifying principle of biology, yet its fundamental concepts are not widely understood or widely disseminated. Teaching evolution--defined as descent with modification from a common ancestor as a result of natural selection acting on genetic variation--has traditionally been a…

  5. eBlack Studies: A Twenty-First-Century Challenge.

    ERIC Educational Resources Information Center

    Alkalimat, Abdul

    2000-01-01

    Calls for the transformation of black studies that moves from ideology to information. Argues that eBlack, the virtualization of the black experience, is the basis for the next stage of this academic discipline. Presents three theoretical principles of eBlack studies (cyberdemocracy, collective intelligence, and information freedom); describes…

  6. Gregor Mendel: Creationist Hero

    ERIC Educational Resources Information Center

    Numbers, Ronald L.

    2015-01-01

    In histories of twentieth-century Darwinism few developments loom larger than the turn-of-the-century rediscovery of Gregor Mendel's genetic research and the later application of Mendelian principles in constructing so-called Neo-Darwinism. Virtually unknown is the equally enthusiastic embrace of Mendel by antievolutionists, who as early as…

  7. Curating and Nudging in Virtual CLIL Environments

    ERIC Educational Resources Information Center

    Nielsen, Helle Lykke

    2014-01-01

    Foreign language teachers can benefit substantially from the notions of curation and nudging when scaffolding CLIL activities on the internet. This article shows how these principles can be integrated into CLILstore, a free multimedia-rich learning tool with seamless access to online dictionaries, and presents feedback from first and second year…

  8. Preparing to Teach in Cyberspace: User Education in Real and Virtual Libraries.

    ERIC Educational Resources Information Center

    Byron, Suzanne

    1995-01-01

    Discussion of librarians' training for teaching user education focuses on experiments at the University of North Texas in providing resources and empowering education for librarians and staff members who teach. The use of computer-based education principles and Ranganathan's laws of library science are explained. (Author/LRW)

  9. Commentary: The Tyranny of Time and the Reality Principle

    ERIC Educational Resources Information Center

    Gersten, Russell

    2016-01-01

    Each of the five articles in this special issue gets "into the weeds" in terms of studying actual classroom or school implementation of evidence-based or promising practices. Virtually all confront the issue of logistics and establishing an infrastructure for ensuring adequate implementation. In general, those studies that ask teachers…

  10. How Do Virtual World Experiences Bring about Learning? A Critical Review of Theories

    ERIC Educational Resources Information Center

    Loke, Swee-Kin

    2015-01-01

    While students do learn real-world knowledge and skills in virtual worlds, educators have yet to adequately theorise how students' virtual world experiences bring about this learning. This paper critically reviewed theories currently used to underpin empirical work in virtual worlds for education. In particular, it evaluated how applicable these…

  11. 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…

  12. Energy Consumption Management of Virtual Cloud Computing Platform

    NASA Astrophysics Data System (ADS)

    Li, Lin

    2017-11-01

    For energy consumption management research on virtual cloud computing platforms, energy consumption management of virtual computers and cloud computing platform should be understood deeper. Only in this way can problems faced by energy consumption management be solved. In solving problems, the key to solutions points to data centers with high energy consumption, so people are in great need to use a new scientific technique. Virtualization technology and cloud computing have become powerful tools in people’s real life, work and production because they have strong strength and many advantages. Virtualization technology and cloud computing now is in a rapid developing trend. It has very high resource utilization rate. In this way, the presence of virtualization and cloud computing technologies is very necessary in the constantly developing information age. This paper has summarized, explained and further analyzed energy consumption management questions of the virtual cloud computing platform. It eventually gives people a clearer understanding of energy consumption management of virtual cloud computing platform and brings more help to various aspects of people’s live, work and son on.

  13. Methodological and ethical issues in research using social media: a metamethod of Human Papillomavirus vaccine studies.

    PubMed

    Gustafson, Diana L; Woodworth, Claire F

    2014-12-02

    Online content is a primary source of healthcare information for internet-using adults and a rich resource for health researchers. This paper explores the methodological and ethical issues of engaging in health research using social media. A metamethod was performed on systematically selected studies that used social media as a data source for exploring public awareness and beliefs about Human Papillomaviruses (HPV) and HPV vaccination. Seven electronic databases were searched using a variety of search terms identified for each of three concepts: social media, HPV vaccine, and research method. Abstracts were assessed for eligibility of inclusion; six studies met the eligibility criteria and were subjected to content analysis. A 10-item coding scheme was developed to assess the clarity, congruence and transparency of research design, epistemological and methodological underpinnings and ethical considerations. The designs of the six selected studies were sound, although most studies could have been more transparent about how they built in rigor to ensure the trustworthiness and credibility of findings. Statistical analysis that intended to measure trends and patterns did so without the benefit of randomized sampling and other design elements for ensuring generalizability or reproducibility of findings beyond the specified virtual community. Most researchers did not sufficiently engage virtual users in the research process or consider the risk of privacy incursion. Most studies did not seek ethical approval from an institutional research board or permission from host websites or web service providers. The metamethod exposed missed opportunities for using the dialogical character of social media as well as a lack of attention to the unique ethical issues inherent in operating in a virtual community where social boundaries and issues of public and private are ambiguous. This suggests the need for more self-conscious and ethical research practices when using social media as a data source. Given the relative newness of virtual communities, researchers and ethics review boards must work together to develop expertise in evaluating the design of studies undertaken with virtual communities. We recommend that the principles of concern for welfare, respect for person, and justice to be applied in research using social media.

  14. Virtual reality games for movement rehabilitation in neurological conditions: how do we meet the needs and expectations of the users?

    PubMed

    Lewis, Gwyn N; Rosie, Juliet A

    2012-01-01

    To review quantitative and qualitative studies that have examined the users' response to virtual reality game-based interventions in people with movement disorders associated with chronic neurological conditions. We aimed to determine key themes that influenced users' enjoyment and engagement in the games and develop suggestions as to how future systems could best address their needs and expectations. There were a limited number of studies that evaluated user opinions. From those found, seven common themes emerged: technology limitations, user control and therapist assistance, the novel physical and cognitive challenge, feedback, social interaction, game purpose and expectations, and the virtual environments. Our key recommendations derived from the review were to avoid technology failure, maintain overt therapeutic principles within the games, encompass progression to promote continuing physical and cognitive challenge, and to provide feedback that is easily and readily associated with success. While there have been few studies that have evaluated the users' perspective of virtual rehabilitation games, our findings indicate that canvassing these experiences provides valuable information on the needs of the intended users. Incorporating our recommendations may enhance the efficacy of future systems to optimize the rehabilitation benefits of virtual reality games.

  15. Virtual bargaining: a theory of social decision-making.

    PubMed

    Misyak, Jennifer B; Chater, Nick

    2014-11-05

    An essential element of goal-directed decision-making in social contexts is that agents' actions may be mutually interdependent. However, the most well-developed approaches to such strategic interactions, based on the Nash equilibrium concept in game theory, are sometimes too broad and at other times 'overlook' good solutions to fundamental social dilemmas and coordination problems. The authors propose a new theory of social decision-making-virtual bargaining-in which individuals decide among a set of moves on the basis of what they would agree to do if they could openly bargain. The core principles of a formal account are outlined (vis-à-vis the notions of 'feasible agreement' and explicit negotiation) and further illustrated with the introduction of a new game, dubbed the 'Boobytrap game' (a modification on the canonical Prisoner's Dilemma paradigm). In the first empirical data of how individuals play the Boobytrap game, participants' experimental choices accord well with a virtual bargaining perspective, but do not match predictions from a standard Nash account. Alternative frameworks are discussed, with specific empirical tests between these and virtual bargaining identified as future research directions. Lastly, it is proposed that virtual bargaining underpins a vast range of human activities, from social decision-making to joint action and communication.

  16. The University of Illinois at Chicago School of Public Health Doctor of Public Health program: an innovative approach to doctoral-level practice leadership development.

    PubMed

    Lenihan, Patrick; Welter, Christina; Brandt-Rauf, Paul; Neuberger, Babette; Pinsker, Eve; Petros, Michael; Risley, Kristine

    2015-03-01

    The University of Illinois at Chicago, School of Public Health, Doctor of Public Health degree is designed to build leadership skills and an ability to contribute to the evidence base of practice. The competency-based, distance-format, doctoral-level program for midcareer professionals features an action learning approach in which students apply leadership principles from the virtual classroom to real-world problems at their work sites. Students demonstrate mastery of the competencies and readiness to advance to the dissertation stage through completing a portfolio by using a process of systematic reflection. The practice-oriented dissertation demonstrates the ability to contribute to the evidence base of public health practice in an area of emphasis. Preliminary evaluation data indicate that the program is meeting its intended purposes.

  17. The University of Illinois at Chicago School of Public Health Doctor of Public Health Program: An Innovative Approach to Doctoral-Level Practice Leadership Development

    PubMed Central

    Welter, Christina; Brandt-Rauf, Paul; Neuberger, Babette; Pinsker, Eve; Petros, Michael; Risley, Kristine

    2015-01-01

    The University of Illinois at Chicago, School of Public Health, Doctor of Public Health degree is designed to build leadership skills and an ability to contribute to the evidence base of practice. The competency-based, distance-format, doctoral-level program for midcareer professionals features an action learning approach in which students apply leadership principles from the virtual classroom to real-world problems at their work sites. Students demonstrate mastery of the competencies and readiness to advance to the dissertation stage through completing a portfolio by using a process of systematic reflection. The practice-oriented dissertation demonstrates the ability to contribute to the evidence base of public health practice in an area of emphasis. Preliminary evaluation data indicate that the program is meeting its intended purposes. PMID:25706020

  18. Retinal projection type super multi-view head-mounted display

    NASA Astrophysics Data System (ADS)

    Takahashi, Hideya; Ito, Yutaka; Nakata, Seigo; Yamada, Kenji

    2014-02-01

    We propose a retinal projection type super multi-view head-mounted display (HMD). The smooth motion parallax provided by the super multi-view technique enables a precise superposition of virtual 3D images on the real scene. Moreover, if a viewer focuses one's eyes on the displayed 3D image, the stimulus for the accommodation of the human eye is produced naturally. Therefore, although proposed HMD is a monocular HMD, it provides observers with natural 3D images. The proposed HMD consists of an image projection optical system and a holographic optical element (HOE). The HOE is used as a combiner, and also works as a condenser lens to implement the Maxwellian view. Some parallax images are projected onto the HOE, and converged on the pupil, and then projected onto the retina. In order to verify the effectiveness of the proposed HMD, we constructed the prototype HMD. In the prototype HMD, the number of parallax images and the number of convergent points on the pupil is three. The distance between adjacent convergent points is 2 mm. We displayed virtual images at the distance from 20 cm to 200 cm in front of the pupil, and confirmed the accommodation. This paper describes the principle of proposed HMD, and also describes the experimental result.

  19. Simultaneous displacement and slope measurement in electronic speckle pattern interferometry using adjustable aperture multiplexing.

    PubMed

    Lu, Min; Wang, Shengjia; Aulbach, Laura; Koch, Alexander W

    2016-08-01

    This paper suggests the use of adjustable aperture multiplexing (AAM), a method which is able to introduce multiple tunable carrier frequencies into a three-beam electronic speckle pattern interferometer to measure the out-of-plane displacement and its first-order derivative simultaneously. In the optical arrangement, two single apertures are located in the object and reference light paths, respectively. In cooperation with two adjustable mirrors, virtual images of the single apertures construct three pairs of virtual double apertures with variable aperture opening sizes and aperture distances. By setting the aperture parameter properly, three tunable spatial carrier frequencies are produced within the speckle pattern and completely separate the information of three interferograms in the frequency domain. By applying the inverse Fourier transform to a selected spectrum, its corresponding phase difference distribution can thus be evaluated. Therefore, we can obtain the phase map due to the deformation as well as its slope of the test surface from two speckle patterns which are recorded at different loading events. By this means, simultaneous and dynamic measurements are realized. AAM has greatly simplified the measurement system, which contributes to improving the system stability and increasing the system flexibility and adaptability to various measurement requirements. This paper presents the AAM working principle, the phase retrieval using spatial carrier frequency, and preliminary experimental results.

  20. High-contrast X-ray micro-radiography and micro-CT of ex-vivo soft tissue murine organs utilizing ethanol fixation and large area photon-counting detector

    PubMed Central

    Dudak, Jan; Zemlicka, Jan; Karch, Jakub; Patzelt, Matej; Mrzilkova, Jana; Zach, Petr; Hermanova, Zuzana; Kvacek, Jiri; Krejci, Frantisek

    2016-01-01

    Using dedicated contrast agents high-quality X-ray imaging of soft tissue structures with isotropic micrometre resolution has become feasible. This technique is frequently titled as virtual histology as it allows production of slices of tissue without destroying the sample. The use of contrast agents is, however, often an irreversible time-consuming procedure and despite the non-destructive principle of X-ray imaging, the sample is usually no longer usable for other research methods. In this work we present the application of recently developed large-area photon counting detector for high resolution X-ray micro-radiography and micro-tomography of whole ex-vivo ethanol-preserved mouse organs. The photon counting detectors provide dark-current-free quantum-counting operation enabling acquisition of data with virtually unlimited contrast-to-noise ratio (CNR). Thanks to the very high CNR even ethanol-only preserved soft-tissue samples without addition of any contrast agent can be visualized in great detail. As ethanol preservation is one of the standard steps of tissue fixation for histology, the presented method can open a way for widespread use of micro-CT with all its advantages for routine 3D non-destructive soft-tissue visualisation. PMID:27461900

  1. Virtual Enterprises and Vocational Training.

    ERIC Educational Resources Information Center

    Kreber, Stefan

    2001-01-01

    Characteristics of virtual enterprises (client oriented, temporary working organizations that dissolve after solving specific problems, extensive technological applications) can be applied to vocational training. Virtual learning centers can provide web-based training intraorganizationally and interorganizationally via intranets and extranets. (SK)

  2. Coercive Narratives, Motivation and Role Playing in Virtual Worlds

    DTIC Science & Technology

    2002-01-01

    resource for making immersive virtual environments highly engaging. Interaction also appeals to our natural desire to discover. Reading a book contains...participation in an open-ended Virtual Environment (VE). I intend to take advantage of a participants’ natural tendency to prefer interaction when possible...I hope this work will expand the potential of experience within virtual worlds. K e y w o r d s : Immersive Environments , Virtual Environments

  3. Middle school students' learning of mechanics concepts through engagement in different sequences of physical and virtual experiments

    NASA Astrophysics Data System (ADS)

    Sullivan, Sarah; Gnesdilow, Dana; Puntambekar, Sadhana; Kim, Jee-Seon

    2017-08-01

    Physical and virtual experimentation are thought to have different affordances for supporting students' learning. Research investigating the use of physical and virtual experiments to support students' learning has identified a variety of, sometimes conflicting, outcomes. Unanswered questions remain about how physical and virtual experiments may impact students' learning and for which contexts and content areas they may be most effective. Using a quasi-experimental design, we examined eighth grade students' (N = 100) learning of physics concepts related to pulleys depending on the sequence of physical and virtual labs they engaged in. Five classes of students were assigned to either the: physical first condition (PF) (n = 55), where students performed a physical pulley experiment and then performed the same experiment virtually, or virtual first condition (VF) (n = 45), with the opposite sequence. Repeated measures ANOVA's were conducted to examine how physical and virtual labs impacted students' learning of specific physics concepts. While we did not find clear-cut support that one sequence was better, we did find evidence that participating in virtual experiments may be more beneficial for learning certain physics concepts, such as work and mechanical advantage. Our findings support the idea that if time or physical materials are limited, using virtual experiments may help students understand work and mechanical advantage.

  4. Supporting Distributed Team Working in 3D Virtual Worlds: A Case Study in Second Life

    ERIC Educational Resources Information Center

    Minocha, Shailey; Morse, David R.

    2010-01-01

    Purpose: The purpose of this paper is to report on a study into how a three-dimensional (3D) virtual world (Second Life) can facilitate socialisation and team working among students working on a team project at a distance. This models the situation in many commercial sectors where work is increasingly being conducted across time zones and between…

  5. Healthy young adults implement distinctive avoidance strategies while walking and circumventing virtual human vs. non-human obstacles in a virtual environment.

    PubMed

    Souza Silva, Wagner; Aravind, Gayatri; Sangani, Samir; Lamontagne, Anouk

    2018-03-01

    This study examines how three types of obstacles (cylinder, virtual human and virtual human with footstep sounds) affect circumvention strategies of healthy young adults. Sixteen participants aged 25.2 ± 2.5 years (mean ± 1SD) were tested while walking overground and viewing a virtual room through a helmet mounted display. As participants walked towards a stationary target in the far space, they avoided an obstacle (cylinder or virtual human) approaching either from the right (+40°), left (-40°) or head-on (0°). Obstacle avoidance strategies were characterized using the position and orientation of the head. Repeated mixed model analysis showed smaller minimal distances (p = 0.007) while avoiding virtual humans as compared to cylinders. Footstep sounds added to virtual humans did not modify (p = 0.2) minimal distances compared to when no sound was provided. Onset times of avoidance strategies were similar across conditions (p = 0.06). Results indicate that the nature of the obstacle (human-like vs. non-human object) matters and can modify avoidance strategies. Smaller obstacle clearances in response to virtual humans may reflect the use of a less conservative avoidance strategy, due to a resemblance of obstacles to pedestrians and a recall of strategies used in daily locomotion. The lack of influence of footstep sounds supports the fact that obstacle avoidance primarily relies on visual cues and the principle of 'inverse effectiveness' whereby multisensory neurons' response to multimodal stimuli becomes weaker when the unimodal sensory stimulus (vision) is strong. Present findings should be taken into consideration to optimize the ecological validity of VR-based obstacle avoidance paradigms used in research and rehabilitation. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Laser principles.

    PubMed

    Bogdan Allemann, Inja; Kaufman, Joely

    2011-01-01

    Since the construction of the first laser in the 1960s, the role that lasers play in various medical specialities, including dermatology, has steadily increased. However, within the last 2 decades, the technological advances and the use of lasers in the field of dermatology have virtually exploded. Many treatments have only become possible with the use of lasers. Especially in aesthetic medicine, lasers are an essential tool in the treatment armamentarium. Due to better research and understanding of the physics of light and skin, there is now a wide and increasing array of different lasers and devices to choose from. The proper laser selection for each indication and treatment requires a profound understanding of laser physics and the basic laser principles. Understanding these principles will allow the laser operator to obtain better results and help avoid complications. This chapter will give an in-depth overview of the physical principles relevant in cutaneous laser surgery. Copyright © 2011 S. Karger AG, Basel.

  7. Dreaming as a 'curtain of illusion': revisiting the 'royal road' with Bion as our guide.

    PubMed

    Grotstein, James S

    2009-08-01

    One of Bion's most unique contributions to psychoanalysis is his conception of dreaming in which he elaborates, modifies, and extends Freud 's ideas. While Freud dealt extensively with dream-work, he showed more interest in dreams themselves and their latent meaning and theorized that dreams ultimately constituted wish-fulfillments originating from the activity of the pleasure principle. Bion, on the other hand, focuses more on the process of dreaming itself and believes that dreaming occurs throughout the day as well as the night and serves the reality principle as well as the pleasure principle. In order for wakeful consciousness to occur, dreaming must absorb (contain) the day residue, and transfer it to System Ucs. from System Cs. for it to be processed (transformed) and then returned to System Cs. through the selectively-permeable contact-barrier. Dreaming, consequently, allows the subject to remain awake by day and asleep by night by its processing of the day's residue. Bion seems to conceive of dreaming as an ever-present invisible filter that overlays much of our mental life, including perception, as well as attention itself. He further believes that dreaming is a form of thinking that normally involves the collaborative yet oppositional (not conflictual) activity of the reality and pleasure principles as well as the primary and secondary processes. He also conflates Freud 's primary and secondary processes into a single 'binary-oppositional' structure (Lévi-Strauss, 1958, 1970) that he terms 'alpha-function', which constitutes a virtual model that corresponds to the in-vivo activity of dreaming. He further believes that the analyst dreams as he or she listens and interprets and that the analysand likewise dreams while he or she freely associates.

  8. Scaling Climate Change Communication for Behavior Change

    NASA Astrophysics Data System (ADS)

    Rodriguez, V. C.; Lappé, M.; Flora, J. A.; Ardoin, N. M.; Robinson, T. N.

    2014-12-01

    Ultimately, effective climate change communication results in a change in behavior, whether the change is individual, household or collective actions within communities. We describe two efforts to promote climate-friendly behavior via climate communication and behavior change theory. Importantly these efforts are designed to scale climate communication principles focused on behavior change rather than soley emphasizing climate knowledge or attitudes. Both cases are embedded in rigorous evaluations (randomized controlled trial and quasi-experimental) of primary and secondary outcomes as well as supplementary analyses that have implications for program refinement and program scaling. In the first case, the Girl Scouts "Girls Learning Environment and Energy" (GLEE) trial is scaling the program via a Massive Open Online Course (MOOC) for Troop Leaders to teach the effective home electricity and food and transportation energy reduction programs. The second case, the Alliance for Climate Education (ACE) Assembly Program, is advancing the already-scaled assembly program by using communication principles to further engage youth and their families and communities (school and local communities) in individual and collective actions. Scaling of each program uses online learning platforms, social media and "behavior practice" videos, mastery practice exercises, virtual feedback and virtual social engagement to advance climate-friendly behavior change. All of these communication practices aim to simulate and advance in-person train-the-trainers technologies.As part of this presentation we outline scaling principles derived from these two climate change communication and behavior change programs.

  9. The role of physicality in rich programming environments

    NASA Astrophysics Data System (ADS)

    Liu, Allison S.; Schunn, Christian D.; Flot, Jesse; Shoop, Robin

    2013-12-01

    Computer science proficiency continues to grow in importance, while the number of students entering computer science-related fields declines. Many rich programming environments have been created to motivate student interest and expertise in computer science. In the current study, we investigated whether a recently created environment, Robot Virtual Worlds (RVWs), can be used to teach computer science principles within a robotics context by examining its use in high-school classrooms. We also investigated whether the lack of physicality in these environments impacts student learning by comparing classrooms that used either virtual or physical robots for the RVW curriculum. Results suggest that the RVW environment leads to significant gains in computer science knowledge, that virtual robots lead to faster learning, and that physical robots may have some influence on algorithmic thinking. We discuss the implications of physicality in these programming environments for learning computer science.

  10. The Virtual Naval Hospital: the digital library as knowledge management tool for nomadic patrons*

    PubMed Central

    D'Alessandro, Michael P.; D'Alessandro, Donna M.; Bakalar, Richard S.; Ashley, Denis E.; Hendrix, Mary J. C.

    2005-01-01

    Objective: To meet the information needs of isolated primary care providers and their patients in the US Navy, a digital health sciences library, the Virtual Naval Hospital, was created through a unique partnership between academia and government. Methods: The creation of the digital library was heavily influenced by the principles of user-centered design and made allowances for the nomadic nature of the digital library's patrons and the heterogeneous access they have to Internet bandwidth. Results: The result is a digital library that has been in operation since 1997, continues to expand in size, is heavily used, and is highly regarded by its patrons. Conclusions: The digital library is dedicated to delivering the right information at the right time to the right person so the right decision can be made, and therefore the Virtual Naval Hospital functions as a knowledge-management system for the US Navy Bureau of Medicine and Surgery. PMID:15685269

  11. Curating Virtual Data Collections

    NASA Technical Reports Server (NTRS)

    Lynnes, Chris; Leon, Amanda; Ramapriyan, Hampapuram; Tsontos, Vardis; Shie, Chung-Lin; Liu, Zhong

    2015-01-01

    NASAs Earth Observing System Data and Information System (EOSDIS) contains a rich set of datasets and related services throughout its many elements. As a result, locating all the EOSDIS data and related resources relevant to particular science theme can be daunting. This is largely because EOSDIS data's organizing principle is affected more by the way they are produced than around the expected end use. Virtual collections oriented around science themes can overcome this by presenting collections of data and related resources that are organized around the user's interest, not around the way the data were produced. Virtual collections consist of annotated web addresses (URLs) that point to data and related resource addresses, thus avoiding the need to copy all of the relevant data to a single place. These URL addresses can be consumed by a variety of clients, ranging from basic URL downloaders (wget, curl) and web browsers to sophisticated data analysis programs such as the Integrated Data Viewer.

  12. Building a Virtual Environment for Diabetes Self-Management Education and Support

    PubMed Central

    Johnson, Constance; Feenan, Kevin; Setliff, Glenn; Pereira, Katherine; Hassell, Nancy; Beresford, Henry F.; Epps, Shelly; Nicollerat, Janet; Tatum, William; Feinglos, Mark; Vorderstrasse, Allison

    2015-01-01

    The authors developed an immersive diabetes community to provide diabetes self-management education and support for adults with type 2 diabetes. In this article the authors describe the procedures used to develop this virtual environment (VE). Second Life Impacts Diabetes Education & Self-Management (SLIDES), the VE for our diabetes community was built in Second Life. Social Cognitive Theory, behavioral principles and key aspects of virtual environments related to usability were applied in the development in this VE. Collaboration between researchers, clinicians and information technology (IT) specialists occurred throughout the development process. An interactive community was successfully built and utilized to provide diabetes self-management education and support. VEs for health applications may be innovative and enticing, yet it must be kept in mind that there are substantial effort, expertise, and usability factors that must be considered in the development of these environments for health care consumers. PMID:25699133

  13. The Virtual Naval Hospital: the digital library as knowledge management tool for nomadic patrons.

    PubMed

    D'Alessandro, Michael P; D'Alessandro, Donna M; Bakalar, Richard S; Ashley, Denis E; Hendrix, Mary J C

    2005-01-01

    To meet the information needs of isolated primary care providers and their patients in the US Navy, a digital health sciences library, the Virtual Naval Hospital, was created through a unique partnership between academia and government. The creation of the digital library was heavily influenced by the principles of user-centered design and made allowances for the nomadic nature of the digital library's patrons and the heterogeneous access they have to Internet bandwidth. The result is a digital library that has been in operation since 1997, continues to expand in size, is heavily used, and is highly regarded by its patrons. The digital library is dedicated to delivering the right information at the right time to the right person so the right decision can be made, and therefore the Virtual Naval Hospital functions as a knowledge-management system for the US Navy Bureau of Medicine and Surgery.

  14. Encountered-Type Haptic Interface for Representation of Shape and Rigidity of 3D Virtual Objects.

    PubMed

    Takizawa, Naoki; Yano, Hiroaki; Iwata, Hiroo; Oshiro, Yukio; Ohkohchi, Nobuhiro

    2017-01-01

    This paper describes the development of an encountered-type haptic interface that can generate the physical characteristics, such as shape and rigidity, of three-dimensional (3D) virtual objects using an array of newly developed non-expandable balloons. To alter the rigidity of each non-expandable balloon, the volume of air in it is controlled through a linear actuator and a pressure sensor based on Hooke's law. Furthermore, to change the volume of each balloon, its exposed surface area is controlled by using another linear actuator with a trumpet-shaped tube. A position control mechanism is constructed to display virtual objects using the balloons. The 3D position of each balloon is controlled using a flexible tube and a string. The performance of the system is tested and the results confirm the effectiveness of the proposed principle and interface.

