Creating an Online Library To Support a Virtual Learning Community.
ERIC Educational Resources Information Center
Sandelands, Eric
1998-01-01
International Management Centres (IMC), an independent business school, and Anbar Electronic Intelligence (AEI), a database publisher, have created a virtual library for IMC's virtual business school. Topics discussed include action learning; IMC's partnership with AEI; the virtual university model; designing virtual library resources; and…
Propagation of crises in the virtual water trade network
NASA Astrophysics Data System (ADS)
Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2015-04-01
The international trade of agricultural goods is associated to the displacement of the water used to produce such goods and embedded in trade as a factor of production. Water virtually exchanged from producing to consuming countries, named virtual water, defines flows across an international network of 'virtual water trade' which enable the assessment of environmental forcings and implications of trade, such as global water savings or country dependencies on foreign water resources. Given the recent expansion of commodity (and virtual water) trade, in both displaced volumes and network structure, concerns have been raised about the exposure to crises of individuals and societies. In fact, if one country had to markedly decrease its export following a socio-economical or environmental crisis, such as a war or a drought, many -if not all- countries would be affected due to a cascade effect within the trade network. The present contribution proposes a mechanistic model describing the propagation of a local crisis into the virtual water trade network, accounting for the network structure and the virtual water balance of all countries. The model, built on data-based assumptions, is tested on the real case study of the Argentinean crisis in 2008-09, when the internal agricultural production (measured as virtual water volume) decreased by 26% and the virtual water export of Argentina dropped accordingly. Crisis propagation and effects on the virtual water trade are correctly captured, showing the way forward to investigations of crises impact and country vulnerability based on the results of the model proposed.
Hirarchical emotion calculation model for virtual human modellin - biomed 2010.
Zhao, Yue; Wright, David
2010-01-01
This paper introduces a new emotion generation method for virtual human modelling. The method includes a novel hierarchical emotion structure, a group of emotion calculation equations and a simple heuristics decision making mechanism, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. A simple heuristics theory is introduced and integrated into decision making process in order to make the virtual humans decision making more like a real human. A data interface which connects the emotion calculation and the decision making structure together has also been designed and simulated to test the method in Virtools environment.
ERIC Educational Resources Information Center
Hosseini, Seyede Mehrnoush
2011-01-01
The research aims to define SECI model of knowledge creation (socialization, externalization, combination, and internalization) as a framework of Virtual class management which can lead to better online teaching-learning mechanisms as well as knowledge creation. It has used qualitative research methodology including researcher's close observation…
Developing virtual REU cohorts: Reflections from the IRIS Undergraduate Internship Program
NASA Astrophysics Data System (ADS)
Hubenthal, M.; Taber, J.; Aster, R.; Frassetto, A.
2007-12-01
Beginning in 2006, the IRIS Education and Outreach program received funding from the National Science Foundation (EAR-0453427) to explore a novel approach to the traditional Research Experience for Undergraduates (REU) model. This model blends the spirit of an REU program, which traditionally hosts participants in one location with successful prior IRIS experience hosting students at widely separated institutions to participate in summer research. A unique feature the IRIS Undergraduate Internship Program is that throughout the summer, interns form and sustain a virtual community, offering assistance, sharing ideas, asking questions, and relaying life experiences while conducting their research at diverse institutions. Key to IRIS's REU model is a combination of: one-on-one mentoring by researchers at IRIS institutions across the US, developing a strong unity among interns through both face-to-face and on-line interactions, participation of an IRIS REU alumni mentor to provide both group and intern-specific guidance developing interns' abilities to self-evaluate and work independently, through carefully designed web-based tools, and increasing interns' awareness of the IRIS and broader Earth Science community; demonstrating the role they will play in this larger community. Virtual interaction is facilitated by 1) bringing students together for face-to-face contact, through a week long orientation held annually at the IRIS PASSCAL Instrument Center on the campus of the New Mexico Institute of Mining and Technology, and 2) the community enabling web infrastructure at http://www.iris.edu/internship/. During the orientation students engage in classes in geophysics basics, career preparation, as well as training to communicate virtually. Our experiences and evaluations from the 2006 and 2007 field seasons have:shown the increasing demand for electronic advertising of REU programs, provided support for several assumptions of the model including the key role of both the orientation week and the alumni mentor, revealed the important role of blogs and discussion forums in the mentoring and self-reflection process, as well as additional technical enhancements to improve the virtual cohort, produced concrete examples of the model applied at its best, and helped the program identify challenges the model faces, e.g communicating during remote fieldwork and sustaining intern's attention and participation in the virtual community.
OtagoNet: One Region's Model for Virtual Schooling
ERIC Educational Resources Information Center
Pratt, Keryn; Pullar, Ken
2013-01-01
Virtual schools are increasingly common in New Zealand and internationally as schools are challenged to meet the needs of their students. This article presents a description of the distance-learning model used by a group of schools in rural Otago for the last decade. The leadership team and roles are described, and the funding model, which is…
Liu, Peter X.; Lai, Pinhua; Xu, Shaoping; Zou, Yanni
2018-01-01
In the present work, the majority of implemented virtual surgery simulation systems have been based on either a mesh or meshless strategy with regard to soft tissue modelling. To take full advantage of the mesh and meshless models, a novel coupled soft tissue cutting model is proposed. Specifically, the reconstructed virtual soft tissue consists of two essential components. One is associated with surface mesh that is convenient for surface rendering and the other with internal meshless point elements that is used to calculate the force feedback during cutting. To combine two components in a seamless way, virtual points are introduced. During the simulation of cutting, the Bezier curve is used to characterize smooth and vivid incision on the surface mesh. At the same time, the deformation of internal soft tissue caused by cutting operation can be treated as displacements of the internal point elements. Furthermore, we discussed and proved the stability and convergence of the proposed approach theoretically. The real biomechanical tests verified the validity of the introduced model. And the simulation experiments show that the proposed approach offers high computational efficiency and good visual effect, enabling cutting of soft tissue with high stability. PMID:29850006
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.
A Data Management System for International Space Station Simulation Tools
NASA Technical Reports Server (NTRS)
Betts, Bradley J.; DelMundo, Rommel; Elcott, Sharif; McIntosh, Dawn; Niehaus, Brian; Papasin, Richard; Mah, Robert W.; Clancy, Daniel (Technical Monitor)
2002-01-01
Groups associated with the design, operational, and training aspects of the International Space Station make extensive use of modeling and simulation tools. Users of these tools often need to access and manipulate large quantities of data associated with the station, ranging from design documents to wiring diagrams. Retrieving and manipulating this data directly within the simulation and modeling environment can provide substantial benefit to users. An approach for providing these kinds of data management services, including a database schema and class structure, is presented. Implementation details are also provided as a data management system is integrated into the Intelligent Virtual Station, a modeling and simulation tool developed by the NASA Ames Smart Systems Research Laboratory. One use of the Intelligent Virtual Station is generating station-related training procedures in a virtual environment, The data management component allows users to quickly and easily retrieve information related to objects on the station, enhancing their ability to generate accurate procedures. Users can associate new information with objects and have that information stored in a database.
NASA Astrophysics Data System (ADS)
Wang, Jin; Xu, Fan; Lu, GuoDong
2017-09-01
More complex problems of simultaneous position and internal force control occur with cooperative manipulator systems than that of a single one. In the presence of unwanted parametric and modelling uncertainties as well as external disturbances, a decentralised position synchronised force control scheme is proposed. With a feedforward neural network estimating engine, a precise model of the system dynamics is not required. Unlike conventional cooperative or synchronised controllers, virtual position and virtual synchronisation errors are introduced for internal force tracking control and task space position synchronisation. Meanwhile joint space synchronisation and force measurement are unnecessary. Together with simulation studies and analysis, the position and the internal force errors are shown to asymptotically converge to zero. Moreover, the controller exhibits different characteristics with selected synchronisation factors. Under certain settings, it can deal with temporary cooperation by an intelligent retreat mechanism, where less internal force would occur and rigid collision can be avoided. Using a Lyapunov stability approach, the controller is proven to be robust in face of the aforementioned uncertainties.
Evolution of the global virtual water trade network.
Dalin, Carole; Konar, Megan; Hanasaki, Naota; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio
2012-04-17
Global freshwater resources are under increasing pressure from economic development, population growth, and climate change. The international trade of water-intensive products (e.g., agricultural commodities) or virtual water trade has been suggested as a way to save water globally. We focus on the virtual water trade network associated with international food trade built with annual trade data and annual modeled virtual water content. The evolution of this network from 1986 to 2007 is analyzed and linked to trade policies, socioeconomic circumstances, and agricultural efficiency. We find that the number of trade connections and the volume of water associated with global food trade more than doubled in 22 years. Despite this growth, constant organizational features were observed in the network. However, both regional and national virtual water trade patterns significantly changed. Indeed, Asia increased its virtual water imports by more than 170%, switching from North America to South America as its main partner, whereas North America oriented to a growing intraregional trade. A dramatic rise in China's virtual water imports is associated with its increased soy imports after a domestic policy shift in 2000. Significantly, this shift has led the global soy market to save water on a global scale, but it also relies on expanding soy production in Brazil, which contributes to deforestation in the Amazon. We find that the international food trade has led to enhanced savings in global water resources over time, indicating its growing efficiency in terms of global water use.
Global effects of local food-production crises: a virtual water perspective
Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2016-01-01
By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008–09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability. PMID:26804492
Global effects of local food-production crises: a virtual water perspective.
Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2016-01-25
By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008-09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.
Global effects of local food-production crises: a virtual water perspective
NASA Astrophysics Data System (ADS)
Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2016-01-01
By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008-09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-20
... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Patch International, Inc., QuadTech International, Inc., Strategic Resources, Ltd., and Virtual Medical Centre, Inc.; Order of Suspension of Trading... lack of current and accurate information concerning the securities of Virtual Medical Centre, Inc...
Patient Satisfaction with Virtual Obstetric Care.
Pflugeisen, Bethann Mangel; Mou, Jin
2017-07-01
Introduction The importance of patient satisfaction in US healthcare is increasing, in tandem with the advent of new patient care modalities, including virtual care. The purpose of this study was to compare the satisfaction of obstetric patients who received one-third of their antenatal visits in videoconference ("Virtual-care") compared to those who received 12-14 face-to-face visits in-clinic with their physician/midwife ("Traditional-care"). Methods We developed a four-domain satisfaction questionnaire; Virtual-care patients were asked additional questions about technology. Using a modified Dillman method, satisfaction surveys were sent to Virtual-care (N = 378) and Traditional-care (N = 795) patients who received obstetric services at our institution between January 2013 and June 2015. Chi-squared tests of association, t-tests, logistic regression, and ANOVA models were used to evaluate differences in satisfaction and self-reported demographics between respondents. Results Overall satisfaction was significantly higher in the Virtual-care cohort (4.76 ± 0.44 vs. 4.47 ± 0.59; p < .001). Parity ≥ 1 was the sole significant demographic variable impacting Virtual-care selection (OR = 2.4, 95% CI: 1.5-3.8; p < .001). Satisfaction of Virtual-care respondents was not significantly impacted by the incorporation of videoconferencing, Doppler, and blood pressure monitoring technology into their care. The questionnaire demonstrated high internal consistency as measured by domain-based correlations and Cronbach's alpha. Discussion Respondents from both models were highly satisfied with care, but those who had selected the Virtual-care model reported significantly higher mean satisfaction scores. The Virtual-care model was selected by significantly more women who already have children than those experiencing pregnancy for the first time. This model of care may be a reasonable alternative to traditional care.
Asensio, C; Gasco, L; Ruiz, M; Recuero, M
2015-02-01
This paper describes a methodology and case study for the implementation of educational virtual laboratories for practice training on acoustic tests according to international standards. The objectives of this activity are (a) to help the students understand and apply the procedures described in the standards and (b) to familiarize the students with the uncertainty in measurement and its estimation in acoustics. The virtual laboratory will not focus on the handling and set-up of real acoustic equipment but rather on procedures and uncertainty. The case study focuses on the application of the virtual laboratory for facade sound insulation tests according to ISO 140-5:1998 (International Organization for Standardization, Geneva, Switzerland, 1998), and the paper describes the causal and stochastic models and the constraints applied in the virtual environment under consideration. With a simple user interface, the laboratory will provide measurement data that the students will have to process to report the insulation results that must converge with the "virtual true values" in the laboratory. The main advantage of the virtual laboratory is derived from the customization of factors in which the student will be instructed or examined (for instance, background noise correction, the detection of sporadic corrupted observations, and the effect of instrument precision).
Katja — the 24th week of virtual pregnancy for dosimetric calculations
NASA Astrophysics Data System (ADS)
Becker, Janine; Zankl, Maria; Fill, Ute; Hoeschen, Christoph
2008-01-01
Virtual human models, a.k.a. voxel models, are currently the
Stereoscopic virtual reality models for planning tumor resection in the sellar region.
Wang, Shou-sen; Zhang, Shang-ming; Jing, Jun-jie
2012-11-28
It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region. To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery. All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images. The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.
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".
Virtual hybrid test control of sinuous crack
NASA Astrophysics Data System (ADS)
Jailin, Clément; Carpiuc, Andreea; Kazymyrenko, Kyrylo; Poncelet, Martin; Leclerc, Hugo; Hild, François; Roux, Stéphane
2017-05-01
The present study aims at proposing a new generation of experimental protocol for analysing crack propagation in quasi brittle materials. The boundary conditions are controlled in real-time to conform to a predefined crack path. Servo-control is achieved through a full-field measurement technique to determine the pre-set fracture path and a simple predictor model based on linear elastic fracture mechanics to prescribe the boundary conditions on the fly so that the actual crack path follows at best the predefined trajectory. The final goal is to identify, for instance, non-local damage models involving internal lengths. The validation of this novel procedure is performed via a virtual test-case based on an enriched damage model with an internal length scale, a prior chosen sinusoidal crack path and a concrete sample. Notwithstanding the fact that the predictor model selected for monitoring the test is a highly simplified picture of the targeted constitutive law, the proposed protocol exhibits a much improved sensitivity to the sought parameters such as internal lengths as assessed from the comparison with other available experimental tests.
Determinants of virtual water flows in the Mediterranean.
Fracasso, Andrea; Sartori, Martina; Schiavo, Stefano
2016-02-01
The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a "refined" version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger 'export' of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water 'exports' ('imports'). Copyright © 2015 Elsevier B.V. All rights reserved.
A case analysis of INFOMED: the Cuban national health care telecommunications network and portal.
Séror, Ann C
2006-01-27
The Internet and telecommunications technologies contribute to national health care system infrastructures and extend global health care services markets. The Cuban national health care system offers a model to show how a national information portal can contribute to system integration, including research, education, and service delivery as well as international trade in products and services. The objectives of this paper are (1) to present the context of the Cuban national health care system since the revolution in 1959, (2) to identify virtual institutional infrastructures of the system associated with the Cuban National Health Care Telecommunications Network and Portal (INFOMED), and (3) to show how they contribute to Cuban trade in international health care service markets. Qualitative case research methods were used to identify the integrated virtual infrastructure of INFOMED and to show how it reflects socialist ideology. Virtual institutional infrastructures include electronic medical and information services and the structure of national networks linking such services. Analysis of INFOMED infrastructures shows integration of health care information, research, and education as well as the interface between Cuban national information networks and the global Internet. System control mechanisms include horizontal integration and coordination through virtual institutions linked through INFOMED, and vertical control through the Ministry of Public Health and the government hierarchy. Telecommunications technology serves as a foundation for a dual market structure differentiating domestic services from international trade. INFOMED is a model of interest for integrating health care information, research, education, and services. The virtual infrastructures linked through INFOMED support the diffusion of Cuban health care products and services in global markets. Transferability of this model is contingent upon ideology and interpretation of values such as individual intellectual property and confidentiality of individual health information. Future research should focus on examination of these issues and their consequences for global markets in health care.
A Case Analysis of INFOMED: The Cuban National Health Care Telecommunications Network and Portal
2006-01-01
Background The Internet and telecommunications technologies contribute to national health care system infrastructures and extend global health care services markets. The Cuban national health care system offers a model to show how a national information portal can contribute to system integration, including research, education, and service delivery as well as international trade in products and services. Objective The objectives of this paper are (1) to present the context of the Cuban national health care system since the revolution in 1959, (2) to identify virtual institutional infrastructures of the system associated with the Cuban National Health Care Telecommunications Network and Portal (INFOMED), and (3) to show how they contribute to Cuban trade in international health care service markets. Methods Qualitative case research methods were used to identify the integrated virtual infrastructure of INFOMED and to show how it reflects socialist ideology. Virtual institutional infrastructures include electronic medical and information services and the structure of national networks linking such services. Results Analysis of INFOMED infrastructures shows integration of health care information, research, and education as well as the interface between Cuban national information networks and the global Internet. System control mechanisms include horizontal integration and coordination through virtual institutions linked through INFOMED, and vertical control through the Ministry of Public Health and the government hierarchy. Telecommunications technology serves as a foundation for a dual market structure differentiating domestic services from international trade. Conclusions INFOMED is a model of interest for integrating health care information, research, education, and services. The virtual infrastructures linked through INFOMED support the diffusion of Cuban health care products and services in global markets. Transferability of this model is contingent upon ideology and interpretation of values such as individual intellectual property and confidentiality of individual health information. Future research should focus on examination of these issues and their consequences for global markets in health care. PMID:16585025
NASA Astrophysics Data System (ADS)
Freund, Eckhard; Rossmann, Juergen
2002-02-01
In 2004, the European COLUMBUS Module is to be attached to the International Space Station. On the way to the successful planning, deployment and operation of the module, computer generated and animated models are being used to optimize performance. Under contract of the German Space Agency DLR, it has become IRF's task to provide a Projective Virtual Reality System to provide a virtual world built after the planned layout of the COLUMBUS module let astronauts and experimentators practice operational procedures and the handling of experiments. The key features of the system currently being realized comprise the possibility for distributed multi-user access to the virtual lab and the visualization of real-world experiment data. Through the capabilities to share the virtual world, cooperative operations can be practiced easily, but also trainers and trainees can work together more effectively sharing the virtual environment. The capability to visualize real-world data will be used to introduce measured data of experiments into the virtual world online in order to realistically interact with the science-reference model hardware: The user's actions in the virtual world are translated into corresponding changes of the inputs of the science reference model hardware; the measured data is than in turn fed back into the virtual world. During the operation of COLUMBUS, the capabilities for distributed access and the capabilities to visualize measured data through the use of metaphors and augmentations of the virtual world may be used to provide virtual access to the COLUMBUS module, e.g. via Internet. Currently, finishing touches are being put to the system. In November 2001 the virtual world shall be operational, so that besides the design and the key ideas, first experimental results can be presented.
To trade or not to trade: Link prediction in the virtual water network
NASA Astrophysics Data System (ADS)
Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2017-12-01
In the international trade network, links express the (temporary) presence of a commercial exchange of goods between any two countries. Given the dynamical behaviour of the trade network, where links are created and dismissed every year, predicting the link activation/deactivation is an open research question. Through the international trade network of agricultural goods, water resources are 'virtually' transferred from the country of production to the country of consumption. We propose a novel methodology for link prediction applied to the network of virtual water trade. Starting from the assumption of having links between any two countries, we estimate the associated virtual water flows by means of a gravity-law model using country and link characteristics as drivers. We consider the links with estimated flows higher than 1000 m3/year as active links, while the others as non-active links. Flows traded along estimated active links are then re-estimated using a similar but differently-calibrated gravity-law model. We were able to correctly model 84% of the existing links and 93% of the non-existing links in year 2011. It is worth to note that the predicted active links carry 99% of the global virtual water flow; hence, missed links are mainly those where a minimum volume of virtual water is exchanged. Results indicate that, over the period from 1986 to 2011, population, geographical distances between countries, and agricultural efficiency (through fertilizers use) are the major factors driving the link activation and deactivation. As opposed to other (network-based) models for link prediction, the proposed method is able to reconstruct the network architecture without any prior knowledge of the network topology, using only the nodes and links attributes; it thus represents a general method that can be applied to other networks such as food or value trade networks.
Tolerance measurements on internal- and external-hexagon implants.
Braian, Michael; De Bruyn, Hugo; Fransson, Håkan; Christersson, Cecilia; Wennerberg, Ann
2014-01-01
To measure the horizontal machining tolerances of the interface between internal- and external-hexagon implants and analogs with corresponding components after delivery from the manufacturer. These values may be a valuable tool for evaluating increasing misfit caused by fabrication, processing, and wear. Seven implants and seven analogs with external- and internal-hexagon connections (Biomet 3i) with corresponding prefabricated gold cylinders and gold screws, prefabricated cylindric plastic cylinders, and laboratory screws were studied. One set of components from the external and internal groups was measured manually and digitally. Measurements from the test subjects were compared with identical measurements from the virtual model to obtain threshold values. The virtual model was then used to obtain optimally oriented cuts. The horizontal machining tolerances for castable plastic abutments on external implants were 12 ± 89 μm, and for internal implants they were 86 ± 47 μm. Tolerance measurements on prefabricated gold abutments for external implants were 44 ± 9 μm, and for internal implants they were 58 ± 28 μm. The groups with metallic components showed the smallest tolerance at < 50 μm for the external group and < 90 μm for the internal group. The prefabricated plastic cylinder groups ranged from < 100 μm for external and < 130 μm for internal connection.
User Modeling for Contextual Suggestion
2014-11-01
information retrieval literature ( Salton et al., 1975). To apply this metric, we converted the user interest model into a vector representation with all...Discovering Virtual Interest Groups across Chat Rooms, International Conference on Knowledge Management and Information Sharing (KMIS 2012). [7] Salton , G., A
Virtual-optical information security system based on public key infrastructure
NASA Astrophysics Data System (ADS)
Peng, Xiang; Zhang, Peng; Cai, Lilong; Niu, Hanben
2005-01-01
A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.
Innovative Culture, Part 2: Virtual Consultancies - Engaging Talent
2016-01-21
Innovative Culture, Part II: Virtual Consultancies – Engaging Talent January 21, 2016 These are the final briefing slides as approved by...Engaging Talent (Innovative Culture, Part II) – Aims to facilitate and capitalize on the vast capacity for internal consultancy within the DoD...for talent with an industry model that values – and makes effective use of – young, fresh, innovative voices With a huge uniformed workforce
2012-04-23
Interactive Virtual Hair Salon , Presence, (05 2007): 237. doi: 2012/04/17 12:55:26 31 Theodore Kim, Jason Sewall, Avneesh Sud, Ming Lin. Fast...in Games , Utrecht, Netherlands, Nov. 2009. Keynote Speaker, IADIS International Conference on Computer Graphics and Visualization, Portugal, June 2009...Keynote Speaker, ACM Symposium on Virtual Reality Software and Technology, Bordeaux, France, October 2008. Invited Speaker, Motion in Games , Utrecht
Bell, Marnie; Robertson, Della; Weeks, Marlene; Yu, Deborah
2002-01-01
Virtual teams are a phenomenon of the Information Era and their existence in health care is anticipated to increase with technology enhancements such as telehealth and groupware. The mobilization and support of high performing virtual teams are important for leading knowledge-based health professionals in the 21st century. Using an adapted McGrath group development model, the four staged maturation process of a virtual team consisting of four masters students is explored in this paper. The team's development is analyzed addressing the interaction of technology with social and task dynamics. Throughout the project, leadership competencies of value to the group that emerged were demonstrated and incorporated into the development of a leadership competency assessment instrument. The demonstration of these competencies illustrated how they were valued and internalized by the group. In learning about the work of this virtual team, the reader will gain understanding of how leadership impacts virtual team performance.
ERIC Educational Resources Information Center
Leppisaari, Irja; Lee, Okhwa
2012-01-01
A new generation of young learners often described as digital native school children are attitudinally and technically equipped to employ social media as a social process in learning. However, few international virtual learning projects have been implemented and researched. This article examines a trial which aimed to combine viable technology…
An international virtual medical school (IVIMEDS): the future for medical education?
Harden, R M; Hart, I R
2002-05-01
The introduction of new learning technologies, the exponential growth of Internet usage and the advent of the World Wide Web have the potential of changing the face of higher education. There are also demands in medical education for greater globalization, for the development of a common core curriculum, for improving access to training, for more flexible and student-centred training programmes including programmes with multi-professional elements and for maintaining quality while increasing student numbers and working within financial constraints. An international virtual medical school (IVIMEDS) with a high-quality education programme embodying a hybrid model of a blended curriculum of innovative e-learning approaches and the best of traditional face-to-face teaching is one response to these challenges. Fifty leading international medical schools and institutions are participating in a feasibility study. This is exploring: innovative thinking and approaches to the new learning technologies including e-learning and virtual reality; new approaches to curriculum planning and mapping and advanced instructional design based on the use of 'reusable learning objects'; an international perspective on medical education which takes into account the trend to globalization; a flexible curriculum which meets the needs of different students and has the potential of increasing access to medicine.
Link prediction in the network of global virtual water trade
NASA Astrophysics Data System (ADS)
Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca
2016-04-01
Through the international food-trade, water resources are 'virtually' transferred from the country of production to the country of consumption. The international food-trade, thus, implies a network of virtual water flows from exporting to importing countries (i.e., nodes). Given the dynamical behavior of the network, where food-trade relations (i.e., links) are created and dismissed every year, link prediction becomes a challenge. In this study, we propose a novel methodology for link prediction in the virtual water network. The model aims at identifying the main factors (among 17 different variables) driving the creation of a food-trade relation between any two countries, along the period between 1986 and 2011. Furthermore, the model can be exploited to investigate the network configuration in the future, under different possible (climatic and demographic) scenarios. The model grounds the existence of a link between any two nodes on the link weight (i.e., the virtual water flow): a link exists when the nodes exchange a minimum (fixed) volume of virtual water. Starting from a set of potential links between any two nodes, we fit the associated virtual water flows (both the real and the null ones) by means of multivariate linear regressions. Then, links with estimated flows higher than a minimum value (i.e., threshold) are considered active-links, while the others are non-active ones. The discrimination between active and non-active links through the threshold introduces an error (called link-prediction error) because some real links are lost (i.e., missed links) and some non-existing links (i.e., spurious links) are inevitably introduced in the network. The major drivers are those significantly minimizing the link-prediction error. Once the structure of the unweighted virtual water network is known, we apply, again, linear regressions to assess the major factors driving the fluxes traded along (modelled) active-links. Results indicate that, on the one hand, population and fertilizer use, together with link properties (such as the distance between nodes), are the major factors driving the links creation; on the other hand, population, distance, and gross domestic product are essential to model the flux entity. The results are promising since the model is able to correctly predict the 85% of the 16422 food-trade links (15% are missed), by spuriously adding to the real network only the 5% of non-existing links. The link-prediction error, evaluated as the sum of the percentage of missed and spurious links, is around 20% and it is constant over the study period. Only the 0.01% of the global virtual water flow is traded along missed links and an even lower flow is added by the spurious links (0.003%).
The Virtual Solar Observatory: Still a Small Box
NASA Technical Reports Server (NTRS)
Gurman, J. B.; Bogart, R. S.; Davey, A. R.; Dimitoglou, G.; Hill, F.; Hourcle, J. A.; Martens, P. C.; Surez-Sola, I.; Tian, K. Q.; Wampler, S.
2005-01-01
Two and a half years after a design study began, and a year and a half after development commenced, version 1.0 of the Virtual Solar Observatory (VSO) was released at the 2004 Fall AGU meeting. Although internal elements of the VSO have changed, the basic design has remained the same, reflecting the team's belief in the importance of a simple, robust mechanism for registering data provider holdings, initiating queries at the appropriate provider sites, aggregating the responses, allowing the user to iterate before making a final selection, and enabling the delivery of data directly from the providers. In order to make the VSO transparent, lightweight, and portable, the developers employed XML for the registry, SOAP for communication between a VSO instance and data services, and HTML for the graphic user interface (GUI's). We discuss the internal data model, the API, and user responses to various trial GUI's as typical design issues for any virtual observatory. We also discuss the role of the "small box" of data search, identification, and delivery services provided by the VSO in the larger, Sun-Solar System Connection virtual observatory (VxO) scheme.
Comprehensive Numerical Modeling of the Blast Furnace Ironmaking Process
NASA Astrophysics Data System (ADS)
Zhou, Chenn; Tang, Guangwu; Wang, Jichao; Fu, Dong; Okosun, Tyamo; Silaen, Armin; Wu, Bin
2016-05-01
Blast furnaces are counter-current chemical reactors, widely utilized in the ironmaking industry. Hot reduction gases injected from lower regions of the furnace ascend, reacting with the descending burden. Through this reaction process, iron ore is reduced into liquid iron that is tapped from the furnace hearth. Due to the extremely harsh environment inside the blast furnace, it is difficult to measure or observe internal phenomena during operation. Through the collaboration between steel companies and the Center for Innovation through Visualization and Simulation, multiple computational fluid dynamics (CFD) models have been developed to simulate the complex multiphase reacting flow in the three regions of the furnace, the shaft, the raceway, and the hearth. The models have been used effectively to troubleshoot and optimize blast furnace operations. In addition, the CFD models have been integrated with virtual reality. An interactive virtual blast furnace has been developed for training purpose. This paper summarizes the developments and applications of blast furnace CFD models and the virtual blast furnace.
Towards a Framework for Virtual Internationalization
ERIC Educational Resources Information Center
Bruhn, Elisa
2017-01-01
Internationalization and digitalization--how do these two higher education trends go together? Projects dealing with virtual mobility, collaborative online international learning (COIL), or virtual transnational education (TNE) have shown that the link between the international and the digital is not only a theoretical possibility but already a…
[Virtual teaching (e-learning) in Pediatric Urology. Master and expert course programme].
Miguélez-Lago, Carlos; López-Pereira, Pedro; de la Fuente-Madero, José Luis; Caparrós-Cayuela, Aurora
2015-01-01
Currently there is a need for specific training and special dedication to pediatric urology (PU). Nevertheless, we lack of a continuous education program, which must be specific and multidisciplinary. To create a complementary training program in PU with the following differential characteristics: 1) University postgraduate, 2) internationally accredited, 3) multidisciplinary, 4) theoretical and practical, 5) through virtual teaching, 6) with on-site support, 7) academically directed and mentored, 8) based on individual and group self learning, 9) with international faculty and alumni 10) objectively evaluable. We developed two original projects of virtual training courses with practices in PU, Master and Expert following the International University of Andalucía (UNIA) regulations and with the support of the Medical College of Malaga. The Master has a general content one year duration and will be repeated yearly. The Expert course has monographic character, half-year duration and will be repeated yearly with different topics. They are credited 60 and 30 ECTS credits respectively. The course has 3 parts well differentiated in objectives and development: 1. Virtual training 2. On-site hospital practices and, 3. Final work. The alumni answered a questionnaire to evaluate the master at the midpoint. The UNIA has considered viable and approved all 3 projects presented: I PU MASTER (2014-2015), II PU MASTER (2015-2016) and Expert Course on pediatric incontinence (2015-2016)First PU MASTER data.- Registration applications: 60 alumni. Admitted alumni 40; mean age 37 years; 8 nationalities, 57% Spanish, 43% Foreigners. Specialities: Urology 14(35%), Pediatric Surgery 24 (60%), Pediatrics (Pediatric nephrology 1), General Medicine 1. Mid term Master evaluation by the alumni (0-100). Difficulty 60. Quality of the topics 92; complementary materials 90; faculty 90; UNIA virtual Campus 89. The demand of registrations demonstrates the need and interest of a pediatric Urology training program, through Master and Expert Courses. Virtual Training, e-learning, within the Virtual Campus of the UNIA is viable. This self-learning model is being highly valued by the international alumni. We offer an interesting supplement for continuous education in PU.
Virtual day of the midwife: a global 'pyjama party'.
Stewart, Sarah
2014-06-01
The Virtual International Day of the Midwife (VIDM) (www.vidm.org) is an annual online conference designed to break down traditional barriers to continuing professional development (CPD); provide online opportunities for international midwifery networking; and model open access communication and collaboration practices. Whilst the VIDM is designed to reach midwives all around the world, issues of access to the Internet, language and cultural differences prevent some midwives from attending, especially those who live in resource-poor countries. Nevertheless, the VIDM has successfully demonstrated how CPD can be delivered to midwives in a flexible and cost-effective way, as well as bring them together in a truly global open and collaborative environment.
[Scientific significance and prospective application of digitized virtual human].
Zhong, Shi-zhen
2003-03-01
As a cutting-edge research project, digitization of human anatomical information combines conventional medicine with information technology, computer technology, and virtual reality technology. Recent years have seen the establishment of, or the ongoing effort to establish various virtual human models in many countries, on the basis of continuous sections of human body that are digitized by means of computational medicine incorporating information technology to quantitatively simulate human physiological and pathological conditions, and to provide wide prospective applications in the fields of medicine and other disciplines. This article addresses 4 issues concerning the progress in virtual human model researches as the following: (1) Worldwide survey of sectioning and modeling of visible human. American visible human database was completed in 1994, which contains both a male and a female datasets, and has found wide application internationally. South Korea also finished the data collection for a male visible Korean human dataset in 2000. (2) Application of the dataset of Visible Human Project (VHP). This dataset has yielded plentiful fruits in medical education and clinical research, and further plans are proposed and practiced to construct a Physical Human and Physiological Human . (3) Scientific significance and prospect of virtual human studies. Digitized human dataset may eventually contribute to the development of many new high-tech industries. (4) Progress of virtual Chinese human project. The 174th session of Xiangshang Science Conferences held in 2001 marked the initiation of digitized virtual human project in China, and some key techniques have been explored. By now the data-collection process for 4 Chinese virtual human datasets have been successfully completed.
ICCE/ICCAI 2000 Full & Short Papers (Virtual Lab/Classroom/School).
ERIC Educational Resources Information Center
2000
This document contains the following full and short papers on virtual laboratories, classrooms, and schools from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction): (1) "A Collaborative Learning Support System Based on Virtual Environment Server for Multiple…
Virtual Reality Simulation of the International Space Welding Experiment
NASA Technical Reports Server (NTRS)
Phillips, James A.
1996-01-01
Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.
Determining of a robot workspace using the integration of a CAD system with a virtual control system
NASA Astrophysics Data System (ADS)
Herbuś, K.; Ociepka, P.
2016-08-01
The paper presents a method for determining the workspace of an industrial robot using an approach consisting in integration a 3D model of an industrial robot with a virtual control system. The robot model with his work environment, prepared for motion simulation, was created in the “Motion Simulation” module of the Siemens PLM NX software. In the mentioned model components of the “link” type were created which map the geometrical form of particular elements of the robot and the components of “joint” type mapping way of cooperation of components of the “link” type. In the paper is proposed the solution in which the control process of a virtual robot is similar to the control process of a real robot using the manual control panel (teach pendant). For this purpose, the control application “JOINT” was created, which provides the manipulation of a virtual robot in accordance with its internal control system. The set of procedures stored in an .xlsx file is the element integrating the 3D robot model working in the CAD/CAE class system with the elaborated control application.
Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors
NASA Technical Reports Server (NTRS)
Bean, Jacob; Fuller, Chris; Schiller, Noah
2016-01-01
Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.
NASA Astrophysics Data System (ADS)
Zhang, Zhuoying; Yang, Hong; Shi, Minjun
2016-04-01
The North China Plain is the most water scarce region in China. Its water security is closely relevant to interregional water movement, which can be realized by real water transfers and/or virtual water transfers. This study investigates the roles of virtual water trade and real water transfer using Interregional Input-Output model. The results show that the region is receiving 19.4 billion m3/year of virtual water from the interregional trade, while exporting 16.4 billion m3/year of virtual water in the international trade. In balance, the region has a net virtual water gain of 3 billion m3/year from outside. Its virtual water inflow is dominated by agricultural products from other provinces, totalling 16.6 billion m3/year, whilst its virtual water export is dominated by manufacturing sectors to other countries, totalling 11.7 billion m3/year. Both virtual water import and real water transfer from South to North Water Diversion Project are important water supplements for the region. The results of this study provide useful scientific references for the establishment of combating strategies to deal with the water scarcity in the future.
Computer Associates International, CA-ACF2/VM Release 3.1
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
Sik Lányi, Cecília; Laky, Viktória; Tilinger, Adám; Pataky, Ilona; Simon, Lajos; Kiss, Bernadett; Simon, Viktória; Szabó, Júlianna; Páll, Attila
2004-01-01
The multimedia and virtual reality projects performed at our laboratory during the last ten years can be grouped into the following groups: 1) tutorial and entertainment programs for handicapped children, 2) rehabilitation programs for stroke patients and patients with phobias. We have developed multimedia software for handicapped children with various impairments: partial vision, hearing difficulties, locomotive difficulties, mental retardation, dyslexia etc. In the present paper we show the advantages of using multimedia software to develop mental skills in handicapped people and deal with the special needs of handicapped children. For the rehabilitation of stroke patients we have developed a computer-controlled method, which enables - contrary to methods used internationally - not only the establishment of a diagnosis, but also measurement of therapy effectiveness: 1) it enables us to produce a database of patients, which contains not only their personal data but also test results, their drawings and audio recordings, 2) it is in itself an intensive therapeutic test and contains tutorial programs. We are currently collecting test results. We have also developed some virtual worlds for treating phobias: a virtual balcony and a ten-story building with an external glass elevator as well as an internal glass elevator in the virtual Atrium Hyatt hotel. We have developed a virtual environment for treating claustrophobia too: a closed lift and a room where the walls can move. For specific phobias (fear of travelling) we have modelled the underground railway system in Budapest. For autistic children, we have developed virtual shopping software too. In this paper we present the advantages of virtual reality in the investigation, evaluation and treatment of perception, behaviour and neuropsychological disorders.
Vulnerability of countries to food-production crises propagating in the virtual water trade network
NASA Astrophysics Data System (ADS)
Tamea, S.; Laio, F.; Ridolfi, L.
2015-12-01
In recent years, the international trade of food and agricultural commodities has undergone a marked increase of exchanged volumes and an expansion of the trade network. This globalization of trade has both positive and negative effects, but the interconnectedness and external dependency of countries generate complex dynamics which are often difficult to understand and model. In this study we consider the volume of water used for the production of agricultural commodities, virtually exchanged among countries through commodity trade, i.e. the virtual water trade. Then, we set up a parsimonious mechanistic model describing the propagation, into the global trade network, of food-production crises generated locally by a social, economic or environmental event (such as war, economic crisis, drought, pest). The model, accounting for the network structure and the virtual water balance of all countries, bases on rules derived from observed virtual water flows and on data-based and statistically verified assumption. It is also tested on real case studies that prove its capability to capture the main features of crises propagation. The model is then employed as the basis for the development of an index of country vulnerability, measuring the exposure of countries to crises propagating in the virtual water trade network. Results of the analysis are discussed within the context of socio-economic and environmental conditions of countries, showing that not only water-scarce, but also wealthy and globalized countries, are among the most vulnerable to external crises. The temporal analysis for the period 1986-2011 reveals that the global average vulnerability has strongly increased over time, confirming the increased exposure of countries to external crises which may occur in the virtual water trade network.
Ferng, Alice S; Oliva, Isabel; Jokerst, Clinton; Avery, Ryan; Connell, Alana M; Tran, Phat L; Smith, Richard G; Khalpey, Zain
2017-08-01
Since the creation of SynCardia's 50 cc Total Artificial Hearts (TAHs), patients with irreversible biventricular failure now have two sizing options. Herein, a case series of three patients who have undergone successful 50 and 70 cc TAH implantation with complete closure of the chest cavity utilizing preoperative "virtual implantation" of different sized devices for surgical planning are presented. Computed tomography (CT) images were used for preoperative planning prior to TAH implantation. Three-dimensional (3D) reconstructions of preoperative chest CT images were generated and both 50 and 70 cc TAHs were virtually implanted into patients' thoracic cavities. During the simulation, the TAHs were projected over the native hearts in a similar position to the actual implantation, and the relationship between the devices and the atria, ventricles, chest wall, and diaphragm were assessed. The 3D reconstructed images and virtual modeling were used to simulate and determine for each patient if the 50 or 70 cc TAH would have a higher likelihood of successful implantation without complications. Subsequently, all three patients received clinical implants of the properly sized TAH based on virtual modeling, and their chest cavities were fully closed. This virtual implantation increases our confidence that the selected TAH will better fit within the thoracic cavity allowing for improved surgical outcome. Clinical implantation of the TAHs showed that our virtual modeling was an effective method for determining the correct fit and sizing of 50 and 70 cc TAHs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
ERIC Educational Resources Information Center
Gonzalez-Perez, Maria Alejandra; Velez-Calle, Andres; Cathro, Virginia; Caprar, Dan V.; Taras, Vasyl
2014-01-01
The increasing importance of global virtual teams in business is reflected in the classroom by the increased adoption of activities that facilitate real-time cross-cultural interaction. This article documents the experience of students from two Colombian universities who participated in a collaborative international project using virtual teams as…
Virtual laboratories: new opportunities for collaborative water science
NASA Astrophysics Data System (ADS)
Ceola, Serena; Arheimer, Berit; Bloeschl, Guenter; Baratti, Emanuele; Capell, Rene; Castellarin, Attilio; Freer, Jim; Han, Dawei; Hrachowitz, Markus; Hundecha, Yeshewatesfa; Hutton, Christopher; Lindström, Goran; Montanari, Alberto; Nijzink, Remko; Parajka, Juraj; Toth, Elena; Viglione, Alberto; Wagener, Thorsten
2015-04-01
Reproducibility and repeatability of experiments are the fundamental prerequisites that allow researchers to validate results and share hydrological knowledge, experience and expertise in the light of global water management problems. Virtual laboratories offer new opportunities to enable these prerequisites since they allow experimenters to share data, tools and pre-defined experimental procedures (i.e. protocols). Here we present the outcomes of a first collaborative numerical experiment undertaken by five different international research groups in a virtual laboratory to address the key issues of reproducibility and repeatability. Moving from the definition of accurate and detailed experimental protocols, a rainfall-runoff model was independently applied to 15 European catchments by the research groups and model results were collectively examined through a web-based discussion. We found that a detailed modelling protocol was crucial to ensure the comparability and reproducibility of the proposed experiment across groups. Our results suggest that sharing comprehensive and precise protocols and running the experiments within a controlled environment (e.g. virtual laboratory) is as fundamental as sharing data and tools for ensuring experiment repeatability and reproducibility across the broad scientific community and thus advancing hydrology in a more coherent way.
Iris: Constructing and Analyzing Spectral Energy Distributions with the Virtual Observatory
NASA Astrophysics Data System (ADS)
Laurino, O.; Budynkiewicz, J.; Busko, I.; Cresitello-Dittmar, M.; D'Abrusco, R.; Doe, S.; Evans, J.; Pevunova, O.
2014-05-01
We present Iris 2.0, the latest release of the Virtual Astronomical Observatory application for building and analyzing Spectral Energy Distributions (SEDs). With Iris, users may read in and display SEDs inspect and edit any selection of SED data, fit models to SEDs in arbitrary spectral ranges, and calculate confidence limits on best-fit parameters. SED data may be loaded into the application from VOTable and FITS files compliant with the International Virtual Observatoy Alliance interoperable data models, or retrieved directly from NED or the Italian Space Agency Science Data Center; data in non-standard formats may also be converted within the application. Users may seamlessy exchange data between Iris and other Virtual Observatoy tools using the Simple Application Messaging Protocol. Iris 2.0 also provides a tool for redshifting, interpolating, and measuring integratd fluxes, and allows simple aperture corrections for individual points and SED segments. Custom Python functions, template models and template libraries may be imported into Iris for fitting SEDs. Iris may be extended through Java plugins; users can install third-party packages, or develop their own plugin using Iris' Software Development Kit. Iris 2.0 is available for Linux and Mac OS X systems.
Origin and Radiative Forcing of Black Carbon Aerosol: Production and Consumption Perspectives.
Meng, Jing; Liu, Junfeng; Yi, Kan; Yang, Haozhe; Guan, Dabo; Liu, Zhu; Zhang, Jiachen; Ou, Jiamin; Dorling, Stephen; Mi, Zhifu; Shen, Huizhong; Zhong, Qirui; Tao, Shu
2018-05-14
Air pollution, a threat to air quality and human health, has attracted ever-increasing attention in recent years. In addition to having local influence, air pollutants can also travel the globe via atmospheric circulation and international trade. Black carbon (BC), emitted from incomplete combustion, is a unique but representative particulate pollutant. This study tracked down the BC aerosol and its direct radiative forcing to the emission sources and final consumers using the global chemical transport model (MOZART-4), the rapid radiative transfer model for general circulation simulations (RRTM), and a multiregional input-output analysis (MRIO). BC was physically transported (i.e., atmospheric transport) from western to eastern countries in the midlatitude westerlies, but its magnitude is near an order of magnitude higher if the virtual flow embodied in international trade is considered. The transboundary effects on East and South Asia by other regions increased from about 3% (physical transport only) to 10% when considering both physical and virtual transport. The influence efficiency on East Asia was also large because of the comparatively large emission intensity and emission-intensive exports (e.g., machinery and equipment). The radiative forcing in Africa imposed by consumption from Europe, North America, and East Asia (0.01 Wm -2 ) was even larger than the total forcing in North America. Understanding the supply chain and incorporating both atmospheric and virtual transport may improve multilateral cooperation on air pollutant mitigation both domestically and internationally.
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…
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…
A Virtual Educational Exchange: A North-South Virtually Shared Class on Sustainable Development
ERIC Educational Resources Information Center
Abrahamse, Augusta; Johnson, Mathew; Levinson, Nanette; Medsker, Larry; Pearce, Joshua M.; Quiroga, Carla; Scipione, Ruth
2015-01-01
Increasingly, international competence is considered an important skill to be acquired from an undergraduate education. Because international exchange presents a challenge to many students, there is a need to develop and implement alternative means for incorporating international and cross-cultural experiences into the undergraduate classroom. We…
National water, food, and trade modeling framework: The case of Egypt.
Abdelkader, A; Elshorbagy, A; Tuninetti, M; Laio, F; Ridolfi, L; Fahmy, H; Hoekstra, A Y
2018-10-15
This paper introduces a modeling framework for the analysis of real and virtual water flows at national scale. The framework has two components: (1) a national water model that simulates agricultural, industrial and municipal water uses, and available water and land resources; and (2) an international virtual water trade model that captures national virtual water exports and imports related to trade in crops and animal products. This National Water, Food & Trade (NWFT) modeling framework is applied to Egypt, a water-poor country and the world's largest importer of wheat. Egypt's food and water gaps and the country's food (virtual water) imports are estimated over a baseline period (1986-2013) and projected up to 2050 based on four scenarios. Egypt's food and water gaps are growing rapidly as a result of steep population growth and limited water resources. The NWFT modeling framework shows the nexus of the population dynamics, water uses for different sectors, and their compounding effects on Egypt's food gap and water self-sufficiency. The sensitivity analysis reveals that for solving Egypt's water and food problem non-water-based solutions like educational, health, and awareness programs aimed at lowering population growth will be an essential addition to the traditional water resources development solution. Both the national and the global models project similar trends of Egypt's food gap. The NWFT modeling framework can be easily adapted to other nations and regions. Copyright © 2018. Published by Elsevier B.V.
Ex-Nihilo: Obstacles Surrounding Teaching the Standard Model
ERIC Educational Resources Information Center
Pimbblet, Kevin A.
2002-01-01
The model of the Big Bang is an integral part of the national curricula in England and Wales. Previous work (e.g. Baxter 1989) has shown that pupils often come into education with many and varied prior misconceptions emanating from both internal and external sources. Whilst virtually all of these misconceptions can be remedied, there will remain…
NASA Astrophysics Data System (ADS)
McGlynn, Thomas; Fabbiano, Giuseppina; Accomazzi, Alberto; Smale, Alan; White, Richard L.; Donaldson, Thomas; Aloisi, Alessandra; Dower, Theresa; Mazzerella, Joseph M.; Ebert, Rick; Pevunova, Olga; Imel, David; Berriman, Graham B.; Teplitz, Harry I.; Groom, Steve L.; Desai, Vandana R.; Landry, Walter
2016-07-01
Since the turn of the millennium a constant concern of astronomical archives have begun providing data to the public through standardized protocols unifying data from disparate physical sources and wavebands across the electromagnetic spectrum into an astronomical virtual observatory (VO). In October 2014, NASA began support for the NASA Astronomical Virtual Observatories (NAVO) program to coordinate the efforts of NASA astronomy archives in providing data to users through implementation of protocols agreed within the International Virtual Observatory Alliance (IVOA). A major goal of the NAVO collaboration has been to step back from a piecemeal implementation of IVOA standards and define what the appropriate presence for the US and NASA astronomy archives in the VO should be. This includes evaluating what optional capabilities in the standards need to be supported, the specific versions of standards that should be used, and returning feedback to the IVOA, to support modifications as needed. We discuss a standard archive model developed by the NAVO for data archive presence in the virtual observatory built upon a consistent framework of standards defined by the IVOA. Our standard model provides for discovery of resources through the VO registries, access to observation and object data, downloads of image and spectral data and general access to archival datasets. It defines specific protocol versions, minimum capabilities, and all dependencies. The model will evolve as the capabilities of the virtual observatory and needs of the community change.
NASA Technical Reports Server (NTRS)
McGlynn, Thomas; Guiseppina, Fabbiano A; Accomazzi, Alberto; Smale, Alan; White, Richard L.; Donaldson, Thomas; Aloisi, Alessandra; Dower, Theresa; Mazzerella, Joseph M.; Ebert, Rick;
2016-01-01
Since the turn of the millennium a constant concern of astronomical archives have begun providing data to the public through standardized protocols unifying data from disparate physical sources and wavebands across the electromagnetic spectrum into an astronomical virtual observatory (VO). In October 2014, NASA began support for the NASA Astronomical Virtual Observatories (NAVO) program to coordinate the efforts of NASA astronomy archives in providing data to users through implementation of protocols agreed within the International Virtual Observatory Alliance (IVOA). A major goal of the NAVO collaboration has been to step back from a piecemeal implementation of IVOA standards and define what the appropriate presence for the US and NASA astronomy archives in the VO should be. This includes evaluating what optional capabilities in the standards need to be supported, the specific versions of standards that should be used, and returning feedback to the IVOA, to support modifications as needed. We discuss a standard archive model developed by the NAVO for data archive presence in the virtual observatory built upon a consistent framework of standards defined by the IVOA. Our standard model provides for discovery of resources through the VO registries, access to observation and object data, downloads of image and spectral data and general access to archival datasets. It defines specific protocol versions, minimum capabilities, and all dependencies. The model will evolve as the capabilities of the virtual observatory and needs of the community change.
Visualization and dissemination of global crustal models on virtual globes
NASA Astrophysics Data System (ADS)
Zhu, Liang-feng; Pan, Xin; Sun, Jian-zhong
2016-05-01
Global crustal models, such as CRUST 5.1 and its descendants, are very useful in a broad range of geoscience applications. The current method for representing the existing global crustal models relies heavily on dedicated computer programs to read and work with those models. Therefore, it is not suited to visualize and disseminate global crustal information to non-geological users. This shortcoming is becoming obvious as more and more people from both academic and non-academic institutions are interested in understanding the structure and composition of the crust. There is a pressing need to provide a modern, universal and user-friendly method to represent and visualize the existing global crustal models. In this paper, we present a systematic framework to easily visualize and disseminate the global crustal structure on virtual globes. Based on crustal information exported from the existing global crustal models, we first create a variety of KML-formatted crustal models with different levels of detail (LODs). And then the KML-formatted models can be loaded into a virtual globe for 3D visualization and model dissemination. A Keyhole Markup Language (KML) generator (Crust2KML) is developed to automatically convert crustal information obtained from the CRUST 1.0 model into KML-formatted global crustal models, and a web application (VisualCrust) is designed to disseminate and visualize those models over the Internet. The presented framework and associated implementations can be conveniently exported to other applications to support visualizing and analyzing the Earth's internal structure on both regional and global scales in a 3D virtual-globe environment.
Prosthetic Leg Control in the Nullspace of Human Interaction.
Gregg, Robert D; Martin, Anne E
2016-07-01
Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection.
Villa, C; Olsen, K B; Hansen, S H
2017-09-01
Post-mortem CT scanning (PMCT) has been introduced at several forensic medical institutions many years ago and has proved to be a useful tool. 3D models of bones, skin, internal organs and bullet paths can rapidly be generated using post-processing software. These 3D models reflect the individual physiognomics and can be used to create whole-body 3D virtual animations. In such way, virtual reconstructions of the probable ante-mortem postures of victims can be constructed and contribute to understand the sequence of events. This procedure is demonstrated in two victims of gunshot injuries. Case #1 was a man showing three perforating gunshot wounds, who died due to the injuries of the incident. Whole-body PMCT was performed and 3D reconstructions of bones, relevant internal organs and bullet paths were generated. Using 3ds Max software and a human anatomy 3D model, a virtual animated body was built and probable ante-mortem postures visualized. Case #2 was a man presenting three perforating gunshot wounds, who survived the incident: one in the left arm and two in the thorax. Only CT scans of the thorax, abdomen and the injured arm were provided by the hospital. Therefore, a whole-body 3D model reflecting the anatomical proportions of the patient was made combining the actual bones of the victim with those obtained from the human anatomy 3D model. The resulted 3D model was used for the animation process. Several probable postures were also visualized in this case. It has be shown that in Case #1 the lesions and the bullet path were not consistent with an upright standing position; instead, the victim was slightly bent forward, i.e. he was sitting or running when he was shot. In Case #2, one of the bullets could have passed through the arm and continued into the thorax. In conclusion, specialized 3D modelling and animation techniques allow for the reconstruction of ante-mortem postures based on both PMCT and clinical CT. Copyright © 2017 Elsevier B.V. All rights reserved.
An assessment of the realism of digital human manikins used for simulation in ergonomics.