  15. Nonlocal postbuckling analysis of graphene sheets with initial imperfection based on first order shear deformation theory

    NASA Astrophysics Data System (ADS)

    Soleimani, Ahmad; Naei, Mohammad Hasan; Mashhadi, Mahmoud Mosavi

    In this paper, the first order shear deformation theory (FSDT) is used to investigate the postbuckling behavior of orthotropic single-layered graphene sheet (SLGS) under in-plane loadings. Nonlocal elasticity theory and von-Karman nonlinear model in combination with the isogeometric analysis (IGA) have been applied to study the postbuckling characteristics of SLGSs. In contrast to the classical model, the nonlocal continuum model developed in this work considers the size-effects on the postbuckling characteristics of SLGSs. FSDT takes into account effects of shear deformations through-the-thickness of plate. Geometric imperfection which is defined as a very small transverse displacement of the mid-plane is applied on undeformed nanoplate to create initial deviation in graphene sheet from being perfectly flat. Nonlinear governing equations of motion for SLGS are derived from the principle of virtual work and a variational formulation. At the end, the results are presented as the postbuckling equilibrium paths of SLGS. The influence of various parameters such as edge length, nonlocal parameter, compression ratio, boundary conditions and aspect ratio on the postbuckling path is investigated. The results of this work show the high accuracy of nonlocal FSDT-based analysis for postbuckling behavior of graphene sheets.

  16. High-Precision Tests of Stochastic Thermodynamics in a Feedback Trap

    NASA Astrophysics Data System (ADS)

    Gavrilov, Momčilo; Jun, Yonggun; Bechhoefer, John

    2015-03-01

    Feedback traps can trap and manipulate small particles and molecules in solution. They have been applied to the measurement of physical and chemical properties of particles and to explore fundamental questions in the non-equilibrium statistical mechanics of small systems. Feedback traps allow one to choose an arbitrary virtual potential, do any time-dependent transformation of the potential, and measure various thermodynamic quantities such as stochastic work, heat, or entropy. In feedback-trap experiments, the dynamics of a trapped object is determined by the imposed potential but is also affected by drifts due to electrochemical reactions and by temperature variations in the electronic amplifier. Although such drifts are small for measurements on the order of seconds, they dominate on time scales of minutes or slower. In this talk, we present a recursive algorithm that allows real-time estimations of drifts and other particle properties. These estimates let us do a real-time calibration of the feedback trap. Having eliminated systematic errors, we were able to show that erasing a one-bit memory requires at least kT ln 2 of work, in accordance with Landauer's principle. This work was supported by NSERC (Canada).

  17. A new compact for owners and directors. The Working Group on Corporate Governance.

    PubMed

    1991-01-01

    The virtual demise of hostile takeovers and leveraged buyouts has not cooled the tensions over corporate governance. In congressional hearings, at annual meetings, and in proxy contests splashed across the business pages, senior executives and powerful shareholders continue to confront each other. The basic issues remain remarkably consistent. When do investors' legitimate needs for returns translate into destructive pressures on long-term corporate prosperity? What kinds of accountability do top managers owe shareholders in terms of strategic consultation and disclosure? What is the precise role of the board of directors as a management monitor and shareholder representative? More than a year ago, a working group of distinguished lawyers representing large public companies and leading institutional investors began a series of meetings to cut through the rancor. Their goal was to reach common ground on a set of principles that reconciles the tensions between owners and managers. Recently, the group agreed on a statement that all eight members endorsed. The statement, "A New Charter for Owners and Managers," deserves wide readership, scrutiny, and commentary. HBR is pleased the working group chose it as the exclusive forum to release its statement.

  18. E-Learning in Science and Technology via a Common Learning Platform in a Lifelong Learning Project

    ERIC Educational Resources Information Center

    Priem, Freddy; De Craemer, Renaat; Calu, Johan; Pedreschi, Fran; Zimmer, Thomas; Saighi, Sylvain; Lilja, Jarmo

    2011-01-01

    This three-year Virtual Measurements Environment curriculum development project for higher education within the Lifelong Learning Programme of the European Union is the result of intense collaboration among four institutions, teaching applied sciences and technology. It aims to apply the principles and possibilities of evolved distance and…

  19. The Development and Deployment of a Virtual Unit Operations Laboratory

    ERIC Educational Resources Information Center

    Vaidyanath, Sreeram; Williams, Jason; Hilliard, Marcus; Wiesner, Theodore

    2007-01-01

    Computer-simulated experiments offer many benefits to engineering curricula in the areas of safety, cost, and flexibility. We report our experience in developing and deploying a computer-simulated unit operations laboratory, driven by the guiding principle of maximum fidelity to the physical lab. We find that, while the up-front investment in…

  20. Promoting Learning of Instructional Design via Overlay Design Tools

    ERIC Educational Resources Information Center

    Carle, Andrew Jacob

    2012-01-01

    I begin by introducing Virtual Design Apprenticeship (VDA), a learning model--built on a solid foundation of education principles and theories--that promotes learning of design skills via overlay design tools. In VDA, when an individual needs to learn a new design skill or paradigm she is provided accessible, concrete examples that have been…

  1. Verbal Interaction in "Second Life": Towards a Pedagogic Framework for Task Design

    ERIC Educational Resources Information Center

    Jauregi, Kristi; Canto, Silvia; de Graaff, Rick; Koenraad, Ton; Moonen, Machteld

    2011-01-01

    Within a European project on Networked Interaction in Foreign Language Acquisition and Research (NIFLAR), "Second Life" was used as a 3D virtual world in which language students can communicate synchronously with native speakers in the target language, while undertaking action together. For this context, a set of design principles for…

  2. Computer-Supported Collaborative Learning: Best Practices and Principles for Instructors

    ERIC Educational Resources Information Center

    Orvis, Kara L., Ed.; Lassiter, Andrea L. R., Ed.

    2008-01-01

    Decades of research have shown that student collaboration in groups doesn't just happen; rather it needs to be a deliberate process facilitated by the instructor. Promoting collaboration in virtual learning environments presents a variety of challenges. This book answers the demand for a thorough resource on techniques to facilitate effective …

  3. VLab: A Science Gateway for Distributed First Principles Calculations in Heterogeneous High Performance Computing Systems

    ERIC Educational Resources Information Center

    da Silveira, Pedro Rodrigo Castro

    2014-01-01

    This thesis describes the development and deployment of a cyberinfrastructure for distributed high-throughput computations of materials properties at high pressures and/or temperatures--the Virtual Laboratory for Earth and Planetary Materials--VLab. VLab was developed to leverage the aggregated computational power of grid systems to solve…

  4. Radical Connections: A Journey through Social Histories, Biography and Politics

    ERIC Educational Resources Information Center

    Martin, Jane

    2010-01-01

    This lecture will revisit nineteenth and twentieth century education policy and politics in the light of the experiences and struggles of a (nowadays) virtually unknown educator activist. Beautiful, tireless, courageous and principled, socialist school teacher Mary Bridges Adams (1855-1939) gave up her life for the Cause. Encouraged by William…

  5. Building and Supporting a Case for Test Use

    ERIC Educational Resources Information Center

    Bachman, Lyle F.

    2005-01-01

    The fields of language testing and educational and psychological measurement have not, as yet, developed a set of principles and procedures for linking test scores and score-based inferences to test use and the consequences of test use. Although Messick (1989) discusses test use and consequences, his framework provides virtually no guidance on how…

  6. Multi-tiered S-SOA, Parameter-Driven New Islamic Syariah Products of Holistic Islamic Banking System (HiCORE): Virtual Banking Environment

    NASA Astrophysics Data System (ADS)

    Halimah, B. Z.; Azlina, A.; Sembok, T. M.; Sufian, I.; Sharul Azman, M. N.; Azuraliza, A. B.; Zulaiha, A. O.; Nazlia, O.; Salwani, A.; Sanep, A.; Hailani, M. T.; Zaher, M. Z.; Azizah, J.; Nor Faezah, M. Y.; Choo, W. O.; Abdullah, Chew; Sopian, B.

    The Holistic Islamic Banking System (HiCORE), a banking system suitable for virtual banking environment, created based on universityindustry collaboration initiative between Universiti Kebangsaan Malaysia (UKM) and Fuziq Software Sdn Bhd. HiCORE was modeled on a multitiered Simple - Services Oriented Architecture (S-SOA), using the parameterbased semantic approach. HiCORE's existence is timely as the financial world is looking for a new approach to creating banking and financial products that are interest free or based on the Islamic Syariah principles and jurisprudence. An interest free banking system has currently caught the interest of bankers and financiers all over the world. HiCORE's Parameter-based module houses the Customer-information file (CIF), Deposit and Financing components. The Parameter based module represents the third tier of the multi-tiered Simple SOA approach. This paper highlights the multi-tiered parameter- driven approach to the creation of new Islamiic products based on the 'dalil' (Quran), 'syarat' (rules) and 'rukun' (procedures) as required by the syariah principles and jurisprudence reflected by the semantic ontology embedded in the parameter module of the system.

  7. Affective Interaction with a Virtual Character Through an fNIRS Brain-Computer Interface.

    PubMed

    Aranyi, Gabor; Pecune, Florian; Charles, Fred; Pelachaud, Catherine; Cavazza, Marc

    2016-01-01

    Affective brain-computer interfaces (BCI) harness Neuroscience knowledge to develop affective interaction from first principles. In this article, we explore affective engagement with a virtual agent through Neurofeedback (NF). We report an experiment where subjects engage with a virtual agent by expressing positive attitudes towards her under a NF paradigm. We use for affective input the asymmetric activity in the dorsolateral prefrontal cortex (DL-PFC), which has been previously found to be related to the high-level affective-motivational dimension of approach/avoidance. The magnitude of left-asymmetric DL-PFC activity, measured using functional near infrared spectroscopy (fNIRS) and treated as a proxy for approach, is mapped onto a control mechanism for the virtual agent's facial expressions, in which action units (AUs) are activated through a neural network. We carried out an experiment with 18 subjects, which demonstrated that subjects are able to successfully engage with the virtual agent by controlling their mental disposition through NF, and that they perceived the agent's responses as realistic and consistent with their projected mental disposition. This interaction paradigm is particularly relevant in the case of affective BCI as it facilitates the volitional activation of specific areas normally not under conscious control. Overall, our contribution reconciles a model of affect derived from brain metabolic data with an ecologically valid, yet computationally controllable, virtual affective communication environment.

  8. Butterfly valve in a virtual environment

    NASA Astrophysics Data System (ADS)

    Talekar, Aniruddha; Patil, Saurabh; Thakre, Prashant; Rajkumar, E.

    2017-11-01

    Assembly of components is one of the processes involved in product design and development. The present paper deals with the assembly of a simple butterfly valve components in a virtual environment. The assembly has been carried out using virtual reality software by trial and error methods. The parts are modelled using parametric software (SolidWorks), meshed accordingly, and then called into virtual environment for assembly.

  9. Teacher Working Conditions: Perceptions of Novice and Experienced K-12 Virtual School Teachers

    ERIC Educational Resources Information Center

    Francis, Tiffany

    2017-01-01

    The purpose of this study was to examine if there is a difference between novice and experienced teachers' perceptions of the working conditions at the K-12 virtual school. This study examined the teachers' total years employed at the school to determine if a difference exists in the groups' perceptions of the teacher working conditions. Teacher…

  10. Avoiding Depletion in Virtual Work: Telework and the Intervening Impact of Work Exhaustion on Commitment and Turnover Intentions

    ERIC Educational Resources Information Center

    Golden, Timothy D.

    2006-01-01

    Despite the tremendous growth of telework and other forms of virtual work, little is known about its impact on organizational commitment and turnover intentions, nor the mechanisms through which telework operates. Drawing upon the conservation of resources model as the theoretical framework, I posit telework's impact is the result of resource…

  11. The concept and science process skills analysis in bomb calorimeter experiment as a foundation for the development of virtual laboratory of bomb calorimeter

    NASA Astrophysics Data System (ADS)

    Kurniati, D. R.; Rohman, I.

    2018-05-01

    This study aims to analyze the concepts and science process skills in bomb calorimeter experiment as a basis for developing the virtual laboratory of bomb calorimeter. This study employed research and development method (R&D) to gain the answer to the proposed problems. This paper discussed the concepts and process skills analysis. The essential concepts and process skills associated with bomb calorimeter are analyze by optimizing the bomb calorimeter experiment. The concepts analysis found seven fundamental concepts to be concerned in developing the virtual laboratory that are internal energy, burning heat, perfect combustion, incomplete combustion, calorimeter constant, bomb calorimeter, and Black principle. Since the concept of bomb calorimeter, perfect and incomplete combustion created to figure out the real situation and contain controllable variables, in virtual the concepts displayed in the form of simulation. Meanwhile, the last four concepts presented in the form of animation because no variable found to be controlled. The process skills analysis detect four notable skills to be developed that are ability to observe, design experiment, interpretation, and communication skills.

  12. 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

  13. 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...

  14. Developing Trust in Virtual Teams

    ERIC Educational Resources Information Center

    Germain, Marie-Line

    2011-01-01

    Rapid globalization, advances in technology, flatter organizational structures, synergistic cooperation among firms, and a shift to knowledge work environments have led to the increasing use of virtual teams in organizations. Selecting, training, and socializing employees in virtual teamwork has therefore become an important human resource…

  15. ChemScreener: A Distributed Computing Tool for Scaffold based Virtual Screening.

    PubMed

    Karthikeyan, Muthukumarasamy; Pandit, Deepak; Vyas, Renu

    2015-01-01

    In this work we present ChemScreener, a Java-based application to perform virtual library generation combined with virtual screening in a platform-independent distributed computing environment. ChemScreener comprises a scaffold identifier, a distinct scaffold extractor, an interactive virtual library generator as well as a virtual screening module for subsequently selecting putative bioactive molecules. The virtual libraries are annotated with chemophore-, pharmacophore- and toxicophore-based information for compound prioritization. The hits selected can then be further processed using QSAR, docking and other in silico approaches which can all be interfaced within the ChemScreener framework. As a sample application, in this work scaffold selectivity, diversity, connectivity and promiscuity towards six important therapeutic classes have been studied. In order to illustrate the computational power of the application, 55 scaffolds extracted from 161 anti-psychotic compounds were enumerated to produce a virtual library comprising 118 million compounds (17 GB) and annotated with chemophore, pharmacophore and toxicophore based features in a single step which would be non-trivial to perform with many standard software tools today on libraries of this size.

  16. Working Group Reports and Presentations: Virtual Worlds and Virtual Exploration

    NASA Technical Reports Server (NTRS)

    LAmoreaux, Claudia

    2006-01-01

    Scientists and engineers are continually developing innovative methods to capitalize on recent developments in computational power. Virtual worlds and virtual exploration present a new toolset for project design, implementation, and resolution. Replication of the physical world in the virtual domain provides stimulating displays to augment current data analysis techniques and to encourage public participation. In addition, the virtual domain provides stakeholders with a low cost, low risk design and test environment. The following document defines a virtual world and virtual exploration, categorizes the chief motivations for virtual exploration, elaborates upon specific objectives, identifies roadblocks and enablers for realizing the benefits, and highlights the more immediate areas of implementation (i.e. the action items). While the document attempts a comprehensive evaluation of virtual worlds and virtual exploration, the innovative nature of the opportunities presented precludes completeness. The authors strongly encourage readers to derive additional means of utilizing the virtual exploration toolset.

  17. Virtual Control Systems Environment (VCSE)

    ScienceCinema

    Atkins, Will

    2018-02-14

    Will Atkins, a Sandia National Laboratories computer engineer discusses cybersecurity research work for process control systems. Will explains his work on the Virtual Control Systems Environment project to develop a modeling and simulation framework of the U.S. electric grid in order to study and mitigate possible cyberattacks on infrastructure.

  18. Effective factor of virtual team: Resolving communication breakdown in IBS construction project

    NASA Astrophysics Data System (ADS)

    Pozin, Mohd Affendi Ahmad; Nawi, Mohd. Nasrun Mohd.

    2016-08-01

    Currently, rapid development of information technology has provided new opportunities to organisation toward increasing the effectiveness of collaboration and teamwork management. Thus the virtual team approach has been implemented in numerous of field. However, there is limited study of virtual team in construction project management. Currently IBS project is still based on traditional construction process which is isolation team working environment. Therefore this approach has been declared as a main barrier to ensure cooperative working relation in term of communication and information in between project stakeholders. Thus, this paper through literature review is attempted to present a discussion of the virtual team approach toward IBS project in developing effective team communication during construction project.

  19. Perfecting scientists’ collaboration and problem-solving skills in the virtual team environment

    USDA-ARS?s Scientific Manuscript database

    Perfecting Scientists’ Collaboration and Problem-Solving Skills in the Virtual Team Environment Numerous factors have contributed to the proliferation of conducting work in virtual teams at the domestic, national, and global levels: innovations in technology, critical developments in software, co-lo...

  20. Making Information Overload Work: The Dragon Software System on a Virtual Reality Responsive Workbench

    DTIC Science & Technology

    1998-03-01

    Research Laboratory’s Virtual Reality Responsive Workbench (VRRWB) and Dragon software system which together address the problem of battle space...and describe the lessons which have been learned. Interactive graphics, workbench, battle space visualization, virtual reality , user interface.

  1. Optoelectronics technologies for Virtual Reality systems

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

    Solutions in the field of virtual reality are very strongly associated with optoelectronic technologies. This applies to both process design and operation of VR applications. Technologies such as 360 cameras and 3D scanners significantly improve the design work. What is more, HMD displays with high field of view or optoelectronic Motion Capture systems and 3D cameras guarantee an extraordinary experience in immersive VR applications. This article reviews selected technologies from the perspective of their use in a broadly defined process of creating and implementing solutions for virtual reality. There is also the ability to create, modify and adapt new approaches that show team own work (SteamVR tracker). Most of the introduced examples are effectively used by authors to create different VR applications. The use of optoelectronic technology in virtual reality is presented in terms of design and operation of the system as well as referring to specific applications. Designers and users of VR systems should take a close look on new optoelectronics solutions, as they can significantly contribute to increased work efficiency and offer completely new opportunities for virtual world reception.

  2. Distributed interactive virtual environments for collaborative experiential learning and training independent of distance over Internet2.

    PubMed

    Alverson, Dale C; Saiki, Stanley M; Jacobs, Joshua; Saland, Linda; Keep, Marcus F; Norenberg, Jeffrey; Baker, Rex; Nakatsu, Curtis; Kalishman, Summers; Lindberg, Marlene; Wax, Diane; Mowafi, Moad; Summers, Kenneth L; Holten, James R; Greenfield, John A; Aalseth, Edward; Nickles, David; Sherstyuk, Andrei; Haines, Karen; Caudell, Thomas P

    2004-01-01

    Medical knowledge and skills essential for tomorrow's healthcare professionals continue to change faster than ever before creating new demands in medical education. Project TOUCH (Telehealth Outreach for Unified Community Health) has been developing methods to enhance learning by coupling innovations in medical education with advanced technology in high performance computing and next generation Internet2 embedded in virtual reality environments (VRE), artificial intelligence and experiential active learning. Simulations have been used in education and training to allow learners to make mistakes safely in lieu of real-life situations, learn from those mistakes and ultimately improve performance by subsequent avoidance of those mistakes. Distributed virtual interactive environments are used over distance to enable learning and participation in dynamic, problem-based, clinical, artificial intelligence rules-based, virtual simulations. The virtual reality patient is programmed to dynamically change over time and respond to the manipulations by the learner. Participants are fully immersed within the VRE platform using a head-mounted display and tracker system. Navigation, locomotion and handling of objects are accomplished using a joy-wand. Distribution is managed via the Internet2 Access Grid using point-to-point or multi-casting connectivity through which the participants can interact. Medical students in Hawaii and New Mexico (NM) participated collaboratively in problem solving and managing of a simulated patient with a closed head injury in VRE; dividing tasks, handing off objects, and functioning as a team. Students stated that opportunities to make mistakes and repeat actions in the VRE were extremely helpful in learning specific principles. VRE created higher performance expectations and some anxiety among VRE users. VRE orientation was adequate but students needed time to adapt and practice in order to improve efficiency. This was also demonstrated successfully between Western Australia and UNM. We successfully demonstrated the ability to fully immerse participants in a distributed virtual environment independent of distance for collaborative team interaction in medical simulation designed for education and training. The ability to make mistakes in a safe environment is well received by students and has a positive impact on their understanding, as well as memory of the principles involved in correcting those mistakes. Bringing people together as virtual teams for interactive experiential learning and collaborative training, independent of distance, provides a platform for distributed "just-in-time" training, performance assessment and credentialing. Further validation is necessary to determine the potential value of the distributed VRE in knowledge transfer, improved future performance and should entail training participants to competence in using these tools.

  3. 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…

  4. Propulsive efficiency of frog swimming with different feet and swimming patterns

    PubMed Central

    Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

    2017-01-01

    ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

  5. From 'circumstances' to 'environment': Herbert Spencer and the origins of the idea of organism-environment interaction.

    PubMed

    Pearce, Trevor

    2010-09-01

    The word 'environment' has a history. Before the mid-nineteenth century, the idea of a singular, abstract entity--the organism--interacting with another singular, abstract entity--the environment--was virtually unknown. In this paper I trace how the idea of a plurality of external conditions or circumstances was replaced by the idea of a singular environment. The central figure behind this shift, at least in Anglo-American intellectual life, was the philosopher Herbert Spencer. I examine Spencer's work from 1840 to 1855, demonstrating that he was exposed to a variety of discussions of the 'force of circumstances' in this period, and was decisively influenced by the ideas of Auguste Comte in the years preceding the publication of Principles of psychology (1855). It is this latter work that popularized the word 'environment' and the corresponding idea of organism--environment interaction--an idea with important metaphysical and methodological implications. Spencer introduced into the English-speaking world one of our most enduring dichotomies: organism and environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. A Novel Soft Pneumatic Artificial Muscle with High-Contraction Ratio.

    PubMed

    Han, Kwanghyun; Kim, Nam-Ho; Shin, Dongjun

    2018-06-20

    There is a growing interest in soft actuators for human-friendly robotic applications. However, it is very challenging for conventional soft actuators to achieve both a large working distance and high force. To address this problem, we present a high-contraction ratio pneumatic artificial muscle (HCRPAM), which has a novel actuation concept. The HCRPAM can contract substantially while generating a large force suitable for a wide range of robotic applications. Our proposed prototyping method allows for an easy and quick fabrication, considering various design variables. We derived a mathematical model using a virtual work principle, and validated the model experimentally. We conducted simulations for the design optimization using this model. Our experimental results show that the HCRPAM has a 183.3% larger contraction ratio and 37.1% higher force output than the conventional pneumatic artificial muscle (McKibben muscle). Furthermore, the actuator has a compatible position tracking performance of 1.0 Hz and relatively low hysteresis error of 4.8%. Finally, we discussed the controllable bending characteristics of the HCRPAM, which uses heterogeneous materials and has an asymmetrical structure to make it comfortable for a human to wear.

  7. SSERVI Opportunities for the Next Generation of Planetary Researchers

    NASA Astrophysics Data System (ADS)

    Bailey, B. E.; Day, B. H.; Minafra, J.; Baer, J.

    2015-12-01

    NASA's Solar System Exploration Research Virtual Institute (SSERVI) was founded as a virtual institute that provides interdisciplinary research centered on the goals of its supporting directorates: NASA Science Mission Directorate (SMD) and the Human Exploration & Operations Mission Directorate (HEOMD). SSERVI consists of a diverse set of domestic teams and (currently) nine international teams, ultimately represented by greater than 75 distinct research institutions and more than 450 individual researchers and EPO specialists. The decline in funding opportunities after the termination of the Apollo missions to the Moon in the early 1970's produced a large gap in both the scientific knowledge and experience of the original lunar Apollo researchers and the resurgent group of young lunar/NEA researchers that have emerged within the last 15 years. One of SSERVI's many goals is to bridge this gap through the many networking and scientific connections made between young researchers and established planetary principle investigators. To this end, SSERVI has supported the establishment of NextGen Lunar Scientists and Engineers group (NGLSE), a group of students and early-career professionals designed to build experience and provide networking opportunities to its members. SSERVI has also created the LunarGradCon, a scientific conference dedicated solely to graduate and undergraduate students working in the lunar field. Additionally, SSERVI produces monthly seminars and bi-yearly virtual workshops that introduce students to the wide variety of exploration science being performed in today's research labs. SSERVI also brokers opportunities for domestic and international student exchange between collaborating laboratories as well as internships at our member institutions. SSERVI provides a bridge that is essential to the continued international success of scientific, as well as human and robotic, exploration.

  8. Sharing Water-related Information to Tackle Changes in the Hydrosphere - for Operational Needs (SWITCH-ON)

    NASA Astrophysics Data System (ADS)

    Arheimer, Berit

    2014-05-01

    A recently started EU project (FP7 project No 603587) called SWITCH-ON will establish new infrastructure for water research in Europe. The overall goal of the project is to make use of open data, and add value to society by repurposing and refining data from various sources. SWITCH-ON will establish new forms of water research and facilitate the development of new products and services based on principles of sharing and community building. The basic for this work is a virtual water-science laboratory, which consists of open data, dedicated software tools and a set of protocols, hosted at the "SWITCH-ON water information" portal at http://water-switch-on.eu/. The laboratory will seamlessly integrate the open data with harmonised modelling tools and facilities the performance of virtual experiments of comparative science. Comparative science is a new form of research, which will advance science by contrasting water related processes in different environments and help understand complex processes in a more holistic way than individual studies The SWITCH-ON objectives are to use open data for implementing: 1) an innovative spatial information platform with open data tailored for direct water assessments, 2) an entirely new form of collaborative research for water-related sciences, 3) fourteen new operational products and services dedicated to appointed end-users, 4) new business and knowledge to inform individual and collective decisions in line with the Europe's smart growth and environmental objectives. The SWITCH-ON project will be one trigger in a contemporary global movement to better address environmental and societal challenges through openness and collaboration. The poster will present the project visions and achievements so far, and invite more research groups to use the virtual water-science laboratory.

  9. An Exploration of the Moderating Effect of Motivation on the Relationship between Work Satisfaction and Utilization of Virtual Team Effectiveness Attributes: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Day, Frederick C.; Burbach, Mark E.

    2015-01-01

    A unique challenge for organizations is in leading diverse, dispersed teams whose members are motivated to work independently, but are willing to collaborate. The purpose of this study was to gain an understanding of how nuanced variations in motivational patterns influences the relationship between work satisfaction and virtual team…

  10. Virtual bargaining: a theory of social decision-making

    PubMed Central

    Misyak, Jennifer B.; Chater, Nick

    2014-01-01

    An essential element of goal-directed decision-making in social contexts is that agents' actions may be mutually interdependent. However, the most well-developed approaches to such strategic interactions, based on the Nash equilibrium concept in game theory, are sometimes too broad and at other times ‘overlook’ good solutions to fundamental social dilemmas and coordination problems. The authors propose a new theory of social decision-making—virtual bargaining—in which individuals decide among a set of moves on the basis of what they would agree to do if they could openly bargain. The core principles of a formal account are outlined (vis-à-vis the notions of ‘feasible agreement’ and explicit negotiation) and further illustrated with the introduction of a new game, dubbed the ‘Boobytrap game’ (a modification on the canonical Prisoner's Dilemma paradigm). In the first empirical data of how individuals play the Boobytrap game, participants' experimental choices accord well with a virtual bargaining perspective, but do not match predictions from a standard Nash account. Alternative frameworks are discussed, with specific empirical tests between these and virtual bargaining identified as future research directions. Lastly, it is proposed that virtual bargaining underpins a vast range of human activities, from social decision-making to joint action and communication. PMID:25267828

  11. A computational model of selection by consequences: log survivor plots.

    PubMed

    Kulubekova, Saule; McDowell, J J

    2008-06-01

    [McDowell, J.J, 2004. A computational model of selection by consequences. J. Exp. Anal. Behav. 81, 297-317] instantiated the principle of selection by consequences in a virtual organism with an evolving repertoire of possible behaviors undergoing selection, reproduction, and mutation over many generations. The process is based on the computational approach, which is non-deterministic and rules-based. The model proposes a causal account for operant behavior. McDowell found that the virtual organism consistently showed a hyperbolic relationship between response and reinforcement rates according to the quantitative law of effect. To continue validation of the computational model, the present study examined its behavior on the molecular level by comparing the virtual organism's IRT distributions in the form of log survivor plots to findings from live organisms. Log survivor plots did not show the "broken-stick" feature indicative of distinct bouts and pauses in responding, although the bend in slope of the plots became more defined at low reinforcement rates. The shape of the virtual organism's log survivor plots was more consistent with the data on reinforced responding in pigeons. These results suggest that log survivor plot patterns of the virtual organism were generally consistent with the findings from live organisms providing further support for the computational model of selection by consequences as a viable account of operant behavior.

  12. The application of total quality management principles to spacecraft mission operations

    NASA Astrophysics Data System (ADS)

    Sweetin, Maury

    1993-03-01

    By now, the philosophies of Total Quality Management have had an impact on every aspect of American industrial life. The trail-blazing work of Deming, Juran, and Crosby, first implemented in Japan, has 're-migrated' across the Pacific and now plays a growing role in America's management culture. While initially considered suited only for a manufacturing environment, TQM has moved rapidly into the 'service' areas of offices, sales forces, and even fast-food restaurants. The next logical step has also been taken - TQM has found its way into virtually all departments of the Federal Government, including NASA. Because of this widespread success, it seems fair to ask whether this new discipline is directly applicable to the profession of spacecraft operations. The results of quality emphasis on OAO Corporation's contract at JPL provide strong support for Total Quality Management as a useful tool in spacecraft operations.

  13. A novel algorithm using an orthotropic material model for topology optimization

    NASA Astrophysics Data System (ADS)

    Tong, Liyong; Luo, Quantian

    2017-09-01

    This article presents a novel algorithm for topology optimization using an orthotropic material model. Based on the virtual work principle, mathematical formulations for effective orthotropic material properties of an element containing two materials are derived. An algorithm is developed for structural topology optimization using four orthotropic material properties, instead of one density or area ratio, in each element as design variables. As an illustrative example, minimum compliance problems for linear and nonlinear structures are solved using the present algorithm in conjunction with the moving iso-surface threshold method. The present numerical results reveal that: (1) chequerboards and single-node connections are not present even without filtering; (2) final topologies do not contain large grey areas even using a unity penalty factor; and (3) the well-known numerical issues caused by low-density material when considering geometric nonlinearity are resolved by eliminating low-density elements in finite element analyses.

  14. Optimisation of assembly scheduling in VCIM systems using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Dao, Son Duy; Abhary, Kazem; Marian, Romeo

    2017-09-01

    Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is quite different from one in traditional production systems because of the difference in the working principles of the two systems. In this article, the assembly scheduling problem in VCIM systems is modeled and then an integrated approach based on genetic algorithm (GA) is proposed to search for a global optimised solution to the problem. Because of dynamic nature of the scheduling problem, a novel GA with unique chromosome representation and modified genetic operations is developed herein. Robustness of the proposed approach is verified by a numerical example.

  15. The application of total quality management principles to spacecraft mission operations

    NASA Technical Reports Server (NTRS)

    Sweetin, Maury

    1993-01-01

    By now, the philosophies of Total Quality Management have had an impact on every aspect of American industrial life. The trail-blazing work of Deming, Juran, and Crosby, first implemented in Japan, has 're-migrated' across the Pacific and now plays a growing role in America's management culture. While initially considered suited only for a manufacturing environment, TQM has moved rapidly into the 'service' areas of offices, sales forces, and even fast-food restaurants. The next logical step has also been taken - TQM has found its way into virtually all departments of the Federal Government, including NASA. Because of this widespread success, it seems fair to ask whether this new discipline is directly applicable to the profession of spacecraft operations. The results of quality emphasis on OAO Corporation's contract at JPL provide strong support for Total Quality Management as a useful tool in spacecraft operations.

  16. Simulations and experiments on gas adsorption in novel microporous polymers

    NASA Astrophysics Data System (ADS)

    Larsen, Gregory Steven

    Microporous materials represent a fascinating class of materials with a broad range of applications. The work presented here focuses on the use of a novel class of microporous material known as polymers of intrinsic micrioporosity, or PIMs, for use in gas separation and storage technologies. The aim of this research is to develop a detailed understanding of the relationship between the monomeric structure and the adsorptive performance of PIMs. First, a generalizable structure generation technique was developed such that simulation samples of PIM-1 recreated experimental densities, scattering, surface areas, pore size distributions, and adsorption isotherms. After validation, the simulations were applied as virtual experiments on several new PIMs with the intent to screen their capabilities as adsorbent materials and elucidate design principles for linear PIMs. The simulations are useful in understanding the unique properties such as pore size distribution and scattering observed experimentally.

  17. Toward a Virtual Solar Observatory: Starting Before the Petabytes Fall

    NASA Technical Reports Server (NTRS)

    Gurman, Joseph; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Although a few, large, space- and groundbased solar physics databases exist at selected locations, there is as yet only limited standardization or interoperability. I describe the outline of a plan to facilitate access to a distributed network of online solar data archives, both large and small. The underlying principle is that the user need not know where- the data are, only how to specify which data are desired. At the least, such an approach could considerably simplify the scientific user's access to the enormous amount of solar physics data to be obtained in the next decade. At best, it might mean the withering away of traditional data centers, and all the bureaucracy they entail. This work is supported by the Sun-Earth Connections Division of NASA Office of Space Science, thanks to an anomalous act of largess on the part of the 2001 SEC Senior Review.

  18. Toward a Virtual Solar Observatory: Starting Before the Petabytes Fall

    NASA Astrophysics Data System (ADS)

    Gurman, J. B.

    2001-12-01

    Although a few, large, space- and groundbased solar physics databases exist at selected locations, there is as yet only limited standardization or interoperability. I describe the outline of a plan to facilitate access to a distributed network of online solar data archives, both large and small. The underlying principle is that the user need not know where the data are, only how to specify which data are desired. At the least, such an approach could considerably simplify the scientific user's access to the enormous amount of solar physics data to be obtained in the next decade. At best, it might mean the withering away of traditional data centers, and all the bureaucracy they entail. This work is supported by the Sun-Earth Connections Division of NASA Office of Space Science, thanks to an anomalous act of largess on the part of the 2001 SEC Senior Review.

  19. Virtual Learning Environments.

    ERIC Educational Resources Information Center

    Follows, Scott B.

    1999-01-01

    Illustrates the possibilities and educational benefits of virtual learning environments (VLEs), based on experiences with "Thirst for Knowledge," a VLE that simulates the workplace of a major company. While working in this virtual office world, students walk through the building, attend meetings, read reports, receive e-mail, answer the telephone,…

  20. Virtual Team Effectiveness: An Empirical Study Using SEM

    ERIC Educational Resources Information Center

    Bhat, Swati Kaul; Pande, Neerja; Ahuja, Vandana

    2016-01-01

    Advances in communication and information technology create new opportunities for organizations to build and manage virtual teams. Virtual teams have become a norm for organizations whose members work across disparate geographical locations, relying primarily or exclusively, on the usage of Information and Communications Technology (ICT) for the…

  1. Highly Sophisticated Virtual Laboratory Instruments in Education

    NASA Astrophysics Data System (ADS)

    Gaskins, T.

    2006-12-01

    Many areas of Science have advanced or stalled according to the ability to see what can not normally be seen. Visual understanding has been key to many of the world's greatest breakthroughs, such as discovery of DNAs double helix. Scientists use sophisticated instruments to see what the human eye can not. Light microscopes, scanning electron microscopes (SEM), spectrometers and atomic force microscopes are employed to examine and learn the details of the extremely minute. It's rare that students prior to university have access to such instruments, or are granted full ability to probe and magnify as desired. Virtual Lab, by providing highly authentic software instruments and comprehensive imagery of real specimens, provides them this opportunity. Virtual Lab's instruments let explorers operate virtual devices on a personal computer to examine real specimens. Exhaustive sets of images systematically and robotically photographed at thousands of positions and multiple magnifications and focal points allow students to zoom in and focus on the most minute detail of each specimen. Controls on each Virtual Lab device interactively and smoothly move the viewer through these images to display the specimen as the instrument saw it. Users control position, magnification, focal length, filters and other parameters. Energy dispersion spectrometry is combined with SEM imagery to enable exploration of chemical composition at minute scale and arbitrary location. Annotation capabilities allow scientists, teachers and students to indicate important features or areas. Virtual Lab is a joint project of NASA and the Beckman Institute at the University of Illinois at Urbana- Champaign. Four instruments currently compose the Virtual Lab suite: A scanning electron microscope and companion energy dispersion spectrometer, a high-power light microscope, and a scanning probe microscope that captures surface properties to the level of atoms. Descriptions of instrument operating principles and uses are also part of Virtual Lab. The Virtual Lab software and its increasingly rich collection of specimens are free to anyone. This presentation describes Virtual Lab and its uses in formal and informal education.

  2. Simplified Virtualization in a HEP/NP Environment with Condor

    NASA Astrophysics Data System (ADS)

    Strecker-Kellogg, W.; Caramarcu, C.; Hollowell, C.; Wong, T.

    2012-12-01

    In this work we will address the development of a simple prototype virtualized worker node cluster, using Scientific Linux 6.x as a base OS, KVM and the libvirt API for virtualization, and the Condor batch software to manage virtual machines. The discussion in this paper provides details on our experience with building, configuring, and deploying the various components from bare metal, including the base OS, creation and distribution of the virtualized OS images and the integration of batch services with the virtual machines. Our focus was on simplicity and interoperability with our existing architecture.

  3. Perception of Virtual Audiences.

    PubMed

    Chollet, Mathieu; Scherer, Stefan

    2017-01-01

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

  4. 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.

  5. Virtual Teams.

    ERIC Educational Resources Information Center

    Geber, Beverly

    1995-01-01

    Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

  6. Disrupting the Discussion: The Story of Disruptive Students in the Online Classroom

    ERIC Educational Resources Information Center

    Cowden, Belle Doyle

    2011-01-01

    Many online classrooms today are designed based on learner-centered principles. Implicit with this design perspective is the goal to create and facilitate a virtual learning community in which students learn from and share with each other through discussion-based computer conferencing. In the current literature, little has been shared on what…

  7. Contemporary Spheres for the Teaching Education: Freire's Principles

    ERIC Educational Resources Information Center

    Gomez, Margarita Victoria

    2006-01-01

    Freire's cogitation on Information Technology (IT), resources for education have been known since the decade of the 50s. And now, within the current context, this analysis outlines the literacy problem as an issue of gnosis and anthropology while existing in a virtual dimension. Based on research/experiences that also were carried out in Brazil,…

  8. Promoting Awareness of Learner Diversity in Prospective Teachers: Signaling Individual and Group Differences within Virtual Classroom Cases

    ERIC Educational Resources Information Center

    Moreno, Roxana; Abercrombie, Sara

    2010-01-01

    We investigated two methods to promote prospective teachers' awareness of learner diversity and application of teaching principles using a problem-based learning environment. In Experiment 1, we examined the effects of presenting a conceptual framework about learners' individual and group differences either before or after instruction on teaching…

  9. Virtual Learning: Possibilities and Realization

    ERIC Educational Resources Information Center

    Kerimbayev, Nurassyl

    2016-01-01

    In the article it was important to consider two basic moments i.e., impact mode of using virtual environment at training process within one faculty of the University, directly at training quality and what outcomes can be reached therewith. The work significance consists of studying the virtual environment effect instead of traditional educational…

  10. Examining the Impact of Collaboration Technology Training Support on Virtual Team Collaboration Effectiveness

    ERIC Educational Resources Information Center

    Wright, Sharon L.

    2013-01-01

    Businesses and governmental agencies are increasingly reliant on virtual teams composed of team members in different location. However, such virtual teams face all the interpersonal challenges inherent in working in a group, plus additional challenges that are a consequence from communicating through electronic methods. Numerous technological…

  11. Engineering Laboratory Instruction in Virtual Environment--"eLIVE"

    ERIC Educational Resources Information Center

    Chaturvedi, Sushil; Prabhakaran, Ramamurthy; Yoon, Jaewan; Abdel-Salam, Tarek

    2011-01-01

    A novel application of web-based virtual laboratories to prepare students for physical experiments is explored in some detail. The pedagogy of supplementing physical laboratory with web-based virtual laboratories is implemented by developing a web-based tool, designated in this work as "eLIVE", an acronym for Engineering Laboratory…

  12. When Rural Reality Goes Virtual.

    ERIC Educational Resources Information Center

    Husain, Dilshad D.

    1998-01-01

    In rural towns where sparse population and few business are barriers, virtual reality may be the only way to bring work-based learning to students. A partnership between a small-town high school, the Ohio Supercomputer Center, and a high-tech business will enable students to explore the workplace using virtual reality. (JOW)

  13. An Ethnographic Study of a Developing Virtual Organization in Education

    ERIC Educational Resources Information Center

    Couch, Stephanie R.

    2012-01-01

    This ethnographic study answers calls for research into the ways that virtual organizations (or innovation-driven collaborative teams) form and develop, what supports and constraints their development, and the leadership models that support the organizations' work. The study examines how a virtual organization emerged from an intersegmental…

  14. Social Impact in Personalised Virtual Professional Development Pathways

    ERIC Educational Resources Information Center

    Owen, Hazel; Whalley, Rick; Dunmill, Merryn; Eccles, Heather

    2018-01-01

    This article presents exploratory research into an education-based virtual mentoring provision, the Virtual Professional Learning and Development (VPLD) program, and uses the Elements of Value Pyramid to help frame findings in a way that highlights the participants' (mentors' and mentees') perceived value of working together. Participants were…

  15. Learning Together and Working Apart: Routines for Organizational Learning in Virtual Teams

    ERIC Educational Resources Information Center

    Dixon, Nancy

    2017-01-01

    Purpose: Research suggests that teaming routines facilitate learning in teams. This paper identifies and details how specific teaming routines, implemented in a virtual team, support its continual learning. The study's focus was to generate authentic and descriptive accounts of the interviewees' experiences with virtual teaming routines.…

  16. Environments for online maritime simulators with cloud computing capabilities

    NASA Astrophysics Data System (ADS)

    Raicu, Gabriel; Raicu, Alexandra

    2016-12-01

    This paper presents the cloud computing environments, network principles and methods for graphical development in realistic naval simulation, naval robotics and virtual interactions. The aim of this approach is to achieve a good simulation quality in large networked environments using open source solutions designed for educational purposes. Realistic rendering of maritime environments requires near real-time frameworks with enhanced computing capabilities during distance interactions. E-Navigation concepts coupled with the last achievements in virtual and augmented reality will enhance the overall experience leading to new developments and innovations. We have to deal with a multiprocessing situation using advanced technologies and distributed applications using remote ship scenario and automation of ship operations.

  17. The virtual windtunnel: Visualizing modern CFD datasets with a virtual environment

    NASA Technical Reports Server (NTRS)

    Bryson, Steve

    1993-01-01

    This paper describes work in progress on a virtual environment designed for the visualization of pre-computed fluid flows. The overall problems involved in the visualization of fluid flow are summarized, including computational, data management, and interface issues. Requirements for a flow visualization are summarized. Many aspects of the implementation of the virtual windtunnel were uniquely determined by these requirements. The user interface is described in detail.

  18. Main principles of passive devices based on graphene and carbon films in microwave-THz frequency range

    NASA Astrophysics Data System (ADS)

    Kuzhir, Polina P.; Paddubskaya, Alesia G.; Volynets, Nadezhda I.; Batrakov, Konstantin G.; Kaplas, Tommi; Lamberti, Patrizia; Kotsilkova, Rumiana; Lambin, Philippe

    2017-07-01

    The ability of thin conductive films, including graphene, pyrolytic carbon (PyC), graphitic PyC (GrPyC), graphene with graphitic islands (GrI), glassy carbon (GC), and sandwich structures made of all these materials separated by polymer slabs to absorb electromagnetic radiation in microwave-THz frequency range, is discussed. The main physical principles making a basis for high absorption ability of these heterostructures are explained both in the language of electromagnetic theory and using representation of equivalent electrical circuits. The idea of using carbonaceous thin films as the main working elements of passive radiofrequency (RF) devices, such as shields, filters, polarizers, collimators, is proposed theoretically and proved experimentally. The important advantage of PyC, GrI, GrPyC, and GC is that, in contrast to graphene, they either can be easily deposited onto a dielectric substrate or are strong enough to allow their transfer from the catalytic substrate without a shuttle polymer layer. This opens a new avenue toward the development of a scalable protocol for cost-efficient production of ultralight electromagnetic shields that can be transferred to commercial applications. A robust design via finite-element method and design of experiment for RF devices based on carbon/graphene films and sandwiches is also discussed in the context of virtual prototyping.

  19. Two-body potential model based on cosine series expansion for ionic materials

    DOE PAGES

    Oda, Takuji; Weber, William J.; Tanigawa, Hisashi

    2015-09-23

    There is a method to construct a two-body potential model for ionic materials with a Fourier series basis and we examine it. For this method, the coefficients of cosine basis functions are uniquely determined by solving simultaneous linear equations to minimize the sum of weighted mean square errors in energy, force and stress, where first-principles calculation results are used as the reference data. As a validation test of the method, potential models for magnesium oxide are constructed. The mean square errors appropriately converge with respect to the truncation of the cosine series. This result mathematically indicates that the constructed potentialmore » model is sufficiently close to the one that is achieved with the non-truncated Fourier series and demonstrates that this potential virtually provides minimum error from the reference data within the two-body representation. The constructed potential models work appropriately in both molecular statics and dynamics simulations, especially if a two-step correction to revise errors expected in the reference data is performed, and the models clearly outperform two existing Buckingham potential models that were tested. Moreover, the good agreement over a broad range of energies and forces with first-principles calculations should enable the prediction of materials behavior away from equilibrium conditions, such as a system under irradiation.« less

  20. Towards a Methodology for Managing Competencies in Virtual Teams - A Systemic Approach

    NASA Astrophysics Data System (ADS)

    Schumacher, Marinita; Stal-Le Cardinal, Julie; Bocquet, Jean-Claude

    Virtual instruments and tools are future trends in Engineering which are a response to the growing complexity of engineering tasks, the facility of communication and strong collaborations on the international market. Outsourcing, off-shoring, and the globalization of organisations’ activities have resulted in the formation of virtual product development teams. Individuals who are working in virtual teams must be equipped with diversified competencies that provide a basis for virtual team building. Thanks to the systemic approach of the functional analysis our paper responds to the need of a methodology of competence management to build virtual teams that are active in virtual design projects in the area of New Product Development (NPD).

  1. 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.

  2. The Inter-Life Project: Researching the Potential of Art, Design and Virtual Worlds as a Vehicle for Assisting Young People with Key Life Changes and Transitions

    ERIC Educational Resources Information Center

    Lally, Victor; Sclater, Madeleine

    2013-01-01

    Careers work in the twenty-first century faces a key challenge in terms of digital technologies: to evaluate their potential for careers work in challenging settings. Given the rapidity of developments, technologies require evaluation in research innovations and naturalistic settings. Virtual worlds offer potential for careers and guidance work,…

  3. Noise and Vibration Risk Prevention Virtual Web for Ubiquitous Training

    ERIC Educational Resources Information Center

    Redel-Macías, María Dolores; Cubero-Atienza, Antonio J.; Martínez-Valle, José Miguel; Pedrós-Pérez, Gerardo; del Pilar Martínez-Jiménez, María

    2015-01-01

    This paper describes a new Web portal offering experimental labs for ubiquitous training of university engineering students in work-related risk prevention. The Web-accessible computer program simulates the noise and machine vibrations met in the work environment, in a series of virtual laboratories that mimic an actual laboratory and provide the…

  4. Evaluating What Works in Blended Learning

    ERIC Educational Resources Information Center

    Education Week, 2012

    2012-01-01

    Blended learning--the mix of virtual education and face-to-face instruction--is evolving quickly in schools across the country, generating a variety of different models. This special report, the second in a three-part 2012-13 series on virtual education, examines several of those approaches and aims to identify what is working and where…

  5. The Virtual Factory Teaching System (VFTS): Project Review and Results.

    ERIC Educational Resources Information Center

    Kazlauskas, E. J.; Boyd, E. F., III; Dessouky, M. M.

    This paper presents a review of the Virtual Factory Teaching (VFTS) project, a Web-based, multimedia collaborative learning network. The system allows students, working alone or in teams, to build factories, forecast demand for products, plan production, establish release rules for new work into the factory, and set scheduling rules for…

  6. Impact of Collaborative Work on Technology Acceptance: A Case Study from Virtual Computing

    ERIC Educational Resources Information Center

    Konak, Abdullah; Kulturel-Konak, Sadan; Nasereddin, Mahdi; Bartolacci, Michael R.

    2017-01-01

    Aim/Purpose: This paper utilizes the Technology Acceptance Model (TAM) to examine the extent to which acceptance of Remote Virtual Computer Laboratories (RVCLs) is affected by students' technological backgrounds and the role of collaborative work. Background: RVCLs are widely used in information technology and cyber security education to provide…

  7. Rapid prototyping 3D virtual world interfaces within a virtual factory environment

    NASA Technical Reports Server (NTRS)

    Kosta, Charles Paul; Krolak, Patrick D.

    1993-01-01

    On-going work into user requirements analysis using CLIPS (NASA/JSC) expert systems as an intelligent event simulator has led to research into three-dimensional (3D) interfaces. Previous work involved CLIPS and two-dimensional (2D) models. Integral to this work was the development of the University of Massachusetts Lowell parallel version of CLIPS, called PCLIPS. This allowed us to create both a Software Bus and a group problem-solving environment for expert systems development. By shifting the PCLIPS paradigm to use the VEOS messaging protocol we have merged VEOS (HlTL/Seattle) and CLIPS into a distributed virtual worlds prototyping environment (VCLIPS). VCLIPS uses the VEOS protocol layer to allow multiple experts to cooperate on a single problem. We have begun to look at the control of a virtual factory. In the virtual factory there are actors and objects as found in our Lincoln Logs Factory of the Future project. In this artificial reality architecture there are three VCLIPS entities in action. One entity is responsible for display and user events in the 3D virtual world. Another is responsible for either simulating the virtual factory or communicating with the real factory. The third is a user interface expert. The interface expert maps user input levels, within the current prototype, to control information for the factory. The interface to the virtual factory is based on a camera paradigm. The graphics subsystem generates camera views of the factory on standard X-Window displays. The camera allows for view control and object control. Control or the factory is accomplished by the user reaching into the camera views to perform object interactions. All communication between the separate CLIPS expert systems is done through VEOS.

  8. A morphologically preserved multi-resolution TIN surface modeling and visualization method for virtual globes

    NASA Astrophysics Data System (ADS)

    Zheng, Xianwei; Xiong, Hanjiang; Gong, Jianya; Yue, Linwei

    2017-07-01

    Virtual globes play an important role in representing three-dimensional models of the Earth. To extend the functioning of a virtual globe beyond that of a "geobrowser", the accuracy of the geospatial data in the processing and representation should be of special concern for the scientific analysis and evaluation. In this study, we propose a method for the processing of large-scale terrain data for virtual globe visualization and analysis. The proposed method aims to construct a morphologically preserved multi-resolution triangulated irregular network (TIN) pyramid for virtual globes to accurately represent the landscape surface and simultaneously satisfy the demands of applications at different scales. By introducing cartographic principles, the TIN model in each layer is controlled with a data quality standard to formulize its level of detail generation. A point-additive algorithm is used to iteratively construct the multi-resolution TIN pyramid. The extracted landscape features are also incorporated to constrain the TIN structure, thus preserving the basic morphological shapes of the terrain surface at different levels. During the iterative construction process, the TIN in each layer is seamlessly partitioned based on a virtual node structure, and tiled with a global quadtree structure. Finally, an adaptive tessellation approach is adopted to eliminate terrain cracks in the real-time out-of-core spherical terrain rendering. The experiments undertaken in this study confirmed that the proposed method performs well in multi-resolution terrain representation, and produces high-quality underlying data that satisfy the demands of scientific analysis and evaluation.

  9. Social Protocols for Agile Virtual Teams

    NASA Astrophysics Data System (ADS)

    Picard, Willy

    Despite many works on collaborative networked organizations (CNOs), CSCW, groupware, workflow systems and social networks, computer support for virtual teams is still insufficient, especially support for agility, i.e. the capability of virtual team members to rapidly and cost efficiently adapt the way they interact to changes. In this paper, requirements for computer support for agile virtual teams are presented. Next, an extension of the concept of social protocol is proposed as a novel model supporting agile interactions within virtual teams. The extended concept of social protocol consists of an extended social network and a workflow model.

  10. Software of Seismic Proportions Promotes Enjoyable Learning

    NASA Technical Reports Server (NTRS)

    2005-01-01

    While working for NASA, Jack Sculley and Terry Brooks had a revelation. They wanted to find a novel and unique way to present the scientific principles of NASA research to the public, so as to not only enlighten, but entertain. Suddenly, their revelation morphed into something even grander. "Why stop at NASA?" they asked themselves. With this thought, Sculley and Brooks left NASA and set out to convey voluminous scientific findings from different organizations in the form of digital, interactive media that would enhance the exploration and adventure interests of people of all ages. Sculley, a former researcher at Ames Research Center, the Jet Propulsion Laboratory (JPL), and Apple, Inc. s and LucasFilm Ltd. s multimedia labs, and Brooks, a former public information officer at JPL and an Emmy award-winning documentary film producer, founded Seismic Entertainment in 1989 to communicate their "edutainment" ideas. The two acknowledge that NASA has provided much of the inspiration and content for Seismic Entertainment over the past decade and a half. Additionally, Sculley s experience as a virtual reality and Mars specialist and Brooks s experience creating NASA public access programs were significant to the San Francisco-based company s success. Its most recent project, "Inside NASA," provides virtual tours of NASA s field centers and allows for a comprehensive focus on the broad range of NASA programs for the benefit of the general public

  11. Output feedback control of a quadrotor UAV using neural networks.

    PubMed

    Dierks, Travis; Jagannathan, Sarangapani

    2010-01-01

    In this paper, a new nonlinear controller for a quadrotor unmanned aerial vehicle (UAV) is proposed using neural networks (NNs) and output feedback. The assumption on the availability of UAV dynamics is not always practical, especially in an outdoor environment. Therefore, in this work, an NN is introduced to learn the complete dynamics of the UAV online, including uncertain nonlinear terms like aerodynamic friction and blade flapping. Although a quadrotor UAV is underactuated, a novel NN virtual control input scheme is proposed which allows all six degrees of freedom (DOF) of the UAV to be controlled using only four control inputs. Furthermore, an NN observer is introduced to estimate the translational and angular velocities of the UAV, and an output feedback control law is developed in which only the position and the attitude of the UAV are considered measurable. It is shown using Lyapunov theory that the position, orientation, and velocity tracking errors, the virtual control and observer estimation errors, and the NN weight estimation errors for each NN are all semiglobally uniformly ultimately bounded (SGUUB) in the presence of bounded disturbances and NN functional reconstruction errors while simultaneously relaxing the separation principle. The effectiveness of proposed output feedback control scheme is then demonstrated in the presence of unknown nonlinear dynamics and disturbances, and simulation results are included to demonstrate the theoretical conjecture.