Nérot, Agathe; Skalli, Wafa; Wang, Xuguang
2015-01-01
In this study, the accuracy of the joint centres of the manikins generated by RAMSIS and Human Builder (HB), two digital human modelling (DHM) systems widely used in industry for virtual ergonomics simulation, was investigated. Eighteen variously sized females and males were generated from external anthropometric dimensions and six joint centres (knee, hip and four spine joints) were compared with their anatomic locations obtained from the three-dimensional reconstructed bones from a low-dose X-ray system. Both RAMSIS and HB could correctly reproduce external anthropometric dimensions, while the estimation of internal joint centres location presented an average error of 27.6 mm for HB and 38.3 mm for RAMSIS. Differences between both manikins showed that a more realistic kinematic linkage led to better accuracy in joint location. This study opens the way to further research on the relationship between the external body geometry and internal skeleton in order to improve the realism of the internal skeleton of DHMs, especially for a biomechanical analysis requiring information of joint load and muscle force estimation. This study assessed two digital human modelling (DHM) systems widely used in industry for virtual ergonomics. Results support the need of a more realistic human modelling, especially for a biomechanical analysis and a standardisation of DHMs.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-15
... Providence Equity Partners VI, L.P. G Virtual Radiologic Corporation. G Virtual Radiologic Corporation. 03... Charles River Laboratories International, Inc. G Charles River Laboratories International, Inc. 20100800 G...
Raising Virtual Laboratories in Australia onto global platforms
NASA Astrophysics Data System (ADS)
Wyborn, L. A.; Barker, M.; Fraser, R.; Evans, B. J. K.; Moloney, G.; Proctor, R.; Moise, A. F.; Hamish, H.
2016-12-01
Across the globe, Virtual Laboratories (VLs), Science Gateways (SGs), and Virtual Research Environments (VREs) are being developed that enable users who are not co-located to actively work together at various scales to share data, models, tools, software, workflows, best practices, etc. Outcomes range from enabling `long tail' researchers to more easily access specific data collections, to facilitating complex workflows on powerful supercomputers. In Australia, government funding has facilitated the development of a range of VLs through the National eResearch Collaborative Tools and Resources (NeCTAR) program. The VLs provide highly collaborative, research-domain oriented, integrated software infrastructures that meet user community needs. Twelve VLs have been funded since 2012, including the Virtual Geophysics Laboratory (VGL); Virtual Hazards, Impact and Risk Laboratory (VHIRL); Climate and Weather Science Laboratory (CWSLab); Marine Virtual Laboratory (MarVL); and Biodiversity and Climate Change Virtual Laboratory (BCCVL). These VLs share similar technical challenges, with common issues emerging on integration of tools, applications and access data collections via both cloud-based environments and other distributed resources. While each VL began with a focus on a specific research domain, communities of practice have now formed across the VLs around common issues, and facilitate identification of best practice case studies, and new standards. As a result, tools are now being shared where the VLs access data via data services using international standards such as ISO, OGC, W3C. The sharing of these approaches is starting to facilitate re-usability of infrastructure and is a step towards supporting interdisciplinary research. Whilst the focus of the VLs are Australia-centric, by using standards, these environments are able to be extended to analysis on other international datasets. Many VL datasets are subsets of global datasets and so extension to global is a small (and often requested) step. Similarly, most of the tools, software, and other technologies could be shared across infrastructures globally. Therefore, it is now time to better connect the Australian VLs with similar initiatives elsewhere to create international platforms that can contribute to global research challenges.
Kong, Seong-Ho; Haouchine, Nazim; Soares, Renato; Klymchenko, Andrey; Andreiuk, Bohdan; Marques, Bruno; Shabat, Galyna; Piechaud, Thierry; Diana, Michele; Cotin, Stéphane; Marescaux, Jacques
2017-07-01
Augmented reality (AR) is the fusion of computer-generated and real-time images. AR can be used in surgery as a navigation tool, by creating a patient-specific virtual model through 3D software manipulation of DICOM imaging (e.g., CT scan). The virtual model can be superimposed to real-time images enabling transparency visualization of internal anatomy and accurate localization of tumors. However, the 3D model is rigid and does not take into account inner structures' deformations. We present a concept of automated AR registration, while the organs undergo deformation during surgical manipulation, based on finite element modeling (FEM) coupled with optical imaging of fluorescent surface fiducials. Two 10 × 1 mm wires (pseudo-tumors) and six 10 × 0.9 mm fluorescent fiducials were placed in ex vivo porcine kidneys (n = 10). Biomechanical FEM-based models were generated from CT scan. Kidneys were deformed and the shape changes were identified by tracking the fiducials, using a near-infrared optical system. The changes were registered automatically with the virtual model, which was deformed accordingly. Accuracy of prediction of pseudo-tumors' location was evaluated with a CT scan in the deformed status (ground truth). In vivo: fluorescent fiducials were inserted under ultrasound guidance in the kidney of one pig, followed by a CT scan. The FEM-based virtual model was superimposed on laparoscopic images by automatic registration of the fiducials. Biomechanical models were successfully generated and accurately superimposed on optical images. The mean measured distance between the estimated tumor by biomechanical propagation and the scanned tumor (ground truth) was 0.84 ± 0.42 mm. All fiducials were successfully placed in in vivo kidney and well visualized in near-infrared mode enabling accurate automatic registration of the virtual model on the laparoscopic images. Our preliminary experiments showed the potential of a biomechanical model with fluorescent fiducials to propagate the deformation of solid organs' surface to their inner structures including tumors with good accuracy and automatized robust tracking.
Behavior believability in virtual worlds: agents acting when they need to.
Avradinis, Nikos; Panayiotopoulos, Themis; Anastassakis, George
2013-12-01
Believability has been a perennial goal for the intelligent virtual agent community. One important aspect of believability largely consists in demonstrating autonomous behavior, consistent with the agent's personality and motivational state, as well as the world conditions. Autonomy, on behalf of the agent, implies the existence of an internal structure and mechanism that allows the agent to have its own needs and interests, based on which the agent will dynamically select and generate goals that will in turn lead to self-determined behavior. Intrinsic motivation allows the agent to function and demonstrate behavior, even when no external stimulus is present, due to the constant change of its internal emotional and physiological state. The concept of motivation has already been investigated by research works on intelligent agents, trying to achieve autonomy. The current work presents an architecture and model to represent and manage internal driving factors in intelligent virtual agents, using the concept of motivations. Based on Maslow and Alderfer's bio-psychological needs theories, we present a motivational approach to represent human needs and produce emergent behavior through motivation synthesis. Particular attention is given to basic, physiological level needs, which are the basis of behavior and can produce tendency to action even when there is no other interaction with the environment.
Analyses of impacts of China's international trade on its water resources and uses
NASA Astrophysics Data System (ADS)
Zhang, Z. Y.; Yang, H.; Shi, M. J.; Zehnder, A. J. B.; Abbaspour, K. C.
2011-04-01
This study provides an insight into the impact of China's international trade of goods and services on its water resources and uses. Virtual water flows associated with China's international trade are quantified in an input-output framework. The analysis is scaled down to the sectoral and provincial levels to trace the origins and destinations of virtual water flows associated with the international trade. The results reveal that China is a net virtual water exporter of 4.7 × 1010 m3 year-1, accounting for 2.1% of its total water resources and 8.9% of the total water use. Water scarce regions tend to have higher percentages of virtual water export relative to their water resources and water uses. In the water scarce Huang-Huai-Hai region, the net virtual water export accounts for 7.9% of the region's water resources and 11.2% of its water uses. For individual sectors, major net virtual water exporters are those where agriculture provides raw materials in the initial process of the production chain and/or pollution intensity is high. The results suggest that China's economic gains from being a world "manufacture factory" have come at a high cost to its water resources and through pollution to its environment.
Spatial organization and drivers of the virtual water trade: a community-structure analysis
NASA Astrophysics Data System (ADS)
D'Odorico, Paolo; Carr, Joel; Laio, Francesco; Ridolfi, Luca
2012-09-01
The trade of agricultural commodities can be associated with a virtual transfer of the local freshwater resources used for the production of these goods. Thus, trade of food products virtually transfers large amounts of water from areas of food production to far consumption regions, a process termed the ‘globalization of water’. We consider the (time-varying) community structure of the virtual water network for the years 1986-2008. The communities are groups of countries with dense internal connections, while the connections are sparser among different communities. Between 1986 and 2008, the ratio between virtual water flows within communities and the total global trade of virtual water has continuously increased, indicating the existence of well defined clusters of virtual water transfers. In some cases (e.g. Central and North America and Europe in recent years) the virtual water communities correspond to geographically coherent regions, suggesting the occurrence of an ongoing process of regionalization of water resources. However, most communities also include countries located on different ‘sides’ of the world. As such, geographic proximity only partly explains the community structure of virtual water trade. Similarly, the global distribution of people and wealth, whose effect on the virtual water trade is expressed through simple ‘gravity models’, is unable to explain the strength of virtual water communities observed in the past few decades. A gravity model based on the availability of and demand for virtual water in different countries has higher explanatory power, but the drivers of the virtual water fluxes are yet to be adequately identified.
An integrated 3D log processing optimization system for small sawmills in central Appalachia
Wenshu Lin; Jingxin Wang
2013-01-01
An integrated 3D log processing optimization system was developed to perform 3D log generation, opening face determination, headrig log sawing simulation, fl itch edging and trimming simulation, cant resawing, and lumber grading. A circular cross-section model, together with 3D modeling techniques, was used to reconstruct 3D virtual logs. Internal log defects (knots)...
NASA Technical Reports Server (NTRS)
Gibbs, K. E.; Schmidt, G. K.
2017-01-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on re-search at the intersection of science and exploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. This talk will describe the international partner re-search efforts and how we are engaging the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships.
Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries.
Thali, Michael J; Braun, Marcel; Dirnhofer, Richard
2003-11-26
Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.
Europlanet/IDIS: Combining Diverse Planetary Observations and Models
NASA Astrophysics Data System (ADS)
Schmidt, Walter; Capria, Maria Teresa; Chanteur, Gerard
2013-04-01
Planetary research involves a diversity of research fields from astrophysics and plasma physics to atmospheric physics, climatology, spectroscopy and surface imaging. Data from all these disciplines are collected from various space-borne platforms or telescopes, supported by modelling teams and laboratory work. In order to interpret one set of data often supporting data from different disciplines and other missions are needed while the scientist does not always have the detailed expertise to access and utilize these observations. The Integrated and Distributed Information System (IDIS) [1], developed in the framework of the Europlanet-RI project, implements a Virtual Observatory approach ([2] and [3]), where different data sets, stored in archives around the world and in different formats, are accessed, re-formatted and combined to meet the user's requirements without the need of familiarizing oneself with the different technical details. While observational astrophysical data from different observatories could already earlier be accessed via Virtual Observatories, this concept is now extended to diverse planetary data and related model data sets, spectral data bases etc. A dedicated XML-based Europlanet Data Model (EPN-DM) [4] was developed based on data models from the planetary science community and the Virtual Observatory approach. A dedicated editor simplifies the registration of new resources. As the EPN-DM is a super-set of existing data models existing archives as well as new spectroscopic or chemical data bases for the interpretation of atmospheric or surface observations, or even modeling facilities at research institutes in Europe or Russia can be easily integrated and accessed via a Table Access Protocol (EPN-TAP) [5] adapted from the corresponding protocol of the International Virtual Observatory Alliance [6] (IVOA-TAP). EPN-TAP allows to search catalogues, retrieve data and make them available through standard IVOA tools if the access to the archive is compatible with IVOA standards. For some major data archives with different standards adaptation tools are available to make the access transparent to the user. EuroPlaNet-IDIS has contributed to the definition of PDAP, the Planetary Data Access Protocol of the International Planetary Data Alliance (IPDA) [7] to access the major planetary data archives of NASA in the USA [8], ESA in Europe [9] and JAXA in Japan [10]. Acknowledgement: Europlanet-RI was funded by the European Commission under the 7th Framework Program, grant 228319 "Capacities Specific Programme" - Research Infrastructures Action. Reference: [1] Details to IDIS and the Europlanet-RI via Web-site: http://www.idis.europlanet-ri.eu/ [2] Demonstrator implementation for Plasma-VO AMDA: http://cdpp-amda.cesr.fr/DDHTML/index.html [3] Demonstrator implementation for the IDIS-VO: http://www.idis-dyn.europlanet-ri.eu/vodev.shtml [4] Europlanet Data Model EPN-DM: http://www.europlanet-idis.fi/documents/public_documents/EPN-DM-v2.0.pdf [5] Europlanet Table Access Protocol EPN-TAP: http://www.europlanet-idis.fi/documents/public_documents/EPN-TAPV_0.26.pdf [6] International Virtual Observatory Alliance IVOA: http://www.ivoa.net [7] International Planetary Data Alliance IPDA: http://planetarydata.org/ [8] NASA's Planetary Data System: http://pds.jpl.nasa.gov/ [9] ESA's Planetary Science Archive PSA: http://www.sciops.esa.int/index.php?project=PSA [10] JAXAs Data Archive and Transmission System DARTS: http://darts.isas.jaxa.jp/
Intelligent Virtual Station (IVS)
NASA Technical Reports Server (NTRS)
2002-01-01
The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.
Russo, Marta; Cesqui, Benedetta; La Scaleia, Barbara; Ceccarelli, Francesca; Maselli, Antonella; Moscatelli, Alessandro; Zago, Myrka; Lacquaniti, Francesco; d'Avella, Andrea
2017-10-01
To accurately time motor responses when intercepting falling balls we rely on an internal model of gravity. However, whether and how such a model is also used to estimate the spatial location of interception is still an open question. Here we addressed this issue by asking 25 participants to intercept balls projected from a fixed location 6 m in front of them and approaching along trajectories with different arrival locations, flight durations, and gravity accelerations (0 g and 1 g ). The trajectories were displayed in an immersive virtual reality system with a wide field of view. Participants intercepted approaching balls with a racket, and they were free to choose the time and place of interception. We found that participants often achieved a better performance with 1 g than 0 g balls. Moreover, the interception points were distributed along the direction of a 1 g path for both 1 g and 0 g balls. In the latter case, interceptions tended to cluster on the upper half of the racket, indicating that participants aimed at a lower position than the actual 0 g path. These results suggest that an internal model of gravity was probably used in predicting the interception locations. However, we found that the difference in performance between 1 g and 0 g balls was modulated by flight duration, the difference being larger for faster balls. In addition, the number of peaks in the hand speed profiles increased with flight duration, suggesting that visual information was used to adjust the motor response, correcting the prediction to some extent. NEW & NOTEWORTHY Here we show that an internal model of gravity plays a key role in predicting where to intercept a fast-moving target. Participants also assumed an accelerated motion when intercepting balls approaching in a virtual environment at constant velocity. We also show that the role of visual information in guiding interceptive movement increases when more time is available. Copyright © 2017 the American Physiological Society.
World Reaction to Virtual Space
NASA Technical Reports Server (NTRS)
1999-01-01
DRaW Computing developed virtual reality software for the International Space Station. Open Worlds, as the software has been named, can be made to support Java scripting and virtual reality hardware devices. Open Worlds permits the use of VRML script nodes to add virtual reality capabilities to the user's applications.
The Virtual Astronomical Observatory: Re-engineering access to astronomical data
NASA Astrophysics Data System (ADS)
Hanisch, R. J.; Berriman, G. B.; Lazio, T. J. W.; Emery Bunn, S.; Evans, J.; McGlynn, T. A.; Plante, R.
2015-06-01
The US Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the US coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the US National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards within the International Virtual Observatory Alliance. The VAO also demonstrated how an operational virtual observatory could be deployed, providing a robust operational environment in which VO services worldwide were routinely checked for aliveness and compliance with international standards. Finally, the VAO engaged in community outreach, developing a comprehensive web site with on-line tutorials, announcements, links to both US and internationally developed tools and services, and exhibits and hands-on training at annual meetings of the American Astronomical Society and through summer schools and community days. All digital products of the VAO Project, including software, documentation, and tutorials, are stored in a repository for community access. The enduring legacy of the VAO is an increasing expectation that new telescopes and facilities incorporate VO capabilities during the design of their data management systems.
E-Global Library: The Academic Campus Library Meets the Internet.
ERIC Educational Resources Information Center
Heilig, Jean M.
2001-01-01
Describes e-global library, the first Internet-based virtual library designed for online students at Jones International University and that has grown into a separately licensable product. Highlights include marketing to other academic libraries, both online and traditional; fees; the e-global library model; collection development policies;…
Predictive Modeling of the CDRA 4BMS
NASA Technical Reports Server (NTRS)
Coker, Robert; Knox, James
2016-01-01
Fully predictive models of the Four Bed Molecular Sieve of the Carbon Dioxide Removal Assembly on the International Space Station are being developed. This virtual laboratory will be used to help reduce mass, power, and volume requirements for future missions. In this paper we describe current and planned modeling developments in the area of carbon dioxide removal to support future crewed Mars missions as well as the resolution of anomalies observed in the ISS CDRA.
NASA Astrophysics Data System (ADS)
Ikelle, Luc T.
2006-02-01
We here describe one way of constructing internal multiples from surface seismic data only. The key feature of our construct of internal multiples is the introduction of the concept of virtual seismic events. Virtual events here are events, which are not directly recorded in standard seismic data acquisition, but their existence allows us to construct internal multiples with scattering points at the sea surface; the standard construct of internal multiples does not include any scattering points at the sea surface. The mathematical and computational operations invoked in our construction of virtual events and internal multiples are similar to those encountered in the construction of free-surface multiples based on the Kirchhoff or Born scattering theory. For instance, our construct operates on one temporal frequency at a time, just like free-surface demultiple algorithms; other internal multiple constructs tend to require all frequencies for the computation of an internal multiple at a given frequency. It does not require any knowledge of the subsurface nor an explicit knowledge of specific interfaces that are responsible for the generation of internal multiples in seismic data. However, our construct requires that the data be divided into two, three or four windows to avoid generating primaries. This segmentation of the data also allows us to select a range of periods of internal multiples that one wishes to construct because, in the context of the attenuation of internal multiples, it is important to avoid generating short-period internal multiples that may constructively average to form primaries at the seismic scale.
Combination of surface and borehole seismic data for robust target-oriented imaging
NASA Astrophysics Data System (ADS)
Liu, Yi; van der Neut, Joost; Arntsen, Børge; Wapenaar, Kees
2016-05-01
A novel application of seismic interferometry (SI) and Marchenko imaging using both surface and borehole data is presented. A series of redatuming schemes is proposed to combine both data sets for robust deep local imaging in the presence of velocity uncertainties. The redatuming schemes create a virtual acquisition geometry where both sources and receivers lie at the horizontal borehole level, thus only a local velocity model near the borehole is needed for imaging, and erroneous velocities in the shallow area have no effect on imaging around the borehole level. By joining the advantages of SI and Marchenko imaging, a macrovelocity model is no longer required and the proposed schemes use only single-component data. Furthermore, the schemes result in a set of virtual data that have fewer spurious events and internal multiples than previous virtual source redatuming methods. Two numerical examples are shown to illustrate the workflow and to demonstrate the benefits of the method. One is a synthetic model and the other is a realistic model of a field in the North Sea. In both tests, improved local images near the boreholes are obtained using the redatumed data without accurate velocities, because the redatumed data are close to the target.
Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization.
Cui, Dongmei; Lynch, James C; Smith, Andrew D; Wilson, Timothy D; Lehman, Michael N
2016-01-01
Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin. © 2015 American Association of Anatomists.
Virtual occlusal definition for orthognathic surgery.
Liu, X J; Li, Q Q; Zhang, Z; Li, T T; Xie, Z; Zhang, Y
2016-03-01
Computer-assisted surgical simulation is being used increasingly in orthognathic surgery. However, occlusal definition is still undertaken using model surgery with subsequent digitization via surface scanning or cone beam computed tomography. A software tool has been developed and a workflow set up in order to achieve a virtual occlusal definition. The results of a validation study carried out on 60 models of normal occlusion are presented. Inter- and intra-user correlation tests were used to investigate the reproducibility of the manual setting point procedure. The errors between the virtually set positions (test) and the digitized manually set positions (gold standard) were compared. The consistency in virtual set positions performed by three individual users was investigated by one way analysis of variance test. Inter- and intra-observer correlation coefficients for manual setting points were all greater than 0.95. Overall, the median error between the test and the gold standard positions was 1.06mm. Errors did not differ among teeth (F=0.371, P>0.05). The errors were not significantly different from 1mm (P>0.05). There were no significant differences in the errors made by the three independent users (P>0.05). In conclusion, this workflow for virtual occlusal definition was found to be reliable and accurate. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
International Virtual Observatory System for Water Resources Information
NASA Astrophysics Data System (ADS)
Leinenweber, Lewis; Bermudez, Luis
2013-04-01
Sharing, accessing, and integrating hydrologic and climatic data have been identified as a critical need for some time. The current state of data portals, standards, technologies, activities, and expertise can be leverage to develop an initial operational capability for a virtual observatory system. This system will allow to link observations data with stream networks and models, and to solve semantic inconsistencies among communities. Prototyping a virtual observatory system is an inter-disciplinary, inter-agency and international endeavor. The Open Geospatial Consortium (OGC) within the OGC Interoperability Program provides the process and expertise to run such collaborative effort. The OGC serves as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. The project coordinated by OGC that is advancing an international virtual observatory system for water resources information is called Climatology-Hydrology Information Sharing Pilot, Phase 1 (CHISP-1). It includes observations and forecasts in the U.S. and Canada levering current networks and capabilities. It is designed to support the following use cases: 1) Hydrologic modeling for historical and near-future stream flow and groundwater conditions. Requires the integration of trans-boundary stream flow and groundwater well data, as well as national river networks (US NHD and Canada NHN) from multiple agencies. Emphasis will be on time series data and real-time flood monitoring. 2) Modeling and assessment of nutrient load into the lakes. Requires accessing water-quality data from multiple agencies and integrating with stream flow information for calculating loads. Emphasis on discrete sampled water quality observations, linking those to specific NHD stream reaches and catchments, and additional metadata for sampled data. The key objectives of these use cases are: 1) To link observations data to the stream network, enabling queries of conditions upstream from a given location to return all relevant gages and well locations. This is currently not practical with the data sources available. 2) To bridge differences in semantics across information models and processes used by the various data producers, to improve the hydrologic and water quality modeling capabilities. Other expected benefits to be derived from this project include: - Leverage a large body of existing data holdings and related activities of multiple agencies in the US and Canada. - Influence data and metadata standards used internationally for web-based information sharing, through multiple agency cooperation and OGC standards setting process. - Reduction of procurement risk through partnership-based development of an initial operating capability verses the cost for building a fully operational system using a traditional "waterfall approach". - Identification and clarification of what is possible, and of the key technical and non-technical barriers to continued progress in sharing and integrating hydrologic and climatic information. - Promote understanding and strengthen ties within the hydro-climatic community. This is anticipated to be the first phase of a multi-phase project, with future work on forecasting the hydrologic consequences of extreme weather events, and enabling more sophisticated water quality modeling.
CCSDS Advanced Orbiting Systems Virtual Channel Access Service for QoS MACHETE Model
NASA Technical Reports Server (NTRS)
Jennings, Esther H.; Segui, John S.
2011-01-01
To support various communications requirements imposed by different missions, interplanetary communication protocols need to be designed, validated, and evaluated carefully. Multimission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE), described in "Simulator of Space Communication Networks" (NPO-41373), NASA Tech Briefs, Vol. 29, No. 8 (August 2005), p. 44, combines various tools for simulation and performance analysis of space networks. The MACHETE environment supports orbital analysis, link budget analysis, communications network simulations, and hardware-in-the-loop testing. By building abstract behavioral models of network protocols, one can validate performance after identifying the appropriate metrics of interest. The innovators have extended the MACHETE model library to include a generic link-layer Virtual Channel (VC) model supporting quality-of-service (QoS) controls based on IP streams. The main purpose of this generic Virtual Channel model addition was to interface fine-grain flow-based QoS (quality of service) between the network and MAC layers of the QualNet simulator, a commercial component of MACHETE. This software model adds the capability of mapping IP streams, based on header fields, to virtual channel numbers, allowing extended QoS handling at link layer. This feature further refines the QoS v existing at the network layer. QoS at the network layer (e.g. diffserv) supports few QoS classes, so data from one class will be aggregated together; differentiating between flows internal to a class/priority is not supported. By adding QoS classification capability between network and MAC layers through VC, one maps multiple VCs onto the same physical link. Users then specify different VC weights, and different queuing and scheduling policies at the link layer. This VC model supports system performance analysis of various virtual channel link-layer QoS queuing schemes independent of the network-layer QoS systems.
Virtual groundwater transfers from overexploited aquifers in the United States
Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J.
2015-01-01
The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use. PMID:26124137
Virtual groundwater transfers from overexploited aquifers in the United States.
Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J
2015-07-14
The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.
The use of virtual reality simulation of head trauma in a surgical boot camp.
Vergara, Victor M; Panaiotis; Kingsley, Darra; Alverson, Dale C; Godsmith, Timothy; Xia, Shan; Caudell, Thomas P
2009-01-01
Surgical "boot camps" provide excellent opportunities to enhance orientation, learning, and preparation of new surgery interns as they enter the clinical arena. This paper describes the utilization of an interactive virtual reality (VR) simulation and associated virtual patient (VP) as an additional tool for surgical boot camps. Complementing other forms of simulation, virtual patients (VPs) require less specialized equipment and can also provide a wide variety of medical scenarios. In this paper we discuss a study that measured the learning effectiveness of a real-world VP simulation used by a class of new surgery interns who operated it with a standard computer interface. The usability of the simulator as a learning tool has been demonstrated and measured. This study brings the use of VR simulation with VPs closer to wider application and integration into a training curriculum, such as a surgery intern boot camp.
Magnetic Polarizability of Virtual (s\\bar{s}) and (c\\bar{c}) Pairs in the Nucleon
NASA Astrophysics Data System (ADS)
Filip, Peter
2017-12-01
We suggest 3 P 0 quantum state of virtual (s\\bar{s}) pairs in the nucleon can be polarised by the internal fields permeating the volume of the nucleon (proton or neutron). Due to the quadratic Zeeman interaction, 3 P 0 wavefunction of virtual (q\\bar{q}) pairs acquires the admixture of 1 P 10 quantum state in the magnetic field, which generates the antiparallel polarization of s and \\bar{s} quarks (in the nucleon). Considering the internal magnetic fields of neutron and proton (originating from their measured magnetic dipole moments), we suggest the induced s-quark polarization in the neutron to be of the oposite direction compared to the proton case. We mention the influence of the internal chromo-magnetic fields on the quantum state of (q\\bar{q}) pairs in the nucleon and we discuss also the expected behaviour of virtual (c\\bar{c}) pairs.
Zago, Myrka; Lacquaniti, Francesco
2005-08-01
Internal model is a neural mechanism that mimics the dynamics of an object for sensory motor or cognitive functions. Recent research focuses on the issue of whether multiple internal models are learned and switched to cope with a variety of conditions, or single general models are adapted by tuning the parameters. Here we addressed this issue by investigating how the manual interception of a moving target changes with changes of the visual environment. In our paradigm, a virtual target moves vertically downward on a screen with different laws of motion. Subjects are asked to punch a hidden ball that arrives in synchrony with the visual target. By using several different protocols, we systematically found that subjects do not develop a new internal model appropriate for constant speed targets, but they use the default gravity model and reduce the central processing time. The results imply that adaptation to zero-gravity targets involves a compression of temporal processing through the cortical and subcortical regions interconnected with the vestibular cortex, which has previously been shown to be the site of storage of the internal model of gravity.
MDA-based EHR application security services.
Blobel, Bernd; Pharow, Peter
2004-01-01
Component-oriented, distributed, virtual EHR systems have to meet enhanced security and privacy requirements. In the context of advanced architectural paradigms such as component-orientation, model-driven, and knowledge-based, standardised security services needed have to be specified and implemented in an integrated way following the same paradigm. This concerns the deployment of formal models, meta-languages, reference models such as the ISO RM-ODP, and development as well as implementation tools. International projects' results presented proceed on that streamline.
Photogrammetric Modeling and Image-Based Rendering for Rapid Virtual Environment Creation
2004-12-01
area and different methods have been proposed. Pertinent methods include: Camera Calibration , Structure from Motion, Stereo Correspondence, and Image...Based Rendering 1.1.1 Camera Calibration Determining the 3D structure of a model from multiple views becomes simpler if the intrinsic (or internal...can introduce significant nonlinearities into the image. We have found that camera calibration is a straightforward process which can simplify the
Splitting a colon geometry with multiplanar clipping
NASA Astrophysics Data System (ADS)
Ahn, David K.; Vining, David J.; Ge, Yaorong; Stelts, David R.
1998-06-01
Virtual colonoscopy, a recent three-dimensional (3D) visualization technique, has provided radiologists with a unique diagnostic tool. Using this technique, a radiologist can examine the internal morphology of a patient's colon by navigating through a surface-rendered model that is constructed from helical computed tomography image data. Virtual colonoscopy can be used to detect early forms of colon cancer in a way that is less invasive and expensive compared to conventional endoscopy. However, the common approach of 'flying' through the colon lumen to visually search for polyps is tedious and time-consuming, especially when a radiologist loses his or her orientation within the colon. Furthermore, a radiologist's field of view is often limited by the 3D camera position located inside the colon lumen. We have developed a new technique, called multi-planar geometry clipping, that addresses these problems. Our algorithm divides a complex colon anatomy into several smaller segments, and then splits each of these segments in half for display on a static medium. Multi-planar geometry clipping eliminates virtual colonoscopy's dependence upon expensive, real-time graphics workstations by enabling radiologists to globally inspect the entire internal surface of the colon from a single viewpoint.
"TEEB begins now": a virtual moment in the production of natural capital.
MacDonald, Kenneth Iain; Corson, Catherine
2012-01-01
This article uses theories of virtualism to analyse the role of The Economics of Ecosystems and Biodiversity (TEEB) project in the production of natural capital. Presented at the 10th Conference of the Parties to the Convention on Biological Diversity, the project seeks to redress the ‘economic invisibility of nature’ by quantifying the value of ecosystems and biodiversity. This endeavour to put an economic value on ecosystems makes nature legible by abstracting it from social and ecological contexts and making it subject to, and productive of, new market devices. In reducing the complexity of ecological dynamics to idealized categories TEEB is driven by economic ideas and idealism, and, in claiming to be a quantitative force for morality, is engaged in the production of practices designed to conform the ‘real’ to the virtual. By rendering a ‘valued’ nature legible for key audiences, TEEB has mobilized a critical mass of support including modellers, policy makers and bankers. We argue that TEEB's rhetoric of crisis and value aligns capitalism with a new kind of ecological modernization in which ‘the market’ and market devices serve as key mechanisms to conform the real and the virtual. Using the case of TEEB, and drawing on data collected at COP10, we illustrate the importance of international meetings as key points where idealized models of biodiversity protection emerge, circulate and are negotiated, and as sites where actors are aligned and articulated with these idealized models in ways that begin further processes of conforming the real with the virtual and the realization of ‘natural capital’.
A Virtual Laboratory for the 4 Bed Molecular Sieve of the Carbon Dioxide Removal Assembly
NASA Technical Reports Server (NTRS)
Coker, Robert; Knox, James; O'Connor, Brian
2016-01-01
Ongoing work to improve water and carbon dioxide separation systems to be used on crewed space vehicles combines sub-scale systems testing and multi-physics simulations. Thus, as part of NASA's Advanced Exploration Systems (AES) program and the Life Support Systems Project (LSSP), fully predictive COMSOL Multiphysics models of the Four Bed Molecular Sieve (4BMS) of the Carbon Dioxide Removal Assembly (CDRA) on the International Space Station (ISS) have been developed. This Virtual Laboratory is being used to help reduce mass, power, and volume requirements for exploration missions. In this paper we describe current and planned modeling developments in the area of carbon dioxide removal to support future missions as well as the resolution of anomalies observed in the ISS CDRA.
ERIC Educational Resources Information Center
Villar-Onrubia, Daniel; Rajpal, Brinder
2016-01-01
Virtual mobility initiatives are one of the most flexible, versatile and inclusive approaches in the provision of international experience opportunities. Given that in most universities only a small fraction of students can benefit from forms of academic mobility that involve travelling abroad, Internet-based intercultural interactions prove to be…
International Offshore Students' Perceptions of Virtual Office Hours
ERIC Educational Resources Information Center
Wdowik, Steven; Michael, Kathy
2013-01-01
Purpose: The main aim of this study is to gauge international offshore students' perceptions of virtual office hours (VOH) to consult with their offshore unit coordinators in Australia. Design/methodology/approach: This paper employs a quantitative and qualitative approach where data was sourced from three offshore campuses over a 12-month period…
The trade of virtual water: do property rights matter?
NASA Astrophysics Data System (ADS)
Xu, Ankai
2016-04-01
My paper examines the determinants of the virtual water trade - embodied in the trade of agriculture products - by estimating a structural gravity model. In particular, it tests the relationship between property rights and the export of water-intensive agricultural products based on water footprint data in Mekonnen and Hoekstra (2011, 2012). Using two different measures of property rights protection, I show that countries with weaker property rights have an apparent comparative advantage in the trade of water-intensive products. After controlling for the economic size, natural resource endowments, and possible effects of reverse causality, the trade flow of virtual water is negatively and significantly correlated with the property rights index of the exporting country. Holding other factors constant, one point increase in the property rights index of a country is associated with a 24% - 36% decrease in its virtual water export, whereas a 1% increase in the natural resource protection index of a country is associated with a 16% decrease in its virtual water export. This paper is the first empirical work that tests the relationship between property rights and trade of water-intensive products, offering a new perceptive in the debate of virtual water trade. The findings provide a possible explanation on the paradoxical evidence that some countries with scarce water resources export water-intensive products. The result is important not only in terms of its theoretical relevance, but also its policy implications. As prescribed by the model of trade and property rights, when countries with weaker property rights open to international trade, they are more likely to over-exploit and thus expedite the depletion of natural resources.
NASA Technical Reports Server (NTRS)
1994-01-01
This symposium on measurement and control in robotics included sessions on: (1) rendering, including tactile perception and applied virtual reality; (2) applications in simulated medical procedures and telerobotics; (3) tracking sensors in a virtual environment; (4) displays for virtual reality applications; (5) sensory feedback including a virtual environment application with partial gravity simulation; and (6) applications in education, entertainment, technical writing, and animation.
Yu, Zheng-yang; Zheng, Shu-sen; Chen, Lei-ting; He, Xiao-qian; Wang, Jian-jun
2005-07-01
This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging.
Yu, Zheng-yang; Zheng, Shu-sen; Chen, Lei-ting; He, Xiao-qian; Wang, Jian-jun
2005-01-01
This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging. PMID:15973760
Observations reveal external driver for Arctic sea-ice retreat
NASA Astrophysics Data System (ADS)
Notz, Dirk; Marotzke, Jochem
2012-04-01
The very low summer extent of Arctic sea ice that has been observed in recent years is often casually interpreted as an early-warning sign of anthropogenic global warming. For examining the validity of this claim, previously IPCC model simulations have been used. Here, we focus on the available observational record to examine if this record allows us to identify either internal variability, self-acceleration, or a specific external forcing as the main driver for the observed sea-ice retreat. We find that the available observations are sufficient to virtually exclude internal variability and self-acceleration as an explanation for the observed long-term trend, clustering, and magnitude of recent sea-ice minima. Instead, the recent retreat is well described by the superposition of an externally forced linear trend and internal variability. For the externally forced trend, we find a physically plausible strong correlation only with increasing atmospheric CO2 concentration. Our results hence show that the observed evolution of Arctic sea-ice extent is consistent with the claim that virtually certainly the impact of an anthropogenic climate change is observable in Arctic sea ice already today.
The application of virtual reality systems as a support of digital manufacturing and logistics
NASA Astrophysics Data System (ADS)
Golda, G.; Kampa, A.; Paprocka, I.
2016-08-01
Modern trends in development of computer aided techniques are heading toward the integration of design competitive products and so-called "digital manufacturing and logistics", supported by computer simulation software. All phases of product lifecycle: starting from design of a new product, through planning and control of manufacturing, assembly, internal logistics and repairs, quality control, distribution to customers and after-sale service, up to its recycling or utilization should be aided and managed by advanced packages of product lifecycle management software. Important problems for providing the efficient flow of materials in supply chain management of whole product lifecycle, using computer simulation will be described on that paper. Authors will pay attention to the processes of acquiring relevant information and correct data, necessary for virtual modeling and computer simulation of integrated manufacturing and logistics systems. The article describes possibilities of use an applications of virtual reality software for modeling and simulation the production and logistics processes in enterprise in different aspects of product lifecycle management. The authors demonstrate effective method of creating computer simulations for digital manufacturing and logistics and show modeled and programmed examples and solutions. They pay attention to development trends and show options of the applications that go beyond enterprise.
Virtual Cities--A Regional Discovery Project.
ERIC Educational Resources Information Center
Stanfel, Julie
1993-01-01
Describes the "Virtual Cities" project, a virtual reality satellite teleconference with students age 12 to 17 from Canada, Italy, and the United States held during the International Council for Educational Media 1992 conference. A visual database overlaid with instructional gaming strategies provided students with the opportunity to…
ERIC Educational Resources Information Center
Truong, Thang Dinh; Hallinger, Philip
2017-01-01
The need for empirical research on leadership in educational organizations across more diverse national settings frames the purpose of the current study of principal leadership in Vietnam. To date, the international literature on school leadership in Vietnam is virtually a blank slate. This research aimed at describing how Vietnamese school…
ICCE/ICCAI 2000 Full & Short Papers (Virtual Reality in Education).
ERIC Educational Resources Information Center
2000
This document contains the full text of the following full and short papers on virtual reality in education from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction): (1) "A CAL System for Appreciation of 3D Shapes by Surface Development (C3D-SD)" (Stephen C. F. Chan, Andy…
NASA Astrophysics Data System (ADS)
Wang, Jing; Qi, Zhaohui; Wang, Gang
2017-10-01
The dynamic analysis of cable-pulley systems is investigated in this paper, where the time-varying length characteristic of the cable as well as the coupling motion between the cable and the pulleys are considered. The dynamic model for cable-pulley systems are presented based on the principle of virtual power. Firstly, the cubic spline interpolation is adopted for modeling the flexible cable elements and the virtual 1powers of tensile strain, inertia and gravity forces on the cable are formulated. Then, the coupled motions between the cable and the movable or fixed pulley are described by the input and output contact points, based on the no-slip assumption and the spatial description. The virtual powers of inertia, gravity and applied forces on the contact segment of the cable, the movable and fixed pulleys are formulated. In particular, the internal node degrees of freedom of spline cable elements are reduced, which results in that only the independent description parameters of the nodes connected to the pulleys are included in the final governing dynamic equations. At last, two cable-pulley lifting mechanisms are considered as demonstrative application examples where the vibration of the lifting process is investigated. The comparison with ADAMS models is given to prove the validity of the proposed method.
Evaluating the impact of virtualization characteristics on SaaS adoption
NASA Astrophysics Data System (ADS)
Tomás, Sara; Thomas, Manoj; Oliveira, Tiago
2018-03-01
Software as a service (SaaS) is a service model in which the applications are accessible from various client devices through internet. Several studies report possible factors driving the adoption of SaaS but none have considered the perception of the SaaS features and the organization's context. We propose an integrated research model that combines the process virtualization theory (PVT), the technology-organization-environment (TOE) framework and the institutional theory (INT). PVT seeks to explain whether processes are suitable for migration into virtual environments via an information technology-based mechanism as SaaS. The TOE framework seeks to explain the effects of the intra-organizational factors, while INT seeks to explain the effects of the inter-organizational factors on the technology adoption. This research addresses a gap in the SaaS adoption literature by studying the internal perception of the technical features of SaaS and technology, organization, and environment perspectives. Additionally, the integration of PVT, the TOE framework, and INT contributes to the information system (IS) discipline, deepening the applicability and strengths of these theories.
Ten years of the Spanish Virtual Observatory
NASA Astrophysics Data System (ADS)
Solano, E.
2015-05-01
The main objective of the Virtual Observatory (VO) is to guarantee an easy and efficient access and analysis of the information hosted in astronomical archives. The Spanish Virtual Observatory (SVO) is a project that was born in 2004 with the goal of promoting and coordinating the VO-related activities at national level. SVO is also the national contact point for the international VO initiatives, in particular the International Virtual Observatory Alliance (IVOA) and the Euro-VO project. The project, led by Centro de Astrobiología (INTA-CSIC), is structured around four major topics: a) VO compliance of astronomical archives, b) VO-science, c) VO- and data mining-tools, and d) Education and outreach. In this paper I will describe the most important results obtained by the Spanish Virtual Observatory in its first ten years of life as well as the future lines of work.
Diedrichs, Phillippa C; von Ranson, Kristin M; Thomas, Jennifer J
2018-06-01
This virtual issue of the International Journal of Eating Disorders (IJED) highlights the excellent and innovative research and practice discussed at the 2018 International Conference on Eating Disorders held in Chicago, Illinois, USA. The virtual issue contains a series of articles recently published in IJED, which we have curated to reflect and expand on the insights delivered during the conference keynote and plenary presentations. In line with the conference theme of Innovation in Research and Practice: Expanding our Community and Perspectives, we hope this collection of articles will spark new ideas for research, practice, and collaboration to accelerate knowledge on eating disorder risk factors and recovery, and the reach and impact of evidence-based treatment, prevention, and policy efforts. © 2018 Wiley Periodicals, Inc.
Virtual Instrument for Emissions Measurement of Internal Combustion Engines
Pérez, Armando; Montero, Gisela; Coronado, Marcos; García, Conrado; Pérez, Rubén
2016-01-01
The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM), and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, and a data acquisition system is used as interface for a computer in order to measure and monitor in real time the emissions of O2, NO, CO, SO2, and CO2 gases. This paper shows the results of the VIEM programming, the integrated circuits diagrams used for the signal conditioning of sensors, and the sensors characterization of O2, NO, CO, SO2, and CO2. VIEM is a low-cost instrument and is simple and easy to use. Besides, it is scalable, making it flexible and defined by the user. PMID:27034893
A Virtual World with Real Results
ERIC Educational Resources Information Center
Hughes, Katherine L.; Golann, Joanne Wang
2008-01-01
This article describes how students learn invaluable job-readiness and academic skills by setting up and running their own businesses in a virtual world. Virtual Enterprises (VE) International is a high school career and technical education (CTE) program that teaches students about business by having a class create and operate its own virtual…
E-Learning and Virtual Science Centers
ERIC Educational Resources Information Center
Hin, Leo Tan Wee, Ed.; Subramaniam, R., Ed.
2005-01-01
"E-Learning and Virtual Science Centers" addresses an aspect of Web-based education that has not attracted sufficient attention in the international research literature--that of virtual science centers, the cyberspace annex of traditional science centers. It is the first book to be published on the rapidly advancing field of science education.…
Virtual Instruction: Issues and Insights from an International Perspective.
ERIC Educational Resources Information Center
Feyten, Carine M., Ed.; Nutta, Joyce W., Ed.
The essays in this book, by contributors from around the world, clarify predominant theoretical issues that pertain to virtual instruction, and offer practical suggestions for implementing these programs in any setting. Chapters include: "Mapping Space and Time: Virtual Instruction as Global Ritual" (Joyce W. Nutta and Carine M. Feyten);…
Latifi, Rifat; Dasho, Erion; Shatri, Zhaneta; Tilley, Elizabeth; Osmani, Kalterina L; Doarn, Charles R; Dogjani, Agron; Olldashi, Fatos; Koçiraj, Agim; Merrell, Ronald C
2015-06-01
The U.S. Government and other developed nations provide billions of dollars annually in relief assistance to countries around the world. The long-term benefits of this aid, however, are often difficult to elucidate. The aim of this article is to present a model of a multipartnership collaboration among U.S. governmental, nongovernmental organizations, and academia to rebuild medical systems using telemedicine as a sustainable model of foreign aid. The International Virtual e-Hospital implemented the "initiate-build-operate-transfer" strategy to establish an effective telemedicine system in Albania that includes the National Telemedicine Center and 12 regional telemedicine centers. This nationwide telemedicine network has active clinical programs, virtual educational programs, and an electronic library that has substantially improved the access to care while advancing medical education. We propose that telemedicine is an optimal, sustainable, low-cost model for rebuilding medical systems of developing countries when implemented through a multipartnership approach.
A Novel and Freely Available Interactive 3d Model of the Internal Carotid Artery.
Valera-Melé, Marc; Puigdellívol-Sánchez, Anna; Mavar-Haramija, Marija; Juanes-Méndez, Juan A; San-Román, Luis; de Notaris, Matteo; Prats-Galino, Alberto
2018-03-05
We describe a new and freely available 3D interactive model of the intracranial internal carotid artery (ICA) and the skull base that also allows to display and compare its main segment classifications. High-resolution 3D human angiography (isometric voxel's size 0.36 mm) and Computed Tomography angiography images were exported to Virtual Reality Modeling Language (VRML) format for processing in a 3D software platform and embedding in a 3D Portable Document Format (PDF) document that can be freely downloaded at http://diposit.ub.edu/dspace/handle/2445/112442 and runs under Acrobat Reader on Mac and Windows computers and Windows 10 tablets. The 3D-PDF allows for visualisation and interaction through JavaScript-based functions (including zoom, rotation, selective visualization and transparentation of structures or a predefined sequence view of the main segment classifications if desired). The ICA and its main branches and loops, the Gasserian ganglion, the petrolingual ligament and the proximal and distal dural rings within the skull base environment (anterior and posterior clinoid processes, silla turcica, ethmoid and sphenoid bones, orbital fossae) may be visualized from different perspectives. This interactive 3D-PDF provides virtual views of the ICA and becomes an innovative tool to improve the understanding of the neuroanatomy of the ICA and surrounding structures.
ERIC Educational Resources Information Center
Gutierrez-Santiuste, Elba; Gallego-Arrufat, Maria-Jesus
2015-01-01
This study investigates the phases of development of synchronous and asynchronous virtual communication produced in a community of inquiry (CoI) by analyzing the internal structure of each intervention in the forum and each chat session to determine the evolution of their social, cognitive and teaching character. It also analyzes the participating…
ERIC Educational Resources Information Center
Zhang, Bo; Robb, Nigel; Eyerman, Joe; Goodman, Lizbeth
2017-01-01
In response to the growing trend of internationalisation in education, it is important to consider approaches to help international students integrate in their new settings. One possible approach involves the use of e-Learning tools, such as virtual worlds and gamification. To maximise the potential effectiveness of such tools, it may be…
Scolozzi, Paolo; Herzog, Georges
2017-07-01
We are reporting the treatment of severe maxillary hypoplasia in two patients with unilateral cleft lip and palate by using a specific approach combining the Le Fort I distraction osteogenesis technique coupled with computer-aided design/computer-aided manufacturing customized surgical guides and internal distractors based on virtual computational planning. This technology allows for the transfer of the virtual planned reconstruction to the operating room by using custom patient-specific implants, surgical splints, surgical cutting guides, and surgical guides to plate or distractor adaptation.
NASA Astrophysics Data System (ADS)
Cox, S. J.; Wyborn, L. A.; Fraser, R.; Rankine, T.; Woodcock, R.; Vote, J.; Evans, B.
2012-12-01
The Virtual Geophysics Laboratory (VGL) is web portal that provides geoscientists with an integrated online environment that: seamlessly accesses geophysical and geoscience data services from the AuScope national geoscience information infrastructure; loosely couples these data to a variety of gesocience software tools; and provides large scale processing facilities via cloud computing. VGL is a collaboration between CSIRO, Geoscience Australia, National Computational Infrastructure, Monash University, Australian National University and the University of Queensland. The VGL provides a distributed system whereby a user can enter an online virtual laboratory to seamlessly connect to OGC web services for geoscience data. The data is supplied in open standards formats using international standards like GeoSciML. A VGL user uses a web mapping interface to discover and filter the data sources using spatial and attribute filters to define a subset. Once the data is selected the user is not required to download the data. VGL collates the service query information for later in the processing workflow where it will be staged directly to the computing facilities. The combination of deferring data download and access to Cloud computing enables VGL users to access their data at higher resolutions and to undertake larger scale inversions, more complex models and simulations than their own local computing facilities might allow. Inside the Virtual Geophysics Laboratory, the user has access to a library of existing models, complete with exemplar workflows for specific scientific problems based on those models. For example, the user can load a geological model published by Geoscience Australia, apply a basic deformation workflow provided by a CSIRO scientist, and have it run in a scientific code from Monash. Finally the user can publish these results to share with a colleague or cite in a paper. This opens new opportunities for access and collaboration as all the resources (models, code, data, processing) are shared in the one virtual laboratory. VGL provides end users with access to an intuitive, user-centered interface that leverages cloud storage and cloud and cluster processing from both the research communities and commercial suppliers (e.g. Amazon). As the underlying data and information services are agnostic of the scientific domain, they can support many other data types. This fundamental characteristic results in a highly reusable virtual laboratory infrastructure that could also be used for example natural hazards, satellite processing, soil geochemistry, climate modeling, agriculture crop modeling.
The Use of Virtual Reality in the Study of People's Responses to Violent Incidents.
Rovira, Aitor; Swapp, David; Spanlang, Bernhard; Slater, Mel
2009-01-01
This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call 'plausibility' - including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents.
The Use of Virtual Reality in the Study of People's Responses to Violent Incidents
Rovira, Aitor; Swapp, David; Spanlang, Bernhard; Slater, Mel
2009-01-01
This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call ‘plausibility’ – including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents. PMID:20076762
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.
NASA Technical Reports Server (NTRS)
Schmidt, Gregory K.
2014-01-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI), originally chartered in 2008 as the NASA Lunar Science Institute (NLSI), is chartered to advance both the scientific goals needed to enable human space exploration, as well as the science enabled by such exploration. NLSI and SSERVI have in succession been "institutes without walls," fostering collaboration between domestic teams (7 teams for NLSI, 9 for SSERVI) as well as between these teams and the institutes' international partners, resulting in a greater global endeavor. SSERVI teams and international partners participate in sharing ideas, information, and data arising from their respective research efforts, and contribute to the training of young scientists and bringing the scientific results and excitement of exploration to the public. The domestic teams also respond to NASA's strategic needs, providing community-based responses to NASA needs in partnership with NASA's Analysis Groups. Through the many partnerships enabled by NLSI and SSERVI, scientific results have well exceeded initial projections based on the original PI proposals, proving the validity of the virtual institute model. NLSI and SSERVI have endeavored to represent not just the selected and funded domestic teams, but rather the entire relevant scientific community; this has been done through many means such as the annual Lunar Science Forum (now re-named Exploration Science Forum), community-based grass roots Focus Groups on a wide range of topics, and groups chartered to further the careers of young scientists. Additionally, NLSI and SSERVI have co-founded international efforts such as the pan-European lunar science consortium, with an overall goal of raising the tide of lunar science (and now more broadly exploration science) across the world.
Astronaut Prepares for Mission With Virtual Reality Hardware
NASA Technical Reports Server (NTRS)
2001-01-01
Astronaut John M. Grunsfeld, STS-109 payload commander, uses virtual reality hardware at Johnson Space Center to rehearse some of his duties prior to the STS-109 mission. The most familiar form of virtual reality technology is some form of headpiece, which fits over your eyes and displays a three dimensional computerized image of another place. Turn your head left and right, and you see what would be to your sides; turn around, and you see what might be sneaking up on you. An important part of the technology is some type of data glove that you use to propel yourself through the virtual world. This technology allows NASA astronauts to practice International Space Station work missions in advance. Currently, the medical community is using the new technologies in four major ways: To see parts of the body more accurately, for study, to make better diagnosis of disease and to plan surgery in more detail; to obtain a more accurate picture of a procedure during surgery; to perform more types of surgery with the most noninvasive, accurate methods possible; and to model interactions among molecules at a molecular level.
Implementing model-based system engineering for the whole lifecycle of a spacecraft
NASA Astrophysics Data System (ADS)
Fischer, P. M.; Lüdtke, D.; Lange, C.; Roshani, F.-C.; Dannemann, F.; Gerndt, A.
2017-09-01
Design information of a spacecraft is collected over all phases in the lifecycle of a project. A lot of this information is exchanged between different engineering tasks and business processes. In some lifecycle phases, model-based system engineering (MBSE) has introduced system models and databases that help to organize such information and to keep it consistent for everyone. Nevertheless, none of the existing databases approached the whole lifecycle yet. Virtual Satellite is the MBSE database developed at DLR. It has been used for quite some time in Phase A studies and is currently extended for implementing it in the whole lifecycle of spacecraft projects. Since it is unforeseeable which future use cases such a database needs to support in all these different projects, the underlying data model has to provide tailoring and extension mechanisms to its conceptual data model (CDM). This paper explains the mechanisms as they are implemented in Virtual Satellite, which enables extending the CDM along the project without corrupting already stored information. As an upcoming major use case, Virtual Satellite will be implemented as MBSE tool in the S2TEP project. This project provides a new satellite bus for internal research and several different payload missions in the future. This paper explains how Virtual Satellite will be used to manage configuration control problems associated with such a multi-mission platform. It discusses how the S2TEP project starts using the software for collecting the first design information from concurrent engineering studies, then making use of the extension mechanisms of the CDM to introduce further information artefacts such as functional electrical architecture, thus linking more and more processes into an integrated MBSE approach.
Creation of 3D Multi-Body Orthodontic Models by Using Independent Imaging Sensors
Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano
2013-01-01
In the field of dental health care, plaster models combined with 2D radiographs are widely used in clinical practice for orthodontic diagnoses. However, complex malocclusions can be better analyzed by exploiting 3D digital dental models, which allow virtual simulations and treatment planning processes. In this paper, dental data captured by independent imaging sensors are fused to create multi-body orthodontic models composed of teeth, oral soft tissues and alveolar bone structures. The methodology is based on integrating Cone-Beam Computed Tomography (CBCT) and surface structured light scanning. The optical scanner is used to reconstruct tooth crowns and soft tissues (visible surfaces) through the digitalization of both patients' mouth impressions and plaster casts. These data are also used to guide the segmentation of internal dental tissues by processing CBCT data sets. The 3D individual dental tissues obtained by the optical scanner and the CBCT sensor are fused within multi-body orthodontic models without human supervisions to identify target anatomical structures. The final multi-body models represent valuable virtual platforms to clinical diagnostic and treatment planning. PMID:23385416
Creation of 3D multi-body orthodontic models by using independent imaging sensors.
Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano
2013-02-05
In the field of dental health care, plaster models combined with 2D radiographs are widely used in clinical practice for orthodontic diagnoses. However, complex malocclusions can be better analyzed by exploiting 3D digital dental models, which allow virtual simulations and treatment planning processes. In this paper, dental data captured by independent imaging sensors are fused to create multi-body orthodontic models composed of teeth, oral soft tissues and alveolar bone structures. The methodology is based on integrating Cone-Beam Computed Tomography (CBCT) and surface structured light scanning. The optical scanner is used to reconstruct tooth crowns and soft tissues (visible surfaces) through the digitalization of both patients' mouth impressions and plaster casts. These data are also used to guide the segmentation of internal dental tissues by processing CBCT data sets. The 3D individual dental tissues obtained by the optical scanner and the CBCT sensor are fused within multi-body orthodontic models without human supervisions to identify target anatomical structures. The final multi-body models represent valuable virtual platforms to clinical diagnostic and treatment planning.