  12. Utilizing media arts principles for developing effective interactive neurorehabilitation systems.

    PubMed

    Rikakis, Thanassis

    2011-01-01

    This paper discusses how interactive neurorehabilitation systems can increase their effectiveness through systematic integration of media arts principles and practice. Media arts expertise can foster the development of complex yet intuitive extrinsic feedback displays that match the inherent complexity and intuitive nature of motor learning. Abstract, arts-based feedback displays can be powerful metaphors that provide re-contextualization, engagement and appropriate reward mechanisms for mature adults. Such virtual feedback displays must be seamlessly integrated with physical components to produce mixed reality training environments that promote active, generalizable learning. The proposed approaches are illustrated through examples from mixed reality rehabilitation systems developed by our team.

  13. Collaborative Project Work Development in a Virtual Environment with Low-Intermediate Undergraduate Colombian Students (Desarrollo de trabajo colaborativo en un ambiente virtual con estudiantes colombianos de pregrado de nivel intermedio-bajo)

    ERIC Educational Resources Information Center

    Salinas Vacca, Yakelin

    2014-01-01

    This paper reports on an exploratory, descriptive, and interpretive study in which the roles of discussion boards, the students, the teacher, and the monitors were explored as they constructed a collaborative class project in a virtual environment. This research was conducted in the virtual program of a Colombian public university. Data were…

  14. Acceptability of Virtual Reality Interoceptive Exposure for the Treatment of Panic Disorder with Agoraphobia

    ERIC Educational Resources Information Center

    Quero, Soledad; Pérez-Ara, M. Ángeles; Bretón-López, Juana; García-Palacios, Azucena; Baños, Rosa M.; Botella, Cristina

    2014-01-01

    Interoceptive exposure (IE) is a standard component of cognitive-behavioural therapy (CBT) for panic disorder and agoraphobia. The virtual reality (VR) program "Panic-Agoraphobia" has several virtual scenarios designed for applying exposure to agoraphobic situations; it can also simulate physical sensations. This work examines patients'…

  15. An Analysis of Dyadic Relationships between Administrators and Employees Working Virtually in Higher Education

    ERIC Educational Resources Information Center

    Anderson, Rhonda L.

    2012-01-01

    The use of virtual teams has become a common practice for organizations across all industries nationally and internationally (Carmel & Agarwal, 2001; Hertel, Geister, & Konradt, 2005; Martins, Gilson, & Maynard, 2004; McDonough, Kahn, & Barczak, 2001). Institutions of higher education are also embracing the use of virtual teams…

  16. Virtual Learning Spaces in the Web: An Agent-Based Architecture of Personalized Collaborative Learning Environment.

    ERIC Educational Resources Information Center

    Nunez Esquer, Gustavo; Sheremetov, Leonid

    This paper reports on the results and future research work within the paradigm of Configurable Collaborative Distance Learning, called Espacios Virtuales de Apredizaje (EVA). The paper focuses on: (1) description of the main concepts, including virtual learning spaces for knowledge, collaboration, consulting, and experimentation, a…

  17. A Comparison Study of Polyominoes Explorations in a Physical and Virtual Manipulative Environment

    ERIC Educational Resources Information Center

    Yuan, Y.; Lee, C. -Y.; Wang, C. -H.

    2010-01-01

    This study develops virtual manipulative, polyominoes kits for junior high school students to explore polyominoes. The current work conducts a non-equivalent group pretest-post-test quasi-experimental design to compare the performance difference between using physical manipulatives and virtual manipulatives in finding the number of polyominoes.…

  18. Treatment of Complicated Grief Using Virtual Reality: A Case Report

    ERIC Educational Resources Information Center

    Botella, C.; Osma, J.; Palacios, A. Garcia; Guillen, V.; Banos, R.

    2008-01-01

    This is the first work exploring the application of new technologies, concretely virtual reality, to facilitate emotional processing in the treatment of Complicated Grief. Our research team has designed a virtual reality environment (EMMA's World) to foster the expression and processing of emotions. In this study the authors present a description…

  19. Conversations with Freudbot in Second Life: Mining the Virtuality of Relationship

    ERIC Educational Resources Information Center

    Heller, Bob

    2017-01-01

    The unstructured conversations of students who chatted with Freudbot in his Second Life virtual office over a 32-month period were examined in order to better understand the nature of the virtual relationship between students and conversational agents (CA) as historical figures. This research builds on past work that examined these conversations…

  20. A Taxonomy of Virtual Worlds Usage in Education

    ERIC Educational Resources Information Center

    Duncan, Ishbel; Miller, Alan; Jiang, Shangyi

    2012-01-01

    Virtual worlds are an important tool in modern education practices as well as providing socialisation, entertainment and a laboratory for collaborative work. This paper focuses on the uses of virtual worlds for education and synthesises over 100 published academic papers, reports and educational websites from around the world. A taxonomy is then…

  1. Virtual Simulations and Serious Games in a Laptop-Based University: Gauging Faculty and Student Perceptions

    ERIC Educational Resources Information Center

    Kapralos, Bill; Hogan, Michelle; Pribetic, Antonin I.; Dubrowski, Adam

    2011-01-01

    Purpose: Gaming and interactive virtual simulation environments support a learner-centered educational model allowing learners to work through problems acquiring knowledge through an active, experiential learning approach. To develop effective virtual simulations and serious games, the views and perceptions of learners and educators must be…

  2. Innovation Education Enabled through a Collaborative Virtual Reality Learning Environment

    ERIC Educational Resources Information Center

    Thorsteinsson, Gisli; Page, Tom; Lehtonen, Miika; Ha, Joong Gyu

    2006-01-01

    This article provides a descriptive account of the development of an approach to the support of design and technology education with 3D Virtual Reality (VR) technologies on an open and distance learning basis. This work promotes an understanding of the implications and possibilities of advanced virtual learning technologies in education for…

  3. Teaching Literature in Virtual Worlds: Immersive Learning in English Studies

    ERIC Educational Resources Information Center

    Webb, Allen, Ed.

    2011-01-01

    What are the realities and possibilities of utilizing on-line virtual worlds as teaching tools for specific literary works? Through engaging and surprising stories from classrooms where virtual worlds are in use, this book invites readers to understand and participate in this emerging and valuable pedagogy. It examines the experience of high…

  4. An Unholy Mess: Why 'The Sanctity of Life Principle' Should Be Jettisoned.

    PubMed

    Jones, David Albert

    2016-11-01

    The aim of this article is to present an account of an important element of medical ethics and law which is widely cited but is often confused. This element is most frequently referred to as 'the principle of the sanctity of life', and it is often assumed that this language has a religious provenance. However, the phrase is neither rooted in the traditions it purports to represent nor is it used consistently in contemporary discourse. Understood as the name of an established 'principle' the 'sanctity of life' is virtually an invention of the late twentieth century. The language came to prominence as the label of a position that was being rejected: it is the name of a caricature. Hence there is no locus classicus for a definition of the terms and different authors freely apply the phrase to divergent and contradictory positions. Appeal to this 'principle' thus serves only to perpetuate confusion. This language is best jettisoned in favour of clearer and more traditional ethical concepts.

  5. Improving Virtual Team Collaboration Outcomes through Collaboration Process Structuring

    ERIC Educational Resources Information Center

    Dittman, Dawn R.; Hawkes, Mark; Deokar, Amit V.; Sarnikar, Surendra

    2010-01-01

    The ability to collaborate in a virtual team is a necessary skill set for today's knowledge workers and students to be effective in their work. Past research indicates that knowledge workers and students need to establish a formal process to perform work, develop clear goals and objectives, and facilitate better communication among team members.…

  6. Working Memory in Wayfinding--A Dual Task Experiment in a Virtual City

    ERIC Educational Resources Information Center

    Meilinger, Tobias; Knauff, Markus; Bulthoff, Heinrich H.

    2008-01-01

    This study examines the working memory systems involved in human wayfinding. In the learning phase, 24 participants learned two routes in a novel photorealistic virtual environment displayed on a 220 degrees screen while they were disrupted by a visual, a spatial, a verbal, or--in a control group--no secondary task. In the following wayfinding…

  7. Research on Modeling Technology of Virtual Robot Based on LabVIEW

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Huo, J. L.; Y Sun, L.; Y Hao, X.

    2017-12-01

    Because of the dangerous working environment, the underwater operation robot for nuclear power station needs manual teleoperation. In the process of operation, it is necessary to guide the position and orientation of the robot in real time. In this paper, the geometric modeling of the virtual robot and the working environment is accomplished by using SolidWorks software, and the accurate modeling and assembly of the robot are realized. Using LabVIEW software to read the model, and established the manipulator forward kinematics and inverse kinematics model, and realized the hierarchical modeling of virtual robot and computer graphics modeling. Experimental results show that the method studied in this paper can be successfully applied to robot control system.

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

    PubMed

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

    2003-03-01

    A clear understanding of the intricate spatial relationships among the structures of the pelvic floor, rectum, and anal canal is essential for the treatment of numerous pathologic conditions. Virtual-reality technology allows improved visualization of three-dimensional structures over conventional media because it supports stereoscopic-vision, viewer-centered perspective, large angles of view, and interactivity. We describe a novel virtual reality-based model designed to teach anorectal and pelvic floor anatomy, pathology, and surgery. A static physical model depicting the pelvic floor and anorectum was created and digitized at 1-mm intervals in a CT scanner. Multiple software programs were used along with endoscopic images to generate a realistic interactive computer model, which was designed to be viewed on a networked, interactive, virtual-reality display (CAVE or ImmersaDesk). A standard examination of ten basic anorectal and pelvic floor anatomy questions was administered to third-year (n = 6) and fourth-year (n = 7) surgical residents. A workshop using the Virtual Pelvic Floor Model was then given, and the standard examination was readministered so that it was possible to evaluate the effectiveness of the Digital Pelvic Floor Model as an educational instrument. Training on the Virtual Pelvic Floor Model produced substantial improvements in the overall average test scores for the two groups, with an overall increase of 41 percent (P = 0.001) and 21 percent (P = 0.0007) for third-year and fourth-year residents, respectively. Resident evaluations after the workshop also confirmed the effectiveness of understanding pelvic anatomy using the Virtual Pelvic Floor Model. This model provides an innovative interactive educational framework that allows educators to overcome some of the barriers to teaching surgical and endoscopic principles based on understanding highly complex three-dimensional anatomy. Using this collaborative, shared virtual-reality environment, teachers and students can interact from locations world-wide to manipulate the components of this model to achieve the educational goals of this project along with the potential for virtual surgery.

  9. ïSCOPE: Safer care for older persons (in residential) environments: A study protocol

    PubMed Central

    2011-01-01

    Background The current profile of residents living in Canadian nursing homes includes elder persons with complex physical and social needs. High resident acuity can result in increased staff workload and decreased quality of work life. Aims Safer Care for Older Persons [in residential] Environments is a two year (2010 to 2012) proof-of-principle pilot study conducted in seven nursing homes in western Canada. The purpose of the study is to evaluate the feasibility of engaging front line staff to use quality improvement methods to integrate best practices into resident care. The goals of the study are to improve the quality of work life for staff, in particular healthcare aides, and to improve residents' quality of life. Methods/design The study has parallel research and quality improvement intervention arms. It includes an education and support intervention for direct caregivers to improve the safety and quality of their care delivery. We hypothesize that this intervention will improve not only the care provided to residents but also the quality of work life for healthcare aides. The study employs tools adapted from the Institute for Healthcare Improvement's Breakthrough Series: Collaborative Model and Canada's Safer Healthcare Now! improvement campaign. Local improvement teams in each nursing home (1 to 2 per facility) are led by healthcare aides (non-regulated caregivers) and focus on the management of specific areas of resident care. Critical elements of the program include local measurement, virtual and face-to-face learning sessions involving change management, quality improvement methods and clinical expertise, ongoing virtual and in person support, and networking. Discussion There are two sustainability challenges in this study: ongoing staff and leadership engagement, and organizational infrastructure. Addressing these challenges will require strategic planning with input from key stakeholders for sustaining quality improvement initiatives in the long-term care sector. PMID:21745382

  10. Stakeholder perspectives on the development of a virtual clinic for diabetes care: qualitative study.

    PubMed

    Armstrong, Natalie; Hearnshaw, Hilary; Powell, John; Dale, Jeremy

    2007-08-09

    The development of the Internet has created new opportunities for health care provision, including its use as a tool to aid the self-management of chronic conditions. We studied stakeholder reactions to an Internet-based "virtual clinic," which would allow people with diabetes to communicate with their health care providers, find information about their condition, and share information and support with other users. The aim of the study was to present the results of a detailed consultation with a variety of stakeholder groups in order to identify what they regard as the desirable, important, and feasible characteristics of an Internet-based intervention to aid diabetes self-management. Three focus groups were conducted with 12 people with type 1 diabetes who used insulin pumps. Participants were recruited through a local diabetes clinic. One-on-one interviews were conducted with 5 health care professionals from the same clinic (2 doctors, 2 nurses, 1 dietitian) and with 1 representative of an insulin pump company. We gathered patient consensus via email on the important and useful features of Internet-based systems used for other chronic conditions (asthma, epilepsy, myalgic encephalopathy, mental health problems). A workshop to gather expert consensus on the use of information technology to improve the care of young people with diabetes was organized. Stakeholder groups identified the following important characteristics of an Internet-based virtual clinic: being grounded on personal needs rather than only providing general information; having the facility to communicate with, and learn from, peers; providing information on the latest developments and news in diabetes; being quick and easy to use. This paper discusses these characteristics in light of a review of the relevant literature. The development of a virtual clinic for diabetes that embodies these principles, and that is based on self-efficacy theory, is described. Involvement of stakeholders is vital early in the development of a complex intervention. Stakeholders have clear and relevant views on what a virtual clinic system should provide, and these views can be captured and synthesized with relative ease. This work has led to the design of a system that is able to meet user needs and is currently being evaluated in a pilot study.

  11. Impact of 3D virtual planning on reconstruction of mandibular and maxillary surgical defects in head and neck oncology.

    PubMed

    Witjes, Max J H; Schepers, Rutger H; Kraeima, Joep

    2018-04-01

    This review describes the advances in 3D virtual planning for mandibular and maxillary reconstruction surgical defects with full prosthetic rehabilitation. The primary purpose is to provide an overview of various techniques that apply 3D technology safely in primary and secondary reconstructive cases of patients suffering from head and neck cancer. Methods have been developed to overcome the problem of control over the margin during surgery while the crucial decision with regard to resection margin and planning of osteotomies were predetermined by virtual planning. The unlimited possibilities of designing patient-specific implants can result in creative uniquely applied solutions for single cases but should be applied wisely with knowledge of biomechanical engineering principles. The high surgical accuracy of an executed 3D virtual plan provides tumor margin control during ablative surgery and the possibility of planned combined use of osseus free flaps and dental implants in the reconstruction in one surgical procedure. A thorough understanding of the effects of radiotherapy on the reconstruction, soft tissue management, and prosthetic rehabilitation is imperative in individual cases when deciding to use dental implants in patients who received radiotherapy.

  12. Stability of Electrons in the Virtual Cathode Region of an IEC

    NASA Astrophysics Data System (ADS)

    Kim, Hyng-Jin; Miley, George; Momota, Hiromu

    2003-04-01

    In the Inertial Electrostatic Confinement (IEC) device, electrons are confined inside a virtual anode that in turn confines ions. Prior stability studies [1, 2] have considered systems in which one species is electrostatically confined by the other, and either or both species are out of local thermal equilibrium. In the present research, electron stability in the virtual cathode region of an ion injected IEC is being studied. The ion density in an IEC is non-uniform due to the radial electrostatic potential, and increases toward the center region. The potential near the virtual cathode is assumed to have a parabolic shape and is determined assuming that the net space charge density is constant in that region. The corresponding ion distribution function is assumed to have the form f = C [sigma] (H W) /L^0.5 and the electron response is taken to be diabatic. Then using a variational principle after linearizing the hydrodynamic equations, stability properties of the electron layer are determined. Results will be presented as a function of injected ion/electron current ratios. 1. L. Chacon and D. C. Barnes, Phys. Plasma 7, 4774 (2000). 2. D. C. Barnes, L. Chacon, and J. M. Finn, Phys. Plasmas 9, 4448 (2002).

  13. 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.

  14. [Construction of information management-based virtual forest landscape and its application].

    PubMed

    Chen, Chongcheng; Tang, Liyu; Quan, Bing; Li, Jianwei; Shi, Song

    2005-11-01

    Based on the analysis of the contents and technical characteristics of different scale forest visualization modeling, this paper brought forward the principles and technical systems of constructing an information management-based virtual forest landscape. With the combination of process modeling and tree geometric structure description, a software method of interactively and parameterized tree modeling was developed, and the corresponding renderings and geometrical elements simplification algorithms were delineated to speed up rendering run-timely. As a pilot study, the geometrical model bases associated with the typical tree categories in Zhangpu County of Fujian Province, southeast China were established as template files. A Virtual Forest Management System prototype was developed with GIS component (ArcObject), OpenGL graphics environment, and Visual C++ language, based on forest inventory and remote sensing data. The prototype could be used for roaming between 2D and 3D, information query and analysis, and virtual and interactive forest growth simulation, and its reality and accuracy could meet the needs of forest resource management. Some typical interfaces of the system and the illustrative scene cross-sections of simulated masson pine growth under conditions of competition and thinning were listed.

  15. Virtualization of event sources in wireless sensor networks for the internet of things.

    PubMed

    Lucas Martínez, Néstor; Martínez, José-Fernán; Hernández Díaz, Vicente

    2014-12-01

    Wireless Sensor Networks (WSNs) are generally used to collect information from the environment. The gathered data are delivered mainly to sinks or gateways that become the endpoints where applications can retrieve and process such data. However, applications would also expect from a WSN an event-driven operational model, so that they can be notified whenever occur some specific environmental changes instead of continuously analyzing the data provided periodically. In either operational model, WSNs represent a collection of interconnected objects, as outlined by the Internet of Things. Additionally, in order to fulfill the Internet of Things principles, Wireless Sensor Networks must have a virtual representation that allows indirect access to their resources, a model that should also include the virtualization of event sources in a WSN. Thus, in this paper a model for a virtual representation of event sources in a WSN is proposed. They are modeled as internet resources that are accessible by any internet application, following an Internet of Things approach. The model has been tested in a real implementation where a WSN has been deployed in an open neighborhood environment. Different event sources have been identified in the proposed scenario, and they have been represented following the proposed model.

  16. Transnational organizational considerations for sociocultural differences in ethics and virtual team functioning in laboratory animal science.

    PubMed

    Pritt, Stacy L; Mackta, Jayne

    2010-05-01

    Business models for transnational organizations include linking different geographies through common codes of conduct, policies, and virtual teams. Global companies with laboratory animal science activities (whether outsourced or performed inhouse) often see the need for these business activities in relation to animal-based research and benefit from them. Global biomedical research organizations can learn how to better foster worldwide cooperation and teamwork by understanding and working with sociocultural differences in ethics and by knowing how to facilitate appropriate virtual team actions. Associated practices include implementing codes and policies transcend cultural, ethnic, or other boundaries and equipping virtual teams with the needed technology, support, and rewards to ensure timely and productive work that ultimately promotes good science and patient safety in drug development.

  17. The Scaled Arrival of K-12 Online Education: Emerging Realities and Implications for the Future of Education

    ERIC Educational Resources Information Center

    Basham, James D.; Smith, Sean J.; Greer, Diana L.; Marino, Matthew T.

    2013-01-01

    This article examines the complex array of variables and implementation models that must be accounted for during the pivot from a purely brick-and-mortar educational system to one that makes use of both virtual and blended environments. The authors call for enhanced emphasis on instructional goals and design principles, rather than available…

  18. An improved tree height measurement technique tested on mature southern pines

    Treesearch

    Don C. Bragg

    2008-01-01

    Virtually all techniques for tree height determination follow one of two principles: similar triangles or the tangent method. Most people apply the latter approach, which uses the tangents of the angles to the top and bottom and a true horizontal distance to the subject tree. However, few adjust this method for ground slope, tree lean, crown shape, and crown...

  19. Telecommunications and disease management in the home environment: new strategies to improve outcomes.

    PubMed

    Meyer, L C

    1997-06-01

    This article provides an overview of the issues and effects of principle-centered health care within organized systems of care; portrays a comprehensive disease management framework for home health care; and offers virtual health management, telecommunications, and mobile computing strategies to enable health management enterprises to achieve health and outcomes maximization accountability demands in managed care.

  20. A Look inside a MUVE Design Process: Blending Instructional Design and Game Principles to Target Writing Skills

    ERIC Educational Resources Information Center

    Warren, Scott J.; Stein, Richard A.; Dondlinger, Mary Jo; Barab, Sasha A.

    2009-01-01

    The number of games, simulations, and multi-user virtual environments designed to promote learning, engagement with subject matter, or intended to contextualize learning has been steadily increasing over the past decade. While the use of these digital designs in educational settings has begun to show promise for improving learning, motivation, and…

  1. 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.

  2. First-principles study of (Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 solid solutions

    NASA Astrophysics Data System (ADS)

    Amoroso, Danila; Cano, Andrés; Ghosez, Philippe

    2018-05-01

    (Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 solid solutions are the building blocks of lead-free piezoelectric materials that attract a renewed interest. We investigate the properties of these systems by means of first-principles calculations, with a focus on the lattice dynamics and the competition between different ferroelectric phases. We first analyze the four parent compounds in order to compare their properties and their different tendency towards ferroelectricity. The core of our study is systematic characterization of the binary systems (Ba ,Ca ) TiO3 and Ba (Ti ,Zr ) O3 within both the virtual crystal approximation and direct supercell calculations. In the case of Ca doping, we find a gradual transformation from B -site to A -site ferroelectricity due to steric effects that largely determines the behavior of the system. In the case of Zr doping, in contrast, the behavior is eventually dominated by cooperative Zr-Ti motions and the local electrostatics. In addition, our comparative study reveals that the specific microscopic physics of these solids sets severe limits to the applicability of the virtual crystal approximation for these systems.

  3. InSPAL: A Novel Immersive Virtual Learning Programme.

    PubMed

    Byrne, Julia; Ip, Horace H S; Shuk-Ying Lau, Kate; Chen Li, Richard; Tso, Amy; Choi, Catherine

    2015-01-01

    In this paper we introduce The Interactive Sensory Program for Affective Learning (InSPAL) a pioneering virtual learning programme designed for the severely intellectually disabled (SID) students, who are having cognitive deficiencies and other sensory-motor handicaps, and thus need more help and attention in overcoming their learning difficulties. Through combining and integrating interactive media and virtual reality technology with the principles of art therapy and relevant pedagogical techniques, InSPAL aims to strengthen SID students' pre-learning abilities, promote their self-awareness, decrease behavioral interferences with learning as well as social interaction, enhance their communication and thus promote their quality of life. Results of our study show that students who went through our programme were more focused, and the ability to do things more independently increased by 15%. Moreover, 50% of the students showed a marked improvement in the ability to raise their hands in response, thus increasing their communication skills. The use of therapeutic interventions enabled a better control to the body, mind and emotions, resulting a greater performance and better participation.

  4. [Application of virtual instrumentation technique in toxicological studies].

    PubMed

    Moczko, Jerzy A

    2005-01-01

    Research investigations require frequently direct connection of measuring equipment to the computer. Virtual instrumentation technique considerably facilitates programming of sophisticated acquisition-and-analysis procedures. In standard approach these two steps are performed subsequently with separate software tools. The acquired data are transfered with export / import procedures of particular program to the another one which executes next step of analysis. The described procedure is cumbersome, time consuming and may be potential source of the errors. In 1987 National Instruments Corporation introduced LabVIEW language based on the concept of graphical programming. Contrary to conventional textual languages it allows the researcher to concentrate on the resolved problem and omit all syntactical rules. Programs developed in LabVIEW are called as virtual instruments (VI) and are portable among different computer platforms as PCs, Macintoshes, Sun SPARCstations, Concurrent PowerMAX stations, HP PA/RISK workstations. This flexibility warrants that the programs prepared for one particular platform would be also appropriate to another one. In presented paper basic principles of connection of research equipment to computer systems were described.

  5. Construction of Virtual-Experiment Systems for Information Science Education

    NASA Astrophysics Data System (ADS)

    She, Jin-Hua; Amano, Naoki

    Practice is very important in education because it not only can stimulate the motivation of learning, but also can deepen the understanding of theory. However, due to the limitations on the time and experiment resources, experiments cannot be simply introduced in every lesson. To make the best use of multimedia technology, this paper designs five virtual experiment systems, which are based on the knowledge of physics at the high-school lever, to improve the effectiveness of teaching data processing. The systems are designed by employing the cognitive theory of multimedia learning and the inner game principle to ensure the easy use and to reduce the cognitive load. The learning process is divided into two stages: the first stage teaches the basic concepts of data processing; and the second stage practices the techniques taught in the first stage and uses them to build a linear model and to carry out estimation. The virtual experiment systems have been tested in an university's data processing course, and have demonstrated their validity.

  6. Fish in the matrix: motor learning in a virtual world.

    PubMed

    Engert, Florian

    2012-01-01

    One of the large remaining challenges in the field of zebrafish neuroscience is the establishment of techniques and preparations that permit the recording and perturbation of neural activity in animals that can interact meaningfully with the environment. Since it is very difficult to do this in freely behaving zebrafish, I describe here two alternative approaches that meet this goal via tethered preparations. The first uses head-fixation in agarose in combination with online imaging and analysis of tail motion. In the second method, paralyzed fish are suspended with suction pipettes in mid-water and nerve root recordings serve as indicators for intended locomotion. In both cases, fish can be immersed into a virtual environment and allowed to interact with this virtual world via real or fictive tail motions. The specific examples given in this review focus primarily on the role of visual feedback~- but the general principles certainly extend to other modalities, including proprioception, hearing, balance, and somatosensation.

  7. Fish in the matrix: motor learning in a virtual world

    PubMed Central

    Engert, Florian

    2013-01-01

    One of the large remaining challenges in the field of zebrafish neuroscience is the establishment of techniques and preparations that permit the recording and perturbation of neural activity in animals that can interact meaningfully with the environment. Since it is very difficult to do this in freely behaving zebrafish, I describe here two alternative approaches that meet this goal via tethered preparations. The first uses head-fixation in agarose in combination with online imaging and analysis of tail motion. In the second method, paralyzed fish are suspended with suction pipettes in mid-water and nerve root recordings serve as indicators for intended locomotion. In both cases, fish can be immersed into a virtual environment and allowed to interact with this virtual world via real or fictive tail motions. The specific examples given in this review focus primarily on the role of visual feedback~– but the general principles certainly extend to other modalities, including proprioception, hearing, balance, and somatosensation. PMID:23355810

  8. The architecture of a virtual grid GIS server

    NASA Astrophysics Data System (ADS)

    Wu, Pengfei; Fang, Yu; Chen, Bin; Wu, Xi; Tian, Xiaoting

    2008-10-01

    The grid computing technology provides the service oriented architecture for distributed applications. The virtual Grid GIS server is the distributed and interoperable enterprise application GIS architecture running in the grid environment, which integrates heterogeneous GIS platforms. All sorts of legacy GIS platforms join the grid as members of GIS virtual organization. Based on Microkernel we design the ESB and portal GIS service layer, which compose Microkernel GIS. Through web portals, portal GIS services and mediation of service bus, following the principle of SoC, we separate business logic from implementing logic. Microkernel GIS greatly reduces the coupling degree between applications and GIS platforms. The enterprise applications are independent of certain GIS platforms, and making the application developers to pay attention to the business logic. Via configuration and orchestration of a set of fine-grained services, the system creates GIS Business, which acts as a whole WebGIS request when activated. In this way, the system satisfies a business workflow directly and simply, with little or no new code.