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…
[Development of a virtual model of fibro-bronchoscopy].
Solar, Mauricio; Ducoing, Eugenio
2011-09-01
A virtual model of fibro-bronchoscopy is reported. The virtual model represents in 3D the trachea and the bronchi creating a virtual world of the bronchial tree. The bronchoscope is modeled to look over the bronchial tree imitating the displacement and rotation of the real bronchoscope. The parameters of the virtual model were gradually adjusted according to expert opinion and allowed the training of specialists with a virtual bronchoscope of great realism. The virtual bronchial tree provides clues of reality regarding the movement of the bronchoscope, creating the illusion that the virtual instrument is behaving as the real one with all the benefits in costs that this means.
Virtual Labs in proteomics: new E-learning tools.
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.
Varol, Altan; Basa, Selçuk
2009-06-01
Maxillary distraction osteogenesis is a challenging procedure when it is performed with internal submerged distractors due to obligation of setting accurate distraction vectors. Five patients with severe maxillary retrognathy were planned with Mimics 10.01 CMF and Simplant 10.01 software. Distraction vectors and rods of distractors were arranged in 3D environment and on STL models. All patients were operated under general anaesthesia and complete Le Fort I downfracture was performed. All distractions were performed according to orientated vectors. All patients achieved stable occlusion and satisfactory aesthetic outcome at the end of the treatment period. Preoperative bending of internal maxillary distractors prevents significant loss of operation time. 3D computer-aided surgical simulation and model surgery provide accurate orientation of distraction vectors for premaxillary and internal trans-sinusoidal maxillary distraction. Combination of virtual surgical simulation and stereolithographic models surgery can be validated as an effective method of preoperative planning for complicated maxillofacial surgery cases.
Infrastructure Suitability Assessment Modeling for Cloud Computing Solutions
2011-09-01
Virtualization vs . Para-Virtualization .......................................................10 Figure 4. Modeling alternatives in relation to model...the conceptual difference between full virtualization and para-virtualization. Figure 3. Full Virtualization vs . Para-Virtualization 2. XEN...Besides Microsoft’s own client implementations, dubbed “Remote Desktop Con- nection Client” for Windows® and Apple ® operating systems, various open
Predictive Modeling of the CDRA 4BMS
NASA Technical Reports Server (NTRS)
Coker, Robert F.; Knox, James C.
2016-01-01
As part of NASA's Advanced Exploration Systems (AES) program and the Life Support Systems Project (LSSP), fully predictive models of the Four Bed Molecular Sieve (4BMS) of the Carbon Dioxide Removal Assembly (CDRA) on the International Space Station (ISS) are being developed. This virtual laboratory will be used to help reduce mass, power, and volume requirements for future missions. In this paper we describe current and planned modeling developments in the area of carbon dioxide removal to support future crewed Mars missions as well as the resolution of anomalies observed in the ISS CDRA.
Hewitt, Anne M; Spencer, Susan S; Ramloll, Rameshsharma; Trotta, Heidi
2008-10-01
Developed by the Center for Disease Control and Prevention in 2002, the Crisis Emergency and Risk Communication (CERC) training module is a nationally and internationally recognized communication model. With the looming threat of a pandemic and the potential for a protracted ongoing siege, a valuable opportunity exists to introduce crisis and emergency preparedness communication best practices to a new population--health care managers and administrators. The CERC toolkit and resources, provide an easy, turn-key solution and a validated template for educators who are not directly involved in public health education but desire to share this content. In this example, graduate students enrolled in an Master of Health Administration program, used a Play2Train scenario, located in the virtual learning environment of SecondLife (2007), to incorporate concepts from the CERC model. By applying the CERC best practices in a real-time virtual learning scenario, students learned collaboration and the leadership competencies necessary to help implement Joint Commission on Accreditation of Health Organizations emergency communication protocols and community collaboration requirements. By expanding the impact of the CERC model and developing unified risk communication responses and information sharing, all health professionals can enhance the effectiveness of their emergency preparedness plans so that the public can be better served.
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).
NASA Astrophysics Data System (ADS)
Merka, J.; Dolan, C. F.
2015-12-01
Finding and retrieving space physics data is often a complicated taskeven for publicly available data sets: Thousands of relativelysmall and many large data sets are stored in various formats and, inthe better case, accompanied by at least some documentation. VirtualHeliospheric and Magnetospheric Observatories (VHO and VMO) help researches by creating a single point of uniformdiscovery, access, and use of heliospheric (VHO) and magnetospheric(VMO) data.The VMO and VHO functionality relies on metadata expressed using theSPASE data model. This data model is developed by the SPASE WorkingGroup which is currently the only international group supporting globaldata management for Solar and Space Physics. The two Virtual Observatories(VxOs) have initiated and lead a development of a SPASE-related standardnamed SPASE Query Language for provided a standard way of submittingqueries and receiving results.The VMO and VHO use SPASE and SPASEQL for searches based on various criteria such as, for example, spatial location, time of observation, measurement type, parameter values, etc. The parameter values are represented by their statisticalestimators calculated typically over 10-minute intervals: mean, median, standard deviation, minimum, and maximum. The use of statistical estimatorsenables science driven data queries that simplify and shorten the effort tofind where and/or how often the sought phenomenon is observed, as we will present.
Virtual reality and planetary exploration
NASA Technical Reports Server (NTRS)
Mcgreevy, Michael W.
1992-01-01
Exploring planetary environments is central to NASA's missions and goals. A new computing technology called Virtual Reality has much to offer in support of planetary exploration. This technology augments and extends human presence within computer-generated and remote spatial environments. Historically, NASA has been a leader in many of the fundamental concepts and technologies that comprise Virtual Reality. Indeed, Ames Research Center has a central role in the development of this rapidly emerging approach to using computers. This ground breaking work has inspired researchers in academia, industry, and the military. Further, NASA's leadership in this technology has spun off new businesses, has caught the attention of the international business community, and has generated several years of positive international media coverage. In the future, Virtual Reality technology will enable greatly improved human-machine interactions for more productive planetary surface exploration. Perhaps more importantly, Virtual Reality technology will democratize the experience of planetary exploration and thereby broaden understanding of, and support for, this historic enterprise.
Virtual reality and planetary exploration
NASA Astrophysics Data System (ADS)
McGreevy, Michael W.
Exploring planetary environments is central to NASA's missions and goals. A new computing technology called Virtual Reality has much to offer in support of planetary exploration. This technology augments and extends human presence within computer-generated and remote spatial environments. Historically, NASA has been a leader in many of the fundamental concepts and technologies that comprise Virtual Reality. Indeed, Ames Research Center has a central role in the development of this rapidly emerging approach to using computers. This ground breaking work has inspired researchers in academia, industry, and the military. Further, NASA's leadership in this technology has spun off new businesses, has caught the attention of the international business community, and has generated several years of positive international media coverage. In the future, Virtual Reality technology will enable greatly improved human-machine interactions for more productive planetary surface exploration. Perhaps more importantly, Virtual Reality technology will democratize the experience of planetary exploration and thereby broaden understanding of, and support for, this historic enterprise.
Material model for physically based rendering
NASA Astrophysics Data System (ADS)
Robart, Mathieu; Paulin, Mathias; Caubet, Rene
1999-09-01
In computer graphics, a complete knowledge of the interactions between light and a material is essential to obtain photorealistic pictures. Physical measurements allow us to obtain data on the material response, but are limited to industrial surfaces and depend on measure conditions. Analytic models do exist, but they are often inadequate for common use: the empiric ones are too simple to be realistic, and the physically-based ones are often to complex or too specialized to be generally useful. Therefore, we have developed a multiresolution virtual material model, that not only describes the surface of a material, but also its internal structure thanks to distribution functions of microelements, arranged in layers. Each microelement possesses its own response to an incident light, from an elementary reflection to a complex response provided by its inner structure, taking into account geometry, energy, polarization, . . ., of each light ray. This model is virtually illuminated, in order to compute its response to an incident radiance. This directional response is stored in a compressed data structure using spherical wavelets, and is destined to be used in a rendering model such as directional radiosity.
Venkatesh, S K; Wang, G; Seet, J E; Teo, L L S; Chong, V F H
2013-03-01
To evaluate the feasibility of magnetic resonance imaging (MRI) for the transformation of preserved organs and their disease entities into digital formats for medical education and creation of a virtual museum. MRI of selected 114 pathology specimen jars representing different organs and their diseases was performed using a 3 T MRI machine with two or more MRI sequences including three-dimensional (3D) T1-weighted (T1W), 3D-T2W, 3D-FLAIR (fluid attenuated inversion recovery), fat-water separation (DIXON), and gradient-recalled echo (GRE) sequences. Qualitative assessment of MRI for depiction of disease and internal anatomy was performed. Volume rendering was performed on commercially available workstations. The digital images, 3D models, and photographs of specimens were archived into a workstation serving as a virtual pathology museum. MRI was successfully performed on all specimens. The 3D-T1W and 3D-T2W sequences demonstrated the best contrast between normal and pathological tissues. The digital material is a useful aid for understanding disease by giving insights into internal structural changes not apparent on visual inspection alone. Volume rendering produced vivid 3D models with better contrast between normal tissue and diseased tissue compared to real specimens or their photographs in some cases. The digital library provides good illustration material for radiological-pathological correlation by enhancing pathological anatomy and information on nature and signal characteristics of tissues. In some specimens, the MRI appearance may be different from corresponding organ and disease in vivo due to dead tissue and changes induced by prolonged contact with preservative fluid. MRI of pathology specimens is feasible and provides excellent images for education and creating a virtual pathology museum that can serve as permanent record of digital material for self-directed learning, improving teaching aids, and radiological-pathological correlation. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Tan, Kian Lam; Lim, Chen Kim
2017-10-01
In the last decade, cultural heritage including historical sites are reconstructed into digital heritage. Based on UNESCO, digital heritage defines as "cultural, educational, scientific and administrative resources, as well as technical, legal, medical and other kinds of information created digitally, or converted into digital form from existing analogue resources". In addition, the digital heritage is doubling in size every two years and expected will grow tenfold between 2013 and 2020. In order to attract and stir the interest of younger generations about digital heritage, gamification has been widely promoted. In this research, a virtual walkthrough combine with gamifications are proposed for learning and exploring historical places in Malaysia by using mobile device. In conjunction with Visit Perak 2017 Campaign, this virtual walkthrough is proposed for Kellie's Castle at Perak. The objectives of this research is two folds 1) modelling and design of innovative mobile game for virtual walkthrough application, and 2) to attract tourist to explore and learn historical places by using sophisticated graphics from Augmented Reality. The efficiency and effectiveness of the mobile virtual walkthrough will be accessed by the International and local tourists. In conclusion, this research is speculated to be pervasively improve the cultural and historical knowledge of the learners.
NASA Technical Reports Server (NTRS)
1995-01-01
The PER-Force Handcontroller was originally developed for the International Space Station under a Johnson Space Center Small Business Innovation Research (SBIR) contract. Produced by Cybernet Systems Corporation, the unit is a force-reflecting system that manipulates robots or objects by "feel." The Handcontroller moves in six degrees of freedom, with real and virtual reality forces simulated by a 3-D molecular modeling software package. It is used in molecular modeling in metallurgy applications, satellite docking research, and in research on military unmanned ground vehicles.
L2 Immersion in 3D Virtual Worlds: The Next Thing to Being There?
ERIC Educational Resources Information Center
Paillat, Edith
2014-01-01
Second Life is one of the many three-dimensional virtual environments accessible through a computer and a fast broadband connection. Thousands of participants connect to this platform to interact virtually with the world, join international communities of practice and, for some, role play groups. Unlike online role play games however, Second Life…
ERIC Educational Resources Information Center
Cummings, Jeffrey
2012-01-01
The introduction of social media has changed the way individuals communicate and collaborate both within and outside the organization. While social media has the potential to change how organizations interact internally, minimal research has examined the impact this media may have within a virtual team environment. This dissertation examines a…
Demystifying Virtual Communities of Practice: A Case Study of IBM
ERIC Educational Resources Information Center
Kok, Ayse
2010-01-01
The purpose of this proposed research study is to empirically explore the nature of virtual communities of practice (CoP) in a global organisation within the context of its International Corporate Volunteer (ICV) Program. This study investigates whether and how the use of virtual CoP evolves and becomes embedded within this organization. Following…
Expedition 11 Training with Krikalev/Henderson
2004-08-12
Expedition 11 Training with Krikalev/Henderson as their continued their training in the Virtual Reality Laboratory in building 9. View includes: Sergei Krikalev and Henderson using the virtual optics to view the International Space Station.
Catching fly balls in virtual reality: a critical test of the outfielder problem.
Fink, Philip W; Foo, Patrick S; Warren, William H
2009-12-14
How does a baseball outfielder know where to run to catch a fly ball? The "outfielder problem" remains unresolved, and its solution would provide a window into the visual control of action. It may seem obvious that human action is based on an internal model of the physical world, such that the fielder predicts the landing point based on a mental model of the ball's trajectory (TP). However, two alternative theories, Optical Acceleration Cancellation (OAC) and Linear Optical Trajectory (LOT), propose that fielders are led to the right place at the right time by coupling their movements to visual information in a continuous "online" manner. All three theories predict successful catches and similar running paths. We provide a critical test by using virtual reality to perturb the vertical motion of the ball in mid-flight. The results confirm the predictions of OAC but are at odds with LOT and TP.
NASA Astrophysics Data System (ADS)
Greco, F.
2008-12-01
This research considers the historical impact of virtual water into the geophysical arena by considering it as a human-led phenomenon that impacts the hydrologic system and, consequently, the environment as a whole. This paper is in line with the idea of including the humans into the water-balance model, and it is deepening the idea that this has to be done not only at the light of each watershed, but globally, looking at the role of water-trade embedded in food and tradable goods. Starting from a definition of what virtual water is, this research explores the role of crops export in the early U.S. Colonial time. As early as 1630 a huge biomass from here was already exported to the UK (the fur trade). In 1700 the tobacco export started, along with cereals exports and timber. An entire ecosystem has been "exported" in terms of water-embedded-in-goods. This was the beginning of a massive depletion of bio-mass stocks and flows, a raise in nitrogen discharge into the environment and its impact on the hydrological systems ( CUAHSI Summer Institute findings). Immigration and its effects on the water balance is also considered in this work. The experiment of interdisciplinary work of CUAHSI Summer Institute 2008 has proven that there is space for a historical reconstruction of evidence of human-led changes to the hydrological systems. This has been possible through the analysis of material stocks and flows, water-balance analysis of these stocks and flows, including human-led changes like international trade and population growth. This proposal will argue that these changes can also be identified by the term of 'socio- economic metabolism', in which societies are trading their goods internationally but taking the primary resources, including water, locally. This work will put the basis for the history of virtual water and its implications on both socio-economic metabolism and local geophysical changes.
ERIC Educational Resources Information Center
Hay, Iain
2008-01-01
This paper offers a critical review of the role of the International Network for Learning and Teaching geography in higher education (INLT) in the production of geographical knowledge. Through an examination of the Network's membership and activities, it explores some of the ways in which INLT--as a global virtual group--may be inadvertently…
ERIC Educational Resources Information Center
International Association of Technological Univ. Libraries, Gothenburg (Sweden).
This proceedings of the International Association of Technological University Libraries (IATUL) contains the opening address by IATUL president Nancy Fjallbrant and the full text of the following papers: "Building Info-Skills by Degrees: Embedding Information Literacy in University Study" (Wendy Abbott and Deborah Peach); "UQ…
Heterogeneous Deformable Modeling of Bio-Tissues and Haptic Force Rendering for Bio-Object Modeling
NASA Astrophysics Data System (ADS)
Lin, Shiyong; Lee, Yuan-Shin; Narayan, Roger J.
This paper presents a novel technique for modeling soft biological tissues as well as the development of an innovative interface for bio-manufacturing and medical applications. Heterogeneous deformable models may be used to represent the actual internal structures of deformable biological objects, which possess multiple components and nonuniform material properties. Both heterogeneous deformable object modeling and accurate haptic rendering can greatly enhance the realism and fidelity of virtual reality environments. In this paper, a tri-ray node snapping algorithm is proposed to generate a volumetric heterogeneous deformable model from a set of object interface surfaces between different materials. A constrained local static integration method is presented for simulating deformation and accurate force feedback based on the material properties of a heterogeneous structure. Biological soft tissue modeling is used as an example to demonstrate the proposed techniques. By integrating the heterogeneous deformable model into a virtual environment, users can both observe different materials inside a deformable object as well as interact with it by touching the deformable object using a haptic device. The presented techniques can be used for surgical simulation, bio-product design, bio-manufacturing, and medical applications.
Worldwide R&D of Virtual Observatory
NASA Astrophysics Data System (ADS)
Cui, C. Z.; Zhao, Y. H.
2008-07-01
Virtual Observatory (VO) is a data intensive online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless and uniform access to astronomical information. The concept of VO was introduced in the late 1990s to meet the challenges brought up with data avalanche in astronomy. In the paper, current status of International Virtual Observatory Alliance, technical highlights from world wide VO projects are reviewed, a brief introduction of Chinese Virtual Observatory is given.
Evaluating the Limits of Network Topology Inference Via Virtualized Network Emulation
2015-06-01
76 xi Figure 5.33 Hop-plot of five best reduction methods. KDD most closely matches the Internet plot...respectively, located around the world. These monitors provide locations from which to perform network measurement experiments, primarily using the ping ...International Symposium on Modeling, Analysis and Simulation of Computer Telecommunication Systems. IEEE, 2001, pp. 346–353. 90 [21] C. Jin , Q. Chen, and S
Plenty of Blame to Go Around: A Qualitative Approach to Attribution of Moral Responsibility
2007-01-01
1 Social psychological research cited in [Mao 2006] indicates that there are differences in the processes used for responsibility for...Mao, W. and Gratch, J. 2005. Social Causality and Responsibility : Modeling and Evaluation. Fifth International Conference on Interactive Virtual...Reasoning Workshop. B. Weiner. 1995. Judgments of Responsibility : A Foundation for a Theory of Social Conduct. Guilford Press. B. Weiner. 2001
Virtual healthcare delivery: defined, modeled, and predictive barriers to implementation identified.
Harrop, V M
2001-01-01
Provider organizations lack: 1. a definition of "virtual" healthcare delivery relative to the products, services, and processes offered by dot.coms, web-compact disk healthcare content providers, telemedicine, and telecommunications companies, and 2. a model for integrating real and virtual healthcare delivery. This paper defines virtual healthcare delivery as asynchronous, outsourced, and anonymous, then proposes a 2x2 Real-Virtual Healthcare Delivery model focused on real and virtual patients and real and virtual provider organizations. Using this model, provider organizations can systematically deconstruct healthcare delivery in the real world and reconstruct appropriate pieces in the virtual world. Observed barriers to virtual healthcare delivery are: resistance to telecommunication integrated delivery networks and outsourcing; confusion over virtual infrastructure requirements for telemedicine and full-service web portals, and the impact of integrated delivery networks and outsourcing on extant cultural norms and revenue generating practices. To remain competitive provider organizations must integrate real and virtual healthcare delivery.
Virtual healthcare delivery: defined, modeled, and predictive barriers to implementation identified.
Harrop, V. M.
2001-01-01
Provider organizations lack: 1. a definition of "virtual" healthcare delivery relative to the products, services, and processes offered by dot.coms, web-compact disk healthcare content providers, telemedicine, and telecommunications companies, and 2. a model for integrating real and virtual healthcare delivery. This paper defines virtual healthcare delivery as asynchronous, outsourced, and anonymous, then proposes a 2x2 Real-Virtual Healthcare Delivery model focused on real and virtual patients and real and virtual provider organizations. Using this model, provider organizations can systematically deconstruct healthcare delivery in the real world and reconstruct appropriate pieces in the virtual world. Observed barriers to virtual healthcare delivery are: resistance to telecommunication integrated delivery networks and outsourcing; confusion over virtual infrastructure requirements for telemedicine and full-service web portals, and the impact of integrated delivery networks and outsourcing on extant cultural norms and revenue generating practices. To remain competitive provider organizations must integrate real and virtual healthcare delivery. PMID:11825189
2015-01-01
The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities. PMID:26569608
Kostrubiec, Viviane; Dumas, Guillaume; Zanone, Pier-Giorgio; Kelso, J A Scott
2015-01-01
The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities.
A Review of Virtual Character's Emotion Model
NASA Astrophysics Data System (ADS)
Liu, Zhen
2008-11-01
Emotional virtual characters are essential to digital entertainment, an emotion is related to virtual environment and a virtual character's inner variables, emotion model of virtual character is a hot topic in many fields, domain knowledge is very important for modeling emotion, and the current research of emotion expression in the world was also summarized, and some new research directions of emotion model are presented.
Allen, R J; Rieger, T R; Musante, C J
2016-03-01
Quantitative systems pharmacology models mechanistically describe a biological system and the effect of drug treatment on system behavior. Because these models rarely are identifiable from the available data, the uncertainty in physiological parameters may be sampled to create alternative parameterizations of the model, sometimes termed "virtual patients." In order to reproduce the statistics of a clinical population, virtual patients are often weighted to form a virtual population that reflects the baseline characteristics of the clinical cohort. Here we introduce a novel technique to efficiently generate virtual patients and, from this ensemble, demonstrate how to select a virtual population that matches the observed data without the need for weighting. This approach improves confidence in model predictions by mitigating the risk that spurious virtual patients become overrepresented in virtual populations.
Peacetime Reprisals Under Article 51: An Argument for Legal Legitimacy in Cases of Terrorism
1997-04-01
legitimize virtually any international use of force under the law, it is more difficult to justify the morality of an action under the application of...lawlessness and barbarism." 149 SIR PAUL VINOGRADOFF, HISTORICAL TYPES OF INTERNATIONAL LAW, IN 1 BIBLIOTECA ViSSERIANA DiSSERTATIONUM Ius... virtually unchallenged, there is basis in state practice for giving Article 51 a broader interpretation, or possibly for the further development of customary
Enabling Virtual Access to Latin-American Southern Observatories
NASA Astrophysics Data System (ADS)
Filippi, G.
2010-12-01
EVALSO (Enabling Virtual Access to Latin-American Southern Observatories) is an international consortium of nine astronomical organisations and research network operators, part-funded under the European Commission FP7, to create and exploit high-speed bandwidth connections to South American observatories. A brief description of the project is presented. The EVALSO Consortium inaugurated a fibre link between the Paranal Observatory and international networks on 4 November 2010 capable of 10 Gigabit per second.
Meeting the challenges of clinical information provision.
Spring, Hannah
2017-12-01
This virtual issue of the Health Information and Libraries Journal (HILJ) has been compiled to mark the 5th International Clinical Librarian Conference 2011. In considering the challenges of clinical information provision, the content selected for the virtual issue offers an international flavour of clinical information provision and covers a variety of different facets of clinical librarianship. The issue broadly covers the areas of information needs and preferences, clinical librarian roles and services, and education and training, and reflects the way in which a normal issue of the HILJ would be presented. This includes a review article, a collection of original articles, and the three regular features which comprise International Perspectives and Initiatives, Learning and Teaching in Action, and Using Evidence in Practice. All papers included in this virtual issue are available free online. © 2011 The authors. Health Information and Libraries Journal © 2011 Health Libraries Group.
Entanglement entropy between virtual and real excitations in quantum electrodynamics
NASA Astrophysics Data System (ADS)
Ardenghi, Juan Sebastián
2018-05-01
The aim of this work is to introduce the entanglement entropy of real and virtual excitations of fermion and photon fields. By rewriting the generating functional of quantum electrodynamics theory as an inner product between quantum operators, it is possible to obtain quantum density operators representing the propagation of real and virtual particles. These operators are partial traces, where the degrees of freedom traced out are unobserved excitations. Then the von Neumann definition of entropy can be applied to these quantum operators and in particular, for the partial traces taken over by the internal or external degrees of freedom. A universal behavior is obtained for the entanglement entropy for different quantum fields at zeroth order in the coupling constant. In order to obtain numerical results at different orders in the perturbation expansion, the Bloch-Nordsieck model is considered, where it is shown that for some particular values of the electric charge, the von Neumann entropy increases or decreases with respect to the noninteracting case.
NASA Astrophysics Data System (ADS)
Castro, Marcelo A.; Peloc, Nora L.; Chien, Aichi; Goldberg, Ezequiel; Putman, Christopher M.; Cebral, Juan R.
2015-03-01
Cerebral aneurysms may rarely coexist with a proximal artery stenosis. In that small percent of patients, such coexistence poses a challenge for interventional neuroradiologists and neurosurgeons to make the best treatment decision. According to previous studies, the incidence of cerebral aneurysms in patients with internal carotid artery stenosis is no greater than five percent, where the aneurysm is usually incidentally detected, being about two percent for aneurysms and stenoses in the same cerebral circulation. Those cases pose a difficult management decision for the physician. Case reports showed patients who died due to aneurysm rupture months after endarterectomy but before aneurysm clipping, while others did not show any change in the aneurysm after plaque removal, having optimum outcome after aneurysm coiling. The aim of this study is to investigate the intra-aneurysmal hemodynamic changes before and after treatment of stenotic plaque. Virtually created moderate stenoses in vascular models of internal carotid artery aneurysm patients were considered in a number of cases reconstructed from three dimensional rotational angiography images. The strategy to create those plaques was based on parameters analyzed in a previous work where idealized models were considered, including relative distance and stenosis grade. Ipsilateral and contralateral plaques were modeled. Wall shear stress and velocity pattern were computed from finite element pulsatile blood flow simulations. The results may suggest that wall shear stress changes depend on relative angular position between the aneurysm and the plaque.
Olszewski, R; Tranduy, K; Reychler, H
2010-07-01
The authors present a new procedure of computer-assisted genioplasty. They determined the anterior, posterior and inferior limits of the chin in relation to the skull and face with the newly developed and validated three-dimensional cephalometric planar analysis (ACRO 3D). Virtual planning of the osteotomy lines was carried out with Mimics (Materialize) software. The authors built a three-dimensional rapid-prototyping multi-position model of the chin area from a medical low-dose CT scan. The transfer of virtual information to the operating room consisted of two elements. First, the titanium plates on the 3D RP model were pre-bent. Second, a surgical guide for the transfer of the osteotomy lines and the positions of the screws to the operating room was manufactured. The authors present the first case of the use of this model on a patient. The postoperative results are promising, and the technique is fast and easy-to-use. More patients are needed for a definitive clinical validation of this procedure. Copyright 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Building a VO-compliant Radio Astronomical DAta Model for Single-dish radio telescopes (RADAMS)
NASA Astrophysics Data System (ADS)
Santander-Vela, Juan de Dios; García, Emilio; Leon, Stephane; Espigares, Victor; Ruiz, José Enrique; Verdes-Montenegro, Lourdes; Solano, Enrique
2012-11-01
The Virtual Observatory (VO) is becoming the de-facto standard for astronomical data publication. However, the number of radio astronomical archives is still low in general, and even lower is the number of radio astronomical data available through the VO. In order to facilitate the building of new radio astronomical archives, easing at the same time their interoperability with VO framework, we have developed a VO-compliant data model which provides interoperable data semantics for radio data. That model, which we call the Radio Astronomical DAta Model for Single-dish (RADAMS) has been built using standards of (and recommendations from) the International Virtual Observatory Alliance (IVOA). This article describes the RADAMS and its components, including archived entities and their relationships to VO metadata. We show that by using IVOA principles and concepts, the effort needed for both the development of the archives and their VO compatibility has been lowered, and the joint development of two radio astronomical archives have been possible. We plan to adapt RADAMS to be able to deal with interferometry data in the future.
NASA Technical Reports Server (NTRS)
Wheeler, Kevin; Jorgensen, Charles
2000-01-01
This paper presents recent results in neuroelectric pattern recognition of electromyographic (EMG) signals used to control virtual computer input devices. The devices are designed to substitute for the functions of both a traditional joystick and keyboard entry method. We demonstrate recognition accuracy through neuroelectric control of a 757 class simulation aircraft landing at San Francisco International Airport using a virtual joystick as shown. This is accomplished by a pilot closing his fist in empty air and performing control movements that are captured by a dry electrode array on the arm which are then analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. We then demonstrate finer grain motor pattern recognition through a virtual keyboard by having a typist tap his traders on a typical desk in a touch typist position. The EMG signals are then translated to keyboard presses and displayed. The paper describes the bioelectric pattern recognition methodology common to both examples. Figure 2 depicts raw EMG data from typing, the numeral '8' and the numeral '9'. These two gestures are very close in appearance and statistical properties yet are distinguishable by our hidden Kharkov model algorithms. Extensions of this work to NASA emissions and robotic control are considered.
Rieger, TR; Musante, CJ
2016-01-01
Quantitative systems pharmacology models mechanistically describe a biological system and the effect of drug treatment on system behavior. Because these models rarely are identifiable from the available data, the uncertainty in physiological parameters may be sampled to create alternative parameterizations of the model, sometimes termed “virtual patients.” In order to reproduce the statistics of a clinical population, virtual patients are often weighted to form a virtual population that reflects the baseline characteristics of the clinical cohort. Here we introduce a novel technique to efficiently generate virtual patients and, from this ensemble, demonstrate how to select a virtual population that matches the observed data without the need for weighting. This approach improves confidence in model predictions by mitigating the risk that spurious virtual patients become overrepresented in virtual populations. PMID:27069777
Virtual water flows in the international trade of agricultural products of China.
Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun
2016-07-01
With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Knapic, C.; Zanichelli, A.; Dovgan, E.; Nanni, M.; Stagni, M.; Righini, S.; Sponza, M.; Bedosti, F.; Orlati, A.; Smareglia, R.
2016-07-01
Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly.
Sensitivity-based virtual fields for the non-linear virtual fields method
NASA Astrophysics Data System (ADS)
Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice
2017-09-01
The virtual fields method is an approach to inversely identify material parameters using full-field deformation data. In this manuscript, a new set of automatically-defined virtual fields for non-linear constitutive models has been proposed. These new sensitivity-based virtual fields reduce the influence of noise on the parameter identification. The sensitivity-based virtual fields were applied to a numerical example involving small strain plasticity; however, the general formulation derived for these virtual fields is applicable to any non-linear constitutive model. To quantify the improvement offered by these new virtual fields, they were compared with stiffness-based and manually defined virtual fields. The proposed sensitivity-based virtual fields were consistently able to identify plastic model parameters and outperform the stiffness-based and manually defined virtual fields when the data was corrupted by noise.
Facilitating learning through an international virtual collaborative practice: A case study.
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.
The electronic-commerce-oriented virtual merchandise model
NASA Astrophysics Data System (ADS)
Fang, Xiaocui; Lu, Dongming
2004-03-01
Electronic commerce has been the trend of commerce activities. Providing with Virtual Reality interface, electronic commerce has better expressing capacity and interaction means. But most of the applications of virtual reality technology in EC, 3D model is only the appearance description of merchandises. There is almost no information concerned with commerce information and interaction information. This resulted in disjunction of virtual model and commerce information. So we present Electronic Commerce oriented Virtual Merchandise Model (ECVMM), which combined a model with commerce information, interaction information and figure information of virtual merchandise. ECVMM with abundant information provides better support to information obtainment and communication in electronic commerce.
A Multi-Paradigm Modeling Framework to Simulate Dynamic Reciprocity in a Bioreactor
Kaul, Himanshu; Cui, Zhanfeng; Ventikos, Yiannis
2013-01-01
Despite numerous technology advances, bioreactors are still mostly utilized as functional black-boxes where trial and error eventually leads to the desirable cellular outcome. Investigators have applied various computational approaches to understand the impact the internal dynamics of such devices has on overall cell growth, but such models cannot provide a comprehensive perspective regarding the system dynamics, due to limitations inherent to the underlying approaches. In this study, a novel multi-paradigm modeling platform capable of simulating the dynamic bidirectional relationship between cells and their microenvironment is presented. Designing the modeling platform entailed combining and coupling fully an agent-based modeling platform with a transport phenomena computational modeling framework. To demonstrate capability, the platform was used to study the impact of bioreactor parameters on the overall cell population behavior and vice versa. In order to achieve this, virtual bioreactors were constructed and seeded. The virtual cells, guided by a set of rules involving the simulated mass transport inside the bioreactor, as well as cell-related probabilistic parameters, were capable of displaying an array of behaviors such as proliferation, migration, chemotaxis and apoptosis. In this way the platform was shown to capture not only the impact of bioreactor transport processes on cellular behavior but also the influence that cellular activity wields on that very same local mass transport, thereby influencing overall cell growth. The platform was validated by simulating cellular chemotaxis in a virtual direct visualization chamber and comparing the simulation with its experimental analogue. The results presented in this paper are in agreement with published models of similar flavor. The modeling platform can be used as a concept selection tool to optimize bioreactor design specifications. PMID:23555740
Virtualization of the Y.E.S. Congress 2009 Roundtable Symposia (Invited)
NASA Astrophysics Data System (ADS)
Gonzales, L. M.; Gaines, S. M.
2009-12-01
The Y.E.S. Congress 2009 was the first international conference organized by the Y.E.S. Network, an association of early-career geoscientists who represent professional societies, geoscience companies, geoscience departments, and interested policy makers from across the world, in collaboration with the International Year of Planet Earth (IYPE). The conference, hosted by the China University of Geosciences in Beijing, focused on scientific and career challenges faced by early-career geoscientists, with a particular emphasis on how the Y.E.S. Network can work collaboratively and internationally towards solving these challenges and furthering the IYPE motto of “Earth Sciences for Society”. A key features of the Y.E.S. Congress was the implementation of “virtualized” roundtable symposia which engaged senior and early-career geoscientists via presentations, panel discussions, and working group sessions in which strategies related to scientific challenges (i.e. climate change in the polar regions, natural hazards, natural resource sustainability) and academic and career pathway challenges (i.e. academic-industry linkages, gender parity in the geosciences, geoscience education sustainability, and international licensure issues) were developed. These strategies were then tasked to the Y.E.S. Network for further development and implementation. The virtualization of the roundtable symposia facilitated active discussion between those participants and speakers who were physically located at the conference facilities in Beijing with a wider international audience of virtual participants and speakers. This talk will address the key features of the roundtable virtualization, the successes and challenges faced during the pre-conference set-up as well as during the roundtable sessions, and potential future applications.
The STRIVE-ONR Project: Stress Resistance in Virtual Environments
2015-07-29
from the Virtual Iraq/Afghanistan Virtual Reality Exposure Therapy (VRET) system at the University of Southern California Institute for Creative...better sense of health outcomes; that is, "how the social environment exerts a cumulative impact on the physical and mental well being of individuals...levels with functional decline in elderly men and women. Geriatrics & gerontology international, 9 3, 282-289. Goldman, N., Turra, C. M., Glei, D
NASA Astrophysics Data System (ADS)
Watanuki, Keiichi; Kojima, Kazuyuki
The environment in which Japanese industry has achieved great respect is changing tremendously due to the globalization of world economies, while Asian countries are undergoing economic and technical development as well as benefiting from the advances in information technology. For example, in the design of custom-made casting products, a designer who lacks knowledge of casting may not be able to produce a good design. In order to obtain a good design and manufacturing result, it is necessary to equip the designer and manufacturer with a support system related to casting design, or a so-called knowledge transfer and creation system. This paper proposes a new virtual reality based knowledge acquisition and job training system for casting design, which is composed of the explicit and tacit knowledge transfer systems using synchronized multimedia and the knowledge internalization system using portable virtual environment. In our proposed system, the education content is displayed in the immersive virtual environment, whereby a trainee may experience work in the virtual site operation. Provided that the trainee has gained explicit and tacit knowledge of casting through the multimedia-based knowledge transfer system, the immersive virtual environment catalyzes the internalization of knowledge and also enables the trainee to gain tacit knowledge before undergoing on-the-job training at a real-time operation site.
NASA Astrophysics Data System (ADS)
Denisenko, P. F.; Maltseva, O. A.; Sotsky, V. V.
2018-03-01
The method of correcting the daytime vertical profiles of electron plasma frequency in the low ionosphere from International Refererence Ionosphere (IRI) model in accordance with the measured data of the virtual heights and absorption of signal radiowaves (method A1) reflected from the bottom of E-region at vertical sounding (VS) is presented. The method is based on the replacement of the IRI model profile by an approximation of analytical dependence with parameters determined according to VS data and partially by the IRI model. The method is tested by the results of four joint ground-based and rocket experiments carried out in the 1970s at midlatitudes of the European part of Russia upon the launches of high-altitude geophysical rockets of the Vertical series. It is shown that the consideration of both virtual reflection heigths and absorption makes it possible to obtain electron density distributions that show the best agreement with the rocket measurements made at most height ranges in the D- and E-regions. In additional, the obtained distributions account more adequately than the IRI model for the contributions of D- and E-regions to absorption of signals reflected above these regions.
Virtual pharmaceutical companies: collaborating flexibly in pharmaceutical development.
Forster, Simon P; Stegmaier, Julia; Spycher, Rene; Seeger, Stefan
2014-03-01
Research and development (R&D) collaborations represent one approach chosen by the pharmaceutical industry to tackle current challenges posed by declining internal R&D success rates and fading of the blockbuster model. In recent years, a flexible concept to collaborate in R&D has emerged: virtual pharmaceutical companies (VPCs). These differ from other R&D companies, such as biotech start-ups, collaborating with big pharmaceutical companies, because they solely comprise experienced teams of managers. VPCs have only been described anecdotally in literature. Thus, we present here the characteristics of a VPC and suggest how big pharma can leverage the concept of VPCs by introducing five possible modes of collaboration. We find that one mode, investing, is particularly promising for big pharma. Copyright © 2013 Elsevier Ltd. All rights reserved.
Space Science Outreach in the Virtual World of Second Life
NASA Astrophysics Data System (ADS)
Crider, Anthony W.; International Spaceflight Museum
2006-12-01
The on-line "game" of Second Life allows users to construct a highly detailed and customized environment. Users often pool talents and resources to construct virtual islands that focus on their common interest. One such group has built the International Spaceflight Museum, committed to constructing and displaying accurate models of rockets, spacecraft, telescopes, and planetariums. Current exhibits include a Saturn V rocket, a Viking lander on Mars, Spaceship One, the New Horizons mission to the Kuiper Belt, and a prototype of the Orion crew exploration vehicle. This museum also hosts public lectures, shuttle launch viewings, and university astronomy class projects. In this presentation, I will focus on how space science researchers and educators may take advantage of this new resource as a means to engage the public.
International practices on climate adaptation in transportation : findings from a virtual review
DOT National Transportation Integrated Search
2015-01-01
The Federal Highway Administration (FHWA) conducted an international review to study how international transportation agencies are addressing issues related to adapting highway infrastructure to the impacts of climate change. The review involved tran...
NREL, EPRI Validate Advanced Microgrid Controller with ESIF's Virtual
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
An information model for a virtual private optical network (OVPN) using virtual routers (VRs)
NASA Astrophysics Data System (ADS)
Vo, Viet Minh Nhat
2002-05-01
This paper describes a virtual private optical network architecture (Optical VPN - OVPN) based on virtual router (VR). It improves over architectures suggested for virtual private networks by using virtual routers with optical networks. The new things in this architecture are necessary changes to adapt to devices and protocols used in optical networks. This paper also presents information models for the OVPN: at the architecture level and at the service level. These are extensions to the DEN (directory enable network) and CIM (Common Information Model) for OVPNs using VRs. The goal is to propose a common management model using policies.
NASA Astrophysics Data System (ADS)
Murphy, M.; Chenaux, A.; Keenaghan, G.; GIbson, V..; Butler, J.; Pybusr, C.
2017-08-01
In this paper the recording and design for a Virtual Reality Immersive Model of Armagh Observatory is presented, which will replicate the historic buildings and landscape with distant meridian markers and position of its principal historic instruments within a model of the night sky showing the position of bright stars. The virtual reality model can be used for educational purposes allowing the instruments within the historic building model to be manipulated within 3D space to demonstrate how the position measurements of stars were made in the 18th century. A description is given of current student and researchers activities concerning on-site recording and surveying and the virtual modelling of the buildings and landscape. This is followed by a design for a Virtual Reality Immersive Model of Armagh Observatory use game engine and virtual learning platforms and concepts.
NASA Technical Reports Server (NTRS)
Clancey, William J.
2004-01-01
This viewgraph presentation provides an overview of past and possible future applications for artifical intelligence (AI) in astronaut instruction and training. AI systems have been used in training simulation for the Hubble Space Telescope repair, the International Space Station, and operations simulation for the Mars Exploration Rovers. In the future, robots such as may work as partners with astronauts on missions such as planetary exploration and extravehicular activities.
NASA Astrophysics Data System (ADS)
Herbuś, K.; Ociepka, P.
2017-08-01
In the work is examined the sequential control system of a technological line in the form of the final part of a system of an internal transport. The process of designing this technological line using the computer-aided approach ran concurrently in two different program environments. In the Mechatronics Concept Designer module of the PLM Siemens NX software was developed the 3D model of the technological line prepared for verification the logic interrelations implemented in the control system. For this purpose, from the whole system of the technological line, it was distinguished the sub-system of actuators and sensors, because their correct operation determines the correct operation of the whole system. Whereas in the application of the virtual controller have been implemented the algorithms of work of the planned line. Then both program environments have been integrated using the OPC server, which enables the exchange of data between the considered systems. The data on the state of the object and the data defining the way and sequence of operation of the technological line are exchanged between the virtual controller and the 3D model of the technological line in real time.
Virtual modeling of robot-assisted manipulations in abdominal surgery.
Berelavichus, Stanislav V; Karmazanovsky, Grigory G; Shirokov, Vadim S; Kubyshkin, Valeriy A; Kriger, Andrey G; Kondratyev, Evgeny V; Zakharova, Olga P
2012-06-27
To determine the effectiveness of using multidetector computed tomography (MDCT) data in preoperative planning of robot-assisted surgery. Fourteen patients indicated for surgery underwent MDCT using 64 and 256-slice MDCT. Before the examination, a specially constructed navigation net was placed on the patient's anterior abdominal wall. Processing of MDCT data was performed on a Brilliance Workspace 4 (Philips). Virtual vectors that imitate robotic and assistant ports were placed on the anterior abdominal wall of the 3D model of the patient, considering the individual anatomy of the patient and the technical capabilities of robotic arms. Sites for location of the ports were directed by projection on the roentgen-positive tags of the navigation net. There were no complications observed during surgery or in the post-operative period. We were able to reduce robotic arm interference during surgery. The surgical area was optimal for robotic and assistant manipulators without any need for reinstallation of the trocars. This method allows modeling of the main steps in robot-assisted intervention, optimizing operation of the manipulator and lowering the risk of injuries to internal organs.
Ribeiro, Taisa Pereira Piacentini; Manarin, Flávia Giovana; Borges de Melo, Eduardo
2018-05-30
To address the rising global demand for food, it is necessary to search for new herbicides that can control resistant weeds. We performed a 2D-quantitative structure-activity relationship (QSAR) study to predict compounds with photosynthesis-inhibitory activity. A data set of 44 compounds (quinolines and naphthalenes), which are described as photosynthetic electron transport (PET) inhibitors, was used. The obtained model was approved in internal and external validation tests. 2D Similarity-based virtual screening was performed and 64 compounds were selected from the ZINC database. By using the VEGA QSAR software, 48 compounds were shown to have potential toxic effects (mutagenicity and carcinogenicity). Therefore, the model was also tested using a set of 16 molecules obtained by a similarity search of the ZINC database. Six compounds showed good predicted inhibition of PET. The obtained model shows potential utility in the design of new PET inhibitors, and the hit compounds found by virtual screening are novel bicyclic scaffolds of this class. Copyright © 2018 Elsevier Inc. All rights reserved.
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.
NASA Astrophysics Data System (ADS)
Palestini, C.; Basso, A.
2017-11-01
In recent years, an increase in international investment in hardware and software technology to support programs that adopt algorithms for photomodeling or data management from laser scanners significantly reduced the costs of operations in support of Augmented Reality and Virtual Reality, designed to generate real-time explorable digital environments integrated to virtual stereoscopic headset. The research analyzes transversal methodologies related to the acquisition of these technologies in order to intervene directly on the phenomenon of acquiring the current VR tools within a specific workflow, in light of any issues related to the intensive use of such devices , outlining a quick overview of the possible "virtual migration" phenomenon, assuming a possible integration with the new internet hyper-speed systems, capable of triggering a massive cyberspace colonization process that paradoxically would also affect the everyday life and more in general, on human space perception. The contribution aims at analyzing the application systems used for low cost 3d photogrammetry by means of a precise pipeline, clarifying how a 3d model is generated, automatically retopologized, textured by color painting or photo-cloning techniques, and optimized for parametric insertion on virtual exploration platforms. Workflow analysis will follow some case studies related to photomodeling, digital retopology and "virtual 3d transfer" of some small archaeological artifacts and an architectural compartment corresponding to the pronaus of Aurum, a building designed in the 1940s by Michelucci. All operations will be conducted on cheap or free licensed software that today offer almost the same performance as their paid counterparts, progressively improving in the data processing speed and management.
Virtual Library: Providing Accessible Online Resources.
ERIC Educational Resources Information Center
Kelly, Rob
2001-01-01
Describes e-global library, a virtual library based on the Jones International University's library that organizes Internet resources to make them more accessible to students at all skill levels. Highlights include online tutorials; research guides; financial aid and career development information; and possible partnerships with other digital…
Armenian Virtual Observatory: Services and Data Sharing
NASA Astrophysics Data System (ADS)
Knyazyan, A. V.; Astsatryan, H. V.; Mickaelian, A. M.
2016-06-01
The main aim of this article is to introduce the data management and services of the Armenian Virtual Observatory (ArVO), which consists of user friendly data management mechanisms, a new and productive cross-correlation service, and data sharing API based on international standards and protocols.
Cloud Computing for Mission Design and Operations
NASA Technical Reports Server (NTRS)
Arrieta, Juan; Attiyah, Amy; Beswick, Robert; Gerasimantos, Dimitrios
2012-01-01
The space mission design and operations community already recognizes the value of cloud computing and virtualization. However, natural and valid concerns, like security, privacy, up-time, and vendor lock-in, have prevented a more widespread and expedited adoption into official workflows. In the interest of alleviating these concerns, we propose a series of guidelines for internally deploying a resource-oriented hub of data and algorithms. These guidelines provide a roadmap for implementing an architecture inspired in the cloud computing model: associative, elastic, semantical, interconnected, and adaptive. The architecture can be summarized as exposing data and algorithms as resource-oriented Web services, coordinated via messaging, and running on virtual machines; it is simple, and based on widely adopted standards, protocols, and tools. The architecture may help reduce common sources of complexity intrinsic to data-driven, collaborative interactions and, most importantly, it may provide the means for teams and agencies to evaluate the cloud computing model in their specific context, with minimal infrastructure changes, and before committing to a specific cloud services provider.
Catching fly balls in virtual reality: a critical test of the outfielder problem
Fink, Philip W.; Foo, Patrick S.; Warren, William H.
2013-01-01
How does a baseball outfielder know where to run to catch a fly ball? The “outfielder problem” remains unresolved, and its solution would provide a window into the visual control of action. It may seem obvious that human action is based on an internal model of the physical world, such that the fielder predicts the landing point based on a mental model of the ball’s trajectory (TP). But two alternative theories, Optical Acceleration Cancellation (OAC) and Linear Optical Trajectory (LOT), propose that fielders are led to the right place at the right time by coupling their movements to visual information in a continuous “online” manner. All three theories predict successful catches and similar running paths. We provide a critical test by using virtual reality to perturb the vertical motion of the ball in mid-flight. The results confirm the predictions of OAC, but are at odds with LOT and TP. PMID:20055547
Drilling Deep Into STEM Education with JOIDES Resolution Education and Outreach Officers
NASA Astrophysics Data System (ADS)
Christiansen, E. A.
2015-12-01
During International Ocean Discovery Program (IODP) expeditions, IODP scientists and Education/Outreach (E/O) Officers enter classrooms and informal science venues via live Internet video links between the JOIDES Resolution (JR) and land-based learning centers. Post-expedition, E/O Officers, serving as JR Ambassadors, deepen and broaden the learning experience by bringing STEM from the JR to the general public through targeted outreach events at those land-based sites. Youth and adult learners participate in scientific inquiry through interactive activities linked directly to the video broadcast experience. Outreach venues include museums, summer camps, and after-school programs; classroom visits from E/O Officers encompass kindergarten to undergraduate school groups and often include professional development for educators. Events are hands-on with simulations, expedition samples, core models, and equipment available for interaction. This program can serve as a model for linking virtual and real experiences; deepening the educational value of virtual field trip events; and bringing cutting edge science into both classrooms and informal science venues.
Maffei, Vincenzo; Mazzarella, Elisabetta; Piras, Fabrizio; Spalletta, Gianfranco; Caltagirone, Carlo; Lacquaniti, Francesco; Daprati, Elena
2016-05-01
Rich behavioral evidence indicates that the brain estimates the visual direction and acceleration of gravity quite accurately, and the underlying mechanisms have begun to be unraveled. While the neuroanatomical substrates of gravity direction processing have been studied extensively in brain-damaged patients, to our knowledge no such study exists for the processing of visual gravitational motion. Here we asked 31 stroke patients to intercept a virtual ball moving along the vertical under either natural gravity or artificial reversed gravity. Twenty-seven of them also aligned a luminous bar to the vertical direction (subjective visual vertical, SVV). Using voxel-based lesion-symptom mapping as well as lesion subtraction analysis, we found that lesions mainly centered on the posterior insula are associated with greater deviations of SVV, consistent with several previous studies. Instead, lesions mainly centered on the parietal operculum decrease the ability to discriminate natural from unnatural gravitational acceleration with a timed motor response in the interception task. Both the posterior insula and the parietal operculum belong to the vestibular cortex, and presumably receive multisensory information about the gravity vector. We speculate that an internal model estimating the effects of gravity on visual objects is constructed by transforming the vestibular estimates of mechanical gravity, which are computed in the brainstem and cerebellum, into internalized estimates of virtual gravity, which are stored in the cortical vestibular network. The present lesion data suggest a specific role for the parietal operculum in detecting the mismatch between predictive signals from the internal model and the online visual signals. Copyright © 2016 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Hanisch, R. J.
2014-11-01
The concept of the Virtual Observatory arose more-or-less simultaneously in the United States and Europe circa 2000. Ten pages of Astronomy and Astrophysics in the New Millennium: Panel Reports (National Academy Press, Washington, 2001), that is, the detailed recommendations of the Panel on Theory, Computation, and Data Exploration of the 2000 Decadal Survey in Astronomy, are dedicated to describing the motivation for, scientific value of, and major components required in implementing the National Virtual Observatory. European initiatives included the Astrophysical Virtual Observatory at the European Southern Observatory, the AstroGrid project in the United Kingdom, and the Euro-VO (sponsored by the European Union). Organizational/conceptual meetings were held in the US at the California Institute of Technology (Virtual Observatories of the Future, June 13-16, 2000) and at ESO Headquarters in Garching, Germany (Mining the Sky, July 31-August 4, 2000; Toward an International Virtual Observatory, June 10-14, 2002). The nascent US, UK, and European VO projects formed the International Virtual Observatory Alliance (IVOA) at the June 2002 meeting in Garching, with yours truly as the first chair. The IVOA has grown to a membership of twenty-one national projects and programs on six continents, and has developed a broad suite of data access protocols and standards that have been widely implemented. Astronomers can now discover, access, and compare data from hundreds of telescopes and facilities, hosted at hundreds of organizations worldwide, stored in thousands of databases, all with a single query.
Virtual Environments in Scientific Visualization
NASA Technical Reports Server (NTRS)
Bryson, Steve; Lisinski, T. A. (Technical Monitor)
1994-01-01
Virtual environment technology is a new way of approaching the interface between computers and humans. Emphasizing display and user control that conforms to the user's natural ways of perceiving and thinking about space, virtual environment technologies enhance the ability to perceive and interact with computer generated graphic information. This enhancement potentially has a major effect on the field of scientific visualization. Current examples of this technology include the Virtual Windtunnel being developed at NASA Ames Research Center. Other major institutions such as the National Center for Supercomputing Applications and SRI International are also exploring this technology. This talk will be describe several implementations of virtual environments for use in scientific visualization. Examples include the visualization of unsteady fluid flows (the virtual windtunnel), the visualization of geodesics in curved spacetime, surface manipulation, and examples developed at various laboratories.
Understanding virtual water flows: A multiregion input-output case study of Victoria
NASA Astrophysics Data System (ADS)
Lenzen, Manfred
2009-09-01
This article explains and interprets virtual water flows from the well-established perspective of input-output analysis. Using a case study of the Australian state of Victoria, it demonstrates that input-output analysis can enumerate virtual water flows without systematic and unknown truncation errors, an issue which has been largely absent from the virtual water literature. Whereas a simplified flow analysis from a producer perspective would portray Victoria as a net virtual water importer, enumerating the water embodiments across the full supply chain using input-output analysis shows Victoria as a significant net virtual water exporter. This study has succeeded in informing government policy in Australia, which is an encouraging sign that input-output analysis will be able to contribute much value to other national and international applications.
ERIC Educational Resources Information Center
Pantelidis, Veronica S.
2009-01-01
Many studies have been conducted on the use of virtual reality in education and training. This article lists examples of such research. Reasons to use virtual reality are discussed. Advantages and disadvantages of using virtual reality are presented, as well as suggestions on when to use and when not to use virtual reality. A model that can be…
Ardalan, Ali; Balikuddembe, Joseph Kimuli; Ingrassia, Pier Luigi; Carenzo, Luca; Della Corte, Francesco; Akbarisari, Ali; Djalali, Ahmadreza
2015-07-13
Disaster education needs innovative educational methods to be more effective compared to traditional approaches. This can be done by using virtual simulation method. This article presents an experience about using virtual simulation methods to teach health professional on disaster medicine in Iran. The workshop on the "Application of New Technologies in Disaster Management Simulation" was held in Tehran in January 2015. It was co-organized by the Disaster and Emergency Health Academy of Tehran University of Medical Sciences and Emergency and the Research Center in Disaster Medicine and Computer Science applied to Medicine (CRIMEDIM), Università del Piemonte Orientale. Different simulators were used by the participants, who were from the health system and other relevant fields, both inside and outside Iran. As a result of the workshop, all the concerned stakeholders are called on to support this new initiative of incorporating virtual training and exercise simulation in the field of disaster medicine, so that its professionals are endowed with field-based and practical skills in Iran and elsewhere. Virtual simulation technology is recommended to be used in education of disaster management. This requires capacity building of instructors, and provision of technologies. International collaboration can facilitate this process.