  9. Freeform object design and simultaneous manufacturing

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Zhang, Weihan; Lin, Heng; Leu, Ming C.

    2003-04-01

    Today's product design, especially the consuming product design, focuses more and more on individuation, originality, and the time to market. One way to meet these challenges is using the interactive and creationary product design methods and rapid prototyping/rapid tooling. This paper presents a novel Freeform Object Design and Simultaneous Manufacturing (FODSM) method that combines the natural interaction feature in the design phase and simultaneous manufacturing feature in the prototyping phase. The natural interactive three-dimensional design environment is achieved by adopting virtual reality technology. The geometry of the designed object is defined through the process of "virtual sculpting" during which the designer can touch and visualize the designed object and can hear the virtual manufacturing environment noise. During the designing process, the computer records the sculpting trajectories and automatically translates them into NC codes so as to simultaneously machine the designed part. The paper introduced the principle, implementation process, and key techniques of the new method, and compared it with other popular rapid prototyping methods.

  10. New developments in digital pathology: from telepathology to virtual pathology laboratory.

    PubMed

    Kayser, Klaus; Kayser, Gian; Radziszowski, Dominik; Oehmann, Alexander

    2004-01-01

    To analyse the present status and future development of computerized diagnostic pathology in terms of work-flow integrative telepathology and virtual laboratory. Telepathology has left its childhood. The technical development of telepathology is mature, in contrast to that of virtual pathology. Two kinds of virtual pathology laboratories are emerging: a) those with distributed pathologists and distributed (>=1) laboratories associated to individual biopsy stations/surgical theatres, and b) distributed pathologists working in a centralized laboratory. Both are under technical development. Telepathology can be used for e-learning and e-training in pathology, as exemplarily demonstrated on Digital Lung Pathology Pathology (www.pathology-online.org). A virtual pathology institution (mode a) accepts a complete case with the patient's history, clinical findings, and (pre-selected) images for first diagnosis. The diagnostic responsibility is that of a conventional institution. The internet serves as platform for information transfer, and an open server such as the iPATH (http://telepath.patho.unibas.ch) for coordination and performance of the diagnostic procedure. The size of images has to be limited, and usual different magnifications have to be used. A group of pathologists is "on duty", or selects one member for a predefined duty period. The diagnostic statement of the pathologist(s) on duty is retransmitted to the sender with full responsibility. First experiences of a virtual pathology institution group working with the iPATH server (Dr. L. Banach, Dr. G. Haroske, Dr. I. Hurwitz, Dr. K. Kayser, Dr. K.D. Kunze, Dr. M. Oberholzer,) working with a small hospital of the Salomon islands are promising. A centralized virtual pathology institution (mode b) depends upon the digitalisation of a complete slide, and the transfer of large sized images to different pathologists working in one institution. The technical performance of complete slide digitalisation is still under development and does not completely fulfil the requirements of a conventional pathology institution at present. VIRTUAL PATHOLOGY AND E-LEARNING: At present, e-learning systems are "stand-alone" solutions distributed on CD or via internet. A characteristic example is the Digital Lung Pathology CD (www.pathology-online.org), which includes about 60 different rare and common lung diseases and internet access to scientific library systems (PubMed), distant measurement servers (EuroQuant), or electronic journals (Elec J Pathol Histol). A new and complete data base based upon this CD will combine e-learning and e-teaching with the actual workflow in a virtual pathology institution (mode a). The technological problems are solved and do not depend upon technical constraints such as slide scanning systems. Telepathology serves as promotor for a new landscape in diagnostic pathology, the so-called virtual pathology institution. Industrial and scientific efforts will probably allow an implementation of this technique within the next two years.

  11. Quality knowledge of science through virtual laboratory as an element of visualization

    NASA Astrophysics Data System (ADS)

    Rizman Herga, Natasa

    Doctoral dissertation discusses the use of virtual laboratory for learning and teaching chemical concepts at science classes in the seventh grade of primary school. The dissertation has got a two-part structure. In the first theoretical part presents a general platform of teaching science in elementary school, teaching forms and methods of teaching and among modern approaches we highlight experimental work. Particular emphasis was placed on the use of new technologies in education and virtual laboratories. Scientific findings on the importance of visualization of science concepts and their triple nature of their understanding are presented. These findings represent a fundamental foundation of empirical research presented in the second part of the doctoral dissertation, whose basic purpose was to examine the effectiveness of using virtual laboratory for teaching and learning chemical contents at science from students' point of view on knowledge and interest. We designed a didactic experiment in which 225 pupils participated. The work was conducted in the experimental and control group. Prior to its execution, the existing school practice among science and chemistry teachers was analysed in terms of: (1) inclusion of experimental work as a fundamental method of active learning chemical contents, (2) the use of visualization methods in the classroom and (3) the use of a virtual laboratory. The main findings of the empirical research, carried out in the school year 2012/2013, in which 48 science and chemistry participated, are that teachers often include experimental work when teaching chemical contents. Interviewed science teachers use a variety of visualization methods when presenting science concepts, in particular computer animation and simulation. Using virtual laboratory as a new strategy for teaching and learning chemical contents is not common because teachers lack special-didactic skills, enabling them to use virtual reality technology. Based on the didactic experiment, carried out over a period of two school years (2012/2013 and 2013/2014) in ten primary schools, the effectiveness of teaching carried out with the support of a virtual laboratory was analyzed. The obtained empirical findings reveal that the use of virtual laboratory has great impact on the pupils' knowledge and interest. At the end of the experiment, pupils in the experimental group had an advantage according to knowledge of chemical contents in science. Also, the use of virtual laboratory had an impact on the sustainability of the acquired knowledge of science contents and pupils' interest at the end of the experiment, because the pupils in the experimental group had a higher interest for learning science contents. The didactic experiment determined, that the use of virtual laboratory enables quality learning and teaching chemical contents of science, because it allows: (1) experimental work as an active learning method, (2) the visualization of abstract concepts and phenomena, (3) dynamic sub micro presentations (4) integration of all three levels of the chemical concept as a whole and (5) positively impacts pupils' interest, knowledge and sustainability of the acquired knowledge.

  12. Introduction to Virtual Reality in Education

    ERIC Educational Resources Information Center

    Dede, Chris

    2009-01-01

    As an emerging technology for learning, virtual reality (VR) dates back four decades, to early work by Ivan Sutherland in the late 1960s. At long last, interactive media are emerging that offer the promise of VR in everyday settings. Quasi-VR already is commonplace in 2-1/2-D virtual environments like Second Life and in massively multiplayer…

  13. The Virtual Research Lab: Research Outcome Expectations, Research Knowledge, and the Graduate Student Experience

    ERIC Educational Resources Information Center

    Stadtlander, Lee; Giles, Martha; Sickel, Amy

    2013-01-01

    This paper examines the complexities of working with student researchers in a virtual lab setting, logistics, and methods to resolve issues. To demonstrate the feasibility of a virtual lab, a mixed-methods study consisting of quantitative surveys and qualitative data examined changes in doctoral students' confidence as measured by research outcome…

  14. Understanding Virtual Epidemics: Children's Folk Conceptions of a Computer Virus

    ERIC Educational Resources Information Center

    Kafai, Yasmin B.

    2008-01-01

    Our work investigates the annual outbreak of Whypox, a virtual epidemic in Whyville.net, a virtual world with over 1.2 million registered players ages 8-16. We examined online and classroom participants' understanding of a computer virus using surveys and design activities. Our analyses reveal that students have a mostly naive understanding of a…

  15. Study of Co-Located and Distant Collaboration with Symbolic Support via a Haptics-Enhanced Virtual Reality Task

    ERIC Educational Resources Information Center

    Yeh, Shih-Ching; Hwang, Wu-Yuin; Wang, Jin-Liang; Zhan, Shi-Yi

    2013-01-01

    This study intends to investigate how multi-symbolic representations (text, digits, and colors) could effectively enhance the completion of co-located/distant collaborative work in a virtual reality context. Participants' perceptions and behaviors were also studied. A haptics-enhanced virtual reality task was developed to conduct…

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  17. Working Collaboratively in Virtual Learning Environments: Using Second Life with Korean High School Students in History Class

    ERIC Educational Resources Information Center

    Kim, Mi Hwa

    2013-01-01

    The purpose of this experimental study was to investigate the impact of the use of a virtual environment for learning Korean history on high school students' learning outcomes and attitudes toward virtual worlds (collaboration, engagement, general use of SL [Second Life], and immersion). In addition, this experiment examined the relationships…

  18. Development and evaluation of a trauma decision-making simulator in Oculus virtual reality.

    PubMed

    Harrington, Cuan M; Kavanagh, Dara O; Quinlan, John F; Ryan, Donncha; Dicker, Patrick; O'Keeffe, Dara; Traynor, Oscar; Tierney, Sean

    2018-01-01

    Consumer-available virtual-reality technology was launched in 2016 with strong foundations in the entertainment-industry. We developed an innovative medical-training simulator on the Oculus™ Gear-VR platform. This novel application was developed utilising internationally recognised Advanced Trauma Life Support (ATLS) principles, requiring decision-making skills for critically-injured virtual-patients. Participants were recruited in June, 2016 at a single-centre trauma-course (ATLS, Leinster, Ireland) and trialled the platform. Simulator performances were correlated with individual expertise and course-performance measures. A post-intervention questionnaire relating to validity-aspects was completed. Eighteen(81.8%) eligible-candidates and eleven(84.6%) course-instructors voluntarily participated. The survey-responders mean-age was 38.9(±11.0) years with 80.8% male predominance. The instructor-group caused significantly less fatal-errors (p < 0.050) and proportions of incorrect-decisions (p < 0.050). The VR-hardware and trauma-application's mean ratings were 5.09 and 5.04 out of 7 respectively. Participants reported it was an enjoyable method of learning (median-6.0), the learning platform of choice (median-5.0) and a cost-effective training tool (median-5.0). Our research has demonstrated evidence of validity-criteria for a concept application on virtual-reality headsets. We believe that virtual-reality technology is a viable platform for medical-simulation into the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. 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.

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

    PubMed

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

    2014-11-01

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

  1. Speed behaviour in work zone crossovers. A driving simulator study.

    PubMed

    Domenichini, Lorenzo; La Torre, Francesca; Branzi, Valentina; Nocentini, Alessandro

    2017-01-01

    Reductions in speed and, more critically, in speed variability between vehicles are considered an important factor to reduce crash risk in work zones. This study was designed to evaluate in a virtual environment the drivers' behaviour in response to nine different configurations of a motorway crossover work zone. Specifically, the speed behaviour through a typical crossover layout, designed in accordance with the Italian Ministerial Decree 10 July 2002, was compared with that of eight alternative configurations which differ in some characteristics such as the sequence of speed limits, the median opening width and the lane width. The influence of variable message signs, of channelizing devices and of perceptual treatments based on Human Factor principles were also tested. Forty-two participants drove in driving simulator scenarios while data on their speeds and decelerations were collected. The results indicated that drivers' speeds are always higher than the temporary posted speed limits for all configurations and that speeds decreases significantly only within the by-passes. However the implementation of higher speed limits, together with a wider median opening and taller channelization devices led to a greater homogeneity of the speeds adopted by the drivers. The presence of perceptual measures generally induced both the greatest homogenization of speeds and the largest reductions in mean speed values. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Building a Virtual Branch at Vancouver Public Library Using Web 2.0 Tools

    ERIC Educational Resources Information Center

    Cahill, Kay

    2009-01-01

    Purpose: The purpose of this paper is to demonstrate the work undertaken by Vancouver Public Library (VPL) in an effort to convert its website into a true virtual branch, both through the functionality of the website itself and by extending its web presence on to external social networking sites. Design/methodology/approach: VPL worked with its…

  3. 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…

  4. Bat noseleaf model: echolocation function, design considerations, and experimental verification.

    PubMed

    Kuc, Roman

    2011-05-01

    This paper describes a possible bat noseleaf echolocation function that improves target elevation resolution. Bats with a protruding noseleaf can rotate the lancet to act as an acoustic mirror that reflects the nostril emission, modeled as a virtual nostril that produces a delayed emission. The cancellation of the nostril and virtual nostril components at a target produces a sharp spectral notch whose frequency location relates to target elevation. This notch can be observed directly from the swept-frequency emission waveform, suggesting cochlear processing capabilities. Physical acoustic principles indicate the design considerations and trade-offs that a bat can accomplish through noseleaf shape and emission characteristics. An experimental model verifies the analysis and exhibits an elevation versus notch frequency sensitivity of approximately 1°/kHz.

  5. 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)

  6. Exploring Infiniband Hardware Virtualization in OpenNebula towards Efficient High-Performance Computing

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

    Pais Pitta de Lacerda Ruivo, Tiago; Bernabeu Altayo, Gerard; Garzoglio, Gabriele

    2014-11-11

    has been widely accepted that software virtualization has a big negative impact on high-performance computing (HPC) application performance. This work explores the potential use of Infiniband hardware virtualization in an OpenNebula cloud towards the efficient support of MPI-based workloads. We have implemented, deployed, and tested an Infiniband network on the FermiCloud private Infrastructure-as-a-Service (IaaS) cloud. To avoid software virtualization towards minimizing the virtualization overhead, we employed a technique called Single Root Input/Output Virtualization (SRIOV). Our solution spanned modifications to the Linux’s Hypervisor as well as the OpenNebula manager. We evaluated the performance of the hardware virtualization on up to 56more » virtual machines connected by up to 8 DDR Infiniband network links, with micro-benchmarks (latency and bandwidth) as well as w a MPI-intensive application (the HPL Linpack benchmark).« less

  7. Virtual environments simulation in research reactor

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  8. Virtual Reality Enhanced Instructional Learning

    ERIC Educational Resources Information Center

    Nachimuthu, K.; Vijayakumari, G.

    2009-01-01

    Virtual Reality (VR) is a creation of virtual 3D world in which one can feel and sense the world as if it is real. It is allowing engineers to design machines and Educationists to design AV [audiovisual] equipment in real time but in 3-dimensional hologram as if the actual material is being made and worked upon. VR allows a least-cost (energy…

  9. Trust, Isolation, and Presence: The Virtual Work Environment and Acceptance of Deep Organizational Change

    ERIC Educational Resources Information Center

    Rose, Laurence Michael

    2013-01-01

    The primary focus of this research was to explore through the use of a grounded theory methodology if the human perceptions of trust, isolation, and presence affected the virtual workers ability to accept deep organizational change. The study found that the virtual workers in the sample defined their acceptance of deep organizational change by…

  10. Using Virtual Field Trips to Connect Students with University Scientists: Core Elements and Evaluation of zipTrips[TM

    ERIC Educational Resources Information Center

    Adedokun, Omolola A.; Hetzel, Kristin; Parker, Loran Carleton; Loizzo, Jamie; Burgess, Wilella D.; Robinson, J. Paul

    2012-01-01

    Physical field trips to scientists' work places have been shown to enhance student perceptions of science, scientists and science careers. Although virtual field trips (VFTs) have emerged as viable alternatives (or supplements) to traditional physical fieldtrips, little is known about the potential of virtual field trips to provide the same or…

  11. Towards the Development of a New Model for Best Practice and Knowledge Construction in Virtual Campuses

    ERIC Educational Resources Information Center

    Cartelli, Antonio; Stansfield, Mark; Connolly, Thomas; Jimoyiannis, Athanassios; Magalhaes, Hugo; Maillet, Katherine

    2008-01-01

    This paper reports on the work of a European Commission DG Education and Culture co-financed project PBP-VC, Promoting Best Practice in Virtual Campuses, which is aimed at providing a deeper understanding of the key issues and critical success factors underlying the implementation of virtual campuses. The paper outlines a tentative model of issues…

  12. Use of Second Life in Social Work Education: Virtual World Experiences and Their Effect on Students

    ERIC Educational Resources Information Center

    Reinsmith-Jones, Kelley; Kibbe, Sharon; Crayton, Traci; Campbell, Elana

    2015-01-01

    During the past 10 years, there has been a growing use of distance education, including the practice of holding classes in virtual world educational formats such as Second Life. Both the psychiatric and medical fields have caught on quickly to the functionality of virtual world teaching, yet social service educators have not ventured likewise.…

  13. Enhancing Intercultural Competence of Engineering Students via GVT (Global Virtual Teams)-Based Virtual Exchanges: An International Collaborative Course in Intralogistics Education

    ERIC Educational Resources Information Center

    Wang, Rui; Rechl, Friederike; Bigontina, Sonja; Fang, Dianjun; Günthner, Willibald A.; Fottner, Johannes

    2017-01-01

    In order to enhance the intercultural competence of engineering students, an international collaborative course in intralogistics education was initiated and realized between the Technical University of Munich in Germany and the Tongji University in China. In this course, students worked in global virtual teams (GVTs) and solved a concrete case…

  14. White Paper for Virtual Control Room

    NASA Technical Reports Server (NTRS)

    Little, William; Tully-Hanson, Benjamin

    2015-01-01

    The Virtual Control Room (VCR) Proof of Concept (PoC) project is the result of an award given by the Fourth Annual NASA T&I Labs Challenge Project Call. This paper will outline the work done over the award period to build and enhance the capabilities of the Augmented/Virtual Reality (AVR) Lab at NASA's Kennedy Space Center (KSC) to create the VCR.

  15. Australian DefenceScience. Volume 16, Number 2, Winter

    DTIC Science & Technology

    2008-01-01

    Making Virtual Advisers speedily interactive To provide an authentically interactive experience for humans working with Virtual Advisers, the Virtual...peer trusted and strong authentication for checking of security credentials without recourse to third parties or infrastructure, thus eliminating...multiple passwords, or carry around multiple security tokens.” Each CodeStick device is readied for use with a biometric authentication process. Since

  16. Academic Library Services in Virtual Worlds: An Examination of the Potential for Library Services in Immersive Environments

    ERIC Educational Resources Information Center

    Ryan, Jenna; Porter, Marjorie; Miller, Rebecca

    2010-01-01

    Current literature on libraries is abundant with articles about the uses and the potential of new interactive communication technology, including Web 2.0 tools. Recently, the advent and use of virtual worlds have received top billing in these works. Many library institutions are exploring these virtual environments; this exploration and the…

  17. Virtual working systems to support R&D groups

    NASA Astrophysics Data System (ADS)

    Dew, Peter M.; Leigh, Christine; Drew, Richard S.; Morris, David; Curson, Jayne

    1995-03-01

    The paper reports on the progress at Leeds University to build a Virtual Science Park (VSP) to enhance the University's ability to interact with industry, grow its applied research and workplace learning activities. The VSP exploits the advances in real time collaborative computing and networking to provide an environment that meets the objectives of physically based science parks without the need for the organizations to relocate. It provides an integrated set of services (e.g. virtual consultancy, workbased learning) built around a structured person- centered information model. This model supports the integration of tools for: (a) navigating around the information space; (b) browsing information stored within the VSP database; (c) communicating through a variety of Person-to-Person collaborative tools; and (d) the ability to the information stored in the VSP including the relationships to other information that support the underlying model. The paper gives an overview of a generic virtual working system based on X.500 directory services and the World-Wide Web that can be used to support the Virtual Science Park. Finally the paper discusses some of the research issues that need to be addressed to fully realize a Virtual Science Park.

  18. The communication in industrialised building system (IBS) construction project: Virtual environment

    NASA Astrophysics Data System (ADS)

    Pozin, Mohd Affendi Ahmad; Nawi, Mohd Nasrun Mohd

    2017-10-01

    Large portion of numbers team organization in the IBS construction sector is known are being fragmented. That is contributed from a segregation of construction activity thus create team working in virtually. Virtual team are the nature when teams are working in distributed area, across culture and time. Therefore, teams can be respond to the task without relocating to the site project and settle down a problem through information and communication technology (ICT). The emergence of virtual team are carry out by advancements in communication technologies as a medium to improve project team communication in project delivery process on IBS construction. Based on literature review from previous study and data collected from interviewing, this paper aim to identified communication challenges among project team members according to current project development practices in IBS construction project. Hence, in attempt to develop effective communication through the advantages of virtual team approach for IBS construction project. In order to ensure the data is gathered comprehensively and accurately, the data was collected from project managers by using semi structured interview method. It was found that virtual team approach could be enable competitive challenges on complexity in the construction project management process.

  19. E-Learning, Multiple Intelligences Theory (MI) and Learner-Centred Instruction: Adapting MI Learning Theoretical Principles to the Instruction of Health and Safety to Construction Managers

    ERIC Educational Resources Information Center

    McNamee, Paul; Madden, Dave; McNamee, Frank; Wall, John; Hurst, Alan; Vrasidas, Charalambos; Chanquoy, Lucile; Baccino, Thierry; Acar, Emrah; Onwy-Yazici, Ela; Jordan, Ann

    2009-01-01

    This paper describes an ongoing EU project concerned with developing an instructional design framework for virtual classes (VC) that is based on the theory of Multiple Intelligences (MI) (1983). The psychological theory of Multiple Intelligences (Gardner 1983) has received much credence within instructional design since its inception and has been…

  20. Foreign Language Vocabulary Development through Activities in an Online 3D Environment

    ERIC Educational Resources Information Center

    Milton, James; Jonsen, Sunniva; Hirst, Steven; Lindenburn, Sharn

    2012-01-01

    On-line virtual 3D worlds offer the opportunity for users to interact in real time with native speakers of the language they are learning. In principle, this ought to be of great benefit to learners, and mimicking the opportunity for immersion that real-life travel to a foreign country offers. We have very little research to show whether this is…

  1. Quantum Bell inequalities from macroscopic locality

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

    Yang, Tzyh Haur; Sheridan, Lana; Navascues, Miguel

    2011-02-15

    We propose a method to generate analytical quantum Bell inequalities based on the principle of macroscopic locality. By imposing locality over binary processings of virtual macroscopic intensities, we establish a correspondence between Bell inequalities and quantum Bell inequalities in bipartite scenarios with dichotomic observables. We discuss how to improve the latter approximation and how to extend our ideas to scenarios with more than two outcomes per setting.

  2. Developing Online Problem-Based Resources for the Professional Development of Teachers of Children with Visual Impairment

    ERIC Educational Resources Information Center

    McLinden, Mike; McCall, Steve; Hinton, Danielle; Weston, Annette; Douglas, Graeme

    2006-01-01

    This article presents a summary of the results from phase 1 of a two-phase research project. Drawing on the principles of problem-based learning (PBL), the aims of phase 1 were to design, develop and evaluate a set of flexible online teaching resources for use within a virtual learning environment. Participants in the project (n = 10) were…

  3. The Rolling with Slipping Experiment in the Virtual Physics Laboratory--Context-Based Teaching Material

    ERIC Educational Resources Information Center

    Maidana, Nora L.; da Fonseca, Monaliza; Barros, Suelen F.; Vanin, Vito R.

    2016-01-01

    The Virtual Laboratory was created as a complementary educational activity, with the aim of working abstract concepts from an experimental point of view. In this work, the motion of a ring rolling and slipping in front of a grid printed panel was recorded. The frames separated from this video received a time code, and the resulting set of images…

  4. To what extent can PBL principles be applied in blended learning: Lessons learned from health master programs.

    PubMed

    de Jong, N; Krumeich, J S M; Verstegen, D M L

    2017-02-01

    Maastricht University has been actively exploring blended learning approaches to PBL in Health Master Programs. Key principles of PBL are, learning should be constructive, self-directed, collaborative, and contextual. The purpose is to explore whether these principles are applicable in blended learning. The programs, Master of Health Services Innovation (case 1), Master Programme in Global Health (case 2), and the Master of Health Professions Education (case 3), used a Virtual Learning Environment for exchanging material and were independently analyzed. Quantitative data were collected for cases 1 and 2. Simple descriptive analyses such as frequencies were performed. Qualitative data for cases 1 and 3 were collected via (focus group) interviews. All PBL principles could be recognized in case 1. Case 2 seemed to be more project-based. In case 3, collaboration between students was not possible because of a difference in time-zones. Important educational aspects: agreement on rules for (online) sessions; visual contact (student-student and student-teacher), and frequent feedback. PBL in a blended learning format is perceived to be an effective strategy. The four principles of PBL can be unified in PBL with a blended learning format, although the extent to which each principle can be implemented can differ.

  5. Virtual reality in surgical skills training.

    PubMed

    Palter, Vanessa N; Grantcharov, Teodor P

    2010-06-01

    With recent concerns regarding patient safety, and legislation regarding resident work hours, it is accepted that a certain amount of surgical skills training will transition to the surgical skills laboratory. Virtual reality offers enormous potential to enhance technical and non-technical skills training outside the operating room. Virtual-reality systems range from basic low-fidelity devices to highly complex virtual environments. These systems can act as training and assessment tools, with the learned skills effectively transferring to an analogous clinical situation. Recent developments include expanding the role of virtual reality to allow for holistic, multidisciplinary team training in simulated operating rooms, and focusing on the role of virtual reality in evidence-based surgical curriculum design. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Kinematic/Dynamic Characteristics for Visual and Kinesthetic Virtual Environments

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  7. Integration of the SSPM and STAGE with the MPACT Virtual Facility Distributed Test Bed.

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

    Cipiti, Benjamin B.; Shoman, Nathan

    The Material Protection Accounting and Control Technologies (MPACT) program within DOE NE is working toward a 2020 milestone to demonstrate a Virtual Facility Distributed Test Bed. The goal of the Virtual Test Bed is to link all MPACT modeling tools, technology development, and experimental work to create a Safeguards and Security by Design capability for fuel cycle facilities. The Separation and Safeguards Performance Model (SSPM) forms the core safeguards analysis tool, and the Scenario Toolkit and Generation Environment (STAGE) code forms the core physical security tool. These models are used to design and analyze safeguards and security systems and generatemore » performance metrics. Work over the past year has focused on how these models will integrate with the other capabilities in the MPACT program and specific model changes to enable more streamlined integration in the future. This report describes the model changes and plans for how the models will be used more collaboratively. The Virtual Facility is not designed to integrate all capabilities into one master code, but rather to maintain stand-alone capabilities that communicate results between codes more effectively.« less

  8. Total Face, Eyelids, Ears, Scalp, and Skeletal Subunit Transplant Cadaver Simulation: The Culmination of Aesthetic, Craniofacial, and Microsurgery Principles.

    PubMed

    Sosin, Michael; Ceradini, Daniel J; Hazen, Alexes; Levine, Jamie P; Staffenberg, David A; Saadeh, Pierre B; Flores, Roberto L; Brecht, Lawrence E; Bernstein, G Leslie; Rodriguez, Eduardo D

    2016-05-01

    The application of aesthetic, craniofacial, and microsurgical principles in the execution of face transplantation may improve outcomes. Optimal soft-tissue face transplantation can be achieved by incorporating subunit facial skeletal replacement and subsequent tissue resuspension. The purpose of this study was to establish a reconstructive solution for a full face and scalp burn and to evaluate outcome precision and consistency. Seven mock face transplants (14 cadavers) were completed in the span of 1 year. Components of the vascularized composite allograft included the eyelids, nose, lips, facial muscles, oral mucosa, total scalp, and ears; and skeletal subunits of the zygoma, nasal bone, and genial segment. Virtual surgical planning was used for osteotomy selection, and to evaluate postoperative precision of hard- and soft-tissue elements. Each transplant experience decreased each subsequent transplant surgical time. Prefabricated cutting guides facilitated a faster dissection of both donor and recipient tissue, requiring minimal alteration to the allograft for proper fixation of bony segments during inset. Regardless of donor-to-recipient size discrepancy, ample soft tissue was available to achieve tension-free allograft inset. Differences between virtual transplant simulation and posttransplant measurements were minimal or insignificant, supporting replicable and precise outcomes. This facial transplant model was designed to optimize reconstruction of extensive soft-tissue defects of the craniofacial region representative of electrical, thermal, and chemical burns, by incorporating skeletal subunits within the allograft. The implementation of aesthetic, craniofacial, and microsurgical principles and computer-assisted technology improves surgical precision, decreases operative time, and may optimize function.

  9. The angular electronic band structure and free particle model of aromatic molecules: High-frequency photon-induced ring current

    NASA Astrophysics Data System (ADS)

    Öncan, Mehmet; Koç, Fatih; Şahin, Mehmet; Köksal, Koray

    2017-05-01

    This work introduces an analysis of the relationship of first-principles calculations based on DFT method with the results of free particle model for ring-shaped aromatic molecules. However, the main aim of the study is to reveal the angular electronic band structure of the ring-shaped molecules. As in the case of spherical molecules such as fullerene, it is possible to observe a parabolic dispersion of electronic states with the variation of angular quantum number in the planar ring-shaped molecules. This work also discusses the transition probabilities between the occupied and virtual states by analyzing the angular electronic band structure and the possibility of ring currents in the case of spin angular momentum (SAM) or orbital angular momentum (OAM) carrying light. Current study focuses on the benzene molecule to obtain its angular electronic band structure. The obtained electronic band structure can be considered as a useful tool to see the transition probabilities between the electronic states and possible contribution of the states to the ring currents. The photoinduced current due to the transfer of SAM into the benzene molecule has been investigated by using analytical calculations within the frame of time-dependent perturbation theory.

  10. Cyberinfrastructure and Scientific Collaboration: Application of a Virtual Team Performance Framework with Potential Relevance to Education. WCER Working Paper No. 2010-12

    ERIC Educational Resources Information Center

    Kraemer, Sara; Thorn, Christopher A.

    2010-01-01

    The purpose of this exploratory study was to identify and describe some of the dimensions of scientific collaborations using high throughput computing (HTC) through the lens of a virtual team performance framework. A secondary purpose was to assess the viability of using a virtual team performance framework to study scientific collaborations using…

  11. Realistic terrain visualization based on 3D virtual world technology

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

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

  12. Realistic terrain visualization based on 3D virtual world technology

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

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

  13. Virtual reality in Latin American clinical psychology and the VREPAR project. Virtual Reality Environments for Psycho-Neuro-physiological Assessment and Rehabilitation.

    PubMed

    Silva, Mauro Rubens

    2002-10-01

    Starting with the excellent collective work done by the European Community (EC)-funded Virtual Reality Environments for Psycho-Neuro-physiological Assessment and Rehabilitation (VREPAR) projects, I try to indicate some possible pathways that would allow a better integration of this advanced technology into the reality of Latin American psychology. I myself use analyses that I did in my master's degree in the PUCSP-Catholic University in São Paulo, Brazil. I also include a brief description of the CD-ROM Clinical Psychology Uses of Virtual Reality (CPUVR) that accompanies my thesis. I point out the importance of collaboration between psychology and other disciplines, including computer science. I explain the method that I used to work with digital information, important for the formation of a critical mass of people thinking in Portuguese and Spanish to accelerate a technological jump.

  14. Introduction

    NASA Astrophysics Data System (ADS)

    Bainbridge, William Sims

    This brief introductory chapter sets the stage for a broad discussion of many aspects of virtual worlds, by comparing episodes experienced by two avatar researchers, one in Second Life (SL), and the other in Star Wars Galaxies (SWG). Interviewer Wilber attends a medieval dance on an SL island created by Starfleet, an innovative and hard-working group of 500 Star Trek fans, who have created working virtual technology and soaring architecture to make real their fantasies about the human future. Algorithma Teq visits the Mos Eisley Cantina in SWG, where Luke Skywalker originally met Han Solo, and is scrutinized by two Imperial storm troopers, even as she attempts to remain aloof from the Star Wars mythos and simply practice her engineering skills in making droids. It can be useful to distinguish gamelike virtual worlds from non-game worlds, yet as these examples show, they are not distinct categories, and virtual worlds inevitably mix fantasy and reality in complex ways.

  15. The HEPiX Virtualisation Working Group: Towards a Grid of Clouds

    NASA Astrophysics Data System (ADS)

    Cass, Tony

    2012-12-01

    The use of virtual machine images, as for example with Cloud services such as Amazon's Elastic Compute Cloud, is attractive for users as they have a guaranteed execution environment, something that cannot today be provided across sites participating in computing grids such as the Worldwide LHC Computing Grid. However, Grid sites often operate within computer security frameworks which preclude the use of remotely generated images. The HEPiX Virtualisation Working Group was setup with the objective to enable use of remotely generated virtual machine images at Grid sites and, to this end, has introduced the idea of trusted virtual machine images which are guaranteed to be secure and configurable by sites such that security policy commitments can be met. This paper describes the requirements and details of these trusted virtual machine images and presents a model for their use to facilitate the integration of Grid- and Cloud-based computing environments for High Energy Physics.

  16. An improved plate theory of order (1,2) for thick composite laminates

    NASA Technical Reports Server (NTRS)

    Tessler, A.

    1992-01-01

    A new (1,2)-order theory is proposed for the linear elasto-static analysis of laminated composite plates. The basic assumptions are those concerning the distribution through the laminate thickness of the displacements, transverse shear strains and the transverse normal stress, with these quantities regarded as some weighted averages of their exact elasticity theory representations. The displacement expansions are linear for the inplane components and quadratic for the transverse component, whereas the transverse shear strains and transverse normal stress are respectively quadratic and cubic through the thickness. The main distinguishing feature of the theory is that all strain and stress components are expressed in terms of the assumed displacements prior to the application of a variational principle. This is accomplished by an a priori least-square compatibility requirement for the transverse strains and by requiring exact stress boundary conditions at the top and bottom plate surfaces. Equations of equilibrium and associated Poisson boundary conditions are derived from the virtual work principle. It is shown that the theory is particularly suited for finite element discretization as it requires simple C(sup 0)- and C(sup -1)-continuous displacement interpolation fields. Analytic solutions for the problem of cylindrical bending are derived and compared with the exact elasticity solutions and those of our earlier (1,2)-order theory based on the assumed displacements and transverse strains.

  17. Interactive computerized learning program exposes veterinary students to challenging international animal-health problems.

    PubMed

    Conrad, Patricia A; Hird, Dave; Arzt, Jonathan; Hayes, Rick H; Magliano, Dave; Kasper, Janine; Morfin, Saul; Pinney, Stephen

    2007-01-01

    This article describes a computerized case-based CD-ROM (CD) on international animal health that was developed to give veterinary students an opportunity to "virtually" work alongside veterinarians and other veterinary students as they try to solve challenging disease problems relating to tuberculosis in South African wildlife, bovine abortion in Mexico, and neurologic disease in horses in Rapa Nui, Chile. Each of the three case modules presents, in a highly interactive format, a problem or mystery that must be solved by the learner. As well as acquiring information via video clips and text about the specific health problem, learners obtain information about the different countries, animal-management practices, diagnostic methods, related disease-control issues, economic factors, and the opinions of local experts. After assimilating this information, the learner must define the problem and formulate an action plan or make a recommendation or diagnosis. The computerized program invokes three principles of adult education: active learning, learner-centered education, and experiential learning. A medium that invokes these principles is a potentially efficient learning tool and template for developing other case-based problem-solving computerized programs. The program is accessible on the World Wide Web at . A broadband Internet connection is recommended, since the modules make extensive use of embedded video and audio clips. Information on how to obtain the CD is also provided.

  18. Nature and origins of virtual environments - A bibliographical essay

    NASA Technical Reports Server (NTRS)

    Ellis, S. R.

    1991-01-01

    Virtual environments presented via head-mounted, computer-driven displays provide a new media for communication. They may be analyzed by considering: (1) what may be meant by an environment; (2) what is meant by the process of virtualization; and (3) some aspects of human performance that constrain environmental design. Their origins are traced from previous work in vehicle simulation and multimedia research. Pointers are provided to key technical references, in the dispersed, archival literature, that are relevant to the development and evaluation of virtual-environment interface systems.

  19. Cognitive Aspects of Collaboration in 3d Virtual Environments

    NASA Astrophysics Data System (ADS)

    Juřík, V.; Herman, L.; Kubíček, P.; Stachoň, Z.; Šašinka, Č.

    2016-06-01

    Human-computer interaction has entered the 3D era. The most important models representing spatial information — maps — are transferred into 3D versions regarding the specific content to be displayed. Virtual worlds (VW) become promising area of interest because of possibility to dynamically modify content and multi-user cooperation when solving tasks regardless to physical presence. They can be used for sharing and elaborating information via virtual images or avatars. Attractiveness of VWs is emphasized also by possibility to measure operators' actions and complex strategies. Collaboration in 3D environments is the crucial issue in many areas where the visualizations are important for the group cooperation. Within the specific 3D user interface the operators' ability to manipulate the displayed content is explored regarding such phenomena as situation awareness, cognitive workload and human error. For such purpose, the VWs offer a great number of tools for measuring the operators' responses as recording virtual movement or spots of interest in the visual field. Study focuses on the methodological issues of measuring the usability of 3D VWs and comparing them with the existing principles of 2D maps. We explore operators' strategies to reach and interpret information regarding the specific type of visualization and different level of immersion.

  20. Virtualization of Event Sources in Wireless Sensor Networks for the Internet of Things

    PubMed Central

    Martínez, Néstor Lucas; Martínez, José-Fernán; Díaz, Vicente Hernández

    2014-01-01

    Wireless Sensor Networks (WSNs) are generally used to collect information from the environment. The gathered data are delivered mainly to sinks or gateways that become the endpoints where applications can retrieve and process such data. However, applications would also expect from a WSN an event-driven operational model, so that they can be notified whenever occur some specific environmental changes instead of continuously analyzing the data provided periodically. In either operational model, WSNs represent a collection of interconnected objects, as outlined by the Internet of Things. Additionally, in order to fulfill the Internet of Things principles, Wireless Sensor Networks must have a virtual representation that allows indirect access to their resources, a model that should also include the virtualization of event sources in a WSN. Thus, in this paper a model for a virtual representation of event sources in a WSN is proposed. They are modeled as internet resources that are accessible by any internet application, following an Internet of Things approach. The model has been tested in a real implementation where a WSN has been deployed in an open neighborhood environment. Different event sources have been identified in the proposed scenario, and they have been represented following the proposed model. PMID:25470489

  1. The virtual digital nuclear power plant: A modern tool for supporting the lifecycle of VVER-based nuclear power units

    NASA Astrophysics Data System (ADS)

    Arkadov, G. V.; Zhukavin, A. P.; Kroshilin, A. E.; Parshikov, I. A.; Solov'ev, S. L.; Shishov, A. V.

    2014-10-01

    The article describes the "Virtual Digital VVER-Based Nuclear Power Plant" computerized system comprising a totality of verified initial data (sets of input data for a model intended for describing the behavior of nuclear power plant (NPP) systems in design and emergency modes of their operation) and a unified system of new-generation computation codes intended for carrying out coordinated computation of the variety of physical processes in the reactor core and NPP equipment. Experiments with the demonstration version of the "Virtual Digital VVER-Based NPP" computerized system has shown that it is in principle possible to set up a unified system of computation codes in a common software environment for carrying out interconnected calculations of various physical phenomena at NPPs constructed according to the standard AES-2006 project. With the full-scale version of the "Virtual Digital VVER-Based NPP" computerized system put in operation, the concerned engineering, design, construction, and operating organizations will have access to all necessary information relating to the NPP power unit project throughout its entire lifecycle. The domestically developed commercial-grade software product set to operate as an independently operating application to the project will bring about additional competitive advantages in the modern market of nuclear power technologies.

  2. Modeling Behavior and Variation for Crowd Animation

    DTIC Science & Technology

    2009-08-01

    Understanding Motion Capture for Computer Animation and Video Games . Morgan Kaufmann Publishers Inc., 1999. ISBN 0124906303. 2.2 [69] Mark Mizuguchi, John...simulation of crowds of virtual characters is needed for applications such as films, games , and virtual reality environments. These simulations are...Discussion and Future Work 95 Bibliography 99 viii List of Figures 1.1 Films and games are applications that motivate our work. Left: A scene from

  3. Improved image guidance technique for minimally invasive mitral valve repair using real-time tracked 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Rankin, Adam; Moore, John; Bainbridge, Daniel; Peters, Terry

    2016-03-01

    In the past ten years, numerous new surgical and interventional techniques have been developed for treating heart valve disease without the need for cardiopulmonary bypass. Heart valve repair is now being performed in a blood-filled environment, reinforcing the need for accurate and intuitive imaging techniques. Previous work has demonstrated how augmenting ultrasound with virtual representations of specific anatomical landmarks can greatly simplify interventional navigation challenges and increase patient safety. These techniques often complicate interventions by requiring additional steps taken to manually define and initialize virtual models. Furthermore, overlaying virtual elements into real-time image data can also obstruct the view of salient image information. To address these limitations, a system was developed that uses real-time volumetric ultrasound alongside magnetically tracked tools presented in an augmented virtuality environment to provide a streamlined navigation guidance platform. In phantom studies simulating a beating-heart navigation task, procedure duration and tool path metrics have achieved comparable performance to previous work in augmented virtuality techniques, and considerable improvement over standard of care ultrasound guidance.

  4. Virtual Jupiter - Real Learning

    NASA Astrophysics Data System (ADS)

    Ruzhitskaya, Lanika; Speck, A.; Laffey, J.

    2010-01-01

    How many earthlings went to visit Jupiter? None. How many students visited virtual Jupiter to fulfill their introductory astronomy courses’ requirements? Within next six months over 100 students from University of Missouri will get a chance to explore the planet and its Galilean Moons using a 3D virtual environment created especially for them to learn Kepler's and Newton's laws, eclipses, parallax, and other concepts in astronomy. The virtual world of Jupiter system is a unique 3D environment that allows students to learn course material - physical laws and concepts in astronomy - while engaging them into exploration of the Jupiter's system, encouraging their imagination, curiosity, and motivation. The virtual learning environment let students to work individually or collaborate with their teammates. The 3D world is also a great opportunity for research in astronomy education to investigate impact of social interaction, gaming features, and use of manipulatives offered by a learning tool on students’ motivation and learning outcomes. Use of 3D environment is also a valuable source for exploration of how the learners’ spatial awareness can be enhanced by working in 3-dimensional environment.

  5. Freeform étendue-preserving optics for light and color mixing

    NASA Astrophysics Data System (ADS)

    Sorgato, Simone; Mohedano, Rubén.; Chaves, Julio; Cvetkovic, Aleksandra; Hernández, Maikel; Benítez, Pablo; Miñano, Juan C.; Thienpont, Hugo; Duerr, Fabian

    2015-09-01

    Today's SSL illumination market shows a clear trend towards high flux packages with higher efficiency and higher CRI, realized by means of multiple color chips and phosphors. Such light sources require the optics to provide both near- and far-field color mixing. This design problem is particularly challenging for collimated luminaries, since traditional diffusers cannot be employed without enlarging the exit aperture and reducing brightness (so increasing étendue). Furthermore, diffusers compromise the light output ratio (efficiency) of the lamps to which they are applied. A solution, based on Köhler integration, consisting of a spherical cap comprising spherical microlenses on both its interior and exterior sides was presented in 2012. When placed on top of an inhomogeneous multichip Lambertian LED, this so-called Shell-Mixer creates a homogeneous (both spatially and angularly) virtual source, also Lambertian, where the images of the chips merge. The virtual source is located at the same position with essentially the same size of the original source. The diameter of this optics was 3 times that of the chip-array footprint. In this work, we present a new version of the Shell-Mixer, based on the Edge Ray Principle, where neither the overall shape of the cap nor the surfaces of the lenses are constrained to spheres or rotational Cartesian ovals. This new Shell- Mixer is freeform, only twice as large as the original chip-array and equals the original model in terms of brightness, color uniformity and efficiency.

  6. The use of virtual environments for percentage view analysis.

    PubMed

    Schofield, Damian; Cox, Christopher J B

    2005-09-01

    It is recognised that Visual Impact Assessment (VIA), unlike many other aspects of Environmental Impact Assessments (EIA), relies less upon measurement than upon experience and judgement. Hence, it is necessary for a more structured and consistent approach towards VIA, reducing the amount of bias and subjectivity. For proposed developments, there are very few quantitative techniques for the evaluation of visibility, and these existing methods can be highly inaccurate and time consuming. Percentage view changes are one of the few quantitative techniques, and the use of computer technology can reduce the inaccuracy and the time spent evaluating the visibility of either existing or proposed developments. For over 10 years, research work undertaken by the authors at the University of Nottingham has employed Computer Graphics (CG) and Virtual Reality (VR) in civilian and industrial contexts for environmental planning, design visualisation, accident reconstruction, risk analysis, data visualisation and training simulators. This paper describes a method to quantitatively assess the visual impact of proposed developments on the landscape using CG techniques. This method allows the determination of accurate percentage view changes with the use of a computer-generated model of the environment and the application of specialist software that has been developed at the University of Nottingham. The principles are easy to understand and therefore planners, authorisation agencies and members of the public can use and understand the results. A case study is shown to demonstrate the application and the capabilities of the technology.

  7. Creating virtual humans for simulation-based training and planning

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

    Stansfield, S.; Sobel, A.

    1998-05-12

    Sandia National Laboratories has developed a distributed, high fidelity simulation system for training and planning small team Operations. The system provides an immersive environment populated by virtual objects and humans capable of displaying complex behaviors. The work has focused on developing the behaviors required to carry out complex tasks and decision making under stress. Central to this work are techniques for creating behaviors for virtual humans and for dynamically assigning behaviors to CGF to allow scenarios without fixed outcomes. Two prototype systems have been developed that illustrate these capabilities: MediSim, a trainer for battlefield medics and VRaptor, a system formore » planning, rehearsing and training assault operations.« less

  8. Handling knowledge via Concept Maps: a space weather use case

    NASA Astrophysics Data System (ADS)

    Messerotti, Mauro; Fox, Peter

    Concept Maps (Cmaps) are powerful means for knowledge coding in graphical form. As flexible software tools exist to manipulate the knowledge embedded in Cmaps in machine-readable form, such complex entities are suitable candidates not only for the representation of ontologies and semantics in Virtual Observatory (VO) architectures, but also for knowledge handling and knowledge discovery. In this work, we present a use case relevant to space weather applications and we elaborate on its possible implementation and adavanced use in Semantic Virtual Observatories dedicated to Sun-Earth Connections. This analysis was carried out in the framework of the Electronic Geophysical Year (eGY) and represents an achievement synergized by the eGY Virtual Observatories Working Group.

  9. Design, analysis and testing of a new piezoelectric tool actuator for elliptical vibration turning

    NASA Astrophysics Data System (ADS)

    Lin, Jieqiong; Han, Jinguo; Lu, Mingming; Yu, Baojun; Gu, Yan

    2017-08-01

    A new piezoelectric tool actuator (PETA) for elliptical vibration turning has been developed based on a hybrid flexure hinge connection. Two double parallel four-bar linkage mechanisms and two right circular flexure hinges were chosen to guide the motion. The two input displacement directional stiffness were modeled according to the principle of virtual work modeling method and the kinematic analysis was conducted theoretically. Finite element analysis was used to carry out static and dynamic analyses. To evaluate the performance of the developed PETA, off-line experimental tests were carried out to investigate the step responses, motion strokes, resolutions, parasitic motions, and natural frequencies of the PETA along the two input directions. The relationship between input displacement and output displacement, as well as the tool tip’s elliptical trajectory in different phase shifts was analyzed. By using the developed PETA mechanism, micro-dimple patterns were generated as the preliminary application to demonstrate the feasibility and efficiency of PETA for elliptical vibration turning.

  10. Energy based simulation of a Timoshenko beam in non-forced rotation. Influence of the piano hammer shank flexibility on the sound

    NASA Astrophysics Data System (ADS)

    Chabassier, Juliette; Duruflé, Marc

    2014-12-01

    A nonlinear model for a vibrating Timoshenko beam in non-forced unknown rotation is derived from the virtual work principle applied to a system of beam with mass at the end. The system represents a piano hammer shank coupled to a hammer head. An energy-based numerical scheme is then provided, obtained by non-classical approaches. A major difficulty for time discretization comes from the nonlinear behavior of the kinetic energy of the system. This new numerical scheme is then coupled to a global energy-preserving numerical solution for the whole piano. The obtained numerical simulations show that the pianistic touch clearly influences the spectrum of the piano sound of equally loud isolated notes. These differences do not come from a possible shock excitation on the structure, or from a changing impact point, or a “longitudinal rubbing motion” on the string, since neither of these features is modeled in our study.

  11. Third-order polynomial model for analyzing stickup state laminated structure in flexible electronics

    NASA Astrophysics Data System (ADS)

    Meng, Xianhong; Wang, Zihao; Liu, Boya; Wang, Shuodao

    2018-02-01

    Laminated hard-soft integrated structures play a significant role in the fabrication and development of flexible electronics devices. Flexible electronics have advantageous characteristics such as soft and light-weight, can be folded, twisted, flipped inside-out, or be pasted onto other surfaces of arbitrary shapes. In this paper, an analytical model is presented to study the mechanics of laminated hard-soft structures in flexible electronics under a stickup state. Third-order polynomials are used to describe the displacement field, and the principle of virtual work is adopted to derive the governing equations and boundary conditions. The normal strain and the shear stress along the thickness direction in the bi-material region are obtained analytically, which agree well with the results from finite element analysis. The analytical model can be used to analyze stickup state laminated structures, and can serve as a valuable reference for the failure prediction and optimal design of flexible electronics in the future.

  12. Aero-Thermo-Dynamic Mass Analysis

    NASA Astrophysics Data System (ADS)

    Shiba, Kota; Yoshikawa, Genki

    2016-07-01

    Each gas molecule has its own molecular weight, while such a microscopic characteristic is generally inaccessible, and thus, it is measured indirectly through e.g. ionization in conventional mass analysis. Here, we present a novel approach to the direct measurement of molecular weight through a nanoarchitectonic combination of aerodynamics, thermodynamics, and mechanics, transducing microscopic events into macroscopic phenomena. It is confirmed that this approach can provide molecular weight of virtually any gas or vaporizable liquid sample in real-time without ionization. Demonstrations through analytical calculations, numerical simulations, and experiments verify the validity and versatility of the novel mass analysis realized by a simple setup with a flexible object (e.g. with a bare cantilever and even with a business card) placed in a laminar jet. Owing to its unique and simple working principle, this aero-thermo-dynamic mass analysis (AMA) can be integrated into various analytical devices, production lines, and consumer mobile platforms, opening new chapters in aerodynamics, thermodynamics, mechanics, and mass analysis.

  13. A model for wave propagation in a porous solid saturated by a three-phase fluid.

    PubMed

    Santos, Juan E; Savioli, Gabriela B

    2016-02-01

    This paper presents a model to describe the propagation of waves in a poroelastic medium saturated by a three-phase viscous, compressible fluid. Two capillary relations between the three fluid phases are included in the model by introducing Lagrange multipliers in the principle of virtual complementary work. This approach generalizes that of Biot for single-phase fluids and allows to determine the strain energy density, identify the generalized strains and stresses, and derive the constitutive relations of the system. The kinetic and dissipative energy density functions are obtained assuming that the relative flow within the pore space is of laminar type and obeys Darcy's law for three-phase flow in porous media. After deriving the equations of motion, a plane wave analysis predicts the existence of four compressional waves, denoted as type I, II, III, and IV waves, and one shear wave. Numerical examples showing the behavior of all waves as function of saturation and frequency are presented.

  14. A general purpose feature extractor for light detection and ranging data.

    PubMed

    Li, Yangming; Olson, Edwin B

    2010-01-01

    Feature extraction is a central step of processing Light Detection and Ranging (LIDAR) data. Existing detectors tend to exploit characteristics of specific environments: corners and lines from indoor (rectilinear) environments, and trees from outdoor environments. While these detectors work well in their intended environments, their performance in different environments can be poor. We describe a general purpose feature detector for both 2D and 3D LIDAR data that is applicable to virtually any environment. Our method adapts classic feature detection methods from the image processing literature, specifically the multi-scale Kanade-Tomasi corner detector. The resulting method is capable of identifying highly stable and repeatable features at a variety of spatial scales without knowledge of environment, and produces principled uncertainty estimates and corner descriptors at same time. We present results on both software simulation and standard datasets, including the 2D Victoria Park and Intel Research Center datasets, and the 3D MIT DARPA Urban Challenge dataset.

  15. A General Purpose Feature Extractor for Light Detection and Ranging Data

    PubMed Central

    Li, Yangming; Olson, Edwin B.

    2010-01-01

    Feature extraction is a central step of processing Light Detection and Ranging (LIDAR) data. Existing detectors tend to exploit characteristics of specific environments: corners and lines from indoor (rectilinear) environments, and trees from outdoor environments. While these detectors work well in their intended environments, their performance in different environments can be poor. We describe a general purpose feature detector for both 2D and 3D LIDAR data that is applicable to virtually any environment. Our method adapts classic feature detection methods from the image processing literature, specifically the multi-scale Kanade-Tomasi corner detector. The resulting method is capable of identifying highly stable and repeatable features at a variety of spatial scales without knowledge of environment, and produces principled uncertainty estimates and corner descriptors at same time. We present results on both software simulation and standard datasets, including the 2D Victoria Park and Intel Research Center datasets, and the 3D MIT DARPA Urban Challenge dataset. PMID:22163474

  16. Imaging with a small number of photons

    PubMed Central

    Morris, Peter A.; Aspden, Reuben S.; Bell, Jessica E. C.; Boyd, Robert W.; Padgett, Miles J.