Kernodle, Michael W; McKethan, Robert N; Rabinowitz, Erik
2008-10-01
Traditional and virtual modeling were compared during learning of a multiple degree-of-freedom skill (fly casting) to assess the effect of the presence or absence of an authority figure on observational learning via virtual modeling. Participants were randomly assigned to one of four groups: Virtual Modeling with an authority figure present (VM-A) (n = 16), Virtual Modeling without an authority figure (VM-NA) (n = 16), Traditional Instruction (n = 17), and Control (n = 19). Results showed significant between-group differences on Form and Skill Acquisition scores. Except for one instance, all three learning procedures resulted in significant learning of fly casting. Virtual modeling with or without an authority figure present was as effective as traditional instruction; however, learning without an authority figure was less effective with regard to Accuracy scores.
Photorealistic virtual anatomy based on Chinese Visible Human data.
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.
Perspectives of IT Professionals on Employing Server Virtualization Technologies
ERIC Educational Resources Information Center
Sligh, Darla
2010-01-01
Server virtualization enables a physical computer to support multiple applications logically by decoupling the application from the hardware layer, thereby reducing operational costs and competitive in delivering IT services to their enterprise organizations. IT organizations continually examine the efficiency of their internal IT systems and…
Using Virtualization to Integrate Weather, Climate, and Coastal Science Education
NASA Astrophysics Data System (ADS)
Davis, J. R.; Paramygin, V. A.; Figueiredo, R.; Sheng, Y.
2012-12-01
To better understand and communicate the important roles of weather and climate on the coastal environment, a unique publically available tool is being developed to support research, education, and outreach activities. This tool uses virtualization technologies to facilitate an interactive, hands-on environment in which students, researchers, and general public can perform their own numerical modeling experiments. While prior efforts have focused solely on the study of the coastal and estuary environments, this effort incorporates the community supported weather and climate model (WRF-ARW) into the Coastal Science Educational Virtual Appliance (CSEVA), an education tool used to assist in the learning of coastal transport processes; storm surge and inundation; and evacuation modeling. The Weather Research and Forecasting (WRF) Model is a next-generation, community developed and supported, mesoscale numerical weather prediction system designed to be used internationally for research, operations, and teaching. It includes two dynamical solvers (ARW - Advanced Research WRF and NMM - Nonhydrostatic Mesoscale Model) as well as a data assimilation system. WRF-ARW is the ARW dynamics solver combined with other components of the WRF system which was developed primarily at NCAR, community support provided by the Mesoscale and Microscale Meteorology (MMM) division of National Center for Atmospheric Research (NCAR). Included with WRF is the WRF Pre-processing System (WPS) which is a set of programs to prepare input for real-data simulations. The CSEVA is based on the Grid Appliance (GA) framework and is built using virtual machine (VM) and virtual networking technologies. Virtualization supports integration of an operating system, libraries (e.g. Fortran, C, Perl, NetCDF, etc. necessary to build WRF), web server, numerical models/grids/inputs, pre-/post-processing tools (e.g. WPS / RIP4 or UPS), graphical user interfaces, "Cloud"-computing infrastructure and other tools into a single ready-to-use package. Thus, the previous ornery task of setting up and compiling these tools becomes obsolete and the research, educator or student can focus on using the tools to study the interactions between weather, climate and the coastal environment. The incorporation of WRF into the CSEVA has been designed to be synergistic with the extensive online tutorials and biannual tutorials hosted by NCAR. Included are working examples of the idealized test simulations provided with WRF (2D sea breeze and squalls, a large eddy simulation, a Held and Suarez simulation, etc.) To demonstrate the integration of weather, coastal and coastal science education, example applications are being developed to demonstrate how the system can be used to couple a coastal and estuarine circulation, transport and storm surge model with downscale reanalysis weather and future climate predictions. Documentation, tutorials and the enhanced CSEVA itself will be found on the web at: http://cseva.coastal.ufl.edu.
Nonlinear vibration absorption for a flexible arm via a virtual vibration absorber
NASA Astrophysics Data System (ADS)
Bian, Yushu; Gao, Zhihui
2017-07-01
A semi-active vibration absorption method is put forward to attenuate nonlinear vibration of a flexible arm based on the internal resonance. To maintain the 2:1 internal resonance condition and the desirable damping characteristic, a virtual vibration absorber is suggested. It is mathematically equivalent to a vibration absorber but its frequency and damping coefficients can be readily adjusted by simple control algorithms, thereby replacing those hard-to-implement mechanical designs. Through theoretical analyses and numerical simulations, it is proven that the internal resonance can be successfully established for the flexible arm, and the vibrational energy of flexible arm can be transferred to and dissipated by the virtual vibration absorber. Finally, experimental results are presented to validate the theoretical predictions. Since the proposed method absorbs rather than suppresses vibrational energy of the primary system, it is more convenient to reduce strong vibration than conventional active vibration suppression methods based on smart material actuators with limited energy output. Furthermore, since it aims to establish an internal vibrational energy transfer channel from the primary system to the vibration absorber rather than directly respond to external excitations, it is especially applicable for attenuating nonlinear vibration excited by unpredictable excitations.
A Web-based cost-effective training tool with possible application to brain injury rehabilitation.
Wang, Peijun; Kreutzer, Ina Anna; Bjärnemo, Robert; Davies, Roy C
2004-06-01
Virtual reality (VR) has provoked enormous interest in the medical community. In particular, VR offers therapists new approaches for improving rehabilitation effects. However, most of these VR assistant tools are not very portable, extensible or economical. Due to the vast amount of 3D data, they are not suitable for Internet transfer. Furthermore, in order to run these VR systems smoothly, special hardware devices are needed. As a result, existing VR assistant tools tend to be available in hospitals but not in patients' homes. To overcome these disadvantages, as a case study, this paper proposes a Web-based Virtual Ticket Machine, called WBVTM, using VRML [VRML Consortium, The Virtual Reality Modeling Language: International Standard ISO/IEC DIS 14772-1, 1997, available at ], Java and EAI (External Authoring Interface) [Silicon Graphics, Inc., The External Authoring Interface (EAI), available at ], to help people with acquired brain injury (ABI) to relearn basic living skills at home at a low cost. As these technologies are open standard and feature usability on the Internet, WBVTM achieves the goals of portability, easy accessibility and cost-effectiveness.
2014-01-01
Virtual worlds (VWs), in which participants navigate as avatars through three-dimensional, computer-generated, realistic-looking environments, are emerging as important new technologies for distance health education. However, there is relatively little documented experience using VWs for international healthcare training. The Geneva Foundation for Medical Education and Research (GFMER) conducted a VW training for healthcare professionals enrolled in a GFMER training course. This paper describes the development, delivery, and results of a pilot project undertaken to explore the potential of VWs as an environment for distance healthcare education for an international audience that has generally limited access to conventionally delivered education. PMID:24555833
2010-10-01
organization in the WoW virtual world. Unlike the real world guilds of olden days (e.g., stone masons, leather workers, apothecaries) and unions of current...oriented sports teams (e.g., football, hockey, rugby ). This is the case in particular with player-vs- player combat. Fourth, organizational learning is...Microsystems Telecom Italia Telus Mobility Text 100 Toyota Trades Union Congress Union Network International New Unionism
Water resources transfers through Chinese interprovincial and foreign food trade
Dalin, Carole; Hanasaki, Naota; Qiu, Huanguang; Mauzerall, Denise L.; Rodriguez-Iturbe, Ignacio
2014-01-01
China’s water resources are under increasing pressure from socioeconomic development, diet shifts, and climate change. Agriculture still concentrates most of the national water withdrawal. Moreover, a spatial mismatch in water and arable land availability—with abundant agricultural land and little water resources in the north—increases water scarcity and results in virtual water transfers from drier to wetter regions through agricultural trade. We use a general equilibrium welfare model and linear programming optimization to model interprovincial food trade in China. We combine these trade flows with province-level estimates of commodities’ virtual water content to build China’s domestic and foreign virtual water trade network. We observe large variations in agricultural water-use efficiency among provinces. In addition, some provinces particularly rely on irrigation vs. rainwater. We analyze the virtual water flow patterns and the corresponding water savings. We find that this interprovincial network is highly connected and the flow distribution is relatively homogeneous. A significant share of water flows is from international imports (20%), which are dominated by soy (93%). We find that China’s domestic food trade is efficient in terms of rainwater but inefficient regarding irrigation, meaning that dry, irrigation-intensive provinces tend to export to wetter, less irrigation-intensive ones. Importantly, when incorporating foreign imports, China’s soy trade switches from an inefficient system to a particularly efficient one for saving water resources (20 km3/y irrigation water savings, 41 km3/y total). Finally, we identify specific provinces (e.g., Inner Mongolia) and products (e.g., corn) that show high potential for irrigation productivity improvements. PMID:24958864
Water resources transfers through Chinese interprovincial and foreign food trade.
Dalin, Carole; Hanasaki, Naota; Qiu, Huanguang; Mauzerall, Denise L; Rodriguez-Iturbe, Ignacio
2014-07-08
China's water resources are under increasing pressure from socioeconomic development, diet shifts, and climate change. Agriculture still concentrates most of the national water withdrawal. Moreover, a spatial mismatch in water and arable land availability--with abundant agricultural land and little water resources in the north--increases water scarcity and results in virtual water transfers from drier to wetter regions through agricultural trade. We use a general equilibrium welfare model and linear programming optimization to model interprovincial food trade in China. We combine these trade flows with province-level estimates of commodities' virtual water content to build China's domestic and foreign virtual water trade network. We observe large variations in agricultural water-use efficiency among provinces. In addition, some provinces particularly rely on irrigation vs. rainwater. We analyze the virtual water flow patterns and the corresponding water savings. We find that this interprovincial network is highly connected and the flow distribution is relatively homogeneous. A significant share of water flows is from international imports (20%), which are dominated by soy (93%). We find that China's domestic food trade is efficient in terms of rainwater but inefficient regarding irrigation, meaning that dry, irrigation-intensive provinces tend to export to wetter, less irrigation-intensive ones. Importantly, when incorporating foreign imports, China's soy trade switches from an inefficient system to a particularly efficient one for saving water resources (20 km(3)/y irrigation water savings, 41 km(3)/y total). Finally, we identify specific provinces (e.g., Inner Mongolia) and products (e.g., corn) that show high potential for irrigation productivity improvements.
Shared virtual environments for aerospace training
NASA Technical Reports Server (NTRS)
Loftin, R. Bowen; Voss, Mark
1994-01-01
Virtual environments have the potential to significantly enhance the training of NASA astronauts and ground-based personnel for a variety of activities. A critical requirement is the need to share virtual environments, in real or near real time, between remote sites. It has been hypothesized that the training of international astronaut crews could be done more cheaply and effectively by utilizing such shared virtual environments in the early stages of mission preparation. The Software Technology Branch at NASA's Johnson Space Center has developed the capability for multiple users to simultaneously share the same virtual environment. Each user generates the graphics needed to create the virtual environment. All changes of object position and state are communicated to all users so that each virtual environment maintains its 'currency.' Examples of these shared environments will be discussed and plans for the utilization of the Department of Defense's Distributed Interactive Simulation (DIS) protocols for shared virtual environments will be presented. Finally, the impact of this technology on training and education in general will be explored.
Photographic coverage of STS-112 during EVA 3 in VR Lab.
2002-08-21
JSC2002-E-34618 (21 August 2002) --- Astronaut Piers J. Sellers, STS-112 mission specialist, uses virtual reality hardware in the Space Vehicle Mockup Facility at the Johnson Space Center (JSC) to rehearse some of his duties on the upcoming mission to the International Space Station (ISS). This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the International Space Station (ISS) hardware with which they will be working.
International trade in meat: the tip of the pork chop.
Galloway, James N; Burke, Marshall; Bradford, G Eric; Naylor, Rosamond; Falcon, Walter; Chapagain, Ashok K; Gaskell, Joanne C; McCullough, Ellen; Mooney, Harold A; Oleson, Kirsten L L; Steinfeld, Henning; Wassenaar, Tom; Smil, Vaclav
2007-12-01
This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost. Results show that Japan's pig and chicken meat imports embody the virtual equivalent of 50% of Japan's total arable land, and half of Japan's virtual nitrogen total is lost in the US. Trade links with China are responsible for 15% of the virtual nitrogen left behind in Brazil due to feed and meat exports, and 20% of Brazil's area is used to grow soybean exports. The complexity of trade in meat, feed, water, and nitrogen is illustrated by the dual roles of the US and The Netherlands as both importers and exporters of meat. Mitigation of environmental damage from industrialized livestock production and trade depends on a combination of direct-pricing strategies, regulatory approaches, and use of best management practices. Our analysis indicates that increased water- and nitrogen-use efficiency and land conservation resulting from these measures could significantly reduce resource costs.
Bringing the Real World in: Reflection on Building a Virtual Learning Environment
ERIC Educational Resources Information Center
Mundkur, Anuradha; Ellickson, Cara
2012-01-01
We reflect on translating participatory and experiential learning methodologies into an online teaching environment through a Virtual Learning Environment (VLE) that simulates the "real-world" contexts of international development in order to develop an applied critical understanding of gender analysis and gender mainstreaming. Rather than being…
Validation of virtual reality as a tool to understand and prevent child pedestrian injury.
Schwebel, David C; Gaines, Joanna; Severson, Joan
2008-07-01
In recent years, virtual reality has emerged as an innovative tool for health-related education and training. Among the many benefits of virtual reality is the opportunity for novice users to engage unsupervised in a safe environment when the real environment might be dangerous. Virtual environments are only useful for health-related research, however, if behavior in the virtual world validly matches behavior in the real world. This study was designed to test the validity of an immersive, interactive virtual pedestrian environment. A sample of 102 children and 74 adults was recruited to complete simulated road-crossings in both the virtual environment and the identical real environment. In both the child and adult samples, construct validity was demonstrated via significant correlations between behavior in the virtual and real worlds. Results also indicate construct validity through developmental differences in behavior; convergent validity by showing correlations between parent-reported child temperament and behavior in the virtual world; internal reliability of various measures of pedestrian safety in the virtual world; and face validity, as measured by users' self-reported perception of realism in the virtual world. We discuss issues of generalizability to other virtual environments, and the implications for application of virtual reality to understanding and preventing pediatric pedestrian injuries.
Asteroseismology and the Virtual Observatory
NASA Astrophysics Data System (ADS)
Suárez, J. C.
2010-12-01
Virtual Observatory is an international project aiming at solving the problem of interoperability among astronomical archives and the scalability in the classical methods of retrieving and analyzing astronomical data in order to deal with huge amounts of datasets. This is being tackled thanks to the standardization of astronomical archives favoring their access in a efficient manner. This project, which is nowadays a reality, is more and more adopted by many fields of Science. In the present paper I will describe the origin of a new era in Stellar Physics whose main role is played by the relationship between asteroseismology and V.O. I will summarize the main concerns of both fields and the current development of VO tools for the development of what we could name as asteroseismology online, in which not only observed datasets are concerned but also the management of model databases.
NASA Astrophysics Data System (ADS)
Priego-Roche, Luz-María; Rieu, Dominique; Front, Agnès
Nowadays, organizations aiming to be successful in an increasingly competitive market tend to group together into virtual organizations. Designing the information system (IS) of such virtual organizations on the basis of the IS of those participating is a real challenge. The IS of a virtual organization plays an important role in the collaboration and cooperation of the participants organizations and in reaching the common goal. This article proposes criteria allowing virtual organizations to be identified and classified at an intentional level, as well as the information necessary for designing the organizations’ IS. Instantiation of criteria for a specific virtual organization and its participants, will allow simple graphical models to be generated in a modelling tool. The models will be used as bases for the IS design at organizational and operational levels. The approach is illustrated by the example of the virtual organization UGRT (a regional stockbreeders union in Tabasco, Mexico).
Intercepting a moving target: On-line or model-based control?
Zhao, Huaiyong; Warren, William H
2017-05-01
When walking to intercept a moving target, people take an interception path that appears to anticipate the target's trajectory. According to the constant bearing strategy, the observer holds the bearing direction of the target constant based on current visual information, consistent with on-line control. Alternatively, the interception path might be based on an internal model of the target's motion, known as model-based control. To investigate these two accounts, participants walked to intercept a moving target in a virtual environment. We degraded the target's visibility by blurring the target to varying degrees in the midst of a trial, in order to influence its perceived speed and position. Reduced levels of visibility progressively impaired interception accuracy and precision; total occlusion impaired performance most and yielded nonadaptive heading adjustments. Thus, performance strongly depended on current visual information and deteriorated qualitatively when it was withdrawn. The results imply that locomotor interception is normally guided by current information rather than an internal model of target motion, consistent with on-line control.
Entropy of Egypt's virtual water trade gravity field
NASA Astrophysics Data System (ADS)
Karakatsanis, Georgios; Bierbach, Sandra
2016-04-01
The study investigates the entropy of Egypt's virtual water trade gravity distribution, in order to provide a chart of Egypt's embodied water balance in agricultural trade, in relation to distances with its major counterparties. Moreover, our calculations on the amount of the embodied water traded between Egypt and each of its partners take place according to a combination of available data on the blue, green and grey water footprints as well as the Food and Agriculture Organization (FAO) database of traded amounts per crop type. A study on the virtual water trade gravity, enables us to enrich former related studies (Fracasso 2014; Fracasso, Sartori and Schiavo 2014) via examining Egypt's water supply dependence on the Nile River and if comparative advantages -purely from the side of water quantities- can be identified via recognizing which water footprint categories are particularly high. Additionally, this methodology can comprise -from a fundamental level- a guide for revealing the importance of water footprint types for Egypt's agricultural sector; hence, Egypt's potential comparative advantages, as far as quantitative water endowments are exclusively concerned (without consideration of water or crop prices). Although it is pointed out very correctly by various authors (Antonelli and Sartori 2014) that the virtual water trade concept does not incorporate many important aspects of water supply -such as heavy water price subsidizing- to be used accurately for the identification of comparative advantages, we consider that the purely quantitative examination can provide strong fundamental indications -especially for green and grey water footprints, which are hypothesized to be less sensitive to subsidizing. In overall, this effect can very well provide a primary indication on the organization of the global alimentation trade network (Yang et al. 2006). The gravity equation used contains water footprint data for the 15 top traded crops and the distances for Egypt's 20 trading partner countries, for a time frame from 1995 to 2013. The calculations -implemented for each country and each crop- display a network that illustrates the gravity of virtual water trade. It is then possible for us to model the entropy of Egypt's virtual water trade gravity field, via the statistical examination of its spatial fragmentation or continuity for each traded crop and for each water footprint type. Hence, with the distribution's entropy we may conduct a targeted analysis on the comparative advantages of the Egyptian agriculture. Keywords: entropy, virtual water trade, gravity model, agricultural trade, water footprint, water subsidies, comparative advantage References 1. Antonelli, Marta and Martina Sartori (2014), Unfolding the potential of the Virtual Water concept. What is still under debate?, MPRA Paper No. 60501, http://mpra.ub.uni-muenchen.de/60501/ 2. Fracasso, Andrea (2014), A gravity model of virtual water trade, Ecological Economics, Vol. 108, p. 215-228 3. Fracasso, Andrea; Martina Sartori and Stefano Schiavo (2014), Determinants of virtual water flows in the Mediterranean, MPRA Paper No. 60500, https://mpra.ub.uni-muenchen.de/60500/ 4. Yang, H. et al. (2006), Virtual water trade: An assessment of water use efficiency in the international food trade, Hydrology and Earth System Sciences 10, p. 443-454
Kim, Dae-Seung; Woo, Sang-Yoon; Yang, Hoon Joo; Huh, Kyung-Hoe; Lee, Sam-Sun; Heo, Min-Suk; Choi, Soon-Chul; Hwang, Soon Jung; Yi, Won-Jin
2014-12-01
Accurate surgical planning and transfer of the planning in orthognathic surgery are very important in achieving a successful surgical outcome with appropriate improvement. Conventionally, the paper surgery is performed based on a 2D cephalometric radiograph, and the results are expressed using cast models and an articulator. We developed an integrated orthognathic surgery system with 3D virtual planning and image-guided transfer. The maxillary surgery of orthognathic patients was planned virtually, and the planning results were transferred to the cast model by image guidance. During virtual planning, the displacement of the reference points was confirmed by the displacement from conventional paper surgery at each procedure. The results of virtual surgery were transferred to the physical cast models directly through image guidance. The root mean square (RMS) difference between virtual surgery and conventional model surgery was 0.75 ± 0.51 mm for 12 patients. The RMS difference between virtual surgery and image-guidance results was 0.78 ± 0.52 mm, which showed no significant difference from the difference of conventional model surgery. The image-guided orthognathic surgery system integrated with virtual planning will replace physical model surgical planning and enable transfer of the virtual planning directly without the need for an intermediate splint. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
Collaboration in a Wireless Grid Innovation Testbed by Virtual Consortium
NASA Astrophysics Data System (ADS)
Treglia, Joseph; Ramnarine-Rieks, Angela; McKnight, Lee
This paper describes the formation of the Wireless Grid Innovation Testbed (WGiT) coordinated by a virtual consortium involving academic and non-academic entities. Syracuse University and Virginia Tech are primary university partners with several other academic, government, and corporate partners. Objectives include: 1) coordinating knowledge sharing, 2) defining key parameters for wireless grids network applications, 3) dynamically connecting wired and wireless devices, content and users, 4) linking to VT-CORNET, Virginia Tech Cognitive Radio Network Testbed, 5) forming ad hoc networks or grids of mobile and fixed devices without a dedicated server, 6) deepening understanding of wireless grid application, device, network, user and market behavior through academic, trade and popular publications including online media, 7) identifying policy that may enable evaluated innovations to enter US and international markets and 8) implementation and evaluation of the international virtual collaborative process.
Kubota, So; Inaba, Yutaka; Kobayashi, Naomi; Choe, Hyonmin; Tezuka, Taro; Saito, Tomoyuki
2017-10-16
While cam resection is essential to achieve a good clinical result with respect to femoroacetabular impingement (FAI), it is unclear whether it should also be performed in cases of borderline developmental dysplasia of the hip (DDH) with a cam deformity. The aim of this study was to evaluate improvements in range of motion (ROM) in cases of cam-type FAI and borderline DDH after virtual osteochondroplasty using a computer impingement simulation. Thirty-eight symptomatic hips in 31 patients (11male and 20 female) diagnosed with cam-type FAI or borderline DDH were analyzed. There were divided into a cam-type FAI group (cam-FAI group: 15 hips), borderline DDH without cam group (DDH W/O cam group: 12 hips), and borderline DDH with cam group (DDH W/ cam group: 11 hips). The bony impingement point on the femoral head-neck junction at 90° flexion and maximum internal rotation of the hip joint was identified using ZedHip® software. Virtual osteochondroplasty of the impingement point was then performed in all cases. The maximum flexion angle and maximum internal rotation angle at 90° flexion were measured before and after virtual osteochondroplasty at two resection ranges (i.e., slight and sufficient). The mean improvement in the internal rotation angle in the DDH W/ cam group after slight resection was significantly greater than that in the DDH W/O cam group (P = 0.046). Furthermore, the mean improvement in the internal rotation angle in the DDH W/ cam and cam-FAI groups after sufficient resection was significantly greater than that in the DDH W/O cam group (DDH W/ cam vs DDH W/O cam: P = 0.002, cam-FAI vs DDH W/O cam: P = 0.043). Virtual osteochondroplasty resulted in a significant improvement in internal rotation angle in DDH W/ cam group but not in DDH W/O cam group. Thus, borderline DDH cases with cam deformity may be better to consider performing osteochondroplasty.
SEARCH: Spatially Explicit Animal Response to Composition of Habitat.
Pauli, Benjamin P; McCann, Nicholas P; Zollner, Patrick A; Cummings, Robert; Gilbert, Jonathan H; Gustafson, Eric J
2013-01-01
Complex decisions dramatically affect animal dispersal and space use. Dispersing individuals respond to a combination of fine-scale environmental stimuli and internal attributes. Individual-based modeling offers a valuable approach for the investigation of such interactions because it combines the heterogeneity of animal behaviors with spatial detail. Most individual-based models (IBMs), however, vastly oversimplify animal behavior and such behavioral minimalism diminishes the value of these models. We present program SEARCH (Spatially Explicit Animal Response to Composition of Habitat), a spatially explicit, individual-based, population model of animal dispersal through realistic landscapes. SEARCH uses values in Geographic Information System (GIS) maps to apply rules that animals follow during dispersal, thus allowing virtual animals to respond to fine-scale features of the landscape and maintain a detailed memory of areas sensed during movement. SEARCH also incorporates temporally dynamic landscapes so that the environment to which virtual animals respond can change during the course of a simulation. Animals in SEARCH are behaviorally dynamic and able to respond to stimuli based upon their individual experiences. Therefore, SEARCH is able to model behavioral traits of dispersing animals at fine scales and with many dynamic aspects. Such added complexity allows investigation of unique ecological questions. To illustrate SEARCH's capabilities, we simulated case studies using three mammals. We examined the impact of seasonally variable food resources on the weight distribution of dispersing raccoons (Procyon lotor), the effect of temporally dynamic mortality pressure in combination with various levels of behavioral responsiveness in eastern chipmunks (Tamias striatus), and the impact of behavioral plasticity and home range selection on disperser mortality and weight change in virtual American martens (Martes americana). These simulations highlight the relevance of SEARCH for a variety of applications and illustrate benefits it can provide for conservation planning.
NASA Astrophysics Data System (ADS)
2015-01-01
The third International Conference on Mathematical Modeling in Physical Sciences (IC-MSQUARE) took place at Madrid, Spain, from Thursday 28 to Sunday 31 August 2014. The Conference was attended by more than 200 participants and hosted about 350 oral, poster, and virtual presentations. More than 600 pre-registered authors were also counted. The third IC-MSQUARE consisted of different and diverging workshops and thus covered various research fields where Mathematical Modeling is used, such as Theoretical/Mathematical Physics, Neutrino Physics, Non-Integrable Systems, Dynamical Systems, Computational Nanoscience, Biological Physics, Computational Biomechanics, Complex Networks, Stochastic Modeling, Fractional Statistics, DNA Dynamics, Macroeconomics etc. The scientific program was rather heavy since after the Keynote and Invited Talks in the morning, three parallel oral sessions and one poster session were running every day. However, according to all attendees, the program was excellent with high level of talks and the scientific environment was fruitful, thus all attendees had a creative time. We would like to thank the Keynote Speaker and the Invited Speakers for their significant contribution to IC-MSQUARE. We also would like to thank the Members of the International Advisory and Scientific Committees as well as the Members of the Organizing Committee.
PREFACE: 4th International Conference on Mathematical Modeling in Physical Sciences (IC-MSquare2015)
NASA Astrophysics Data System (ADS)
Vlachos, Dimitrios; Vagenas, Elias C.
2015-09-01
The 4th International Conference on Mathematical Modeling in Physical Sciences (IC-MSQUARE) took place in Mykonos, Greece, from Friday 5th June to Monday 8th June 2015. The Conference was attended by more than 150 participants and hosted about 200 oral, poster, and virtual presentations. There were more than 600 pre-registered authors. The 4th IC-MSQUARE consisted of different and diverging workshops and thus covered various research fields where Mathematical Modeling is used, such as Theoretical/Mathematical Physics, Neutrino Physics, Non-Integrable Systems, Dynamical Systems, Computational Nanoscience, Biological Physics, Computational Biomechanics, Complex Networks, Stochastic Modeling, Fractional Statistics, DNA Dynamics, Macroeconomics etc. The scientific program was rather intense as after the Keynote and Invited Talks in the morning, three parallel oral and one poster session were running every day. However, according to all attendees, the program was excellent with a high quality of talks creating an innovative and productive scientific environment for all attendees. We would like to thank the Keynote Speaker and the Invited Speakers for their significant contribution to IC-MSQUARE. We also would like to thank the Members of the International Advisory and Scientific Committees as well as the Members of the Organizing Committee.
(Virtual) Water-repellent Law? Why Legal Studies Should Be Brought Into the Virtual Water Debate
NASA Astrophysics Data System (ADS)
Turrini, Paolo
2014-05-01
Virtual water studies are a marvelous example of the much praised "interdisciplinary approach", efficaciously intertwining many threads woven by scholars of very diverse fields of research. After all, if water is an object of biological interest and the word "virtual" becomes especially significant in the framework of the international trade flows, why should agronomists and economists not work together? And, with them, hydrologists, environmental engineers, network analysis experts… either working side by side or, at least, following one another's steps. Browsing the relevant academic literature one may notice that a vast array of disciplines is dealing with the topic. As a consequence, it may come as a surprise that lawyers seem to have remained almost deaf to the charming call of virtual water. A social science thoroughly "social" even if sometimes deemed (also by its practitioners) akin to humanities - and for this reason not always timely in catching the hints by hard sciences - law has a lot to say about virtual water and its manifold aspects. And it is so, in my opinion, in at least two respects. First of all, legal provisions can be determinants of social facts no less than other types of norms, such as physical or economic laws. Law shapes the human behavior by giving incentives or establishing constraints to the conduct of virtually any kind of social actor, be they farmers needing to decide what to grow, entrepreneurs willing to invest in the water market, or governments requested to address their communities' problems. All of them will make their choices in consideration of the costs, opportunities, and limits set by a number of regulations. In the second place, and strictly connected with the first reason, law may offer some answers to the challenges that virtual water and, more in general, the water-food nexus bring with them. In fact, understanding the way legal provisions affect the taking of decisions in the water sector, one may try to devise policies for solving the problem of water (and food) security. This is not easy task, of course: many are the fields of law, both at the national and international level, which cross the path of virtual water. This, however, is the very reason why it is important to sketch even briefly a picture where the main legal areas of interest are introduced and their role assessed. My presentation aims at doing right this: a review of all the relevant fields of law - especially international law, which is particularly apt at developing coordinated solutions to the worldwide problem of irrational virtual water flows - in order for the "legal factor" to be taken into account when engaging the challenge of virtual water.
Development of Virtual Blade Model for Modelling Helicopter Rotor Downwash in OpenFOAM
2013-12-01
UNCLASSIFIED Development of Virtual Blade Model for Modelling Helicopter Rotor Downwash in OpenFOAM Stefano Wahono Aerospace...Georgia Institute of Technology. The OpenFOAM predicted result was also shown to compare favourably with ANSYS Fluent predictions. RELEASE...UNCLASSIFIED Development of Virtual Blade Model for Modelling Helicopter Rotor Downwash in OpenFOAM Executive Summary The Infrared
Representative Model of the Learning Process in Virtual Spaces Supported by ICT
ERIC Educational Resources Information Center
Capacho, José
2014-01-01
This paper shows the results of research activities for building the representative model of the learning process in virtual spaces (e-Learning). The formal basis of the model are supported in the analysis of models of learning assessment in virtual spaces and specifically in Dembo´s teaching learning model, the systemic approach to evaluating…
LeRouge, Cynthia; Dickhut, Kathryn; Lisetti, Christine; Sangameswaran, Savitha; Malasanos, Toree
2016-01-01
This research focuses on the potential ability of animated avatars (a digital representation of the user) and virtual agents (a digital representation of a coach, buddy, or teacher) to deliver computer-based interventions for adolescents' chronic weight management. An exploration of the acceptance and desire of teens to interact with avatars and virtual agents for self-management and behavioral modification was undertaken. The utilized approach was inspired by community-based participatory research. Data was collected from 2 phases: Phase 1) focus groups with teens, provider interviews, parent interviews; and Phase 2) mid-range prototype assessment by teens and providers. Data from all stakeholder groups expressed great interest in avatars and virtual agents assisting self-management efforts. Adolescents felt the avatars and virtual agents could: 1) reinforce guidance and support, 2) fit within their lifestyle, and 3) help set future goals, particularly after witnessing the effect of their current behavior(s) on the projected physical appearance (external and internal organs) of avatars. Teens wanted 2 virtual characters: a virtual agent to act as a coach or teacher and an avatar (extension of themselves) to serve as a "buddy" for empathic support and guidance and as a surrogate for rewards. Preferred modalities for use include both mobile devices to accommodate access and desktop to accommodate preferences for maximum screen real estate to support virtualization of functions that are more contemplative and complex (e.g., goal setting). Adolescents expressed a desire for limited co-user access, which they could regulate. Data revealed certain barriers and facilitators that could affect adoption and use. The current study extends the support of teens, parents, and providers for adding avatars or virtual agents to traditional computer-based interactions. Data supports the desire for a personal relationship with a virtual character in support of previous studies. The study provides a foundation for further work in the area of avatar-driven motivational interviewing. This study provides evidence supporting the use of avatars and virtual agents, designed using participatory approaches, to be included in the continuum of care. Increased probability of engagement and long-term retention of overweight, obese adolescent users and suggests expanding current chronic care models toward more comprehensive, socio-technical representations. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Three-Dimensional Modeling of Fracture Clusters in Geothermal Reservoirs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ghassemi, Ahmad
The objective of this is to develop a 3-D numerical model for simulating mode I, II, and III (tensile, shear, and out-of-plane) propagation of multiple fractures and fracture clusters to accurately predict geothermal reservoir stimulation using the virtual multi-dimensional internal bond (VMIB). Effective development of enhanced geothermal systems can significantly benefit from improved modeling of hydraulic fracturing. In geothermal reservoirs, where the temperature can reach or exceed 350oC, thermal and poro-mechanical processes play an important role in fracture initiation and propagation. In this project hydraulic fracturing of hot subsurface rock mass will be numerically modeled by extending the virtual multiplemore » internal bond theory and implementing it in a finite element code, WARP3D, a three-dimensional finite element code for solid mechanics. The new constitutive model along with the poro-thermoelastic computational algorithms will allow modeling the initiation and propagation of clusters of fractures, and extension of pre-existing fractures. The work will enable the industry to realistically model stimulation of geothermal reservoirs. The project addresses the Geothermal Technologies Office objective of accurately predicting geothermal reservoir stimulation (GTO technology priority item). The project goal will be attained by: (i) development of the VMIB method for application to 3D analysis of fracture clusters; (ii) development of poro- and thermoelastic material sub-routines for use in 3D finite element code WARP3D; (iii) implementation of VMIB and the new material routines in WARP3D to enable simulation of clusters of fractures while accounting for the effects of the pore pressure, thermal stress and inelastic deformation; (iv) simulation of 3D fracture propagation and coalescence and formation of clusters, and comparison with laboratory compression tests; and (v) application of the model to interpretation of injection experiments (planned by our industrial partner) with reference to the impact of the variations in injection rate and temperature, rock properties, and in-situ stress.« less
Where Social and Professional Networking Meet: The Virtual Association Chapter
ERIC Educational Resources Information Center
Noxon, Rose
2011-01-01
Online Capella University wanted to sponsor an International Society for Performance Improvement (ISPI) chapter. Using social networking platforms, a new type of chapter was designed. The virtual chapter breaks new ground on more than the chapter's platform; it is also the first university-sponsored chapter and has a unique approach to…
Authentic e-Learning in a Multicultural Context: Virtual Benchmarking Cases from Five Countries
ERIC Educational Resources Information Center
Leppisaari, Irja; Herrington, Jan; Vainio, Leena; Im, Yeonwook
2013-01-01
The implementation of authentic learning elements at education institutions in five countries, eight online courses in total, is examined in this paper. The International Virtual Benchmarking Project (2009-2010) applied the elements of authentic learning developed by Herrington and Oliver (2000) as criteria to evaluate authenticity. Twelve…
Kanbay's Global Leadership Development Program: A Case Study of Virtual Action Learning
ERIC Educational Resources Information Center
Marsh, Catherine; Johnson, Carrie
2005-01-01
This study examines action learning as a vehicle for the transfer of organizational values in a multi-cultural, virtual-team based leadership development process. A Case Study of Kanbay International's Global Leadership Development Program is used as a lens through which HRD researchers and practitioners may glimpse new possibilities for the…
Impacts of a Redesigned Virtual Internship Program on Preservice Teachers' Skills and Attitudes
ERIC Educational Resources Information Center
Faucette, Nell; Nugent, Peg
2015-01-01
An important issue in teacher education is how to design and implement effective virtual internships for future educators. Today, these experiences should reflect best practices (as found in more traditional programs) by infusing constructivist values and strategies into the process. Interns can develop needed content knowledge and delivery skills…
Remote laboratories for optical metrology: from the lab to the cloud
NASA Astrophysics Data System (ADS)
Osten, W.; Wilke, M.; Pedrini, G.
2012-10-01
The idea of remote and virtual metrology has been reported already in 2000 with a conceptual illustration by use of comparative digital holography, aimed at the comparison of two nominally identical but physically different objects, e.g., master and sample, in industrial inspection processes. However, the concept of remote and virtual metrology can be extended far beyond this. For example, it does not only allow for the transmission of static holograms over the Internet, but also provides an opportunity to communicate with and eventually control the physical set-up of a remote metrology system. Furthermore, the metrology system can be modeled in the environment of a 3D virtual reality using CAD or similar technology, providing a more intuitive interface to the physical setup within the virtual world. An engineer or scientist who would like to access the remote real world system can log on to the virtual system, moving and manipulating the setup through an avatar and take the desired measurements. The real metrology system responds to the interaction between the avatar and the 3D virtual representation, providing a more intuitive interface to the physical setup within the virtual world. The measurement data are stored and interpreted automatically for appropriate display within the virtual world, providing the necessary feedback to the experimenter. Such a system opens up many novel opportunities in industrial inspection such as the remote master-sample-comparison and the virtual assembling of parts that are fabricated at different places. Moreover, a multitude of new techniques can be envisaged. To them belong modern ways for documenting, efficient methods for metadata storage, the possibility for remote reviewing of experimental results, the adding of real experiments to publications by providing remote access to the metadata and to the experimental setup via Internet, the presentation of complex experiments in classrooms and lecture halls, the sharing of expensive and complex infrastructure within international collaborations, the implementation of new ways for the remote test of new devices, for their maintenance and service, and many more. The paper describes the idea of remote laboratories and illustrates the potential of the approach on selected examples with special attention to optical metrology.
Virtual Reality Exploration and Planning for Precision Colorectal Surgery.
Guerriero, Ludovica; Quero, Giuseppe; Diana, Michele; Soler, Luc; Agnus, Vincent; Marescaux, Jacques; Corcione, Francesco
2018-06-01
Medical software can build a digital clone of the patient with 3-dimensional reconstruction of Digital Imaging and Communication in Medicine images. The virtual clone can be manipulated (rotations, zooms, etc), and the various organs can be selectively displayed or hidden to facilitate a virtual reality preoperative surgical exploration and planning. We present preliminary cases showing the potential interest of virtual reality in colorectal surgery for both cases of diverticular disease and colonic neoplasms. This was a single-center feasibility study. The study was conducted at a tertiary care institution. Two patients underwent a laparoscopic left hemicolectomy for diverticular disease, and 1 patient underwent a laparoscopic right hemicolectomy for cancer. The 3-dimensional virtual models were obtained from preoperative CT scans. The virtual model was used to perform preoperative exploration and planning. Intraoperatively, one of the surgeons was manipulating the virtual reality model, using the touch screen of a tablet, which was interactively displayed to the surgical team. The main outcome was evaluation of the precision of virtual reality in colorectal surgery planning and exploration. In 1 patient undergoing laparoscopic left hemicolectomy, an abnormal origin of the left colic artery beginning as an extremely short common trunk from the inferior mesenteric artery was clearly seen in the virtual reality model. This finding was missed by the radiologist on CT scan. The precise identification of this vascular variant granted a safe and adequate surgery. In the remaining cases, the virtual reality model helped to precisely estimate the vascular anatomy, providing key landmarks for a safer dissection. A larger sample size would be necessary to definitively assess the efficacy of virtual reality in colorectal surgery. Virtual reality can provide an enhanced understanding of crucial anatomical details, both preoperatively and intraoperatively, which could contribute to improve safety in colorectal surgery.
Interface for Physics Simulation Engines
NASA Technical Reports Server (NTRS)
Damer, Bruce
2007-01-01
DSS-Prototyper is an open-source, realtime 3D virtual environment software that supports design simulation for the new Vision for Space Exploration (VSE). This is a simulation of NASA's proposed Robotic Lunar Exploration Program, second mission (RLEP2). It simulates the Lunar Surface Access Module (LSAM), which is designed to carry up to four astronauts to the lunar surface for durations of a week or longer. This simulation shows the virtual vehicle making approaches and landings on a variety of lunar terrains. The physics of the descent engine thrust vector, production of dust, and the dynamics of the suspension are all modeled in this set of simulations. The RLEP2 simulations are drivable (by keyboard or joystick) virtual rovers with controls for speed and motor torque, and can be articulated into higher or lower centers of gravity (depending on driving hazards) to enable drill placement. Gravity also can be set to lunar, terrestrial, or zero-g. This software has been used to support NASA's Marshall Space Flight Center in simulations of proposed vehicles for robotically exploring the lunar surface for water ice, and could be used to model all other aspects of the VSE from the Ares launch vehicles and Crew Exploration Vehicle (CEV) to the International Space Station (ISS). This simulator may be installed and operated on any Windows PC with an installed 3D graphics card.
Baig, Mohammad H; Balaramnavar, Vishal M; Wadhwa, Gulshan; Khan, Asad U
2015-01-01
TEM and SHV are class-A-type β-lactamases commonly found in Escherichia coli and Klebsiella pneumoniae. Previous studies reported S130G and K234R mutations in SHVs to be 41- and 10-fold more resistant toward clavulanic acid than SHV-1, respectively, whereas TEM S130G and R244S also showed the same level of resistance. These selected mutants confer higher level of resistance against clavulanic acid. They also show little susceptibility against other commercially available β-lactamase inhibitors. In this study, we have used docking-based virtual screening approach in order to screen potential inhibitors against some of the major resistant mutants of SHV and TEM types β-lactamase. Two different inhibitor-resistant mutants from SHV and TEM were selected. Moreover, we have retained the active site water molecules within each enzyme. Active site water molecules were placed within modeled structure of the mutant whose structure was unavailable with protein databank. The novelty of this work lies in the use of multilayer virtual screening approach for the prediction of best and accurate results. We are reporting five inhibitors on the basis of their efficacy against all the selected resistant mutants. These inhibitors were selected on the basis of their binding efficacies and pharmacophore features. © 2015 International Union of Biochemistry and Molecular Biology, Inc.
Linking water resources to food security through virtual water
NASA Astrophysics Data System (ADS)
Tamea, Stefania
2014-05-01
The largest use of global freshwater resources is related to food production. While each day we drink about 2 liters of water, we consume (eating) about 4000 liters of ''virtual water'', which represents the freshwater used to produce crop-based and livestock-based food. Considering human water consumption as a whole, most part originates from agriculture (85.8%), and only minor parts come from industry (9.6%) or households (4.6%). These numbers shed light on the great pressure of humanity on global freshwater resources and justify the increasing interest towards this form of environmental impact, usually known as ''water footprint''. Virtual water is a key variable in establishing the nexus between water and food. In fact, water resources used for agricultural production determine local food availability, and impact the international trade of agricultural goods. Trade, in turn, makes food commodities available to nations which are not otherwise self-sufficient, in terms of water resources or food, and it establishes an equilibrium between food demand and production at the global scale. Therefore, food security strongly relies on international food trade, but also on the use of distant and foreign water resources, which need to be acknowledged and investigated. Virtual water embedded in production and international trade follows the fate of food on the trade network, generating virtual flows of great magnitude (e.g., 2800 km3 in 2010) and defining local and global virtual water balances worldwide. The resulting water-food nexus is critical for the societal and economic development, and it has several implications ranging from population dynamics to the competing use of freshwater resources, from dietary guidelines to globalization of trade, from externalization of pollution to policy making and to socio-economic wealth. All these implications represent a great challenge for future research, not only in hydrology but in the many fields related to this interdisciplinary topic. Virtual water and water footprint accounting provide the tools for understanding such implications and to describe, quantify, and investigate the inextricable link existing between water resources and food security.
Radaelli, A G; Augsburger, L; Cebral, J R; Ohta, M; Rüfenacht, D A; Balossino, R; Benndorf, G; Hose, D R; Marzo, A; Metcalfe, R; Mortier, P; Mut, F; Reymond, P; Socci, L; Verhegghe, B; Frangi, A F
2008-07-19
This paper presents the results of the Virtual Intracranial Stenting Challenge (VISC) 2007, an international initiative whose aim was to establish the reproducibility of state-of-the-art haemodynamical simulation techniques in subject-specific stented models of intracranial aneurysms (IAs). IAs are pathological dilatations of the cerebral artery walls, which are associated with high mortality and morbidity rates due to subarachnoid haemorrhage following rupture. The deployment of a stent as flow diverter has recently been indicated as a promising treatment option, which has the potential to protect the aneurysm by reducing the action of haemodynamical forces and facilitating aneurysm thrombosis. The direct assessment of changes in aneurysm haemodynamics after stent deployment is hampered by limitations in existing imaging techniques and currently requires resorting to numerical simulations. Numerical simulations also have the potential to assist in the personalized selection of an optimal stent design prior to intervention. However, from the current literature it is difficult to assess the level of technological advancement and the reproducibility of haemodynamical predictions in stented patient-specific models. The VISC 2007 initiative engaged in the development of a multicentre-controlled benchmark to analyse differences induced by diverse grid generation and computational fluid dynamics (CFD) technologies. The challenge also represented an opportunity to provide a survey of available technologies currently adopted by international teams from both academic and industrial institutions for constructing computational models of stented aneurysms. The results demonstrate the ability of current strategies in consistently quantifying the performance of three commercial intracranial stents, and contribute to reinforce the confidence in haemodynamical simulation, thus taking a step forward towards the introduction of simulation tools to support diagnostics and interventional planning.
Statistical virtual eye model based on wavefront aberration
Wang, Jie-Mei; Liu, Chun-Ling; Luo, Yi-Ning; Liu, Yi-Guang; Hu, Bing-Jie
2012-01-01
Wavefront aberration affects the quality of retinal image directly. This paper reviews the representation and reconstruction of wavefront aberration, as well as the construction of virtual eye model based on Zernike polynomial coefficients. In addition, the promising prospect of virtual eye model is emphasized. PMID:23173112
Managing International Consulting Projects and International Business Courses Using Virtual Teams
ERIC Educational Resources Information Center
Prachyl, Cheryl; Quintanilla, Hector; Gutiérrez, Luis Antonio
2011-01-01
The Instituto Tecnologico y de Estudios Superiores de Monterrey and Texas Wesleyan University used technology based courses to enhance internationalization of their curricula. These courses required students to use computer technology as the distance communication medium and to complete an applied international consulting project as part of each…
International Cross-Cultural Online Learning and Teaching: Effective Tools and Approaches
ERIC Educational Resources Information Center
Titarenko, Larissa; Little, Craig B.
2017-01-01
"Study abroad" college programs can transform domestic students into a kind of "global citizens" with international experience and cross-cultural competences demanded in the emerging global market. Can a full-time international online undergraduate class serve as a virtual alternative to study abroad experience? Two questions…
Haptic simulation framework for determining virtual dental occlusion.
Wu, Wen; Chen, Hui; Cen, Yuhai; Hong, Yang; Khambay, Balvinder; Heng, Pheng Ann
2017-04-01
The surgical treatment of many dentofacial deformities is often complex due to its three-dimensional nature. To determine the dental occlusion in the most stable position is essential for the success of the treatment. Computer-aided virtual planning on individualized patient-specific 3D model can help formulate the surgical plan and predict the surgical change. However, in current computer-aided planning systems, it is not possible to determine the dental occlusion of the digital models in the intuitive way during virtual surgical planning because of absence of haptic feedback. In this paper, a physically based haptic simulation framework is proposed, which can provide surgeons with the intuitive haptic feedback to determine the dental occlusion of the digital models in their most stable position. To provide the physically realistic force feedback when the dental models contact each other during the searching process, the contact model is proposed to describe the dynamic and collision properties of the dental models during the alignment. The simulated impulse/contact-based forces are integrated into the unified simulation framework. A validation study has been conducted on fifteen sets of virtual dental models chosen at random and covering a wide range of the dental relationships found clinically. The dental occlusions obtained by an expert were employed as a benchmark to compare the virtual occlusion results. The mean translational and angular deviations of the virtual occlusion results from the benchmark were small. The experimental results show the validity of our method. The simulated forces can provide valuable insights to determine the virtual dental occlusion. The findings of this work and the validation of proposed concept lead the way for full virtual surgical planning on patient-specific virtual models allowing fully customized treatment plans for the surgical correction of dentofacial deformities.
Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm.
Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A; Przekwas, Andrzej; Francis, Joseph T; Lytton, William W
2015-01-01
Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of limb prosthetics.
Xia, Kelin
2017-12-20
In this paper, a multiscale virtual particle based elastic network model (MVP-ENM) is proposed for the normal mode analysis of large-sized biomolecules. The multiscale virtual particle (MVP) model is proposed for the discretization of biomolecular density data. With this model, large-sized biomolecular structures can be coarse-grained into virtual particles such that a balance between model accuracy and computational cost can be achieved. An elastic network is constructed by assuming "connections" between virtual particles. The connection is described by a special harmonic potential function, which considers the influence from both the mass distributions and distance relations of the virtual particles. Two independent models, i.e., the multiscale virtual particle based Gaussian network model (MVP-GNM) and the multiscale virtual particle based anisotropic network model (MVP-ANM), are proposed. It has been found that in the Debye-Waller factor (B-factor) prediction, the results from our MVP-GNM with a high resolution are as good as the ones from GNM. Even with low resolutions, our MVP-GNM can still capture the global behavior of the B-factor very well with mismatches predominantly from the regions with large B-factor values. Further, it has been demonstrated that the low-frequency eigenmodes from our MVP-ANM are highly consistent with the ones from ANM even with very low resolutions and a coarse grid. Finally, the great advantage of MVP-ANM model for large-sized biomolecules has been demonstrated by using two poliovirus virus structures. The paper ends with a conclusion.
CATIA V5 Virtual Environment Support for Constellation Ground Operations
NASA Technical Reports Server (NTRS)
Kelley, Andrew
2009-01-01
This summer internship primarily involved using CATIA V5 modeling software to design and model parts to support ground operations for the Constellation program. I learned several new CATIA features, including the Imagine and Shape workbench and the Tubing Design workbench, and presented brief workbench lessons to my co-workers. Most modeling tasks involved visualizing design options for Launch Pad 39B operations, including Mobile Launcher Platform (MLP) access and internal access to the Ares I rocket. Other ground support equipment, including a hydrazine servicing cart, a mobile fuel vapor scrubber, a hypergolic propellant tank cart, and a SCAPE (Self Contained Atmospheric Protective Ensemble) suit, was created to aid in the visualization of pad operations.
Gupta, Punkaj; Rettiganti, Mallikarjuna; Gossett, Jeffrey M; Daufeldt, Jennifer; Rice, Tom B; Wetzel, Randall C
2018-01-01
To create a novel tool to predict favorable neurologic outcomes during ICU stay among children with critical illness. Logistic regression models using adaptive lasso methodology were used to identify independent factors associated with favorable neurologic outcomes. A mixed effects logistic regression model was used to create the final prediction model including all predictors selected from the lasso model. Model validation was performed using a 10-fold internal cross-validation approach. Virtual Pediatric Systems (VPS, LLC, Los Angeles, CA) database. Patients less than 18 years old admitted to one of the participating ICUs in the Virtual Pediatric Systems database were included (2009-2015). None. A total of 160,570 patients from 90 hospitals qualified for inclusion. Of these, 1,675 patients (1.04%) were associated with a decline in Pediatric Cerebral Performance Category scale by at least 2 between ICU admission and ICU discharge (unfavorable neurologic outcome). The independent factors associated with unfavorable neurologic outcome included higher weight at ICU admission, higher Pediatric Index of Morality-2 score at ICU admission, cardiac arrest, stroke, seizures, head/nonhead trauma, use of conventional mechanical ventilation and high-frequency oscillatory ventilation, prolonged hospital length of ICU stay, and prolonged use of mechanical ventilation. The presence of chromosomal anomaly, cardiac surgery, and utilization of nitric oxide were associated with favorable neurologic outcome. The final online prediction tool can be accessed at https://soipredictiontool.shinyapps.io/GNOScore/. Our model predicted 139,688 patients with favorable neurologic outcomes in an internal validation sample when the observed number of patients with favorable neurologic outcomes was among 139,591 patients. The area under the receiver operating curve for the validation model was 0.90. This proposed prediction tool encompasses 20 risk factors into one probability to predict favorable neurologic outcome during ICU stay among children with critical illness. Future studies should seek external validation and improved discrimination of this prediction tool.
Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos
2016-01-01
Abstract Background During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CTvlab) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. New information The Micro-CTvlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CTvlab can be accessed either on a normal computer or through a dedicated version for mobile devices. PMID:27956848
Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos
2016-01-01
During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CT vlab ) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CT vlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CT vlab can be accessed either on a normal computer or through a dedicated version for mobile devices.
Science Initiatives of the US Virtual Astronomical Observatory
NASA Astrophysics Data System (ADS)
Hanisch, R. J.
2012-09-01
The United States Virtual Astronomical Observatory program is the operational facility successor to the National Virtual Observatory development project. The primary goal of the US VAO is to build on the standards, protocols, and associated infrastructure developed by NVO and the International Virtual Observatory Alliance partners and to bring to fruition a suite of applications and web-based tools that greatly enhance the research productivity of professional astronomers. To this end, and guided by the advice of our Science Council (Fabbiano et al. 2011), we have focused on five science initiatives in the first two years of VAO operations: 1) scalable cross-comparisons between astronomical source catalogs, 2) dynamic spectral energy distribution construction, visualization, and model fitting, 3) integration and periodogram analysis of time series data from the Harvard Time Series Center and NASA Star and Exoplanet Database, 4) integration of VO data discovery and access tools into the IRAF data analysis environment, and 5) a web-based portal to VO data discovery, access, and display tools. We are also developing tools for data linking and semantic discovery, and have a plan for providing data mining and advanced statistical analysis resources for VAO users. Initial versions of these applications and web-based services are being released over the course of the summer and fall of 2011, with further updates and enhancements planned for throughout 2012 and beyond.