    2015-01-01

    Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. A high-quality digital camera based on a multi-megapixel array will typically record an image by collecting of order 105 photons per pixel, but by how much could this photon flux be reduced? In this work we demonstrate a single-photon imaging system based on a time-gated intensified camera from which the image of an object can be inferred from very few detected photons. We show that a ghost-imaging configuration, where the image is obtained from photons that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single photons ensures that the background counts can be virtually eliminated from the recorded images. By applying principles of image compression and associated image reconstruction, we obtain high-quality images of objects from raw data formed from an average of fewer than one detected photon per image pixel. PMID:25557090

  17. Coincidence avoidance principle in surface haptic interpretation

    PubMed Central

    Manuel, Steven G.; Klatzky, Roberta L.; Peshkin, Michael A.; Colgate, James Edward

    2015-01-01

    When multiple fingertips experience force sensations, how does the brain interpret the combined sensation? In particular, under what conditions are the sensations perceived as separate or, alternatively, as an integrated whole? In this work, we used a custom force-feedback device to display force signals to two fingertips (index finger and thumb) as they traveled along collinear paths. Each finger experienced a pattern of forces that, taken individually, produced illusory virtual bumps, and subjects reported whether they felt zero, one, or two bumps. We varied the spatial separation between these bump-like force-feedback regions, from being much greater than the finger span to nearly exactly the finger span. When the bump spacing was the same as the finger span, subjects tended to report only one bump. We found that the results are consistent with a quantitative model of perception in which the brain selects a structural interpretation of force signals that relies on minimizing coincidence stemming from accidental alignments between fingertips and inferred surface structures. PMID:25675477

  18. Refined Zigzag Theory for Laminated Composite and Sandwich Plates

    NASA Technical Reports Server (NTRS)

    Tessler, Alexander; DiSciuva, Marco; Gherlone, Marco

    2009-01-01

    A refined zigzag theory is presented for laminated-composite and sandwich plates that includes the kinematics of first-order shear deformation theory as its baseline. The theory is variationally consistent and is derived from the virtual work principle. Novel piecewise-linear zigzag functions that provide a more realistic representation of the deformation states of transverse-shear-flexible plates than other similar theories are used. The formulation does not enforce full continuity of the transverse shear stresses across the plate s thickness, yet is robust. Transverse-shear correction factors are not required to yield accurate results. The theory is devoid of the shortcomings inherent in the previous zigzag theories including shear-force inconsistency and difficulties in simulating clamped boundary conditions, which have greatly limited the accuracy of these theories. This new theory requires only C(sup 0)-continuous kinematic approximations and is perfectly suited for developing computationally efficient finite elements. The theory should be useful for obtaining relatively efficient, accurate estimates of structural response needed to design high-performance load-bearing aerospace structures.

  19. Refined Zigzag Theory for Homogeneous, Laminated Composite, and Sandwich Plates: A Homogeneous Limit Methodology for Zigzag Function Selection

    NASA Technical Reports Server (NTRS)

    Tessler, Alexander; DiSciuva, Marco; Gherlone, marco

    2010-01-01

    The Refined Zigzag Theory (RZT) for homogeneous, laminated composite, and sandwich plates is presented from a multi-scale formalism starting with the inplane displacement field expressed as a superposition of coarse and fine contributions. The coarse kinematic field is that of first-order shear-deformation theory, whereas the fine kinematic field has a piecewise-linear zigzag distribution through the thickness. The condition of limiting homogeneity of transverse-shear properties is proposed and yields four distinct sets of zigzag functions. By examining elastostatic solutions for highly heterogeneous sandwich plates, the best-performing zigzag functions are identified. The RZT predictive capabilities to model homogeneous and highly heterogeneous sandwich plates are critically assessed, demonstrating its superior efficiency, accuracy ; and a wide range of applicability. The present theory, which is derived from the virtual work principle, is well-suited for developing computationally efficient CO-continuous finite elements, and is thus appropriate for the analysis and design of high-performance load-bearing aerospace structures.

  20. Teacher training as a behavior change process: principles and results from a longitudinal study.

    PubMed

    Kealey, K A; Peterson, A V; Gaul, M A; Dinh, K T

    2000-02-01

    For students to realize the benefits of behavior change curricula for disease prevention, programs must be implemented effectively. However, implementation failure is a common problem documented in the literature. In this article, teacher training is conceptualized as a behavior change process with explicit teacher motivation components included to help effect the intended behavior (i.e., implementation). Using this method, the Hutchinson Smoking Prevention Project, a randomized controlled trial in school-based smoking prevention, conducted 65 in-service programs, training nearly 500 teachers (Grades 3-10) from 72 schools. Implementation was monitored by teacher self-report and classroom observations by project staff. The results were favorable. All eligible teachers received training, virtually all trained teachers implemented the research curriculum, and 89% of observed lessons worked as intended. It is concluded that teacher training conceptualized as a behavior change process and including explicit teacher motivation components can promote effective implementation of behavior change curricula in public school classrooms.

  1. Using semantic technologies and the OSU ontology for modelling context and activities in multi-sensory surveillance systems

    NASA Astrophysics Data System (ADS)

    Gómez A, Héctor F.; Martínez-Tomás, Rafael; Arias Tapia, Susana A.; Rincón Zamorano, Mariano

    2014-04-01

    Automatic systems that monitor human behaviour for detecting security problems are a challenge today. Previously, our group defined the Horus framework, which is a modular architecture for the integration of multi-sensor monitoring stages. In this work, structure and technologies required for high-level semantic stages of Horus are proposed, and the associated methodological principles established with the aim of recognising specific behaviours and situations. Our methodology distinguishes three semantic levels of events: low level (compromised with sensors), medium level (compromised with context), and high level (target behaviours). The ontology for surveillance and ubiquitous computing has been used to integrate ontologies from specific domains and together with semantic technologies have facilitated the modelling and implementation of scenes and situations by reusing components. A home context and a supermarket context were modelled following this approach, where three suspicious activities were monitored via different virtual sensors. The experiments demonstrate that our proposals facilitate the rapid prototyping of this kind of systems.

  2. Leading virtual teams: hierarchical leadership, structural supports, and shared team leadership.

    PubMed

    Hoch, Julia E; Kozlowski, Steve W J

    2014-05-01

    Using a field sample of 101 virtual teams, this research empirically evaluates the impact of traditional hierarchical leadership, structural supports, and shared team leadership on team performance. Building on Bell and Kozlowski's (2002) work, we expected structural supports and shared team leadership to be more, and hierarchical leadership to be less, strongly related to team performance when teams were more virtual in nature. As predicted, results from moderation analyses indicated that the extent to which teams were more virtual attenuated relations between hierarchical leadership and team performance but strengthened relations for structural supports and team performance. However, shared team leadership was significantly related to team performance regardless of the degree of virtuality. Results are discussed in terms of needed research extensions for understanding leadership processes in virtual teams and practical implications for leading virtual teams. (c) 2014 APA, all rights reserved.

  3. Constraint, Intelligence, and Control Hierarchy in Virtual Environments. Chapter 1

    NASA Technical Reports Server (NTRS)

    Sheridan, Thomas B.

    2007-01-01

    This paper seeks to deal directly with the question of what makes virtual actors and objects that are experienced in virtual environments seem real. (The term virtual reality, while more common in public usage, is an oxymoron; therefore virtual environment is the preferred term in this paper). Reality is difficult topic, treated for centuries in those sub-fields of philosophy called ontology- "of or relating to being or existence" and epistemology- "the study of the method and grounds of knowledge, especially with reference to its limits and validity" (both from Webster s, 1965). Advances in recent decades in the technologies of computers, sensors and graphics software have permitted human users to feel present or experience immersion in computer-generated virtual environments. This has motivated a keen interest in probing this phenomenon of presence and immersion not only philosophically but also psychologically and physiologically in terms of the parameters of the senses and sensory stimulation that correlate with the experience (Ellis, 1991). The pages of the journal Presence: Teleoperators and Virtual Environments have seen much discussion of what makes virtual environments seem real (see, e.g., Slater, 1999; Slater et al. 1994; Sheridan, 1992, 2000). Stephen Ellis, when organizing the meeting that motivated this paper, suggested to invited authors that "We may adopt as an organizing principle for the meeting that the genesis of apparently intelligent interaction arises from an upwelling of constraints determined by a hierarchy of lower levels of behavioral interaction. "My first reaction was "huh?" and my second was "yeah, that seems to make sense." Accordingly the paper seeks to explain from the author s viewpoint, why Ellis s hypothesis makes sense. What is the connection of "presence" or "immersion" of an observer in a virtual environment, to "constraints" and what types of constraints. What of "intelligent interaction," and is it the intelligence of the observer or the intelligence of the environment (whatever the latter may mean) that is salient? And finally, what might be relevant about "upwelling" of constraints as determined by a hierarchy of levels of interaction?

  4. Shaping America's Future III: Proceedings of the National Forum on Transforming Our System of Educating Youth with W. Edwards Deming (June 8, 1992).

    ERIC Educational Resources Information Center

    National Educational Service, Bloomington, IN.

    On June 8, 1992, the presidents of the nation's two largest teachers unions joined the directors and presidents of virtually every educational organization, as well as political leaders and executives from Ford, General Motors, and Chrysler in an effort to redesign U.S. schools using the quality principles of W. Edwards Deming. Panelists spent the…

  5. JPRS Report, Soviet Union, Kommunist, No. 3, February 1987.

    DTIC Science & Technology

    1987-06-05

    everyday realities and that of ostentatious well-being. The ideology and mentality of stagnation were also reflected on the state of culture, literature...society and in the behavior of some party members and make the decisions urgently required by reality . Despite their tremendous possibilities and...although they existed in virtually - all labor collective, many primary party organizations were unable to hold principled positions. Few of them mounted a

  6. Analyzing Von Neumann machines using decentralized symmetries

    NASA Astrophysics Data System (ADS)

    Fang, Jie

    2013-10-01

    The artificial intelligence method to e-business is defined not only by the study of fiber-optic cables, but also by the unproven need for vacuum tubes. Given the current status of virtual archetypes, theorists clearly desire the exploration of semaphores, which embodies the compelling principles of cryptoanalysis. We present an algorithm for probabilistic theory (Buck), which we use to disprove that write-back caches can be made decentralized, lossless, and reliable.

  7. Gregor Mendel: Creationist Hero

    NASA Astrophysics Data System (ADS)

    Numbers, Ronald L.

    2015-01-01

    In histories of twentieth-century Darwinism few developments loom larger than the turn-of-the-century rediscovery of Gregor Mendel's genetic research and the later application of Mendelian principles in constructing so-called Neo-Darwinism. Virtually unknown is the equally enthusiastic embrace of Mendel by antievolutionists, who as early as 1917 adopted the Austrian monk as their most celebrated scientific hero, a status he continues to hold down to the present day.

  8. Enhancing Soldier-Centered Learning with Emerging Training Technologies and Integrated Assessments

    DTIC Science & Technology

    2013-12-01

    classroom and game -based training platform. The mobile training focuses on declarative knowledge and covers basic terminology and principles for...International, has over 20 years of experience in instructional design with focus on game -based training for Defense-related projects. Jessie Hyland...training content, which teaches Soldiers how to operate a common piece of signal equipment, is delivered via a mobile device, virtual classroom and game

  9. Authentication in Virtual Organizations: A Reputation Based PKI Interconnection Model

    NASA Astrophysics Data System (ADS)

    Wazan, Ahmad Samer; Laborde, Romain; Barrere, Francois; Benzekri, Abdelmalek

    Authentication mechanism constitutes a central part of the virtual organization work. The PKI technology is used to provide the authentication in each organization involved in the virtual organization. Different trust models are proposed to interconnect the different PKIs in order to propagate the trust between them. While the existing trust models contain many drawbacks, we propose a new trust model based on the reputation of PKIs.

  10. Virtual Reality Rehabilitation from Social Cognitive and Motor Learning Theoretical Perspectives in Stroke Population

    PubMed Central

    Imam, Bita; Jarus, Tal

    2014-01-01

    Objectives. To identify the virtual reality (VR) interventions used for the lower extremity rehabilitation in stroke population and to explain their underlying training mechanisms using Social Cognitive (SCT) and Motor Learning (MLT) theoretical frameworks. Methods. Medline, Embase, Cinahl, and Cochrane databases were searched up to July 11, 2013. Randomized controlled trials that included a VR intervention for lower extremity rehabilitation in stroke population were included. The Physiotherapy Evidence Database (PEDro) scale was used to assess the quality of the included studies. The underlying training mechanisms involved in each VR intervention were explained according to the principles of SCT (vicarious learning, performance accomplishment, and verbal persuasion) and MLT (focus of attention, order and predictability of practice, augmented feedback, and feedback fading). Results. Eleven studies were included. PEDro scores varied from 3 to 7/10. All studies but one showed significant improvement in outcomes in favour of the VR group (P < 0.05). Ten VR interventions followed the principle of performance accomplishment. All the eleven VR interventions directed subject's attention externally, whereas nine provided training in an unpredictable and variable fashion. Conclusions. The results of this review suggest that VR applications used for lower extremity rehabilitation in stroke population predominantly mediate learning through providing a task-oriented and graduated learning under a variable and unpredictable practice. PMID:24523967

  11. An Absolute Phase Space for the Physicality of Matter

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

    Valentine, John S.

    2010-12-22

    We define an abstract and absolute phase space (''APS'') for sub-quantum intrinsic wave states, in three axes, each mapping directly to a duality having fundamental ontological basis. Many aspects of quantum physics emerge from the interaction algebra and a model deduced from principles of 'unique solvability' and 'identifiable entity', and we reconstruct previously abstract fundamental principles and phenomena from these new foundations. The physical model defines bosons as virtual continuous waves pairs in the APS, and fermions as real self-quantizing snapshots of those waves when simple conditions are met. The abstraction and physical model define a template for the constitutionmore » of all fermions, a template for all the standard fundamental bosons and their local interactions, in a common framework and compactified phase space for all forms of real matter and virtual vacuum energy, and a distinct algebra for observables and unobservables. To illustrate our scheme's potential, we provide examples of slit experiment variations (where the model finds theoretical basis for interference only occurring between two final sources), QCD (where we may model most attributes known to QCD, and a new view on entanglement), and we suggest approaches for other varied applications. We believe this is a viable candidate for further exploration as a foundational proposition for physics.« less

  12. Principles of liquids working in heat engines

    PubMed Central

    Allen, P. C.; Knight, W. R.; Paulson, D. N.; Wheatley, J. C.

    1980-01-01

    The thermodynamic and thermophysical properties of liquids suggest that they should be powerful working fluids in heat engines. Their use requires heat engines based conceptually on the Stirling and Malone principles. The principles are explained, and then experiments on propylene are presented that demonstrate the principles and confirm the thermodynamic analysis. PMID:16592756

  13. Judging the 'passability' of dynamic gaps in a virtual rugby environment.

    PubMed

    Watson, Gareth; Brault, Sebastien; Kulpa, Richard; Bideau, Benoit; Butterfield, Joe; Craig, Cathy

    2011-10-01

    Affordances have recently been proposed as a guiding principle in perception-action research in sport (Fajen, Riley, & Turvey, 2009). In the present study, perception of the 'passability' affordance of a gap between two approaching defenders in rugby is explored. A simplified rugby gap closure scenario was created using immersive, interactive virtual reality technology where 14 novice participants (attacker) judged the passability of the gap between two virtual defenders via a perceptual judgment (button press) task. The scenario was modeled according to tau theory (Lee, 1976) and a psychophysical function was fitted to the response data. Results revealed that a tau-based informational quantity could account for 82% of the variance in the data. Findings suggest that the passability affordance in this case, is defined by this variable and participants were able to use it in order to inform prospective judgments as to passability. These findings contribute to our understanding of affordances and how they may be defined in this particular sporting scenario; however, some limitations regarding methodology, such as decoupling perception and action are also acknowledged. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Using virtual reality to rehabilitate neglect.

    PubMed

    Sedda, A; Borghese, N A; Ronchetti, M; Mainetti, R; Pasotti, F; Beretta, G; Bottini, G

    2013-01-01

    Virtual Reality (VR) platforms gained a lot of attention in the rehabilitation field due to their ability to engage patients and the opportunity they offer to use real world scenarios. As neglect is characterized by an impairment in exploring space that greatly affects daily living, VR could be a powerful tool compared to classical paper and pencil tasks and computer training. Nevertheless, available platforms are costly and obstructive. Here we describe a low cost platform for neglect rehabilitation, that using consumer equipments allows the patient to train at home in an intensive fashion. We tested the platform on IB, a chronic neglect patient, who did not benefit from classical rehabilitation. Our results show that IB improved both in terms of neglect and attention. Importantly, these ameliorations lasted at a follow up evaluation 5 months after the last treatment session and generalized to everyday life activities. VR platforms built using equipment technology and following theoretical principles on brain functioning may induce greater ameliorations in visuo-spatial deficits than classical paradigms possibly thanks to the real world scenarios in association with the "visual feedback" of the patient's own body operating in the virtual environment.

  15. Fragment-based virtual screening approach and molecular dynamics simulation studies for identification of BACE1 inhibitor leads.

    PubMed

    Manoharan, Prabu; Ghoshal, Nanda

    2018-05-01

    Traditional structure-based virtual screening method to identify drug-like small molecules for BACE1 is so far unsuccessful. Location of BACE1, poor Blood Brain Barrier permeability and P-glycoprotein (Pgp) susceptibility of the inhibitors make it even more difficult. Fragment-based drug design method is suitable for efficient optimization of initial hit molecules for target like BACE1. We have developed a fragment-based virtual screening approach to identify/optimize the fragment molecules as a starting point. This method combines the shape, electrostatic, and pharmacophoric features of known fragment molecules, bound to protein conjugate crystal structure, and aims to identify both chemically and energetically feasible small fragment ligands that bind to BACE1 active site. The two top-ranked fragment hits were subjected for a 53 ns MD simulation. Principle component analysis and free energy landscape analysis reveal that the new ligands show the characteristic features of established BACE1 inhibitors. The potent method employed in this study may serve for the development of potential lead molecules for BACE1-directed Alzheimer's disease therapeutics.

  16. 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.

  17. High speed all optical networks

    NASA Technical Reports Server (NTRS)

    Chlamtac, Imrich; Ganz, Aura

    1990-01-01

    An inherent problem of conventional point-to-point wide area network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. The first solution to wavelength division multiplexing (WDM) based WAN networks that overcomes this limitation is presented. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs. The principle of the Lightnet architecture is the construction and use of virtual topology networks, embedded in the original network in the wavelength domain. For this construction Lightnets utilize the new concept of lightpaths which constitute the links of the virtual topology. Lightpaths are all-optical, multihop, paths in the network that allow data to be switched through intermediate nodes using high throughput passive optical switches. The use of the virtual topologies and the associated switching design introduce a number of new ideas, which are discussed in detail.

  18. Grids, Clouds, and Virtualization

    NASA Astrophysics Data System (ADS)

    Cafaro, Massimo; Aloisio, Giovanni

    This chapter introduces and puts in context Grids, Clouds, and Virtualization. Grids promised to deliver computing power on demand. However, despite a decade of active research, no viable commercial grid computing provider has emerged. On the other hand, it is widely believed - especially in the Business World - that HPC will eventually become a commodity. Just as some commercial consumers of electricity have mission requirements that necessitate they generate their own power, some consumers of computational resources will continue to need to provision their own supercomputers. Clouds are a recent business-oriented development with the potential to render this eventually as rare as organizations that generate their own electricity today, even among institutions who currently consider themselves the unassailable elite of the HPC business. Finally, Virtualization is one of the key technologies enabling many different Clouds. We begin with a brief history in order to put them in context, and recall the basic principles and concepts underlying and clearly differentiating them. A thorough overview and survey of existing technologies provides the basis to delve into details as the reader progresses through the book.

  19. Exploration Science Opportunities for Students within Higher Education

    NASA Astrophysics Data System (ADS)

    Bailey, Brad; Minafra, Joseph; Schmidt, Gregory

    2016-10-01

    The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on exploration science related to near-term human exploration targets, training the next generation of lunar scientists, and education and public outreach. As part of the SSERVI mission, we act as a hub for opportunities that engage the public through education and outreach efforts in addition to forming new interdisciplinary, scientific collaborations.SSERVI provides opportunities for students to bridge the scientific and generational gap currently existing in the planetary exploration field. This bridge is essential to the continued international success of scientific, as well as human and robotic, exploration.The decline in funding opportunities after the termination of the Apollo missions to the Moon in the early 1970's produced a large gap in both the scientific knowledge and experience of the original lunar Apollo researchers and the resurgent group of young lunar/NEA researchers that have emerged within the last 15 years. One of SSERVI's many goals is to bridge this gap through the many networking and scientific connections made between young researchers and established planetary principle investigators. To this end, SSERVI has supported the establishment of NextGen Lunar Scientists and Engineers group (NGLSE), a group of students and early-career professionals designed to build experience and provide networking opportunities to its members. SSERVI has also created the LunarGradCon, a scientific conference dedicated solely to graduate and undergraduate students working in the lunar field. Additionally, SSERVI produces monthly seminars and bi-yearly virtual workshops that introduce students to the wide variety of exploration science being performed in today's research labs. SSERVI also brokers opportunities for domestic and international student exchange between collaborating laboratories as well as internships at our member institutions. SSERVI provides a bridge that is essential to the continued international success of scientific, as well as human and robotic, exploration.

  20. Formalizing and Promoting Collaboration in 3D Virtual Environments - A Blueprint for the Creation of Group Interaction Patterns

    NASA Astrophysics Data System (ADS)

    Schmeil, Andreas; Eppler, Martin J.

    Despite the fact that virtual worlds and other types of multi-user 3D collaboration spaces have long been subjects of research and of application experiences, it still remains unclear how to best benefit from meeting with colleagues and peers in a virtual environment with the aim of working together. Making use of the potential of virtual embodiment, i.e. being immersed in a space as a personal avatar, allows for innovative new forms of collaboration. In this paper, we present a framework that serves as a systematic formalization of collaboration elements in virtual environments. The framework is based on the semiotic distinctions among pragmatic, semantic and syntactic perspectives. It serves as a blueprint to guide users in designing, implementing, and executing virtual collaboration patterns tailored to their needs. We present two team and two community collaboration pattern examples as a result of the application of the framework: Virtual Meeting, Virtual Design Studio, Spatial Group Configuration, and Virtual Knowledge Fair. In conclusion, we also point out future research directions for this emerging domain.

  1. Ethical aspects of limiting residents' work hours.

    PubMed

    Wiesing, Urban

    2007-09-01

    The regulation of residents' work hours involves several ethical conflicts which need to be systematically analysed and evaluated. ARGUMENTS AND CONCLUSION: The most important ethical principle when regulating work hours is to avoid the harm resulting from the over-work of physicians and from an excessive division of labour. Additionally, other ethical principles have to be taken into account, in particular the principles of nonmaleficence and beneficence for future patients and for physicians. The article presents arguments for balancing the relevant ethical principles and analyses the structural difficulties that occur unavoidably in any regulation of the complex activities of physicians.

  2. Creating objects and object categories for studying perception and perceptual learning.

    PubMed

    Hauffen, Karin; Bart, Eugene; Brady, Mark; Kersten, Daniel; Hegdé, Jay

    2012-11-02

    In order to quantitatively study object perception, be it perception by biological systems or by machines, one needs to create objects and object categories with precisely definable, preferably naturalistic, properties. Furthermore, for studies on perceptual learning, it is useful to create novel objects and object categories (or object classes) with such properties. Many innovative and useful methods currently exist for creating novel objects and object categories (also see refs. 7,8). However, generally speaking, the existing methods have three broad types of shortcomings. First, shape variations are generally imposed by the experimenter, and may therefore be different from the variability in natural categories, and optimized for a particular recognition algorithm. It would be desirable to have the variations arise independently of the externally imposed constraints. Second, the existing methods have difficulty capturing the shape complexity of natural objects. If the goal is to study natural object perception, it is desirable for objects and object categories to be naturalistic, so as to avoid possible confounds and special cases. Third, it is generally hard to quantitatively measure the available information in the stimuli created by conventional methods. It would be desirable to create objects and object categories where the available information can be precisely measured and, where necessary, systematically manipulated (or 'tuned'). This allows one to formulate the underlying object recognition tasks in quantitative terms. Here we describe a set of algorithms, or methods, that meet all three of the above criteria. Virtual morphogenesis (VM) creates novel, naturalistic virtual 3-D objects called 'digital embryos' by simulating the biological process of embryogenesis. Virtual phylogenesis (VP) creates novel, naturalistic object categories by simulating the evolutionary process of natural selection. Objects and object categories created by these simulations can be further manipulated by various morphing methods to generate systematic variations of shape characteristics. The VP and morphing methods can also be applied, in principle, to novel virtual objects other than digital embryos, or to virtual versions of real-world objects. Virtual objects created in this fashion can be rendered as visual images using a conventional graphical toolkit, with desired manipulations of surface texture, illumination, size, viewpoint and background. The virtual objects can also be 'printed' as haptic objects using a conventional 3-D prototyper. We also describe some implementations of these computational algorithms to help illustrate the potential utility of the algorithms. It is important to distinguish the algorithms from their implementations. The implementations are demonstrations offered solely as a 'proof of principle' of the underlying algorithms. It is important to note that, in general, an implementation of a computational algorithm often has limitations that the algorithm itself does not have. Together, these methods represent a set of powerful and flexible tools for studying object recognition and perceptual learning by biological and computational systems alike. With appropriate extensions, these methods may also prove useful in the study of morphogenesis and phylogenesis.

  3. From flamingo dance to (desirable) drug discovery: a nature-inspired approach.

    PubMed

    Sánchez-Rodríguez, Aminael; Pérez-Castillo, Yunierkis; Schürer, Stephan C; Nicolotti, Orazio; Mangiatordi, Giuseppe Felice; Borges, Fernanda; Cordeiro, M Natalia D S; Tejera, Eduardo; Medina-Franco, José L; Cruz-Monteagudo, Maykel

    2017-10-01

    The therapeutic effects of drugs are well known to result from their interaction with multiple intracellular targets. Accordingly, the pharma industry is currently moving from a reductionist approach based on a 'one-target fixation' to a holistic multitarget approach. However, many drug discovery practices are still procedural abstractions resulting from the attempt to understand and address the action of biologically active compounds while preventing adverse effects. Here, we discuss how drug discovery can benefit from the principles of evolutionary biology and report two real-life case studies. We do so by focusing on the desirability principle, and its many features and applications, such as machine learning-based multicriteria virtual screening. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Virtual Facility at Fermilab: Infrastructure and Services Expand to Public Clouds

    DOE PAGES

    Timm, Steve; Garzoglio, Gabriele; Cooper, Glenn; ...

    2016-02-18

    In preparation for its new Virtual Facility Project, Fermilab has launched a program of work to determine the requirements for running a computation facility on-site, in public clouds, or a combination of both. This program builds on the work we have done to successfully run experimental workflows of 1000-VM scale both on an on-site private cloud and on Amazon AWS. To do this at scale we deployed dynamically launched and discovered caching services on the cloud. We are now testing the deployment of more complicated services on Amazon AWS using native load balancing and auto scaling features they provide. Themore » Virtual Facility Project will design and develop a facility including infrastructure and services that can live on the site of Fermilab, off-site, or a combination of both. We expect to need this capacity to meet the peak computing requirements in the future. The Virtual Facility is intended to provision resources on the public cloud on behalf of the facility as a whole instead of having each experiment or Virtual Organization do it on their own. We will describe the policy aspects of a distributed Virtual Facility, the requirements, and plans to make a detailed comparison of the relative cost of the public and private clouds. Furthermore, this talk will present the details of the technical mechanisms we have developed to date, and the plans currently taking shape for a Virtual Facility at Fermilab.« less

  5. Virtual Facility at Fermilab: Infrastructure and Services Expand to Public Clouds

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

    Timm, Steve; Garzoglio, Gabriele; Cooper, Glenn

    In preparation for its new Virtual Facility Project, Fermilab has launched a program of work to determine the requirements for running a computation facility on-site, in public clouds, or a combination of both. This program builds on the work we have done to successfully run experimental workflows of 1000-VM scale both on an on-site private cloud and on Amazon AWS. To do this at scale we deployed dynamically launched and discovered caching services on the cloud. We are now testing the deployment of more complicated services on Amazon AWS using native load balancing and auto scaling features they provide. Themore » Virtual Facility Project will design and develop a facility including infrastructure and services that can live on the site of Fermilab, off-site, or a combination of both. We expect to need this capacity to meet the peak computing requirements in the future. The Virtual Facility is intended to provision resources on the public cloud on behalf of the facility as a whole instead of having each experiment or Virtual Organization do it on their own. We will describe the policy aspects of a distributed Virtual Facility, the requirements, and plans to make a detailed comparison of the relative cost of the public and private clouds. Furthermore, this talk will present the details of the technical mechanisms we have developed to date, and the plans currently taking shape for a Virtual Facility at Fermilab.« less

  6. Developmental gender differences in children in a virtual spatial memory task.

    PubMed

    León, Irene; Cimadevilla, José Manuel; Tascón, Laura

    2014-07-01

    Behavioral achievements are the product of brain maturation. During postnatal development, the medial temporal lobe completes its maturation, and children acquire new memory abilities. In recent years, virtual reality-based tasks have been introduced in the neuropsychology field to assess different cognitive functions. In this work, desktop virtual reality tasks are combined with classic psychometric tests to assess spatial abilities in 4- to 10-year-old children. Fifty boys and 50 girls 4-10-years of age participated in this study. Spatial reference memory and spatial working memory were assessed using a desktop virtual reality-based task. Other classic psychometric tests were also included in this work (e.g., the Corsi Block Tapping Test, digit tests, 10/36 Spatial Recall Test). In general terms, 4- and 5-year-old groups showed poorer performance than the older groups. However, 5-year-old children showed basic spatial navigation abilities with little difficulty. In addition, boys outperformed girls from the 6-8-year-old groups. Gender differences only emerged in the reference-memory version of the spatial task, whereas both sexes displayed similar performances in the working-memory version. There was general improvement in the performance of different tasks in children older than 5 years. However, results also suggest that brain regions involved in allocentric memory are functional even at the age of 5. In addition, the brain structures underlying reference memory mature later in girls than those required for the working memory.

  7. The Primacy of Principles: Exploring Journalism Educators' Democratic Imperative to Do Good Work

    ERIC Educational Resources Information Center

    Winters, Caryn L.

    2013-01-01

    By engaging in an interdisciplinary examination of the democracy-education relationship, this humanistic inquiry will identify and explore the principles that define journalism educators' special obligation to do good work. My thesis is prefaced on the notion that determining the principles that guide what it means for educators to do good work in…

  8. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-05-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based modeling and third approach is Close range photogrammetry based modeling. Literature study shows that till date, there is no complete solution available to create complete 3D city model by using images. These image based methods also have limitations This paper gives a new approach towards image based virtual 3D city modeling by using close range photogrammetry. This approach is divided into three sections. First, data acquisition process, second is 3D data processing, and third is data combination process. In data acquisition process, a multi-camera setup developed and used for video recording of an area. Image frames created from video data. Minimum required and suitable video image frame selected for 3D processing. In second section, based on close range photogrammetric principles and computer vision techniques, 3D model of area created. In third section, this 3D model exported to adding and merging of other pieces of large area. Scaling and alignment of 3D model was done. After applying the texturing and rendering on this model, a final photo-realistic textured 3D model created. This 3D model transferred into walk-through model or in movie form. Most of the processing steps are automatic. So this method is cost effective and less laborious. Accuracy of this model is good. For this research work, study area is the campus of department of civil engineering, Indian Institute of Technology, Roorkee. This campus acts as a prototype for city. Aerial photography is restricted in many country and high resolution satellite images are costly. In this study, proposed method is based on only simple video recording of area. Thus this proposed method is suitable for 3D city modeling. Photo-realistic, scalable, geo-referenced virtual 3D city model is useful for various kinds of applications such as for planning in navigation, tourism, disasters management, transportations, municipality, urban and environmental managements, real-estate industry. Thus this study will provide a good roadmap for geomatics community to create photo-realistic virtual 3D city model by using close range photogrammetry.

  9. Go with the Flow: Examining the Effects of Engagement Using Flow Theory and Its Relationship to Achievement and Performance in the 3-Dimensional Virtual Learning Environment of Second Life

    ERIC Educational Resources Information Center

    Cooper, Karen E.

    2009-01-01

    Virtual Worlds have become an attractive platform for work, play, and learning. Businesses, including the public sector and academia, are increasingly investing their time, money, and attention to understanding the value of virtual worlds as a productivity tool. For example, educators are leading the way with research in Second Life, one of the…

  10. Virtual Reality and Online Databases: Will "Look and Feel" Literally Mean "Look" and "Feel"? [and]"Online" Interviews Dr. Thomas A. Furness III, Virtual Reality Pioneer.

    ERIC Educational Resources Information Center

    Miller, Carmen

    1992-01-01

    The first of two articles discusses virtual reality (VR) and online databases; the second one reports on an interview with Thomas A. Furness III, who defines VR and explains work at the Human Interface Technology Laboratory (HIT). Sidebars contain a glossary of VR terms and a conversation with Toni Emerson, the HIT lab's librarian. (LRW)

  11. Kinematics and dynamics of robotic systems with multiple closed loops

    NASA Astrophysics Data System (ADS)

    Zhang, Chang-De

    The kinematics and dynamics of robotic systems with multiple closed loops, such as Stewart platforms, walking machines, and hybrid manipulators, are studied. In the study of kinematics, focus is on the closed-form solutions of the forward position analysis of different parallel systems. A closed-form solution means that the solution is expressed as a polynomial in one variable. If the order of the polynomial is less than or equal to four, the solution has analytical closed-form. First, the conditions of obtaining analytical closed-form solutions are studied. For a Stewart platform, the condition is found to be that one rotational degree of freedom of the output link is decoupled from the other five. Based on this condition, a class of Stewart platforms which has analytical closed-form solution is formulated. Conditions of analytical closed-form solution for other parallel systems are also studied. Closed-form solutions of forward kinematics for walking machines and multi-fingered grippers are then studied. For a parallel system with three three-degree-of-freedom subchains, there are 84 possible ways to select six independent joints among nine joints. These 84 ways can be classified into three categories: Category 3:3:0, Category 3:2:1, and Category 2:2:2. It is shown that the first category has no solutions; the solutions of the second category have analytical closed-form; and the solutions of the last category are higher order polynomials. The study is then extended to a nearly general Stewart platform. The solution is a 20th order polynomial and the Stewart platform has a maximum of 40 possible configurations. Also, the study is extended to a new class of hybrid manipulators which consists of two serially connected parallel mechanisms. In the study of dynamics, a computationally efficient method for inverse dynamics of manipulators based on the virtual work principle is developed. Although this method is comparable with the recursive Newton-Euler method for serial manipulators, its advantage is more noteworthy when applied to parallel systems. An approach of inverse dynamics of a walking machine is also developed, which includes inverse dynamic modeling, foot force distribution, and joint force/torque allocation.

  12. Virtual reality at work

    NASA Technical Reports Server (NTRS)

    Brooks, Frederick P., Jr.

    1991-01-01

    The utility of virtual reality computer graphics in telepresence applications is not hard to grasp and promises to be great. When the virtual world is entirely synthetic, as opposed to real but remote, the utility is harder to establish. Vehicle simulators for aircraft, vessels, and motor vehicles are proving their worth every day. Entertainment applications such as Disney World's StarTours are technologically elegant, good fun, and economically viable. Nevertheless, some of us have no real desire to spend our lifework serving the entertainment craze of our sick culture; we want to see this exciting technology put to work in medicine and science. The topics covered include the following: testing a force display for scientific visualization -- molecular docking; and testing a head-mounted display for scientific and medical visualization.

  13. Psychophysical evaluation of three-dimensional auditory displays

    NASA Technical Reports Server (NTRS)

    Wightman, Frederic L.

    1991-01-01

    Work during this reporting period included the completion of our research on the use of principal components analysis (PCA) to model the acoustical head related transfer functions (HRTFs) that are used to synthesize virtual sources for three dimensional auditory displays. In addition, a series of studies was initiated on the perceptual errors made by listeners when localizing free-field and virtual sources. Previous research has revealed that under certain conditions these perceptual errors, often called 'confusions' or 'reversals', are both large and frequent, thus seriously comprising the utility of a 3-D virtual auditory display. The long-range goal of our work in this area is to elucidate the sources of the confusions and to develop signal-processing strategies to reduce or eliminate them.

  14. Distribution Locational Real-Time Pricing Based Smart Building Control and Management

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

    Hao, Jun; Dai, Xiaoxiao; Zhang, Yingchen

    This paper proposes an real-virtual parallel computing scheme for smart building operations aiming at augmenting overall social welfare. The University of Denver's campus power grid and Ritchie fitness center is used for demonstrating the proposed approach. An artificial virtual system is built in parallel to the real physical system to evaluate the overall social cost of the building operation based on the social science based working productivity model, numerical experiment based building energy consumption model and the power system based real-time pricing mechanism. Through interactive feedback exchanged between the real and virtual system, enlarged social welfare, including monetary cost reductionmore » and energy saving, as well as working productivity improvements, can be achieved.« less

  15. The use of physical and virtual manipulatives in an undergraduate mechanical engineering (Dynamics) course

    NASA Astrophysics Data System (ADS)

    Pan, Edward A.

    Science, technology, engineering, and mathematics (STEM) education is a national focus. Engineering education, as part of STEM education, needs to adapt to meet the needs of the nation in a rapidly changing world. Using computer-based visualization tools and corresponding 3D printed physical objects may help nontraditional students succeed in engineering classes. This dissertation investigated how adding physical or virtual learning objects (called manipulatives) to courses that require mental visualization of mechanical systems can aid student performance. Dynamics is one such course, and tends to be taught using lecture and textbooks with static diagrams of moving systems. Students often fail to solve the problems correctly and an inability to mentally visualize the system can contribute to student difficulties. This study found no differences between treatment groups on quantitative measures of spatial ability and conceptual knowledge. There were differences between treatments on measures of mechanical reasoning ability, in favor of the use of physical and virtual manipulatives over static diagrams alone. There were no major differences in student performance between the use of physical and virtual manipulatives. Students used the physical and virtual manipulatives to test their theories about how the machines worked, however their actual time handling the manipulatives was extremely limited relative to the amount of time they spent working on the problems. Students used the physical and virtual manipulatives as visual aids when communicating about the problem with their partners, and this behavior was also seen with Traditional group students who had to use the static diagrams and gesture instead. The explanations students gave for how the machines worked provided evidence of mental simulation; however, their causal chain analyses were often flawed, probably due to attempts to decrease cognitive load. Student opinions about the static diagrams and dynamic models varied by type of model (static, physical, virtual), but were generally favorable. The Traditional group students, however, indicated that the lack of adequate representation of motion in the static diagrams was a problem, and wished they had access to the physical and virtual models.

  16. The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope Control Center System

    NASA Technical Reports Server (NTRS)

    Lehtonen, Ken

    1999-01-01

    This is a report to the Third Annual International Virtual Company Conference, on The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope (HST) Control Center System. It begins with a HST Science "Commercial": Brief Tour of Our Universe showing various pictures taken from the Hubble Space Telescope. The presentation then reviews the project background and goals. Evolution of the Control Center System ("CCS Inc.") is then reviewed. Topics of Interest to "virtual companies" are reviewed: (1) "How To Choose A Team" (2) "Organizational Model" (3) "The Human Component" (4) "'Virtual Trust' Among Teaming Companies" (5) "Unique Challenges to Working Horizontally" (6) "The Cultural Impact" (7) "Lessons Learned".

  17. Proliferation assessment in breast carcinomas using digital image analysis based on virtual Ki67/cytokeratin double staining.

    PubMed

    Røge, Rasmus; Riber-Hansen, Rikke; Nielsen, Søren; Vyberg, Mogens

    2016-07-01

    Manual estimation of Ki67 Proliferation Index (PI) in breast carcinoma classification is labor intensive and prone to intra- and interobserver variation. Standard Digital Image Analysis (DIA) has limitations due to issues with tumor cell identification. Recently, a computer algorithm, DIA based on Virtual Double Staining (VDS), segmenting Ki67-positive and -negative tumor cells using digitally fused parallel cytokeratin (CK) and Ki67-stained slides has been introduced. In this study, we compare VDS with manual stereological counting of Ki67-positive and -negative cells and examine the impact of the physical distance of the parallel slides on the alignment of slides. TMAs, containing 140 cores of consecutively obtained breast carcinomas, were stained for CK and Ki67 using optimized staining protocols. By means of stereological principles, Ki67-positive and -negative cell profiles were counted in sampled areas and used for the estimation of PIs of the whole tissue core. The VDS principle was applied to both the same sampled areas and the whole tissue core. Additionally, five neighboring slides were stained for CK in order to examine the alignment algorithm. Correlation between manual counting and VDS in both sampled areas and whole core was almost perfect (correlation coefficients above 0.97). Bland-Altman plots did not reveal any skewness in any data ranges. There was a good agreement in alignment (>85 %) in neighboring slides, whereas agreement decreased in non-neighboring slides. VDS gave similar results compared with manual counting using stereological principles. Introduction of this method in clinical and research practice may improve accuracy and reproducibility of Ki67 PI.

  18. An experimental study on CHVE's performance evaluation.

    PubMed

    Paiva, Paulo V F; Machado, Liliane S; Oliveira, Jauvane C

    2012-01-01

    Virtual reality-based training simulators, with collaborative capabilities, are known to improve the way users interact with one another while learning or improving skills on a given medical procedure. Performance evaluation of Collaborative Haptic Virtual Environments (CHVE) allows us to understand how such systems can work in the Internet, as well as the requirements for multisensorial and real-time data. This work discloses new performance evaluation results for the collaborative module of the CyberMed VR framework.

  19. [Applying a social network for the practice and learning of psychiatry].

    PubMed

    Mondin, Estefanía; Matusevich, Daniel

    2014-01-01

    Social networking is a virtual space in which people relate and build their identity, share information, publish content and intervene on the content posted by others. We will describe an experiment carried out in the psychiatry service of Italian Hospital in Buenos Aires, in which we use Whatsapp Social Network applied to the development of clinical work and teaching task. From these new ways of relating between professional, emerge a new way to work, participate in groups or try to evaluate various options for dealing with a patient. We analyze the usefulness of this virtual platform as a working tool.

  20. 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.

  1. How virtual reality works: illusions of vision in "real" and virtual environments

    NASA Astrophysics Data System (ADS)

    Stark, Lawrence W.

    1995-04-01

    Visual illusions abound in normal vision--illusions of clarity and completeness, of continuity in time and space, of presence and vivacity--and are part and parcel of the visual world inwhich we live. These illusions are discussed in terms of the human visual system, with its high- resolution fovea, moved from point to point in the visual scene by rapid saccadic eye movements (EMs). This sampling of visual information is supplemented by a low-resolution, wide peripheral field of view, especially sensitive to motion. Cognitive-spatial models controlling perception, imagery, and 'seeing,' also control the EMs that shift the fovea in the Scanpath mode. These illusions provide for presence, the sense off being within an environment. They equally well lead to 'Telepresence,' the sense of being within a virtual display, especially if the operator is intensely interacting within an eye-hand and head-eye human-machine interface that provides for congruent visual and motor frames of reference. Interaction, immersion, and interest compel telepresence; intuitive functioning and engineered information flows can optimize human adaptation to the artificial new world of virtual reality, as virtual reality expands into entertainment, simulation, telerobotics, and scientific visualization and other professional work.

  2. Modeling and computational simulation and the potential of virtual and augmented reality associated to the teaching of nanoscience and nanotechnology

    NASA Astrophysics Data System (ADS)

    Ribeiro, Allan; Santos, Helen

    With the advent of new information and communication technologies (ICTs), the communicative interaction changes the way of being and acting of people, at the same time that changes the way of work activities related to education. In this range of possibilities provided by the advancement of computational resources include virtual reality (VR) and augmented reality (AR), are highlighted as new forms of information visualization in computer applications. While the RV allows user interaction with a virtual environment totally computer generated; in RA the virtual images are inserted in real environment, but both create new opportunities to support teaching and learning in formal and informal contexts. Such technologies are able to express representations of reality or of the imagination, as systems in nanoscale and low dimensionality, being imperative to explore, in the most diverse areas of knowledge, the potential offered by ICT and emerging technologies. In this sense, this work presents computer applications of virtual and augmented reality developed with the use of modeling and simulation in computational approaches to topics related to nanoscience and nanotechnology, and articulated with innovative pedagogical practices.

  3. Maggi's equations of motion and the determination of constraint reactions

    NASA Astrophysics Data System (ADS)

    Papastavridis, John G.

    1990-04-01

    This paper presents a geometrical derivation of the constraint reaction-free equations of Maggi for mechanical systems subject to linear (first-order) nonholonomic and/or holonomic constraints. These results follow directly from the proper application of the concepts of virtual displacement and quasi-coordinates to the variational equation of motion, i.e., Lagrange's principle. The method also makes clear how to compute the constraint reactions (kinetostatics) without introducing Lagrangian multipliers.

  4. Virtual experiment of optical spatial filtering in Matlab environment

    NASA Astrophysics Data System (ADS)

    Ji, Yunjing; Wang, Chunyong; Song, Yang; Lai, Jiancheng; Wang, Qinghua; Qi, Jing; Shen, Zhonghua

    2017-08-01

    The principle of spatial filtering experiment has been introduced, and the computer simulation platform with graphical user interface (GUI) has been made out in Matlab environment. Using it various filtering processes for different input image or different filtering purpose will be completed accurately, and filtering effect can be observed clearly with adjusting experimental parameters. The physical nature of the optical spatial filtering can be showed vividly, and so experimental teaching effect will be promoted.

  5. 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.

  6. 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…

  7. Touring by Design: Using Information Architecture To Create a Virtual Library Tour.

    ERIC Educational Resources Information Center

    Kittelson, Pat; Jones, Sarah

    2002-01-01

    Describes the development of a Web-based virtual tour of the University of Otago (New Zealand) science library. Highlights include information literacy learning outcomes; information architecture, including information organization and navigation; integrating the tour into course work; and evaluation results. (LRW)

  8. [Nursing workloads and working conditions: integrative review].

    PubMed

    Schmoeller, Roseli; Trindade, Letícia de Lima; Neis, Márcia Binder; Gelbcke, Francine Lima; de Pires, Denise Elvira Pires

    2011-06-01

    This study reviews theoretical production concerning workloads and working conditions for nurses. For that, an integrative review was carried out using scientific articles, theses and dissertations indexed in two Brazilian databases, Virtual Health Care Library (Biblioteca Virtual de Saúde) and Digital Database of Dissertations (Banco Digital de Teses), over the last ten years. From 132 identified studies, 27 were selected. Results indicate workloads as responsible for professional weariness, affecting the occurrence of work accidents and health problems. In order to adequate workloads studies indicate some strategies, such as having an adequate numbers of employees, continuing education, and better working conditions. The challenge is to continue research that reveal more precisely the relationships between workloads, working conditions, and health of the nursing team.

  9. Promoting health and safety virtually: key recommendations for occupational health nurses.

    PubMed

    Wolf, Debra M; Anton, Bonnie B; Wenskovitch, John

    2014-07-01

    Nurses' use of the Internet and social media has surfaced as a critical concern requiring further exploration and consideration by all health care organizations and nursing associations. In an attempt to support this need, the American Nurses Association (2011) published six principles of social networking that offered guidance and direction for nurses. In addition, the National Council of State Boards of Nursing (2011) published a nurse's guide to using social media. Surfing the Internet and using social media for professional and personal needs is extremely common among nurses. What is concerning is when nurses do not separate their professional and personal presence in the virtual world. This article presents an Institutional Review Board-approved pilot survey that explored nurses' use of social media personally and professionally and offers recommendations specifically directed to the occupational health nurse. Copyright 2014, SLACK Incorporated.

  10. A kinase-focused compound collection: compilation and screening strategy.

    PubMed

    Sun, Dongyu; Chuaqui, Claudio; Deng, Zhan; Bowes, Scott; Chin, Donovan; Singh, Juswinder; Cullen, Patrick; Hankins, Gretchen; Lee, Wen-Cherng; Donnelly, Jason; Friedman, Jessica; Josiah, Serene

    2006-06-01

    Lead identification by high-throughput screening of large compound libraries has been supplemented with virtual screening and focused compound libraries. To complement existing approaches for lead identification at Biogen Idec, a kinase-focused compound collection was designed, developed and validated. Two strategies were adopted to populate the compound collection: a ligand shape-based virtual screening and a receptor-based approach (structural interaction fingerprint). Compounds selected with the two approaches were cherry-picked from an existing high-throughput screening compound library, ordered from suppliers and supplemented with specific medicinal compounds from internal programs. Promising hits and leads have been generated from the kinase-focused compound collection against multiple kinase targets. The principle of the collection design and screening strategy was validated and the use of the kinase-focused compound collection for lead identification has been added to existing strategies.

  11. 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.

  12. Integration of the Peruvian Air Force Information Systems through an Integrated LAN/WAN

    DTIC Science & Technology

    1991-03-01

    telecommunication systems are virtually indistinguishable from computer systems. These two technologies meet to work together. 3. Types of Telecommunications...information are virtually out of control. What limits on access exist tend to be the result of habit and tradition, as well as of the sheer difficulty...organization cannot be related to one another, it is virtually impossible for information to be shared or accessed in a timely manner. D. PZRUVIAN AIR FORCE

  13. Virtual Labs in proteomics: new E-learning tools.

    PubMed

    Ray, Sandipan; Koshy, Nicole Rachel; Reddy, Panga Jaipal; Srivastava, Sanjeeva

    2012-05-17

    Web-based educational resources have gained enormous popularity recently and are increasingly becoming a part of modern educational systems. Virtual Labs are E-learning platforms where learners can gain the experience of practical experimentation without any direct physical involvement on real bench work. They use computerized simulations, models, videos, animations and other instructional technologies to create interactive content. Proteomics being one of the most rapidly growing fields of the biological sciences is now an important part of college and university curriculums. Consequently, many E-learning programs have started incorporating the theoretical and practical aspects of different proteomic techniques as an element of their course work in the form of Video Lectures and Virtual Labs. To this end, recently we have developed a Virtual Proteomics Lab at the Indian Institute of Technology Bombay, which demonstrates different proteomics techniques, including basic and advanced gel and MS-based protein separation and identification techniques, bioinformatics tools and molecular docking methods, and their applications in different biological samples. This Tutorial will discuss the prominent Virtual Labs featuring proteomics content, including the Virtual Proteomics Lab of IIT-Bombay, and E-resources available for proteomics study that are striving to make proteomic techniques and concepts available and accessible to the student and research community. This Tutorial is part of the International Proteomics Tutorial Programme (IPTP 14). Details can be found at: http://www.proteomicstutorials.org/. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. 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.

  15. Virtual reality and 3D visualizations in heart surgery education.

    PubMed

    Friedl, Reinhard; Preisack, Melitta B; Klas, Wolfgang; Rose, Thomas; Stracke, Sylvia; Quast, Klaus J; Hannekum, Andreas; Gödje, Oliver

    2002-01-01

    Computer assisted teaching plays an increasing role in surgical education. The presented paper describes the development of virtual reality (VR) and 3D visualizations for educational purposes concerning aortocoronary bypass grafting and their prototypical implementation into a database-driven and internet-based educational system in heart surgery. A multimedia storyboard has been written and digital video has been encoded. Understanding of these videos was not always satisfying; therefore, additional 3D and VR visualizations have been modelled as VRML, QuickTime, QuickTime Virtual Reality and MPEG-1 applications. An authoring process in terms of integration and orchestration of different multimedia components to educational units has been started. A virtual model of the heart has been designed. It is highly interactive and the user is able to rotate it, move it, zoom in for details or even fly through. It can be explored during the cardiac cycle and a transparency mode demonstrates coronary arteries, movement of the heart valves, and simultaneous blood-flow. Myocardial ischemia and the effect of an IMA-Graft on myocardial perfusion is simulated. Coronary artery stenoses and bypass-grafts can be interactively added. 3D models of anastomotique techniques and closed thrombendarterectomy have been developed. Different visualizations have been prototypically implemented into a teaching application about operative techniques. Interactive virtual reality and 3D teaching applications can be used and distributed via the World Wide Web and have the power to describe surgical anatomy and principles of surgical techniques, where temporal and spatial events play an important role, in a way superior to traditional teaching methods.

  16. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

    PubMed

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-03-01

    The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

  17. Virtual terrain: a security-based representation of a computer network

    NASA Astrophysics Data System (ADS)

    Holsopple, Jared; Yang, Shanchieh; Argauer, Brian

    2008-03-01

    Much research has been put forth towards detection, correlating, and prediction of cyber attacks in recent years. As this set of research progresses, there is an increasing need for contextual information of a computer network to provide an accurate situational assessment. Typical approaches adopt contextual information as needed; yet such ad hoc effort may lead to unnecessary or even conflicting features. The concept of virtual terrain is, therefore, developed and investigated in this work. Virtual terrain is a common representation of crucial information about network vulnerabilities, accessibilities, and criticalities. A virtual terrain model encompasses operating systems, firewall rules, running services, missions, user accounts, and network connectivity. It is defined as connected graphs with arc attributes defining dynamic relationships among vertices modeling network entities, such as services, users, and machines. The virtual terrain representation is designed to allow feasible development and maintenance of the model, as well as efficacy in terms of the use of the model. This paper will describe the considerations in developing the virtual terrain schema, exemplary virtual terrain models, and algorithms utilizing the virtual terrain model for situation and threat assessment.

  18. Optical versus virtual: teaching assistant perceptions of the use of virtual microscopy in an undergraduate human anatomy course.

    PubMed

    Collier, Larissa; Dunham, Stacey; Braun, Mark W; O'Loughlin, Valerie Dean

    2012-01-01

    Many studies that evaluate the introduction of technology in the classroom focus on student performance and student evaluations. This study focuses on instructor evaluation of the introduction of virtual microscopy into an undergraduate anatomy class. Semi-structured interviews were conducted with graduate teaching assistants (TA) and analyzed through qualitative methods. This analysis showed that the teaching assistants found the virtual microscope to be an advantageous change in the classroom. They cite the ease of use of the virtual microscope, access to histology outside of designated laboratory time, and increasing student collaboration in class as the primary advantages. The teaching assistants also discuss principal areas where the use of the virtual microscope can be improved from a pedagogical standpoint, including requiring students to spend more time working on histology in class. Copyright © 2011 American Association of Anatomists.

  19. A workout for virtual bodybuilders (design issues for embodiment in multi-actor virtual environments)

    NASA Technical Reports Server (NTRS)

    Benford, Steve; Bowers, John; Fahlen, Lennart E.; Greenhalgh, Chris; Snowdon, Dave

    1994-01-01

    This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which support cooperative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative systems). The main part of the paper identifies a list of embodiment design issues including: presence, location, identity, activity, availability, history of activity, viewpoint, action point, gesture, facial expression, voluntary versus involuntary expression, degree of presence, reflecting capabilities, manipulating the user's view of others, representation across multiple media, autonomous and distributed body parts, truthfulness and efficiency. Following this, we show how these issues are reflected in our own DIVE and MASSIVE prototype collaborative virtual environments.

  20. 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

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