NASA Technical Reports Server (NTRS)
Schmidt, Greg; Bailey, Brad; Gibbs, Kristina
2015-01-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and exploration, training the next generation of lunar scientists, and development and support of the international community. As part of its mission, SSERVI acts as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. The nine domestic SSERVI teams that comprise the U.S. complement of the Institute engage with the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships. SSERVI represents a close collaboration between science, technology and exploration enabling a deeper, integrated understanding of the Moon and other airless bodies as human exploration moves beyond low Earth orbit. SSERVI centers on the scientific aspects of exploration as they pertain to the Moon, Near Earth Asteroids (NEAs) and the moons of Mars, with additional aspects of related technology development, including a major focus on human exploration-enabling efforts such as resolving Strategic Knowledge Gaps (SKGs). The Institute focuses on interdisciplinary, exploration-related science focused on airless bodies targeted as potential human destinations. Areas of study represent the broad spectrum of lunar, NEA, and Martian moon sciences encompassing investigations of the surface, interior, exosphere, and near-space environments as well as science uniquely enabled from these bodies. This research profile integrates investigations of plasma physics, geology/geochemistry, technology integration, solar system origins/evolution, regolith geotechnical properties, analogues, volatiles, ISRU and exploration potential of the target bodies. New opportunities for both domestic and international partnerships are continually generated through these research and community development efforts, and SSERVI can further serve as a model for joint international scientific efforts through its creation of bridges across disciplines and between countries. Since the inception of the NASA Lunar Science Institute (SSERVIs predecessor), it has and will continue to contribute in many ways toward the advancement of lunar science and the eventual human exploration of the Moon.
NASA Astrophysics Data System (ADS)
Colella, H.; Hubenthal, M.; Brudzinski, M. R.
2013-12-01
The benefits for student participants of undergraduate research opportunities have been well documented. However, advancements in information and communications technologies (ICT) and cultural shifts around online education and virtual peer-to-peer interaction have lead to new models in which to structure such experiences. Currently, these ICT-enabled Research Experiences for Undergraduates (REU) programs connect geographically distributed interns in supportive e-learning communities while maintaining a traditional local mentoring arrangement. To document and explore the effects of distributed REU Sites in more depth, six interns from such a program, the Incorporated Research Institution for Seismology (IRIS) REU, were selected at random and asked to be interviewed about the REU experience. The primary targets of the interviews are to understand the mentor/mentee relationships, feeling of support and development and value of near-peer and far-peer relationships throughout their internship in a distributed REU program, and whether they receive the training necessary to gain confidence as a researcher. We also examine the various communication technologies as well as best practices and strategies that can increase intern connectedness. Pre-internship interviews were conducted in-person at the start of the centralized internship orientation week, while post-internship interviews were virtual (e.g. video chat with Skype or Google Hangout). These semi-structured interviews have full audio recordings and subsequent transcriptions. An additional, virtual follow-up interview will be conducted next spring after the interns have an opportunity to attend and present their research at a national conference (e.g., AGU). Interview material will be analyzed through a process of coding, sorting, local integration, and inclusive integration. Results will also be triangulated with pre- and post- survey data both from participants and other survey data from previous years of the IRIS program. Our presentation will highlight the key findings of these analyses. GeoCorps and RESESS will begin to employ this interview style assessment beginning this fall and next year, respectively, which will facilitate detailed comparisons between distributed and non-distributed REU approaches.
Virtual Field Reconnaissance to enable multi-site collaboration in geoscience fieldwork in Chile.
NASA Astrophysics Data System (ADS)
Hughes, Leanne; Bateson, Luke; Ford, Jonathan; Napier, Bruce; Creixell, Christian; Contreras, Juan-Pablo; Vallette, Jane
2017-04-01
The unique challenges of geological mapping in remote terrains can make cross-organisation collaboration challenging. Cooperation between the British and Chilean Geological Surveys and the Chilean national mining company used the BGS digital Mapping Workflow and virtual field reconnaissance software (GeoVisionary) to undertake geological mapping in a complex area of Andean Geology. The international team undertook a pre-field evaluation using GeoVisionary to integrate massive volumes of data and interpret high resolution satellite imagery, terrain models and existing geological information to capture, manipulate and understand geological features and re-interpret existing maps. This digital interpretation was then taken into the field and verified using the BGS digital data capture system (SIGMA.mobile). This allowed the production of final geological interpretation and creation of a geological map. This presentation describes the digital mapping workflow used in Chile and highlights the key advantages of increased efficiency and communication to colleagues, stakeholders and funding bodies.
Coil motion effects in watt balances: a theoretical check
NASA Astrophysics Data System (ADS)
Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.
2016-04-01
A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.
Towards a Global Service Registry for the World-Wide LHC Computing Grid
NASA Astrophysics Data System (ADS)
Field, Laurence; Alandes Pradillo, Maria; Di Girolamo, Alessandro
2014-06-01
The World-Wide LHC Computing Grid encompasses a set of heterogeneous information systems; from central portals such as the Open Science Grid's Information Management System and the Grid Operations Centre Database, to the WLCG information system, where the information sources are the Grid services themselves. Providing a consistent view of the information, which involves synchronising all these informations systems, is a challenging activity that has lead the LHC virtual organisations to create their own configuration databases. This experience, whereby each virtual organisation's configuration database interfaces with multiple information systems, has resulted in the duplication of effort, especially relating to the use of manual checks for the handling of inconsistencies. The Global Service Registry aims to address this issue by providing a centralised service that aggregates information from multiple information systems. It shows both information on registered resources (i.e. what should be there) and available resources (i.e. what is there). The main purpose is to simplify the synchronisation of the virtual organisation's own configuration databases, which are used for job submission and data management, through the provision of a single interface for obtaining all the information. By centralising the information, automated consistency and validation checks can be performed to improve the overall quality of information provided. Although internally the GLUE 2.0 information model is used for the purpose of integration, the Global Service Registry in not dependent on any particular information model for ingestion or dissemination. The intention is to allow the virtual organisation's configuration databases to be decoupled from the underlying information systems in a transparent way and hence simplify any possible future migration due to the evolution of those systems. This paper presents the Global Service Registry architecture, its advantages compared to the current situation and how it can support the evolution of information systems.
Predictive encoding of moving target trajectory by neurons in the parabigeminal nucleus
Ma, Rui; Cui, He; Lee, Sang-Hun; Anastasio, Thomas J.
2013-01-01
Intercepting momentarily invisible moving objects requires internally generated estimations of target trajectory. We demonstrate here that the parabigeminal nucleus (PBN) encodes such estimations, combining sensory representations of target location, extrapolated positions of briefly obscured targets, and eye position information. Cui and Malpeli (Cui H, Malpeli JG. J Neurophysiol 89: 3128–3142, 2003) reported that PBN activity for continuously visible tracked targets is determined by retinotopic target position. Here we show that when cats tracked moving, blinking targets the relationship between activity and target position was similar for ON and OFF phases (400 ms for each phase). The dynamic range of activity evoked by virtual targets was 94% of that of real targets for the first 200 ms after target offset and 64% for the next 200 ms. Activity peaked at about the same best target position for both real and virtual targets. PBN encoding of target position takes into account changes in eye position resulting from saccades, even without visual feedback. Since PBN response fields are retinotopically organized, our results suggest that activity foci associated with real and virtual targets at a given target position lie in the same physical location in the PBN, i.e., a retinotopic as well as a rate encoding of virtual-target position. We also confirm that PBN activity is specific to the intended target of a saccade and is predictive of which target will be chosen if two are offered. A Bayesian predictor-corrector model is presented that conceptually explains the differences in the dynamic ranges of PBN neuronal activity evoked during tracking of real and virtual targets. PMID:23365185
From Vesalius to Virtual Reality: How Embodied Cognition Facilitates the Visualization of Anatomy
ERIC Educational Resources Information Center
Jang, Susan
2010-01-01
This study examines the facilitative effects of embodiment of a complex internal anatomical structure through three-dimensional ("3-D") interactivity in a virtual reality ("VR") program. Since Shepard and Metzler's influential 1971 study, it has been known that 3-D objects (e.g., multiple-armed cube or external body parts) are visually and…
Clinical Results From the Virtual Iraq Exposure Therapy Application for PTSD
2008-12-01
Post Traumatic Stress Disorder ( PTSD ) is reported to be caused by traumatic events that...a significant percentage of service members (SMs) at risk for developing Post Traumatic Stress Disorder ( PTSD ) upon the return home. According to...Related Post Traumatic Stress Disorder . Proceedings of The 6th International Conference on Disability, Virtual Reality and Associated
ERIC Educational Resources Information Center
Beckmann, Jennifer; Weber, Peter
2016-01-01
Purpose: The purpose of this study is to introduce a virtual collaborative learning setting called "Net Economy", which we established as part of an international learning network of currently six universities, and present our approach to continuously improve the course in each cycle. Design/ Methodology/Approach: Using the community of…
The Virtual Data Center Tagged-Format Tool - Introduction and Executive Summary
Evans, John R.; Squibb, Melinda; Stephens, Christopher D.; Savage, W.U.; Haddadi, Hamid; Kircher, Charles A.; Hachem, Mahmoud M.
2008-01-01
This Report introduces and summarizes the new Virtual Data Center (VDC) Tagged Format (VTF) Tool, which was developed by a diverse group of seismologists, earthquake engineers, and information technology professionals for internal use by the COSMOS VDC and other interested parties for the exchange, archiving, and analysis of earthquake strong-ground-motion data.
Applicability of Virtual Environments as C4ISR Displays
2006-06-01
simulator sickness questionnaire (ssq): A method for quantifying simulator sickness. International Journal of Aviation Psychology, 3(3):203ff. Ergonomie ...Displays Thomas Alexander FGAN - Research Institute for Communication, Information Processing, and Ergonomics Wachtberg, Germany Ergonomie und...Führungssysteme FORSCHUNGSINSTITUT FÜR KOMMUNIKATION, INFORMATIONSVERARBEITUNG UND ERGONOMIE 1 FGAN Applicability of Virtual Environments as C4ISR Displays
Technical Evaluation Report (Mental Health and Well-Being across the Military Spectrum)
2011-04-01
presented: these include virtual reality training, neurofeedback and telerehabilitation. The technologies look promising but currently lack sufficient...third location decompression, telerehabilitation, virtual reality, neurofeedback , PCL, SCID, DSM-IV. 2.0 INTRODUCTION Resolving international... Neurofeedback : Victor Kallen48 presented some recent developments in the use of bio- and neurofeedback to support and enhance recovery and recuperation
ERIC Educational Resources Information Center
Beckmann, Jennifer; Weber, Peter
2015-01-01
The paper introduces a virtual collaborative learning setting called "Net Economy," which we established as part of an international learning network of currently seven universities. Using the Community of Inquiry framework as guidance and Canonical Action Research (CAR) as the chosen research design, the discussion forum of the online…
Lee, Hyemin; Cha, Jooly; Chun, Youn-Sic; Kim, Minji
2018-06-19
The occlusal registration of virtual models taken by intraoral scanners sometimes shows patterns which seem much different from the patients' occlusion. Therefore, this study aims to evaluate the accuracy of virtual occlusion by comparing virtual occlusal contact area with actual occlusal contact area using a plaster model in vitro. Plaster dental models, 24 sets of Class I models and 20 sets of Class II models, were divided into a Molar, Premolar, and Anterior group. The occlusal contact areas calculated by the Prescale method and the virtual occlusion by scanning method were compared, and the ratio of the molar and incisor area were compared in order to find any particular tendencies. There was no significant difference between the Prescale results and the scanner results in both the molar and premolar groups (p = 0.083 and 0.053, respectively). On the other hand, there was a significant difference between the Prescale and the scanner results in the anterior group with the scanner results presenting overestimation of the occlusal contact points (p < 0.05). In Molars group, the regression analysis shows that the two variables express linear correlation and has a linear equation with a slope of 0.917. R 2 is 0.930. Groups of Premolars and Anteriors had a week linear relationship and greater dispersion. Difference between the actual and virtual occlusion revealed in the anterior portion, where overestimation was observed in the virtual model obtained from the scanning method. Nevertheless, molar and premolar areas showed relatively accurate occlusal contact area in the virtual model.
Analysis towards VMEM File of a Suspended Virtual Machine
NASA Astrophysics Data System (ADS)
Song, Zheng; Jin, Bo; Sun, Yongqing
With the popularity of virtual machines, forensic investigators are challenged with more complicated situations, among which discovering the evidences in virtualized environment is of significant importance. This paper mainly analyzes the file suffixed with .vmem in VMware Workstation, which stores all pseudo-physical memory into an image. The internal file structure of .vmem file is studied and disclosed. Key information about processes and threads of a suspended virtual machine is revealed. Further investigation into the Windows XP SP3 heap contents is conducted and a proof-of-concept tool is provided. Different methods to obtain forensic memory images are introduced, with both advantages and limits analyzed. We conclude with an outlook.
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.
Kim, Dong Seong; Park, Jong Sou
2014-01-01
It is important to assess availability of virtualized systems in IT business infrastructures. Previous work on availability modeling and analysis of the virtualized systems used a simplified configuration and assumption in which only one virtual machine (VM) runs on a virtual machine monitor (VMM) hosted on a physical server. In this paper, we show a comprehensive availability model using stochastic reward nets (SRN). The model takes into account (i) the detailed failures and recovery behaviors of multiple VMs, (ii) various other failure modes and corresponding recovery behaviors (e.g., hardware faults, failure and recovery due to Mandelbugs and aging-related bugs), and (iii) dependency between different subcomponents (e.g., between physical host failure and VMM, etc.) in a virtualized servers system. We also show numerical analysis on steady state availability, downtime in hours per year, transaction loss, and sensitivity analysis. This model provides a new finding on how to increase system availability by combining both software rejuvenations at VM and VMM in a wise manner. PMID:25165732
The Virtual Physiological Human - a European initiative for in silico human modelling -.
Viceconti, Marco; Clapworthy, Gordon; Van Sint Jan, Serge
2008-12-01
The Virtual Physiological Human (VPH) is an initiative, strongly supported by the European Commission (EC), that seeks to develop an integrated model of human physiology at multiple scales from the whole body through the organ, tissue, cell and molecular levels to the genomic level. VPH had its beginnings in 2005 with informal discussions amongst like-minded scientists which led to the STEP project, a Coordination Action funded by the EC that began in early 2006. The STEP project greatly accelerated the progress of the VPH and proved to be a catalyst for wide-ranging discussions within Europe and for outreach activities designed to develop a broad international approach to the huge scientific and technological challenges involved in this area. This paper provides an overview of the VPH and the developments it has engendered in the rapidly expanding worldwide activities associated with the physiome. It then uses one particular project, the Living Human Project, to illustrate the type of advances that are taking place to further the aims of the VPH and similar initiatives worldwide.
Fuertinger, Doris H; Topping, Alice; Kappel, Franz; Thijssen, Stephan; Kotanko, Peter
2018-04-01
In silico approaches have been proposed as a novel strategy to increase the repertoire of clinical trial designs. Realistic simulations of clinical trials can provide valuable information regarding safety and limitations of treatment protocols and have been shown to assist in the cost-effective planning of clinical studies. In this report, we present a blueprint for the stepwise integration of internal, external, and ecological validity considerations in virtual clinical trials (VCTs). We exemplify this approach in the context of a model-based in silico clinical trial aimed at anemia treatment in patients undergoing hemodialysis (HD). Hemoglobin levels and subsequent anemia treatment were simulated on a per patient level over the course of a year and compared to real-life clinical data of 79,426 patients undergoing HD. The novel strategies presented here, aimed to improve external and ecological validity of a VCT, significantly increased the predictive power of the discussed in silico trial. © 2018 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.
Le Cabec, Adeline; Tang, Nancy; Tafforeau, Paul
2015-01-01
Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine) and matching of stress patterns (internal accentuated lines and hypoplasias) are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands). Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ) were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong’s algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual’s dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were found to form over a rather surprisingly long time (> 4.5 years). This approach provides tools for maximizing the recovery of developmental information in teeth, especially in the most difficult cases. PMID:25901602
Le Cabec, Adeline; Tang, Nancy; Tafforeau, Paul
2015-01-01
Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine) and matching of stress patterns (internal accentuated lines and hypoplasias) are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands). Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ) were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong's algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual's dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were found to form over a rather surprisingly long time (> 4.5 years). This approach provides tools for maximizing the recovery of developmental information in teeth, especially in the most difficult cases.
NASA Astrophysics Data System (ADS)
Xuan, Hejun; Wang, Yuping; Xu, Zhanqi; Hao, Shanshan; Wang, Xiaoli
2017-11-01
Virtualization technology can greatly improve the efficiency of the networks by allowing the virtual optical networks to share the resources of the physical networks. However, it will face some challenges, such as finding the efficient strategies for virtual nodes mapping, virtual links mapping and spectrum assignment. It is even more complex and challenging when the physical elastic optical networks using multi-core fibers. To tackle these challenges, we establish a constrained optimization model to determine the optimal schemes of optical network mapping, core allocation and spectrum assignment. To solve the model efficiently, tailor-made encoding scheme, crossover and mutation operators are designed. Based on these, an efficient genetic algorithm is proposed to obtain the optimal schemes of the virtual nodes mapping, virtual links mapping, core allocation. The simulation experiments are conducted on three widely used networks, and the experimental results show the effectiveness of the proposed model and algorithm.
Using a 3D Virtual Supermarket to Measure Food Purchase Behavior: A Validation Study
Jiang, Yannan; Steenhuis, Ingrid Hendrika Margaretha; Ni Mhurchu, Cliona
2015-01-01
Background There is increasing recognition that supermarkets are an important environment for health-promoting interventions such as fiscal food policies or front-of-pack nutrition labeling. However, due to the complexities of undertaking such research in the real world, well-designed randomized controlled trials on these kinds of interventions are lacking. The Virtual Supermarket is a 3-dimensional computerized research environment designed to enable experimental studies in a supermarket setting without the complexity or costs normally associated with undertaking such research. Objective The primary objective was to validate the Virtual Supermarket by comparing virtual and real-life food purchasing behavior. A secondary objective was to obtain participant feedback on perceived sense of “presence” (the subjective experience of being in one place or environment even if physically located in another) in the Virtual Supermarket. Methods Eligible main household shoppers (New Zealand adults aged ≥18 years) were asked to conduct 3 shopping occasions in the Virtual Supermarket over 3 consecutive weeks, complete the validated Presence Questionnaire Items Stems, and collect their real supermarket grocery till receipts for that same period. Proportional expenditure (NZ$) and the proportion of products purchased over 18 major food groups were compared between the virtual and real supermarkets. Data were analyzed using repeated measures mixed models. Results A total of 123 participants consented to take part in the study. In total, 69.9% (86/123) completed 1 shop in the Virtual Supermarket, 64.2% (79/123) completed 2 shops, 60.2% (74/123) completed 3 shops, and 48.8% (60/123) returned their real supermarket till receipts. The 4 food groups with the highest relative expenditures were the same for the virtual and real supermarkets: fresh fruit and vegetables (virtual estimate: 14.3%; real: 17.4%), bread and bakery (virtual: 10.0%; real: 8.2%), dairy (virtual: 19.1%; real: 12.6%), and meat and fish (virtual: 16.5%; real: 16.8%). Significant differences in proportional expenditures were observed for 6 food groups, with largest differences (virtual – real) for dairy (in expenditure 6.5%, P<.001; in items 2.2%, P=.04) and fresh fruit and vegetables (in expenditure: –3.1%, P=.04; in items: 5.9%, P=.002). There was no trend of overspending in the Virtual Supermarket and participants experienced a medium-to-high presence (88%, 73/83 scored medium; 8%, 7/83 scored high). Conclusions Shopping patterns in the Virtual Supermarket were comparable to those in real life. Overall, the Virtual Supermarket is a valid tool to measure food purchasing behavior. Nevertheless, it is important to improve the functionality of some food categories, in particular fruit and vegetables and dairy. The results of this validation will assist in making further improvements to the software and with optimization of the internal and external validity of this innovative methodology. PMID:25921185
Using a 3D virtual supermarket to measure food purchase behavior: a validation study.
Waterlander, Wilma Elzeline; Jiang, Yannan; Steenhuis, Ingrid Hendrika Margaretha; Ni Mhurchu, Cliona
2015-04-28
There is increasing recognition that supermarkets are an important environment for health-promoting interventions such as fiscal food policies or front-of-pack nutrition labeling. However, due to the complexities of undertaking such research in the real world, well-designed randomized controlled trials on these kinds of interventions are lacking. The Virtual Supermarket is a 3-dimensional computerized research environment designed to enable experimental studies in a supermarket setting without the complexity or costs normally associated with undertaking such research. The primary objective was to validate the Virtual Supermarket by comparing virtual and real-life food purchasing behavior. A secondary objective was to obtain participant feedback on perceived sense of "presence" (the subjective experience of being in one place or environment even if physically located in another) in the Virtual Supermarket. Eligible main household shoppers (New Zealand adults aged ≥18 years) were asked to conduct 3 shopping occasions in the Virtual Supermarket over 3 consecutive weeks, complete the validated Presence Questionnaire Items Stems, and collect their real supermarket grocery till receipts for that same period. Proportional expenditure (NZ$) and the proportion of products purchased over 18 major food groups were compared between the virtual and real supermarkets. Data were analyzed using repeated measures mixed models. A total of 123 participants consented to take part in the study. In total, 69.9% (86/123) completed 1 shop in the Virtual Supermarket, 64.2% (79/123) completed 2 shops, 60.2% (74/123) completed 3 shops, and 48.8% (60/123) returned their real supermarket till receipts. The 4 food groups with the highest relative expenditures were the same for the virtual and real supermarkets: fresh fruit and vegetables (virtual estimate: 14.3%; real: 17.4%), bread and bakery (virtual: 10.0%; real: 8.2%), dairy (virtual: 19.1%; real: 12.6%), and meat and fish (virtual: 16.5%; real: 16.8%). Significant differences in proportional expenditures were observed for 6 food groups, with largest differences (virtual - real) for dairy (in expenditure 6.5%, P<.001; in items 2.2%, P=.04) and fresh fruit and vegetables (in expenditure: -3.1%, P=.04; in items: 5.9%, P=.002). There was no trend of overspending in the Virtual Supermarket and participants experienced a medium-to-high presence (88%, 73/83 scored medium; 8%, 7/83 scored high). Shopping patterns in the Virtual Supermarket were comparable to those in real life. Overall, the Virtual Supermarket is a valid tool to measure food purchasing behavior. Nevertheless, it is important to improve the functionality of some food categories, in particular fruit and vegetables and dairy. The results of this validation will assist in making further improvements to the software and with optimization of the internal and external validity of this innovative methodology.
High power microwave generator
Minich, Roger W.
1988-01-01
A device (10) for producing high-powered and coherent microwaves is described. The device comprises an evacuated, cylindrical, and hollow real cathode (20) that is driven to inwardly field emit relativistic electrons. The electrons pass through an internally disposed cylindrical and substantially electron-transparent cylindrical anode (24), proceed toward a cylindrical electron collector electrode (26), and form a cylindrical virtual cathode (32). Microwaves are produced by spatial and temporal oscillations of the cylindrical virtual cathode (32), and by electrons that reflex back and forth between the cylindrical virtual cathode (32) and the cylindrical real cathode (20).
Current Status of VO Compliant Data Service in Japanese Virtual Observatory
NASA Astrophysics Data System (ADS)
Shirasaki, Y.; Komiya, Y.; Ohishi, M.; Mizumoto, Y.; Ishihara, Y.; Tsutsumi, J.; Hiyama, T.; Nakamoto, H.; Sakamoto, M.
2012-09-01
In these years, standards to build a Virtual Observatory (VO) data service have been established with the efforts in the International Virtual Observatory Alliance (IVOA). We applied these newly established standards (SSAP, TAP) to our VO service toolkit which was developed to implement earlier VO standards SIAP and (deprecated) SkyNode. The toolkit can be easily installed and provides a GUI interface to construct and manage VO service. In this paper, we describes the architecture of our toolkit and how it is used to start hosting VO service.
Advanced Modeling in Excel: from Water Jets to Big Bang
NASA Astrophysics Data System (ADS)
Ignatova, Olga; Chyzhyk, D.; Willis, C.; Kazachkov, A.
2006-12-01
An international students’ project is presented focused on application of Open Office and Excel spreadsheets for modeling of projectile-motion type dynamical systems. Variation of the parameters of plotted and animated families of jets flowing at different angles out of the holes in the wall of water-filled reservoir [1,2] revealed unexpected peculiarities of the envelopes, vertices, intersections and landing points of virtual trajectories. Comparison with real-life systems and rigorous calculations were performed to prove predictions of computer experiments. By same technique, the kinematics of fireworks was analyzed. On this basis two-dimensional ‘firework’ computer model of Big Bang was designed and studied, its relevance and limitations checked. 1.R.Ehrlich, Turning the World Inside Out, (Princeton University Press, Princeton, NJ, 1990), pp. 98-100. 2.A.Kazachkov, Yu.Bogdan, N.Makarovsky, N.Nedbailo. A Bucketful of Physics, in R.Pinto, S.Surinach (eds), International Conference Physics Teacher Education Beyond 2000. Selected Contributions (Elsevier Editions, Paris, 2001), pp.563-564. Sponsored by Courtney Willis.
NASA Astrophysics Data System (ADS)
Schmidt, Gregory
2016-07-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and explora-tion, training the next generation of lunar scientists, and community development. The institute is a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdis-ciplinary, research-focused collaborations. Its relative-ly large domestic teams work together along with in-ternational partners in both traditional and virtual set-tings to bring disparate approaches together for mutual benefit. This talk will describe the research efforts of the nine domestic teams that constitute the U.S. com-plement of the Institute and how it is engaging the in-ternational science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships. The Institute is centered on the scientific aspects of exploration as they pertain to the Moon, Near Earth Asteroids (NEAs) and the moons of Mars. It focuses on interdisciplinary, exploration-related science cen-tered around all airless bodies targeted as potential human destinations. Areas of study reported here will represent the broad spectrum of lunar, NEA, and Mar-tian moon sciences encompassing investigations of the surface, interior, exosphere, and near-space environ-ments as well as science uniquely enabled from these bodies. The technical focus ranges from investigations of plasma physics, geology/geochemistry, technology integration, solar system origins/evolution, regolith geotechnical properties, analogues, volatiles, ISRU and exploration potential of the target bodies. SSERVI enhances the widening knowledgebase of planetary research by acting as a bridge between several differ-ent groups and bringing together researchers from the scientific and exploration communities, multiple disci-plines across the full range of planetary sciences, and domestic and international communities and partner-ships.
Vision-based navigation in a dynamic environment for virtual human
NASA Astrophysics Data System (ADS)
Liu, Yan; Sun, Ji-Zhou; Zhang, Jia-Wan; Li, Ming-Chu
2004-06-01
Intelligent virtual human is widely required in computer games, ergonomics software, virtual environment and so on. We present a vision-based behavior modeling method to realize smart navigation in a dynamic environment. This behavior model can be divided into three modules: vision, global planning and local planning. Vision is the only channel for smart virtual actor to get information from the outside world. Then, the global and local planning module use A* and D* algorithm to find a way for virtual human in a dynamic environment. Finally, the experiments on our test platform (Smart Human System) verify the feasibility of this behavior model.
Human responses to augmented virtual scaffolding models.
Hsiao, Hongwei; Simeonov, Peter; Dotson, Brian; Ammons, Douglas; Kau, Tsui-Ying; Chiou, Sharon
2005-08-15
This study investigated the effect of adding real planks, in virtual scaffolding models of elevation, on human performance in a surround-screen virtual reality (SSVR) system. Twenty-four construction workers and 24 inexperienced controls performed walking tasks on real and virtual planks at three virtual heights (0, 6 m, 12 m) and two scaffolding-platform-width conditions (30, 60 cm). Gait patterns, walking instability measurements and cardiovascular reactivity were assessed. The results showed differences in human responses to real vs. virtual planks in walking patterns, instability score and heart-rate inter-beat intervals; it appeared that adding real planks in the SSVR virtual scaffolding model enhanced the quality of SSVR as a human - environment interface research tool. In addition, there were significant differences in performance between construction workers and the control group. The inexperienced participants were more unstable as compared to construction workers. Both groups increased their stride length with repetitions of the task, indicating a possibly confidence- or habit-related learning effect. The practical implications of this study are in the adoption of augmented virtual models of elevated construction environments for injury prevention research, and the development of programme for balance-control training to reduce the risk of falls at elevation before workers enter a construction job.
Vicher: A Virtual Reality Based Educational Module for Chemical Reaction Engineering.
ERIC Educational Resources Information Center
Bell, John T.; Fogler, H. Scott
1996-01-01
A virtual reality application for undergraduate chemical kinetics and reactor design education, Vicher (Virtual Chemical Reaction Model) was originally designed to simulate a portion of a modern chemical plant. Vicher now consists of two programs: Vicher I that models catalyst deactivation and Vicher II that models nonisothermal effects in…
Partnering Principal and Teacher Candidates: Exploring a Virtual Coaching Model in Teacher Education
ERIC Educational Resources Information Center
Stapleton, Joy; Tschida, Christina; Cuthrell, Kristen
2017-01-01
Colleges of education are constantly searching for innovations to develop stronger graduates. This paper describes and shares findings from a study of a virtual coaching partnership model that links a principal candidate with a teacher candidate. Through the use of existing virtual coaching software, this model provides teacher candidates with…
Research on 3D virtual campus scene modeling based on 3ds Max and VRML
NASA Astrophysics Data System (ADS)
Kang, Chuanli; Zhou, Yanliu; Liang, Xianyue
2015-12-01
With the rapid development of modem technology, the digital information management and the virtual reality simulation technology has become a research hotspot. Virtual campus 3D model can not only express the real world objects of natural, real and vivid, and can expand the campus of the reality of time and space dimension, the combination of school environment and information. This paper mainly uses 3ds Max technology to create three-dimensional model of building and on campus buildings, special land etc. And then, the dynamic interactive function is realized by programming the object model in 3ds Max by VRML .This research focus on virtual campus scene modeling technology and VRML Scene Design, and the scene design process in a variety of real-time processing technology optimization strategy. This paper guarantees texture map image quality and improve the running speed of image texture mapping. According to the features and architecture of Guilin University of Technology, 3ds Max, AutoCAD and VRML were used to model the different objects of the virtual campus. Finally, the result of virtual campus scene is summarized.
Optical network democratization.
Nejabati, Reza; Peng, Shuping; Simeonidou, Dimitra
2016-03-06
The current Internet infrastructure is not able to support independent evolution and innovation at physical and network layer functionalities, protocols and services, while at same time supporting the increasing bandwidth demands of evolving and heterogeneous applications. This paper addresses this problem by proposing a completely democratized optical network infrastructure. It introduces the novel concepts of the optical white box and bare metal optical switch as key technology enablers for democratizing optical networks. These are programmable optical switches whose hardware is loosely connected internally and is completely separated from their control software. To alleviate their complexity, a multi-dimensional abstraction mechanism using software-defined network technology is proposed. It creates a universal model of the proposed switches without exposing their technological details. It also enables a conventional network programmer to develop network applications for control of the optical network without specific technical knowledge of the physical layer. Furthermore, a novel optical network virtualization mechanism is proposed, enabling the composition and operation of multiple coexisting and application-specific virtual optical networks sharing the same physical infrastructure. Finally, the optical white box and the abstraction mechanism are experimentally evaluated, while the virtualization mechanism is evaluated with simulation. © 2016 The Author(s).
Liu, Kaijun; Fang, Binji; Wu, Yi; Li, Ying; Jin, Jun; Tan, Liwen; Zhang, Shaoxiang
2013-09-01
Anatomical knowledge of the larynx region is critical for understanding laryngeal disease and performing required interventions. Virtual reality is a useful method for surgical education and simulation. Here, we assembled segmented cross-section slices of the larynx region from the Chinese Visible Human dataset. The laryngeal structures were precisely segmented manually as 2D images, then reconstructed and displayed as 3D images in the virtual reality Dextrobeam system. Using visualization and interaction with the virtual reality modeling language model, a digital laryngeal anatomy instruction was constructed using HTML and JavaScript languages. The volume larynx models can thus display an arbitrary section of the model and provide a virtual dissection function. This networked teaching system of the digital laryngeal anatomy can be read remotely, displayed locally, and manipulated interactively.
Validation of virtual-reality-based simulations for endoscopic sinus surgery.
Dharmawardana, N; Ruthenbeck, G; Woods, C; Elmiyeh, B; Diment, L; Ooi, E H; Reynolds, K; Carney, A S
2015-12-01
Virtual reality (VR) simulators provide an alternative to real patients for practicing surgical skills but require validation to ensure accuracy. Here, we validate the use of a virtual reality sinus surgery simulator with haptic feedback for training in Otorhinolaryngology - Head & Neck Surgery (OHNS). Participants were recruited from final-year medical students, interns, resident medical officers (RMOs), OHNS registrars and consultants. All participants completed an online questionnaire after performing four separate simulation tasks. These were then used to assess face, content and construct validity. anova with post hoc correlation was used for statistical analysis. The following groups were compared: (i) medical students/interns, (ii) RMOs, (iii) registrars and (iv) consultants. Face validity results had a statistically significant (P < 0.05) difference between the consultant group and others, while there was no significant difference between medical student/intern and RMOs. Variability within groups was not significant. Content validity results based on consultant scoring and comments indicated that the simulations need further development in several areas to be effective for registrar-level teaching. However, students, interns and RMOs indicated that the simulations provide a useful tool for learning OHNS-related anatomy and as an introduction to ENT-specific procedures. The VR simulations have been validated for teaching sinus anatomy and nasendoscopy to medical students, interns and RMOs. However, they require further development before they can be regarded as a valid tool for more advanced surgical training. © 2015 John Wiley & Sons Ltd.
Creating Higher Education Academic and Information Technology Resources in an International Context
ERIC Educational Resources Information Center
Baron, Josh; Willis, Jerry; Lee, Reba-Anna
2010-01-01
A number of contemporary factors have combined to create a situation that encourages and supports international collaboration among institutions of higher education. Factors such as the globalization of the economy, the increasingly international nature of higher education, and the development of an inexpensive and virtually worldwide system of…
Virtual reality: new method of teaching anorectal and pelvic floor anatomy.
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.
Image fusion in craniofacial virtual reality modeling based on CT and 3dMD photogrammetry.
Xin, Pengfei; Yu, Hongbo; Cheng, Huanchong; Shen, Shunyao; Shen, Steve G F
2013-09-01
The aim of this study was to demonstrate the feasibility of building a craniofacial virtual reality model by image fusion of 3-dimensional (3D) CT models and 3 dMD stereophotogrammetric facial surface. A CT scan and stereophotography were performed. The 3D CT models were reconstructed by Materialise Mimics software, and the stereophotogrammetric facial surface was reconstructed by 3 dMD patient software. All 3D CT models were exported as Stereo Lithography file format, and the 3 dMD model was exported as Virtual Reality Modeling Language file format. Image registration and fusion were performed in Mimics software. Genetic algorithm was used for precise image fusion alignment with minimum error. The 3D CT models and the 3 dMD stereophotogrammetric facial surface were finally merged into a single file and displayed using Deep Exploration software. Errors between the CT soft tissue model and 3 dMD facial surface were also analyzed. Virtual model based on CT-3 dMD image fusion clearly showed the photorealistic face and bone structures. Image registration errors in virtual face are mainly located in bilateral cheeks and eyeballs, and the errors are more than 1.5 mm. However, the image fusion of whole point cloud sets of CT and 3 dMD is acceptable with a minimum error that is less than 1 mm. The ease of use and high reliability of CT-3 dMD image fusion allows the 3D virtual head to be an accurate, realistic, and widespread tool, and has a great benefit to virtual face model.
Simulation of Complex Cracking in Plain Weave C/SiC Composite under Biaxial Loading
NASA Technical Reports Server (NTRS)
Cheng, Ron-Bin; Hsu, Su-Yuen
2012-01-01
Finite element analysis is performed on a mesh, based on computed geometry of a plain weave C/SiC composite with assumed internal stacking, to reveal the pattern of internal damage due to biaxial normal cyclic loading. The simulation encompasses intertow matrix cracking, matrix cracking inside the tows, and separation at the tow-intertow matrix and tow-tow interfaces. All these dissipative behaviors are represented by traction-separation cohesive laws. Not aimed at quantitatively predicting the overall stress-strain relation, the simulation, however, does not take the actual process of fiber debonding into account. The fiber tows are represented by a simple rule-of-mixture model where the reinforcing phase is a hypothetical one-dimensional material. Numerical results indicate that for the plain weave C/SiC composite, 1) matrix-crack initiation sites are primarily determined by large intertow matrix voids and interlayer tow-tow contacts, 2) the pattern of internal damage strongly depends on the loading path and initial stress, 3) compressive loading inflicts virtually no damage evolution. KEY WORDS: ceramic matrix composite, plain weave, cohesive model, brittle failure, smeared crack model, progressive damage, meso-mechanical analysis, finite element.
Health care globalization: a need for virtual leadership.
Holland, J Brian; Malvey, Donna; Fottler, Myron D
2009-01-01
As health care organizations expand and move into global markets, they face many leadership challenges, including the difficulty of leading individuals who are geographically dispersed. This article provides global managers with guidelines for leading and motivating individuals or teams from a distance while overcoming the typical challenges that "virtual leaders" and "virtual teams" face: employee isolation, confusion, language barriers, cultural differences, and technological breakdowns. Fortunately, technological advances in communications have provided various methods to accommodate geographically dispersed or "global virtual teams." Health care leaders now have the ability to lead global teams from afar by becoming "virtual leaders" with a responsibility to lead a "virtual team." Three models of globalization presented and discussed are outsourcing of health care services, medical tourism, and telerobotics. These models require global managers to lead virtually, and a positive relationship between the virtual leader and the virtual team member is vital in the success of global health care organizations.
Virtual Energetic Particle Observatory for the Heliospheric Data Environment
NASA Technical Reports Server (NTRS)
Cooper, J. F.; Armstrong, T. P.; Hill, M. E.; Lal, N.; McGuire, R. E.; McKibben, R. B.; Narock, T. W.; Szabo, A.; Tranquille, C.
2007-01-01
The heliosphere is pervaded by interplanetary energetic particles, traditionally also called cosmic rays, from solar, internal heliospheric, and galactic sources. The particles species of interest to heliophysics extend from plasma energies to the GeV energies of galactic cosmic rays still measurably affected by heliospheric modulation and the still higher energies contributing to atmospheric ionization. The NASA and international Heliospheric Network of operational and legacy spacecraft measures interplanetary fluxes of these particles. Spatial coverage extends from the inner heliosphere and geospace to the heliosheath boundary region now being traversed by Voyager 1 and soon by Voyager 2. Science objectives include investigation of solar flare and coronal mass ejection events, acceleration and transport of interplanetary particles within the inner heliosphere, cosmic ray interactions with planetary surfaces and atmospheres, sources of suprathermal and anomalous cosmic ray ions in the outer heliosphere, and solar cycle modulation of galactic cosmic rays. The Virtual Energetic Particle Observatory (VEPO) will improve access and usability of selected spacecraft and sub-orbital NASA heliospheric energetic particle data sets as a newly approved effort within the evolving heliophysics virtual observatory environment. In this presentation, we will describe current VEPO science requirements, our initial priorities and an overview of our strategy to implement VEPO rapidly and at minimal cost by working within the high-level framework of the Virtual Heliospheric Observatory (VHO). VEPO will also leverage existing data services of NASA's Space Physics Data Facility and other existing capabilities of the U.S. and international heliospheric research communities.
Spiritual and Affective Responses to a Physical Church and Corresponding Virtual Model.
Murdoch, Matt; Davies, Jim
2017-11-01
Architectural and psychological theories posit that built environments have the potential to elicit complex psychological responses. However, few researchers have seriously explored this potential. Given the increasing importance and fidelity of virtual worlds, such research should explore whether virtual models of built environments are also capable of eliciting complex psychological responses. The goal of this study was to test these hypotheses, using a church, a corresponding virtual model, and an inclusive measure of state spirituality ("spiritual feelings"). Participants (n = 33) explored a physical church and corresponding virtual model, completing a measure of spiritual feelings after exploring the outside and inside of each version of the church. Using spiritual feelings after exploring the outside of the church as a baseline measure, change in state spirituality was assessed by taking the difference between spiritual feelings after exploring the inside and outside of the church (inside-outside) for both models. Although this change was greater in response to the physical church, there was no significant difference between the two models in eliciting such change in spiritual feelings. Despite the limitations of this exploratory study, these findings indicate that both built environments and corresponding virtual models are capable of evoking complex psychological responses.
ERIC Educational Resources Information Center
Barbalios, N.; Ioannidou, I.; Tzionas, P.; Paraskeuopoulos, S.
2013-01-01
This paper introduces a realistic 3D model supported virtual environment for environmental education, that highlights the importance of water resource sharing by focusing on the tragedy of the commons dilemma. The proposed virtual environment entails simulations that are controlled by a multi-agent simulation model of a real ecosystem consisting…
Analysis of a virtual memory model for maintaining database views
NASA Technical Reports Server (NTRS)
Kinsley, Kathryn C.; Hughes, Charles E.
1992-01-01
This paper presents an analytical model for predicting the performance of a new support strategy for database views. This strategy, called the virtual method, is compared with traditional methods for supporting views. The analytical model's predictions of improved performance by the virtual method are then validated by comparing these results with those achieved in an experimental implementation.
ERIC Educational Resources Information Center
Sclater, Madeleine; Lally, Victor
2013-01-01
The dialectical relationship between social justice, active participation and the development of aesthetic sensibilities is re-emerging as a theme among art and design educators as concerns mount for the future of art and design education in the curriculum--particularly in the UK, but also internationally. This article explores the potential of…
A Meeting of the Minds: ITEC Virtual Conference '96 (ITEC VC '96) Proceedings (Australia, 1996).
ERIC Educational Resources Information Center
Hay, Lyn, Ed.; Henri, James, Ed.
In these proceedings of the Teacher Librarian Strand of the ITEC Virtual Conference (1996), international contributors present papers on 12 key topics of interest to teacher librarians. The following papers topics are addressed: (A) Censorship and the Internet in Schools: Problems and Solutions; (B) Hot Spots on the Web for TLs; (C) Children's…
STS-105 Crew Training in VR Lab
2001-03-15
JSC2001-00751 (15 March 2001) --- Astronaut Scott J. Horowitz, STS-105 mission commander, uses the virtual reality lab at the Johnson Space Center (JSC) to train for his duties aboard the Space Shuttle Discovery. This type of computer interface paired with virtual reality training hardware and software helps to prepare the entire team for dealing with International Space Station (ISS) elements.
STS-105 Crew Training in VR Lab
2001-03-15
JSC2001-00758 (15 March 2001) --- Astronaut Frederick W. Sturckow, STS-105 pilot, uses the virtual reality lab at the Johnson Space Center (JSC) to train for his duties aboard the Space Shuttle Discovery. This type of computer interface paired with virtual reality training hardware and software helps to prepare the entire team for dealing with International Space Station (ISS) elements.
ERIC Educational Resources Information Center
UNESCO-UNEVOC International Centre for Technical and Vocational Education and Training, 2014
2014-01-01
This virtual conference is part of a larger consultation process through which UNESCO will consult with practitioners and researchers; representatives of key stakeholder groupings such as employers' federations, trade unions and youth organizations; other international agencies and Member States in order to draft a new Revised Recommendation that…
AstroCloud, a Cyber-Infrastructure for Astronomy Research: Data Access and Interoperability
NASA Astrophysics Data System (ADS)
Fan, D.; He, B.; Xiao, J.; Li, S.; Li, C.; Cui, C.; Yu, C.; Hong, Z.; Yin, S.; Wang, C.; Cao, Z.; Fan, Y.; Mi, L.; Wan, W.; Wang, J.
2015-09-01
Data access and interoperability module connects the observation proposals, data, virtual machines and software. According to the unique identifier of PI (principal investigator), an email address or an internal ID, data can be collected by PI's proposals, or by the search interfaces, e.g. conesearch. Files associated with the searched results could be easily transported to cloud storages, including the storage with virtual machines, or several commercial platforms like Dropbox. Benefitted from the standards of IVOA (International Observatories Alliance), VOTable formatted searching result could be sent to kinds of VO software. Latter endeavor will try to integrate more data and connect archives and some other astronomical resources.
Toward a hydro-political water cycle: virtual water,hydrology and international political economy
NASA Astrophysics Data System (ADS)
Greco, Francesca
2014-05-01
At the light of global food trade, no water cycle can be considered "closed" under a political point of view. While the hydrological cycle is a circular closed environment, if we open up our perspectives to social sciences, we will demonstrate how, thanks to virtual water, it is today possible to elaborate how much water 'enters or leave' any water body under the form crop-export, in terms of " water used for the production of agri-food products'. This new 'hydro-political cycle' will be discussed at the light of different theoretical perspectives: food trade theories, hydrology, international water law, socio-economic metabolism, material flow analysis.
SHARED VIRTUAL ENVIRONMENTS FOR COLLECTIVE TRAINING
NASA Technical Reports Server (NTRS)
Loftin, R. Bowen
2000-01-01
Historically NASA has trained teams of astronauts by bringing them to the Johnson Space Center in Houston to undergo generic training, followed by mission-specific training. This latter training begins after a crew has been selected for a mission (perhaps two years before the launch of that mission). While some Space Shuttle flights have included an astronaut from a foreign country, the International Space Station will be consistently crewed by teams comprised of astronauts from two or more of the partner nations. The cost of training these international teams continues to grow in both monetary and personal terms. Thus, NASA has been seeking alternative training approaches for the International Space Station program. Since 1994 we have been developing, testing, and refining shared virtual environments for astronaut team training, including the use of virtual environments for use while in or in transit to the task location. In parallel with this effort, we have also been preparing applications for training teams of military personnel engaged in peacekeeping missions. This paper will describe the applications developed to date, some of the technological challenges that have been overcome in their development, and the research performed to guide the development and to measure the efficacy of these shared environments as training tools.
2014-01-01
Background Research has shown that nursing students find it difficult to translate and apply their theoretical knowledge in a clinical context. Virtual patients (VPs) have been proposed as a learning activity that can support nursing students in their learning of scientific knowledge and help them integrate theory and practice. Although VPs are increasingly used in health care education, they still lack a systematic consistency that would allow their reuse outside of their original context. There is therefore a need to develop a model for the development and implementation of VPs in nursing education. Objective The aim of this study was to develop and evaluate a virtual patient model optimized to the learning and assessment needs in nursing education. Methods The process of modeling started by reviewing theoretical frameworks reported in the literature and used by practitioners when designing learning and assessment activities. The Outcome-Present State Test (OPT) model was chosen as the theoretical framework. The model was then, in an iterative manner, developed and optimized to the affordances of virtual patients. Content validation was performed with faculty both in terms of the relevance of the chosen theories but also its applicability in nursing education. The virtual patient nursing model was then instantiated in two VPs. The students’ perceived usefulness of the VPs was investigated using a questionnaire. The result was analyzed using descriptive statistics. Results A virtual patient Nursing Design Model (vpNDM) composed of three layers was developed. Layer 1 contains the patient story and ways of interacting with the data, Layer 2 includes aspects of the iterative process of clinical reasoning, and finally Layer 3 includes measurable outcomes. A virtual patient Nursing Activity Model (vpNAM) was also developed as a guide when creating VP-centric learning activities. The students perceived the global linear VPs as a relevant learning activity for the integration of theory and practice. Conclusions Virtual patients that are adapted to the nursing paradigm can support nursing students’ development of clinical reasoning skills. The proposed virtual patient nursing design and activity models will allow the systematic development of different types of virtual patients from a common model and thereby create opportunities for sharing pedagogical designs across technical solutions. PMID:24727709
The economic impact of restricted water supply: a computable general equilibrium analysis.
Berrittella, Maria; Hoekstra, Arjen Y; Rehdanz, Katrin; Roson, Roberto; Tol, Richard S J
2007-04-01
Water problems are typically studied at the level of the river catchment. About 70% of all water is used for agriculture, and agricultural products are traded internationally. A full understanding of water use is impossible without understanding the international market for food and related products, such as textiles. The water embedded in commodities is called virtual water. Based on a general equilibrium model, we offer a method for investigating the role of water resources and water scarcity in the context of international trade. We run five alternative scenarios, analyzing the effects of water scarcity due to reduced availability of groundwater. This can be a consequence of physical constraints, and of policies curbing water demand. Four scenarios are based on a "market solution", where water owners can capitalize their water rent or taxes are recycled. In the fifth "non-market" scenario, this is not the case; supply restrictions imply productivity losses. Restrictions in water supply would shift trade patterns of agriculture and virtual water. These shifts are larger if the restriction is larger, and if the use of water in production is more rigid. Welfare losses are substantially larger in the non-market situation. Water-constrained agricultural producers lose, but unconstrained agricultural produces gain; industry gains as well. As a result, there are regional winners and losers from water supply constraints. Because of the current distortions of agricultural markets, water supply constraints could improve allocative efficiency; this welfare gain may more than offset the welfare losses due to the resource constraint.
NASA Astrophysics Data System (ADS)
2014-03-01
The second International Conference on Mathematical Modeling in Physical Sciences (IC-MSQUARE) took place at Prague, Czech Republic, from Sunday 1 September to Thursday 5 September 2013. The Conference was attended by more than 280 participants and hosted about 400 oral, poster, and virtual presentations while counted more than 600 pre-registered authors. The second IC-MSQUARE consisted of different and diverging workshops and thus covered various research fields where Mathematical Modeling is used, such as Theoretical/Mathematical Physics, Neutrino Physics, Non-Integrable Systems, Dynamical Systems, Computational Nanoscience, Biological Physics, Computational Biomechanics, Complex Networks, Stochastic Modeling, Fractional Statistics, DNA Dynamics, Macroeconomics. The scientific program was rather heavy since after the Keynote and Invited Talks in the morning, three parallel sessions were running every day. However, according to all attendees, the program was excellent with high level of talks and the scientific environment was fruitful, thus all attendees had a creative time. We would like to thank the Keynote Speaker and the Invited Speakers for their significant contribution to IC-MSQUARE. We also would like to thank the Members of the International Advisory and Scientific Committees as well as the Members of the Organizing Committee. Further information on the editors, speakers and committees is available in the attached pdf.
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.
Virtual 3d City Modeling: Techniques and Applications
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2013-08-01
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. There are various terms used for 3D city models such as "Cybertown", "Cybercity", "Virtual City", or "Digital City". 3D city models are basically a computerized or digital model of a city contains the graphic representation of buildings and other objects in 2.5 or 3D. Generally three main Geomatics approach are using for Virtual 3-D City models generation, in first approach, researcher are using Conventional techniques such as Vector Map data, DEM, Aerial images, second approach are based on High resolution satellite images with LASER scanning, In third method, many researcher are using Terrestrial images by using Close Range Photogrammetry with DSM & Texture mapping. We start this paper from the introduction of various Geomatics techniques for 3D City modeling. These techniques divided in to two main categories: one is based on Automation (Automatic, Semi-automatic and Manual methods), and another is Based on Data input techniques (one is Photogrammetry, another is Laser Techniques). After details study of this, finally in short, we are trying to give the conclusions of this study. In the last, we are trying to give the conclusions of this research paper and also giving a short view for justification and analysis, and present trend for 3D City modeling. This paper gives an overview about the Techniques related with "Generation of Virtual 3-D City models using Geomatics Techniques" and the Applications of Virtual 3D City models. Photogrammetry, (Close range, Aerial, Satellite), Lasergrammetry, GPS, or combination of these modern Geomatics techniques play a major role to create a virtual 3-D City model. Each and every techniques and method has some advantages and some drawbacks. Point cloud model is a modern trend for virtual 3-D city model. Photo-realistic, Scalable, Geo-referenced virtual 3-D City model is a very useful for various kinds of applications such as for planning in Navigation, Tourism, Disasters Management, Transportations, Municipality, Urban Environmental Managements and Real-estate industry. So the Construction of Virtual 3-D city models is a most interesting research topic in recent years.
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.
Cortical Spiking Network Interfaced with Virtual Musculoskeletal Arm and Robotic Arm
Dura-Bernal, Salvador; Zhou, Xianlian; Neymotin, Samuel A.; Przekwas, Andrzej; Francis, Joseph T.; Lytton, William W.
2015-01-01
Embedding computational models in the physical world is a critical step towards constraining their behavior and building practical applications. Here we aim to drive a realistic musculoskeletal arm model using a biomimetic cortical spiking model, and make a robot arm reproduce the same trajectories in real time. Our cortical model consisted of a 3-layered cortex, composed of several hundred spiking model-neurons, which display physiologically realistic dynamics. We interconnected the cortical model to a two-joint musculoskeletal model of a human arm, with realistic anatomical and biomechanical properties. The virtual arm received muscle excitations from the neuronal model, and fed back proprioceptive information, forming a closed-loop system. The cortical model was trained using spike timing-dependent reinforcement learning to drive the virtual arm in a 2D reaching task. Limb position was used to simultaneously control a robot arm using an improved network interface. Virtual arm muscle activations responded to motoneuron firing rates, with virtual arm muscles lengths encoded via population coding in the proprioceptive population. After training, the virtual arm performed reaching movements which were smoother and more realistic than those obtained using a simplistic arm model. This system provided access to both spiking network properties and to arm biophysical properties, including muscle forces. The use of a musculoskeletal virtual arm and the improved control system allowed the robot arm to perform movements which were smoother than those reported in our previous paper using a simplistic arm. This work provides a novel approach consisting of bidirectionally connecting a cortical model to a realistic virtual arm, and using the system output to drive a robotic arm in real time. Our techniques are applicable to the future development of brain neuroprosthetic control systems, and may enable enhanced brain-machine interfaces with the possibility for finer control of limb prosthetics. PMID:26635598
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.
A collaborative molecular modeling environment using a virtual tunneling service.
Lee, Jun; Kim, Jee-In; Kang, Lin-Woo
2012-01-01
Collaborative researches of three-dimensional molecular modeling can be limited by different time zones and locations. A networked virtual environment can be utilized to overcome the problem caused by the temporal and spatial differences. However, traditional approaches did not sufficiently consider integration of different computing environments, which were characterized by types of applications, roles of users, and so on. We propose a collaborative molecular modeling environment to integrate different molecule modeling systems using a virtual tunneling service. We integrated Co-Coot, which is a collaborative crystallographic object-oriented toolkit, with VRMMS, which is a virtual reality molecular modeling system, through a collaborative tunneling system. The proposed system showed reliable quantitative and qualitative results through pilot experiments.
a Methodology to Adapt Photogrammetric Models to Virtual Reality for Oculus Gear VR
NASA Astrophysics Data System (ADS)
Colmenero Fdez, A.
2017-11-01
In this paper, we will expose the process of adapting a high resolution model (laser and photogrammetry) into a virtual reality application for mobile phones. It is a virtual archeology project carried out on the site of Lugo's Mitreo, Spain.
Virtual hydrology observatory: an immersive visualization of hydrology modeling
NASA Astrophysics Data System (ADS)
Su, Simon; Cruz-Neira, Carolina; Habib, Emad; Gerndt, Andreas
2009-02-01
The Virtual Hydrology Observatory will provide students with the ability to observe the integrated hydrology simulation with an instructional interface by using a desktop based or immersive virtual reality setup. It is the goal of the virtual hydrology observatory application to facilitate the introduction of field experience and observational skills into hydrology courses through innovative virtual techniques that mimic activities during actual field visits. The simulation part of the application is developed from the integrated atmospheric forecast model: Weather Research and Forecasting (WRF), and the hydrology model: Gridded Surface/Subsurface Hydrologic Analysis (GSSHA). Both the output from WRF and GSSHA models are then used to generate the final visualization components of the Virtual Hydrology Observatory. The various visualization data processing techniques provided by VTK are 2D Delaunay triangulation and data optimization. Once all the visualization components are generated, they are integrated into the simulation data using VRFlowVis and VR Juggler software toolkit. VR Juggler is used primarily to provide the Virtual Hydrology Observatory application with fully immersive and real time 3D interaction experience; while VRFlowVis provides the integration framework for the hydrologic simulation data, graphical objects and user interaction. A six-sided CAVETM like system is used to run the Virtual Hydrology Observatory to provide the students with a fully immersive experience.
ERIC Educational Resources Information Center
Terry, Laura Robin
2012-01-01
The implementation of the American School Counselor Association (ASCA) national model has not been studied in nontraditional settings such as in virtual schools. The purpose of this quantitative research study was to examine the implementation of the career domain of the ASCA national model into the virtual high school setting. Social cognitive…
ERIC Educational Resources Information Center
Hubain, Bryan S.
2017-01-01
The experiences of international students along the lines of race and ethnicity, sexuality, gender, and nationality are virtually unknown. This study utilizes experience-centered narrative inquiry to explore the experiences of Black gay international students, and how they are racialized and sexualized in American higher education. Using a Queer…
Introduction of Virtualization Technology to Multi-Process Model Checking
NASA Technical Reports Server (NTRS)
Leungwattanakit, Watcharin; Artho, Cyrille; Hagiya, Masami; Tanabe, Yoshinori; Yamamoto, Mitsuharu
2009-01-01
Model checkers find failures in software by exploring every possible execution schedule. Java PathFinder (JPF), a Java model checker, has been extended recently to cover networked applications by caching data transferred in a communication channel. A target process is executed by JPF, whereas its peer process runs on a regular virtual machine outside. However, non-deterministic target programs may produce different output data in each schedule, causing the cache to restart the peer process to handle the different set of data. Virtualization tools could help us restore previous states of peers, eliminating peer restart. This paper proposes the application of virtualization technology to networked model checking, concentrating on JPF.
Manufacturing data analytics using a virtual factory representation.
Jain, Sanjay; Shao, Guodong; Shin, Seung-Jun
2017-01-01
Large manufacturers have been using simulation to support decision-making for design and production. However, with the advancement of technologies and the emergence of big data, simulation can be utilised to perform and support data analytics for associated performance gains. This requires not only significant model development expertise, but also huge data collection and analysis efforts. This paper presents an approach within the frameworks of Design Science Research Methodology and prototyping to address the challenge of increasing the use of modelling, simulation and data analytics in manufacturing via reduction of the development effort. The use of manufacturing simulation models is presented as data analytics applications themselves and for supporting other data analytics applications by serving as data generators and as a tool for validation. The virtual factory concept is presented as the vehicle for manufacturing modelling and simulation. Virtual factory goes beyond traditional simulation models of factories to include multi-resolution modelling capabilities and thus allowing analysis at varying levels of detail. A path is proposed for implementation of the virtual factory concept that builds on developments in technologies and standards. A virtual machine prototype is provided as a demonstration of the use of a virtual representation for manufacturing data analytics.
Abdoli-Eramaki, Mohammad; Stevenson, Joan M; Agnew, Michael J; Kamalzadeh, Amin
2009-04-01
The purpose of this study was to validate a 3D dynamic virtual model for lifting tasks against a validated link segment model (LSM). A face validation study was conducted by collecting x, y, z coordinate data and using them in both virtual and LSM models. An upper body virtual model was needed to calculate the 3D torques about human joints for use in simulated lifting styles and to estimate the effect of external mechanical devices on human body. Firstly, the model had to be validated to be sure it provided accurate estimates of 3D moments in comparison to a previously validated LSM. Three synchronised Fastrak units with nine sensors were used to record data from one male subject who completed dynamic box lifting under 27 different load conditions (box weights (3), lifting techniques (3) and rotations (3)). The external moments about three axes of L4/L5 were compared for both models. A pressure switch on the box was used to denote the start and end of the lift. An excellent agreement [image omitted] was found between the two models for dynamic lifting tasks, especially for larger moments in flexion and extension. This virtual model was considered valid for use in a complete simulation of the upper body skeletal system. This biomechanical virtual model of the musculoskeletal system can be used by researchers and practitioners to give a better tool to study the causes of LBP and the effect of intervention strategies, by permitting the researcher to see and control a virtual subject's motions.
NASA Astrophysics Data System (ADS)
Herbuś, K.; Ociepka, P.
2016-08-01
The development of methods of computer aided design and engineering allows conducting virtual tests, among others concerning motion simulation of technical means. The paper presents a method of integrating an object in the form of a virtual model of a Stewart platform with an avatar of a vehicle moving in a virtual environment. The area of the problem includes issues related to the problem of fidelity of mapping the work of the analyzed technical mean. The main object of investigations is a 3D model of a Stewart platform, which is a subsystem of the simulator designated for driving learning for disabled persons. The analyzed model of the platform, prepared for motion simulation, was created in the “Motion Simulation” module of a CAD/CAE class system Siemens PLM NX. Whereas the virtual environment, in which the moves the avatar of the passenger car, was elaborated in a VR class system EON Studio. The element integrating both of the mentioned software environments is a developed application that reads information from the virtual reality (VR) concerning the current position of the car avatar. Then, basing on the accepted algorithm, it sends control signals to respective joints of the model of the Stewart platform (CAD).
Benda, Lee; Miller, Daniel; Barquin, Jose; McCleary, Richard; Cai, TiJiu; Ji, Y
2016-03-01
Modern land-use planning and conservation strategies at landscape to country scales worldwide require complete and accurate digital representations of river networks, encompassing all channels including the smallest headwaters. The digital river networks, integrated with widely available digital elevation models, also need to have analytical capabilities to support resource management and conservation, including attributing river segments with key stream and watershed data, characterizing topography to identify landforms, discretizing land uses at scales necessary to identify human-environment interactions, and connecting channels downstream and upstream, and to terrestrial environments. We investigate the completeness and analytical capabilities of national to regional scale digital river networks that are available in five countries: Canada, China, Russia, Spain, and United States using actual resource management and conservation projects involving 12 university, agency, and NGO organizations. In addition, we review one pan-European and one global digital river network. Based on our analysis, we conclude that the majority of the regional, national, and global scale digital river networks in our sample lack in network completeness, analytical capabilities or both. To address this limitation, we outline a general framework to build as complete as possible digital river networks and to integrate them with available digital elevation models to create robust analytical capabilities (e.g., virtual watersheds). We believe this presents a global opportunity for in-country agencies, or international players, to support creation of virtual watersheds to increase environmental problem solving, broaden access to the watershed sciences, and strengthen resource management and conservation in countries worldwide.
Building Virtual Watersheds: A Global Opportunity to Strengthen Resource Management and Conservation
NASA Astrophysics Data System (ADS)
Benda, Lee; Miller, Daniel; Barquin, Jose; McCleary, Richard; Cai, TiJiu; Ji, Y.
2016-03-01
Modern land-use planning and conservation strategies at landscape to country scales worldwide require complete and accurate digital representations of river networks, encompassing all channels including the smallest headwaters. The digital river networks, integrated with widely available digital elevation models, also need to have analytical capabilities to support resource management and conservation, including attributing river segments with key stream and watershed data, characterizing topography to identify landforms, discretizing land uses at scales necessary to identify human-environment interactions, and connecting channels downstream and upstream, and to terrestrial environments. We investigate the completeness and analytical capabilities of national to regional scale digital river networks that are available in five countries: Canada, China, Russia, Spain, and United States using actual resource management and conservation projects involving 12 university, agency, and NGO organizations. In addition, we review one pan-European and one global digital river network. Based on our analysis, we conclude that the majority of the regional, national, and global scale digital river networks in our sample lack in network completeness, analytical capabilities or both. To address this limitation, we outline a general framework to build as complete as possible digital river networks and to integrate them with available digital elevation models to create robust analytical capabilities (e.g., virtual watersheds). We believe this presents a global opportunity for in-country agencies, or international players, to support creation of virtual watersheds to increase environmental problem solving, broaden access to the watershed sciences, and strengthen resource management and conservation in countries worldwide.
Customizing G Protein-coupled receptor models for structure-based virtual screening.
de Graaf, Chris; Rognan, Didier
2009-01-01
This review will focus on the construction, refinement, and validation of G Protein-coupled receptor models for the purpose of structure-based virtual screening. Practical tips and tricks derived from concrete modeling and virtual screening exercises to overcome the problems and pitfalls associated with the different steps of the receptor modeling workflow will be presented. These examples will not only include rhodopsin-like (class A), but also secretine-like (class B), and glutamate-like (class C) receptors. In addition, the review will present a careful comparative analysis of current crystal structures and their implication on homology modeling. The following themes will be discussed: i) the use of experimental anchors in guiding the modeling procedure; ii) amino acid sequence alignments; iii) ligand binding mode accommodation and binding cavity expansion; iv) proline-induced kinks in transmembrane helices; v) binding mode prediction and virtual screening by receptor-ligand interaction fingerprint scoring; vi) extracellular loop modeling; vii) virtual filtering schemes. Finally, an overview of several successful structure-based screening shows that receptor models, despite structural inaccuracies, can be efficiently used to find novel ligands.
Innovative application of virtual display technique in virtual museum
NASA Astrophysics Data System (ADS)
Zhang, Jiankang
2017-09-01
Virtual museum refers to display and simulate the functions of real museum on the Internet in the form of 3 Dimensions virtual reality by applying interactive programs. Based on Virtual Reality Modeling Language, virtual museum building and its effective interaction with the offline museum lie in making full use of 3 Dimensions panorama technique, virtual reality technique and augmented reality technique, and innovatively taking advantages of dynamic environment modeling technique, real-time 3 Dimensions graphics generating technique, system integration technique and other key virtual reality techniques to make sure the overall design of virtual museum.3 Dimensions panorama technique, also known as panoramic photography or virtual reality, is a technique based on static images of the reality. Virtual reality technique is a kind of computer simulation system which can create and experience the interactive 3 Dimensions dynamic visual world. Augmented reality, also known as mixed reality, is a technique which simulates and mixes the information (visual, sound, taste, touch, etc.) that is difficult for human to experience in reality. These technologies make virtual museum come true. It will not only bring better experience and convenience to the public, but also be conducive to improve the influence and cultural functions of the real museum.
Digital Immersive Virtual Environments and Instructional Computing
ERIC Educational Resources Information Center
Blascovich, Jim; Beall, Andrew C.
2010-01-01
This article reviews theory and research relevant to the development of digital immersive virtual environment-based instructional computing systems. The review is organized within the context of a multidimensional model of social influence and interaction within virtual environments that models the interaction of four theoretical factors: theory…
Software forecasting as it is really done: A study of JPL software engineers
NASA Technical Reports Server (NTRS)
Griesel, Martha Ann; Hihn, Jairus M.; Bruno, Kristin J.; Fouser, Thomas J.; Tausworthe, Robert C.
1993-01-01
This paper presents a summary of the results to date of a Jet Propulsion Laboratory internally funded research task to study the costing process and parameters used by internally recognized software cost estimating experts. Protocol Analysis and Markov process modeling were used to capture software engineer's forecasting mental models. While there is significant variation between the mental models that were studied, it was nevertheless possible to identify a core set of cost forecasting activities, and it was also found that the mental models cluster around three forecasting techniques. Further partitioning of the mental models revealed clustering of activities, that is very suggestive of a forecasting lifecycle. The different forecasting methods identified were based on the use of multiple-decomposition steps or multiple forecasting steps. The multiple forecasting steps involved either forecasting software size or an additional effort forecast. Virtually no subject used risk reduction steps in combination. The results of the analysis include: the identification of a core set of well defined costing activities, a proposed software forecasting life cycle, and the identification of several basic software forecasting mental models. The paper concludes with a discussion of the implications of the results for current individual and institutional practices.
STS-133 crew during MSS/EVAA TEAM training in Virtual Reality Lab
2010-10-01
JSC2010-E-170885 (1 Oct. 2010) --- NASA astronauts Alvin Drew (left) and Tim Kopra, both STS-133 mission specialists, use virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of their duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
STS-133 crew during MSS/EVAA TEAM training in Virtual Reality Lab
2010-10-01
JSC2010-E-170892 (1 Oct. 2010) --- NASA astronaut Alvin Drew, STS-133 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
STS-133 crew during MSS/EVAA TEAM training in Virtual Reality Lab
2010-10-01
JSC2010-E-170871 (1 Oct. 2010) --- NASA astronaut Tim Kopra, STS-133 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Crew trainer David Homan assisted Kopra. Photo credit: NASA or National Aeronautics and Space Administration
STS-133 crew during MSS/EVAA TEAM training in Virtual Reality Lab
2010-10-01
JSC2010-E-170897 (1 Oct. 2010) --- NASA astronaut Tim Kopra, STS-133 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
STS-133 crew during MSS/EVAA TEAM training in Virtual Reality Lab
2010-10-01
JSC2010-E-170873 (1 Oct. 2010) --- NASA astronaut Tim Kopra, STS-133 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Crew trainer David Homan assisted Kopra. Photo credit: NASA or National Aeronautics and Space Administration
STS-134 crew in Virtual Reality Lab during their MSS/EVAA SUPT2 Team training
2010-08-27
JSC2010-E-121053 (27 Aug. 2010) --- NASA astronaut Greg Chamitoff, STS-134 mission specialist, uses virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of his duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
“Elegant Tool” Delivers Genome-Level Science for Electrolytes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Keith Arterburn
Now, a ‘disruptive, virtual scientific simulation tool’ delivers a new, genome-level investigation for electrolytes to develop better, more efficient batteries. Dr. Kevin Gering, an Idaho National Laboratory researcher, has developed the Advanced Electrolyte Model (AEM), a copyrighted molecular-based simulation tool that has been scientifically proven and validated using at least a dozen ‘real-world’ physical metrics. Nominated for the 2014 international R&D 100 Award, AEM revolutionizes electrolyte materials selection, optimizing combinations and key design elements to make battery design and experimentation quick, accurate and responsive to specific needs.
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.
Effect of CNC-milling on the marginal and internal fit of dental ceramics: a pilot study.
Schaefer, Oliver; Kuepper, Harald; Thompson, Geoffrey A; Cachovan, Georg; Hefti, Arthur F; Guentsch, Arndt
2013-08-01
Machined restorations have been investigated for their preciseness before, while detailed information on the milling-step itself are lacking. Therefore, the aim of this laboratory study was to quantify the effect of a novel milling-procedure on the marginal and internal fit of ceramic restorations. An acrylic model of a lower left first molar was prepared to receive a ceramic partial crown and was duplicated by one step dual viscosity impressions. Gypsum casts were formed and laser-scanned to realize virtual datasets, before restorations were designed, exported (PRE) and machined from lithium disilicate blanks. Crowns were digitized by a structure-light-scanner to obtain post-milling-data (POST). PRE and POST were virtually superimposed on the reference tooth and subjected to computer-aided-inspection. Visual fit-discrepancies were displayed with colors, while root mean square deviations (RMSD) and degrees of similarity (DS) were computed and analysed by t-tests for paired samples (n=5, α=0.05). The milling procedure resulted in a small increase of the marginal and internal fit discrepancies (RMSD mean: 3μm and 6μm, respectively). RMSD differences were not statistically significant (p=0.495 and p=0.160 for marginal and internal fit, respectively). These results were supported by the DS data. The products of digital dental workflows are prone to imprecisions. However, the present findings suggest that differences between computer-aided designed and actually milled restorations are small, especially when compared to typical fit discrepancies observed clinically. Imprecisions introduced by digital design or production processes are small. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Virtual reality in surgical training.
Lange, T; Indelicato, D J; Rosen, J M
2000-01-01
Virtual reality in surgery and, more specifically, in surgical training, faces a number of challenges in the future. These challenges are building realistic models of the human body, creating interface tools to view, hear, touch, feel, and manipulate these human body models, and integrating virtual reality systems into medical education and treatment. A final system would encompass simulators specifically for surgery, performance machines, telemedicine, and telesurgery. Each of these areas will need significant improvement for virtual reality to impact medicine successfully in the next century. This article gives an overview of, and the challenges faced by, current systems in the fast-changing field of virtual reality technology, and provides a set of specific milestones for a truly realistic virtual human body.
Direct Visuo-Haptic 4D Volume Rendering Using Respiratory Motion Models.
Fortmeier, Dirk; Wilms, Matthias; Mastmeyer, Andre; Handels, Heinz
2015-01-01
This article presents methods for direct visuo-haptic 4D volume rendering of virtual patient models under respiratory motion. Breathing models are computed based on patient-specific 4D CT image data sequences. Virtual patient models are visualized in real-time by ray casting based rendering of a reference CT image warped by a time-variant displacement field, which is computed using the motion models at run-time. Furthermore, haptic interaction with the animated virtual patient models is provided by using the displacements computed at high rendering rates to translate the position of the haptic device into the space of the reference CT image. This concept is applied to virtual palpation and the haptic simulation of insertion of a virtual bendable needle. To this aim, different motion models that are applicable in real-time are presented and the methods are integrated into a needle puncture training simulation framework, which can be used for simulated biopsy or vessel puncture in the liver. To confirm real-time applicability, a performance analysis of the resulting framework is given. It is shown that the presented methods achieve mean update rates around 2,000 Hz for haptic simulation and interactive frame rates for volume rendering and thus are well suited for visuo-haptic rendering of virtual patients under respiratory motion.
A virtual maintenance-based approach for satellite assembling and troubleshooting assessment
NASA Astrophysics Data System (ADS)
Geng, Jie; Li, Ying; Wang, Ranran; Wang, Zili; Lv, Chuan; Zhou, Dong
2017-09-01
In this study, a Virtual Maintenance (VM)-based approach for satellite troubleshooting assessment is proposed. By focusing on various elements in satellite assemble troubleshooting, such as accessibility, ergonomics, wiring, and extent of damage, a systematic, quantitative, and objective assessment model is established to decrease subjectivity in satellite assembling and troubleshooting assessment. Afterwards, based on the established assessment model and satellite virtual prototype, an application process of this model suitable for a virtual environment is presented. Finally, according to the application process, all the elements in satellite troubleshooting are analyzed and assessed. The corresponding improvements, which realize the transformation from a conventional way to a virtual simulation and assessment, are suggested, and the flaws in assembling and troubleshooting are revealed. Assembling or troubleshooting schemes can be improved in the early stage of satellite design with the help of a virtual prototype. Repetition in the practical operation is beneficial to companies as risk and cost are effectively reduced.
STS-111 Training in VR lab with Expedition IV and V Crewmembers
2001-10-18
JSC2001-E-39090 (18 October 2001) --- Cosmonaut Valeri G. Korzun, Expedition Five mission commander representing Rosaviakosmos, uses the virtual reality lab at the Johnson Space Center (JSC) to train for his duties on the International Space Station (ISS). This type of computer interface paired with virtual reality training hardware and software helps the entire team for dealing with ISS elements.
Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.
Kockro, Ralf A; Hwang, Peter Y K
2009-05-01
We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. The virtual model was based on the tomographic data of the Visible Human Project. The male Visible Human's computed tomographic data were volumetrically reconstructed as virtual bone tissue, and the individual photographic slices provided the basis for segmentation of the middle and inner ear structures, cranial nerves, vessels, and brainstem. These structures were created by using outlining and tube editing tools, allowing structural modeling either directly on the basis of the photographic data or according to information from textbooks and cadaver dissections. For training and teaching, the virtual model was accessed in the previously described 3-dimensional workspaces of the Dextroscope or Dextrobeam (Volume Interactions Pte, Ltd., Singapore), whose interfaces enable volumetric exploration from any perspective and provide virtual tools for drilling and measuring. We have simulated several cranial base procedures including approaches via the floor of the middle fossa and the lateral petrous bone. The virtual model suitably illustrated the core facts of anatomic spatial relationships while simulating different stages of bone drilling along a variety of surgical corridors. The system was used for teaching during training courses to plan and discuss operative anatomy and strategies. The Virtual Temporal Bone and its surrounding 3-dimensional workspace provide an effective way to study the essential surgical anatomy of this complex region and to teach and train operative strategies, especially when used as an adjunct to cadaver dissections.
Evaluating open-source cloud computing solutions for geosciences
NASA Astrophysics Data System (ADS)
Huang, Qunying; Yang, Chaowei; Liu, Kai; Xia, Jizhe; Xu, Chen; Li, Jing; Gui, Zhipeng; Sun, Min; Li, Zhenglong
2013-09-01
Many organizations start to adopt cloud computing for better utilizing computing resources by taking advantage of its scalability, cost reduction, and easy to access characteristics. Many private or community cloud computing platforms are being built using open-source cloud solutions. However, little has been done to systematically compare and evaluate the features and performance of open-source solutions in supporting Geosciences. This paper provides a comprehensive study of three open-source cloud solutions, including OpenNebula, Eucalyptus, and CloudStack. We compared a variety of features, capabilities, technologies and performances including: (1) general features and supported services for cloud resource creation and management, (2) advanced capabilities for networking and security, and (3) the performance of the cloud solutions in provisioning and operating the cloud resources as well as the performance of virtual machines initiated and managed by the cloud solutions in supporting selected geoscience applications. Our study found that: (1) no significant performance differences in central processing unit (CPU), memory and I/O of virtual machines created and managed by different solutions, (2) OpenNebula has the fastest internal network while both Eucalyptus and CloudStack have better virtual machine isolation and security strategies, (3) Cloudstack has the fastest operations in handling virtual machines, images, snapshots, volumes and networking, followed by OpenNebula, and (4) the selected cloud computing solutions are capable for supporting concurrent intensive web applications, computing intensive applications, and small-scale model simulations without intensive data communication.
Virtual Reference, Real Money: Modeling Costs in Virtual Reference Services
ERIC Educational Resources Information Center
Eakin, Lori; Pomerantz, Jeffrey
2009-01-01
Libraries nationwide are in yet another phase of belt tightening. Without an understanding of the economic factors that influence library operations, however, controlling costs and performing cost-benefit analyses on services is difficult. This paper describes a project to develop a cost model for collaborative virtual reference services. This…
Reduced-Drift Virtual Gyro from an Array of Low-Cost Gyros.
Vaccaro, Richard J; Zaki, Ahmed S
2017-02-11
A Kalman filter approach for combining the outputs of an array of high-drift gyros to obtain a virtual lower-drift gyro has been known in the literature for more than a decade. The success of this approach depends on the correlations of the random drift components of the individual gyros. However, no method of estimating these correlations has appeared in the literature. This paper presents an algorithm for obtaining the statistical model for an array of gyros, including the cross-correlations of the individual random drift components. In order to obtain this model, a new statistic, called the "Allan covariance" between two gyros, is introduced. The gyro array model can be used to obtain the Kalman filter-based (KFB) virtual gyro. Instead, we consider a virtual gyro obtained by taking a linear combination of individual gyro outputs. The gyro array model is used to calculate the optimal coefficients, as well as to derive a formula for the drift of the resulting virtual gyro. The drift formula for the optimal linear combination (OLC) virtual gyro is identical to that previously derived for the KFB virtual gyro. Thus, a Kalman filter is not necessary to obtain a minimum drift virtual gyro. The theoretical results of this paper are demonstrated using simulated as well as experimental data. In experimental results with a 28-gyro array, the OLC virtual gyro has a drift spectral density 40 times smaller than that obtained by taking the average of the gyro signals.
A Collaborative Molecular Modeling Environment Using a Virtual Tunneling Service
Lee, Jun; Kim, Jee-In; Kang, Lin-Woo
2012-01-01
Collaborative researches of three-dimensional molecular modeling can be limited by different time zones and locations. A networked virtual environment can be utilized to overcome the problem caused by the temporal and spatial differences. However, traditional approaches did not sufficiently consider integration of different computing environments, which were characterized by types of applications, roles of users, and so on. We propose a collaborative molecular modeling environment to integrate different molecule modeling systems using a virtual tunneling service. We integrated Co-Coot, which is a collaborative crystallographic object-oriented toolkit, with VRMMS, which is a virtual reality molecular modeling system, through a collaborative tunneling system. The proposed system showed reliable quantitative and qualitative results through pilot experiments. PMID:22927721
Modeling Environmental Impacts on Cognitive Performance for Artificially Intelligent Entities
2017-06-01
of the agent behavior model is presented in a military-relevant virtual game environment. We then outline a quantitative approach to test the agent...relevant virtual game environment. We then outline a quantitative approach to test the agent behavior model within the virtual environment. Results show...x Game View of Hot Environment Condition Displaying Total “f” Cost for Each Searched Waypoint Node
A web-system of virtual morphometric globes
NASA Astrophysics Data System (ADS)
Florinsky, Igor; Garov, Andrei; Karachevtseva, Irina
2017-04-01
Virtual globes — programs implementing interactive three-dimensional (3D) models of planets — are increasingly used in geo- and planetary sciences. We develop a web-system of virtual morphometric globes. As the initial data, we used the following global digital elevation models (DEMs): (1) a DEM of the Earth extracted from SRTM30_PLUS database; (2) a DEM of Mars extracted from the Mars Orbiter Laser Altimeter (MOLA) gridded data record archive; and (3) A DEM of the Moon extracted from the Lunar Orbiter Laser Altimeter (LOLA) gridded data record archive. From these DEMs, we derived global digital models of the following 16 local, nonlocal, and combined morphometric variables: horizontal curvature, vertical curvature, mean curvature, Gaussian curvature, minimal curvature, maximal curvature, unsphericity curvature, difference curvature, vertical excess curvature, horizontal excess curvature, ring curvature, accumulation curvature, catchment area, dispersive area, topographic index, and stream power index (definitions, formulae, and interpretations can be found elsewhere [1]). To calculate local morphometric variables, we applied a finite-difference method intended for spheroidal equal angular grids [1]. Digital models of a nonlocal and combined morphometric variables were derived by a method of Martz and de Jong adapted to spheroidal equal angular grids [1]. DEM processing was performed in the software LandLord [1]. The calculated morphometric models were integrated into the testing version of the system. The following main functions are implemented in the system: (1) selection of a celestial body; (2) selection of a morphometric variable; (3) 2D visualization of a calculated global morphometric model (a map in equirectangular projection); (4) 3D visualization of a calculated global morphometric model on the sphere surface (a globe by itself); (5) change of a globe scale (zooming); and (6) globe rotation by an arbitrary angle. The testing version of the system represents morphometric models with the resolution of 15'. In the final version of the system, we plan to implement a multiscale 3D visualization for models of 17 morphometric variables with the resolution from 15' to 30". The web-system of virtual morphometric globes is designed as a separate unit of a 3D web GIS for storage, processing, and access to planetary data [2], which is currently developed as an extension of an existing 2D web GIS (http://cartsrv.mexlab.ru/geoportal). Free, real-time web access to the system of virtual globes will be provided. The testing version of the system is available at: http://cartsrv.mexlab.ru/virtualglobe. The study is supported by the Russian Foundation for Basic Research, grant 15-07-02484. References 1. Florinsky, I.V., 2016. Digital Terrain Analysis in Soil Science and Geology. 2nd ed. Academic Press, Amsterdam, 486 p. 2. Garov, A.S., Karachevtseva, I.P., Matveev, E.V., Zubarev, A.E., and Florinsky, I.V., 2016. Development of a heterogenic distributed environment for spatial data processing using cloud technologies. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 41(B4): 385-390.
ICCE/ICCAI 2000 Full & Short Papers (Creative Learning).
ERIC Educational Resources Information Center
2000
This document contains the following full and short papers on creative learning from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction): (1) "A Collaborative Learning Support System Based on Virtual Environment Server for Multiple Agents" (Takashi Ohno, Kenji…
International Distance Education: The Digital Communities Project.
ERIC Educational Resources Information Center
Howard-Vital, Michelle R.; Rosenkoetter, Marlene
This paper describes the participation of the University of North Carolina at Wilmington (UNCW) in the virtual university component of the Digital Communities Project in Japan. It examines the characteristics of an experimental, international, distance-learning collaboration and explores the politics and practicalities related to international…
Human and natural influences on the changing thermal structure of the atmosphere
Santer, Benjamin D.; Painter, Jeffrey F.; Bonfils, Céline; Mears, Carl A.; Solomon, Susan; Wigley, Tom M. L.; Gleckler, Peter J.; Schmidt, Gavin A.; Doutriaux, Charles; Gillett, Nathan P.; Taylor, Karl E.; Thorne, Peter W.; Wentz, Frank J.
2013-01-01
Since the late 1970s, satellite-based instruments have monitored global changes in atmospheric temperature. These measurements reveal multidecadal tropospheric warming and stratospheric cooling, punctuated by short-term volcanic signals of reverse sign. Similar long- and short-term temperature signals occur in model simulations driven by human-caused changes in atmospheric composition and natural variations in volcanic aerosols. Most previous comparisons of modeled and observed atmospheric temperature changes have used results from individual models and individual observational records. In contrast, we rely on a large multimodel archive and multiple observational datasets. We show that a human-caused latitude/altitude pattern of atmospheric temperature change can be identified with high statistical confidence in satellite data. Results are robust to current uncertainties in models and observations. Virtually all previous research in this area has attempted to discriminate an anthropogenic signal from internal variability. Here, we present evidence that a human-caused signal can also be identified relative to the larger “total” natural variability arising from sources internal to the climate system, solar irradiance changes, and volcanic forcing. Consistent signal identification occurs because both internal and total natural variability (as simulated by state-of-the-art models) cannot produce sustained global-scale tropospheric warming and stratospheric cooling. Our results provide clear evidence for a discernible human influence on the thermal structure of the atmosphere. PMID:24043789
Virtual reality and paranoid ideations in people with an 'at-risk mental state' for psychosis.
Valmaggia, Lucia R; Freeman, Daniel; Green, Catherine; Garety, Philippa; Swapp, David; Antley, Angus; Prescott, Corinne; Fowler, David; Kuipers, Elizabeth; Bebbington, Paul; Slater, Mel; Broome, Matthew; McGuire, Philip K
2007-12-01
Virtual reality provides a means of studying paranoid thinking in controlled laboratory conditions. However, this method has not been used with a clinical group. To establish the feasibility and safety of using virtual reality methodology in people with an at-risk mental state and to investigate the applicability of a cognitive model of paranoia to this group. Twenty-one participants with an at-risk mental state were assessed before and after entering a virtual reality environment depicting the inside of an underground train. Virtual reality did not raise levels of distress at the time of testing or cause adverse experiences over the subsequent week. Individuals attributed mental states to virtual reality characters including hostile intent. Persecutory ideation in virtual reality was predicted by higher levels of trait paranoia, anxiety, stress, immersion in virtual reality, perseveration and interpersonal sensitivity. Virtual reality is an acceptable experimental technique for use with individuals with at-risk mental states. Paranoia in virtual reality was understandable in terms of the cognitive model of persecutory delusions.
NASA Astrophysics Data System (ADS)
Yang, W. B.; Yen, Y. N.; Cheng, H. M.
2015-08-01
The integration of preservation of heritage and the digital technology is an important international trend in the 21st century. The digital technology not only is able to record and preserve detailed documents and information of heritage completely, but also brings the value-added features effectively. In this study, 3D laser scanning is used to perform the digitalized archives for the interior and exterior body work of the building which contains integration of 3D scanner technology, mobile scanning collaboration and multisystem reverse modeling and integration technology. The 3D model is built by combining with multi-media presentations and reversed modeling in real scale to perform the simulation of virtual reality (VR). With interactive teaching and presentation of augmented reality to perform the interaction technology to extend the continuously update in traditional architecture information. With the upgrade of the technology and value-added in digitalization, the cultural asset value can be experienced through 3D virtual reality which makes the information presentation from the traditional reading in the past toward user operation with sensory experience and keep exploring the possibilities and development of cultural asset preservation by using digital technology makes the presentation and learning of cultural asset information toward diversification.
A review of virtual cutting methods and technology in deformable objects.
Wang, Monan; Ma, Yuzheng
2018-06-05
Virtual cutting of deformable objects has been a research topic for more than a decade and has been used in many areas, especially in surgery simulation. We refer to the relevant literature and briefly describe the related research. The virtual cutting method is introduced, and we discuss the benefits and limitations of these methods and explore possible research directions. Virtual cutting is a category of object deformation. It needs to represent the deformation of models in real time as accurately, robustly and efficiently as possible. To accurately represent models, the method must be able to: (1) model objects with different material properties; (2) handle collision detection and collision response; and (3) update the geometry and topology of the deformable model that is caused by cutting. Virtual cutting is widely used in surgery simulation, and research of the cutting method is important to the development of surgery simulation. Copyright © 2018 John Wiley & Sons, Ltd.
Lee, Jae M; Ku, Jeong H; Jang, Dong P; Kim, Dong H; Choi, Young H; Kim, In Y; Kim, Sun I
2002-06-01
The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology enabled us to use virtual reality (VR) for the treatment of the fear of public speaking. There have been two techniques used to construct a virtual environment for the treatment of the fear of public speaking: model-based and movie-based. Virtual audiences and virtual environments made by model-based technique are unrealistic and unnatural. The movie-based technique has a disadvantage in that each virtual audience cannot be controlled respectively, because all virtual audiences are included in one moving picture file. To address this disadvantage, this paper presents a virtual environment made by using image-based rendering (IBR) and chroma keying simultaneously. IBR enables us to make the virtual environment realistic because the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma keying allows a virtual audience to be controlled individually. In addition, a real-time capture technique was applied in constructing the virtual environment to give the subjects more interaction, in that they can talk with a therapist or another subject.
AstroGrid: the UK's Virtual Observatory Initiative
NASA Astrophysics Data System (ADS)
Mann, Robert G.; Astrogrid Consortium; Lawrence, Andy; Davenhall, Clive; Mann, Bob; McMahon, Richard; Irwin, Mike; Walton, Nic; Rixon, Guy; Watson, Mike; Osborne, Julian; Page, Clive; Allan, Peter; Giaretta, David; Perry, Chris; Pike, Dave; Sherman, John; Murtagh, Fionn; Harra, Louise; Bentley, Bob; Mason, Keith; Garrington, Simon
AstroGrid is the UK's Virtual Observatory (VO) initiative. It brings together the principal astronomical data centres in the UK, and has been funded to the tune of ˜pounds 5M over the next three years, via PPARC, as part of the UK e--science programme. Its twin goals are the provision of the infrastructure and tools for the federation and exploitation of large astronomical (X-ray to radio), solar and space plasma physics datasets, and the delivery of federations of current datasets for its user communities to exploit using those tools. Whilst AstroGrid's work will be centred on existing and future (e.g. VISTA) UK datasets, it will seek solutions to generic VO problems and will contribute to the developing international virtual observatory framework: AstroGrid is a member of the EU-funded Astrophysical Virtual Observatory project, has close links to a second EU Grid initiative, the European Grid of Solar Observations (EGSO), and will seek an active role in the development of the common standards on which the international virtual observatory will rely. In this paper we shall primarily describe the concrete plans for AstroGrid's one-year Phase A study, which will centre on: (i) the definition of detailed science requirements through community consultation; (ii) the undertaking of a ``functionality market survey" to test the utility of existing technologies for the VO; and (iii) a pilot programme of database federations, each addressing different aspects of the general database federation problem. Further information on AstroGrid can be found at AstroGrid .
A virtual therapeutic environment with user projective agents.
Ookita, S Y; Tokuda, H
2001-02-01
Today, we see the Internet as more than just an information infrastructure, but a socializing place and a safe outlet of inner feelings. Many personalities develop aside from real world life due to its anonymous environment. Virtual world interactions are bringing about new psychological illnesses ranging from netaddiction to technostress, as well as online personality disorders and conflicts in multiple identities that exist in the virtual world. Presently, there are no standard therapy models for the virtual environment. There are very few therapeutic environments, or tools especially made for virtual therapeutic environments. The goal of our research is to provide the therapy model and middleware tools for psychologists to use in virtual therapeutic environments. We propose the Cyber Therapy Model, and Projective Agents, a tool used in the therapeutic environment. To evaluate the effectiveness of the tool, we created a prototype system, called the Virtual Group Counseling System, which is a therapeutic environment that allows the user to participate in group counseling through the eyes of their Projective Agent. Projective Agents inherit the user's personality traits. During the virtual group counseling, the user's Projective Agent interacts and collaborates to recover and increase their psychological growth. The prototype system provides a simulation environment where psychologists can adjust the parameters and customize their own simulation environment. The model and tool is a first attempt toward simulating online personalities that may exist only online, and provide data for observation.
Palma, Gisele Carla Dos Santos; Freitas, Tatiana Beline; Bonuzzi, Giordano Márcio Gatinho; Soares, Marcos Antonio Arlindo; Leite, Paulo Henrique Wong; Mazzini, Natália Araújo; Almeida, Murilo Ruas Groschitz; Pompeu, José Eduardo; Torriani-Pasin, Camila
2017-05-01
This review determines the effects of virtual reality interventions for stroke subjects based on the International Classification of Functioning, Disability,and Health (ICF) framework. Virtual reality is a promising tool for therapy for stroke rehabilitation, but the effects of virtual reality interventions on post-stroke patients based on the specific ICF domains (Body Structures, Body Functions, Activity, and Participation) have not been investigated. A systematic review was conducted, including trials with adults with a clinical diagnosis of a chronic, subacute, or acute stroke. Eligible trials had to include studies with an intervention protocol and follow-up, with a focus on upper limbs and/or lower limbs and/or balance. The Physiotherapy Evidence Database (PEDro) was used to assess the methodological quality of randomized controlled trials. Each trial was separated according to methodological quality into a high-quality trial (PEDro ≥ 6) and a low-quality trial (PEDro ≤ 6). Only high-quality trials were analyzed specifically based on the outcome of these trials. In total, 54 trials involving 1811 participants were included. Of the papers included and considered high quality, 14 trials evaluated areas of the Body Structures component, 20 trials of the Body Functions domain, 17 trials of the Activity component, and 8 trials of the Participation domain. In relation to ICF Part 2, four trials evaluated areas of the Personal Factors component and one trial evaluated domains of the Environmental Factors component. The effects of virtual reality on stroke rehabilitation based on the ICF framework are positive in Body Function and Body Structure. However, the results in the domains Activity and Participation are inconclusive. More high-quality clinical trials are needed to confirm the effectiveness of virtual reality in the domains of Activity and Participation.
NASA Technical Reports Server (NTRS)
Smith, Jeffrey D.; Twombly, I. Alexander; Maese, A. Christopher; Cagle, Yvonne; Boyle, Richard
2003-01-01
The International Space Station demonstrates the greatest capabilities of human ingenuity, international cooperation and technology development. The complexity of this space structure is unprecedented; and training astronaut crews to maintain all its systems, as well as perform a multitude of research experiments, requires the most advanced training tools and techniques. Computer simulation and virtual environments are currently used by astronauts to train for robotic arm manipulations and extravehicular activities; but now, with the latest computer technologies and recent successes in areas of medical simulation, the capability exists to train astronauts for more hands-on research tasks using immersive virtual environments. We have developed a new technology, the Virtual Glovebox (VGX), for simulation of experimental tasks that astronauts will perform aboard the Space Station. The VGX may also be used by crew support teams for design of experiments, testing equipment integration capability and optimizing the procedures astronauts will use. This is done through the 3D, desk-top sized, reach-in virtual environment that can simulate the microgravity environment in space. Additional features of the VGX allow for networking multiple users over the internet and operation of tele-robotic devices through an intuitive user interface. Although the system was developed for astronaut training and assisting support crews, Earth-bound applications, many emphasizing homeland security, have also been identified. Examples include training experts to handle hazardous biological and/or chemical agents in a safe simulation, operation of tele-robotic systems for assessing and diffusing threats such as bombs, and providing remote medical assistance to field personnel through a collaborative virtual environment. Thus, the emerging VGX simulation technology, while developed for space- based applications, can serve a dual use facilitating homeland security here on Earth.
NASA Technical Reports Server (NTRS)
Dunn, Mariea C.; Alves, Jeffrey R.; Hutchinson, Sonya L.
1999-01-01
This paper describes the human engineering analysis performed on the Materials Science Research Rack-1 and Quench Module Insert (MSRR-1/QMI) using Transom Jack (Jack) software. The Jack software was used to model a virtual environment consisting of the MSRR-1/QMI hardware configuration and human figures representing the 95th percentile male and 5th percentile female. The purpose of the simulation was to assess the human interfaces in the design for their ability to meet the requirements of the Pressurized Payloads Interface Requirements Document - International Space Program, Revision C (SSP 57000). Jack was used in the evaluation because of its ability to correctly model anthropometric body measurements and the physical behavior of astronauts working in microgravity, which is referred to as the neutral body posture. The Jack model allows evaluation of crewmember interaction with hardware through task simulation including but not limited to collision avoidance behaviors, hand/eye coordination, reach path planning, and automatic grasping to part contours. Specifically, this virtual simulation depicts the human figures performing the QMI installation and check-out, sample cartridge insertion and removal, and gas bottle drawer removal. These tasks were evaluated in terms of adequate clearance in reach envelopes, adequate accessibility in work envelopes, appropriate line of sight in visual envelopes, and accommodation of full size range for male and female stature maneuverability. The results of the human engineering analysis virtual simulation indicate that most of the associated requirements of SSP 57000 were met. However, some hardware design considerations and crew procedures modifications are recommended to improve accessibility, provide an adequate work envelope, reduce awkward body posture, and eliminate permanent protrusions.
The National Virtual Observatory
NASA Astrophysics Data System (ADS)
Hanisch, Robert J.
2001-06-01
The National Virtual Observatory is a distributed computational facility that will provide access to the ``virtual sky''-the federation of astronomical data archives, object catalogs, and associated information services. The NVO's ``virtual telescope'' is a common framework for requesting, retrieving, and manipulating information from diverse, distributed resources. The NVO will make it possible to seamlessly integrate data from the new all-sky surveys, enabling cross-correlations between multi-Terabyte catalogs and providing transparent access to the underlying image or spectral data. Success requires high performance computational systems, high bandwidth network services, agreed upon standards for the exchange of metadata, and collaboration among astronomers, astronomical data and information service providers, information technology specialists, funding agencies, and industry. International cooperation at the onset will help to assure that the NVO simultaneously becomes a global facility. .
Centrally managed unified shared virtual address space
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wilkes, John
Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontendmore » interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.« less
Procedural wound geometry and blood flow generation for medical training simulators
NASA Astrophysics Data System (ADS)
Aras, Rifat; Shen, Yuzhong; Li, Jiang
2012-02-01
Efficient application of wound treatment procedures is vital in both emergency room and battle zone scenes. In order to train first responders for such situations, physical casualty simulation kits, which are composed of tens of individual items, are commonly used. Similar to any other training scenarios, computer simulations can be effective means for wound treatment training purposes. For immersive and high fidelity virtual reality applications, realistic 3D models are key components. However, creation of such models is a labor intensive process. In this paper, we propose a procedural wound geometry generation technique that parameterizes key simulation inputs to establish the variability of the training scenarios without the need of labor intensive remodeling of the 3D geometry. The procedural techniques described in this work are entirely handled by the graphics processing unit (GPU) to enable interactive real-time operation of the simulation and to relieve the CPU for other computational tasks. The visible human dataset is processed and used as a volumetric texture for the internal visualization of the wound geometry. To further enhance the fidelity of the simulation, we also employ a surface flow model for blood visualization. This model is realized as a dynamic texture that is composed of a height field and a normal map and animated at each simulation step on the GPU. The procedural wound geometry and the blood flow model are applied to a thigh model and the efficiency of the technique is demonstrated in a virtual surgery scene.
Modeling and simulation of five-axis virtual machine based on NX
NASA Astrophysics Data System (ADS)
Li, Xiaoda; Zhan, Xianghui
2018-04-01
Virtual technology in the machinery manufacturing industry has shown the role of growing. In this paper, the Siemens NX software is used to model the virtual CNC machine tool, and the parameters of the virtual machine are defined according to the actual parameters of the machine tool so that the virtual simulation can be carried out without loss of the accuracy of the simulation. How to use the machine builder of the CAM module to define the kinematic chain and machine components of the machine is described. The simulation of virtual machine can provide alarm information of tool collision and over cutting during the process to users, and can evaluate and forecast the rationality of the technological process.
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…
Surface matching for correlation of virtual models: Theory and application
NASA Technical Reports Server (NTRS)
Caracciolo, Roberto; Fanton, Francesco; Gasparetto, Alessandro
1994-01-01
Virtual reality can enable a robot user to off line generate and test in a virtual environment a sequence of operations to be executed by the robot in an assembly cell. Virtual models of objects are to be correlated to the real entities they represent by means of a suitable transformation. A solution to the correlation problem, which is basically a problem of 3-dimensional adjusting, has been found exploiting the surface matching theory. An iterative algorithm has been developed, which matches the geometric surface representing the shape of the virtual model of an object, with a set of points measured on the surface in the real world. A peculiar feature of the algorithm is to work also if there is no one-to-one correspondence between the measured points and those representing the surface model. Furthermore the problem of avoiding convergence to local minima is solved, by defining a starting point of states ensuring convergence to the global minimum. The developed algorithm has been tested by simulation. Finally, this paper proposes a specific application, i.e., correlating a robot cell, equipped for biomedical use with its virtual representation.
A Stochastic Model of Plausibility in Live Virtual Constructive Environments
2017-09-14
objective in virtual environment research and design is the maintenance of adequate consistency levels in the face of limited system resources such as...provides some commentary with regard to system design considerations and future research directions. II. SYSTEM MODEL DVEs are often designed as a...exceed the system’s requirements. Research into predictive models of virtual environment consistency is needed to provide designers the tools to
4 CFR 83.7 - GAO policy and requirements.
Code of Federal Regulations, 2010 CFR
2010-01-01
... management objectives as required by statute, GAO internal directive, or formal agreements between GAO and... may develop in the future. Both Government-wide and internal agency personnel records shall contain... another party; (3) There is virtually no risk that information collected from other parties, if inaccurate...
28 CFR 105.10 - Definitions, purpose, and scope.
Code of Federal Regulations, 2010 CFR
2010-07-01
... foreign pilot or flight engineer license issued by a member of the Assembly of the International Civil Aviation Organization, as established by Article 43 of the Convention on International Civil Aviation..., and flight schools. Virtually all private providers of instruction in the operation of aircraft with a...
Flexible Virtual Structure Consideration in Dynamic Modeling of Mobile Robots Formation
NASA Astrophysics Data System (ADS)
El Kamel, A. Essghaier; Beji, L.; Lerbet, J.; Abichou, A.
2009-03-01
In cooperative mobile robotics, we look for formation keeping and maintenance of a geometric configuration during movement. As a solution to these problems, the concept of a virtual structure is considered. Based on this idea, we have developed an efficient flexible virtual structure, describing the dynamic model of n vehicles in formation and where the whole formation is kept dependant. Notes that, for 2D and 3D space navigation, only a rigid virtual structure was proposed in the literature. Further, the problem was limited to a kinematic behavior of the structure. Hence, the flexible virtual structure in dynamic modeling of mobile robots formation presented in this paper, gives more capabilities to the formation to avoid obstacles in hostile environment while keeping formation and avoiding inter-agent collision.
Effect of Virtual Analytical Chemistry Laboratory on Enhancing Student Research Skills and Practices
ERIC Educational Resources Information Center
Bortnik, Boris; Stozhko, Natalia; Pervukhina, Irina; Tchernysheva, Albina; Belysheva, Galina
2017-01-01
This article aims to determine the effect of a virtual chemistry laboratory on university student achievement. The article describes a model of a laboratory course that includes a virtual component. This virtual component is viewed as a tool of student pre-lab autonomous learning. It presents electronic resources designed for a virtual laboratory…
Virtual experiments: a new approach for improving process conceptualization in hillslope hydrology
NASA Astrophysics Data System (ADS)
Weiler, Markus; McDonnell, Jeff
2004-01-01
We present an approach for process conceptualization in hillslope hydrology. We develop and implement a series of virtual experiments, whereby the interaction between water flow pathways, source and mixing at the hillslope scale is examined within a virtual experiment framework. We define these virtual experiments as 'numerical experiments with a model driven by collective field intelligence'. The virtual experiments explore the first-order controls in hillslope hydrology, where the experimentalist and modeler work together to cooperatively develop and analyze the results. Our hillslope model for the virtual experiments (HillVi) in this paper is based on conceptualizing the water balance within the saturated and unsaturated zone in relation to soil physical properties in a spatially explicit manner at the hillslope scale. We argue that a virtual experiment model needs to be able to capture all major controls on subsurface flow processes that the experimentalist might deem important, while at the same time being simple with few 'tunable parameters'. This combination makes the approach, and the dialog between experimentalist and modeler, a useful hypothesis testing tool. HillVi simulates mass flux for different initial conditions under the same flow conditions. We analyze our results in terms of an artificial line source and isotopic hydrograph separation of water and subsurface flow. Our results for this first set of virtual experiments showed how drainable porosity and soil depth variability exert a first order control on flow and transport at the hillslope scale. We found that high drainable porosity soils resulted in a restricted water table rise, resulting in more pronounced channeling of lateral subsurface flow along the soil-bedrock interface. This in turn resulted in a more anastomosing network of tracer movement across the slope. The virtual isotope hydrograph separation showed higher proportions of event water with increasing drainable porosity. When combined with previous experimental findings and conceptualizations, virtual experiments can be an effective way to isolate certain controls and examine their influence over a range of rainfall and antecedent wetness conditions.
Building Virtuality into University-Based Human Resources Policy in China's Universities
ERIC Educational Resources Information Center
Guoliang, Zhang
2005-01-01
On the basis of discussing the notion of virtual human resources and its structure, this paper analyzes the necessity of building up virtual university teaching staff and proposes a model for the structural makeup of virtual university teaching staff.
Coarse-Grained Model for Water Involving a Virtual Site.
Deng, Mingsen; Shen, Hujun
2016-02-04
In this work, we propose a new coarse-grained (CG) model for water by combining the features of two popular CG water models (BMW and MARTINI models) as well as by adopting a topology similar to that of the TIP4P water model. In this CG model, a CG unit, representing four real water molecules, consists of a virtual site, two positively charged particles, and a van der Waals (vdW) interaction center. Distance constraint is applied to the bonds formed between the vdW interaction center and the positively charged particles. The virtual site, which carries a negative charge, is determined by the locations of the two positively charged particles and the vdW interaction center. For the new CG model of water, we coined the name "CAVS" (charge is attached to a virtual site) due to the involvment of the virtual site. After being tested in molecular dynamic (MD) simulations of bulk water at various time steps, under different temperatures and in different salt (NaCl) concentrations, the CAVS model offers encouraging predictions for some bulk properties of water (such as density, dielectric constant, etc.) when compared to experimental ones.
van Dongen, Koen W; Ahlberg, Gunnar; Bonavina, Luigi; Carter, Fiona J; Grantcharov, Teodor P; Hyltander, Anders; Schijven, Marlies P; Stefani, Alessandro; van der Zee, David C; Broeders, Ivo A M J
2011-01-01
Virtual reality (VR) simulators have been demonstrated to improve basic psychomotor skills in endoscopic surgery. The exercise configuration settings used for validation in studies published so far are default settings or are based on the personal choice of the tutors. The purpose of this study was to establish consensus on exercise configurations and on a validated training program for a virtual reality simulator, based on the experience of international experts to set criterion levels to construct a proficiency-based training program. A consensus meeting was held with eight European teams, all extensively experienced in using the VR simulator. Construct validity of the training program was tested by 20 experts and 60 novices. The data were analyzed by using the t test for equality of means. Consensus was achieved on training designs, exercise configuration, and examination. Almost all exercises (7/8) showed construct validity. In total, 50 of 94 parameters (53%) showed significant difference. A European, multicenter, validated, training program was constructed according to the general consensus of a large international team with extended experience in virtual reality simulation. Therefore, a proficiency-based training program can be offered to training centers that use this simulator for training in basic psychomotor skills in endoscopic surgery.
USEQ: A Short Questionnaire for Satisfaction Evaluation of Virtual Rehabilitation Systems.
Gil-Gómez, José-Antonio; Manzano-Hernández, Pilar; Albiol-Pérez, Sergio; Aula-Valero, Carmen; Gil-Gómez, Hermenegildo; Lozano-Quilis, José-Antonio
2017-07-07
New emerging technologies have proven their efficacy in aiding people in their rehabilitation. The tests that are usually used to evaluate usability (in general) or user satisfaction (in particular) of this technology are not specifically focused on virtual rehabilitation and patients. The objective of this contribution is to present and evaluate the USEQ (User Satisfaction Evaluation Questionnaire). The USEQ is a questionnaire that is designed to properly evaluate the satisfaction of the user (which constitutes part of usability) in virtual rehabilitation systems. Forty patients with balance disorders completed the USEQ after their first session with ABAR (Active Balance Rehabilitation), which is a virtual rehabilitation system that is designed for the rehabilitation of balance disorders. Internal consistency analysis and exploratory factor analysis were carried out to identify the factor structure of the USEQ. The six items of USEQ were significantly associated with each other, and the Cronbach alpha coefficient for the questionnaire was 0.716. In an analysis of the principal components, a one-factor solution was considered to be appropriate. The findings of the study suggest that the USEQ is a reliable questionnaire with adequate internal consistency. With regard to patient perception, the patients found the USEQ to be an easy-to-understand questionnaire with a convenient number of questions.
Procter, Paula M; Brixey, Juliana J; Honey, Michelle L L; Todhunter, Fern
2016-01-01
The authors have all engaged in using social media with students as a means for collaboration across national and international boundaries for various educational purposes. Following the explosion of big data in health the authors are now moving this concept forward within undergraduate and postgraduate nursing curricula for the development of population health virtual exchanges. Nursing has a global presence and yet it appears as though students have little knowledge of the health and social care needs and provision outside their local environment. This development will allow for explorative exchange amongst students in three countries, enhancing their understanding of their own and the selected international population health needs and solutions through asking and responding to questions amongst the learning community involved. The connection of the students will be recorded for their use in reflection; of particular interest will be the use of information included by the students to answer questions about their locality.
Kononowicz, Andrzej A; Narracott, Andrew J; Manini, Simone; Bayley, Martin J; Lawford, Patricia V; McCormack, Keith; Zary, Nabil
2014-01-23
Virtual patients are increasingly common tools used in health care education to foster learning of clinical reasoning skills. One potential way to expand their functionality is to augment virtual patients' interactivity by enriching them with computational models of physiological and pathological processes. The primary goal of this paper was to propose a conceptual framework for the integration of computational models within virtual patients, with particular focus on (1) characteristics to be addressed while preparing the integration, (2) the extent of the integration, (3) strategies to achieve integration, and (4) methods for evaluating the feasibility of integration. An additional goal was to pilot the first investigation of changing framework variables on altering perceptions of integration. The framework was constructed using an iterative process informed by Soft System Methodology. The Virtual Physiological Human (VPH) initiative has been used as a source of new computational models. The technical challenges associated with development of virtual patients enhanced by computational models are discussed from the perspectives of a number of different stakeholders. Concrete design and evaluation steps are discussed in the context of an exemplar virtual patient employing the results of the VPH ARCH project, as well as improvements for future iterations. The proposed framework consists of four main elements. The first element is a list of feasibility features characterizing the integration process from three perspectives: the computational modelling researcher, the health care educationalist, and the virtual patient system developer. The second element included three integration levels: basic, where a single set of simulation outcomes is generated for specific nodes in the activity graph; intermediate, involving pre-generation of simulation datasets over a range of input parameters; advanced, including dynamic solution of the model. The third element is the description of four integration strategies, and the last element consisted of evaluation profiles specifying the relevant feasibility features and acceptance thresholds for specific purposes. The group of experts who evaluated the virtual patient exemplar found higher integration more interesting, but at the same time they were more concerned with the validity of the result. The observed differences were not statistically significant. This paper outlines a framework for the integration of computational models into virtual patients. The opportunities and challenges of model exploitation are discussed from a number of user perspectives, considering different levels of model integration. The long-term aim for future research is to isolate the most crucial factors in the framework and to determine their influence on the integration outcome.
Narracott, Andrew J; Manini, Simone; Bayley, Martin J; Lawford, Patricia V; McCormack, Keith; Zary, Nabil
2014-01-01
Background Virtual patients are increasingly common tools used in health care education to foster learning of clinical reasoning skills. One potential way to expand their functionality is to augment virtual patients’ interactivity by enriching them with computational models of physiological and pathological processes. Objective The primary goal of this paper was to propose a conceptual framework for the integration of computational models within virtual patients, with particular focus on (1) characteristics to be addressed while preparing the integration, (2) the extent of the integration, (3) strategies to achieve integration, and (4) methods for evaluating the feasibility of integration. An additional goal was to pilot the first investigation of changing framework variables on altering perceptions of integration. Methods The framework was constructed using an iterative process informed by Soft System Methodology. The Virtual Physiological Human (VPH) initiative has been used as a source of new computational models. The technical challenges associated with development of virtual patients enhanced by computational models are discussed from the perspectives of a number of different stakeholders. Concrete design and evaluation steps are discussed in the context of an exemplar virtual patient employing the results of the VPH ARCH project, as well as improvements for future iterations. Results The proposed framework consists of four main elements. The first element is a list of feasibility features characterizing the integration process from three perspectives: the computational modelling researcher, the health care educationalist, and the virtual patient system developer. The second element included three integration levels: basic, where a single set of simulation outcomes is generated for specific nodes in the activity graph; intermediate, involving pre-generation of simulation datasets over a range of input parameters; advanced, including dynamic solution of the model. The third element is the description of four integration strategies, and the last element consisted of evaluation profiles specifying the relevant feasibility features and acceptance thresholds for specific purposes. The group of experts who evaluated the virtual patient exemplar found higher integration more interesting, but at the same time they were more concerned with the validity of the result. The observed differences were not statistically significant. Conclusions This paper outlines a framework for the integration of computational models into virtual patients. The opportunities and challenges of model exploitation are discussed from a number of user perspectives, considering different levels of model integration. The long-term aim for future research is to isolate the most crucial factors in the framework and to determine their influence on the integration outcome. PMID:24463466
VirtualPlant: A Software Platform to Support Systems Biology Research1[W][OA
Katari, Manpreet S.; Nowicki, Steve D.; Aceituno, Felipe F.; Nero, Damion; Kelfer, Jonathan; Thompson, Lee Parnell; Cabello, Juan M.; Davidson, Rebecca S.; Goldberg, Arthur P.; Shasha, Dennis E.; Coruzzi, Gloria M.; Gutiérrez, Rodrigo A.
2010-01-01
Data generation is no longer the limiting factor in advancing biological research. In addition, data integration, analysis, and interpretation have become key bottlenecks and challenges that biologists conducting genomic research face daily. To enable biologists to derive testable hypotheses from the increasing amount of genomic data, we have developed the VirtualPlant software platform. VirtualPlant enables scientists to visualize, integrate, and analyze genomic data from a systems biology perspective. VirtualPlant integrates genome-wide data concerning the known and predicted relationships among genes, proteins, and molecules, as well as genome-scale experimental measurements. VirtualPlant also provides visualization techniques that render multivariate information in visual formats that facilitate the extraction of biological concepts. Importantly, VirtualPlant helps biologists who are not trained in computer science to mine lists of genes, microarray experiments, and gene networks to address questions in plant biology, such as: What are the molecular mechanisms by which internal or external perturbations affect processes controlling growth and development? We illustrate the use of VirtualPlant with three case studies, ranging from querying a gene of interest to the identification of gene networks and regulatory hubs that control seed development. Whereas the VirtualPlant software was developed to mine Arabidopsis (Arabidopsis thaliana) genomic data, its data structures, algorithms, and visualization tools are designed in a species-independent way. VirtualPlant is freely available at www.virtualplant.org. PMID:20007449
Wang, Y Y; Zhang, H Q; Fan, S; Zhang, D M; Huang, Z Q; Chen, W L; Ye, J T; Li, J S
2016-11-01
This study evaluated the accuracy of mandibular reconstruction and assessed clinical outcomes in both virtual planning and conventional surgery patients. ProPlan CMF surgical planning software was used preoperatively in the virtual planning group. In the virtual planning group, fibula flaps were harvested and osteotomized, and the mandibles were resected and reconstructed assisted by the prefabricated cutting guides and templates. The main outcome measures included the operative time, postoperative computed tomography (CT) scans, facial appearance, and occlusal function. The ischemia time and total operation time were shorter in the virtual planning group than in the conventional surgery group. High precision with the use of the cutting guides and templates was found for both the fibula and mandible, and a good fit was noted among the pre-bent plate, mandible, and fibula segments in the virtual planning group. Postoperative CT scans also showed excellent mandibular contours of the fibula flaps in accordance with virtual plans in the virtual planning group. This study demonstrated that virtual surgical planning was able to achieve more accurate mandibular reconstruction than conventional surgery. The use of prefabricated cutting guides and plates makes fibula flap moulding and placement easier, minimizes the operating time, and improves clinical outcomes. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Virtual microphone sensing through vibro-acoustic modelling and Kalman filtering
NASA Astrophysics Data System (ADS)
van de Walle, A.; Naets, F.; Desmet, W.
2018-05-01
This work proposes a virtual microphone methodology which enables full field acoustic measurements for vibro-acoustic systems. The methodology employs a Kalman filtering framework in order to combine a reduced high-fidelity vibro-acoustic model with a structural excitation measurement and small set of real microphone measurements on the system under investigation. By employing model order reduction techniques, a high order finite element model can be converted in a much smaller model which preserves the desired accuracy and maintains the main physical properties of the original model. Due to the low order of the reduced-order model, it can be effectively employed in a Kalman filter. The proposed methodology is validated experimentally on a strongly coupled vibro-acoustic system. The virtual sensor vastly improves the accuracy with respect to regular forward simulation. The virtual sensor also allows to recreate the full sound field of the system, which is very difficult/impossible to do through classical measurements.
An efficient and scalable deformable model for virtual reality-based medical applications.
Choi, Kup-Sze; Sun, Hanqiu; Heng, Pheng-Ann
2004-09-01
Modeling of tissue deformation is of great importance to virtual reality (VR)-based medical simulations. Considerable effort has been dedicated to the development of interactively deformable virtual tissues. In this paper, an efficient and scalable deformable model is presented for virtual-reality-based medical applications. It considers deformation as a localized force transmittal process which is governed by algorithms based on breadth-first search (BFS). The computational speed is scalable to facilitate real-time interaction by adjusting the penetration depth. Simulated annealing (SA) algorithms are developed to optimize the model parameters by using the reference data generated with the linear static finite element method (FEM). The mechanical behavior and timing performance of the model have been evaluated. The model has been applied to simulate the typical behavior of living tissues and anisotropic materials. Integration with a haptic device has also been achieved on a generic personal computer (PC) platform. The proposed technique provides a feasible solution for VR-based medical simulations and has the potential for multi-user collaborative work in virtual environment.
NASA Astrophysics Data System (ADS)
Michaelis, A.; Nemani, R. R.; Wang, W.; Votava, P.; Hashimoto, H.
2010-12-01
Given the increasing complexity of climate modeling and analysis tools, it is often difficult and expensive to build or recreate an exact replica of the software compute environment used in past experiments. With the recent development of new technologies for hardware virtualization, an opportunity exists to create full modeling, analysis and compute environments that are “archiveable”, transferable and may be easily shared amongst a scientific community or presented to a bureaucratic body if the need arises. By encapsulating and entire modeling and analysis environment in a virtual machine image, others may quickly gain access to the fully built system used in past experiments, potentially easing the task and reducing the costs of reproducing and verify past results produced by other researchers. Moreover, these virtual machine images may be used as a pedagogical tool for others that are interested in performing an academic exercise but don't yet possess the broad expertise required. We built two virtual machine images, one with the Community Earth System Model (CESM) and one with Weather Research Forecast Model (WRF), then ran several small experiments to assess the feasibility, performance overheads costs, reusability, and transferability. We present a list of the pros and cons as well as lessoned learned from utilizing virtualization technology in the climate and earth systems modeling domain.
Visualized modeling platform for virtual plant growth and monitoring on the internet
NASA Astrophysics Data System (ADS)
Zhou, De-fu; Tian, Feng-qui; Ren, Ping
2009-07-01
Virtual plant growth is a key research topic in Agriculture Information Technique and Computer Graphics. It has been applied in botany, agronomy, environmental sciences, computre sciences and applied mathematics. Modeling leaf color dynamics in plant is of significant importance for realizing virtual plant growth. Using systematic analysis method and dynamic modeling technology, a SPAD-based leaf color dynamic model was developed to simulate time-course change characters of leaf SPAD on the plant. In addition, process of plant growth can be computer-stimulated using Virtual Reality Modeling Language (VRML) to establish a vivid and visible model, including shooting, rooting, blooming, as well as growth of the stems and leaves. In the resistance environment, e.g., lacking of water, air or nutrient substances, high salt or alkaline, freezing injury, high temperature, suffering from diseases and insect pests, the changes from the level of whole plant to organs, tissues and cells could be computer-stimulated. Changes from physiological and biochemistry could also be described. When a series of indexes were input by the costumers, direct view and microcosmic changes could be shown. Thus, the model has a good performance in predicting growth condition of the plant, laying a foundation for further constructing virtual plant growth system. The results revealed that realistic physiological and pathological processes of 3D virtual plants could be demonstrated by proper design and effectively realized in the internet.
Schmid, W.; Hanson, R.T.
2007-01-01
Water-rights driven surface-water allocations for irrigated agriculture can be simulated using the farm process for MODFLOW-2000. This paper describes and develops a model, which simulates routed surface-water deliveries to farms limited by streamflow, equal-appropriation allotments, or a ranked prior-appropriation system. Simulated diversions account for deliveries to all farms along a canal according to their water-rights ranking and for conveyance losses and gains. Simulated minimum streamflow requirements on diversions help guarantee supplies to senior farms located on downstream diverting canals. Prior appropriation can be applied to individual farms or to groups of farms modeled as "virtual farms" representing irrigation districts, irrigated regions in transboundary settings, or natural vegetation habitats. The integrated approach of jointly simulating canal diversions, surface-water deliveries subject to water-rights constraints, and groundwater allocations is verified on numerical experiments based on a realistic, but hypothetical, system of ranked virtual farms. Results are discussed in light of transboundary water appropriation and demonstrate the approach's suitability for simulating effects of water-rights hierarchies represented by international treaties, interstate stream compacts, intrastate water rights, or ecological requirements. ?? 2007 ASCE.
Research and Teaching About the Deep Earth
NASA Astrophysics Data System (ADS)
Williams, Michael L.; Mogk, David W.; McDaris, John
2010-08-01
Understanding the Deep Earth: Slabs, Drips, Plumes and More; Virtual Workshop, 17-19 February and 24-26 February 2010; Images and models of active faults, subducting plates, mantle drips, and rising plumes are spurring new excitement about deep-Earth processes and connections between Earth's internal systems and plate tectonics. The new results and the steady progress of Earthscope's USArray across the country are also providing a special opportunity to reach students and the general public. The pace of discoveries about the deep Earth is accelerating due to advances in experimental, modeling, and sensing technologies; new data processing capabilities; and installation of new networks, especially the EarthScope facility. EarthScope is an interdisciplinary program that combines geology and geophysics to study the structure and evolution of the North American continent. To explore the current state of deep-Earth science and ways in which it can be brought into the undergraduate classroom, 40 professors attended a virtual workshop given by On the Cutting Edge, a program that strives to improve undergraduate geoscience education through an integrated cooperative series of workshops and Web-based resources. The 6-day two-part workshop consisted of plenary talks, large and small group discussions, and development and review of new classroom and laboratory activities.
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.
Waterlander, Wilma E; Blakely, Tony; Nghiem, Nhung; Cleghorn, Christine L; Eyles, Helen; Genc, Murat; Wilson, Nick; Jiang, Yannan; Swinburn, Boyd; Jacobi, Liana; Michie, Jo; Ni Mhurchu, Cliona
2016-07-19
There is a need for accurate and precise food price elasticities (PE, change in consumer demand in response to change in price) to better inform policy on health-related food taxes and subsidies. The Price Experiment and Modelling (Price ExaM) study aims to: I) derive accurate and precise food PE values; II) quantify the impact of price changes on quantity and quality of discrete food group purchases and; III) model the potential health and disease impacts of a range of food taxes and subsidies. To achieve this, we will use a novel method that includes a randomised Virtual Supermarket experiment and econometric methods. Findings will be applied in simulation models to estimate population health impact (quality-adjusted life-years [QALYs]) using a multi-state life-table model. The study will consist of four sequential steps: 1. We generate 5000 price sets with random price variation for all 1412 Virtual Supermarket food and beverage products. Then we add systematic price variation for foods to simulate five taxes and subsidies: a fruit and vegetable subsidy and taxes on sugar, saturated fat, salt, and sugar-sweetened beverages. 2. Using an experimental design, 1000 adult New Zealand shoppers complete five household grocery shops in the Virtual Supermarket where they are randomly assigned to one of the 5000 price sets each time. 3. Output data (i.e., multiple observations of price configurations and purchased amounts) are used as inputs to econometric models (using Bayesian methods) to estimate accurate PE values. 4. A disease simulation model will be run with the new PE values as inputs to estimate QALYs gained and health costs saved for the five policy interventions. The Price ExaM study has the potential to enhance public health and economic disciplines by introducing internationally novel scientific methods to estimate accurate and precise food PE values. These values will be used to model the potential health and disease impacts of various food pricing policy options. Findings will inform policy on health-related food taxes and subsidies. Australian New Zealand Clinical Trials Registry ACTRN12616000122459 (registered 3 February 2016).
Culbertson, Heather; Kuchenbecker, Katherine J
2017-01-01
Interacting with physical objects through a tool elicits tactile and kinesthetic sensations that comprise your haptic impression of the object. These cues, however, are largely missing from interactions with virtual objects, yielding an unrealistic user experience. This article evaluates the realism of virtual surfaces rendered using haptic models constructed from data recorded during interactions with real surfaces. The models include three components: surface friction, tapping transients, and texture vibrations. We render the virtual surfaces on a SensAble Phantom Omni haptic interface augmented with a Tactile Labs Haptuator for vibration output. We conducted a human-subject study to assess the realism of these virtual surfaces and the importance of the three model components. Following a perceptual discrepancy paradigm, subjects compared each of 15 real surfaces to a full rendering of the same surface plus versions missing each model component. The realism improvement achieved by including friction, tapping, or texture in the rendering was found to directly relate to the intensity of the surface's property in that domain (slipperiness, hardness, or roughness). A subsequent analysis of forces and vibrations measured during interactions with virtual surfaces indicated that the Omni's inherent mechanical properties corrupted the user's haptic experience, decreasing realism of the virtual surface.
NASA's Solar System Exploration Research Virtual Institute: Combining Science and Exploration
NASA Astrophysics Data System (ADS)
Bailey, B.; Schmidt, G.; Daou, D.; Pendleton, Y.
2015-10-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science andexploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. This talk will describe the research efforts of the nine domestic teams that constitute the U.S. complement of the Institute and how we will engage the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships.
STS-134 crew in Virtual Reality Lab during their MSS/EVAA SUPT2 Team training
2010-08-27
JSC2010-E-121058 (27 Aug. 2010) --- NASA astronauts Michael Fincke (foreground) and Greg Chamitoff, both STS-134 mission specialists, use virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of their duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
STS-134 crew in Virtual Reality Lab during their MSS/EVAA SUPT2 Team training
2010-08-27
JSC2010-E-121052 (27 Aug. 2010) --- NASA astronauts Michael Fincke (foreground) and Greg Chamitoff, both STS-134 mission specialists, use virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of their duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
STS-134 crew in Virtual Reality Lab during their MSS/EVAA SUPT2 Team training
2010-08-27
JSC2010-E-121055 (27 Aug. 2010) --- NASA astronauts Michael Fincke (right) and Greg Chamitoff, both STS-134 mission specialists, use virtual reality hardware in the Space Vehicle Mock-up Facility at NASA's Johnson Space Center to rehearse some of their duties on the upcoming mission to the International Space Station. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the station hardware with which they will be working. Photo credit: NASA or National Aeronautics and Space Administration
Estimation of the state of solar activity type stars by virtual observations of CrAVO
NASA Astrophysics Data System (ADS)
Dolgov, A. A.; Shlyapnikov, A. A.
2012-05-01
The results of precosseing of negatives with direct images of the sky from CrAO glass library are presented in this work, which became a part of on-line archive of the Crimean Astronomical Virtual Observatory (CrAVO). Based on the obtained data, the parameters of dwarf stars have been estimated, included in the catalog "Stars with solar-type activity" (GTSh10). The following matters are considered: searching methodology of negatives with positions of studied stars and with calculated limited magnitude; image viewing and reduction with the facilities of the International Virtual Observatory; the preliminary results of the photometry of studied objects.
UkrVO astronomical WEB services
NASA Astrophysics Data System (ADS)
Mazhaev, A.
2017-02-01
Ukraine Virtual Observatory (UkrVO) has been a member of the International Virtual Observatory Alliance (IVOA) since 2011. The virtual observatory (VO) is not a magic solution to all problems of data storing and processing, but it provides certain standards for building infrastructure of astronomical data center. The astronomical databases help data mining and offer to users an easy access to observation metadata, images within celestial sphere and results of image processing. The astronomical web services (AWS) of UkrVO give to users handy tools for data selection from large astronomical catalogues for a relatively small region of interest in the sky. Examples of the AWS usage are showed.
ICCE/ICCAI 2000 Full & Short Papers (Interactive Learning Environments).
ERIC Educational Resources Information Center
2000
This document contains the full and short papers on interactive learning environments from ICCE/ICCAI 2000 (International Conference on Computers in Education/International Conference on Computer-Assisted Instruction) covering the following topics: a CAL system for appreciation of 3D shapes by surface development; a constructivist virtual physics…
A Place We Call "Home"--International Students in Virtual Context
ERIC Educational Resources Information Center
Zhu, Zheng
2012-01-01
This paper examines how Chinese international students from a public land-grant university used online community to construct their cultural and ethnic identities. The author delves into the question of how online community enables these students to gain successful cultural assimilation. Extending on Baym's (2000) theoretical framework of online…
Turbulence and Dilemma: Implications of Diversity and Multilingualism in Australian Education
ERIC Educational Resources Information Center
Heugh, Kathleen
2014-01-01
An international interest in multilingualism and multilingual education has burgeoned since the turn of the twenty-first century, accompanying apparently significant changes in the physical and virtual mobilities of people, international frameworks, and commitments and goals for socially just education. It has also accompanied major political…
Malerba, Martino E; Heimann, Kirsten; Connolly, Sean R
2016-09-07
Ecologists have often used indirect proxies to represent variables that are difficult or impossible to measure directly. In phytoplankton, the internal concentration of the most limiting nutrient in a cell determines its growth rate. However, directly measuring the concentration of nutrients within cells is inaccurate, expensive, destructive, and time-consuming, substantially impairing our ability to model growth rates in nutrient-limited phytoplankton populations. The red chlorophyll autofluorescence (hereafter "red fluorescence") signal emitted by a cell is highly correlated with nitrogen quota in nitrogen-limited phytoplankton species. The aim of this study was to evaluate the reliability of including flow cytometric red fluorescence as a proxy for internal nitrogen status to model phytoplankton growth rates. To this end, we used the classic Quota model and designed three approaches to calibrate its model parameters to data: where empirical observations on cell internal nitrogen quota were used to fit the model ("Nitrogen-Quota approach"), where quota dynamics were inferred only from changes in medium nutrient depletion and population density ("Virtual-Quota approach"), or where red fluorescence emission of a cell was used as an indirect proxy for its internal nitrogen quota ("Fluorescence-Quota approach"). Two separate analyses were carried out. In the first analysis, stochastic model simulations were parameterized from published empirical relationships and used to generate dynamics of phytoplankton communities reared under nitrogen-limited conditions. Quota models were fitted to the dynamics of each simulated species with the three different approaches and the performance of each model was compared. In the second analysis, we fit Quota models to laboratory time-series and we calculate the ability of each calibration approach to describe the observed trajectories of internal nitrogen quota in the culture. Results from both analyses concluded that the Fluorescence-Quota approach including per-cell red fluorescence as a proxy of internal nitrogen substantially improved the ability of Quota models to describe phytoplankton dynamics, while still accounting for the biologically important process of cell nitrogen storage. More broadly, many population models in ecology implicitly recognize the importance of accounting for storage mechanisms to describe the dynamics of individual organisms. Hence, the approach documented here with phytoplankton dynamics may also be useful for evaluating the potential of indirect proxies in other ecological systems. Copyright © 2016 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Jacobson, Michael J.; Taylor, Charlotte E.; Richards, Deborah
2016-01-01
In this paper, we propose computational scientific inquiry (CSI) as an innovative model for learning important scientific knowledge and new practices for "doing" science. This approach involves the use of a "game-like" virtual world for students to experience virtual biological fieldwork in conjunction with using an agent-based…
Virtual Application of Darul Arif Palace from Serdang Sultanate using Virtual Reality
NASA Astrophysics Data System (ADS)
Syahputra, M. F.; Annisa, T.; Rahmat, R. F.; Muchtar, M. A.
2017-01-01
Serdang Sultanate is one of Malay Sultanate in Sumatera Utara. In the 18th century, many Malay Aristocrats have developed in Sumatera Utara. Social revolution has happened in 1946, many sultanates were overthrown and member of PKI (Communist Party of Indonesia) did mass killing on members of the sultanate families. As the results of this incident, many cultural and historical heritage destroyed. The integration of heritage preservation and the digital technology has become recent trend. The digital technology is not only able to record, preserve detailed documents and information of heritage completely, but also effectively bring the value-added. In this research, polygonal modelling techniques from 3D modelling technology is used to reconstruct Darul Arif Palace of Serdang Sultanate. After modelling the palace, it will be combined with virtual reality technology to allow user to explore the palace and the environment around the palace. Virtual technology is simulation of real objects in virtual world. The results in this research is that virtual reality application can run using Head-Mounted Display.
Accessing Multi-Dimensional Images and Data Cubes in the Virtual Observatory
NASA Astrophysics Data System (ADS)
Tody, Douglas; Plante, R. L.; Berriman, G. B.; Cresitello-Dittmar, M.; Good, J.; Graham, M.; Greene, G.; Hanisch, R. J.; Jenness, T.; Lazio, J.; Norris, P.; Pevunova, O.; Rots, A. H.
2014-01-01
Telescopes across the spectrum are routinely producing multi-dimensional images and datasets, such as Doppler velocity cubes, polarization datasets, and time-resolved “movies.” Examples of current telescopes producing such multi-dimensional images include the JVLA, ALMA, and the IFU instruments on large optical and near-infrared wavelength telescopes. In the near future, both the LSST and JWST will also produce such multi-dimensional images routinely. High-energy instruments such as Chandra produce event datasets that are also a form of multi-dimensional data, in effect being a very sparse multi-dimensional image. Ensuring that the data sets produced by these telescopes can be both discovered and accessed by the community is essential and is part of the mission of the Virtual Observatory (VO). The Virtual Astronomical Observatory (VAO, http://www.usvao.org/), in conjunction with its international partners in the International Virtual Observatory Alliance (IVOA), has developed a protocol and an initial demonstration service designed for the publication, discovery, and access of arbitrarily large multi-dimensional images. The protocol describing multi-dimensional images is the Simple Image Access Protocol, version 2, which provides the minimal set of metadata required to characterize a multi-dimensional image for its discovery and access. A companion Image Data Model formally defines the semantics and structure of multi-dimensional images independently of how they are serialized, while providing capabilities such as support for sparse data that are essential to deal effectively with large cubes. A prototype data access service has been deployed and tested, using a suite of multi-dimensional images from a variety of telescopes. The prototype has demonstrated the capability to discover and remotely access multi-dimensional data via standard VO protocols. The prototype informs the specification of a protocol that will be submitted to the IVOA for approval, with an operational data cube service to be delivered in mid-2014. An associated user-installable VO data service framework will provide the capabilities required to publish VO-compatible multi-dimensional images or data cubes.
Virtual Learning Effectiveness: An Examination of the Process
ERIC Educational Resources Information Center
Stonebraker, Peter W.; Hazeltine, James E.
2004-01-01
This study defines, examines, and measures the effectiveness of a corporate virtual learning program. Initially, distinctions between traditional and virtual learning and university and corporate programs are defined. Then, based on the literature, an integrative model of the perceived effectiveness of a virtual learning environment is developed…
Application of 3d Model of Cultural Relics in Virtual Restoration
NASA Astrophysics Data System (ADS)
Zhao, S.; Hou, M.; Hu, Y.; Zhao, Q.
2018-04-01
In the traditional cultural relics splicing process, in order to identify the correct spatial location of the cultural relics debris, experts need to manually splice the existing debris. The repeated contact between debris can easily cause secondary damage to the cultural relics. In this paper, the application process of 3D model of cultural relic in virtual restoration is put forward, and the relevant processes and ideas are verified with the example of Terracotta Warriors data. Through the combination of traditional cultural relics restoration methods and computer virtual reality technology, virtual restoration of high-precision 3D models of cultural relics can provide a scientific reference for virtual restoration, avoiding the secondary damage to the cultural relics caused by improper restoration. The efficiency and safety of the preservation and restoration of cultural relics have been improved.
Mishra, Pooja; Kesar, Seema; Paliwal, Sarvesh K; Chauhan, Monika; Madan, Kirtika
2018-05-29
Glycogen synthase kinase-3β plays a significant role in the regulation of various pathological pathways relating to central nervous system (CNS). Dysregulation of Glycogen synthase kinase 3 (GSK-3) activity gives a rise to numerous neuroinflammation and neurodegenerative related disorders that affect the whole central nervous system. By the sequential application of in-silico tools, efforts have been attempted to design the novel GSK-3β inhibitors. Owing to the potential role of GSK-3β in nervous disorders, we have attempted to develop the quantitative four featured pharmacophore model comprising two hydrogen bond acceptors (HBA), one ring aromatic (RA), and one hydrophobe (HY), which were further affirmed by cost-function analysis, rm2 matrices, internal and external test set validation and Güner-Henry (GH) scoring analysis. Validated pharmacophoric model was used for virtual screening and out of 345 compounds, two potential virtual hits were finalized that were on the basis of fit value, estimated activity and Lipinski's violation. The chosen compounds were subjected to dock within the active site of GSK-3β Result: Four essential features, i.e., two hydrogen bond acceptors(HBA), one ring aromatic(RA), and one hydrophobe(HY), were subjected to build the pharmacophoric model and showed good correlation coefficient, RMSD and cost difference values of 0.91, 0.94 and 42.9 respectively and further model was validated employing cost-function analysis, rm2-matrices, internal and external test set prediction with r2 value of 0.77 and 0.84. Docked conformations showed potential interactions in between the features of the identified hits (NCI 4296, NCI 3034) and the amino acids present in the active site. In line with the overhead discussion, and through our stepwise computational approaches, we have identified novel, structurally diverse glycogen synthase kinase inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Roland, Michelle; Hull, M L; Howell, S M
2011-05-01
In a previous paper, we reported the virtual axis finder, which is a new method for finding the rotational axes of the knee. The virtual axis finder was validated through simulations that were subject to limitations. Hence, the objective of the present study was to perform a mechanical validation with two measurement modalities: 3D video-based motion analysis and marker-based roentgen stereophotogrammetric analysis (RSA). A two rotational axis mechanism was developed, which simulated internal-external (or longitudinal) and flexion-extension (FE) rotations. The actual axes of rotation were known with respect to motion analysis and RSA markers within ± 0.0006 deg and ± 0.036 mm and ± 0.0001 deg and ± 0.016 mm, respectively. The orientation and position root mean squared errors for identifying the longitudinal rotation (LR) and FE axes with video-based motion analysis (0.26 deg, 0.28 m, 0.36 deg, and 0.25 mm, respectively) were smaller than with RSA (1.04 deg, 0.84 mm, 0.82 deg, and 0.32 mm, respectively). The random error or precision in the orientation and position was significantly better (p=0.01 and p=0.02, respectively) in identifying the LR axis with video-based motion analysis (0.23 deg and 0.24 mm) than with RSA (0.95 deg and 0.76 mm). There was no significant difference in the bias errors between measurement modalities. In comparing the mechanical validations to virtual validations, the virtual validations produced comparable errors to those of the mechanical validation. The only significant difference between the errors of the mechanical and virtual validations was the precision in the position of the LR axis while simulating video-based motion analysis (0.24 mm and 0.78 mm, p=0.019). These results indicate that video-based motion analysis with the equipment used in this study is the superior measurement modality for use with the virtual axis finder but both measurement modalities produce satisfactory results. The lack of significant differences between validation techniques suggests that the virtual sensitivity analysis previously performed was appropriately modeled. Thus, the virtual axis finder can be applied with a thorough understanding of its errors in a variety of test conditions.
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.
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
Samosky, Joseph T; Allen, Pete; Boronyak, Steve; Branstetter, Barton; Hein, Steven; Juhas, Mark; Nelson, Douglas A; Orebaugh, Steven; Pinto, Rohan; Smelko, Adam; Thompson, Mitch; Weaver, Robert A
2011-01-01
We are developing a simulator of peripheral nerve block utilizing a mixed-reality approach: the combination of a physical model, an MRI-derived virtual model, mechatronics and spatial tracking. Our design uses tangible (physical) interfaces to simulate surface anatomy, haptic feedback during needle insertion, mechatronic display of muscle twitch corresponding to the specific nerve stimulated, and visual and haptic feedback for the injection syringe. The twitch response is calculated incorporating the sensed output of a real neurostimulator. The virtual model is isomorphic with the physical model and is derived from segmented MRI data. This model provides the subsurface anatomy and, combined with electromagnetic tracking of a sham ultrasound probe and a standard nerve block needle, supports simulated ultrasound display and measurement of needle location and proximity to nerves and vessels. The needle tracking and virtual model also support objective performance metrics of needle targeting technique.
Archive interoperability in the Virtual Observatory
NASA Astrophysics Data System (ADS)
Genova, Françoise
2003-02-01
Main goals of Virtual Observatory projects are to build interoperability between astronomical on-line services, observatory archives, databases and results published in journals, and to develop tools permitting the best scientific usage from the very large data sets stored in observatory archives and produced by large surveys. The different Virtual Observatory projects collaborate to define common exchange standards, which are the key for a truly International Virtual Observatory: for instance their first common milestone has been a standard allowing exchange of tabular data, called VOTable. The Interoperability Work Area of the European Astrophysical Virtual Observatory project aims at networking European archives, by building a prototype using the CDS VizieR and Aladin tools, and at defining basic rules to help archive providers in interoperability implementation. The prototype is accessible for scientific usage, to get user feedback (and science results!) at an early stage of the project. ISO archive participates very actively to this endeavour, and more generally to information networking. The on-going inclusion of the ISO log in SIMBAD will allow higher level links for users.
Distractibility in Attention/Deficit/ Hyperactivity Disorder (ADHD): the virtual reality classroom.
Adams, Rebecca; Finn, Paul; Moes, Elisabeth; Flannery, Kathleen; Rizzo, Albert Skip
2009-03-01
Nineteen boys aged 8 to 14 with a diagnosis of ADHD and 16 age-matched controls were compared in a virtual reality (VR) classroom version of a continuous performance task (CPT), with a second standard CPT presentation using the same projection display dome system. The Virtual Classroom included simulated "real-world" auditory and visual distracters. Parent ratings of attention, hyperactivity, internalizing problems, and adaptive skills on the Behavior Assessment System for Children (BASC) Monitor for ADHD confirmed that the ADHD children had more problems in these areas than controls. The difference between the ADHD group (who performed worse) and the control group approached significance (p = .05; adjusted p = .02) in the Virtual Classroom presentation, and the classification rate of the Virtual Classroom was better than when the standard CPT was used (87.5% versus 68.8%). Children with ADHD were more affected by distractions in the VR classroom than those without ADHD. Results are discussed in relation to distractibility in ADHD.
NASA Technical Reports Server (NTRS)
Twombly, I. Alexander; Smith, Jeffrey; Bruyns, Cynthia; Montgomery, Kevin; Boyle, Richard
2003-01-01
The International Space Station will soon provide an unparalleled research facility for studying the near- and longer-term effects of microgravity on living systems. Using the Space Station Glovebox Facility - a compact, fully contained reach-in environment - astronauts will conduct technically challenging life sciences experiments. Virtual environment technologies are being developed at NASA Ames Research Center to help realize the scientific potential of this unique resource by facilitating the experimental hardware and protocol designs and by assisting the astronauts in training. The Virtual GloveboX (VGX) integrates high-fidelity graphics, force-feedback devices and real- time computer simulation engines to achieve an immersive training environment. Here, we describe the prototype VGX system, the distributed processing architecture used in the simulation environment, and modifications to the visualization pipeline required to accommodate the display configuration.
Image-based 3D reconstruction and virtual environmental walk-through
NASA Astrophysics Data System (ADS)
Sun, Jifeng; Fang, Lixiong; Luo, Ying
2001-09-01
We present a 3D reconstruction method, which combines geometry-based modeling, image-based modeling and rendering techniques. The first component is an interactive geometry modeling method which recovery of the basic geometry of the photographed scene. The second component is model-based stereo algorithm. We discus the image processing problems and algorithms of walking through in virtual space, then designs and implement a high performance multi-thread wandering algorithm. The applications range from architectural planning and archaeological reconstruction to virtual environments and cinematic special effects.
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…
Advanced Collaborative Environments Supporting Systems Integration and Design
2003-03-01
concurrently view a virtual system or product model while maintaining natural, human communication . These virtual systems operate within a computer-generated...These environments allow multiple individuals to concurrently view a virtual system or product model while simultaneously maintaining natural, human ... communication . As a result, TARDEC researchers and system developers are using this advanced high-end visualization technology to develop future
The Virtual Museum of Minerals and Molecules: Molecular Visualization in a Virtual Hands-On Museum
ERIC Educational Resources Information Center
Barak, Phillip; Nater, Edward A.
2005-01-01
The Virtual Museum of Minerals and Molecules (VMMM) is a web-based resource presenting interactive, 3-D, research-grade molecular models of more than 150 minerals and molecules of interest to chemical, earth, plant, and environmental sciences. User interactivity with the 3-D display allows models to be rotated, zoomed, and specific regions of…
3D virtual environment of Taman Mini Indonesia Indah in a web
NASA Astrophysics Data System (ADS)
Wardijono, B. A.; Wardhani, I. P.; Chandra, Y. I.; Pamungkas, B. U. G.
2018-05-01
Taman Mini Indonesia Indah known as TMII is a largest recreational park based on culture in Indonesia. This park has 250 acres that consist of houses from provinces in Indonesia. In TMII, there are traditional houses of the various provinces in Indonesia. The official website of TMII has informed the traditional houses, but the information was limited to public. To provide information more detail about TMII to the public, this research aims to create and develop virtual traditional houses as 3d graphics models and show it via website. The Virtual Reality (VR) technology was used to display the visualization of the TMII and the surrounding environment. This research used Blender software to create the 3D models and Unity3D software to make virtual reality models that can be showed on a web. This research has successfully created 33 virtual traditional houses of province in Indonesia. The texture of traditional house was taken from original to make the culture house realistic. The result of this research was the website of TMII including virtual culture houses that can be displayed through the web browser. The website consists of virtual environment scenes and internet user can walkthrough and navigates inside the scenes.
Accuracy of contacts calculated from 3D images of occlusal surfaces.
DeLong, R; Knorr, S; Anderson, G C; Hodges, J; Pintado, M R
2007-06-01
Compare occlusal contacts calculated from 3D virtual models created from clinical records to contacts identified clinically using shimstock and transillumination. Upper and lower full arch alginate impressions and vinyl polysiloxane centric interocclusal records were made of 12 subjects. Stone casts made from the alginate impressions and the interocclusal records were optically scanned. Three-dimensional virtual models of the dental arches and interocclusal records were constructed using the Virtual Dental Patient Software. Contacts calculated from the virtual interocclusal records and from the aligned upper and lower virtual arch models were compared to those identified clinically using 0.01mm shimstock and transillumination of the interocclusal record. Virtual contacts and transillumination contacts were compared by anatomical region and by contacting tooth pairs to shimstock contacts. Because there is no accepted standard for identifying occlusal contacts, methods were compared in pairs with one labeled "standard" and the second labeled "test". Accuracy was defined as the number of contacts and non-contacts of the "test" that were in agreement with the "standard" divided by the total number of contacts and non-contacts of the "standard". Accuracy of occlusal contacts calculated from virtual interocclusal records and aligned virtual casts compared to transillumination were: 0.87+/-0.05 and 0.84+/-0.06 by region and 0.95+/-0.07 and 0.95+/-0.05 by tooth, respectively. Comparisons with shimstock were: 0.85+/-0.15 (record), 0.84+/-0.14 (casts), and 81+/-17 (transillumination). The virtual record, aligned virtual arches, and transillumination methods of identifying contacts are equivalent, and show better agreement with each other than with the shimstock method.
Peters, Betts; Bieker, Gregory; Heckman, Susan M; Huggins, Jane E; Wolf, Catherine; Zeitlin, Debra; Fried-Oken, Melanie
2015-03-01
More than 300 researchers gathered at the 2013 International Brain-Computer Interface (BCI) Meeting to discuss current practice and future goals for BCI research and development. The authors organized the Virtual Users' Forum at the meeting to provide the BCI community with feedback from users. We report on the Virtual Users' Forum, including initial results from ongoing research being conducted by 2 BCI groups. Online surveys and in-person interviews were used to solicit feedback from people with disabilities who are expert and novice BCI users. For the Virtual Users' Forum, their responses were organized into 4 major themes: current (non-BCI) communication methods, experiences with BCI research, challenges of current BCIs, and future BCI developments. Two authors with severe disabilities gave presentations during the Virtual Users' Forum, and their comments are integrated with the other results. While participants' hopes for BCIs of the future remain high, their comments about available systems mirror those made by consumers about conventional assistive technology. They reflect concerns about reliability (eg, typing accuracy/speed), utility (eg, applications and the desire for real-time interactions), ease of use (eg, portability and system setup), and support (eg, technical support and caregiver training). People with disabilities, as target users of BCI systems, can provide valuable feedback and input on the development of BCI as an assistive technology. To this end, participatory action research should be considered as a valuable methodology for future BCI research. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
The fourth dimension of life: fractal geometry and allometric scaling of organisms.
West, G B; Brown, J H; Enquist, B J
1999-06-04
Fractal-like networks effectively endow life with an additional fourth spatial dimension. This is the origin of quarter-power scaling that is so pervasive in biology. Organisms have evolved hierarchical branching networks that terminate in size-invariant units, such as capillaries, leaves, mitochondria, and oxidase molecules. Natural selection has tended to maximize both metabolic capacity, by maximizing the scaling of exchange surface areas, and internal efficiency, by minimizing the scaling of transport distances and times. These design principles are independent of detailed dynamics and explicit models and should apply to virtually all organisms.
McLean, Thomas R; Richards, Edward P
2006-01-01
Growth in the global market for telemedical services is being driven by economics. Two operational models are already recognizable. "Nighthawk" providers are virtually indistinguishable from their domestic counterparts with respect to medical malpractice liability and price for service. Indian providers, in contrast, offer deep price discounts on services, but jurisdictional loopholes are likely to allow these providers a method to avoid medical malpractice liability. Hospitals that outsource their radiology services need to be aware of these differences, because hiring Indian telemedical providers will likely result in a shift of medical malpractice liability from providers to hospitals.
Virtual sensors for robust on-line monitoring (OLM) and Diagnostics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tipireddy, Ramakrishna; Lerchen, Megan E.; Ramuhalli, Pradeep
Unscheduled shutdown of nuclear power facilities for recalibration and replacement of faulty sensors can be expensive and disruptive to grid management. In this work, we present virtual (software) sensors that can replace a faulty physical sensor for a short duration thus allowing recalibration to be safely deferred to a later time. The virtual sensor model uses a Gaussian process model to process input data from redundant and other nearby sensors. Predicted data includes uncertainty bounds including spatial association uncertainty and measurement noise and error. Using data from an instrumented cooling water flow loop testbed, the virtual sensor model has predictedmore » correct sensor measurements and the associated error corresponding to a faulty sensor.« less
Promoting motivation with virtual agents and avatars: role of visual presence and appearance.
Baylor, Amy L
2009-12-12
Anthropomorphic virtual agents can serve as powerful technological mediators to impact motivational outcomes such as self-efficacy and attitude change. Such anthropomorphic agents can be designed as simulated social models in the Bandurian sense, providing social influence as virtual 'role models'. Of particular value is the capacity for designing such agents as optimized social models for a target audience and context. Importantly, the visual presence and appearance of such agents can have a major impact on motivation and affect regardless of the underlying technical sophistication. Empirical results of different instantiations of agent presence and appearance are reviewed for both autonomous virtual agents and avatars that represent a user.
Research on The Construction of Flexible Multi-body Dynamics Model based on Virtual Components
NASA Astrophysics Data System (ADS)
Dong, Z. H.; Ye, X.; Yang, F.
2018-05-01
Focus on the harsh operation condition of space manipulator, which cannot afford relative large collision momentum, this paper proposes a new concept and technology, called soft-contact technology. In order to solve the problem of collision dynamics of flexible multi-body system caused by this technology, this paper also proposes the concepts of virtual components and virtual hinges, and constructs flexible dynamic model based on virtual components, and also studies on its solutions. On this basis, this paper uses NX to carry out model and comparison simulation for space manipulator in 3 different modes. The results show that using the model of multi-rigid body + flexible body hinge + controllable damping can make effective control on amplitude for the force and torque caused by target satellite collision.
The role of internal dynamics in the coherent evolution of indirect excitons
NASA Astrophysics Data System (ADS)
Grasselli, Federico; Bertoni, Andrea; Goldoni, Guido
2017-08-01
We study the time-dependent quantum scattering of a spatially indirect exciton by an external potential, taking fully into account the relative quantum dynamics of the electron-hole (e-h) pair. Exact calculations for an e-h wave packet show that transfer of energy between centre-of-mass (c.m.) and relative degrees of freedom may result in a genuine correction to the evolution during the scattering and eventually at asymptotic times. We show in experimentally relevant regimes and device configurations, that transmission resonances, tunnelling probabilities, diffraction patterns and wave packet fragmentation of indirect excitons are largely determined by the internal dynamics, and could not be reproduced by point-like dipole models or mean-field calculations. We show that a properly-designed local self-energy potential to be added to the c.m. Hamiltonian embeds the effects of the c.m.-internal motion correlation at a small fraction of the computation load needed for full-propagation calculations. The explicit form of this self-energy emphasises the dominant role of internal virtual transitions in determining scattering coefficients of indirect excitons.
Virtual Reality Visualization of Permafrost Dynamics Along a Transect Through Northern Alaska
NASA Astrophysics Data System (ADS)
Chappell, G. G.; Brody, B.; Webb, P.; Chord, J.; Romanovsky, V.; Tipenko, G.
2004-12-01
Understanding permafrost dynamics poses a significant challenge for researchers and planners. Our project uses nontraditional visualization tools to create a 3-D interactive virtual-reality environment in which permafrost dynamics can be explored and experimented with. We have incorporated a numerical soil temperature model by Gennadiy Tipenko and Vladimir Romanovsky of the Geophysical institute at the University of Alaska Fairbanks into an animated tour in space and time in the virtual reality facility of the Arctic Region Supercomputing Center at the University of Alaska Fairbanks. The software is being written by undergraduate interns Patrick Webb and Jordanna Chord under the direction of Professors Chappell and Brody. When using our software, the user appears to be surrounded by a 3-D computer-generated model of the state of Alaska. The eastern portion of the state is displaced upward from the western portion. The data are represented on an animated vertical strip running between the two parts, as if eastern Alaska were raised up, and the soil at the cut could be viewed. We use coloring to highlight significant properties and features of the soil: temperature, the active layer, etc. The user can view data from various parts of the state simply by walking to the appropriate location in the model, or by using a flying-style interface to cover longer distances. Using a control panel, the user can also alter the time, viewing the data for a particular date, or watching the data change with time: a high-speed movie in which long-term changes in permafrost are readily apparent. In the second phase of the project, we connect the visualization directly to the model, running in real time. We allow the user to manipulate the input data and get immediate visual feedback. For example, the user might specify the kind and placement of ground cover, by ``painting'' snowpack, plant species, or fire damage, and be able to see the effect on permafrost stability with no significant time lag.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McCorkle, D.; Yang, C.; Jordan, T.
2007-06-01
Modeling and simulation tools are becoming pervasive in the process engineering practice of designing advanced power generation facilities. These tools enable engineers to explore many what-if scenarios before cutting metal or constructing a pilot scale facility. While such tools enable investigation of crucial plant design aspects, typical commercial process simulation tools such as Aspen Plus®, gPROMS®, and HYSYS® still do not explore some plant design information, including computational fluid dynamics (CFD) models for complex thermal and fluid flow phenomena, economics models for policy decisions, operational data after the plant is constructed, and as-built information for use in as-designed models. Softwaremore » tools must be created that allow disparate sources of information to be integrated if environments are to be constructed where process simulation information can be accessed. At the Department of Energy’s (DOE) National Energy Technology Laboratory (NETL), the Advanced Process Engineering Co-Simulator (APECS) has been developed as an integrated software suite that combines process simulation (e.g., Aspen Plus) and high-fidelity equipment simulation (e.g., Fluent® CFD), together with advanced analysis capabilities including case studies, sensitivity analysis, stochastic simulation for risk/uncertainty analysis, and multi-objective optimization. In this paper, we discuss the initial phases of integrating APECS with the immersive and interactive virtual engineering software, VE-Suite, developed at Iowa State University and Ames Laboratory. VE-Suite utilizes the ActiveX (OLE Automation) controls in Aspen Plus wrapped by the CASI library developed by Reaction Engineering International to run the process simulation and query for unit operation results. This integration permits any application that uses the VE-Open interface to integrate with APECS co-simulations, enabling construction of the comprehensive virtual engineering environment needed for the rapid engineering of advanced power generation facilities.« less
NASA Astrophysics Data System (ADS)
Ren, Yilong; Duan, Xitong; Wu, Lei; He, Jin; Xu, Wu
2017-06-01
With the development of the “VR+” era, the traditional virtual assembly system of power equipment has been unable to satisfy our growing needs. In this paper, based on the analysis of the traditional virtual assembly system of electric power equipment and the application of VR technology in the virtual assembly system of electric power equipment in our country, this paper puts forward the scheme of establishing the virtual assembly system of power equipment: At first, we should obtain the information of power equipment, then we should using OpenGL and multi texture technology to build 3D solid graphics library. After the completion of three-dimensional modeling, we can use the dynamic link library DLL package three-dimensional solid graphics generation program to realize the modularization of power equipment model library and power equipment model library generated hidden algorithm. After the establishment of 3D power equipment model database, we set up the virtual assembly system of 3D power equipment to separate the assembly operation of the power equipment from the space. At the same time, aiming at the deficiency of the traditional gesture recognition algorithm, we propose a gesture recognition algorithm based on improved PSO algorithm for BP neural network data glove. Finally, the virtual assembly system of power equipment can really achieve multi-channel interaction function.
Master-slave system with force feedback based on dynamics of virtual model
NASA Technical Reports Server (NTRS)
Nojima, Shuji; Hashimoto, Hideki
1994-01-01
A master-slave system can extend manipulating and sensing capabilities of a human operator to a remote environment. But the master-slave system has two serious problems: one is the mechanically large impedance of the system; the other is the mechanical complexity of the slave for complex remote tasks. These two problems reduce the efficiency of the system. If the slave has local intelligence, it can help the human operator by using its good points like fast calculation and large memory. The authors suggest that the slave is a dextrous hand with many degrees of freedom able to manipulate an object of known shape. It is further suggested that the dimensions of the remote work space be shared by the human operator and the slave. The effect of the large impedance of the system can be reduced in a virtual model, a physical model constructed in a computer with physical parameters as if it were in the real world. A method to determine the damping parameter dynamically for the virtual model is proposed. Experimental results show that this virtual model is better than the virtual model with fixed damping.
Niu, Qiang; Chi, Xiaoyi; Leu, Ming C; Ochoa, Jorge
2008-01-01
This paper describes image processing, geometric modeling and data management techniques for the development of a virtual bone surgery system. Image segmentation is used to divide CT scan data into different segments representing various regions of the bone. A region-growing algorithm is used to extract cortical bone and trabecular bone structures systematically and efficiently. Volume modeling is then used to represent the bone geometry based on the CT scan data. Material removal simulation is achieved by continuously performing Boolean subtraction of the surgical tool model from the bone model. A quadtree-based adaptive subdivision technique is developed to handle the large set of data in order to achieve the real-time simulation and visualization required for virtual bone surgery. A Marching Cubes algorithm is used to generate polygonal faces from the volumetric data. Rendering of the generated polygons is performed with the publicly available VTK (Visualization Tool Kit) software. Implementation of the developed techniques consists of developing a virtual bone-drilling software program, which allows the user to manipulate a virtual drill to make holes with the use of a PHANToM device on a bone model derived from real CT scan data.
Interoperability in planetary research for geospatial data analysis
NASA Astrophysics Data System (ADS)
Hare, Trent M.; Rossi, Angelo P.; Frigeri, Alessandro; Marmo, Chiara
2018-01-01
For more than a decade there has been a push in the planetary science community to support interoperable methods for accessing and working with geospatial data. Common geospatial data products for planetary research include image mosaics, digital elevation or terrain models, geologic maps, geographic location databases (e.g., craters, volcanoes) or any data that can be tied to the surface of a planetary body (including moons, comets or asteroids). Several U.S. and international cartographic research institutions have converged on mapping standards that embrace standardized geospatial image formats, geologic mapping conventions, U.S. Federal Geographic Data Committee (FGDC) cartographic and metadata standards, and notably on-line mapping services as defined by the Open Geospatial Consortium (OGC). The latter includes defined standards such as the OGC Web Mapping Services (simple image maps), Web Map Tile Services (cached image tiles), Web Feature Services (feature streaming), Web Coverage Services (rich scientific data streaming), and Catalog Services for the Web (data searching and discoverability). While these standards were developed for application to Earth-based data, they can be just as valuable for planetary domain. Another initiative, called VESPA (Virtual European Solar and Planetary Access), will marry several of the above geoscience standards and astronomy-based standards as defined by International Virtual Observatory Alliance (IVOA). This work outlines the current state of interoperability initiatives in use or in the process of being researched within the planetary geospatial community.
Beamforming applied to surface EEG improves ripple visibility.
van Klink, Nicole; Mol, Arjen; Ferrier, Cyrille; Hillebrand, Arjan; Huiskamp, Geertjan; Zijlmans, Maeike
2018-01-01
Surface EEG can show epileptiform ripples in people with focal epilepsy, but identification is impeded by the low signal-to-noise ratio of the electrode recordings. We used beamformer-based virtual electrodes to improve ripple identification. We analyzed ten minutes of interictal EEG of nine patients with refractory focal epilepsy. EEGs with more than 60 channels and 20 spikes were included. We computed ∼79 virtual electrodes using a scalar beamformer and marked ripples (80-250 Hz) co-occurring with spikes in physical and virtual electrodes. Ripple numbers in physical and virtual electrodes were compared, and sensitivity and specificity of ripples for the region of interest (ROI; based on clinical information) were determined. Five patients had ripples in the physical electrodes and eight in the virtual electrodes, with more ripples in virtual than in physical electrodes (101 vs. 57, p = .007). Ripples in virtual electrodes predicted the ROI better than physical electrodes (AUC 0.65 vs. 0.56, p = .03). Beamforming increased ripple visibility in surface EEG. Virtual ripples predicted the ROI better than physical ripples, although sensitivity was still poor. Beamforming can facilitate ripple identification in EEG. Ripple localization needs to be improved to enable its use for presurgical evaluation in people with epilepsy. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
2014-01-01
characteristics. (Doctoral dissertation, George Washington University , 2008). Dissertation Abstracts International , 70(11-A), 4257. *Swezey, R. W...Assessments Robert C. Brusso Robert A. Wisher Arthur Paddock Joshua Hatfield ICF International January 2014...Approved for public release: distribution is unlimited U.S. Army Research Institute for the
How to Merge Courses via Skype™? Lessons from an International Blended Learning Project
ERIC Educational Resources Information Center
Akbaba, Yasemin; Baskan, Filiz
2017-01-01
This study reports on an international project in which students taking the course "Contemporary Issues in Turkish Politics" in spring 2011 and fall 2011 at two institutions of higher education, "Gettysburg College" in the United States and "Izmir University of Economics" in Turkey, worked together in virtual learning…
The Virtual Liver: Modeling Chemical-Induced Liver Toxicity
The US EPA Virtual Liver (v-Liver) project is aimed at modeling chemical-induced processes in hepatotoxicity and simulating their dose-dependent perturbations. The v-Liver embodies an emerging field of research in computational tissue modeling that integrates molecular and cellul...
Development of a virtual reality training system for endoscope-assisted submandibular gland removal.
Miki, Takehiro; Iwai, Toshinori; Kotani, Kazunori; Dang, Jianwu; Sawada, Hideyuki; Miyake, Minoru
2016-11-01
Endoscope-assisted surgery has widely been adopted as a basic surgical procedure, with various training systems using virtual reality developed for this procedure. In the present study, a basic training system comprising virtual reality for the removal of submandibular glands under endoscope assistance was developed. The efficacy of the training system was verified in novice oral surgeons. A virtual reality training system was developed using existing haptic devices. Virtual reality models were constructed from computed tomography data to ensure anatomical accuracy. Novice oral surgeons were trained using the developed virtual reality training system. The developed virtual reality training system included models of the submandibular gland and surrounding connective tissues and blood vessels entering the submandibular gland. Cutting or abrasion of the connective tissue and manipulations, such as elevation of blood vessels, were reproduced by the virtual reality system. A training program using the developed system was devised. Novice oral surgeons were trained in accordance with the devised training program. Our virtual reality training system for endoscope-assisted removal of the submandibular gland is effective in the training of novice oral surgeons in endoscope-assisted surgery. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.
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.
Papafaklis, Michail I; Muramatsu, Takashi; Ishibashi, Yuki; Bourantas, Christos V; Fotiadis, Dimitrios I; Brilakis, Emmanouil S; Garcia-Garcia, Héctor M; Escaned, Javier; Serruys, Patrick W; Michalis, Lampros K
2018-03-01
Fractional flow reserve (FFR) has been established as a useful diagnostic tool. The distal coronary pressure to aortic pressure (Pd/Pa) ratio at rest is a simpler physiologic index but also requires the use of the pressure wire, whereas recently proposed virtual functional indices derived from coronary imaging require complex blood flow modelling and/or are time-consuming. Our aim was to test the diagnostic performance of virtual resting Pd/Pa using routine angiographic images and a simple flow model. Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by FFR. The resting Pd/Pa for each lesion was assessed by computational fluid dynamics. The discriminatory power of virtual resting Pd/Pa against FFR (reference: ≤0.80) was high (area under the receiver operator characteristic curve [AUC]: 90.5% [95% CI: 85.4-95.6%]). Diagnostic accuracy, sensitivity and specificity for the optimal virtual resting Pd/Pa cut-off (≤0.94) were 84.9%, 90.4% and 81.6%, respectively. Virtual resting Pd/Pa demonstrated superior performance (p<0.001) versus 3D-QCA %area stenosis (AUC: 77.5% [95% CI: 69.8-85.3%]). There was a good correlation between virtual resting Pd/Pa and FFR (r=0.69, p<0.001). Virtual resting Pd/Pa using routine angiographic data and a simple flow model provides fast functional assessment of coronary lesions without requiring the pressure-wire and hyperaemia induction. The high diagnostic performance of virtual resting Pd/Pa for predicting FFR shows promise for using this simple/fast virtual index in clinical practice. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
Virtual Team Governance: Addressing the Governance Mechanisms and Virtual Team Performance
NASA Astrophysics Data System (ADS)
Zhan, Yihong; Bai, Yu; Liu, Ziheng
As technology has improved and collaborative software has been developed, virtual teams with geographically dispersed members spread across diverse physical locations have become increasingly prominent. Virtual team is supported by advancing communication technologies, which makes virtual teams able to largely transcend time and space. Virtual teams have changed the corporate landscape, which are more complex and dynamic than traditional teams since the members of virtual teams are spread on diverse geographical locations and their roles in the virtual team are different. Therefore, how to realize good governance of virtual team and arrive at good virtual team performance is becoming critical and challenging. Good virtual team governance is essential for a high-performance virtual team. This paper explores the performance and the governance mechanism of virtual team. It establishes a model to explain the relationship between the performance and the governance mechanisms in virtual teams. This paper is focusing on managing virtual teams. It aims to find the strategies to help business organizations to improve the performance of their virtual teams and arrive at the objectives of good virtual team management.
Zenner, Andre; Kruger, Antonio
2017-04-01
We define the concept of Dynamic Passive Haptic Feedback (DPHF) for virtual reality by introducing the weight-shifting physical DPHF proxy object Shifty. This concept combines actuators known from active haptics and physical proxies known from passive haptics to construct proxies that automatically adapt their passive haptic feedback. We describe the concept behind our ungrounded weight-shifting DPHF proxy Shifty and the implementation of our prototype. We then investigate how Shifty can, by automatically changing its internal weight distribution, enhance the user's perception of virtual objects interacted with in two experiments. In a first experiment, we show that Shifty can enhance the perception of virtual objects changing in shape, especially in length and thickness. Here, Shifty was shown to increase the user's fun and perceived realism significantly, compared to an equivalent passive haptic proxy. In a second experiment, Shifty is used to pick up virtual objects of different virtual weights. The results show that Shifty enhances the perception of weight and thus the perceived realism by adapting its kinesthetic feedback to the picked-up virtual object. In the same experiment, we additionally show that specific combinations of haptic, visual and auditory feedback during the pick-up interaction help to compensate for visual-haptic mismatch perceived during the shifting process.
NASA Astrophysics Data System (ADS)
Hubenthal, M.; Wysession, M. E.; Aster, R. C.
2009-12-01
Since 1998, the IRIS Consortium REU program has facilitated research opportunities and career development for 71 undergraduate students to work with leaders in seismological research, travel to exciting locations for fieldwork, and engage in significant research for presentation and recognition at major professional conferences. A principal program goal is to encourage more students, representing a more diverse population, to choose careers in Earth science. Of the forty-six internship alumni that have completed their undergraduate degrees thus far, 85% have attained or are currently pursuing a graduate degree in a geoscience field and an additional 6% are working in a geoscience career with an undergraduate degree. The IRIS Consortium’s program differs from traditional REUs in that students are hosted at IRIS member institutions that are geographically distributed. To capture the sprit of a traditional REU cohort, IRIS has developed and refined a model that bonds students into a cohort. Key to the model are: a) research projects that have a common focus within seismology, b) a weeklong orientation where students get to know one another, share common experiences and establish a “social presence” with the other interns, c) a cyber infrastructure to maintain their connectedness in a way that enables both learning and collaboration, d) an alumni mentor that supports the interns and serves both as a role model and an unbiased and experienced third-party to the mentor/mentee relationship, and e) an alumni reception, and scientific presentation, at the annual Fall AGU Meeting to reconnect and share experiences. Through their virtual community interns offer each other assistance, share ideas, ask questions, and relate life experiences while conducting their own unique research. In addition to developing a model for encouraging virtual cohorts, IRIS has also carefully examined recruitment strategies to increase and diversify the applicant pool. Based on applicant surveys we believe that the best method to advertise REU programs has shifted away from the traditional and expensive hardcopy fliers tacked to bulletin board in the halls of science departments. Instead we have found that the two most common methods for students to learn about the program were by visiting the IRIS website to view video clips or slideshow presentations and via personal notification/encouragement from faculty or staff at their institutions. The importance of personal notification was even more pronounced for applicants from minority serving institutions. Given the importance both the web and faculty advising in encouraging students to apply, the IRIS REU has adopted the following three recruitment strategies: 1) Engage students through the website by providing access to traditional text and photos, narrated video clips and other media, as well as links to previous intern’s blogs, 2) Empower and encourage faculty to recruit students by providing resources for easy use in classes such as annotated slideshows and narrated videos, and 3) Reach out to minority students personally through a speaker series featuring minority alumni of the IRIS REU program.
ERIC Educational Resources Information Center
Merchant, Zahira; Goetz, Ernest T.; Keeney-Kennicutt, Wendy; Kwok, Oi-man; Cifuentes, Lauren; Davis, Trina J.
2012-01-01
We examined a model of the impact of a 3D desktop virtual reality environment on the learner characteristics (i.e. perceptual and psychological variables) that can enhance chemistry-related learning achievements in an introductory college chemistry class. The relationships between the 3D virtual reality features and the chemistry learning test as…
ERIC Educational Resources Information Center
Stedrak, Luke J.
2012-01-01
This study contains an analysis of virtual schools, public policy, and funding in the United States. The purpose of this study was to determine what public policies and legislation were in place regarding the funding models of virtual education on a state by state basis. Furthermore, this study addressed how allocations were being made by state…
A modeling study of 2006 Huntington Beach (Lake Erie) beach bacteria concentrations indicates multi-variable linear regression (MLR) can effectively estimate bacteria concentrations compared to the persistence model. Our use of the Virtual Beach (VB) model affirms that fact. VB i...
The Gran Telescopio Canarias and Calar Alto Virtual Observatory Compliant Archives
NASA Astrophysics Data System (ADS)
Alacid, J. M.; Solano, E.; Jiménez-Esteban, F. M.; Velasco, A.
2014-05-01
The Gran Telescopio Canarias and Calar Alto archives are the result of the collaboration agreements between the Centro de Astrobiología and two entities: GRANTECAN S.A. and the Centro Astronómico Hispano Alemán (CAHA). The archives have been developed in the framework of the Spanish Virtual Observatory and are maintained by the Data Archive Unit at Centro de Astrobiología. The archives contain both raw and science ready data and have been designed in compliance with the standards defined by the International Virtual Observatory Alliance, which guarantees a high level of data accessibility and handling. In this paper we describe the main characteristics and functionalities of both archives.
The Gran Telescopio Canarias and Calar Alto Virtual Observatory compliant archives
NASA Astrophysics Data System (ADS)
Solano, Enrique; Gutiérrez, Raúl; Alacid, José Manuel; Jiménez-Esteban, Francisco; Velasco Trasmonte, Almudena
2012-09-01
The Gran Telescopio Canarias (GTC) and Calar Alto archives are the result of the collaboration agreements between the Centro de Astrobiología (CAB, INTA-CSIC)) and two entities: GRANTECAN S.A. and the Centro Astronómico Hispano Alemán (CAHA). The archives have been developed in the framework of the Spanish Virtual Observatory and are maintained by the Data Archive Unit at CAB. The archives contain both raw and science ready data and have been designed in compliance with the standards defined by the International Virtual Observatory Alliance (IVOA) which guarantees a high level of data accessibility and handling. In this paper we describe the main characteristics and functionalities of both archives.
Hospital admission avoidance through the introduction of a virtual ward.
Jones, Joanne; Carroll, Andrea
2014-07-01
The ageing British population is placing increased demands on the delivery of care in mainstream health-care institutions. While people are living longer, a significant percentage is also living with one or more long-term conditions. These issues, alongside continuing financial austerity measures, require a radical improvement in the care of patients away from hospitals. The Wyre Forest Clinical Commissioning Group introduced a virtual ward model for two main purposes: to save on spiralling costs of hospital admissions, and, secondly, to ensure the preferred wishes of most patients to be cared for and even die at home were achieved. This commentary describes how the virtual ward model was implemented and the impact of preventing unplanned emergency admissions to hospitals. The setting up of enhanced care services and virtual wards in one county is discussed, aiming to highlight success points and potential pitfalls to avoid. The results from the implementation of the virtual ward model show a significant reduction in emergency and avoidable patient admissions to hospital. The success of virtual wards is dependent on integrated working between different health-care disciplines.
STS-105 Crew Training in VR Lab
2001-03-15
JSC2001-00754 (15 March 2001) --- Astronaut Patrick G. Forrester, STS-105 mission specialist, uses specialized gear in the virtual reality lab at the Johnson Space Center (JSC) to train for his duties aboard the Space Shuttle Discovery. This type of virtual reality training allows the astronauts to wear a helmet and special gloves while looking at computer displays simulating actual movements around the various locations on the International Space Station (ISS) hardware with which they will be working.
International Space Station (ISS)
2007-05-21
STS-118 astronaut and mission specialist Dafydd R. “Dave” Williams, representing the Canadian Space Agency, uses Virtual Reality Hardware in the Space Vehicle Mock Up Facility at the Johnson Space Center to rehearse some of his duties for the upcoming mission. This type of virtual reality training allows the astronauts to wear special gloves and other gear while looking at a computer that displays simulating actual movements around the various locations on the station hardware which with they will be working.
STS-111 Training in VR lab with Expedition IV and V Crewmembers
2001-10-18
JSC2001-E-39082 (18 October 2001) --- Cosmonaut Valeri G. Korzun (left), Expedition Five mission commander, and astronaut Carl E. Walz, Expedition Four flight engineer, use the virtual reality lab at the Johnson Space Center (JSC) to train for their duties on the International Space Station (ISS). This type of computer interface paired with virtual reality training hardware and software helps the entire team for dealing with ISS elements. Korzun represents Rosaviakosmos.
Staghorn: An Automated Large-Scale Distributed System Analysis Platform
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gabert, Kasimir; Burns, Ian; Elliott, Steven
2016-09-01
Conducting experiments on large-scale distributed computing systems is becoming significantly easier with the assistance of emulation. Researchers can now create a model of a distributed computing environment and then generate a virtual, laboratory copy of the entire system composed of potentially thousands of virtual machines, switches, and software. The use of real software, running at clock rate in full virtual machines, allows experiments to produce meaningful results without necessitating a full understanding of all model components. However, the ability to inspect and modify elements within these models is bound by the limitation that such modifications must compete with the model,more » either running in or alongside it. This inhibits entire classes of analyses from being conducted upon these models. We developed a mechanism to snapshot an entire emulation-based model as it is running. This allows us to \\freeze time" and subsequently fork execution, replay execution, modify arbitrary parts of the model, or deeply explore the model. This snapshot includes capturing packets in transit and other input/output state along with the running virtual machines. We were able to build this system in Linux using Open vSwitch and Kernel Virtual Machines on top of Sandia's emulation platform Firewheel. This primitive opens the door to numerous subsequent analyses on models, including state space exploration, debugging distributed systems, performance optimizations, improved training environments, and improved experiment repeatability.« less
NASA Astrophysics Data System (ADS)
Pasian, F.
2015-06-01
The origins of the Italian contribution to the international Virtual Observatory (VO) were mainly tied to the definition and implementation of a Data Grid using Grid standards. From there on, by means of a step-wise evolution, activities started including the implementation of VO-aware tools and facilities, or the production of services accessing data archives in ways compliant to the international VO standards. An important activity the Italian VO community has carried out is the dissemination of the VO capabilities to professionals, students and amateurs: in particular, an important and maybe unique success has been bringing to the classrooms the VO, and using it as a powerful tool to teach astronomy at all levels, from junior high school to undergraduate courses. Lately, there has been also direct involvement of the Italian community in the definition of standards and services within the framework of the International Virtual Observatory Alliance (IVOA), and participation and leadership in the IVOA Working Groups. Along this path, the national funding for these activities has been rather low, although essential to carry the activities on. There were no bursts of funding to allow a quick rise in activities leading to the fast realisation of tools and systems. Rather, the manpower involved in VObs.it has been always fairly low but steady. In the view of managing a national VO initiative with a low budget, strategic choices were made to exploit the available resources and to guarantee a constant background activity, mainly geared at providing services to the community, development in lower-priority VO areas, dissemination and support.
NASA Technical Reports Server (NTRS)
Knox, James C.; Stanley, Christine M.
2015-01-01
The Life Support Systems Project (LSSP) under the Advanced Exploration Systems (AES) program builds upon the work performed under the AES Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project focusing on the numerous technology development areas. The Carbon Dioxide (CO2) removal and associated air drying development efforts are focused on improving the current state-of-the-art system on the International Space Station (ISS) utilizing fixed beds of sorbent pellets by seeking more robust pelletized sorbents, evaluating structured sorbents, and examining alternate bed configurations to improve system efficiency and reliability. A component of the CO2 removal effort utilizes a virtual Carbon Dioxide Removal Assembly, revision 4 (CDRA-4) test bed to test a large number of potential operational configurations with independent variations in flow rate, cycle time, heater ramp rate, and set point. Initial ground testing will provide prerequisite source data and provide baseline data in support of the virtual CDRA. Once the configurations with the highest performance and lowest power requirements are determined by the virtual CDRA, the results will be confirmed by testing these configurations with the CDRA-4EU ground test hardware. This paper describes the initial ground testing of select configurations. The development of the virtual CDRA under the AES-LSS Project will be discussed in a companion paper.
Wall shear stress in intracranial aneurysms and adjacent arteries☆
Wang, Fuyu; Xu, Bainan; Sun, Zhenghui; Wu, Chen; Zhang, Xiaojun
2013-01-01
Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries. PMID:25206394
From Panoramic Photos to a Low-Cost Photogrammetric Workflow for Cultural Heritage 3d Documentation
NASA Astrophysics Data System (ADS)
D'Annibale, E.; Tassetti, A. N.; Malinverni, E. S.
2013-07-01
The research aims to optimize a workflow of architecture documentation: starting from panoramic photos, tackling available instruments and technologies to propose an integrated, quick and low-cost solution of Virtual Architecture. The broader research background shows how to use spherical panoramic images for the architectural metric survey. The input data (oriented panoramic photos), the level of reliability and Image-based Modeling methods constitute an integrated and flexible 3D reconstruction approach: from the professional survey of cultural heritage to its communication in virtual museum. The proposed work results from the integration and implementation of different techniques (Multi-Image Spherical Photogrammetry, Structure from Motion, Imagebased Modeling) with the aim to achieve high metric accuracy and photorealistic performance. Different documentation chances are possible within the proposed workflow: from the virtual navigation of spherical panoramas to complex solutions of simulation and virtual reconstruction. VR tools make for the integration of different technologies and the development of new solutions for virtual navigation. Image-based Modeling techniques allow 3D model reconstruction with photo realistic and high-resolution texture. High resolution of panoramic photo and algorithms of panorama orientation and photogrammetric restitution vouch high accuracy and high-resolution texture. Automated techniques and their following integration are subject of this research. Data, advisably processed and integrated, provide different levels of analysis and virtual reconstruction joining the photogrammetric accuracy to the photorealistic performance of the shaped surfaces. Lastly, a new solution of virtual navigation is tested. Inside the same environment, it proposes the chance to interact with high resolution oriented spherical panorama and 3D reconstructed model at once.
Colman, Kerri L; Dobbe, Johannes G G; Stull, Kyra E; Ruijter, Jan M; Oostra, Roelof-Jan; van Rijn, Rick R; van der Merwe, Alie E; de Boer, Hans H; Streekstra, Geert J
2017-07-01
Almost all European countries lack contemporary skeletal collections for the development and validation of forensic anthropological methods. Furthermore, legal, ethical and practical considerations hinder the development of skeletal collections. A virtual skeletal database derived from clinical computed tomography (CT) scans provides a potential solution. However, clinical CT scans are typically generated with varying settings. This study investigates the effects of image segmentation and varying imaging conditions on the precision of virtual modelled pelves. An adult human cadaver was scanned using varying imaging conditions, such as scanner type and standard patient scanning protocol, slice thickness and exposure level. The pelvis was segmented from the various CT images resulting in virtually modelled pelves. The precision of the virtual modelling was determined per polygon mesh point. The fraction of mesh points resulting in point-to-point distance variations of 2 mm or less (95% confidence interval (CI)) was reported. Colour mapping was used to visualise modelling variability. At almost all (>97%) locations across the pelvis, the point-to-point distance variation is less than 2 mm (CI = 95%). In >91% of the locations, the point-to-point distance variation was less than 1 mm (CI = 95%). This indicates that the geometric variability of the virtual pelvis as a result of segmentation and imaging conditions rarely exceeds the generally accepted linear error of 2 mm. Colour mapping shows that areas with large variability are predominantly joint surfaces. Therefore, results indicate that segmented bone elements from patient-derived CT scans are a sufficiently precise source for creating a virtual skeletal database.
Design and analysis of a global sub-mesoscale and tidal dynamics admitting virtual ocean.
NASA Astrophysics Data System (ADS)
Menemenlis, D.; Hill, C. N.
2016-02-01
We will describe the techniques used to realize a global kilometerscale ocean model configuration that includes representation of sea-ice and tidal excitation, and spans scales from planetary gyres to internal tides. A simulation using this model configuration provides a virtual ocean that admits some sub-mesoscale dynamics and tidal energetics not normally represented in global calculations. This extends simulated ocean behavior beyond broadly quasi-geostrophic flows and provides a preliminary example of a next generation computational approach to explicitly probing the interactions between instabilities that are usually parameterized and dominant energetic scales in the ocean. From previous process studies we have ascertained that this can lead to a qualitative improvement in the realism of many significant processes including geostrophic eddy dynamics, shelf-break exchange and topographic mixing. Computationally we exploit high-degrees of parallelism in both numerical evaluation and in recording model state to persistent disk storage. Together this allows us to compute and record a full three-dimensional model trajectory at hourly frequency for a timeperiod of 5 months with less than 9 million core hours of parallel computer time, using the present generation NASA Ames Research Center facilities. We have used this capability to create a 5 month trajectory archive, sampled at high spatial and temporal frequency for an ocean configuration that is initialized from a realistic data-assimilated state and driven with reanalysis surface forcing from ECMWF. The resulting database of model state provides a novel virtual laboratory for exploring coupling across scales in the ocean, and for testing ideas on the relationship between small scale fluxes and large scale state. The computation is complemented by counterpart computations that are coarsened two and four times respectively. In this presentation we will review the computational and numerical technologies employed and show how the high spatio-temporal frequency archive of model state can provide a new and promising tool for researching richer ocean dynamics at scale. We will also outline how computations of this nature could be combined with next generation computer hardware plans to help inform important climate process questions.
World Virtual Observatory Organization
NASA Astrophysics Data System (ADS)
Ignatyev, Mikhail; Pinigin, Gennadij
On the base of experience of our Unoversity and Observatory we investigate the seven blocks model of virtual organization for consolidation of resources. This model consists of the next blocks: 1.Population-scientists students robots and agents. 2.Aspiration of population groups. 3.Territory. 4.Production. 5.Ecology and safety. 6.Finance. 7. External relations - input and output flows of population information resources.The world virtual observatory is the virtual world which consists of three groups of variables - appearances essences and structured uncertainty which defines the number and distribution of arbitrary coefficients in equivalent equations. The consolodation of recources permit to create the large telescopes with distributed structure on our planet and cosmos. Virtual instruments can have the best characteristics by means of collective effects which have investigated in our paper.
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.
"NASA's Solar System Exploration Research Virtual Institute" - Expanded Goals and More Partners
NASA Astrophysics Data System (ADS)
Daou, D.; Schmidt, G.; Pendleton, Y.; Bailey, B.; Morrison, D.
2015-10-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) has been pursuing international partnerships since its inceptionas the NASA Lunar Science Institute (NLSI), in order to both leverage the science being done by its domestic member institutions as well as to help lunar science and exploration become a greater global endeavor. The international partners of the I nstitute have pursued a broad program of lunar science stimulated by scientific partnerships enabled by the SSERVI community. Furthermore, regional partnerships have been formed such as the new pan- European lunar science consortium, which promises both new scientific approaches and mission concepts.International partner membership requires longterm commitment from both the partner and SSERVI, together with tangible and specific plans for scientific interaction that will produce results of mutual benefit to both the institute's U.S. Teams and the international partner.International partners are invited to participate in all aspects of the Institute's activities and programs, on a basis of no exchange of funds. Through these activities, SSERVI researchers and international partners participate in sharing ideas, information, and data arising from their respective research efforts, and contribute to the training of young scientists.This talk will present an overview of the Institute and the international nodes. We will also discuss the various processes to become a SSERVI partner as well as the opportunities available for collaborations with the SSERVI national teams.
NASAs Solar System Exploration Research Virtual Institute- Expanded Goals and More Partners
NASA Technical Reports Server (NTRS)
Schmidt, G. K.; Daou, D.; Pendleton, Y.; Bailey, B. E.
2015-01-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) has been pursuing international partnerships since its inception as the NASA Lunar Science Institute (NLSI), in order to both leverage the science being done by its domestic member institutions as well as to help lunar science and exploration become a greater global endeavor. The international partners of the Institute have pursued a broad program of lunar science stimulated by scientific partnerships enabled by the SSERVI community. Furthermore, regional partnerships have been formed such as the new pan-European lunar science consortium, which promises both new scientific approaches and mission concepts. International partner membership requires long-term commitment from both the partner and SSERVI, together with tangible and specific plans for scientific interaction that will produce results of mutual benefit to both the institute's U.S. Teams and the international partner. International partners are invited to participate in all aspects of the Institute's activities and programs, on a basis of no exchange of funds. Through these activities, SSERVI researchers and international partners participate in sharing ideas, information, and data arising from their respective research efforts, and contribute to the training of young scientists. This talk will present an overview of the Institute and the international nodes. We will also discuss the various processes to become a SSERVI partner as well as the opportunities available for collaborations with the SSERVI national teams.
"NASA's Solar System Exploration Research Virtual Institute"; - Expanded Goals and New Teams
NASA Astrophysics Data System (ADS)
Daou, D.; Schmidt, G. K.; Pendleton, Y.; Bailey, B. E.
2014-04-01
The NASA Solar System Exploration Research Virtual Institute (SSERVI) has been pursuing international partnerships since its inception as the NASA Lunar Science Institute (NLSI), in order to both leverage the science being done by its domestic member institutions as well as to help lunar science and exploration become a greater global endeavor. The international partners of the Institute have pursued a broad program of lunar science stimulated by scientific partnerships enabled by the SSERVI community. Furthermore, regional partnerships have been formed such as the new pan-European lunar science consortium, which promises both new scientific approaches and mission concepts. International partner membership requires long-term commitment from both the partner and SSERVI, together with tangible and specific plans for scientific interaction that will produce results of mutual benefit to both the institute's U.S. Teams and the international partner. International partners are invited to participate in all aspects of the Institute's activities and programs, on a basis of no exchange of funds. Through these activities, SSERVI researchers and international partners participate in sharing ideas, information, and data arising from their respective research efforts, and contribute to the training of young scientists. This talk will present an overview of the Institute and the international nodes. We will also discuss the various processes to become a SSERVI partner as well as the opportunities available for collaborations with the SSERVI national teams.
A User-Centric Knowledge Creation Model in a Web of Object-Enabled Internet of Things Environment
Kibria, Muhammad Golam; Fattah, Sheik Mohammad Mostakim; Jeong, Kwanghyeon; Chong, Ilyoung; Jeong, Youn-Kwae
2015-01-01
User-centric service features in a Web of Object-enabled Internet of Things environment can be provided by using a semantic ontology that classifies and integrates objects on the World Wide Web as well as shares and merges context-aware information and accumulated knowledge. The semantic ontology is applied on a Web of Object platform to virtualize the real world physical devices and information to form virtual objects that represent the features and capabilities of devices in the virtual world. Detailed information and functionalities of multiple virtual objects are combined with service rules to form composite virtual objects that offer context-aware knowledge-based services, where context awareness plays an important role in enabling automatic modification of the system to reconfigure the services based on the context. Converting the raw data into meaningful information and connecting the information to form the knowledge and storing and reusing the objects in the knowledge base can both be expressed by semantic ontology. In this paper, a knowledge creation model that synchronizes a service logistic model and a virtual world knowledge model on a Web of Object platform has been proposed. To realize the context-aware knowledge-based service creation and execution, a conceptual semantic ontology model has been developed and a prototype has been implemented for a use case scenario of emergency service. PMID:26393609
A User-Centric Knowledge Creation Model in a Web of Object-Enabled Internet of Things Environment.
Kibria, Muhammad Golam; Fattah, Sheik Mohammad Mostakim; Jeong, Kwanghyeon; Chong, Ilyoung; Jeong, Youn-Kwae
2015-09-18
User-centric service features in a Web of Object-enabled Internet of Things environment can be provided by using a semantic ontology that classifies and integrates objects on the World Wide Web as well as shares and merges context-aware information and accumulated knowledge. The semantic ontology is applied on a Web of Object platform to virtualize the real world physical devices and information to form virtual objects that represent the features and capabilities of devices in the virtual world. Detailed information and functionalities of multiple virtual objects are combined with service rules to form composite virtual objects that offer context-aware knowledge-based services, where context awareness plays an important role in enabling automatic modification of the system to reconfigure the services based on the context. Converting the raw data into meaningful information and connecting the information to form the knowledge and storing and reusing the objects in the knowledge base can both be expressed by semantic ontology. In this paper, a knowledge creation model that synchronizes a service logistic model and a virtual world knowledge model on a Web of Object platform has been proposed. To realize the context-aware knowledge-based service creation and execution, a conceptual semantic ontology model has been developed and a prototype has been implemented for a use case scenario of emergency service.
verification statistics Grumbine, R. W., Virtual Floe Ice Drift Forecast Model Intercomparison, Weather and Forecasting, 13, 886-890, 1998. MMAB Note: Virtual Floe Ice Drift Forecast Model Intercomparison 1996 pdf ~47
Computer Vision Assisted Virtual Reality Calibration
NASA Technical Reports Server (NTRS)
Kim, W.
1999-01-01
A computer vision assisted semi-automatic virtual reality (VR) calibration technology has been developed that can accurately match a virtual environment of graphically simulated three-dimensional (3-D) models to the video images of the real task environment.
NASA Astrophysics Data System (ADS)
Takács, Ondřej; Kostolányová, Kateřina
2016-06-01
This paper describes the Virtual Teacher that uses a set of rules to automatically adapt the way of teaching. These rules compose of two parts: conditions on various students' properties or learning situation; conclusions that specify different adaptation parameters. The rules can be used for general adaptation of each subject or they can be specific to some subject. The rule based system of Virtual Teacher is dedicated to be used in pedagogical experiments in adaptive e-learning and is therefore designed for users without education in computer science. The Virtual Teacher was used in dissertation theses of two students, who executed two pedagogical experiments. This paper also describes the phase of simulating and modeling of the theoretically prepared adaptive process in the modeling tool, which has all the required parameters and has been created especially for the occasion. The experiments are being conducted on groups of virtual students and by using a virtual study material.
Marshall Engineers Use Virtual Reality
NASA Technical Reports Server (NTRS)
1993-01-01
Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall Spce Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).
Virtual reality for dermatologic surgery: virtually a reality in the 21st century.
Gladstone, H B; Raugi, G J; Berg, D; Berkley, J; Weghorst, S; Ganter, M
2000-01-01
In the 20th century, virtual reality has predominantly played a role in training pilots and in the entertainment industry. Despite much publicity, virtual reality did not live up to its perceived potential. During the past decade, it has also been applied for medical uses, particularly as training simulators, for minimally invasive surgery. Because of advances in computer technology, virtual reality is on the cusp of becoming an effective medical educational tool. At the University of Washington, we are developing a virtual reality soft tissue surgery simulator. Based on fast finite element modeling and using a personal computer, this device can simulate three-dimensional human skin deformations with real-time tactile feedback. Although there are many cutaneous biomechanical challenges to solve, it will eventually provide more realistic dermatologic surgery training for medical students and residents than the currently used models.
Computer Applications and Virtual Environments (CAVE)
NASA Technical Reports Server (NTRS)
1993-01-01
Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. Marshall SPace Flight Center (MSFC) is begirning to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models are used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup is to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provides general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC).
ComputerApplications and Virtual Environments (CAVE)
NASA Technical Reports Server (NTRS)
1993-01-01
Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Center (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability providedgeneral visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.
ComputerApplications and Virtual Environments (CAVE)
NASA Technical Reports Server (NTRS)
1993-01-01
Virtual Reality (VR) can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The Marshall Space Flight Centerr (MSFC) in Huntsville, Alabama began to utilize VR for design analysis in the X-34 experimental reusable space vehicle. Analysts at MSFC's Computer Applications and Virtual Environments (CAVE) used Head Mounted Displays (HMD) (pictured), spatial trackers and gesture inputs as a means to animate or inhabit a properly sized virtual human model. These models were used in a VR scenario as a way to determine functionality of space and maintenance requirements for the virtual X-34. The primary functions of the virtual X-34 mockup was to support operations development and design analysis for engine removal, the engine compartment and the aft fuselage. This capability provided general visualization support to engineers and designers at MSFC and to the System Design Freeze Review at Orbital Sciences Corporation (OSC). The X-34 program was cancelled in 2001.
Wei, Gaofeng; Tang, Gang; Fu, Zengliang; Sun, Qiuming; Tian, Feng
2010-10-01
The China Mechanical Virtual Human (CMVH) is a human musculoskeletal biomechanical simulation platform based on China Visible Human slice images; it has great realistic application significance. In this paper is introduced the construction method of CMVH 3D models. Then a simulation system solution based on Creator/Vega is put forward for the complex and gigantic data characteristics of the 3D models. At last, combined with MFC technology, the CMVH simulation system is developed and a running simulation scene is given. This paper provides a new way for the virtual reality application of CMVH.
NASA Technical Reports Server (NTRS)
Shearrow, Charles A.
1999-01-01
One of the identified goals of EM3 is to implement virtual manufacturing by the time the year 2000 has ended. To realize this goal of a true virtual manufacturing enterprise the initial development of a machinability database and the infrastructure must be completed. This will consist of the containment of the existing EM-NET problems and developing machine, tooling, and common materials databases. To integrate the virtual manufacturing enterprise with normal day to day operations the development of a parallel virtual manufacturing machinability database, virtual manufacturing database, virtual manufacturing paradigm, implementation/integration procedure, and testable verification models must be constructed. Common and virtual machinability databases will include the four distinct areas of machine tools, available tooling, common machine tool loads, and a materials database. The machine tools database will include the machine envelope, special machine attachments, tooling capacity, location within NASA-JSC or with a contractor, and availability/scheduling. The tooling database will include available standard tooling, custom in-house tooling, tool properties, and availability. The common materials database will include materials thickness ranges, strengths, types, and their availability. The virtual manufacturing databases will consist of virtual machines and virtual tooling directly related to the common and machinability databases. The items to be completed are the design and construction of the machinability databases, virtual manufacturing paradigm for NASA-JSC, implementation timeline, VNC model of one bridge mill and troubleshoot existing software and hardware problems with EN4NET. The final step of this virtual manufacturing project will be to integrate other production sites into the databases bringing JSC's EM3 into a position of becoming a clearing house for NASA's digital manufacturing needs creating a true virtual manufacturing enterprise.
ERIC Educational Resources Information Center
Dempsey, Jennifer Camille
2014-01-01
This dissertation seeks to create a vision for virtuality culture through a theoretical expansion of Walter Ong's literacy and orality culture model. It investigates the ubiquitous and multimodal nature of the virtuality cultural phenomenon that is mediated by contemporary technology and not explained by pre-existing cultural conventions. Through…
A Virtual Campus Based on Human Factor Engineering
ERIC Educational Resources Information Center
Yang, Yuting; Kang, Houliang
2014-01-01
Three Dimensional or 3D virtual reality has become increasingly popular in many areas, especially in building a digital campus. This paper introduces a virtual campus, which is based on a 3D model of The Tourism and Culture College of Yunnan University (TCYU). Production of the virtual campus was aided by Human Factor and Ergonomics (HF&E), an…
ERIC Educational Resources Information Center
Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima
2016-01-01
In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this…
Algorithms for extraction of structural attitudes from 3D outcrop models
NASA Astrophysics Data System (ADS)
Duelis Viana, Camila; Endlein, Arthur; Ademar da Cruz Campanha, Ginaldo; Henrique Grohmann, Carlos
2016-05-01
The acquisition of geological attitudes on rock cuts using traditional field compass survey can be a time consuming, dangerous, or even impossible task depending on the conditions and location of outcrops. The importance of this type of data in rock-mass classifications and structural geology has led to the development of new techniques, in which the application of photogrammetric 3D digital models has had an increasing use. In this paper we present two algorithms for extraction of attitudes of geological discontinuities from virtual outcrop models: ply2atti and scanline, implemented with the Python programming language. The ply2atti algorithm allows for the virtual sampling of planar discontinuities appearing on the 3D model as individual exposed surfaces, while the scanline algorithm allows the sampling of discontinuities (surfaces and traces) along a virtual scanline. Application to digital models of a simplified test setup and a rock cut demonstrated a good correlation between the surveys undertaken using traditional field compass reading and virtual sampling on 3D digital models.
Astronomical virtual observatory and the place and role of Bulgarian one
NASA Astrophysics Data System (ADS)
Petrov, Georgi; Dechev, Momchil; Slavcheva-Mihova, Luba; Duchlev, Peter; Mihov, Bojko; Kochev, Valentin; Bachev, Rumen
2009-07-01
Virtual observatory could be defined as a collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. Several countries have initiated national virtual observatory programs that combine existing databases from ground-based and orbiting observatories, scientific facility especially equipped to detect and record naturally occurring scientific phenomena. As a result, data from all the world's major observatories will be available to all users and to the public. This is significant not only because of the immense volume of astronomical data but also because the data on stars and galaxies has been compiled from observations in a variety of wavelengths-optical, radio, infrared, gamma ray, X-ray and more. In a virtual observatory environment, all of this data is integrated so that it can be synthesized and used in a given study. During the autumn of the 2001 (26.09.2001) six organizations from Europe put the establishment of the Astronomical Virtual Observatory (AVO)-ESO, ESA, Astrogrid, CDS, CNRS, Jodrell Bank (Dolensky et al., 2003). Its aims have been outlined as follows: - To provide comparative analysis of large sets of multiwavelength data; - To reuse data collected by a single source; - To provide uniform access to data; - To make data available to less-advantaged communities; - To be an educational tool. The Virtual observatory includes: - Tools that make it easy to locate and retrieve data from catalogues, archives, and databases worldwide; - Tools for data analysis, simulation, and visualization; - Tools to compare observations with results obtained from models, simulations and theory; - Interoperability: services that can be used regardless of the clients computing platform, operating system and software capabilities; - Access to data in near real-time, archived data and historical data; - Additional information - documentation, user-guides, reports, publications, news and so on. This large growth of astronomical data and the necessity of an easy access to those data led to the foundation of the International Virtual Observatory Alliance (IVOA). IVOA was formed in June 2002. By January 2005, the IVOA has grown to include 15 funded VO projects from Australia, Canada, China, Europe, France, Germany, Hungary, India, Italy, Japan, Korea, Russia, Spain, the United Kingdom, and the United States. At the time being Bulgaria is not a member of European Astronomical Virtual Observatory and as the Bulgarian Virtual Observatory is not a legal entity, we are not members of IVOA. The main purpose of the project is Bulgarian Virtual Observatory to join the leading virtual astronomical institutions in the world. Initially the Bulgarian Virtual Observatory will include: - BG Galaxian virtual observatory; - BG Solar virtual observatory; - Department Star clusters of IA, BAS; - WFPDB group of IA, BAS. All available data will be integrated in the Bulgarian centers of astronomical data, conducted by the Wide Field Plate Archive data centre. For the above purpose POSTGRESQL or/and MySQL will be installed on the server of BG-VO and SAADA tools, ESO-MEX or/and DAL ToolKit to transform our FITS files in standard format for VO-tools. A part of the participants was acquainted with the principles of these products during the "Days of virtual observatory in Sofia" January, 2008.
Sirimanna, Pramudith; Gladman, Marc A
2017-10-01
Proficiency-based virtual reality (VR) training curricula improve intraoperative performance, but have not been developed for laparoscopic appendicectomy (LA). This study aimed to develop an evidence-based training curriculum for LA. A total of 10 experienced (>50 LAs), eight intermediate (10-30 LAs) and 20 inexperienced (<10 LAs) operators performed guided and unguided LA tasks on a high-fidelity VR simulator using internationally relevant techniques. The ability to differentiate levels of experience (construct validity) was measured using simulator-derived metrics. Learning curves were analysed. Proficiency benchmarks were defined by the performance of the experienced group. Intermediate and experienced participants completed a questionnaire to evaluate the realism (face validity) and relevance (content validity). Of 18 surgeons, 16 (89%) considered the VR model to be visually realistic and 17 (95%) believed that it was representative of actual practice. All 'guided' modules demonstrated construct validity (P < 0.05), with learning curves that plateaued between sessions 6 and 9 (P < 0.01). When comparing inexperienced to intermediates to experienced, the 'unguided' LA module demonstrated construct validity for economy of motion (5.00 versus 7.17 versus 7.84, respectively; P < 0.01) and task time (864.5 s versus 477.2 s versus 352.1 s, respectively, P < 0.01). Construct validity was also confirmed for number of movements, path length and idle time. Validated modules were used for curriculum construction, with proficiency benchmarks used as performance goals. A VR LA model was realistic and representative of actual practice and was validated as a training and assessment tool. Consequently, the first evidence-based internationally applicable training curriculum for LA was constructed, which facilitates skill acquisition to proficiency. © 2017 Royal Australasian College of Surgeons.
NASA Technical Reports Server (NTRS)
Estes, Samantha; Parker, Nelson C. (Technical Monitor)
2001-01-01
Virtual reality and simulation applications are becoming widespread in human task analysis. These programs have many benefits for the Human Factors Engineering field. Not only do creating and using virtual environments for human engineering analyses save money and time, this approach also promotes user experimentation and provides increased quality of analyses. This paper explains the human engineering task analysis performed on the Environmental Control and Life Support System (ECLSS) space station rack and its Distillation Assembly (DA) subsystem using EAI's human modeling simulation software, Jack. When installed on the International Space Station (ISS), ECLSS will provide the life and environment support needed to adequately sustain crew life. The DA is an Orbital Replaceable Unit (ORU) that provides means of wastewater (primarily urine from flight crew and experimental animals) reclamation. Jack was used to create a model of the weightless environment of the ISS Node 3, where the ECLSS is housed. Computer aided drawings of the ECLSS rack and DA system were also brought into the environment. Anthropometric models of a 95th percentile male and 5th percentile female were used to examine the human interfaces encountered during various ECLSS and DA tasks. The results of the task analyses were used in suggesting modifications to hardware and crew task procedures to improve accessibility, conserve crew time, and add convenience for the crew. This paper will address some of those suggested modifications and the method of presenting final analyses for requirements verification.
An incremental anomaly detection model for virtual machines.
Zhang, Hancui; Chen, Shuyu; Liu, Jun; Zhou, Zhen; Wu, Tianshu
2017-01-01
Self-Organizing Map (SOM) algorithm as an unsupervised learning method has been applied in anomaly detection due to its capabilities of self-organizing and automatic anomaly prediction. However, because of the algorithm is initialized in random, it takes a long time to train a detection model. Besides, the Cloud platforms with large scale virtual machines are prone to performance anomalies due to their high dynamic and resource sharing characters, which makes the algorithm present a low accuracy and a low scalability. To address these problems, an Improved Incremental Self-Organizing Map (IISOM) model is proposed for anomaly detection of virtual machines. In this model, a heuristic-based initialization algorithm and a Weighted Euclidean Distance (WED) algorithm are introduced into SOM to speed up the training process and improve model quality. Meanwhile, a neighborhood-based searching algorithm is presented to accelerate the detection time by taking into account the large scale and high dynamic features of virtual machines on cloud platform. To demonstrate the effectiveness, experiments on a common benchmark KDD Cup dataset and a real dataset have been performed. Results suggest that IISOM has advantages in accuracy and convergence velocity of anomaly detection for virtual machines on cloud platform.
An incremental anomaly detection model for virtual machines
Zhang, Hancui; Chen, Shuyu; Liu, Jun; Zhou, Zhen; Wu, Tianshu
2017-01-01
Self-Organizing Map (SOM) algorithm as an unsupervised learning method has been applied in anomaly detection due to its capabilities of self-organizing and automatic anomaly prediction. However, because of the algorithm is initialized in random, it takes a long time to train a detection model. Besides, the Cloud platforms with large scale virtual machines are prone to performance anomalies due to their high dynamic and resource sharing characters, which makes the algorithm present a low accuracy and a low scalability. To address these problems, an Improved Incremental Self-Organizing Map (IISOM) model is proposed for anomaly detection of virtual machines. In this model, a heuristic-based initialization algorithm and a Weighted Euclidean Distance (WED) algorithm are introduced into SOM to speed up the training process and improve model quality. Meanwhile, a neighborhood-based searching algorithm is presented to accelerate the detection time by taking into account the large scale and high dynamic features of virtual machines on cloud platform. To demonstrate the effectiveness, experiments on a common benchmark KDD Cup dataset and a real dataset have been performed. Results suggest that IISOM has advantages in accuracy and convergence velocity of anomaly detection for virtual machines on cloud platform. PMID:29117245
Huang, Yukun; Chen, Rong; Wei, Jingbo; Pei, Xilong; Cao, Jing; Prakash Jayaraman, Prem; Ranjan, Rajiv
2014-01-01
JNI in the Android platform is often observed with low efficiency and high coding complexity. Although many researchers have investigated the JNI mechanism, few of them solve the efficiency and the complexity problems of JNI in the Android platform simultaneously. In this paper, a hybrid polylingual object (HPO) model is proposed to allow a CAR object being accessed as a Java object and as vice in the Dalvik virtual machine. It is an acceptable substitute for JNI to reuse the CAR-compliant components in Android applications in a seamless and efficient way. The metadata injection mechanism is designed to support the automatic mapping and reflection between CAR objects and Java objects. A prototype virtual machine, called HPO-Dalvik, is implemented by extending the Dalvik virtual machine to support the HPO model. Lifespan management, garbage collection, and data type transformation of HPO objects are also handled in the HPO-Dalvik virtual machine automatically. The experimental result shows that the HPO model outweighs the standard JNI in lower overhead on native side, better executing performance with no JNI bridging code being demanded.
Zhou, Xiangmin; Zhang, Nan; Sha, Desong; Shen, Yunhe; Tamma, Kumar K; Sweet, Robert
2009-01-01
The inability to render realistic soft-tissue behavior in real time has remained a barrier to face and content aspects of validity for many virtual reality surgical training systems. Biophysically based models are not only suitable for training purposes but also for patient-specific clinical applications, physiological modeling and surgical planning. When considering the existing approaches for modeling soft tissue for virtual reality surgical simulation, the computer graphics-based approach lacks predictive capability; the mass-spring model (MSM) based approach lacks biophysically realistic soft-tissue dynamic behavior; and the finite element method (FEM) approaches fail to meet the real-time requirement. The present development stems from physics fundamental thermodynamic first law; for a space discrete dynamic system directly formulates the space discrete but time continuous governing equation with embedded material constitutive relation and results in a discrete mechanics framework which possesses a unique balance between the computational efforts and the physically realistic soft-tissue dynamic behavior. We describe the development of the discrete mechanics framework with focused attention towards a virtual laparoscopic nephrectomy application.
NASA Astrophysics Data System (ADS)
Aktas, Mehmet; Aydin, Galip; Donnellan, Andrea; Fox, Geoffrey; Granat, Robert; Grant, Lisa; Lyzenga, Greg; McLeod, Dennis; Pallickara, Shrideep; Parker, Jay; Pierce, Marlon; Rundle, John; Sayar, Ahmet; Tullis, Terry
2006-12-01
We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas.
The International Outer Planets Watch atmospheres node database of giant-planet images
NASA Astrophysics Data System (ADS)
Hueso, R.; Legarreta, J.; Sánchez-Lavega, A.; Rojas, J. F.; Gómez-Forrellad, J. M.
2011-10-01
The Atmospheres Node of the International Outer Planets Watch (IOPW) is aimed to encourage the observations and study of the atmospheres of the Giant Planets. One of its main activities is to provide an interaction between the professional and amateur astronomical communities maintaining an online and fully searchable database of images of the giant planets obtained from amateur astronomers and available to both professional and amateurs [1]. The IOPW database contains about 13,000 image observations of Jupiter and Saturn obtained in the visible range with a few contributions of Uranus and Neptune. We describe the organization and structure of the database as posted in the Internet and in particular the PVOL software (Planetary Virtual Observatory & Laboratory) designed to manage the site and based in concepts from Virtual Observatory projects.
Virtual Astronomy: The Legacy of the Virtual Astronomical Observatory
NASA Astrophysics Data System (ADS)
Hanisch, Robert J.; Berriman, G. B.; Lazio, J.; Szalay, A. S.; Fabbiano, G.; Plante, R. L.; McGlynn, T. A.; Evans, J.; Emery Bunn, S.; Claro, M.; VAO Project Team
2014-01-01
Over the past ten years, the Virtual Astronomical Observatory (VAO, http://usvao.org) and its predecessor, the National Virtual Observatory (NVO), have developed and operated a software infrastructure consisting of standards and protocols for data and science software applications. The Virtual Observatory (VO) makes it possible to develop robust software for the discovery, access, and analysis of astronomical data. Every major publicly funded research organization in the US and worldwide has deployed at least some components of the VO infrastructure; tens of thousands of VO-enabled queries for data are invoked daily against catalog, image, and spectral data collections; and groups within the community have developed tools and applications building upon the VO infrastructure. Further, NVO and VAO have helped ensure access to data internationally by co-founding the International Virtual Observatory Alliance (IVOA, http://ivoa.net). The products of the VAO are being archived in a publicly accessible repository. Several science tools developed by the VAO will continue to be supported by the organizations that developed them: the Iris spectral energy distribution package (SAO), the Data Discovery Tool (STScI/MAST, HEASARC), and the scalable cross-comparison service (IPAC). The final year of VAO is focused on development of the data access protocol for data cubes, creation of Python language bindings to VO services, and deployment of a cloud-like data storage service that links to VO data discovery tools (SciDrive). We encourage the community to make use of these tools and services, to extend and improve them, and to carry on with the vision for virtual astronomy: astronomical research enabled by easy access to distributed data and computational resources. Funding for VAO development and operations has been provided jointly by NSF and NASA since May 2010. NSF funding will end in September 2014, though with the possibility of competitive solicitations for VO-based tool development. NASA intends to maintain core VO services such as the resource registry (the index of VO-accessible data collections), monitoring services, and a website as part of the remit of HEASARC, IPAC (IRSA, NED), and MAST.
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.
Four Bed Molecular Sieve - Exploration (4BMS-X) Virtual Heater Design and Optimization
NASA Technical Reports Server (NTRS)
Schunk, R. Gregory; Peters, Warren T.; Thomas, John T., Jr.
2017-01-01
A 4BMS-X (Four Bed Molecular Sieve - Exploration) design and heater optimization study for CO2 sorbent beds in proposed exploration system architectures is presented. The primary objectives of the study are to reduce heater power and thermal gradients within the CO2 sorbent beds while minimizing channeling effects. Some of the notable changes from the ISS (International Space Station) CDRA (Carbon Dioxide Removal Assembly) to the proposed exploration system architecture include cylindrical beds, alternate sorbents and an improved heater core. Results from both 2D and 3D sorbent bed thermal models with integrated heaters are presented. The 2D sorbent bed models are used to optimize heater power and fin geometry while the 3D models address end effects in the beds for more realistic thermal gradient and heater power predictions.
Virtual Engine a Tool for Truck Reliability Increase
NASA Astrophysics Data System (ADS)
Stodola, Jiri; Novotny, Pavel
2017-06-01
The internal combustion engine development process requires CAD models which deliver results for the concept phase at a very early stage and which can be further detailed on the same program platform as the development process progresses. The vibratory and acoustic behaviour of the powertrain is highly complex, consisting of many components that are subject to loads that vary greatly in magnitude and which operate at a wide range of speeds. The interaction of the crank and crankcase is a major problem for powertrain designers when optimising the vibration and noise characteristics of the powertrain. The Finite Element Method (FEM) and Multi-Body Systems (MBS) are suitable for the creation of 3-D calculation models. Non-contact measurements make it possible to verify complex calculation models. All numerical simulations and measurements are performed on a Diesel six-cylinder in-line engine.
The Application of Leap Motion in Astronaut Virtual Training
NASA Astrophysics Data System (ADS)
Qingchao, Xie; Jiangang, Chao
2017-03-01
With the development of computer vision, virtual reality has been applied in astronaut virtual training. As an advanced optic equipment to track hand, Leap Motion can provide precise and fluid tracking of hands. Leap Motion is suitable to be used as gesture input device in astronaut virtual training. This paper built an astronaut virtual training based Leap Motion, and established the mathematics model of hands occlusion. At last the ability of Leap Motion to handle occlusion was analysed. A virtual assembly simulation platform was developed for astronaut training, and occlusion gesture would influence the recognition process. The experimental result can guide astronaut virtual training.
ERIC Educational Resources Information Center
O'Neill, Eunhee Jung
2007-01-01
In today's global society, individuals with an understanding of different cultures that have the ability to apply this understanding to real world problem solving are more likely to become leaders. Preparing students for a global society is becoming a significant part of education. While many international online exchange projects have been…
ERIC Educational Resources Information Center
Spiro, Jane
2011-01-01
In this paper the process of building an international student community is explored. Strategies discussed include guided interaction within a virtual environment between home students studying in their own culture and international students studying at a distance. The context includes both the state and private sector in South East Asia, Latin…
Experiences and Challenges of International Students in Technology-Rich Learning Environments
ERIC Educational Resources Information Center
Habib, Laurence; Johannesen, Monica; Øgrim, Leikny
2014-01-01
This article presents a study of international students and their use of technology in a Scandinavian institution of Higher Education. A special emphasis is placed on patterns of use of a virtual learning environment (VLE) that is available to all the study programmes at the institution. Actor-Network Theory (ANT) is used as a theoretical approach…